1,044 research outputs found

    Proteomic identification of heterogeneous nuclear ribonucleoprotein L as a novel component of SLM/Sam68 nuclear bodies

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    Background: Active pre-mRNA splicing occurs co-transcriptionally, and takes place throughout the nucleoplasm of eukaryotic cells. Splicing decisions are controlled by networks of nuclear RNA-binding proteins and their target sequences, sometimes in response to signalling pathways. Sam68 (Src-associated in mitosis 68 kDa) is the prototypic member of the STAR (Signal Transduction and Activation of RNA) family of RNA-binding proteins, which regulate splicing in response to signalling cascades. Nuclear Sam68 protein is concentrated within subnuclear organelles called SLM/Sam68 Nuclear Bodies (SNBs), which also contain some other splicing regulators, signalling components and nucleic acids. Results: We used proteomics to search for the major interacting protein partners of nuclear Sam68. In addition to Sam68 itself and known Sam68-associated proteins (heterogeneous nuclear ribonucleoproteins hnRNP A1, A2/B1 and G), we identified hnRNP L as a novel Sam68-interacting protein partner. hnRNP L protein was predominantly present within small nuclear protein complexes approximating to the expected size of monomers and dimers, and was quantitatively associated with nucleic acids. hnRNP L spatially co-localised with Sam68 as a novel component of SNBs and was also observed within the general nucleoplasm. Localisation within SNBs was highly specific to hnRNP L and was not shared by the closely-related hnRNP LL protein, nor any of the other Sam68-interacting proteins we identified by proteomics. The interaction between Sam68 and hnRNP L proteins was observed in a cell line which exhibits low frequency of SNBs suggesting that this association also takes place outside SNBs. Although ectopic expression of hnRNP L and Sam68 proteins independently affected splicing of CD44 variable exon v5 and TJP1 exon 20 minigenes, these proteins did not, however, co-operate with each other in splicing regulation of these target exons. Conclusion: Here we identify hnRNP L as a novel SNB component. We show that, compared with other identified Sam68-associated hnRNP proteins and hnRNP LL, this co-localisation within SNBs is specific to hnRNP L. Our data suggest that the novel Sam68-hnRNP L protein interaction may have a distinct role within SNBs

    Antibiotic Prophylaxis For Transrectal Prostate Biopsy.

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    Transrectal prostate biopsy (TRPB) is a well established procedure used to obtain tissue for the histological diagnosis of carcinoma of the prostate. Despite the fact that TRPB is generally considered a safe procedure, it may be accompanied by traumatic and infective complications, including asymptomatic bacteriuria (bacteria in the urine), urinary tract infection (UTI), transitory bacteremia (bacteria in the blood), fever episodes, and sepsis (pathogenic microorganisms or their toxins in the blood). Although infective complications after TRPB are well known, there is uncertainty about the necessity and effectiveness of routine prophylactic antibiotics and their adverse effects, as well as a clear lack of standardization. To evaluate the effectiveness and adverse effects of prophylactic antibiotic treatment in TRPB. The search covered the principal electronic databases: MEDLINE, EMBASE, LILACS and the Cochrane Central Register of Controlled Trials (CENTRAL). Experts were consulted and references from the relevant articles were scanned. All randomized, controlled trials (RCTs) of men who underwent TRPB and received prophylactic antibiotics or placebo/no treatment, were selected, and all RCTs looking at one type of antibiotic versus another, including comparable dosages, routes of administration, frequency of administration, and duration of antibiotic treatment. Two reviewers (ELZ, OACC) independently selected included trials and extracted study data. Any disagreements were resolved by a third party (NRNJ). Overall, more than 3500 references were considered and 19 original reports with a total of 3599 patients were included.There were 9 trials analysing antibiotics versus placebo/no treatment, with all outcomes significantly favouring antibiotic use (P < 0.05) (I(2) = 0%), including bacteriuria (risk ratio (RR) 0.25 (95% confidence interval (CI) 0.15 to 0.42), bacteremia (RR 0.67, 95% CI 0.49 to 0.92), fever (RR 0.39, 95% CI 0.23 to 0.64), urinary tract infection (RR 0.37, 95% CI 0.22 to 0.62), and hospitalization (RR 0.13, 95% CI 0.03 to 0.55). Several classes of antibiotics were effective prophylactically for TRPB, while the quinolones, with the highest number of studies (5) and patients (1188), were the best analysed. For 'antibiotics versus enema', we analysed four studies with a limited number of patients. The differences between groups for all outcomes were not significant. For 'antibiotic versus antibiotic + enema', only the risk of bacteremia (RR 0.25, 95% CI 0.08 to 0.75) was diminished in the 'antibiotic + enema group'. Seven trials reported the effects of short-course (1 day) versus long-course (3 days) antibiotics. Long course was significantly better than short-course treatment only for bacteriuria (RR 2.09, 95% CI 1.17 to 3.73). For 'single versus multiple dose', there was significantly greater risk of bacteriuria for single-dose treatment (RR 1.98, 95% CI 1.18 to 3.33). Comparing oral versus systemic administration - intramuscular injection (IM), or intravenous (IV) - of antibiotics, there were no significant differences in the groups for bacteriuria, fever, UTI and hospitalization. Antibiotic prophylaxis is effective in preventing infectious complications following TRPB. There is no definitive data to confirm that antibiotics for long-course (3 days) are superior to short-course treatments (1 day), or that multiple-dose treatment is superior to single-dose.

