Budapest, Hungary
Budapest, Hungary

The Hungarian Academy of science ) is the most important and prestigious learned society of Hungary. Its seat is at the bank of the Danube in Budapest. The main responsibilities are the cultivation of science, disseminate the results of science, the supporting of research and development and the representation of Hungarian science domestically and around the world. Wikipedia.


Time filter

Source Type

Laszlo A.,Hungarian Academy of Sciences
Journal of Physics A: Mathematical and Theoretical | Year: 2017

A group theoretical mechanism for unification of local gauge and spacetime symmetries is introduced. No-go theorems prohibiting such unification are circumvented by slightly relaxing the usual requirement on the gauge group: only the so called Levi factor of the gauge group needs to be compact semisimple, not the entire gauge group. This allows a non-conventional supersymmetry-like extension of the gauge group, glueing together the gauge and spacetime symmetries, but not needing any new exotic gauge particles. It is shown that this new relaxed requirement on the gauge group is nothing but the minimal condition for energy positivity. The mechanism is demonstrated to be mathematically possible and physically plausible on a U(1) based gauge theory setting. The unified group, being an extension of the group of spacetime symmetries, is shown to be different than that of the conventional supersymmetry group, thus overcoming the McGlinn and Coleman-Mandula no-go theorems in a non-supersymmetric way. © 2017 IOP Publishing Ltd.


Joo D.,Hungarian Academy of Sciences | Mincheva K.,Yale University
Selecta Mathematica, New Series | Year: 2017

A new definition of prime congruences in additively idempotent semirings is given using twisted products. This class turns out to exhibit some analogous properties to the prime ideals of commutative rings. In order to establish a good notion of radical congruences it is shown that the intersection of all primes of a semiring can be characterized by certain twisted power formulas. A complete description of prime congruences is given in the polynomial and Laurent polynomial semirings over the tropical semifield (Formula presented.), the semifield (Formula presented.) and the two element semifield (Formula presented.). The minimal primes of these semirings correspond to monomial orderings, and their intersection is the congruence that identifies polynomials that have the same Newton polytope. It is then shown that the radical of every finitely generated congruence in each of these cases is an intersection of prime congruences with quotients of Krull dimension 1. An improvement of a result from Bertram and Easton (Adv Math 308:36–82, 2017) is proven which can be regarded as a Nullstellensatz for tropical polynomials. © 2017 Springer International Publishing


Pal L.,Hungarian Academy of Sciences | Pazsit I.,Chalmers University of Technology
Annals of Nuclear Energy | Year: 2017

The purpose of this work is to elaborate a master equation formalism for the evolution of the probability distribution of the cumulative energy generated by fissions in a multiplying system with delayed neutrons. The formalism accounts for the fact that the fission energy χ is also a random variable, thus the fluctuations of the total energy generated are due to both the fluctuations of the number of fissions, as well as to the fluctuations of the energy per fission. By comparing to the case where the fission energy is taken as constant, the significance of the fluctuations of the fission energy can be assessed. The first two moments of the cumulative fission energy are determined explicitly, and the time dependence of the expectation and the variance is calculated for different reactivities. As expected, the variance of the energy per fission does not play a significant role in the variance of the cumulative fission energy. © 2016 Elsevier Ltd


FRANKL P.,Hungarian Academy of Sciences
Combinatorics Probability and Computing | Year: 2017

Let (Formula presented.) ⊂ 2[n] be a family of subsets. The diameter of (Formula presented.) is the maximum of the size of symmetric differences among pairs of members of (Formula presented.). In 1966 Kleitman determined the maximum of |(Formula presented.)| for fixed diameter. However, this important classical result lacked a characterization of the families meeting the bound. This is remedied in the present paper, where a best possible stability result is established as well. In Section 4 we introduce a ‘parity trick’ that provides an easy way of deducing the odd case from the even case in both Kleitman's original theorem and its stability version. Copyright © Cambridge University Press 2017


Meszaros B.,Hungarian Academy of Sciences | Kumar M.,Structural and Computational Biology Unit | Gibson T.J.,Structural and Computational Biology Unit | Uyar B.,Berlin Institute for Medical Systems Biology | Dosztanyi Z.,Eötvös Loránd University
Science Signaling | Year: 2017

Degrons are the elements that are used by E3 ubiquitin ligases to target proteins for degradation. Most degrons are short linear motifs embedded within the sequences of modular proteins. As regulatory sites for protein abundance, they are important for many different cellular processes, such as progression through the cell cycle and monitoring cellular hypoxia. Degrons enable the elimination of proteins that are no longer required, preventing their possible dysfunction. Although the human genome encodes ∼600 E3 ubiquitin ligases, only a fraction of these enzymes have well-defined target degrons. Thus, for most cellular proteins, the destruction mechanisms are poorly understood. This is important for many diseases, especially for cancer, a disease that involves the enhanced expression of oncogenes and the persistence of encoded oncoproteins coupled with reduced abundance of tumor suppressors. Loss0of-function mutations occur in the degrons of several oncoproteins, such as the transcription factors MYC and NRF2, and in various mitogenic receptors, such as NOTCH1 and several receptor tyrosine kinases. Mutations eliminating the function of the β-catenin degron are found in many cancers and are considered one of the most abundant mutations driving carcinogenesis. In this Review, we describe the current knowledge of degrons in cancer and suggest that increased research on the "dark degrome" (unknown degron-E3 relationships) would enhance progress in cancer research. © 2017 The Authors, some rights reserved.


Tyihak E.,Hungarian Academy of Sciences
Journal of Planar Chromatography - Modern TLC | Year: 2017

The most current in vitro and in vivo results in the BioArena system and under greenhouse conditions provide a good opportunity for a fundamental renewal of biological detections and interactions in layer liquid chromatography. The adsorbent bed in a column liquid arrangement is not suitable for biological detection because the living cells do not grow there. Contrarily, the planar adsorbent layer enables the in situ biodetection of antimicrobials and the interactions among separated compounds, cells, and further various cofactors (molecules), making the study of mechanisms of action possible. The basic elements of the time-and dose-dependent quadruple immune response of plants to pathogens in relation to the function and reactions of formaldehyde and its reaction products (mainly endogenous ozone) were demonstrated. This fnding opens a new horizon in the feld of disease resistance in plants and perhaps in general in the biological world. These results give a good basis and possibility for studying and understanding the unique high-dilution phenomena as well, and at that time, they promise the elimination of century contradictions in this feld. © Akadémiai Kiadó, Budapest.


Szalay V.,Hungarian Academy of Sciences
Journal of Chemical Physics | Year: 2017

Recently, a general expression for Eckart-frame Hamilton operators has been obtained by the gateway Hamiltonian method [V. Szalay, J. Chem. Phys. 142, 174107 (2015) and V. Szalay, J. Chem. Phys. 143, 064104 (2015)]. The kinetic energy operator in this general Hamiltonian is nearly identical to that of the Eckart-Watson operator even when curvilinear vibrational coordinates are employed. Its different realizations correspond to different methods of calculating Eckart displacements. There are at least two different methods for calculating such displacements: rotation and projection. In this communication, the application of Eckart Hamiltonian operators constructed by rotation and projection, respectively, is numerically demonstrated in calculating vibrational energy levels. The numerical examples confirm that there is no need for rotation to construct an Eckart ro-vibrational Hamiltonian. The application of the gateway method is advantageous even when rotation is used since it obviates the need for differentiation of the matrix rotating into the Eckart frame. Simple geometrical arguments explain that there are infinitely many different methods for calculating Eckart displacements. The geometrical picture also suggests that a unique Eckart displacement vector may be defined as the shortest (mass-weighted) Eckart displacement vector among Eckart displacement vectors corresponding to configurations related by rotation. Its length, as shown analytically and demonstrated by numerical examples, is equal to or less than that of the Eckart displacement vector one can obtain by rotation to the Eckart frame. © 2017 Author(s).


Vari A.,Hungarian Academy of Sciences | Toth V.R.,Hungarian Academy of Sciences
Aquatic Botany | Year: 2017

Life-history traits like dominance of certain reproductive modes (e.g. vegetative, specialized, unspecialized or sexual propagules) and overwintering strategies (evergreen or re-sprouting) determine the success and timing of the ability of aquatic plants to colonize new areas. In the present experiment the distribution of these reproductive modes was examined in-situ, where new gaps were experimentally formed and establishment of new vegetation observed on a monthly bases in ten plots. During a period of 126 days, altogether 73% of all established plants (n = 1822) colonized by rhizomatic growth and 11% by rooting of vegetative fragments. Myriophyllum spicatum was observed to use mostly fragment rooting (81%), while Potamogeton perfoliatus followed a more mixed strategy combining re-rooting fragments and rhizomatic growth (31% and 41%, respectively). Stuckenia pectinata also preferred colonisation by rhizomes (84%). No colonisation by specialized vegetative units (tubers or turions) was observed during the study period The importance of surrounding vegetation was shown by comparing colonisation on inner and marginal sections of the plots (30% vs.70%). Three different patterns of timing of peak colonisation intensities were observed, related to species’ life-history traits. While several experimental works have been done on the regeneration and colonisation abilities of different species under laboratory conditions, information on the in-situ application of the different strategies is scarce. Insights on the modes by which plants succeed in colonising gaps helps us understand how (re)establishment of aquatic vegetation might function in lake ecosystems recovering after eutrophication. © 2016 Elsevier B.V.


Levai G.,Hungarian Academy of Sciences
Annals of Physics | Year: 2017

The accidental crossing of energy levels is studied for a number of exactly solvable PT-symmetric potentials in one spatial dimension. This phenomenon occurs when the potential possesses two series of bound-state levels discriminated by the q=± quasi-parity quantum number and a potential parameter is tuned to specific values. In contrast with the coalescing of two such real-energy levels with the same n quantum number and continuing as a complex conjugate pair, corresponding to the breakdown of PT symmetry, accidental crossing occurs for energy levels with different n and q. In this case the energy eigenvalues become degenerate, and the corresponding wave functions become linearly dependent. It is shown that besides the known examples, the PT-symmetric harmonic oscillator, Coulomb and Scarf II potentials, this phenomenon occurs for any member of the Natanzon potential class for which the q quantum number can be defined. Two such potentials are discussed as concrete examples: the PT-symmetric generalized Ginocchio potential and a four-parameter subset of the Natanzon potential class. These potentials have been described in detail previously, however, the accidental crossing of their energy eigenvalues has not been noticed then. © 2017 Elsevier Inc.


Andric F.,University of Belgrade | Heberger K.,Hungarian Academy of Sciences
Journal of Chromatography A | Year: 2017

Comparison and selection of chromatographic columns is an important part of development as well as validation of analytical methods. Presently there is abundant number of methods for selection of the most similar and orthogonal columns, based on the application of limited number of test compounds as well as quantitative structure retention relationship models (QSRR), from among Snyder's hydrophobic-subtraction model (HSM) have been most extensively used.Chromatographic data of 67 compounds were evaluated using principal component analysis (PCA), hierarchical cluster analysis (HCA), non-parametric ranking methods as sum of ranking differences (SRD) and generalized pairwise correlation method (GPCM), both applied as a consensus driven comparison, and complemented by the comparison with one variable at a time (COVAT) approach. The aim was to compare the ability of the HSM approach and the approach based on primary retention data of test solutes (log. k values) to differentiate among ten highly similar C18 columns.The ranking (clustering) pattern of chromatographic columns based on primary retention data and HSM parameters gave different results in all instances. Patterns based on retention coefficients were in accordance with expectations based on columns' physicochemical parameters, while HSM parameters provided a different clustering.Similarity indices calculated from the following dissimilarity measures: SRD, GPCM Fisher's conditional exact probability weighted (CEPW) scores; Euclidian, Manhattan, Chebyshev, and cosine distances; Pearson's, Spearman's, and Kendall's, correlation coefficients have been ranked by the consensus based SRD. Analysis of variance confirmed that the HSM model produced statistically significant increases of SRD values for the majority of similarity indices, i.e. HS transformation of original retention data yields significant loss of information, and finally results in lower performance of HSM methodology. The best similarity measures were obtained using primary retention data, and derived from Kendal's and Spearman's correlation coefficients, as well as GPCM and SRD score values. Selectivity function, Fs, originally proposed by Snyder, demonstrated moderate performance. © 2017 Elsevier B.V.


Kiraly B.,Budapest University of Technology and Economics | Szabo G.,Hungarian Academy of Sciences
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2017

Multistrategy evolutionary games are studied on a square lattice when the pair interactions are composed of coordinations between strategy pairs and an additional term with self-dependent payoff. We describe a method for determining the strength of each elementary coordination component in n-strategy potential games. Using analytical and numerical methods, the presence and absence of Ising-type order-disorder phase transitions are studied when a single pair coordination is extended by some types of self-dependent elementary games. We also introduce noise-dependent three-strategy equivalents of the n-strategy elementary coordination games. © 2017 American Physical Society.


Bertrand A.,Hungarian Academy of Sciences | Sue C.,University of Franche Comte
Swiss Journal of Geosciences | Year: 2017

The significance of late-stage fracturing in the European Alps in a large geodynamic context is reappraised by studying brittle deformations over the entire belt. In the internal Western Alps, paleostress datasets display a major occurrence of orogen-parallel extension resulting in normal faulting and associated strike-slip mode. There the direction of subhorizontal extension rotates with the bending of the Alpine belt. In the Central Alps, paleostress tensors also indicate orogen-parallel extensional regimes, both in the Bergell area and the Lepontine Dome, where the brittle structures are associated with ductile structures related to the formation of large-scale upright folds that accommodate most of the collisional shortening due to the north-directed component of the movement of the South-Alpine indenter. This brittle deformation phase is of Miocene age and is coeval with the propagation of the Alpine front toward the external Alpine domains. In the Eastern Alps, brittle deformation of the Tauern Window displays an overwhelming occurrence of orogen-parallel normal faulting and associated strike-slip regimes again, which is inferred to be driven by lateral extrusion of the orogenic wedge toward the Pannonian basin, partly due to indentation on the Dolomites indenter. The major orogen-parallel extensional signal of the brittle Cenozoic deformations appears remarkably stable all over the internal Alps. Extensional brittle structures are part of a late phase of collisional deformation, during which the propagation of the Alpine front of the Western Alps and the northward movement of the Southern Alpine and the Dolomites indenters in the Central and Eastern Alps were accommodated by orogen-parallel extension in the inner zones, at the scale of the entire chain. © 2017 Swiss Geological Society


Cao Y.,Hong Kong Polytechnic University | Sandeep R.B.,Indian Institute of Technology Hyderabad | Sandeep R.B.,Hungarian Academy of Sciences
Proceedings of the Annual ACM-SIAM Symposium on Discrete Algorithms | Year: 2017

Performing Gaussian elimination to a sparse matrix may turn some zeroes into nonzero values, so called fill-ins, which we want to minimize to keep the matrix sparse. Let n denote the rows of the matrix and k the number of fill-ins. For the minimum fill-in problem, we exclude the existence of polynomial time approximation schemes, assuming P6=NP, and the existence of 2O(n1)-time approximation schemes for any positive , assuming the Exponential Time Hypothesis. Also implied is a 2O(k1=2) nO(1) parameterized lower bound. Behind these results is a new reduction from vertex cover, which might be of its own interest: All previous reductions for similar problems are from some kind of graph layout problems. Copyright © by SIAM.


Fox J.,Stanford University | Pach J.,Hungarian Academy of Sciences | Suk A.,University of Illinois at Chicago
SIAM Journal on Computing | Year: 2016

In this paper, we prove several extremal results for geometrically defined hypergraphs. In particular, we establish an improved lower bound, single exponentially decreasing in k, on the best constant δ; > 0 such that the vertex classes P1,..., Pk of every k-partite k-uniform semialgebraic hypergraph H = (P1 • • • Pk, E) with |E| ≥ ϵIIk j=1 |Pi| have, for 1 ≤ i ≤ k, δ|Pi|-element subsets P'i Pi satisfying P'1 x • • • x P'k E. The best previously known lower bound on δ due to Bukh and Hubard decreased triple exponentially fast in k. We give three geometric applications of our results. In particular, we establish the following strengthening of the so-called same-type lemma of Barany and Valtr: Any disjoint finite sets P1,..., Pk Rd (k > d) have, for 1 ≤ i ≤ k, subsets P'i of size at least 2-O(d3k log k |Pi| with the property that every k-tuple formed by taking one point from each P'i has the same order type. We also improve a result of Fox, Gromov, Lafforgue, Naor, and Pach, who established a regularity lemma for semialgebraic k-uniform hypergraphs of bounded complexity, showing that for each ϵ > 0 the vertex set can be equitably partitioned into a bounded number of parts (in terms of ϵ and the complexity) so that all but an ϵ-fraction of the k-tuples of parts are homogeneous. Here, we prove that the number of parts can be taken to be polynomial in 1/ϵ. Our improved regularity lemma can be applied to geometric problems and to the following general question on property testing: is it possible to decide, with query complexity polynomial in the reciprocal of the approximation parameter, whether a hypergraph has a given hereditary property? We give an affirmative answer for testing typical hereditary properties for semialgebraic hypergraphs of bounded complexity. © 2016 Societ y for Industrial and Applied Mathematics.


Bonnet E.,Hungarian Academy of Sciences | Paschos V.Th.,CNRS Laboratory for the Analysis and Modeling of Decision Systems
RAIRO - Operations Research | Year: 2017

We discuss approximability in FPT-time for the class of subset optimization graph problems where a feasible solution S is a subset of the vertex set of the input graph. This class encompasses many well-known problems, such as min dominating set, min vertex cover, max independent set, min feedback vertex set. We study approximability of such problems with respect to the dual parameter n - k where n is size of the vertex set and k the standard parameter. We show that under such parameterization, many of these problems, while W[·]-hard, admit parameterized approximation schemata. © EDP Sciences, ROADEF, SMAI 2017.


Neszmelyi B.,Hungarian Academy of Sciences | Horvath J.,Hungarian Academy of Sciences
Psychophysiology | Year: 2017

Experimental paradigms investigating the processing of self-induced stimuli are often based on the implicit assumption that motor processes are invariable regardless of their consequences: It is presumed that actions with different sets of predictable sensory consequences do not differ in their physical characteristics or in their brain signal reflections. The present experiment explored this assumption in the context of action-related auditory attenuation by comparing actions (pinches) with and without auditory consequences. The results show that motor processes are not invariable: Pinches eliciting a tone were softer than pinches without auditory effects. This indicates that self-induced auditory stimuli are not perceived as irrelevant side effects: The tones are used as feedback to optimize the tone-eliciting actions. The comparison of ERPs related to actions with different physical parameters (strong and soft pinches) revealed a significant ERP difference in the time range of the action-related N1 attenuation (strong pinches resulted in more negative amplitudes), suggesting that a motor correction bias may contribute to this auditory ERP attenuation effect, which is usually attributed to action-related predictive processes. © 2017 Society for Psychophysiological Research.


Viharos Z.J.,Hungarian Academy of Sciences | Kis K.B.,Hungarian Academy of Sciences
2016 IEEE International Conference on Systems, Man, and Cybernetics, SMC 2016 - Conference Proceedings | Year: 2016

The paper is aimed to present how Neuro-Fuzzy Systems can be applied for identifying a general system model of a given problem defined by a set of variables. Neuro-Fuzzy Systems are favored in many application fields because they provide fair accuracy and their inner computational model can be interpreted through the fuzzy rules they encapsulate. The proposed input-output search algorithm is able to find optimal system configuration of an arbitrary set of variables. By placing the algorithm on a Neuro-Fuzzy basis the resulted system model became more interpretable through the inner rules of the Neuro-Fuzzy model. This makes the algorithm more interpretable by revealing more information about the inner connections between the variables of a specific problem. © 2016 IEEE.


News Article | April 17, 2017
Site: www.futurity.org

Whereas humans can look at a complex landscape like a mountain vista and almost immediately orient themselves to navigate its multiple regions over long distances, other mammals such as rodents orient relative to physical cues—like approaching and sniffing a wall—that build up over time. This ability to navigate our surroundings and understand our relative position includes an environment-dependent scaling mechanism, according to a new study. “Our research, based on human data, redefines the fundamental properties of the internal coordinate system,” says Zoltan Nadasdy, lead author of the study and an adjunct assistant professor in the University of Texas at Austin’s psychology department. Nadasdy is also a researcher at Eötvös Loránd University and the Sarah Cannon Research Institute at St. David’s Medical Center. “Dysfunction in this system causes memory problems and disorientation, such as we see in Alzheimer’s disease and age-related decline. So, it’s vital that we continue to further our understanding of this part of the brain,” he says. Through a partnership with Seton Healthcare Family, the researchers in the UT Austin Human Brain Stimulation and Electrophysiology Lab were able to measure relevant brain activity of epileptic patients whose diagnostic procedure requires that they have electrodes planted in the entorhinal cortex of the brain. Neurons there serve as the internal coordinate system for humans. (The brains of individuals with epilepsy function normally when not undergoing a seizure.) Patients performed a virtual navigation task on a tablet computer in four environments daily for seven to eight consecutive days. By measuring their brain activity, the researchers identified three previously unknown traits of the system: The findings illuminate the fabric of the human memory and spatial navigation, which are vulnerable to disease and deterioration. Deeper knowledge of these neuronal mechanisms can inform the development of techniques to prolong the health of this part of the brain and combat diseases such as Alzheimer’s. The study, published in the Proceedings of the National Academy of Sciences, builds on earlier Nobel Prize-winning research exploring the entorhinal cortex of rodents. Due to the differences discovered between the human and rodent systems of navigation, the researchers emphasize that generalizing results from studies on animal subjects may provide inaccurate conjectures. This study is one of the few on human subjects that report on the activity of individual neuron behavior, says György Buzsáki, an expert from New York University Medical Center who was not involved in the research. “They not only confirm a previous report but extend the findings by showing that the size of the neuronal representation by entorhinal grid cells scales with the environment,” Buzsáki says. “Our hypothesis is challenging the definition of a universal spatial scale of environment predominant in lower mammals, which may open up important avenues of discovery,” says Robert Buchanan, another lead author of the study and an associate professor at Dell Medical School. He is also an adjunct associate professor in the university’s psychology department and a chief of neurosurgery at Seton Brain and Spine Institute. “Now, we can continue to explore this key component of what it means to be human—how we think about our past and future, how we imagine and plan,” Buchanan says. By using virtual reality, the researchers also refined a new experimental technology for facilitating spatial experiences that can’t be reproduced in a laboratory. The data implies that humans can seamlessly switch between reality and virtual reality—a finding that can be applied in other studies of the brain. Additional coauthors are from Baylor College of Medicine; Eötvös Loránd University and Hungarian Academy of Sciences; and UT Austin’s Dell Medical School and Seton Brain and Spine Institute. The Brain and Behavior Research Foundation and the Seton Seed Grant for Research supported the work.


Mondello S.,Banyan Biomarkers, Inc. | Buki A.,Hungarian Academy of Sciences | Italiano D.,Messina University | Jeromin A.,Banyan Biomarkers, Inc.
Neurology | Year: 2013

Objective: The study aims to examine α-synuclein in the CSF of patients with severe traumatic brain injury (TBI) and its relationship with clinical characteristics and long-term outcomes. Methods: This prospective case-control study enrolled patients with severe TBI (Glasgow Coma Score ≤8) who underwent ventriculostomy. CSF samples were taken from each TBI patient at admission and daily for up to 8 days after injury and successively assessed by ELISA. Control CSF was collected for analysis from subjects receiving lumbar puncture for other medical reasons. We used trajectory analysis to identify distinct temporal profiles of CSF α-synuclein that were compared with clinical outcomes. Results: CSF α-synuclein was elevated in TBI patients after injury as compared to controls (p = 0.0008). Overall, patients who died had higher concentrations (area under the curve) over 8 days of observation compared to those who survived at 6 months postinjury (p = 0.002). Two distinct temporal α-synuclein profiles were recognized over time. Subjects who died had consistently elevated α-synuclein levels compared to those who survived with α-synuclein levels near controls. High-risk trajectory was a strong and accurate predictor of death with 100%specificity and a very high sensitivity (83%). Conclusions: Taken together, these data support the hypothesis that in severe TBI patients, substantial increase of CSF α-synuclein may indicate widespread neurodegeneration and reflect secondary neuropathologic events occurring after injury. The determination of CSF α-synuclein may be a valuable prognostic marker, adding to the clinical assessment and creating opportunities for medical intervention. © 2013 American Academy of Neurology.


Schansker G.,Hungarian Academy of Sciences | Toth S.Z.,Hungarian Academy of Sciences | Holzwarth A.R.,Max Planck Institute for Chemical Energy Conversion | Garab G.,Hungarian Academy of Sciences
Photosynthesis Research | Year: 2014

Chlorophyll a fluorescence is a non-invasive tool widely used in photosynthesis research. According to the dominant interpretation, based on the model proposed by Duysens and Sweers (1963, Special Issue of Plant and Cell Physiology, pp 353-372), the fluorescence changes reflect primarily changes in the redox state of QA, the primary quinone electron acceptor of photosystem II (PSII). While it is clearly successful in monitoring the photochemical activity of PSII, a number of important observations cannot be explained within the framework of this simple model. Alternative interpretations have been proposed but were not supported satisfactorily by experimental data. In this review we concentrate on the processes determining the fluorescence rise on a dark-to-light transition and critically analyze the experimental data and the existing models. Recent experiments have provided additional evidence for the involvement of a second process influencing the fluorescence rise once QA is reduced. These observations are best explained by a light-induced conformational change, the focal point of our review. We also want to emphasize that - based on the presently available experimental findings - conclusions on α/ß-centers, PSII connectivity, and the assignment of FV/FM to the maximum PSII quantum yield may require critical re-evaluations. At the same time, it has to be emphasized that for a deeper understanding of the underlying physical mechanism(s) systematic studies on light-induced changes in the structure and reaction kinetics of the PSII reaction center are required. © 2013 Springer Science+Business Media Dordrecht.


Rezen T.,University of Ljubljana | Rozman D.,University of Ljubljana | Pascussi J.-M.,Montpellier University | Monostory K.,Hungarian Academy of Sciences
Biochimica et Biophysica Acta - Proteins and Proteomics | Year: 2011

Cholesterol biosynthetic and metabolic pathways contain several branching points towards physiologically active molecules, such as coenzyme Q, vitamin D, glucocorticoid and steroid hormones, oxysterols, or bile acids. Sophisticated regulatory mechanisms are involved in maintenance of the homeostasis of not only cholesterol but also other cholesterogenic molecules. In addition to endogenous cues, cholesterol homeostasis needs to accommodate also to exogenous cues that are imported into the body, such as chemicals and medications. Steroid and nuclear receptors together with sterol regulatory element-binding protein (SREBP) mediate the fine tuning of biosynthetic and metabolic routes as well as transports of cholesterol and its derivatives. Similarly, drug/xenobiotic metabolism is the subject to the feedback regulation of cytochrome P450 enzymes and transporters. The regulatory mechanisms that maintain the homeostasis of cholesterogenic molecules and are involved in drug metabolism share similarities. Cholesterol and cholesterogenic compounds (bile acids, glucocorticoids, vitamin D, etc.) regulate the xenosensor signaling in drug-mediated induction of the major drug-metabolizing cytochrome P450 enzymes. The key cellular receptors, pregnane X receptor (PXR), constitutive androstane receptor (CAR), vitamin D receptor (VDR), and glucocorticoid receptor (GR) provide a functional cross-talk between the pathways maintaining cholesterol homeostasis and controlling the expression of drug-metabolizing enzymes. These receptors serve as metabolic sensors, resulting in a coordinate regulation of cholesterogenic compounds metabolism and of the defense against xenobiotic and endobiotic toxicity. Herein we present a comprehensive review of functional interactions between cholesterol homeostasis and drug metabolism involving the main nuclear and steroid receptors. © 2010 Elsevier B.V. All rights reserved.


Rauscher T.,University of Hertfordshire | Rauscher T.,Hungarian Academy of Sciences | Rauscher T.,University of Basel
Physical Review Letters | Year: 2013

The Sm146/Sm144 ratio in the early solar system has been constrained by Nd/Sm isotope ratios in meteoritic material. Predictions of Sm146 and Sm144 production in the γ process in massive stars are at odds with these constraints, and this is partly due to deficiencies in the prediction of the reaction rates involved. The production ratio depends almost exclusively on the (γ,n)/(γ,α) branching at Gd148. A measurement of Sm144(α,γ)Gd148 at low energy had discovered considerable discrepancies between cross-section predictions and the data. Although this reaction cross section mainly depends on the optical α+nucleus potential, no global optical potential has yet been found that can consistently describe the results of this and similar α-induced reactions at the low energies encountered in astrophysical environments. The untypically large deviation in Sm144(α,γ) and the unusual energy dependence can be explained, however, by low-energy Coulomb excitation, which is competing with compound nucleus formation at very low energies. Considering this additional reaction channel, the cross sections can be described with the usual optical potential variations, compatible with findings for (n, α) reactions in this mass range. Low-energy (α, γ) and (α, n) data on other nuclei can also be consistently explained in this way. Since Coulomb excitation does not affect α emission, the Gd148(γ,α) rate is much higher than previously assumed. This leads to very small Sm146/Sm144 stellar production ratios, in even more pronounced conflict with the meteorite data. © 2013 American Physical Society.


Hornos T.,University of Oslo | Gali A.,Hungarian Academy of Sciences | Svensson B.G.,University of Oslo
Materials Science Forum | Year: 2011

Large-scale and gap error free calculations of the electronic structure of vacancies in 4H- SiC have been carried out using a hybrid density functional (HSE06) and an accurate charge correction scheme. Based on the results the carbon vacancy is proposed to be responsible for the Z1/2 and EH 6/7 DLTS centers. © (2011) Trans Tech Publications.


Levai G.,Hungarian Academy of Sciences | Arias J.M.,University of Seville
Physical Review C - Nuclear Physics | Year: 2010

The spherical to deformed γ-unstable shape transition in nuclei is discussed in terms of the sextic oscillator as a γ-independent potential in the Bohr Hamiltonian. The wave functions, energy eigenvalues, and electric quadrupole and monopole transition rates are calculated in closed analytical form for the lowest-lying energy levels. It is shown that the locus of critical points for the spherical to deformed γ-unstable shape phase transition corresponds to a parabola in the parameter space of the model. The ratios of energy eigenvalues and electromagnetic transition probabilities are constant along this parabola. It is thus possible to associate parameter-free benchmark values to the ratios of relevant observables at the critical point of the transition that can be compared to experimental data. In addition, systematic studies of the shape evolution in isotope chains can be performed within the model. As an application, the model parameters are fitted to the energy spectra of the chains of even-even Ru, Pd, and Cd isotopes and the electric quadrupole transition probabilities are calculated. It is found that Ru104, Pd102, and Cd106,108 nuclei, which are usually considered to be good candidates for the E(5) symmetry, lie rather close to the critical parabola that separates the spherical and deformed γ-unstable domains. The isotope Cd116 is proposed as a new candidate for a similar critical-point nucleus. © 2010 The American Physical Society.


Lukaszewski A.J.,University of California at Riverside | Kopecky D.,Institute of Experimental Botany | Linc G.,Hungarian Academy of Sciences
Chromosoma | Year: 2012

In many species, including wheat, crossing over is distal, and the proximal regions of chromosome arms contribute little to genetic maps. This was thought to be a consequence of terminal initiation of synapsis favoring distal crossing over. However, in an inverted rye chromosome arm, the pattern of metaphase I chiasmata was also inverted, suggesting that crossover frequencies were specific to chromosome segments. Here, wheat chromosome arms 2BS and 4AL, with essentially entire arms inverted in reverse tandem duplications (rtd), were studied in the MI of meiosis. Inversion-duplication placed the recombining segments in the middle of the arms. While the overall pairing frequencies of the inverted-duplicated arms were considerably reduced relative to normal arms, chiasmata, if present, were always located in the same regions as in structurally normal arms, and relative chiasma frequencies remained the same. The frequencies of fragment or fragment + bridge configurations in AI and AII indicated that of the two tandemly arranged copies of segments in rtds, the more distal inverted segments were more likely to cross over than the segments in their original orientations. These observations show that also in wheat, relative crossover frequencies along chromosome arms are predetermined and independent of the segment location. The segments normally not licensed to cross over do not do so even when placed in seemingly most favorable positions for it. © 2011 Springer-Verlag.


Kurucz Z.,University of Aarhus | Kurucz Z.,Hungarian Academy of Sciences | Wesenberg J.H.,National University of Singapore | Molmer K.,University of Aarhus
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

The enhanced collective coupling to weak quantum fields may turn atomic or spin ensembles into an important component in quantum information processing architectures. Inhomogeneous broadening can, however, significantly reduce the coupling and the lifetime of the collective excitation that represent the quantum information. In this paper we show that the width and shape of the inhomogeneous broadening have a striking influence on the dynamics of the cavity-ensemble system and may lead to narrowing of the linewidth of the collective states. We underpin our findings with the examples of a Gaussian and a Lorentzian profile of the inhomogeneity. © 2011 American Physical Society.


Fodor N.,Hungarian Academy of Sciences | Mika J.,Hungarian Meteorological Service | Mika J.,Eszterházy Károly College
Agricultural and Forest Meteorology | Year: 2011

Using analogies from soil science a new global radiation estimation method was developed and tested on a large North-American meteorological database. The newly developed procedure was compared to the well-known, Donatelli-Campbell method. Both the overall indicators and the more detailed analysis of the model performance confirmed that the new method is more efficient than the Donatelli-Campbell method. The improved performance is due to the greater number of parameters, as well as to the more adequate function type it uses during the calculation. Results suggest that it is sufficient to have 2 year-long data series for parameterizing the new method to provide at least as accurate radiation estimates as provided by the Donatelli-Campbell method. The new method can be efficiently used for locations with no radiation measurement by combining it with a simple spatial interpolation technique. © 2010 Elsevier B.V.


Yang T.H.,National University of Singapore | Vertesi T.,Hungarian Academy of Sciences | Bancal J.-D.,National University of Singapore | Scarani V.,National University of Singapore | Navascues M.,University of Bristol
Physical Review Letters | Year: 2014

Self-testing refers to the fact that, in some quantum devices, both states and measurements can be assessed in a black-box scenario, on the sole basis of the observed statistics, i.e., without reference to any prior device calibration. Only a few examples of self-testing are known, and they just provide nontrivial assessment for devices performing unrealistically close to the ideal case. We overcome these difficulties by approaching self-testing with the semidefinite programing hierarchy for the characterization of quantum correlations. This allows us to improve dramatically the robustness of previous self-testing schemes; e.g., we show that a Clauser-Horne-Shimony-Holt violation larger than 2.57 certifies a singlet fidelity of more than 70%. In addition, the versatility of the tool brings about self-testing of hitherto impossible cases, such as the robust self-testing of nonmaximally entangled two-qutrit states in the Collins-Gisin-Linden-Massar-Popescu scenario. © 2014 American Physical Society.


Wippermann S.,University of California at Davis | Voros M.,Budapest University of Technology and Economics | Rocca D.,University of California at Davis | Gali A.,Budapest University of Technology and Economics | And 3 more authors.
Physical Review Letters | Year: 2013

We present density functional and many body perturbation theory calculations of the electronic, optical, and impact ionization properties of Si nanoparticles (NPs) with core structures based on high-pressure bulk Si phases. Si particles with a BC8 core structure exhibit significantly lower optical gaps and multiple exciton generation (MEG) thresholds, and an order of magnitude higher MEG rate than diamondlike ones of the same size. Several mechanisms are discussed to further reduce the gap, including surface reconstruction and chemistry, excitonic effects, and embedding pressure. Experiments reported the formation of BC8 NPs embedded in amorphous Si and in amorphous regions of femtosecond-laser doped "black silicon." For all these reasons, BC8 nanoparticles may be promising candidates for MEG-based solar energy conversion. © 2013 American Physical Society.


Vukics A.,Hungarian Academy of Sciences | Griesser T.,University of Innsbruck | Domokos P.,Hungarian Academy of Sciences
Physical Review Letters | Year: 2014

We generalize the Power-Zineau-Woolley transformation to obtain a canonical Hamiltonian of cavity quantum electrodynamics for arbitrary geometry of boundaries. This Hamiltonian is free from the A-square term and the instantaneous Coulomb interaction between distinct atoms. The single-mode models of cavity QED (Dicke, Tavis-Cummings, Jaynes-Cummings) are justified by a term by term mapping to the proposed microscopic Hamiltonian. As one straightforward consequence, the basis of no-go argumentations concerning the Dicke phase transition with atoms in electromagnetic fields dissolves. © 2014 American Physical Society.


Kereszturi A.,Hungarian Academy of Sciences | Kereszturi A.,Nagy Karoly Astronomical Foundation
Astrobiology | Year: 2012

The astrobiological significance of certain environment types on Mars strongly depends on the temperature, duration, and chemistry of liquid water that was present there in the past. Recent works have focused on the identification of signs of ancient water on Mars, as it is more difficult to estimate the above-mentioned parameters. In this paper, two important factors are reviewed, the duration and the volume of water at different environment types on past and present Mars. Using currently available information, we can only roughly estimate these values, but as environment types show characteristic differences in this respect, it is worth comparing them and the result may have importance for research in astrobiology. Impact-induced and geothermal hydrothermal systems, lakes, and valley networks were in existence on Mars over the course of from 102 to 106 years, although they would have experienced substantially different temperature regimes. Ancient oceans, as well as water in outflow channels and gullies, and at the microscopic scale as interfacial water layers, would have had inherently different times of duration and overall volume: oceans may have endured from 104 to 10 6 years, while interfacial water would have had the smallest volume and residence time of liquid phase on Mars. Martian wet environments with longer residence times of liquid water are believed to have existed for that amount of time necessary for life to develop on Earth between the Late Heavy Bombardment and the age of the earliest fossil record. The results of this review show the necessity for more detailed analysis of conditions within geothermal heat-induced systems to reconstruct the conditions during weathering and mineral alteration, as well as to search for signs of reoccurring wet periods in ancient crater lakes. © 2012, Mary Ann Liebert, Inc.


Krasznahorkay A.,Hungarian Academy of Sciences | Paar N.,University of Zagreb | Vretenar D.,University of Zagreb | Harakeh M.N.,University of Groningen
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013

We examine a method to determine the neutron-skin thickness of nuclei using data on the charge-exchange anti-analog giant dipole resonance (AGDR). Calculations performed using the relativistic proton-neutron quasiparticle random-phase approximation (pn-RQRPA) reproduce the isotopic trend of the excitation energies of the AGDR, as well as that of the spin-flip giant dipole resonances (IVSGDR), in comparison to available data for the even-even isotopes 112-124Sn. It is shown that the excitation energies of the AGDR, obtained using a set of density-dependent effective interactions which span a range of the symmetry energy at saturation density, supplemented with the experimental values, provide a stringent constraint on value of the neutron-skin thickness. For 124Sn, in particular, we determine the value δRpn=0.21±0.05 fm. The result of the present study shows that a measurement of the excitation energy of the AGDR in (p, n) reactions using rare-isotope beams in inverse kinematics, provides a valuable method for the determination of neutron-skin thickness in exotic nuclei. © 2013 Elsevier B.V.


Corboz P.,ETH Zurich | Corboz P.,Institute Of Theorie Des Phenomenes Physiques | Lauchli A.M.,Max Planck Institute For Physik Komplexer Systeme | Lauchli A.M.,University of Innsbruck | And 3 more authors.
Physical Review Letters | Year: 2011

Using infinite projected entangled-pair states, exact diagonalization, and flavor-wave theory, we show that the SU(4) Heisenberg model undergoes a spontaneous dimerization on the square lattice, in contrast with its SU(2) and SU(3) counterparts, which develop Néel and three-sublattice stripelike long-range order. Since the ground state of a dimer is not a singlet for SU(4) but a 6-dimensional irreducible representation, this leaves the door open for further symmetry breaking. We provide evidence that, unlike in SU(4) ladders, where dimers pair up to form singlet plaquettes, here the SU(4) symmetry is additionally broken, leading to a gapless spectrum in spite of the broken translational symmetry. © 2011 American Physical Society.


Szabo G.,Discovery Chemistry | Keseru G.M.,Hungarian Academy of Sciences
Current Topics in Medicinal Chemistry | Year: 2014

This review summarizes drug discovery efforts on mGluR2 positive allosteric modulators (PAMs) from 2000 to 2013. Medicinal chemistry programs and the identified 21 chemotypes are analyzed and compared in terms of their biological activity and ligand efficiency. Comparative analysis of ligand efficiency metrics including ligand efficiency and lipophilic ligand efficiency allowed us to identify the most promising chemotypes. The perspective of their clinical development was evaluated in the light of recent human data. © 2014 Bentham Science Publishers


Rozman D.,University of Ljubljana | Monostory K.,Hungarian Academy of Sciences
Pharmacology and Therapeutics | Year: 2010

This review focuses on the non-statin strategies for the treatment of hyperlipidemias in humans. Even if statins remain the major hypolipidemic drugs at present, an increasing number of patients that are treated with statins raises as well the numbers of patients suffering from side effects or not responding well to the therapy. Thus, development of novel approaches to battle the world epidemics of hyperlipidemia remains relevant. The non-statin strategies include the decrease of cholesterol absorption from the diet, lowering the atherogenic lipoprotein release and increasing HDL levels, or increasing elimination of cholesterol by bile acid binding. Representative non-statin drugs that are on the market or are in development phases are described herein in comparison to statins. In addition to 3β-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), as the major regulatory enzyme of cholesterol synthesis that is the target of statins, some other enzymes of this multi-step pathway represent perspective targets for the development of novel hypolipidemics. None of these inhibitors are currently approved for use in humans. We describe the characteristics of the later enzymes of cholesterol synthesis, starting from the squalene synthase step. Inhibitors of these enzymes are critically evaluated, particularly concerning safety in humans (teratogenic potential, toxicity, and other side effects) and their hypolipidemic effects compared to the statins. Since only a limited number of publications discuss the non-statin approaches for the treatment of hyperlipidemias, this review represents a valuable up-to date summary, with a take-home message, that novel approaches deserve more attention in the future, irrespective of the success of statins. © 2010 Elsevier Inc.


