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The Sapienza University of Rome, officially Sapienza – Università di Roma, also called simply Sapienza formerly known as Università degli studi di Roma "La Sapienza", is a coeducational, autonomous state university in Rome, Italy. It is the largest European university by enrollments and the oldest of Rome's four state universities, founded in 1303. In Italian, sapienza means "wisdom" or "knowledge".Being the biggest Italian University, Sapienza is member of several national and international groups, as: European Spatial Development Planning, Partnership of a European Group of Aeronautics and Space Universities, CINECA, Santander Network, Institutional Network of the Universities from the Capitals of Europe, Mediterranean Universities Union.Sapienza is present in all major international university rankings. It is among the best Italian universities.According to the Academic Ranking of World Universities compiled by the Jiao Tong University of Shanghai, Sapienza is regularly ranked first among Italian universities. Sapienza is positioned within the 101-150 group of universities and among the top 3% of universities in the world.According to webometrics.info La Sapienza is #8th in Europe and #1 in Italy.In 2013, the Center for World University Rankings ranked the Sapienza University of Rome 62nd in the world and the top in Italy in its World University Rankings.According to the American society "U.S News & World Report", La Sapienza is the most prestigious Italian University Wikipedia.


Llamas M.A.,Estacion Experimental del Zaidin Consejo Superior de Investigaciones Cientificas | Imperi F.,University of Rome La Sapienza | Visca P.,Third University of Rome | Lamont I.L.,University of Otago
FEMS Microbiology Reviews | Year: 2014

Membrane-spanning signaling pathways enable bacteria to alter gene expression in response to extracytoplasmic stimuli. Many such pathways are cell-surface signaling (CSS) systems, which are tripartite molecular devices that allow Gram-negative bacteria to transduce an extracellular stimulus into a coordinated transcriptional response. Typically, CSS systems are composed of the following: (1) an outer membrane receptor, which senses the extracellular stimulus; (2) a cytoplasmic membrane-spanning protein involved in signal transduction from the periplasm to the cytoplasm; and (3) an extracytoplasmic function (ECF) sigma factor that initiates expression of the stimulus-responsive gene(s). Members of genus Pseudomonas provide a paradigmatic example of how CSS systems contribute to the global control of gene expression. Most CSS systems enable self-regulated uptake of iron via endogenous (pyoverdine) or exogenous (xenosiderophores, heme, and citrate) carriers. Some are also implicated in virulence, biofilm formation, and cell-cell interactions. Incorporating insights from the well-characterized alginate regulatory circuitry, this review will illustrate common themes and variations at the level of structural and functional properties of Pseudomonas CSS systems. Control of the expression and activity of ECF sigma factors are central to gene regulation via CSS, and the variety of intrinsic and extrinsic factors influencing these processes will be discussed. © 2014 Federation of European Microbiological Societies. Source


Atriplex elongata Guss. (Amaranthaceae) is giving as an heterotypic synonym of Atriplex patula L. This first name is also lectotypified on a herbarium specimen kept in NAP. The identity of the species is clarified based on literature analysis and examination of type material and other herbarium specimens. © CONSERVATOIRE ET JARDIN BOTANIQUES DE GENÈVE 2012. Source


De Santoli L.,The Interdisciplinary Center | Lo Basso G.,The Interdisciplinary Center | Bruschi D.,University of Rome La Sapienza
Energy | Year: 2013

The methane enrichment with hydrogen amounts can improve environmental and mechanical performances of an ICE (internal combustion engine).The paper presents data resulting by the experimental campaign carried out over 42 days on a demo commercial CHP (combined heat and power) (60kWel) fuelled with hydrogen enriched methane blends.The tests have been carried out at partial load 55kWel with hydrogen percentages of 0%, 5% and 8%. In order to evaluate the CHP energy consumption and environmental performance, the analysis was conducted for 336h, using a continuous flue gas analyzer and two mass flow metres for hydrogen and methane.The aim of this paper is to demonstrate how the use of the hydrogen enrichment in a CHP plant represents a valid alternative to the same commercial energy systems, regarding the CO and CO2 emissions avoidance.The data analysis shows that modifying engine settings and increasing hydrogen amount significant energy effects occur. Consequently, the CHP fuelled with mixtures provides a lower thermal power, penalizing the heat recovery efficiency. The energy losses are due to unrecovered heat which is wasted like sensible heat to the stack. This alternative feeding system was developed in order to assess the energy penalty related to this carbon avoidance technique. © 2013 Elsevier Ltd. Source


Pirozzoli S.,University of Rome La Sapienza
Annual Review of Fluid Mechanics | Year: 2011

We review numerical methods for direct numerical simulation (DNS) and large-eddy simulation (LES) of turbulent compressible flow in the presence of shock waves. Ideal numerical methods should be accurate and free from numerical dissipation in smooth parts of the flow, and at the same time they must robustly capture shock waves without significant Gibbs ringing, which may lead to nonlinear instability. Adapting to these conflicting goals leads to the design of strongly nonlinear numerical schemes that depend on the geometrical properties of the solution. For low-dissipation methods for smooth flows, numerical stability can be based on physical conservation principles for kinetic energy and/or entropy. Shock-capturing requires the addition of artificial dissipation, in more or less explicit form, as a surrogate for physical viscosity, to obtain nonoscillatory transitions. Methods suitable for both smooth and shocked flows are discussed, and the potential for hybridization is highlighted. Examples of the application of advanced algorithms to DNS/LES of turbulent, compressible flows are presented. © 2011 by Annual Reviews. All rights reserved. Source


Campostrini M.,DellUniversity Pisa | Pelissetto A.,University of Rome La Sapienza | Vicari E.,DellUniversity Pisa
Physical Review B - Condensed Matter and Materials Physics | Year: 2014

We develop the finite-size scaling (FSS) theory at quantum transitions. We consider various boundary conditions, such as open and periodic boundary conditions, and characterize the corrections to the leading FSS behavior. Using renormalization-group (RG) theory, we generalize the classical scaling ansatz to describe FSS in the quantum case, classifying the different sources of scaling corrections. We identify nonanalytic corrections due to irrelevant (bulk and boundary) RG perturbations and analytic contributions due to regular backgrounds and analytic expansions of the nonlinear scaling fields. To check the general predictions, we consider the quantum XY chain in a transverse field. For this model exact or numerically accurate results can be obtained by exploiting its fermionic quadratic representation. We study the FSS of several observables, such as the free energy, the energy differences between low-energy levels, correlation functions of the order parameter, etc., confirming the general predictions in all cases. Moreover, we consider bipartite entanglement entropies, which are characterized by the presence of additional scaling corrections, as predicted by conformal field theory. © 2014 American Physical Society. Source


Nervi C.,University of Rome La Sapienza | Grignani F.,University of Perugia
Sub-Cellular Biochemistry | Year: 2014

MicroRNAs (miRNAs) are small noncoding RNAs acting as endogenous regulators of gene expression. Their discovery is one of the major recent breakthroughs in molecular biology. miRNAs establish a multiplicity of relationships with target mRNAs and exert pleiotropic biological effects in many cell physiological pathways during development and adult life. The dynamic nature of gene expression regulation by Retinoic Acid (RA) is consistent with an extensive functional interplay with miRNA activities. In fact, RA regulates the expression of many different miRNAs, thus suggesting a relevant function of miRNAs in RA-controlled gene expression programmes. miRNAs have been extensively studied as targets and mediators of the biological activity of RA during embryonic development as well as in normal and neoplastic cells. However, relatively few studies have experimentally explored the direct contribution of miRNA function to the RA signalling pathway. Here, we provide an overview of the mechanistic aspects that allow miRNA biogenesis, functional activation and regulation, focusing on recent evidence that highlights a functional interplay between miRNAs and RA-regulated molecular networks. We report examples of tissue-specific roles of miRNAs modulated by RA in stem cell pluripotency maintenance and regeneration, embryonic development, hematopoietic and neural differentiation, and other biological model systems, underlining their role in disease pathogenesis. We also address novel areas of research linking the RA signalling pathway to the nuclear activity of miRNAs. © Springer Science+Business Media Dordrecht 2014. Source


Pacella E.,University of Rome La Sapienza
La Clinica terapeutica | Year: 2013

This observational study was performed to evaluate the efficacy and safety of intra-vitreal injections of pegaptanib during a 12-month follow-up period. Forty eyes (20 patients) affected by diabetic macular edema were monitored. Twenty were subjected to treatment, and 20 were controls. The treatment involved a cycle of three intravitreal injections of pegaptanib (0.3 mg every 6 weeks), at the end of which treated patients were submitted to a monthly follow-up for a period of 12 months. The aim was to evaluate the clinical condition of the eye after therapy and gauge the efficacy of the long-term use of this drug. Specific criteria were used to measure the efficacy and safety of pegaptanib. Regarding efficacy, we considered the following: an average improvement in the power of vision, or visual acuity, of →10 letters (2 lines), equivalent to an average logMAR score of →0.2, and a reduction in the central macular thickness of →250 μm. Regarding safety, we considered the occurrence of undesired eye and systemic side effects correlated to either the drug itself or the injection procedure. The logMAR score for the measurement of visual acuity at T3 (third intra-vitreal injection at week 13) with respect to T0 decreased from 0.7 ± 0.277 to 0.445 ± 0.216, suggesting an improvement, while the mean Early Treatment Diabetic Retinopathy Study (ETDRS) score increased from 25.75 ± 13.046 to 34.300 ± 11.770 letters. The central macular thickness was reduced from the initial value of 746.95 ± 293.601 to 334.050 ± 93.997 μm. In seven controls, we registered a worsening both in terms of visual acuity and macular thickness in some eyes, justifying a continuation of therapy in eight eyes of the control group. Pegaptanib proved to be efficacious and safe for the treatment of diabetic macular edema throughout the 12-month followup. To evaluate its long-term efficacy, further studies are required with larger numbers of patients and longer observational follow-up periods. Source


Carnevale D.,I.R.C.C.S Neuromed | Lembo G.,University of Rome La Sapienza
Biochemical Society Transactions | Year: 2011

Genetic AD (Alzheimer's disease) accounts for only few AD cases and is almost exclusively associated with increased amyloid production in the brain. Instead, most patients are affected with the sporadic form of AD and typically have altered clearance mechanisms. The identification of factors that influence the onset and progression of sporadic AD is a key step towards understanding its mechanism(s) and developing successful therapies. An increasing number of epidemiological studies describe a strong association between AD and cardiovascular risk factors, particularly hypertension, that exerts detrimental effects on the cerebral circulation, favouring chronic brain hypoperfusion. However, a clear demonstration of a pathophysiological link between cardiovascular risk factors and AD aetiology is still missing. To increase our knowledge of the mechanisms involved in the brain's response to hypertension and their possible role in promoting amyloid deposition in the brain, we have performed and investigated in depth different murine models of hypertension, induced either pharmacologically or mechanically, leading in the long term to plaque formation in the brain parenchyma and around blood vessels. In the present paper, we review the major findings in this particular experimental setting that allow us to study the pathogenetic mechanisms of sporadic AD triggered by vascular risk factors. ©The Authors Journal compilation ©2011 Biochemical Society. Source


Alessandri N.,University of Rome La Sapienza
European review for medical and pharmacological sciences | Year: 2013

The contrast-induced nephropathy (CIN) is the third most common cause of acute renal failure (ARF) and the worsening in a pre-existing chronic renal failure (CRF), with a foreseeable increase of morbidity, mortality, length of the stay in hospital and, as a consequence, of the health costs. We studied the effectiveness of N-acetylcysteine (NAC) associated with sodium bicarbonate (Na2HCO3) infusion in order to prevent CIN in patients undergoing coronary angiography with administration of contrast medium. 296 patients with indication to perform coronary angiography were included in a randomized, observational study. All patients were randomly assigned to receive pre- and post-contrast hydration with 1500 ml of 0.9% saline solution infusion (Group A) or NAC (1200 mg × 2 days) + Na2HCO3 (Group B). The primary end-point was to examine CIN appearance, defined as a raise in serum values of Cr (Creatinine) ≥ 0.5 mg/dl or ≥ 25% within 24-72 hours after the exposure to the contrast medium. It has been observed a frequency of CIN of 9.4% in Gr. A compared to 7.2% in Gr. B. Nevertheless, when we put these results through a more accurate screening according to gender, degree of raise in creatinine levels and the extent of change in GFR (glomerular filtration rate), we observed a very different behaviour. In patients with normal Cr and CrCl (Clearance of Creatinine) the frequency of CIN was similar in both group A and B (approximately 5%). In patients with normal Cr but reduced ClCr the use of NAC was more effective than hydration in preventing CIN (0% vs 18% in prevalence respectively in B and A group). In patients with moderately reduced Cr and CrCl, hydration with saline solution was more effective than NAC + Na2HCO3 (8.6% vs 17.6%) while in patients with severe CRF the combined use of NAC + Na2HCO3 showed off to be very successful in preventing CIN compared to the merely hydration (0% vs 50%). In patients affected by severe CRF who are undergoing investigations with contrast medium administration, such as coronary angiography, the combined use of NAC + Na2HCO3 infusion significantly reduces the risk of developing CIN. In other circumstances the final result is related to the degree of previous GFR or creatinine values alteration or to gender. In such situations the combined use of both substances is more questionable and sometimes ineffective. Source


Fontana L.,Third University of Rome | Quintino A.,University of Rome La Sapienza
Building and Environment | Year: 2014

Today it is common practice to try and obtain airborne contamination control through pressurization-depressurization areas. Moreover, there is some qualitative evidence that turbulence induced by the operation of a door between different pressure areas, could overcome the differential pressurization effect, and cause a pouring effect between zones, and consequently a contamination. The paper investigates the described matter through an experimental setup, with a scale physical model. Obtained results confirm that door operation is able to produce a dirty air transfer in the clean room, and that transfer entity is almost independent from differential pressure and flow rate imbalance, at least for the experimentally tested values, while it appears strongly related to air volume displaced in the door opening operation, and has the same order of magnitude of it. © 2014 Elsevier Ltd. Source


Iagnocco A.,University of Rome La Sapienza
Clinical and Experimental Rheumatology | Year: 2014

Ultrasound (US) is a valuable imaging modality in the evaluation of joint and periarticular abnormalities in osteoarthritis (OA). It is able to image structural lesions as well as inflammatory changes in early and late disease. US is a relatively inexpensive, safe and quick-to-perform tool that can be used as a bedside procedure in the assessment of patients with OA. US shows abnormalities at different peripheral joint sites that can be assessed for variable aspects during the same scanning session. The easy accessibility of equipment facilitates its use and applications in the clinical practice. US is helpful in guiding local procedures (i.e. aspirations of joint and periarticular fluid collections, drug injections, biopsy) that can be easily and safely performed with optimal patient's tolerance. In addition, US allows for a monitoring of the disease process and follow-up of local and systemic treatments. copy; Clinical and Experimental Rheumatology 2014. Source


Trovato C.M.,University of Rome La Sapienza
American Journal of Gastroenterology | Year: 2015

OBJECTIVES:In 2012, European Society of Pediatric Gastroenterology, Hepatology, and Nutrition published novel guidelines on celiac disease (CD) diagnosis. Symptomatic children with serum anti-transglutaminase (anti-tTG) antibody levels ≥10 times upper limit of normal (ULN) could avoid duodenal biopsies after positive HLA test and serum anti-endomysial antibodies (EMAs). So far, both asymptomatic and symptomatic patients with anti-tTG titer <10 times ULN should undergo upper endoscopy with duodenal biopsies to confirm diagnosis. The aim of this study was to assess the accuracy of serological tests to diagnose CD in asymptomatic patients.METHODS:We retrospectively reviewed data of 286 patients (age range: 10 months to 17 years) with CD diagnosis based on elevated titer of anti-tTG, EMA positivity, and histology. All patients were distinguished between symptomatic and asymptomatic; histological lesions were graded according to the Marsh–Oberhuber (MO) criteria. Fisher exact test was applied to analyze both groups in terms of diagnostic reliability of serological markers.RESULTS:A total of 196 patients (68.53%) had anti-tTG titers ≥10 times ULN. Among them, a group of 156 patients (79.59%) also had symptoms suggestive of CD (“high-titer” symptomatic); of these, 142 patients (91.02%) showed severe lesion degree (3a, 3b, 3c MO). Conversely, 40 out of 196 patients (20.40%) were asymptomatic (“high-titer” asymptomatic) and 37 patients (92.5%) of them showed severe lesion degree (3a, 3b, 3c MO). No difference in histological damage was found between “high-titer” symptomatic and “high-titer” asymptomatic children (Fisher exact test, P=1.000).CONCLUSIONS:If confirmed in large multicenter prospective studies, the “biopsy-sparing” protocol seems to be applicable to both symptomatic and asymptomatic patients with anti-tTG titer ≥10 times ULN, positive EMA, and HLA-DQ2/DQ8.Am J Gastroenterol advance online publication, 15 September 2015; doi:10.1038/ajg.2015.285. © 2015 American College of Gastroenterology Source


Fargion D.,University of Rome La Sapienza
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2011

Since the earliest UHECR anisotropy findings [2] till today, recent ICRC09 AUGER [1] updated maps and clustering confirm our understanding of Centaurus A (NGC 5128), Cen A, as the main nearby UHECR source, whose events are mostly lightest nuclei, such as He. The events are spread by galactic fields. The main UHECR events along Cen A spread vertically (with respect to horizontal spiral galactic fields) by random (and a final coherent) Lorentz forces. The He-nuclei dominance is also well probed by detailed AUGER composition data. The lightest nuclei are still compatible with the most recent HIRES composition results. Such lightest UHECR nuclei are opaque even to the nearest Universe offering a very narrow local (10 Mpc) view. Explaining at best the otherwise puzzling Virgo persistent absence; therefore the He disruption should lead to halves energy tail clustering (along the same Cen A group), events of deuterium, He 3 and protons (or unstable neutrons). They may rise in smeared cluster of events along the same Cen A group edges at energies among 1.54.5×1019 eV. The He-like UHECR photo-disruption should also produce energetic gamma (extremely opaque with CMB and therefore local and hard to detect in nosy knee CR) and GZK neutrinos at tens-hundred PeVs energy. Contrary to widely expected GZK ν at EeVs energy (due to its widely believed UHECR proton nature) our foreseen UHE neutrino by UHECR lightest nuclei, at tens-a hundred PeV, may rise in AUGER and TA telescopes via quite inclined (about 5°) upward fluorescent tau air-showers at nearest (14 km) horizons, at middle-low telescope view zenith angles (below 20°). Their air-showers will be opening and extending in widest azimuth angle (above 120°) and fastest angular velocity spread contrary to far EeV tau expected by popular GZK neutrinos. Even more hard to observe, these tau air-showers at tens and hundred PeVs may soon shine (in a peculiar way) at near telescope views and within a short (years) time, both in AUGER, HEAT and TA. © 2010 Elsevier B.V. All rights reserved. Source


Ferrari V.,University of Rome La Sapienza
Bulletin of the Astronomical Society of India | Year: 2011

Non radial oscillations of neutron stars are associated with the emission of gravitational waves. The characteristic frequencies of these oscillations can be computed using the theory of stellar perturbations, and they are shown to carry detailed information on the internal structure of the emitting source. Moreover, they appear to be encoded in various radiative processes, as for instance in the tail of the giant flares of Soft Gamma Repeaters. Thus, their determination is central to the theory of stellar perturbation. A viable approach to the problem consists in formulating this theory as a problem of resonant scattering of gravitational waves incident on the potential barrier generated by the spacetime curvature. This approach discloses some unexpected correspondences between the theory of stellar perturbations and the theory of quantum mechanics, and allows us to predict new relativistic effects. Source


Adrover A.,University of Rome La Sapienza
Physics of Fluids | Year: 2011

We focus on the characterization of dispersion processes in microchannels with fractal boundaries (and translational symmetry in the longitudinal direction) in the presence of laminar axial velocity field. This article extends the theory of laminar dispersion in finite-length channel flows at high Peclet numbers by analyzing the role of the fractal cross-section in the convection-dominated transport regime. In this regime, the properties of the dispersion boundary layer and the values of the scaling exponents controlling the dependence of the moment hierarchy on the Peclet number are determined by the local near-wall behavior of the axial velocity. Specifically, different scaling laws in the behavior of the moment hierarchy occur, depending whether the cross-sectional boundary is smooth or nonsmooth (e.g., presenting corner points or cusps). The limit case of a fractal boundary is analyzed in detail. Analytical and numerical results are presented for two fractal cross-sections (the classical Koch curve and the Koch snowflake) in the Stokes regime. © 2011 American Institute of Physics. Source


Muscaritoli M.,University of Rome La Sapienza
Current Opinion in Clinical Nutrition and Metabolic Care | Year: 2016

PURPOSE OF REVIEW: Cancer represents one of the most feared diseases. Despite an increasing number of available scientific data, most people remain unaware of those basic dietary and healthy lifestyle measures, which might reduce their risk to develop cancer. Environmental factors, diet, and lifestyle play a crucial role in the development of several different neoplastic diseases, particularly gastrointestinal cancer. In this article, we aimed at focusing on foods and their components able to increase gastrointestinal cancer risk. RECENT FINDINGS: During the last few years, major emphasis has been addressed on the relation between red meat and gastrointestinal cancer. Many potential mechanisms linked red meat consumption and cancer risk, including heterocyclic amines, polycyclic aromatic hydrocarbons, N-nitroso compounds, and heme iron. Other chemical substances, contaminating food, such as acrylamide, showed gastrointestinal carcinogenic properties. SUMMARY: Correct diet and lifestyle are clinically relevant strategies in preventing gastrointestinal cancer. In the fight against cancer, nutritional educative intervention programs are necessary to spread the knowledge on healthy eating and appropriate nutrition to reduce cancer risk. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. Source


PURPOSE:: To correlate choroidal thickness (CT) and age with vascularized retinal layer and outer retinal layer thickness in normal eyes. METHODS:: This was a prospective, cross-sectional study. Complete ophthalmological examination, biometry, and enhanced depth imaging spectral domain optical coherence tomography were performed. Choroidal and individual retinal layer thickness measurements were obtained. Thickness maps for all layers were evaluated using the 1 mm, 3 mm, and 6 mm early treatment diabetic retinopathy study (ETDRS) macular grid areas. RESULTS:: One hundred and twenty eyes were included. Choroidal thickness correlated negatively with age in all ETDRS areas. The ganglion cell layer (GCL) in the 1 mm; the GCL and inner plexiform layer (IPL) in the 3 mm and 6 mm; and the GCL, IPL, and inner nuclear layer in the 6 mm areas correlated negatively with age and positively with CT. Retinal nerve fiber layer thickness in the 6 mm area correlated negatively with age. The retinal pigment epithelium-photoreceptor layer in all areas correlated negatively with age and positively with CT. CONCLUSION:: In normal subjects, vascularized retinal layer thicknesses and outer retinal layer thickness correlate positively with CT and negatively with age. The role of neuronal versus vascular components should be considered when evaluating individual retinal layer thicknesses. © 2016 by Ophthalmic Communications Society, Inc. Source


Bergshoeff E.A.,University of Groningen | Riccioni F.,University of Rome La Sapienza
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2011

We show that the branes of ten-dimensional IIA/IIB string theory must satisfy, upon toroidal compactification, specific wrapping rules in order to reproduce the number of supersymmetric branes that follows from a supergravity analysis. The realization of these wrapping rules suggests that IIA/IIB string theory contains a whole class of generalized Kaluza-Klein monopoles. © 2011 Elsevier B.V. Source


Caciari T.,University of Rome La Sapienza
Annali di igiene : medicina preventiva e di comunità | Year: 2012

The aim of this study is to estimate if low dose of occupational exposure to ionizing radiations can cause alterations of plasma concentrations of total white blood cells, lymphocytes, monocytes and granulocytes (eosinophils, basophils, neutrophils), in the health workers of a big hospital. 266 non smokers subjects of both sexes (133 health workers and 133 controls) were included in this study, compared on the basis of sex, age and working seniority. The complete blood count (CBC) was performed in all included workers. The differences between the mean values were compared using Student T-test for unpaired data. The frequencies of the single variables were compared using Chi (2) test with Yates correction. The differences were considered significant when the P values were < 0.05. The mean values and the distribution of the mean values of total white blood cell were significantly decreased in health workers of both sexes compared to controls. The average values of granulocytes neutrophils were significantly low in female health workers compared to female controls. The obtained results suggest that low dose of occupational exposure to ionizing radiations is able to influence some lines of the hematopoietic system in exposed workers. Source


Caracciolo G.,University of Rome La Sapienza
Bioinspired, Biomimetic and Nanobiomaterials | Year: 2013

At present, ligand binding to nanoparticle surface is the most widespread strategy for targeting specific tissues by a receptormediated mechanism. However, the nanoparticles are immediately covered by a protein-rich layer when administrated in vivo, the so-called "protein corona", with the immediate consequence that the ligand-receptor recognition may be obscured. It is not the nanoparticle-bulk composition or surface functionalization but rather the identity, arrangement and residence time of the proteins of the corona that determine the nanoparticle bioidentity, and this is an emerging concept available for use to target specific cell types in a controlled manner. An in-depth understanding of the relationship between surface properties of nanoparticles and composition of the "protein corona" is a fundamental step toward the design of nanoparticles that, once in the blood, become covered by specific proteins able to deliver them at the right site of action and promote efficient cell internalization. This "protein corona effect" is a formidable challenge that could lead to a complete renewal of the current strategies of targeted drug delivery. Source


Orsi G.B.,University of Rome La Sapienza
Annali di igiene : medicina preventiva e di comunità | Year: 2013

Vancomycin-resistant enterococci (VRE) are among the most common healthcare associated multidrug-resistant organisms. Purpose of the article was to review recent data regarding the epidemiology, clinical issues and infection control of this organisms. A PubMed-MEDLINE search was carried out. The European Antimicrobial Resistance Surveillance System (EARSS) highlights a large variability between the various european countries, with VRE ranging from <2% (Finland, Holland) to >20% (Ireland, Greece, Portugal). Italy shows a low rate level (4.2%). In USA according to the National Healthcare Safety Network (NHSN) in 2006-2007 overall 33% of enterococci were resistant to vancomycin, whereas in Canada VRE prevalence showed to be much lower <10%. Although with some methodological limits, several studies showed that infections caused by VRE are more serious and associated to a higher mortality rate and economic burden compared to those caused by vancomycin susceptible enterococci (VSE). The average increased associated mortality was over two-fold. Resistance to newer antimicrobial agents as daptomycin and linezolid has been described, complicating treatment options for infections caused by these organisms. Control measures aimed at reducing the incidence of VRE colonization and infection in healthcare settings should include: hand washing with an antiseptic or a waterless antiseptic agent, routine screening for vancomycin resistance among clinical isolates, rectal surveillance cultures, contact isolation for patients with VRE and antimicrobial stewardship. Source


Pompili M.,University of Rome La Sapienza
Bipolar disorders | Year: 2013

Suicidal behavior is a major public health problem worldwide, and its prediction and prevention represent a challenge for everyone, including clinicians. The aim of the present paper is to provide a systematic review of the existing literature on the epidemiology of completed suicides in adult patients with bipolar disorder (BD). We performed a Pubmed/Medline, Scopus, PsycLit, PsycInfo, and Cochrane database search to identify all relevant papers published between 1980 and 2011. A total of 34 articles meeting our inclusion criteria were included in the present review. Several prospective follow-up contributions, many retrospective analyses, and a few psychological autopsy studies and review articles investigated the epidemiology of completed suicides in patients with BD. The main finding of the present review was that the risk for suicide among BD patients was up to 20-30 times greater than that for the general population. Special attention should be given to the characteristics of suicides in patients with BD. Better insight and understanding of suicide and suicidal risk in this very disabling illness should ultimately help clinicians to adequately detect, and thus prevent, suicidal acts in patients with BD. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. Source


Coccia M.E.,University of Florence | Rizzello F.,University of Rome La Sapienza
Annals of the New York Academy of Sciences | Year: 2011

Modern imaging techniques allow for the noninvasive diagnosis of endometriosis. Preoperative staging of pelvic endometriosis helps the gynecologist plan therapy and offer a prognosis to patients. The challenge of creating a satisfactory classification of endometriosis remains. The ability of the current classification schemes to predict pregnancy outcome, or aid in the management of pelvic pain, is recognized to be inadequate. The study of deeply infiltrating endometriosis and adenomyosis is greatly hampered by a lack of clear terminology and the absence of a consensus classification of the lesions. A reviewed consensus classification of endometriosis in general, with a more detailed consideration on deep endometriosis, is urgently required. We suggest a new staging system for deep, infiltrating endometriosis based on ultrasonographic findings. Prospective data collection and review in large centers may provide a larger clinical base from which to derive empirical point scores and breakpoints in the classification scheme. © 2011 New York Academy of Sciences. Source


Bianco P.,University of Rome La Sapienza
Journal of Cellular Biochemistry | Year: 2011

The last decade was dominated by dissemination of the notion that postnatal "mesenchymal stem cells," found primarily in bone marrow but also in other tissues, can generate multiple skeletal and nonskeletal tissues, and thus can be exploited to regenerate a broad range of tissues and organs. The concept of "mesenchymal stem cells" and its applicative implications represent a significant departure from the solidly proven notion that skeletal stem cells are found in the bone marrow (and not in other tissues). Recent data that sharpen our understanding of the identity, nature, origin, and in vivo function of the archetypal "mesenchymal stem cells" (bone marrow skeletal stem cells) point to their microvascular location, mural cell identity, and function as organizers and regulators of the hematopoietic microenvironment/niche. These advances bring back the original concept from which the notion of "mesenchymal stem cells" evolved, and clarify a great deal of experimental data that accumulated in the past decade. As a novel paradigm emerges that accounts for many facets of the biology of skeletal stem cells, a novel paradigm independently emerges for their applicative/translational use. The two paradigms meet each other back in the future. © 2011 Wiley-Liss, Inc. Source


Pastori D.,University of Rome La Sapienza
Journal of the American Heart Association | Year: 2013

