366 research outputs found

    From quantum to classical dynamics: The relativistic O(N)O(N) model in the framework of the real-time functional renormalization group

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    We investigate the transition from unitary to dissipative dynamics in the relativistic O(N)O(N) vector model with the λ(φ2)2\lambda (\varphi^{2})^{2} interaction using the nonperturbative functional renormalization group in the real-time formalism. In thermal equilibrium, the theory is characterized by two scales, the interaction range for coherent scattering of particles and the mean free path determined by the rate of incoherent collisions with excitations in the thermal medium. Their competition determines the renormalization group flow and the effective dynamics of the model. Here we quantify the dynamic properties of the model in terms of the scale-dependent dynamic critical exponent zz in the limit of large temperatures and in 2≤d≤42 \leq d \leq 4 spatial dimensions. We contrast our results to the behavior expected at vanishing temperature and address the question of the appropriate dynamic universality class for the given microscopic theory.Comment: 32 pages, 12 captioned figures; revised and extended version accepted for publication in PR

    Search for Cosmic-Ray Antideuterons

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    We performed a search for cosmic-ray antideuterons using data collected during four BESS balloon flights from 1997 to 2000. No candidate was found. We derived, for the first time, an upper limit of 1.9E-4 (m^2 s sr GeV/nucleon)^(-1) for the differential flux of cosmic-ray antideuterons, at the 95% confidence level, between 0.17 and 1.15 GeV/nucleon at the top of the atmosphere.Comment: 4 pages, 3 figures, submitted to Phys. Rev. Let

    Escala De Atitude Diante Da Sexualidade

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    The study describes the elaboration of a psychometric measure of attitudes towards human sexuality. One hundred and two items were initially built in order to cover 22 dimensions of sexuality. They were answered by 1434 subjects of 25 Brazilian cities, and the answers were submitted to a factor analysis by means of the principal components. Six factors emerged: sex, something shameful, dangerous and useless; legitimacy of pre- and extra-marital relatins; sex, a conscious and free engagement; legitimacy of homosexuality; legitimacy of masturbation; pregnancy, a human headache. All factors, except one, present good reliability scores. There appear also three second order factors: Sex, a human degrading activity; sex, a human socially disallowed activity; sex, an erotic activity.O estudo apresenta a elaboração de um instrumento de medida das atitudes diante da sexualidade humana. Os 152 itens inicialmente construídos cobriam 22 dimensões da sexualidade. A escala foi aplicada a 1434 sujeitos de 25 cidades brasileiras e os dados submetidos à análise fatorial dos componentes principais. Resultaram seis fatores: sexo como algo vergonhoso, perigoso e inútil; legitimidade das relações pré- e extraconjugais; sexo como envolvimento consciente e livre; legitimidade da homossexualidade; legitimidade da masturbação; gravidez como um transtorno. Todos os fatores apresentam boa precisão, menos o fator "sexo como envolvimento consciente e livre". Aparecem três fatores de segunda ordem: sexo, uma atividade humana degradante; sexo, uma atividade humana socialmente escusa; sexo, uma atividade erótica

    Lipid membranes for membrane proteins

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    Andreas Kukol, ‘Lipid membranes for membrane proteins in Molecular Modeling of Proteins (Clifton: Humana Press/Sringer, 2015), ISBN: 978-1-4939-1464-7, e-BOOK ISBN: 978-1-4939-1465-4Peer reviewe

    Measurements of Proton, Helium and Muon Spectra at Small Atmospheric Depths with the BESS Spectrometer

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    The cosmic-ray proton, helium, and muon spectra at small atmospheric depths of 4.5 -- 28 g/cm^2 were precisely measured during the slow descending period of the BESS-2001 balloon flight. The variation of atmospheric secondary particle fluxes as a function of atmospheric depth provides fundamental information to study hadronic interactions of the primary cosmic rays with the atmosphere.Comment: 21 pages, 11 figures, 4 table

    Measurements of Primary and Atmospheric Cosmic-Ray Spectra with the BESS-TeV Spectrometer

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    Primary and atmospheric cosmic-ray spectra were precisely measured with the BESS-TeV spectrometer. The spectrometer was upgraded from BESS-98 to achieve seven times higher resolution in momentum measurement. We report absolute fluxes of primary protons and helium nuclei in the energy ranges, 1-540 GeV and 1-250 GeV/n, respectively, and absolute flux of atmospheric muons in the momentum range 0.6-400 GeV/c.Comment: 26 pages, 9 figures, 3 tables, Submitted to Phys. Lett.

    Plasmodium knowlesi Genome Sequences from Clinical Isolates Reveal Extensive Genomic Dimorphism.