    Eimeria species occurrence varies between geographic regions and poultry production systems and may influence parasite genetic diversity

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    Coccidiosis is one of the biggest challenges faced by the global poultry industry. Recent studies have highlighted the ubiquitous distribution of all Eimeria species which can cause this disease in chickens, but intriguingly revealed a regional divide in genetic diversity and population structure for at least one species, Eimeria tenella. The drivers associated with such distinct geographic variation are unclear, but may impact on the occurrence and extent of resistance to anticoccidial drugs and future subunit vaccines. India is one of the largest poultry producers in the world and includes a transition between E. tenella populations defined by high and low genetic diversity. The aim of this study was to identify risk factors associated with the prevalence of Eimeria species defined by high and low pathogenicity in northern and southern states of India, and seek to understand factors which vary between the regions as possible drivers for differential genetic variation. Faecal samples and data relating to farm characteristics and management were collected from 107 farms from northern India and 133 farms from southern India. Faecal samples were analysed using microscopy and PCR to identify Eimeria occurrence. Multiple correspondence analysis was applied to transform correlated putative risk factors into a smaller number of synthetic uncorrelated factors. Hierarchical cluster analysis was used to identify poultry farm typologies, revealing three distinct clusters in the studied regions. The association between clusters and presence of Eimeria species was assessed by logistic regression. The study found that large-scale broiler farms in the north were at greatest risk of harbouring any Eimeria species and a larger proportion of such farms were positive for E. necatrix, the most pathogenic species. Comparison revealed a more even distribution for E. tenella across production systems in south India, but with a lower overall occurrence. Such a polarised region- and system-specific distribution may contribute to the different levels of genetic diversity observed previously in India and may influence parasite population structure across much of Asia and Africa. The findings of the study can be used to prioritise target farms to launch and optimise appropriate anticoccidial strategies for long-term control

    Vegetation's Red Edge: A Possible Spectroscopic Biosignature of Extraterrestrial Plants

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    Earth's deciduous plants have a sharp order-of-magnitude increase in leaf reflectance between approximately 700 and 750 nm wavelength. This strong reflectance of Earth's vegetation suggests that surface biosignatures with sharp spectral features might be detectable in the spectrum of scattered light from a spatially unresolved extrasolar terrestrial planet. We assess the potential of Earth's step-function-like spectroscopic feature, referred to as the "red edge", as a tool for astrobiology. We review the basic characteristics and physical origin of the red edge and summarize its use in astronomy: early spectroscopic efforts to search for vegetation on Mars and recent reports of detection of the red edge in the spectrum of Earthshine (i.e., the spatially integrated scattered light spectrum of Earth). We present Earthshine observations from Apache Point Observatory to emphasize that time variability is key to detecting weak surface biosignatures such as the vegetation red edge. We briefly discuss the evolutionary advantages of vegetation's red edge reflectance, and speculate that while extraterrestrial "light harvesting organisms" have no compelling reason to display the exact same red edge feature as terrestrial vegetation, they might have similar spectroscopic features at different wavelengths than terrestrial vegetation. This implies that future terrestrial-planet-characterizing space missions should obtain data that allow time-varying, sharp spectral features at unknown wavelengths to be identified. We caution that some mineral reflectance edges are similar in slope and strength to vegetation's red edge (albeit at different wavelengths); if an extrasolar planet reflectance edge is detected care must be taken with its interpretation.Comment: 19 pages, 6 figures, to appear in Astrobiolog

