2,088 research outputs found

    Elementary Hadronic Interactions at the CERN SPS

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    New data from the NA49 experiment at the CERN SPS concerning hadron+proton and hadron+nucleus interactions are discussed and compared to nucleus+nucleus collisions. Detailed information on baryonic momentum distributions and nuclear enhancement factors for kaons and cascade baryons are extracted.Comment: 11 pages, 9 figures, to be published in the Proceedings of the XVIth International Conference on Ultrarelativistic Nucleus-Nucleus Collisions "Quark Matter 2002", Nantes, France, July 200

    New ophthalmosaurid ichthyosaurs from the European lower cretaceous demonstrate extensive ichthyosaur survival across the Jurassic–Cretaceous boundary

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    Background Ichthyosauria is a diverse clade of marine amniotes that spanned most of the Mesozoic. Until recently, most authors interpreted the fossil record as showing that three major extinction events affected this group during its history: one during the latest Triassic, one at the Jurassic–Cretaceous boundary (JCB), and one (resulting in total extinction) at the Cenomanian-Turonian boundary. The JCB was believed to eradicate most of the peculiar morphotypes found in the Late Jurassic, in favor of apparently less specialized forms in the Cretaceous. However, the record of ichthyosaurs from the Berriasian–Barremian interval is extremely limited, and the effects of the end-Jurassic extinction event on ichthyosaurs remains poorly understood. Methodology/Principal Findings Based on new material from the Hauterivian of England and Germany and on abundant material from the Cambridge Greensand Formation, we name a new ophthalmosaurid, Acamptonectes densus gen. et sp. nov. This taxon shares numerous features with Ophthalmosaurus, a genus now restricted to the Callovian–Berriasian interval. Our phylogenetic analysis indicates that Ophthalmosauridae diverged early in its history into two markedly distinct clades, Ophthalmosaurinae and Platypterygiinae, both of which cross the JCB and persist to the late Albian at least. To evaluate the effect of the JCB extinction event on ichthyosaurs, we calculated cladogenesis, extinction, and survival rates for each stage of the Oxfordian–Barremian interval, under different scenarios. The extinction rate during the JCB never surpasses the background extinction rate for the Oxfordian–Barremian interval and the JCB records one of the highest survival rates of the interval. Conclusions/Significance There is currently no evidence that ichthyosaurs were affected by the JCB extinction event, in contrast to many other marine groups. Ophthalmosaurid ichthyosaurs remained diverse from their rapid radiation in the Middle Jurassic to their total extinction at the beginning of the Late Cretaceous

    Paradigm of tunable clustering using binarization of consensus partition matrices (Bi-CoPaM) for gene discovery

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    Copyright @ 2013 Abu-Jamous et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Clustering analysis has a growing role in the study of co-expressed genes for gene discovery. Conventional binary and fuzzy clustering do not embrace the biological reality that some genes may be irrelevant for a problem and not be assigned to a cluster, while other genes may participate in several biological functions and should simultaneously belong to multiple clusters. Also, these algorithms cannot generate tight clusters that focus on their cores or wide clusters that overlap and contain all possibly relevant genes. In this paper, a new clustering paradigm is proposed. In this paradigm, all three eventualities of a gene being exclusively assigned to a single cluster, being assigned to multiple clusters, and being not assigned to any cluster are possible. These possibilities are realised through the primary novelty of the introduction of tunable binarization techniques. Results from multiple clustering experiments are aggregated to generate one fuzzy consensus partition matrix (CoPaM), which is then binarized to obtain the final binary partitions. This is referred to as Binarization of Consensus Partition Matrices (Bi-CoPaM). The method has been tested with a set of synthetic datasets and a set of five real yeast cell-cycle datasets. The results demonstrate its validity in generating relevant tight, wide, and complementary clusters that can meet requirements of different gene discovery studies.National Institute for Health Researc

    Job requirements compared to medical school education: differences between graduates from problem-based learning and conventional curricula

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    Background: Problem-based Learning (PBL) has been suggested as a key educational method of knowledge acquisition to improve medical education. We sought to evaluate the differences in medical school education between graduates from PBL-based and conventional curricula and to what extent these curricula fit job requirements. Methods: Graduates from all German medical schools who graduated between 1996 and 2002 were eligible for this study. Graduates self-assessed nine competencies as required at their day-to-day work and as taught in medical school on a 6-point Likert scale. Results were compared between graduates from a PBL-based curriculum (University Witten/Herdecke) and conventional curricula. Results: Three schools were excluded because of low response rates. Baseline demographics between graduates of the PBL-based curriculum (n = 101, 49% female) and the conventional curricula (n = 4720, 49% female) were similar. No major differences were observed regarding job requirements with priorities for "Independent learning/working" and "Practical medical skills". All competencies were rated to be better taught in PBL-based curriculum compared to the conventional curricula (all p < 0.001), except for "Medical knowledge" and "Research competence". Comparing competencies required at work and taught in medical school, PBL was associated with benefits in "Interdisciplinary thinking" (Δ + 0.88), "Independent learning/working" (Δ + 0.57), "Psycho-social competence" (Δ + 0.56), "Teamwork" (Δ + 0.39) and "Problem-solving skills" (Δ + 0.36), whereas "Research competence" (Δ - 1.23) and "Business competence" (Δ - 1.44) in the PBL-based curriculum needed improvement. Conclusion: Among medical graduates in Germany, PBL demonstrated benefits with regard to competencies which were highly required in the job of physicians. Research and business competence deserve closer attention in future curricular development