Hemorrhagic risk assessment is a crucial issue in patients with nonvalvular atrial fibrillation (NVAF) who are receiving oral anticoagulant therapy (OAT). Our aim was to analyze the relationship between vitamin E, which possesses anticoagulant properties, and bleeding events in NVAF patients. In this retrospective observational study we analyzed baseline serum cholesterol-adjusted vitamin E (vit E/chol) levels in 566 consecutive patients (59% males, mean age 73.6 years) receiving OAT followed up for a mean time of 22 months. Mean time in therapeutic INR range (TTR) was 64%. The overall incidence rate of any bleeding event was 9.2/100 person-years. Compared to patients who did not bleed, those who experienced bleeding events (n=92, 73 minor and 15 major bleedings and 4 cerebral hemorrhages according to International Society on Thrombosis and Haemostasis [ISTH] ) classification) showed a significant difference for history of coronary heart disease (P=0.039), HAS-BLED score (P=0.002), and vit E/chol levels (P<0.001). Higher vit E/chol serum levels were found in patients who bled compared to those who did not (5.27 ± 1.93 versus 4.48 ± 1.97 μmol/cholesterol; P<0.001), with a progressive increase from minor (5.16 ± 1.91 μmol/mmol cholesterol, P=0.006) to major bleedings (5.72 ± 2.0 μmol/mmol cholesterol, P=0.008). A Cox proportional hazard model demonstrated that serum vit E/chol quartiles (global P=0.0189) and HAS-BLED scores (P=0.005) predicted bleeding events. In a NVAF population being treated with warfarin, serum vitamin E predicted hemorrhagic events. Further study is necessary to see if the relationship between serum levels of vitamin E and bleeding is still maintained with the use of new anticoagulants. Source


Leonardi S.,University of Rome La Sapienza | Roughgarden T.,Stanford University
Proceedings of the Annual ACM Symposium on Theory of Computing | Year: 2012

Prior-free auctions are robust auctions that assume no distribution over bidders' valuations and provide worst-case (input-by-input) approximation guarantees. In contrast to previous work on this topic, we pursue good prior-free auctions with non-identical bidders. Prior-free auctions can approximate meaningful benchmarks for non-identical bidders only when "sufficient qualitative information" about the bidder asymmetry is publicly known. We consider digital goods auctions where there is a total ordering of the bidders that is known to the seller, where earlier bidders are in some sense thought to have higher valuations. We use the framework of Hartline and Roughgarden (STOC '08) to define an appropriate revenue benchmark: the maximum revenue that can be obtained from a bid vector using prices that are nonincreasing in the bidder ordering and bounded above by the second-highest bid. This monotone-price benchmark is always as large as the well-known fixed-price benchmark F (2), so designing prior-free auctions with good approximation guarantees is only harder. By design, an auction that approximates the monotone-price benchmark satisfies a very strong guarantee: it is, in particular, simultaneously near-optimal for essentially every Bayesian environment in which bidders' valuation distributions have nonincreasing monopoly prices, or in which the distribution of each bidder stochastically dominates that of the next. Of course, even if there is no distribution over bidders' valuations, such an auction still provides a quantifiable input-by-input performance guarantee. In this paper, we design a simple prior-free auction for digital goods with ordered bidders, the Random Price Restriction (RPR) auction. We prove that its expected revenue on every bid profile b is Ω(M (2)(b)/log* n), where M (2) denotes the monotone-price benchmark and log* n denotes the number of times that the log 2 operator can be applied to n before the result drops below a fixed constant. © 2012 ACM. Source


Sansoni J.,University of Rome La Sapienza
Annali di igiene : medicina preventiva e di comunità | Year: 2013

Informal caring or caregiving is very common in our postindustrial society. Caregiving burden grows with the worsening of cognitive impairment of the patient and is one of the factors influencing institutionalization. Alzheimer's disease (AD) is a type of dementia that is chronic and deteriorative. The symptoms of this neuropsychiatric disorder generally begin to manifest after the age of sixty and currently 8.9 million family caregivers provide assistance to someone with AD or a related dementia. As the patient's condition worsens, it increases the burden on the caregivers, due to the physical, psychological, and emotional stresses that result from caring for the patient. A search of the literature was conducted on electronic database: PubMed, Google Scholar, Science direct, CINAHL in a exploratory way. Inclusion criteria were: articles in English and Italian published between 1999-2011 which mentioned Alzheimer's caregivers, burden, stressors, and institutionalization. The exclusion criterion was failure to mention the word "caregivers". About 100 titles were found and 30 articles abstracts with key words in the title were reviewed. Of the 30 articles selected for further review based on the relevance to the study purpose, 17 articles were finally selected for inclusion in this literature review. Results display that caregiver burden is influenced by patient behavioral and cognitive status, hours involved in care, stress, social isolation, gender, relationship to the patient, availability of support resources, and caregiver characteristics. Assessment tools available to assess and recognize risk factors and burden in caregivers are useful both in terms of caregivers health and decision on istitutionalization. Literature suggests to provide information for health care providers to reduce burden and support caregiver health and well-being. Assessment tools available to assess and recognize risk factors and burden in caregivers should be used more often to contribute to reducing caregiver stress and the impact of institutionalization. Source


Menotti A.,Association for Cardiac Research | Puddu P.E.,University of Rome La Sapienza
Nutrition, Metabolism and Cardiovascular Diseases | Year: 2015

The Seven Countries Study of Cardiovascular Diseases was started at the end of the 1950s and it continues to be run after >50 years. It enrolled, at entry, 16 population cohorts in eight nations of seven countries for a total of 12,763 middle-aged men. It was the prototype of epidemiological studies seeking cultural contrasts and the first to compare cardiovascular disease (CVD) rates related to diet differences. The study has shown that populations suffer widely different incidence and mortality rates from coronary heart disease (CHD) as well as from other CVDs and overall mortality. Higher rates were found in North America and northern Europe, and lower rates in southern Europe - Mediterranean countries - and Japan. These differences in CHD rates were strongly associated with different levels of saturated fat consumption and average serum cholesterol levels, with lowest rates in Greece and Japan where the total fat intake was very different. The cohorts were also different in dietary patterns defined by the ratio of calories derived from plant foods and fish on the one hand and calories derived from animal foods and sugar on the other. These findings pointed to the so-called Mediterranean diet, which is characterized by large values of that plant/animal ratio, a pattern associated with lower incidence and mortality from CHD and also with the lowest death rates and the greatest survival rates. More recent studies have refined these concepts and documented on a larger scale the virtues of these eating habits. © 2014 Elsevier B.V.. Source


Bianco P.,University of Rome La Sapienza
Annual review of cell and developmental biology | Year: 2014

Two opposing descriptions of so-called mesenchymal stem cells (MSCs) exist at this time. One sees MSCs as the postnatal, self-renewing, and multipotent stem cells for the skeleton. This cell coincides with a specific type of bone marrow perivascular cell. In skeletal physiology, this skeletal stem cell is pivotal to the growth and lifelong turnover of bone and to its native regeneration capacity. In hematopoietic physiology, its role as a key player in maintaining hematopoietic stem cells in their niche and in regulating the hematopoietic microenvironment is emerging. In the alternative description, MSCs are ubiquitous in connective tissues and are defined by in vitro characteristics and by their use in therapy, which rests on their ability to modulate the function of host tissues rather than on stem cell properties. Here, I discuss how the two views developed, conceptually and experimentally, and attempt to clarify the confusion arising from their collision. Source


Scrivo R.,University of Rome La Sapienza
Current allergy and asthma reports | Year: 2014

Metabolomics is the analysis of the concentration profiles of low molecular weight compounds present in biological fluids. Metabolites are nonpeptide molecules representing the end products of cellular activity. Therefore, changes in metabolite concentrations reveal the range of biochemical effects induced by a disease or its therapeutic intervention. Metabolomics has recently become feasible with the accessibility of new technologies, including mass spectrometry and high-resolution proton nuclear magnetic resonance, and has already been applied to several disorders. Indeed, it has the advantage of being a nontargeted approach for identifying potential biomarkers, which means that it does not require a preliminary knowledge of the substances to be studied. In this review, we summarize the main studies in which metabolomic approach was used in some allergic (asthma, atopic dermatitis) and rheumatic diseases (rheumatoid arthritis, systemic lupus erythematosus) to explore the feasibility of this technique as a novel diagnostic tool in these complex disorders. Source


Bianco P.,University of Rome La Sapienza
Blood | Year: 2011

The revived interest in (hematopoietic) stem cell (HSC) niches has highlighted the role of multiple cellular players found in the bone environment. Initially focused on the role of osteoblasts and sinusoid endothelial cells, the quest for HSC niche cells has recently focused on a unique role for osteoprogenitor cells (skeletal stem cells, mesenchymal stem cells). Strongly validated by observations of HSC dysregulation dictated by the dysregulation of osteoprogenitors, the role of osteoprogenitors in the HSC niche integrates data from different studies into a unified view. As preosteoblastic, periendothelial cells residing at the sinusoid wall, skeletal progenitors reconcile the notions of "osteoblastic" and "sinusoidal" niches with one another. In addition, they bring into focus the cross-regulation of skeletal and hematopoietic physiology as rooted into the interplay of two stem cells (hematopoietic and skeletal) sharing a single niche. As direct regulators of hematopoietic space formation, sinusoid development, and hematopoietic function(s), as well as direct progenitors of positive and negative regulators of HSCs such as osteoblasts and adipocytes, skeletal progenitors have emerged as pivotal organizers of a complex, highly plastic niche. This development seems to represents an evolutionary advance over the deterministic stem cell niches found in archetypal invertebrate systems. © 2011 by The American Society of Hematology. Source


This paper is an Italian Expert Consensus Document on multidimensional treatment of obesity and eating disorders. The Document is based on a wide survey of expert opinion. It presents, in particular, considerations regarding how clinicians go about choosing the most appropriate site of treatment for a given patient suffering from obesity and/or eating disorders: outpatient, partial hospitalization, residential rehabilitation centre, inpatient hospitalization. In a majority of instances obesity and eating disorders are long-term diseases and require a multiprofessional team-approach. In determining an initial level of care or a change to a different level of care, it is essential to consider together the overall physical condition, medical complications, disabilities, psychiatric comorbidity, psychology, behaviour, family, social resources, environment, and available services. We first created a review manuscript, a skeleton algorithm and two rating scales, based on the published guidelines and the existing research literature. As the second point we highlighted a number of clinical questions that had to be addressed in the specific context of our National Health Service and available specialized care units. Then we submitted eleven progressive revisions of the Document to the experts up to the final synthesis that was approved by the group. Of course, from point to point, some of the individual experts would differ with the consensus view. The document can be viewed as an expert consultation and the clinical judgement must always be tailored to the particular needs of each clinical situation. We will continue to revise the Document periodically based on new research information and on reassessment of expert opinion to keep it up-to-date. The Document was not financially sponsored. Source


Fabrizi C.,University of Rome La Sapienza
Journal of biological regulators and homeostatic agents | Year: 2011

Many studies demonstrated that human adult cardiac progenitor cells in the form of cardiospheres (CSps) could represent a powerful candidate for cardiac cell therapy. To achieve the clinical translation of this biotechnological product, the development of well-defined culture conditions is required to optimize their proliferation and differentiation. Thrombin, a serine protease acting through the protease-activated receptor 1 (PAR-1) signalling to modulate many cellular functions such as proliferation and differentiation in several cell types, is one of the factors included in the CSps medium. Therefore, the assessment of the effective dependence of the thrombin related cellular effects from PAR-signalling is strategic both for understanding the biological potential of these cells and for the GMP translation of the medium formulation, using synthesised analogs. In this study the effects of thrombin on human CSps and their potential relationship with the specific proteolytic activation of PAR-1 have been investigated in different culture conditions, including thrombin inhibitor hirudin and PAR-1 agonist/ antagonist peptides TFLLR and MUMB2. In this study we show that, in the presence of thrombin and TFLLR, CSps, in which PAR-1 expression was evidenced by immunofluorescence and western blot analysis, increase their proliferation activity (BrdU assay). Such increased proliferative rate was consistently associated with a higher phosphorylation level of the cell cycle inhibitor GSK3. Concerning the assessment of the potential effects of thrombin and its agonist on differentiation, both western blot and real-time PCR analysis for stemness, cardiac and vascular markers (such as cKit, cx43 and KDR) showed that CSps commitment was substantially unaffected, except for GATA4 mRNA, whose transcription was down-regulated in the presence of the natural protease, but not after treatment with TFLLR. In conclusion, activation of PAR-1-dependent signalling is important to support CSps proliferative potential, keeping unaltered or at best stable their differentiation properties. The availability of thrombin agonists, such as TFLLR, able to guarantee the required growth effect without affecting CSps lineage commitment, could represent a technological improvement for cost-effective, easy-to-handle and GMPtranslatable synthetic media. Source


Martelletti P.,University of Rome La Sapienza
Expert Opinion on Pharmacotherapy | Year: 2015

The therapeutic management of cluster headache is based on a very stable triad of drugs. Acute treatment has, in subcutaneous sumatriptan, its gold standard if compared to pure oxygen or indomethacin. Preventative treatment is based on verapamil at high doses (≥ 360 mg) and is a gold standard if compared to lithium carbonate or topiramate. Transitional treatments, based on the short-term use of corticosteroids with either systemic or local administration (GON), can be useful for the suppression of most resistant cluster periods, but with a well-known carry-over phenomenon related to the length of the cluster period itself. The role of invasive or noninvasive neuromodulation approaches must still be determined on a large scale; therefore, its use is not recommended as of yet. Lifestyle changes, including alcohol avoidance during the active phase of the disease, sleep hygiene and use of vasodilation drugs, should be carefully considered and the patients should be fully informed. © 2015 Informa UK, Ltd. Source


Bergshoeff E.A.,University of Groningen | Riccioni F.,University of Rome La Sapienza
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2011

We probe doubled geometry with dual fundamental branes, i.e. solitons. Restricting ourselves first to solitonic branes with more than two transverse directions we find that the doubled geometry requires an effective wrapping rule for the solitonic branes which is dual to the wrapping rule for fundamental branes. This dual wrapping rule can be understood by the presence of Kaluza-Klein monopoles. Extending our analysis to supersymmetric solitonic branes with less than or equal to two transverse directions we show that such solitons are precisely obtained by applying the same dual wrapping rule to these cases as well. This extended wrapping rule cannot be explained by the standard Kaluza-Klein monopole alone. Instead, it suggests the existence of a class of generalized Kaluza-Klein monopoles in ten-dimensional string theory. © 2011 Elsevier B.V. Source


Xue S.-S.,University of Rome La Sapienza
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2011

The recent OPERA measurement of high-energy neutrino velocity, once independently verified, implies new physics in the neutrino sector. We revisit the theoretical inconsistency of the fundamental high-energy cutoff attributing to quantum gravity with the parity-violating gauge symmetry of local quantum field theory describing neutrinos. This inconsistency suggests high-dimension operators of neutrino interactions. Based on these studies, we try to view the OPERA result, high-energy neutrino oscillations and indicate to observe the restoration of parity conservation by measuring the asymmetry of high-energy neutrinos colliding with left- and right-handed polarized electrons. © 2011 Elsevier B.V. Source


Cianfrani F.,University of Rome La Sapienza
Classical and Quantum Gravity | Year: 2011

In this work, it is demonstrated how the kinematical Hilbert space of loop quantum gravity (LQG) can be inferred from the configuration space of BF theories via the imposition of the Hamiltonian constraints. In particular, it is outlined how the projection to the representations associated with Ashtekar-Barbero connections provides the correct procedure to implement second-class constraints and the corresponding nontrivial induced symplectic structure. Then, the reduction to SU(2) invariant intertwiners is analyzed and the properties of LQG states under Lorentz transformations are discussed. © 2011 IOP Publishing Ltd. Source


Rosati R.,University of Rome La Sapienza
Journal of Computer and System Sciences | Year: 2011

In this paper we study queries over relational databases with integrity constraints (ICs). The main problem we analyze is OWA query answering, i.e., query answering over a database with ICs under open-world assumption. The kinds of ICs that we consider are inclusion dependencies and functional dependencies, in particular key dependencies; the query languages we consider are conjunctive queries and unions of conjunctive queries. We present results about the decidability of OWA query answering under ICs. In particular, we study OWA query answering both over finite databases and over unrestricted databases, and identify the cases in which such a problem is finitely controllable, i.e., when OWA query answering over finite databases coincides with OWA query answering over unrestricted databases. Moreover, we are able to easily turn the above results into new results about implication of ICs and query containment under ICs, due to the deep relationship between OWA query answering and these two classical problems in database theory. In particular, we close two long-standing open problems in query containment, since we prove finite controllability of containment of conjunctive queries both under arbitrary inclusion dependencies and under key and foreign key dependencies. The results of our investigation are very relevant in many research areas which have recently dealt with databases under an incomplete information assumption: e.g., data integration, data exchange, view-based information access, ontology-based information systems, and peer data management systems. © 2010 Elsevier Inc. All rights reserved. Source


Piazzo L.,University of Rome La Sapienza
IEEE Transactions on Vehicular Technology | Year: 2011

In an earlier paper, a simple and fast bit loading algorithm for orthogonal frequency-division-multiplex (OFDM) systems was presented. A drawback of the algorithm is that the solution obtained is suboptimal. This drawback is removed in this paper, where we show that the algorithm can be improved and turned into an optimal algorithm with a negligible impact on the computational complexity. © 2011 IEEE. Source


Brunori M.,University of Rome La Sapienza
Protein Science | Year: 2010

Over the last half century, myoglobin (Mb) has been an excellent model system to test a number of concepts, theories, and new experimental methods that proved valuable to investigate protein structure, function, evolution, and dynamics. Mb's function, most often considered just an oxygen repository, has considerably diversified over the last 15 years, especially because it was shown to have a role in the biochemistry of quenching and synthesizing nitric oxide in the red muscle, thereby protecting the cell. To tackle protein's structural dynamics by innovative biophysical methods, Mb has been the best prototype; laser flash technology made it possible to obtain molecular movies by time-resolved Laue crystallography (with ps resolution). This approach unveiled the complexity of the energy landscape and the structural basis of the stretched interconversion between conformational substates of a protein. © 2009 The Protein Society. Source


Corleto V.D.,University of Rome La Sapienza
Current Opinion in Endocrinology, Diabetes and Obesity | Year: 2010

PURPOSE OF REVIEW: Somatostatin influences motility, secretion, and absorption and often has in vivo a modulating, indirect effect on target cells in the gastrointestinal tract. Knowledge on tissue-specific expression of the five somatostatin receptors (SSTRs), their capacities for internalization and downregulation, their subtype-specific intracellular messengers, and the possibility of forming functionally distinct homodimers or heterodimers, has further complicated the actual in-vivo mechanism of action of somatostatin. This review reports recent in-vivo and in-vitro studies on somatostatin effects on the gastrointestinal tract and pancreas, most of them using a new engineered animal model able to define specific roles of somatostatin and/or its receptor subtypes. RECENT FINDINGS: SSTR2 knockout mice showed normal circulating gastrin and unchanged acid output, suggesting a high degree of plasticity behind gastric acid secretion. Intestinal inflammation significantly increased somatostatin mRNA in SSTR2 null compared to wild type suggesting that somatostatin mediates inflammation also in SSTR2 null mice. In pancreatic islets of SSTR1-5 null mice no variations of islet size, cellular organization or glucagon or insulin content was shown when compared with null SSTRs and control mice. SUMMARY: Although none of the recent findings produced on somatostatin seem ready to be considered for clinical application, recent developments of animal models such as SSTR knockout mice have highlighted promising results to better understand the direct and indirect effects of somatostatin on gastrointestinal tract functions. © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins. Source


Navarra M.A.,University of Rome La Sapienza
MRS Bulletin | Year: 2013

This article reports the search for nonflammable, stable electrolytes based on ionic liquid (IL) compounds, able to effectively improve the needed safety and reliability of lithium batteries. The most significant results are reviewed with the aim of elucidating critical aspects governing the properties of IL electrolytes, including (1) transport properties affecting ionic conductivity and the cycling rate of battery systems, (2) electrochemical/chemical stability toward most conventional electrode materials, and (3) thermal properties determining the range of applicability. Both liquid and polymer electrolytes, adopting ILs as the main component or as an additive to standard electrolyte solutions, are considered. Very promising results, in terms of battery prototype performances in scaled-up configurations, demonstrate the validity of the use of ILs for practical applications. Even though further improvements are necessary, particularly at high current density operations in both lithium-metal and lithium-ion systems, the realization of safer, high-performance batteries based on IL electrolytes is certainly possible. It can be concluded that ILs represent a viable solution to disappointing compromises between energy density and acceptable safety features in lithium batteries. © 2013 Materials Research Society. Source


Belyaev A.K.,University of Rome La Sapienza
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

The quantum reprojection method within the standard adiabatic Born-Oppenheimer approach is derived for multielectron collision systems. The method takes nonvanishing asymptotic nonadiabatic couplings into account and distinguishes asymptotic currents in molecular-state channels and in atomic-state channels. The method is demonstrated for the example of low-energy inelastic Li + Na collisions for which the conventional application of the standard adiabatic Born-Oppenheimer approach fails and leads to paradoxes such as infinite inelastic cross sections. © 2010 The American Physical Society. Source


Pirozzoli S.,University of Rome La Sapienza | Colonius T.,California Institute of Technology
Journal of Computational Physics | Year: 2013

We develop numerical boundary conditions for the compressible Navier-Stokes equations based on a generalized relaxation approach (GRCBC), which hinges on locally one-dimensional characteristic projection at the computational boundaries, supplemented with available information from the flow exterior. The basic idea is to estimate the amplitude of incoming characteristic waves through first-order one-sided finite-difference approximations which involve the value of the reference flow state at the first exterior (ghost) point. Unlike other characteristic-based relaxation methods, the present one requires minimal user-supplied input, including the reference flow state, which may be totally or partially known, and in general may vary both in space and time. Furthermore, it can be applied to any type of computational boundary, either inflow or outflow, either subsonic or supersonic. The method is theoretically predicted to convey reduced reflection of waves at computational boundaries compared to other ones, and to have better properties of frequency response to injected disturbances. Numerical tests confirm the improvement of the nonreflecting performance, and demonstrate high degree of flexibility, also for problems with non-trivial far-field boundary conditions (e.g. flows in rotating reference frames) and for the artificial stimulation of subsonic turbulent boundary layers. © 2013 Elsevier Inc. Source


DiNuzzo M.,Magnetic Resonance for Brain Investigation Laboratory | DiNuzzo M.,University of Rome La Sapienza
Journal of Cerebral Blood Flow and Metabolism | Year: 2013

A biophysical model of the glycogen molecule is developed, which takes into account the points of attack of synthase and phosphorylase at the level of the individual glucose chain. Under the sole assumption of steric effects governing enzyme accessibility to glucosyl residues, the model reproduces the known equilibrium structure of cellular glycogen at steady state. In particular, experimental data are reproduced assuming that synthase (1) operates preferentially on inner chains of the molecule and (2) exhibits a faster mobility than phosphorylase in translocating from an attacked chain to another. The model is then used to examine the turnover of outer versus inner tiers during the labeling process of isotopic enrichment (IE) experiments. Simulated data are fitted to in vivo 13 C nuclear magnetic resonance spectroscopy measurements obtained in the human brain under resting conditions. Within this experimental set-up, analysis of simulated label incorporation and retention shows that 7% to 35% of labeled glucose is lost from the rapidly turning-over surface of the glycogen molecule when stimulation onset is delayed by 7 to 11.5 hours after the end of 1-13 Cglucose infusion as done in actual procedures. The substantial label washout before stimulation suggests that much of the subsequent activation-induced glycogenolysis could remain undetected. Overall, these results show that the molecular structure significantly affects the patterns of synthesis and degradation of glycogen, which is relevant for appropriate design of labeling experiments aiming at investigating the functional roles of this glucose reserve. © 2013 ISCBFM All rights reserved. Source


Capuani S.,University of Rome La Sapienza
Microporous and Mesoporous Materials | Year: 2013

In this paper, by means of in vivo experiments, a porous system model suitable for investigating the structural properties of cancellous bone by using diffusion MRI techniques is described and corroborated. Toward this goal a cancellous bone model is described on the basis of some recent evidence obtained in both calf bone samples and human vertebrae. Then, the calcaneus and the femoral neck of healthy, osteopenic and osteoporotic subjects were investigating, as classified by the bone mineral density (BMD) parameter, by measuring the apparent diffusion coefficient (ADC), together with the marrow fat content (Mfc) and assessing associations between bone mineral-density index T-score, Mfc and ADC. MR spectroscopy (1H-MRS) and diffusion weighted imaging (DWI) with b-value = 2500 s/mm2 and b-value = 8000 s/mm2 to investigate femoral neck and calcaneus, respectively, were obtained in each subject using a 3T MR scanner. One-way ANOVA and Pearson correlation analyses were applied. ADC results as a function of Mfc and BMD obtained in calcaneus and femoral neck, seem to validate the cancellous bone model described in this paper. Although the MR results are still preliminary, and based on a small number (n = 60) of subjects, they suggest the ability of the ADC parameter to identify enhanced risk of osteoporosis. As a consequence, diffusion assessment in combination with 1H-MRS investigations obtained in large populations, might increase our pathophysiological understanding of osteoporosis and might also improve the diagnosis of osteoporosis. © 2013 Elsevier Inc. All rights reserved. Source


Mai A.,University of Rome La Sapienza
Epigenomics | Year: 2010

Suberoylanilide hydroxamic acid (vorinostat) was the first of the histone deacetylase inhibitors (HDACi) to be entered as therapy for the treatment of cutaneous T-cell lymphoma. Since then, a number of HDACi belonging to the short-chain fatty acid, hydroxamate, cyclic peptide or benzamide classes have been investigated in Phase II or III clinical trials (alone or in combination) for the treatment of many kinds of tumors. In addition, HDACi can be useful in antimalarial and antifungal therapies, and can reactivate HIV-1 expression in latent cellular reservoirs, thus suggesting that they could be used in combination with highly active antiretroviral therapy. Moreover, they have also proved their efficacy in neurodegenerative diseases, such as Huntingtons disease, Parkinsons disease and Friedreichs ataxia. In particular, a new series of bis-anilides demonstrating a peculiar mechanism of action displayed highly beneficial effects against Huntingtons disease and Friedreichs ataxia. In addition, a number of sirtuin inhibitors demonstrated antiproliferative effects in cell assays as well as in mouse tumor models, thus suggesting a role of such compounds in therapy against cancer. Furthermore, the SIRT2-selective AGK-2 has been reported to have protective effects against Parkinsons disease, and resveratrol and other sirtuin activators can be useful for the treatment of Alzheimers disease. © 2010 Future Medicine Ltd. Source


Bellelli A.,University of Rome La Sapienza
Current Protein and Peptide Science | Year: 2010

Cooperative interactions within biological macromolecules are of fundamental physiological relevance and have been studied in great detail. Yet, even in the best investigated case of oxygen binding by hemoglobin, our understanding of the structural and thermodynamic bases of cooperativity is far from satisfactory. Several theoretical models have been proposed to explain cooperative O2 binding to hemoglobin, among which the two-state model by Monod, Wyman and Changeux, has been the most successful and the most thoroughly tested. This model explains the functional properties of hemoglobin as resulting from the equilibrium of two quaternary conformations, named R and T, characterized by different ligand affinity, and is capable of very accurate (but not always exact) predictions. This review focuses on the experiments carried out to test the models of cooperativity, and especially the two-state model, and identifies two major deviations, or groups of deviations, between the predictions of this model and the actual experimental results, namely (i) the changes in the behaviour of the T- and R-state due to solvent components; (ii) the appearance of R-like reactivity under experimental conditions in which the T-state should be largely prevalent. Modern models of cooperativity, devised to account for these discrepancies while maintaining the basic two-state hypothesis of Monod, Wyman and Changeux, are also reviewed. © 2010 Bentham Science Publishers Ltd. Source


De Divitiis N.,University of Rome La Sapienza
Theoretical and Computational Fluid Dynamics | Year: 2011

The present work studies the isotropic and homogeneous turbulence for incompressible fluids through a specific Lyapunov analysis. The analysis consists in the calculation of the velocity fluctuation through the Lyapunov theory applied to the local deformation using the Navier-Stokes equations, and in the study of the mechanism of energy cascade through the finite scale Lyapunov analysis of the relative motion between two particles. The analysis provides an explanation for the mechanism of energy cascade, leads to the closure of the von Kármán-Howarth equation, and describes the statistics of the velocity difference. Several tests and numerical results are presented. © 2010 Springer-Verlag. Source


Gornung E.,University of Rome La Sapienza
Cytogenetic and Genome Research | Year: 2013

Molecular cytogenetic data on the number and position of 45S ribosomal RNA genes (rDNA; located in nucleolus organizing regions, NORs) detected by FISH in 330 species of 77 families and 22 orders of bony fishes (Teleostei) and, additionally, 11 species of basal ray-finned fishes are compiled and analyzed. The portion of species with single rDNA sites in the sample amounts to 72%. The percentage of species with multiple NORs decreases with increasing numbers of rDNA loci per genome, i.e. scarcely 3% of species carry 4 or more rDNA-bearing chromosome pairs. 43% of all rDNA sites analyzed occur terminally on the short arms of chromosomes or constitute them. In general, terminal rDNA sites account for 87% of all examined cases. Interspecific variation in the location of single rDNA sites among related taxa, polymorphisms of multiple NORs in some groups of teleosts and analytical outcomes on the subject are reviewed. © 2013 S. Karger AG, Basel. Source


Salvadore F.,CASPUR | Bernardini M.,University of Rome La Sapienza | Botti M.,CASPUR
Journal of Computational Physics | Year: 2013

Graphical processing units (GPUs), characterized by significant computing performance, are nowadays very appealing for the solution of computationally demanding tasks in a wide variety of scientific applications. However, to run on GPUs, existing codes need to be ported and optimized, a procedure which is not yet standardized and may require non trivial efforts, even to high-performance computing specialists. In the present paper we accurately describe the porting to CUDA (Compute Unified Device Architecture) of a finite-difference compressible Navier-Stokes solver, suitable for direct numerical simulation (DNS) of turbulent flows. Porting and validation processes are illustrated in detail, with emphasis on computational strategies and techniques that can be applied to overcome typical bottlenecks arising from the porting of common computational fluid dynamics solvers. We demonstrate that a careful optimization work is crucial to get the highest performance from GPU accelerators. The results show that the overall speedup of one NVIDIA Tesla S2070 GPU is approximately 22 compared with one AMD Opteron 2352 Barcelona chip and 11 compared with one Intel Xeon X5650 Westmere core. The potential of GPU devices in the simulation of unsteady three-dimensional turbulent flows is proved by performing a DNS of a spatially evolving compressible mixing layer. © 2012 Elsevier Inc. Source


Imperi F.,University of Rome La Sapienza | Visca P.,Third University of Rome
FEBS Letters | Year: 2013

