Time filter

Source Type

Munster, Germany

The University of Münster is a public university located in the city of Münster, North Rhine-Westphalia in Germany. The WWU is part of the Deutsche Forschungsgemeinschaft, a society of Germany's leading research universities. Wikipedia.

Missler M.,University of Munster | Sudhof T.C.,Howard Hughes Medical Institute | Biederer T.,Yale University
Cold Spring Harbor Perspectives in Biology | Year: 2012

Chemical synapses are asymmetric intercellular junctions that mediate synaptic transmission. Synaptic junctions are organized by trans-synaptic cell adhesion molecules bridging the synaptic cleft. Synaptic cell adhesion molecules not only connect pre- and postsynaptic compartments, but also mediate trans-synaptic recognition and signaling processes that are essential for the establishment, specification, and plasticity of synapses. A growing number of synaptic cell adhesion molecules that include neurexins and neuroligins, Igdomain proteins such as SynCAMs, receptor phosphotyrosine kinases and phosphatases, and several leucine-rich repeat proteins have been identified. These synaptic cell adhesion molecules use characteristic extracellular domains to perform complementary roles in organizing synaptic junctions that are only now being revealed. The importance of synaptic cell adhesion molecules for brain function is highlighted by recent findings implicating several such molecules, notably neurexins and neuroligins, in schizophrenia and autism. © 2012 Cold Spring Harbor Laboratory Press; all rights reserved. Source

Buchholz S.,University of Munster
Biodiversity and Conservation | Year: 2010

Open inland sand ecosystems harbour a specialised flora and fauna and are among the most endangered habitats in Central Europe. Land-use changes and lack of habitat dynamics are acknowledged as significant drivers for habitat loss and degradation. It is imperative for nature conservation to obtain criteria such as community structure and biodiversity of model groups to assess the conservation value of threatened habitats. By investigating the correlation between ground spider assemblages and habitat structure, the study aimed to find out the indicator potential of spiders in order to promote conservation objectives and management strategies for open inland sand ecosystems. Non-metric multidimensional scaling revealed four habitat groups with distinct spider assemblages that clearly reflected the whole variety of habitat structure types within the study area. Species distribution was constrained by biotic and abiotic gradients while the ecological traits of spiders differed significantly among the groups. Generalised linear models showed that abundances of particular species were significantly correlated with environmental factors and habitat structure, making them thus suitable as focal species to assess natural habitat modifications as well as success of management efforts. Based on these findings, we derived major aims for successful habitat management of inland sand ecosystems taking into account also the needs of arthropod conservation. Management should include both small and large reserves when aiming for higher levels of disturbance, and sand dynamics to prevent increasing scrub encroachment and to create a larger number of early succession stages. © 2010 Springer Science+Business Media B.V. Source

Tudzynski B.,University of Munster
Frontiers in Microbiology | Year: 2014

Fungi occupy diverse environments where they are constantly challenged by stressors such as extreme pH, temperature, UV exposure, and nutrient deprivation. Nitrogen is an essential requirement for growth, and the ability to metabolize a wide variety of nitrogen sources enables fungi to colonize different environmental niches and survive nutrient limitations. Favored nitrogen sources, particularly ammonium and glutamine, are used preferentially, while the expression of genes required for the use of various secondary nitrogen sources is subject to a regulatory mechanism called nitrogen metabolite repression. Studies on gene regulation in response to nitrogen availability were carried out first in Saccharomyces cerevisiae, Aspergillus nidulans, and Neurospora crassa. These studies revealed that fungi respond to changes in nitrogen availability with physiological and morphological alterations and activation of differentiation processes. In all fungal species studied, the major GATA transcription factor AreA and its co-repressor Nmr are central players of the nitrogen regulatory network. In addition to growth and development, the quality and quantity of nitrogen also affects the formation of a broad range of secondary metabolites (SMs). Recent studies, mainly on species of the genus Fusarium, revealed that AreA does not only regulate a large set of nitrogen catabolic genes, but can also be involved in regulating production of SMs. Furthermore, several other regulators, e.g., a second GATA transcription factor, AreB, that was proposed to negatively control nitrogen catabolic genes by competing with AreA for binding to GATA elements, was shown to act as activator of some nitrogen-repressed as well as nitrogen-induced SM gene clusters. This review highlights our latest understanding of canonical (AreA-dependent) and non-canonical nitrogen regulation mechanisms by which fungi may regulate biosynthesis of certain SMs in response to nitrogen availability. © 2014 Tudzynski. Source

Oberleithner H.,University of Munster
Pflugers Archiv European Journal of Physiology | Year: 2015

Negatively charged surfaces of erythrocytes (RBC) reflect properties of the endothelial glycocalyx. Plasma electrolytes counteract these charges and thus control the repulsive forces between RBC and endothelium. Although Na+ is supposed to exert a rather high affinity to the RBC surface, a direct comparison between Na+ and K+ in counteracting the RBC surface has been never made. Therefore, we measured Na+/K+ selectivity of the RBC surface in 20 healthy volunteers applying the previously published salt blood test (SBT). It turned out that the Na+/K+ selectivity ratio of the RBC glycocalyx is on average 6.1 ± 0.39 (ranging from 3 to 9 in different individuals). Considering standard plasma Na+ and K+ concentrations, binding probability of Na+/K+ at the RBC surface is about 180:1. The SBT reveals that plasma K+ counteracts only about 7 % of the negative charges in the RBC glycocalyx. As an in vivo proof of principle, a volunteer’s blood was continuously tested over 6 months while applying a glycocalyx protective polyphenol-rich natural compound (hawthorn extract). It turned out that RBC Na+ sensitivity (the inverse of Na+ buffer capacity) decreased significantly by about 25 % while Na+/K+ selectivity of the RBC glycocalyx declined only slightly by about 8 %. Taken together, (i) plasma Na+ selectively buffers the negative charges of the RBC glycocalyx, (ii) the contribution of K+ in counteracting these negative surface charges is small, and (iii) natural polyphenols applied in vivo increase RBC surface negativity. In conclusion, low plasma Na+ is supposed to favor frictionless RBC-slipping through blood vessels. © 2014, The Author(s). Source

Lanz M.A.,University of Basel | Klostermeier D.,University of Basel | Klostermeier D.,University of Munster
Nucleic Acids Research | Year: 2011

DNA gyrase catalyzes ATP-dependent negative supercoiling of DNA in a strand passage mechanism. A double-stranded segment of DNA, the T-segment, is passed through the gap in a transiently cleaved G-segment by coordinated closing and opening of three protein interfaces in gyrase. T-segment capture is thought to be guided by the C-terminal domains of the GyrA subunit of gyrase that wrap DNA around their perimeter and cause a DNA-crossing with a positive handedness. We show here that the C-terminal domains are in a downward-facing orientation in the absence of DNA, but swing up and rotate away from the gyrase body when DNA binds. The upward movement of the C-terminal domains is an early event in the catalytic cycle of gyrase that is triggered by binding of a G-segment, and first contacts of the DNA with the C-terminal domains, and contributes to T-segment capture and subsequent strand passage. © The Author(s) 2011. Published by Oxford University Press. Source

Zipp F.,Johannes Gutenberg University Mainz | Gold R.,Ruhr University Bochum | Wiendl H.,University of Munster
JAMA Neurology | Year: 2013

IMPORTANCE: Although multiple sclerosis (MS) has long been considered the prototype for an inflammatory, demyelinating disease of the central nervous system, modern histopathology and imaging techniques show that significant damage to neuronal structures already start occurring in the earliest stages of the disease. As the disease progresses, the extent of neuronal pathology accumulates. Therapeutic progress in terms of the prevention of increased disability has only just begun. OBJECTIVE: To review possible diagnostic improvements of neuronal compartment pathology as well as direct therapeutic interventions based on reports from the last decade and outline clinical results from studies and perspectives on the progression of MS. EVIDENCE REVIEW: Literature search focused on publications and the references contained therein, relating to neuronal compartment pathology and direct therapeutic interventions published in the last decade in well-established peer-reviewed journals. The quality of the cited works was ensured by their acceptance by peer review, participation in clinical trials, and authors' own expert assessment. FINDINGS: Current MS therapies aswell as medications that are in late phase 3 trials or under approval exhibit primarily anti-inflammatory properties. However, clinical and imaging data demonstrate the potential of using novel therapies to prevent neuronal damage. Whether these exhibit effects on the neuronal compartment due to interference with the immune system or additional direct effects depends without question on the specific mechanism of action. CONCLUSIONS AND RELEVANCE: Combining anti-inflammatory and direct neuroprotective, neuroregenerative/ repair therapy strategiesmay open up new avenues in the treatment of MS. Copyright 2013 American Medical Association. All rights reserved. Source

Holtmeier F.-K.,University of Munster | Broll G.,University of Osnabruck
Physical Geography | Year: 2010

The altitudinal treeline ecotone is a windy environment where wind velocities and directions are controlled by local mountain topography and also by the distribution pattern and structures of tree stands. Wind may override the role of heat deficiency in determining treeline position, spatial pattern, ecological conditions, and tree growth. Regular strong permanent winds restrict tree height and usually cause asymmetric and suppressed growth forms that are common in the treeline ecotone. Apart from direct physiological and mechanical effects on trees and ground vegetation, wind also disperses seeds, relocates snow, and locally erodes soils in the treeline ecotone. Wind effects must be considered an important factor that may delay or even preclude establishment of seedling trees on wind-swept terrain. Discussions of a potential climatically driven upward shift of the treeline at the landscape and smaller scales should give greater attention to the varying wind effects because warming cannot compensate for these other factors. The relative importance of microsite facilitation providing shelter from the wind will increase in parallel with the upslope migration of the tree limit into a much windier environment. Source

Holzheid A.,University of Munster
Chemical Geology | Year: 2010

This experimental study explores the controls of run duration, oxygen fugacity, silicate melt structure and sulfide melt composition on the size of sulfide melt droplets that generate in sulfur saturated silicate liquids. The sizes of the formed sulfide melt droplets influence the physical behavior of the separate sulfide phases during magma evolution within the Earth's mantle and crust. The relative enrichments of Rh, Pt, and Pd in the primitive mantle melts and of Os, Ir, and Ru in mantle residue mirror the physical and geochemical behavior of sulfide droplets that are finely dispersed in silicate melts and get entrained by ascending primitive mantle melts.fc Hypotheses, that are based on kinetic constraints, to model the formation of the magmatic sulfide deposits of Kambalda and Sudbury can be reinforced by the expected physical behavior of separate sulfide phases within the parental magmas of the magmatic deposits, while formation scenarios of the deposits of Bushveld and Skaergaard remain ambiguous when combining kinetic constraints with expected physical behavior of separate sulfide phases within the parental magmas. © 2010 Elsevier B.V. Source

Nieschlag E.,University of Munster
Deutsches Arzteblatt International | Year: 2013

Conclusion: The diagnosis of KS would be less frequently missed if doctors were more aware of, and attentive to, its key manifestations, particularly the small, firm testes, erectile dysfunction, and the comorbidities mentioned above. If the diagnosis were made more often, patients would more often be able to receive early treatment, which would improve their quality of life.Background: Klinefelter syndrome (KS) with the karyotype 47, XXY is one of the commonest types of congenital chromosomal disorder in males, with an incidence of 0.1% to 0.2% of newborn male infants. It causes hypogonadism and infertility. Until now, however, only about one-quarter of all persons with KS received the diagnosis during their lifetimes.Methods: Selective review of the literature.Results: KS is caused by aneuploidy of the sex chromosomes. Small, firm testes, the manifestations of androgen deficiency (sparse development of male-pattern body hair, greater than average height, lack of libido, erectile dysfunction) and, in more than 90% of affected men, azoospermia are its main features in adults. Affected boys may have verbalization difficulties and problems with learning and socialization. KS is often accompanied by other disturbances such as gynecomastia, varicose veins, thrombosis, osteoporosis, the metabolic syndrome, type 2 diabetes, and epilepsy. The most important therapeutic measure is testosterone supplementation, which should be initiated if the testosterone concentration drops below 12 nmol/L and should be given as directed in the guidelines for the treatment of hypogonadism. This recommendation is made even though there have not been any randomized controlled trials documenting the efficacy of testosterone therapy in adolescents or young adults. In some cases, viable sperm can be obtained from individual testicular tubules by biopsy, so that these patients are able to become fathers. Source

Schmitz J.,University of Munster
Genome Dynamics | Year: 2012

SINEs are short interspersed elements derived from cellular RNAs that repetitively retropose via RNA intermediates and integrate more or less randomly back into the genome. SINEs propagate almost entirely vertically within their host cells and, once established in the germline, are passed on from generation to generation. As non-autonomous elements, their reverse transcription (from RNA to cDNA) and genomic integration depends on the activity of the enzymatic machinery of autonomous retrotransposons, such as long interspersed elements (LINEs). SINEs are widely distributed in eukaryotes, but are especially effectively propagated in mammalian species. For example, more than a million Alu-SINE copies populate the human genome (approximately 13% of genomic space), and few master copies of them are still active. In the organisms where they occur, SINEs are a challenge to genomic integrity, but in the long term also can serve as beneficial building blocks for evolution, contributing to phenotypic heterogeneity and modifying gene regulatory networks. They substantially expand the genomic space and introduce structural variation to the genome. SINEs have the potential to mutate genes, to alter gene expression, and to generate new parts of genes. A balanced distribution and controlled activity of such properties is crucial to maintaining the organism's dynamic and thriving evolution. Copyright © 2012 S. Karger AG, Basel. Source

Chattoraj J.,University Paris Est Creteil | Chattoraj J.,University of Munster | Lemaitre A.,University Paris Est Creteil
Physical Review Letters | Year: 2013

Using numerical simulation of a 2D Lennard-Jones system, we study the crossover from shear thinning to Newtonian flow. We find that the short-time elastic response of our system essentially does not change through this crossover, and show that, in the Newtonian regime, thermal activation triggers shear transformations, i.e., local irreversible shear events that produce Eshelby (long-ranged, anisotropic) deformation fields as previously seen in low-T glasses. Quite surprisingly, these Eshelby fields are found to persist much beyond the α-relaxation time, and shear thinning to coincide with the emergence of correlations between shear relaxation centers. © 2013 American Physical Society. Source

Klaus V.H.,University of Munster
Restoration Ecology | Year: 2013

Urbanization is one of the most severe threats to biodiversity, so why should not we use green space in cities to counteract the biodiversity loss as much as possible? Urban grasslands provide a large number of social, financial, recreational, and environmental ecosystem services but can also support high biodiversity. In this article, I describe the importance of urban grasslands for (local) biodiversity and recommend strengthening restoration ecological research and efforts to optimize these novel ecosystems for conservation purposes. The management intensity of a high proportion of urban grasslands decreased over the last decades. However, species richness of these grasslands is still low, although there is now a great potential for higher plant, but also animal diversity. While communal authorities are interested in cost-efficient but at the same time biodiversity-friendly management of urban grasslands, a well-founded scientific basis for the restoration of urban grassland is still missing. I argue that besides all challenges associated with the restoration of urban habitats we should urgently proceed in the development of appropriate and effective restoration approaches and communicate knowledge gained to urban planners and stakeholders. Widening the scope of restoration ecological research to novel ecosystems such as urban grasslands is one of the most important recent challenges for biodiversity restoration and it gives urban habitats the significance they deserve. © 2013 Society for Ecological Restoration. Source

Within the last couple of years, the understanding of the molecular mechanisms that drive the pathogenesis of diffuse large B-cell lymphoma (DLBCL) has significantly improved. Large-scale gene expression profiling studies have led to the discovery of several molecularly defined subtypes that are characterized by specific oncogene addictions and significant differences in their outcome. Next generation sequencing efforts combined with RNA interference screens frequently identify crucial oncogenes that lead to constitutive activation of various signaling pathways that drive lymphomagenesis. This review summarizes our current understanding of the molecular pathogenesis of the activated B-cell-like (ABC) DLBCL subtype that is characterized by poor prognosis. A special emphasis is put on findings that might impact therapeutic strategies of affected patients. © 2015 by the author; licensee MDPI, Basel, Switzerland. Source

Luttjohann A.,Radboud University Nijmegen | Luttjohann A.,University of Munster | Van Luijtelaar G.,Radboud University Nijmegen
Frontiers in Physiology | Year: 2015

Network mechanisms relevant for the generation, maintenance and termination of spike-wave discharges (SWD), the neurophysiological hallmark of absence epilepsy, are still enigmatic and widely discussed. Within the last years, however, improvements in signal analytical techniques, applied to both animal and human fMRI, EEG, MEG, and ECoG data, greatly increased our understanding and challenged several, dogmatic concepts of SWD. This review will summarize these recent data, demonstrating that SWD are not primary generalized, are not sudden and unpredictable events. It will disentangle different functional contributions of structures within the cortico-thalamo-cortical system, relevant for the generation, generalization, maintenance, and termination of SWD and will present a new "network based" scenario for these oscillations. Similarities and differences between rodent and human data are presented demonstrating that in both species a local cortical onset zone of SWD exists, although with different locations; that in both some forms of cortical and thalamic precursor activity can be found, and that SWD occur through repetitive cyclic activity between cortex and thalamus. The focal onset zone in human data could differ between patients with varying spatial and temporal dynamics; in rats the latter is still poorly investigated. © 2015 Lüttjohann and van Luijtelaar. Source

Oberleithner H.,University of Munster
Pflugers Archiv European Journal of Physiology | Year: 2012

About one third of the population worldwide is supposed to be salt sensitive which is a major cause for arterial hypertension later in life. For preventive actions it is thus desirable to identify salt-sensitive individuals before the appearance of clinical symptoms. Recent observations suggest that the vascular endothelium consists of two saltsensitive barriers in series, the glycocalyx that buffers sodium and the endothelial cell membrane that contains sodium channels. Glycocalyx sodium buffer capacity and sodium channel activity are conversely related to each other. For proof of concept, a so-called salt provocation test (SPT) was developed that should unmask vascular salt sensitivity in humans at virtually any age. Nineteen healthy subjects, ranging from 25 to 63 years of age, underwent two series of 1-h blood pressure measurements after acute ingestion of a salt cocktail with or without addition of a sodium channel blocker effective in vascular endothelium. Differential analysis of the changes in diastolic blood pressure (net ?DP) identified 12 individuals (63 %) as being salt resistant (net ?DP0-0.05±0.62 mmHg) and seven individuals (37 %) as being salt sensitive (net ?DP0+6.98±0.75 mmHg). Vascular salt sensitivity was not related to the age of the study participants. It is concluded that the SPT could be useful for identifying vascular salt sensitivity in humans already early in life. © Springer-Verlag 2012. Source

Hujo W.,University of Munster | Grimme S.,University of Bonn
Journal of Chemical Theory and Computation | Year: 2013

The nonlocal, electron density dependent dispersion correction of Vydrov and Van Voorhis (Vydrov, O. A.; Van Voorhis, T. J. Chem. Phys.2010, 133, 244103), termed VV10 or DFT-NL, has been implemented for structural optimizations of molecules. It is tested in combination with the four (hybrid)GGA density functionals TPSS, TPSS0, B3LYP, and revPBE38 for inter- and intramolecular noncovalent interactions (NCI) and compared to results from atom-pairwise dispersion corrected DFT-D3. The methods are applied to a wide range of different problems, namely the S22 and S66 test sets, large transition metal complexes, water hexamer clusters, hexahelicene, and four other difficult cases of intramolecular NCI. Critical interatomic distances are computed remarkably accurately by both dispersion corrections compared to theoretical or experimental reference data and inter- and intramolecular interactions are treated on equal footing. The methods can be recommended as reliable and robust tools for geometry optimizations of large systems in which long-range dispersion forces are crucial. © 2012 American Chemical Society. Source

Sieg G.,University of Munster
Transportation | Year: 2015

This study presents a cost–benefit analysis of a law requiring cyclists to wear a helmet when riding a bicycle in Germany. The cost benefit-analysis takes into account the benefit of increased security when cyclists wear a helmet or use a transport mode that is less risky than cycling. The analysis also considers the cost of purchasing helmets, reduced fitness when cycling is replaced by a motorized transport mode, the discomfort of wearing helmets and environmental externalities. The benefits of a helmet law are estimated at about 0.7 of the costs. A bicycle helmet law for Germany is found to be a waste of resources. © 2015 Springer Science+Business Media New York Source

Hensen P.,University of Munster
Teaching and Learning in Medicine | Year: 2010

Background: The introduction of the Bologna Process, in particular the implementation of a tiered structure of study programs and degrees, imposes quite some changes in most European higher education systems. The purpose of this article is to introduce some major points of the Bologna Process with regard to medical education in Germany and Europe and to reflect the process of the adoption of a two-cycle bachelor-master system in medicine. Summary: International positions and perspectives of professionals, students, and politicians are discussed which underline the complexity and dynamics of the whole process in contemporary higher education. A short reflection to key aspects of the two-cycle system, and student mobility is provided. Conclusions: Higher education in the whole health care sector may benefit from the Bologna objectives leading to a more permeable, comparable, and compatible medical education system across Europe. © 2010, Taylor & Francis Group, LLC. Source

Nofer J.-R.,University of Munster
Clinical Lipidology | Year: 2013

Antiatherogenic functions exerted by HDLs are impaired in coronary heart disease and other pathologic conditions associated with increased cardiovascular risk; however, the direct assessment of HDL functionality is challenging. In the evaluated study, Dullaart et al. report the inverse association between plasma serum amyloid A (SAA) concentrations and the capacity of HDL to inhibit LDL oxidation in healthy individuals, but not in patients with metabolic syndrome. These findings provide the first indication that SAA determination might be helpful as an indirect measure for the antioxidative capacity of HDL. However, the utility of SAA measurement as a proxy for HDL functionality may be limited to certain populations. © 2013 Future Medicine Ltd. Source

Schafer H.J.,University of Munster
Comptes Rendus Chimie | Year: 2011

In organic electrosynthesis C-C bond formation and functional group interconversion proceed via reactive intermediates that are generated by electron transfer at the anode and cathode. Electron transfer combined with a chemical reaction provides conversions that are not available in non-electrochemical reactions. These are potential selectivity, redox-umpolung, and the substitution of a hydrogen atom for a nucleophile or the addition of two nucleophiles to a double bond in one-pot reactions. Furthermore electrolysis is well suited for oxidation and reduction of functional groups. Electrochemical syntheses need mostly fewer steps, produce less waste, provide a cheaper reagent, require less auxiliaries and allow often an easier scale-up than non-electrochemical syntheses. In addition, they can be conducted at ambient temperature and pressure. All these qualities agree well with the rules of green chemistry. This statement is substantiated with examples of C-C bond formation and functional group interconversion at the anode and cathode. © 2011 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved. Source

Erker G.,University of Munster
Comptes Rendus Chimie | Year: 2011

Frustrated Lewis pairs, comprised of combinations of sterically encumbered phosphine (or amine) Lewis bases with boron Lewis acids containing the strongly electron withdrawing bulky pentafluorophenyl substituents, show very remarkable reaction behaviour. They are able to cooperatively induce heterolytic splitting of dihydrogen under mild conditions. They cooperatively add to various unsaturated organic compounds, including carbon dioxide. With some substrates competing 1,1-carboboration reactions become important. The latter reaction has methodically been developed into a conceptual alternative to the ubiquitous hydroboration reaction and has been used for the development of a novel way of carbon-carbon bond activation. © 2011 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved. Source

Antel J.,Montreal Neurological Institute | Antel S.,Montreal Neurological Institute | Caramanos Z.,Montreal Neurological Institute | Arnold D.L.,Montreal Neurological Institute | Kuhlmann T.,University of Munster
Acta Neuropathologica | Year: 2012

Multiple sclerosis (MS), the most frequent demyelinating disease, is characterized by a variable disease course. The majority of patients starts with relapsing remitting (RR) disease; approximately 50-60% of these patients progress to secondary progressive (SP) disease. Only about 15% of the patients develop a progressive disease course from onset, termed primary progressive multiple sclerosis (PPMS); the underlying pathogenic mechanisms responsible for onset of the disease with either PPMS or relapsing remitting multiple sclerosis (RRMS) are unknown. Patients with PPMS do not show a female predominance and usually have a later onset of disease compared to patients with RRMS. Monozygous twins can be concordant or discordant for disease courses indicating that the disease course is not only genetically determined. Primary progressive multiple sclerosis and secondary progressive multiple sclerosis (SPMS) share many similarities in imaging and pathological findings. Differences observed among the different disease courses are more of a quantitative than qualitative nature suggesting that the different phenotypes are part of a disease spectrum modulated by individual genetic predisposition and environmental influences. In this review, we summarize the knowledge regarding the clinical, epidemiological, imaging, and pathological characteristics of PPMS and compare those characteristics with RRMS and SPMS. © Springer-Verlag 2012. Source

Echterhoff G.,University of Munster
Behavioral and Brain Sciences | Year: 2013

In examining the utility of the action view advanced in the Pickering & Garrod (P&G) target article, I first consider its contribution to the analysis of language vis-à-vis earlier language-as-action approaches. Second, I assess the relation between coordinated joint action, which serves as a blueprint for dialogue coordination, and the experience of shared reality, a key concomitant and product of interpersonal communication. Copyright © 2013 Cambridge University Press. Source

Dabritz J.,Murdoch Childrens Research Institute | Dabritz J.,University of Melbourne | Dabritz J.,University of Munster | Dabritz J.,The Interdisciplinary Center
American Journal of Physiology - Gastrointestinal and Liver Physiology | Year: 2014

Current literature consolidates the view of Crohn's disease (CD) as a form of immunodeficiency highlighting dysregulation of intestinal innate immunity in the pathogenesis of CD. Intestinal macrophages derived from blood monocytes play a key role in sustaining the innate immune homeostasis in the intestine, suggesting that the monocyte/macrophage compartment might be an attractive therapeutic target for the management of CD. Granulocyte macrophage colony-stimulating factor (GM-CSF) is a hematopoietic growth factor that also promotes myeloid cell activation, proliferation, and differentiation. GM-CSF has a protective effect in human CD and mouse models of colitis. However, the role of GM-CSF in immune and inflammatory reactions in the intestine is not well defined. Beneficial effects exerted by GM-CSF during intestinal inflammation could relate to modulation of the mucosal barrier function in the intestine, including epithelial cell proliferation, survival, restitution, and immunomodulatory actions. The aim of this review is to summarize potential mechanistic roles of GM-CSF in intestinal innate immune cell homeostasis and to highlight its central role in maintenance of the intestinal immune barrier in the context of immunodeficiency in CD. © 2014 the American Physiological Society. Source

Nieschlag E.,University of Munster
Handbook of experimental pharmacology | Year: 2010

The principle of hormonal male contraception based on suppression of gonadotropins and spermatogenesis has been established over the last three decades. All hormonal male contraceptives use testosterone, but only in East Asian men can testosterone alone suppress spermatogenesis to a level compatible with contraceptive protection. In Caucasians, additional agents are required of which progestins are favored. Current clinical trials concentrate on testosterone combined with norethisterone, desogestrel, etonogestrel, DMPA, or nestorone. The first randomized, placebo-controlled clinical trial performed by the pharmaceutical industry demonstrated the effectiveness of a combination of testosterone undecanoate and etonogestrel in suppressing spermatogenesis in volunteers. Source

Bauer J.,University Childrens Hospital of Muenster | Gerss J.,University of Munster
Clinical Nutrition | Year: 2011

Background & aims: The primary objective of this study was to investigate the composition of breast milk of mothers with extremely preterm infants (<28 weeks) for their nutrient content over the first 8 weeks of lactation, and to compare premature to term milk. Methods: Breast milk from 102 mothers who had delivered preterm infants and from 10 mothers who had delivered term infants were collected longitudinally. Fat, protein, carbohydrate, minerals and energy content were estimated weekly in each participant. Milk samples were representative of complete 24-h cycles. Results: Carbohydrate, fat and energy concentrations were significantly higher in preterm than in term milk (p < 0.05). Protein content of both preterm and term milk decreased with the progress of lactation demonstrating significantly higher values in extremely preterm milk (<28 weeks) than in moderately preterm and term milk (p < 0.0001). The sodium levels of preterm milk were significantly elevated (p < 0.05) only in the first week. Other changes in mineral content were detected neither in preterm nor term milk. Conclusions: Our data provide new information on the macronutrient content of milk in mothers of extremely preterm infants with possible implications for the nutrition of this population. © 2010 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. Source

