6,662 research outputs found

    Chromodynamic Weibel instabilities in relativistic nuclear collisions

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    Employing a previously derived formulation, and extending the treatment from purely transverse modes to wave vectors having a longitudinal component, we discuss the prospects for the occurrence of Weibel-type color-current filamentation in high-energy nuclear collisions. Numerical solutions of the dispersion equation for a number of scenarios relevant to RHIC and LHC suggest that modes with (predominantly transverse) wave numbers of several hundred MeV may become moderately agitated during the early collision stage. The emergence of filamentation helps to speed up the equilibration of the parton plasma and it may lead to non-statistical azimuthal patterns in the hadron final state.Comment: 11 pages, RevTex, 13 (e)ps files (revised for PRC

    Methods for a rapid systematic review and meta-analysis in evaluating selective serotonin reuptake inhibitors for premature ejaculation

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    The aim of this study was to evaluate a rapid systematic review method in which randomised controlled trial (RCT) data was extracted from existing reviews and subsequent RCTs. The method enabled: identification of RCTs not included by existing reviews; cross-checking RCT data for consistency where there was more than one review; double data extraction due to time saved by extracting data from existing reviews; correction of data synthesis errors in existing reviews; and pooling data across all RCTs to produce contemporary effect estimates. When subsequently compared to extracting data directly from all RCT original publications, the findings and conclusions concurred

    Ferlins Show Tissue-Specific Expression and Segregate as Plasma Membrane/Late Endosomal or Trans-Golgi/Recycling Ferlins

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    © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. Ferlins are an ancient family of Ca2+-binding, multi-C2 domain vesicle fusion proteins. Of the six human ferlins, mutations in dysferlin cause muscular dystrophy and otoferlin cause deafness. We detail the tissue-distribution, subcellular localization and endocytic trafficking of the human ferlins. Dysferlin and myoferlin, type-I ferlins, localize to the plasma membrane and late endosomes, which display potential for occasional recycling. Otoferlin and Fer1L6, type-II ferlins, localize to dedicated recycling subcompartments of the trans-Golgi network. We establish that type-I and type-II ferlins segregate into late-endosomal and recycling trans-Golgi compartments. Ferlins are a family of transmembrane-anchored vesicle fusion proteins uniquely characterized by 5-7 tandem cytoplasmic C2 domains, Ca2+-regulated phospholipid-binding domains that regulate vesicle fusion in the synaptotagmin family. In humans, dysferlin mutations cause limb-girdle muscular dystrophy type 2B (LGMD2B) due to defective Ca2+-dependent, vesicle-mediated membrane repair and otoferlin mutations cause non-syndromic deafness due to defective Ca2+-triggered auditory neurotransmission. In this study, we describe the tissue-specific expression, subcellular localization and endocytic trafficking of the ferlin family. Studies of endosomal transit together with 3D-structured illumination microscopy reveals dysferlin and myoferlin are abundantly expressed at the PM and cycle to Rab7-positive late endosomes, supporting potential roles in the late-endosomal pathway. In contrast, Fer1L6 shows concentrated localization to a specific compartment of the trans-Golgi/recycling endosome, cycling rapidly between this compartment and the PM via Rab11 recycling endosomes. Otoferlin also shows trans-Golgi to PM cycling, with very low levels of PM otoferlin suggesting either brief PM residence, or rare incorporation of otoferlin molecules into the PM. Thus, type-I and type-II ferlins segregate as PM/late-endosomal or trans-Golgi/recycling ferlins, consistent with different ferlins mediating vesicle fusion events in specific subcellular locations

    Coulomb Explosion Dynamics of Chlorocarbonylsulfenyl Chloride

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    The Coulomb explosion dynamics following strong field ionization of chlorocarbonylsulfenyl chloride was studied using multimass coincidence detection and covariance imaging analysis, supported by density functional theory calculations. These results show evidence of multiple dissociation channels from various charge states. Double ionization to low-lying electronic states leads to a dominant C-S cleavage channel, while higher states can alternatively correlate to the loss of Cl+. Triple ionization leads to a double dissociation channel, the observation of which is confirmed via three-body covariance analysis, while further ionization leads primarily to atomic or diatomic fragments whose relative momenta depend strongly on the starting structure of the molecule