The peptidic siderophore pyoverdine is the primary iron uptake system of fluorescent pseudomonads, and a virulence factor in the opportunistic pathogen Pseudomonas aeruginosa. Pyoverdine biogenesis is a co-ordinate process requiring several precursor-generating enzymes and large nonribosomal peptide synthetases (NRPSs) in the cytoplasm, followed by extracytoplasmic maturation. By using cell fractionation, protein-protein interaction, and in vivo labeling assays we obtained evidence that, in P. aeruginosa, pyoverdine NRPSs assemble with precursor-generating enzymes into a membrane-bound multi-enzymatic complex, for which we propose the name "siderosome". The pyoverdine biogenetic complex represents a novel example of subcellular compartmentalization of a secondary metabolic pathway in prokaryotes. © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved. Source


Coccia E.,University of LAquila | Varsano D.,University of Rome La Sapienza | Guidoni L.,University of LAquila
Journal of Chemical Theory and Computation | Year: 2013

The accurate determination of the geometrical details of the dark state of 11-cis retinal in rhodopsin represents a fundamental step for the rationalization of the protein role in the optical spectral tuning in the vision mechanism. We have calculated geometries of the full retinal protonated Schiff base chromophore in the gas phase and in the protein environment using the correlated variational Monte Carlo method. The bond length alternation of the conjugated carbon chain of the chromophore in the gas phase shows a significant reduction when moving from the β-ionone ring to the nitrogen, whereas, as expected, the protein environment reduces the electronic conjugation. The proposed dark state structure is fully compatible with solid-state NMR data reported by Carravetta et al. [J. Am. Chem. Soc. 2004, 126, 3948-3953]. TDDFT/B3LYP calculations on such geometries show a blue opsin shift of 0.28 and 0.24 eV induced by the protein for S1 and S2 states, consistently with literature spectroscopic data. The effect of the geometrical distortion alone is a red shift of 0.21 and 0.16 eV with respect to the optimized gas phase chromophore. Our results open new perspectives for the study of the properties of chromophores in their biological environment using correlated methods. © 2012 American Chemical Society. Source


De Giacomo G.,University of Rome La Sapienza | Vardi M.Y.,Rice University
IJCAI International Joint Conference on Artificial Intelligence | Year: 2013

In this paper we look into the assumption of interpreting LTL over finite traces. In particular we show that LTLf, i.e., LTL under this assumption, is less expressive than what might appear at first sight, and that at essentially no computational cost one can make a significant increase in expressiveness while maintaining the same intuitiveness of LTLf. Indeed, we propose a logic, LDLf for Linear Dynamic Logic over finite traces, which borrows the syntax from Propositional Dynamic Logic (PDL), but is interpreted over finite traces. Satisfiability, validity and logical implication (as well as model checking) for LDLf are PSPACE-complete as for LTLf (and LTL). Source


Khalili M.A.,University of Rome La Sapienza
European journal of histochemistry : EJH | Year: 2012

Since the introduction of human assisted reproduction, oocyte cryopreservation has been regarded as an attractive option to capitalize the reproductive potential of surplus oocytes and preserve female fertility. However, for two decades the endeavor to store oocytes has been limited by the not yet optimized methodologies, with the consequence of poor clinical outcome or of uncertain reproducibility. Vitrification has been developed as the promising technology of cryopreservation even if slow freezing remains a suitable choice. Nevertheless, the insufficiency of clinical and correlated multidisciplinary data is still stirring controversy on the impact of this technique on oocyte integrity. Morphological studies may actually provide a great insight in this debate. Phase contrast microscopy and other light microscopy techniques, including cytochemistry, provided substantial morphofunctional data on cryopreserved oocyte, but are unable to unraveling fine structural changes. The ultrastructural damage is one of the most adverse events associated with cryopreservation, as an effect of cryo-protectant toxicity, ice crystal formation and osmotic stress. Surprisingly, transmission electron microscopy has attracted only limited attention in the field of cryopreservation. In this review, the subcellular structure of human mature oocytes following vitrification is discussed at the light of most relevant ultrastructural studies. Source


Benvenuti L.,University of Rome La Sapienza
Systems and Control Letters | Year: 2011

In this paper, we study the geometrical properties of the set of reachable states of a single input third-order discrete-time linear system with positive controls. This set is a cone and we give a complete geometrical characterization of this set when the system has a complex conjugate pair of eigenvalues. More in detail, we give necessary and sufficient conditions for properness and polyhedrality of the cone and provide the number of its edges in terms of eigenvalue locations. © 2011 Elsevier B.V. All rights reserved. Source


Breccia M.,University of Rome La Sapienza | Lo-Coco F.,University of Rome Tor Vergata
Expert Opinion on Pharmacotherapy | Year: 2012

Introduction: Acute promyelocytic leukemia (APL), the most rapidly fatal leukemia only two decades ago, has been converted into the most frequently curable leukemia by the advent of all-trans retinoic acid (ATRA) and its combination with anthracycline-based chemotherapy. More recently, arsenic trioxide (ATO) has been shown to be the most effective single agent in this disease and has been approved for the treatment of relapsed patients both in the United States and Europe. Moreover, ATO has been included in the design of several front-line studies, with the aim to reduce therapy-related toxicity while maintaining the potential of cure. Areas covered: First, this review briefly discusses the mechanisms of action and the toxicity profile of ATO. Furthermore, the reported experience on the use of ATO as single agent or in combinatorial schemes both in relapsed and in newly diagnosed patients with APL is critically reviewed. Finally, the use of this agent in special subsets of patients unfit to receive conventional chemotherapy is discussed, along with its potential role in maintenance therapy. Expert opinion: While the role of ATO as single agent or in combination with ATRA is well established and recommended by the European LeukemiaNet guidelines as a first option for relapsed patients, the role of the drug in newly diagnosed patients is still uncertain and based only on evidence levels mostly originating from non-randomized trials. The results of ongoing randomized studies should better define the role of ATO in front-line therapy. © 2012 Informa UK, Ltd. Source


Brosens I.,Leuven Institute for Fertility and Embryology | Brosens J.,Clinical Research Laboratories | Benagiano G.,University of Rome La Sapienza
Human Reproduction | Year: 2013

We elaborate on a new theory to explain pelvic endometriosis, including endometriosis in premenarcheal girls, based on the finding that the neonatal endometrium can display secretory activity immediately after birth and, in some cases, changes analogous to those seen at menstruation in adults. The neonatal uterus is therefore capable of shedding its endometrium. Indeed, occult vaginal bleeding occurs in a majority of neonates, although overt bleeding is estimated to occur in only 5% of neonates. This may be due to functional plugging of the endocervical canal in the neonate, which in turn would promote retrograde flux of endometrial cells contained in menstrual debris. Ectopic endometrial implantation in a newborn with hydrometrocolpos has been documented. These data, coupled with the observation of a significantly increased risk of endometriosis in adolescents with cervical outflow obstruction and patent Fallopian tubes, indicate that endometriosis, especially in children and young adolescents, may originate from retrograde uterine bleeding soon after birth. © 2013 © The Author 2013. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com. Source


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

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


Borra S.,University of Rome Tor Vergata | Di Ciaccio A.,University of Rome La Sapienza
Computational Statistics and Data Analysis | Year: 2010

The estimators most widely used to evaluate the prediction error of a non-linear regression model are examined. An extensive simulation approach allowed the comparison of the performance of these estimators for different non-parametric methods, and with varying signal-to-noise ratio and sample size. Estimators based on resampling methods such as Leave-one-out, parametric and non-parametric Bootstrap, as well as repeated Cross Validation methods and Hold-out, were considered. The methods used are Regression Trees, Projection Pursuit Regression and Neural Networks. The repeated-corrected 10-fold Cross-Validation estimator and the Parametric Bootstrap estimator obtained the best performance in the simulations. © 2010 Elsevier B.V. All rights reserved. Source


Marietti M.,University of Rome La Sapienza
European Journal of Combinatorics | Year: 2010

The parabolic analogue of the Kazhdan-Lusztig and R-polynomials has been introduced by Deodhar [V. Deodhar, On some geometric aspects of Bruhat orderings. II. The parabolic analogue of Kazhdan-Lusztig polynomials, J. Algebra 111 (1987) 483-506]. Answering a question of Brenti, we give closed combinatorial product formulae for the parabolic R-polynomials and for the parabolic Kazhdan-Lusztig polynomials of type q in the case where the indexing permutations are smaller than the top transposition in Bruhat order. These formulae are valid in complete generality on the parabolic subgroup WJ. © 2009 Elsevier Ltd. All rights reserved. Source


The matrix metalloproteinase (MMP) family has been shown to play a critical role in tissue remodeling and tumor infiltration. Their activity is normally strictly controlled by tissue inhibitors of metalloproteinases (TIMPs). However, TIMPs act indirectly through modulation of protease activity or directly through cell surface receptors to direct cell fate. These molecules have been proposed as markers of malignant cancer. Previous studies on MMP and TIMP expression in kidney carcinoma have been limited and have reported variable observations. The current study measured the content of MMP-2 and -9 and TIMP-1 and -2 in the sera and urine of patients with kidney carcinoma by enzyme-linked immunosorbent assay. Of these patients, 16 exhibited clear cell renal cell carcinoma (ccRCC) and 4 exhibited oncocytoma. Sera and urine samples of 53 healthy subjects were used as controls. In the sera of the control group, MMP-2 and TIMP-2 were detectable in all samples, while MMP-9 and TIMP-1 were below the sensitivity of the assay. In the pathological specimens, the mean serum values of MMP-2 and TIMP-1 and -2 were similar in the ccRCC and oncocytoma patients, whereas the value for MMP-9 was 2-fold higher in the ccRCC patients compared with the oncocytoma patients. With regard to the urine specimens, all four molecules were undetectable in the normal healthy samples and in a few pathological samples. The mean values for MMP-2 and -9 and TIMP-2 in the positive urine specimens were similar in the ccRCC and oncocytoma patients, whereas the mean value of TIMP-1 was higher in the ccRCC patients compared with that of the oncocytoma patients. The mean urinary levels of the four molecules were less than those of the sera. Statistical analysis of the data did not reveal any correlation between the tumor grades and expression levels of the molecules examined. Source


Bruzzese C.,University of Rome La Sapienza | Joksimovic G.,University of Montenegro
IEEE Transactions on Industrial Electronics | Year: 2011

This paper shows that a static eccentricity makes rise a double fundamental frequency ripple in the rotor current of salient-pole synchronous machines. This ripple leads, under conditions ruled by the stator windings, to precise signatures in the no-load voltage spectrum. Both rotor current ripple and voltage harmonics can be used for diagnosis. The fault-related voltage harmonics are theoretically previewed in this paper through analysis of the windings. Simulations performed by using the winding function approach confirm the theoretical predictions. A four-pole 15-kVA generator was used for experiments, featuring an innovative flange with exact and easy regulation of mixed-type eccentricities. Rotor current monitoring has advantages of single-sensor measure and accentuate fault sensitivity. Experiments also showed an additional rotor-rotation frequency ripple in the rotor current, in case of mixed-type fault. © 2010 IEEE. Source


Biagi M.,University of Rome La Sapienza
IEEE Communications Letters | Year: 2011

Power Line Communications (PLCs) enable new and highly convenient networking functions in the framework of Smart-Grids and use an already built-in network. A Multiple Input Multiple Output (MIMO) architecture can strongly improve the PLC performances and links' reliability. In this contribution the effect of self-interference generated by relay nodes has been considered and the MIMO potentials for spatial multiplexing and interference suppression have been taken into account. The importance of channel knowledge has been also considered from a numerical result point of view in order to give some instruments for network planning. © 2011 IEEE. Source


Amelino-Camelia G.,University of Rome La Sapienza
Symmetry | Year: 2010

I report, emphasizing some key open issues and some aspects that are particularly relevant for phenomenology, on the status of the development of "doubly-special" relativistic ("DSR") theories with both an observer-independent high-velocity scale and an observer-independent small-length/large-momentum scale, possibly relevant for the Planck-scale/quantum-gravity realm. I also give a true/false characterization of the structure of these theories. In particular, I discuss a DSR scenario without modification of the energy-momentum dispersion relation and without the (-Poincaré Hopf algebra, a scenario with deformed Poincaré symmetries which is not a DSR scenario, some scenarios with both an invariant length scale and an invariant velocity scale which are not DSR scenarios, and a DSR scenario in which it is easy to verify that some observable relativistic (but non-special-relativistic) features are insensitive to possible nonlinear redefinitions of symmetry generators. © 2010 by the author. Source


Benvenuti L.,University of Rome La Sapienza
Systems and Control Letters | Year: 2011

In this paper we study the geometrical properties of the set of reachable states of a single-input third-order discrete-time linear system with positive controls. This set is a cone and we give a complete geometrical characterization of this set when the system has all real eigenvalues. More in detail, we give necessary and sufficient conditions for properness and polyhedrality of the cone and provide the number of its edges in terms of eigenvalue locations. Moreover, we provide necessary and sufficient conditions for finite time reachability of every reachable state and characterize the minimum number of steps needed to reach every state in terms of eigenvalue locations. © 2011 Elsevier B.V. All rights reserved. Source


Folli V.,University of Rome La Sapienza | Folli V.,CNR Institute of Neuroscience | Conti C.,CNR Institute of Neuroscience
Physical Review Letters | Year: 2010

We investigate the evolution of solitary waves in a nonlocal medium in the presence of disorder. By using a perturbational approach, we show that an increasing degree of nonlocality may largely hamper the Brownian motion of self-trapped wave packets. The result is valid for any kind of nonlocality and in the presence of nonparaxial effects. Analytical predictions are compared with numerical simulations based on stochastic partial differential equations. © 2010 The American Physical Society. Source


Di Santo R.,University of Rome La Sapienza
Natural Product Reports | Year: 2010

Fungi have emerged worldwide as increasingly frequent causes of healthcare-associated infections, but fungal infections have generally been considered curable, and thus the demand for new antifungal agents has been very low. Although superficial fungal infections of the skin and nails are common and are for the most part treated successfully with existing antifungal agents, serious fungal infections are becoming a growing danger for human health. This is particularly true for AIDS patients, but also for recipients of transplants, and users of antineoplastic agents, corticoids, and even antibiotics. A major problem is the increasing emergence of resistance to antimycotic agents, and since azoles-the most used class of antifungals-suffer a significant incidence of resistance, new efforts are now devoted to the discovery of new agents with different mechanisms of action. Not so long ago, combinatorial chemistry appeared to be the future for drug discovery, but in the late 1990s synthetic chemists realized that combinatorial libraries lacked the "complexity" usually associated with natural compounds. Research into biologically active natural products has thus had a reprise, in particular with the advent of the concept of diversity-oriented synthesis. This review reports what is so far known about natural products as antifungal agents, and provides an overview of natural compounds with both known and unknown mechanisms of action. © 2010 The Royal Society of Chemistry. Source


Cantisani V.,University of Rome La Sapienza
European review for medical and pharmacological sciences | Year: 2013

Adrenal pseudocysts are rare cystic masses that arise from the adrenal gland and which are usually non-functional and asymptomatic. We report a rare case of a giant hemorrhagic adrenal pseudocyst presenting with abdominal pain and we discussed the radiological features. A 75 year old man was admitted with acute abdominal pain post mild-trauma. Computed tomography (CT) of abdomen revealed a hemorrhagic mass measuring 18 cm located in the right suprarenal region, displacing the right kidney and liver. He subsequently underwent to contrast enhancement ultrasound (CEUS), which showed features suggestive for hemorrhagic adrenal pseudocyst. A complete endocrine working didn't show any hormonal hypersecretion. The patient underwent laparotomy and right adrenal mass was excised. Histological examination revealed giant hemorrhagic adrenal pseudocyst. The abdominal pain resolved after surgery. to the best our knowledge, this is the first case studied with CEUS reported in the literature. Source


Quevedo H.,University of Rome La Sapienza
General Relativity and Gravitation | Year: 2011

We present the Ernst potential and the line element of an exact solution of Einstein's vacuum field equations that contains as arbitrary parameters the total mass, the angular momentum, and the quadrupole moment of a rotating mass distribution. We show that in the limiting case of slowly rotating and slightly deformed configuration, there exists a coordinate transformation that relates the exact solution with the approximate Hartle solution. It is shown that this approximate solution can be smoothly matched with an interior perfect fluid solution with physically reasonable properties. This opens the possibility of considering the quadrupole moment as an additional physical degree of freedom that could be used to search for a realistic exact solution, representing both the interior and exterior gravitational field generated by a self-gravitating axisymmetric distribution of mass of perfect fluid in stationary rotation. © 2010 Springer Science+Business Media, LLC. Source


Monaco S.,University of Rome La Sapienza | Normand-Cyrot D.,Supelec
Systems and Control Letters | Year: 2011

A novel notion of average passivity is proposed. On this basis, Passivity Based ControllersPBCsuch as the discrete-time versions of the well-known continuous-time negative output feedback and LgV controllers, are introduced and discussed. © 2011 Elsevier B.V. All rights reserved. Source


Romano M.,University of Rome La Sapienza
Earth-Science Reviews | Year: 2015

Uniformitarianism is a classical term of the geological sciences, coined in 1832 by Whewell to indicate a specific part of Lyell's hypothesis. However, over the years uniformitarianism has been used with different meanings, finally becoming synonymous with the entire theoretical system proposed by Lyell in his Principles. The popularity of this term and its frequently kaleidoscopic usage in the literature may be due in large part to the apparent simplicity of the "principle" of uniformitarianism. This is often summarized by the classical adage "the present is the key to the past", a reductionist motto that has been passed through many generations of Earth scientists. In the text that follows, the major revisions of the term by Gould, Mayr and Rudwick are discussed in detail. These revisions are used as solid epistemological basis for understanding the countless "shades of meaning" attributed to the term over time, and the main reasons that led to the overgrowth of a semantic chaos; one that poorly fits a modern scientific discipline. Apart from the "invariance of natural laws" in space and time (the basic assumptions made in all scientific disciplines), all remaining "principles" historically related to, or imbedded within uniformitarianism, have been definitively falsified. Even the "Uniformity of process", which is essentially coincident with the term "actualism", can be applied only to certain categories of products and processes (or to some particular stages in the evolution of our planet). In many cases, an extension of a current process to the past and vice versa is not warranted, in view of the crucial importance played by "configurational causes" during the evolution of our planet. On the whole the analysis carried out highlights a real need to reconsider and investigate the epistemological underpinning of the Earth sciences, with one main effort aimed at solid preparation of young geologists, beginning with the basic courses of university education. © 2015 Elsevier B.V. Source


Calogero F.,University of Rome La Sapienza
Journal of Nonlinear Mathematical Physics | Year: 2010

Two new solvable dynamical systems of goldfish type are identified, as well as their isochronous variants. The equilibrium configurations of these isochronous variants are simply related to the zeros of appropriate Laguerre and Jacobi polynomials. © 2010 The Author(s). Source


The paper presents three examples of a solution of a simple multi-variable optimization problem: the "optimal configuration" of a branch of a pipe of circular cross-section with a given initial radius r0 and delivering a given mass flow rate m0. Three cases, two presented in previous papers and a novel one, are used to illustrate two theses: first, that for a given design "task", the configurations (shapes) displaying the minimal entropy generation are compatible with the shapes observed in nature; second, that an EGM analysis not only leads to the identification of a thermodynamically optimal solution, but offers substantial additional insight into the flow characteristics even in simple -but realistic- cases as the ones discussed here, for which an analytical solution to the Navier Stokes equations exists. The entropy generation rate is due-in all three examples- only to viscous flow effects within the tubes, and several simplifying assumptions are made to reduce the problem to a multi-variable optimization in 2 (for the tube with wall suction) or 3 (for the branchings) independent variables: the aspect ratio of the domain served by the flow, the diameter ratio of the primary and secondary branches, and the length of the secondary branch (the location of both the "source" of the fluid and the "sink", i.e. the place of desired delivery of the fluid, being a datum). It is shown that the solution is strongly dependent both on the aspect ratio and on the diameter ratio, and in the case of wall suction, to the wall porosity. The study is divided in two parts: the analysis presented in this first paper is useful from a theoretical point of view, because it sheds some light on the phenomenology of the configurations studied here. The final purpose is twofold: the a priori identification of more efficient geometries for the channels of heat exchangers and flow devices through a preliminary EGM analysis, and a better understanding of the teleology of some of the structures observed in nature. The present study and its conclusions are still preliminary, but since the procedure can be easily "falsified", and all numerical experiments on more complex flow geometries to date do not disprove the present findings, it is indeed a topic that warrants further investigation. Source


Cavallini M.,University of Rome La Sapienza
Applied Physics A: Materials Science and Processing | Year: 2013

Thermodynamics allows us to understand the chemical reactions occurring inside an experimental archaeometallurgical shaft furnace for iron smelting. The production of an iron bloom, with the so-called direct process, is described in a daily pyrometallurgical cycle. The experiences suggest that, as higher and better blown furnaces were built for improving the production, different reactions have been involved and a new material, pig iron, has been obtained © 2013 Springer-Verlag Berlin Heidelberg. Source


The search for the true nature and origin of fossils gave rise, starting about the beginning of the sixteenth century and throughout the seventeenth century, to a heated debate between the supporters of the inorganic nature of these objects and proponents of an interpretation of fossils as ex-vivi. Among the latter, a key figure is the Italian painter Agostino Scilla (1629-1700), who represents one of the first naturalists who was able to accumulate substantial evidence to support the interpretation of fossils as once-living marine organisms. The world view of Scilla and his real contribution to paleontology are here analysed and contextualised, taking into account the state of knowledge characterising the time of his activities. Scilla was not only a pioneer in the field of paleontology, but he prepared the groundwork for the achievement of milestone geological concepts such as actualism, taphonomy and recognition of internal and external moulds (in the instance of non-representation of original hard parts); Scilla deserves further recognition as one of the first to attempt sedimentological interpretation of rocky bodies observed directly in the field. © 2013 © 2013 Taylor & Francis. Source


Benagiano G.,University of Rome La Sapienza | Brosens I.,Leuven Institute for Fertility and Embryology
Fertility and Sterility | Year: 2011

Although uterine adenomyoma and endometriosis were described around the turn of the 19th century, the history of the identification of endometriosis has remained controversial and continues to confuse recent literature affecting the management of the disease. Using histologic parameters of endometrial structure and activity, the first scientist to identify the condition, under the name "adenomyoma," was Thomas Cullen. John Sampson was the first to identify the pathogenesis of the condition. © 2011 American Society for Reproductive Medicine, Published by Elsevier Inc. Source


Evaluating the prevalence and the degree of steatosis in geriatric patients (65 to 85 years of age) with Metabolic Syndrome (defined by ATP III criteria); searching for metabolic factors which are predictive for the degree of steatosis; evaluating the efficacy of Ursodeoxycholic Acid (UDCA) for 6 months in the treatment of patients with NAFLD or NASH. We studied 87 geriatric patients with Metabolic Syndrome. Steatosis was diagnosed and graded by laboratory assessment and ultrasonography, method based on the determination of liver/kidney ratio through grey-scale intensity, which was calculated as an index of the severity of the steatosis: it could oscilates from 0 (none) to 3 (severe). We randomized the geriatric patients into two groups: Ursodeoxycholic Acid (UDCA)-treated group (n=43 pz) and diet-treated group (1200 Kcal/die for female, 1500 Kcal/die for male) (n=44 pz), for a period of 6 months. BMI, principal symptoms, liver function, blood lipids, ultrasonography liver were evaluated respectively before and after treatment. The prevalence of steatosis was 100% (26 mild steatosis cases, 38 moderate cases and 23 severe cases) in our patients with Metabolic Syndrome. Of the 43 subjects assigned to receive 300-450 mg/d of UDCA and diet, the hepatic steatosis index decreased on the average, of the 75%. Serum AST, ALT and γ-GT decreased significantly at 3 months already (p<0.001). UDCA improves liver enzymes and ultrasonography immaging in geriatric patients with NAFLD or NASH. Unexpectedly, UDCA has resulted in beneficial effects on glycemic control and insulin sensitivity. Source


Sciortino F.,University of Rome La Sapienza | Saika-Voivod I.,Memorial University of Newfoundland | Poole P.H.,St. Francis Xavier University
Physical Chemistry Chemical Physics | Year: 2011

We perform successive umbrella sampling grand canonical Monte Carlo computer simulations of the original ST2 model of water in the vicinity of the proposed liquid-liquid critical point, at temperatures above and below the critical temperature. Our results support the previous work of Y. Liu, A. Z. Panagiotopoulos and P. G. Debenedetti [J. Chem. Phys., 2009, 131, 104508], who provided evidence for the existence and location of the critical point for ST2 using the Ewald method to evaluate the long-range forces. Our results therefore demonstrate the robustness of the evidence for critical behavior with respect to the treatment of the electrostatic interactions. In addition, we verify that the liquid is equilibrated at all densities on the Monte Carlo time scale of our simulations, and also that there is no indication of crystal formation during our runs. These findings demonstrate that the processes of liquid-state relaxation and crystal nucleation are well separated in time. Therefore, the bimodal shape of the density of states, and hence the critical point itself, is a purely liquid-state phenomenon that is distinct from the crystal-liquid transition. © the Owner Societies 2011. Source


Angelaccio S.,University of Rome La Sapienza
BioMed research international | Year: 2013

Recent advances in molecular and structural biology have improved the availability of virtually any biocatalyst in large quantity and have also provided an insight into the detailed structure-function relationships of many of them. These results allowed the rational exploitation of biocatalysts for use in organic synthesis. In this context, extremophilic enzymes are extensively studied for their potential interest for many biotechnological and industrial applications, as they offer increased rates of reactions, higher substrate solubility, and/or longer enzyme half-lives at the conditions of industrial processes. Serine hydroxymethyltransferase (SHMT), for its ubiquitous nature, represents a suitable model for analyzing enzyme adaptation to extreme environments. In fact, many SHMT sequences from Eukarya, Eubacteria and Archaea are available in data banks as well as several crystal structures. In addition, SHMT is structurally conserved because of its critical metabolic role; consequently, very few structural changes have occurred during evolution. Our research group analyzed the molecular basis of SHMT adaptation to high and low temperatures, using experimental and comparative in silico approaches. These structural and functional studies of SHMTs purified from extremophilic organisms can help to understand the peculiarities of the enzyme activity at extreme temperatures, indicating possible strategies for rational enzyme engineering. Source


Restivo A.,University of Rome La Sapienza
Anatomical record (Hoboken, N.J. : 2007) | Year: 2013

This study concerns the morphological differentiation between double outlet right ventricle (DORV) and aortic dextroposition (AD) defects, namely tetralogy of Fallot and Eisenmenger anomaly. Indeed, despite the similar condition in terms of sequential ventriculo-arterial connections, DORV and AD are two distinct morphological entities. It is proposed that the borderline between these two groups of malformations is represented by the specific insertion of the infundibular septum into the left anterior cranial division of the septomarginal trabeculation (or septal band) occurring in ADs and lacking in DORV. Furthermore, the spiraliform versus straight parallel arrangement of the great arteries in the two groups of anomalies is emphasized as an additional and distinctive morphological feature. Emphasis is also given to the association of straight parallel great arteries conotruncal malformations, DORV and transposition of the great arteries, with the asplenia type of heterotaxy laterality defects. Within this context, the absence of subaortic ventricular septal defect and concomitantly of spiraliform great arteries in the asplenia group of heterotaxy anomalies, as detected by this study, further substantiates our belief of not mixing collectively the ADs with the DORV in clinico-pathological diagnosis. Copyright © 2013 Wiley Periodicals, Inc. Source


Corcione M.,University of Rome La Sapienza
Heat Transfer Engineering | Year: 2012

A semi-empirical model for predicting the effective dynamic viscosity of nanofluids, based on a single set of experimental data available in the literature for silica nanoparticles suspended into ethanol, is presented and discussed. The equation, which includes the overall effects of the friction at the solid-liquid interface, the nanoparticle colloidal interactions, and the formation of aggregates, expresses the ratio between the effective dynamic viscosity of the suspension and the dynamic viscosity of the pure base liquid as a function of the nanoparticle size and concentration. The predicted results are in rather good agreement with a wide variety of data relative to nanofluids consisting of several combinations of solid and liquid phases, extracted from different sources. The accuracy and ease of application of the proposed equation make it interesting from the engineering point of view, for both numerical simulation purposes and thermal design tasks. © 2012 Copyright Taylor and Francis Group, LLC. Source


Castori M.,University of Rome La Sapienza
Molecular Syndromology | Year: 2013

Maternal diabetes mellitus is one of the strongest human teratogens. Despite recent advances in the fields of clinical embryology, experimental teratology and preventive medicine, diabetes-related perturbations of the maternofetal unit maintain a considerable impact on the Healthcare System. Classic consequences of prenatal exposure to hyperglycemia encompass (early) spontaneous abortions, perinatal death and malformations. The spectrum of related malformations comprises some recurrent blastogenic monotopic patterns, i.e. holoprosencephaly, caudal dysgenesis and oculoauriculovertebral spectrum, as well as pleiotropic syndromes, i.e. femoral hypoplasia-unusual face syndrome. Despite this, most malformed fetuses display multiple blastogenic defects of the VACTERL type, whose (apparently) casual combination preclude recognizing recurrent patterns, but accurately testifies to their developmental stage at onset. With the application of developmental biology in modern medicine, the effects of diabetes on the unborn patient are expanded to include the predisposition to develop insulin resistance in adulthood. The mechanisms underlying the transgenerational correlation between maternal diabetes and proneness to adult disorders in the offspring remain unclear, and the epigenetic plasticity may represent the missing link. In this scenario, a development-driven summary of the multifaced consequences of maternal diabetes on fertility and child health may add a practical resource to the repertoire of available information on early stages of embryogenesis. © 2012 S. Karger AG, Basel. Source


De Divitiis N.,University of Rome La Sapienza
Theoretical and Computational Fluid Dynamics | Year: 2012

In this work, we calculate the self-similar longitudinal velocity correlation function and the statistics of the velocity difference, using the results of the Lyapunov analysis of the fully developed isotropic homogeneous turbulence just presented by the author in a previous work (de Divitiis, Theor Comput Fluid Dyn, doi:10.1007/s00162-010-0211-9). There, a closure of the von Kármán-Howarth equation is proposed and the statistics of velocity difference is determined through a specific statistical analysis of the Fourier-transformed Navier-Stokes equations. The longitudinal correlation functions correspond to steady-state solutions of the von Kármán- Howarth equation under the self-similarity hypothesis introduced by von Kármán. These solutions and the corresponding statistics of the velocity difference are numerically determined for different Taylorscale Reynolds numbers. The obtained results adequately describe the several properties of the fully developed isotropic turbulence. © The Author(s) 2011. Source