Erker G.,University of Munster
Dalton Transactions | Year: 2011

Frustrated Lewis pairs are playing an increasingly important role in organometallic chemistry. Examples are presented and discussed where organometallic systems themselves serve as the Lewis base or Lewis acid components in frustrated Lewis pair chemistry, mostly through their attached functional groups. Activation of dihydrogen takes place easily in many of these systems. This may lead to the generation of novel catalyst systems but also in many cases to the occurrence of specific reactions at the periphery of the organometallic frameworks. Increasingly, FLP reactions are used to carry out functional group conversions in organometallic systems under mild reaction conditions. The limits of typical FLP reactivity are explored with selected organometallic examples, a discussion that points toward new developments, such as the discovery of facile new 1,1-carboboration reactions. Learning more and more about the broad spectrum of frustrated Lewis pair chemistry helps us to find novel reactions and applications. © The Royal Society of Chemistry 2011. Source

Edwards P.G.,University of Cardiff | Hahn F.E.,University of Munster
Dalton Transactions | Year: 2011

Poly-NHC (NHC = N-heterocyclic carbene) ligands emerged almost immediately after the first stable NHCs had been described. Macrocyclic ligands, featuring NHC donor groups and their metal complexes, however, remained rare until recently. This perspective highlights modern developments in the fields of synthesis and coordination chemistry of macrocyclic poly-NHC ligands. These include the synthesis of tetracarbene ligands which were obtained from complexes of β-functionalized isocyanides followed by cyclization of the coordinated iscocyanide ligands to NH,NH-functionalized NHCs and the subsequent metal template controlled bridging alkylation of the NH,NH-NHCs to yield the macrocycle. The template synthesis of ligands featuring a mixed NHC/phosphine donor set like [11]ane-P2CNHC and [16]ane-P 2CNHC 2 by linkage of NH,NH-NHCs to different phosphines is also presented. Finally, methods for the preparation of cyclic polyazolium salts, their deprotonation and metalation and the different modes of coordination of such macrocyclic poly-NHC ligands are discussed. © 2011 The Royal Society of Chemistry. Source

Functional group chemistry at the group 4 bent metallocenes is still a challenge, due to the special features of these early-metal systems. Nevertheless, an increasing number of reactions and protocols is being developed for attaching organic functional groups at the bent-metallocene frameworks and for carrying out reactions with them. Here some bio-organometallic bent metallocene systems are discussed. Chemical transformations are presented and discussed, including olefin metathesis and even variants of the Mannich reaction. It is shown that intramolecular [2 + 2] cycloaddition reactions between alkenyl substituents at the Cp or indenyl rings under dynamic topochemical reaction control can lead to ansa-metallocenes. Frustrated Lewis pair chemistry provides tools, for example, for reduction reactions under very mild conditions. © 2011 American Chemical Society. Source

Purwins H.-G.,University of Munster
IEEE Transactions on Plasma Science | Year: 2011

Various partly strange self-organized patterns can be observed experimentally in the distribution of the luminescence radiation density and the corresponding current density in planar low-temperature dielectric barrier gas discharge systems. © 2006 IEEE. Source

Dugas M.,University of Munster
BMC Medical Informatics and Decision Making | Year: 2015

Background: Clinical trials apply standards approved by regulatory agencies for Electronic Data Capture (EDC). Operational Data Model (ODM) from Clinical Data Interchange Standards Consortium (CDISC) is commonly used. Electronic Health Record (EHR) systems for patient care predominantly apply HL7 standards, specifically Clinical Document Architecture (CDA). In recent years more and more patient data is processed in electronic form. Results: An open source reference implementation was designed and implemented to convert forms between ODM and CDA format. There are limitations of this conversion method due to different scope and design of ODM and CDA. Specifically, CDA has a multi-level hierarchical structure and CDA nodes can contain both XML values and XML attributes. Conclusions: Automated transformation of ODM files to CDA and vice versa is technically feasible in principle. © 2015 Dugas; licensee BioMed Central. Source

Pottgen R.,University of Munster
Zeitschrift fur Anorganische und Allgemeine Chemie | Year: 2014

Group-subgroup relations are a compact and concise tool for structure systemization. The present review summarizes the use of Bärnighausen trees for classification of intermetallic structures into structural families. The overview starts with group-subgroup relationships between the structures of the metallic elements (W, In, α-Po, β-Po, Pa, α-Sn, β-Sn) followed by examples for ordered close-packed arrangements that derive from fcc, hcp, and bcc subcells (e.g. CuAu, Cu3Au, MoNi4, ZrAl 3, FeAl, MoSi2). The main focus lies on more complex structures that derive from aristotypes with comparatively high space group symmetry: AlB2, Fe2P, U3Si2, BaAl4, La3Al11, NaZn13, CaCu 5, and Re3B. The symmetry reductions arise from coloring of sites with different atoms or from distortions / puckering due to size restrictions (different radii of atoms). The resulting superstructures are discussed along with the consequences for diffraction experiments, chemical bonding, and physical properties. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Studer A.,University of Munster | Curran D.P.,University of Pittsburgh
Nature Chemistry | Year: 2014

The electron is an efficient catalyst for conducting various types of radical cascade reaction that proceed by way of radical and radical ion intermediates. But because electrons are omnipresent, catalysis by electrons often passes unnoticed. In this Review, a simple analogy between acid/base catalysis and redox catalysis is presented. Conceptually, the electron is a catalyst in much the same way that a proton is a catalyst. The 'electron is a catalyst' paradigm unifies mechanistically an assortment of synthetic transformations that otherwise have little or no apparent relationship. Diverse radical cascades, including unimolecular radical substitution reactions (S RN 1-type chemistry), base-promoted homolytic aromatic substitutions (BHAS), radical Heck-type reactions, radical cross-dehydrogenative couplings (CDC), direct arene trifluoromethylations and radical alkoxycarbonylations, can all be viewed as electron-catalysed reactions. Source

Dhermain F.G.,Institute Gustave Roussy | Hau P.,University of Regensburg | Lanfermann H.,Hannover Medical School | Jacobs A.H.,University of Munster | And 2 more authors.
The Lancet Neurology | Year: 2010

Imaging techniques are important for accurate diagnosis and follow-up of patients with gliomas. T1-weighted MRI, with or without gadolinium, is the gold standard method. However, this technique only reflects biological activity of the tumour indirectly by detecting the breakdown of the blood-brain barrier. Therefore, especially for low-grade glioma or after treatment, T1-weighted MRI enhanced with gadolinium has substantial limitations. Development of more advanced imaging methods to improve outcomes for individual patients is needed. New imaging methods based on MRI and PET can be employed in various stages of disease to target the biological activity of the tumour cells (eg, increased uptake of aminoacids or nucleoside analogues), the changes in diffusivity through the interstitial space (diffusion-weighted MRI), the tumour-induced neovascularisation (perfusion-weighted MRI or contrast-enhanced MRI, or increased uptake of aminoacids in endothelial wall), and the changes in concentrations of metabolites (magnetic resonance spectroscopy). These techniques have advantages and disadvantages, and should be used in conjunction to best help individual patients. Advanced imaging techniques need to be validated in clinical trials to ensure standardisation and evidence-based implementation in routine clinical practice. © 2010 Elsevier Ltd. Source

Hirshberg I.,Ben - Gurion University of the Negev | Winter W.,University of Munster | Zacharias J.,University of Glasgow
Communications in Mathematical Physics | Year: 2015

We develop the concept of Rokhlin dimension for integer and for finite group actions on C*-algebras. Our notion generalizes the so-called Rokhlin property, which can be thought of as Rokhlin dimension 0. We show that finite Rokhlin dimension is prevalent and appears in cases in which the Rokhlin property cannot be expected: the property of having finite Rokhlin dimension is generic for automorphisms of Z-stable C*-algebras, where Z denotes the Jiang–Su algebra. Moreover, crossed products by automorphisms with finite Rokhlin dimension preserve the property of having finite nuclear dimension, and under a mild additional hypothesis also preserve Z -stability. In topological dynamics our notion may be interpreted as a topological version of the classical Rokhlin lemma: automorphisms arising from minimal homeomorphisms of finite dimensional compact metrizable spaces always have finite Rokhlin dimension. The latter result has by now been generalized by Szabó to the case of free and aperiodic Z-actions on compact metrizable and finite dimensional spaces. © 2015, The Author(s). Source

Busch A.,Copenhagen University | Hippler M.,University of Munster
Biochimica et Biophysica Acta - Bioenergetics | Year: 2011

Eukaryotic photosystem I consists of two functional moieties: the photosystem I core, harboring the components for the light-driven charge separation and the subsequent electron transfer, and the peripheral light-harvesting complex (LHCI). While the photosystem I-core remained highly conserved throughout the evolution, with the exception of the oxidizing side of photosystem I, the LHCI complex shows a high degree of variability in size, subunits composition and bound pigments, which is due to the large variety of different habitats photosynthetic organisms dwell in. Besides summarizing the most current knowledge on the photosystem I-core structure, we will discuss the composition and structure of the LHCI complex from different eukaryotic organisms, both from the red and the green clade. Furthermore, mechanistic insights into electron transfer between the donor and acceptor side of photosystem I and its soluble electron transfer carrier proteins will be given. This article is part of a Special Issue entitled: Regulation of Electron Transport in Chloroplasts. © 2010 Published by Elsevier B.V. Source

Jacobi A.M.,University of Munster | Dorner T.,Charite University Medicine Berlin and Deutsches Rheumaforschungszentrum Berlin
Current Opinion in Pharmacology | Year: 2010

Although B cells represent major contributors to rheumatoid arthritis (RA) pathogenesis, their precise roles in the induction and maintenance of abnormal immune activation in this entity remains poorly understood. As proof of principle, rituximab, a chimeric B cell depleting anti-CD20-antibody, has demonstrated that depletion of B cells can substantially improve signs and symptoms as well as physical function and inhibit radiologic progression that led to the approval of this agent to treat patients with moderate to severe RA lacking response to TNF-alpha blocking agents in 2006. Placebo-controlled clinical trials as well as subsequent studies and experiences further contributed to our understanding of the mechanism of action of rituximab, but a number of open questions remain. This review summarizes some lessons learned from B cell depletion in RA including particular safety aspects. Of importance using this therapy is that it apparently provides the highest likelihood of response in seropositive RA patients. This observation differentiates it from other currently available therapies and closes the conceptual loop that the underlying immunopathogenesis involves B cells requiring 'targeted' therapy. © 2010 Elsevier Ltd. Source

Mata J.A.,Jaume I University | Hahn F.E.,University of Munster | Peris E.,Jaume I University
Chemical Science | Year: 2014

This minireview reports the most recent advances in the use of heterometallic catalysts based on single-frame N-heterocyclic carbene ligands. The article describes the synthetic strategies for the preparation of heterometallic catalysts, and their applications in the design of tandem processes by combining the catalytic properties associated with the two (or more) different metal centers. Several examples are discussed in which the use of heterometallic complexes results in a clear enhancement of the catalytic outcome compared to the results provided by mixtures of related homometallic complexes. The field constitutes a research area that is full of potential and is at its very earliest stage. © 2014 the Partner Organisations. Source

Stephan D.W.,University of Toronto | Erker G.,University of Munster
Chemical Science | Year: 2014

Frustrated Lewis pairs have been used to activate a variety of small molecules. In this review we focus on the recent chemistry of FLPs with CO 2, CO, N2O, NO and SO2. While FLP capture of these small molecule is achieved in all of these cases, subsequent applications of the products include stoichiometric and catalytic reductions of CO 2, C-O bond scission of CO and use of FLP-NO radicals in polymerization. © 2014 the Partner Organisations. Source

Willich N.,University of Munster
Strahlentherapie und Onkologie : Organ der Deutschen Röntgengesellschaft ... [et al] | Year: 2012

Technical and methodical developments have changed radiation oncology substantially over the last 40 years. Modern imaging methods, e.g., computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and ultrasound (US), have not only improved the detection of tumors but have also become tools for computed treatment planning. Megavoltage irradiation with accelerators using photons and electrons with large and small fields, intensity modulation (IMRT), image-guided radiotherapy (IGRT), stereotactic irradiation and radiosurgery, intraoperative radiotherapy (IORT), and modern remote controlled afterloading brachytherapy have made high precision radiotherapy increasingly possible. Hadron therapy has potential for further developments. Radiation oncology today is an interdisciplinary modality and increasingly considers interactions with new drugs and differentiated surgical methods. There is a strong need for comprehensive evaluation of the new methods and also for translational research in biology of tumors and normal tissue biology as well as in medical physics and techniques. Source

Fetzner S.,University of Munster
Journal of Biotechnology | Year: 2014

Bacteria use cell-to-cell communication systems based on chemical signal molecules to coordinate their behavior within the population. These quorum sensing systems are potential targets for antivirulence therapies, because many bacterial pathogens control the expression of virulence factors via quorum sensing networks. Since biofilm maturation is also usually influenced by quorum sensing, quenching these systems may contribute to combat biofouling. One possibility to interfere with quorum sensing is signal inactivation by enzymatic degradation or modification. Such quorum quenching enzymes are wide-spread in the bacterial world and have also been found in eukaryotes. Lactonases and acylases that hydrolyze N-acyl homoserine lactone (AHL) signaling molecules have been investigated most intensively, however, different oxidoreductases active toward AHLs or 2-alkyl-4(1. H)-quinolone signals as well as other signal-converting enzymes have been described. Several approaches have been assessed which aim at alleviating virulence, or biofilm formation, by reducing the signal concentration in the bacterial environment. These involve the application or stimulation of signal-degrading bacteria as biocontrol agents in the protection of crop plants against soft-rot disease, the use of signal-degrading bacteria as probiotics in aquaculture, and the immobilization or entrapment of quorum quenching enzymes or bacteria to control biofouling in membrane bioreactors. While most approaches to use quorum quenching as antivirulence strategy are still in the research phase, the growing number of organisms and enzymes known to interfere with quorum sensing opens up new perspectives for the development of innovative antibacterial strategies. © 2014 Elsevier B.V. Source

Kruglyak V.V.,University of Exeter | Demokritov S.O.,University of Munster | Grundler D.,TU Munich
Journal of Physics D: Applied Physics | Year: 2010

Magnonics is a young field of research and technology emerging at the interfaces between the study of spin dynamics, on the one hand, and a number of other fields of nanoscale science and technology, on the other. We review the foundations and recent achievements in magnonics in view of guiding further progress from studying fundamental magnonic phenomena towards applications. We discuss the major challenges that have to be addressed in future research in order to make magnonics a pervasive technology. © 2010 IOP Publishing Ltd. Source

This review focuses on infants' emerging awareness of mental states and demonstrates how cultural models-consisting of parenting beliefs and practices-interact dynamically with biologically prepared developmental potentialities in shaping infant behavior and development. Contrasting very different cultural contexts, it is suggested that caregivers' visual contingent responsiveness and associated processes are key features of early mother-infant interaction. They (a) are informed by intuitive parenting and culture-specific ethnotheories that, as a consequence, (b) differentially sensitize infants for internal mental states in the 1st year and beyond, and thereby (c) provide mechanisms that specify how culture not only shapes human behavior and experience but also produces culture-specific developmental pathways. © 2015 The Author. Source

Zarbock A.,University of Munster | Milles K.,Heinrich Heine University Dusseldorf
Current Opinion in Anaesthesiology | Year: 2015

Purpose of review Acute kidney injury (AKI) is a common and serious complication that significantly increases morbidity, mortality, and cost of care after surgery. In this article, we review recent studies that deal with strategies for renal protection and the prevention of AKI after surgery. Recent findings A prerequisite for any prophylactic intervention is the identification of patients at risk for AKI or those with acute kidney damage before kidney function deteriorates. In this context, new biomarkers can help to detect cellular injury early. This way, a window for interventions can be opened. Several studies demonstrated the tissue-protective effect of remote ischemic preconditioning in various organs. There is clear evidence that use of balanced crystalloid fluids and the avoidance of hyperchloremic solutions for infusion therapy can reduce the incidence of AKI. Preliminary data show a protective effect if dexmedetomidine is used as a sedative agent following cardiac surgery. The most important intervention with proven efficacy to protect from AKI is aggressive hemodynamic stabilization. Summary Early identification of patients at risk for AKI is crucial to apply any protective intervention. An improved perioperative management is required to prevent AKI. Although pharmacological therapies aiming to protect AKI are under evaluation, hemodynamic optimization and avoidance of nephrotoxic drugs are critical for perioperative patient. © 2015 Wolters Kluwer Health, Inc. All rights reserved. Source

Atilla-Gokcumen G.E.,Dana-Farber Cancer Institute | Atilla-Gokcumen G.E.,State University of New York at Buffalo | Muro E.,Kings College London | Relat-Goberna J.,Kings College London | And 7 more authors.
Cell | Year: 2014

Although massive membrane rearrangements occur during cell division, little is known about specific roles that lipids might play in this process. We report that the lipidome changes with the cell cycle. LC-MS-based lipid profiling shows that 11 lipids with specific chemical structures accumulate in dividing cells. Using AFM, we demonstrate differences in the mechanical properties of live dividing cells and their isolated lipids relative to nondividing cells. In parallel, systematic RNAi knockdown of lipid biosynthetic enzymes identified enzymes required for division, which highly correlated with lipids accumulated in dividing cells. We show that cells specifically regulate the localization of lipids to midbodies, membrane-based structures where cleavage occurs. We conclude that cells actively regulate and modulate their lipid composition and localization during division, with both signaling and structural roles likely. This work has broader implications for the active and sustained participation of lipids in basic biology. © 2014 The Authors. Source

Langelage J.,Bielefeld University | Philipsen O.,University of Munster
Journal of High Energy Physics | Year: 2010

In this paper we calculate the pressure of pure lattice Yang-Mills theories and lattice QCD with heavy quarks by means of strong coupling expansions. Dynamical fermions are introduced with a hopping parameter expansion, which also allows for the incorporation of finite quark chemical potential. We show that in leading orders the results are in full agreement with expectations from the hadron resonance gas model, thus validating it with a first principles calculation. For pure Yang-Mills theories we obtain the corresponding ideal glueball gas, in QCD with heavy quarks our result equals that of an ideal gas of mesons and baryons. Another finding is that the Yang-Mills pressure in the large N limit is of order ̃ N 0 to the calculated orders, when the inverse 't Hooft coupling is used as expansion parameter. This property is expected in the confined phase, where our calculations take place. © SISSA 2010. Source

Zarbock A.,University of Munster | Kellum J.A.,University of Pittsburgh
Critical Care Medicine | Year: 2016

Acute kidney injury is a common complication in critically ill patients and is associated with increased morbidity and mortality. Sepsis, major surgery, and nephrotoxic drugs are the most common causes of acute kidney injury. There is currently no effective strategy available to prevent or treat acute kidney injury. Therefore, novel treatment regimens are required to decrease acute kidney injury prevalence and to improve clinical outcomes. Remote ischemic preconditioning, triggered by brief episodes of ischemia and reperfusion applied in distant tissues or organs before the injury of the target organ, attempts to invoke adaptive responses that protect against acute kidney injury. We sought to evaluate the clinical evidence for remote ischemic preconditioning as a potential strategy to protect the kidney and to review the underlying mechanisms in light of recent studies. Data Sources: We searched PubMed for studies reporting the effect of remote ischemic preconditioning on kidney function in surgical patients (search terms: "remote ischemic preconditioning," "kidney function," and "surgery"). We also reviewed bibliographies of relevant articles to identify additional citations. Study Selection: Published studies, consisting of randomized controlled trials, are reviewed. Data Extraction: The authors used consensus to summarize the evidence behind the use of remote ischemic preconditioning. Data Synthesis: In addition, the authors suggest patient populations and clinical scenarios in which remote ischemic preconditioning might be best applied. Conclusions: Several experimental and clinical studies have shown tissue-protective effects of remote ischemic preconditioning in various target organs, including the kidneys. Remote ischemic preconditioning may offer a novel, noninvasive, and inexpensive treatment strategy for decreasing acute kidney injury prevalence in high-risk patients. Although many new studies have further advanced our knowledge in this area, the appropriate intensity of remote ischemic preconditioning, its mechanisms of action, and the role of biomarkers for patient selection and monitoring are still unknown. © 2016 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. Source

Stummer W.,University of Munster | Van Den Bent M.J.,Erasmus University Rotterdam | Westphal M.,Universitatsklinikum Eppendorf
Acta Neurochirurgica | Year: 2011

Background: This article discusses data from 3 randomized phase 3 trials, supporting a role for surgery in glioblastoma. Methods: Data were reviewed by extent of resection during primary surgery from the ALA-Glioma Study (fluorescence-guided versus conventional resection), the BCNU wafer study (BCNU wafer versus placebo), and the EORTC Study 26981-22981 (radiotherapy versus chemoradiotherapy with temozolomide). Results: For glioblastoma patients in the ALA study, median survival was 16.7 and 11.8 months for complete versus partial resection, respectively (P<0.0001). Survival effects were maintained after correction for differences in age and tumor location. For glioblastoma patients who received ≥90% resection in the BCNU wafer study, median survival increased for BCNU wafer versus placebo (14.5 versus 12.4 months, respectively; P=0.02), but no survival increase was found for <90% resection (11.7 versus 10.6 months, respectively; P=0.98). In the EORTC study, absolute median gain in survival with chemoradiotherapy versus radiotherapy was greatest for complete resections (+4.1 months; P=0.0001), compared with partial resections (+1.8 months; P=0.0001), or biopsies (+1.5 months; P=0.088), suggesting surgery enhanced adjuvant treatment. Conclusion: Complete resection appears to improve survival and may increase the efficacy of adjunct/adjuvant therapies. If safely achievable, complete resection should be the surgical goal for glioblastoma. © 2011 Springer-Verlag. Source

Klotz L.,University of Munster | Knolle P.,University of Bonn
FEBS Letters | Year: 2011

IL-17 producing T helper (TH17) cells have recently been identified as a new subset involved in the pathogenesis of various autoimmune diseases. Exogenous factors promoting TH17 induction have been intensely characterized, whereas the T cell-intrinsic mechanisms influencing TH17 development are less established. The transcription factor RORγt, which belongs to the nuclear receptor superfamily, serves as master transcription factor essential for TH17 differentiation, whereas other members of the nuclear receptor family control TH17 differentiation and contribute to protection from TH17-mediated autoimmunity. In this review, we will highlight the most recent understandings about the regulatory function of nuclear receptors during TH17 cell differentiation. © 2011 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved. Source

Poll R.,University of Munster
Program | Year: 2010

Purpose: The purpose of this paper is to present results of NUMERIC, a project of the European Commission that started out to define measures and methods for assessing the current state of digitisation in Europe's cultural institutions (archives, libraries and museums). The central task of the NUMERIC project was to develop a framework for the collection of statistical data that would be most suitable to give a national overview of digitisation. Design/methodology/approach: The project developed definitions and data collection methods for the intended survey. After testing the survey in a number of archives, libraries and museums, the project team collaborated with nominated experts in each member country for choosing an adequate sample of cultural institutions throughout Europe. Findings: In spite of all differences between countries and institutions, the project attempted an estimate of the present state of digitisation in Europe. According to the statements of the responding institutions in the sample, only about 19 per cent of the analogue collections in cultural institutions have as yet been digitised, for about 30 per cent the institutions do not plan digitisation, and at least 50 per cent of the analogue collections in cultural institutions are still waiting digitisation. Research limitations/implications: As many questions in the survey could only be answered by some of the institutions, some results - especially usage data - are not statistically valid. Different samples of cultural institutions in the countries, different completion rates of answers for each question and differing interpretations of "digitisation" have affected the results. Originality/value: The paper acquaints professionals in culture statistics and in digitisation projects with the set of well-defined statistical data that was tested in the NUMERIC project. It also shows the problems and limitations of these data. © Emerald Group Publishing Limited. Source

Evers S.,University of Munster
Current Pain and Headache Reports | Year: 2013

Studies on the acute treatment of migraine in children and adolescents are rare and difficult to design. In particular, the high placebo response in some trials makes it difficult to prove efficacy of a verum drug. All available placebo-controlled trials on the acute migraine treatment in children and adolescents with a triptan were analyzed with respect to different end points (rate of pain free and pain relief at 2 hours; rate of adverse events). We identified 6 crossover and 11 parallel group trials. Although the trials were heterogenous with respect to the triptans and the dosage, pooled data were calculated. The pooled responder rate of triptans for 2 hours pain free was 36.0 % in crossover trials (significant difference to placebo with 17.7 %) and 32.5 % in parallel group trials (significant difference to placebo with 26.3 %). Triptans also showed a significantly higher pain relief rate at 2 hours than placebo both in crossover and parallel group trials. The rate of adverse events was significantly higher after triptans than after placebo. However, triptans were well tolerated in all trials. At least 1 trial with significant efficacy was found for sumatriptan (10-20 mg nasal spray), zolmitriptan (2.5-5 mg tablet), rizatriptan (5-10 mg tablet), and almotriptan (12.5-25 mg tablet). Placebo rates for efficacy were considerably lower in crossover trials than in parallel group trials. This analysis suggests that parallel group trials on the acute treatment of migraine in children and adolescents with a triptan show a very low therapeutic gain because of a high placebo rate. The verum response rates, however, are very similar to those seen in adulthood trials. However, there is sufficient evidence that at least some triptans are efficacious even in childhood and adolescence. © 2013 Springer Science+Business Media New York. Source

Nofer J.-R.,University of Munster | Nofer J.-R.,University of Modena and Reggio Emilia | Van Eck M.,Leiden University
Current Opinion in Lipidology | Year: 2011

Purpose of Review: HDL cholesterol levels have been inversely correlated with thrombosis and HDL has been shown to mediate various antithrombotic effects. However, molecular mechanisms underlying the suppressing effect of HDL on platelet reactivity are not completely understood. The present review summarizes the recent advancements in understanding the role played by scavenger receptor class B type I (SR-BI)-an HDL receptor-in modulating platelet function and mediating platelet-HDL interactions. Recent Findings: SR-BI is expressed on platelet surface and platelets from SR-BI knockout animals are characterized by increased free-to-total cholesterol ratio, abnormal morphology, increased reactivity to strong platelets agonists, enhanced adherence to immobilized fibrinogen, and a propensity to form arterial thrombi. Crossover incubation experiments and a bone marrow transplantation approach reveal increased wild-type platelet reactivity in plasma from SR-BI mice and normal or decreased SR-BI-deficient platelet reactivity in wild-type plasma. A similar functional platelet phenotype has been observed in human carriers of an SR-BI genetic variant. SR-BI ligands interfere with HDL binding to murine platelets and impede the agonist-induced platelet activation as effectively as native HDL. The inhibitory effects of native HDL, moderately oxidized HDL, and SR-BI ligands are abolished in SR-BI-deficient platelets but not in CD36-deficient platelets. Summary: SR-BI exerts an indirect influence on platelet reactivity via maintaining normal plasma cholesterol homeostasis. In addition, SR-BI is a functional receptor for native and moderately oxidized HDL on platelets that generates an inhibitory signal for platelet activation. © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins. Source

Rottner K.,Helmholtz Center for Infection Research | Rottner K.,University of Bonn | Stradal T.E.B.,Helmholtz Center for Infection Research | Stradal T.E.B.,University of Munster
Current Opinion in Cell Biology | Year: 2011

Cell migration is a highly coordinated process involving a multitude of separable but intertwined phenomena traditionally studied in multiple cell types, tissues and model systems. In spite of the multitude of mechanisms and modes of motility described in all these different systems, the ability to dynamically reorganize the actin cytoskeleton is common to all of them. However, defining the key molecular players in motility and their precise molecular functions continues to be challenging, last not least owing to robustness and flexibility common to complex biological phenomena. Here we will draft the future steps essential for achieving true progress towards the goal to increase our understanding of actin cytoskeleton dynamics driving cell migration. © 2011 Elsevier Ltd. Source