    The effect of surface character on flows in microchannels

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    A technique for quantifying velocity profiles of fluids flowing in circular microchannels is presented. The primary purpose of this technique is to provide a robust method for quantifying the effect Of Surface character on the bulk fluid behaviour. A laser-scanning confocal microscope has been used to obtain fluorescent particle images from a 1 micron thick plane along the centreline of hydrophobic and hydrophilic glass capillaries. The velocities of fluorescent particles being carried in pressure-driven laminar flow of a Newtonian fluid have been evaluated at the centreplane of 57.5 micron capillaries using a variation of particle tracking velocimetry (PTV). This work aims to clarify inconsistencies in previously reported [1-12] slip velocities observed in water over hydrophobically modified surfaces at micron and submicron lengthscales. A change in the velocity profile is observed for water flowing in hydrophobic capillaries, although the behaviour appears to be a result of an optical distortion at the fluid-wall interface. This may point to previous suggestions of a thin layer of air adsorbing to the surface. Notwithstanding, the results do not confidently suggest evidence of slip of water on hydrophobic surfaces in microchannels

    Diel turbidity cycles in a headwater stream: evidence of nocturnal bioturbation?

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    Purpose: A small number of recent studies have linked daily cycles in stream turbidity to nocturnal bioturbation by aquatic fauna, principally crayfish, and demonstrated this process can significantly impact upon water quality under baseflow conditions. Adding to this limited body of research, we use high-resolution water quality monitoring data to investigate evidence of diel turbidity cycles in a lowland, headwater stream with a known signal crayfish (Pacifastacus leniusculus) population and explore a range of potential causal mechanisms. Materials and methods: Automatic bankside monitoring stations measured turbidity and other water quality parameters at 30-min resolution at three locations on the River Blackwater, Norfolk, UK during 2013. Specifically, we focused on two 20-day periods of baseflow conditions during January and April 2013 which displayed turbidity trends typical of winter and spring seasons, respectively. The turbidity time-series, which were smoothed with 6.5 hour Savitzky-Golay filters to highlight diel trends, were correlated against temperature, stage, dissolved oxygen and pH to assess the importance of abiotic influences on turbidity. Turbidity was also calibrated against suspended particulate matter (SPM) over a wide range of values via linear regression. Results and discussion: Pronounced diel turbidity cycles were found at two of the three sites under baseflow conditions during April. Spring night-time turbidity values consistently peaked between 21:00 and 04:00 with values increasing by ~10 nephelometric turbidity units (NTU) compared with the lowest recorded daytime values which occurred between 10:00 and 14:00. This translated into statistically significant increases in median midnight SPM concentration of up to 76% compared with midday, with night-time (18:00 – 05:30) SPM loads also up to 30% higher than that recorded during the daytime (06:00 – 17:30). Relating turbidity to other water quality parameters exhibiting diel cycles revealed there to be neither any correlation that might indicate a causal link, nor any obvious mechanistic connections to explain the temporal turbidity trends. Diel turbidity cycles were less prominent at all sites during the winter. Conclusions: Considering the seasonality and timing of elevated turbidity, visual observations of crayfish activity, and an absence of mechanistic connections with other water quality parameters, the results presented here are consistent with the hypothesis that nocturnal bioturbation is responsible for generating diel turbidity cycles under baseflow conditions in headwater streams. However, further research in a variety of fluvial environments is required to better assess the spatial extent, importance and causal mechanisms of this phenomenon

    CD4 cell responses to combination antiretroviral therapy in patients starting therapy at high CD4 cell counts