Tomei G.,University of Rome La Sapienza
Annali di igiene : medicina preventiva e di comunità | Year: 2012

The purpose of this study is to evaluate, using a questionnaire developed by our research group, whether occupational exposure to physical, chemical and psychosocial urban stressors can lead to alterations in perceived stress in a group of both male and female outdoor workers. The study also examines possible correlations between the levels of stress as inferred from the scores of the questionnaire and the levels of certain stress-related parameters (prolactin levels, consumption of coffee, chocolate, alcohol and cigarette smoking). We evaluated a final sample of 480 subjects (342 male and 138 female). All workers included in the study were divided into three groups on the basis of scores of the questionnaire. About 60% of workers showed a moderate or severe stress condition, with a statistically significant prevalence of female workers and younger subjects. There was a statistically significant correlation between the questionnaire score and the mean levels of stress-related parameters. The increase of perceived stress increases significantly the mean levels of prolactin and the consumption of coffee, chocolate and cigarettes. There was no statistically significant differences for alcohol consumption. The results show that exposure to chemical physical and psycho-social urban stressors can influence perceived stress in outdoor workers. The questionnaire used in our research could be an useful instruments for physicians during the health surveillance visits Source


Iuliano L.,University of Rome La Sapienza
Chemistry and Physics of Lipids | Year: 2011

Cholesterol has many functions, including those that affect biophysical properties of membranes, and is a precursor to hormone synthesis. These actions are governed by enzymatic pathways that modify the sterol nucleus or the isooctyl tail. The addition of oxygen to the cholesterol backbone produces its derivatives known as oxysterols. In addition to having an enzymatic origin, oxysterols can be formed in the absence of enzymatic catalysis in a pathway usually termed "autoxidation," which has been known for almost a century and observed under various experimental conditions. Autoxidation of cholesterol can occur through reactions initiated by free radical species, such as those arising from the superoxide/hydrogen peroxide/hydroxyl radical system and by non-radical highly reactive oxygen species such as singlet oxygen, HOCl, and ozone. The susceptibility of cholesterol to non-enzymatic oxidation has raised considerable interest in the function of oxysterols as biological effectors and potential biomarkers for the non-invasive study of oxidative stress in vivo. © 2011 Elsevier Ireland Ltd. Source


De Blasio F.V.,University of Milan Bicocca | De Blasio F.V.,University of Rome La Sapienza
Earth and Planetary Science Letters | Year: 2011

The enigmatic deposits building up the Olympus Mons aureole on Mars are likely among the largest landslide remnants in the Solar System. These deposits exhibit an extraordinary run-out distance (up to nearly 700. km), in spite of a fall height some 100 times smaller.After quantifying the mobility of the Olympus Mons aureole lobes it is suggested, based on dynamical considerations and morphological analysis, that the aureole could be the consequence of a series of gigantic subaqueous landslides. In order to bring evidence in favor of this interpretation, comparisons are drawn between the different landslide deposits on Earth and Mars, emphasizing the similarity with the rock avalanches of the Canary Islands and the Hawaii. The results of experimental subaqueous debris flows are also analyzed, and numerical calculations are introduced to simulate the dynamics of flow. In analogy with certain subaqueous landslides on Earth, it is possible that the outstanding run-out of the aureole lobes was a consequence of hydroplaning, a natural lubrication by water during flow. © 2011 Elsevier B.V. Source


Present work provides in-situ structural data at a fine temperature scale from RT to the melting point of nitratine, NaNO3. From the analysis of log e33 versus log t plots, it is possible to prove that an univocal indication on the R3̄c (low temperature, LT) → R3̄m (high temperature, HT) transition mechanism cannot be obtained because of the relevant role played by the arbitrary assumptions required for defining the c0 dependence from temperature of the HT phase. This is due to the occurrence of excess thermal expansion for the HT phase. A significantly better fit for an Ising-spin structural model over a non-Ising rigid-body one has been obtained for the LT phase. Moreover, the Ising model led to a smooth variation of the oxygen site x fractional coordinate throughout the transition. The structure of the HT polymorph has been successfully refined considering an oxygen site at x, 0, 1/2, with 50% occupancy. Such model was the only acceptable one from the crystal chemical point of view as the alternative model (oxygen site at x, y, z with 25% occupancy) led to unrealistically aplanar NO- 3 groups. © 2011 Springer-Verlag. Source


Casale P.,University of Rome La Sapienza
Fish and Fisheries | Year: 2011

Sea turtle by-catch data in the Mediterranean were reviewed and analysed with fishing effort. The results indicate over 132000 captures per year, with probably over 44000 incidental deaths per year, while many others are killed intentionally. Small vessels using set net, demersal longline or pelagic longline represent most of the Mediterranean fleet and likely cause more incidental or intentional deaths than large vessels typically using bottom trawl or pelagic longline. When interactions, mortality, intentional killing, size (a proxy for reproductive value) and turtle populations are considered, results indicate that Mediterranean green (Chelonia mydas) and loggerhead turtles (Caretta caretta) are more affected (i) by fishing gears such as bottom trawlers, demersal longlines and set nets, (ii) by small-scale fisheries, and (iii) by fishing in the eastern basin. Although small-scale fisheries should be the priority target, available measures are easier to implement on the fewer large vessels. Moreover, these measures are few, and they are not implemented yet, while others should still be tested for the Mediterranean fisheries. Thus, measures for reducing captures or mortality through changing gear-specific characteristics may help, but probably a more holistic conservation strategy aimed to an ecosystem-based fishery management for a sustainable fishing would be the only solution for the long-term survival of Mediterranean Sea turtle populations and their habitats. Small-scale fisheries should manage marine resources, including turtles, in a responsible and sustainable way. Turtles may not only benefit from but can also help this process if their non-consumptive value is fully recognized. © 2010 Blackwell Publishing Ltd. Source


Thermal behavior of calcite has been analyzed in the 303-1098 K thermal range by laboratory parallel-beam transmission X-ray powder diffraction. Present results provide a clear indication of the possibility to extract high-quality structural data from such instrumental set up. Such quality has been proved to be at the same level of a mid eighties X-ray single crystal investigation. Analysis of the spontaneous strain e33 provides a critical exponent β of 0.2499(5) consistent with the value of 1/4 expected for a tricritical behavior. Structure refinements seemengly support the Ising model of disorder. Source


Ottini L.,University of Rome La Sapienza
Nature Reviews Cancer | Year: 2014

There are similarities between breast cancers that arise in men and women but there are also differences. What can be learned from male breast cancer to gain insight into breast cancer pathogenesis?. Source


Gallotti R.,University of Rome La Sapienza | Gallotti R.,University of Bordeaux 1
Journal of Human Evolution | Year: 2013

In the 1970s and 1980s, the emergence of the Acheulean at Melka Kunture (Upper Awash, Ethiopia) was dated to 1Ma (million years ago), based on the typo-metrical analysis of the lithic assemblage of Garba XIIJ. Older sites such as Gombore I, Karre I, and Garba IV (1.7-1.5Ma) were classified as Oldowan/Developed Oldowan. Consequently, the Oldowan and the Acheulean at Melka Kunture were interpreted as two distinct technologies separated by a chronological gap of 0.5Ma.The archaeostratigraphic unit D of Garba IV, dated to ~1.5Ma, yielded one of the richest Early Stone Age lithic series in East Africa. In this paper, a review traces methods of technological analysis, based on the concept of chaîne opératoire, to update our knowledge of the techno-economic behaviours at this site. The results show two major elements characteristic of cultural changes in the Melka Kunture sequence: (1) the emergence of a new chaîne opératoire focused on large flake/large cutting tool (LCT) production, and (2) a large variability of small débitage modalities with systematic preparation of the striking platform and the appearance of a certain degree of predetermination.These technological traits are shared by the contemporaneous sites in East Africa and are considered to be typical of the early Acheulean. This suggests an older origin for the Acheulean at Melka Kunture, 0.5Ma than previously inferred. © 2013 Elsevier Ltd. Source


Pazzaglia M.,University of Rome La Sapienza
Behavioral and Brain Sciences | Year: 2013

I evaluate the bottlenecks involved in the simulation mechanism underpinning superior predictive abilities for upcoming actions. This perceptual-motor state is characterized by a complex interrelationship designed to make predictions using a highly fine-tuned and constrained motor operation. The extension of such mechanisms to language may occur only in sensorimotor circuits devoted to the action domain. Copyright © 2013 Cambridge University Press. Source


Bruzzone P.,University of Rome La Sapienza
Transplantation Proceedings | Year: 2010

Financial incentives for organ donation (from living or brain-dead donors) have been considered ethically acceptable by some authors and have been accepted locally in some countries. In the United States of America, eight federal proposals have been rejected, while some kind of incentives have been approved at a local or state level. There is still a widespread concern that the acceptance of economic incentives could bring a commodification of the human body, constituting a "slippery slope" toward organ commercialism. © 2010 Elsevier Inc. All rights reserved. Source


Bruzzone P.,University of Rome La Sapienza
Transplantation Proceedings | Year: 2010

In Italy death of a human being must be declared either after brain death or after 20 minutes of cardiac arrest, certified by continuous electrocardiography (EKG) recording. It is my personal opinion that in such circumstances after cardiac death (DCD) will allow at best only the retrieval of few marginal kidneys and some tissues, and therefore will not be very helpful for our waiting list patients. I suggest instead modifying first the Italian law in order to be able to declare cardiac death after only 5 minutes of cardiac arrest, certified by continuous EKG recording. © 2010 Elsevier Inc. All rights reserved. Source


Bosi F.,University of Rome La Sapienza
Canadian Mineralogist | Year: 2011

Extension of the local bond-valence approach from Mg-Al to Fe 2+-Fe3+ short-range arrangements is explored in the structure of tourmaline. Stable local arrangements involving trivalent (R 3+) cations (Al, Fe3+) and divalent (Zr2+) cations (Mg, Fe2+) around the W and V anion sites in Li-free tourmaline result from short-range bond-valence requirements. The coupling of these stable local arrangements determines the formation of larger clusters of octahedra of general form [WY3VZ2], which can have either ordered or disordered distributions of A3+ and R2+ cations. These clusters are related through four different expressions: 1) 2 YR2+ + zR3+ + W(OH) 1- ⇄ 2 YR3+ + ZR2+ + WO2-, 2) 2 YR2+ + 2 ZR3+ + W(OH)1- ⇄ 2 YR3+ + 2 ZR2+ + WO 2-, 3) YR2+ + 2 ZR3+ ⇄ YR3+ + 2ZR2+, and 4) YT2+ + ZR3+ ⇄ YR3+ + ZR2+. Such relations describe the occurrence of both R3+ cations at the octahedrally coordinated Y site and R2+ cations at the octahedrally coordinated Z site of tourmaline, and lead to long-range ordered or disordered arrangements. In nature, disordered structural formulae are the rule owing to long-range requirements of geometrical fit and the minimization of strain. Source


Caggiati A.,University of Rome La Sapienza
European Journal of Vascular and Endovascular Surgery | Year: 2016

Background: In daily practice, ultrasonography (US) is used only to designate the location and pattern of venous lesions. Skin US is not performed between routine venous investigations. Methods: Skin morphology is evaluated by the same probes used for routine Duplex evaluation of superficial veins. US findings from evident skin lesions are comparatively evaluated with those from the surrounding apparently normal skin and from the contralateral leg. Results: Inflammation and dermal edema can be found in the apparently normal skin of C2 legs. Swollen legs show thickening of the subcutaneous layer as a result of diffuse soaking or anechoic cavities, with or without dermal edema. Chronic hypodermitis is characterized by inflammatory edema in initial phases, and by liposclerosis in advanced cases. Recrudescence of inflammation provokes focal rarefactions of the subcutaneous layer, possibly related to ulcer opening. Conclusion: In legs with venous disorders, sonography refines clinical evaluation of the skin and may reveal changes not highlighted by inspection. Some of these changes could require further investigation because they have not yet been explained or described. Skin sonography should improve knowledge of the natural history of skin changes, as well as contribute to a better grading of venous diseases severity In particular, US evidence of cutaneous and subcutaneous changes in C2 legs should be considered to stratify the treatment in C2 legs, by identifying those in which varicose veins are not simply a cosmetic problem. © 2016 European Society for Vascular Surgery. Source


Sadori L.,University of Rome La Sapienza | Peyron O.,University of Franche Comte
Holocene | Year: 2011

This paper provides a synthesis of available palynological data from central Mediterranean lacustrine records, studying the causes of the important vegetation changes which occurred in the mid Holocene. They are illustrated by seven well-dated records, lakes Accesa, Mezzano, Vico, and Pergusa in Italy, Maliq, Voulkaria and Malo J. in the Balkans. A good tool for disentangling climate change and human impact is the combined interpretation of pollen percentage and concentration/influx data. Pollen concentration/influx drops are an indication of increased erosion in the catchment, mainly ascribable to forest reduction. There is no doubt that major synchronous changes could not have been caused by humans alone. Many southern European records show substantial differences between early- and late-Holocene vegetation, suggesting a general evolution from wetter to drier climatic conditions, in agreement with arid phases recognised by other, independent palaeoclimatic methods. Other pollen records show a different trend. The role of changing seasonality seems important for this region of the Mediterranean. Precipitation seasonality increased during the early to mid Holocene with winter precipitation attaining a maximum, and summer precipitation a minimum. At least three rapid climate events with changes in plant biomass are in evidence: an abrupt and short change around 8200 yr BP, another one centred around 6000 yr BP, and one soon after 3000 yr BP. From the beginning of the Bronze Age (c. 4400 yr BP in this region) human impact overlapped with a climate change, probably bipartite, towards dryness. Our results show that this aridification trend began around 8000 yr BP, and culminated around 4000 yr BP. © The Author(s) 2011. Source


Magliulo G.,University of Rome La Sapienza
Otolaryngology - Head and Neck Surgery (United States) | Year: 2013

Objective. The aim of this study was to compare the results of application of 2 types of superelastic nitinol prostheses. Study Design. Temporal bones study with planned data collection. Setting. Tertiary referral center. Subjects and Methods. Malleostapedotomy was performed in 15 human temporal bones implanting 3 different prostheses: manually crimping polytetrafluoroethylene (MCPTFE) piston, nitinol self-crimping polytetrafluoroethylene (SC-PTFE) piston, and a modified nitinol self-crimping polytetrafluoroethylene (mSC-PTFE) piston. The first 2 have a diameter of 0.4 mm and length of 7 mm, whereas the mSC-PTFE piston has a diameter of 0.4 mm but a length of 7.75 mm. We evaluated various parameters of prosthesis attachment-that is, the time for implantation of SC and mSC nitinol loop pistons and the MC platinum loop piston, the quality of attachment of the prostheses to the malleus, their positions with respect to the center of the stapes footplate, and the protrusion of the piston into the vestibule. Results. The mSC-PTFE superelastic nitinol prosthesis showed a statistically significant difference in mean operation time (mSC vs SC, P<.0001; SC vs MC, P<0001; mSC vs MC, P <.0001). The protrusion of the piston into the vestibule was highly reproducible in all 3 prostheses. Conclusion. Because of its greater length, the mSC-PTFE allows for management of the most varied anatomical conditions. At the same time, its self-crimping nature prevents the risk of distortion of the prosthesis by the crimping process and reduces the operation time in combination with standardized bending of the prosthesis shaft. © American Academy of Otolaryngology-Head and Neck Surgery Foundation 2013. Source


Baldoni R.,University of Rome La Sapienza
Electronic Government | Year: 2012

Federated Identity Management (FIdM) systems are at the heart of any online service in a public, private or hybrid autonomous cooperating system. This paper reviews and compares several existing approaches for building FIdM systems in the specific sector of e-government by showing Identity Management (IdM) schemes employed by several countries representatives of different realities by size, geographical location and Public Administration (PA) traditions. The paper analyses then the case of Italy by introducing the ongoing effort for defining and developing a nationwide e-government Enterprise Architecture to guarantee a flexible approach for integrated application services, respecting local and central administrations' autonomy. The paper finally focuses on the FIdM aspects employed within the Italian Enterprise Architecture. Copyright © 2012 Inderscience Enterprises Ltd. Source


Venditti I.,University of Rome La Sapienza
Nanotechnology | Year: 2010

Chemical interactive materials (CIM), based on poly(methylmethacrylate-co-bis(benzocyclobutene)) P(MMA-co-BCB) and poly(styrene-co-bis(benzocyclobutene)) P(S-co-BCB) nanoparticles, have been prepared through modified emulsion technique. Experimental conditions, in particular the co-monomer ratio and reaction time, have been tuned to modulate nanoparticles' dimension and optimize their monodispersity. Resistive relative humidity (RH) sensors based on self-assembled copolymeric nanoparticles, cast deposited onto metal interdigitated electrodes (Al, Au, Cr), have been fabricated. The electrical response and the devices' stability have been studied in the range 10-90% RH. Applying 1 V to interdigitated electrodes, a variation of four orders of magnitude, from 10(-12) to 10(-8) A, has been observed and a response time of 130 s has been calculated. Response reproducibility and stability have been tested in subsequent cycles of measurements (working times as long as two days and after six months), confirming the stable performance of the CIMs. Copolymeric nanoparticle assembly has also been studied by quartz microbalance (QMB) devices, where phase shift occurred, by varying RH in the range 10-90%. The CIM coated device shows a sensitivity of about 30 Hz/% (at 10-70% RH), that rapidly increases up to about 2000 Hz/% at 90% RH. The results give evidence for versatile applications of P(MMA-co-BCB) and P(S-co-BCB) nanoparticles for sensing applications. Source


Franz J.,University of Bonn | Gianturco F.A.,University of Rome La Sapienza
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

In the present work we are reporting detailed quantum scattering calculations that describe the diffusion of a beam of low-energy positrons interacting with the pyrimidine target as a gas-phase partner. The calculations have employed an essentially ab initio model for the short-range correlation interaction and for the electrostatic interaction of an impinging positron and the electron+nuclear structure of the target molecule at its equilibrium geometry. The available experiments were also performed in the low-energy region below about 30 eV and have been reported by two different experimental groups cited in the main text. Those data include integral elastic plus rotationally and vibrationally summed cross sections, together with angular distributions over the same range of energies. The effects on the scattering observables which stem from the permanent dipole moment of the title molecule are carefully analyzed and computational corrections which ensure numerical convergence are introduced and discussed. The additional uncertainties introduced by the angular discrimination error present in the experiments are also discussed and analyzed, thereby providing a numerical procedure for correcting all available data. The final comparison between experimental angular distributions and the computed counterparts produced in the present work turns out to be very good. The same applies to the comparison in size and energy dependence of the integral cross sections, where we show that our calculated quantities and the corrected experiments are in very good agreement over the whole range of available energies. © 2013 American Physical Society. Source


A phytosociological study on the most extensive dry grassland communities of the coastal limestone massif of the Ausoni-Aurunci mountains (southern Latium, central Italy) is here presented. Violo pseudogracilis-Koelerietum splendentis ass. nova is restricted to the montane belt of the Aurunci mountains where it is dynamically related to the mesophilous Ostrya carpinifolia or Fagus sylvatica woodlands. Helichryso italici-Brometum erecti ass. nova is found within the upper hilly and submontane belt of both the Ausoni mountains (typical aspect) and the Aurunci mountains (subassociation saturejetosum montanae), where it is dynamically related with termophilous Ostrya carpinifolia woods and mesophilous Quercus ilex woods. Helichryso-Brometum is differentiated from Violo-Koelerietum in that it has a higher incidence of the steno-Mediterranean therophytic component. As far as the higher rank syntaxa are concerned, in this study the following changes were made in accordance with the rules of ICPN: the name Phleo ambigui-Bromion erecti Biondi et al. 1995 was considered invalid due to the invalidity of its nomenclatural type Asperulo purpureae-Brometum erecti. In contrast, the validity of the old name Cytiso spinescentis-Bromion erecti Bonin 1978 was demonstrated and its nomenclatural type, Lavandulo-Asphodelinetum luteae Bonin 1978, was lectotypified. Thus Cytiso spinescenti-Bromion erecti Bonin 1978 henceforth substitutes Phleo ambigui-Bromion erecti (nom. inval.) as the syntaxonomical reference for the endemic alliance of the hilly and montane limestone dry grasslands of the central and southern Apennines. Cytiso-Bromion is here divided into two suballiances: Sideritidenion italicae Biondi et al. 1995, Phleo ambigui-Bromenion erecti Biondi et al. ex Di Pietro suball. nov. Cytiso-Bromion belong to the new suborder Festuco circummediterraneae- Seslerienalia nitidae (Ubaldi 2003) stat. nov. and to the order Artemisio albae-Brometalia erecti Ubaldi ex Mucina & Dengler 2009. New and updated packages of characteristic and differential species for both Cytiso spinescenti-Bromion erecti and its related suballiances are proposed. Furthermore the validity of the name Astragaletum calabrici Giacomini & Gentile ex Bonin 1978, was proved and the association lectotypified. This association, which was previously included in Cytiso-Bromion erecti, is moved into Koelerio brutiae-Astragalion calabrici. Finally some interesting coenological and syndynamical similarities with Scorzonero-Chrysopogonetalia western Dalmatia submediterranean dry pastures are discussed. Source


Orlandi P.,University of Rome La Sapienza
Journal of Turbulence | Year: 2011

Direct Numerical Simulations of flows in channels are presented to demonstrate that the wall-normal Reynolds stress is a fundamental quantity to assess when the flow past smooth and rough surfaces becomes turbulent. In this paper it is demonstrated that only when ũ' 2 ′+{pipe} w (+ indicates wall units and w the value at the plane of the crest of the roughness elements) is greater than the threshold value of 0.6, there is a transition from a laminar to a turbulent regime. This statement has been checked by changing the shape, the density and the distribution of solid obstacles. The threshold value for ũ' 2 ′+{pipe} w is reached only if the height k + of the protuberance is greater than 15. In addition, the simulations for distributed elements have been used to understand the deformation of the Tollmien-Schlichting (T-S) waves by the roughness. Animations show the formation of elongated streaks near the smooth wall, and indicate difference in the shape of structures near the rough surface. © 2011 Taylor & Francis. Source


Farcomeni A.,University of Rome La Sapienza
Biometrika | Year: 2011

We introduce a general class of capture-recapture models in which capture probabilities depend on capture history. We discuss constrained versions of the saturated model based on equality constraints. Inference can be performed through a simple estimating equation. The approach is illustrated on a dataset concerning Great Copper butterflies in Willamette Valley of Oregon. © 2011 Biometrika Trust. Source


Callisto L.,University of Rome La Sapienza
Geotechnique | Year: 2014

An earth-retaining structure consists of structural elements that interact with a soil mass. The study of the soil-structure interaction becomes especially complex under seismic conditions, because the inertial forces reach a portion of soil that is already mobilising part of its strength to sustain the excavation: a suitable soil model would need to include, in addition to non-linearity and damping, the progressive mobilisation of the soil strength. However, for design purposes it may be unnecessary to predict the detailed dynamic behaviour of the system: it could be sufficient to endow the system with features that will ensure a desirable behaviour under a severe seismic event. In this paper, it is maintained that a desirable behaviour for cantilevered and singly propped retaining walls subjected to a severe earthquake is to mobilise a plastic mechanism deriving from the attainment of the strength in the volume of soil that directly interacts with the wall, while preserving the integrity of the structural members. Following this line of thought, it is shown that it is possible to use relatively simple pseudo-static tools, essentially based on the strength properties of the soil, to study the plastic mechanism associated with the desired behaviour, and to derive the internal forces that the structural elements are called to resist in order to ensure that the plastic mechanism will be maintained at its full strength during the seismic event. This approach is applied to a number of schematic retaining structures; results of full dynamic analyses of the soil-structure interaction are employed to validate the proposed approach and to evidence its limitations. Source


Barich B.E.,University of Rome La Sapienza
Quaternary International | Year: 2014

The area of Jebel Gharbi, west of Cyrenaica province and the research area of the Italian-Libyan Joint Project (Sapienza University of Rome and Cassino), showed a continuity of occupation even during the most difficult periods of the Last Glaciation, marked by the abandonment of much of North Africa. One of the main research subjects of the project concerns the transformation of hunting societies during the Holocene, with the gradual transition to a food production economy, and the type of Neolithic organization on the coastal Libyan territory.This paper emphasizes this theme and takes into account especially the areas that have allowed for palaeoclimatic and geo-archaeological reconstruction in a broader perspective, including changes in the settlement pattern and the economic system. These conditions were recognized in the Jefara, the plain which begins at the slopes of the Jebel Gharbi plateau and reaches the coast.I describe the principal characteristics of the sites investigated along a belt that runs from Shakshūk to El Jawsh, where a long period of climate stability in the mid-Holocene and particularly between 6.7 and 5.4ka cal BP, was recognized through the presence of large ponds and marshes that became an important focus for human occupation. Taking into account the palaeoenvironmental context, the paper suggests a model of economic change in the Jebel Gharbi/Jefara region through three different phases of development (Jefara A, B, C), that can be compared with the most recent results of research in other areas of Libya and the Maghreb. © 2013 Elsevier Ltd and INQUA. Source


De Santoli L.,University of Rome La Sapienza
Energy and Buildings | Year: 2015

The AiCARR Guidelines "Energy Efficiency in Historic Buildings" (February 2014) provide information to evaluate and improve the energy performance of historic buildings, fully respecting their significance and expression; where applicable these Guidelines will include the most recent legislation on the subject existing in Italy. These guidelines are intended for both design engineers and superintendencies. They provide the design engineers with a tool for the energy audit of the historic building and offer a framework for the design of possible energy upgrades, which are conceptually similar to that provided for non-protected buildings, but appropriately tailored to the needs and peculiarities of the cultural heritage. On the other hand, these Guidelines provide the institutions responsible for protecting the building, the possibility to objectively decide on the level of energy efficiency achieved as a result of the rehabilitation in accordance with the conservation criteria. © 2014 Elsevier B.V. All rights reserved. Source


Gentile G.,University of Rome La Sapienza
Transportmetrica A: Transport Science | Year: 2014

This article presents a new algorithm for traffic assignment, called Local User Cost Equilibrium (LUCE), which iteratively solves a sequence of user-equilibrium problems associated with flows exiting from a node. The method is based on the idea of assigning users directed towards each destination separately; these flows form a bush, i.e. an acyclic sub-graph that connects every node to that destination. For each node, the algorithm considers the arcs of its forward star as the set of travel alternatives available to users and seeks a deterministic equilibrium of flows towards the same destination. The cost function associated with each of these local route choices expresses the average impedance to reaching the destination if a user continues the trip on a particular arc. The method is 'local' in an analytical sense, because the cost function is linearised at the current flow pattern, as if it was independent from the other splitting rates of the same node. The method is also 'local' in a topological sense, as nodes are processed through a polynomial visit of the current bush, inspired by dynamic programming. The node problem is formulated as a quadratic program in terms of destination-specific flows. We prove that its solution recursively applied in topological order provides a descent direction with respect to the sum-integral objective function of traffic assignment. The local equilibrium problem at nodes is solved through a greedy algorithm resembling the ad-hoc method used to compute shortest hyperpaths in transit assignment. The latter is the main contribution of this article. The main advantage of LUCE is to achieve a fast convergence rate that compares favourably with the existing methods, and to implicitly assign the demand flow of each origin-destination pair on several paths at once. © 2012 © 2012 Hong Kong Society for Transportation Studies Limited. Source


The paper discusses a simple multi-variable optimization problem: the bifurcation of a branch of a pipe of circular cross-section with a given initial radius r 0 and delivering a given mass flow rate m 0.The optimization is performed using an objective function that prescribes the minimization of the entropy generation rate due - in this simple case - only to viscous flow effects within the tubes. Several fundamental simplifying assumptions are made to reduce the problem to a multi-variable optimization in three independent variables: the aspect ratio of the domain served by the flow, the diameter ratio of the primary and secondary branches, and the length of the secondary branch (the location of both the "source" of the fluid and the "sink", i.e., the place of desired delivery of the fluid, being a datum).It is shown that the solution is strongly dependent both on the aspect ratio and on the diameter ratio, and that the "optimal" configurations display some resemblance to the branching patterns observed in natural structures. The study poses a challenge both to Designers and to Natural Scientists: are the optima suggested by the present procedure compatible with the structures currently used in heat exchangers and flow devices? Are they compatible with the structures observed in nature? No final answer is provided in this preliminary study, but a possible "falsification" procedure is outlined in the conclusions. © 2010 by the author. Source


Papetti L.,University of Rome La Sapienza
The journal of headache and pain | Year: 2010

There is a serious lack of controlled studies on the pharmacological treatment of primary migraine in the developmental age; there is, consequently, an urgent need for new, evidence-based approaches to this long-neglected field of research. Moreover, previous studies have stated that the placebo response is greater in pediatric patients than in adults and that a reduction in the attack frequency in the absence of any pharmacological treatment is observed more frequently in pediatric migraine patients than in adults. Besides these preliminary considerations, the shorter duration of migraine attacks and other characteristic semeiological features of the clinical picture in children are such that the design of randomized controlled trial (RCT) is more problematic in the developmental age than in the adult. Bearing in mind all these weak points, the aim of this review was to summarize and update recent guidelines for the treatment of primary migraine in children and adolescents. The most recent guidelines are those published by the Italian Society for the study of Headache, the French Society for the study of Migraine and Headache, and the American Academy of Neurology. We have incorporated into these guidelines the results from the few, recent RCTs, clinical controlled trials, open-label studies, meta-analyses and reviews that have been published since 2004; owing to the lack of strong evidence in this field of research, we have sometimes even mentioned pilot non-controlled studies, case series and expert opinions. Lastly, evidence was classified and the recommendations were categorized according to different levels. Source


Ferrari V.,University of Rome La Sapienza
Classical and Quantum Gravity | Year: 2010

In this paper, we give a brief overview of how the detection of gravitational waves emitted by neutron stars may impact on our understanding of the physics of neutron stars. © 2010 IOP Publishing Ltd. Source


Mortelliti A.,University of Rome La Sapienza
Biodiversity and Conservation | Year: 2013