Foldesy P.,Hungarian Academy of Sciences | Foldesy P.,Pázmány Péter Catholic University
Optics Letters | Year: 2012

A single-shot quadrature phase-shifting interferometry architecture is presented that is applicable to antenna coupled detector technologies. The method is based on orthogonally polarized object and reference beams and on linear and circular polarization sensitive antennas in space-division multiplexing. The technique can be adapted to two-, three-, and four-step and Gabor holography recordings. It is also demonstrated that the space-division multiplexing does not necessarily cause sparse sampling. A sub-THz detector array is presented containing multiple on-chip antennas and FET plasma wave detectors implemented in a 90 nm complementary metal-oxide semiconductor technology. As an example, two-step phase-shifting reconstruction results are given at 360 GHz. © 2012 Optical Society of America.


Bywalez W.G.,Ludwig Maximilians University of Munich | Bywalez W.G.,University of Regensburg | Patirniche D.,Ludwig Maximilians University of Munich | Rupprecht V.,University of Regensburg | And 7 more authors.
Neuron | Year: 2015

Neuronal dendritic spines have been speculated to function as independent computational units, yet evidence for active electrical computation in spines is scarce. Here we show that strictly local voltage-gated sodium channel (Nav) activation can occur during excitatory postsynaptic potentials in the spines of olfactory bulb granule cells, which we mimic and detect via combined two-photon uncaging of glutamate andcalcium imaging in conjunction with whole-cell recordings. We find that local Nav activation boosts calcium entry into spines through high-voltage-activated calcium channels and accelerates postsynaptic somatic depolarization, without affecting NMDA receptor-mediated signaling. Hence, Nav-mediated boosting promotes rapid output from the reciprocal granule cell spine onto the lateral mitral cell dendrite and thus can speed up recurrent inhibition. This striking example of electrical compartmentalization both adds to the understanding of olfactory network processing and broadens the general view of spine function. © 2015 Elsevier Inc.


Hajheidari M.,Max Planck Institute for Plant Breeding Research | Koncz C.,Max Planck Institute for Plant Breeding Research | Koncz C.,Hungarian Academy of Sciences | Eick D.,Helmholtz Center Munich
Trends in Plant Science | Year: 2013

Post-translational modifications of the carboxy-terminal domain of the largest subunit of RNA polymerase II (RNAPII CTD) provide recognition marks to coordinate recruitment of numerous nuclear factors controlling transcription, cotranscriptional RNA processing, chromatin remodeling, and RNA export. Compared with the progress in yeast and mammals, deciphering the regulatory roles of position-specific combinatorial CTD modifications, the so-called CTD code, is still at an early stage in plants. In this review, we discuss some of the recent advances in understanding of the molecular mechanisms controlling the deposition and recognition of RNAPII CTD marks in plants during the transcriptional cycle and highlight some intriguing differences between regulatory components characterized in yeast, mammals, and plants. © 2013 Elsevier Ltd.


Hajheidari M.,Max Planck Institute for Plant Breeding Research | Farrona S.,Max Planck Institute for Plant Breeding Research | Huettel B.,Max Planck Institute for Plant Breeding Research | Koncz Z.,Max Planck Institute for Plant Breeding Research | And 2 more authors.
Plant Cell | Year: 2012

Phosphorylation of conserved Y1S2P3T4S5P6S7 repeats in the C-terminal domain of largest subunit of RNA polymerase II (RNAPII CTD) plays a central role in the regulation of transcription and cotranscriptional RNA processing. Here, we show that Ser phosphorylation of Arabidopsis thaliana RNAPII CTD is governed by CYCLIN-DEPENDENT KINASE F;1 (CDKF;1), a unique plant-specific CTD S7-kinase. CDKF;1 is required for in vivo activation of functionally redundant CYCLIN-DEPENDENT KINASE Ds (CDKDs), which are major CTD S5-kinases that also phosphorylate in vitro the S2 and S7 CTD residues. Inactivation of CDKF;1 causes extreme dwarfism and sterility. Inhibition of CTD S7-phosphorylation in germinating cdkf;1 seedlings is accompanied by 39-polyadenylation defects of pre-microRNAs and transcripts encoding key regulators of small RNA biogenesis pathways. The cdkf;1 mutation also decreases the levels of both precursor and mature small RNAs without causing global downregulation of the protein-coding transcriptome and enhances the removal of introns that carry premicroRNA stem-loops. A triple cdkd knockout mutant is not viable, but a combination of null and weak cdkd;3 alleles in a triple cdkd123* mutant permits semidwarf growth. Germinating cdkd123* seedlings show reduced CTD S5-phosphorylation, accumulation of uncapped precursor microRNAs, and a parallel decrease in mature microRNA. During later development of cdkd123* seedlings, however, S7-phosphorylation and unprocessed small RNA levels decline similarly as in the cdkf;1 mutant. Taken together, cotranscriptional processing and stability of a set of small RNAs and transcripts involved in their biogenesis are sensitive to changes in the phosphorylation of RNAPII CTD by CDKF;1 and CDKDs. © 2012 American Society of Plant Biologists. All rights reserved.


Tarcsay A.,Discovery Chemistry | Keseru G.M.,Hungarian Academy of Sciences
Journal of Medicinal Chemistry | Year: 2013

In contrast to designed polypharmacology that can result in efficient drugs for complex disorders, unintended drug promiscuity has detrimental contribution to side effects and toxicology. Characterization of promiscuous compounds enhances the understanding of complex interaction patterns and aids the design of compounds with broader selectivity against off-targets that has a major impact on medicinal chemistry outcome. In this Miniperspective we provide insights to the effect of physicochemical parameters on promiscuity. Information collected from recent, large-scale in vitro studies enabled us to discuss the relationships between physicochemical properties and promiscuity in detail. In light of these data, lipophilicity and basic character have the highest influence. On the basis of the accumulated knowledge, we propose the extensive use of pre- and postsynthesis metrics, as well as strict control of physicochemical properties during medicinal chemistry optimizations. © 2013 American Chemical Society.


Schlingloff D.,Hungarian Academy of Sciences | Schlingloff D.,Semmelweis University | Kali S.,Hungarian Academy of Sciences | Kali S.,Pázmány Péter Catholic University | And 4 more authors.
Journal of Neuroscience | Year: 2014

Replay of neuronal activity during hippocampal sharp wave-ripples (SWRs) is essential in memory formation. To understand the mechanisms underlying the initiation of irregularly occurring SWRs and the generation of periodic ripples, we selectively manipulated different components of the CA3 network in mouse hippocampal slices. We recorded EPSCs and IPSCs to examine the buildup of neuronal activity preceding SWRs and analyzed the distribution of time intervals between subsequent SWR events. Our results suggest that SWRs are initiated through a combined refractory and stochastic mechanism. SWRs initiate when firing in a set of spontaneously active pyramidal cells triggers a gradual, exponential buildup of activity in the recurrent CA3 network. We showed that this tonic excitatory envelope drives reciprocally connected parvalbumin-positive basket cells, which start ripple-frequency spiking that is phase-locked through reciprocal inhibition. The synchronized GABAA receptor-mediated currents give rise to a major component of the ripple-frequency oscillation in the local field potential and organize the phase-locked spiking of pyramidal cells. Optogenetic stimulation of parvalbumin-positive cells evoked full SWRs and EPSC sequences in pyramidal cells. Even with excitation blocked, tonic driving of parvalbumin-positive cells evoked ripple oscillations. Conversely, optogenetic silencing of parvalbumin-positive cells interrupted the SWRs or inhibited their occurrence. Local drug applications and modeling experiments confirmed that the activity of parvalbumin-positive perisomatic inhibitory neurons is both necessary and sufficient for ripple-frequency current and rhythm generation. These interneurons are thus essential in organizing pyramidal cell activity not only during gamma oscillation, but, in a different configuration, during SWRs. © 2014 the authors.


Sandner R.,University of Innsbruck | Vukics A.,Hungarian Academy of Sciences
Computer Physics Communications | Year: 2014

The v2 Milestone 10 release of C++QED is primarily a feature release, which also corrects some problems of the previous release, especially as regards the build system. The adoption of C++11 features has led to many simplifications in the codebase. A full doxygen-based API manual [1] is now provided together with updated user guides. A largely automated, versatile new testsuite directed both towards computational and physics features allows for quickly spotting arising errors. The states of trajectories are now savable and recoverable with full binary precision, allowing for trajectory continuation regardless of evolution method (single/ensemble Monte Carlo wave-function or Master equation trajectory). As the main new feature, the framework now presents Python bindings to the highest-level programming interface, so that actual simulations for given composite quantum systems can now be performed from Python. © 2014 Elsevier B.V. All rights reserved.


Marx D.,Hungarian Academy of Sciences | Wollan P.,University of Rome
Proceedings of the Annual ACM-SIAM Symposium on Discrete Algorithms | Year: 2015

We study the following general disjoint paths problem: given a supply graph G, a set T C V(G) of terminals, a demand graph H on the vertices T, and an integer k, the task is to find a set of k pairwise vertex-disjoint valid paths, where we say that a path of the supply graph G is valid if its endpoints are in T and adjacent in the demand graph H. For a class H of graphs, we denote by Maximum Disjoint 'H-Paths the restriction of this problem when the demand graph H is assumed to be a member of T-L. We study the fixed-parameter tractability of this family of problems, parameterized by k. Our main result is a complete characterization of the fixed-parameter tractable cases of Maximum Disjoint H-Paths for every hereditary class T-L of graphs: it turns out that complexity depends on the existence of large induced matchings and large induced skew bicliques in the demand graph H (a skew biclique is a bipartite graph on vertices a1, ⋯, an, b1, ⋯, bn with a1 and bj being adjacent if and only if i ≤ j). Specifically, we prove the following classification for every hereditary class H. If H does not contain every matching and does not contain every skew biclique, then maximum Disjoint H-Paths is FPT. If H does not contain every matching, but contains every skew biclique, then Maximum Disjoint H-Paths is W[l]-hard, admits an FPT approximation, and the valid paths satisfy an analog of the Erdos-Posa property. If H contains every matching, then Maximum Disjoint W-Paths is W[l]-hard and the valid paths do not satisfy the analog of the Erdos-Pósa property. © 2015 by the Society for Industrial and Applied Mathmatics.


Szolgay D.,Pázmány Péter Catholic University | Sziranyi T.,Hungarian Academy of Sciences
IEEE Transactions on Image Processing | Year: 2012

In this paper, a new decomposition method is introduced that splits the image into geometric (or cartoon) and texture parts. Following a total variation based preprocesssing, the core of the proposed method is an anisotropic diffusion with an orthogonality-based parameter estimation and stopping condition. The quality criterion is defined by the theoretical assumption that the cartoon and the texture components of an image are orthogonal to each other. The presented method has been compared with other decomposition algorithms through visual and numerical evaluation to prove its superiority. © 1992-2012 IEEE.


Ritsch H.,University of Innsbruck | Domokos P.,Hungarian Academy of Sciences | Brennecke F.,ETH Zurich | Esslinger T.,ETH Zurich
Reviews of Modern Physics | Year: 2013

This is a review of state-of-the-art theory and experiment of the motion of cold and ultracold atoms coupled to the radiation field within a high-finesse optical resonator in the dispersive regime of the atom-field interaction with small internal excitation. The optical dipole force on the atoms together with the backaction of atomic motion onto the light field gives rise to a complex nonlinear coupled dynamics. As the resonator constitutes an open driven and damped system, the dynamics is nonconservative and in general enables cooling and confining the motion of polarizable particles. In addition the emitted cavity field allows for real-time monitoring of the particle's position with minimal perturbation up to subwavelength accuracy. For many-body systems, the resonator field mediates controllable long-range atom-atom interactions, which set the stage for collective phenomena. Besides the correlated motion of distant particles, one finds critical behavior and nonequilibrium phase transitions between states of different atomic order in conjunction with superradiant light scattering. Quantum-degenerate gases inside optical resonators can be used to emulate optomechanics as well as novel quantum phases such as supersolids and spin glasses. Nonequilibrium quantum phase transitions as predicted by, e.g., the Dicke Hamiltonian can be controlled and explored in real time via monitoring the cavity field. In combination with optical lattices, the cavity field can be utilized for nondestructive probing Hubbard physics and tailoring long-range interactions for ultracold quantum systems. © 2013 American Physical Society.


Hrabovszky E.,Hungarian Academy of Sciences | Liposits Z.,Hungarian Academy of Sciences | Liposits Z.,Pázmány Péter Catholic University
Frontiers in Endocrinology | Year: 2013

Understanding the regulation of the human menstrual cycle represents an important ultimate challenge of reproductive neuroendocrine research. However, direct translation of information from laboratory animal experiments to the human is often complicated by strikingly different and unique reproductive strategies and central regulatory mechanisms that can be present in even closely related animal species. In all mammals studied so far, type-I gonadotropin releasing hormone (GnRH) synthesizing neurons form the final common output way from the hypothalamus in the neuroendocrine control of the adenohypophysis. Under various physiological and pathological conditions, hormonal and metabolic signals either regulate GnRH neurons directly or act on upstream neuronal circuitries to influence the pattern of pulsatile GnRH secretion into the hypophysial portal circulation. Neuronal afferents to GnRH cells convey important metabolic-, stress-, sex steroid-, lactational-, and circadian signals to the reproductive axis, among other effects. This article gives an overview of the available neuroanatomical literature that described the afferent regulation of human GnRH neurons by peptidergic, monoaminergic, and amino acidergic neuronal systems. Recent studies of human genetics provided evidence that central peptidergic signaling by kisspeptins and neurokinin B (NKB) play particularly important roles in puberty onset and later, in the sex steroid-dependent feedback regulation of GnRH neurons. This review article places special emphasis on the topographic distribution, sexual dimorphism, aging-dependent neuroanatomical changes, and plastic connectivity to GnRH neurons of the critically important human hypothalamic kisspeptin and NKB systems. © 2013 Hrabovszky and Liposits.


Fekete C.,Hungarian Academy of Sciences | Fekete C.,Tupper Research Institute | Lechan R.M.,Tupper Research Institute | Lechan R.M.,Tufts University
Endocrine Reviews | Year: 2014

TRH is a tripeptide amide that functions as a neurotransmitter but also serves as a neurohormone that has a critical role in the central regulation of the hypothalamic-pituitary-thyroid axis. Hypophysiotropic TRH neurons involved in this neuroendocrine process are located in the hypothalamic paraventricular nucleus and secrete TRH into the pericapillary space of the external zone of the median eminence for conveyance to anterior pituitary thyrotrophs. Under basal conditions, the activity of hypophysiotropic TRH neurons is regulated by the negative feedback effects of thyroid hormone to ensure stable, circulating, thyroid hormone concentrations, a mechanism that involves complex interactions between hypophysiotropic TRH neurons and the vascular system, cerebrospinal fluid, and specializedglial cells called tanycytes.HypophysiotropicTRHneuronsalso integrateotherhumoralandneuronalinputsthat can alter the setpoint for negative feedback regulation by thyroid hormone. This mechanism facilitates adaptation of the organism to changing environmental conditions, including the shortage of food and a cold environment. The thyroid axis is also affected by other adverse conditions such as infection, but the central mechanisms mediating suppression of hypophysiotropicTRHmaybepathophysiological. In this review,wediscuss currentknowledgeabout the mechanisms that contribute to the regulation of hypophysiotropic TRH neurons under physiological and pathophysiological conditions. © 2014 by the Endocrine Society.


Hajnal A.,Hungarian Academy of Sciences | Forgacs I.,4D Soft Kft.
Journal of software: Evolution and Process | Year: 2012

Maintenance of aging legacy COBOL systems is labor-intensive and is becoming a more and more difficult problem. Program slicing is a potentially useful analysis for aiding different maintenance activities, including program comprehension, reverse engineering, debugging, and testing. Numerous techniques have been proposed in the past decades; however, in interactive contexts, we found none of them suitable for slicing industrial-scale COBOL systems due to their large space or preprocessing requirements. This paper proposes a novel static program slicing approach, which is based on context-sensitive token propagation over control flow graphs (CFGs). CFGs require less space compared with program dependence graphs (PDGs) used by other techniques, and the token propagation method computes the necessary information only, on demand. Algorithms are presented for data flow and full slicing to calculate precise program slices. Preliminary application experiences on industrial-scale COBOL systems are also summarized. © 2011 John Wiley & Sons, Ltd.


Corboz P.,ETH Zurich | Lajko M.,Hungarian Academy of Sciences | Lajko M.,Budapest University of Technology and Economics | Lauchli A.M.,University of Innsbruck | And 3 more authors.
Physical Review X | Year: 2012

The main characteristic of Mott insulators, as compared to band insulators, is to host low-energy spin fluctuations. In addition, Mott insulators often possess orbital degrees of freedom when crystal-field levels are partially filled. While in the majority of Mott insulators, spins and orbitals develop long-range order, the possibility for the ground state to be a quantum liquid opens new perspectives. In this paper, we provide clear evidence that the spin-orbital SU(4) symmetric Kugel-Khomskii model of Mott insulators on the honeycomb lattice is a quantum spin-orbital liquid. The absence of any form of symmetry breaking- lattice or SU(N)-is supported by a combination of semiclassical and numerical approaches: flavor-wave theory, tensor network algorithm, and exact diagonalizations. In addition, all properties revealed by these methods are very accurately accounted for by a projected variational wave function based on the π-flux state of fermions on the honeycomb lattice at 1=4 filling. In that state, correlations are algebraic because of the presence of a Dirac point at the Fermi level, suggesting that the symmetric Kugel-Khomskii model on the honeycomb lattice is an algebraic quantum spin-orbital liquid. This model provides an interesting starting point to understanding the recently discovered spin-orbital-liquid behavior of Ba3CuSb2O9. The present results also suggest the choice of optical lattices with honeycomb geometry in the search for quantum liquids in ultracold four-color fermionic atoms.


Foldesy P.,Hungarian Academy of Sciences | Foldesy P.,Pázmány Péter Catholic University
Optics Letters | Year: 2013

An antenna-coupled field effect transistor (FET) as a plasma wave terahertz detector is used with the current steering to record separately the gate-source and gate-drain photoresponses and their phase sensitive combination. This method is based on the observation that the plasmon-terminal coupling is cut off in saturation, resulting in only one-sided sensitivity. A polarimetric example is presented with intensity and polarization angle reconstruction using a single three-terminal antenna-coupled Si-metal-oxide semiconductor FET (MOSFET). The technique is applicable to various detection schemes and technologies (high electron mobility transistors and GaAs-, GaN-, and Si-MOSFETs), and other application possibilities are discussed. © 2013 Optical Society of America.


Grant
Agency: European Commission | Branch: FP7 | Program: CP | Phase: ICT-2013.3.3 | Award Amount: 3.86M | Year: 2013

The paradigm of societal uses protected by biometric identification (ID) from national security and controlled access, to health care, banking and leisure requires coming up with ever more reliable built-in ID detection systems. In this context, PiezoMAT proposes a new technology of high-resolution fingerprint sensors based on a matrix of interconnected piezoelectric nanowires (NWs). The long term objective of PiezoMAT is to offer high performance fingerprint sensors with minimal volume occupation for integration into built-in systems able to compete on the market with the best existing products.PiezoMAT proceeds by local deformation of an array of individually contacted piezoelectric NWs and reconstruction from generated potentials, whose amplitudes are proportional to the NW displacement. Each NW and its associated electronics constitute a sensor, or pixel. The sub-micron dimension of NWs allows for high spatial frequency sampling of every fingerprint feature, enabling extremely reliable fingerprint differentiation through detection of the smallest minutiae (pores and ridge shapes). Charge collection efficiency is very dependent on the electrode configuration on each NW. PiezoMAT explores several possible configurations associated with gradual levels of technological challenges and risks, with a strong focus on developing reliable device design tools for present and future application-related adaptability. For the purpose of the PiezoMAT research, it is foreseen to collect generated charges and analogue output signals via metal lines connected to deported electronics on a printed circuit board. This configuration does not allow for maximum NW integration density but is designed to yield sufficient resolution to demonstrate the concept, major technological achievements and actual performance increase as compared to the state-of-the-art. Long term developments will pursue full electronics integration for an optimal sensor resolution.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-IP | Phase: KBBE-2009-1-2-04 | Award Amount: 7.82M | Year: 2010

SOLIBAM will develop specific and novel breeding approaches integrated with management practices to improve the performance, quality, sustainability and stability of crops adapted to organic and low-input systems, in their diversity in Europe and taking into account small-scale farms in Africa. SOLIBAM will: 1. Identify traits specific for adaptation to low-input/organic conditions over a wide range of agro-climatic conditions in Europe 2. Develop efficient phenotyping, genotyping and molecular tools to monitor heritable variation during selection. Molecular analysis of functional polymorphisms will increase accuracy in breeding methodologies and improve monitoring of genetic diversity and adaptation along generations. It will also increase the understanding of adaptive phenomena 3. Develop the use of within-crop diversity to stabilise yield and quality in the face of current and increasing variation in organic and low-input agriculture 4. Design, develop and test innovative arable and vegetable cropping systems based on integration of a high level of diversification in crop management with the use of genetically diverse populations or varieties 5. Compare the effectiveness of different breeding strategies under conventional, low input and certified organic farming to set up optimal strategies for the production of varieties suitable for organic and low input farming taking into account the traits which are avoided in conventional breeding 6. Develop methodologies for farmers participatory research that exploit SOLIBAMs advances in low-input and organic farming 7. Quantify the effects and interactions of breeding and management innovations on crop nutritional, organoleptic and end-use quality 8. Evaluate socio-economic and environmental impacts of SOLIBAM breeding and management innovations in order to identify farm business, consumer preference, food supply and legislation related issues that are likely to influence their adoption


Grant
Agency: European Commission | Branch: FP7 | Program: CP | Phase: ICT-2011.9.11 | Award Amount: 9.20M | Year: 2013

Most cognitive functions are based on computations that take place in the cerebral cortex, composed of a larger number of areas, each with a complex anatomical structure, with neurons of different types and in different layers interacting according to a precise scheme. The anatomical organization of cortical areas is similar, with some modulation according to its sensory, motor or associative function. Several areas have a columnar organization, but in all areas a similar vertical organization of cortical modules is repeated, suggesting that the same fundamental computation scheme is carried out. Despite the large amount of available data, this processing capability of the cortical module is still poorly understood. Two key technological advances to explore cortical computation have been ensemble electrophysiology, the use of multiple electrodes to record groups of neurons, and optogenetics. However, the optogenetic tools are still critically lacking in layer and cell-type specificity, and the recording techniques still do not attain the yields necessary to properly characterize the cortical microcircuit. To overcome these limitations, we propose a new probe that dramatically increases the density of electrodes providing an unprecedented view of currents in the extracellular medium. This will be complemented with an optical stimulator, capable of activating excitatory and inhibitory channelrhodopsins with a 100 m resolution. We will take full advantage of the rich data that can be obtained with these new devices by producing new strategies for signal classification, to locate cells in cortical layers and assign them to a cell type based on the spatiotemporal fingerprint generated at each action potential. We will analyze cortical function at multiple scales in a number of contexts, from memory formation, to ongoing processing during decision making, and to sensorimotor integration for actions, advancing our understanding of cortical representations.


Grant
Agency: European Commission | Branch: FP7 | Program: CSA-SA | Phase: FP7-PEOPLE-2011-NIGHT | Award Amount: 117.68K | Year: 2011

We will focus on enhancing researchers public recognition. Researchers, presented as persons that everyday people can relate to, can draw attention to science; and can make science seen as a casual but interesting adventure. Better understanding science can also lead to improving researchers recognition. Thus, the main message of the event will emphasize the human, accessible yet important figure of the researcher working for the benefit of the society. RN is an event that attracts a growing number of visitors and cooperating bodies each year. This year we plan a brand new exciting project that retains some indispensable elements from the previous events. We will actively involve young people because we believe that future scientific and technological development lies in their hands. The main driving forces and themes of our programmes are connection and interaction. Connection and interaction between different scientific fields, Science and Arts, scientists, science and children/pupils/students, researchers and laymen, science and companies, research and everyday life, research and hobby; between partner universities, research institutes and industrial companies. Connection and interaction with media is also indispensable in order to enhance researchers public recognition and to raise awareness of the importance of science and research by putting in the spotlight scientific achievements and researchers. Our choice of key theme is reinforced and further coloured by the fact that 2011 is the International Year of Chemistry so we will closely examine chemical bonds, unions and interactions as well. Again, we will involve the public in a wide range of exciting scientific activities that are interconnected and are implemented through intense cooperation between the consortium members. Visitors will have the opportunity to meet researchers and get more deeply acquainted with the world of science.


Grant
Agency: European Commission | Branch: FP7 | Program: CSA-SA | Phase: FP7-2008-PEOPLE-NIGHT | Award Amount: 187.14K | Year: 2008

The 2008 edition of the Researchers Night is an expanded and updated version of the 2007 event. Tempus Public Foundation together with 13 prestigious institutions of the Hungarian higher education and research community - University of Technology and Economics; Corvinus University of Budapest; Eszterhzy Kroly University; Etvs Lornd University; Pzmny Pter Catholic University; Szent Istvn University; Szchenyi Istvn University; University of Debrecen; University of Miskolc; University of Pcs; University of Szeged; University of West Hungary, and the Agricultural Research Institute of the HAS - undertake the organisation of the event in 2008. The consortium consists of last years RN partners strengthened by two other universities. Our event fits well in the Europe-wide festival series with the entertaining and serious, but user-friendly scientific programmes focusing on science and researchers, and on researchers and society. We wish to involve the public in a wide range of various activities including hands-on experiments, laboratory and cave visits, creative contests, University CSI, music and theatre performances, exhibition of research results, investigating order and disorder in nature, an obstacle race in a Botanical Garden, a library night, games on wildlife, programmes linked to Renaissance Year, The Year of the Bible, and to the International Year of Languages initiatives and innumerable other exciting programmes. Visitors will meet and play with many researchers and get more acquainted with the world of science. The events will take place in 15 towns; most of Hungary will be covered ensuring that the RN will reach a large audience. The professional background and organizational experience of the participants ensure that the activities will be efficiently co-ordinated and both the serious and the entertaining programmes will display a high standard of quality.


Grant
Agency: European Commission | Branch: FP7 | Program: CSA-SA | Phase: FP7-PEOPLE-2009-NIGHT | Award Amount: 166.85K | Year: 2010

The 2010 HEURECA Researchers night will build upon the experience the consortium gained in organizing the event in the previous years. It will actually consist of a further expanded version of the previous events. Partnership will be enlarged by 3 new cooperating bodies joining the 18 experienced partners, and possibly by several non profit organisations and companies having already expressed their interest in participating in the project. The messages conveyed will relate to the fully human yet important figure of the researcher carrying out work to the benefit of the society, underlining also the important asset represented by science. A broad range of edutainment activities will be offered, some of them being linked to the central theme of the year of biodiversity. The events will take place in 19 towns, covering most part of the Hungarian territory, on 24th September 2010. Most programmes will take place from late Friday afternoon until the early hours of Saturday, with some exceptions regarding specific programmes addressing school children starting earlier. The programme of activities, covering over 600 different activities through all venues, will offer the visitors a broad range of hands-on experiments, demos, shows, guided visits, etc., allowing the public at large to enjoy themselves regardless of age or scientific background and to get directly in touch with the researchers hosting the activities of the night.


Grant
Agency: European Commission | Branch: FP7 | Program: CSA-SA | Phase: PEOPLE-2007-5-1.NIGHT | Award Amount: 162.81K | Year: 2007

The 2007 edition of the Researchers Night in Hungary is expected to be a nation-wide series of events organised by 12 prestigious representatives of the Hungarian higher education and research community: Tempus Public Foundation as coordinator and the Agricultural Research Institute of the Hungarian Academy of Sciences, Budapest University of Technology and Economics, Corvinus University of Budapest, Etvs Lornd University, Eszterhzy Kroly University, Pzmny Pter Catholic University, Szchenyi Istvn University, University of Debrecen, University of Miskolc, University of Szeged and the University of West Hungary as project partners. The hereby proposed activities will take place in 8 towns all over the country and at 3 locations in the capital city ensuring that the idea of the Researchers Night will reach mass audiences. The institutions represent 195.000 students, 9.800 lecturers and 98 PhD schools of the national higher education system. The message we wish to put across is the importance of science and research embedded in a European context; the fully human yet important figure of the researcher carrying out his work to the benefit of the society; the appeal of a researchers career and Europes role in supporting scientific work. The proposed programmes include laboratory visits, spectacular public experiments, nuclear reactor and flight simulator visits, ethology demonstrations, skills development for disabled, creative programmes and drawing competition for kids, researchers pubs, a beer garden, wine tasting, a library night, art exhibitions, music concerts, theatre performances, poems and lawsuits presented by researchers, a science bus, a street ball, sport tournaments, cooking with researchers, spaghetti bridge construction and innumerable other exciting programmes. Visitors will have the opportunity to interact and converse with the more than 600 participating researchers and get more deeply acquainted with the world of science.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-CSA-Infra | Phase: INFRA-2007-2.2-01 | Award Amount: 5.87M | Year: 2007

The objective of the ELIXIR preparatory phase is to produce a memorandum or memoranda of understanding between organisations (government agencies, research councils, funding bodies and scientific organisations) within the member states, with the purpose of constructing a world class and globally positioned European infrastructure for the management and integration of information in the life sciences. To achieve this, we will address the following tasks and issues: 1 Define the scope of the infrastructure, its role and benefits 2 Define an appropriate governance and legal structure 3 Define a long term funding structure to provide a sustainable infrastructure 4 Define the requirements for the European Data Centre in the next 5-10 years and makes plans to meet these needs 5 Involve all relevant stakeholders, including users, data providers, tools providers to ensure that the infrastructure meets their needs 6 Explore integration and interoperability between core and specialised data resources and the development of standards in newly emerging fields 7 Define the critical interdisciplinary links that need to be forged between the biological and related scientific disciplines, including medicine, agriculture and the environment 8 Define the needs of related European industries 9 Define a training strategy to ensure that Europe effectively exploits all the available information The specific activities of the preparatory phase will include: A Holding stakeholder meetings to bring together national representatives, key scientific opinion and funding organisations. B Establishing working parties, supported by technical feasibility studies where appropriate, to address the tasks and issues above with final reports at month 18. C Consolidating these reports into a management and funding proposal to be sent to member states and funding agencies with draft MoU by month 38 and to seek agreement on the MoU and establish an Interim ELIXIR Board by month 50. D To establish the detailed organization of ELIXIR; and to draft and work toward the signing of the ELIXIR International Consortium Agreement


Grant
Agency: European Commission | Branch: H2020 | Program: SGA-RIA | Phase: FETFLAGSHIP | Award Amount: 89.00M | Year: 2016

Understanding the human brain is one of the greatest scientific challenges of our time. Such an understanding can provide profound insights into our humanity, leading to fundamentally new computing technologies, and transforming the diagnosis and treatment of brain disorders. Modern ICT brings this prospect within reach. The HBP Flagship Initiative (HBP) thus proposes a unique strategy that uses ICT to integrate neuroscience data from around the world, to develop a unified multi-level understanding of the brain and diseases, and ultimately to emulate its computational capabilities. The goal is to catalyze a global collaborative effort. During the HBPs first Specific Grant Agreement (SGA1), the HBP Core Project will outline the basis for building and operating a tightly integrated Research Infrastructure, providing HBP researchers and the scientific Community with unique resources and capabilities. Partnering Projects will enable independent research groups to expand the capabilities of the HBP Platforms, in order to use them to address otherwise intractable problems in neuroscience, computing and medicine in the future. In addition, collaborations with other national, European and international initiatives will create synergies, maximizing returns on research investment. SGA1 covers the detailed steps that will be taken to move the HBP closer to achieving its ambitious Flagship Objectives.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-TP | Phase: KBBE.2011.1.2-04 | Award Amount: 4.89M | Year: 2012

ADAPTAWHEAT will show how flowering time variation can be exploited for the genetic improvement of the European wheat crop to optimise adaptation and performance in the light of predicted climate change. It will test current hypotheses that postulate specific changes in ear emergence and the timing and duration of developmental phases, which are thought of as components of ear emergence, will improve wheat productivity. Precise genetic stocks varying in specific flowering time elements and subjected to genotyping and characterisation with diagnostic markers for key flowering time genes will be used to test these hypotheses. They will be phenotyped at the molecular (transcript abundance), physiological (growth stage dissection) and agronomic (yield components) levels in multiple field trials located at sites in Europe that represent regional agricultural diversity and at non European locations that have mega environments of relevance. Controlled environment experiments will investigate specific environmental interactions including day length, ambient temperature, and heat stress. Data analysis will aid the construction of new wheat flowering models that can be used to refine existing hypotheses. They will allow standing genetic variation for flowering time in European germplasm to be deployed more efficiently in wheat breeding programmes. This knowledge will be used to inform searches for specific phenotypic and molecular variants in diverse and non adapted wheat germplasm panels provided by consortium members. Vital novel genetic variation will be efficiently imported into the germplasm of European wheat breeders. The project will deliver new diagnostic markers for genotyping, molecular reporters for novel breeding selection strategies and the tools and knowledge necessary for a combined physiology and genomics led predictive wheat breeding programme. A conduit for these outcomes will be three SMEs, who will exploit the tools developed to deliver these outcomes.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-CSA-Infra-PP | Phase: INFRA-2010-2.2.6 | Award Amount: 5.05M | Year: 2010

The EU-OPENSCREEN Preparatory Phase forms the basis for the construction and operation of a pan-European infrastructure of open screening platforms for Chemical Biology. EU-OPENSCREEN will bring together leading laboratories from 14 European countries covering all aspects of Chemical Biology from high-throughput screening with a dedicated compound library to assay development, chemical synthesis for hit-optimisation, bio-profiling and in vivo studies, as well as a central database, training for scientists and platform staff and dissemination activities. The infrastructure will be used by researchers from universities, research institutes and SMEs across Europe, who either have only limited in-house facilities or no access at all to such resources and expertise. The EU-OPENSCREEN infrastructure will keep Europe at the forefront of the biological and medical sciences and will stimulate industrial research and commercial exploitation. In order to prepare the creation of an efficient network of centres which provide users with optimal resources, the EU-OPENSCREEN Preparatory Phase will address the following issues: - A user-focused access strategy. - The physical infrastructure requirements. - Suitable data standards and the framework for a database to archive and make the results available to the scientific community. - A financial management plan for the construction and sustainable operation of the infrastructure in co-operation with national funding bodies. - The legal approach regarding intellectual property issues. - An appropriate legal and governance structure. - The development of a Chemical Biology education package to ensure adequate training of scientists and platform staff. - A central Chemical Biology information gateway in form of a website. - The dissemination of the business plan to stakeholders and decision makers and co-ordination with national funding strategies.


Tarcsay A.,Discovery Chemistry | Keseru G.M.,Hungarian Academy of Sciences
Drug Discovery Today | Year: 2015

Thermodynamics of ligand binding is influenced by the interplay between enthalpy and entropy contributions of the binding event. The impact of these binding free energy components, however, is not limited to the primary target only. Here, we investigate the relationship between binding thermodynamics and selectivity profiles by combining publicly available data from broad off-target assay profiling and the corresponding thermodynamics measurements. Our analysis indicates that compounds binding their primary targets with higher entropy contributions tend to hit more off-targets compared with those ligands that demonstrated enthalpy-driven binding. © 2014 Elsevier Ltd. All rights reserved.


Grant
Agency: European Commission | Branch: FP7 | Program: CPCSA | Phase: ICT-2013.9.9 | Award Amount: 72.73M | Year: 2013

Understanding the human brain is one of the greatest challenges facing 21st century science. If we can rise to the challenge, we can gain profound insights into what makes us human, develop new treatments for brain diseases and build revolutionary new computing technologies. Today, for the first time, modern ICT has brought these goals within sight. The goal of the Human Brain Project, part of the FET Flagship Programme, is to translate this vision into reality, using ICT as a catalyst for a global collaborative effort to understand the human brain and its diseases and ultimately to emulate its computational capabilities. The Human Brain Project will last ten years and will consist of a ramp-up phase (from month 1 to month 36) and subsequent operational phases.\nThis Grant Agreement covers the ramp-up phase. During this phase the strategic goals of the project will be to design, develop and deploy the first versions of six ICT platforms dedicated to Neuroinformatics, Brain Simulation, High Performance Computing, Medical Informatics, Neuromorphic Computing and Neurorobotics, and create a user community of research groups from within and outside the HBP, set up a European Institute for Theoretical Neuroscience, complete a set of pilot projects providing a first demonstration of the scientific value of the platforms and the Institute, develop the scientific and technological capabilities required by future versions of the platforms, implement a policy of Responsible Innovation, and a programme of transdisciplinary education, and develop a framework for collaboration that links the partners under strong scientific leadership and professional project management, providing a coherent European approach and ensuring effective alignment of regional, national and European research and programmes. The project work plan is organized in the form of thirteen subprojects, each dedicated to a specific area of activity.\nA significant part of the budget will be used for competitive calls to complement the collective skills of the Consortium with additional expertise.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-IP | Phase: NMP.2012.1.4-1 | Award Amount: 13.40M | Year: 2013

In this proposed integrating project we will develop innovative in-line high throughput manufacturing technologies which are all based on atmospheric pressure (AP) vapour phase surface and on AP plasma processing technologies. Both approaches have significant potential for the precise synthesis of nano-structures with tailored properties, but their effective simultaneous combination is particularly promising. We propose to merge the unique potential of atmospheric pressure atomic layer deposition (AP-ALD), with nucleation and growth chemical vapour deposition (AP-CVD) with atmospheric pressure based plasma technologies e.g. for surface nano-structuring by growth control or chemical etching and, sub-nanoscale nucleation (seed) layers. The potential for cost advantages of such an approach, combined with the targeted innovation, make the technology capable of step changes in nano-manufacturing. Compatible with high volume and flexible multi-functionalisation, scale-up to pilot-lines will be a major objective. Pilot lines will establish equipment platforms which will be targeted for identified, and substantial potential applications, in three strategically significant industrial areas: (i) energy storage by high capacity batteries and hybridcapacitors with enhanced energy density, (ii) solar energy production and, (iii) energy efficient (lightweight) airplanes. A further aim is to develop process control concepts based on in-situ monitoring methods allowing direct correlation of synthesis parameters with nanomaterial structure and composition. Demonstration of the developed on-line monitoring tools in pilot lines is targeted. The integrating project targets a strategic contribution to establishing a European high value added nano-manufacturing industry. New, cost efficient production methods will improve quality of products in high market value segments in industries such as renewable energy production, energy storage, aeronautics, and space. DoW adaptations being made responding on requests from Phase-2 Evaluation Report In Phase-2 of the evaluation process, a number of points were noted by the evaluators where the project had insufficient information or could benefit from upgrading or justification. Our response and actions against each point raised has been summarized and send to the project officer, Dr. Rene Martins, in a separate document.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-IP | Phase: KBBE-2009-1-2-05 | Award Amount: 9.72M | Year: 2010

DROPS will develop novel methods and strategies aimed at yield maintenance under fluctuating water deficit and at enhanced plant water-use efficiency. We deal with high genotype x environment interaction in the field (any trait can have positive, negative or no effect depending on drought scenarios) with an approach combining Physiology, Genetics, field testing and Ecophysiological modelling. The project targets four traits : seed abortion, vegetative growth maintenance, root system architecture and transpiration efficiency. It deals with maize and durum wheat, plus bread wheat and sorghum for specific tasks. DROPS will: - Develop new screens for identifying drought tolerant genotypes, from phenotyping platforms to the field with indicators which are (i) stable characteristics of genotypes with high heritability in phenotyping platforms (ii) based on novel knowledge (e.g. combinations of metabolite concentrations, sensitivity parameters of models or hormonal balances) (iii) genetically related to target traits and able to predict genotype performance in the field via simulation and/or statistical models. - Explore the natural variation of the four target traits by (i) linking the target traits to physiological pathways, genes or genomic regions (ii) assessing the effects of a large allelic diversity for the four target traits via association genetics. - Support crop improvement strategies by developing methods for estimating the comparative advantages of relevant alleles and traits in fields with contrasting drought scenarios. This will be performed via field experiments and by developing a new generation of crop model able to estimate the effects of alleles on crop growth, yield and water-use efficiency Results and methods will be diffused (i) to breeders via the participation of seed companies and a partnership with a breeder association, (ii) to scientists and students via academic publications, and via practical courses and virtual courses in its website.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-CSA-Infra | Phase: INFRA-2011-1.1.6. | Award Amount: 10.57M | Year: 2011

The BioStruct-X consortium has 19 partners from 11 EU member and associated states, who lead in facility provision and research in structural biology using high brilliance X-rays, provided by state-of-the art synchrotrons and a free electron laser. BioStruct-X will provide integrated transnational access via 42 installations in four key areas: macromolecular X-ray crystallography, small angle X-ray scattering, X-ray imaging, protein production and high-throughput crystallisation. All installations provide on-line data analysis tools and remote experiment control. Transnational access will be critically enhanced by four targeted joint research activities: a) new data processing tools, to the benefit of access to applications in macromolecular X-ray crystallography; b) an integrated on-line sample characterisation system, to the benefit of the access to small angle X-ray scattering, c) correlated fluorescence light microscopy components that will enhance X-ray imaging applications offered for access; d) a toolbox for mammalian cell line expression, to the direct benefit of the access to protein production facilities. The BioStruct-X project will offer a central Batch Allocation Group proposal mechanism to promote project excellence by combining different methods and encouraging multi-site applications. The networking activity integrates all activities and combines them with those of other I3 actions under the ESFRI project INSTRUCT for future coordinated infrastructure activities in structural biology. The efficient management structure has four transparent layers: the coordinator, a six-member executive board, three work package coordinators and the general assembly comprising three user representatives and all partners. Thus, BioStruct-X will establish a state-of-the-art coordinated and multi-site infrastructure for current and emerging key methods in 21st century structural biology, thus advancing the European Research Area in biomedical sciences.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-CSA-Infra | Phase: INFRA-2010-1.1.8 | Award Amount: 10.93M | Year: 2010

In the past two decades spectacular insight into basic principles of life has been obtained from paradigmatic high-resolution structural investigations providing a rational basis for biological experiments. NMR is an indispensable enabling technology for determining such structures and their interactions in solution, the immobilized state and living cells. The power of NMR to link structural, dynamic, kinetic and thermodynamic information makes it an essential component of cutting edge research in medicine and biology. Bio-NMR pools pan-European resources of the most relevant bio-NMR infrastructures. Eleven partners will provide access to researchers involved in structural biology following the EU-NMR I3 project. This initiative successfully responded to the increasing demand for access since 1994. Seven other excellent partners, including the leading NMR manufacturer Bruker, are included in the new consortium. Jointly, they will develop methods aimed at pushing the frontiers of biological NMR and improving the quality of access to allow users to tackle ever more challenging goals in cellular structural biology. Finally, all nineteen partners, amongst them a company specialized in NMR technology dissemination, are involved in the networking activities. These include (1) knowledge transfer among consortium members, Bio-NMR users and other NMR researchers, (2) the demonstration to biologists of the potential of structural biology with NMR , and lowering the barriers to their becoming users, (3) interactions with industrial and medical communities, and (4) raising awareness of the impact of the results achieved through Bio-NMR among society, financing and governing bodies with the final aim of developing a business plan for self-sustainability. The overall project and its management have been conceived in coordination with INSTRUCT, which will contribute to the cultural frame and networking activities of Bio-NMR.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-IP | Phase: NMP-2007-2.5-1 | Award Amount: 13.86M | Year: 2008

The MORGaN project addresses the need for a new materials for electronic devices and sensors that operate in extreme conditions, especially high temperature, high electric field and highly corrosive environment. It will take advantage of the excellent physical properties of diamond and gallium nitride heterostructures. The association of the two materials will give rise to the best materials and devices for ultimate performance in extreme environments. Both materials possess durability and robustness to high temperature, radiation and electric field. Diamond material exhibits the best mechanical robustness and thermal conductivity, while GaN presents also high electron mobility, giving high power handling and efficiency. III-N systems have other desirable properties for sensor applications in extreme environments. It is the only highly polar semiconductor matrix that has ceramic-like stability and can form heterostructures. It has the highest spontaneous polarisation with a Curie temperature above 1000C for AlN: a lattice matched III-N heterostructure with a built-in polarisation discontinuity is expected to enable transistor action above 1000C. The packaging and metallisation of an electronic device or sensor are important elements in extreme conditions. Metal contacts must be stable and the package must be thermally compatible with the device requirements and chemically stable. MORGaN proposes a novel technological solution to electron device and sensor modules. Advanced 3D ceramic packaging and new metallisation techniques based on the emerging technology of MN\1AXN alloys will also be explored. As such, the vision of MORGaN for materials for extreme conditions is holistic, involving 2 large industrial partners, 2 industrial labs, 6 SMEs and 13 public research partners. The project includes research, demonstration, management, training and dissemination activities.