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    Objective: To examine CD4 cell responses to combination antiretroviral therapy (cART) in patients enrolled in the Australian HIV Observational Database who commenced cART at CD4 cell counts >350 cells per microliter. Methods: CD4 cell counts were modelled using random effects, repeated measurement models in 432 HIV-infected adults from Australian HIV Observational Database who commenced their first cART regimen and had a baseline CD4 count >350 cells per microliter. Using published AIDS and/or death incidence rates combined with the data summarized by time and predicted CD4 cell count, we calculated the expected reduction in risk of an event for different starting baseline CD4 strata. Results: Mean CD4 counts increased above 500 cells per microliter in all baseline CD4 strata by 12 months (means of 596, 717, and 881 cells/μL in baseline CD4 strata 351-500, 501-650, and >650 cells/μL, respectively) and after 72 months since initiating cART, mean CD4 cell counts (by increasing baseline CD4 strata) were 689, 746, 742 cells per microliter. The expected reduction in risk of mortality for baseline CD4 counts >650 cells per microliter relative to 351-500 cells per microliter was approximately 8%, an absolute risk reduction 0.33 per 1000 treated patient-years. Conclusions: Patients starting cART at high CD4 cell counts (>650 cells/μL) tend to maintain this immunological level over 6 years of follow-up. Patients starting from 351 to 500 CD4 cells per microliter achieve levels of >650 cells per microliter after approximately 3 years of cART. Initiating cART with a baseline CD4 count 501-650 or >650 cells per microliter relative to 351-500 cells per microliter indicated a minimal reduction in risk of AIDS incidence and/or death. Copyright © 2011 Lippincott Williams & Wilkins

    Calpains, Cleaved Mini-Dysferlin(C72), and L-Type Channels Underpin Calcium-Dependent Muscle Membrane Repair

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    Dysferlin is proposed as a key mediator of calcium-dependent muscle membrane repair, although its precise role has remained elusive. Dysferlin interacts with a new membrane repair protein, mitsugumin 53 (MG53), an E3 ubiquitin ligase that shows rapid recruitment to injury sites. Using a novel ballistics assay in primary human myotubes, we show it is not full-length dysferlin recruited to sites of membrane injury but an injury-specific calpain-cleavage product, mini-dysferlin(C72). Mini-dysferlin(C72)-rich vesicles are rapidly recruited to injury sites and fuse with plasma membrane compartments decorated by MG53 in a process coordinated by L-type calcium channels. Collective interplay between activated calpains, dysferlin, and L-type channels explains how muscle cells sense a membrane injury and mount a specialized response in the unique local environment of a membrane injury. Mini-dysferlin(C72) and MG53 form an intricate lattice that intensely labels exposed phospholipids of injury sites, then infiltrates and stabilizes the membrane lesion during repair. Our results extend functional parallels between ferlins and synaptotagmins. Whereas otoferlin exists as long and short splice isoforms, dysferlin is subject to enzymatic cleavage releasing a synaptotagmin-like fragment with a specialized protein-or phospholipid-binding role for muscle membrane repair

    The Human Gene Mutation Database: 2008 update

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    The Human Gene Mutation Database (HGMD®) is a comprehensive core collection of germline mutations in nuclear genes that underlie or are associated with human inherited disease. Here, we summarize the history of the database and its current resources. By December 2008, the database contained over 85,000 different lesions detected in 3,253 different genes, with new entries currently accumulating at a rate exceeding 9,000 per annum. Although originally established for the scientific study of mutational mechanisms in human genes, HGMD has since acquired a much broader utility for researchers, physicians, clinicians and genetic counselors as well as for companies specializing in biopharmaceuticals, bioinformatics and personalized genomics. HGMD was first made publicly available in April 1996, and a collaboration was initiated in 2006 between HGMD and BIOBASE GmbH. This cooperative agreement covers the exclusive worldwide marketing of the most up-to-date (subscription) version of HGMD, HGMD Professional, to academic, clinical and commercial users
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