Although improving the quality of habitat patches in fragmented landscapes is a main conservation target few studies have examined patch management in relation to the surrounding landscape. Tackling such an issue needs a cross-scale approach that takes the hierarchical nature of landscapes into account. Here I show the results of a cross-scale study focusing on the distribution patterns of ten forest vertebrate species (birds and mammals). The overarching goal of this study was to understand the strength of patch scale determinants of distribution, following the appropriate control for relevant landscape properties (e. g. habitat loss vs. habitat subdivision). I show how, after controlling for uncertainty in the detection of the species and for the role of landscape properties, patch scale variables still played an important role in determining occupancy patterns of forest vertebrates. For some species variation in the values of patch structure variables increased occurrence probability with only moderate levels of habitat loss, highlighting the fact that habitat management should be targeted towards precise landscape conditions. In other cases the effect of patch variables was strong therefore variation in their values always brought substantial increase/decrease of presence probability. Overall these results strongly suggest that habitat management should never be carried out irrespective of the properties of the surrounding landscape, rather, it should be carefully targeted towards specific landscape contexts (e. g. above a certain amount of habitat) where it is more likely to be effective. © 2012 Springer Science+Business Media Dordrecht. Source


Eramo V.,University of Rome La Sapienza
Journal of Lightwave Technology | Year: 2010

Power consumption is expected to become the main limiting factor for scaling the current network architectures to capabilities of hundreds of terabit or even petabits. The use of optical switching fabrics (SFs) could relax the limitations to some extent but large optical buffers occupy larger area and dissipate more power than electronic ones. In this paper, we evaluate the power consumption of bufferless optical packet switches (OPSs), using the wavelength conversion to solve the output packet contentions. Sophisticated analytical models are introduced to evaluate the power consumption of synchronous and asynchronous OPSs (SOPSs and AOPSs) versus the offered traffic, the main switch parameters, and the used device characteristics. The power consumption in SOPSs and AOPSs is compared when commercial semiconductor optical amplifiers are used to implement SFs and wavelength converters (WCs). The obtained results show that the high power consumption in synchronization stage makes SOPS less effective than AOPS in terms of power consumption. For instance, when the OPSs are dimensioned with a sufficient number of WCs and offered traffic is 0.8, SOPS consumes 140% of power more than does the AOPS. Finally, though power consumption due to cooling system is not considered in the proposed model, we observe that both SOPSs and AOPSs consume much less power per gigabit per second carried than commercial routers. © 2010 IEEE. Source


Pontone S.,University of Rome La Sapienza
World Journal of Gastroenterology | Year: 2012

The outpatient-based study by Deng et al [World J Gastroenterol 2011 July 14; 17(26): 3133-3139] on the factors that may influence the colorectal cancer (CRC) screening feasibility, encouraged our curiosity. Establishing a simple method for quickly assessing the educational level of patients and modulating a questionnaire for each type of patient, may be an effective protocol to increase the people participation, mainly in countries where sufficient medical resources and financial support are lacking. In fact, the knowledge directly affects the feasibility when screening is offered. Patient educational level influences the understanding of the knowledge and the screening method. This factor may affect patient's priority level on the study participation, the understanding of questions, and the motivation to complete the questionnaire and, consequently, the screening success. Recent studies have found a relationship between high educational level and CRC screening participation, and emphasized the questionnaire ineffectiveness in the illiterate people. Although the questionnaire is an excellent method for this kind of evaluation, physician's contribution could be the most important factor associated with the screening method. Thus, further studies should be conducted to explore the compliance of patients with low educational level and to look for the best solutions for their enrollment. © 2012 Baishideng. All rights reserved. Source


Sciubba E.,University of Rome La Sapienza
Ecological Indicators | Year: 2013

Environmental considerations are becoming an essential part of any energy conversion assessment: the concept of "environmental impact" has substantially evolved in the last decade, from a pure "assessment of ecological damage" (pollution) to a more complex and omnicomprehensive, but at the same time more detailed, examination of the local and global implications of the interactions of anthropic processes with the biosphere at large. This paper proposes an Environmental Indicator derived strictly on thermodynamic concepts and defines a procedure for its application to both local and global scales in a rationally sound and convenient fashion. The new indicator is the extended exergy cost, eeC, and is a measure of the primary (exergy) resources embodied in a material or immaterial product. It is shown that such an EI can successfully include the "externalities" (Labor, Capital and Environmental Remediation costs) that affect the planning of anthropic energy conversion systems, and that it can also be employed to assess the evolutionary patterns of natural systems. Some conceptual examples of application are provided to demonstrate that eeC is indeed a useful tool for the quantification of real -i.e., resource based- environmental costs and for their proper internalization in both engineering and system studies. © 2012 Elsevier Ltd. Source


Di Clemente L.,University of Rome La Sapienza
The journal of headache and pain | Year: 2013

Lack of habituation during repetitive stimulation is the most consistent interictal abnormality of cortical information processing observed in migraine. Preventive migraine treatments might act by stabilizing cortical excitability level and thus the habituation to external stimuli. We examined the effects of preventive treatment with topiramate on migraineur's habituation to nociceptive stimulation. Scalp potentials were evoked by Nd-YAP Laser stimulation of the hand dorsum and supraorbital region in 13 patients with migraine without aura (MO) and 15 healthy volunteers (HV). The exam was repeated in MO before and after treatment. We observed a lack of habituation and lower initial amplitudes in MO compared to HV. These abnormalities reached statistical significance for N1 LEPs component, generated in the secondary somatosensory cortex (SII), but not for N2/P2 complex, generated in the insula and anterior cingulated cortex (ACC). Topiramate normalized the N1 habituation pattern in MO, with a significant correlation between clinical effects and normalization of neurophysiological responses. Our results indicate a modulating action of topiramate on cortical processing of sensorial stimuli, mainly regarding the sensory-discriminative component of pain, elaborated by SII, without a significant effect on the affective dimension of pain, in which the ACC has an important role. Source


Esposito K.,The Second University of Naples | Chiodini P.,The Second University of Naples | Colao A.,University of Naples Federico II | Lenzi A.,University of Rome La Sapienza | Giugliano D.,The Second University of Naples
Diabetes Care | Year: 2012

OBJECTIVE - Available evidence supports the emerging hypothesis that metabolic syndrome may be associated with the risk of some common cancers. We did a systematic review and meta-analysis to assess the association between metabolic syndrome and risk of cancer at different sites. RESEARCH DESIGN AND METHODS - We conducted an electronic search for articles published through October 2011 without restrictions and by reviewing reference lists from retrieved articles. Every included study was to report risk estimates with 95% CIs for the association between metabolic syndrome and cancer. RESULTS - We analyzed 116 datasets from 43 articles, including 38,940 cases of cancer. In cohort studies in men, the presence of metabolic syndrome was associated with liver (relative risk 1.43, P < 0.0001), colorectal (1.25, P < 0.001), and bladder cancer (1.10, P = 0.013). In cohort studies in women, the presence of metabolic syndrome was associated with endometrial (1.61, P = 0.001), pancreatic (1.58, P < 0.0001), breast postmenopausal (1.56, P = 0.017), rectal (1.52, P = 0.005), and colorectal (1.34, P = 0.006) cancers. Associations with metabolic syndrome were stronger in women than in men for pancreatic (P = 0.01) and rectal (P = 0.01) cancers. Associations were different between ethnic groups: we recorded stronger associations in Asia populations for liver cancer (P = 0.002), in European populations for colorectal cancer in women (P = 0.004), and in U.S. populations (whites) for prostate cancer (P = 0.001). CONCLUSIONS - Metabolic syndrome is associated with increased risk of common cancers; for some cancers, the risk differs betweens sexes, populations, and de finitions of metabolic syndrome. © 2012 by the American Diabetes Association. Source


Parisi G.,University of Rome La Sapienza | Zamponi F.,Laboratoire Of Physique Theorique
Reviews of Modern Physics | Year: 2010

Hard spheres are ubiquitous in condensed matter: they have been used as models for liquids, crystals, colloidal systems, granular systems, and powders. Packings of hard spheres are of even wider interest as they are related to important problems in information theory, such as digitalization of signals, error correcting codes, and optimization problems. In three dimensions the densest packing of identical hard spheres has been proven to be the fcc lattice, and it is conjectured that the closest packing is ordered (a regular lattice, e.g., a crystal) in low enough dimension. Still, amorphous packings have attracted much interest because for polydisperse colloids and granular materials the crystalline state is not obtained in experiments for kinetic reasons. A theory of amorphous packings, and more generally glassy states, of hard spheres is reviewed here, that is based on the replica method: this theory gives predictions on the structure and thermodynamics of these states. In dimensions between two and six these predictions can be successfully compared with numerical simulations. The limit of large dimension is also discussed where an exact solution is possible. Some of the results presented here were published, but others are original: in particular, an improved discussion of the large dimension limit and new results on the correlation function and the contact force distribution in three dimensions. The main assumptions that are beyond the theory presented are clarified and, in particular, the relation between static computation and the dynamical procedures used to construct amorphous packings. There remain many weak points in the theory that should be better investigated. © 2010 The American Physical Society. Source


Di Domenico A.,University of Rome La Sapienza
Foundations of Physics | Year: 2010

The neutral kaon system offers a unique possibility to perform fundamental tests of CPT invariance, as well as of the basic principles of quantum mechanics. The most recent limits obtained by the KLOE experiment at the DAΦNE e+e- collider on several kinds of possible CPT violation and decoherence mechanisms, which in some cases might be justified in a quantum gravity framework, are reviewed. No deviation from the expectations of quantum mechanics and CPT symmetry is observed, while the precision of the measurements, in some cases, reaches the interesting Planck scale region. Finally, prospects for this kind of experimental studies at KLOE-2 are presented. © 2009 Springer Science+Business Media, LLC. Source


Quevedo H.,University of Rome La Sapienza
International Journal of Modern Physics D | Year: 2011

We investigate the gravitational field of a static mass with quadrupole moment in empty space. It is shown that in general this configuration is characterized by the presence of curvature singularities without a surrounding event horizon. These naked singularities generate an effective field of repulsive gravity which, in turn, drastically changes the behavior of test particles. As a possible consequence, the accretion disk around a naked singularity presents a particular discontinuous structure. © 2011 World Scientific Publishing Company. Source


Di Feliciantonio C.,University of Rome La Sapienza
Antipode | Year: 2016

How can we analyse the (re)emergence of squatting in relation to the current housing crisis in Italy? Centred on the case of Rome, the paper theorizes this return as resulting from processes of subjectification in the housing sector linked to the raising of indebtedness as a main dispositif of capitalism under neoliberal/austerity urbanism agendas. The political economy-oriented literature on neoliberal/austerity urbanism is bridged with the post-Marxist approach of Maurizio Lazzarato. Debt is seen as the archetype of social relations, shaping and controlling subjectivities, making the "work on yourself" essential to the reproduction of (indebted) society. However, given the circular nature of power, indebtedness can be generative of new processes of subjectification aimed at subverting the same power relation. In this sense, the paper operationalizes the conceptualization of Foucauldian subjectification recently proposed by Judith Revel, emphasizing how subjectification always results from (1) an action/gesture and (2) a consequent deconstruction of the identity. © Antipode Foundation. Source


Pompili M.,University of Rome La Sapienza | Pompili M.,Harvard University
Suicide and Life-Threatening Behavior | Year: 2010

Phenomenology studies conscious experience as experienced from the subjective or first-person point of view. This paper was developed with the aim of shedding light on the phenomenology of suicide; that is, to focus on suicide as a phenomenon affecting a unique individual with unique motives for the suicidal act. To explore this topic, the author looks back at the past centuries to understand why suicide was thought to be confined to psychiatric illness and to document the bias in studies supporting this notion. One major step forward in the conceptualization of suicide as a psychological disorder was provided by Edwin Shneidman, who focused on the pain of negative emotions. Such a radical approach is laudable in an era where diagnostic criterria and the need to cure are more important than understanding what is not working at the emotional level. Source


It is well known that, for a given compressor technology, gas turbine efficiency increases with the turbine inlet temperature (TIT): both modern aeronautical and land-based gas turbines operate at very high temperatures (1500-2000K) -and correspondingly high pressure ratios. As the TIT increases, the heat transferred from the expanding gas to the turbine blade also increases, and the need to extend the operational life make it necessary to adopt internal air cooling to reduce blade creep, oxidation and low-cycle fatigue. The cooling medium is usually air extracted from the high-pressure compressor stages, and since this extraction decreases the thermal efficiency and power output of the engine, it is important to bleed the minimum amount of coolant to attain a prescribed maximum material temperature in the blade with the maximum possible uniformity (lower thermal stresses): thence the need to properly model the cooling system for a given turbine blade geometry under realistic engine operating conditions. In the preliminary design of the first statoric and rotoric blading, it is essential for designers to rely on simple models that often neglect the small scales effects on the external flows and also by force adopt a much simplified treatment of the internal ones, and as a result attain a substantially lower degree of approximation than that offered by more complex and expensive numerical simulations. The goal in the design of a lumped model is therefore to make it both sufficiently general and accurate to analyze blade shapes and cooling channels structures that can be further refined by means of more accurate, but also more computationally intensive, models. This paper presents a simple, globally lumped thermodynamic model of blade cooling whose most important feature is its being analytical, so that the solution is devoid of numerical approximations and leads to closed-form expressions that can be easily manipulated to accommodate for different process parameters, blade arrangements, cooling channel structure and fluid properties. The model predicts the mass-averaged gas temperature along the channel and the required cooling air flowrate, under the assumption of a constant metal temperature along and inside of the blade: therefore, thermo-mechanical effects are completely neglected. The results are validated against some published data, and the agreement is found to be quite satisfactory: when discrepancies arise, a phenomenological explanation is offered. © 2015 Elsevier Ltd. Source


Di Giacomo F.,University of Rome La Sapienza
Journal of Chemical Education | Year: 2015

The RRKM Theory of Unimolecular Reactions and Marcus Theory of Electron Transfer are here briefly discussed in a historical perspective. In the final section, after a general discussion on the educational usefulness of teaching chemistry in a historical framework, hints are given on how some characteristics of Marcus' work could be introduced in courses of physical chemistry or chemical kinetics to show how experiments drive the formulation of theories and, on the other hand, how the predictions of theories may suggest experiments and even predate their results. © 2014 The American Chemical Society and Division of Chemical Education, Inc. Source


D'Andrea D.,University of Rome La Sapienza
Nucleic acids research | Year: 2013

The results of differential expression analyses provide scientists with hundreds to thousands of differentially expressed genes that need to be interpreted in light of the biology of the specific system under study. This requires mapping the genes to functional classifications that can be, for example, the KEGG pathways or InterPro families they belong to, their GO Molecular Function, Biological Process or Cellular Component. A statistically significant overrepresentation of one or more category terms in the set of differentially expressed genes is an essential step for the interpretation of the biological significance of the results. Ideally, the analysis should be performed by scientists who are well acquainted with the biological problem, as they have a wealth of knowledge about the system and can, more easily than a bioinformatician, discover less obvious and, therefore, more interesting relationships. To allow experimentalists to explore their data in an easy and at the same time exhaustive fashion within a single tool and to test their hypothesis quickly and effortlessly, we developed FIDEA. The FIDEA server is located at http://www.biocomputing.it/fidea; it is free and open to all users, and there is no login requirement. Source


Cava E.,University of Washington | Cava E.,University of Rome La Sapienza | Fontana L.,University of Washington | Fontana L.,University of Salerno
Aging | Year: 2013

Calorie Restriction (CR) without malnutrition slows aging and increases average and maximal lifespan in simple model organisms and rodents. In rhesus monkeys long-term CR reduces the incidence of type 2 diabetes, cardiovascular disease and cancer, and protects against age-associated sarcopenia and neurodegeneration. However, so far CR significantly increased average lifespan only in the Wisconsin, but not in the NIA monkey study. Differences in diet composition and study design between the 2 on-going trials may explain the discrepancies in survival and disease. Nevertheless, many of the metabolic and hormonal adaptations that are typical of the long-lived CR rodents did not occur in either the NIA or WNPRC CR monkeys. Whether or not CR will extend lifespan in humans is not yet known, but accumulating data indicate that moderate CR with adequate nutrition has a powerful protective effect against obesity, type 2 diabetes, inflammation, hypertension, cardiovascular disease and reduces metabolic risk factors associated with cancer. Moreover, CR in human beings improves markers of cardiovascular aging, and rejuvenates the skeletal muscle transcriptional profile. More studies are needed to understand the interactions between CR, diet composition, exercise, and other environmental and psychological factors on metabolic and molecular pathways that regulate health and longevity. © Cava and Fontana. Source


Boguna M.,University of Barcelona | Castellano C.,CNR Institute for Complex Systems | Castellano C.,University of Rome La Sapienza | Pastor-Satorras R.,Polytechnic University of Catalonia
Physical Review Letters | Year: 2013

We develop an analytical approach to the susceptible-infected-susceptible epidemic model that allows us to unravel the true origin of the absence of an epidemic threshold in heterogeneous networks. We find that a delicate balance between the number of high degree nodes in the network and the topological distance between them dictates the existence or absence of such a threshold. In particular, small-world random networks with a degree distribution decaying slower than an exponential have a vanishing epidemic threshold in the thermodynamic limit. © 2013 American Physical Society. Source


Breccia M.,University of Rome La Sapienza | Lo-Coco F.,University of Rome Tor Vergata
Expert Opinion on Biological Therapy | Year: 2011

Introduction: Acute promyelocytic leukemia (APL) is characterized by peculiar biological features and high sensitivity to therapeutic agents such as anthracyclines, all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). Because cure rates of up to 80 90% have been reported using various combinations of the above agents, future strategies will probably aim at reducing therapy-related toxicity while maintaining therapeutic efficacy. Gemtuzumab ozogamicin (GO) is a calicheamicin-conjugated mAb directed against CD33, a surface antigen highly expressed on APL blasts. GO has been shown to be effective in this disease and better tolerated than conventional chemotherapy. Areas covered: This review looks at the mechanism of action, pathways associated with resistance and toxicity profile of GO. Reported experience on the use of GO for relapsed or newly diagnosed APL is also discussed along with evidence on its efficacy and relative tolerability in APL management. In addition to its activity in advanced disease, data suggest that GO in various combinations may replace chemotherapy in APL front-line therapy. This should apply in particular to some subsets such as elderly patients or those unfit to receive conventional chemotherapy. Expert opinion: GO has proven effective and relatively safe as a single agent in advanced APL. In combinations with ATRA and/or ATO, GO may substitute for conventional chemotherapy of APL, particularly in unfit patients. © 2011 Informa UK, Ltd. Source


Ballirano P.,University of Rome La Sapienza
Physics and Chemistry of Minerals | Year: 2012

The paper reports a crystal chemical investigation of a haüyne sample, (Na 4.4K 1.1Ca 2.1) Σ 7.6[Si 6Al 6O 24](SO 4) 1. 6(S 3) 0. 3(CO 2) 0. 1, from Sacrofano, Italy, conciliating spectroscopic, chemical, and room temperature (RT) X-ray single-crystal diffraction data. The RT structure refinement provides a detailed description of the extra-framework cations and anionic groups mutual arrangement. The occurrence of minor amounts of the S 3 - poly-sulphur radical, responsible of the light-blue colour of the sample, revealed by Raman spectroscopy, has been shown to play an important role in modifying the cation partition among the three sites: M1, M2, and M3. Moreover, traces of enclathrated CO 2 were revealed by FTIR. Besides, the thermal behaviour has been investigated, up to 1,098 K, by in situ HT-XRPD. Results indicate relevant differences with respect to reference data. The sample at RT shows weak satellite reflections that disappear at 673 K. As expected, the geometry of the rigid TO 4 tetrahedra is independent from temperature, whereas the framework expands by decreasing the angle of rotation of both the SiO 4 (φ Si) and AlO 4 (φ Al) tetrahedra as a function of temperature. The quadric dependence of both φ Si and φ Al from temperature ends at 973 K, in correspondence of angles of rotation of ca. 3°, indicating the attainment of a nearly full expansion of the framework. At temperatures exceeding such value, only weak tetrahedral expansion acts. As a result of such thermal expansion mechanism, the dependence of the a-parameter from temperature shows a change of regime at 973 K. Such thermal expansion model is similar, albeit non-identical, to that of several cancrinite-sodalite group minerals. © 2012 Springer-Verlag. Source


De Michele C.,University of Rome La Sapienza
Computer Physics Communications | Year: 2011

Event-driven molecular dynamics is a valuable tool in condensed and soft matter physics when particles can be modeled as hard objects or more generally if their interaction potential can be modeled in a stepwise fashion. Hard spheres model has been indeed widely used both for the computational and theoretical description of physical systems. Recently further developments of computational techniques allow simulations of hard rigid objects of generic shape. In the present paper we will present some optimizations for event-driven simulations that offered a significant speedup over previous methods. In particular we will describe a generalization of the well-known linked cell list method and an improvement on the nearest neighbor list method recently proposed by us. © 2010 Elsevier B.V. All rights reserved. Source


An in situ high-temperature X-ray powder diffraction study of the thermal behavior of realgar (α-As 4S 4) has been carried out. Data, measured in transmission geometry on a non-hermetically sealed capillary, indicate that the realgar → β-As 4S 4 phase transition starts at 558 K and is completed at 573 K due to kinetics. Melting starts at 578 K and is completed at 588 K. Thermal expansion of realgar is significant and fairly isotropic. In fact, the a- and b-parameters expand almost at the same rate, whereas the c-parameter is slightly softer against heating. Moreover, the β-angle contracts as temperature is raised. The geometry of the As 4S 4 molecule is largely independent from heating. The lengthening of a few As-S and As-As contacts above or near the sum of the As,S van der Waals radii represents the driving force of the phase transition. In addition, the thermal behavior of arsenolite As 2O 3 and non-stoichiometric As 8S 8+x crystals produced from As 4S 4 melt recrystallization has been investigated. Two members located along the β-As 4S 4-alacranite (As 8S 9) series joint were identified at RT: a term close to the β-As 4S 4 end-member (As 8S 8+x: x = ca. 0.1) and one term of approximate As 8S 8.3 composition. The thermal expansion of β-As 4S 4 is significantly anisotropic following the αb > αa > αc relationship. This is clearly the result of the different packing scheme of the As 4S 4 cages in β-As 4S 4 with respect to realgar. The dependence of cell parameters and volume of As 8S 8.3 is more complicated. In fact, a strong discontinuity on the dependence of cell parameters and volume is observed in the 403-443 K thermal range, i.e., that at which As 8S 8.3 converts partly to realgar. A significant volume expansion is observed as a result of a change of composition to As 8S 8.7. Source


Spadaro A.,University of Rome La Sapienza
Rheumatology (Oxford, England) | Year: 2013

The primary objective of this retrospective study was to investigate the possibility of achieving partial remission (PR) in AS patients treated with anti-TNF-α antagonists, such as adalimumab (ADA), etanercept (ETA) and infliximab (INF), in a real clinical practice setting. Predictors of PR were also evaluated. A retrospective study was conducted in patients with AS treated with ADA, ETA and INF from 2000 to 2012. Kaplan-Meier survival curves were plotted to determine the rates of PR during the treatment with anti-TNF-α drugs. A total of 283 patients with AS were treated with ADA (18.7%), ETA (26.8%) and INF (54.4%) as first anti-TNF-α drugs, with a PR rate of 57.6%. The probability of obtaining PR with ADA, ETA or INF was not significantly different among all anti-TNF-α patients. AS patients treated with a second anti-TNF-α drug had a PR rate of 40.5%, but after switching for lack of response, the probability of obtaining PR with a second anti-TNF-α drug was significantly lower from that of the first anti-TNF-α drug (P = 0.0039). The probability of obtaining PR in patients with enthesitis (P = 0.04) or psoriasis (P = 0.0016) or low levels of CRP (P = 0.0225) was significantly lower compared with that of patients without these manifestations at baseline. Our real-life study on PR confirmed the effectiveness of ADA, ETA or INF as first or second anti-TNF-α drugs. The presence at baseline of enthesitis or psoriasis or low CRP values yielded a lower probability of obtaining PR. Source


The present work analyses the thermal behaviour of alum-(K), KAl(SO4)2·12H2O, by in situ laboratory high-temperature powder X-ray diffraction data from 303 K to melting, which starts at 355 K and is completed, due to kinetics, at 359 K. The calculated a 0 linear thermal expansion coefficient is of 14.68(11) × 10-6 K-1 within the investigated thermal range. The k disorder parameter, describing the extension of the orientational disorder of the sulfate group, has been found to decrease from ∼0.70 to ∼0.65 just before melting. It has been demonstrated that the occurrence of the disorder implies the coexistence of K+ ions in both six- and seven-fold coordination. This is necessary for assigning a reasonable bond-valence sum of 0.81 valence units (vu) to the 'average' K+ ion a instead of 0.66 vu, which is obtained in the case of six-fold coordination alone. We can describe the temperature dependence of k from 93-355 K by means of the empirical equation k = 0.798(12) + 2.5(11) × 10-4 T - 1.9(2) × 10-6 T 2, which includes reference low-temperature data. Bond-valence analysis has shown that, on cooling, an increase of the k disorder parameter and shortening of the K-O2 bond distance act together to maintain constancy in the bond-valence sum at the K site, stabilizing the structure. Therefore, the need for keeping the 'average' K+ ion at a reasonable bond-valence sum appears to be the driving force for the ordering process involving the sulfate group. © 2015 The Mineralogical Society. Source


Alibert J.-J.,University of Toulon | Della Corte A.,University of Rome La Sapienza
Zeitschrift fur Angewandte Mathematik und Physik | Year: 2015

Since the works by Gabrio Piola, it has been debated the relevance of higher-gradient continuum models in mechanics. Some authors even questioned the logical consistency of higher-gradient theories, and the applicability of generalized continuum theories seems still open. The present paper considers a pantographic plate constituted by Euler beams suitably interconnected and proves that Piola’s heuristic homogenization method does produce an approximating continuum in which deformation energy depends only on second gradients of displacements. The Γ-convergence argument presented herein shows indeed that Piola’s conjecture can be rigorously proven in a Banach space whose norm is physically dictated by energetic considerations. © 2015, Springer Basel. Source


Corcione M.,University of Rome La Sapienza
International Journal of Thermal Sciences | Year: 2010

The heat transfer features of buoyancy-driven nanofluids inside rectangular enclosures differentially heated at the vertical walls, are investigated theoretically. The main idea upon which the present work is based is that nanofluids behave more like a single-phase fluid rather than a conventional solid-liquid mixture, which implies that all the convective heat transfer correlations available for single-phase flows can be extended to nanoparticle suspensions, provided that the thermophysical properties appearing in them are the nanofluid effective properties calculated at the reference temperature. In this connection, two empirical equations, based on a wide variety of experimental data reported in the literature, are developed for the evaluation of the nanofluid effective thermal conductivity and dynamic viscosity, whereas the other effective properties are evaluated by the conventional mixing theory. The heat transfer enhancement across the differentially heated enclosure that derives from the dispersion of nano-sized solid particles into a host liquid is calculated for different operating conditions, nanoparticle diameters, combinations of suspended nanoparticles and base liquid, and cavity aspect ratios. The fundamental result obtained is the existence of an optimal particle loading for maximum heat transfer. Specifically, for any assigned combination of solid and liquid phases, the optimal volume fraction is found to increase slightly with decreasing the nanoparticle size, and to increase much more remarkably with increasing both the nanofluid average temperature and the slenderness of the enclosure. © 2010 Elsevier Masson SAS. All rights reserved. Source


Brosens I.,Leuven Institute for Fertility and Embryology | Gordts S.,Leuven Institute for Fertility and Embryology | Benagiano G.,University of Rome La Sapienza
Human Reproduction | Year: 2013

Endometriosis in the adolescent has, in recent years, been discovered to be a challenging problem in gynaecology. Although the pain may start at a young age, even before the onset of menstruation, the diagnosis by laparoscopy is almost always postponed for several years, by which time destructive lesions have affected the tubo-ovarian structures and severely compromised fecundability. Several factors may play a role, but one important reason for this disease progression is likely to be the delay in diagnosis. Therefore, transvaginal ultrasounds and transvaginal access with a less invasive needle endoscopy are recommended for exploration of the pelvis, diagnosis of endometriosis and treatment at an early stage before severe lesions develop. © The Author 2013. Source


Lo Vasco V.R.,University of Rome La Sapienza
Journal of Affective Disorders | Year: 2015

A number of studies suggested that suicide may be associated with specific neurobiological abnormalities. Neurobiology studies focused upon abnormalities of signalling mechanisms with special regard to the serotonin system and the related Phosphoinositide (PI) signalling system. Previous data suggested the involvement of the PI-specific phospholipase C (PLC) family in neuropsychiatric disorders. By using PCR and morphological microscopy observation we examined the whole panel of expression of PLC isoforms in the brains of 28 individuals who committed suicide and in normal controls in order to evaluate the involvement of specific PLC isoforms. The overall PLC expression was reduced and a complex reorganization of the isoforms was observed. The knowledge of the complex network of neurobiological molecules and interconnected signal transduction pathways in the brain of suicide victims might be helpful to understand the natural history and the pathogenesis of the suicidal behavior. That might lead to obtain prognostic suggestions in order to prevent suicide and to new therapeutic agents targeting specific sites in this signalling cascade. © 2014 Elsevier B.V. All rights reserved. Source


Lanzo G.,University of Rome La Sapienza | Pagliaroli A.,CNR Institute of Environmental Geology and Geoengineering
Soil Dynamics and Earthquake Engineering | Year: 2012

An M w=6.3 earthquake originating at a normal fault in proximity of the city of L'Aquila produced a significant amount of near-fault strong-motion data recorded by an array deployed in the upper Aterno River Valley, NW of L'Aquila. This set of data deserves attention since it is the first well documented earthquake occurring in a near-fault area which was recorded from a moderate magnitude earthquake on a normal fault. For most of the stations geotechnical conditions are ascertained by means of drilling and geophysical investigation. To provide insights on the relevance of site conditions on measured near-source ground motions, peak and spectral values of acceleration and velocity recordings at stiff soil sites are compared with those at "rock" reference sites. Events of magnitude ranging between 3.0 and 6.3 (main event) were used. The results show that peak and response spectra values of ground motion, for the horizontal component and to a lesser extent for the vertical one, are affected by soil profile characteristics, especially for the station located on alluvium at the centre of the valley. For this station, observed amplification ratios were compared with numerical ones computed from 1D site response analyses. Evidence is presented that 1D numerical modelling is not able to completely explain the recorded motions. © 2012 Elsevier Ltd. Source


Amelino-Camelia G.,University of Rome La Sapienza | Amelino-Camelia G.,National Institute of Nuclear Physics, Italy
Physical Review Letters | Year: 2013