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    Plasmodium knowlesi is a newly described zoonosis that causes malaria in the human population that can be severe and fatal. The study of P. knowlesi parasites from human clinical isolates is relatively new and, in order to obtain maximum information from patient sample collections, we explored the possibility of generating P. knowlesi genome sequences from archived clinical isolates. Our patient sample collection consisted of frozen whole blood samples that contained excessive human DNA contamination and, in that form, were not suitable for parasite genome sequencing. We developed a method to reduce the amount of human DNA in the thawed blood samples in preparation for high throughput parasite genome sequencing using Illumina HiSeq and MiSeq sequencing platforms. Seven of fifteen samples processed had sufficiently pure P. knowlesi DNA for whole genome sequencing. The reads were mapped to the P. knowlesi H strain reference genome and an average mapping of 90% was obtained. Genes with low coverage were removed leaving 4623 genes for subsequent analyses. Previously we identified a DNA sequence dimorphism on a small fragment of the P. knowlesi normocyte binding protein xa gene on chromosome 14. We used the genome data to assemble full-length Pknbpxa sequences and discovered that the dimorphism extended along the gene. An in-house algorithm was developed to detect SNP sites co-associating with the dimorphism. More than half of the P. knowlesi genome was dimorphic, involving genes on all chromosomes and suggesting that two distinct types of P. knowlesi infect the human population in Sarawak, Malaysian Borneo. We use P. knowlesi clinical samples to demonstrate that Plasmodium DNA from archived patient samples can produce high quality genome data. We show that analyses, of even small numbers of difficult clinical malaria isolates, can generate comprehensive genomic information that will improve our understanding of malaria parasite diversity and pathobiology

    High frequency chest wall oscillation for asthma and chronic obstructive pulmonary disease exacerbations: a randomized sham-controlled clinical trial

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    <p>Abstract</p> <p>Background</p> <p>High frequency chest wall oscillation (HFCWO) is used for airway mucus clearance. The objective of this study was to evaluate the use of HFCWO early in the treatment of adults hospitalized for acute asthma or chronic obstructive pulmonary disease (COPD).</p> <p>Methods</p> <p>Randomized, multi-center, double-masked phase II clinical trial of active or sham treatment initiated within 24 hours of hospital admission for acute asthma or COPD at four academic medical centers. Patients received active or sham treatment for 15 minutes three times a day for four treatments. Medical management was standardized across groups. The primary outcomes were patient adherence to therapy after four treatments (minutes used/60 minutes prescribed) and satisfaction. Secondary outcomes included change in Borg dyspnea score (≥ 1 unit indicates a clinically significant change), spontaneously expectorated sputum volume, and forced expired volume in 1 second.</p> <p>Results</p> <p>Fifty-two participants were randomized to active (n = 25) or sham (n = 27) treatment. Patient adherence was similarly high in both groups (91% vs. 93%; p = 0.70). Patient satisfaction was also similarly high in both groups. After four treatments, a higher proportion of patients in the active treatment group had a clinically significant improvement in dyspnea (70.8% vs. 42.3%, p = 0.04). There were no significant differences in other secondary outcomes.</p> <p>Conclusions</p> <p>HFCWO is well tolerated in adults hospitalized for acute asthma or COPD and significantly improves dyspnea. The high levels of patient satisfaction in both treatment groups justify the need for sham controls when evaluating the use of HFCWO on patient-reported outcomes. Additional studies are needed to more fully evaluate the role of HFCWO in improving in-hospital and post-discharge outcomes in this population.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00181285">NCT00181285</a></p

    Requirement of Interaction between Mast Cells and Skin Dendritic Cells to Establish Contact Hypersensitivity

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    The role of mast cells (MCs) in contact hypersensitivity (CHS) remains controversial. This is due in part to the use of the MC-deficient Kit W/Wv mouse model, since Kit W/Wv mice congenitally lack other types of cells as a result of a point mutation in c-kit. A recent study indicated that the intronic enhancer (IE) for Il4 gene transcription is essential for MCs but not in other cell types. The aim of this study is to re-evaluate the roles of MCs in CHS using mice in which MCs can be conditionally and specifically depleted. Transgenic Mas-TRECK mice in which MCs are depleted conditionally were newly generated using cell-type specific gene regulation by IE. Using this mouse, CHS and FITC-induced cutaneous DC migration were analyzed. Chemotaxis assay and cytoplasmic Ca2+ imaging were performed by co-culture of bone marrow-derived MCs (BMMCs) and bone marrow-derived dendritic cells (BMDCs). In Mas-TRECK mice, CHS was attenuated when MCs were depleted during the sensitization phase. In addition, both maturation and migration of skin DCs were abrogated by MC depletion. Consistently, BMMCs enhanced maturation and chemotaxis of BMDC in ICAM-1 and TNF-α dependent manners Furthermore, stimulated BMDCs increased intracellular Ca2+ of MC upon direct interaction and up-regulated membrane-bound TNF-α on BMMCs. These results suggest that MCs enhance DC functions by interacting with DCs in the skin to establish the sensitization phase of CHS

    APBSmem: A Graphical Interface for Electrostatic Calculations at the Membrane

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    Electrostatic forces are one of the primary determinants of molecular interactions. They help guide the folding of proteins, increase the binding of one protein to another and facilitate protein-DNA and protein-ligand binding. A popular method for computing the electrostatic properties of biological systems is to numerically solve the Poisson-Boltzmann (PB) equation, and there are several easy-to-use software packages available that solve the PB equation for soluble proteins. Here we present a freely available program, called APBSmem, for carrying out these calculations in the presence of a membrane. The Adaptive Poisson-Boltzmann Solver (APBS) is used as a back-end for solving the PB equation, and a Java-based graphical user interface (GUI) coordinates a set of routines that introduce the influence of the membrane, determine its placement relative to the protein, and set the membrane potential. The software Jmol is embedded in the GUI to visualize the protein inserted in the membrane before the calculation and the electrostatic potential after completing the computation. We expect that the ease with which the GUI allows one to carry out these calculations will make this software a useful resource for experimenters and computational researchers alike. Three examples of membrane protein electrostatic calculations are carried out to illustrate how to use APBSmem and to highlight the different quantities of interest that can be calculated
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