    Digital Well-Being and Manipulation Online

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    Social media use is soaring globally. Existing research of its ethical implications predominantly focuses on the relationships amongst human users online, and their effects. The nature of the software-to-human relationship and its impact on digital well-being, however, has not been sufficiently addressed yet. This paper aims to close the gap. I argue that some intelligent software agents, such as newsfeed curator algorithms in social media, manipulate human users because they do not intend their means of influence to reveal the user’s reasons. I support this claim by defending a novel account of manipulation and by showing that some intelligent software agents are manipulative in this sense. Apart from revealing a priori reason for thinking that some intelligent software agents are manipulative, the paper offers a framework for further empirical investigation of manipulation online

    Electrospinning polypropylene with an amino acid as a strategy to bind the antimicrobial peptide Cys-LC-LL-37

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    Hospital isolation gowns are increasingly competitive, with brands and manufacturers contesting consumer preferences. The textile materials in contact with the skin can acquire secretions and multiresistant microorganisms, causing discomfort and health risks, respectively. A new nanofibrous substrate---polypropylene grafted with l-Cys---was developed with an increased crystallinity, providing its surface with --SH hooks necessary to efficiently cross-link the antimicrobial peptide Cys-LC-LL-37 in order to protect against nosocomial pathogens and their spread to community. Furthermore, this application does not require environmental control of humidity, and it is not susceptible to enzyme and microorganism degradation.The authors acknowledge the Fundação para a Ciência e Tecnologia (FCT) for the PhD Grant SFRH/ BD/91444/2012 and Programa Operacional Capital Humano (POCH) and European Union for co-funding the work.info:eu-repo/semantics/publishedVersio

    Status and Plans of the NA49 pp and pA Programme

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    Short memorandum in context of the presentation of the status and plans of the NA49 pp and pA Programme at the SPSC-83 open session

    Policy design for the Anthropocene

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    This is the author accepted manuscript. The final version is available from Nature Research via the DOI in this recordToday, more than ever, ‘Spaceship Earth’ is an apt metaphor as we chart the boundaries for a safe planet1. Social scientists both analyse why society courts disaster by approaching or even overstepping these boundaries and try to design suitable policies to avoid these perils. Because the threats of transgressing planetary boundaries are global, long-run, uncertain and interconnected, they must be analysed together to avoid conflicts and take advantage of synergies. To obtain policies that are effective at both international and local levels requires careful analysis of the underlying mechanisms across scientific disciplines and approaches, and must take politics into account. In this Perspective, we examine the complexities of designing policies that can keep Earth within the biophysical limits favourable to human life.Stockholm Resilience CentreBECC - Biodiversity and Ecosystem services in a Changing ClimateMistra Carbon Exi

    The Spider Effect: Morphological and Orienting Classification of Microglia in Response to Stimuli in Vivo

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    The different morphological stages of microglial activation have not yet been described in detail. We transected the olfactory bulb of rats and examined the activation of the microglial system histologically. Six stages of bidirectional microglial activation (A) and deactivation (R) were observed: from stage 1A to 6A, the cell body size increased, the cell process number decreased, and the cell processes retracted and thickened, orienting toward the direction of the injury site; until stage 6A, when all processes disappeared. In contrast, in deactivation stages 6R to 1R, the microglia returned to the original site exhibiting a stepwise retransformation to the original morphology. Thin highly branched processes re-formed in stage 1R, similar to those in stage 1A. This reverse transformation mirrored the forward transformation except in stages 6R to 1R: cells showed multiple nuclei which were slowly absorbed. Our findings support a morphologically defined stepwise activation and deactivation of microglia cells

    Routine prophylactic antibiotic use in the management of snakebite

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    BACKGROUND: Routine antibiotic prophylaxis following snakebite is not recommended but evidence suggests that it may be common practice in Zimbabwe. This study set out to determine and describe the extent of this practice at Parirenyatwa Hospital, a large teaching hospital in Zimbabwe METHODS: A retrospective case review (1996 to 1999 inclusive) of all cases of snakebite was undertaken at Parirenyatwa Hospital. Cases with a diagnosis of snakebite, presenting within 24 hours of the bite and with no complications or concurrent illness were defined as "routine prophylactic antibiotic use". RESULTS: From 78 cases which satisfied the inclusion criteria, 69 (88.5%) received antibiotics. Ten different antibiotics from 6 different classes were used with penicillins the most commonly prescribed (benzylpenicillin in 29% of cases, alone or in combination). Over 40% of antibiotics were given parenterally although all patients were conscious on admission. The total cost of antibiotics used was estimated at US$522.98. CONCLUSION: Routine prophylactic use of antibiotics in snakebite at Parirenyatwa Hospital is common practice. This may highlight the lack of a clearly defined policy leading to wasteful inappropriate antibiotic use which is costly and may promote bacterial antibiotic resistance. Further work is required to investigate the reasons for this practice and to design appropriate interventions to counter it
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