Over the last decade, a growing number of quantum-gravity researchers has been looking for opportunities for the first ever experimental evidence of a Planck-length quantum property of spacetime. These studies are usually based on the analysis of some candidate indirect implications of spacetime quantization, such as a possible curvature of momentum space. Some recent proposals have raised hope that we might also gain direct experimental access to quantum properties of spacetime, by finding evidence of limitations to the measurability of the center-of-mass coordinates of some macroscopic bodies. However, I here observe that the arguments that originally led to speculating about spacetime quantization do not apply to the localization of the center of mass of a macroscopic body. And, I also analyze some popular formalizations of the notion of quantum spacetime, finding that when the quantization of spacetime is Planckian for the constituent particles, then for the center of mass of a composite macroscopic body the quantization of spacetime is much weaker than Planckian. These results suggest that the center-of-mass observables of macroscopic bodies should not provide good opportunities for uncovering quantum properties of spacetime. And, they also raise some conceptual challenges for theories of mechanics in quantum spacetime, in which, for example, free protons and free atoms should feel the effects of spacetime quantization differently. © 2013 American Physical Society. Source


Caracciolo G.,University of Rome La Sapienza | Amenitsch H.,Austrian Academy of Sciences
European Biophysics Journal | Year: 2012

Gene-based therapeutic approaches are based upon the concept that, if a disease is caused by a mutation in a gene, then adding back the wild-type gene should restore regular function and attenuate the disease phenotype. To deliver the gene of interest, both viral and nonviral vectors are used. Viruses are efficient, but their application is impeded by detrimental side-effects. Among nonviral vectors, cationic liposomes are the most promising candidates for gene delivery. They form stable complexes with polyanionic DNA (lipoplexes). Despite several advantages over viral vectors, the transfection efficiency (TE) of lipoplexes is too low compared with those of engineered viral vectors. This is due to lack of knowledge about the interactions between complexes and cellular components. Rational design of efficient lipoplexes therefore requires deeper comprehension of the interactions between the vector and the DNA as well as the cellular pathways and mechanisms involved. The importance of the lipoplex structure in biological function is revealed in the application of synchrotron small-angle X-ray scattering in combination with functional TE measurements. According to current understanding, the structure of lipoplexes can change upon interaction with cellular membranes and such changes affect the delivery efficiency. Recently, a correlation between the mechanism of gene release from complexes, the structure, and the physical and chemical parameters of the complexes has been established. Studies aimed at correlating structure and activity of lipoplexes are reviewed herein. This is a fundamental step towards rational design of highly efficient lipid gene vectors. © 2012 European Biophysical Societies' Association. Source


Rossi G.C.,University of Rome Tor Vergata | Testa M.,University of Rome La Sapienza
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We show how to define and compute in a nonperturbative way the potential between q and q̄ color sources in the singlet and octet (adjoint) representations of the color group. © 2013 American Physical Society. Source


Grani G.,University of Rome La Sapienza
La Clinica terapeutica | Year: 2012

Several studies have been undertaken to investigate a possible link between breast cancer and thyroid diseases, notably thyroid carcinoma and autoimmune thyroid diseases, but the issue remains unresolved. The aim of this study is to evaluate, in thyropathic women with and without breast cancer, the following effects: the distribution of different thyroid diseases, the breast-cancer-related prevalence of anti-thyroperoxidase and anti-thyroglobulin antibodies and the role in thyroid pathology of breast-cancer post-surgery therapy with tamoxifene. One-hundred-ninety thyropathic women with breast cancer (BC group) were recruited, and compared with a control group (C group) of one-hundred-ninety thyropathic women without breast cancer. Nodular disease is the most frequent pathology in both groups. The difference in the incidence of thyroid carcinoma is also not statistically significant. The biochemical increase in the positivity of autoantibodies in BC-group patients is confirmed, but there is no statistically significant difference in the rate of clinical autoimmune diseases between the two groups. No difference in the frequency of any particular thyroid disease is found between those patients who underwent post-operative tamoxifene therapy and those who did not. It can be concluded, on the basis of these results, that it is advisable to reduce the clinical weight of the issue. A routine thyroid screening is recommended in women with BC for the management of chronic comorbidities, as would be for women in the general population having the same age and coming from the same iodine-intake area. Source


Burrascano S.,University of Rome La Sapienza
Biodiversity and Conservation | Year: 2010

The importance of harmonizing the group of terms used to indicate 'natural' forests is reported in several studies. In a recent paper the term virgin forest is proposed as a unifying concept for forests which are not influenced by man in their development. In response to that paper my aim is to clarify the terms virgin and old-growth. My response focuses on two points: the term virgin forest is generally used to indicate forests that have not been influenced by people even in the distant past, therefore something different from what described by the authors; the definition drawn up for the proposed term substantially overlaps with the definition of old-growth forest resulting from a long history of studies on this theme. I think that the overlap between the two analyzed terms can ultimately only increase the existing confusion on this group of forest terms. © 2010 Springer Science+Business Media B.V. Source


Kasteleijn-Nolst Trenite D.,University of Rome La Sapienza
Epilepsia | Year: 2012

Gowers gave migraine a place in the borderland of epilepsy, justified by many relations and the fact that distinction of these two diseases is difficult. Gowers based his ideas on clinical histories from his patients, and he concluded that in extremely rare instances one may develop while the other goes on. In modern times, patient testimonies of the problem of differentiating migraine from epilepsy are given in health-chat Websites. It shows clearly that distinction between the two conditions is still problematic and that migralepsy is either nonexisting or extremely rare as Gowers noticed. Wiley Periodicals, Inc. © 2012 International League Against Epilepsy. Source


Lo Vasco V.R.,University of Rome La Sapienza
Neuroscience Bulletin | Year: 2012

The development of the nervous system is under the strict control of a number of signal transduction pathways, often interconnected. Among them, the phosphoinositide (PI) pathway and the related phospholipase C (PI-PLC) family of enzymes have been attracting much attention. Besides their well-known role in the regulation of intracellular calcium levels, PI-PLC enzymes interact with a number of molecules belonging to further signal transduction pathways, contributing to a specific and complex network in the developing nervous system. In this review, the connections of PI signalling with further transduction pathways acting during neural development are discussed, with special regard to the role of the PI-PLC family of enzymes. © 2012 Shanghai Institutes for Biological Sciences, CAS and Springer-Verlag Berlin Heidelberg. Source


Vasileiou V.,Montpellier University | Granot J.,Open University of Israel | Piran T.,Hebrew University of Jerusalem | Amelino-Camelia G.,University of Rome La Sapienza
Nature Physics | Year: 2015

Wheeler's 'spacetime-foam'picture of quantum gravity (QG) suggests spacetime fuzziness (fluctuations leading to non-deterministic effects) at distances comparable to the Planck length, L Pl â ‰ 1.62 × 10 â '33 cm, the inverse (in natural units) of the Planck energy, E Pl â ‰ 1.22 × 10 19 GeV. The resulting non-deterministic motion of photons on the Planck scale is expected to produce energy-dependent stochastic fluctuations in their speed. Such a stochastic deviation from the well-measured speed of light at low photon energies, c, should be contrasted with the possibility of an energy-dependent systematic, deterministic deviation. Such a systematic deviation, on which observations by the Fermi satellite set Planck-scale limits for linear energy dependence, is more easily searched for than stochastic deviations. Here, for the first time, we place Planck-scale limits on the more generic spacetime-foam prediction of energy-dependent fuzziness in the speed of photons. Using high-energy observations from the Fermi Large Area Telescope (LAT) of gamma-ray burst GRB090510, we test a model in which photon speeds are distributed normally around c with a standard deviation proportional to the photon energy. We constrain the model's characteristic energy scale beyond the Planck scale at >2.8E Pl (>1.6E Pl), at 95% (99%) confidence. Our results set a benchmark constraint to be reckoned with by any QG model that features spacetime quantization. © 2015 Macmillan Publishers Limited. All rights reserved. Source


Sancini A.,University of Rome La Sapienza
Annali di igiene : medicina preventiva e di comunità | Year: 2012

Chronic venous disorder is a public health problem that affects the western industrialized countries. The aim of this study is to evaluate the etiology and prevalence of venous disease of the lower limb in workers, and to identify some risk factors using a detailed and systematic analysis of the literature from 1964 to 2011. There is an important relationship between standing position at work and venous disease. The prolonged orthostatic position of the body implies: venostasis, high pressure and risks of blood clots and thrombosis; in standing workers there is an overproduction of reactive oxygen species (ROS) with oxidation of the components of cell membranes, endothelial damage and increase in vascular permeability. Other risk factors were investigated: sitting during work time, weight lifting-moving and exposure to heat sources, the data suggest that this risk factors are less important than orthostatic body position. Age, sex and familiarity are relevant as the extra-occupational risk factors. For a more accurate study of the role of the prolonged orthostatic position on the development of venous disease in the lover limb all authors should define exactly the population, the role and the length of standing time at work. They should also set a universal language to define the correct standing position (ie. within 1 m2 or steps) and time (ie. one hour or 50%-70% of work time). Attention should be given to prevention, to use early therapeutic measures in view of mortality as a consequence of venous disease, of the high social costs related to the loss of working days, of medical care and of residual disability. Source


Quaranta G.,University of Rome La Sapienza
Computer Methods in Applied Mechanics and Engineering | Year: 2011

This paper presents a general method for the finite element analysis of linear mechanical systems by taking into account probability density functions whose parameters are affected by fuzziness. Within this framework, the standard perturbation-based stochastic finite element method is relaxed in order to incorporate uncertain probabilities in static, dynamic and modal analyses. General formulae are provided for assessing the (fuzzy) structural reliability and several typologies of optimization problems (reliability-based design, robust design, robust/reliability-based design) are formalized. In doing this the credibility theory is extensively used to extract qualified crisp data from the available set of fuzzy results, so that standard optimizers can be adopted to solve the most important design problems. It is shown that the proposed methodology is a general and versatile tool for finite element analyses because it is able to consider, both, probabilistic and non-probabilistic sources of uncertainties, such as randomness, vagueness, ambiguity and imprecision. © 2010 Elsevier B.V. Source


Lecian O.M.,University of Rome La Sapienza
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

Cosmological billiards arise as a map of the solution to the Einstein equations, when the most general symmetry of the metric tensor is implemented, under the Belinskii, Khalatnikov and Lifshitz (BKL) paradigm, for which points are spatially decoupled in the asymptotical limit close to the cosmological singularity. Cosmological billiards in 4=3+1 dimensions for the case of pure gravity are analyzed for those features, for which the content of Weyl reflections in the BKL maps requires the definition of a three-dimensional restricted phase space. The role of Poincaré sections in these processes is outlined. The quantum regime is investigated within this framework: as a result, one-epoch BKL eras are found to be the most probable configuration at which the wave functions have to be evaluated; furthermore, BKL eras containing na1 epochs are shown to be a less probable configuration for the wave functions. This description of the dynamics allows one to gain information about the connections between the statistical characterization of the maps which imply the different symmetry-quotienting mechanisms and the characterization of the semiclassical limit of the wave functions, for which evidence is produced for the phenomenon of "scars," here for the first time outlined for the wave function of the universe in cosmological billiards, analyzed for the lowest silver ratios, and compared with the implications of a Farey map. The connections between the classical BKL probabilties and the quanum BKL probabilities for the "scarred" wave functions of the universe are provided and compared within different expansions according to different limits of the BKL statistics © 2013 American Physical Society. Source


Pachon L.A.,University of Antioquia | Rueda J.A.,University of Rome La Sapienza | Valenzuela-Toledo C.A.,University of Santiago de Cali
Astrophysical Journal | Year: 2012

Whether or not analytic exact vacuum (electrovacuum) solutions of the Einstein (Einstein-Maxwell) field equations can accurately describe the exterior space-time of compact stars still remains an interesting open question in relativistic astrophysics. As an attempt to establish their level of accuracy, the radii of the innermost stable circular orbits (ISCOs) of test particles given by analytic exterior space-time geometries have been compared with those given by numerical solutions for neutron stars (NSs) obeying a realistic equation of state (EOS). It has been so shown that the six-parametric solution of Pachón et al. (PRS) more accurately describes the NS ISCO radii than other analytic models do. We propose here an additional test of accuracy for analytic exterior geometries based on the comparison of orbital frequencies of neutral test particles. We compute the Keplerian, frame-dragging, and precession and oscillation frequencies of the radial and vertical motions of neutral test particles for the Kerr and PRS geometries and then compare them with the numerical values obtained by Morsink & Stella for realistic NSs. We identify the role of high-order multipole moments such as the mass quadrupole and current octupole in the determination of the orbital frequencies, especially in the rapid rotation regime. The results of this work are relevant to cast a separatrix between black hole and NS signatures and to probe the nuclear-matter EOS and NS parameters from the quasi-periodic oscillations observed in low-mass X-ray binaries. © 2012. The American Astronomical Society. All rights reserved. Source


Pelissetto A.,University of Rome La Sapienza | Vicari E.,University of Pisa
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We investigate the nature of the finite-temperature chiral transition in QCD with two light flavors, in the case of an effective suppression of the U(1)A symmetry breaking induced by the axial anomaly, which implies the symmetry breaking U(2)L⊠- U(2)R→ U(2)V, instead of SU(2)L⊠- SU(2) R→SU(2)V. For this purpose, we perform a high-order field-theoretical perturbative study of the renormalization-group flow of the corresponding three-dimensional multiparameter Landau-Ginzburg-Wilson Φ4 theory with the same symmetry-breaking pattern. We confirm the existence of a stable fixed point and determine its attraction domain in the space of the bare quartic parameters. Therefore, the chiral QCD transition might be continuous also if the U(1)A symmetry is effectively restored at Tc. However, the corresponding universality class differs from the O(4) vector universality class which would describe a continuous transition in the presence of a substantial U(1)A symmetry breaking at Tc. We estimate the critical exponents of the U(2)L⊠- U(2)R→U(2)V universality class by computing and analyzing the corresponding perturbative expansions. These results are important to discriminate among the different scenarios for the scaling behavior of QCD with two light flavors close to the chiral transition. © 2013 American Physical Society. Source


Curtin D.,State University of New York at Stony Brook | Galloway J.,University of Rome La Sapienza | Wacker J.G.,SLAC
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We evaluate the potential of a dedicated search for tt̄h production in the SSDL+2b channel. Such a measurement provides direct access to the top Yukawa coupling, since the sensitivity is not convolved with the loop-level hγγ as is the case for present tt̄h searches. Furthermore, susceptibility to uncertainties in the Higgs width can be reduced by considering a ratio of SSDL+2b rates with those of the performed Wh→WWW * measurement. The SSDL channel can therefore rely primarily on the already well-measured h→WW* decay. This feasibility study required the development of a new calculation method for "fake" leptons, which constitute the dominant background to our search. Combining measurements from LHC7, LHC8, and in the future LHC14 for the Higgs coupling fit would help resolve any remaining ambiguity between the top Yukawa coupling and a beyond standard model contribution to the hgg coupling. © 2013 American Physical Society. Source


Background: The increasing popularity of commercial movies showing three dimensional (3D) images has raised concern about possible adverse side effects on viewers. Methods and Findings: A prospective carryover observational study was designed to assess the effect of exposure (3D vs. 2D movie views) on self reported symptoms of visually induced motion sickness. The standardized Simulator Sickness Questionnaire (SSQ) was self administered on a convenience sample of 497 healthy adult volunteers before and after the vision of 2D and 3D movies. Viewers reporting some sickness (SSQ total score>15) were 54.8% of the total sample after the 3D movie compared to 14.1% of total sample after the 2D movie. Symptom intensity was 8.8 times higher than baseline after exposure to 3D movie (compared to the increase of 2 times the baseline after the 2D movie). Multivariate modeling of visually induced motion sickness as response variables pointed out the significant effects of exposure to 3D movie, history of car sickness and headache, after adjusting for gender, age, self reported anxiety level, attention to the movie and show time. Conclusions: Seeing 3D movies can increase rating of symptoms of nausea, oculomotor and disorientation, especially in women with susceptible visual-vestibular system. Confirmatory studies which include examination of clinical signs on viewers are needed to pursue a conclusive evidence on the 3D vision effects on spectators. © 2013 Angelo G. Source


Cametti C.,University of Rome La Sapienza
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2010

We have investigated the dielectric properties of water-in-oil microemulsions composed of sodium bis(2-ethyl-hexyl)sulfosuccinate, water, and decane, using radiofrequency impedance spectroscopy, below the percolation threshold, where the system behaves as surfactant-coated individual water droplets dispersed in a continuous oil phase. The analysis of the dielectric spectra has evidenced that the whole dielectric response below percolation is due to two different contributions, which give rise to two partially overlapping dielectric relaxations, approximately in the frequency range from 10 to 500 MHz. The first of these mechanisms is originated by the bulk polarization of counterions distributed in the electrical double layer of the droplet interior. The second mechanism is associated with a correlated motion of the anionic head groups SO 3- at the surfactant-water interface. The introduction of this latter contribution allows us to justify the experimentally observed increase in the low-frequency permittivity as a function of temperature up to temperatures very close to percolation. The present study shows that deviations from the expected values on the basis of dielectric theories of heterogeneous systems (Maxwell-Wagner effect) observed when percolation is approaching can be accounted for, in a reasonable way, by the introduction of a further polarization mechanism, which involves the anionic surfactant groups. Only very close to percolation, when microemulsions undergo a scaling behavior, deviations of the permittivity (and electrical conductivity as well) are a print of the structural rearrangement of the whole system and models based on colloidal particle suspension theories fail. Even if the whole picture of the dielectric properties of microemulsion systems does not change in deep, nevertheless, the refinement introduced in this paper demonstrates how different polarization mechanisms could be simultaneously present in these rather complex systems and, above all, how the individual particle colloidal properties are maintained up to very close to the percolation threshold. © 2010 The American Physical Society. Source


Innocenti G.M.,Karolinska Institutet | Vercelli A.,University of Turin | Caminiti R.,University of Rome La Sapienza
Cerebral Cortex | Year: 2014

In primates, different cortical areas send axons of different diameters into comparable tracts, notably the corpus callosum (Tomasi S, Caminiti R, Innocenti GM. 2012. Areal differences in diameter and length of corticofugal projections. Cereb Cortex. 22:1463-1472). We now explored if an area also sends axons of different diameters to different targets. We find that the parietal area PEc sends thicker axons to area 4 and 6, and thinner ones to the cingulate region (area 24). Areas 4 and 9, each sends axons of different diameters to the nucleus caudatus, to different levels of the internal capsule, and to the thalamus. The internal capsule receives the thickest axon, followed by thalamus and nucleus caudatus. The 2 areas (4 and 9) differ in the diameter and length of axons to corresponding targets. We calculated how diameter determines conduction velocity of the axons and together with pathway length determines transmission delays between different brain sites. We propose that projections from and within the cerebral cortex consist of a complex system of lines of communication with different geometrical and time computing properties. © The Author 2013. Source


Bonini M.,University of Rome La Sapienza
The Cochrane database of systematic reviews | Year: 2013

It is well known that physical exercise can trigger asthma symptoms and can induce bronchial obstruction in people without clinical asthma. International guidelines on asthma management recommend the use of beta2-agonists at any stage of the disease. At present, however, no consensus has been reached about the efficacy and safety of beta2-agonists in the pretreatment of exercise-induced asthma and exercise-induced bronchoconstriction. For the purpose of the present review, both of these conditions are referred to by the acronymous EIA, independently from the presence of an underlying chronic clinical disease. To assess the effects of inhaled short- and long-acting beta2-agonists, compared with placebo, in the pretreatment of children and adults with exercise-induced asthma (or exercise-induced bronchoconstriction). Trials were identified by electronic searching of the Cochrane Airways Group Specialised Register of Trials and by handsearching of respiratory journals and meetings. Searches are current as of August 2013. We included randomised, double-blind, placebo-controlled trials of any study design, published in full text, that assessed the effects of inhaled beta2-agonists on EIA in adults and children. We excluded studies that did not clearly state diagnostic criteria for EIA. We used standard methodological procedures as expected by The Cochrane Collaboration. We included 53 trials consisting of 1139 participants. Forty-eight studies used a cross-over design, and five were performed in accordance with a parallel-group design. Forty-five studies addressed the effect of a single beta2-agonist administration, and eight focused on long-term treatment. We addressed these two different intervention regimens as different comparisons.Among primary outcomes for short-term administration, data on maximum fall in forced expiratory volume in 1 second (FEV1) showed a significant protective effect for both short-acting beta-agonists (SABA) and long-acting beta-agonists (LABA) compared with placebo, with a mean difference of -17.67% (95% confidence interval (CI) -19.51% to -15.84%, P = 0.00001, 799 participants from 72 studies). The subgroup analysis of studies performed in adults compared with those performed in children showed high heterogeneity confined to children, despite the comparable mean bronchoprotective effect.Secondary outcomes on other pulmonary function parameters confirmed a more positive and protective effect of beta2-agonists on EIA compared with placebo. Occurrence of side effects was not significantly different between beta2-agonists and placebo.Overall evaluation of the included long-term studies suggests a beta2-agonist bronchoprotective effect for the first dose of treatment. However, long-term use of both SABA and LABA induced the onset of tolerance and decreased the duration of drug effect, even after a short treatment period. Evidence of low to moderate quality shows that beta2-agonists, both SABA and LABA, when administered in a single dose, are effective and safe in preventing EIA.Long-term regular administration of inhaled beta2-agonists induces tolerance and lacks sufficient safety data. This finding appears to be of particular clinical relevance in view of the potential for prolonged regular use of beta2-agonists as monotherapy in the pretreatment of EIA, despite the warnings of drug agencies (FDA, EMA) regarding LABA. Source


Loffredo L.,University of Rome La Sapienza
Internal and emergency medicine | Year: 2011

Chronic granulomatous disease (CGD) is a rare primary immunodeficiency due to an abnormal function of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase; NADPH oxidase is a key enzyme for the cellular "respiratory burst", the cellular process that converts molecular oxygen to the oxygen free-radical superoxide. As a consequence of NADPH oxidase defect, CGD patients suffer from recurrent life-threatening infections and from exceeding inflammatory responses leading to granulomas. This article analyzes clinical aspects of CGD. Furthermore, using the CGD model, we focused on the future perspective to reduce atherosclerosis and its complications. Source


Arzano M.,University of Rome La Sapienza | Calcagni G.,CSIC - Institute for the Structure of Matter
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

The density of states reproducing the Bekenstein-Hawking entropy-area scaling can be modeled via a nonlocal field theory. We define a diffusion process based on the kinematics of this theory and find a spectral dimension whose flow exhibits surprising properties. While it asymptotes four from above in the infrared, in the ultraviolet the spectral dimension diverges at a finite (Planckian) value of the diffusion length, signaling a breakdown of the notion of diffusion on a continuum spacetime below that scale. We comment on the implications of this minimal diffusion scale for the entropy bound in a holographic and field-theoretic context. © 2013 American Physical Society. Source


Di Lorenzo P.,University of Rome La Sapienza | Sayed A.H.,University of California at Los Angeles
IEEE Transactions on Signal Processing | Year: 2013

This article proposes diffusion LMS strategies for distributed estimation over adaptive networks that are able to exploit sparsity in the underlying system model. The approach relies on convex regularization, common in compressive sensing, to enhance the detection of sparsity via a diffusive process over the network. The resulting algorithms endow networks with learning abilities and allow them to learn the sparse structure from the incoming data in real-time, and also to track variations in the sparsity of the model. We provide convergence and mean-square performance analysis of the proposed method and show under what conditions it outperforms the unregularized diffusion version. We also show how to adaptively select the regularization parameter. Simulation results illustrate the advantage of the proposed filters for sparse data recovery. © 1991-2012 IEEE. Source


Cercato M.,University of Rome La Sapienza
Geophysical Prospecting | Year: 2011

Practical applications of surface wave inversion demand reliable inverted shear-wave profiles and a rigorous assessment of the uncertainty associated to the inverted parameters. As a matter of fact, the surface wave inverse problem is severely affected by solution non-uniqueness: the degree of non-uniqueness is closely related to the complexity of the observed dispersion pattern and to the experimental inaccuracies in dispersion measurements. Moreover, inversion pitfalls may be connected to specific problems such as inadequate model parametrization and incorrect identification of the surface wave modes. Consequently, it is essential to tune the inversion problem to the specific dataset under examination to avoid unnecessary computations and possible misinterpretations. In the heuristic inversion algorithm presented in this paper, different types of model constraints can be easily introduced to bias constructively the solution towards realistic estimates of the 1D shear-wave profile. This approach merges the advantages of global inversion, like the extended exploration of the parameter space and a theoretically rigorous assessment of the uncertainties on the inverted parameters, with the practical approach of Lagrange multipliers, which is often used in deterministic inversion, which helps inversion to converge towards models with desired properties (e.g., 'smooth' or 'minimum norm' models). In addition, two different forward kernels can be alternatively selected for direct-problem computations: either the conventional modal inversion or, instead, the direct minimization of the secular function, which allows the interpreter to avoid mode identification. A rigorous uncertainty assessment of the model parameters is performed by posterior covariance analysis on the accepted solutions and the modal superposition associated to the inverted models is investigated by full-waveform modelling. This way, the interpreter has several tools to address the more probable sources of inversion pitfalls within the framework of a rigorous and well-tested global inversion algorithm. The effectiveness and the versatility of this approach, as well as the impact of the interpreter's choices on the final solution and on its posterior uncertainty, are illustrated using both synthetic and real data. In the latter case, the inverted shear velocity profiles are blind compared with borehole data. © 2010 European Association of Geoscientists & Engineers. Source


Salvati L.,Council of Research in Agriculture | Carlucci M.,University of Rome La Sapienza
Ecological Economics | Year: 2011

This paper analyses the economic performances of the rural system and the level of land sensitivity to degradation in Italy. Three indicators (district value added, share of agriculture on total product, and a composite index of land sensitivity) were used to classify 784 Italian local districts into eight performance classes. Four classes share a combination of high environmental quality (in terms of land degradation), high (or low) economic performances, and high (or low) productivity of the primary sector. The remaining four are characterised by a combination of low (and declining) environmental quality, high (or low) economic performances, and high (or low) productivity of the primary sector. The eight classes were grouped into four 'environmental quality' types and four 'target performance' categories to discriminate among high- and low-performance districts by considering twelve additional variables within a Discriminant Function Analysis (DFA). 148 high environmental performance districts (18% of total) were identified mainly across the Alps and Apennine while 314 districts (41%) were classified in the lowest performance class and concentrated in flat areas of southern Italy. The districts with high environmental performances were characterised, on average, by medium to low district value added, moderately low economic weight of the primary sector, and tourism specialisation. Districts with high economic performances and low environmental performances were characterised by high sensitivity to LD, low district value added, high share of agriculture in total product, and the lowest productivity of labour in all economic sectors. In these districts the risk of entering a downward spiral of rural poverty and environmental degradation is potentially high. © 2011 Elsevier B.V. Source


Pastor-Satorras R.,Polytechnic University of Catalonia | Castellano C.,CNR Institute for Complex Systems | Castellano C.,University of Rome La Sapienza | Van Mieghem P.,Technical University of Delft | And 2 more authors.
Reviews of Modern Physics | Year: 2015

In recent years the research community has accumulated overwhelming evidence for the emergence of complex and heterogeneous connectivity patterns in a wide range of biological and sociotechnical systems. The complex properties of real-world networks have a profound impact on the behavior of equilibrium and nonequilibrium phenomena occurring in various systems, and the study of epidemic spreading is central to our understanding of the unfolding of dynamical processes in complex networks. The theoretical analysis of epidemic spreading in heterogeneous networks requires the development of novel analytical frameworks, and it has produced results of conceptual and practical relevance. A coherent and comprehensive review of the vast research activity concerning epidemic processes is presented, detailing the successful theoretical approaches as well as making their limits and assumptions clear. Physicists, mathematicians, epidemiologists, computer, and social scientists share a common interest in studying epidemic spreading and rely on similar models for the description of the diffusion of pathogens, knowledge, and innovation. For this reason, while focusing on the main results and the paradigmatic models in infectious disease modeling, the major results concerning generalized social contagion processes are also presented. Finally, the research activity at the forefront in the study of epidemic spreading in coevolving, coupled, and time-varying networks is reported. © 2015 American Physical Society. © 2015 American Physical Society. Source


Pelissetto A.,University of Rome La Sapienza
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

We consider the O(N)-symmetric ϕ4 theory in two and three dimensions and determine the nonperturbative mass renormalization needed to obtain the ϕ4 continuum theory. The required nonperturbative information is obtained by resumming high-order perturbative series in the massive renormalization scheme, taking into account their Borel summability and the known large-order behavior of the coefficients. The results are in good agreement with those obtained in lattice calculations. © 2015 The Authors. Source


Malvestuto F.M.,University of Rome La Sapienza
Kybernetika | Year: 2014

We generalize Jiroušek's (right) composition operator in such a way that it can be applied to distribution functions with values in a "semifield", and introduce (parenthesized) compositional expressions, which in some sense generalize Jiroušek's "generating sequences" of compositional models. We say that two compositional expressions are equivalent if their evaluations always produce the same results whenever they are defined. Our first result is that a set system H is star-like with centre X if and only if every two compositional expressions with "base scheme" H and "key" X are equivalent. This result is stronger than Jiroušek's result which states that, if H is star-like with centre X, then every two generating sequences with base scheme H and key X are equivalent. Then, we focus on canonical expressions, by which we mean compositional expressions θ such that the sequence of the sets featured in θ and arranged in order of appearance enjoys the "running intersection property". Since every compositional expression, whose base scheme is a star-like set system with centre X and whose key is X, is a canonical expression, we investigate the equivalence between two canonical expressions with the same base scheme and the same key. We state a graphical characterization of those set systems H such that every two canonical expressions with base scheme H and key X are equivalent, and also provide a graphical algorithm for their recognition. Finally, we discuss the problem of detecting conditional independences that hold in a compositional model. Source


Parrino L.,University of Parma | Ferri R.,Oasi Institute for Research on Mental Retardation and Brain Aging IRCCS | Bruni O.,University of Rome La Sapienza | Terzano M.G.,University of Parma
Sleep Medicine Reviews | Year: 2012

Cyclic alternating pattern CAP is the EEG marker of unstable sleep, a concept which is poorly appreciated among the metrics of sleep physiology. Besides, duration, depth and continuity, sleep restorative properties depend on the capacity of the brain to create periods of sustained stable sleep. This issue is not confined only to the EEG activities but reverberates upon the ongoing autonomic activity and behavioral functions, which are mutually entrained in a synchronized oscillation. CAP can be identified both in adult and children sleep and therefore represents a sensitive tool for the investigation of sleep disorders across the lifespan. The present review illustrates the story of CAP in the last 25 years, the standardized scoring criteria, the basic physiological properties and how the dimension of sleep instability has provided new insight into pathophysiolology and management of sleep disorders. © 2011 Elsevier Ltd. Source