Influenza is still one of the major plagues worldwide with the threatening potential to cause pandemics. In recent years, increasing levels of resistance to the four FDA approved anti-influenza virus drugs have been described. This situation underlines the urgent need for novel anti-virals in preparation for future influenza epidemics or pandemics. Although the anti-virals currently in use target viral factors such as the neuraminidase or the M2 ion channel, there is an increase in pre-clinical approaches that focus on cellular factors or pathways that directly or indirectly interact with virus replication. This does not only include inhibitors of virus-supportive signaling cascades but also interaction blockers of viral proteins with host cell proteins. This review aims to highlight some of these novel approaches that represent a paradigm change in anti-viral strategies against the influenza virus. Although most of these approaches are still in an early phase of preclinical development they might be very promising particularly with respect to the prevention of viral resistance to potential drugs. © 2011 by Walter de Gruyter Berlin Boston. Source

Nofer J.-R.,University of Munster | Nofer J.-R.,University of Modena and Reggio Emilia
Journal of Molecular Endocrinology | Year: 2012

Estrogens not only play a pivotal role in sexual development but are also involved in several physiological processes in various tissues including vasculature. While several epidemiological studies documented an inverse relationship between plasma estrogen levels and the incidence of cardiovascular disease and related it to the inhibition of atherosclerosis, an interventional trial showed an increase in cardiovascular events among postmenopausal women on estrogen treatment. The development of atherosclerotic lesions involves complex interplay between various pro- or anti-atherogenic processes that can be effectively studied only in vivo in appropriate animal models. With the advent of genetic engineering, transgenic mouse models of atherosclerosis have supplemented classical dietary cholesterolinduced disease models such as the cholesterol-fed rabbit. In the last two decades, these models were widely applied along with in vitro cell systems to specifically investigate the influence of estrogens on the development of early and advanced atherosclerotic lesions. The present review summarizes the results of these studies and assesses their contribution toward better understanding of molecular mechanisms underlying anti- and/or pro-atherogenic effects of estrogens in humans. © 2012 Society for Endocrinology. Source

Paluch E.K.,University College London | Paluch E.K.,International Institute of Molecular Cell Biology | Raz E.,University of Munster
Current Opinion in Cell Biology | Year: 2013

Blebs are cellular protrusions that have been shown to be instrumental for cell migration in development and disease. Bleb expansion is driven by hydrostatic pressure generated in the cytoplasm by the contractile actomyosin cortex. The mechanisms of bleb formation thus fundamentally differ from the actin polymerization-based mechanisms responsible for lamellipodia expansion. In this review, we summarize recent findings relevant for the mechanics of bleb formation and the underlying molecular pathways. We then review the processes involved in determining the type of protrusion formed by migrating cells, in particular in vivo, in the context of embryonic development. Finally, we discuss how cells utilize blebs for their forward movement in the presence or absence of strong substrate attachment. © 2013 Elsevier Ltd. Source

Ramot Y.,Hebrew University of Jerusalem | Paus R.,University of Manchester | Paus R.,University of Munster
BioEssays | Year: 2014

Human skin produces numerous neurohormones and neuropeptides. Recent evidence has shown that the neuroendocrine regulation of human skin biology also extends to keratins, the major structural components of epithelial cells. For example, thyrotropin-releasing hormone, thyrotropin, opioids, prolactin, and cannabinoid receptor 1-ligands profoundly modulate human keratin gene and protein expression in human epidermis and/or hair follicle epithelium in situ. Since selected keratins are now understood to exert important regulatory functions beyond mechanical stability, we argue that neuroendocrine pathways of keratin regulation are important for maintaining skin and hair follicle homeostasis. This invites innovative neuroendocrine therapeutic interventions for skin disorders characterized by abnormal keratin expression, ranging from psoriasis to genodermatoses, and for promoting skin wound healing and hair growth. This strategy can be probed in simple, but instructive and readily available human skin and hair follicle organ culture assays as ideal models for exploring this new neuroendocrine frontier in translational epithelial biology. © 2014 WILEY Periodicals, Inc. Source

Suhr W.,University of Munster
European Journal of Physics | Year: 2012

The interest in the phenomenon of frustrated total internal reflection dates back to the time of Newton. Because of its technological relevance, it has become a standard topic covered by advanced courses in physics. In practical courses optical setups especially designed to demonstrate the phenomenon are commonly used. As an alternative, this paper proposes the use of so-called antibubbles, which provide the necessary conditions spontaneously, for the same purpose. The hands-on-experiments that will be introduced are appropriate for the level of graduate studies. They are based on low-cost materials and can be used for the observation of the phenomenon, based on which conclusions on the structure of antibubbles can be drawn. © 2012 IOP Publishing Ltd. Source

Yaguna C.E.,University of Munster
Journal of Cosmology and Astroparticle Physics | Year: 2012

WIMP (Weakly Interacting Massive Particle), FIMP (Feebly interacting Massive Particle) and EWIP (Extremely Weakly Interacting Particle) dark matter are different theoretical frameworks that have been postulated to explain the dark matter. In this paper we examine an intermediate scenario that combines features from these three frameworks. It consists of a weakly interacting particle - la WIMP - that does not reach thermal equilibrium in the early Universe - la FIMP - and whose relic density is determined by the reheating temperature of the Universe - la EWIP. As an example, an explicit realization of this framework, based on the singlet scalar model of dark matter, is analyzed in detail. In particular, the relic density is studied as a function of the parameters of the model, and the new viable region within this intermediate scenario is determined. Finally, it is shown that this alternative framework of dark matter allows for arbitrarily heavy dark matter particles and that it suggests a connection between dark matter and inflation. © 2012 IOP Publishing Ltd and SISSA. Source

Cai J.,Leiden University | Pardali E.,University of Munster | Sanchez-Duffhues G.,Leiden University | Ten Dijke P.,Leiden University
FEBS Letters | Year: 2012

Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-β (TGF-β) family that signal via type I and type II serine/threonine kinase receptors and intracellular Smad transcription factors. BMPs are multifunctional regulators of development and tissue homeostasis and they were initially characterized as inducers of bone regeneration. Genetic studies in humans and mice showed that perturbations in BMP signaling lead to various diseases, such as skeletal diseases, vascular diseases and cancer. Mutations in BMP type II receptor and BMP type I receptor/activin receptor-like kinase 1 have been linked to pulmonary arterial hypertension and hereditary hemorrhagic telangiectasia, respectively. BMPs have also been implicated in promoting vascular calcification and tumor angiogenesis. In this review we discuss the role of BMP signaling in vascular diseases and the value of BMP signaling as a vascular disease marker or a therapeutic target. © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved. Source

Seidler D.G.,University of Munster
Current Opinion in Structural Biology | Year: 2012

Decorin, a member of the small leucine-rich proteoglycans, is involved in many physiological and pathological processes. Decorin functions not only as structural molecule in organizing the extracellular matrix but also as signaling molecule controlling cell growth, morphogenesis and immunity. Mutations in decorin or alterations in the post-translational modifications of the glycosaminoglycan (GAG) chain lead to connective tissue disorders such as the congenital stromal corneal dystrophy and the Ehlers-Danlos syndrome. The summarized data reveal that decorin has a large impact on biological processes also because of the complex structure of the GAG chain. The complexity of decorin also covers the binding and sequestering of growth factors and their signaling. This shows that the decorin protein and the dermatan sulfate chain of decorin have both a structural function and a signaling function. Since defects in the biosynthesis of either the protein core or the GAG chain lead to structural alterations in the extracellular matrix and changes in the protein expression profile of the cells embedded in the matrix, this review focuses on the insights of structural function of decorin and includes data about dermatan sulfate. © 2012 Elsevier Ltd. Source

Adachi K.,Max Planck Institute for Molecular Biomedicine | Scholer H.R.,Max Planck Institute for Molecular Biomedicine | Scholer H.R.,University of Munster
Current Opinion in Genetics and Development | Year: 2012

The pluripotent state is governed by specifically expressed transcription factors forming a highly interconnected regulatory network in concert with more widely expressed transcription factors. The transcriptional network exhibits a hierarchical structure, with a small number of transcription factors playing an essential role in maintaining pluripotency and controlling the more numerous auxiliary transcription factors. When the set of master transcription factors comprising Oct4, Sox2, Klf4, and Myc is expressed ectopically in somatic cells, the transcriptional network is propelled to organize itself in such a way as to support a pluripotent state. These transcription factors play distinct but interdependent roles in remodeling gene expression by influencing the local chromatin status during reprogramming. © 2012 Elsevier Ltd. Source

Sorokin L.,University of Munster
Nature Reviews Immunology | Year: 2010

The advent of in situ immunology and intravital analyses of leukocyte movement in tissues has drawn attention to the previously neglected extracellular matrix (ECM) and its role in modulating immune cell behaviour in inflamed tissues. The ECM exists in different biochemical and structural forms; both their individual components and three-dimensional ultrastructure impart specific signals to cells that modulate basic functions that are important for the early steps in inflammation, such as immune cell migration into inflamed tissues and immune cell differentiation. In chronically inflamed tissues, aberrant ECM expression and fragments of the ECM that are derived from tissue-remodelling processes can influence immune cell activation and survival, thereby actively contributing to immune responses at these sites. © 2010 Macmillan Publishers Limited. All rights reserved. Source

Kliesch S.,University of Munster
European Urology, Supplements | Year: 2014

The diagnostic workflow to evaluate male infertility follows a systematic approach to elucidate previous factors influencing fertility and the present status. The medical history should be taken, preferably in the presence of the female partner, and a clinical examination focusing on testicular morphology and function is done, followed by laboratory tests of gonadotropins and androgens as well as semen analysis according to the World Health Organization criteria. Depending on the results, more elaborate investigations may be necessary, such as the genetic background of male infertility or analysis of testicular spermatogenesis. To better characterize the functional capability of spermatozoa, modern analytical instruments such as DNA fragmentation and methylation analysis or Raman spectroscopy of spermatozoa are used for scientific evaluation. Finally, the differential diagnosis of hypothalamic-pituitary or testicular malfunction will determine the treatment options. Endocrine, surgical, or empirical treatment options such as assisted reproductive techniques can be applied after interdisciplinary diagnosis of both partners, male and female, by the andrologist and a specialized gynecologist to obtain optimal treatment options for the couple. © 2014. Source

Stephan D.W.,University of Toronto | Erker G.,University of Munster
Angewandte Chemie - International Edition | Year: 2015

Frustrated Lewis pairs (FLPs) are combinations of Lewis acids and Lewis bases in solution that are deterred from strong adduct formation by steric and/or electronic factors. This opens pathways to novel cooperative reactions with added substrates. Small-molecule binding and activation by FLPs has led to the discovery of a variety of new reactions through unprecedented pathways. Hydrogen activation and subsequent manipulation in metal-free catalytic hydrogenations is a frequently observed feature of many FLPs. The current state of this young but rapidly expanding field is outlined in this Review and the future directions for its broadening sphere of impact are considered. Let's not get together: Frustrated Lewis pairs (FLP) are combinations of Lewis acids and Lewis bases which are prevented from forming a stable adduct by steric or electronic hindrance. The growth of the field of FLP chemistry during the last four years has been rapid, including small-molecule activation, applications in catalysis, and the development of unprecedented reactions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Vilatela J.J.,IMDEA Madrid Institute for Advanced Studies | Eder D.,University of Munster
ChemSusChem | Year: 2012

There is an ever-growing need to protect our environment by increasing energy efficiency and developing "clean" energy sources. These are global challenges, and their resolution is vital to our energy security. Although many conventional materials, such as metals, ceramics, and plastics, cannot fulfil all requirements for these new technologies, many material combinations can offer synergistic effects that create improved and even new properties. The implementation of nanocarbons, such as graphene and carbon nanotubes, into nanocomposites and, more recently, into the new class of hybrids, are very promising examples. In contrast to classical nanocomposites, where a low volume fraction of the carbon component is mixed into a polymer or ceramic matrix, hybrids are materials in which nanocarbon is coated with a thin layer of the functional compound, which introduces the interface as a powerful new parameter. Based on interfacial charge and energy transfer processes, nanocarbon hybrids have shown increased sensitivities in gas sensors, improved efficiencies in photovoltaics, superior activities in photocatalysts, and enhanced capacities in supercapacitors. This review compares the characteristics and potentials of both nanocarbon composites and hybrids, highlights recent developments in their synthesis and discusses key challenges for their use in various energy applications. Composites and hybrids go energy: The combination of graphene and carbon nanotubes into composites and, more recently, into the new class of hybrids creates new functional energy materials, whose synergistic effects are based on interfacial charge and heat transfer processes. In this Minireview, we provide a critical distinction between nanocomposites and nanocarbon hybrids with specific relation to sustainability as well as an overview of synthesis strategies. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Kaese S.,University of Munster | Verheule S.,Maastricht University
Frontiers in Physiology | Year: 2012

Over the last decade, mouse models have become a popular instrument for studying cardiac arrhythmias. This review assesses in which respects a mouse heart is a miniature human heart, a suitable model for studying mechanisms of cardiac arrhythmias in humans and in which respects human and murine hearts differ. Section I considers the issue of scaling of mammalian cardiac (electro) physiology to body mass. Then, we summarize differences between mice and humans in cardiac activation (section II) and the currents underlying the action potential in the murine working myocardium (section III). Changes in cardiac electrophysiology in mouse models of heart disease are briefly outlined in section IV, while section V discusses technical considerations pertaining to recording cardiac electrical activity in mice. Finally, section VI offers general considerations on the influence of cardiac size on the mechanisms of tachy-arrhythmias. © 2012 Kaese and Verheule. Source

Sabour D.,Max Planck Institute for Molecular Biomedicine | Scholer H.R.,Max Planck Institute for Molecular Biomedicine | Scholer H.R.,University of Munster
Current Opinion in Cell Biology | Year: 2012

The germline represents a unique cell type that can transmit genetic material to the next generation. During early embryonic development, somatic cells give rise to a small population of cells known as germ cells, which eventually differentiate into mature gametes. Germ cells undergo a process of removing and resetting relevant epigenetic information, mainly by DNA demethylation. This extensive epigenetic reprogramming leads to the conversion of germ cells into immortal cells that can pass on the genome to the next generation. In the absence of germline-specific reprogramming, germ cells would preserve the old, parental epigenetic memory, which would prevent the transfer of heritable information to the offspring. On the contrary, somatic cells cannot reset epigenetic information by preserving the full methylation pattern on imprinting genes. In this review, we focus on the capacity of germ cells and somatic cells (soma) to transfer genetic information to the next generation, and thus revisit the Weismann theory of heredity. © 2012 Elsevier Ltd. Source

Kandukuri S.R.,TU Berlin | Kandukuri S.R.,University of Munster | Schiffner J.A.,TU Berlin | Oestreich M.,TU Berlin
Angewandte Chemie - International Edition | Year: 2012

The endo trick: An endo ring closure onto the trigonal β carbon atom of α,β-unsaturated acceptors that are tethered to the indole nitrogen atom followed by amide cleavage enables the diastereoselective C-2 alkenylation of indoles with fully substituted double bonds. The carboxy group functions as a synthetically useful temporary tether (see scheme). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Sterneckert J.,Max Planck Institute for Molecular Biomedicine | Hoing S.,Max Planck Institute for Molecular Biomedicine | Scholer H.R.,Max Planck Institute for Molecular Biomedicine | Scholer H.R.,University of Munster
Stem Cells | Year: 2012

Through cellular differentiation, a single cell eventually gives rise to all the various lineages of an organism. This process has traditionally been viewed as irreversible. However, nuclear transfer experiments have demonstrated that differentiated cells can be reprogrammed to form even an entire organism. Yamanaka electrified the world with the discovery that expression of only four transcription factors was sufficient to induce pluripotency in differentiated somatic cells of mammals. Expansion of this work has shown that expression of the master pluripotency gene Oct4 is sufficient to induce pluripotency in neural stem cells. In contrast to somatic cells, germline cells express Oct4 and can acquire pluripotency without the addition of exogenous transcription factors. More recently, it has been possible to also induce an alternative cell fate directly by the transdifferentiation of cells mediated by the introduction of specific transcription factors, including Oct4. Therefore, we suggest that Oct4 is the gatekeeper into a reprogramming expressway that can be directed by altering the experimental conditions. Source

Kowert R.,University of Munster | Oldmeadow J.A.,Swinburne University of Technology
Computers in Human Behavior | Year: 2015

Internet connectivity has changed the way video games are played by allowing individuals to connect worldwide in shared gaming spaces. These highly social environments allow players to connect, interact with, and learn from each other. However, there is a growing concern that these social environments also have the potential to displace real-world connections and interactions, contributing to a variety of losses in 'offline' sociability. The current study aims to elucidate what users may be gaining or losing (socially) as a result of continued participation in online video game environments, and what potentially underlies these social changes, by examining the associations between social skills and online video game involvement through the perspective of attachment theory. The results challenge the assumption that online video game play is inexorably associated with negative social consequences for the player and indicates the potential for online gaming spaces to serve critical attachment functions by providing a social outlet that promotes a sense of closeness, belonging, and security that satisfies attachment needs for those high in attachment avoidance. © 2014 Elsevier Ltd. Source

Schluter M.A.,University of Munster | Margolis B.,University of Michigan
Experimental Cell Research | Year: 2012

The apicobasal polarization of epithelia is critical for many aspects of kidney function. Over the last decade there have been major advances in our understanding of the mechanisms that underlie this polarity. Critical to this understanding has been the identification of protein complexes on the apical and basolateral sides of epithelial cells that act in a mutually antagonistic manner to define these domains. Concomitant with the creation of apical and basolateral domains is the formation of highly specialized cell-cell junctions including adherens junctions and tight junctions. Recent research points to variability in the polarity and junctional complexes amongst different species and between different cell types of the kidney. Defects in apicobasal polarity are prominent in several disorders including acute renal failure and polycystic kidney disease. © 2012 Elsevier Inc. Source

Lorek S.,Sustainable Europe Research Institute | Fuchs D.,University of Munster
Journal of Cleaner Production | Year: 2013

This paper aims to link two debates and literatures at the cutting edge of sustainable development research and governance: sustainable consumption and degrowth. Interestingly, these literatures have only recently started to exchange and integrate insights, despite their similar interest in the fundamental systemic challenges to sustainable development. The paper argues that this lack of connection is due to a predominance of perspectives in sustainable consumption governance that focus almost exclusively on questions of efficiency gains. This "weak sustainable consumption" governance, however, is not able to address the challenges to sustainable development arising from overconsumption in general or the rebound effect and distributive issues in particular. In contrast, a "strong sustainable consumption" perspective provides a basis for a promising inquiry into the linkages between consumption and sustainable development as well as a fruitful exchange with degrowth. Specifically, it allows the delineation of relevant insights on the role of values in governance, obstacles to political reform, and promising political strategies for the degrowth debate and literature. © 2011 Elsevier Ltd. All rights reserved. Source

Dreisewerd K.,University of Munster | Dreisewerd K.,The Interdisciplinary Center
Analytical and Bioanalytical Chemistry | Year: 2014

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is widely used for characterization of large, thermally labile biomolecules. Advantages of this analytical technique are high sensitivity, robustness, high-throughput capacity, and applicability to a wide range of compound classes. For some years, MALDI-MS has also been increasingly used for mass spectrometric imaging as well as in other areas of clinical research. Recently, several new concepts have been presented that have the potential to further advance the performance characteristics of MALDI. Among these innovations are novel matrices with low proton affinities for particularly efficient protonation of analyte molecules, use of wavelength-tunable lasers to achieve optimum excitation conditions, and use of liquid matrices for improved quantification. Instrumental modifications have also made possible MALDI-MS imaging with cellular resolution as well as an efficient generation of multiply charged MALDI ions by use of heated vacuum interfaces. This article reviews these recent innovations and gives the author's personal outlook of possible future developments. [Figure not available: see fulltext.] © 2014 Springer-Verlag Berlin Heidelberg. Source

Baxter E.F.,Boston University | Scherer E.E.,University of Munster
Elements | Year: 2013

Garnet's potential as a chronometer of tectonometamorphic processes and conditions was fi rst recognized over 30 years ago. The Sm-Nd and Lu-Hf systems have since emerged as the most effective chronometers, permitting age precision of better than ±1 My, even on tiny samples such as concentric growth zones within individual crystals. New, robust analytical methods mitigate the effects of ubiquitous mineral inclusions, improving the precision and accuracy of garnet dates. Important differences between Sm- Nd and Lu-Hf with respect to partitioning, diffusivity, contaminant phases, and isotopic analysis make these two systems powerfully complementary. © DECEMBER 2013. Source

Verheule S.,Maastricht University | Kaese S.,University of Munster
Frontiers in Pharmacology | Year: 2013

Cardiac conduction is mediated by gap junction channels that are formed by connexin (Cx) protein subunits. The connexin family of proteins consists of more than 20 members varying in their biophysical properties and ability to combine with other connexins into heteromeric gap junction channels. The mammalian heart shows regional differences both in connexin expression profile and in degree of electrical coupling. The latter reflects functional requirements for conduction velocity which needs to be low in the sinoatrial and atrioventricular nodes and high in the ventricular conduction system. Over the past 20 years knowledge of the biology of gap junction channels and their role in the genesis of cardiac arrhythmias has increased enormously. This review focuses on the insights gained from transgenic mouse models. The mouse heart expresses Cx30, 30.2, 37, 40, 43, 45, and 46. For these connexins a variety of knock-outs, heart-specific knock-outs, conditional knock-outs, double knock-outs, knock-ins and overexpressors has been studied. We discuss the cardiac phenotype in these models and compare Cx expression between mice and men. Mouse models have enhanced our understanding of (patho)-physiological implications of Cx diversity in the heart. In principle connexin-specific modulation of electrical coupling in the heart represents an interesting treatment strategy for cardiac arrhythmias and conduction disorders. © 2013 Verheule and Kaese. Source

Schulz A.,University of Munster
Journal of Graph Algorithms and Applications | Year: 2011

We study the problem how to obtain a small drawing of a 3-polytope with Euclidean distance between any two points at least 1. The problem can be reduced to a one-dimensional problem, since it is su_cient to guarantee distinct integer x-coordinates. We develop an algorithm that yields an embedding with the desired property such that the polytope is contained inside a 2(n - 2) ×2 ×1 box. The constructed embedding can be scaled to a grid embedding whose x-coordinates are contained in [0; 2(n - 2)]. Furthermore, the point set of the embedding has a small spread, which di_ers from the best possible spread only by a multiplicative constant. Source

Burger M.,University of Munster
Inverse Problems | Year: 2011

This paper reviews several inverse problems related to biological ion channels and polymer nanopores. Different problems arise at different scales and thus lead to different inversion tasks, which can be modelled as parameter identification in systems of partial differential equations, ordinary differential equations, or as the solution of integral equations. Due to the high potential for future developments, we will not only discuss the previous results and approaches, but in particular highlight a variety of open issues and unsolved inverse problems, as well as biological questions that could be modeled as inverse problems and might lead to interesting future developments. © 2011 IOP Publishing Ltd. Source

Natterer F.,University of Munster
Inverse Problems | Year: 2011

This paper is concerned withwave equation reflection imaging for source pulses that do not have low frequencies. It is well known that the lack of these low frequencies causes serious difficulties in image reconstruction. We show that under favorable circumstances good images can be obtained nevertheless by a data completion procedure. © 2011 IOP Publishing Ltd. Source

Poti F.,University of Modena and Reggio Emilia | Simoni M.,University of Modena and Reggio Emilia | Nofer J.-R.,University of Modena and Reggio Emilia | Nofer J.-R.,University of Munster
Cardiovascular Research | Year: 2014

Numerous epidemiological studies documented an inverse relationship between plasma high-density lipoprotein (HDL) cholesterol levels and the extent of atherosclerotic disease. However, clinical interventions targeting HDL cholesterol failed to show clinical benefits with respect to cardiovascular risk reduction, suggesting that HDL components distinct from cholesterol may account for anti-atherogenic effects attributed to this lipoprotein. Sphingosine-1-phosphate (S1P) - a lysosphingolipid exerting its biological activity via binding to specific G protein-coupled receptors and regulating a wide array of biological responses in a variety of different organs and tissues including the cardiovascular system - has been identified as an integral constituent of HDL particles. In the present review, we discuss current evidence from epidemiological studies, experimental approaches in vitro, and animal models of atherosclerosis, suggesting that S1P contributes to atheroprotective effects exerted by HDL particles. © The Author 2014. Source

Kurlemann G.,University of Munster
Handbook of Clinical Neurology | Year: 2012

The skin is the largest organ of the body. Both the skin and the central nervous system (CNS) are ectodermal in origin and development, and, because of this close relationship, the skin mirrors the CNS regarding the characteristic findings of neurocutaneous disorders. Diagnosis is always possible on the basis of visible symptoms. The principal neurocutaneous syndromes include: neurofibromatosis type 1; neurofibromatosis type 2; tuberous sclerosis; Sturge-Weber syndrome; incontinentia pigmenti achromians; incontinentia pigmenti Bloch-Sulzberger syndrome; ataxia telangiectasia; neurocutaneous melanosis; Schimmelpenning syndrome; and Parry-Romberg syndrome. There are many other different skin conditions that are characteristic of rare, neurocutaneous diseases. Careful examination of the skin of patients with neurological disorders, also using a Wood's lamp, is beneficial and indispensible. © 2012 Elsevier B.V. Source

Debove J.,CNRS Laboratory of Subatomic Physics & Cosmology | Fuks B.,CNRS Hubert Curien Multi-disciplinary Institute | Klasen M.,University of Munster
Nuclear Physics B | Year: 2011

We calculate direct gaugino pair production at hadron colliders at next-to-leading order of perturbative QCD, resumming simultaneously large logarithms in the small transverse-momentum and threshold regions to next-to-leading logarithmic accuracy. Numerical predictions are presented for transverse momentum and invariant mass spectra as well as for total cross sections and compared to results obtained at fixed order and with pure transverse-momentum and threshold resummation. We find that our new results are in general in good agreement with the previous ones, but often even more precise. © 2011 Elsevier B.V. Source

Proikas-Cezanne T.,University of Tubingen | Robenek H.,University of Munster
Journal of Cellular and Molecular Medicine | Year: 2011

Autophagy defines the lifespan of eukaryotic organisms by ensuring cellular survival through regulated bulk clearance of proteins, organelles and membranes. Pathophysiological consequences of improper autophagy give rise to a variety of age-related human diseases such as cancer and neurodegeneration. Rational therapeutic implementation of autophagy modulation remains problematic, as fundamental molecular details such as the generation of autophagosomes, unique double-membrane vesicles formed to permit the process of autophagy, are insufficiently understood. Here, freeze-fracture replica immunolabelling reveals WD-repeat protein interacting with phosphoinositides 1 and 2 (WIPI-1 and WIPI-2) as membrane components of autophagosomes and the plasma membrane (PM). In addition, WIPI-1 is also present in membranes of the endoplasmic reticulum (ER) and WIPI-2 was further detected in membranes close to the Golgi cisternae. Our results identify WIPI-1 and WIPI-2 as novel protein components of autophagosomes, and of membrane sites from which autophagosomes might originate (ER, PM, Golgi area). Hence therapeutic modulation of autophagy could involve approaches that functionally target human WIPI proteins. © 2011 The Authors Journal compilation © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd. Source