Grant
Agency: European Commission | Branch: FP7 | Program: CP | Phase: ICT-2013.3.3 | Award Amount: 11.05M | Year: 2013

SEA4KET (Semiconductor Equipment Assessment for Key Enabling Technologies) is an IP proposal taking the consequent step from equipment R&D to equipment assessment experiments. The strategic objective is to effectively combine resources and expertise in a joint assessment of novel equipment for key enabling technologies to foster and accelerate the successful transfer of novel European equipment into the world-wide market.\nSEA4KET builds on the proven principle established in previous European SEA programs and projects: to take novel, innovative and promising equipment that has left the R&D phase into a joint assessment activity this bridges the well-known gap between the phase of having an engineered tool available and finding the first user and finally success in the market for it.\nWhile proven principles from previous SEA activities are kept, SEA4KET takes them to the new field of assessing equipment for Key Enabling Technologies: SEA4KET concentrates on process and metrology systems for important enablers of future technologies: 450 mm wafer equipment, SiC material and 3D processing. The proposal comprises 15 sub-projects each dedicated to a specific equipment. The assessment activities were to a lesser extent chosen by high S&T excellence, but by their expected chance on the market.\nWhile leading R&D institutes are active in each assessment experiment to support individual final developments, several cross-cut R&D activities were identified (and combined in a dedicated sub-project) that are relevant to multiple assessments. Training material will be provided and workshops will be organized, to support and strengthen the individual dissemination activities.\nSEA4KET will significantly strengthen the European equipment and material industry for the emerging market for Key Enabling Technologies in a sustainable way by combining advanced R&D with equipment assessment involving users, institutes and equipment suppliers with specific benefit for SME suppliers.


News Article | August 16, 2016
Site: www.techtimes.com

Four fundamental forces, namely gravitation, electromagnetism, strong nuclear forces and weak nuclear forces, are currently accepted in the study of physics. Without these fundamental forces, all matter in the universe would fall apart. A new study, however, suggests that there may be a fifth force of nature. Jonathan Feng, from the University of California, Irvine, and colleagues conducted an analysis of data that were gathered by researchers from the Hungarian Academy of Sciences during a research on the so-called dark photons. The mid-2015 study detected evidence of the previously unknown subatomic particle 30 times heavier than electron. Dark photon, the hypothetical elementary particle, is proposed as an electromagnetic force carrier for dark matter, which comprises 85 percent of the mass of the universe. It was first proposed in 2008. The Hungarian physicists' study merely indicated the discovery of a new particle, but findings of the new study by Feng and colleagues suggest that it was not dark photon that was discovered but a protophobic X boson. The existence of this particle could be an indication of a fifth force of nature. Electromagnetic forces act on both protons and electrons, but the newly found particle appears to only interact with electrons and neutrons at short distances. The possible fifth force, according to Feng, may also be linked to electromagnetic force, as well as strong and weak nuclear forces embodying one grander and more fundamental force. A separate sphere of physics, a dark sector in contrast to the standard model with dark matter and dark forces, is also possible. The researchers said that these two sectors may interact with each other through fundamental but veiled interactions. "This dark sector force may manifest itself as this protophobic force we're seeing as a result of the Hungarian experiment," Feng said, adding that this fits in with their original research that aimed to shed light on the nature of dark matter. The researchers, however, said that the interpretations still require further studies. "We present anomaly-free extensions of the Standard Model that contain protophobic gauge bosons with the desired couplings to explain the 8Be anomaly," the researchers wrote in their study, which is published in the Physical Review Letters. "The models predict relatively large charged lepton couplings ~ 0.001 that can resolve the discrepancy in the muon anomalous magnetic moment and are amenable to many experimental probes. The models also contain vectorlike leptons at the weak scale that may be accessible to near future LHC searches." © 2016 Tech Times, All rights reserved. Do not reproduce without permission.


News Article | November 28, 2016
Site: www.eurekalert.org

László Erdős of the Institute of Science and Technology Austria and Horng-Tzer Yau (of Harvard University will receive the 2017 AMS Leonard Eisenbud Prize for Mathematics and Physics. The two are honored "for proving the universality of eigenvalue statistics of Wigner random matrices." A matrix is a two-dimensional array of numbers. For example, data about the height and weight of members of a certain population could be arranged as entries in a matrix. Matrices are used across all areas science and engineering to represent quantitative information. Their spectrum, or eigenvalues, comprise the essential properties of these data. In the 1950s, physicist Eugene Wigner, who would go on to win the Nobel Prize, was studying energy levels in atomic nuclei. Because it was not possible at that time to predict these energy levels based on fundamental physical principles, Wigner represented their statistical behavior by the eigenvalues of a matrix in which the entries were chosen at random. This was an extraordinary leap of intuition. Wigner's insight has turned out to be very useful and has been verified in many different experimental situations. Nevertheless, scientists still cannot prove exactly why it models physical reality so well. Since that time, random matrices have been used across many areas of physics and, more recently, in such areas as statistical analysis, finance, wireless communications, and materials science. These developments, together with mysterious connections observed between random matrices and prime numbers, have led to the burgeoning of random matrix theory as a major subject within mathematics. There are many different ways of randomly choosing the entries in a random matrix. In simulations of large random matrices, researchers observed the same statistical patterns emerging from the matrices, regardless of which way was used for the random choice of the entries. These patterns seemed to be "universal," and the question of whether the observations could be nailed down in a mathematical proof became known as the "universality conjecture." It is this conjecture that Erdős and Yau settled in their prize-winning work, an amazing feat that has received wide acclaim from scientists and mathematicians. Born in Budapest in 1966, László Erdős completed university education in mathematics at the Lorand Eötvös University in 1990 and a PhD at Princeton University in 1994. After postdoctoral positions in Zurich and New York, he joined the faculty at the Georgia Institute of Technology. In 2003, he was appointed to a chair professorship at the Ludwig-Maximilian University in Munich. Since 2013 he has been a professor at the Institute of Science and Technology Austria, near Vienna. He was an invited speaker at the International Congress of Mathematicians (2014), and is a corresponding member of the Austrian Academy of Sciences, an external member of the Hungarian Academy of Sciences, and a member of the Academia Europaea. Born in Taiwan in 1959, Horng-Tzer Yau received his B.Sc. in 1981 from National Taiwan University and his PhD in 1987 from Princeton University. The following year, he joined the faculty of the Courant Institute of Mathematical Sciences at New York University. In 2003, he moved to Stanford University and then in 2005 assumed his present position as professor of mathematics at Harvard University. He was a member of the Institute for Advanced Study in Princeton in 1987-88, 1991-92, and 2003, and was an IAS Distinguished Visiting Professor in 2013-14. Yau was elected to the US National Academy of Sciences (2013) and received a MacArthur Foundation "genius" award (2000). Presented every three years, the AMS Eisenbud Prize recognizes a work or group of works that brings mathematics and physics closer together. The prize will be awarded Thursday, January 5, 2017, at the Joint Mathematics Meetings in Atlanta. Find out more about AMS prizes and awards at http://www. . Founded in 1888 to further mathematical research and scholarship, today the American Mathematical Society fulfills its mission through programs and services that promote mathematical research and its uses, strengthen mathematical education, and foster awareness and appreciation of mathematics and its connections to other disciplines and to everyday life.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-IP | Phase: SSH.2011.1.2-1 | Award Amount: 10.37M | Year: 2012

The objective of this 4-year project is to provide the analytical basis for a socio-ecological transition in Europe: the change to a new growth path with smart, sustainable and inclusive growth as is envisaged in the EU 2020 strategy. In order to support the transition, we analyse the need, the feasibility and best practice for change, specifying the institutional changes needed at all policy levels to implement these options. The old and new challenges Europe is facing define the starting point: globalisation, new technologies and postindustrialisation, demographic change and ecology in the context of welfare systems that have come under stress due to high public deficits. The vision is that Europe will become a role model for a high road growth path which actively incorporates social and ecological goals, employment, gender and cultural aspects in an ambitious, forward looking way while continuing to be competitive in a globalised world. To achieve these objectives, the consortium will carry out and synthesise robust research in research areas covering the challenges to the welfare system, the biophysical dimension of socio-economic development, the identification of drivers towards socio-ecological transition, the role of governance and institutions on the European as well as the regional level. The consortium will benefit from ongoing dialogue with international experts in the form of expert panels and sounding boards, taking into account their views on the direction and feasibility for this new growth path. The project will be carried out by a consortium of 34 partners from universities and research institutes with international and interdisciplinary expertise. It represents 12 member states. High level Scientific and Policy Boards will monitor the analysis and the policy conclusions to guarantee the impact and dissemination of the results.


News Article | October 26, 2016
Site: www.nature.com

Hungary premier splits science academy Five foreign members of the Hungarian Academy of Sciences (HAS) have resigned in protest at what they consider to be antidemocratic actions by the populist government of Prime Minister Viktor Orbán (pictured) — and the academy’s failure to confront them. The protest was prompted by the closure this month of the country’s largest quality newspaper, Népszabadság, which had been critical of the government. On 19 October, the five, including Nobel-prizewinning neuroscientist Torsten Wiesel, published an open letter inviting other external members to resign and calling on the academy to “raise its voice in defence of freedom and justice in Hungary”. More than 150 academicians and HAS scientists published an open letter to academy president László Lovász on 14 October asking him to launch scholarly debates on the issues. He responded that the academy is not a political organization. JUNO trouble A computer glitch interrupted communication with NASA’s Juno spacecraft on 18 October. The probe entered into ‘safe mode’ about 13 hours before the closest approach to Jupiter in its second fly-by, but remained safely in its 53.4-day orbit around the giant planet. Juno, which has slipped into its temporary shut-down mode several times since its launch in 2011, aims to shed light on Jupiter’s origin, atmosphere and core. As Nature went to press, engineers were still trying to restore communications. Mars lander site A NASA spacecraft may have spotted the remains of Schiaparelli, the European Space Agency’s (ESA’s) missing Mars lander. Two new features on the red planet’s surface in images taken by the Mars Reconnaissance Orbiter are probably signs of Schiaparelli, ESA announced on 21 October. The lander was part of a joint European–Russian mission that reached Mars on 19 October. The first portion, the Trace Gas Orbiter, successfully entered orbit around the planet, while the lander began its descent to the surface. But towards the end of its six-minute landing procedure, Schiaparelli’s signal cut out and the craft has not been heard from since. A successful landing on Mars would have been a first for the agency. NSF pay rule The US National Science Foundation announced on 21 October that universities must now pay 10% of the salaries of faculty members who work with the agency to manage research programmes. The agency employs nearly 200 university researchers per year on a temporary basis, with the goal of learning from working scientists in different fields. Under a limited budget, the agency is aiming to reduce costs with the policy change, which also includes ending reimbursements for faculty members who miss out on consulting opportunities while working for the federal government. Kuwait DNA law Kuwait will scale back a controversial law that would have mandated the compulsory collection of DNA information from residents and visitors. The government had said that the data could be used to fight terrorism, but the law, passed in July 2015, faced widespread backlash from scientists and human-rights groups, as well as a legal challenge from a Kuwaiti law firm in September on constitutional grounds. On 19 October, Kuwait’s emir requested a review of the law. According to Kuwaiti lawyer Adel Abdulhadi, whose firm brought the challenge, the law will not be implemented in its current form and is likely to be amended so that it applies only to accused or convicted criminals. Glaciologist dies A US glaciologist died on a research trip in Antarctica on 22 October when the snowmobile he was riding fell into a crevasse. Gordon Hamilton (pictured) of the University of Maine in Orono had been working in a heavily crevassed area near the main US base, McMurdo Station, where the Ross and McMurdo ice shelves meet. Hamilton, who was 50, studied the stability of ice sheets and their larger role in the climate system, including sea-level rise. UN urban agenda Delegates from 167 countries agreed on 20 October to promote sustainable urban development at the United Nations’ Habitat III conference in Quito, Ecuador. Attendees adopted the New Urban Agenda, a non-binding document that sets broad goals to promote cleaner, healthier and more socially inclusive cities. It includes a call for universal access to modern energy services and a commitment to reduce greenhouse-gas emissions. However, scientific organizations such as Future Earth and the International Council for Science argue that the agreement lacks urgency, and call for an agenda that brings scientists on board and aligns with the UN Sustainable Development Goals. Europe’s trial data The European Medicines Agency (EMA), based in London, has started publishing details of the full clinical-trial data that it receives from drug companies. On 20 October, the agency published around 100 clinical reports (roughly 260,000 pages) about two EMA-approved medicines (carfilzomib, a cancer drug, and lesinurad, a gout treatment). The disclosures make the EMA the first major drug regulatory agency to publish the full results of clinical investigations that drug developers submit when they apply for the agency’s approval to market medicines. Species threat A court of appeal in the United States ruled on 24 October that federal agencies can rely on projections of future climate change to determine whether a species is threatened under the Endangered Species Act. The state of Alaska, several oil associations and groups representing Alaska’s indigenous people had claimed that a subspecies of the Pacific bearded seal (Erignathus barbatus nauticus) should not be protected by the act, because the animals were not yet in danger and climate predictions were conjecture. But the court rejected this, citing a climate projection that calculated that sea-ice loss would leave the species endangered by 2095. Nike funds science Phil Knight, co-founder of sports-clothing giant Nike, and his wife Penny announced on 17 October that they will give US$500 million to the University of Oregon in Eugene to create a Campus for Accelerating Scientific Impact. The centre will host dozens of scientists and hundreds of students and postdocs. The Knights’ philanthropic support is the first part of what the university hopes will be a $1-billion initiative focused on turning scientific discoveries into innovations. The gift is the among largest ever to a public US university. Phil Knight graduated from Oregon in 1959. Gene-drive centre An Indian philanthropic organization has awarded US$70 million to a California university to develop genetic tools for mosquito control. The gift from Tata Trusts in Mumbai, announced on 23 October, will fund the creation of the Tata Institute for Genetics and Society at the University of California, San Diego. The institute plans to develop gene-drive technologies — which can rapidly propagate a mutation through a population — to control malaria-carrying mosquitoes and improve crops, among other applications. Statistics prize Five statistical associations have created a prize in the hope of capturing broader recognition for their field. The inaugural US$75,000 International Prize in Statistics, announced on 19 October, was awarded to statistician David Cox at the University of Oxford, UK, for the ‘proportional hazards model’, which is widely used to identify risk factors and evaluate treatments across medical research. “Most people don’t have the slightest idea what statisticians do or why it matters,” says Ron Wasserstein, head of the American Statistical Association in Alexandria, Virginia. He hopes that the prize will encourage scientists to forge deeper collaborations with statisticians. The average atmospheric level of carbon dioxide reached the symbolic threshold of 400 parts per million (p.p.m.) in 2015, noted an annual report on 24 October. CO levels have crossed the threshold in certain months, but a global annual average has never done so in recorded history. The increase from 2014 was spurred by a strong El Niño event, which reduced CO uptake by natural vegetation because of drought. Preliminary data suggest that global CO may permanently top 400 p.p.m. in 2016. 7–18 November Delegates gather in Marrakesh, Morocco, for the United Nations COP22 climate summit and the first meeting of the parties to the Paris climate agreement. go.nature.com/2dtfo9v 12–16 November The 46th annual meeting of the Society for Neuroscience takes place in San Diego, California. go.nature.com/2el6nup


Krar M.,University of Pannonia | Kovacs S.,University of Pannonia | Kallo D.,Hungarian Academy of Sciences | Hancsok J.,University of Pannonia
Bioresource Technology | Year: 2010

The importance of the economical production and usage of new generation biofuels, the so-called bio gas oil (paraffins from triglycerides) and the results of the investigation for their productability on the CoMo/Al2O3 catalyst, which was activated by reduction, are presented. The conversion of triglycerides, the yield of total organic fractions and the target product, furthermore the type and ratio of deoxygenation reactions were determined as a function of process parameters. The advantageous process parameters were found (380°C, 40-60bar, 500-600Nm3/m3 H2/sunflower oil ratio, 1.0h-1), where the conversion of triglycerides was 100% and the yield of the target fraction [high paraffin containing (>99%) gas oil boiling range product] was relatively high (73.7-73.9%). The deoxygenation of triglycerides the reduction as well as the decarboxylation/decarbonylation reactions took place. The yield of the target fractions did not achieve the theoretical values (81.4-86.5%). That is why it is necessary to separate the target fraction and recirculate the heavy fraction. © 2010 Elsevier Ltd.


Wang Z.,Hong Kong Baptist University | Szolnoki A.,Hungarian Academy of Sciences | Perc M.,University of Maribor
Journal of Theoretical Biology | Year: 2014

Evolution of cooperation in the prisoner[U+05F3]s dilemma and the public goods game is studied, where initially players belong to two independent structured populations. Simultaneously with the strategy evolution, players whose current utility exceeds a threshold are rewarded by an external link to a player belonging to the other population. Yet as soon as the utility drops below the threshold, the external link is terminated. The rewarding of current evolutionary fitness thus introduces a time-varying interdependence between the two populations. We show that, regardless of the details of the evolutionary game and the interaction structure, the self-organization of fitness and reward gives rise to distinguished players that act as strong catalysts of cooperative behavior. However, there also exist critical utility thresholds beyond which distinguished players are no longer able to percolate. The interdependence between the two populations then vanishes, and cooperators are forced to rely on traditional network reciprocity alone. We thus demonstrate that a simple strategy-independent form of rewarding may significantly expand the scope of cooperation on structured populations. The formation of links outside the immediate community seems particularly applicable in human societies, where an individual is typically member in many different social networks. © 2014 Elsevier Ltd.


Szolnoki A.,Hungarian Academy of Sciences | Perc M.,University of Maribor
Physical Review X | Year: 2014

Economic experiments reveal that humans value cooperation and fairness. Punishing unfair behavior is therefore common, and according to the theory of strong reciprocity, it is also directly related to rewarding cooperative behavior. However, empirical data fail to confirm that positive and negative reciprocity are correlated. Inspired by this disagreement, we determine whether the combined application of reward and punishment is evolutionarily advantageous. We study a spatial public goods game, where in addition to the three elementary strategies of defection, rewarding, and punishment, a fourth strategy that combines the latter two competes for space. We find rich dynamical behavior that gives rise to intricate phase diagrams where continuous and discontinuous phase transitions occur in succession. Indirect territorial competition, spontaneous emergence of cyclic dominance, as well as divergent fluctuations of oscillations that terminate in an absorbing phase are observed. Yet, despite the high complexity of solutions, the combined strategy can survive only in very narrow and unrealistic parameter regions. Elementary strategies, either in pure or mixed phases, are much more common and likely to prevail. Our results highlight the importance of patterns and structure in human cooperation, which should be considered in future experiments.


Chen X.,University of Electronic Science and Technology of China | Chen X.,International Institute For Applied Systems Analysis | Szolnoki A.,Hungarian Academy of Sciences | Szolnoki A.,Institute of Mathematics | Perc M.,University of Maribor
New Journal of Physics | Year: 2014

Cooperators that refuse to participate in sanctioning defectors create the second-order free-rider problem. Such cooperators will not be punished because they contribute to the public good, but they also eschew the costs associated with punishing defectors. Altruistic punishers - those that cooperate and punish - are at a disadvantage, and it is puzzling how such behaviour has evolved. We show that sharing the responsibility to sanction defectors rather than relying on certain individuals to do so permanently can solve the problem of costly punishment. Inspired by the fact that humans have strong but also emotional tendencies for fair play, we consider probabilistic sanctioning as the simplest way of distributing the duty. In well-mixed populations the public goods game is transformed into a coordination game with full cooperation and defection as the two stable equilibria, while in structured populations pattern formation supports additional counterintuitive solutions that are reminiscent of Parrondos paradox. © 2014 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.


Horvath O.,University of Pannonia | Valicsek Z.,University of Pannonia | Harrach G.,University of Pannonia | Lendvay G.,University of Pannonia | And 2 more authors.
Coordination Chemistry Reviews | Year: 2012

The location of the metal center in the porphyrin complexes strongly depends on its size, charge and spin multiplicity. Metal ions can form normal (in-plane) metalloporphyrins, or several of them, being too large to fit into the coordination cavity of the porphyrin ring, are located above the ligand plane, resulting in out-of-plane (OOP) complexes. The distorted structure of the latter type induces special photophysical and photochemical features that are characteristic of all OOP complexes. Efficient LMCT processes can take place upon excitation of these compounds. In this paper we review the results of recent studies on water-soluble (1:1) porphyrin complexes of several metal ions to reveal how the size (and partly the oxidation state) of the metal center influences their structure and photoinduced behavior. The effects of the pre-distortion (via bromination) and the charge of the porphyrin ligand on the structure and photoreactivity of these complexes are also discussed. While the porphyrin complex of Ag 2+ (r ion=94pm) formed in the reaction of the Ag + ion and the TSPP 6- ligand (H 2TSPP 4-=5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin anion) displays OOP features, the corresponding complex also of open-shell Au 3+ (r ion=85pm) is unambiguously of planar structure, and does not show any fluorescence and photoredox degradation. In the case of the anionic complex of Cd 2+ (r ion=95pm), octabromination of the TSPP 6- ligand results in significant red-shifts in the absorption and emission spectra, dramatically diminishes the fluorescence quantum yield and lifetime, and turns the photodegradation into a very oxygen-sensitive reaction. The axial coordination of HO - ligand further increases the distortion and photoreactivity. The efficiency for the photoinduced LMCT reaction of the cationic complex of Bi 3+ (r ion=103pm) formed with the TMPyP 2+ ligand (H 2TMPyP 4+=5,10,15,20-tetrakis(1-methyl-4-pyridinium)porphyrin cation) is significantly lower than that for anionic BiTSPP 3-, due to the weaker Lewis-basicity of the positively charged porphyrin. DFT calculations of the geometrical structures show good correlation with the observed photophysical and photochemical properties. Deviating from the inner-sphere LMCT reaction of OOP complexes, the cationic ligand (such as TMPyP 2+ and TAPP 2+ (H 2TAPP 4+=5,10,15,20-tetrakis(4-trimethylammonium phenyl)porphyrin cation)) is favorable for the outer-sphere photoinduced reduction of the metal center in the in-plane manganese(III) porphyrins because the anionic porphyrin ligands of higher Lewis-basicity stabilize the +3 oxidation state. The cationic porphyrin ligands enhance the formation of manganese(II) complexes with OOP characteristics, and can be utilized in photocatalytic systems applicable for water splitting. © 2012 Elsevier B.V.


Tompa P.,Vrije Universiteit Brussel | Tompa P.,Hungarian Academy of Sciences | Davey N.E.,University of California at San Francisco | Gibson T.J.,Structural and Computational Biology Unit | Babu M.M.,University of Cambridge
Molecular Cell | Year: 2014

A molecular description of functional modules in the cell is the focus of many high-throughput studies in the postgenomic era. A large portion of biomolecular interactions in virtually all cellular processes is mediated by compact interaction modules, referred to as peptide motifs. Such motifs are typically less than ten residues in length, occur within intrinsically disordered regions, and are recognized and/or posttranslationally modified by structured domains of the interacting partner. In this review, we suggest that there might be over a million instances of peptide motifs in the human proteome. While this staggering number suggests that peptide motifs are numerous and the most understudied functional module in the cell, it also holds great opportunities for new discoveries. © 2014 Elsevier Inc.


Renart A.,Rutgers University | De La Rocha J.,Rutgers University | De La Rocha J.,New York University | Bartho P.,Rutgers University | And 7 more authors.
Science | Year: 2010

Correlated spiking is often observed in cortical drcuits, but its functional role is controversial. It is believed that correlations are a consequence of shared inputs between nearby neurons and could severely constrain information decoding. Here we show theoretically that recurrent neural networks can generate an asynchronous state characterized by arbitrarily low mean spiking correlations despite substantial amounts of shared input. In this state, spontaneous fluctuations in the activity of excitatory and inhibitory populations accurately track each other, generating negative correlations in synaptic currents which cancel the effect of shared input. Near-zero mean correlations were seen experimentally in recordings from rodent neocortex in vivo. Our results suggest a reexamination of the sources underlying observed correlations and their functional consequences for information processing.


Toth G.,University of the Basque Country | Toth G.,Ikerbasque | Toth G.,Hungarian Academy of Sciences | Mitchell M.W.,ICFO - Institute of Photonic Sciences
New Journal of Physics | Year: 2010

We study squeezing of the spin uncertainties by quantum nondemolition (QND) measurement in non-polarized spin ensembles. Unlike the case of polarized ensembles, the QND measurements can be performed with negligible back-action, which allows, in principle, perfect spin squeezing as quantified by Tóth et al (2007 Phys. Rev. Lett. 99 250405). The generated spin states approach many-body singlet states and contain a macroscopic number of entangled particles even when individual spin is large. We introduce the Gaussian treatment of unpolarized spin states and use it to estimate the achievable spin squeezing for realistic experimental parameters. Our proposal might have applications for magnetometry with a high spatial resolution or quantum memories storing information in decoherence free subspaces. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.


Navascues M.,Complutense University of Madrid | Vertesi T.,Hungarian Academy of Sciences
Physical Review Letters | Year: 2011

We find two two-qubit bipartite states ρ1,ρ2 such that arbitrarily many copies of one or the other cannot exhibit nonlocal correlations in a two-setting-two-outcome Bell scenario. However, the bipartite state ρ1-ρ2 violates the Clauser-Horne-Shimony- Holt (CHSH) Bell inequality by an amount of 2.023. We also identify a CHSH-local state ρ such that ρ-2 is CHSH inequality-violating. The tools employed can be easily adapted to find instances of nonlocality activation in arbitrary Bell scenarios.© 2011 American Physical Society.


Vitagliano G.,University of the Basque Country | Hyllus P.,University of the Basque Country | Egusquiza I.L.,University of the Basque Country | Toth G.,University of the Basque Country | And 2 more authors.
Physical Review Letters | Year: 2011

We determine the complete set of generalized spin squeezing inequalities, given in terms of the collective angular momentum components, for particles with an arbitrary spin. They can be used for the experimental detection of entanglement in an ensemble in which the particles cannot be individually addressed. We also present a large set of criteria involving collective observables different from the angular momentum coordinates. We show that some of the inequalities can be used to detect k-particle entanglement and bound entanglement. © 2011 American Physical Society.


Atserias A.,Polytechnic University of Catalonia | Grohe M.,RWTH Aachen | Marx D.,Hungarian Academy of Sciences
SIAM Journal on Computing | Year: 2013

Relational joins are at the core of relational algebra, which in turn is the core of the standard database query language SQL. As their evaluation is expensive and very often dominated by the output size, it is an important task for database query optimizers to compute estimates on the size of joins and to find good execution plans for sequences of joins. We study these problems from a theoretical perspective, both in the worst-case model and in an average-case model where the database is chosen according to a known probability distribution. In the former case, our first key observation is that the worst-case size of a query is characterized by the fractional edge cover number of its underlying hypergraph, a combinatorial parameter previously known to provide an upper bound. We complete the picture by proving a matching lower bound and by showing that there exist queries for which the join-project plan suggested by the fractional edge cover approach may be substantially better than any join plan that does not use intermediate projections. On the other hand, we show that in the average-case model, every join-project plan can be turned into a plan containing no projections in such a way that the expected time to evaluate the plan increases only by a constant factor independent of the size of the database. Not surprisingly, the key combinatorial parameter in this context is the maximum density of the underlying hypergraph. We show how to make effective use of this parameter to eliminate the projections. © 2013 Society for Industrial and Applied Mathematics.


Szolnoki A.,Hungarian Academy of Sciences | Perc M.,University of Maribor | Perc M.,King Abdulaziz University
New Journal of Physics | Year: 2015

If rock beats scissors and scissors beat paper, one might assume that rock beats paper too. But this is not the case for intransitive relationships that make up the famous rock-paper-scissors game. However, the sole presence of paper might prevent rock from beating scissors, simply because paper beats rock. This is the blueprint for the rock-paper-scissors game with protection spillovers, which has recently been introduced as a new paradigm for biodiversity in well-mixed microbial populations. Here we study the game in structured populations, demonstrating that protection spillovers give rise to spatial patterns that are impossible to observe in the classical rock-paper-scissors game. We show that the spatiotemporal dynamics of the system is determined by the density of stable vortices, which may ultimately transform to frozen states, to propagating waves, or to target waves with reversed propagation direction, depending further on the degree and type of randomness in the interactions among the species. If vortices are rare, the fixation to waves and complex oscillatory solutions is likelier. Moreover, annealed randomness in interactions favors the emergence of target waves, while quenched randomness favors collective synchronization. Our results demonstrate that protection spillovers may fundamentally change the dynamics of cyclic dominance in structured populations, and they outline the possibility of programming pattern formation in microbial populations. © 2015 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.


Edge J.M.,KTH Royal Institute of Technology | Asboth J.K.,Hungarian Academy of Sciences
Physical Review B - Condensed Matter and Materials Physics | Year: 2015

We investigate time-independent disorder on several two-dimensional discrete-time quantum walks. We find numerically that, contrary to claims in the literature, random onsite phase disorder, spin-dependent or otherwise, cannot localize the Hadamard quantum walk; rather, it induces diffusive spreading of the walker. In contrast, split-step quantum walks are generically localized by phase disorder. We explain this difference by showing that the Hadamard walk is a special case of the split-step quantum walk, with parameters tuned to a critical point at a topological phase transition. We show that the topological phase transition can also be reached by introducing strong disorder in the rotation angles. We determine the critical exponent for the divergence of the localization length at the topological phase transition, and find ν=2.6, in both cases. This places the two-dimensional split-step quantum walk in the universality class of the quantum Hall effect. © 2015 American Physical Society.


Fuxreiter M.,Hungarian Academy of Sciences | Fuxreiter M.,Medical Research Council
Molecular BioSystems | Year: 2012

Proteins are dynamic creatures. Intrinsically disordered proteins (IDPs) function as multiplicity of structures and their activities can only be described by stochastic structure-function relationships. In their complex forms, however, IDPs were thought to lose their plasticity and behave similarly to globular proteins. Although various IDPs indeed fold upon binding, this view is not valid in general. IDPs usually interact with their partners via short motifs, which require malleable environments to function. Consequently, segments of IDPs could retain their disordered state in the complex, a phenomenon termed as fuzziness. Since its recognition, the number of structurally characterized fuzzy complexes, both with protein and DNA, rapidly increases. Here I review recent advances in our understanding of fuzziness. Four basic mechanisms are described how conformationally heterogeneous regions impact specificity or binding affinity of protein complexes. A novel allostery-model is proposed, where the regulatory site modulates the conformational equilibrium of the binding interface without adopting a unique structure. Protein-protein interactions, post-translational modifications or alternative splicing of the highly flexible/disordered regions offer further opportunities for regulation and expand the functional repertoire of fuzzy complexes.


Mocsai A.,Semmelweis University | Mocsai A.,Hungarian Academy of Sciences | Walzog B.,Ludwig Maximilians University of Munich | Lowell C.A.,University of California at San Francisco
Cardiovascular Research | Year: 2015

Recruitment of leucocytes such as neutrophils to the extravascular space is a critical step of the inflammation process and plays a major role in the development of various diseases including several cardiovascular diseases. Neutrophils themselves play a very active role in that process by sensing their environment and responding to the extracellular cues by adhesion and de-Adhesion, cellular shape changes, chemotactic migration, and other effector functions of cell activation. Those responses are co-ordinated by a number of cell surface receptors and their complex intracellular signal transduction pathways. Here, we review neutrophil signal transduction processes critical for recruitment to the site of inflammation. The two key requirements for neutrophil recruitment are the establishment of appropriate chemoattractant gradients and the intrinsic ability of the cells to migrate along those gradients. We will first discuss signalling steps required for sensing extracellular chemoattractants such as chemokines and lipid mediators and the processes (e.g. PI3-kinase pathways) leading to the translation of extracellular chemoattractant gradients to polarized cellular responses. We will then discuss signal transduction by leucocyte adhesion receptors (e.g. tyrosine kinase pathways) which are critical for adhesion to, and migration through the vessel wall. Finally, additional neutrophil signalling pathways with an indirect effect on the neutrophil recruitment process, e.g. through modulation of the inflammatory environment, will be discussed. Mechanistic understanding of these pathways provide better understanding of the inflammation process and may point to novel therapeutic strategies for controlling excessive inflammation during infection or tissue damage. © The Author 2015. All rights reserved.


Haas J.,Eötvös Loránd University | Gotz A.E.,TU Darmstadt | Palfy J.,Hungarian Academy of Sciences
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2010

Sedimentary and organic facies of a continuous Late Triassic-Early Jurassic toe-of-slope to basin succession of the NE Transdanubian Range (N Hungary) was studied in order to reconstruct the palaeogeographical and eustatic evolution of the Cso{double-acute}vár Basin, an intraplatform basin of the NW Neotethys margin. Characteristic facies successions point to sea-level changes of different hierarchies. Cyclic patterns, inferred to result from orbital eccentricity forcing, are also reflected in the stratigraphical distribution of sedimentary organic matter. Furthermore, both palaeontological and isotope data document drastic climatic changes around the Triassic-Jurassic boundary. Detecting sea-level changes leads to a more accurate interpretation of the Late Triassic palaeogeographic setting and evolution of the Transdanubian Range's carbonate platform. Our integrated sedimentological and palynological data suggest a complex topography and dynamic sea-level history, which contradicts a previous model of broad, uniform platform setting and lack of any major drowning and emersion events during the Late Triassic. © 2010 Elsevier B.V. All rights reserved.


Szolnoki A.,Hungarian Academy of Sciences | Perc M.,University of Maribor | Perc M.,King Abdulaziz University
Journal of the Royal Society Interface | Year: 2015

The pursuit of highest payoffs in evolutionary social dilemmas is risky and sometimes inferior to conformity. Choosing the most common strategy within the interaction range is safer because it ensures that the payoff of an individual will not be much lower than average. Herding instincts and crowd behaviour in humans and social animals also compel to conformity in their own right. Motivated by these facts, we here study the impact of conformity on the evolution of cooperation in social dilemmas.We show that an appropriate fraction of conformists within the population introduces an effective surface tension around cooperative clusters and ensures smooth interfaces between different strategy domains. Payoff-driven players brake the symmetry in favour of cooperation and enable an expansion of clusters past the boundaries imposed by traditional network reciprocity. Thismechanismworks even under themost testing conditions, and it is robust against variations of the interaction network as long as degree-normalized payoffs are applied. Conformity may thus be beneficial for the resolution of social dilemmas. © 2014 The Author(s) Published by the Royal Society. All rights reserved.


Szolnoki A.,Hungarian Academy of Sciences | Perc M.,University of Maribor | Szabo G.,Hungarian Academy of Sciences
Physical Review Letters | Year: 2012

Experiments on the ultimatum game have revealed that humans are remarkably fond of fair play. When asked to share an amount of money, unfair offers are rare and their acceptance rate small. While empathy and spatiality may lead to the evolution of fairness, thus far considered continuous strategies have precluded the observation of solutions that would be driven by pattern formation. Here we introduce a spatial ultimatum game with discrete strategies, and we show that this simple alteration opens the gate to fascinatingly rich dynamical behavior. In addition to mixed stationary states, we report the occurrence of traveling waves and cyclic dominance, where one strategy in the cycle can be an alliance of two strategies. The highly webbed phase diagram, entailing continuous and discontinuous phase transitions, reveals hidden complexity in the pursuit of human fair play. © 2012 American Physical Society.


Gaudeul M.,French Natural History Museum | Giraud T.,University Paris - Sud | Kiss L.,Hungarian Academy of Sciences | Shykoff J.A.,University Paris - Sud
PLoS ONE | Year: 2011

Background: Ambrosia artemisiifolia is a North American native that has become one of the most problematic invasive plants in Europe and Asia. We studied its worldwide population genetic structure, using both nuclear and chloroplast microsatellite markers and an unprecedented large population sampling. Our goals were (i) to identify the sources of the invasive populations; (ii) to assess whether all invasive populations were founded by multiple introductions, as previously found in France; (iii) to examine how the introductions have affected the amount and structure of genetic variation in Europe; (iv) to document how the colonization of Europe proceeded; (v) to check whether populations exhibit significant heterozygote deficiencies, as previously observed. Principal Findings: We found evidence for multiple introductions of A. artemisiifolia, within regions but also within populations in most parts of its invasive range, leading to high levels of diversity. In Europe, introductions probably stem from two different regions of the native area: populations established in Central Europe appear to have originated from eastern North America, and Eastern European populations from more western North America. This may result from differential commercial exchanges between these geographic regions. Our results indicate that the expansion in Europe mostly occurred through long-distance dispersal, explaining the absence of isolation by distance and the weak influence of geography on the genetic structure in this area in contrast to the native range. Last, we detected significant heterozygote deficiencies in most populations. This may be explained by partial selfing, biparental inbreeding and/or a Wahlund effect and further investigation is warranted. Conclusions: This insight into the sources and pathways of common ragweed expansion may help to better understand its invasion success and provides baseline data for future studies on the evolutionary processes involved during range expansion in novel environments. © 2011 Gaudeul et al.


Wang L.,KTH Royal Institute of Technology | Wang X.V.,KTH Royal Institute of Technology | Gao L.,Huazhong University of Science and Technology | Vancza J.,Hungarian Academy of Sciences | Vancza J.,Budapest University of Technology and Economics
CIRP Annals - Manufacturing Technology | Year: 2014

The modern manufacturing industry calls for a new generation of integration models that are more interoperable, intelligent, adaptable and distributed. Evolved from service-oriented architecture, web-based manufacturing and cloud computing, cloud manufacturing is considered worldwide a new enabling technology for manufacturing enterprises to respond quickly and effectively to the changing global market. For Waste Electrical and Electronic Equipment (WEEE) in particular, it is a critical necessity to recycle, reuse and remanufacture WEEE products by setting up a cloud-based information system. In this paper, a novel service-oriented remanufacturing platform is proposed based on the cloud manufacturing concept. © 2014 CIRP.