Ceragioli F.,Polytechnic University of Turin | De Persis C.,University of Twente | De Persis C.,University of Rome La Sapienza | Frasca P.,Polytechnic University of Turin
Automatica | Year: 2011

We consider continuous-time average consensus dynamics in which the agents' states are communicated through uniform quantizers. Solutions to the resulting system are defined in the Krasowskii sense and are proven to converge to conditions of "practical consensus". To cope with undesired chattering phenomena we introduce a hysteretic quantizer, and we study the convergence properties of the resulting dynamics by a hybrid system approach. © 2011 Elsevier Ltd. All rights reserved. Source


Pietrabissa A.,University of Rome La Sapienza
European Journal of Control | Year: 2011

This paper defines a reinforcement learning (RL) approach to call control algorithms in links with variable capacity supporting multiple classes of service. The novelties of the document are the following: i) the problem is modeled as a constrained Markov decision process (MDP); ii) the constrained MDP is solved via a RL algorithm by using the Lagrangian approach and state aggregation. The proposed approach is capable of controlling classlevel quality of service in terms of both blocking and dropping probabilities. Numerical simulations show the effectiveness of the approach. © 2011 EUCA. Source


Perluigi M.,University of Rome La Sapienza | Butterfield D.A.,University of Kentucky
Current Gerontology and Geriatrics Research | Year: 2012

Down syndrome (DS) is one of the most frequent genetic abnormalities characterized by multiple pathological phenotypes. Indeed, currently life expectancy and quality of life for DS patients have improved, although with increasing age pathological dysfunctions are exacerbated and intellectual disability may lead to the development of Alzheimer's type dementia (AD). The neuropathology of DS is complex and includes the development of AD by middle age, altered free radical metabolism, and impaired mitochondrial function, both of which contribute to neuronal degeneration. Understanding the molecular basis that drives the development of AD is an intense field of research. Our laboratories are interested in understanding the role of oxidative stress as link between DS and AD. This review examines the current literature that showed oxidative damage in DS by identifying putative molecular pathways that play a central role in the neurodegenerative processes. In addition, considering the role of mitochondrial dysfunction in neurodegenerative phenomena, results demonstrating the involvement of impaired mitochondria in DS pathology could contribute a direct link between normal aging and development of AD-like dementia in DS patients. Copyright © 2012 Marzia Perluigi and D. Allan Butterfield. Source


Celani F.,University of Rome La Sapienza
Automatica | Year: 2011

The present work deals with the design of a feedback controller that solves an output regulation problem for the nonlinear benchmark example known as TORA. The controller uses only measurements of the rotational position and is obtained through a certainty-equivalence approach. © 2011 Elsevier Ltd. All rights reserved. Source


Colone F.,University of Rome La Sapienza
IET Radar, Sonar and Navigation | Year: 2011

In this study, the effects of bistatic clutter spectral dispersion on space-time adaptive processing (STAP) techniques are considered. A robust spectral slope-based approach is presented for mitigating the bistatic geometry-induced performance loss by pre-processing the secondary data used for covariance estimation. Owing to its capability to compensate both the clutter spectral centres misalignment and the trace slope variability over range, this approach is shown to yield further dispersion reduction with respect to previously proposed strategies, thus improving the performance of STAP. An adaptive version of the proposed approach is also introduced, which is able to extract the required parameters from the same data set used for the covariance matrix estimation, without requiring prior knowledge or ancillary data. The performance analysis against synthetic clutter data shows that the proposed slope-based compensation technique is rather robust with respect to the spectral trace shape and estimation errors, providing equal or better performance with respect to previously derived techniques, depending on the specific bistatic geometry. © 2011 The Institution of Engineering and Technology. Source


Moult J.,University of Maryland College Park | Fidelis K.,University of California at Davis | Kryshtafovych A.,University of California at Davis | Schwede T.,Swiss Institute of Bioinformatics | Tramontano A.,University of Rome La Sapienza
Proteins: Structure, Function and Bioinformatics | Year: 2014

This article is an introduction to the special issue of the journal PROTEINS, dedicated to the tenth Critical Assessment of Structure Prediction (CASP) experiment to assess the state of the art in protein structure modeling. The article describes the conduct of the experiment, the categories of prediction included, and outlines the evaluation and assessment procedures. The 10 CASP experiments span almost 20 years of progress in the field of protein structure modeling, and there have been enormous advances in methods and model accuracy in that period. Notable in this round is the first sustained improvement of models with refinement methods, using molecular dynamics. For the first time, we tested the ability of modeling methods to make use of sparse experimental three-dimensional contact information, such as may be obtained from new experimental techniques, with encouraging results. On the other hand, new contact prediction methods, though holding considerable promise, have yet to make an impact in CASP testing. The nature of CASP targets has been changing in recent CASPs, reflecting shifts in experimental structural biology, with more irregular structures, more multi-domain and multi-subunit structures, and less standard versions of known folds. When allowance is made for these factors, we continue to see steady progress in the overall accuracy of models, particularly resulting from improvement of non-template regions. © 2013 Wiley Periodicals, Inc. Source


Frangipane M.,University of Rome La Sapienza
Proceedings of the National Academy of Sciences of the United States of America | Year: 2015

After briefly examining the forms of cultural contact in pre- and protohistoric societies in relation to the problem of the varying perception of territories and their "borders" as well as of "membership" in those societies, and after a brief reconsideration of the concept of culture and ethnicity in such archaic contexts, this paper then examines three examples of multiethnic societies in the Near East, and specifically in Upper Mesopotamia and Southeast Anatolia, in the fifth, fourth, and at the beginning of the third millennia before the common era (BCE), respectively. These examples are dealt with as emblematic cases of different models of society, types of interaction with alien groups, levels of integration, and development dynamics. Each of these cases is examined with respect to its socioeconomic context, the archeological evidence of "multiethnicity," the types of interaction between different components, the degree of cultural integration achieved, and the effects on the dynamics of change and the development of the societies examined. By analyzing and comparing these examples, the paper aims to show how interethnic contact impacted differently on different societies according to their types, the reasons and purposes of the interaction, and the degree of integration achieved. Source


Caprara G.V.,University of Rome La Sapienza
Epidemiologia e psichiatria sociale | Year: 2010

AIM: Literature documents that the judgments people hold about themselves, their life, and their future are important ingredients of their psychological functioning and well-being, and are commonly related to each other. METHODS: We used confirmatory factor analysis (CFA) under the classical test theory, regression analysis, and a cross national design. RESULTS: This study provides new findings attesting to the hypothesis that evaluations about oneself, one's life, and one's future rest on a common mode of viewing experiences which we named "Positive Orientation". CONCLUSIONS: Results from an Italian and a Canadian study are presented, attesting to a latent dimension that lies at the core of positive evaluations and that corroborates the utility of the new construct as a critical component of individuals' well-functioning. Source


Morone P.,University of Rome La Sapienza
Biofuels, Bioproducts and Biorefining | Year: 2016

Significant changes are ahead of us: most notably, the world's population is projected to increase by almost one billion people within the next decade and the global middle class is expected to nearly triple by 2030. These trends add pressure to the world economic system and environment: greenhouse gas emissions keep growing at global scale, materials and energy sources are fast approaching their physical limits, and the amount of waste produced under the current system seems to be reaching a new peak. Against this background, a transition from a society heavily based on mass consumption, uncontrolled waste generation, and heavy fossil-fuels exploitation toward one based on resource-efficiency, new production and consumption behaviours, waste reduction, reuse, and valorization, seems a desirable and much-needed feat. This change involves a paradigm shift, which goes beyond technological change – it involves big societal and institutional changes as much as the development of radically new technologies and would give rise, in a long-term perspective, to the beginning of a new long wave of sustained (and sustainable) growth. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd. Source


Benhar O.,University of Rome La Sapienza
Physical Review C - Nuclear Physics | Year: 2013

The convolution approach, which is widely employed to describe final-state interactions in the response of many-body systems, is derived from the expression of the nuclear response in the zeroth-order ladder approximation. Within this framework, the folding function, accounting for the effects of interactions between the struck particle and the spectator system, can be immediately related to the spectral function of particle states. The role of nucleon-nucleon correlations in determining the energy dependence is analyzed. © 2013 American Physical Society. Source


Sciarretta S.,The New School | Volpe M.,I.R.C.C.S Neuromed | Volpe M.,University of Rome La Sapienza | Sadoshima J.,The New School
Circulation Research | Year: 2014

The protein kinase mammalian or mechanistic target of rapamycin (mTOR) is an atypical serine/threonine kinase that exerts its main cellular functions by interacting with specific adaptor proteins to form 2 different multiprotein complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). mTORC1 regulates protein synthesis, cell growth and proliferation, autophagy, cell metabolism, and stress responses, whereas mTORC2 seems to regulate cell survival and polarity. The mTOR pathway plays a key regulatory function in cardiovascular physiology and pathology. However, the majority of information available about mTOR function in the cardiovascular system is related to the role of mTORC1 in the unstressed and stressed heart. mTORC1 is required for embryonic cardiovascular development and for postnatal maintenance of cardiac structure and function. In addition, mTORC1 is necessary for cardiac adaptation to pressure overload and development of compensatory hypertrophy. However, partial and selective pharmacological and genetic inhibition of mTORC1 was shown to extend life span in mammals, reduce pathological hypertrophy and heart failure caused by increased load or genetic cardiomyopathies, reduce myocardial damage after acute and chronic myocardial infarction, and reduce cardiac derangements caused by metabolic disorders. The optimal therapeutic strategy to target mTORC1 and increase cardioprotection is under intense investigation. This article reviews the information available regarding the effects exerted by mTOR signaling in cardiovascular physiology and pathological states. © 2013 American Heart Association, Inc. Source


Cristiani E.,University of Rome La Sapienza | Piccoli B.,Rutgers University | Tosin A.,Polytechnic University of Turin
Multiscale Modeling and Simulation | Year: 2011

In this paper a new multiscale modeling technique is proposed. It relies on a recently introduced measure-theoretic approach, which allows one to manage the microscopic and the macroscopic scale under a unique framework. In the resulting coupled model the two scales coexist and share information. This way it is possible to perform numerical simulations in which the trajectories and the density of the particles affect each other. Crowd dynamics is the motivating application throughout the paper. © 2011 Society for Industrial and Applied Mathematics. Source


Sciubba E.,University of Rome La Sapienza
Ecological Modelling | Year: 2011

Extended Exergy Accounting (" EEA" ) is a method to compute the space- and time integral of the primary exergy required to produce a good or a service: the extended exergy of a commodity measures its " embodied exergy" , including externalities (Labour, Capital and Environmental Costa). A crucial point of the method is the calculation of two econometric coefficients, commonly referred to as " α" and " β" ,used to calculate the extended exergy equivalents of Labour and Capital respectively. In previous applications of the EEA method, these coefficients have been assigned approximate values estimated on the basis of global system considerations. In this paper, a novel procedure is described that leads to the calculation of " exact" values of both econometric coefficients, based on detailed exergy- and monetary balances of the Society to which the EEA is applied. It is shown that both α and β depend in a non-trivial way from the consumption patterns, the technological level and the life- and socio-economic standards of each Country. It is also shown that the values are substantially different for developed (OECD) and underdeveloped Countries, and representative samples of values are calculated and critically analysed. On the basis of these new model coefficients, the specific exergy equivalents of Labour (ee L) and of Capital (ee K) are calculated, and shown to differ from the values used in previous EEA calculations. © 2010 Elsevier B.V. Source


Bruzzese C.,University of Rome La Sapienza
2013 3rd International Conference on Electric Power and Energy Conversion Systems, EPECS 2013 | Year: 2013

A squirrel-cage three-phase induction motor with eccentric rotor and parallel connections in the stator can be represented by five equivalent sequence-circuits of virtually centered-rotor machines, as mathematically proved in a companion paper. The five circuits allow the calculation of stator and rotor fault-related currents, in form of 2(p±1)-pole space vectors for 2p-pole machines. The formal calculation of fault-related currents is very useful for defining fault indicators and tools for diagnosis, and in case of parallel-connected stators (like in many traction motors) the split-phase current signature analysis becomes possible. This paper validates the sequence-circuit modeling by comparing the theoretical results with simulations of a 1130kW traction induction motor with static, dynamic, and mixed faults in both no-load and full-load conditions. The simulations are carried out by using a full mesh-model of the motor, implemented by winding functions. A good match is obtained between theoretical calculations and simulations. Moreover, the role of the cage damping on the eccentricity-related current signatures is evidenced. It is shown that the cage damps not only the signature of static fault but also that of dynamic fault, and that the damping itself is load-dependent in the latter case. © 2013 IEEE. Source


Marcucci E.,Third University of Rome | Gatta V.,University of Rome La Sapienza
Journal of Transport Geography | Year: 2011

The analysis of origin airports in multi-airport regions has a well established tradition in transportation and regional economics. The main goal of the paper is to estimate the importance of the different attributes that determine origin airport choice. In our case we adopt a stated preference approach to study this problem and evaluate the effects of possible policy interventions. We also perform a detailed segmentation of the sample studied according to the socio-economic variables that prove statistically relevant when interacted with the attributes used to characterise airport choice. Moreover, in order to test for the presence of heterogeneity in agents' preferences we estimate several mixed logit models with different specifications, including heteroscedasticity and error component. With respect to previous studies we develop and extend the traditional SP approach by also analysing the role and relevance of attribute cut-offs in this research field. The policy simulations produced are based on the estimation of airport-specific attributes. The study concentrates on a multi-airport region in central Italy where four competing airports are located. © 2009 Elsevier Ltd. Source


Degasperis A.,University of Rome La Sapienza
Journal of Physics A: Mathematical and Theoretical | Year: 2010

Nonlinear optics, more than other subjects, has surprisingly produced quite a number of approximate models which are integrable. Here we briefly mention these models with the aim of showing contacts between the mathematical and applicative sides of the theory of integrable dynamical systems. In particular, we illustrate the recent impact of boomeronic-type wave equations on applicative issues in the special context of the resonant interaction of three waves. © 2010 IOP Publishing Ltd. Source


Piemonte V.,University of Rome La Sapienza
Journal of Polymers and the Environment | Year: 2011

The pressing need to reduce the consumption of non-renewable resources and the emission of greenhouse gases into the environment, in recent decades has led to the wide development of bio-based plastics that are produced from renewable sources, such as corn, wheat, oil seeds etc. Actually, the most important bio-based plastics on the market are the poly(lactic acid) (PLA) produced from Nature Works (USA) and the Mater-Bi, a starch based bioplastics, made from Novamont (Italy). The aim of this work is not only to assess the actual energy and greenhouse gases (GHGs) savings resulting from the production of bioplastics, compared with the production of conventional plastics, but also to analyze what might be the best final disposition of bioplastic wastes in order to maximize the energy saving. Therefore, by using the Life Cycle Assessment (LCA) methodology, LCAs cradle to gate and cradle to grave were carried out both for PLA and Mater-Bi, taking into consideration as final scenarios composting, incineration, anaerobic digestion and mechanical recycling processes. The work demonstrates how incineration, composting and anaerobic digestion processes are clearly under-performing, from an environmental point of view, with respect to the mechanical recycling process. © 2011 Springer Science+Business Media, LLC. Source


Sciubba E.,University of Rome La Sapienza
Ecological Modelling | Year: 2011

This paper presents a critical discussion of the so-called " maximum power principle", often quoted in studies about the energy balance of living systems and also known in the emergy literature as " maximum em-power principle" Several authors consider this principle highly relevant and some even proposed it as a " fourth law of thermodynamics" A critical analysis of the original source, namely Alfred Lotka's 1921-22 papers, conducted both in an historical perspective (the connection between Lotka's writings and the ongoing debate at his time) and in a more modern context, leads to a more detailed and less biased assessment. It turns out that in spite of Lotka's very anticipatory and incredibly sharp vision of the possible interconnections between the second law of thermodynamics and evolutionism, doubts arise about the general applicability of his " maximum power principle" From an accurate analysis of his writings, it can be concluded that: (a) Lotka explicitly and consistently addressed the " optimal use" of the flow of exergy (available energy), and therefore the quantity defined as " em-power" is an incorrect interpretation of Lotka's constrained maximum power principle; (b) " Lotka's principle" can be reformulated within Ziegler's " maximum entropy production" or Prigogine " minimum entropy generation" paradigm only under two different respective sets of rather stringent additional conditions which Lotka was probably already aware of but never explicitly stated. © 2011 Elsevier B.V. Source


Caracciolo G.,University of Rome La Sapienza
Nanomedicine: Nanotechnology, Biology, and Medicine | Year: 2015

Active targeting that exploits the (over)expression of surface receptors in target cells by ligand incorporation is a central concept in nanomedicine research. Despite unprecedented efforts, no targeted liposome-based therapeutics is commercially available for clinical practice. What is inhibiting the efficient translation of targeted liposome technology from bench to bedside? After introduction in the bloodstream, the lipid surface is immediately modified by the adsorption of a "protein corona" and preserving the surface functionality appears to be challenging. On the other hand, a long-standing corona with receptor-binding sites could associate with the target cell long enough to activate the cell's uptake machinery, triggering liposome endocytosis and intracellular cargo delivery. This opens the intriguing possibility to manipulate the corona composition by liposome design. This review will focus on the emerging field of liposome-protein corona research from basic, descriptive research to readily applicable knowledge and technologies for implementation in drug improvement and development. © 2015 Elsevier Inc. Source


Salemi S.,Azienda Ospedaliera S. Andrea | D'Amelio R.,University of Rome La Sapienza
International Reviews of Immunology | Year: 2010

Autoimmune reactions to vaccinations may rarely be induced in predisposed individuals by molecular mimicry or bystander activation mechanisms. Autoimmune reactions reliably considered vaccine-associated, include Guillain-Barré syndrome after 1976 swine influenza vaccine, immune thrombocytopenic purpura after measles/mumps/rubella vaccine, and myopericarditis after smallpox vaccination, whereas the suspected association between hepatitis B vaccine and multiple sclerosis has not been further confirmed, even though it has been recently reconsidered, and the one between childhood immunization and type 1 diabetes seems by now to be definitively gone down. Larger epidemiological studies are needed to obtain more reliable data in most suggested associations. Copyright © 2010 Informa Healthcare USA, Inc. Source


Pirri F.,University of Rome La Sapienza
Artificial Intelligence | Year: 2010

The well-designed logical robot paradigmatically represents, in the words of McCarthy, the abilities that a robot-child should have to reveal the structure of reality within a "language of thought". In this paper we partially support McCarthy's hypothesis by showing that early perception can trigger an inference process leading to the "language of thought". We show this by defining a systematic transformation of structures of different formal languages sharing the same signature kernel for actions and states. Starting from early vision, visual features are encoded by descriptors mapping the space of features into the space of actions. The densities estimated in this space form the observation layer of a hidden states model labelling the identified actions as observations and the states as action preconditions and effects. The learned parameters are used to specify the probability space of a first-order probability model. Finally we show how to transform the probability model into a model of the Situation Calculus in which the learning phase has been reified into axioms for preconditions and effects of actions and, of course, these axioms are expressed in the language of thought. This shows, albeit partially, that there is an underlying structure of perception that can be brought into a logical language. © 2010 Elsevier B.V. All rights reserved. Source


De Michele C.,University of Rome La Sapienza
Journal of Computational Physics | Year: 2010

Several physical systems in condensed matter have been modeled approximating their constituent particles as hard objects. The hard spheres model has been indeed one of the cornerstones of the computational and theoretical description in condensed matter. The next level of description is to consider particles as rigid objects of generic shape, which would enrich the possible phenomenology enormously. This kind of modeling will prove to be interesting in all those situations in which steric effects play a relevant role. These include biology, soft matter, granular materials and molecular systems. With a view to developing a general recipe for event-driven molecular dynamics simulations of hard rigid bodies, two algorithms for calculating the distance between two convex hard rigid bodies and the contact time of two colliding hard rigid bodies solving a non-linear set of equations will be described. Building on these two methods, an event-driven molecular dynamics algorithm for simulating systems of convex hard rigid bodies will be developed and illustrated in details. In order to optimize the collision detection between very elongated hard rigid bodies, a novel nearest-neighbor list method based on an oriented bounding box will be introduced and fully explained. Efficiency and performance of the new algorithm proposed will be extensively tested for uniaxial hard ellipsoids and superquadrics. Finally applications in various scientific fields will be reported and discussed. © 2010 Elsevier Inc. Source


Passerini S.,University of Munster | Appetecchi G.B.,University of Rome La Sapienza
MRS Bulletin | Year: 2013

Ionic liquids (ILs) are a very interesting new class of fluid materials because of their unique characteristics, such as wide chemical, thermal, and electrochemical stability, high ion conduction, non-detectable vapor pressure, nonflammability, and good-to-excellent capability to dissolve inorganic, organic, and polymer compounds. ILs are proposed for a very wide variety of applications, including electrochemical devices. However, high purity ILs, particularly for high-energy electrochemical applications, are not widely available commercially. In addition, solvent restriction and environmental impact, as well as the possibility to fully recycle chemicals and reagents, represent the most stringent requirements for the future synthesis processes of ILs. This article reviews synthesis route improvements in terms of environment impact solvents, chemical recycling and cost, and process yield for obtaining high purity (below 50 ppm) ILs. © 2013 Materials Research Society. Source


Esposito A.,Columbia University | Guerrieri A.L.,University of Rome Tor Vergata | Pilloni A.,University of Rome La Sapienza
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

The nature of the so-called XYZ states is a long-standing problem. It has been suggested that such particles may be described as compact four-quark states or loosely bound meson molecules. In the present work we analyze the Zc(')→ηcρ decay using both approaches. Such channel might provide useful insights on the nature of the Zc('), helping discriminating between the two different models. © 2015 The Authors. Source


Polosa A.D.,University of Rome La Sapienza | Polosa A.D.,National Institute of Nuclear Physics, Italy
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

The precise measurement of binding energy, total width and DDπ branching fraction, constrains, in a model independent way, the loosely bound hadron molecule interpretation of X(3872). A full discernment is not yet possible on the basis of present data. Similar considerations might be extended to all those Y, Z resonances susceptible of a molecular description. © 2015 The Author. Source


Carlucci Aiello L.,University of Rome La Sapienza
Artificial Intelligence | Year: 2016

Ada Lovelace (1815-1852), the Victorian-era mathematician daughter of the Romantic poet Lord Byron, is famous for her work with Charles Babbage on the Analytic Engine and is widely celebrated as the first computer programmer. Her work has been recognized over the years, and even though the bearing of her contribution has often been questioned, she has always been acknowledged as a pioneering figure by the Computer Science community. Recently she has been chosen as a symbol of the achievements of women in Science, Technology, Engineering and Mathematics (STEM). Ada was worldwide celebrated on December 10th 2015, on the occasion of her 200th birthday, with workshops, meetings, and publications. In particular, ACM contributed with a book: an interdisciplinary collection of papers inspired by Ada's life, work, and legacy. The book covers Ada's collaboration with Babbage, her position in the Victorian and steampunk literature, her representation in contemporary art and comics, and her increasing relevance in promoting women in science and technology. I here review the book, focusing in particular on Ada's visionary ideas of software, on her relation with Alan Turing and the inception of Artificial Intelligence. © 2016 Published by Elsevier B.V. Source


Kieseier B.C.,Heinrich Heine University Dusseldorf | Pozzilli C.,University of Rome La Sapienza
Multiple Sclerosis Journal | Year: 2012

Most patients with multiple sclerosis (MS) eventually experience walking disability. The objective of this review was to evaluate the clinical utility of measures specific for walking in MS. Walking assessments had high reliability and were correlated with related measures, including the 12-item multiple sclerosis walking scale (MSWS-12). Shorter timed walking tests (Timed 25-foot Walk (T25FW), 10-metre Timed Walk, 30-metre Timed Walk) measure overall walking disability and are best suited for clinical settings, whereas longer timed or distance tests (100-metre Timed Walk, 6-minute Walk Test, 2-minute Walk Test) are better for the assessment of walking fatigability, distance limitations and functional capacity. The MSWS-12 measures different, but related, aspects of walking than the objective tests. The T25FW is the best characterised objective measure of walking disability and can be used across a wide range of walking disabilities. Additional work is needed to fully characterise the other objective walking assessments in MS. © The Author(s) 2012. Source


Prodan S.,University of Toronto | Antonini F.,University of Toronto | Antonini F.,University of Rome La Sapienza | Perets H.B.,Technion - Israel Institute of Technology
Astrophysical Journal | Year: 2015

Here we discuss the evolution of binaries around massive black holes (MBHs) in nuclear stellar clusters. We focus on their secular evolution due to the perturbation by the MBHs, while simplistically accounting for their collisional evolution. Binaries with highly inclined orbits with respect to their orbits around MBHs are strongly affected by secular processes, which periodically change their eccentricities and inclinations (e.g., Kozai-Lidov cycles). During periapsis approach, dissipative processes such as tidal friction may become highly efficient, and may lead to shrinkage of a binary orbit and even to its merger. Binaries in this environment can therefore significantly change their orbital evolution due to the MBH third-body perturbative effects. Such orbital evolution may impinge on their later stellar evolution. Here we follow the secular dynamics of such binaries and its coupling to tidal evolution, as well as the stellar evolution of such binaries on longer timescales. We find that stellar binaries in the central parts of nuclear stellar clusters (NSCs) are highly likely to evolve into eccentric and/or short-period binaries, and become strongly interacting binaries either on the main sequence (at which point they may even merge), or through their later binary stellar evolution. The central parts of NSCs therefore catalyze the formation and evolution of strongly interacting binaries, and lead to the enhanced formation of blue stragglers, X-ray binaries, gravitational wave sources, and possible supernova progenitors. Induced mergers/collisions may also lead to the formation of G2-like cloud-like objects such as the one recently observed in the Galactic center. © 2015. The American Astronomical Society. All rights reserved.. Source


Xue S.-S.,ICRANet | Xue S.-S.,University of Rome La Sapienza
Nuclear Physics B | Year: 2015

With a basic varying space-time cutoff ℓ~, we study a regularized and quantized Einstein-Cartan gravitational field theory and its domains of ultraviolet-unstable fixed point gir≳0 and ultraviolet-stable fixed point guv≈4/3 of the gravitational gauge coupling g=(4/3)G/GNewton. Because the fundamental operators of quantum gravitational field theory are dimension-2 area operators, the cosmological constant is inversely proportional to the squared correlation length Λ∝ξ-2. The correlation length ξ characterizes an infrared size of a causally correlate patch of the universe. The cosmological constant Λ and the gravitational constant G are related by a generalized Bianchi identity. As the basic space-time cutoff ℓ~ decreases and approaches to the Planck length ℓpl, the universe undergoes inflation in the domain of the ultraviolet-unstable fixed point gir, then evolves to the low-redshift universe in the domain of ultraviolet-stable fixed point guv. We give the quantitative description of the low-redshift universe in the scaling-invariant domain of the ultraviolet-stable fixed point guv, and its deviation from the ΛCDM can be examined by low-redshift (z ≲1) cosmological observations, such as supernova Type Ia. © 2015 The Author. Source


Romano F.,University of Oxford | Sciortino F.,University of Rome La Sapienza
Physical Review Letters | Year: 2015

We design an all-DNA system that behaves like vitrimers, innovative plastics with self-healing and stress-releasing properties. The DNA sequences are engineered to self-assemble first into tetra- and bifunctional units which, upon further cooling, bind to each other forming a fully bonded network gel. An innovative design of the binding regions of the DNA sequences, exploiting a double toehold-mediated strand displacement, generates a network gel which is able to reshuffle its bonds, retaining at all times full bonding. As in vitrimers, the rate of bond switching can be controlled via a thermally activated catalyst, which in the present design is very short DNA strands. © 2015 American Physical Society. Source


de Divitiis N.,University of Rome La Sapienza
Annals of Physics | Year: 2015

This note studies the mechanism of turbulent energy cascade through an opportune bifurcations analysis of the Navier-Stokes equations, and furnishes explanations on the more significant characteristics of the turbulence. A statistical bifurcations property of the Navier-Stokes equations in fully developed turbulence is proposed, and a spatial representation of the bifurcations is presented, which is based on a proper definition of the fixed points of the velocity field. The analysis first shows that the local deformation can be much more rapid than the fluid state variables, then explains the mechanism of energy cascade through the aforementioned property of the bifurcations, and gives reasonable argumentation of the fact that the bifurcations cascade can be expressed in terms of length scales. Furthermore, the study analyzes the characteristic length scales at the transition through global properties of the bifurcations, and estimates the order of magnitude of the critical Taylor-scale Reynolds number and the number of bifurcations at the onset of turbulence. © 2015 Elsevier Inc. Source


Bruzzese C.,University of Rome La Sapienza
IEEE Transactions on Industrial Electronics | Year: 2014

This work shows a method to quantify rotor eccentricities in synchronous machines by exploiting the unbalance caused in the split-phase currents. The paper first develops a machine model comprehensive of eccentricities and parallel circuits in the stator, by using symmetrical components. Then, the model is used for formal calculation of the unbalanced currents. Finally, the equations are reversed to obtain eccentricity degrees from current measurements. Practical formulas are given for fault assessment, only requiring machine line voltage and synchronous reactance. The method can be applied on load. This paper provides full details of the theory underlying the method. The theory also clarifies some aspects about split-phase currents, not deepened before. It is proven that the air gap flux modulation due to eccentricities, acting through additional 2(p ± 1) -pole flux waves in 2p-pole machines, stimulates additional currents, which circulate in the stator and turn into 2(p ± 1)-pole rotating space vectors in the complex domain. Vector trajectories have shape and amplitude dictated by eccentricity type and degree, respectively. This study is limited to 2p-pole machines with p ≥ 2. The theory is corroborated by simulations of a practical 1950-kVA generator in this paper. Experimental proofs and simulations of a laboratory 17-kVA machine are provided in a sequel of this paper. © 1982-2012 IEEE. Source


Bruzzese C.,University of Rome La Sapienza
IEEE Transactions on Industrial Electronics | Year: 2014