Botrytis cinerea is the causal agent of gray mold disease in various plant species and produces grayish macroconidia and/or black sclerotia at the end of the infection cycle. It has been suggested that the pigmentation is due to the accumulation of 1,8-dihydroxynaphthalene (DHN) melanin. To unravel its basis and regulation, the putative melanogenic and regulatory genes were identified and functionally characterized. Unlike other DHN melanin-producing fungi, B. cinerea and other Leotiomycetes contain two key enzyme (PKS)-encoding enzymes. Bcpks12 and bcpks13 are developmentally regulated and are required for melanogenesis in sclerotia and conidia respectively. BcYGH1 converts the BcPKS13 product and contributes thereby to conidial melanogenesis. In contrast, enzymes acting downstream in conversion of the PKS products (BcBRN2, BcSCD1 and BcBRN1) are required for both, sclerotial and conidial melanogenesis, suggesting that DHN melanogenesis in B. cinerea follows a non-linear pathway that is rather unusual for secondary metabolic pathways. Regulation of the melanogenic genes involves three pathway-specific transcription factors (TFs) that are clustered with bcpks12 or bcpks13 and other developmental regulators such as light-responsive TFs. Melanogenic genes are dispensable in vegetative mycelia for proper growth and virulence. However, DHN melanin is considered to contribute to the longevity of the reproduction structures. © 2016 John Wiley & Sons Ltd. Source

Lindemann F.,University of Munster | Ropinski T.,Linkoping University
IEEE Transactions on Visualization and Computer Graphics | Year: 2011

In this paper, we present a user study in which we have investigated the influence of seven state-of-the-art volumetric illumination models on the spatial perception of volume rendered images. Within the study, we have compared gradient-based shading with half angle slicing, directional occlusion shading, multidirectional occlusion shading, shadow volume propagation, spherical harmonic lighting as well as dynamic ambient occlusion. To evaluate these models, users had to solve three tasks relying on correct depth as well as size perception. Our motivation for these three tasks was to find relations between the used illumination model, user accuracy and the elapsed time. In an additional task, users had to subjectively judge the output of the tested models. After first reviewing the models and their features, we will introduce the individual tasks and discuss their results. We discovered statistically significant differences in the testing performance of the techniques. Based on these findings, we have analyzed the models and extracted those features which are possibly relevant for the improved spatial comprehension in a relational task. We believe that a combination of these distinctive features could pave the way for a novel illumination model, which would be optimized based on our findings. © 2011 IEEE. Source

Smiatek J.,University of Munster | Schmid F.,Bielefeld University
Computer Physics Communications | Year: 2011

We review recent dissipative particle dynamics (DPD) simulations of electrolyte flow in nanochannels. A method is presented by which the slip length δB at the channel boundaries can be tuned systematically from negative to infinity by introducing suitably adjusted wall-fluid friction forces. Using this method, we study electroosmotic flow (EOF) in nanochannels for varying surface slip conditions and fluids of different ionic strength. Analytic expressions for the flow profiles are derived from the Stokes equation, which are in good agreement with the numerical results. Finally, we investigate the influence of EOF on the effective mobility of polyelectrolytes in nanochannels. The relevant quantity characterizing the effect of slippage is found to be the dimensionless quantity κδB, where 1/κ is an effective electrostatic screening length at the channel boundaries. © 2010 Elsevier B.V. All rights reserved. Source

Background: Fibroblast growth factor 2, a well-characterized heparin-binding growth factor, is involved in many biological processes like embryogenesis, cell proliferation and angiogenesis. However, this growth factor is very unstable and shows rapid degradation in aqueous solution. Beside the well-known stabilization of FGF2 by heparin or heparan sulphate, the recently discovered binding to ATP also shows a stabilizing and protective effect on this growth factor. Results: Here we determined the dissociation constant of ATP on FGF2 by equilibrium microdialysis (K D: 59.8 M) and analyzed the impact of this binding on secondary structure by CD-spectroscopy. ATP-binding to FGF2 significantly changed the secondary structure of this growth factor with a shift to random coil structure elements. We also analyzed the influence of this binding on the stability of FGF2 in aqueous solution over a period of 2 h. While the amount of untreated FGF2 is reduced drastically over this period of time, ATP-binding reduces the degradation considerably. Conclusions: Taken together, our data suggest an important role of ATP in FGF2-stabilization beside the well known-role of heparin and heparan sulphate. © 2011 Rose; licensee BioMed Central Ltd. Source

Herold S.,Justus Liebig University | Ludwig S.,University of Munster | Pleschka S.,Justus Liebig University | Wolff T.,Robert Koch Institute
Journal of Leukocyte Biology | Year: 2012

Programmed cell death is a crucial cellular response frequently observed in IV-infected tissue. This article reviews the current knowledge on the molecular virus- host interactions that induce apoptosis pathways in an IV-infected cell and the functional implications of these cellular signaling events on viral propagation at distinct steps during the viral replication cycle. Furthermore, it summarizes the role of IV-induced apoptosis pathways in equilibrating the host's antiviral immune response between effective viral clearance and development of severe apoptotic lung injury. © Society for Leukocyte Biology. Source

Gotte M.,University of Munster
Minerva Ginecologica | Year: 2010

Micro RNAs (miRNAs) are small non-coding RNAs which regulate fundamental cellular and developmental processes at the transcriptional and translational level. In breast cancer, expression of miRNAs is frequently dysregulated. Both tumor suppressor activity and oncogenic properties have been assigned to specific miRNAs, which modulate virtually all relevant stages of breast cancer progression, including tumor cell proliferation, apoptosis resistance, cancer cell migration, invasiveness and metastasis, tumor angiogenesis and cancer stem cell self-renewal. miRNA expression has been studied by microarray profiling, bead-based technologies and quantitative real-time PCR in archived formalin-fixed paraffin-embedded tumor specimens as well as blood and serum samples, allowing to identify specific miRNAs as novel diagnostic, prognostic and predictive markers. Moreover, the investigation of single nucleotide polymorphisms both in putative miRNA binding sites in the 3′UTRs of target genes, as well as in miRNA-endocing genes have revealed their diagnostic potential. In vitro experiments employing established breast cancer cell lines and in vivo xenograft studies have demonstrated the efficacy of oligonucleotide-based overexpression and inhibitor approaches of miRNA-targeted experimental therapies. Numerous studies have identified specific targets of miRNA action in breast cancer, including the established markers Her2/neu and ERalpha, TP53, and markers of angiogenesis. The future application of locked-nucleic acid miRNA inhibitors, and synergistic approaches involving conventional breast cancer therapeutics opens up promising new perspectives in breast cancer therapy. Source

Kuhl H.,Goethe University Frankfurt | Schneider H.P.G.,University of Munster
Climacteric | Year: 2013

Based on the results of a French cohort of postmenopausal women, it has been claimed that micronized progesterone does not enhance breast cancer risk. The impact of reproductive factors on breast cancer risk and a high prevalence of occult breast carcinomas at the time of menopause suggest an involvement of endogenous progesterone in the development of breast cancer. High mammographic density in the luteal phase and during treatment with estrogen/progestogen combinations reflect a change in the composition of mammary stroma and an increased water accumulation in the extracellular matrix which is caused by hygroscopic hyaluronan-proteoglycan aggregates. Proteoglycans are also involved in the regulation of proliferation, migration, and differentiation of epithelial cells and angiogenesis, and may influence malignant transformation of breast cells and progression of tumors. Reports on a lack of effect of estrogen/progesterone therapy on breast cancer risk may be rooted in a selective prescription to overweight women and/or to the very low progesterone serum levels after oral administration owing to a strong inactivation rate. The contradictory results concerning the proliferative effect of progesterone may be associated with a different local metabolism in normal compared to malignant breast tissue. Similar to other progestogens, hormone replacement therapy with progesterone seems to promote the development of breast cancer, provided that the progesterone serum levels have reached the threshold for endometrial protection. © 2013 International Menopause Society. Source

Harding G.,GE Security | Harding E.,University of Munster
Applied Radiation and Isotopes | Year: 2010

This review discusses the principles and technological realisation of a technique, termed Compton scatter imaging (CSI), which is based on spatially resolved detection of Compton scattered X-rays. The applicational focus of this review is to objects of historical interest. Following a historical survey of CSI, a description is given of the major characteristics of Compton X-ray scatter. In particular back-scattered X-rays allow massive objects to be imaged, which would otherwise be too absorbing for the conventional transmission X-ray technique. The ComScan (an acronym for Compton scatter scanner) is a commercially available backscatter imaging system, which is discussed here in some detail. ComScan images from some artefacts of historical interest, namely a fresco, an Egyptian mummy and a mediaeval clasp are presented and their use in historical analysis is indicated. The utility of scientific and technical advance for not only exploring history, but also restoring it, is briefly discussed. © 2010 Elsevier Ltd. All rights reserved. Source

Leitner J.,Max Planck Institute for Chemistry | Vollmer C.,University of Munster | Hoppe P.,Max Planck Institute for Chemistry | Zipfel J.,Forschungsinstitut und Naturmuseum Senckenberg
Astrophysical Journal | Year: 2012

We investigated the inventory of presolar silicate, oxide, and silicon carbide (SiC) grains in the CR2 chondrite Northwest Africa (NWA) 852. Thirty-one O-anomalous grains were detected: 24 were identified as silicates (78ppm); the remaining 7 are Al-rich oxides (38ppm). NWA 852 is the first C2 chondrite containing O-anomalous presolar dust in concentrations comparable to other more primitive meteorites. Eight presolar SiC grains have been found, representing the highest abundance (160ppm) observed so far in primitive meteorites. 15N-enriched matter is also present, although very heterogeneously distributed. Twenty-six of the O-anomalous grains are enriched in 17O, originating from the outflows of low-mass asymptotic giant branch (AGB) stars. We calculate a silicate/oxide abundance ratio of 2, which indicates a higher degree of aqueous alteration than observed for other presolar-grain-rich meteorites. NWA 852 thus stands between the presolar-grain-rich CR3 chondrites (MET00426, QUE99177) and CR2 chondrites with low presolar grain abundances (Renazzo, NWA530). We calculate an initial presolar silicate abundance of 800ppm for NWA852, if silicate destruction by aqueous alteration is taken into account. Transmission electron microscope (TEM) investigation of one presolar Al-rich grain of an AGB star origin revealed that the grain mainly consists of a single crystal of hibonite with slightly varying orientations. A distinct subgrain (d < 100nm) with a Ca/Ti ratio of 1 is located in the central region, most likely indicating a perovskite-like phase. Our data suggest this phase to be a primary condensate and not an alteration product. © 2012. The American Astronomical Society. All rights reserved. Source

Kleine T.,University of Munster | Rudge J.F.,University of Cambridge
Elements | Year: 2011

The planets of the Solar System grew by collisions, starting with the aggregation of tiny dust particles within the solar nebula and culminating in giant collisions between large planetary bodies. These giant impacts occasionally caused the formation of satellites such as the Earth's Moon. Our understanding of planet formation is based on information from various sources, including meteorites - leftovers from the earliest stages of planet formation - and samples from the Earth and Moon. By combining results from isotopic dating of these materials with dynamic modelling of the solar nebula and planet formation, researchers can reconstruct the accretion and early evolution of planetary bodies during the first ∼100 million years of Solar System history. Source

A viable spermatozoon is the prerequisite for initiating fertilization in intracytoplasmic sperm injection. Usually motility is the primary sign used to determine a sperm's viability. However, in every in vitro fertilization (IVF) laboratory cases are observed in which none or only few spermatozoa are motile. This can occur in treatment cycles involving ejaculated samples but is most common in cases where surgically extracted testicular spermatozoa are used. To aid in selection, several techniques have been developed to identify viable spermatozoa from the immotile fraction. Amongst the more commonly used approaches are (i) the hypo-osmotic swelling test (ii) chemical substances for induction of tail movements (iii) the sperm tail flexibility test and (iv) laser-assisted immotile sperm selection. All can be used routinely in an IVF laboratory with each having both strengths and weaknesses. It is the purpose of this short review to focus on the technical issues involved in the performance of each of these techniques and to highlight the advantages and disadvantages of each approach. © 2014 American Society of Andrology and European Academy of Andrology. Source

Xu H.,Tsinghua University | Schonhoff M.,University of Munster | Zhang X.,Tsinghua University
Small | Year: 2012

Layer-by-layer assembly (LbL) is a rich, versatile, and powerful technique for fabricating multilayer thin films with controlled architecture and functions. Singly charged, uncharged, or water-repellent molecules cannot be used directly in conventional LbL assembly. This problem can be solved with unconventional LbL methods, by employing the preassembly of building blocks in solution and the use of these assemblies for LbL formation at the interface. This Concept summarizes different methods of unconventional LbL assembly, including electrostatic complex formation, hydrogen-bonded complexes, block-copolymer micelles, and π-π interaction complexes. These preassembly treatments endow the building blocks with enhanced abilities for advanced functionality, in particular, surface molecular imprinting, a new concept emerging from unconventional LbL. Molecular imprinting approaches are thus conceptually described based on different types of interactions and their great potential in applications is demonstrated by examples such as selective surface patterning and selective filtration. Preassembling singly charged, uncharged, or water-repellent building blocks in an unconventional layer-by-layer fashion enhances the ability for advanced functionality, in particular, surface molecular imprinting, of the resulting multilayer film. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Evers S.,University of Munster
Headache | Year: 2010

Sleep and trigeminal pain processing share several common pathways with respect to neurotransmission and functions of distinct brain areas. In this review, the role of the most important brain stem and midbrain regions for this link is discussed. The central structure involved in both headache and sleep is the hypothalamus in which the orexinergic neurons originate. These neurons project to the periaqueductal grey and are probably the anatomic and physiological link between headache and sleep. Another relevant system for this interrelationship is the melatonin metabolism. However, basic research in this field is still very preliminary and a holistic hypothesis on how sleep physiology impacts headache and vice versa is still missing. © 2010 American Headache Society. Source

Lehrnbecher T.,Goethe University Frankfurt | Groll A.H.,University of Munster
Pediatric Blood and Cancer | Year: 2010

Invasive fungal infections are a major cause of morbidity and mortality in children with hematological malignancies and those undergoing allogeneic hematopoietic stem-cell transplantation (HSCT). Although several new antifungal compounds recently became available, some are not yet approved for the use in the pediatric population. Among the new class of echinocandins, micafungin has been licensed in Europe and Japan for children including neonates. Because micafungin is well tolerated and exhibits few clinical relevant drug-drug interactions, the compound is of particular interest for prophylaxis and treatment of invasive mycoses in pediatric patients with cancer or following allogeneic HSCT. This review will focus on the currently available pediatric data of micafungin with emphasis on pharmacokinetics, efficacy, and safety. © 2010 Wiley-Liss, Inc. Source

Bracht H.,University of Munster
Physica Status Solidi (A) Applications and Materials Science | Year: 2014

State of the art nanoelectronic devices are mainly fabricated on silicon (Si). In order to take advantage of the properties of germanium (Ge) in advanced electronic nanodevices all steps of device fabrication must be controlled. This, in particular, concerns the diffusion, doping, and activation of dopants in Ge. In this paper, the mechanism of self- and dopant diffusion in Ge under thermal equilibrium and non-equilibrium conditions are reviewed. Non-equilibrium conditions can, e.g., be realized by irradiation, implantation, and the dissolution of unstable defect clusters. Defect reactions mediating dopant diffusion and dopant deactivation in Ge under different experimental conditions are discussed. Special attention is paid to the charge states of the involved point defects and their Coulomb interactions that explain numerous results on dopant diffusion and dopant deactivation. Controlling the formation of vacancies V and self-interstitials I is the key to develop successful defect engineering strategies that are required to achieve the objectives for the fabrication of Ge-based devices. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Foulkes W.D.,McGill University | Clarke B.A.,University of Toronto | Hasselblatt M.,University of Munster | Majewski J.,McGill University | And 2 more authors.
Journal of Pathology | Year: 2014

Whole-exome sequencing (WES) is revolutionizing medical diagnostics and taxonomy. In less than 5 years since its first use, WES has revealed unexpected molecular drivers of numerous cancers. Here, we describe our use of WES to uncover the true nature of an enigmatic pathological entity, small-cell carcinoma of the ovary, hypercalcaemic type (SCCOHT), which has resisted definitive characterisation since it was first described in 1979. We conducted WES using three families with SCCOHT and identified deleterious mutations in the chromatin-remodelling gene SMARCA4 (encoding BRG1) in all cases. Follow-up of these findings, using both Sanger sequencing and WES of formalin-fixed paraffin-embedded tumours, showed that virtually all SCCOHTs we studied lacked functional SMARCA4/BRG1. Notably, this gene, and the related SMARCB1 gene, is mutated in most, if not all, atypical teratoid/rhabdoid tumours and malignant rhabdoid tumours. Other groups have similar findings. We review the relationship between these three neoplasms, discuss how they were distinguished from morphologically similar neoplasms, consider their similarities and show how WES has revealed that SCCOHTs are in fact rhabdoid tumours. We propose that SCCOHT be renamed 'malignant rhabdoid tumour of the ovary' (MRTO) to reflect these observations. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Source

Rentmeister A.,University of Munster
Angewandte Chemie - International Edition | Year: 2015

It cuts both ways: The CRISPR/Cas9 genome engineering system has been extended from DNA to RNA. The sequence-specific targeting and cleavage of RNA can be achieved with S. pyogenes Cas9-gRNA if an appropriate short single-stranded oligonucleotide, the "PAMmer", is added. This technique could lead to a general approach for sequence-specific RNA manipulation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

King E.M.,University of California at Berkeley | Stellmach S.,University of Munster | Aurnou J.M.,University of California at Los Angeles
Journal of Fluid Mechanics | Year: 2012

Turbulent, rapidly rotating convection has been of interest for decades, yet there exists no generally accepted scaling law for heat transfer behaviour in this system. Here, we develop an exact scaling law for heat transfer by geostrophic convection, Nu= (Ra/Ra c) 3 = 0. 0023 Ra 3 E 4, by considering the stability of the thermal boundary layers, where Nu, Ra and E are the Nusselt, Rayleigh and Ekman numbers, respectively, and Ra c is the critical Rayleigh number for the onset of convection. Furthermore, we use the scaling behaviour of the thermal and Ekman boundary layer thicknesses to quantify the necessary conditions for geostrophic convection: Ra ≈ E -3/2. Interestingly, the predictions of both heat flux and regime transition do not depend on the total height of the fluid layer. We test these scaling arguments with data from laboratory and numerical experiments. Adequate agreement is found between theory and experiment, although there is a paucity of convection data for low Ra E 3/2. © 2011 Cambridge University Press. Source

Delvos L.B.,TU Berlin | Vyas D.J.,University of Munster | Oestreich M.,TU Berlin
Angewandte Chemie - International Edition | Year: 2013

Gamma way: Regio- and enantioselective allylic substitution with a silicon nucleophile generated by copper(I)-catalyzed Si-B bond activation provides direct access to α-chiral allylic silanes from linear acceptors. The enantioconvergent catalysis employing McQuade's six-membered N-heterocyclic-carbene-copper(I) catalyst is applicable to aryl- and alkyl-substituted allylic phosphates (see scheme). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Protein lipid modification of cysteine residues, referred to as S-palmitoylation or S-acylation, is an important secondary and reversible modification that regulates membrane association, trafficking, and function of target proteins. This enzymatic reaction is mediated by protein S-acyl transferases (PATs). Here, the phylogeny, genomic organization, protein topology, expression, and localization pattern of the 24 PAT family members from Arabidopsis (Arabidopsis thaliana) is described. Most PATs are expressed at ubiquitous levels and tissues throughout the development, while few genes are expressed especially during flower development preferentially in pollen and stamen. The proteins display large sequence and structural variations but exhibit a common protein topology that is preserved in PATs from various organisms. Arabidopsis PAT proteins display a complex targeting pattern and were detected at the endoplasmic reticulum, Golgi, endosomal compartments, and the vacuolar membrane. However, most proteins were targeted to the plasma membrane. This large concentration of plant PAT activity to the plasma membrane suggests that the plant cellular S-acylation machinery is functionally different compared with that of yeast (Saccharomyces cerevisiae) and mammalians. © 2012 American Society of Plant Biologists. Source

Nicoli S.,University of Massachusetts Medical School | Nicoli S.,Yale Cardiovascular Research Center | Knyphausen C.-P.,University of Massachusetts Medical School | Knyphausen C.-P.,University of Munster | And 3 more authors.
Developmental Cell | Year: 2012

Angiogenesis requires coordination of distinct cell behaviors between tip and stalk cells. Although thisprocess is governed by regulatory interactions between the vascular endothelial growth factor (Vegf) and Notch signaling pathways, little is known about the potential role of microRNAs. Through deep sequencing and functional screening in zebrafish, we find that miR-221 is essential for angiogenesis. miR-221 knockdown phenocopied defects associated with loss of the tip cell-expressed Flt4 receptor. Furthermore, miR-221 was required for tip cell proliferation and migration, as well as tip cell potential in mosaic blood vessels. miR-221 knockdown also prevented " hyper-angiogenesis" defects associated with Notch deficiency and miR-221 expression was inhibited by Notch signaling. Finally, miR-221 promoted tip cell behavior through repression of two targets: cyclin dependent kinase inhibitor 1b (cdkn1b) and. phosphoinositide-3-kinase regulatory subunit 1 (pik3r1). These results identify miR-221 as an important regulatory node through which tip cell migration and proliferation are controlled during angiogenesis. Angiogenesis requires coordination of distinct cell behaviors between sprouting tip cells and the stalk cells connected to the patent circulatory system. Nicoli etal. identify a microRNA, miR-221, that is required for tip cell migration and proliferation through the repression of targets involved in PI3K signaling and cell cycle inhibition. © 2012 Elsevier Inc. Source

Oberleithner H.,University of Munster
Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association | Year: 2014

In humans, when plasma sodium concentration rises slightly beyond 140 mM, vascular endothelium sharply stiffens and nitric oxide release declines. In search of a vascular sodium sensor, the endothelial glycocalyx was identified as being a negatively charged biopolymer capable of selectively buffering sodium ions. Sodium excess damages the glycocalyx and renders vascular endothelium increasingly permeable for sodium. In the long term, sodium accumulates in the interstitium and gradually damages the organism. It was discovered that circulating red blood cells (RBC) 'report' surface properties of the vascular endothelium. To some extent, the RBC glycocalyx mirrors the endothelial glycocalyx. A poor (charge-deprived) endothelial glycocalyx causes a poor RBC glycocalyx and vice versa. This observation led to the assumption that the current state of an individual's vascular endothelium in terms of electrical surface charges and sodium-buffering capabilities could be read simply from a blood sample. Recently, a so-called salt blood test was introduced that quantifies the RBC sodium buffer capacity and thus characterizes the endothelial function. The arguments are outlined in this article spanning a bridge from cellular nano-mechanics to clinical application. Source

Denz C.,University of Munster
Annalen der Physik | Year: 2015

Continuous developments have been made in the field of looking glass since Antoni van Leuwenhoek first invented microscope. Driven by the founder of cell biology, Matthias Schleiden, a Jena-based entrepreneur from Germany, Carl Zeiss made an effort to improve and systematically craft reproducible high-resolution lenses. For this purpose he hired in 1866 young physicist Ernst Abbe as a freelancer and asked him to systematically improve lenses by introducing a mathematical basis. He developed a theory of image formation in a microscope that led to the discovery of the resolution limit due to the wave nature of light, namely diffraction. It was, however, only in 1911-1913 that the well-known players in microscopy, Carl Zeiss in Jena and Carl Reichert in Vienna developed a fluorescence microscope that was commercially successful. In the late 1970s, Christoph and Thomas Cremer first came up with a path-breaking idea of using two oppositely placed objectives in a microscope to obtain interference in the focal plane, a so-called 4π technique in the confocal fluorescence microscopy that improved resolution as well as inspection of the depth of field. The 1990s also witnessed another approach to superresolution microscopy based on wide-field microscopy to image cellular nanostructures stained with fluorescent markers. It is based on the statistical fluorescence behavior of single fluorescence emitters known as 'blinking' that can be exploited for single-molecule detection. Source

Frigerio M.,CNRS Charles Coulomb Laboratory | Yaguna C.E.,University of Munster
European Physical Journal C | Year: 2015

We show that novel paths to dark matter generation and baryogenesis are open when the standard model is extended with three sterile neutrinos Niand a charged scalar δ+. Specifically, we propose a new production mechanism for the dark matter particle—a multi-keV sterile neutrino,N1—that does not depend on the active-sterile mixing angle and does not rely on a large primordial lepton asymmetry. Instead,N1 is produced, via freeze-in, by the decays ofδ+ while it is in equilibrium in the early Universe. In addition, we demonstrate that, thanks to the couplings between the heavier sterile neutrinos N2,3 andδ+, baryogenesis via leptogenesis can be realized close to the electroweak scale. The lepton asymmetry is generated either by N2,3-decays for masses M2,3≳TeV, or by N2,3-oscillations for M2,3∼ GeV. Experimental signatures of this scenario include an X-ray line from dark matter decays, and the direct production ofδ+ at the LHC. This model thus describes a minimal, testable scenario for neutrino masses, the baryon asymmetry, and dark matter. © 2015, The Author(s). Source

Itz M.L.,Friedrich - Schiller University of Jena | Schweinberger S.R.,Friedrich - Schiller University of Jena | Schulz C.,University of Munster | Kaufmann J.M.,Friedrich - Schiller University of Jena
NeuroImage | Year: 2014

Spatially caricatured faces were recently shown to benefit face learning (Schulz et al., 2012a). Moreover, spatial information may be particularly important for encoding unfamiliar faces, but less so for recognizing familiar faces (Kaufmann et al., 2013). To directly test the possibility of a major role of reflectance information for the recognition of familiar faces, we compared effects of selective photorealistic caricaturing in either shape or reflectance on face learning and recognition. Participants learned 3D-photographed faces across different viewpoints, and different images were presented at learning and test. At test, performance benefits for both types of caricatures were modulated by familiarity: Benefits for learned faces were substantially larger for reflectance caricatures, whereas benefits for novel faces were numerically larger for shape caricatures. ERPs confirmed a consistent reduction of the occipitotemporal P200 (200-240. ms) by shape caricaturing, whereas the most prominent effect of reflectance caricaturing was seen in an enhanced posterior N250 (240-400. ms), a component that has been related to the activation of acquired face representations. Our results suggest that performance benefits for face learning caused by distinctive spatial versus reflectance information are mediated by different neural processes with different timing and support a prominent role of reflectance for the recognition of learned faces. © 2014 Elsevier Inc. Source

Reiter J.,University of Munster | Nadherna M.,Charles University
Electrochimica Acta | Year: 2012

An ionic liquid, N-allyl-N-methylpiperidinium bis(trifluoromethanesulfonyl) imide PP13 *TFSI has been successfully tested as a solid electrolyte interface (SEI) forming agent for graphite composite anode at elevated temperature of 55 °C in a purely ionic liquid-based electrolyte: 0.5 m LiTFSI in a mixture of PP 13 *TFSI-PP 13TFSI (20-80wt.%) The reversible discharge capacity was 340-350mAhg -1 with only a small irreversible capacity loss per cycle. The electrochemical polymerisation of the allylic double bond participates on the SEI formation on the graphite surface. In the absence of unsaturated ionic liquid, the piperidinium cation is co-intercalated into graphite and causes its exfoliation with permanent loss of capacity. The electrolyte is thermally stable up to 320 °C and reasonably conductive (2.4mScm -1 at 55°C). © 2012 Elsevier Ltd. All rights reserved. Source

Schneider J.,Bielefeld University | Niermann K.,University of Munster | Wendisch V.F.,Bielefeld University
Journal of Biotechnology | Year: 2011

Amino acid production processes with Corynebacterium glutamicum are based on media containing glucose from starch hydrolysis or fructose and sucrose as present in molasses. Simultaneous utilization of various carbon sources, including glucose, fructose and sucrose, in blends is a typical characteristic of this bacterium. The renewable non-food carbon source arabinose, which is present in hemicellulosic hydrolysates, cannot be utilized by most C. glutamicum strains. Heterologous expression of the araBAD operon from Escherichia coli in the wild-type and in an l-lysine producing strain of C. glutamicum was shown to enable production of l-glutamate and l-lysine, respectively, from arabinose as sole carbon source. l-Ornithine and l-arginine producing strains were constructed and shown to produce l-ornithine and l-arginine from arabinose when araBAD from E. coli was expressed. Moreover, the recombinant strains produced l-glutamate, l-lysine, l-ornithine and l-arginine respectively, from arabinose also when glucose-arabinose blends were used as carbon sources. © 2010 Elsevier B.V. Source