Petrovski G.,Hungarian Academy of Sciences | Gurusamy N.,University of Connecticut | Das D.K.,University of Connecticut
Annals of the New York Academy of Sciences | Year: 2011

Resveratrol, initially used for cancer therapy, has shown beneficial effects against most degenerative and cardiovascular diseases from atherosclerosis, hypertension, ischemia/reperfusion, and heart failure to diabetes, obesity, and aging. The cardioprotective effects of resveratrol are associated with its preconditioning-like action potentiated by its adaptive response. During preconditioning, small doses of resveratrol can exert an adaptive stress response, forcing the expression of cardioprotective genes and proteins such as heat shock and antioxidant proteins. Similarly, resveratrol can induce autophagy, another form of stress adaptation for degrading damaged or long-lived proteins, as a first line of protection against oxidative stress. Resveratrol's interaction with multiple molecular targets of diverse intracellular pathways (e.g., action on sirtuins and FoxOs through multiple transcription factors and protein targets) intertwines with those of the autophagic pathway to give support in the modified redox environment after stem cell therapy, which leads to prolonged survival of cells. The successful application of resveratrol in therapy is based upon its hormetic action similar to any toxin: exerting beneficial effects at lower doses and cytotoxic effects at higher doses. © 2011 New York Academy of Sciences.


Szolnoki A.,Hungarian Academy of Sciences | Perc M.,University of Maribor
Scientific Reports | Year: 2014

We study the evolution of cooperation in the spatial prisoner's dilemma game, where besides unconditional cooperation and defection, tit-for-tat, win-stay-lose-shift and extortion are the five competing strategies. While pairwise imitation fails to sustain unconditional cooperation and extortion regardless of game parametrization, myopic updating gives rise to the coexistence of all five strategies if the temptation to defect is sufficiently large or if the degree distribution of the interaction network is heterogeneous. This counterintuitive evolutionary outcome emerges as a result of an unexpected chain of strategy invasions. Firstly, defectors emerge and coarsen spontaneously among players adopting win-stay-lose-shift. Secondly, extortioners and players adopting tit-for-tat emerge and spread via neutral drift among the emerged defectors. And lastly, among the extortioners, cooperators become viable too. These recurrent evolutionary invasions yield a five-strategy phase that is stable irrespective of the system size and the structure of the interaction network, and they reveal the most unexpected mechanism that stabilizes extortion and cooperation in an evolutionary setting.


Szolnoki A.,Hungarian Academy of Sciences | Mobilia M.,University of Leeds | Jiang L.-L.,Wenzhou University | Szczesny B.,University of Leeds | And 2 more authors.
Journal of the Royal Society Interface | Year: 2014

Rock is wrapped by paper, paper is cut by scissors and scissors are crushed by rock. This simple game is popular among children and adults to decide on trivial disputes that have no obvious winner, but cyclic dominance is also at the heart of predator-prey interactions, the mating strategy of side-blotched lizards, the overgrowth of marine sessile organisms and competition in microbial populations. Cyclical interactions also emerge spontaneously in evolutionary games entailing volunteering, reward, punishment, and in fact are common when the competing strategies are three or more, regardless of the particularities of the game. Here, we review recent advances on the rock- paper-scissors (RPS) and related evolutionary games, focusing, in particular, on pattern formation, the impact of mobility and the spontaneous emergence of cyclic dominance. We also review mean-field and zero-dimensional RPS models and the application of the complex Ginzburg-Landau equation, and we highlight the importance and usefulness of statistical physics for the successful study of large-scale ecological systems. Directions for future research, related, for example, to dynamical effects of coevolutionary rules and invasion reversals owing to multi-point interactions, are also outlined. © 2014 The Author(s) Published by the Royal Society. All rights reserved.


Vertesi T.,Hungarian Academy of Sciences | Navascues M.,Complutense University of Madrid
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

We study under which conditions it is possible to assert that a joint measurement cannot be simulated by local operations and classical communication. More concretely, we consider a scenario where two parties, Alice and Bob, send each a state selected from a labeled set of unknown states to a third party, Charlie, who in turn interacts with the states in some undisclosed way and then announces an outcome. We show that, under the assumption that Alice and Bob know the dimensionality of their systems, there exist situations where the statistics of the outcomes reveals the nature of Charlie's measurement. © 2011 American Physical Society.


Rojas C.R.,KTH Royal Institute of Technology | Hjalmarsson H.,KTH Royal Institute of Technology | Gerencsr L.,Hungarian Academy of Sciences | Martensson J.,KTH Royal Institute of Technology
Automatica | Year: 2011

An adaptive algorithm, consisting of a recursive estimator for a finite impulse response model having two non-zero lags only, and an adaptive input are presented. The model is parametrized in terms of the first impulse response coefficient and the model zero. For linear time-invariant single-input single-output systems with real rational transfer functions possessing at least one real-valued non-minimum phase zero of multiplicity one, it is shown that the model zero converges to such a zero of the true system. In the case of multiple non-minimum phase zeros, the algorithm can be tailored to converge to a particular zero. The result is shown to hold for systems and noise spectra of arbitrary degree. The algorithm requires prior knowledge of the sign of the high frequency gain of the system as well as an interval to which the non-minimum phase zero of interest belongs. © 2011 Elsevier Ltd. All rights reserved.


Feczko T.,Hungarian Academy of Sciences | Voncina B.,University of Maribor
Current Organic Chemistry | Year: 2013

Photochromic organic dyes can be widely used in materials for optically rewritable data storage, photonic switches, memories, sensors, or actuators. In recent years photochromic materials based on nanoparticles became particularly focused, since they can be dispersed in colloidal aqueous suspensions or incorporated in thin films, avoiding problems of light scattering or shallow light penetration in bulk materials. Spiropyrans, spirooxazines and diarylethenes were by far the most researched photochromes in nanoparticulate systems. Great effort was made to investigate photochromic dyes incorporated into organic nanoparticles via self-assembly strategies, covalent linkage or dispersion of the molecular species in polymers (doping). Nanoparticles composed of solely photochromic dyes were prepared by laser ablation and reprecipitation techniques. Photochromic dyes were microencapsulated by self-assembly, soap free-, emulsion/ microemulsion/miniemulsion or free radical- (co)polymerization. Sol-gel processing from silane precursors to poly(organo)siloxane matrix is a common method to synthesize doped or core-shell photochromic organogels. Colored forms of some photochromes display fluorescence; however, a more effective strategy for fluorescence modulation with photochromic molecules is integrating them, covalently or noncovalently, with a separate fluorophore in the same nanoparticles. These photoresponsive nanoparticles may find applications particularly in biological fields such as cell labelling and bioimaging. The purpose of this review is to summarize the preparation methods of organic nanoparticles containing photochromic dyes and to investigate their typical properties derived from their nanoparticulate character. © 2013 Bentham Science Publishers.


Kotai B.,Hungarian Academy of Sciences | Kardos G.,Hungarian Academy of Sciences | Hamza A.,Hungarian Academy of Sciences | Farkas V.,MTA ELTE Protein Modelling Research Group | And 2 more authors.
Chemistry - A European Journal | Year: 2014

A joint experimental-theoretical study of a bifunctional squaramide-amine-catalyzed Michael addition reaction between 1,3-dioxo nucleophiles and nitrostyrene has been undertaken to gain insight into the nature of bifunctional organocatalytic activation. For this highly stereoselective reaction, three previously proposed mechanistic scenarios for the critical C-C bond-formation step were examined. Accordingly, the formation of the major stereoisomeric products is most plausible by one of the bifunctional pathways that involve electrophile activation by the protonated amine group of the catalyst. However, some of the minor product isomers are also accessible through alternative reaction routes. Structural analysis of transition states points to the structural invariance of certain fragments of the transition state, such as the protonated catalyst and the anionic fragment of approaching reactants. Our topological analysis provides deeper insight and a more general understanding of bifunctional noncovalent organocatalysis. Finding the path: The mechanism of bifunctional squaramide-promoted Michael addition of prochiral 1,3-dioxo nucleophiles and nitroolefin has been studied on the basis of DFT calculations. Among the investigated mechanistic scenarios, the pathway corresponding to electrophile activation via the protonated amine unit is found to be the most feasible (see figure). For some of the minor stereoisomeric products, alternative pathways are also accessible. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Toth G.,University of the Basque Country | Toth G.,Ikerbasque | Toth G.,Hungarian Academy of Sciences
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

We present several entanglement criteria in terms of the quantum Fisher information that help to relate various forms of multipartite entanglement to the sensitivity of phase estimation. We show that genuine multipartite entanglement is necessary to reach the maximum sensitivity in some very general metrological tasks using a two-arm linear interferometer. We also show that it is needed to reach the maximum average sensitivity in a certain combination of such metrological tasks. © 2012 American Physical Society.


Vorberger J.,University of Warwick | Donko Z.,Hungarian Academy of Sciences | Tkachenko I.M.,Polytechnic University of Valencia | Gericke D.O.,University of Warwick
Physical Review Letters | Year: 2012

The dynamics of the ion structure in warm dense matter is determined by molecular dynamics simulations using an effective ion-ion potential. This potential is obtained from abinitio simulations and has a strong short-range repulsion added to a screened Coulomb potential. Models based on static or dynamic local field corrections are found to be insufficient to describe the data. An extended Mermin approach, a hydrodynamic model, and the method of moments with local constraints are capable of reproducing the numerical results but have rather limited predictive powers as they all need some numerical data as input. The method of moments is found to be the most promising. © 2012 American Physical Society.


Leshem E.,Centers for Disease Control and Prevention | Lopman B.,Centers for Disease Control and Prevention | Glass R.,U.S. National Institutes of Health | Gentsch J.,Centers for Disease Control and Prevention | And 3 more authors.
The Lancet Infectious Diseases | Year: 2014

Background: Concerns exist about whether monovalent (RV1) and pentavalent (RV5) rotavirus vaccines provide adequate protection against diverse strains and whether vaccine introduction will lead to selective pressure. We aimed to investigate the distribution of rotavirus strains and strain-specific rotavirus vaccine effectiveness after vaccine introduction. Methods: We did a systematic review of published work to assess the strain-specific effectiveness of RV1 and RV5 rotavirus vaccines. We classified strains as homotypic, partly heterotypic, and fully heterotypic based on the amount of antigen-matching between strain and vaccine. When studies reported vaccine effectiveness against single antigens (G-type or P-type), we categorised them as either single-antigen vaccine type or single-antigen non-vaccine type. Our primary outcome was strain-specific vaccine effectiveness, comparing effectiveness of homotypic strains with fully or partly heterotypic strains. A secondary outcome was the prevalence of rotavirus strains after vaccine introduction. We estimated pooled odds ratios using random-effect regression models, stratified by country income level and vaccine type, and tested for differences in strain-specific vaccine effectiveness. We assessed strain distribution trends from surveillance reports. Findings: In high-income countries, RV1 pooled vaccine effectiveness was 94% (95% CI 80-98) against homotypic strains, 71% (39-86) against partly heterotypic strains, and 87% (76-93) against fully heterotypic strains. In middle-income settings, respective pooled data were 59% (36-73), 72% (58-81), and 47% (28-61). In high-income countries, RV5 vaccine effectiveness was 83% (78-87) against homotypic strains, 82% (70-89) against single-antigen vaccine type strains, 82% (70-89) against partly heterotypic strains, and 75% (47-88) against single-antigen non-vaccine type strains. In middle-income settings, RV5 vaccine effectiveness was 70% (58-78) against single-antigen vaccine type strains, 37% (10-56) against partly heterotypic strains, and 87% (38-97) against single-antigen non-vaccine type strains. No difference was noted in vaccine effectiveness for either RV1 or RV5 in any setting (all p>0·05). Prevalent strains in countries using RV1 were G2P[4] (2198 of 4428, 50%) and G1P[8] (953, 22%), and those in countries using RV5 were G1P[8] (1280 of 3875, 33%) and G2P[4] (1169, 30%). Sustained predominance of a single strain was not recorded. Interpretation: RV1 and RV5 exert similar effectiveness against homotypic and heterotypic rotavirus strains. Persistence of specific strains was not recorded, suggesting vaccine-induced selective pressure did not occur. Expansion of rotavirus surveillance efforts to low-income countries and ongoing surveillance are crucial to identify emergence of new strains and to assess strain-specific vaccine effectiveness in various settings. © 2014 Elsevier Ltd.


Rokob T.A.,Czech Institute of Organic Chemistry And Biochemistry | Rokob T.A.,Hungarian Academy of Sciences | Bako I.,Hungarian Academy of Sciences | Stirling A.,Hungarian Academy of Sciences | And 2 more authors.
Journal of the American Chemical Society | Year: 2013

Two alternative qualitative reactivity models have recently been proposed to interpret the facile heterolytic cleavage of H2 by frustrated Lewis pairs (FLPs). Both models assume that the reaction takes place via reactive intermediates with preorganized acid/base partners; however, they differ in the mode of action of the active centers. In the electron transfer (ET) model, the hydrogen activation is associated with synergistic electron donation processes with the simultaneous involvement of active centers and the bridging hydrogen, showing similarity to transition-metal-based and other H 2-activating systems. In contrast, the electric field (EF) model suggests that the heterolytic bond cleavage occurs as a result of polarization by the strong EF present in the cavity of the reactive intermediates. To assess the applicability of the two conceptually different mechanistic views, we examined the structural and electronic rearrangements as well as the EFs along the H2 splitting pathways for a representative set of reactions. The analysis reveals that electron donations developing already in the initial phase are general characteristics of all studied reactions, and the related ET model provides qualitative interpretation for the main features of the reaction pathways. On the other hand, several arguments have emerged that cast doubt on the relevance of EF effects as a conceptual basis in FLP-mediated hydrogen activation. © 2013 American Chemical Society.


Perc M.,University of Maribor | Gomez-Gardenes J.,University of Zaragoza | Szolnoki A.,Hungarian Academy of Sciences | Floria L.M.,University of Zaragoza | And 2 more authors.
Journal of the Royal Society Interface | Year: 2013

Interactions among living organisms, from bacteria colonies to human societies, are inherently more complex than interactions among particles and non-living matter. Group interactions are a particularly important and widespread class, representative of which is the public goods game. In addition, methods of statistical physics have proved valuable for studying pattern formation, equilibrium selection and self-organization in evolutionary games. Here, we review recent advances in the study of evolutionary dynamics of group interactions on top of structured populations, including lattices, complex networks and coevolutionary models. We also compare these results with those obtained on well-mixed populations. The review particularly highlights that the study of the dynamics of group interactions, like several other important equilibrium and non-equilibrium dynamical processes in biological, economical and social sciences, benefits from the synergy between statistical physics, network science and evolutionary game theory. © 2013 The Authors.


Szolnoki A.,Hungarian Academy of Sciences | Perc M.,University of Maribor
Journal of Theoretical Biology | Year: 2013

Collective actions, from city marathons to labor strikes, are often mass-driven and subject to the snowball effect. Motivated by this, we study evolutionary advantages of conditional punishment in the spatial public goods game. Unlike unconditional punishers who always impose the same fines on defectors, conditional punishers do so proportionally with the number of other punishers in the group. Phase diagrams in dependence on the punishment fine and cost reveal that the two types of punishers cannot coexist. Spontaneous coarsening of the two strategies leads to an indirect territorial competition with the defectors, which is won by unconditional punishers only if the sanctioning is inexpensive. Otherwise conditional punishers are the victors of the indirect competition, indicating that under more realistic conditions they are indeed the more effective strategy. Both continuous and discontinuous phase transitions as well as tricritical points characterize the complex evolutionary dynamics, which is due to multipoint interactions that are introduced by conditional punishment. We propose indirect territorial competition as a generally applicable mechanism relying on pattern formation, by means of which spatial structure can be utilized by seemingly subordinate strategies to avoid evolutionary extinction. © 2013 Elsevier Ltd.


Longstaff C.,UK National Institute for Biological Standards and Control | Thelwell C.,UK National Institute for Biological Standards and Control | Williams S.C.,UK National Institute for Biological Standards and Control | Silva M.M.C.G.,UK National Institute for Biological Standards and Control | And 2 more authors.
Blood | Year: 2011

Regulation of tissue-type plasminogen activator (tPA) depends on fibrin binding and fibrin structure. tPA structure/function relationships were investigated in fibrin formed by high or low thrombin concentrations to produce a fine mesh and small pores, or thick fibers and coarse structure, respectively. Kinetics studies were performed to investigate plasminogen activation and fibrinolysis in the 2 types of fibrin, using wild-type tPA (F-G-K1-K2-P, F and K2 binding), K1K1-tPA (F-G-K1-K1-P, F binding), and delF-tPA (G-K1-K2-P, K2 binding). There was a trend of enzyme potency of tPA > K1K1-tPA > delF-tPA, highlighting the importance of the finger domain in regulating activity, but the differences were less apparent in fine fibrin. Fine fibrin was a better surface for plasminogen activation but more resistant to lysis. Scanning electron and confocal microscopy using orange fluorescent fibrin with green fluorescent protein-labeled tPA variants showed that tPA was strongly associated with agglomerates in coarse but not in fine fibrin. In later lytic stages, delF-tPA-green fluorescent protein diffused more rapidly through fibrin in contrast to full-length tPA, highlighting the importance of finger domainagglomerate interactions. Thus, the regulation of fibrinolysis depends on the starting nature of fibrin fibers and complex dynamic interaction between tPA and fibrin structures that vary over time. © 2011 by The American Society of Hematology.


Szolnoki A.,Hungarian Academy of Sciences | Perc M.,University of Maribor
New Journal of Physics | Year: 2012

Our well-being depends on both our personal success and the success of our society. The realization of this fact makes cooperation an essential trait. Experiments have shown that rewards can elevate our readiness to cooperate, but since giving a reward inevitably entails paying a cost for it, the emergence and stability of such behavior remains elusive. Here we show that allowing for the act of rewarding to self-organize in dependence on the success of cooperation creates several evolutionary advantages that instill new ways through which collaborative efforts are promoted. Ranging from indirect territorial battle to the spontaneous emergence and destruction of coexistence, phase diagrams and the underlying spatial patterns reveal fascinatingly rich social dynamics that explain why this costly behavior has evolved and persevered. Comparisons with adaptive punishment, however, uncover an Achilles heel of adaptive rewarding, coming from over-aggression, which in turn hinders optimal utilization of network reciprocity. This may explain why, despite its success, rewarding is not as firmly embedded into our societal organization as punishment. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.


Perc M.,University of Maribor | Szolnoki A.,Hungarian Academy of Sciences
New Journal of Physics | Year: 2012

Cooperation is crucial for the remarkable evolutionary success of the human species. Not surprisingly, some individuals are willing to bear additional costs in order to punish defectors. Current models assume that, once set, the fine and cost of punishment do not change over time. Here we show that relaxing this assumption by allowing players to adapt their sanctioning efforts in dependence on the success of cooperation can explain both the spontaneous emergence of punishment and its ability to deter defectors and those unwilling to punish them with globally negligible investments. By means of phase diagrams and the analysis of emerging spatial patterns, we demonstrate that adaptive punishment promotes public cooperation through the invigoration of spatial reciprocity, the prevention of the emergence of cyclic dominance, or the provision of competitive advantages to those that sanction antisocial behavior. The results presented indicate that the process of self-organization significantly elevates the effectiveness of punishment, and they reveal new mechanisms by means of which this fascinating and widespread social behavior could have evolved. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.


Jiang L.-L.,Wenzhou University | Perc M.,University of Maribor | Szolnoki A.,Hungarian Academy of Sciences
PLoS ONE | Year: 2013

Punishment may deter antisocial behavior. Yet to punish is costly, and the costs often do not offset the gains that are due to elevated levels of cooperation. However, the effectiveness of punishment depends not only on how costly it is, but also on the circumstances defining the social dilemma. Using the snowdrift game as the basis, we have conducted a series of economic experiments to determine whether severe punishment is more effective than mild punishment. We have observed that severe punishment is not necessarily more effective, even if the cost of punishment is identical in both cases. The benefits of severe punishment become evident only under extremely adverse conditions, when to cooperate is highly improbable in the absence of sanctions. If cooperation is likely, mild punishment is not less effective and leads to higher average payoffs, and is thus the much preferred alternative. Presented results suggest that the positive effects of punishment stem not only from imposed fines, but may also have a psychological background. Small fines can do wonders in motivating us to chose cooperation over defection, but without the paralyzing effect that may be brought about by large fines. The later should be utilized only when absolutely necessary. © 2013 Jiang et al.


Lucke B.,Leibniz University of Hanover | Peise J.,Leibniz University of Hanover | Vitagliano G.,University of the Basque Country | Arlt J.,University of Aarhus | And 5 more authors.
Physical Review Letters | Year: 2014

Recent experiments demonstrate the production of many thousands of neutral atoms entangled in their spin degrees of freedom. We present a criterion for estimating the amount of entanglement based on a measurement of the global spin. It outperforms previous criteria and applies to a wider class of entangled states, including Dicke states. Experimentally, we produce a Dicke-like state using spin dynamics in a Bose-Einstein condensate. Our criterion proves that it contains at least genuine 28-particle entanglement. We infer a generalized squeezing parameter of -11.4(5) dB. © 2014 Published by American Physical Society.


Kasza T.,MOL Hungarian Oil and Gas Plc. | Kallo D.,Hungarian Academy of Sciences | Hancsok J.,University of Pannonia
Fuel | Year: 2014

Quality improvement of bio-paraffin by isomerization was studied in presence of fatty acid over Pt/SAPO-11 catalyst in order to produce second generation biogasoil. The reaction rates and activation energy of the isomerization having high importance in both reactor design and process control were determined. The increase of the fatty acid content of feedstock significantly decreased the rate of isomerization of bio-origin octadecane, but did not affect the activation energy being 143 ± 3 kJ/mol. Industrial application of the favourable results and the excellent quality properties of end products were also demonstrated. © 2013 Elsevier Ltd. All rights reserved.


Toth G.,University of the Basque Country | Toth G.,Ikerbasque | Toth G.,Hungarian Academy of Sciences | Apellaniz I.,University of the Basque Country
Journal of Physics A: Mathematical and Theoretical | Year: 2014

We summarize important recent advances in quantum metrology, in connection to experiments in cold gases, trapped cold atoms and photons. First we review simple metrological setups, such as quantum metrology with spin squeezed states, with Greenberger-Horne-Zeilinger states, Dicke states and singlet states. We calculate the highest precision achievable in these schemes. Then, we present the fundamental notions of quantum metrology, such as shot-noise scaling, Heisenberg scaling, the quantum Fisher information and the Cramér-Rao bound. Using these, we demonstrate that entanglement is needed to surpass the shot-noise scaling in very general metrological tasks with a linear interferometer. We discuss some applications of the quantum Fisher information, such as how it can be used to obtain a criterion for a quantum state to be a macroscopic superposition. We show how it is related to the speed of a quantum evolution, and how it appears in the theory of the quantum Zeno effect. Finally, we explain how uncorrelated noise limits the highest achievable precision in very general metrological tasks. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to '50 years of Bell's theorem'. © 2014 IOP Publishing Ltd.


Szolnoki A.,Hungarian Academy of Sciences | Perc M.,University of Maribor
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2013

We study the evolution of cooperation in the spatial public goods game, focusing on the effects that are brought about by the delayed distribution of goods that accumulate in groups due to the continuous investments of cooperators. We find that intermediate delays enhance network reciprocity because of a decelerated invasion of defectors, who are unable to reap the same high short-term benefits as they do in the absence of delayed distribution. Long delays, however, introduce a risk because the large accumulated wealth might fall into the wrong hands. Indeed, as soon as the curvature of a cooperative cluster turns negative, the engulfed defectors can collect the heritage of many generations of cooperators and by doing so start a waning-moon pattern that nullifies the benefits of decelerated invasion. Accidental meeting points of growing cooperative clusters may also act as triggers for the waning-moon effect, thus linking the success of cooperators with their propensity to fail in a rather bizarre way. Our results highlight that "investing in the future" is a good idea only if that future is sufficiently near and not likely to be burdened by inflation. © 2013 American Physical Society.


Szolnoki A.,Hungarian Academy of Sciences | Xie N.-G.,Anhui University of Technology | Ye Y.,Anhui University of Technology | Perc M.,University of Maribor
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2013

We show that the resolution of social dilemmas in random graphs and scale-free networks is facilitated by imitating not the strategy of better-performing players but, rather, their emotions. We assume sympathy and envy to be the two emotions that determine the strategy of each player in any given interaction, and we define them as the probabilities of cooperating with players having a lower and a higher payoff, respectively. Starting with a population where all possible combinations of the two emotions are available, the evolutionary process leads to a spontaneous fixation to a single emotional profile that is eventually adopted by all players. However, this emotional profile depends not only on the payoffs but also on the heterogeneity of the interaction network. Homogeneous networks, such as lattices and regular random graphs, lead to fixations that are characterized by high sympathy and high envy, while heterogeneous networks lead to low or modest sympathy but also low envy. Our results thus suggest that public emotions and the propensity to cooperate at large depend, and are in fact determined by, the properties of the interaction network. © 2013 American Physical Society.


Szolnoki A.,Hungarian Academy of Sciences | Perc M.,University of Maribor
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2014

Extortion strategies can dominate any opponent in an iterated prisoner's dilemma game. But if players are able to adopt the strategies performing better, extortion becomes widespread and evolutionary unstable. It may sometimes act as a catalyst for the evolution of cooperation, and it can also emerge in interactions between two populations, yet it is not the evolutionarily stable outcome. Here we revisit these results in the realm of spatial games. We find that pairwise imitation and birth-death dynamics return known evolutionary outcomes. Myopic best response strategy updating, on the other hand, reveals counterintuitive solutions. Defectors and extortioners coarsen spontaneously, which allows cooperators to prevail even at prohibitively high temptations to defect. Here extortion strategies play the role of a Trojan horse. They may emerge among defectors by chance, and once they do, cooperators become viable as well. These results are independent of the interaction topology, and they highlight the importance of coarsening, checkerboard ordering, and best response updating in evolutionary games. © 2014 American Physical Society.


Szolnoki A.,Hungarian Academy of Sciences | Perc M.,University of Maribor | Mobilia M.,University of Leeds
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2014

Reciprocity is firmly established as an important mechanism that promotes cooperation. An efficient information exchange is likewise important, especially on structured populations, where interactions between players are limited. Motivated by these two facts, we explore the role of facilitators in social dilemmas on networks. Facilitators are here mirrors to their neighbors - they cooperate with cooperators and defect with defectors - but they do not participate in the exchange of strategies. As such, in addition to introducing direct reciprocity, they also obstruct information exchange. In well-mixed populations, facilitators favor the replacement and invasion of defection by cooperation as long as their number exceeds a critical value. In structured populations, on the other hand, there exists a delicate balance between the benefits of reciprocity and the deterioration of information exchange. Extensive Monte Carlo simulations of social dilemmas on various interaction networks reveal that there exists an optimal interplay between reciprocity and information exchange, which sets in only when a small number of facilitators occupy the main hubs of the scale-free network. The drawbacks of missing cooperative hubs are more than compensated for by reciprocity and, at the same time, the compromised information exchange is routed via the auxiliary hubs with only marginal losses in effectivity. These results indicate that it is not always optimal for the main hubs to become leaders of the masses, but rather to exploit their highly connected state to promote tit-for-tat-like behavior. © 2014 American Physical Society.


Wang Z.,Hong Kong Baptist University | Szolnoki A.,Hungarian Academy of Sciences | Perc M.,University of Maribor
Scientific Reports | Year: 2013

Recent research has identified interactions between networks as crucial for the outcome of evolutionary games taking place on them. While the consensus is that interdependence does promote cooperation by means of organizational complexity and enhanced reciprocity that is out of reach on isolated networks, we here address the question just how much interdependence there should be. Intuitively, one might assume the more the better. However, we show that in fact only an intermediate density of sufficiently strong interactions between networks warrants an optimal resolution of social dilemmas. This is due to an intricate interplay between the heterogeneity thatcauses an asymmetric strategy flow because of the additional links between the networks, and the independent formation of cooperative patterns on each individual network. Presented results are robust to variations of the strategy updating rule, the topology of interdependent networks, and the governing social dilemma, thus suggesting a high degree of universality. © 2013 Macmillan Publishers Limited.


Szolnoki A.,Hungarian Academy of Sciences | Vukov J.,Hungarian Academy of Sciences | Perc M.,University of Maribor
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2014

We study the rock-paper-scissors game in structured populations, where the invasion rates determine individual payoffs that govern the process of strategy change. The traditional version of the game is recovered if the payoffs for each potential invasion stem from a single pairwise interaction. However, the transformation of invasion rates to payoffs also allows the usage of larger interaction ranges. In addition to the traditional pairwise interaction, we therefore consider simultaneous interactions with all nearest neighbors, as well as with all nearest and next-nearest neighbors, thus effectively going from single pair to group interactions in games of cyclic dominance. We show that differences in the interaction range affect not only the stationary fractions of strategies but also their relations of dominance. The transition from pairwise to group interactions can thus decelerate and even revert the direction of the invasion between the competing strategies. Like in evolutionary social dilemmas, in games of cyclic dominance, too, the indirect multipoint interactions that are due to group interactions hence play a pivotal role. Our results indicate that, in addition to the invasion rates, the interaction range is at least as important for the maintenance of biodiversity among cyclically competing strategies. © 2014 American Physical Society.


Chen X.,International Institute For Applied Systems Analysis | Szolnoki A.,Hungarian Academy of Sciences | Perc M.,University of Maribor
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2012

A collective-risk social dilemma implies that personal endowments will be lost if contributions to the common pool within a group are too small. Failure to reach the collective target thus has dire consequences for all group members, independently of their strategies. Wanting to move away from unfavorable locations is therefore anything but surprising. Inspired by these observations, we here propose and study a collective-risk social dilemma where players are allowed to move if the collective failure becomes too probable. More precisely, this so-called risk-driven migration is launched depending on the difference between the actual contributions and the declared target. Mobility therefore becomes an inherent property that is utilized in an entirely self-organizing manner. We show that under these assumptions cooperation is promoted much more effectively than under the action of manually determined migration rates. For the latter, we in fact identify parameter regions where the evolution of cooperation is greatly inhibited. Moreover, we find unexpected spatial patterns where cooperators that do not form compact clusters outperform those that do, and where defectors are able to utilize strikingly different ways of invasion. The presented results support the recently revealed importance of percolation for the successful evolution of public cooperation, while at the same time revealing surprisingly simple methods of self-organization towards socially desirable states. © 2012 American Physical Society.


Odor G.,Hungarian Academy of Sciences | Pastor-Satorras R.,Polytechnic University of Catalonia
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2012

We show that generic, slow dynamics can occur in the contact process on complex networks with a tree-like structure and a superimposed weight pattern, in the absence of additional (nontopological) sources of quenched disorder. The slow dynamics is induced by rare-region effects occurring on correlated subspaces of vertices connected by large weight edges and manifests in the form of a smeared phase transition. We conjecture that more sophisticated network motifs could be able to induce Griffiths phases, as a consequence of purely topological disorder. © 2012 American Physical Society.


Wang Z.,Nankai University | Wang Z.,Hong Kong Baptist University | Szolnoki A.,Hungarian Academy of Sciences | Perc M.,University of Maribor
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2012

While worldwide census data provide statistical evidence that firmly link the population density with several indicators of social welfare, the precise mechanisms underlying these observations are largely unknown. Here we study the impact of population density on the evolution of public cooperation in structured populations and find that the optimal density is uniquely related to the percolation threshold of the host graph irrespective of its topological details. We explain our observations by showing that spatial reciprocity peaks in the vicinity of the percolation threshold, when the emergence of a giant cooperative cluster is hindered neither by vacancy nor by invading defectors, thus discovering an intuitive yet universal law that links the population density with social prosperity. © 2012 American Physical Society.


Szolnoki A.,Hungarian Academy of Sciences | Perc M.,University of Maribor
New Journal of Physics | Year: 2013

More often than not, bad decisions are bad regardless of where and when they are made. Information sharing might thus be utilized to mitigate them. Here we show that sharing information about strategy choice between players residing on two different networks reinforces the evolution of cooperation. In evolutionary games, the strategy reflects the action of each individual that warrants the highest utility in a competitive setting. We therefore assume that identical strategies on the two networks reinforce themselves by lessening their propensity to change. Besides network reciprocity working in favour of cooperation on each individual network, we observe the spontaneous emergence of correlated behaviour between the two networks, which further deters defection. If information is shared not just between individuals but also between groups, the positive effect is even stronger, and this despite the fact that information sharing is implemented without any assumptions with regard to content. © IOP Publishing and Deutsche Physikalische Gesellschaft.


Yan B.,University of Bremen | Rurali R.,CSIC - Institute of Materials Science | Gali A.,Hungarian Academy of Sciences | Gali A.,Budapest University of Technology and Economics
Nano Letters | Year: 2012

A phosphorus (P) donor has been extensively studied in bulk Si to realize the concept of Kane quantum computers. In most cases the quantum bit was realized as an entanglement between the donor electron spin and the nonzero nuclei spin of the donor impurity mediated by the hyperfine coupling between them. The donor ionization energies and the spin-lattice relaxation time limited the temperatures to a few kelvin in these experiments. Here, we demonstrate by means of ab initio density functional theory calculations that quantum confinement in thin Si nanowires (SiNWs) results in (i) larger excitation energies of donor impurity and (ii) a sensitive manipulation of the hyperfine coupling by external electric field. We propose that these features may allow to realize the quantum bit (qubit) experiments at elevated temperatures with a strength of electric fields applicable in current field-effect transistor technology. We also show that the strength of quantum confinement and the presence of strain induced by the surface termination may significantly affect the ground and excited states of the donors in thin SiNWs, possibly allowing an optical read-out of the electron spin. © 2012 American Chemical Society.


Asboth J.K.,Hungarian Academy of Sciences | Edge J.M.,KTH Royal Institute of Technology
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2015

Quantum walks on translation-invariant regular graphs spread quadratically faster than their classical counterparts. The same coherence that gives them this quantum speedup inhibits or even stops their spread in the presence of disorder. We ask how to create an efficient transport channel from a fixed source site (A) to fixed target site (B) in a disordered two-dimensional discrete-time quantum walk by cutting some of the links. We show that the somewhat counterintuitive strategy of cutting links along a single line connecting A to B creates such a channel. The efficient transport along the cut is due to topologically protected chiral edge states, which exist even though the bulk Chern number in this system vanishes. We give a realization of the walk as a periodically driven lattice Hamiltonian and identify the bulk topological invariant responsible for the edge states as the quasienergy winding of this Hamiltonian. © 2015 American Physical Society.


Patko D.,Hungarian Academy of Sciences | Patko D.,University of Pannonia | Cottier K.,Creoptix | Hamori A.,Hungarian Academy of Sciences | Horvath R.,Hungarian Academy of Sciences
Optics Express | Year: 2012

Grating Coupled Interferometry (GCI) using high quality waveguides with two incoupling and one outcoupling grating areas is introduced to increase and precisely control the sensing length of the device; and to make the sensor design suitable for plate-based multiplexing. In contrast to other interferometric arrangements, the sensor chips are interrogated with a single expanded laser beam illuminating both incoupling gratings simultaneously. In order to obtain the interference signal, only half of the beam is phase modulated using a laterally divided two-cell liquid crystal modulator. The developed highly symmetrical arrangement of the interferometric arms increases the stability and at the same time offers straightforward integration of parallel sensing channels. The device characteristics are demonstrated for both TE and TM polarized modes. © 2012 Optical Society of America.


Petrovski G.,Hungarian Academy of Sciences | Das S.,University of Connecticut | Juhasz B.,Debrecen University | Kertesz A.,Debrecen University | And 2 more authors.
Antioxidants and Redox Signaling | Year: 2011

This study tested the hypothesis that the induction of autophagy by producing therapeutic amounts of endoplasmic reticulum (ER) stress in the heart before an ischemic insult would ameliorate/reduce subsequent lethal myocardial ischemic/reperfusion (I/R) injury (similar to ischemic preconditioning). A dose-response study with both tunicamycin and thapsigargin was performed to determine the optimal dose (0.3 mg/kg) for inducing autophagy for cardioprotection. The Sprague-Dawley rats weighing between 250 and 300 g were randomly assigned into five groups: normal control (injected with saline only), high (3 mg/kg), and low (0.3 mg/kg) doses of tunicamycin or thapsigargin, respectively. After 48 h, the rats were subjected to an isolated working heart preparation: 30 min ischemia followed by 2 h of reperfusion with continuous left ventricular function monitoring. At the end, the hearts were subjected to either measurement of infarct size or cardiomyocyte apoptosis. Some hearts (from different sets of experiments) were used for transmission electron microscopy (TEM), confocal microscopy, or Western blot analysis. Tunicamycin and thapsigargin, irrespective of the dose, induced sufficient ER stress, as evidenced by the increased phosphorylation or activation of eIF2α and PERK. Such ER stress potentiated autophagy in the heart, as evidenced by an increase in LC3-II, beclin-1, and Atg5. This was also supported by TEM, clearly showing the production of autophagosomes, and by confocal microscopy, showing upregulation of eIF2α and beclin-1. The autophagy produced with lower doses of tunicamycin and thapsigargin in the face of myocardial I/R resulted in reduction of the I/R injury, as evidenced by improved left ventricular function and reduced myocardial infarct size and cardiomyocyte apoptosis. In concert, an induction of GRP78 and activation of Akt and Bcl-2 occurred. The higher doses conversely were detrimental for the heart and were associated with induction of CHOP and downregulation of Akt. The results thus display the proof of concept that induction of autophagy by ER stress (therapeutic amount) before ischemia (similar to ischemic preconditioning) could reduce subsequent lethal ischemic reperfusion injury. © Mary Ann Liebert, Inc.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: HEALTH-2007-2.2.1-7 | Award Amount: 6.29M | Year: 2008

At present more than 5 million people in the EU suffer from dementia and other neurodegenerative diseases and that number will grow as the average age of the population continues to increase. The efficacy of current medicines is limited and new therapeutic targets are sorely needed. Several independent lines of evidence have established an important role of prolyl oligopeptidase (PREP) in brain function and dysfunction. Aberrant PREP activity is involved in the progression of neurodegenerative disorders and PREP inhibitors are being developed for the treatment of memory and cognition deficits. Now a consortium of expert scientists from 8 academic institutes and 3 SMEs come together for 4 years in this NEUROPRO project to boost European research aimed at 1) unravelling the biological role of PREP and PREP-like proteins in neuropathology, 2) determining the mode of action of PREP inhibitors and 3) firmly establishing their therapeutic potential. Specialists from different disciplines cell and molecular biology, enzymology, chemistry, crystallography, biology and pharmacology will work in a concerted and focussed way to achieve the goals using 6 work packages concentrating on PREP-regulated pathways in health and disease, PREP substrates, inhibitor target identification, drug development and validation, and generation of specific cell lines and animal models of neurodegenerative diseases. The SMEs involved are leaders in PREP inhibitor development and peptide analysis, and have in the past already brought novel therapeutics on the market. By the end of the project we expect to have proof of concept that PREP inhibition is a valid therapeutic target which will ultimately lead to new methods for the early detection, prevention or restoration of PREP-related neurodegeneration. The project also comprises instruments to translate basic research into clinical applications and will thus broaden the scope of treatments available to Europes ageing population.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: NMP-2007-1.1-1 | Award Amount: 4.95M | Year: 2008

EXCELL is a novel innovative approach to explore interaction mechanisms between biological materials and systems/nanostructures. It involves a forward-looking cross-disciplinary and design-based research to generate an integrated, biologically inspired technological platform of high complexity, able to monitor cell dynamics at nano-scale. Expertise in cellular and molecular biology, nanosciences, material engineering, biophysics, biotechnology, modelling, and analytical chemistry, are combined to address the targeted goals, which go beyond the state of the art methods used in traditional biotechnology and systems biology. EXCELL will provide a complete Lab-in-a-Cell (LIC) sensor and actuator platform, which is capable of: (1) studying single cells in their natural environment surrounded by other cells or a complex mixture of different cells/tissue, (2) following the dynamics and interdependence of single cell processes from gene, protein, metabolite to compound secretion, exocytosis and cell-to-cell communication, (3) testing how and where various stimuli affect the different levels of the molecular machinery and finally (4) programming cells to be able to differentiate into a particular phenotype. A major task is the design of suitable biocompatible nano/bio interfaces that ensures a sustainable cellular environment. EXCELL provides a unique opportunity for developing advanced, novel experimental tools to address fundamental problems of stem cell research and poses a potential for possible diversification and modulation of developmental programs of stem cells to differentiate them into specific phenotypes. EXCELL has the capacity to drive new discoveries having a significant impact not only in the field of stem cell research and clinical use, but also on molecular engineering, nanosciences, sensor development, diagnostics, therapeutics, biotechnology and industry (smart materials, medical diagnostics, pharmaceutical companies, start-ups)


Grant
Agency: GTR | Branch: EPSRC | Program: | Phase: Fellowship | Award Amount: 219.53K | Year: 2011

Combinatorics is a branch of mathematics studying finite structures. The generality of these questions suggests wide applicability of combinatorics in other areas of pure mathematics (most notably in algebra, number theory, probability, and topology), as well as in real-world applications (discrete optimization, computer science).One of the oldest and most central parts of combinatorics are graph theory and enumerative combinatorics. Graph theory models networks (such as road connections, or internet users), and enumerative combinatorics concerns studying counting questions of various kinds.Extremal graph theory is a broad part of graph theory which investigates interplay between various graph parameters. One of the main tools in Extremal graph theory is the so-called Szemeredi Regularity Lemma. This tool (developed in the 70s) has become one of the corner-stones of modern mathematics. Recently, using the insights gained from the Regularity Lemma, Lovasz and Szegedy initiated study of graph limits.The proposed research project addresses major open questions in extremal graph theory and aims contribute to general theories the Regularity Lemma, graph limits, and by developing novel tools which will be used in enumerative combinatorics.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: NMP.2012.1.4-2 | Award Amount: 5.18M | Year: 2013

UNION will develop nanoparticle (NP) assembly techniques, and assembly monitoring technologies to prepare novel hierarchically-ordered nanoparticle clusters (NPCs). By improving control over the synthesis and assembly of NPs we will produce materials with tailored and predictable properties. Furthermore, by incorporating hierarchical control into the assembly (through the type, size and spatial distribution of the NPs) it will be possible to assess the influence of the hierarchy on properties and develop new functionalities. UNION will investigate how the emergent properties of the assemblies are determined by the architecture of the assembly, the extent of order, and the properties of the component NPs. This will enable tuning of the primary NP properties and the assembly processes to develop significant breakthroughs in nano-devices and next generation complex nanotechnology products. As the ultimate aim is commercial exploitation of our results, in each stage of the development process we will use application driven, scalable and cost-effective processes, incorporating EHS assessment and roadmap preparation towards future industrial deployment. UNION will achieve its objectives through a three stage approach. - Improved NP preparation providing optimised surface chemistry for subsequent assembly - Novel NPC formation (hierarchical nanoparticle assembly) methods - Roll-out of NPCs for three application areas NPC applications will be developed within three core areas corresponding to the different hierarchical structural levels; in suspensions of individual NPCs (biomedical), in supported 2D NPC arrays (optical), and in 3D arrays or nanocomposites (thermoelectric). Our consortium is comprised of multidisciplinary research groups involving 8 partners with ex-pertise in preparation and application of nano-materials. It includes significant industrial participation with 4 companies with specific knowledge and testing capability for the target application areas.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-IP | Phase: KBBE-2009-2-2-01 | Award Amount: 7.98M | Year: 2010

NeuroFAST is a multidisciplinary project, involving ten teams from seven countries, to explore the neurobiology of addiction and eating behaviour and the complex socio-psychological forces that can lead to its dysregulation. These forces include dietary components (including highly palatable foods and alcohol), some of which may have addictive properties, but also cultural and social pressures, everyday stressors, and family-genetic influences on these. The project will provide new data from human studies, including human nutritional studies, that is needed to inform health policy initiatives. This will be underpinned by state-of-the art mechanistic research to establish a solid scientific basis for this advice. The European added value lies in building up the necessary critical mass in several fields of expertise: psychology, epidemiology, human genetics related to eating disorders, human nutrition, eating and addictive behaviour disorders, endocrinology, human brain imaging, together with studies of the basic mechanisms of eating behaviour and addiction, (neuro)endocrine regulators, stress, opiate dependence, and cannabinoid actions. To provide scientific support for European public health policies, a focus will be on a socio-psychological analysis of determinants of food addiction and substance abuse, and of how risk factors like stress in the workplace are driving addictive behaviour. We will establish an evidence base for inter-relationships, linking eating disorder research with obesity research, stress research and addiction research, and involving studies of selected individual food components using novel designed foods with controlled components. In summary, we will use a synergistic combination of controlled laboratory studies, characterization of patient groups, and examination of real-world scenarios based on epidemiological community samples that will be relevant to policy development.