    The glassy response of solid He-4 to torsional oscillations

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    We calculated the glassy response of solid He-4 to torsional oscillations assuming a phenomenological glass model. Making only a few assumptions about the distribution of glassy relaxation times in a small subsystem of otherwise rigid solid He-4, we can account for the magnitude of the observed period shift and concomitant dissipation peak in several torsion oscillator experiments. The implications of the glass model for solid He-4 are threefold: (1) The dynamics of solid He-4 is governed by glassy relaxation processes. (2) The distribution of relaxation times varies significantly between different torsion oscillator experiments. (3) The mechanical response of a torsion oscillator does not require a supersolid component to account for the observed anomaly at low temperatures, though we cannot rule out its existence.Comment: 9 pages, 4 figures, presented at QFS200

    Beyond the Bedside: Protocol for a scoping review exploring the experiences of non-practicing healthcare professionals within health professions education

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    Background: The number of healthcare professionals leaving clinical practice and transitioning to alternative careers in health professions education is increasing. Among these non-practicing healthcare professionals, concerns have been reported regarding tensions in relation to identity, role, and credibility in their new field. There are suggestions that this is a particularly pressing issue for minoritised professionals who make this transition. Support is critical to attract and retain diverse talent within health professions education teaching and research. The purpose of this scoping review is to explore the career experiences of non-practicing healthcare professionals who work in health professions education internationally.Methods: Arksey and O’Malley’s framework has been utilised to guide the design of this scoping review process and will be used throughout the course of the review. A comprehensive search of seven electronic databases and limited search of Google Scholar will be conducted, as well as a hand search of eligible article reference lists. Two reviewers will independently screen all articles based on inclusion criteria, with conflicts resolved by a third reviewer. Data from included articles will be charted, collated, and analysed thematically. Meta-data will be summarised quantitatively.Discussion: This scoping review aims to explore the role and experiences of non-practicing healthcare professionals working within health professions education. The review will follow established scoping review guidelines and will include studies from various regions and languages, provided an English translation is available. The study remit will be broad, including both quantitative and qualitative studies, as well as reviews and opinion papers. Limitations may include the exclusion of non-English articles and potential difficulty of identifying papers which discuss the experiences of non-practicing clinicians. However, the review will provide insight into the current knowledge on what it is like to be a non-practicing clinician working within health professions education and identify gaps for both future research, and future support for those making this career transition

    Measurements of the Composite Fermion masses from the spin polarization of 2-D electrons in the region 1<ν<21<\nu<2

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    Measurements of the reflectivity of a 2-D electron gas are used to deduce the polarization of the Composite Fermion hole system formed for Landau level occupancies in the regime 1<\nu<2. The measurements are consistent with the formation of a mixed spin CF system and allow the density of states or `polarization' effective mass of the CF holes to be determined. The mass values at \nu=3/2 are found to be ~1.9m_{e} for electron densities of 4.4 x 10^{11} cm^{-2}, which is significantly larger than those found from measurements of the energy gaps at finite values of effective magnetic field.Comment: 4 pages, 3 fig

    General properties of the pion production reaction in nuclear matter

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    The pion production reaction π+π+π±\pi^+ \to \pi^+\pi^{\pm} on 45Sc^{45}Sc was studied at incident pion energies of Tπ+T_{\pi^{+}} = 240, 260, 280, 300, and 320 MeV. The experiment was performed using the M11M11 pion-channel at TRIUMF, and multiparticle events, (π+,π+π±\pi^+,\pi^+\pi^{\pm}) and (π+,π+π±p\pi^+,\pi^+\pi^{\pm}p), were detected with the CHAOS spectrometer. Results are reported in the form of both differential and total cross sections, and are compared to theoretical predictions and the reaction phase space. The present investigation of the T-dependence of the π+Aπ+π±A\pi^+ A \to \pi^+\pi^{\pm} A' reaction complements earlier examinations of the A-dependence of the reaction, which was measured using 2H^{2}H, 4He^{4}He, 12C^{12}C, 16O^{16}O, 40Ca^{40}Ca, and 208Pb^{208}Pb targets at \sim280 MeV. Some general properties of the pion-induced pion production reaction in nuclear matter will be presented, based on the combined results of the two studies.Comment: 23 pages, Latex, accepted for publication in Nucl. Phys.

    Theory of laser ion acceleration from a foil target of nanometers

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    A theory for laser ion acceleration is presented to evaluate the maximum ion energy in the interaction of ultrahigh contrast (UHC) intense laser with a nanometer-scale foil. In this regime the energy of ions may be directly related to the laser intensity and subsequent electron dynamics. This leads to a simple analytical expression for the ion energy gain under the laser irradiation of thin targets. Significantly, higher energies for thin targets than for thicker targets are predicted. Theory is concretized to the details of recent experiments which may find its way to compare with these results.Comment: 22 pages 7 figures. will be submitted to NJ
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