Gerke V.,University of Munster
EMBO Journal | Year: 2011

The large glycoprotein von Willebrand factor (vWF) serves an important role in orchestrating the blood vessel's response to injury. It is released from activated endothelial cells and forms long multimeric strings that bind exposed extracellular matrix and circulating platelets and thereby initiate the formation of a platelet plug sealing the wound. Central to this process is the rapid transition of multimeric vWF from a tightly packed storage form present in acidic intraendothelial granules, to the elongated string that is active at neutral vascular pH. In this issue of The EMBO Journal, Zhou and coworkers now provide compelling structural evidence for internal conformational changes that accompany this transition and thereby serve important regulatory functions. They show that the C-terminal part of the protein zips up into a dimeric bouquet at the acidic internal pH of the storage granules but opens up at the neutral pH of plasma, thereby assisting the establishment of elongated vWF strings capable of efficiently capturing platelets. © 2011 European Molecular Biology Organization | All Rights Reserved. Source

Daitche A.,University of Munster | Tel T.,Eotvos Lorand University
Physical Review Letters | Year: 2011

A systematic investigation of the effect of the history force on particle advection is carried out in a paradigmatic model flow of chaotic advection, the von Kármán flow. All investigated properties turn out to heavily depend on the presence of memory when compared to previous studies neglecting this force. We find a weaker tendency for accumulation and for caustics formation. The Lyapunov exponent of transients becomes larger, the escape rates are strongly altered. Attractors are found to be suppressed by the history force, and periodic ones have a very slow, t -1/2-type convergence towards the asymptotic form. © 2011 American Physical Society. Source

Schirmeisen A.,University of Munster
Nature Materials | Year: 2010

A team of researchers performed simulations that revealed that gold clusters entered a a new regime of ballistic friction, featuring a peculiar anticorrelation between translation and rotation on atomically flat graphite. Close observation of this random-walk mechanism showed a strong correlation between the rotational and positional degrees of freedom. This mechanism was visualized as skidding of gold nanoparticles on a sea of thermally excited graphite waves. Another peculiar feature of the ballistic regime was concerned with the correlation between rotation and translation. It was observed that the particle was randomly hit by a thermal 'bump' while skidding in such a way that rotation was initiated. Source

Dietzel D.,Justus Liebig University | Feldmann M.,Justus Liebig University | Schwarz U.D.,Yale University | Fuchs H.,University of Munster | Schirmeisen A.,Justus Liebig University
Physical Review Letters | Year: 2013

"Structural lubricity" refers to a unique friction state in which two flat surfaces are sliding past each other with ultralow resistance due to incommensurate atomic lattice structures. In this case, theory anticipates sublinear scaling for the area dependence of friction. Here, we experimentally confirm these predictions by measuring the sliding resistance of amorphous antimony and crystalline gold nanoparticles on crystalline graphite. For the amorphous particles a square root relation between friction and contact area is observed. For crystalline gold particles we find a more complex scaling behavior related to variations in particle shape and orientation. These results allow us to link mesoscopic friction to atomic principles. © 2013 American Physical Society. Source

Nimmo F.,University of California at Santa Cruz | O'Brien D.P.,Planetary Science Institute | Kleine T.,University of Munster
Earth and Planetary Science Letters | Year: 2010

We couple the results of N-body simulations of late-stage accretion (O'Brien et al., 2006) to a hafnium-tungsten (Hf-W) isotopic evolution code to investigate the evolution of planetary bodies in the inner solar system. Simulations can simultaneously produce planets having Earth- and Mars-like masses and Hf-W systematics by assuming that the tungsten partition coefficient decreases with increasing semi-major axis (e.g. due to increasing oxidation). Simulations assuming that Jupiter and Saturn occupy circular orbits are more successful at reproducing the Hf-W systematics than those assuming present-day Jupiter and Saturn orbits. To generate Earth-like tungsten anomalies, 30-80% of each impactor core is required to re-equilibrate with the target mantle. Some model outcomes yield a target and final impactor having similar (Earth- and Moon-like) tungsten anomalies. However, in no case can the inferred lunar Hf/W ratio be simultaneously matched. This result suggests that the Moon isotopically equilibrated with the Earth's mantle in the aftermath of the giant impact (cf. Pahlevan and Stevenson, 2007). Alternatively, either the dynamical models which show the Moon being derived primarily from the impactor mantle, or the accretion timescales obtained by the N-body simulations, are incorrect. © 2010 Elsevier B.V. Source

Martineau M.,University of Munster
Biochemical Society Transactions | Year: 2013

The release of neuromodulators, called gliotransmitters, by astrocytes is proposed to modulate neurotransmission and synaptic plasticity, and thereby cognitive functions; but they are also proposed to have a role in diverse neurological disorders. Two main routes have been proposed to ensure gliotransmitter release: non-exocytotic release from cytosolic pools through plasma membrane proteins, and Ca2+ - regulated exocytosis through the fusion of gliotransmitter-storing secretory organelles. Regulated Ca 2+ - dependent glial exocytosis has received much attention and is appealing since its existence endows astrocytes with some of the basic properties thought to be exclusive to neurons and neuroendocrine cells. The present review summarizes recent findings regarding the exocytotic mechanisms underlying the release of two excitatory amino acids, l-glutamate and d-serine. © 2013 Biochemical Society. Source

Grimme S.,University of Munster | Djukic J.-P.,CNRS Strasbourg Institute of Chemistry
Inorganic Chemistry | Year: 2010

The concept of a dative metal-metal bond is generally used to designate the donor-acceptor (DA) Interaction of an electron-saturated metal center with another electron-deficient-or unsaturated-metal center. This type of DA bonding extended to the field of coordination complexes constitutes a borderline case of weak metal-metal interaction, among which the so-called metallophilic interactions occurring with 4d, 5d, and other late-transltion-metal complexes are the most documented and representative examples. From a general standpoint, the peculiar position of the so-called dative metal-metal bond in chemical bonding stems from its presumed covalent character, which contrasts with the situation encountered with metallophilic interactions, which are essentially supported by dispersion and electrostatic forces and somewhat sustained by relativists effects. In this study, the nature of the metal-metal bond in nonbridged 5d-3d Os-Cr and 5d-5d Os-W adducts, i.e., (Me3P)(CO) 4Os-M(CO)5 (M=Cr, W) and (CO)5Os-Cr(CO) 5, was addressed by resorting to state-of-the-art quantum-chemical methods. Semilocal density functional theory (DFT) approximations like Becke-Perdew or TPSS, the double-hybrid B2PLYP functional, as well as the corresponding dispersion, including TPSS-D and B2PLYP-D functionals and the wave-function-based spincomponent-scaled second-order perturbatlve Møller-Plesset theory (SCS-MP2), were used. Energy decomposition analysis combined with the analysis of palrwise interfragment correlation energies from Pipek-Mezey localized molecular orbitais in combination with SCS-MP2 led to a clear demonstration of the significant role of dispersion (London) forces In the stabilization of the title adducts, wherein the Os-metal DA bond bears a rather low covalent character. These results plead In favor of a systematic recourse to dispersion including DFT approximations when addressing organometallic and coordination complexes. © 2010 American Chemical Society. Source

Bahlburg H.,University of Munster | Vervoort J.D.,Washington State University | DuFrane S.A.,Washington State University
Gondwana Research | Year: 2010

We have examined the provenance and tectonic setting of the Middle Cambrian and Ordovician siliciclastic deposits and associated volcanic rocks of the Bavarian Facies, Franconia, Germany, in the Saxothuringian Zone of the Variscan orogen. The units were deposited on the North African rifted margin of Gondwana and represent deep-water equivalents of the shallow marine mature sandstone successions of the areally extensive Thuringian Facies. U-Pb ages of detrital zircons of the Middle Cambrian Wildensteiner Formation, the Middle Ordovician Plattensandstone of the Randschiefer Series, and the Upper Ordovician Döbra sandstone fall into four distinct age groups: 2.4 to 1.8 Ga (15%), 0.75 to 0.54 Ga (55%) and 0.54 to 0.44 Ga (14%); minor abundances (4%) occur around 1 Ga. This age distribution is consistent with a northern Gondwanan derivation, mainly from the Cadomian continental magmatic arc in northern Africa. The c. 2 Ga ages indicate a provenance from Eburnean or equivalent sources on the West Africa craton and in northeast Africa and Arabia. The scarcity of grains of Kibaran age (c. 1 Ga) is characteristic of a derivation from metamorphic and magmatic sources on the Arabian-Nubian Shield, rather than from distant major Kibaran age terrains. The youngest group mainly reflects Late Cambrian to Ordovician rift magmatism widespread in the northern Gondwanan Cadomian terranes. The Hf isotopic compositions of selected dated zircons at the time of their crystallization (εHf(t); T = 3.5-0.47 Ga) vary between - 30 and + 7. Zircons with positive εHf(t) values are almost exclusively restricted to the age group between 0.5 and 0.9 Ga. The Hf isotope data suggest that magmatism associated with the Cadomian continental magmatic arc and post-Cadomian (late Cambrian-Ordovician) marginal rifts in northern Gondwana mainly involved mixing of juvenile magmas with Paleoproterozoic crust. © 2009 International Association for Gondwana Research. Source

Frolov T.,University of California at Berkeley | Divinski S.V.,University of Munster | Asta M.,University of California at Berkeley | Mishin Y.,George Mason University
Physical Review Letters | Year: 2013

Recent experimental measurements of Ag impurity diffusion in the Σ5(310) grain boundary (GB) in Cu revealed an unusual non-Arrhenius behavior suggestive of a possible structural transformation Divinski, [Phys. Rev. B 85, 144104 (2012)]. On the other hand, atomistic computer simulations have recently discovered phase transformations in high-angle GBs in metals Frolov, [Nat. Commun. 4, 1899 (2013)]. In this Letter we report on atomistic simulations of Ag diffusion and segregation in two different structural phases of the Cu Σ5(310) GB which transform to each other with temperature. The obtained excellent agreement with the experimental data validates the hypothesis that the unusual diffusion behavior seen in the experiment was caused by a phase transformation. The simulations also predict that the low-temperature GB phase exhibits a monolayer segregation pattern while the high-temperature phase features a bilayer segregation. Together, the simulations and experiment provide the first convincing evidence for the existence of structural phase transformations in high-angle metallic GBs and demonstrate the possibility of their detection by GB diffusion measurements and atomistic simulations. © 2013 American Physical Society. Source

Evers S.,University of Munster | Jensen R.,Copenhagen University
European Journal of Neurology | Year: 2011

Background: Medication overuse headache is a common condition with a population-based prevalence of more than 1-2%. Treatment is based on education, withdrawal treatment (detoxification), and prophylactic treatment. It also includes management of withdrawal headache. Aims: This guideline aims to give treatment recommendations for this headache. Materials and methods: Evaluation of the scientific literature. Results: Abrupt withdrawal or tapering down of overused medication is recommended, the type of withdrawal therapy is probably not relevant for the outcome of the patient. However, inpatient withdrawal therapy is recommended for patients overusing opioids, benzodiazepine, or barbiturates. It is further recommended to start individualized prophylactic drug treatment at the first day of withdrawal therapy or even before. The only drug with moderate evidence for the prophylactic treatment in patients with chronic migraine and medication overuse is topiramate up to 200mg. Corticosteroids (at least 60mg prednisone or prednisolone) and amitriptyline (up to 50mg) are possibly effective in the treatment of withdrawal symptoms. Patients after withdrawal therapy should be followed up regularly to prevent relapse of medication overuse. Discussion and conclusion: Medication overuse headache can be treated according to evidence-based recommendations. Click for the corresponding questions to this CME article. © 2011 The Author(s). European Journal of Neurology © 2011 EFNS. Source

Piorkowski A.,AGH University of Science and Technology | Kempny A.,University of Munster
IEEE Transactions on Biomedical Engineering | Year: 2013

Simulators are a new tool in education in many fields, including medicine, where they greatly improve familiarity with medical procedures, reduce costs, and, importantly, cause no harm to patients. This is so in the case of transesophageal echocardiography (TEE), in which the use of a simulator facilitates spatial orientation and helps in case studies. The aim of the project described in this paper is to simulate an examination by TEE. This research makes use of available computed tomography data to simulate the corresponding echocardiographic view. This paper describes the essential characteristics that distinguish these two modalities and the key principles of the wave phenomena that should be considered in the simulation process, taking into account the conditions specific to the echocardiography. The construction of the CT2TEE (Web-based TEE simulator) is also presented. The considerations include ray-tracing and ray-casting techniques in the context of ultrasound beam and artifact simulation. An important aspect of the interaction with the user is raised. © 1964-2012 IEEE. Source

Gebbert S.,Thunen Institute of Climate Smart Agriculture | Pebesma E.,University of Munster
Environmental Modelling and Software | Year: 2014

Time in geographic information systems has been a research theme for more than two decades, resulting in comprehensive theoretical work, many research prototypes and several working solutions. However, none of the available solutions provides the ability to manage, analyze, process and visualize large environmental spatio-temporal datasets and the investigation and assessment of temporal relationships between them. We present in this paper a freely available field based temporal GIS (TGRASS) that fulfills these requirements. Our approach is based on the integration of time in the open source Geographic Resources Analysis Support System (GRASS). We introduce the concept of a space time dataset that is defined as a collection of time stamped raster, voxel or vector data. A dedicated set of spatio-temporal tools was implemented to manage, process and analyze space time datasets and their temporal and spatial relationships. We demonstrate the temporal GIS and environmental modeling capabilities of TGRASS by analyzing a multi-decadal European climate dataset. © 2013 Elsevier Ltd. Source

Berger K.,University of Munster
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz | Year: 2014

Background: Headache is a symptom experienced by many individuals throughout life. It is a complex, multidimensional construct that, for the purpose of diagnosis, relies on the subjective symptom descriptions of those affected. The classification of headaches is influenced by the frequency of the respective pain as well as the different pain qualities and their perception. In the classification of headache, a number of different methodological problems arise that influence the estimation of prevalence and incidence rates of single headache types. The aim of this manuscript is (a) to describe and discuss the methodological problems in the assessment and classification of headache in general and single headache disorders in detail and (b) to summarize their frequency in studies of the German adult population. Methods: Cross-sectional and prospective cohort studies that assessed headache in general or the prevalence and incidence rates of single headache disorders in Germany are described and methodological problems of the assessment are discussed. Results: The application of different methods, especially in the classification of the most frequent primary headache disorders - migraine and tension-type headache - hinders the comparability of published studies. There is a clear lack of prospective cohort studies that allow a classification of single headache disorders. Conclusions: Given the high frequency and considerable consequences of headache disorders in Germany, only a few studies report results on the prevalence and/or incidence rates, risk factors, and individual as well as economic consequences of different headache disorders. Methodological problems in the assessment and classification of single headache disorders have contributed to this situation. Further standardization of methods in future studies is necessary. © 2014 Springer-Verlag Berlin Heidelberg. Source

DeLong K.A.,University of California at San Diego | Quante L.,University of Munster | Kutas M.,University of California at San Diego
Neuropsychologia | Year: 2014

Van Petten and Luka's (2012, International Journal of Psychophysiology, 83(2), 176-190) literature survey of late positive ERP components elicited by more or less predictable words during sentence processing led them to propose two topographically and functionally distinct positivities: a parietal one associated with semantically incongruent words related to semantic reanalysis and a frontal one with unknown significance associated with congruent but lexically unpredicted words. With the goal of testing this hypothesis within a single set of experimental materials and participants, we report results from two ERP studies: Experiment 1, a post-hoc analysis of a dataset that varied on dimensions of both cloze probability (predictability) and plausibility, and Experiment 2, a follow-up study in which these factors were manipulated in a controlled fashion. In both studies, we observed distinct post-N400 positivities: a more anterior one to plausible, but not anomalous, low cloze probability sentence medial words, and a more posterior one to semantically anomalous sentence continuations. Taken together with an observed canonical cloze-modulated N400, these dual positivities indicate a dissociation between brain processes relating to written words' sentential predictability versus plausibility, clearly an important distinction for any viable neural or psycholinguistic model of written sentence processing. © 2014 Elsevier Ltd. Source

Erker G.,University of Munster
Pure and Applied Chemistry | Year: 2012

The chemistry of some reactive frustrated Lewis pairs (FLPs) is reported. This includes intramolecular P/B and N/B FLPs, some of which were used as catalysts for the hydrogenation of electron-rich olefin substrates. Some advanced intermolecular FLPs are reported, which includes systems derived from very bulky alkenyl boranes obtained from 1,1-carboboration reactions of 1-alkynes with tris(pentafluorophenyl)borane. Some such systems activate dihydrogen and transfer the resulting proton/hydride pair even to some electron-poor alkynes. Eventually, we report on the reaction of our intramolecular ethylenebridged P/B FLP with nitric oxide (NO). N,B-addition of the P-Lewis base/B-Lewis acid combination is observed to form a new type of a persistent aminoxyl radical. Some of the chemistry of the new FLP-NO radicals is presented and discussed. © 2012 IUPAC. Source

Bettenworth D.,University of Munster | Rieder F.,Cleveland Clinic
Fibrogenesis and Tissue Repair | Year: 2014

Crohn's disease (CD) is a chronic remitting and relapsing disease. Fibrostenosing complications such as intestinal strictures, stenosis and ultimately obstruction are some of its most common long-term complications. Despite recent advances in the pathophysiological understanding of CD and a significant improvement of anti-inflammatory therapeutics, medical therapy for stricturing CD is still inadequate. No specific anti-fibrotic therapy exists and the incidence rate of strictures has essentially remained unchanged. Therefore, the current therapy of established fibrotic strictures comprises mainly endoscopic dilation as well as surgical approaches. However, these treatment options are associated with major complications as well as high recurrence rates. Thus, a specific anti-fibrotic therapy for CD is urgently needed. Importantly, there is now a growing body of evidence for prevention as well as effective medical treatment of fibrotic diseases of other organs such as the skin, lung, kidney and liver. In face of the similarity of molecular mechanisms of fibrogenesis across these organs, translation of therapeutic approaches from other fibrotic diseases to the intestine appears to be a promising treatment strategy. In particular transforming growth factor beta (TGF-β) neutralization, selective tyrosine kinase inhibitors, blockade of components of the renin-angiotensin system, IL-13 inhibitors and mammalian target of rapamycin (mTOR) inhibitors have emerged as potential drug candidates for anti-fibrotic therapy and may retard progression or even reverse established intestinal fibrosis. However, major challenges have to be overcome in the translation of novel anti-fibrotics into intestinal fibrosis therapy, such as the development of appropriate biomarkers that predict the development and accurately monitor therapeutic responses. Future clinical studies are a prerequisite to evaluate the optimal timing for anti-fibrotic treatment approaches, to elucidate the best routes of application, and to evaluate the potential of drug candidates to reach the ultimate goal: the prevention or reversal of established fibrosis and strictures in CD patients. © 2014 Bettenworth and Rieder; licensee BioMed Central Ltd. Source

Summ O.,University of Munster | Evers S.,Krankenhaus Lindenbrunn Coppenbrugge
Current Pain and Headache Reports | Year: 2013

Indomethacin, as a member of the non-steroidal anti-inflammatory drug class, plays a special role in the treatment of headaches. By definition, it is completely efficacious in the treatment of the primary headache disorders paroxysmal hemicrania and hemicrania continua. Therefore, indomethacin is also used as a tool for differential diagnosis in headache clinics. Indomethacin has a clear action as a cyclooxygenase inhibitor. Additional mechanisms and interactions with cell signaling pathways and inflammatory pathways are considered in this article. However, it is not known what mechanism or interaction with pathophysiological mechanisms is the key to indomethacin’s specific pharmacology in headache therapy. Focusing on headache therapy, we summarize the current knowledge of pharmacology, treatment options, and recommendations for the use of indomethacin in primary headaches. New findings from the field of headache research, as well as from Alzheimer’s disease and cancer research on the pharmacological actions of indomethacin and their potential implications on the pathophysiology of indomethacin sensitive headaches, are discussed. © Springer Science+Business Media New York 2013. Source

Khoukaz A.,University of Munster
Acta Physica Polonica B | Year: 2014

Differential and total cross sections for the dp → 3He η reaction have been measured with both unpolarised and tensor/vector polarised deuteron beams at the COSY-ANKE experiment near threshold. The data have been taken by using a continuous beam energy ramp up to an excess energy Q of 10MeV with essentially 100% acceptance of the detection system. The data allowed the determination of the energy dependence of the tensor analysing power t20 and hence of the two s-wave production amplitudes at threshold. The observed very weak energy dependence of these quantities supports the hypothesis that the rapid energy variation of the scattering amplitude for this reaction is dominantly given by a strong s-wave η3He final state interaction, which is discussed to be a signal for the existence of a possible quasi-bound eta-mesic state. Source

The present study shows how foot loading patterns may be deliberately altered by either in-toeing or out-toeing gait during barefoot walking. The results indicate that in-toeing increasingly loads the lateral aspects of the midfoot and forefoot by as much as 61% and 49%, respectively, whereas out-toeing intensifies the load on the medial aspect, i.e. predominantly the medial midfoot and medial forefoot by as much as 72% and 52%. These findings are being discussed with respect to the potential benefits of consciously altering the gait pattern in order to off-load certain plantar regions. © 2013 Elsevier B.V. Source

Zumbro T.,University of Munster
Housing Studies | Year: 2014

The article investigates the relationship between homeownership and life satisfaction in Germany, using German Socio-Economic Panel Study data from 1992 to 2009. The data not only allow controlling for a wide range of variables, but also tackle various measurement problems of previous studies. Ordered logit models support a positive relationship between homeownership and life satisfaction. In addition, regression models with fixed effects also reveal unobserved differences between homeowners and renters. Further results show that homeownership is particularly important for low-income households and that there is a significant interaction between homeownership and the condition of the dwelling as well as homeownership and the financial burden of the household. Overall, the findings indicate that policies aim at a higher degree if life satisfaction should not focus on the promotion of homeownership alone, but also support home maintenance costs. © 2013 Taylor & Francis. Source

Studer A.,University of Munster | Curran D.P.,University of Pittsburgh
Angewandte Chemie - International Edition | Year: 2011

A radical outlook: Recently published "organocatalytic C-H activation reactions" have now been interpreted as base-promoted homolytic substitutions. The addition of an aryl radical to an arene followed by deprotonation (see above) and electron transfer form part of the chain reaction. Although these new results are not conceptual breakthroughs, they could be experimental breakthroughs because they presage new transformations in radical (anion) chemistry. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

In this article I analyze the strategies of indigenous peoples as norm entrepreneurs in UN climate negotiations. I set out a conceptual linkage between the emerging literature on institutional interaction and social constructivist agency. It is shown, against the background of a descriptive account of the development of REDD+ negotiations within the UNFCCC, that indigenous peoples have been able to influence the agenda by crafting their immaterial power resources through the transfer of knowledge resources and normative instances from distinct institutions. This strategy of "importing power" to the target institution, the UNFCCC, was accompanied by support of key individuals and favorable national governments. Furthermore, indigenous peoples' demand to have their rights considered in the REDD+ agreement resonated with more established frames of global environmental politics that focus on synergies, cost-effectiveness, and management approaches. However, further research is required to figure out argumentative dynamics within the indigenous community itself and to identify the conditions that determined the level of success of their advocacy strategies. © 2014 by the author(s). Source

Daitche A.,University of Munster | Tel T.,A.P.S. University
New Journal of Physics | Year: 2014

A systematic investigation of the effect of the history force on particle advection is carried out for both heavy and light particles. General relations are given to identify parameter regions where the history force is expected to be comparable with the Stokes drag. As an illustrative example, a paradigmatic two-dimensional flow, the von Kármán flow is taken. For small (but not extremely small) particles all investigated dynamical properties turn out to heavily depend on the presence of memory when compared to the memoryless case: the history force generates a rather non-trivial dynamics that appears to weaken (but not to suppress) inertial effects, it enhances the overall contribution of viscosity. We explore the parameter space spanned by the particle size and the density ratio, and find a weaker tendency for accumulation in attractors and for caustics formation. The Lyapunov exponent of transients becomes larger with memory. Periodic attractors are found to have a very slow, type convergence towards the asymptotic form. We find that the concept of snapshot attractors is useful to understand this slow convergence: an ensemble of particles converges exponentially fast towards a snapshot attractor, which undergoes a slow shift for long times. © 2014 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. Source

Schirmer B.,University of Munster | Grimme S.,University of Bonn
Topics in Current Chemistry | Year: 2013

We discuss methodological aspects of the computation of structures and energies of three common FLPs which are able to activate dihydrogen under ambient conditions. The effect of London dispersion corrections by the DFT-D3 scheme and solvent as well as rovibrational corrections to yield free reaction enthalpies in solutions are described. Common density functionals of semi-local, hybrid, and double-hybrid type as well as (SCS-)MP2 wave function based methods with very large AO basis sets are investigated. It is found that reliable structures (in comparison to X-ray data) are already obtained using relatively cheap DFT methods like TPSS-D3/TZ. The variations between different density functionals for electronic reaction energies are small to moderate (1-2 kcal/mol which is about 10% of the H2 was addition energy). Dispersion corrections are found to be essential for accurate thermochemistry. Computed free H2 reaction enthalpies in the gas phase are close to zero while values computed in common solvents with the COSMO-RS continuum solvation model are strongly exergonic (about -10 kcal/mol in CH2Cl2). This new finding emphasizes the important role of the solvent for FLP chemistry involving zwitterionic species. According to our results the future for reliable quantum chemistry of FLP processes is bright. © 2013 Springer-Verlag Berlin Heidelberg. Source

Heilmann C.,University of Munster
Advances in Experimental Medicine and Biology | Year: 2011

Staphylococcal adherence to an either biotic or abiotic surface is the critical first event in the establishment of an infection with these serious pathogens. Especially Staphylococcus aureus harbours a variety of proteinaceous and non-proteinaceous adhesins that mediate attachment to a multitude of host factors, such as extracellular matrix and plasma proteins and human host cells, or intercellular adhesion, which is essential for biofilm accumulation. Proteinaceous adhesins may be classified in covalently surface-anchored proteins of the MSCRAMM (microbial surface components recognizing adhesive matrix molecules) family or in proteins that are surface-associated by different means, such as ionic or hydrophobic interactions. Non-covalently surface-associated proteins include the autolysin/adhesins, proteins of the SERAM (secretable expanded repertoire adhesive molecules) family, or membrane-spanning proteins. Non-proteinaceous adhesins comprise the polysaccharide PIA (polysaccharide intercellular adhesin) and wall teichoic and lipoteichoic acids. The features and functions of surface and surface-associated protein adhesins as well as of non-proteinaceous adhesins are discussed. © 2011 Springer Science+Business Media B.V. Source

Zarbock A.,University of Munster | Gomez H.,University of Pittsburgh | Kellum J.A.,University of Pittsburgh
Current Opinion in Critical Care | Year: 2014

Purpose of review Acute kidney injury (AKI) is a common complication in critically ill patients and is associated with increased morbidity and mortality. Sepsis is the most common cause of AKI. Considerable evidence now suggests that the pathogenic mechanisms of sepsis-induced AKI are different from those seen in other causes of AKI. This review focuses on the recent advances in this area and discusses possible therapeutic interventions that might derive from these new insights into the pathogenesis of sepsis-induced AKI. Recent findings The traditional paradigm that sepsis-induced AKI arises from ischemia has been challenged by recent evidence that total renal blood flow in is not universally impaired during sepsis, and AKI can develop in the presence of normal or even increased renal blood flow. Animal and human studies suggest that adaptive responses of tubular epithelial cells to injurious signals are responsible for renal dysfunction. Simultaneously occurring renal inflammation and microcirculatory dysfunction further amplify these mechanisms. Summary An understanding of the pathologic mechanisms of sepsis-induced AKI emphasizes the important role of maladaptive responses to the septic insult. Preventive and therapeutic measures should be based on counteracting these maladaptive responses of tubular epithelial cells, inflammation, and microvascular dysfunction. Copyright © Lippincott Williams & Wilkins. Source