Grant
Agency: European Commission | Branch: FP7 | Program: MC-ITN | Phase: FP7-PEOPLE-ITN-2008 | Award Amount: 3.48M | Year: 2009

The EU is currently directing intensive research efforts into nanotechnology. Carbon Nanotubes (CNTs), with the electrical conductivity of copper and an E-modulus 10 times greater than steel, are one of the most promising developments, enabling the creation of materials with revolutionary characteristics. The commercial potential is huge, but only a fraction of the possible applications have reached the market. Collaboration is needed between academia and industry, so that processes developed on a laboratory scale can be upscaled for industrial application. This consortium, which achieves an optimal balance between academia and industry (50:50) in the field of CNTs, and which spans the entire value added chain from CNT synthesis to implementation in saleable products, is convinced that the 576 person-months spent on this project will achieve this aim. 18 researchers, in unique collaboration with cutting-edge teams, will work to overcome recognised limitations in the state of the art, including the adjustment of CNT surface properties, CNT dispersion in thermosets and thermoplastics, reliable analysis and characterisation. Carefully structured networking will ensure the efficient exchange of knowledge between researchers, the partners and society. Focus on 3 specific end-use applications (construction, wind blades, electrodes) will ensure quantifiable and tangible results. The predicted growth of nanotechnology can only be sustained through the education of scientists. The vast teaching experience of the partners will ensure a high-quality training program. Through mentoring by world-class researchers, conferences, courses ranging from leadership for women to presentation skills, interdisciplinary and intersectoral experience, the appointed researchers will gain scientific know-how and the complementary skills necessary to exploit it. The S&T and training elements will combine to form a structured program, adaptable to each researchers needs.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-IP | Phase: NMP-2007-3.5-1 | Award Amount: 10.45M | Year: 2008

Outstanding progress has been made in recent years in developing novel structures and applications for direct fabrication of 3D nanosurfaces. However, exploitation is limited by lack of suitable manufacturing technologies. In this project we will develop innovative in-line high throughput technologies based on atmospheric pressure surface and plasma technologies. The two identified approaches to direct 3D nanostructuring are etching for manufacturing of nanostructures tailored for specific applications, and coating. Major impact areas were selected, demonstrating different application fields. Impact Area 1 focuses on structures for solar cell surfaces. Nanostructured surfaces have the potential to improve efficiencies of cells by up to 25% (rel), having dramatic impact on commercial viability. Impact Area 2 focuses on biocidal surface structures. Increasing concerns about infections leading to the conclusion, that only multi-action approaches for control of infection transfer can be effective. We plan to combine such surfaces with 3D nanostructures, which will both immobilise and deactivate pathogenic organisms on surfaces. Impact Area 3 is the direct growth of aligned carbon nanotubes on electrode surfaces. The material is under investigation for use in high load capacitors which are seen as key components for energy storage systems, e.g. for Hybrid Electric Vehicle. Impact Area 4 focuses on tailored interfaces to achieve durable adhesion on polymer surfaces by 3D nanostructuring and coating. Target is to reduce energy consumption by introducing lightweight materials. The N2P partners have been chosen to ensure a strong capability to exploit and disseminate the outcomes. Involved end-user industries represent high market value segments: photovoltaics, aeronautics, automotive, steel. The consortium includes 7 technology leading SMEs and 4 multi-national industries, cooperating with 9 institutes for industrial research and a public body from 8 European countries.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: HEALTH.2010.2.2.2-2 | Award Amount: 8.56M | Year: 2011

Healthy aging requires maintenance of homeostatic control of the physiological systems and functions that are integrated by the hypothalamus. Driven by work in previous EU projects (Crescendo/Lifespan) highlighting insulin signalling and the hypothalamic/pituitary/adrenal and thyroid axes in the regulation of aging, SWITCHBOX will examine the flexibility of these neuroendocrine systems in response to environmental challenges in three established human cohorts with variable aging potential. These human cohorts include offspring of exceptionally long-lived siblings and their partners (controls), people with good vs bad cognitive performance or with high vs low cognitive engagement. Maintaining brain function is emphasised as it reflects an individuals overall well-being, a major goal in aging research, and because age-related brain disorders represent a major socioeconomic burden. To determine the genetic and cellular underpinnings of the findings in humans, hypothesis-based studies in rodents sharing phenotypes with the human cohorts will be carried out. To clarify the role of the brain in the differential regulation of endocrine axes critical for healthy aging, SWITCHBOX will examine the neuroendocrine and metabolic effects of intranasal (humans) and intra-cerebroventricular (rodents) administration of peptides involved in controlling metabolic homeostasis (e.g. insulin, -MSH). State-of-the-art technology will be used to measure circadian endocrine and metabolic profiles, brain structure and function (fMRI) and cognitive performance, as well as cellular and molecular features. All data will be entered into an already operational open access database. The work aims to take key findings from basic research and translate them into clinically relevant concepts. It will benefit from combining expertise of gerontologists, endocrinologists, molecular and cellular neuroscientists and neuropsychologists. SWITCHBOX ultimately aims to develop conceptually new approaches for the prevention and treatment of age-related disorders.


Toth G.,University of the Basque Country | Toth G.,Ikerbasque | Toth G.,Hungarian Academy of Sciences | Moroder T.,University of Siegen | Guhne O.,University of Siegen
Physical Review Letters | Year: 2015

We show a powerful method to compute entanglement measures based on convex roof constructions. In particular, our method is applicable to measures that, for pure states, can be written as low order polynomials of operator expectation values. We show how to compute the linear entropy of entanglement, the linear entanglement of assistance, and a bound on the dimension of the entanglement for bipartite systems. We discuss how to obtain the convex roof of the three-tangle for three-qubit states. We also show how to calculate the linear entropy of entanglement and the quantum Fisher information based on partial information or device independent information. We demonstrate the usefulness of our method by concrete examples. © Published by the American Physical Society.


Wang Z.,Hong Kong Baptist University | Szolnoki A.,Hungarian Academy of Sciences | Szolnoki A.,Institute of Mathematics | Perc M.,University of Maribor
New Journal of Physics | Year: 2014

Coevolution between strategy and network structure is established as a means to arrive at the optimal conditions needed to resolve social dilemmas. Yet recent research has highlighted that the interdependence between networks may be just as important as the structure of an individual network. We therefore introduce the coevolution of strategy and network interdependence to see whether this can give rise to elevated levels of cooperation in the prisoner's dilemma game. We show that the interdependence between networks self-organizes so as to yield optimal conditions for the evolution of cooperation. Even under extremely adverse conditions, cooperators can prevail where on isolated networks they would perish. This is due to the spontaneous emergence of a two-class society, with only the upper class being allowed to control and take advantage of the interdependence. Spatial patterns reveal that cooperators, once arriving at the upper class, are much more competent than defectors in sustaining compact clusters of followers. Indeed, the asymmetric exploitation of interdependence confers to them a strong evolutionary advantage that may resolve even the toughest of social dilemmas. © 2014 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.


News Article | February 15, 2017
Site: www.scientificamerican.com

A Harvard Medical School professor recently rocked the Internet: “Since dogs are generally extremely attached to their human owners, it’s likely your dog is dreaming of your face, your smell and of pleasing or annoying you,” psychologist Deirdre Barrett told People magazine. And then hearts everywhere exploded. Barrett’s sleep research focuses on humans, while an interest in evolutionary psychology helps her consider the sleep of non-human mammals. Both have similar sleep cycles, she notes, which could suggest parallels in sleep quality or experience. But an open access study in Scientific Reports out yesterday moves away from extrapolation and toward hard data. Researchers in Hungary have devised a way to non-invasively peer into the sleeping dog’s brain to explore the content and function of their sleep. Sleep in dogs is good for a number of things, including, but not limited to cuteness, cuteness, and more cuteness. But you’ve also probably heard that sleep is good for memory. Before a big test we’re often told, “Get a good night’s rest,” which is actually shorthand for—give memory consolidation a chance. “Memory consolidation” is the process where your brain pulls together pieces of information and packages them into memories that can be used in the future. Memory is also important for dogs. Working dogs need to learn—and retain—a wide variety of job-specific skills, and companion dogs often learn basic skills to successfully live alongside humans. When a dog learns something new, can sleep help the dog perform those skills better? Should training sessions incorporate naptime? Anna Kis of the Hungarian Academy of Sciences and colleagues—including members of the well-known Family Dog Project—set out to explore the relationship between sleep and memory in companion dogs. Their study involved two experiments: the first gave dogs a learning task and then peered into their sleep via non-invasive electroencephalogram (EEG)—a test that detects brain electrical activity using small electrodes attached to the scalp. The second experiment explored whether different type of post-learning activities (such as sleep) affect memory consolidation, both in the short- and long-term. All experiments were performed with consenting companion dogs and their helpful owners. First up, the sleep study, also known as polysomnography if you want to be fancy about it. Fifteen companion dogs participated in both a learning and a non-learning condition. The experimenters taught the dogs the commands for “sit” and “lie down” in a foreign language (English). As you’d expect, no learning took place in the non-learning condition—dogs simply practiced the “sit” and “lie down” commands that they already knew in Hungarian. Nothing new. Old hat. (Most dogs don’t wear hats. Old collar?) For the critical phase of the experiment, dogs went to sleep (gosh I love science). Dog snoozing-related brain activity was then monitored over the next three hours. Afterwards, dogs in the learning condition were retested on “sit” and “lie down” in English to determine whether sleep helped the dogs process what they had learned. Not only did the sleep affect dogs’ learning, the learning affected dogs’ sleep. Dogs did better responding to “sit” and “lie down” in English after taking a snooze. But even before the dogs in the learning condition were retested, two notable wave patterns stood out in the EEG spectrum in the non-REM phase (the dreamless part of sleep). There was an increase of delta power, similar to what is found in humans, and a decrease in alpha activity, which could suggest “an increase in sleep depth after learning.” These two findings are related. Dogs learned a task, which alters their brain activity during sleep, then they performed better on the task. “This suggests that the newly acquired information is re-processed and consolidated during sleep,” Kis explained over email. More specifically, the correlation between the post-sleep improvement in performance and certain EEG patterns “is the strongest indicator that the changes in sleep EEG we see after learning are functionally related to memory consolidation,” added Kis. Neat. Taking a snooze can improve subsequent performance (at least for this type of command learning task). But how do we make things stick? Is sleep more or less effective than other strategies for retaining information? A second behavioral experiment investigated the effect of different post-learning activities (including sleep) on subsequent memory. Fifty-three new companion dogs learned “sit” and “lie down” to new words (again, English). Dogs were then put in one of four different post-learning groups, spending the next hour either sleeping, walking, learning more (learning new behaviors via the luring training method), or eating from and playing with a Kong dog toy. When the hour was up, dogs were retested on the English commands they’d just learned.* The type of post-learning activity seemed to affect dog performance in the short term, but not exactly as the researchers had expected. In the short term, both sleeping and walking improved subsequent performance, while more learning and Kong play did not. On the other hand, when dogs came back a week later, presumably after many sleeps, dogs in the sleep, walk, and Kong play conditions showed marked improvement with the English commands. Dogs who had done more learning did not improve. Dog lovers often think about learning and obedience in terms of dogs doing it “right” or “wrong.” Factors surrounding learning, this study reminds, can affect memory consolidation and later performance. Kis recommends: “Learning a new command should be followed by an activity that does not interfere with this new memory trace (e.g. sleeping, walking, playing–but not learning other things) in order to achieve the highest subsequent performance in the long run.” At the same time, Kis noted that dogs in the sleeping condition might have performed even better if the nap extended beyond an hour (possibly for memory consolidation to fully take place), or if, after waking up, the dogs had a few more minutes to shake off their sleepiness before performing the tasks again. Human-sleep scientists refer to this latter phenomenon of decreased cognitive performance in the few minutes after waking up as “sleep inertia.” Don’t pretend you’ve never woken up, walked to the bathroom, and tried to brush your teeth with your comb. Since no sleep inertia interval has been established for dogs, Kis says, they can’t rule out the possibility that the dogs were still sleep zombies when they were retested. Non-invasive studies of dogs and sleep are new. We haven’t yet studied whether your dog is dreaming of your face or your glorious smell, but if you care about learning in dogs, this study suggests you give sleep a chance. * Maybe you’re wondering why there wasn’t a condition after learning where dogs simply rested—rather than slept—and then had their memory tested. This ‘resting’ awake condition is typically found in human memory consolidation studies because it’s the closest match to the ‘sleep’ condition. But this condition was not included for dogs, the researchers explain, “as preventing dogs from falling asleep while requested to stay in a laying position for one hour would presumably induce stress in the animals. Stress is known to have an impact on memory, and also raises animal welfare issues, thus we decided to avoid such a condition.” Kis et al. (2017). The interrelated effect of sleep and learning in dogs (Canis familiaris); an EEG and behavioural study. Scientific Reports 7, 41873.


Heberger K.,Hungarian Academy of Sciences | Zenkevich I.G.,Saint Petersburg State University
Journal of Chromatography A | Year: 2010

The comparison of different polarity measures (parameters, descriptors, variables, scales, etc.) indicates that evaluation of interrelations between these measures is important for better understanding and interpretation of chemical and/or analytical data, especially for chromatographic separation. The best linear correlation between gas chromatographic and non-chromatographic polarity descriptors is revealed for the first time: this pair of variables is the difference of gas chromatographic retention indices on standard polar and non-polar phases as well as the difference between non-dimensional indices of boiling points (known in chromatography since mid-1980s as dispersion indices) and indices of molar refractions. The correlation helps chromatographers to find preferable chemical variables (features) to understand better the separation phenomena and to find better correlations in QSRR models. Principal component analysis (PCA) of ten frequently applied polarity measures shows their similarity and, at the same time, it shows the absence of anomalies within the set of simple organic molecules. A novel ranking method for ten polarity parameters points out that the two most informative polarity measures are (i) the non-dimensional index for boiling point and (ii) the difference in chromatographic retention indices on standard polar and non-polar stationary phases. On the other hand, the hydrophobicity parameter, log P, sometimes considered as polarity parameter in HPLC seems to be the worst one in description of "polarity" in gas chromatography. Surprisingly, such polarity measures like dipole moment and permittivity used often in organic chemistry does not provide the best correlation with gas chromatographic polarity measures. © 2010 Elsevier B.V.


Castelletto S.,RMIT University | Johnson B.C.,University of Melbourne | Johnson B.C.,Japan Atomic Energy Agency | Ivady V.,Hungarian Academy of Sciences | And 6 more authors.
Nature Materials | Year: 2014

Over the past few years, single-photon generation has been realized in numerous systems: single molecules, quantum dots, diamond colour centres and others. The generation and detection of single photons play a central role in the experimental foundation of quantum mechanics and measurement theory. An efficient and high-quality single-photon source is needed to implement quantum key distribution, quantum repeaters and photonic quantum information processing. Here we report the identification and formation of ultrabright, room-temperature, photostable single-photon sources in a device-friendly material, silicon carbide (SiC). The source is composed of an intrinsic defect, known as the carbon antisite-vacancy pair, created by carefully optimized electron irradiation and annealing of ultrapure SiC. An extreme brightness (2×10 6 counts s -1) resulting from polarization rules and a high quantum efficiency is obtained in the bulk without resorting to the use of a cavity or plasmonic structure. This may benefit future integrated quantum photonic devices. © 2014 Macmillan Publishers Limited. All rights reserved.


Munoz M.A.,University of Granada | Juhasz R.,Hungarian Academy of Sciences | Castellano C.,University of Rome La Sapienza | Odor G.,Research Institute for Technical Physics and Materials Science
Physical Review Letters | Year: 2010

Quenched disorder is known to play a relevant role in dynamical processes and phase transitions. Its effects on the dynamics of complex networks have hardly been studied. Aimed at filling this gap, we analyze the contact process, i.e., the simplest propagation model, with quenched disorder on complex networks. We find Griffiths phases and other rare-region effects, leading rather generically to anomalously slow (algebraic, logarithmic,...) relaxation, on Erdos-Rényi networks. Similar effects are predicted to exist for other topologies with a finite percolation threshold. More surprisingly, we find that Griffiths phases can also emerge in the absence of quenched disorder, as a consequence of topological heterogeneity in networks with finite topological dimension. These results have a broad spectrum of implications for propagation phenomena and other dynamical processes on networks. © 2010 The American Physical Society.


Benczur A.A.,Hungarian Academy of Sciences | Karger D.R.,Cambridge Intelligence
SIAM Journal on Computing | Year: 2015

We describe random sampling techniques for approximately solving problems that involve cuts and flows in graphs. We give a near-linear-time randomized combinatorial construction that transforms any graph on n vertices into an O(n log n)-edge graph on the same vertices whose cuts have approximately the same value as the original graph's. In this new graph, for example, we can run the Õ (m3/2)-time maximum flow algorithm of Goldberg and Rao to find an s-t minimum cut in Õ(n3/2) time. This corresponds to a (1 + ε)-times minimum s-t cut in the original graph. A related approach leads to a randomized divide-and-conquer algorithm producing an approximately maximum flow in Õ(m √n) time. Our algorithm can also be used to improve the running time of sparsest cut approximation algorithms from Õ(mn) to Õ (n2) and to accelerate several other recent cut and flow algorithms. Our algorithms are based on a general theorem analyzing the concentration of random graphs' cut values near their expectations. Our work draws only on elementary probability and graph theory. © 2015 Andras Benczúr and David R. Karger.


Jakusch T.,University of Szeged | Costa Pessoa J.,University of Lisbon | Kiss T.,University of Szeged | Kiss T.,Hungarian Academy of Sciences
Coordination Chemistry Reviews | Year: 2011

A knowledge of the speciation of vanadium in human serum is essential for an understanding of the biotransformation of antidiabetic vanadium complexes in human blood and of how vanadium is transported to the target cells. Such information may be acquired by two completely different approaches: separation techniques and modeling calculations. This review focuses on the latter.The two major metal ion binders in human serum are apotransferrin (apoTf) and human serum albumin (HSA), the interactions of which with VIVO and VV are discussed in detail. A partially new model for HSA-VIVO interactions is introduced, in which the two binding sites (one for two and one for one metal ion) compete not only with each other, but also with hydrolysis of the metal ion.Focus is also placed on the possibility and importance of ternary complex formation between VIVO, serum proteins and drug candidate ligands (maltol (mal), 1,2-dimethyl-3-hydroxy-4(1H)-pyridinone (dhp), acetylacetone (acac) and picolinic acid, (pic)): the structures and formation constants of different ternary complexes reported by the different research groups are critically reviewed.The serum speciations for VIVO and VV are calculated through use of the most recent stability constants; at biologically relevant concentrations (~1μM, but definitely <10μM) the apoTf complexes predominate for both metal ions. This has the consequences that the primary role of the drug candidate ligands of the original complexes is a carrier function until the vanadium is taken up into the serum, and the vanadium ion itself is the active metabolite responsible for the antidiabetic effect. © 2011 Elsevier B.V.


Thirunavukkuarasu K.,University of Augsburg | Hennrich F.,Karlsruhe Institute of Technology | Kamaras K.,Hungarian Academy of Sciences | Kuntscher C.A.,University of Augsburg
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

The electronic properties of as-prepared and purified unoriented single-walled carbon nanotube (SWCNT) films were studied by transmission measurements over a broad frequency range (far-infrared up to visible) as a function of temperature (15-295 K) and external pressure (up to 8 GPa). Both the as-prepared and the purified SWCNT films exhibit nearly temperature-independent properties. With increasing pressure the low-energy absorbance decreases suggesting an increasing carrier localization due to pressure-induced deformations. The energy of the optical transitions in the SWCNTs decreases with increasing pressure, which can be attributed to pressure-induced hybridization and symmetry-breaking effects. We find an anomaly in the pressure-induced shift of the optical transitions at ∼2GPa due to a structural phase transition. © 2010 The American Physical Society.


Pulawska J.,Research Institute of Horticulture | Willems A.,Ghent University | De Meyer S.E.,Ghent University | Sule S.,Hungarian Academy of Sciences
Systematic and Applied Microbiology | Year: 2012

Five Gram-negative, rod-shaped, non-spore-forming bacteria were isolated from galls on different plant species in Hungary: strain 39/7T from Prunus cerasifera Myrobalan, strain 0 from grapevine var. Ezerjó, strain 7/1 from raspberry var. Findus and in Poland, strain C3.4.1 from Colt rootstock (Prunus avium×Prunus pseudocerasus) and strain CP17.2.2 from Prunus avium. Only one of these isolates, strain 0, is able to cause crown gall on different plant species. On the basis of 16S rRNA gene sequence similarity, the strains cluster together and belong to the genus Rhizobium and their closest relative is Rhizobium radiobacter (99.1%). Phylogenetic analysis of the novel strains using housekeeping genes atpD, glnA, gyrB, recA and rpoB revealed their distinct position separate from other known Rhizobium species and confirmed their relation to Rhizobium radiobacter. The major cellular fatty acids are 18:1 w7c, 16:0, 16:0 3OH, summed feature 2 (comprising 12:0 aldehyde, 16:1 iso I and/or 14:0 3OH) and summed feature 3 (comprising 16:1 w7c and/or 15 iso 2OH). DNA-DNA hybridization of strain 39/7T with the type strain of R. radiobacter LMG 140T revealed 45% DNA-DNA hybridization. Phenotypic and physiological properties differentiate the novel isolates from other closely related species.On the basis of the results obtained, the five isolates are considered to represent a novel species of the genus Rhizobium, for which the name Rhizobium nepotum sp. nov. (type strain 39/7T=LMG 26435T=CFBP 7436T) is proposed. © 2012 Elsevier GmbH.


Fekete Z.,Albert Ludwigs University of Freiburg | Fekete Z.,Hungarian Academy of Sciences
Sensors and Actuators, B: Chemical | Year: 2015

Abstract Developments in neurotechnology are recently driven by newly national and international brain research initiatives worldwide. The challenging goal of understanding how the human brain works requires a vast amount of information gained by neural sensors. Microelectrodes implanted in the central nervous system are extensively used to record electric activity inside the brain tissue. More recently, deep-brain stimulation in Parkinson disease proved the feasibility of such electrodes in human medical treatments as well. To add novel sensor or even actuator functions to these microelectrodes, limitations of recent fabrication technologies have to be considered. To date, silicon microtechnology offered the highest potential to meet the demands of neural applications regarding multiple functions integrated on a single implantable microsystem. Besides reproducibility and low variability of silicon-based microelectrodes, combination of various functionalities like standard electrophysiology, integrated signal processing, local drug delivery, neurochemical detection and optogenetic stimulation is also possible using these microsystems. This ability makes silicon microelectrodes good candidates to provide high-resolution recording and stimulation in the electric, fluidic, chemical or optical domain in more complex neurophysiological experiments in the future. The aim of this review is to give an overview on various aspects of silicon-based implantable neural microelectrodes and microsystems developed in the last decade. Microfabrication approaches of 2-D and 3-D arrays are summarized. Features of the latest active microelectrodes including CMOS signal processing circuitry are compared. Integration methods of convection enhanced drug delivery functions for local administration of pharmacons are demonstrated. Performance of recent silicon-based chemical sensors for the detection of neurotransmitters is also studied. An analysis on the latest developments in silicon-based optrodes for optogenetic and thermogenetic stimulation is also included in this paper. Microelectrode-tissue interaction is described through the evaluation of recent experimental studies on in vitro and in vivo biocompatibility. © 2015 Elsevier B.V. All rights reserved.


Andric F.,University of Belgrade | Heberger K.,Hungarian Academy of Sciences
Journal of Chromatography A | Year: 2015

Lipophilicity (log. P) represents one of the most studied and most frequently used fundamental physicochemical properties. At present there are several possibilities for its quantitative expression and many of them stems from chromatographic experiments. Numerous attempts have been made to compare different computational methods, chromatographic methods vs. computational approaches, as well as chromatographic methods and direct shake-flask procedure without definite results or these findings are not accepted generally.In the present work numerous chromatographically derived lipophilicity measures in combination with diverse computational methods were ranked and clustered using the novel variable discrimination and ranking approaches based on the sum of ranking differences and the generalized pair correlation method. Available literature logP data measured on HILIC, and classical reversed-phase combining different classes of compounds have been compared with most frequently used multivariate data analysis techniques (principal component and hierarchical cluster analysis) as well as with the conclusions in the original sources. Chromatographic lipophilicity measures obtained under typical reversed-phase conditions outperform the majority of computationally estimated logPs. Oppositely, in the case of HILIC none of the many proposed chromatographic indices overcomes any of the computationally assessed logPs. Only two of them (logkmin and kmin) may be selected as recommended chromatographic lipophilicity measures. Both ranking approaches, sum of ranking differences and generalized pair correlation method, although based on different backgrounds, provides highly similar variable ordering and grouping leading to the same conclusions. © 2015.


Bersanini L.,University of Turku | Battchikova N.,University of Turku | Jokel M.,University of Turku | Rehman A.,Hungarian Academy of Sciences | And 3 more authors.
Plant Physiology | Year: 2014

Oxygenic photosynthesis evolved with cyanobacteria, the ancestors of plant chloroplasts. The highly oxidizing chemistry of water splitting required concomitant evolution of efficient photoprotection mechanisms to safeguard the photosynthetic machinery. The role of flavodiiron proteins (FDPs), originally called A-type flavoproteins or Flvs, in this context has only recently been appreciated. Cyanobacterial FDPs constitute a specific protein group that evolved to protect oxygenic photosynthesis. There are four FDPs in Synechocystis sp. PCC 6803 (Flv1 to Flv4). Two of them, Flv2 and Flv4, are encoded by an operon together with a Sll0218 protein. Their expression, tightly regulated by CO2 levels, is also influenced by changes in light intensity. Here we describe the overexpression of the flv4-2 operon in Synechocystis sp. PCC 6803 and demonstrate that it results in improved photochemistry of PSII. The flv4-2/OE mutant is more resistant to photoinhibition of PSII and exhibits a more oxidized state of the plastoquinone pool and reduced production of singlet oxygen compared with control strains. Results of biophysical measurements indicate that the flv4-2 operon functions in an alternative electron transfer pathway from PSII, and thus alleviates PSII excitation pressure by channeling up to 30% of PSII-originated electrons. Furthermore, intact phycobilisomes are required for stable expression of the flv4-2 operon genes and for the Flv2/Flv4 heterodimer-mediated electron transfer mechanism. The latter operates in photoprotection in a complementary way with the orange carotenoid protein-related nonphotochemical quenching. Expression of the flv4-2 operon and exchange of the D1 forms in PSII centers upon light stress, on the contrary, are mutually exclusive photoprotection strategies among cyanobacteria. © 2014 American Society of Plant Biologists. All rights reserved.


Teglas E.,Central European University | Teglas E.,Hungarian Academy of Sciences | Gergely A.,Eötvös Loránd University | Kupan K.,Hungarian Academy of Sciences | And 2 more authors.
Current Biology | Year: 2012

Recent evidence suggests that preverbal infants' gaze following can be triggered only if an actor's head turn is preceded by the expression of communicative intent [1]. Such connectedness between ostensive and referential signals may be uniquely human, enabling infants to effectively respond to referential communication directed to them. In the light of increasing evidence of dogs' social communicative skills [2], an intriguing question is whether dogs' responsiveness to human directional gestures [3] is associated with the situational context in an infant-like manner. Borrowing a method used in infant studies [1], dogs watched video presentations of a human actor turning toward one of two objects, and their eye-gaze patterns were recorded with an eye tracker. Results show a higher tendency of gaze following in dogs when the human's head turning was preceded by the expression of communicative intent (direct gaze, addressing). This is the first evidence to show that (1) eye-tracking techniques can be used for studying dogs' social skills and (2) the exploitation of human gaze cues depends on the communicatively relevant pattern of ostensive and referential signals in dogs. Our findings give further support to the existence of a functionally infant-analog social competence in this species. © 2012 Elsevier Ltd All rights reserved.


Kiss J.,Agricultural Biotechnology Center | Nagy B.,Hungarian Academy of Sciences | Olasz F.,Agricultural Biotechnology Center
PLoS ONE | Year: 2012

Background: The Salmonella genomic island 1 (SGI1) is a 42.4 kb integrative mobilizable element containing several antibiotic resistance determinants embedded in a complex integron segment In104. The numerous SGI1 variants identified so far, differ mainly in this segment and the explanations of their emergence were mostly based on comparative structure analyses. Here we provide experimental studies on the stability, entrapment and variant formation of this peculiar gene cluster originally found in S. Typhimurium. Methodology/Principal Findings: Segregation and conjugation tests and various molecular techniques were used to detect the emerging SGI1 variants in Salmonella populations of 17 Salmonella enterica serovar Typhimurium DT104 isolates from Hungary. The SGI1s in these isolates proved to be fully competent in excision, conjugal transfer by the IncA/C helper plasmid R55, and integration into the E. coli chromosome. A trap vector has been constructed and successfully applied to capture the island on a plasmid. Monitoring of segregation of SGI1 indicated high stability of the island. SGI1-free segregants did not accumulate during long-term propagation, but several SGI1 variants could be obtained. Most of them appeared to be identical to SGI1-B and SGI1-C, but two new variants caused by deletions via a short-homology-dependent recombination process have also been detected. We have also noticed that the presence of the conjugation helper plasmid increased the formation of these deletion variants considerably. Conclusions/Significance: Despite that excision of SGI1 from the chromosome was proven in SGI1 + Salmonella populations, its complete loss could not be observed. On the other hand, we demonstrated that several variants, among them two newly identified ones, arose with detectable frequencies in these populations in a short timescale and their formation was promoted by the helper plasmid. This reflects that IncA/C helper plasmids are not only involved in the horizontal spreading of SGI1, but may also contribute to its evolution. © 2012 Kiss et al.


Czigany Z.,Hungarian Academy of Sciences | Hultman L.,Linköping University
Ultramicroscopy | Year: 2010

The short range order in amorphous and fullerene-like carbon compounds has been characterized by selected area electron diffraction (SAED) patterns and compared with simulations of model nanoclusters. Broad rings in SAED pattern from fullerene-like CNx at ~1.2, ~2, and ~3.5Å indicate short-range order similar to that in graphite, but peak shifts indicate sheet curvature in agreement with high-resolution transmission electron microscopy images. Fullerene-like CPx exhibits rings at ~1.6 and 2.6Å, which can be explained if it consists of fragments with short-range order and high curvature similar to that of C20. © 2010 Elsevier B.V.


Murg V.,University of Vienna | Verstraete F.,University of Vienna | Legeza O.,University of Marburg | Legeza O.,Hungarian Academy of Sciences | Noack R.M.,University of Marburg
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

We present a tree-tensor-network-based method to study strongly correlated systems with nonlocal interactions in higher dimensions. Although the momentum-space and quantum-chemistry versions of the density-matrix renormalization group (DMRG) method have long been applied to such systems, the spatial topology of DMRG-based methods allows efficient optimizations to be carried out with respect to one spatial dimension only. Extending the matrix-product-state picture, we formulate a more general approach by allowing the local sites to be coupled to more than two neighboring auxiliary subspaces. Following, we treat a treelike network ansatz with arbitrary coordination number z, where the z=2 case corresponds to the one-dimensional (1D) scheme. For this ansatz, the long-range correlation deviates from the mean-field value polynomially with distance, in contrast to the matrix-product ansatz, which deviates exponentially. The computational cost of the tree-tensor-network method is significantly smaller than that of previous DMRG-based attempts, which renormalize several blocks into a single block. In addition, we investigate the effect of unitary transformations on the local basis states and present a method for optimizing such transformations. For the 1D interacting spinless fermion model, the optimized transformation interpolates smoothly between real space and momentum space. Calculations carried out on small quantum chemical systems support our approach. © 2010 The American Physical Society.


Hornok C.,Hungarian Academy of Sciences | Koren M.,Central European University
Review of Economics and Statistics | Year: 2015

Using detailed U.S. and Spanish export data, we document that trade costs of a per-shipment nature are associated with less frequent and larger shipments (i.e., more lumpiness) in international trade. This finding is pervasive across broad product categories, but most apparent for industrial supplies, parts and accessories, and food products. © 2015 by the President and Fellows of Harvard College and the Massachusetts Institute of Technology.


Grant
Agency: European Commission | Branch: FP7 | Program: CP | Phase: ICT-2011.5.5 | Award Amount: 3.33M | Year: 2012

The objective of the LITERACY project is to create an advanced online portal, which will aid both dyslexic youths and adults. The Portal will provide personalized e-learning programs, useful tools and methods for helping people with dyslexia to improve their abilities in reading, writing and then function in society. The Portal will also provide entry to an accessible online community of peers. Employing novel modelling algorithms the system will assess the users level of literacy and particular strengths/weaknesses in learning. It will on this basis automatically adjust to provide the required personalized services for that specific user. A specialized interface and Community Zone with programs and services will improve users skills, drastically simplifying otherwise complicated tasks. This will be done by utilizing advanced novel tools which will be integrated with both existing and adapted ICT tools and hardware. Dyslexic users will be able to access this portal independently and receive real-time feedback on their progress. The Portal will be based on input of content by educational professionals in both EU and Associate countries, providing an array of levels and in several languages.\nThe Portal will empower and support dyslexic youth and adults to help themselves succeed in literacy related achievements, ultimately strengthening their success and inclusion in school, university, work and their social lives.


Kovacs A.M.,Hungarian Academy of Sciences | Kovacs A.M.,Central European University | Kovacs A.M.,International School for Advanced Studies | Teglas E.,Hungarian Academy of Sciences | And 4 more authors.
Science | Year: 2010

Human social interactions crucially depend on the ability to represent other agents' beliefs even when these contradict our own beliefs, leading to the potentially complex problem of simultaneously holding two conflicting representations in mind. Here, we show that adults and 7-month-olds automatically encode others' beliefs, and that, surprisingly, others' beliefs have similar effects as the participants' own beliefs. In a visual object detection task, participants' beliefs and the beliefs of an agent (whose beliefs were irrelevant to performing the task) both modulated adults' reaction times and infants' looking times. Moreover, the agent's beliefs influenced participants' behavior even after the agent had left the scene, suggesting that participants computed the agent's beliefs online and sustained them, possibly for future predictions about the agent's behavior. Hence, the mere presence of an agent automatically triggers powerful processes of belief computation that may be part of a "social sense" crucial to human societies.


Kurucz Z.,University of Aarhus | Kurucz Z.,Hungarian Academy of Sciences | Molmer K.,University of Aarhus
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

We show that an ensemble of identical d-level atoms can be efficiently described by d-1 collective oscillator degrees of freedom in the vicinity of a product state with all atoms in the same, but otherwise arbitrary single-particle state. We apply our description to two different kinds of spin squeezing: (i) when each spin-F atom is individually squeezed without creating interatomic entanglement and (ii) when a particular collective atomic oscillator mode is squeezed via quantum nondemolition (QND) measurement and feedback. When combined in sequence, the order of the two methods is relevant in the final degree of squeezing. We also discuss the role of the two kinds of squeezing when multisublevel atoms are used as quantum memories for light. © 2010 The American Physical Society.


Grant
Agency: European Commission | Branch: FP7 | Program: MC-ITN | Phase: FP7-PEOPLE-ITN-2008 | Award Amount: 3.25M | Year: 2009

Any material in contact with water or moisture during its life-cycle is rapidly colonised by microbial species which can be the source of severe deterioration processes, such as microbially influenced corrosion (MIC), also called biocorrosion. The annual direct and derived costs of corrosion are estimated to be around 4% of the GNP of developed countries, of which 10-20% are related to biocorrosion. Today the main treatment against biocorrosion is the massive application of biocides that lead to significant environmental pollution. Currently, European research teams are concentrating efforts on biocorrosion, but there is a lack of harmonisation and collaboration due to the differences of approaches, analytical methodologies and disciplines involved, from chemistry through materials to biology. The objectives of BIOCOR are: 1) to develop a new profile of researcher, capable to address and manage all aspects of scientific and/or industrial problems related to MIC and 2) to provide the European industries with alternative multidisciplinary expertise in this area. The problem-oriented approach developed in the project is essential when dealing with such a complex topic as MIC. This pioneer training programme will open the road to new generations of research project managers capable to lead groups of experts from different disciplines and countries. Such results will ultimately lead to increase the competitiveness of the European scientific and industrial communities. The objectives will be achieved by: 1) linking up 10 research teams and 4 associated partners from 9 different countries during 4 years, from both scientific and industrial sectors, and 2) by implementing a new research methodology based on multidisciplinary and combined analytical approaches, and a close intersectorial arrow From the field through the lab to the field. The project will offer an overall effort of 488 person-months of which 81% will be dedicated to ESRs.


Grant
Agency: European Commission | Branch: FP7 | Program: CSA-CA | Phase: NMP-2007-2.1-3 | Award Amount: 717.21K | Year: 2008

Our project aims to gather, improve, catalogue and present characterisation techniques, methods and equipment for nanomechanical testing. European-wide activities coordinated by a new virtual centre will improve existing nanoindentation metrology to reveal structure-properties relationship at the nano-scale. These methods are the only tools to characterise nanocomposite, nanolayer and interface mechanical behaviours in the nanometre range. This work will also lay down a solid base for subsequent efforts for defining and preparing new standards to support measurement technology in the field of nanomaterials characterisation. Steps include development of the classical and the dynamic nanoindentation method and its application to new fields, application of modified nano-indenters to new fields as scratching and wear measurement, firm and uniform determination of instrumental parameters and defining new standard samples for the new applications. The virtual centre will disseminate information based on a new Nanocharacterisation database built on two definite levels: on a broader level partners will inventory and process all novel nanocharacterisation techniques and, in narrower terms, they will concentrate on nanomechanical characterisation. This will be achieved through the synchronisation of efforts set around a core of round robins but the database will include data of other channels as parallel research work and literature recherch. Core activities comprise detailed dissemination activities. Indirect connections to the stakeholders by a webpage with a build-in interactive database will be complemented by direct events such as participation in workshops (oral and poster presentations), and regular technical reports in international journals. Activities above will lead to detailed descriptions of novel characterisation techniques. The development and definition of new standards and good practices will support design of intrinsically safe nanomaterials for wide industrial applications.