The windings of power synchronous machines are often parallel connected to obtain the desired machine voltage and current ratings. Ideally, the split-phase currents are equal in symmetrical windings, so as to avoid parasitic circulation of current in the parallel branches. However, the symmetry is broken in case of rotor eccentricity, and the split-phase currents become unbalanced. Part I of this paper analyzed the theoretical behavior of the unbalanced currents by using symmetrical components. A new fault diagnosis method was shown, based on a combined space-vector/fast Fourier transformation (FFT) analysis of signatures in the split-phase currents. This Part II applies the split-phase current signature analysis to a laboratory 17-kVA synchronous generator with artificial faults. Method performances have been evaluated with mixed static/dynamic type fault, in no-load and loaded conditions. The experiments are matched with time-stepping finite-element simulations, which help explain the effect of saturation and load on the diagnosis accuracy. The feasibility of installation of current probes in practical machines is also discussed. © 1982-2012 IEEE. Source


Xue S.-S.,ICRANet | Xue S.-S.,University of Rome La Sapienza
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

In the fermion content and gauge symmetry of the standard model (SM), we study the four-fermion operators in the torsion-free Einstein-Cartan theory. The collider signatures of irrelevant operators are suppressed by the high-energy cutoff (torsion-field mass) Λ, and cannot be experimentally accessible at TeV scales. Whereas the dynamics of relevant operators accounts for (i) the SM symmetry-breaking in the domain of infrared-stable fixed point with the energy scale v≈239.5GeV and (ii) composite Dirac particles restoring the SM symmetry in the domain of ultraviolet-stable fixed point with the energy scale E≳5 TeV. To search for the resonant phenomena of composite Dirac particles with peculiar kinematic distributions in final states, we discuss possible high-energy processes: multi-jets and dilepton Drell-Yan process in LHC pp collisions, the resonant cross-section in e-e+ collisions annihilating to hadrons and deep inelastic lepton-hadron e-p scatterings. To search for the nonresonant phenomena due to the form-factor of Higgs boson, we calculate the variation of Higgs-boson production and decay rate with the CM energy in LHC. We also present the discussions on four-fermion operators in the lepton sector and the mass-squared differences for neutrino oscillations in short baseline experiments. © 2015 The Author. Source


Allanach B.,University of Cambridge | Biswas S.,University of Rome La Sapienza | Mondal S.,Harish Chandra Research Institute | Mitra M.,Durham University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

Recent CMS searches for dileptoquark production report local excesses of 2.4σ in an eejj channel and 2.6σ in an epTjj channel. Here, we simultaneously explain both excesses with resonant slepton production in R-parity violating supersymmetry. We consider resonant slepton production, which decays to a lepton and a chargino/neutralino, followed by three-body decays of the neutralino/chargino via an R-parity violating coupling. There are regions of parameter space which are also compatible at the 95% confidence level with a 2.8σ eejj excess in a recent CMS WR search, while being compatible with other direct search constraints. Phase II of the GERDA neutrinoless double beta decay (0νββ) experiment will probe a sizable portion of the good-fit region. © 2015 American Physical Society. Source


Di Carlo A.,University of Rome La Sapienza
Oncology Reports | Year: 2012

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases, capable of degrading all the molecular components of extracellular matrix. MMPs have been shown to play critical roles in tumor cell invasion and metastasis. We verified the activity of MMPs in the sera and in the urine of patients with kidney carcinoma by gelatin zymography. Of these patients, 16 had clear cell renal carcinoma (ccRCC) and 4 patients had oncocytoma. The sera and the urine of 16 healthy subjects were used as controls. In the sera, zymography analysis showed gelatinolytic bands at 72 kDa (gelatinase A) at 92, 130 and 240 kDa (gelatinase B). MMP-9 activity was slightly enhanced in sera from ccRCC compared with oncocytoma patients. Serum MMP-2 activity was similar in ccRCC and in oncocytoma patients. In the urine, 2 oncocytoma patients and 3 (33%) of the ccRCC patients showed gelatinolytic activity, whereas MMPs could not be detected in the concentrated urine of healthy subjects. The most abundant lytic activity was at 92 kDa, whereas MMP-2 was present in lesser quantities. However, there was broad overlap of the data and we did not find any correlation to type, stage or grade. Therefore, despite previous evidence, MMP-2 and -9 activity in serum and urine may not be useful biomarker for kidney carcinomas. Source


Amato C.,University of Rome La Sapienza
International journal of psychology : Journal international de psychologie | Year: 2014

This research investigated the relationship between regulatory mode orientations (locomotion and assessment), time management behaviours and the perceived control of time. "Locomotion" refers to the aspect of self-regulation involving the movement from state to state, whereas "assessment" is the comparative aspect of self-regulation that refers to the critical evaluation of alternative goals and the means for achieving them. The Italian versions of the Time Management Behavior Scale and the Perceived Control of Time Scale, as well as the Locomotion and Assessment Regulatory Modes Scales were administered to 339 Italian participants (249 students and 90 employees). The results supported the notion that locomotors and assessors differ in the ways they perceive the control of time. Locomotion was found to be positively related to perceived control of time. In contrast, assessment was negatively related to perceived control of time. Furthermore, the two time management dimensions of setting goals and priorities and preference for organisation were shown to mediate the relationship between locomotion and perceived control of time, whereas assessment proved to be unrelated to all time management behaviours. These findings highlight the importance of regulatory modes for human behaviour regarding time management and perceived control of time. © 2014 International Union of Psychological Science. Source


Panno A.,University of Rome La Sapienza
International journal of psychology : Journal international de psychologie | Year: 2014

In the context of decision-making research, people's regulatory orientation mode (i.e., assessment and locomotion modes) has been included among the most prominent individual difference variables, which may potentially account for choice behaviour. Thus, the main objective of our experiment was to investigate the relations between habitual use of regulatory mode and risk-taking through people's time horizon. Risk-taking was appraised using a behavioural measure (i.e., BART) 1 month following evaluation of habitual use of regulatory mode. The findings revealed a significant negative association between the assessment mode and risk-taking through individual differences in time horizon. © 2013 International Union of Psychological Science. Source


Matteocci A.,Immunohematology and Transfusion Medicine Unit | Pierelli L.,Immunohematology and Transfusion Medicine Unit | Pierelli L.,University of Rome La Sapienza
Vox Sanguinis | Year: 2014

Red blood cell (RBC) transfusions are a milestone in the treatment for sickle cell anaemia (SSA) and for thalassaemia. RBC alloimmunization remains a major challenge of chronic transfusion therapy, and it can lead to adverse life-threatening events. The alloimmunization risk could depend on multiple factors such as the number of transfusions and, most of all, the genetic background. Different ethnic groups are predisposed to immunization because of a significant degree of RBC antigenic mismatch between donor and recipient. There is no universal agreement and standards for the most appropriate selection of RBC units in chronically transfused subjects. Current practice only deals with compatibility of ABO, Rh and K antigens. Molecular RBC antigenic matching extended to other blood group systems is an innovative strategy to ensure a better quality and effectiveness of transfusion therapy. © 2013 International Society of Blood Transfusion. Source


Marini F.,University of Rome La Sapienza
Current Analytical Chemistry | Year: 2010

Pattern recognition methods, i.e. the methods concentrating on the possibility of assigning an object to a class based on the result of a set of measurements are ubiquitous in chemometrics. In this paper, the main chemometric classification methods are discussed in terms of their nature, behavior, advantages and drawbacks. Both parametric and non parametric or discriminant and modeling techniques are illustrated together with a discussion of some applications to real world problems. © 2010 Bentham Science Publishers Ltd. Source


Iamonico D.,University of Rome La Sapienza
Taxon | Year: 2014

The typification of the names Amaranthus flavus L., A. mangostanus L., A. polygamus L., A. sanguineus L. and A. tristis L. (Amaranthaceae) are discussed as well as their current recognition. Specimens from the Linnaean Herbarium (LINN) are designated as lectotypes for these four names. Amaranthus mangostanus, A. polygamus and A. tristis are treated as synonyms of A. tricolor L., while A. flavus and A. sanguineus are synonyms of A. cruentus L. © International Association for Plant Taxonomy (IAPT) 2014. Source


Bianchi S.,University of Rome La Sapienza
Applied Optics | Year: 2014

When laser light illuminates a rough surface it is scattered into a speckle pattern that is strongly dependent on the surface geometry. Here, we show that it is possible to sense surface vibrations by measuring signal variations from a single pixel detector that collects a small portion of the scattered light. By carefully tuning the probing laser beam size and the detector's aperture it was possible to record a good quality signal in the acoustic band. This approach eliminates the need for an interferometer and thus opens the door to the possibility of detecting vibrations at distances of few hundreds of meters. © 2014 Optical Society of America. Source


Xue S.-S.,ICRANet | Xue S.-S.,University of Rome La Sapienza
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014

We present a further study of the dynamics of high-dimension fermion operators attributed to the theoretical inconsistency of the fundamental cutoff (quantum gravity) and the parity-violating gauge symmetry of the standard model. Studying the phase transition from a symmetry-breaking phase to a strong-coupling symmetric phase and the β-function behavior in terms of four-fermion coupling strength, we discuss the critical transition point as a ultraviolet-stable fixed point where a quantum field theory preserving the standard model gauge symmetry with composite particles can be realized. The form-factors and masses of composite particles at TeV scales are estimated by extrapolating the solution of renormalization-group equations from the infrared-stable fixed point where the quantum field theory of standard model is realized and its phenomenology including Higgs mass has been experimentally determined. We discuss the probability of composite-particle formation and decay that could be experimentally verified in the LHC by measuring the invariant mass of relevant final states and their peculiar kinetic distributions. © 2014 The Author. Published by Elsevier B.V. Source


A meta-analysis approach was used to test for chromosomal speciation in rodents. Forty-one pairs of sister species, identified in the two most species-rich rodent families (Cricetidae and Muridae), were used as phylogenetically independent data points, each resulting from a speciation event. About 30% of sister species have an identical karyotype. There was a significant difference in the number of chromosomal differences between sympatric and allopatric sister species, compatible with a direct role of chromosomal rearrangements in speciation. © 2013 The Mammal Society and John Wiley & Sons Ltd. Source


We develop an asymptotic likelihood ratio test for multivariate lognormal data with a point mass at zero in each dimension. The test generalizes Wilks' lambda and Hotelling T-test to the case of semicontinuous data. Simulations show that the resulting test statistic attains the nominal Type I error rate and has good power for reasonable alternatives. We conclude with an application to exploration of ecological niches of trees of South Africa. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Heidstra R.,Wageningen University | Sabatini S.,University of Rome La Sapienza
Nature Reviews Molecular Cell Biology | Year: 2014

The astonishingly long lives of plants and their regeneration capacity depend on the activity of plant stem cells. As in animals, stem cells reside in stem cell niches, which produce signals that regulate the balance between self-renewal and the generation of daughter cells that differentiate into new tissues. Plant stem cell niches are located within the meristems, which are organized structures that are responsible for most post-embryonic development. The continuous organ production that is characteristic of plant growth requires a robust regulatory network to keep the balance between pluripotent stem cells and differentiating progeny. Components of this network have now been elucidated and provide a unique opportunity for comparing strategies that were developed in the animal and plant kingdoms, which underlie the logic of stem cell behaviour. © 2014 Macmillan Publishers Limited. Source


Pugliese G.,University of Rome La Sapienza
Acta Diabetologica | Year: 2014

Diabetic nephropathy (DN) is a major cause of morbidity and mortality in patients with both types of diabetes and the leading cause of end-stage renal disease (ESRD) worldwide. The classical, five-stage natural history of DN, after an initial phase of hyperfiltration, is characterized by a progressive increase of albuminuria from normoalbuminuria to proteinuria, followed by a decline of glomerular filtration rate (GFR). Accumulating evidence indicates that clinical course of DN has changed profoundly, likely as a consequence of changes in treatment. In fact, remission/regression of microalbuminuria is a common feature of both type 1 and 2 diabetes which far outweighs progression to proteinuria. Moreover, GFR loss has been shown to occur independently of albuminuria or even in the absence of it. Nonalbuminuric renal impairment probably represents a different pathway to loss of renal function, which might recognize different pathogenic mechanisms, prognostic implications, and possibly therapeutic measures, as compared with the albuminuric pathway. The nonalbuminuric phenotype might be related to macroangiopathy instead of microangiopathy and/or be the consequence of repeated and/or unresolved episodes of acute kidney injury, even of mild degree. Reduced GFR and albuminuria are both powerful risk factor for cardiovascular events, whereas albuminuria appears to predict death and progression to ESRD better than GFR loss. Finally, it is unclear whether reduced GFR and albuminuria warrant different interventions and whether GFR decline may also regress in response to treatment, as proteinuria does. Further epidemiological, pathologic, pathophysiological, and intervention studies are needed to clarify the distinctive features of nonalbuminuric renal impairment. © 2014, Springer-Verlag Italia. Source


Belvedere B.,University of Rome La Sapienza
Il Giornale di chirurgia | Year: 2012

The incidence of anastomotic stricture following colorectal surgery has increased in recent years. This complication is observed in 2-5% of all operated patients and is probably due to the greater number of low anastomoses performed with surgical staplers. We observed 31 patients with postoperative stricture, arising from one to nine months post-surgery. All patients had been treated for colorectal cancer and underwent endoscopy either during routine follow-up or for symptoms of stenosis. In 16 patients (group A) the stricture diameter was less than 4 mm and the patients had symptoms attributable to partial bowel obstruction. In the remaining 15 patients (group B), who had difficult bowel movements, the stricture diameter ranged from 4 to 8 mm. All patients were treated with endoscopic dilation using achalasia balloons. The results were considered good when the post-dilation anastomosis diameter achieved was at least 13 mm, fair when it was 9-12 mm and poor when it was less than 9 mm. The short term results (3 weeks) were good in 27 patients (87.2%), fair in 3 patients (9.6%), and poor in 1 patient (3.2%). After several unsuccessful dilations, the latter was treated by surgery. Follow-up at 3-4 months of the remaining 30 patients revealed good results in 20 (66.6%), fair in 6 (20%), and poor in 4 (13.3%). In 1 of these 4 patients, cancer recurrence was observed and a new surgical resection was performed. In 2 patients a self-expandable metal stent was inserted for 4-6 weeks, with satisfactory results. In 1 patient a biodegradable polydioxanone stent was inserted with good results after 6 months. Follow-up at 3-4 months showed good results in 25 patients. After 38 months, cancer recurrence in the area of the anastomosis was observed in 1 patient, who was treated surgically. Endoscopic dilatation should be considered the first therapeutic approach in case of anastomotic strictures, as it is immediately effective, repeatable, and does not preclude surgery if this should become necessary. Source


Businaro R.,University of Rome La Sapienza
Journal of Neuroimmune Pharmacology | Year: 2013

Atherosclerosis is a chronic inflammatory process, lasting for several decades until the onset of its clinical manifestations. The progression of the atherosclerotic lesion to a stable fibrotic plaque, narrowing the vascular lumen, or to a vulnerable plaque leading to main vascular complications, is associated to the involvement of several cell subpopulations of the innate as well as of the adaptive immunity, and to the release of chemokines and pro-inflammatory cytokines. Emerging evidence outlines that the cardiovascular risk is dependent on stress-mediators influencing cell migration and vascular remodeling. The view that atherosclerosis is initiated by monocytes and lymphocytes adhering to dysfunctional endothelial cells is substantiated by experimental and clinical observations. Macrophages, dendritic cells, T and B lymphocytes, granulocytes accumulating into the subendothelial space secrete and are stimulated by soluble factors, including peptides, proteases and cytokines acting synergistically. The final step of the disease, leading to plaque destabilization and rupture, is induced by the release, at the level of the fibrous cap, of metalloproteinases and elastases by the activated leukocytes which accumulate locally. Recruitment of specific cell subpopulations as well as the progression of atherosclerotic lesions towards a stable or an unstable phenotype, are related to the unbalance between pro-atherogenic and anti-atherogenic factors. In this connection stress hormones deserve particular attention, since their role in vascular remodeling, via vascular smooth cell proliferation, as well as in neoangiogenesis, via stimulation of endothelial cell proliferation and migration, has been already established. © 2012 Springer Science+Business Media New York. Source


Brunori M.,University of Rome La Sapienza
FEBS Journal | Year: 2014

Conformational selection between pre-existing structural states of an oligomeric protein was the conceptual step behind the formulation of Monod-Wyman-Changeux (MWC) allosteric theory. Variations on the basic theme of allosteric control are briefly illustrated in this paper by reference to some hemoglobins from different species whose functional properties were found to respond to specific physiological requirements. In my opinion the enormous success of the allosteric theory may be attributed not only to its efficiency in accounting for data and its formal mathematical elegance, but also because the selective mechanism conforms to the founding concept of Darwinian evolution. © 2013 FEBS. Source


Meroni P.-L.,University of Milan | Valesini G.,University of Rome La Sapienza
BioDrugs | Year: 2014

Rheumatoid arthritis (RA) is one of the most prevalent autoimmune conditions, affecting approximately 1 % of the adult population. It is associated with decreased quality of life and considerable morbidity and mortality. Various inflammatory cells, including macrophages, neutrophils, mast cells, natural killer cells, B and T cells and stromal cells play key pathophysiological roles in joint inflammation and RA progression. Several cytokines, including interleukin (IL)-1α and/or IL-1β, and tumour necrosis factor (TNF)-α, are involved at each stage of RA pathogenesis; namely, by augmenting autoimmunity, sustaining long-term inflammatory synovitis and promoting joint damage. Different cell types are involved in RA pathogenesis through upregulation of several cytokine and soluble pro-inflammatory mediators. As early as the late 1980s, TNF had been identified as a potential target in RA. Five anti-TNF drugs, infliximab, adalimumab, certolizumab pegol, etanercept and golimumab, are now approved for the treatment of RA in various countries. All are bivalent monoclonal antibodies, with the exception of the monovalent certolizumab and etanercept, which is an engineered dimeric receptor. Although all react with and neutralise soluble TNF in vitro, structural differences in the molecules may contribute to differences in their therapeutic effects and the occurrence of side effects. Pegylated certolizumab permits once-monthly dosing. Other mechanisms of action proposed to be important for the efficacy of anti-TNF agents are as follows: induction of apoptosis of both monocytes and T cells; neutralization of membrane TNF; antibody-dependent cell-mediated and complement-dependent cytotoxicity; and reverse signaling via membrane TNF. © 2014 Springer International Publishing Switzerland. Source


Perluigi M.,University of Rome La Sapienza | Swomley A.M.,University of Kentucky | Butterfield D.A.,University of Kentucky
Ageing Research Reviews | Year: 2014

It is well established that the risk to develop neurodegenerative disorders increases with chronological aging. Accumulating studies contributed to characterize the age-dependent changes either at gene and protein expression level which, taken together, show that aging of the human brain results from the combination of the normal decline of multiple biological functions with environmental factors that contribute to defining disease risk of late-life brain disorders. Finding the "way out" of the labyrinth of such complex molecular interactions may help to fill the gap between "normal" brain aging and development of age-dependent diseases. To this purpose, proteomics studies are a powerful tool to better understand where to set the boundary line of healthy aging and age-related disease by analyzing the variation of protein expression levels and the major post translational modifications that determine "protein" physio/pathological fate. Increasing attention has been focused on oxidative modifications due to the crucial role of oxidative stress in aging, in addition to the fact that this type of modification is irreversible and may alter protein function. Redox proteomics studies contributed to decipher the complexity of brain aging by identifying the proteins that were increasingly oxidized and eventually dysfunctional as a function of age. The purpose of this review is to summarize the most important findings obtained by applying proteomics approaches to murine models of aging with also a brief overview of some human studies, in particular those related to dementia. © 2014. Source


This review covers the various aspects of the immune system that allows the relationship between the hepatitis-C virus, the host and chronic low-level inflammation, to be highly flexible and able to defend the host from persistent infections. This ambiguity mainly stems from the property of the immune system that can be both protective and harmful. Immunity cannot be fully protective without producing a certain degree of damage (acute hepatitis resulting in resolving HCV infection). In addition, the balance between protection and tissue damage is critical for the development of chronic HCV infection. The establishment of a state of chronic low-level inflammation is instrumental to limit liver immunopathology, to limit viral spread, and ultimately to ensure a long-lasting survival of the host. It is dictated by a fine equilibrium maintained by multiple immunologic mechanisms, including: sensory perception of innate immunity, virus-specific T and B cell functions, control of immune responses, and finally the balance between immunity and immunopathology that has principally evolved to favor the survival of the species. © 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved. Source


Minisola S.,University of Rome La Sapienza
Expert Opinion on Biological Therapy | Year: 2014

The Wnt pathway has an important role in bone formation. Inactivation of sclerostin, an inhibitor of this pathway, has been associated with increased bone mass both in animal experiments and in human clinical trials. Romosozumab is a humanized monoclonal antibody targeting sclerostin. Preclinical studies showed that this antibody primarily increases bone formation resulting in increased bone mineral density. Initial studies carried out in humans are in line with data obtained in animals. If these results are confirmed in larger studies with fracture end-points, this monoclonal antibody with its anabolic action, will become a key drug in the treatment of osteoporosis. © Informa UK, Ltd. Source


Campostrini M.,University of Pisa | Nespolo J.,University of Pisa | Pelissetto A.,University of Rome La Sapienza | Vicari E.,University of Pisa
Physical Review Letters | Year: 2014

We study finite-size effects at first-order quantum transitions (FOQTs). We show that the low-energy properties show a finite-size scaling (FSS) behavior, the relevant scaling variable being the ratio of the energy associated with the perturbation driving the transition and the finite-size energy gap at the FOQT point. The size dependence of the scaling variable is therefore essentially determined by the size dependence of the gap at the transition, which in turn depends on the boundary conditions. Our results have broad validity and, in particular, apply to any FOQT characterized by the degeneracy and crossing of the two lowest-energy states in the infinite-volume limit. In this case, a phenomenological two-level theory provides exact expressions for the scaling functions. Numerical results for the quantum Ising chain in transverse and parallel magnetic fields support the FSS Ansätzes. © 2014 American Physical Society. Source


Portalone G.,University of Rome La Sapienza
Acta Crystallographica Section C: Crystal Structure Communications | Year: 2010

Four organic salts, namely benzamidinidium orotate (2,6-di-oxo-1,2,3,6- tetra-hydro-pyrimidine-4-carboxyl-ate) hemi-hydrate, C7H 9N2+·C5H3N 2O4-·0.5H2O (BenzamH +·Or-), (I), benzamidinium isoorotate (2,4-dioxo-1,2,3,4-tetra-hydro-pyrimidine-5-carboxyl-ate) trihydrate, C 7H9N2+·C5H 3N2O4-·3H2O (BenzamH+·Isor-), (II), benzamidinium diliturate (5-nitro-2,6-dioxo-1,2,3,6-tetra-hydro-pyrimidin-4-olate) di-hydrate, C 7H9N2+·C4H 2N3O5-·2H2O (BenzamH+·Dil-), (III), and benzamidinium 5-nitro-uracilate (5-nitro-2,4-dioxo-1,2,3,4-tetra-hydro-pyrimidin-1-ide), C7H9N2+·C4H 2N3O4- (BenzamH+· Nit-), (IV), have been synthesized by a reaction between benzamidine (benzene-carboximidamide or Benzam) and the appropriate carboxylic acid. Proton transfer occurs to the benzamidine imino N atom. In all four acid-base adducts, the asymmetric unit consists of one tautomeric amino-oxo anion (Or-, Isor-, Dil- and Nit-) and one monoprotonated benzamidinium cation (BenzamH+), plus one-half (which lies across a twofold axis), three and two solvent water mol-ecules in (I), (II) and (III), respectively. Due to the presence of protonated benzamidine, these acid-base complexes form supra-molecular synthons characterized by N+- H⋯O- and N+-H⋯N- (±)-charge-assisted hydrogen bonds (CAHB). © 2010 International Union of Crystallography. Source


Di Santo R.,University of Rome La Sapienza
Journal of Medicinal Chemistry | Year: 2014

HIV integrase (IN) catalyzes the insertion into the genome of the infected human cell of viral DNA produced by the retrotranscription process. The discovery of raltegravir validated the existence of the IN, which is a new target in the field of anti-HIV drug research. The mechanism of catalysis of IN is depicted, and the characteristics of the inhibitors of the catalytic site of this viral enzyme are reported. The role played by the resistance is elucidated, as well as the possibility of bypassing this problem. New approaches to block the integration process are depicted as future perspectives, such as development of allosteric IN inhibitors, dual inhibitors targeting both IN and other enzymes, inhibitors of enzymes that activate IN, activators of IN activity, as well as a gene therapy approach. © 2013 American Chemical Society. Source


Azatov A.,University of Rome La Sapienza | Azatov A.,National Institute of Nuclear Physics, Italy | Paul A.,National Institute of Nuclear Physics, Italy
Journal of High Energy Physics | Year: 2014

Possible extensions of the Standard Model predict modifications of the Higgs couplings to gluons and to the SM top quark. The values of these two couplings can, in general, be independent. We discuss a way to measure these interactions by studying the Higgs production at high p T within an effective field theory formalism. We also propose an observable r ± with reduced theoretical errors and suggest its experimental interpretation. © 2014 SISSA. Source


Maharaj E.A.,Monash University | D'Urso P.,University of Rome La Sapienza
Information Sciences | Year: 2011

Traditional and fuzzy cluster analyses are applicable to variables whose values are uncorrelated. Hence, in order to cluster time series data which are usually serially correlated, one needs to extract features from the time series, the values of which are uncorrelated. The periodogram which is an estimator of the spectral density function of a time series is a feature that can be used in the cluster analysis of time series because its ordinates are uncorrelated. Additionally, the normalized periodogram and the logarithm of the normalized periodogram are also features that can be used. In this paper, we consider a fuzzy clustering approach for time series based on the estimated cepstrum. The cepstrum is the spectrum of the logarithm of the spectral density function. We show in our simulation studies for the typical generating processes that have been considered, fuzzy clustering based on the cepstral coefficients performs very well compared to when it is based on other features. © 2010 Elsevier Inc. All rights reserved. Source


Cassetta M.,University of Rome La Sapienza
The International journal of periodontics & restorative dentistry | Year: 2013

The purpose of this in vivo retrospective study was to evaluate the accuracy of a computer-designed stereolithographic surgical guide. One hundred eleven implants were placed in 10 patients. Pre- and postoperative computed tomography images were compared using specific software. Global, angular, depth, and lateral deviations were calculated between planned and placed implants. Mean global deviations between planned and placed implants at the coronal and apical aspects were 1.52 mm (range, 0.13 to 3.00 mm) and 1.97 mm (range, 0.34 to 4.23 mm), respectively, while the mean angular deviation was 4.68 degrees (range, 0.10 to 15.25 degrees). This study highlighted a reasonable mean accuracy with relatively high maximum deviations between the postoperative position and the preoperative plan. These results should serve as a warning for the clinician if implants are placed near vital structures. Source


Sun Y.-K.,Hanyang University | Oh S.-M.,Hanyang University | Park H.-K.,LG Corp | Scrosati B.,University of Rome La Sapienza
Advanced Materials | Year: 2011

Micrometer-sized LiMn 0.85Fe 0.15PO 4 particles with a unique morphology and high tap density were synthesized via co-precipitation. The micro-LiMn 0.85Fe 0.15PO 4 electrode resulted in 1.4 times greater volumetric energy density compared to the conventional nano-LiMn 0.85Fe 0.15PO 4 electrode. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


La Torre F.,University of Rome La Sapienza | de la Portilla F.,Hospital Universitario Virgen Del Rocio
Colorectal Disease | Year: 2013

Aim: Randomized, controlled trials have demonstrated the efficacy and safety of injectable bulking agents for the treatment of faecal incontinence (FI), although the long-term outcome has not been assessed. NASHA/Dx gel, a biocompatible, nonallergenic bulking agent consisting of nonanimal stabilized hyaluronic acid and dextranomer microspheres, has demonstrated efficacy and safety for up to 12months after treatment. The objective of this study was to evaluate the long-term efficacy and safety of NASHA/Dx, assessed 24months after treatment. Method: This study was a 24-month follow-up assessment of patients treated with NASHA/Dx under open-label conditions. Data on FI episodes and quality of life measures were collected from diaries over the 28-day period immediately preceding the 24-month assessment. Adverse events were collected. Results: Eighty-three of 115 patients completed the 24-month follow-up assessment. At 24months, 62.7% of patients were considered responders and experienced a ≥50% reduction in the total number of FI episodes. The median number of FI episodes declined by 68.8% (P<0.001). Episodes of both solid and liquid stool incontinence decreased. The mean number of incontinence-free days increased from 14.6 at baseline to 21.7 at 24months (P<0.001). Incontinence scores and FI quality of life scores also showed significant improvements. The most common adverse events (AEs) were proctalgia (13.3%) and pyrexia (9.6%). The majority of AEs were mild to moderate, self-limited and resolved within 1month of the injection. Conclusion: NASHA/Dx is safe, effective and durable over a 24-month period with a majority of patients experiencing significant improvement in multiple symptoms associated with FI. © 2013 The Authors Colorectal Disease © 2013 The Association of Coloproctology of Great Britain and Ireland. Source


The objective of the study was to obtain reliable data from recent surveys carried out in Italy on the prevalence of overweight (OW) and obesity (OB) in children. We searched in MEDLINE/Pubmed and Scopus. The keywords included "overweight ", "obesity", "children", "aged 6-11 years", "Italy", associated to the boolean operators AND/OR. The limits applied to the research were: English AND/OR Italian language, publication time period January 2000-September 2010, target of 6-11 years; Body Mass Index assessed according to IOTF criteria. StatsDirect 2.7.8 was utilized to perform statistical analysis. 25 studies have been select, the percentage of overweight varied between 18% and 33,7% and obesity between 5,5% and 21,9%. The highest values were in Southern Italy (OW: 25,6%, CI95% 24,8-26,3; OB: 15,2%, CI95% 13-17,5) vs Central Italy (OW: 22,6%, CI95% 21-24,1; OB: 9,3%, CI95% 7,9-10,7) vs Northern Italy (OW: 21%, CI95% 19,6-22,3; OB: 8,2%, CI95% 6,8-9,7). A relevant prevalence of overweight and obesity was found In Italian children; the excess weight concerns one child out of four. There are significant differences in the prevalence of overweight and obesity in relation to geographical distribution (Northern, Central and Southern Italy), the high prevalence of overweight and obesity resulted statistically significant in the Southern compared to Central and Northern Italy. These differences are likely linked to different geographical areas in relation to socioeconomic and environmental condition that must be further investigated. There is a need of promoting better eating habits in young children in Italy, above all in areas with highest prevalence. Source


Bergshoeff E.A.,University of Groningen | Ortin T.,Institute Fisica Teorica UAM CSIC |