Raccichini R.,University of Munster | Raccichini R.,Helmholtz Institute Ulm | Raccichini R.,Karlsruhe Institute of Technology | Varzi A.,Helmholtz Institute Ulm | And 5 more authors.
Nature Materials | Year: 2015

Since its first isolation in 2004, graphene has become one of the hottest topics in the field of materials science, and its highly appealing properties have led to a plethora of scientific papers. Among the many affected areas of materials science, this 'graphene fever' has influenced particularly the world of electrochemical energy-storage devices. Despite widespread enthusiasm, it is not yet clear whether graphene could really lead to progress in the field. Here we discuss the most recent applications of graphene-both as an active material and as an inactive component-from lithium-ion batteries and electrochemical capacitors to emerging technologies such as metal-air and magnesium-ion batteries. By critically analysing state-of-the-art technologies, we aim to address the benefits and issues of graphene-based materials, as well as outline the most promising results and applications so far. © 2015 Macmillan Publishers Limited. All rights reserved. Source

Niewerth D.,VU University Amsterdam | Creutzig U.,University of Munster | Bierings M.B.,University Utrecht | Kaspers G.J.L.,VU University Amsterdam
Blood | Year: 2010

Survival of pediatric acute myeloid leukemia (AML) has improved considerably over the past decades. Since 1985, allogeneic stem cell transplantation (allo-SCT) is widely recommended for patients who have a matched sibling donor. However, it remains controversial whether allo-SCT is superior to chemotherapy for children with newly diagnosed AML. This review summarizes phase 3 clinical trials that compared allo-SCT with chemotherapy (including autologous SCT) in pediatric AML, excluding studies that did not use the intention-to-treat analysis or correct for time-to-transplantation. Although allo-SCT might prevent more relapses than chemotherapy, the number needed for transplantation (with allo-SCT) to prevent one relapse is in the order of 10 patients. Moreover, overall survival is similar with both methods in most recent studies, apparently because of increased salvagability of a relapse when initial therapy concerned chemotherapy only, and because of a higher treatment-related mortality with allo-SCT. Because allo-SCT also gives more severe side effects and results more often in secondary malignancies than chemotherapy, we do not recommend allo-SCT in first remission for pediatric AML in general. Further research should focus on the possibility that subgroups might benefit from allo-SCT, aiming at further improvements in the prognosis of pediatric AML. © 2010 by The American Society of Hematology. Source

Schaefer L.,Goethe University Frankfurt | Schaefer R.M.,University of Munster
Cell and Tissue Research | Year: 2010

Our knowledge of proteoglycan biology has significantly expanded over the past decade with the discovery of a host of new members of this multifunctional family leading to their present classification into three major categories: (1) small leucine-rich proteoglycans, 2) modular proteoglycans, and 3) cell-surface proteoglycans. In addition to being structural proteins, proteoglycans play a major role in signal transduction with regulatory functions in various cellular processes. Being mostly extracellular, they are upstream of many signaling cascades and are capable of affecting intracellular phosphorylation events and modulating distinct pathways, including those driven by bone morphogenetic protein/transforming growth factor superfamily members, receptor tyrosine kinases, the insulin-like growth factor-I receptor, and Toll-like receptors. Mechanistic insights into the molecular and cellular functions of proteoglycans have revealed both the sophistication of these regulatory proteins and the challenges that remain in uncovering the entirety of their biological functions. This review aims to summarize the multiple functions of proteoglycans with special emphasis on their intricate composition and the newly described signaling events in which these molecules play a key role. © 2009 Springer-Verlag. Source

Extracellular matrices (ECM) not only serve as structural scaffolds in organs and tissues, but also determine critical cellular functions through cell-matrix interactions. These are mediated by cell surface receptors that recognise specific structural features of ECMs and, hence, overall physical properties of the acellular environment. ECM structures are subject to hierarchic organisations, which are tightly adapted to the functions of tissues and organs. Only a few specialised tasks are reserved for isolated ECM macromolecules. Instead, molecular ECM components attain their prominent functions only after polymerising into insoluble suprastructural elements, i.e. fibrils, microfibrils, or networks that, in turn, are assembled into regional tissue structures, such as fibres or basement membranes. As an outstanding feature, most, if not all, ECM suprastructures are co-polymers of more than one molecular species that differ in their identity and relative abundance. Thus, ECM suprastructures are composite biological amalgamates. The analogy to metal alloys refers to structural and functional characteristics of ECM composites, which differ from those of each homo-polymeric aggregate. At the tissue level, biological alloys can themselves be assembled into conglomerates that again assume properties distinct from those of each individual alloy. Nevertheless, most studies in matrix biology solely focus on molecular features and mechanisms. Progress has however been made in identifying principles of interactions within suprastructural elements and their functional consequences. We are now only beginning to understand the impact of suprastructural organisation on the assembly and the functions of whole tissues and many fundamental issues in this almost pristine field await discovery. © 2009 Springer-Verlag. Source

Lammert H.,University of California at San Diego | Heuer A.,University of Munster
Physical Review Letters | Year: 2010

Ion transport in structurally disordered inorganic ion conductors can be interpreted as cation jumps between sites provided by the network. Because of the small number of vacant sites and strong intercationic Coulomb interaction, their dynamics is very complex. Based on molecular dynamics simulations we recast the ion dynamics via a sophisticated mapping procedure into the corresponding vacancy dynamics. Remarkably, in this framework, the transport can be interpreted to a very good approximation as a noninteracting single-particle processes. In particular, the macroscopic conductivity can be directly obtained from the local vacancy hopping rates. © 2010 The American Physical Society. Source

Complexes bearing "protic" N-heterocyclic carbene (NHC) ligands (NR,NH-NHCs) have been shown to use the N-H group of the NHC ligand for the formation of hydrogen bonds to selected substrates. This type of hydrogen bond can be used for substrate recognition, selection, and orientation. In contrast to related systems, the hydrogen bond donor and thus the molecular recognition unit is located in proximity to the metal center. This concept article discusses major strategies for the preparation of complexes bearing protic NHC ligands and their potential applications. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Hennecke U.,University of Munster
Chemistry - An Asian Journal | Year: 2012

The addition of electrophilic reagents to the carbon-carbon double bond is one of the most fundamental reactions in organic chemistry. Halogen electrophiles constitute probably the most important class of electrophiles and have been widely used to induce electrophilic addition reactions to alkenes like halolactonizations or dihalogenations. Despite their long history and high importance, catalytic, asymmetric variants of these reactions have been underdeveloped until very recently. During the last two years this has changed and many novel approaches have been reported. This review aims to cover these new developments through discussing the common themes as well as the suggested mechanistic scenarios. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Yamaguchi K.,Nagoya University | Yamaguchi J.,Nagoya University | Studer A.,University of Munster | Itami K.,Nagoya University
Chemical Science | Year: 2012

A new Pd-catalyzed C-H/C-B coupling of sterically hindered heteroarenes and arylboronic acids has been identified. The newly established Pd(OAc) 2/bisoxazoline/TEMPO system not only enables the synthesis of sterically hindered heterobiaryls but also offers an opportunity for enantioselective biaryl coupling through C-H functionalization. © 2012 The Royal Society of Chemistry. Source

Nestler S.,University of Munster
British Journal of Mathematical and Statistical Psychology | Year: 2014

Parameters in structural equation models are typically estimated using the maximum likelihood (ML) approach. Bollen (1996) proposed an alternative non-iterative, equation-by-equation estimator that uses instrumental variables. Although this two-stage least squares/instrumental variables (2SLS/IV) estimator has good statistical properties, one problem with its application is that parameter equality constraints cannot be imposed. This paper presents a mathematical solution to this problem that is based on an extension of the 2SLS/IV approach to a system of equations. We present an example in which our approach was used to examine strong longitudinal measurement invariance. We also investigated the new approach in a simulation study that compared it with ML in the examination of the equality of two latent regression coefficients and strong measurement invariance. Overall, the results show that the suggested approach is a useful extension of the original 2SLS/IV estimator and allows for the effective handling of equality constraints in structural equation models. © 2013 The British Psychological Society. Source

Ibrahim S.A.,Cairo University | Hassan H.,Cairo University | Gotte M.,University of Munster
FEBS Journal | Year: 2014

MicroRNAs are small noncoding RNAs acting as physiological regulators of gene expression at the post-transcriptional level. In cancer, the expression of microRNAs is dysregulated compared to healthy tissue, suggesting a mechanistic role in disease progression. Recent experimental evidence supports the important molecular role of proteoglycans as microRNA targets in this process. Misexpression of specific microRNAs results in aberrant expression patterns of proteoglycans, as well as their biosynthetic enzymes. Consequently, cell proliferation and apoptosis, adhesion, migration, invasiveness, epithelial-to-mesenchymal transition and cancer stem cell properties are affected as a result of the multifunctional properties of proteoglycans. A pharmacological targeting of the microRNA-proteoglycan axis emerges as a new therapeutic concept in cancer. © 2014 FEBS. Source

Frijhoff J.,Karolinska Institutet | Dagnell M.,Karolinska Institutet | Godfrey R.,University of Munster | Ostman A.,Karolinska Institutet
Antioxidants and Redox Signaling | Year: 2014

Significance: Redox-regulated control of protein tyrosine phosphatases (PTPs) through inhibitory reversible oxidation of their active site is emerging as a novel and general mechanism for control of cell surface receptor-activated signaling. This mechanism allows for a previously unrecognized crosstalk between redox regulators and signaling pathways, governed by, for example, receptor tyrosine kinases and integrins, which control cell proliferation and migration. Recent Advances: A large number of different molecules, in addition to hydrogen peroxide, have been found to induce PTP inactivation, including lipid peroxides, reactive nitrogen species, and hydrogen sulfide. Characterization of oxidized PTPs has identified different types of oxidative modifications that are likely to display differential sensitivity to various reducing systems. Accumulating evidence demonstrates that PTP oxidation occurs in a temporally and spatially restricted manner. Studies in cell and animal models indicate altered PTP oxidation in models of common diseases, such as cancer and metabolic/ cardiovascular disease. Novel methods have appeared that allow characterization of global PTP oxidation. Critical Issues: As the understanding of the molecular and cellular biology of PTP oxidation is developing, it will be important to establish experimental procedures that allow analyses of PTP oxidation, and its regulation, in physiological and pathophysiological settings. Future studies should also aim to establish specific connections between various oxidants, specific PTPs, and defined signaling contexts. Future Directions: Modulation of PTP activity still appears as a valid strategy for correction or inhibition of dys-regulated cell signaling. Continued studies on PTP oxidation might present yet unrecognized means to exploit this regulatory mechanism for pharmacological purposes. © 2014, Mary Ann Liebert, Inc. 2014. Source

Breier G.,TU Dresden | Grosser M.,TU Dresden | Rezaei M.,University of Munster
Cell and Tissue Research | Year: 2014

Cadherins are cell adhesion receptors that play important roles in embryogenesis and tissue homoeostasis. Endothelial cells express various members of the cadherin superfamily, in particular vascular endothelial (VE-) cadherin, which is the main adhesion receptor of endothelial adherens junctions and neural (N-) cadherin, which is normally localized outside the junctions and may mediate adhesion between endothelial cells and non-endothelial cells. Dysregulation of cadherin expression has been implicated in tumor progression, in particular the loss of epithelial (E-) cadherin expression or function and the gain of N-cadherin. Moreover, more recently, aberrant expression of VE-cadherin was observed in certain cancer types. In breast carcinoma, VE-cadherin was shown to promote tumor cell proliferation and invasion through enhancing TGF-β signaling. Thus, in breast cancer, the cadherin switch involves another player, vascular endothelial cadherin, which is part of an intricate interplay of classical cadherins in breast cancer progression. © 2014 Springer-Verlag Berlin Heidelberg. Source

DEAD-box helicases catalyze the ATP-dependent destabilization of RNA duplexes. Hera is a DEAD-box helicase from Thermus thermophilus that consists of a helicase core, followed by a C-terminal extension comprising a dimerization domain and an RNA-binding domain. The combined structural information on individual Hera domains provides a molecular model of the Hera dimer. The modular architecture with flexible connections between individual domains affords different relative orientations of the RBD relative to the Hera helicase core, and of the two helicase cores within the dimer. Presumably, domain movements are intimately linked to RNA binding, to the interplay of the RBD and the helicase core, and to RNA unwinding, and may impact on the functional cooperation of the two helicase cores in RNA unwinding. The in vivo function of Hera is unknown. The Hera RBD recognizes two distinct elements in the RNA substrate, a single-stranded and a structured region. The helicase core then unwinds an adjacent RNA duplex in an ATP-dependent reaction. Overall, this mode of action is reminiscent of DEAD-box proteins that act as general RNA chaperones. This review summarizes the current knowledge on Hera structure and function, and discusses a possible role of Hera in the Thermus thermophilus cold-shock response. Copyright © 2013 Wiley Periodicals, Inc. Source

Stephan D.W.,University of Toronto | Erker G.,University of Munster
Topics in Current Chemistry | Year: 2013

The development and use of frustrated Lewis pairs (FLPs) as both stoichiometric and catalytic reductants for the hydrogenation of a variety of organic substrate is described. © 2013 Springer-Verlag Berlin Heidelberg. Source

Funke K.,University of Munster
Science and Technology of Advanced Materials | Year: 2013

Solid State Ionics has its roots essentially in Europe. First foundations were laid by Michael Faraday who discovered the solid electrolytes Ag 2S and PbF2 and coined terms such as cation and anion, electrode and electrolyte. In the 19th and early 20th centuries, the main lines of development toward Solid State Ionics, pursued in Europe, concerned the linear laws of transport, structural analysis, disorder and entropy and the electrochemical storage and conversion of energy. Fundamental contributions were then made by Walther Nernst, who derived the Nernst equation and detected ionic conduction in heterovalently doped zirconia, which he utilized in his Nernst lamp. Another big step forward was the discovery of the extraordinary properties of alpha silver iodide in 1914. In the late 1920s and early 1930s, the concept of point defects was established by Yakov Il'ich Frenkel, Walter Schottky and Carl Wagner, including the development of point-defect thermodynamics by Schottky and Wagner. In terms of point defects, ionic (and electronic) transport in ionic crystals became easy to visualize. In an 'evolving scheme of materials science', point disorder precedes structural disorder, as displayed by the AgI-type solid electrolytes (and other ionic crystals), by ion-conducting glasses, polymer electrolytes and nano-composites. During the last few decades, much progress has been made in finding and investigating novel solid electrolytes and in using them for the preservation of our environment, in particular in advanced solid state battery systems, fuel cells and sensors. Since 1972, international conferences have been held in the field of Solid State Ionics, and the International Society for Solid State Ionics was founded at one of them, held at Garmisch-Partenkirchen, Germany, in 1987. © 2013 National Institute for Materials Science. Source

The India-Asia collision zone is a key area for understanding continental plateau formation and mountain building. Two fundamental questions in this context are how the northeastward motion of India is partitioned between strike-slip and thrust faults and how mountain building is counteracted by erosion. Cosmogenic nuclides allow us to address these questions, because they provide age constraints on tectonically offset landforms and constraints on erosion rates. After considerable debate on whether or not major strike-slip faults move at high rates of up to 20-30. mm/yr and absorb most of the continental deformation, it now appears that the three largest faults (Altyn Tagh, Haiyuan, Kunlun) have millennial slip rates of no more than 8-13. mm/yr, consistent with rates of elastic strain accumulation determined by geodetic methods. Furthermore, a significant portion of the lateral slip on these faults is transferred to thrust faults within the collision zone. Both observations indicate that the eastward tectonic escape of material along these faults is less important than often assumed. With respect to mountain building and erosion, cosmogenic nuclide studies show that thrust faults at the northeastern and eastern margins of Tibet (Qilian Shan, Longmen Shan) have vertical slip rates of ~. 0.3 to ~. 2. mm/yr while catchment-wide erosion rates vary from ~. 0.02 to ~. 1.0. mm/yr, with high-relief areas eroding significantly faster than the plateau interior and growing mountains in the foreland. The deeply incised regions have apparently reached an erosional steady-state, in which rock uplift is balanced by erosion. River terraces at active mountain fronts document repeated changes between sediment deposition and fluvial incision. During the Quaternary, incision and terrace formation occurred predominantly at glacial-interglacial transitions but also during interglacial periods. Hence, flights of terraces at the fault-bounded mountain fronts record the interplay between sustained rock uplift and a temporally variable climate. © 2012 Elsevier B.V. Source

Schonhoff M.,University of Munster
Current Opinion in Colloid and Interface Science | Year: 2013

NMR methods provide chemically selective tools, particularly suitable to detect the molecular environment of molecular species in micro-heterogeneous materials. They are consequently applied to solve many questions in colloid science. The present review covers NMR studies of molecular adsorption onto particle surfaces as well as sorption into colloidal particles. Various methods ranging from liquid or solid state spectral analysis over spin relaxation to pulsed field gradient diffusion NMR have been employed in this field, monitoring either the chemical environment or the restricted dynamics of adsorbed or encapsulated guest molecules. Adsorption systems include surfactant layers, stabilizing ligands, small molecules, polymer layers or polyelectrolyte multilayers at the surface of various types of particles. Sorption into colloidal particles and detection of their position in specific compartments of the colloid are particularly relevant in systems employed as colloidal carriers, such as micelles, vesicles, or hollow polymeric capsules. With guest molecules considered as model compounds for drugs these studies have large relevance for the development of nanoparticle drug delivery systems. © 2013 Elsevier Ltd. Source

Wencel-Delord J.,University of Strasbourg | Glorius F.,University of Munster
Nature Chemistry | Year: 2013

The beginning of the twenty-first century has witnessed significant advances in the field of C-H bond activation, and this transformation is now an established piece in the synthetic chemists' toolbox. This methodology has the potential to be used in many different areas of chemistry, for example it provides a perfect opportunity for the late-stage diversification of various kinds of organic scaffolds, ranging from relatively small molecules like drug candidates, to complex polydisperse organic compounds such as polymers. In this way, C-H activation approaches enable relatively straightforward access to a plethora of analogues or can help to streamline the lead-optimization phase. Furthermore, synthetic pathways for the construction of complex organic materials can now be designed that are more atom- and step-economical than previous methods and, in some cases, can be based on synthetic disconnections that are just not possible without C-H activation. This Perspective highlights the potential of metal-catalysed C-H bond activation reactions, which now extend beyond the field of traditional synthetic organic chemistry. © 2013 Macmillan Publishers Limited. Source

Steinbicker A.U.,University of Munster | Muckenthaler M.U.,University of Heidelberg | Muckenthaler M.U.,Molecular Medicine Partnership Unit MMPU
Nutrients | Year: 2013

Iron is an essential element in our daily diet. Most iron is required for the de novo synthesis of red blood cells, where it plays a critical role in oxygen binding to hemoglobin. Thus, iron deficiency causes anemia, a major public health burden worldwide. On the other extreme, iron accumulation in critical organs such as liver, heart, and pancreas causes organ dysfunction due to the generation of oxidative stress. Therefore, systemic iron levels must be tightly balanced. Here we focus on the regulatory role of the hepcidin/ferroportin circuitry as the major regulator of systemic iron homeostasis. We discuss how regulatory cues (e.g., iron, inflammation, or hypoxia) affect the hepcidin response and how impairment of the hepcidin/ferroportin regulatory system causes disorders of iron metabolism. © 2013 by the authors; licensee MDPI, Basel, Switzerland. Source

Hucklenbroich P.,University of Munster
Journal of Medicine and Philosophy (United Kingdom) | Year: 2014

Philosophical debates about the concept of disease, particularly of mental disease, might benefit from reconsideration and a closer look at the established terminology and conceptual structure of contemporary medical pathology and clinical nosology. The concepts and principles of medicine differ, to a considerable extent, from the ideas and notions of philosophical theories of disease. In medical theory, the concepts of disease entity and pathologicity are, besides the concept of disease itself, of fundamental importance, and they are essentially connected to the concepts cause of disease or etiological factor, natural course or natural history of disease, and pathological disposition. It is the concept of disease entity that is of key importance for understanding medical pathology and theory of disease. Its central role is shown by a short reconstruction of its main features and its intrinsic connection to the concept of pathologicity. The meaning of pathologicity is elucidated by explicating the underlying criteria. © The Author 2014. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. All rights reserved. Source

Wiley J.S.,Purdue University | Shelley J.T.,Purdue University | Shelley J.T.,University of Munster | Cooks R.G.,Purdue University
Analytical Chemistry | Year: 2013

We describe a handheld, wireless low-temperature plasma (LTP) ambient ionization source and its performance on a benchtop and a miniature mass spectrometer. The source, which is inexpensive to build and operate, is battery-powered and utilizes miniature helium cylinders or air as the discharge gas. Comparison of a conventional, large-scale LTP source against the handheld LTP source, which uses less helium and power than the large-scale version, revealed that the handheld source had similar or slightly better analytical performance. Another advantage of the handheld LTP source is the ability to quickly interrogate a gaseous, liquid, or solid sample without requiring any setup time. A small, 7.4-V Li-polymer battery is able to sustain plasma for 2 h continuously, while the miniature helium cylinder supplies gas flow for approximately 8 continuous hours. Long-distance ion transfer was achieved for distances up to 1 m. © 2013 American Chemical Society. Source

Fustero S.,University of Valencia | Fustero S.,Research Center Principe Felipe | Simon-Fuentes A.,University of Valencia | Barrio P.,University of Valencia | Haufe G.,University of Munster
Chemical Reviews | Year: 2015

Olefin metathesis and organofluorine chemistry, have witnessed an impressive development. The discovery of well-defined ruthenium and molybdenum-based alkylidene complexes has made such catalysts much more available while greatly increasing the functional group tolerance, among other virtues. the synthesis of fluorine-containing heterocycles, including cyclic amino acid derivatives, saccharide analogues, and other biologically relevant skeletons, has undergone the impact of olefin metathesis in organofluorine chemistry. Cross metathesis has enabled the synthesis of natural product analogues and vicinal fluoroalkanes, otherwise inaccessible by current methodologies. The search for increasingly sophisticated materials has redoubled efforts in the field of metathesis polymerization fluorinated substrates playing a major role due to the unique properties exhibited by fluorine-containing polymers. In addition to the great applicability that fluorinated substrates have found in olefin metathesis reactions, the introduction of fluorine atoms in the catalysts' ligand framework has also proven beneficial in many cases. Source

Zhang B.,China Pharmaceutical University | Studer A.,University of Munster
Chemical Society Reviews | Year: 2015

Nitrogen heterocycles belong to a highly important class of compounds which are found in various natural products, biologically active structures, and medicinally relevant compounds. Therefore, there is continuing interest in the development of novel synthetic methods for the construction of nitrogen containing heterocycles. Recently, radical insertion reactions into isonitriles have emerged as an efficient and powerful strategy for the construction of nitrogen heterocycles, such as phenanthridines, indoles, quinolines, quinoxalines, and isoquinolines. This review highlights recent advances in this fast growing research area and also includes important pioneering studies in this area. © The Royal Society of Chemistry 2015. Source

Roder P.,Robert Bosch GmbH | Baba N.,Robert Bosch GmbH | Wiemhofer H.-D.,University of Munster
Journal of Power Sources | Year: 2014

Accelerating rate calorimetry (ARC) and differential scanning calorimetry (DSC) were used to study the thermal behaviour of a commercially available lithium-ion cell. Both the complete cell (pouch type, 2 Ah) and its electrode materials, respectively, were investigated. As positive electrode material a blend system consisting of NCM (=Li[Ni0.33Co0.33Mn 0.33]O2) and LMO (=LiMn2O4) with a weight ratio of 4:1 was identified. The main exothermic behaviour is dominated by the positive electrode-electrolyte reaction. ARC studies on the positive electrode material in presence of our reference electrolyte show an inhibiting effect of the conducting salt LiPF6 towards the oxidation of the organic based electrolyte by released oxygen. X-ray diffraction measurements were performed to study the thermal decomposition behaviour of the positive active material. Both the blend system and the single components, NCM and LMO, were investigated at different temperatures. A significant phase transformation from the hexagonal layered to a cubic structure as well as various reduction products could be identified. Finally, the thermal behaviour of the NCM/LMO-blend and its single phases, NCM and LMO, at different states of charge (SOC) was investigated. Therefore, detailed investigations based on differential scanning calorimetry (DSC) and cyclic voltammetry (CV) were performed. © 2013 Elsevier B.V. All rights reserved. Source

Spaniol J.,Ryerson University | Schain C.,University of Munster | Bowen H.J.,Ryerson University
Journals of Gerontology - Series B Psychological Sciences and Social Sciences | Year: 2014

Objectives. We investigated how the anticipation of remote monetary reward modulates intentional episodic memory formation in younger and older adults. On the basis of prior findings of preserved reward-cognition interactions in aging, we predicted that reward anticipation would be associated with enhanced memory in both younger and older adults. On the basis of previous demonstrations of a time-dependent effect of reward anticipation on memory, we expected the memory enhancement to increase with study-test delay. Method. In Experiment 1, younger and older participants encoded a series of picture stimuli associated with highor low-reward values. At test (24-hr postencoding), recognition hits resulted in either high or low monetary rewards, whereas false alarms were penalized to discourage guessing. Experiment 2 was similar to Experiment 1, but the study- test delay was manipulated within subjects (immediate vs 24 hr). Results. In Experiment 1, younger and older adults showed enhanced recognition for high-reward pictures compared with low-reward pictures. Experiment 2 replicated this finding and additionally showed that the effect did not extend to immediate recognition. Discussion. The current findings provide support for a time-dependent mechanism of reward-based memory enhancement. They also suggest that aging leaves intact the positive influence of reward anticipation on intentional long-term memory formation. © The Author 2013. Source

Grosse H.,University of Vienna | Wulkenhaar R.,University of Munster
Journal of Geometry and Physics | Year: 2012

Observing that the Hamiltonian of the renormalisable scalar field theory on 4-dimensional Moyal space A is the square of a Dirac operator D of spectral dimension 8, we complete (A,D) to a compact 8-dimensional spectral triple. We add another Connes-Lott copy and compute the spectral action of the corresponding U(1)-Yang-Mills-Higgs model. We find that in the Higgs potential the square φ 2 of the Higgs field is shifted to φ{star operator}φ+const{dot operator}X μ{star operator}X μ, where X μ is the covariant coordinate. The classical field equations of our model imply that the vacuum is no longer given by a constant Higgs field, but both the Higgs and gauge fields receive non-constant vacuum expectation values. © 2012. Source

Schiffer B.,University of Duisburg - Essen | Vonlaufen C.,University of Munster
Journal of Sexual Medicine | Year: 2011

Introduction. There is some evidence that child molesters show neuropsychological abnormalities which might reflect specific structural and/or functional brain alterations, but there are also inconsistencies in the existing findings which need to be clarified. Most of the different outcomes can either be explained by the fact that different types of child molesters were examined or by not having accounted for basically confounding factors such as age, education/intelligence, or criminality. Aim. The present study therefore sought to determine whether pedophilic and nonpedophilic child molesters, compared to relevant control groups, show different profiles of executive dysfunction when accounting for potentially confounding factors. Methods. The performance of 30 child molesters (15 pedophilic and 15 nonpedophilic) and 33 age- and education-matched controls (16 nonsexual offenders and 17 healthy controls) was assessed regarding several neuropsychological functions. Main Outcome Measures. Scores on different neurocognitive tests and semistructured diagnostical interviews. Results. Results indicate that pedophilic child molesters exhibited less performance deficits in cognitive functioning than nonpedophilic child molesters. Compared to healthy controls and nonsexual offenders, the pedophilic child molesters only showed executive dysfunction concerning response inhibition, whereas the nonpedophilic child molesters revealed more severe dysfunction, especially on tasks associated with cognitive flexibility and verbal memory. Conclusions. These results enhance our knowledge about executive dysfunction associated with criminality and/or pedophilia, as they suggest different profiles of impairment between groups. In summary, data suggest that nonpedophilic child molesters showed more severe cognitive deficits than pedophilic child molesters. However, as response inhibition is associated with prefrontal (i.e., orbitofrontal) functioning, the deficits observed in both child molester groups indicate dysfunction in the orbitofrontal cortex. This has to be further examined with functional imaging approaches in larger samples and a full-factorial approach which allows for a clear distinction between criminality and pedophilia in a factorial manner. © 2010 International Society for Sexual Medicine. Source