Grant
Agency: European Commission | Branch: FP7 | Program: CP | Phase: ICT-2009.3.8 | Award Amount: 3.63M | Year: 2010

The detection of chemical or biological substances increasingly appears as an essential concern in order to prevent human or animal health and security related problems. Present analytical techniques are expensive and often require highly specialized staff and infrastructures. The principal need is to perform screening tests, which can be carried out in non-specialized infrastructures, e.g. Point of Care, schools and field, before unambiguous identification in a specialized laboratory. There is thus a need to develop a new detection system that has low-cost and is portable but at the same time offers high sensitivity, selectivity and multi-analyte detection from a sample containing various components (e.g. blood, serum, saliva, etc.).\n\nThe objective of P3SENS is to design, fabricate and validate a multichannel (50 or more) polymer photonic crystal based label-free disposable biosensor allowing for a positive/negative detection scheme of ultra small concentrations of analytes in solution (< 1 ng/mL). The biosensor will be encapsulated in a specifically designed microfluidic system in order to deliver the sample to the multiple sensing zones. The design of the biochip will allow it to be easily inserted in a compact measurement platform, usable by non-specialized practitioners outside of specialized laboratories for carrying simultaneous multi-analyte detection, delivering real-time monitoring, and with an assay duration that will not exceed a few tens of minutes.\n\nThe photonic chip proposed in this project will be based on polymer Photonic Crystal (PhC) micro-cavities coupled into a planar waveguide optical distribution circuit. The photonic chip will be fabricated with available fabrication technologies - and with an emphasis on low cost substrates (polymer) and fabrication processes (nano-imprint lithography). More generally, P3SENS will push forward the development of low cost disposable biochips based on photonics.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: HEALTH.2013.1.3-2 | Award Amount: 7.20M | Year: 2013

Europe is confronted by a demographic challenge as a decreasing work force has to support an increasing elderly population. The economic risk implied by this burden could be addressed by efforts to achieve an increase in Healthy Life Years. One key element would be to ensure unrestricted mobility for especially the elderly, allowing them to stay at work for longer. Irreversible joint deterioration often requires a joint replacement. Implantation of artificial joints is one of the most successful orthopaedic interventions. However, an increasing number of patients receive revision surgery with these 10 % of these contract an infection and 50 % develop an adverse immune reaction (AIR) to conventional implant material. At the moment the reasons for the development of AIR are inadequately understood. Our proposal contains innovative solutions concerning this problem. A predictive approach using biomarkers will identify patients with risk to develop AIR. These patients will receive hypoallergenic endoprostheses, avoiding AIR to conventional material. Novel hypoallergenic material combinations will be developed in the frame of this consortium by material scientists and implant manufacturer. Via immunological, microbiological and biocompatibility testing the development and production process will be improved constantly. The matching of implant material with the allergenic background of patients will avoid complicated and cost-intensive reverse reactions and is a step towards personalised medicine. A further approach is to achieve a better understanding of mechanisms of AIR, and its faster and easier diagnosis using sensitive diagnostic biomarkers for an accurate differentiation from low-grade infection. Additionally, mathematical modelling of results from different methods will show us the gene regulatory network that leads to an amplification of the adverse immune response triggered by prosthetic implants and will develop predictive models of AIR process.


Nagy D.,Hungarian Academy of Sciences | Konya G.,Hungarian Academy of Sciences | Szirmai G.,Hungarian Academy of Sciences | Szirmai G.,ICFO - Institute of Photonic Sciences | Domokos P.,Hungarian Academy of Sciences
Physical Review Letters | Year: 2010

We show that the motion of a laser-driven Bose-Einstein condensate in a high-finesse optical cavity realizes the spin-boson Dicke model. The quantum phase transition of the Dicke model from the normal to the superradiant phase corresponds to the self-organization of atoms from the homogeneous into a periodically patterned distribution above a critical driving strength. The fragility of the ground state due to photon measurement induced backaction is calculated. © 2010 The American Physical Society.


Adam-Vizi V.,Hungarian Academy of Sciences | Starkov A.A.,Cornell University
Journal of Alzheimer's Disease | Year: 2010

A number of recent discoveries indicate that abnormal Ca2+ signaling, oxidative stress, and mitochondrial dysfunction are involved in the neuronal damage in Alzheimer's disease. However, the literature on the interactions between these factors is controversial especially in the interpretation of the cause-effect relationship between mitochondrial damage induced by Ca2+ overload and the production of reactive oxygen species (ROS). In this review, we survey the experimental observations on the Ca2+-induced mitochondrial ROS production, explain the sources of controversy in interpreting these results, and discuss the different molecular mechanisms underlying the effect of Ca2+ on the ROS emission by brain mitochondria. © 2010 IOS Press and the authors. All rights reserved.


Stefanics G.,ETH Zurich | Stefanics G.,University of Zürich | Kremlacek J.,Charles University | Czigler I.,Hungarian Academy of Sciences
Frontiers in Human Neuroscience | Year: 2014

An increasing number of studies investigate the visual mismatch negativity (vMMN) or use the vMMN as a tool to probe various aspects of human cognition. This paper reviews the theoretical underpinnings of vMMN in the light of methodological considerations and provides recommendations for measuring and interpreting the vMMN. The following key issues are discussed from the experimentalist's point of view in a predictive coding framework: (1) experimental protocols and procedures to control “refractoriness” effects; (2) methods to control attention; (3) vMMN and veridical perception. © 2014 Stefanics, Kremláček and Czigler.


Navascues M.,University of Bristol | de la Torre G.,ICFO - Institute of Photonic Sciences | Vertesi T.,Hungarian Academy of Sciences
Physical Review X | Year: 2014

The future progress of semi-device-independent quantum information science depends crucially on our ability to bound the strength of the nonlocal correlations achievable with finite-dimensional quantum resources. In this work, we characterize quantum nonlocality under local dimension constraints via a complete hierarchy of semidefinite programming relaxations. In the bipartite case, we find that the first level of the hierarchy returns nontrivial bounds in all cases considered, allowing us to study nonlocality scenarios with four measurement settings on one side and twelve on the other in a normal desktop. In the tripartite case, we apply the hierarchy to derive a Bell-type inequality that can only be violated when each of the three parties has local dimension greater than 2, hence certifying three-dimensional tripartite entanglement in a device-independent way. Finally, we show how the new method can be trivially modified to detect nonseparable measurements in two-qubit scenarios.


Lachenmaier S.M.,Charité - Medical University of Berlin | Deli M.A.,Hungarian Academy of Sciences | Meissner M.,University of Heidelberg | Liesenfeld O.,Charité - Medical University of Berlin
Journal of Neuroimmunology | Year: 2011

Toxoplasma gondii establishes latent infection in the central nervous system of immunocompentent hosts. Toxoplasmic encephalitis is a life threatening reactivation of latent infection in the brain of immunocompromised patients. To further understand the mechanisms of entry into the brain of T. gondii we investigated host molecules and cells involved in the passage of the parasite through the blood-brain barrier. First, using microarrays brain endothelial cells were found to upregulate, among others, chemokines and adhesion molecules following infection with tachyzoites. Using flow cytometry we observed upregulated ICAM-1 expression on the surface of brain endothelial cells following infection; ICAM-1 expression was further increased after pre-incubation with IFN-γ. Compared to RH tachyzoites, ME49 tachyzoites induced a stronger upregulation of ICAM-1 and an earlier and stronger IL-6 and MCP-1 secretion by brain endothelial cells. Using an in vitro coculture model of the BBB (primary glia cells and brain endothelial cells) we found a stronger migration of infected antigen-presenting cells compared to lymphocytes (4.63% vs. 0.6% of all cells) across the BBB. Among all antigen-presenting cells CD11b+/CD11c+ cells showed the highest infection rate, whereas the majority of infected cells that migrated through the blood-brain barrier were CD11b+/CD11c- cells. Infection of PBMCs with type I or type II Toxoplasma strains resulted in similar patterns of cell migration across the in vitro BBB model.In conclusion, these results suggest that T. gondii modulates gene expression of brain endothelial cells to promote its own migration through the blood-brain barrier in a 'Trojan horse' manner. Cells expressing CD11b either with or without CD11c are likely candidate cells for the intracellular transport of T. gondii across the BBB. T. gondii type I and type II strains induced similar migration patterns of antigen-presenting cells across the in vitro BBB. © 2010 Elsevier B.V.


Kirchner T.,York University | Khazai N.,York University | Gulyas L.,Hungarian Academy of Sciences
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2014

We study excitation and ionization in the 1.5-MeV/amu O8+Li collision system, which was the subject of a recent reaction-microscope-type experiment [D. Fischer, Phys. Rev. Lett. 109, 113202 (2012)PRLTAO0031-900710.1103/ PhysRevLett.109.113202]. Starting from an independent-electron model based on determinantal wave functions and using a single-electron basis generator method calculation and a single-electron continuum distorted-wave with eikonal initial-state calculation, we show that pure single ionization of a lithium K-shell electron is too weak a process to explain the measured electron-energy-differential cross section. Rather, our analysis suggests that two-electron excitation-ionization processes occur and have to be taken into account when comparing with the data. Good agreement is obtained only if we replace the independent-electron calculation by an independent-event model for one of the excitation-ionization processes and also take a shake-off process into account. © 2014 American Physical Society.


Gali A.,Budapest University of Technology and Economics | Gali A.,Hungarian Academy of Sciences | Simon T.,Budapest University of Technology and Economics | Lowther J.E.,University of Witwatersrand
New Journal of Physics | Year: 2011

The negatively charged nitrogen-vacancy (NV) defect (NV center) in diamond is a leading candidate to realize solid-state qubits and ultrasensitive magnetometers in ambient conditions. A new interpretation of some of the properties of the center is presented. We show that the double peak in the absorption phonon sidebands may correspond to the local a1 and e vibration modes of the defect that have very similar energies, and that tunneling of nitrogen atoms in the vacancy does not occur as had been previously suggested. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.


Miklos I.,Renyi Institute | Miklos I.,Hungarian Academy of Sciences | Tannier E.,French Institute for Research in Computer Science and Automation
Bioinformatics | Year: 2010

Motivation: When comparing the organization of two genomes, it is important not to draw conclusions on their modes of evolution from a single most parsimonious scenario explaining their differences. Better estimations can be obtained by sampling many different genomic rearrangement scenarios. For this problem, the Double Cut and Join (DCJ) model, while less relevant, is computationally easier than the Hannenhalli-Pevzner (HP) model. Indeed, in some special cases, the total number of DCJ sorting scenarios can be analytically calculated, and uniformly distributed random DCJ scenarios can be drawn in polynomial running time, while the complexity of counting the number of HP scenarios and sampling from the uniform distribution of their space is unknown, and conjectured to be #P-complete. Statistical methods, like Markov chain Monte Carlo (MCMC) for sampling from the uniform distribution of the most parsimonious or the Bayesian distribution of all possible HP scenarios are required. Results: We use the computational facilities of the DCJ model to draw a sampling of HP scenarios. It is based on a parallel MCMC method that cools down DCJ scenarios to HP scenarios. We introduce two theorems underlying the theoretical mixing properties of this parallel MCMC method. The method was tested on yeast and mammalian genomic data, and allowed us to provide estimates of the different modes of evolution in diverse lineages. © The Author 2010. Published by Oxford University Press. All rights reserved.


Navascues M.,Bilkent University | Vertesi T.,Hungarian Academy of Sciences | Vertesi T.,University of Geneva
Physical Review Letters | Year: 2015

We describe a simple method to derive high performance semidefinite programing relaxations for optimizations over complex and real operator algebras in finite dimensional Hilbert spaces. The method is very flexible, easy to program, and allows the user to assess the behavior of finite dimensional quantum systems in a number of interesting setups. We use this method to bound the strength of quantum nonlocality in Bell scenarios where the dimension of the parties is bounded from above. We derive new results in quantum communication complexity and prove the soundness of the prepare-and-measure dimension witnesses introduced in Gallego et al., Phys. Rev. Lett. 105, 230501 (2010). Finally, we propose a new dimension witness that can distinguish between classical, real, and complex two-level systems. © 2015 American Physical Society. © 2015 American Physical Society.


Miklos I.,Renyi Institute | Zadori Z.,Hungarian Academy of Sciences
PLoS Computational Biology | Year: 2012

HD amino acid duplex has been found in the active center of many different enzymes. The dyad plays remarkably different roles in their catalytic processes that usually involve metal coordination. An HD motif is positioned directly on the amyloid beta fragment (Aβ) and on the carboxy-terminal region of the extracellular domain (CAED) of the human amyloid precursor protein (APP) and a taxonomically well defined group of APP orthologues (APPOs). In human Aβ HD is part of a presumed, RGD-like integrin-binding motif RHD; however, neither RHD nor RXD demonstrates reasonable conservation in APPOs. The sequences of CAEDs and the position of the HD are not particularly conserved either, yet we show with a novel statistical method using evolutionary modeling that the presence of HD on CAEDs cannot be the result of neutral evolutionary forces (p&0.0001). The motif is positively selected along the evolutionary process in the majority of APPOs, despite the fact that HD motif is underrepresented in the proteomes of all species of the animal kingdom. Position migration can be explained by high probability occurrence of multiple copies of HD on intermediate sequences, from which only one is kept by selective evolutionary forces, in a similar way as in the case of the "transcription binding site turnover." CAED of all APP orthologues and homologues are predicted to bind metal ions including Amyloid-like protein 1 (APLP1) and Amyloid-like protein 2 (APLP2). Our results suggest that HDs on the CAEDs are most probably key components of metal-binding domains, which facilitate and/or regulate inter- or intra-molecular interactions in a metal ion-dependent or metal ion concentration-dependent manner. The involvement of naturally occurring mutations of HD (Tottori (D7N) and English (H6R) mutations) in early onset Alzheimer's disease gives additional support to our finding that HD has an evolutionary preserved function on APPOs. © 2012 Miklós, Zadori.


Szirmai G.,Hungarian Academy of Sciences | Szirmai G.,ICFO - Institute of Photonic Sciences | Nagy D.,Hungarian Academy of Sciences | Domokos P.,Hungarian Academy of Sciences
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

A Bose-Einstein condensate of ultracold atoms inside the field of a laser-driven optical cavity exhibits dispersive optical bistability. We describe this system by using mean-field approximation and by analyzing the correlation functions of the linearized quantum fluctuations around the mean-field solution. The entanglement and the statistics of the atom-field quadratures are given in the stationary state. It is shown that the mean-field solution, that is, the Bose-Einstein condensate, is robust against entanglement generation for most of the phase diagram. © 2010 The American Physical Society.


Habchi J.,Aix - Marseille University | Habchi J.,CNRS Architecture and Functions of Biological Macromolecules Lab | Tompa P.,Vrije Universiteit Brussel | Tompa P.,Hungarian Academy of Sciences | And 4 more authors.
Chemical Reviews | Year: 2014

Proteins are the major component of the living cell. They play crucial roles in the maintenance of life, and their dysfunctions are known to cause different pathologies. Simple amino acid propensities reflect some basic physical or sequence features. Such propensity-based predictors rely on simple statistics of amino acid propensity, on the physical/chemical features of amino acids, or on a preliminary concept on the physical background of disorder. Regions of missing electron density in the PDB are generally short, as long regions prevent crystallization. As such, short disorder is overrepresented in the database of disordered regions, and hence these predictors tend to perform better in predicting short disorder than long disorder. Predictors can also be classified based on the binary nature of the prediction. Examples of binary predictors are the CH plot and the cumulative distribution function (CDF) analysis.


Gulyas L.,Hungarian Academy of Sciences | Igarashi A.,University of Miyazaki | Kirchner T.,York University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

Double and transfer ionization processes are theoretically investigated for collisions of He atoms with bare energetic projectile ions. Two-electron transition amplitudes are described by linear combinations of products of one-electron transition amplitudes, which enables one to incorporate the effects of electron correlation in the asymptotic channels. A collision mechanism in which the projectile interacts separately with both electrons gives a realistic account of the processes only at medium impact energies, while the final state correlation and the shake-off mechanism together with correlations in the initial state are found to be important for the lower and higher collision energies, respectively. © 2012 American Physical Society.


Temleitner L.,Hungarian Academy of Sciences | Temleitner L.,Japan Synchrotron Radiation Research Institute | Pusztai L.,Hungarian Academy of Sciences
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

The liquid, plastic crystalline and ordered crystalline phases of CBr4 were studied using neutron-powder diffraction. The measured total scattering differential cross sections were modeled by reverse Monte Carlo simulation techniques (RMC++ and RMCPOW). Following successful simulations, the single-crystal-diffraction pattern of the plastic phase as well as partial radial distribution functions and orientational correlations for all the three phases have been calculated from the atomic coordinates (particle configurations). The single-crystal pattern, calculated from a configuration that had been obtained from modeling the powder pattern, shows identical behavior to the recent single-crystal data of Folmer [Phys. Rev. B 77, 144205 (2008)]. The BrBr partial radial-distribution functions of the liquid and plastic crystalline phases are almost the same while CC correlations clearly display long-range ordering in the latter phase. Orientational correlations also suggest strong similarities between liquid and plastic crystalline phases whereas the monoclinic phase behaves very differently. Orientations of the molecules are distinct in the ordered phase whereas in the plastic crystal their distribution seems to be isotropic. © 2010 The American Physical Society.


Krakovsky I.,Charles University | Szekely N.K.,Hungarian Academy of Sciences
European Polymer Journal | Year: 2011

Distribution of water in stoichiometric hydrophilic epoxy network swollen in heavy water to different degrees (epoxy-based hydrogels) at 25 °C has been investigated by small-angle neutron scattering (SANS) and differential scanning calorimetry (DSC). Nanophase separated structure of the hydrogels consisting of water-rich and water-poor domains was revealed by SANS. Two regimes for hydrogel structure were found: (a) at low water content hydrogel consists of isolated water-rich domains dispersed in continuous water-poor phase and (b) at high water content the water-rich domains form another continuous phase. Isosbestic point of scattering curves was found by SANS in the latter region and attributed to conservation of Porod's length of the nanophase separated structure. Thermal properties of the system are qualitatively different in the two regions: in the former one the glass transition temperature decreases with growing water content while in the latter one it remains constant. Percolation threshold separating both regimes is reflected in a jump of glass transition temperature and inversion of the dependence of the specific heat difference at glass transition. © 2011 Elsevier Ltd. All rights reserved.


Grant
Agency: European Commission | Branch: FP7 | Program: MC-ERG | Phase: PEOPLE-2007-2-2.ERG | Award Amount: 45.00K | Year: 2008

In case of successful evaluation of the present application Robert Horvath plans to join to the Research Institute of Technical Physics and Materials Science (MFA) and can return work in his home country, continuing the momentum built up by 7 years of very fruitful research abroad. At the host institute a long term strategic plan is to build up a strong research direction in the field of bio- and chemical sensing and conduct basic and applied research in these fields. The applicant could strengthen this research direction with his relevant experiences in the field of optical waveguide based biosensors and their applications. Particularly, the present project aims to develop novel optical waveguide based sensors capable of supporting more detailed information about the structure of thin films or living cells with increased sensitivity in a label-free manner. This is achieved by designing and fabricating novel waveguide configurations supporting several modes and using different excitation wavelengths. Especially, novel Si and metal-oxide processing technology available at the host institute will be explored and combined with the applicants experience in soft lithography. The fabricated sensors will be applied to test and develop a novel sensor matrix based on functionalized protein assemblies for detecting small analytes and living cells. Theoretical modelling of these resonator structures and their sensing capabilities will be an important part of the research.


Grant
Agency: European Commission | Branch: FP7 | Program: MC-ITN | Phase: FP7-PEOPLE-ITN-2008 | Award Amount: 2.63M | Year: 2010

The Initial Training Network Integrated Training Programme for Analysis, Assessment and Advice on EUs External Action and its Institutional Architecture (EXACT) aims at preparing 12 Early Stage Researchers (ESR) for professional and academic careers in universities as well as in the public and private sector in academically based consulting for policy makers. The training network focuses its research on major current and future challenges of the EU in the fields of Commercial Policy, Common Foreign and Security Policy, Common European Defence Policy and Development Cooperation (e.g. EU crisis management in Georgia). The training provided through EXACT intends to bridge the gap between Ph.D. training within the academic world on the one hand and the down-to-earth need of potential employers in consulting or advisory circles on the other. Therefore, the project pursues an integrated two track curriculum that involves three universities and six think tanks: The scientific track concentrates on academic training leading to a Ph.D. degree, track II focuses on the training of professional skills. Given the growing market for academically trained EU experts in both public and private sectors, the integrated curriculum develops a triple A catalogue of skills: theory-led Analysis and Assessment of potential future scenarios in the field of EUs external action and Advice for strategies. The early stage researchers will attend a 36 month training programme including local and network-wide activities (e.g. individual research projects and Network Seminars) provided by universities and think tanks in the network. The early stage researchers will be given the opportunity to obtain a double PhD degree (co-tutelle) from two participating universities as well as the EXACT Certificate issued by all participating organisations.


Grant
Agency: European Commission | Branch: FP7 | Program: MC-ITN | Phase: FP7-PEOPLE-2010-ITN | Award Amount: 3.25M | Year: 2010

Life Sciences and Nano Sciences interact today mainly in two areas: in the evaluation of accidental health and environmental effects derived from engineered nanomaterials, and in development and biological/clinical evaluation of nanoparticles with intended biological effects for application in medicine and biotechnology. It is essential for producers, distributors, consumers and regulators that the safety of products containing nanomaterials can be certified with reliable, validated assays. Research efforts are under way to establish suitable test methods and to understand mechanisms potentially leading to a detrimental impact of nanomaterials on human health and on the environment. However, this important field still urgently lacks sufficient trained personnel. The ITN Nanotechnology: Training Of Experts in Safety (NanoTOES) will establish a network of research projects working towards the refinement and standardisation of existing methods, will develop novel assays, and will during this process provide interdisciplinary training to Early Stage Researchers (ESR) and Experienced Researchers (ER) working at the intersection of biosciences and nanosciences. A suite of methods developed and validated in the NanoTOES project shall have utility in characterising the biological effects of nanomaterials, including their impact on the environment, and will add significantly to our understanding of the biological actions of nanomaterials and their resultant effects on human health and the environment. Equally, the influence of biological entities (molecules, cells, tissues) on the properties of nanomaterials will be investigated. This aspect is crucial to understanding the properties of nanomaterials in organisms and in the environment, but nevertheless this issue has been so far not sufficiently explored. These timely and novel studies will address the pressing need for such trained personnel, and enable European science in this area to remain globally competitive.


News Article | November 3, 2016
Site: www.scientificcomputing.com

In the search for the mysterious dark matter, physicists have used elaborate computer calculations to come up with an outline of the particles of this unknown form of matter. To do this, the scientists extended the successful Standard Model of particle physics which allowed them, among other things, to predict the mass of so-called axions, promising candidates for dark matter. The German-Hungarian team of researchers led by Professor Zoltán Fodor of the University of Wuppertal, Eötvös University in Budapest and Forschungszentrum Jülich carried out its calculations on Jülich's supercomputer JUQUEEN (BlueGene/Q) and presents its results in the journal Nature. "Dark matter is an invisible form of matter which until now has only revealed itself through its gravitational effects. What it consists of remains a complete mystery," explains co-author Dr Andreas Ringwald, who is based at DESY and who proposed the current research. Evidence for the existence of this form of matter comes, among other things, from the astrophysical observation of galaxies, which rotate far too rapidly to be held together only by the gravitational pull of the visible matter. High-precision measurements using the European satellite "Planck" show that almost 85 percent of the entire mass of the universe consists of dark matter. All the stars, planets, nebulae and other objects in space that are made of conventional matter account for no more than 15 percent of the mass of the universe. "The adjective 'dark' does not simply mean that it does not emit visible light," says Ringwald. "It does not appear to give off any other wavelengths either - its interaction with photons must be very weak indeed." For decades, physicists have been searching for particles of this new type of matter. What is clear is that these particles must lie beyond the Standard Model of particle physics, and while that model is extremely successful, it currently only describes the conventional 15 percent of all matter in the cosmos. From theoretically possible extensions to the Standard Model physicists not only expect a deeper understanding of the universe, but also concrete clues in what energy range it is particularly worthwhile looking for dark-matter candidates. The unknown form of matter can either consist of comparatively few, but very heavy particles, or of a large number of light ones. The direct searches for heavy dark-matter candidates using large detectors in underground laboratories and the indirect search for them using large particle accelerators are still going on, but have not turned up any dark matter particles so far. A range of physical considerations make extremely light particles, dubbed axions, very promising candidates. Using clever experimental setups, it might even be possible to detect direct evidence of them. "However, to find this kind of evidence it would be extremely helpful to know what kind of mass we are looking for," emphasises theoretical physicist Ringwald. "Otherwise the search could take decades, because one would have to scan far too large a range." The existence of axions is predicted by an extension to quantum chromodynamics (QCD), the quantum theory that governs the strong interaction, responsible for the nuclear force. The strong interaction is one of the four fundamental forces of nature alongside gravitation, electromagnetism and the weak nuclear force, which is responsible for radioactivity. "Theoretical considerations indicate that there are so-called topological quantum fluctuations in quantum chromodynamics, which ought to result in an observable violation of time reversal symmetry," explains Ringwald. This means that certain processes should differ depending on whether they are running forwards or backwards. However, no experiment has so far managed to demonstrate this effect. The extension to quantum chromodynamics (QCD) restores the invariance of time reversals, but at the same time it predicts the existence of a very weakly interacting particle, the axion, whose properties, in particular its mass, depend on the strength of the topological quantum fluctuations. However, it takes modern supercomputers like Jülich's JUQUEEN to calculate the latter in the temperature range that is relevant in predicting the relative contribution of axions to the matter making up the universe. "On top of this, we had to develop new methods of analysis in order to achieve the required temperature range," notes Fodor who led the research. The results show, among other things, that if axions do make up the bulk of dark matter, they should have a mass of 50 to 1500 micro-electronvolts, expressed in the customary units of particle physics, and thus be up to ten billion times lighter than electrons. This would require every cubic centimetre of the universe to contain on average ten million such ultra-lightweight particles. Dark matter is not spread out evenly in the universe, however, but forms clumps and branches of a weblike network. Because of this, our local region of the Milky Way should contain about one trillion axions per cubic centimetre. Thanks to the Jülich supercomputer, the calculations now provide physicists with a concrete range in which their search for axions is likely to be most promising. "The results we are presenting will probably lead to a race to discover these particles," says Fodor. Their discovery would not only solve the problem of dark matter in the universe, but at the same time answer the question why the strong interaction is so surprisingly symmetrical with respect to time reversal. The scientists expect that it will be possible within the next few years to either confirm or rule out the existence of axions experimentally. The Institute for Nuclear Research of the Hungarian Academy of Sciences in Debrecen, the Lendület Lattice Gauge Theory Research Group at the Eötvös University, the University of Zaragoza in Spain, and the Max Planck Institute for Physics in Munich were also involved in the research.


News Article | November 6, 2016
Site: www.sciencedaily.com

In the search for the mysterious dark matter, physicists have used elaborate computer calculations to come up with an outline of the particles of this unknown form of matter. To do this, the scientists extended the successful Standard Model of particle physics which allowed them, among other things, to predict the mass of so-called axions, promising candidates for dark matter. The German-Hungarian team of researchers led by Professor Zoltán Fodor of the University of Wuppertal, Eötvös University in Budapest and Forschungszentrum Jülich carried out its calculations on Jülich's supercomputer JUQUEEN (BlueGene/Q) and presents its results in the journal Nature. "Dark matter is an invisible form of matter which until now has only revealed itself through its gravitational effects. What it consists of remains a complete mystery," explains co-author Dr Andreas Ringwald, who is based at DESY and who proposed the current research. Evidence for the existence of this form of matter comes, among other things, from the astrophysical observation of galaxies, which rotate far too rapidly to be held together only by the gravitational pull of the visible matter. High-precision measurements using the European satellite "Planck" show that almost 85 percent of the entire mass of the universe consists of dark matter. All the stars, planets, nebulae and other objects in space that are made of conventional matter account for no more than 15 percent of the mass of the universe. "The adjective 'dark' does not simply mean that it does not emit visible light," says Ringwald. "It does not appear to give off any other wavelengths either -- its interaction with photons must be very weak indeed." For decades, physicists have been searching for particles of this new type of matter. What is clear is that these particles must lie beyond the Standard Model of particle physics, and while that model is extremely successful, it currently only describes the conventional 15 percent of all matter in the cosmos. From theoretically possible extensions to the Standard Model physicists not only expect a deeper understanding of the universe, but also concrete clues in what energy range it is particularly worthwhile looking for dark-matter candidates. The unknown form of matter can either consist of comparatively few, but very heavy particles, or of a large number of light ones. The direct searches for heavy dark-matter candidates using large detectors in underground laboratories and the indirect search for them using large particle accelerators are still going on, but have not turned up any dark matter particles so far. A range of physical considerations make extremely light particles, dubbed axions, very promising candidates. Using clever experimental setups, it might even be possible to detect direct evidence of them. "However, to find this kind of evidence it would be extremely helpful to know what kind of mass we are looking for," emphasises theoretical physicist Ringwald. "Otherwise the search could take decades, because one would have to scan far too large a range." The existence of axions is predicted by an extension to quantum chromodynamics (QCD), the quantum theory that governs the strong interaction, responsible for the nuclear force. The strong interaction is one of the four fundamental forces of nature alongside gravitation, electromagnetism and the weak nuclear force, which is responsible for radioactivity. "Theoretical considerations indicate that there are so-called topological quantum fluctuations in quantum chromodynamics, which ought to result in an observable violation of time reversal symmetry," explains Ringwald. This means that certain processes should differ depending on whether they are running forwards or backwards. However, no experiment has so far managed to demonstrate this effect. The extension to quantum chromodynamics (QCD) restores the invariance of time reversals, but at the same time it predicts the existence of a very weakly interacting particle, the axion, whose properties, in particular its mass, depend on the strength of the topological quantum fluctuations. However, it takes modern supercomputers like Jülich's JUQUEEN to calculate the latter in the temperature range that is relevant in predicting the relative contribution of axions to the matter making up the universe. "On top of this, we had to develop new methods of analysis in order to achieve the required temperature range," notes Fodor who led the research. The results show, among other things, that if axions do make up the bulk of dark matter, they should have a mass of 50 to 1500 micro-electronvolts, expressed in the customary units of particle physics, and thus be up to ten billion times lighter than electrons. This would require every cubic centimetre of the universe to contain on average ten million such ultra-lightweight particles. Dark matter is not spread out evenly in the universe, however, but forms clumps and branches of a weblike network. Because of this, our local region of the Milky Way should contain about one trillion axions per cubic centimetre. Thanks to the Jülich supercomputer, the calculations now provide physicists with a concrete range in which their search for axions is likely to be most promising. "The results we are presenting will probably lead to a race to discover these particles," says Fodor. Their discovery would not only solve the problem of dark matter in the universe, but at the same time answer the question why the strong interaction is so surprisingly symmetrical with respect to time reversal. The scientists expect that it will be possible within the next few years to either confirm or rule out the existence of axions experimentally. The Institute for Nuclear Research of the Hungarian Academy of Sciences in Debrecen, the Lendület Lattice Gauge Theory Research Group at the Eötvös University, the University of Zaragoza in Spain, and the Max Planck Institute for Physics in Munich were also involved in the research.


News Article | November 2, 2016
Site: www.eurekalert.org

In the search for the mysterious dark matter, physicists have used elaborate computer calculations to come up with an outline of the particles of this unknown form of matter. To do this, the scientists extended the successful Standard Model of particle physics which allowed them, among other things, to predict the mass of so-called axions, promising candidates for dark matter. The German-Hungarian team of researchers led by Professor Zoltán Fodor of the University of Wuppertal, Eötvös University in Budapest and Forschungszentrum Jülich carried out its calculations on Jülich's supercomputer JUQUEEN (BlueGene/Q) and presents its results in the journal Nature. "Dark matter is an invisible form of matter which until now has only revealed itself through its gravitational effects. What it consists of remains a complete mystery," explains co-author Dr Andreas Ringwald, who is based at DESY and who proposed the current research. Evidence for the existence of this form of matter comes, among other things, from the astrophysical observation of galaxies, which rotate far too rapidly to be held together only by the gravitational pull of the visible matter. High-precision measurements using the European satellite "Planck" show that almost 85 percent of the entire mass of the universe consists of dark matter. All the stars, planets, nebulae and other objects in space that are made of conventional matter account for no more than 15 percent of the mass of the universe. "The adjective 'dark' does not simply mean that it does not emit visible light," says Ringwald. "It does not appear to give off any other wavelengths either - its interaction with photons must be very weak indeed." For decades, physicists have been searching for particles of this new type of matter. What is clear is that these particles must lie beyond the Standard Model of particle physics, and while that model is extremely successful, it currently only describes the conventional 15 percent of all matter in the cosmos. From theoretically possible extensions to the Standard Model physicists not only expect a deeper understanding of the universe, but also concrete clues in what energy range it is particularly worthwhile looking for dark-matter candidates. The unknown form of matter can either consist of comparatively few, but very heavy particles, or of a large number of light ones. The direct searches for heavy dark-matter candidates using large detectors in underground laboratories and the indirect search for them using large particle accelerators are still going on, but have not turned up any dark matter particles so far. A range of physical considerations make extremely light particles, dubbed axions, very promising candidates. Using clever experimental setups, it might even be possible to detect direct evidence of them. "However, to find this kind of evidence it would be extremely helpful to know what kind of mass we are looking for," emphasises theoretical physicist Ringwald. "Otherwise the search could take decades, because one would have to scan far too large a range." The existence of axions is predicted by an extension to quantum chromodynamics (QCD), the quantum theory that governs the strong interaction, responsible for the nuclear force. The strong interaction is one of the four fundamental forces of nature alongside gravitation, electromagnetism and the weak nuclear force, which is responsible for radioactivity. "Theoretical considerations indicate that there are so-called topological quantum fluctuations in quantum chromodynamics, which ought to result in an observable violation of time reversal symmetry," explains Ringwald. This means that certain processes should differ depending on whether they are running forwards or backwards. However, no experiment has so far managed to demonstrate this effect. The extension to quantum chromodynamics (QCD) restores the invariance of time reversals, but at the same time it predicts the existence of a very weakly interacting particle, the axion, whose properties, in particular its mass, depend on the strength of the topological quantum fluctuations. However, it takes modern supercomputers like Jülich's JUQUEEN to calculate the latter in the temperature range that is relevant in predicting the relative contribution of axions to the matter making up the universe. "On top of this, we had to develop new methods of analysis in order to achieve the required temperature range," notes Fodor who led the research. The results show, among other things, that if axions do make up the bulk of dark matter, they should have a mass of 50 to 1500 micro-electronvolts, expressed in the customary units of particle physics, and thus be up to ten billion times lighter than electrons. This would require every cubic centimetre of the universe to contain on average ten million such ultra-lightweight particles. Dark matter is not spread out evenly in the universe, however, but forms clumps and branches of a weblike network. Because of this, our local region of the Milky Way should contain about one trillion axions per cubic centimetre. Thanks to the Jülich supercomputer, the calculations now provide physicists with a concrete range in which their search for axions is likely to be most promising. "The results we are presenting will probably lead to a race to discover these particles," says Fodor. Their discovery would not only solve the problem of dark matter in the universe, but at the same time answer the question why the strong interaction is so surprisingly symmetrical with respect to time reversal. The scientists expect that it will be possible within the next few years to either confirm or rule out the existence of axions experimentally. The Institute for Nuclear Research of the Hungarian Academy of Sciences in Debrecen, the Lendület Lattice Gauge Theory Research Group at the Eötvös University, the University of Zaragoza in Spain, and the Max Planck Institute for Physics in Munich were also involved in the research. Deutsches Elektronen-Synchrotron DESY is the leading German accelerator centre and one of the leading in the world. DESY is a member of the Helmholtz Association and receives its funding from the German Federal Ministry of Education and Research (BMBF) (90 per cent) and the German federal states of Hamburg and Brandenburg (10 per cent). At its locations in Hamburg and Zeuthen near Berlin, DESY develops, builds and operates large particle accelerators, and uses them to investigate the structure of matter. DESY's combination of photon science and particle physics is unique in Europe. For the search for axion-like particles, the experiment ALPS II is currently being built by an international collaboration at DESY. Calculation of the axion mass based on high-temperature lattice quantum chromodynamics; S. Borsanyi, Z. Fodor, J. Gunther, K.-H. Kampert, S. D. Katz, T. Kawanai, T. G. Kovacs, S. W. Mages, A. Pasztor, F. Pittler, J. Redondo, A. Ringwald & K. K. Szabo; Nature, 2016; DOI: 10.1038/nature20115


"Dark matter is an invisible form of matter which until now has only revealed itself through its gravitational effects. What it consists of remains a complete mystery," explains co-author Dr Andreas Ringwald, who is based at DESY and who proposed the current research. Evidence for the existence of this form of matter comes, among other things, from the astrophysical observation of galaxies, which rotate far too rapidly to be held together only by the gravitational pull of the visible matter. High-precision measurements using the European satellite "Planck" show that almost 85 percent of the entire mass of the universe consists of dark matter. All the stars, planets, nebulae and other objects in space that are made of conventional matter account for no more than 15 percent of the mass of the universe. "The adjective 'dark' does not simply mean that it does not emit visible light," says Ringwald. "It does not appear to give off any other wavelengths either - its interaction with photons must be very weak indeed." For decades, physicists have been searching for particles of this new type of matter. What is clear is that these particles must lie beyond the Standard Model of particle physics, and while that model is extremely successful, it currently only describes the conventional 15 percent of all matter in the cosmos. From theoretically possible extensions to the Standard Model physicists not only expect a deeper understanding of the universe, but also concrete clues in what energy range it is particularly worthwhile looking for dark-matter candidates. The unknown form of matter can either consist of comparatively few, but very heavy particles, or of a large number of light ones. The direct searches for heavy dark-matter candidates using large detectors in underground laboratories and the indirect search for them using large particle accelerators are still going on, but have not turned up any dark matter particles so far. A range of physical considerations make extremely light particles, dubbed axions, very promising candidates. Using clever experimental setups, it might even be possible to detect direct evidence of them. "However, to find this kind of evidence it would be extremely helpful to know what kind of mass we are looking for," emphasises theoretical physicist Ringwald. "Otherwise the search could take decades, because one would have to scan far too large a range." The existence of axions is predicted by an extension to quantum chromodynamics (QCD), the quantum theory that governs the strong interaction, responsible for the nuclear force. The strong interaction is one of the four fundamental forces of nature alongside gravitation, electromagnetism and the weak nuclear force, which is responsible for radioactivity. "Theoretical considerations indicate that there are so-called topological quantum fluctuations in quantum chromodynamics, which ought to result in an observable violation of time reversal symmetry," explains Ringwald. This means that certain processes should differ depending on whether they are running forwards or backwards. However, no experiment has so far managed to demonstrate this effect. The extension to quantum chromodynamics (QCD) restores the invariance of time reversals, but at the same time it predicts the existence of a very weakly interacting particle, the axion, whose properties, in particular its mass, depend on the strength of the topological quantum fluctuations. However, it takes modern supercomputers like Jülich's JUQUEEN to calculate the latter in the temperature range that is relevant in predicting the relative contribution of axions to the matter making up the universe. "On top of this, we had to develop new methods of analysis in order to achieve the required temperature range," notes Fodor who led the research. The results show, among other things, that if axions do make up the bulk of dark matter, they should have a mass of 50 to 1500 micro-electronvolts, expressed in the customary units of particle physics, and thus be up to ten billion times lighter than electrons. This would require every cubic centimetre of the universe to contain on average ten million such ultra-lightweight particles. Dark matter is not spread out evenly in the universe, however, but forms clumps and branches of a weblike network. Because of this, our local region of the Milky Way should contain about one trillion axions per cubic centimetre. Thanks to the Jülich supercomputer, the calculations now provide physicists with a concrete range in which their search for axions is likely to be most promising. "The results we are presenting will probably lead to a race to discover these particles," says Fodor. Their discovery would not only solve the problem of dark matter in the universe, but at the same time answer the question why the strong interaction is so surprisingly symmetrical with respect to time reversal. The scientists expect that it will be possible within the next few years to either confirm or rule out the existence of axions experimentally. The Institute for Nuclear Research of the Hungarian Academy of Sciences in Debrecen, the Lendület Lattice Gauge Theory Research Group at the Eötvös University, the University of Zaragoza in Spain, and the Max Planck Institute for Physics in Munich were also involved in the research. Explore further: 3 knowns and 3 unknowns about dark matter More information: S. Borsanyi et al, Calculation of the axion mass based on high-temperature lattice quantum chromodynamics, Nature (2016). DOI: 10.1038/nature20115


Brunner N.,University of Geneva | Brunner N.,University of Bristol | Navascues M.,University of Bristol | Vertesi T.,Hungarian Academy of Sciences
Physical Review Letters | Year: 2013

Dimension witnesses allow one to test the dimension of an unknown physical system in a device-independent manner, that is, without placing assumptions about the functioning of the devices used in the experiment. Here we present simple and general dimension witnesses for quantum systems of arbitrary Hilbert space dimension. Our approach is deeply connected to the problem of quantum state discrimination, hence establishing a strong link between these two research topics. Finally, our dimension witnesses can distinguish between classical and quantum systems of the same dimension, making them potentially useful for quantum information processing. © 2013 American Physical Society.


Liang Y.-C.,University of Geneva | Liang Y.-C.,University of Sydney | Vertesi T.,Hungarian Academy of Sciences | Brunner N.,University of Bristol
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

Detection and quantification of entanglement in quantum resources are two key steps in the implementation of various quantum-information processing tasks. Here, we show that Bell-type inequalities are not only useful in verifying the presence of entanglement but can also be used to bound the entanglement of the underlying physical system. Our main tool consists of a family of Clauser-Horne-like Bell inequalities that cannot be violated maximally by any finite-dimensional maximally entangled state. Using these inequalities, we demonstrate the explicit construction of both lower and upper bounds on the concurrence for two-qubit states. The fact that these bounds arise from Bell-type inequalities also allows them to be obtained in a semi-device- independent manner, that is, with assumption of the dimension of the Hilbert space but without resorting to any knowledge of the actual measurements being performed on the individual subsystems. © 2011 American Physical Society.