Schumacher S.D.,Heinrich Heine University Dusseldorf | Jose J.,University of Munster
Journal of Biotechnology | Year: 2012

The cytochrome P450 enzyme system comprises a large group of enzymes catalyzing a broad diversity of reactions and an extensive substrate specificity, which makes them the most versatile known catalysts. CYP3A4 is one of the important human P450 enzymes and involved in the oxidation of a large range of substrates including toxins and pharmaceuticals. Bottlenecks in studying this enzyme include the difficulty in expressing it in a bacterial host, its need for membrane surroundings and the limited substrate accessibility of enzymes expressed within the cell. To circumvent these difficulties, human CYP3A4 was expressed on the outer membrane of Escherichia coli using Autodisplay. Transport of CYP3A4 to the cell surface was monitored by SDS-PAGE and Western blot analysis of outer membrane proteins. Localization on the cell envelope was determined by flow cytometry after immunolabeling, a whole cell ELISA and a protease accessibility assay. A HPLC assay confirmed the catalytic activity of displayed CYP3A4, using testosterone as a substrate. This activity required the external addition of electron supplying enzymes, however surprisingly, we found that the external addition of a heme group was not necessary. Our results indicate that human CYP3A4 can be recombinantly expressed by surface display in a gram-negative bacterium. © 2012 Elsevier B.V. Source

Nahrstedt A.,University of Munster | Butterweck V.,University of Florida
Journal of Natural Products | Year: 2010

The example of St. John's wort offers convincing evidence for the concept that modern methods of pharmacological and phytochemical research are effective in advancing the development of traditional herbal remedies. As a consequence of these efforts, it is known today that several compounds from different structural groups and with different mechanisms of action seem to be responsible for the observed antidepressant efficacy of St. John's Wort. Co-effectors in the extract improve the bioavailability of active constituents such as hypericin (1) (pharmacokinetic synergy). Unwanted side effects are preventable without remarkable loss of activity when the responsible constituent(s) are carefully removed during the extraction process, as demonstrated for hyperforin (3), which is responsible for the induction of cytochrome P450 (CYP)-metabolizing enzymes (CYP3A4, in particular). On the basis of our findings, it is likely that positive interactions between single compounds occur more frequently in traditionally used herbal preparations than is known presently. © 2010 The American Chemical Society and American Society of Pharmacognosy. Source

Metzler K.,University of Munster
Meteoritics and Planetary Science | Year: 2012

Unequilibrated ordinary chondrites (UOCs) of all groups (H, L, LL) contain unique chondrite clasts, which are characterized by a close-fit texture of deformed and indented chondrules. These clasts, termed "cluster chondrites," occur in 41% of the investigated samples with modal abundances between 5 and 90 vol% and size variations between <1mm and 10cm. They show the highest chondrule abundances compared with all chondrite classes (82-92 vol%) and only low amounts of fine-grained interchondrule matrix and rims (3-9 vol%). The mean degree of chondrule deformation varies between 11% and 17%, compared to 5% in the clastic portions of their host breccias and to values of 3-5% found in UOC literature, respectively. The maximum deformation of individual chondrules is about 50%, a value which seemingly cannot be exceeded due to geometric limitations. Both viscous and brittle chondrule deformation is observed. A model for cluster chondrite formation is proposed where hot and deformable chondrules together with only small amounts of co-accreting matrix formed a planetesimal or reached the surface of an already existing body within hours to a few days after chondrule formation. They deformed in a hot stage, possibly due to collisional compression by accreting material. Later, the resulting rocks were brecciated by impact processes. Thus, cluster chondrite clasts are interpreted as relicts of primary accretionary rocks of unknown original dimensions. If correct, this places a severe constraint on chondrule-forming conditions. Cluster chondrites would document local chondrule formation, where chondrule-forming heating events and the accretion of chondritic bodies were closely linked in time and space. © 2012 The Meteoritical Society. Source

Herwartz D.,University of Bonn | Nagel T.J.,University of Bonn | Munker C.,University of Cologne | Scherer E.E.,University of Munster | Froitzheim N.,University of Bonn
Nature Geoscience | Year: 2011

Subduction of rocks into the mantle results in high-pressure metamorphism and the formation of eclogites from basaltic precursor rocks. At the Earth's surface, eclogites often occur as isolated fragments embedded in crustal rocks that lack evidence for high-pressure conditions. The high-pressure rocks are therefore often viewed as dismembered fragments that have been assembled and intercalated with rocks devoid of any high-pressure history at shallow crustal levels, forming a tectonic mélange. Such mélange models were supported by age discrepancies among high-pressure rocks from the Adula nappe (Central Alps), which was thought to represent a classic example of such a situation. Here we present Lu-Hf age data from two populations of the high-pressure mineral garnet, found within a single eclogite sample taken from Trescolmen, in the Central Adula nappe. We report a minimum Variscan age of 332.7 Myr and a maximum Alpine age of 38 Myr for the two populations. We suggest that the Trescolmen eclogite was subducted to mantle depth and subsequently exhumed, becoming part of a continental crust during the Variscan orogeny. Later, during the Alpine orogeny, the Adula nappe must have been subducted to-and exhumed from-mantle depth a second time, as one coherent unit. We conclude that the Adula nappe is not a mélange, and therefore, the crustal rocks that envelope the eclogites have also been subjected to high-pressure conditions through deep subduction during the Alpine event. © 2011 Macmillan Publishers Limited. All rights reserved. Source

Fischer-Godde M.,Free University of Berlin | Fischer-Godde M.,University of Munster | Becker H.,Free University of Berlin
Geochimica et Cosmochimica Acta | Year: 2012

The concentrations of highly siderophile elements (HSE: Re, Os, Ir, Ru, Pt, Rh, Pd, Au) and 187Os/ 188Os isotope compositions have been determined for 67 subsamples of six lunar impact rocks from the Apollo 14, 16 and 17 landing sites, and the lunar meteorite Dar al Gani (DaG) 400 using inductively coupled plasma mass spectrometry (ICP-MS) and negative thermal ionization mass spectrometry (N-TIMS).We report the first Re-Os isochron age on a lunar impact melt rock. 187Re- 187Os isotope systematics for Apollo 16 sample 67935 define an isochron age of 4.21±0.13Ga (MSWD=1.5), which is interpreted to reflect localized partitioning processes between solid metal-liquid metal as this rock melted. The new age adds further constraints on the significance of pre-4.0Ga basin forming impacts on the Moon and possible mixing of ancient impactor compositions in lunar impact rocks.Linear correlations displayed by subsamples of a given impact rock in plots of HSE versus Ir concentrations are explained by dilution processes through essentially HSE-free anorthositic lunar crustal target rocks or binary mixing between a high HSE meteoritic end-member and a low HSE end-member composition. Slope-derived HSE ratios and 187Os/ 188Os of the meteoritic component in granulitic impactites 67915, 67955 and 79215 are similar to slightly volatile element depleted carbonaceous chondrites. Suprachondritic ratios of Ru/Ir, Pt/Ir, Rh/Ir, and Pd/Ir for Apollo 14 impact melt rock 14310 are similar to ratios observed for other Apollo 14 samples and Apollo 17 poikilitic impact melt rocks. Apollo 16 poikilitic and subophitic impact melt rocks 60315 and 67935 show slightly subchondritic Os/Ir and suprachondritic ratios of 187Os/ 188Os, Ru/Ir, Pt/Ir, Rh/Ir, Pd/Ir and Au/Ir. Their strongly fractionated HSE compositions are similar to some members of the IVA iron meteorite group and provide further evidence for an iron meteorite impactor component in Apollo 16 impact melt rocks.The range of chondritic to suprachondritic ratios of 187Os/ 188Os, Ru/Ir, Pt/Ir, Pd/Ir, and chondritic to slightly subchondritic Os/Ir of Apollo 17 and 14 impact melt rocks may be explained by variable mixing of a carbonaceous chondrite-like HSE composition (as in granulitic impactites) with a suprachondritic iron meteorite-like impactor composition as inferred from 67935 and 60315, and subsequent homogenization by younger impact events. The inferred dispersal of these two components across the lunar nearside and their antiquity (4.2Ga) suggest at least two basin-forming impacts that predate the 3.9-3.8Ga basin forming era. The HSE composition of the silicate Earth can be matched by a late veneer comprised of ~80% volatile depleted carbonaceous chondrite-like material and ~20% differentiated meteoritic metal, similar to what has been identified in ancient lunar impact rocks. © 2011 Elsevier Ltd. Source

Langenhorst F.,Friedrich - Schiller University of Jena | Deutsch A.,University of Munster
Elements | Year: 2012

The hypervelocity impact of extraterrestrial objects causes unequivocal changes in the target due to extreme deformation rates, pressures up to hundreds of gigapascals, and postshock temperatures that may even vaporize silicates. This article introduces the basic principles of shock compression, as required to understand the formation and geological significance of shock-metamorphic effects in minerals. Special emphasis is placed on the formation of high-pressure phases such as stishovite and diamond as well as on the decomposition of carbonates. Source

Beck M.,University of Munster
Journal of Physics: Conference Series | Year: 2010

The KArlsruhe TRitium Neutrino mass experiment, KATRIN, aims to search for the mass of the electron neutrino with a sensitivity of 0.2eV/c2 (90% C.L.) and a detection limit of 0.35 eV/c2 (5σ). Both a positive or a negative result will have far reaching implications for cosmology and the standard model of particle physics and will give new input for astroparticle physics and cosmology. The major components of KATRIN are being set up at the Karlsruhe Institut of Technology in Karlsruhe, Germany, and test measurements of the individual components have started. Data taking with tritium is scheduled to start in 2012. © 2010 IOP Publishing Ltd. Source

Nieschlag E.,University of Munster
Contraception | Year: 2010

Research has established the principle of hormonal male contraception based on suppression of gonadotropins and spermatogenesis. All hormonal male contraceptives use testosterone, but only in East Asian men can testosterone alone suppress spermatogenesis to a level compatible with contraceptive protection. In Caucasians, additional agents are required of which progestins are favored. Clinical trials concentrate on testosterone combined with norethisterone, desogestrel, etonogestrel or depot-medroxyprogesterone acetate. The first randomized, placebo-controlled clinical trial performed by the pharmaceutical industry demonstrated the effectiveness of a combination of testosterone undecanoate and etonogestrel in suppressing spermatogenesis in volunteers. © 2010 Elsevier Inc. All rights reserved. Source

Graler B.,University of Munster
Spatial Statistics | Year: 2014

Studying phenomena that follow a skewed distribution and entail an extremal behaviour is important in many disciplines. How to describe and model the dependence of skewed spatial random fields is still a challenging question. Especially when one is interested in interpolating a sample from a spatial random field that exhibits extreme events, classical geostatistical tools like kriging relying on the Gaussian assumption fail in reproducing the extremes. Originating from the multivariate extreme value theory partly driven by financial mathematics, copulas emerged in recent years being capable of describing different kinds of joint tail behaviours beyond the Gaussian realm. In this paper spatial vine copulas are introduced that are parametrized by distance and allow to include extremal behaviour of a spatial random field. The newly introduced distributions are fitted to the widely studied emergency and routine scenario data set from the spatial interpolation comparison 2004 (SIC2004). The presented spatial vine copula ranks within the top 5 approaches and is superior to all approaches in terms of the mean absolute error. © 2014 The Author. Source

Dhar T.,TU Dortmund | Mootz H.D.,TU Dortmund | Mootz H.D.,University of Munster
Chemical Communications | Year: 2011

The naturally split Npu DnaE intein can be used for ligation of an exogenous polypeptide to membrane proteins on living cells. No reducing agents or other factors are required. The approach is rapid and virtually traceless, because the intein removes itself during the reaction. © 2011 The Royal Society of Chemistry. Source

Ohuchi H.,Japan National Cardiovascular Center Research Institute | Diller G.-P.,University of Munster
Heart Failure Clinics | Year: 2014

Most adults with congenital heart disease show high levels of natriuretic peptide (NP) when compared with normal controls. Levels of norepinephrine and NP were strongly related to outcome in studies that included many symptomatic patients, especially those with unrepaired congenital heart disease, Eisenmenger syndrome, and pulmonary hypertension. Limited data are available regarding serial assessment of biomarkers; such information could provide additional important information to help identify patients at risk, as demonstrated during patient follow-up and pregnancy. © 2014 Elsevier Inc. Source

Targeted gene inactivation is extensively used in the plant pathogenic fungus Botrytis cinerea for gene function analysis while strategies involving the expression of reporter genes have been rarely used due to the lack of appropriate expression vectors. Hence, an approach was initiated to establish an expression system for B. cinerea possessing the following features: (i) the targeted integration of constructs at defined gene loci which are dispensable under standard growth conditions, (ii) the use of promoter and terminator sequences allowing optimal gene expression, (iii) the use of codon-optimized reporter genes (Leroch et al., 2011), (iv) the use of multiple selection markers, and (v) the incorporation of a highly efficient cloning system. A set of basic vectors was generated by yeast recombinational cloning permitting a variety of protein fusions. The successful application of the expression system for labeling F-actin, the cytosol, the nuclei, the membrane, the ER and the peroxisomes was demonstrated. In addition, cloning vectors for bimolecular fluorescence complementation (BiFC) analyses for studying protein-protein interactions in situ were generated by splitting the codon-optimized gfp. The functionality of the constructed BiFC vectors was validated by demonstrating the interaction of the two white collar-like transcription factors BcWCL1 and BcWCL2 in the nuclei of growing B. cinerea hyphae. © 2012 Elsevier Inc. Source

Singhal N.,Max Planck Institute for Molecular Biomedicine | Graumann J.,Max Planck Institute of Biochemistry | Wu G.,Max Planck Institute for Molecular Biomedicine | Arauzo-Bravo M.J.,Max Planck Institute for Molecular Biomedicine | And 6 more authors.
Cell | Year: 2010

Reprogramming of somatic cells achieved by combination of the four transcription factors Oct4, Sox2, Klf4, and c-Myc has very low efficiency. To increase the reprogramming efficiency and better understand the process, we sought to identify factors that mediate reprogramming with higher efficiency. We established an assay to screen nuclear fractions from extracts of pluripotent mouse cells based on Oct4 reactivation. Using proteomics, we identified components of the ATP-dependent BAF chromatin-remodeling complex, which significantly increases reprogramming efficiency when used together with the four factors. The reprogrammed cells could transmit to the germline and exhibited pluripotency. Reprogramming remained highly efficient when c-Myc was not present but BAF components were overexpressed. BAF complex components mediate this effect by facilitating enhanced Oct4 binding to target promoters during reprogramming. Thus, somatic cell reprogramming using chromatin-remodeling molecules represents an efficient method of generating reprogrammed cells. © 2010 Elsevier Inc. Source

Grosse H.,University of Vienna | Wulkenhaar R.,University of Munster
Communications in Mathematical Physics | Year: 2014

We study quartic matrix models with partition function Z[E, J] = ∫ dM exp(trace(JM - EM2 - λ/4M4)). The integral is over the space of Hermitean N × N -matrices, the external matrix E encodes the dynamics, λ > 0 is a scalar coupling constant and the matrix J is used to generate correlation functions. For E not a multiple of the identity matrix, we prove a universal algebraic recursion formula which gives all higher correlation functions in terms of the 2-point function and the distinct eigenvalues of E. The 2-point function itself satisfies a closed non-linear equation which must be solved case by case for given E. These results imply that if the 2-point function of a quartic matrix model is renormalisable by mass and wavefunction renormalisation, then the entire model is renormalisable and has vanishing β-function. As the main application we prove that Euclidean φ{symbol}4 -quantum field theory on four-dimensional Moyal space with harmonic propagation, taken at its self-duality point and in the infinite volume limit, is exactly solvable and non-trivial. This model is a quartic matrix model, where E has for N → ∞ the same spectrum as the Laplace operator in four dimensions. Using the theory of singular integral equations of Carleman type we compute (for N → ∞ and after renormalisation of E, λ) the free energy density (1/volume) log(Z[E, J]/Z[E, 0]) exactly in terms of the solution of a non-linear integral equation. Existence of a solution is proved via the Schauder fixed point theorem. The derivation of the non-linear integral equation relies on an assumption which in subsequent work is verified for coupling constants λ ≤ 0. © 2014 Springer-Verlag Berlin Heidelberg. Source

Van Luijtelaar G.,Radboud University Nijmegen | Zobeiri M.,Radboud University Nijmegen | Zobeiri M.,University of Munster
Current Medicinal Chemistry | Year: 2014

The WAG/Rij model is a well characterized and validated genetic animal epilepsy model in which the for absence epilepsy highly characteristic spike-wave discharges (SWDs) develop spontaneously. In this review we discuss first some older and many new studies, with an emphasis on pharmacological and neurochemical studies towards the role of GABA and glutamate and the ion channels involved in the pathological firing patterns. Next, new insights and highlights from the last 5-10 years of reaearch in WAG/Rij rats are discussed. First, early environmental factors modulate SWD characteristics and antiepileptogenesis is possible. Also new is that the classically assumed association between sleep spindles and SWDs seems no longer valid as an explanatory role for the occurrence of SWDs in the genetic rodent models. A role of cortical and thalamic glial cells has been revealed, indicating a putative role for inflammatory cytokines. Neurophysiologic and signal analytical studies in this and in another rodent model (GAERS) point towards a cortical site of origin, that SWDs do not have a sudden onset, and propose a more important role for the posterior thalamus than was previously assumed. Finally it is proposed that the reticular nucleus of the thalamus might be heterogeneous with respect to its role in propagation and maintenance of SWDs. The presence of a well-established cortical region in which SWDs are elicited allows for research towards new non-invasive treatment options, such as transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS). The first results show the feasibility of this new approach. © 2014 Bentham Science Publishers. Source

Klasen M.,University of Munster
Nuclear and Particle Physics Proceedings | Year: 2016

The existence of dark matter provides compelling evidence for physics beyond the Standard Model. Minimal extensions of the Standard Model with additional scalars or fermions allow to explain the observed dark matter relic density in an economic way. We analyse several of these possibilities like the inert Higgs and radiative seesaw models in the light of the recent Higgs discovery and study prospects for the direct and indirect detection of dark matter in these models. © 2015 Elsevier B.V. Source

Gurevich S.V.,University of Munster
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2013

We are interested in stability properties of a single localized structure in a three-component reaction-diffusion system subjected to the time-delayed feedback. We shall show that variation in the product of the delay time and the feedback strength leads to complex dynamical behavior of the system, including formation of target patterns, spontaneous motion, and spontaneous breathing as well as various complex structures, arising from combination of different oscillatory instabilities. In the case of spontaneous motion, we provide a bifurcation analysis of the delayed system and derive an order parameter equation for the position of the localized structure, explicitly describing its temporal evolution in the vicinity of the bifurcation point. This equation is a subject to a nonlinear delay differential equation, which can be transformed to the normal form of the pitchfork drift bifurcation. © 2013 American Physical Society. Source

Metz M.,Charite - Medical University of Berlin | Stander S.,University of Munster
Journal of the European Academy of Dermatology and Venereology | Year: 2010

Chronic pruritus is a major symptom in numerous dermatological and systemic diseases. Similar to chronic pain, chronic pruritus can have a dramatic impact on the quality of life and can worsen the general condition of the patient considerably. The pathogenesis of itch is diverse and involves a complex network of cutaneous and neuronal cells. In recent years, more and more itch-specific mediators and receptors, such as interleukin-31, gastrin-releasing peptide receptor or histamine H4 receptor have been identified and the concept of itch-specific neurons has been further characterized. Understanding of the basic principles is important for development of target-specific treatment of patients with chronic pruritus. In this review, we summarize the current knowledge about the pathophysiological principles of itch and provide an overview about current and future treatment options. © 2010 The Authors. Source

Kuhn W.,University of Munster
International Journal of Geographical Information Science | Year: 2012

Geographic information science is emerging from its niche 'behind the systems', getting ready to contribute to transdisciplinary research. To succeed, a conceptual consensus across multiple disciplines on what spatial information is and how it can be used is needed. This article proposes a set of 10 core concepts of spatial information, intended to be meaningful to scientists who are not specialists of spatial information: location, neighbourhood, field, object, network, event, granularity, accuracy, meaning, and value. Each proposed concept is briefly characterized, demonstrating the need to map between their different disciplinary uses. © 2012 Copyright Taylor and Francis Group, LLC. Source

Haferkamp N.,University of Munster | Kramer N.C.,University of Duisburg - Essen
Cyberpsychology, Behavior, and Social Networking | Year: 2011

Through their features-such as profile photographs or the personal vita-online profiles on social-networking sites offer a perfect basis for social comparison processes. By looking at the profile photograph, the user gains an impression of a person's physical attractiveness, and the user's vita shows which career path the person is pursuing. Against the background of Festinger's Social Comparison Theory, the focus of this research is on the effects of online profiles on their recipients. Therefore, qualitative interviews (N=12) and two online experiments were conducted in which virtual online profiles of either physically attractive or unattractive persons (N=93) and profiles of users with either high or low occupational attainment (N=103) were presented to the participants. Although qualitative interviews did not initially give reason to expect online profiles to constitute a basis for comparison processes, results of the experiments proved otherwise. The first study indicates that recipients have a more negative body image after looking at beautiful users than persons who were shown the less attractive profile pictures. Male participants of the second study, who were confronted with profiles of successful males, showed a higher perceived discrepancy between their current career status and an ideal vita than male participants who looked at profiles of less successful persons. © Copyright 2011, Mary Ann Liebert, Inc. Source

MacHnikowski P.,Wroclaw University of Technology | Kuhn T.,University of Munster
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

We formulate a model of the time-resolved Kerr rotation experiment on an ensemble of independent holes in a semiconductor nanostructure (e.g., confined in a quantum dot or trapped in a quantum well) in a tilted magnetic field. We use a generic Markovian description of the hole and trion dephasing and focus on the interpretation of the time-resolved signal in terms of the microscopic evolution of the spin polarization. We show that the signal in an off-plane field contains components that reveal both the spin relaxation rate and the spin coherence dephasing rate. We derive analytical formulas for the hole spin polarization, which may be used to extract the two relevant rates by fitting to the measurement data. © 2010 The American Physical Society. Source

Weinheimer C.,University of Munster | Zuber K.,TU Dresden
Annalen der Physik | Year: 2013

The various experiments on neutrino oscillation evidence that neutrinos have indeed non-zero masses but cannot provide the absolute neutrino mass scale. This scale of neutrino masses is very important for understanding the evolution and the structure formation of the universe as well as for nuclear and particle physics beyond the present Standard Model. Complementary to deducing constraints on the sum of all neutrino masses from cosmological observations, two different methods to determine the neutrino mass scale in the laboratory are pursued: the search for neutrinoless double β-decay and the direct neutrino mass search by investigating single β-decays or electron captures. The former method is not only sensitive to neutrino masses but also probes the Majorana character of neutrinos and thus lepton number violation with high sensitivity. Currently quite a few experiments using different techniques are being constructed, commissioned, or are even running, which aim for a sensitivity on the neutrino mass of O(100) meV. The principal methods and these experiments are discussed in this short review. © 2013 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Grimme S.,University of Munster
Wiley Interdisciplinary Reviews: Computational Molecular Science | Year: 2011

Dispersion corrections to standard Kohn-Sham density functional theory (DFT) are reviewed. The focus is on computationally efficient methods for large systems that do not depend on virtual orbitals or rely on separated fragments. The recommended approaches (van der Waals density functional and DFT-D) are asymptotically correct and can be used in combination with standard or slightly modified (short-range) exchange-correlation functionals. The importance of the dispersion energy in intramolecular cases (conformational problems and thermochemistry) is highlighted. © 2011 John Wiley & Sons, Ltd. Source

Nieschlag E.,University of Munster | Kumar N.,Center for Biomedical Research | Sitruk-Ware R.,Center for Biomedical Research
Contraception | Year: 2013

Testosterone is an essential part of all regimens for hormonal male contraception tested to date. Initial efficacy trials revealed that the half-life of the testosterone preparations available at that time was too short to be used for male contraception. The ensuing search for long-acting preparations yielded testosterone buciclate and undecanoate as well as 7α-methyl-19-nortestosterone (MENT). Following description of the principle of male hormonal contraception and the efficacy trials performed to date, the systematic development of MENT for substitution of male hypogonadism and use in male contraception by the Population Council is reviewed here. © 2013 Published by Elsevier Inc. Source

Eble J.A.,University of Munster
Antioxidants and Redox Signaling | Year: 2014

What do oxygen and its radicals have to do with cell adhesion? Several years ago, even experts in the research fields of redox biology and cell adhesion likely would have answered this question innocuously or evasively. Is there really little to talk about? Some of the former hypotheses on redox biology of cell adhesion have substantialized in the meantime. This Forum provides insights into the interplay between oxygen radical species and the cellular contacts with the extracellular matrix, including the subsequent steps, such as cytoskeleton rearrangement. Moreover, it describes evidences that the cell-matrix contact influences the production of reactive oxygen species (ROS), thereby underlying the potential liaison between redox biology and cell adhesion. © 2014, Mary Ann Liebert, Inc. 2014. Source

Diezemann G.,University Mainz | Heuer A.,University of Munster
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2011

We investigate the memory effect in a simple model for glassy relaxation, a trap model with a Gaussian density of states. In this model, thermal equilibrium is reached at all finite temperatures and we therefore can consider jumps from low to high temperatures in addition to the quenches usually considered in aging studies. We show that the evolution of the energy following the Kovacs protocol can approximately be expressed as a difference of two monotonously decaying functions and thus show the existence of a so-called Kovacs hump whenever these functions are not single exponentials. It is well established that the Kovacs effect also occurs in the linear response regime, and we show that most of the gross features do not change dramatically when large temperature jumps are considered. However, there is one distinguishing feature that only exists beyond the linear regime, which we discuss in detail. For the memory experiment with inverted temperatures, i.e., jumping up and then down again, we find a very similar behavior apart from an opposite sign of the hump. © 2011 American Physical Society. Source

Wegener J.,University of Regensburg | Seebach J.,University of Munster
Cell and Tissue Research | Year: 2014

Endothelial cells line the inner surface of all blood vessels and constitute a selective barrier between blood and tissue. Permeation of solutes across the endothelial cell monolayer occurs either paracellularly through specialized endothelial cell-cell junctions or transcellularly via special transport mechanisms including transcytosis, via the formation of transcellular channels, or by cell membrane transport proteins. Several in vitro assays have been developed in the past few decades to analyze the molecular mechanisms of transendothelial permeability. Measurement of the electrical resistance of the cell monolayer has proven to be particularly suitable for analyzing paracellular barrier function with high-time resolution over long time periods. We review the various permeability assays and focus on the electrical impedance analysis of endothelial cell monolayers. We also address current progress in the development of techniques used to investigate endothelial permeability with high-lateral resolution and under mechanical loads. © 2014 Springer-Verlag Berlin Heidelberg. Source

Hiesinger H.,University of Munster | Helbert J.,German Aerospace Center
Planetary and Space Science | Year: 2010

Scheduled for launch on board the BepiColombo Mercury Planetary Orbiter (MPO) in 2014, the Mercury Radiometer and Thermal Infrared Spectrometer (MERTIS) is an innovative instrument for studying the surface composition and mineralogy of planet Mercury. MERTIS combines an uncooled grating push broom IR-spectrometer (TIS) with a radiometer (TIR), which will operate in the wavelength region of 7-14 and 7-40 μm, respectively. The spatial resolution of the MERTIS observations will be about 500 m globally and better than 500 m for approximately 5-10% of the surface. The thermal infrared range offers unique diagnostic capabilities to study the surface composition of Mercury. In particular, feldspars can easily be detected and characterized, because they show several diagnostic spectral signatures in the 7-14 μm range: the Christiansen feature, reststrahlen bands, and the transparency feature. In addition, MERTIS will allow the identification and mapping of elemental sulfur, pyroxenes, olivines, and other complex minerals. The scientific objectives of MERTIS include: (1) characterization of Mercury's surface composition, (2) identification of rock-forming minerals, (3) mapping of the surface mineralogy, and (4) study of surface temperature variations and the thermal inertia. In preparation for the MERTIS data interpretation, we are performing spectral measurements of appropriate analogue materials in the Planetary Emissivity Laboratory (PEL) and are building a spectral library (Berlin Emissivity Database (BED)) of these materials for a variety of grain sizes. © 2008 Elsevier Ltd. All rights reserved. Source

Raap U.,Hannover Medical School | Stander S.,University of Munster | Metz M.,Charite - Medical University of Berlin
Current Opinion in Allergy and Clinical Immunology | Year: 2011

Purpose of Review: Itch represents one of the most bothersome symptoms in allergic disorders and numerous dermatological and systemic diseases. Chronic itch has a dramatic impact on the quality of life. The pathophysiology of itch is diverse and involves a complex network of cutaneous and neuronal cells. Thus, we highlight the current pathophysiological aspects of itch together with new treatment options. Recent Findings: Apart from histamine, several mediators and receptors including the neurotrophins nerve growth factor (NGF), brain-derived neurotrophic factor, neurokinins/neuropeptides such as substance P, gastrin-releasing peptide, cytokines such as interleukin-31, autotaxin and the histamine H4 receptor have been identified for playing a role in the pathophysiology of itch. In the skin, tissue resident cells such as keratinocytes, mast cells and cells of the inflammatory infiltrate including lymphocytes and eosinophils have been described to interact with neuronal cells, for example via the release of neurotrophins, neuropeptides and cytokines, adding novel regulatory pathways for the modulation of itch. Accordingly, promising treatment strategies such as the neurokinin-1 receptor antagonist aprepitant have been introduced for a successful management of itch. Summary: In this review, we highlight novel key players in the pathophysiology of itch with subsequent introduction of promising, novel and experimental treatment strategies. © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins. Source

Vicente A.,University of Liege | Yaguna C.E.,University of Munster
Journal of High Energy Physics | Year: 2015

Abstract: We study the impact that future lepton flavor violating experiments will have on the viable parameter space of the scotogenic model. Within this model, the dark matter particle is assumed to be the lightest singlet fermion and two cases are considered depending on how its relic density is obtained: via self-annihilations or via coannihilations with the scalars. For each case, a scan over the parameter space of the model is used to obtain a large sample of viable points, which we subsequently analyze. We find that future lepton flavor violating experiments, in particular those searching for μ → 3e and μ-e conversion in nuclei, will probe the parameter space of the scotogenic model in a significant way. They may exclude a large fraction of the models where the dark matter density is determined by coannihilations, and could rule out all the models where it is determined by annihilations. © 2015, The Author(s). Source

Muller J.,University of Munster
Metallomics | Year: 2010

Metal ions are inevitably involved in almost every aspect of nucleic acid chemistry. Their most prominent role is certainly the maintenance of nucleic acid structural integrity. However, they serve various other roles as well, e.g. as catalytic co-factors in ribozymes, in determining the secondary structure of tetra-stranded helices, during RNA folding, and possibly even in enabling nucleobase-centred acid/base catalysis under physiological conditions and in modulating homogeneous genetic recombination. This tutorial review gives a compact overview of the multifaceted situations in which metal ions exert specific functions in nucleic acids, also including a discussion of structural metal ions in regular DNA and RNA as well as triple helices, guanine quadruplexes, and helical junctions. It has a strong focus on metal ions that are naturally present in living systems and only occasionally includes a description of the interaction of exogenous metal complexes with nucleic acids (or their components), provided that the results of these studies can be transferred into the context of endogenous metal ions. © 2010 The Royal Society of Chemistry. Source

Barber I.,University of Leicester | Scharsack J.P.,University of Munster
Parasitology | Year: 2010

Plerocercoids of the pseudophyllidean cestode Schistocephalus solidus infect the three-spined stickleback Gasterosteus aculeatus, with important consequences for the biology of host fish. Techniques for culturing the parasite in vitro and generating infective stages that can be used to infect sticklebacks experimentally have been developed, and the system is increasingly used as a laboratory model for investigating aspects of host-parasite interactions. Recent experimental laboratory studies have focused on the immune responses of hosts to infection, the consequences of infection for the growth and reproductive development of host fish and the effects of infection on host behaviour. Here we introduce the host and the parasite, review the major findings of these recent experimental infection studies and identify further aspects of host parasite interactions that might be investigated using the system. © 2009 Cambridge University Press. Source

Nieschlag E.,University of Munster | Nieschlag E.,King Abdulaziz University
Best Practice and Research: Clinical Endocrinology and Metabolism | Year: 2015

All forms of hypogonadism - primary, secondary and late-onset - require testosterone substitution. The indication is given when the patient presents with symptoms of androgen deficiency and the serum testosterone levels are below normal. Several testosterone preparations and modes of application are available of which those producing physiologic serum levels should be preferred e.g. preferentially transdermal gels and long-acting intramuscular testosterone undecanoate. Testosterone substitution must be monitored at regular intervals, best at 3, 6 and 12 months after initiation and then annually. Parameters for surveillance include well-being, libido and sexual activity, measurement of serum testosterone levels, haemoglobin and haematocrit, PSA and digital rectal examination, and, biannually, bone mineral density. Testosterone has positive effects on comorbidities such as obesity, metabolic syndrome, diabetes type II, cardiovascular diseases and osteoporosis. © 2014 Elsevier Ltd. All rights reserved. Source

Dammaschke T.,University of Munster
Laboratory Animals | Year: 2010

The aim of this review is to evaluate the suitability of rat molar teeth in preclinical evaluation of medical devices for direct pulp capping. The ISO standard 7405 states clearly that only non-rodent mammals are suitable species for animal research in dentistry. Furthermore, without clear justification a considerable number of researchers previously rejected results of animal experiments concerning preclinical evaluation of the biocompatibility of dental materials undertaken in rat molar teeth. However, in the past 50 years about 70 studies have been published using rat molar teeth in order to evaluate direct pulp capping, pulpotomies and tissue reactions after pulp exposure. Numerous studies showed that the healing of rat molar pulp tissue after direct pulp capping is histologically comparable with humans and other animal species pulp tissue. Rat molar teeth, including pulp tissue, can be seen anatomically, histologically, biologically, and physiologically as miniature human molar teeth. Hence, the essential biological reactions of the pulp tissue and the interaction during the different stages of wound healing of rat molar teeth are comparable with that of other mammals. Rat molar teeth are a valid study model in order to provide valuable data concerning pulp tissue reaction after direct pulp capping and related questions in dentistry. Therefore, the use of rats may significantly reduce the number of currently used higher animals in research. Tests in higher developed animals should be limited to experiments which clarify inconsistent results. However, some technical difficulties, like the small size of rat molar teeth must be dealt with before undertaking any research. Source

Kowert R.,University of Munster | Oldmeadow J.A.,University of York
Computers in Human Behavior | Year: 2013

Affordable and accessible Internet has changed the way video games are played, allowing individuals to connect worldwide in shared gaming spaces. On the surface participation within these environments may seem socially beneficial, as these highly social, playful spaces allow players to connect, interact with, and learn from others. However, there is a growing concern that increased participation within online gaming environments comes with a wide variety of social consequences, contributing to numerous losses in 'offline' sociability. While considerable research has examined these claims, consistent relationships between social competence and online video game involvement have yet to be established. The current work (N = 515) aimed to examine the extent to which online video game involvement may support, or undermine, the development and maintenance of traditional social skills. The results indicate that there are unique relationships between social skills and video game involvement within online gaming populations. However, among online video game players, these links were not as negative or broad as hypothesized. The results of this assessment dispute the anecdotal attribution of a global level of social ineptitude amongst online video game players and provide insight into the potential effects of online video game play on skill development and maintenance. © 2013 Elsevier Ltd. All rights reserved. Source

Rueping M.,RWTH Aachen | Kuenkel A.,RWTH Aachen | Frohlich R.,University of Munster
Chemistry - A European Journal | Year: 2010

"Chemical Equotion Presentation" Domino catalysis: Two consecutive quaternary stereocenters, three functional groups, and four stereogenic centers have been created in the newly developed domino Michael-Henry reaction (see scheme) employing small amounts of a bifunctional organocatalyst. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA. Source

Kuhn A.,University of Munster | Kuhn A.,German Cancer Research Center | Landmann A.,German Cancer Research Center
Journal of Autoimmunity | Year: 2014

Lupus erythematosus (LE) is an inflammatory connective tissue disease of generalized autoimmunity characterized by pathogenic autoantibodies and immune complexes, attributed to loss of immune tolerance. Cutaneous involvement, which appears in the majority of patients with the disease, can present as LE-specific or LE-nonspecific manifestations. The LE-nonspecific manifestations include e.g. vascular skin changes and may be associated with systemic organ manifestations or other autoimmune diseases. In contrast, the LE-specific manifestations encompass the various subtypes of cutaneous lupus erythematosus (CLE), which are classified as separate entities without or with less severe systemic organ involvement. In the "Duesseldorf Classification", CLE is subdivided into four different categories: acute CLE (ACLE), subacute CLE (SCLE), chronic CLE (CCLE), and intermittent CLE (ICLE). Differentiation between these subtypes is based on clinical features and average duration of the cutaneous lesions, but can also consider histological changes of skin biopsy specimens and laboratory abnormalities. In addition, direct immunofluorescence and photoprovocation may be applied to confirm the diagnosis in specific cases. Further investigations should be considered dependent on the clinical symptoms of the CLE patient and the results of the laboratory tests. A revised scoring system, the Cutaneous Lupus Erythematosus Disease Area and Severity Index (RCLASI) has recently been validated to assess disease activity and damage in CLE. In this review, we focus on the classification of CLE and the diagnostic procedures to identify and confirm the different subtypes of the disease. © 2014 Elsevier Ltd. Source

Bruns A.,Queensland University of Technology | Stieglitz S.,University of Munster
Journal of Technology in Human Services | Year: 2012

To date, the available literature mainly discusses Twitter activity patterns in the context of individual case studies, while comparative research on a large number of communicative events and their dynamics and patterns is missing. By conducting a comparative study of more than 40 different cases (covering topics such as elections, natural disasters, corporate crises, and televised events) we identify a number of distinct types of discussion that can be observed on Twitter. Drawing on a range of communicative metrics, we show that thematic and contextual factors influence the usage of different communicative tools available to Twitter users, such as original tweets, @replies, retweets, and URLs. Based on this first analysis of the overall metrics of Twitter discussions, we also demonstrate stable patterns in the use of Twitter in the context of major topics and events. © 2012, Taylor & Francis Group, LLC. Source

de Lussanet M.H.E.,University of Munster
Evolution and Development | Year: 2011

Of the major deuterostome groups, the echinoderms with their multiple forms and complex development are arguably the most mysterious. Although larval echinoderms are bilaterally symmetric, the adult body seems to abandon the larval body plan and to develop independently a new structure with different symmetries. The prevalent pentamer structure, the asymmetry of Lovén's rule and the variable location of the periproct and madrepore present enormous difficulties in homologizing structures across the major clades, despite the excellent fossil record. This irregularity in body forms seems to place echinoderms outside the other deuterostomes. Here I propose that the predominant five-ray structure is derived from a hexamer structure that is grounded directly in the structure of the bilaterally symmetric larva. This hypothesis implies that the adult echinoderm body can be derived directly from the larval bilateral symmetry and thus firmly ranks even the adult echinoderms among the bilaterians. In order to test the hypothesis rigorously, a model is developed in which one ray is missing between rays IV-V (Lovén's schema) or rays C-D (Carpenter's schema). The model is used to make predictions, which are tested and verified for the process of metamorphosis and for the morphology of recent and fossil forms. The theory provides fundamental insight into the M-plane and the Ubisch', Lovén's, and Carpenter's planes and generalizes them for all echinoderms. The theory also makes robust predictions about the evolution of the pentamer structure and its developmental basis. © 2011 Wiley Periodicals, Inc. Source

Luu P.-L.,Max Planck Institute for Molecular Biomedicine | Scholer H.R.,Max Planck Institute for Molecular Biomedicine | Scholer H.R.,University of Munster | Arauzo-Bravo M.J.,Max Planck Institute for Molecular Biomedicine
Genome Research | Year: 2013

Gene expression regulation is gated by promoter methylation states modulating transcription factor binding. The known DNA methylation/unmethylation mechanisms are sequence unspecific, but different cells with the same genome have different methylomes. Thus, additional processes bringing specificity to the methylation/unmethylation mechanisms are required. Searching for such processes, we demonstrated that CpG methylation states are influenced by the sequence context surrounding the CpGs. We used such a property to develop a CpG methylation motif discovery algorithm. The newly discovered motifs reveal "methylation/unmethylation factors" that could recruit the "methylation/unmethylation machinery" to the loci specified by the motifs. Our methylation motif discovery algorithm provides a synergistic approach to the differently methylated region algorithms. Since our algorithm searches for commonly methylated regions inside the same sample, it requires only a single sample to operate. The motifs that were found discriminate between hypomethylated and hypermethylated regions. The hypomethylation-associated motifs have a high CG content, their targets appear in conserved regions near transcription start sites, they tend to co-occur within transcription factor binding sites, they are involved in breaking the H3K4me3/H3K27me3 bivalent balance, and they transit the enhancers from repressive H3K27me3 to active H3K27ac during ES cell differentiation. The new methylation motifs characterize the pluripotent state shared between ES and iPS cells. Additionally, we found a collection of motifs associated with the somatic memory inherited by the iPS from the initial fibroblast cells, thus revealing the existence of epigenetic somatic memory on a fine methylation scale. © 2013 Luu et al. Source

Pedersen S.F.,Copenhagen University | Stock C.,University of Munster
Cancer Research | Year: 2013

Over the last 15 years it has become increasingly clear that dysregulated expression, splicing, and/or function of ion channels and transporters (ICT) occur in all cancers. Being linked to the widely accepted hallmarks of cancer, ICTs represent novel therapeutic, diagnostic, and prognostic targets. To discuss the current status of the field, a colloquium on "Ion Transport and Cancer" was held, covering the roles of ICTs in cancer cell proliferation, apoptosis, motility, and invasion, and in both the generation of and the interaction of the cancer cells with the tumor environment. Additional sessions dealt with pancreatic ductal adenocarcinoma and transport protein-based therapeutic and diagnostic concepts. There was overall consensus that essential contributions of ICT dysregulation to the cancer process have been demonstrated. Future research should be directed toward further elucidating the mechanisms and developing therapeutic applications. © 2012 American Association for Cancer Research. Source

Schmerr N.,Carnegie Institution of Washington | Thomas C.,University of Munster
Earth and Planetary Science Letters | Year: 2011

We seismically image both thermal and chemical heterogeneity of the mantle beneath the Kurile subduction zone using P-wave energy reflected from the underside of discontinuities, arriving as precursors to the seismic phase PP. We take advantage of new broadband seismic data provided by the High Lava Plains Seismic Experiment and EarthScope's USArray, collecting a dataset of 31 high-quality Sumatran earthquakes sampling beneath the Kuriles. We employ high-resolution array analysis techniques, including migration and vespagrams, to identify precursory arrivals and study lateral variations in discontinuity depth, sharpness, and impedance of the mantle transition zone. We find the 410. km boundary is at 395. km near the subducting Kurile slab, though the boundary is 410-425. km deep elsewhere. In regions away from subduction, we do not detect a laterally continuous underside reflection of P-waves from the 660. km discontinuity. However, in the vicinity of the subducting Kurile slab, we detect robust P660P reflections from interfaces near 620-670. km depth, signifying an increase in the impedance contrast at 660. km depth. We also detect deeper reflectors, down to 720. km depth, beneath the Kurile slab in a localized area. Cold, aluminum-depleted harzburgitic lithosphere residing at the base of the transition zone best explains the local enhancement of the 660. km discontinuity P-wave impedance contrast. Our new discontinuity measurements support the hypothesis of cold, depleted lithosphere stagnating at the 660. km discontinuity beneath the Kuriles subduction zone, and imply the 660. km boundary can locally impede mantle flow and produce chemical heterogeneity within the transition zone. © 2011 Elsevier B.V. Source

Hazra C.K.,TU Berlin | Hazra C.K.,University of Munster | Oestreich M.,TU Berlin
Organic Letters | Year: 2012

Copper(I)-catalyzed propargylic substitution of linear precursors with (Me 2PhSi) 2Zn predominantly yields the γ isomer independent of the propargylic leaving group. The thus formed allenylic silane reacts regioselectively with another equivalent of (Me 2PhSi) 2Zn, yielding a bifunctional building block with allylic and vinylic silicon groups. The reaction rates of both steps are well-balanced for chloride (γ:α ≥ 99:1) where the propargylic displacement occurs quantitatively prior to the addition step. Substitutions of α-branched propargylic phosphates are also reported. © 2012 American Chemical Society. Source

Schwabe T.,Stanford University | Neuert H.,University of Munster | Clandinin T.R.,Stanford University
Cell | Year: 2013

Neuronal growth cones select synaptic partners through interactions with multiple cell surfaces in their environment. Many of these interactions are adhesive, yet it is unclear how growth cones integrate adhesive cues to direct their movements. Here, we examine the mechanisms that enable photoreceptors in the Drosophila visual system to choose synaptic partners. We demonstrate that the classical cadherin, N-cadherin, and an atypical cadherin, Flamingo, act redundantly to instruct the targeting choices made by every photoreceptor axon. These molecules gradually bias the spatial distribution of growth cone filopodia, polarizing each growth cone toward its future synaptic target before direct contact with the target occurs. We demonstrate that these molecules are localized to distinct subcellular domains and create a network of adhesive interactions distributed across many growth cones. Because this network comprises multiple redundant interactions, a complex wiring diagram can be constructed with extraordinary fidelity, suggesting a general principle. © 2013 Elsevier Inc. Source

Buddenkotte J.,University of Munster | Steinhoff M.,University of California at San Francisco
Allergy: European Journal of Allergy and Clinical Immunology | Year: 2010

Pruritus (itch) is a major characteristic and one of the most debiliating symptoms in allergic and atopic diseases and the diagnostic hallmark of atopic dermatitis. Pruritus is regularly defined as an unpleasant sensation provoking the desire to scratch. Although we achieved rather good knowledge about certain inducers of itch such as neuropeptides, amines, μ-opioids, cytokines and proteases, for example, less is known about the pathophysiological specifities among the different diseases, and the therapeutic consequences which may derive thereoff. This review dissects the role of mediators, receptors and itch inhibitors on peripheral nerve endings, dorsal root ganglia, the spinal cord and the CNS leading to the amplification or - vice versa - suppression of pruritus. As the treatment of pruritus in allergic and atopic skin disease is still not satisfactory, knowing these pathways and mechanisms may lead to novel therapeutic approaches against this frequently encountered skin symptom. © 2010 John Wiley & Sons A/S. Source

Lack of insight and delusional thinking are hallmarks of a series of psychological disorders such as psychotic disorders and body dysmorphic disorder (BDD). The purpose of the present study was to evaluate the German version of the clinician-administered Brown Assessment of Beliefs Scale (BABS; Am J Psychiatry 1998;155:e102-e108), which consists of 7 items assessing the degree of delusionality in the individual's disorder-related belief (e.g., "The person behind me is staring at me", "My nose looks disgusting"). Specifically, the original BABS was translated and back-translated according to established translation guidelines and administered in 70 individuals diagnosed with BDD. Internal consistency as well as convergent and divergent validity was high, suggesting that the German version of the BABS is a reliable and valid instrument to assess delusional thinking in psychological disorders such as BDD. © 2014 Elsevier Inc. Source

Osteoarthritis is characterized by a progressive degradation of articular cartilage leading to loss of joint function. The molecular mechanisms regulating pathogenesis and progression of osteoarthritis are poorly understood. Remarkably, some characteristics of this joint disease resemble chondrocyte differentiation processes during skeletal development by endochondral ossification. In healthy articular cartilage, chondrocytes resist proliferation and terminal differentiation. By contrast, chondrocytes in diseased cartilage progressively proliferate and develop hypertrophy. Moreover, vascularization and focal calcification of joint cartilage are initiated. Signaling molecules that regulate chondrocyte activities in both growth cartilage and permanent articular cartilage during osteoarthritis are thus interesting targets for disease-modifying osteoarthritis therapies. © 2010 BioMed Central Ltd. Source

Innerhofer P.,Innsbruck Medical University | Kienast J.,University of Munster
Best Practice and Research: Clinical Anaesthesiology | Year: 2010

Perioperative coagulopathy impacts on patient outcome by influencing final blood loss and transfusion requirements. The recognition of pre-existing disturbances and the basic understanding of the principles of and dynamic changes of haemostasis during surgery are pre-conditions for safe patient management. The newly developed cellular model of coagulation facilitates the understanding of coagulation, thereby underscoring the importance of the tissue factor-bearing cell and the activated platelet. Amount of blood loss as well as amount and type of fluids used are the main factors involved in the development of dilutional coagulopathy, which is the most frequently observed cause of coagulopathy in the otherwise healthy surgical patient. Recent data from studies using viscoelastic coagulation studies confirm the central role of fibrinogen in stable clot formation and provide essential knowledge about its changes during blood loss and fluid administration. Besides early decrease in clot firmness during mild-to-moderate dilution, profound dilution results in a critical decrease in thrombin generation as well as a reduction in numbers and function of platelets. Although our knowledge of perioperative coagulopathy has dramatically increased over the past few years, several questions such as critical thresholds for fibrinogen, platelets, impact of FXIII and TAFI remain unanswered and need to be investigated further. © 2009 Elsevier Ltd. All rights reserved. Source

Li Y.,CAS Institute of Chemistry | Yang W.,CAS Institute of Chemistry | Liu H.,CAS Institute of Chemistry | Chi L.,University of Munster
Small | Year: 2012

Mechanically interlocked molecules, such as catenanes and rotaxanes, are at the heart of the development of molecular machines chemistry. They are able to self-organize, self-assemble, and self-control themselves into new materials with potential application as molecular devices. In this review, an overview of some recent progress on molecular machines is given, including new methodologies for their synthesis and self-assembly and their recent applications as dual or multilevel fluorescent molecular switches, as potential sensors, and even as a molecular-level transporter. In one development, a molecular machine containing a charge-transfer chromophore was designed to generate controllable aggregate structures through the reversible movement of a macrocycle over a thread; this was done in order to better understand the application of a molecular shuttle in solid state. Light is shed on how the novel properties and functions of molecular machines are extended, and examples of the ways in which molecular machines have been applied to the design and process of intelligentized systems are provided. Recent progress in the construction of functional smart molecular machines based on conjugated organic molecules with photo-electronic activity is summarized. Additionally, light is shed on how the novel functions of molecular machines are extended, and examples of the ways in which conjugated organic molecules have been, or can be, applied to the design and process of intelligentized systems are presented. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Kessler C.,University of Munster
Knowledge and Information Systems | Year: 2012

Result rankings from context-aware information retrieval are inherently dynamic, as the same query can lead to significantly different outcomes in different contexts. For example, the search term Digital Camera will lead to different-albeit potentially overlapping-results in the contexts customer reviews and shops, respectively. The comparison of such result rankings can provide useful insights into the effects of context changes on the information retrieval results. In particular, the impact of single aspects of the context in complex applications can be analyzed to identify the most (and least) influential context parameters. While a multitude of methods exists for assessing the relevance of a result ranking with respect to a given query, the question how different two result rankings are from a user's point of view has not been tackled so far. This paper introduces DIR, a cognitively plausible dissimilarity measure for information retrieval result sets that is based solely on the results and thus applicable independently of the retrieval method. Unlike statistical correlation measures, this dissimilarity measure reflects how human users quantify the changes in information retrieval result rankings. The DIR measure supports cognitive engineering tasks for information retrieval, such as work flow and interface design: using the measure, developers can identify which aspects of context heavily influence the outcome of the retrieval task and should therefore be in the focus of the user's interaction with the system. The cognitive plausibility of DIR has been evaluated in two human participants tests, which demonstrate a strong correlation with user judgments. © 2011 Springer-Verlag London Limited. Source

Hennecke U.,University of Munster
Angewandte Chemie - International Edition | Year: 2012

Chiral anions can do it: Asymmetric phase-transfer catalysis is no longer limited to cationic catalysts. Lipophilic BINOL phosphate anions are superior catalysts for the asymmetric electrophilic fluorination of alkenes under phase-transfer conditions (see picture). Now complex fluorinated compounds can be synthesized selectively from simple alkene starting materials. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Grimme S.,University of Bonn | Muck-Lichtenfeld C.,University of Munster
Israel Journal of Chemistry | Year: 2012

Four contemporary density functionals of meta-GGA, hybrid-GGA, meta-GGA-hybrid, and double-hybrid type connected with two versions of our recent dispersion correction (DFT-D3) are tested for the description of the geometric and electronic structures of typical cyclophanes. Strain energies (SE) as well as aromatic interaction energies (AIE) are considered. The systems [2.2]para- and [2.2]metacyclophane, []cyclophane, [2.2]paracyclonaphthane, [2.2](9,10)anthracenophane, and [2.2](1,4) anthracenophane are investigated. Computed structures are compared to experimental X-ray data. For the three smallest cyclophanes, accurate CCSD(T)/CBS reference SE and AIE values are computed to assess the accuracy of the DFT methods. It is found that medium-range dispersion (correlation) effects are important for all cyclophanes. Dispersion corrections in the Becke-Johnson damping (BJ) variant of the DFT-D3 method provide the most accurate results. The best density functionals yield relative (strain) energies accurate to within about 5-10%. Inter-ring distances can be computed very accurately with errors less than about 0.003Å while, for example, uncorrected B3LYP yields large average errors of almost 0.1Å for this property. The PW6B95-D3(BJ) and TPSS-D3(BJ) general purpose quantum chemical methods overall perform best and can be recommended also for studies of cyclophanes. The strain energies are partitioned to chemically meaningful components and the effect of the crystal environment is discussed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Muck-Lichtenfeld C.,University of Munster | Grimme S.,University of Bonn
Dalton Transactions | Year: 2012

The energy profiles of the activation reaction of small molecules (H 2, Br 2 and CO 2) with boron/phosphorus frustrated Lewis pairs (FLPs) have been calculated with dispersion corrected DFT (TPSS-D3). We have investigated the cooperative nature of the reactions by analyzing interaction energies in the ternary system and for reactant pairs. The non-additive contributions to the total interaction energy add to the driving force of the activation reaction, even at early stages of the process. We propose the isosurface representation of the many-body deformation density Δρ mb as a qualitative tool to visualize cooperative, non-additive effects in complex chemical systems. This journal is © 2012 The Royal Society of Chemistry. Source

Mezger K.,University of Bern | Debaille V.,TIME Higher School | Kleine T.,University of Munster
Space Science Reviews | Year: 2013

Geochemical investigation of Martian meteorites (SNC meteorites) yields important constraints on the chemical and geodynamical evolution of Mars. These samples may not be representative of the whole of Mars; however, they provide constraints on the early differentiation processes on Mars. The bulk composition of Martian samples implies the presence of a metallic core that formed concurrently as the planet accreted. The strong depletion of highly siderophile elements in the Martian mantle is only possible if Mars had a large scale magma ocean early in its history allowing efficient separation of a metallic melt from molten silicate. The solidification of the magma ocean created chemical heterogeneities whose ancient origin is manifested in the heterogeneous 142Nd and 182W abundances observed in different meteorite groups derived from Mars. The isotope anomalies measured in SNC meteorites imply major chemical fractionation within