Vertesi T.,Hungarian Academy of Sciences | Pironio S.,University of Geneva | Brunner N.,University of Bristol
Physical Review Letters | Year: 2010

We show that the detection efficiencies required for closing the detection loophole in Bell tests can be significantly lowered using quantum systems of dimension larger than two. We introduce a series of asymmetric Bell tests for which an efficiency arbitrarily close to 1/N can be tolerated using N-dimensional systems, and a symmetric Bell test for which the efficiency can be lowered down to 61.8% using four-dimensional systems. Experimental perspectives for our schemes look promising considering recent progress in atom-photon entanglement and in photon hyperentanglement. © 2010 The American Physical Society.


Quintino M.T.,University of Geneva | Vertesi T.,Hungarian Academy of Sciences | Brunner N.,University of Geneva
Physical Review Letters | Year: 2014

We investigate the relation between the incompatibility of quantum measurements and quantum nonlocality. We show that a set of measurements is not jointly measurable (i.e., incompatible) if and only if it can be used for demonstrating Einstein-Podolsky-Rosen steering, a form of quantum nonlocality. Moreover, we discuss the connection between Bell nonlocality and joint measurability, and give evidence that both notions are inequivalent. Specifically, we exhibit a set of incompatible quantum measurements and show that it does not violate a large class of Bell inequalities. This suggests the existence of incompatible quantum measurements which are Bell local, similarly to certain entangled states which admit a local hidden variable model. © 2014 American Physical Society.


Burketova L.,Academy of Sciences of the Czech Republic | Trda L.,Academy of Sciences of the Czech Republic | Ott P.G.,Hungarian Academy of Sciences | Valentova O.,Institute of Chemical Technology Prague
Biotechnology Advances | Year: 2015

An increasing demand for environmentally acceptable alternative for traditional pesticides provides an impetus to conceive new bio-based strategies in crop protection. Employing induced resistance is one such strategy, consisting of boosting the natural plant immunity. Upon infections, plants defend themselves by activating their immune mechanisms. These are initiated after the recognition of an invading pathogen via the microbe-associated molecular patterns (MAMPs) or other microbe-derived molecules. Triggered responses inhibit pathogen spread from the infected site. Systemic signal transport even enables to prepare, i.e. prime, distal uninfected tissues for more rapid and enhanced response upon the consequent pathogen attack. Similar defense mechanisms can be triggered by purified MAMPs, pathogen-derived molecules, signal molecules involved in plant resistance to pathogens, such as salicylic and jasmonic acid, or a wide range of other chemical compounds. Induced resistance can be also conferred by plant-associated microorganisms, including beneficial bacteria or fungi. Treatment with resistance inducers or beneficial microorganisms provides long-lasting resistance for plants to a wide range of pathogens. This study surveys current knowledge on resistance and its mechanisms provided by microbe-, algae- and plant-derived elicitors in different crops. The main scope deals with bacterial substances and fungus-derived molecules chitin and chitosan and algae elicitors, including naturally sulphated polysaccharides such as ulvans, fucans or carageenans. Recent advances in the utilization of this strategy in practical crop protection are also discussed. © 2015 Elsevier Inc.


Bowles J.,University of Geneva | Vertesi T.,Hungarian Academy of Sciences | Quintino M.T.,University of Geneva | Brunner N.,University of Geneva | Brunner N.,University of Bristol
Physical Review Letters | Year: 2014

Einstein-Podolsky-Rosen steering is a form of quantum nonlocality exhibiting an inherent asymmetry between the observers, Alice and Bob. A natural question is then whether there exist entangled states which are one-way steerable, that is, Alice can steer Bob's state, but it is impossible for Bob to steer the state of Alice. So far, such a phenomenon has been demonstrated for continuous variable systems, but with a strong restriction on allowed measurements, namely, considering only Gaussian measurements. Here we present a simple class of entangled two-qubit states which are one-way steerable, considering arbitrary projective measurements. This shows that the nonlocal properties of entangled states can be fundamentally asymmetrical. © 2014 American Physical Society.


Lunden W.D.M.,State University of New York at Stony Brook | Sandor P.,State University of New York at Stony Brook | Weinacht T.C.,State University of New York at Stony Brook | Rozgonyi T.,Hungarian Academy of Sciences
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2014

We present a simple model for calculating strong-field atomic and molecular ionization dominated by Freeman resonances. Our model combines multiphoton coupling between bound states, including dynamic Stark shifts, with coupling to a discretized continuum. The simplicity of the model allows us to interpret pulse-shape-dependent strong-field ionization yields and to demonstrate the relevance of strong-field atomic or molecular phase matching to ionization, as well as bound-state population transfer. Comparison with experimental measurements demonstrates that the calculations capture the essence of the pulse-shape-dependent ionization yields. © 2014 American Physical Society.


Bai P.,Debrecen University | Bai P.,Hungarian Academy of Sciences | Canto C.,Nestlé
Cell Metabolism | Year: 2012

While originally described as DNA damage repair agents, recent data suggest a role for poly(ADP-ribose) polymerase (PARP) enzymes in metabolic regulation by influencing mitochondrial function and oxidative metabolism. Here we review how PARP activity has a major metabolic impact and the role of PARP-1 and PARP-2 in diverse metabolic complications. © 2012 Elsevier Inc.


Brunner N.,University of Bristol | Brunner N.,University of Geneva | Vertesi T.,Hungarian Academy of Sciences
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

The behavior under particle loss of entanglement and nonlocality is investigated in multipartite quantum systems. In particular, we define a notion of persistency of nonlocality, which leads to device-independent tests of persistent entanglement. We investigate the persistency of various classes of multipartite quantum states, exhibiting a variety of different behaviors. A particular attention is devoted to states featuring maximal persistency. Finally we discuss a link between the symmetry of a state and its persistency, illustrating the fact that too much symmetry reduces the strength of correlations among subsystems. These ideas also lead to a device-independent estimation of the asymmetry of a quantum state. © 2012 American Physical Society.


Antonioli L.,University of Pisa | Antonioli L.,Rutgers University | Pacher P.,U.S. National Institutes of Health | Vizi E.S.,Hungarian Academy of Sciences | And 2 more authors.
Trends in Molecular Medicine | Year: 2013

The enzymatic activities of CD39 and CD73 play strategic roles in calibrating the duration, magnitude, and chemical nature of purinergic signals delivered to immune cells through the conversion of ADP/ATP to AMP and AMP to adenosine, respectively. This drives a shift from an ATP-driven proinflammatory environment to an anti-inflammatory milieu induced by adenosine. The CD39/CD73 pathway changes dynamically with the pathophysiological context in which it is embedded. It is becoming increasingly appreciated that altering this catabolic machinery can change the course or dictate the outcome of several pathophysiological events, such as AIDS, autoimmune diseases, infections, atherosclerosis, ischemia-reperfusion injury, and cancer, suggesting these ectoenzymes are novel therapeutic targets for managing a variety of disorders. © 2013 Elsevier Ltd.


Mezei P.,Hungarian Academy of Sciences | Cserfalvi T.,Aqua Concorde
Sensors (Switzerland) | Year: 2012

Electrolyte Cathode Discharge (ELCAD) spectrometry, a novel sensitive multielement direct analytical method for metal traces in aqueous solutions, was introduced in 1993 as a new sensing principle. Since then several works have tried to develop an operational mechanism for this exotic atmospheric glow plasma technique, however these attempts cannot be combined into a valid model description. In this review we summarize the conceptual and technical problems we found in this upcoming research field of direct sensors. The TG gas temperature and the ne electron density values published up to now for ELCAD are very confusing. These data were evaluated by three conditions. The first is the gas composition of the ELCAD plasma, since TG was determined from the emitted intensity of the N2 and OH bands. Secondly, since the ELCAD is an atmospheric glow discharge, thus, the obtained TG has to be close to the Te electron temperature. This can be used for the mutual validation of the received temperature data. Thirdly, as a consequence of the second condition, the values of TG and ne have to agree with the Engel-Brown approximation of the Saha-equation related to weakly ionized glow discharge plasmas. Application of non-adequate experimental methods and theoretical treatment leads to unreliable descriptions which cannot be used to optimize the detector performance. © 2012 by the authors; licensee MDPI, Basel, Switzerland.


Lazarovits B.,Rutgers University | Lazarovits B.,Hungarian Academy of Sciences | Kim K.,Rutgers University | Haule K.,Rutgers University | Kotliar G.,Rutgers University
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

We present cluster-dynamic mean field theory (DMFT) (continuous time quantum Monte Carlo method) calculations based on a downfolded tight-binding model in order to study the electronic structure of vanadium dioxide (VO 2) both in the low-temperature (M1) and high-temperature (rutile) phases. Motivated by the recent efforts directed toward tuning the physical properties of VO2 by depositing films on different supporting surfaces of different orientations, we performed calculations for different geometries for both phases. In order to investigate the effects of the different growing geometries we applied both contraction and expansion for the lattice parameter along the rutile c axis in the three-dimensional translationally invariant systems miming the real situation. Our main focus is to identify the mechanisms governing the formation of the gap characterizing the M1 phase and its dependence on strain. We found that the increase of the bandwidth with compression along the axis corresponding to the rutile c axis is more important than the Peierls bonding-antibonding splitting. © 2010 The American Physical Society.


Vertesi T.,Hungarian Academy of Sciences | Brunner N.,University of Geneva
Nature Communications | Year: 2015

Quantum entanglement has a central role in many areas of physics. To grasp the essence of this phenomenon, it is fundamental to understand how different manifestations of entanglement relate to each other. In 1999, Peres conjectured that Bell nonlocality is equivalent to distillability of entanglement. The intuition of Peres was that the non-classicality of an entangled state, as witnessed via Bell inequality violation, implies that pure entanglement can be distilled from this state, hence making it useful for quantum information protocols. Subsequently, the Peres conjecture was shown to hold true in several specific cases, and became a central open question in quantum information theory. Here we disprove the Peres conjecture by showing that an undistillable bipartite entangled state - a bound entangled state - can violate a Bell inequality. Hence Bell nonlocality implies neither entanglement distillability, nor non-positivity under partial transposition. This clarifies the relation between three fundamental aspects of entanglement. © 2014 Macmillan Publishers Limited. All rights reserved.


Grant
Agency: European Commission | Branch: FP7 | Program: MC-IRSES | Phase: FP7-PEOPLE-2012-IRSES | Award Amount: 142.50K | Year: 2012

Owing to very small dimensions of nanostructures in one or more directions, spatial confinement of charge carriers is fully achieved, providing thereby a discrete spectrum of their energy states. In addition, intrinsic spatial inhomogeneity of nanostructures dictates nanoscale inhomogeneity of the surrounding electromagnetic fields. Therefore, understanding the properties of nanostructures requires to deal with the intricate characters of their atomic structure, electronic structure and electromagnetic environment. Coming within the scope of this new field of nano-electromagnetics, the present project aims at understanding how and why carbon nanostructures might have interesting electromagnetic properties. The core of the project is the development, the experimental validation and the exploitation of a consistent theory of the electromagnetic response in radio, microwave and THz frequency ranges of regular carbon nano structures and polymer composites based on nanocarbons. In particular, the project intends to: - to provide a forum for scientists specialized in different areas of the nanocarbon, and nanocarbon materials synthesis and applications; - interpret experimental electromagnetic data collected; - define physical grounds and perform experiments for the design of a new generation of ultra-light materials with controlled electromagnetic properties; - explore the possibility of using chemically-modified nanocarbons in thin bio-medical and nanophotonics applications. At this aim, seven teams belonging to three different scientific areas will joint efforts. The partners will equally contribute to the achievements of the objective of this multi-disciplinary project by bringing their expertise in condensed-matter physics, electromagnetic theory, and applied electromagnetism. The research efforts, both theoretical and experimental, are articulated around four work packages all involving strong collaborative links and knowledge transfer across the consortium.


Motter A.E.,Northwestern University | Gruiz M.,Eötvös Loránd University | Karolyi G.,Budapest University of Technology and Economics | Tel T.,Eötvös Loránd University | Tel T.,Hungarian Academy of Sciences
Physical Review Letters | Year: 2013

Chaos is an inherently dynamical phenomenon traditionally studied for trajectories that are either permanently erratic or transiently influenced by permanently erratic ones lying on a set of measure zero. The latter gives rise to the final state sensitivity observed in connection with fractal basin boundaries in conservative scattering systems and driven dissipative systems. Here we focus on the most prevalent case of undriven dissipative systems, whose transient dynamics fall outside the scope of previous studies since no time-dependent solutions can exist for asymptotically long times. We show that such systems can exhibit positive finite-time Lyapunov exponents and fractal-like basin boundaries which nevertheless have codimension one. In sharp contrast to its driven and conservative counterparts, the settling rate to the (fixed-point) attractors grows exponentially in time, meaning that the fraction of trajectories away from the attractors decays superexponentially. While no invariant chaotic sets exist in such cases, the irregular behavior is governed by transient interactions with transient chaotic saddles, which act as effective, time-varying chaotic sets. © 2013 American Physical Society.


Bruckmann F.,University of Regensburg | Endrodi G.,University of Regensburg | Kovacs T.G.,Hungarian Academy of Sciences
Journal of High Energy Physics | Year: 2013

We study the physical mechanism of how an external magnetic field influences the QCD quark condensate. Two competing mechanisms are identified, both relying on the interaction between the magnetic field and the low quark modes. While the coupling to valence quarks enhances the condensate, the interaction with sea quarks suppresses it in the transition region. The latter “sea effect” acts by ordering the Polyakov loop and, thereby, reduces the number of small Dirac eigenmodes and the condensate. It is most effective around the transition temperature, where the Polyakov loop effective potential is flat and a small correction to it by the magnetic field can have a significant effect. Around the critical temperature, the sea suppression overwhelms the valence enhancement, resulting in a net suppression of the condensate, named inverse magnetic catalysis. We support this physical picture by lattice simulations including continuum extrapolated results on the Polyakov loop as a function of temperature and magnetic field. We argue that taking into account the increase in the Polyakov loop and its interaction with the low-lying modes is essential to obtain the full physical picture, and should be incorporated in effective models for the description of QCD in magnetic fields in the transition region. © 2013, SISSA.


Trunov M.L.,Uzhgorod National University | Lytvyn P.M.,Institute of Semiconductor Physics of Ukraine | Nagy P.M.,Hungarian Academy of Sciences | Dyachyns'Ka O.M.,Institute of Semiconductor Physics of Ukraine
Applied Physics Letters | Year: 2010

We present direct measurements of the kinetics of surface relief gratings (SRGs) formation in amorphous Asx Se100-x (20 xAs 50) thin films. SRGs are induced in different holographic schemes of recording using near-band-gap light and their growth is further facilitated by illumination with an interference pattern and observed in real time by in situ atomic force microscopy. It is found that the kinetics of SRG formation depends upon film composition and incident light polarization. The light-stimulated vectorial surface deformations are maximized for Se-rich glasses and increase even further by additional illumination during recording. © 2010 American Institute of Physics.


Szederkenyi G.,Bio Process Engineering Group | Szederkenyi G.,Hungarian Academy of Sciences | Banga J.R.,Bio Process Engineering Group | Alonso A.A.,Bio Process Engineering Group
Bioinformatics | Year: 2012

Chemical reaction network theory is widely used in modeling and analyzing complex biochemical systems such as metabolic networks and cell signalling pathways. Being able to produce all the biologically and chemically important qualitative dynamical features, chemical reaction networks (CRNs) have attracted significant attention in the systems biology community. It is well-known that the reliable inference of CRN models generally requires thorough identifiability and distinguishability analysis together with carefully selected prior modeling assumptions. Here, we present a software toolbox CRNreals that supports the distinguishability and identifiability analysis of CRN models using recently published optimization-based procedures. © The Author 2012. Published by Oxford University Press. All rights reserved.


Szilvasi T.,Budapest University of Technology and Economics | Gali A.,Budapest University of Technology and Economics | Gali A.,Hungarian Academy of Sciences
Journal of Physical Chemistry C | Year: 2014

We systematically study the fluorination of nanometer-sized diamond cages, diamondoids, by time-dependent density functional theory. We find that fluorination affects both the highest occupied and lowest unoccupied molecular orbitals. Partial fluorination may decrease the energy of the excited state, and the lowest unoccupied molecular orbital becomes less exposed to the environment around the fluorinated surface. These new features of fluorinated diamondoids could be very useful in several potential applications of fluorescent nanodiamonds such as nitrogen-vacancy center based sensing at nanoscale. © 2014 American Chemical Society.


Leskinen M.V.,University of Jyväskylä | Madarasz A.,Hungarian Academy of Sciences | Yip K.-T.,University of Jyväskylä | Vuorinen A.,University of Jyväskylä | And 3 more authors.
Journal of the American Chemical Society | Year: 2014

Cross-dehydrogenative coupling reactions between β-ketoesters and electron-rich arenes, such as indoles, proceed with high regiochemical fidelity with a range of β-ketoesters and indoles. The mechanism of the reaction between a prototypical β-ketoester, ethyl 2-oxocyclopentanonecarboxylate, and N-methylindole has been studied experimentally by monitoring the temporal course of the reaction by 1H NMR, kinetic isotope effect studies, and control experiments. DFT calculations have been carried out using a dispersion-corrected range-separated hybrid functional (?B97X-D) to explore the basic elementary steps of the catalytic cycle. The experimental results indicate that the reaction proceeds via two catalytic cycles. Cycle A, the dehydrogenation cycle, produces an enone intermediate. The dehydrogenation is assisted by N-methylindole, which acts as a ligand for Pd(II). The computational studies agree with this conclusion, and identify the turnover-limiting step of the dehydrogenation step, which involves a change in the coordination mode of the β-keto ester ligand from an O,O′-chelate to an α-C-bound Pd enolate. This ligand tautomerization event is assisted by the p-bound indole ligand. Subsequent scission of the β′-C-H bond takes place via a proton-assisted electron transfer mechanism, where Pd(II) acts as an electron sink and the trifluoroacetate ligand acts as a proton acceptor, to produce the Pd(0) complex of the enone intermediate. The coupling is completed in cycle B, where the enone is coupled with indole. Pd(TFA)2 and TFA-catalyzed pathways were examined experimentally and computationally for this cycle, and both were found to be viable routes for the coupling step. © 2014 American Chemical Society.


Romhanyi J.,Budapest University of Technology and Economics | Penc K.,Budapest University of Technology and Economics | Penc K.,Hungarian Academy of Sciences
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

We consider the square-lattice antiferromagnetic Heisenberg Hamiltonian extended with a single-ion axial anisotropy term as a minimal model for the multiferroic Ba2CoGe2O7. Developing a multiboson spin-wave theory, we investigate the dispersion of the spin excitations in this spin-3/2 system. As a consequence of a strong single-ion anisotropy, a stretching (longitudinal) spin mode appears in the spectrum. The inelastic neutron scattering spectra of Zheludev are successfully reproduced by the low energy modes in the multiboson spin-wave theory, and we anticipate the appearance of the spin stretching modes at 4 meV that can be identified using the calculated dynamical spin structure factors. We expect the appearance of spin stretching modes for any S 1/2 compound where the single-ion anisotropy is significant. © 2012 American Physical Society.


Takacs D.,Hungarian Academy of Sciences | Stepan G.,Budapest University of Technology and Economics
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences | Year: 2013

It has been shown recently that the shimmy motion of towed wheels can be predicted in a wide range of parameters by means of the so-called memory effect of tyres. This delay effect is related to the existence of a travelling-wave-like motion of the tyre points in contact with the ground relative to the wheel. This study shows that the dynamics within the small-scale contact patch can have an essential effect on the global dynamics of a four-wheeled automobile on a large scale. The stability charts identify narrow parameter regions of increased fuel consumption and tyre noise with the help of the delay models that are effective tools in dynamical problems through multiple scales. © 2013 The Author(s) Published by the Royal Society. All rights reserved.


Gyorffy N.,Hungarian Academy of Sciences | Tungler A.,Hungarian Academy of Sciences | Fodor M.,Budapest University of Technology and Economics
Journal of Catalysis | Year: 2010

The kinetic resolution of 3,5,5-trimethyl cyclohexanone (TMCH) and asymmetric hydrogenation of isophorone (3,5,5-trimethyl cyclohex-2-enone, IP) were investigated on different Pd catalysts in the presence of (S)-proline (Pr). It could be proven that in isophorone hydrogenation the optically active TMCH was formed not only by kinetic resolution but also through asymmetric C{double bond, long}C hydrogenation. The activity and stereoselectivity of different Pd catalysts depended on the support material, preparation method, and reaction conditions as well, confirming our assumption that enantiodifferentiation takes also place on the catalyst surface and not only in the homogeneous liquid phase condensation reaction. © 2010.


Voros M.,Budapest University of Technology and Economics | Demjen T.,Eötvös Loránd University | Demjen T.,Hungarian Academy of Sciences | Szilvasi T.,Budapest University of Technology and Economics | And 2 more authors.
Physical Review Letters | Year: 2012

The optical gap of nanometer sized diamond cages, i.e., diamondoids, lies in the ultraviolet spectral region. Here we show by hybrid functional based time-dependent density-functional calculations that, by varying the number of CS double bonds at the surface of diamondoids, the absorption onset can be tuned toward the infrared spectral region. Our finding has an important implication for invivo biological applications where toxic and unstable dye molecules may be substituted by the luminescent sulfurized diamondoids. © 2012 American Physical Society.


Horvath A.,Hungarian Academy of Sciences | Vertessy B.G.,Hungarian Academy of Sciences | Vertessy B.G.,Budapest University of Technology and Economics
Nucleic Acids Research | Year: 2010

Uracil may occur in DNA due to either cytosine deamination or thymine replacing incorporation. Its quantitative characterization is important in assessing DNA damages in cells with perturbed thymidylate metabolism or within different DNA segments involved in immunoglobulin gene diversification. The archaeal DNA polymerase from Pyrococcus furiosus binds strongly to the deaminated base uracil and stalls on uracil-containing templates. Here, we present a straightforward method for quantitative assessment of uracil in DNA within specific genomic segments. We use wild-type P. furiosus polymerase in parallel with its point mutant version which lacks the uracil-binding specificity on synthetic and genomic DNA samples to quantify the uracil content in a single-step real-time PCR assay. Quantification of the PCR results is based on an approach analogous to template copy number determination in comparing different samples. Data obtained on synthetic uracil-containing templates are verified by direct isotopic measurements. The method is also tested on physiological DNA samples from Escherichia coli and mouse cell lines with perturbed thymidylate biosynthesis. The present PCR-based method is easy to use and measures the uracil content within a genomic segment defined by the primers. Using distinct sets of primers, the method allows the analysis of heterogeneity of uracil distribution within the genome. © 2010 The Author(s).


Lajko M.,Hungarian Academy of Sciences | Lajko M.,Budapest University of Technology and Economics | Sindzingre P.,CNRS Condensed Matter Physics Laboratory | Penc K.,Hungarian Academy of Sciences
Physical Review Letters | Year: 2012

We consider a spin-1/2 tube (a three-leg ladder with periodic boundary conditions) with a Hamiltonian given by two projection operators-one on the triangles and the other on the square plaquettes on the side of the tube-that can be written in terms of Heisenberg and four-spin ring exchange interactions. We identify 3 phases: (i) for strongly antiferromagnetic exchange on the triangles, an exact ground state with a gapped spectrum can be given as an alternation of spin and chirality singlet bonds between nearest triangles; (ii) for ferromagnetic exchange on the triangles, we recover the phase of the spin-3/2 Heisenberg chain; (iii) between these two phases, a gapless incommensurate phase exists. We construct an exact ground state with two deconfined domain walls and a gapless excitation spectrum at the quantum phase transition point between the incommensurate and dimerized phases. © 2012 American Physical Society.


Szucs J.,Hungarian Academy of Sciences | Gyurcsanyi R.E.,Hungarian Academy of Sciences | Gyurcsanyi R.E.,Budapest University of Technology and Economics
Electroanalysis | Year: 2012

Microfluidic paper-based assays represent a new approach to address the need for simple and cost-effective medical diagnostics. In an effort to couple paper-based assays with a similarly simple signal transduction, here we explored the feasibility of using potentiometric detection as a new modality to quantify affinity assays performed on a paper platform. As proof of principle a dot-blot model assay based on using IgE aptamer-gold nanoparticle conjugates was developed for the quantitative determination of IgE. The gold nanoparticle conjugates further catalyzed the deposition of silver nanoparticles that by oxidative dissolution generated silver ions. The silver ions were detected directly in the wet paper matrix by using a silver ion selective electrode. The analytical performance of potentiometric dot-blot assay matched that of reflectance-based assays, which suggests that potentiometric detection might represent a viable alternative to the conventionally used optical detection. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Csiszar E.,Budapest University of Technology and Economics | Fekete E.,Hungarian Academy of Sciences
Langmuir | Year: 2011

Cotton and linen fibers were ground in a ball-mill, and the effect of grinding on the microstructure and surface properties of the fibers was determined by combining a couple of simple tests with powerful techniques of surface and structure analysis. Results clearly proved that the effect of grinding on cotton fiber was much less severe than on linen. For both fibers, the degree of polymerization reduced (by 14.5% and 30.5% for cotton and linen, respectively) with a simultaneous increase in copper number. The increased water sorption capacity of the ground substrates was in good agreement with the X-ray results, which proved a less perfect crystalline structure in the ground samples. Data from XPS and SEM-EDS methods revealed that the concentration of oxygen atoms (bonded especially in acetal and/or carbonyl groups) on the ground surfaces increased significantly, resulting in an increase in oxygen/carbon atomic ratio (XPS data: from 0.11 to 0.14 and from 0.16 to 0.29 for cotton and linen, respectively). Although grinding created new surfaces rich in O atoms, the probable higher energy of the surface could not be measured by IGC, most likely due to the limited adsorption of the n-alkane probes on the less perfect crystalline surfaces. © 2011 American Chemical Society.


Kemeny F.,Budapest University of Technology and Economics | Lukacs A.,Hungarian Academy of Sciences
Journal of Clinical and Experimental Neuropsychology | Year: 2010

The Weather Prediction (WP) Task is a classical task of probabilistic category learning generally used for examining the dissociation of procedural and declarative memory. The current study focuses on performance of children with language impairment (LI) and compares their performance to that of typically developing (TD) children and adults with the aim of testing the procedural deficit hypothesis of LI (PDH; Ullman & Pierpont, 2005), which states that language impairment is not a specific linguistic phenomenon, but results from the dysfunction of a more general cognitive system: the procedural system. To test the generality of the procedural impairment, we needed a task that is dissimilar from language in that it does not build on sequential information. Children with language impairment show deficient learning on the Weather Prediction Task, which already appears at the early stages of the task. These results, in line with the PDH, point to the deficit of the procedural system in language impairment going beyond the language system. Whether this deficit is selective to the procedural system or is complemented by deficits in the declarative system is the subject of future studies. © 2009 Psychology Press.


Gali A.,Hungarian Academy of Sciences | Gali A.,Budapest University of Technology and Economics | Maze J.R.,University of Santiago de Chile
Physical Review B - Condensed Matter and Materials Physics | Year: 2013

The split silicon-vacancy (SiV) defect in diamond is an electrically and optically active color center. Recently, it has been shown that this color center is bright and can be detected at the single defect level. In addition, the SiV defect shows a nonzero electronic spin ground state that potentially makes this defect an alternative candidate for quantum optics and metrology applications beside the well-known nitrogen-vacancy color center in diamond. However, the electronic structure of the defect, the nature of optical excitations and other related properties are not well understood. Here we present advanced ab initio study on SiV defect in diamond. We determine the formation energies, charge transition levels, and the nature of excitations of the defect. Our study unravels the origin of the dark or shelving state for the negatively charged SiV defect associated with the 1.68-eV photoluminescence center. © 2013 American Physical Society.


Bachrathy D.,Hungarian Academy of Sciences | Stepan G.,Budapest University of Technology and Economics
CIRP Annals - Manufacturing Technology | Year: 2013

Industrial application of chatter prediction in cutting processes requires reliable and fast stability calculations for a given machining operation, and also the reconstruction of corresponding stability charts. An efficient and robust technique is developed for this task when no time is available for the mathematical treatment of FRFs that represent the complex real-world machine tool dynamics possibly measured with rotating spindle and/or moving tool-holder between two subsequent cutting operations. In a real-case study, an extended multi-frequency-solution is introduced to present the effects of imperfect FRFs of diagonal, symmetric, non-symmetric or filtered types on the computed stability charts that provide instant information to avoid harmful vibrations. © 2013 CIRP.


Probst N.,University of Jyväskylä | Madarasz U.,Hungarian Academy of Sciences | Valkonen A.,University of Jyväskylä | Papai I.,Hungarian Academy of Sciences | And 3 more authors.
Angewandte Chemie - International Edition | Year: 2012

Hold them tight: Guided by X-ray structures, bifunctional thiourea catalysts containing an activating intramolecular hydrogen bond were redesigned. The new catalysts were used to effect a highly enantioselective Mannich reaction between malonates and both aliphatic and aromatic imines (see scheme; Boc=tert-butoxycarbonyl).


Sahoo G.,University of Jyväskylä | Rahaman H.,University of Jyväskylä | Madarasz A.,Hungarian Academy of Sciences | Papai I.,Hungarian Academy of Sciences | And 3 more authors.
Angewandte Chemie - International Edition | Year: 2012

The organocatalytic enantioselective Michael addition of aldehydes to nitroalkenes through enamine catalysis has been studied intensively in recent years. Pioneering mechanistic studies by Seebach and Hayashi and co-workers, as well as by the Blackmond group, on reactions catalyzed by diaryl prolinol ethers have identified cyclobutane (CB) species 6a (Scheme 1) as a key intermediate and the resting state of the amine catalyst. Although these studies clearly demonstrated that the rate-determining step in the catalytic cycle takes place after the formation of 6a, and possibly involves the protonation of the iminium nitronate 5a, the detailed mechanism of the rate-determining step was not addressed. More recently, the Blackmond group suggested a modified catalytic cycle where the cyclobutane species 6a is first deprotonated to give the anion 10 a, followed by protonation to form the enamine 8a. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.


Mayer I.,Hungarian Academy of Sciences | Matito E.,University Of Szczecin
Physical Chemistry Chemical Physics | Year: 2010

The recent formula for decomposing the expectation value 〈Ŝ2〉 of the total spin operator for general (correlated) wave functions has been rewritten in terms of the cumulant and is realized numerically for the first time. The results confirm its conformity with the physical expectations. © 2010 the Owner Societies.


Gyorgy A.,Hungarian Academy of Sciences | Neu G.,Budapest University of Technology and Economics
IEEE International Symposium on Information Theory - Proceedings | Year: 2011

We consider the problem of limited-delay lossy coding of individual sequences. Here the goal is to design (fixed-rate) compression schemes to minimize the normalized expected distortion redundancy relative to a reference class of coding schemes, measured as the difference between the average distortion of the algorithm and that of the best coding scheme in the reference class. In compressing a sequence of length T, the best schemes available in the literature achieve an O(T-1/3) normalized distortion redundancy relative to finite reference classes of limited delay and limited memory. It has also been shown that the distortion redundancy is at least of order 1/√T in certain cases. In this paper we narrow the gap between the upper and lower bounds, and give a compression scheme whose distortion redundancy is O(√ln(T)/T), only a logarithmic factor larger than the lower bound. The method is based on the recently introduced Shrinking Dartboard prediction algorithm, a variant of the exponentially weighted average prediction. Our method is also applied to the problem of zero-delay scalar quantization, where O(ln(T)/√T) distortion redundancy is achieved relative to the (infinite) class of scalar quantizers of a given rate, almost achieving the known lower bound of order 1/√T. © 2011 IEEE.


Mezgar I.,Hungarian Academy of Sciences | Mezgar I.,Budapest University of Technology and Economics | Rauschecker U.,Fraunhofer Institute for Manufacturing Engineering and Automation
Computers in Industry | Year: 2014

Manufacturing enterprises have to organize themselves into effective system architectures forming different types of Networked Enterprises (NE) to match fast changing market demands. Cloud Computing (CC) is an important up to date computing concept for NE, as it offers significant financial and technical advantages beside high-level collaboration possibilities. As cloud computing is a new concept the solutions for handling interoperability, portability, security, privacy and standardization challenges have not been solved fully yet. The paper introduces the main characteristics of future Internet-based enterprises and the different CC models. An overview is given on interoperability and actual standardization issues in CC environments. A taxonomy on possible connecting forms of networked enterprises and cloud-based IT systems with reference on interoperability is introduced, parallel presenting four use cases as well. Finally, an example of connecting cloud and NE is presented as an effective application of cloud computing in manufacturing industry. © 2014 Elsevier B.V.


Kali G.,Hungarian Academy of Sciences | Vavra S.,Budapest University of Technology and Economics | Laszlo K.,Budapest University of Technology and Economics | Ivan B.,Hungarian Academy of Sciences
Macromolecules | Year: 2013

Novel amphiphilic conetworks (APCN) consisting of thermoresponsive poly(N-isoproplyacrylamide) (PNiPAAm) cross-linked by hydrophobic methacrylate-telechelic polyisobutylene (MA-PIB-MA) were successfully synthesized in a broad composition range. The resulting PNiPAAm-l-PIB conetworks ("l" stands for "linked by") were obtained by radical copolymerization of NiPAAm with MA-PIB-MA in tetrahydrofuran, a cosolvent for all the components. Low amounts of extractables substantiated efficient network formation. The composition dependent two glass transition temperatures (T g) by DSC analysis indicate microphase separation of the cross-linked components without mixed phases. It was found that the PNiPAAm-l-PIB conetworks are uniformly swellable in both water and n-hexane; i.e., these new materials behave either as hydrogels or as hydrophobic gels in aqueous or nonpolar media, respectively. The uniform swelling in both polar and nonpolar solutes indicates cocontinuous (bicontinuous) phase morphology. The equilibrium swelling degrees (R) depend on composition, that is, the higher the PIB content, the lower the R in water and the higher in n-hexane. The PNiPAAm phase keeps its thermoresponsive behavior in the conetworks as shown by significant decrease of the swelling degree in water between 20 and 35 °C. The lower critical solubility temperature (LCST) values determined by DSC are found to decrease from 34.1 °C (for the pure PNiPAAm homopolymer) to the range of 25-28 °C in the conetworks, and the extent of the LCST decrease is proportional with the PIB content. Deswelling-swelling, i.e., heating-cooling, cycle indicates insignificant hysteresis in these new thermoresponsive materials. This indicates that PNiPAAm-l-PIB conetworks with predetermined and thermoresponsive swelling behavior can be designed and utilized in several advanced applications on the basis of results obtained in the course of this study. © 2013 American Chemical Society.


Bojnec S.,University of Primorska | Ferto I.,Hungarian Academy of Sciences
World Economy | Year: 2012

This paper examines the impact of EU enlargement on agro-food export performance across 12 new EU member states and five newly independent states in the EU markets covering the period 1999 to 2007. The performance is examined by duration of export and hazard model. We find larger duration for the agro-food exports from the new EU member states. The results confirm gains from the eastward EU enlargement and governance on export increases and longer duration for exporting higher value-added specialized consumer-ready food and more competitive niche agro-food products. © 2012 Blackwell Publishing Ltd.


Rahaman H.,University of Jyväskylä | Madarasz U.,Hungarian Academy of Sciences | Papai I.,Hungarian Academy of Sciences | Pihko P.M.,University of Jyväskylä
Angewandte Chemie - International Edition | Year: 2011

It takes two to tango: A dual catalyst system, composed of a highly enantioselective enamine catalyst and a multiple-hydrogen-bond catalyst, enabled the chemoselective union of two aldehydes and a nitromethane unit with near-perfect enantioselectivities, excellent diastereoselectivities, and high yields under neutral conditions (see scheme). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Geier J.,Stereo Vision | Hudak M.,Budapest University of Technology and Economics | Hudak M.,Hungarian Academy of Sciences
PLoS ONE | Year: 2011

The Chevreul illusion is a well-known 19 th century brightness illusion, comprising adjacent homogeneous grey bands of different luminance, which are perceived as inhomogeneous. It is generally explained by lateral inhibition, according to which brighter areas projected to the retina inhibit the sensitivity of neighbouring retinal areas. Lateral inhibition has been considered the foundation-stone of early vision for a century, upon which several computational models of brightness perception are built. One of the last strongholds of lateral inhibition is the Chevreul illusion, which is often illustrated even in current textbooks. Here we prove that lateral inhibition is insufficient to explain the Chevreul illusion. For this aim, we placed the Chevreul staircase in a luminance ramp background, which noticeably changed the illusion. In our psychophysical experiments, all 23 observers reported a strong illusion, when the direction of the ramp was identical to that of the staircase, and all reported homogeneous steps (no illusion) when its direction was the opposite. When the background of the staircase was uniform, 14 saw the illusion, and 9 saw no illusion. To see whether the change of the entire background area or that of the staircase boundary edges were more important, we placed another ramp around the staircase, whose direction was opposite to that of the original, larger ramp. The result is that though the inner ramp is rather narrow (mean = 0.51 deg, SD = 0.48 deg, N = 23), it still dominates perception. Since all conditions of the lateral inhibition account were untouched within the staircase, lateral inhibition fails to model these perceptual changes. Area ratios seem insignificant; the role of boundary edges seems crucial. We suggest that long range interactions between boundary edges and areas enclosed by them, such that diffusion-based models describe, provide a much more plausible account for these brightness phenomena, and local models are insufficient. © 2011 Geier, Hudák.


Kiss T.,French National Center for Scientific Research | Kiss T.,Hungarian Academy of Sciences | Fayet-Lebaron E.,French National Center for Scientific Research | Jady B.E.,French National Center for Scientific Research
Molecular Cell | Year: 2010

Box H/ACA RNAs represent an abundant, evolutionarily conserved class of small noncoding RNAs. All H/ACA RNAs associate with a common set of proteins, and they function as ribonucleoprotein (RNP) enzymes mainly in the site-specific pseudouridylation of ribosomal RNAs (rRNAs) and small nuclear RNAs (snRNAs). Some H/ACA RNPs function in the nucleolytic processing of precursor rRNA (pre-rRNA) and synthesis of telomeric DNA. Thus, H/ACA RNPs are essential for three fundamental cellular processes: protein synthesis, mRNA splicing, and maintenance of genome integrity. Recently, great progress has been made toward understanding of the biogenesis, intracellular trafficking, structure, and function of H/ACA RNPs. © 2010 Elsevier Inc. All rights reserved.


Gali A.,Hungarian Academy of Sciences | Gali A.,Budapest University of Technology and Economics
Physica Status Solidi (B) Basic Research | Year: 2011

A common fingerprint of the electrically active point defects in semiconductors is the transition between their localized defect states upon excitation, which may result in characteristic absorption or photoluminescence spectrum. While density functional calculations have been very successful in exploring the ground-state properties like formation energies or hyperfine tensors the density functional theory (DFT), in principle, is not capable of providing reliable excitation spectrum. Time-dependent (TD)-DFT, however, addresses this issue which makes possible to study the properties of point defects associated with their excited states. In this paper, we apply the TD-DFT on two characteristic examples: the well-known nitrogen-vacancy defect in diamond and the less known divacancy in silicon carbide. The former defect is a leading candidate in solid state quantum bit applications where detailed knowledge about the excitation spectrum is extremely important. The excitation property of divacancy will be also studied and its relevance in different applications will be discussed. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Somogyi B.,Budapest University of Technology and Economics | Zolyomi V.,Hungarian Academy of Sciences | Gali A.,Budapest University of Technology and Economics | Gali A.,Hungarian Academy of Sciences
Nanoscale | Year: 2012

Molecule-sized fluorescent emitters are much sought-after to probe biomolecules in living cells. We demonstrate here by time-dependent density functional calculations that the experimentally achievable 1-2 nm sized silicon carbide nanocrystals can emit light in the near-infrared region after introducing appropriate color centers in them. These near-infrared luminescent silicon carbide nanocrystals may act as ideal fluorophores for in vivo bioimaging. This journal is © 2012 The Royal Society of Chemistry.


Emmerich H.,University of Bayreuth | Lowen H.,Heinrich Heine University Düsseldorf | Wittkowski R.,Heinrich Heine University Düsseldorf | Gruhn T.,University of Bayreuth | And 4 more authors.
Advances in Physics | Year: 2012

Here, we review the basic concepts and applications of the phase-field-crystal (PFC) method, which is one of the latest simulation methodologies in materials science for problems, where atomic- and microscales are tightly coupled. The PFC method operates on atomic length and diffusive time scales, and thus constitutes a computationally efficient alternative to molecular simulation methods. Its intense development in materials science started fairly recently following the work by Elder et al. [Phys. Rev. Lett. 88 (2002), p. 245701]. Since these initial studies, dynamical density functional theory and thermodynamic concepts have been linked to the PFC approach to serve as further theoretical fundamentals for the latter. In this review, we summarize these methodological development steps as well as the most important applications of the PFC method with a special focus on the interaction of development steps taken in hard and soft matter physics, respectively. Doing so, we hope to present today's state of the art in PFC modelling as well as the potential, which might still arise from this method in physics and materials science in the nearby future. © 2012 Copyright Taylor and Francis Group, LLC.


Smeltzer B.,Bates College | Childress L.,Bates College | Gali A.,Hungarian Academy of Sciences | Gali A.,Budapest University of Technology and Economics
New Journal of Physics | Year: 2011

The electronic spin associated with the nitrogen-vacancy (NV) centre in diamond interacts with an environment formed by isotopic impurities and paramagnetic defects; the strength of these interactions depends on the location of each impurity relative to the NV centre. From the electron spin resonance spectra of individual NV centres we infer the possible values and signs of hyperfine splittings from nearby 13C nuclear spins at different lattice sites. Moreover, single-defect-centre nuclear magnetic resonance allows the examination of some of the inhomogeneities associated with the mesoscopic environment of NV-13C systems. These measurements provide a check on ab initio calculations of electron spin density and have relevance for potential applications in nuclear spin quantum registers. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.


Chitnis R.,University of Maryland University College | Hajiaghayi M.,University of Maryland University College | Marx D.,Humboldt University of Berlin | Marx D.,Hungarian Academy of Sciences
Proceedings of the Annual ACM-SIAM Symposium on Discrete Algorithms | Year: 2012

Given a directed graph G, a set of k terminals and an integer p, the DIRECTED VERTEX MULTIWAY CUT problem asks if there is a set S of at most p (nonterminal) vertices whose removal disconnects each terminal from all other terminals. DIRECTED EDGE MULTIWAY CUT is the analogous problem where 5 is a set of at most ñedges. These two problems indeed are known to be equivalent. A natural generalization of the multiway cut is the multicut problem, in which we want to disconnect only a set of k given pairs instead of all pairs. Marx (Theor. Comp. Sei. 2006) showed that in undirected graphs multiway cut is fixed-parameter tractable (FPT) parameterized by p. Marx and Razgon (STOC 2011) showed that undirected multicut is FPT and directed multicut is W[1]-hard parameterized by p. We complete the picture here by our main result which is that both DIRECTED VERTEX MULTIWAY CUT and DIRECTED EDGE MULTIWAY CUT can be solved in time 2 2O(p) n O(1) i.e., FPT parameterized by size p of the cutset of the solution. This answers an open question raised by Marx (Theor. Comp. Sci. 2006) and Marx and Razgon (STOC 2011). It follows from our result that DIRECTED MULTICUT is FFT for the case of k = 2 terminal pairs, which answers another open problem raised in Marx and Razgon (STOC 2011). Copyright © SIAM.


Bognar J.,Budapest University of Technology and Economics | Szucs J.,Hungarian Academy of Sciences | Dorko Z.,Budapest University of Technology and Economics | Horvath V.,Hungarian Academy of Sciences | Gyurcsanyi R.E.,Budapest University of Technology and Economics
Advanced Functional Materials | Year: 2013

A versatile approach based on nanosphere lithography is proposed to generate surface-imprinted polymers for selective protein recognition. A layer of 750 nm diameter latex bead-protein conjugate is deposited onto the surface of gold-coated quartz crystals followed by the electrosynthesis of a poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) film with thicknesses on the order of the bead radius. The removal of the polymer bead-protein conjugates, facilitated by using a cleavable protein-nanosphere linkage is shown to result in 2D arrays of periodic complementary size cavities. Here it is demonstrated by nanogravimetric measurements that the imprinting proceeds further at molecular level and the protein (avidin) coating of the beads generates selective recognition sites for avidin on the surface of the PEDOT/PSS film. The binding capacity of such surface-imprinted polymer films is ca. 6.5 times higher than that of films imprinted with unmodified beads. They also exhibit excellent selectivity against analogues of avidin, i.e., extravidin, streptavidin, and neutravidin, the latter being in fact undetectable. This methodology, if coupled with properly oriented conjugation of the macromolecular template to the nanoparticles, offers the possibility of site-directed imprinting. A versatile approach based on nanosphere lithography is proposed to generate surface-imprinted polymers for selective protein recognition. Nanogravimetric measurements demonstrate that the protein (avidin) coating of the nanospheres generates selective recognition sites for avidin on the surface of the PEDOT/PSS film. This methodology coupled with oriented conjugation of the macromolecular template to the nanospheres offers the possibility of site-directed imprinting. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Somogyi B.,Budapest University of Technology and Economics | Gali A.,Budapest University of Technology and Economics | Gali A.,Hungarian Academy of Sciences
Journal of Physics Condensed Matter | Year: 2014

Fluorescent semiconductor nanocrystals (or quantum dots) are very promising agents for bioimaging applications because their optical properties are superior compared to those of conventional organic dyes. However, not all the properties of these quantum dots suit the stringent criteria of in vivo applications, i.e. their employment in living organisms that might be of importance in therapy and medicine. In our review, we first summarize the properties of an 'ideal' biomarker needed for in vivo applications. Despite recent efforts, no such hand-made fluorescent quantum dot exists that may be considered as 'ideal' in this respect. We propose that ab initio atomistic simulations with predictive power can be used to design 'ideal' in vivo fluorescent semiconductor nanoparticles. We briefly review such ab initio methods that can be applied to calculate the electronic and optical properties of very small nanocrystals, with extra emphasis on density functional theory (DFT) and time-dependent DFT which are the most suitable approaches for the description of these systems. Finally, we present our recent results on this topic where we investigated the applicability of nanodiamonds and silicon carbide nanocrystals for in vivo bioimaging. © 2014 IOP Publishing Ltd.


Szakacs G.,Hungarian Academy of Sciences | Hall M.D.,U.S. National Institutes of Health | Gottesman M.M.,U.S. National Institutes of Health | Boumendjel A.,CNRS Molecular Pharmacochemistry Department | And 6 more authors.
Chemical Reviews | Year: 2014

The development of multidrug resistance (MDR) in patients suffering cancer remains a significant clinical challenge, with drug efflux by ABC (ATP-binding cassette) transporters contributing significantly. Theoretically, one could restore the efficacy of first-line drugs by circumventing these resistance mechanisms. However, cancer is a heterogeneous disease that can exhibit different characteristics from patient to patient or even within a single patient. Spatial and temporal heterogeneity is a result of continuous adaptation to selective pressures through sequential genetic changes that ultimately convert a normal cell into intractable cancer. Thus, cancer cells are moving targets, as individual cells in a tumor mass constantly adapt to local environmental challenges. Biological membranes represent a significant permeation barrier and thus play a critical role in the protection of pharmacokinetic compartments. Conversely, the activity of a drug ultimately depends on the ability of the compound to reach its target, which might reside in a well-protected pharmacological sanctuary.


Csiszar I.,Hungarian Academy of Sciences | Narayan P.,University of Maryland University College
IEEE Transactions on Information Theory | Year: 2013

Shannon theoretic secret key generation by several parties is considered for models in which a secure noisy channel with multiple input and output terminals and a public noiseless channel of unlimited capacity are available for accomplishing this goal. The secret key is generated for a set A of terminals of the noisy channel, with the remaining terminals (if any) cooperating in this task through their public communication. Single-letter lower and upper bounds for secrecy capacities are obtained when secrecy is required from an eavesdropper that observes only the public communication and perhaps also a set of terminals disjoint from A. These bounds coincide in special cases, but not in general. We also consider models in which different sets of terminals share multiple keys, one for the terminals in each set with secrecy required from the eavesdropper as well as from the terminals not in this set. Partial results include showing links among the associated secrecy capacity region for multiple keys, the transmission capacity region of the multiple access channel defined by the secure noisy channel, and achievable rates for a single secret key for all the terminals. © 2012 IEEE.


Ahn C.,Ewha Womans University | Bajnok Z.,Hungarian Academy of Sciences | Bombardelli D.,Ewha Womans University | Nepomechie R.I.,University of Miami
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2010

We propose that certain twists of the su(2|2) S-matrix elements describe the β-deformation of N=4 supersymmetric Yang-Mills theory. We compute the perturbative four-loop anomalous dimension of the Konishi operator of the deformed gauge theory from the LÜscher formula based on these twisted S-matrix elements. The result agrees exactly with the perturbative gauge theory computations. © 2010 Elsevier B.V.


Szarka A.,Budapest University of Technology and Economics | Tomasskovics B.,Budapest University of Technology and Economics | Banhegyi G.,Hungarian Academy of Sciences
International Journal of Molecular Sciences | Year: 2012

The life of any living organism can be defined as a hurdle due to different kind of stresses. As with all living organisms, plants are exposed to various abiotic stresses, such as drought, salinity, extreme temperatures and chemical toxicity. These primary stresses are often interconnected, and lead to the overproduction of reactive oxygen species (ROS) in plants, which are highly reactive and toxic and cause damage to proteins, lipids, carbohydrates and DNA, which ultimately results in oxidative stress. Stress-induced ROS accumulation is counteracted by enzymatic antioxidant systems and non-enzymatic low molecular weight metabolites, such as ascorbate, glutathione and α-tocopherol. The above mentioned low molecular weight antioxidants are also capable of chelating metal ions, reducing thus their catalytic activity to form ROS and also scavenge them. Hence, in plant cells, this triad of low molecular weight antioxidants (ascorbate, glutathione and α-tocopherol) form an important part of abiotic stress response. In this work we are presenting a review of abiotic stress responses connected to these antioxidants. © 2012 by the authors; licensee MDPI, Basel, Switzerland.


Monostori L.,Hungarian Academy of Sciences | Monostori L.,Budapest University of Technology and Economics
Procedia CIRP | Year: 2014

One of the most significant directions in the development of computer science and information and communication technologies is represented by Cyber-Physical Systems (CPSs) which are systems of collaborating computational entities which are in intensive connection with the surrounding physical world and its on-going processes, providing and using, at the same time, data-Accessing and data-processing services available on the internet. Cyber-Physical Production Systems (CPPSs), relying on the newest and foreseeable further developments of computer science, information and communication technologies on the one hand, and of manufacturing science and technology, on the other, may lead to the 4th Industrial Revolution, frequently noted as Industry 4.0. The key-note will underline that there are significant roots generally -And particularly in the CIRP community -which point towards CPPSs. Expectations and the related new R&D challenges will be outlined. © 2014 Elsevier B.V. This is an open access article under the CC BY-NC-ND license.


Nemes-Incze P.,Research Institute for Technical Physics and Materials Science | Magda G.,Budapest University of Technology and Economics | Kamaras K.,Hungarian Academy of Sciences | Biro L.P.,Research Institute for Technical Physics and Materials Science
Nano Research | Year: 2010

Graphene has many advantageous properties, but its lack of an electronic band gap makes this two-dimensional material impractical for many nanoelectronic applications, for example, field-effect transistors. This problem can be circumvented by opening up a confinement-induced gap, through the patterning of graphene into ribbons having widths of a few nanometres. The electronic properties of such ribbons depend on both their size and the crystallographic orientation of the ribbon edges. Therefore, etching processes that are able to differentiate between the zigzag and armchair type edge terminations of graphene are highly sought after. In this contribution we show that such an anisotropic, dry etching reaction is possible and we use it to obtain graphene ribbons with zigzag edges. We demonstrate that the starting positions for the carbon removal reaction can be tailored at will with precision. © The Author(s) 2010.


Heberger K.,Hungarian Academy of Sciences | Kollar-Hunek K.,Budapest University of Technology and Economics
Journal of Chemometrics | Year: 2011

This paper describes the theoretical background, algorithm and validation of a recently developed novel method of ranking based on the sum of ranking differences [TrAC Trends Anal. Chem. 2010; 29: 101-109]. The ranking is intended to compare models, methods, analytical techniques, panel members, etc. and it is entirely general. First, the objects to be ranked are arranged in the rows and the variables (for example model results) in the columns of an input matrix. Then, the results of each model for each object are ranked in the order of increasing magnitude. The difference between the rank of the model results and the rank of the known, reference or standard results is then computed. (If the golden standard ranking is known the rank differences can be completed easily.) In the end, the absolute values of the differences are summed together for all models to be compared. The sum of ranking differences (SRD) arranges the models in a unique and unambiguous way. The closer the SRD value to zero (i.e. the closer the ranking to the golden standard), the better is the model. The proximity of SRD values shows similarity of the models, whereas large variation will imply dissimilarity. Generally, the average can be accepted as the golden standard in the absence of known or reference results, even if bias is also present in the model results in addition to random error. Validation of the SRD method can be carried out by using simulated random numbers for comparison (permutation test). A recursive algorithm calculates the discrete distribution for a small number of objects (n<14), whereas the normal distribution is used as a reasonable approximation if the number of objects is large. The theoretical distribution is visualized for random numbers and can be used to identify SRD values for models that are far from being random. The ranking and validation procedures are called Sum of Ranking differences (SRD) and Comparison of Ranks by Random Numbers (CRNN), respectively. Copyright © 2010 John Wiley & Sons, Ltd.


Imre B.,Hungarian Academy of Sciences | Pukanszky B.,Budapest University of Technology and Economics
European Polymer Journal | Year: 2013

The production and use of biopolymers increases continuously with a very high rate thus all information on these materials is very important. This feature article first defines the terms used in the area then discusses the distinction between degradation and biodegradation as well as their importance for practice. Biopolymers often have inferior properties compared to commodity polymers. Modification is a way to improve properties and achieve property combinations required for specific applications. One technique is blending which allows considerable improvement in the impact resistance of brittle polymers. However, further study is needed on the miscibility-structure-property relationships of these materials to utilize all potentials of the approach. The chemical structure of biopolymers opens up possibilities to their reactive modification. Copolymerization, grafting, trans-esterification, the use of reactive coupling agents have all been utilized with success to achieve polymers and blends with improved properties. Several examples are shown for the various approaches and their outcome. Biopolymers and their blends are applied successfully in several areas from agriculture to consumer goods, packaging and automotive. © 2013 Elsevier B.V. All rights reserved.


Imre B.,Hungarian Academy of Sciences | Pukanszky B.,Budapest University of Technology and Economics
European Polymer Journal | Year: 2013

The increasing environmental awareness of the society has become an important factor in recent decades affecting legislation, commerce and industry as well as research and development to a great extent. The ability of natural systems to fulfill a certain function, on the other hand, lies in their complexity, thus virgin, extracted natural compounds can rarely be applied without modification. Lignin, for instance, represents a renewable source of aromatic compounds being able to provide a wide range of chemicals. Synthetic phenolic antioxidants are widely applied as stabilizers for polyolefins and many other polymers to protect them during processing and application. The possible effect of the reaction products of these compounds on the environment as well as on human health, however, raised several questions recently, thus their substitution with environmentally friendly alternatives would be highly desirable.


Deak A.,Budapest University of Technology and Economics | Szunyogh L.,Budapest University of Technology and Economics | Ujfalussy B.,Hungarian Academy of Sciences
Physical Review B - Condensed Matter and Materials Physics | Year: 2011

We present a detailed study of the ground-state magnetic structure of ultrathin Fe films on the surface of fcc Ir(001). We use the spin-cluster expansion technique in combination with the relativistic disordered local moment scheme to obtain parameters of spin models and then determine the favored magnetic structure of the system by means of a mean-field approach and atomistic spin dynamics simulations. For the case of a single monolayer of Fe, we find that layer relaxations very strongly influence the ground-state spin configurations, whereas Dzyaloshinskii-Moriya (DM) interactions and biquadratic couplings also have remarkable effects. To characterize the latter effect, we introduce and analyze spin collinearity maps of the system. While for two monolayers of Fe we find a single-q spin spiral as ground state due to DM interactions, for the case of four monolayers, the system shows a noncollinear spin structure with nonzero net magnetization. These findings are consistent with experimental measurements indicating ferromagnetic order in films of four monolayers and thicker. © 2011 American Physical Society.


Bacsi A.,Budapest University of Technology and Economics | Virosztek A.,Budapest University of Technology and Economics | Virosztek A.,Hungarian Academy of Sciences
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

We investigate the local density of states and Friedel oscillation in graphene around a well-localized impurity in Born approximation. In our analytical calculations Green's function technique has been used taking into account both the localized atomic wave functions in a tight-binding scheme and the corresponding symmetries of the lattice. As a result we obtained long wavelength oscillations in the density of electrons with long-range behavior proportional to the inverse square of the distance from the impurity. These leading oscillations are out of phase on nearby lattice sites (in fact for an extended defect they cancel each other within one unit cell), therefore a probe with resolution worse than a few unit cells will experience only the next to leading inverse cube decay of density oscillations even for a short-range scatterer. © 2010 The American Physical Society.


Gali A.,Hungarian Academy of Sciences | Gali A.,Budapest University of Technology and Economics
Journal of Materials Research | Year: 2012

A common fingerprint of the electrically active point defects in semiconductors is the transition among their localized defect states upon excitation, which may result in characteristic absorption- or photoluminescence spectrum. Identification of such point defects by means of density functional theory (DFT) calculations with traditional (semi) local functionals suffers from two problems: the "band gap error" and the many-body nature of the electron-hole interaction of the excited state. We show that non local hybrid density functionals may effectively mimic the quasiparticle correction of the band edges and the defect levels within the band gap in group-IV semiconductors, thus they can effectively heal the "band gap error." The electron-hole interaction can be calculated by time-dependent DFT (TD-DFT) method. Here, we apply TD-DFT on three topical examples: nitrogen-vacancy defect in diamond, silicon-vacancy and divacancy defects in silicon carbide that are candidates in effective development of solid-state quantum bits. © Copyright Materials Research Society 2012.


Borcs A.,Hungarian Academy of Sciences | Borcs A.,Budapest University of Technology and Economics | Benedek C.,Hungarian Academy of Sciences
IEEE Transactions on Geoscience and Remote Sensing | Year: 2014

In this paper, we present a new object-based hierarchical model for the joint probabilistic extraction of vehicles and groups of corresponding vehicles - called traffic segments - in airborne light detection and ranging (Lidar) point clouds collected from dense urban areas. First, the 3-D point set is classified into terrain, vehicle, roof, vegetation, and clutter classes. Then, the points with the corresponding class labels and echo strength (i.e., intensity) values are projected to the ground. In the obtained 2-D class and intensity maps, we approximate the top view projections of vehicles by rectangles. Since our tasks are simultaneously the extraction of the rectangle population which describes the position, size, and orientation of the vehicles and grouping the vehicles into the traffic segments, we propose a hierarchical two-level marked point process (MPP) (L2MPP) model for the problem. The output vehicle and traffic segment configurations are extracted by an iterative stochastic optimization algorithm. We have tested the proposed method with real data of a discrete-return Lidar sensor providing up to four range measurements for each laser pulse. Using manually annotated ground-truth information on a data set containing 1009 vehicles, we provide quantitative evaluation results showing that the L2MPP model surpasses two earlier grid-based approaches, a 3-D point-cloud-based process and a single-layer MPP solution. The accuracy of the proposed method measured in F-rate is 97% at object level, 83% at pixel level, and 95% at group level. © 1980-2012 IEEE.


Chitnis R.,University of Maryland University College | Hajiaghayi M.,University of Maryland University College | Marx D.,Hungarian Academy of Sciences
Proceedings of the Annual ACM-SIAM Symposium on Discrete Algorithms | Year: 2014

Given a vertex-weighted directed graph G = (V,E) and a set T = {t 1 ,t2,...,tk} of k terminals, the objective of the Strongly Connected Steiner Subgraph (SCSS) problem is to find a vertex set H ⊆ V of minimum weight such that G[H] contains a ti →; tj path for each i ≠ j. The problem is NP-hard, but Feldman and Ruhl (FOCS '99; SICOMP '06) gave a novel nO(k) algorithm for the SCSS problem, where n is the number of vertices in the graph and k is the number of terminals. We explore how much easier the problem becomes on planar directed graphs. Our main algorithmic result is a 2 O(k log k ) · n O(√k) algorithm for planar SCSS, which is an improvement of a factor of O(√k) in the exponent over the algorithm of Feldman and Ruhl. Our main hardness result is a matching lower bound for our algorithm: we show that planar SCSS does not have an f(k) · no(√k) algorithm for any com-putable function /, unless the Exponential Time Hypothesis (ETH) fails. The algorithm eventually relies on the excluded grid theorem for planar graphs, but we stress that it is not simply a straightforward application of treewidth-based techniques: we need several layers of abstraction to arrive to a problem formulation where the speedup due to planarity can be exploited. To obtain the lower bound matching the algorithm, we need a delicate construction of gadgets arranged in a grid-like fashion to tightly control the number of terminals in the created instance. The following additional results put our upper and lower bounds in context: Our 2O(k log k) · n o(√k) algorithm for planar directed graphs can be generalized to graphs excluding a fixed minor. In general graphs, we cannot hope for such a dramatic improvement over the nO(k) algorithm of Feldman and Ruhl: Assuming ETH, SCSS in general graphs does not have an f(k)· n o(k/ log k) algorithm for any computable function /. Feldman and Ruhl generalized their nO(k) algorithm to the more general Directed Steiner Forest (DSF) problem; here the task is to find a subgraph of minimum weight such that for every source si, there is a path to the corresponding terminal ti.We show that that, assuming ETH, there is no f(k) · no(k)time algorithm for DSF on acyclic planar graphs. Copyright © 2014 by the Society for Industrial and Applied Mathematics.


Marx D.,Hungarian Academy of Sciences | Schlotter I.,Budapest University of Technology and Economics
Algorithmica | Year: 2013

We investigate a special case of the INDUCED SUBGRAPH ISOMORPHISM problem, where both input graphs are interval graphs. We show the NP-hardness of this problem, and we prove fixed-parameter tractability of the problem with nonstandard parameterization, where the parameter is the difference |V (G)| - |V (H)|, with G and H being the larger and the smaller input graph, respectively. Intuitively, we can interpret this problem as "cleaning" the graph G, regarded as a pattern containing extra vertices indicating errors, in order to obtain the graph H representing the original pattern. We also prove W[1]-hardness for the standard parameterization where the parameter is |V (H)|. © Springer Science+Business Media, LLC 2011.


Kollar-Hunek K.,Budapest University of Technology and Economics | Heberger K.,Hungarian Academy of Sciences
Chemometrics and Intelligent Laboratory Systems | Year: 2013

Significant progress has been achieved since the introduction of the new similarity measure: the sum of absolute ranking differences (SRDs) [TrAC - Trends in Anal. Chem. 29 (2010) 101-109]. Empirical evidences were accumulated about scaling, selection of the reference (benchmark) vector, cross-validation and grouping of variables (features, models, methods, etc.). The theory has been developed including the repeated observations (ties):. (i)The exact theoretical distribution (null distribution) for 48) an approximation has been developed using the Gaussian distribution fitted on the SRD distribution given by generating of three million n-dimensional random vectors.The validity and features of the SRD methodology with ties are illustrated using two case studies: evaluation of a sensory panel and ranking of financial indicators. © 2013 Elsevier B.V.


Grant
Agency: European Commission | Branch: H2020 | Program: RIA | Phase: PHC-03-2015 | Award Amount: 6.00M | Year: 2016

We hypothesize that inappropriate thyroid hormone action in target cells is a common mechanism underlying susceptibility to age-related degenerative diseases and co-morbidities. Although regulation of systemic thyroid status is well understood and underpins treatment of common thyroid disease, it is only in the last decade that the importance of local regulation of thyroid hormone action in tissue development, homeostasis and repair has been identified. During evolution, this complex temporal and cell-specific regulation has been optimized for development and reproductive fitness but NOT for ageing. Humans with their exceptional longevity are thus exposed to a prolonged period of suboptimal local thyroid hormone action. Consistent with this, thyroid status is a continuous variable within the population that is related to fracture risk, muscle mass and cognitive decline. Moreover, in healthy longevity thyroid status is characterized by thyroid stimulating hormone in the upper half of the reference range. In these studies, we will determine how local regulation of thyroid hormone action controls tissue homeostasis and repair, whilst its dysregulation is a common mechanism underlying chronic disease development during ageing. We focus on osteoporosis, osteoarthritis, neurodegeneration and sarcopenia as paradigm age-related, degenerative disorders. Using cutting-edge technology, we will (i) identify thyroid hormone dependent biomarkers for disease susceptibility in bone, cartilage, central nervous system and skeletal muscle, (ii) manipulate cell-specific thyroid hormone action in these tissues and (iii) develop cell-type specific modulators of thyroid hormone action. THYRAGE integrates cross-disciplinary expertise from clinical and basic scientists, endocrinologists, neuroscientists, gerontologists, and industry-based peptide scientists. These studies will identify and validate novel strategies for prevention and treatment of chronic age-related degenerative disease.


Grant
Agency: European Commission | Branch: FP7 | Program: CP | Phase: ICT-2007.2.2 | Award Amount: 3.48M | Year: 2009

Analysing fine motor activity in articulatory structures of humans or animals in combination with the sounds they emit yields information about their intentions and likely future actions. In this project we propose to develop a cognitive acoustic scene analysis system that is able to synthesize composite representations of animate entities and their behaviour by integrating information from active and passive sound signatures; i.e. from actively self-generated (sonar) sounds and from passively received sounds emitted by those entities. The system is an acoustic analogy to a camera-based visual scene analysis system, particularly suited to detecting the presence and characterising the behaviour of living entities in the environment. This highly innovative proposal builds upon fundamental research on perceptual organisation in natural systems, recent advances in models of auditory processing, and technological developments in ultra-low power, distributed neuromorphic systems and state-of-the-art micro-sonar technology. The biologically inspired architecture and processing mechanisms of the proposed system support autonomous real-time context-dependent operation, allowing it to parse complex mixtures of sounds into meaningful units and categorise them. We propose novel methodologies for evaluating the emergence of representations in autonomous systems, and for communicating the ongoing internal state of the system to human observers. Work on the project will significantly advance scientific understanding of auditory perceptual organisation, technological developments in neuromorphic systems, and the potential impact of artificial cognitive systems. Successful achievement of our objectives will result in the development of a ground breaking proof-of-concept cognitive acoustic scene analysis system capable of robust operation in real-world environments and suitable for deployment in situations where visual information may be unavailable, unobtainable or even undesirable.


Egri P.,Hungarian Academy of Sciences | Vancza J.,Hungarian Academy of Sciences | Vancza J.,Budapest University of Technology and Economics
International Journal of Production Economics | Year: 2012

In this paper, after surveying short-term two-echelon supply channel coordination methods, we present an extended version of the newsvendor model in which the supplier has to fulfil all demand of the customer, even if this calls for an additional setup of production. Given uncertain demand forecast, the solution is an optimal production quantity that minimises the expected total cost including setup, inventory holding and obsolete inventory costs. Then, the model is studied in a decentralised setting where the customer has private information about the demand forecast, while the supplier knows the various cost factors. We suggest such a coordination protocol and payment scheme that provides both partners the right incentive for minimising the total cost: the customer is interested in sharing her unbiased demand forecast and uncertainty, while the suppliers rational decision concurs with the overall optimum. Hence, local decisions based on asymmetric information coordinate the channel in the global sense. The results are also demonstrated by taking some real-life test cases from an industrial study that motivated our work. © 2010 Elsevier B.V. All rights reserved.


News Article | August 22, 2016
Site: www.materialstoday.com

The recipient of the 2017 Acta Materialia Gold Medal is Dr. John J. Jonas, Henry Birks Professor Emeritus, Department of Mining and Materials Engineering, McGill University, Montreal, Canada.   Dr. Jonas was born in Montreal and graduated from McGill University with a bachelor’s degree in Metallurgical Engineering in 1954.  After working for one year at the Steel Company of Wales in Port Talbot, he attended Cambridge University on an Athlone Fellowship and received a Ph.D. degree in Mechanical Sciences in 1960.  On returning to Montreal, he began teaching “mechanical metallurgy” at McGill and built up a research laboratory that includes a number of specialized testing machines and is particularly well equipped for experimental investigations in the field of high temperature deformation. Professor Jonas’ most important scientific contributions are related to determining what happens to sheet steel when it is red hot and flying through a rolling mill at 100 km/hr. The basic phenomena involved include dynamic and post-dynamic recrystallization, dynamic transformation and retransformation, and the dynamic and strain-induced precipitation of carbonitrides.  He and his co-workers have made seminal contributions to all three of these areas of research.  An important related innovation was establishment of the laboratory method of determining the T  (temperature of no-recrystallization) during rolling, a procedure that is now employed in rolling mills worldwide.  This work has resulted in major improvements in the understanding and control of the microstructural changes taking place during steel processing and has led to more accurate computer models for the control of industrial rolling mills. In addition to his research in ferrous metallurgy, Professor Jonas has made numerous contributions to the understanding of the deformation behavior of non-ferrous metals. These have included explanations of variant selection of twins in Mg and Ti, of the causes of plastic instability and flow localization during metal forming, and of texture development during deformation, annealing and phase transformation. He has received numerous awards for this work, including the Réaumur and Gold Medals of the French Metallurgical Society, the Hatchett Medal of the Metals Society (U.K.), the Airey, Dofasco and Alcan Awards of the Canadian Institute of Mining and Metallurgy, the Gold Medal of the Canadian Metal Physics Association, the NSERC Award of Excellence, the Killam Prize for Engineering, the Michael Tenenbaum Award of the American Institute of Metallurgical Engineers, the Hunt Silver Medal of the US Iron and Steel Society, the Barrett Silver Medal and G. Macdonald Young Award of the American Society for Metals, the Alexander von Humboldt Research Award (Germany), and the Yukawa Silver Medal and two Sawamura Bronze Medals of the Iron and Steel Institute of Japan. Professor Jonas has been elected a Fellow of the American Society for Metals, Royal Society of Canada, Canadian Academy of Engineering, Canadian Institute of Mining and Metallurgy, and Hungarian Academy of Sciences.  He is an Honorary Member of the Iron and Steel Institute of Japan and of the Indian Institute of Metals.  He was made an Officer of the Order of Canada in 1993, a Chevalier of the Order of Quebec in 2000, and received the Quebec prize for science (Prix du Québec - Marie Victorin) in 1995.  He has served as a visiting professor in numerous countries, including Argentina, Australia, Belgium, Brazil, Britain, China, France, Germany, Holland, Hungary, India, Iran, Israel, Japan, Mexico, South Africa, South Korea, Spain, Taiwan, the USA and the USSR. In 1985, Dr. Jonas was appointed to the CSIRA/NSERC Chair of Steel Processing at McGill, a position which was funded jointly by the Canadian Steel Industry Research Association and the Natural Sciences and Engineering Research Council of Canada.  In this capacity, he worked closely with the Canadian steel industry, and collaborated in the solution of a number of important processing problems.  He and his colleagues have been granted five sets of international patents associated with steel rolling, three of which have been assigned to the sponsoring companies. He has trained over 200 students and research fellows in the specializations outlined above and he and his students have published more than 800 papers, 100 of them in Acta and Scripta Materialia.  His current h-index (Hirsch number) is 83 and he has more than 25,000 citations to his credit. The Acta Materialia Gold Medal, established in 1972, is awarded annually by the Board of Governors of Acta Materialia, Inc., with partial financial support from Elsevier, Ltd.  Nominees are solicited each year from the Cooperating Societies and Sponsoring Societies of Acta Materialia, Inc., based on demonstrated ability and leadership in materials research.  Dr. Jonas will receive the Gold Medal at the TMS Annual Meeting in San Diego in March 2017.


Keser G.M.,Hungarian Academy of Sciences | Soos T.,Hungarian Academy of Sciences | Kappe C.O.,University of Graz
Chemical Society Reviews | Year: 2014

How do skilled synthetic chemists develop good intuitive expertise? Why can we only access such a small amount of the available chemical space - both in terms of the reactions used and the chemical scaffolds we make? We argue here that these seemingly unrelated questions have a common root and are strongly interdependent. We performed a comprehensive analysis of organic reaction parameters dating back to 1771 and discovered that there are several anthropogenic factors that limit reaction parameters and thus the scope of synthetic chemistry. Nevertheless, many of the anthropogenic limitations such as narrow parameter space and the opportunity for rapid and clear feedback on the progress of reactions appear to be crucial for the acquisition of valid and reliable chemical intuition. In parallel, however, all of these same factors represent limitations for the exploration of available chemistry space and we argue that these are thus at least partly responsible for limited access to new chemistries. We advocate, therefore, that the present anthropogenic boundaries can be expanded by a more conscious exploration of "off-road" chemistry that would also extend the intuitive knowledge of trained chemists. This journal is © the Partner Organisations 2014.


Dyke G.J.,University College Dublin | Osi A.,Hungarian Academy of Sciences
Geological Journal | Year: 2010

We review the previously described Late Cretaceous (Santonian) bird remains from the Csehbánya Formation in the Bakony Mountains of Hungary, augmenting initial work by Ó́si (2008), and add a number of newly collected fossils. All together, the eight fossil specimens so far collected from this site are important to our understanding of avian evolution because they document a large range of taxon body sizes from at least one major lineage (Enantiornithes) and come from a critically undersampled time period in the Cretaceous. Globally, very little fossil bird material has been collected from the middle stages of the Late Cretaceous, the Coniacian and Santonian; most known taxa are either Early Cretaceous (ca. 120 Ma) in age or are from the terminal Campanian and Maastrichtian (ca. 70-65 Ma). Indeed, one of the Csehbánya Formation fossil birds is recognized as a new taxon of large enantiornithine, an avisaurid apparently similar in its largely unfused foot morphology to the Argentine Soroavisaurus and to the North American Avisaurus. The Central European records reviewed in this paper highlight the wide distribution of some Late Cretaceous fossil birds, particularly avisaurid enantiornithines, and lead us to a brief discussion of avian biogeography at the end of the Mesozoic. © 2010 John Wiley & Sons, Ltd.


Giordano M.,Hungarian Academy of Sciences | Meggiolaro E.,University of Pisa
Journal of High Energy Physics | Year: 2014

We show how to obtain the leading energy dependence of hadronic total cross sections, in the framework of the nonperturbative approach to soft high-energy scattering based on Wilson-loop correlation functions, if certain nontrivial analyticity assumptions are satisfied. The total cross sections turn out to be of "Froissart" type, σtothh (s) ~ B log2 s for s → ∞. We also discuss under which conditions the coefficient B is universal, i.e., independent of the hadrons involved in the scattering process. In the most natural scenarios for universality, B can be related to the stable spectrum of QCD, and is predicted to be B th ≠0.22 mb, in fair agreement with experimental results. If we consider, instead, the stable spectrum of the quenched (i.e., pure-gauge) theory, we obtain a quite larger value Bth (Q) ≥ 0.42 mb, suggesting (quite surprisingly) large unquenching effects due to the sea quarks. © 2014 The Author(s).


Giordano M.,Hungarian Academy of Sciences | Meggiolaro E.,University of Pisa
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

We discuss how hadronic total cross sections at high energy depend on the details of QCD, namely on the number of colours Nc and the quark masses. We find that while a "Froissart"-type behaviour σtot~Blog2s is rather general, relying only on the presence of higher-spin stable particles in the spectrum, the value of B depends quite strongly on the quark masses. Moreover, we argue that B is of order O(Nc0) at large Nc, and we discuss a bound for B which does not become singular in the Nf=2 chiral limit, unlike the Froissart-Łukaszuk-Martin bound. © 2015.


Giordano M.,Hungarian Academy of Sciences | Meggiolaro E.,University of Pisa
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

We determine the large-distance behavior of the static dipole-dipole potential for a wide class of gauge theories on nonperturbative grounds, exploiting only general properties of the theory. In the case of QCD, we recover the known results in the regime of small dipole sizes and discuss recent nonperturbative calculations. Moreover, we discuss the case of pure-gauge theories and compare our prediction with the available lattice results. © 2015 American Physical Society.


Schreiber A.,Max Planck Institute for the Science of Light | Cassemiro K.N.,Max Planck Institute for the Science of Light | Potocek V.,Czech Technical University | Gabris A.,Czech Technical University | And 4 more authors.
Physical Review Letters | Year: 2011

We investigate the impact of decoherence and static disorder on the dynamics of quantum particles moving in a periodic lattice. Our experiment relies on the photonic implementation of a one-dimensional quantum walk. The pure quantum evolution is characterized by a ballistic spread of a photon's wave packet along 28 steps. By applying controlled time-dependent operations we simulate three different environmental influences on the system, resulting in a fast ballistic spread, a diffusive classical walk, and the first Anderson localization in a discrete quantum walk architecture. © 2011 American Physical Society.


Schmera D.,University of Basel | Schmera D.,Hungarian Academy of Sciences | Podani J.,A.P.S. University
Ecological Indicators | Year: 2013

Diversity partitioning has been generally used to estimate the contribution of different levels of sampling hierarchy to landscape diversity. However, beta diversity values derived by partitioning strongly depend on focus and sample size and the partitioning is inadequate to express the contribution of landscape elements to community variation. Pairwise dissimilarities are also frequently used to express community turnover, but related approaches capture only limited aspects of it, especially for hierarchical sampling designs. To avoid these shortcomings, we suggest a procedure which quantifies the role of different levels of sampling hierarchy (relative beta diversity) and the share of landscape elements in the corresponding relative beta diversity (contribution value). Our novel method uses pairwise dissimilarities and is based on partitioning a dissimilarity matrix of sampling units. It is suitable to testing various null hypotheses via permutation techniques as demonstrated by artificial and actual data. The method is a valuable tool in ecology because it complements existing approaches while providing a unique way to understand community diversity in space. © 2012 Elsevier Ltd. All rights reserved.


Brangwynne C.P.,Princeton University | Tompa P.,Vrije Universiteit Brussel | Tompa P.,Hungarian Academy of Sciences | Pappu R.V.,Washington University in St. Louis
Nature Physics | Year: 2015

Intracellular organelles are either membrane-bound vesicles or membrane-less compartments that are made up of proteins and RNA. These organelles play key biological roles, by compartmentalizing the cell to enable spatiotemporal control of biological reactions. Recent studies suggest that membrane-less intracellular compartments are multicomponent viscous liquid droplets that form via phase separation. Proteins that have an intrinsic tendency for being conformationally heterogeneous seem to be the main drivers of liquid-liquid phase separation in the cell. These findings highlight the relevance of classical concepts from the physics of polymeric phase transitions for understanding the assembly of intracellular membrane-less compartments. However, applying these concepts is challenging, given the heteropolymeric nature of protein sequences, the complex intracellular environment, and non-equilibrium features intrinsic to cells. This provides new opportunities for adapting established theories and for the emergence of new physics. © 2015 Macmillan Publishers Limited. All rights reserved.


Nelson K.S.,Northwestern University | Khan Z.,Princeton University | Khan Z.,University of Chicago | Molna I.,Hungarian Academy of Sciences | And 4 more authors.
Nature Cell Biology | Year: 2012

Networks of epithelial and endothelial tubes are essential for the function of organs such as the lung, kidney and vascular system. The sizes and shapes of these tubes are highly regulated to match their individual functions. Defects in tube size can cause debilitating diseases such as polycystic kidney disease and ischaemia. It is therefore critical to understand how tube dimensions are regulated. Here we identify the tyrosine kinase Src as an instructive regulator of epithelial-tube length in the Drosophila tracheal system. Loss-of-function Src42 mutations shorten tracheal tubes, whereas Src42 overexpression elongates them. Surprisingly, Src42 acts distinctly from known tube-size pathways and regulates both the amount of apical surface growth and, with the conserved formin dDaam, the direction of growth. Quantitative three-dimensional image analysis reveals that Src42-and dDaam-mutant tracheal cells expand more in the circumferential than the axial dimension, resulting in tubes that are shorter in length-but larger in diameter-than wild-type tubes. Thus, Src42 and dDaam control tube dimensions by regulating the direction of anisotropic growth, a mechanism that has not previously been described. © 2012 Macmillan Publishers Limited. All rights reserved.


Chernichenko K.,University of Helsinki | Madarasz A.,Hungarian Academy of Sciences | Papai I.,Hungarian Academy of Sciences | Nieger M.,University of Helsinki | And 2 more authors.
Nature Chemistry | Year: 2013

Frustrated Lewis pairs are compounds containing both Lewis acidic and Lewis basic moieties, where the formation of an adduct is prevented by steric hindrance. They are therefore highly reactive, and have been shown to be capable of heterolysis of molecular hydrogen, a property that has led to their use in hydrogenation reactions of polarized multiple bonds. Here, we describe a general approach to the hydrogenation of alkynes to cis-alkenes under mild conditions using the unique ansa-aminohydroborane as a catalyst. Our approach combines several reactions as the elementary steps of the catalytic cycle: hydroboration (substrate binding), heterolytic hydrogen splitting (typical frustrated-Lewis-pair reactivity) and facile intramolecular protodeborylation (product release). The mechanism is verified by experimental and computational studies. © 2013 Macmillan Publishers Limited. All rights reserved.


Hu S.,Max Planck Institute For Physik Komplexer Systeme | Turner A.M.,Johns Hopkins University | Penc K.,Hungarian Academy of Sciences | Pollmann F.,Max Planck Institute For Physik Komplexer Systeme
Physical Review Letters | Year: 2014

We investigate the effect of the Berry phase on quadrupoles that occur, for example, in the low-energy description of spin models. Specifically, we study here the one-dimensional bilinear-biquadratic spin-one model. An open question for many years about this model is whether it has a nondimerized fluctuating nematic phase. The dimerization has recently been proposed to be related to Berry phases of the quantum fluctuations. We use an effective low-energy description to calculate the scaling of the dimerization according to this theory and then verify the predictions using large scale density-matrix renormalization group simulations, giving good evidence that the state is dimerized all the way up to its transition into the ferromagnetic phase. We furthermore discuss the multiplet structure found in the entanglement spectrum of the ground state wave functions. © 2014 American Physical Society.


Lindqvist M.,University of Helsinki | Borre K.,University of Helsinki | Axenov K.,University of Helsinki | Kotai B.,Hungarian Academy of Sciences | And 4 more authors.
Journal of the American Chemical Society | Year: 2015

We report the synthesis and reactivity of a chiral aminoborane displaying both rapid and reversible H2 activation. The catalyst shows exceptional reactivity in asymmetric hydrogenation of enamines and unhindered imines with stereoselectivities of up to 99% ee. DFT analysis of the reaction mechanism pointed to the importance of both repulsive steric and stabilizing intermolecular non-covalent forces in the stereodetermining hydride transfer step of the catalytic cycle. © 2015 American Chemical Society