343 research outputs found

    The role of science in physical natural hazard assessment : report to the UK Government by the Natural Hazard Working Group

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    Following the tragic Asian tsunami on 26 December 2004, the Prime Minister asked the Government’s Chief Scientific Adviser, Sir David King, to convene a group of experts (the Natural Hazard Working Group) to advise on the mechanisms that could and should be established for the detection and early warning of global physical natural hazards. 2. The Group was asked to examine physical hazards which have high global or regional impact and for which an appropriate early warning system could be put in place. It was also asked to consider the global natural hazard frameworks currently in place and under development and their effectiveness in using scientific evidence; to consider whether there is an existing appropriate international body to pull together the international science community to advise governments on the systems that need to be put in place, and to advise on research needed to fill current gaps in knowledge. The Group was asked to make recommendations on whether a new body was needed, or whether other arrangements would be more effective

    Complex spine deformities in young patients with severe osteogenesis imperfecta: current concepts review

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    The severity of osteogenesis imperfecta (OI), the associated reduced quality and quantity of collagen type I, the degree of bone fragility, ligamentous laxity, vertebral fractures and multilevel vertebral deformities all impair the mechanical integrity of the whole spinal architecture and relate to the high prevalence of progressive kyphoscoliotic deformities during growth. Bisphosphonate therapy may at best slow down curve progression but does not seem to lower the prevalence of deformities or the incidence of surgery. Brace treatment is problematic due to pre-existing chest wall deformities, stiffness of the curve and the brittleness of the ribs which limit transfer of corrective forces from the brace shell to the spine. Progressive curves entail loss of balance, chest deformities, pain and compromise of pulmonary function and eventually require surgical stabilization, usually around puberty. Severe vertebral deformities including deformed, small pedicles, highly brittle bones and chest deformities, short deformed trunks and associated issues like C-spine and cranial base abnormalities (basilar impressions, cervical kyphosis) as well as deformed lower and upper extremities are posing multiple peri-and intraoperative challenges. Hence, an early multidisciplinary approach (anaesthetist, pulmonologist, paediatric orthopaedic spine surgeon) is mandatory.This paper was written under the guidance of the Spine Study Group of the European Paediatric Orthopaedic Society. It highlights the most pertinent information given in the current literature and various practical aspects on surgical care of spine deformities in young OI patients based on the personal experience of the contributing authors

    Unifying Parsimonious Tree Reconciliation

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    Evolution is a process that is influenced by various environmental factors, e.g. the interactions between different species, genes, and biogeographical properties. Hence, it is interesting to study the combined evolutionary history of multiple species, their genes, and the environment they live in. A common approach to address this research problem is to describe each individual evolution as a phylogenetic tree and construct a tree reconciliation which is parsimonious with respect to a given event model. Unfortunately, most of the previous approaches are designed only either for host-parasite systems, for gene tree/species tree reconciliation, or biogeography. Hence, a method is desirable, which addresses the general problem of mapping phylogenetic trees and covering all varieties of coevolving systems, including e.g., predator-prey and symbiotic relationships. To overcome this gap, we introduce a generalized cophylogenetic event model considering the combinatorial complete set of local coevolutionary events. We give a dynamic programming based heuristic for solving the maximum parsimony reconciliation problem in time O(n^2), for two phylogenies each with at most n leaves. Furthermore, we present an exact branch-and-bound algorithm which uses the results from the dynamic programming heuristic for discarding partial reconciliations. The approach has been implemented as a Java application which is freely available from http://pacosy.informatik.uni-leipzig.de/coresym.Comment: Peer-reviewed and presented as part of the 13th Workshop on Algorithms in Bioinformatics (WABI2013

    Influenza pandemic and professional duty: family or patients first? A survey of hospital employees

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    BACKGROUND: Conflicts between professional duties and fear of influenza transmission to family members may arise among health care professionals (HCP). METHODS: We surveyed employees at our university hospital regarding ethical issues arising during the management of an influenza pandemic. RESULTS: Of 644 respondents, 182 (28%) agreed that it would be professionally acceptable for HCP to abandon their workplace during a pandemic in order to protect themselves and their families, 337 (52%) disagreed with this statement and 125 (19%) had no opinion, with a higher rate of disagreement among physicians (65%) and nurses (54%) compared with administrators (32%). Of all respondents, 375 (58%) did not believe that the decision to report to work during a pandemic should be left to the individual HCP and 496 (77%) disagreed with the statement that HCP should be permanently dismissed for not reporting to work during a pandemic. Only 136 (21%) respondents agreed that HCW without children should primarily care for the influenza patients. CONCLUSION: Our results suggest that a modest majority of HCP, but only a minority of hospital administrators, recognises the obligation to treat patients despite the potential risks. Professional ethical guidelines allowing for balancing the needs of society with personal risks are needed to help HCP fulfil their duties in the case of a pandemic influenza

    Stable isotope analysis provides new information on winter habitat use of declining avian migrants that is relevant to their conservation

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    Winter habitat use and the magnitude of migratory connectivity are important parameters when assessing drivers of the marked declines in avian migrants. Such information is unavailable for most species. We use a stable isotope approach to assess these factors for three declining African-Eurasian migrants whose winter ecology is poorly known: wood warbler Phylloscopus sibilatrix, house martin Delichon urbicum and common swift Apus apus. Spatially segregated breeding wood warbler populations (sampled across a 800 km transect), house martins and common swifts (sampled across a 3,500 km transect) exhibited statistically identical intra-specific carbon and nitrogen isotope ratios in winter grown feathers. Such patterns are compatible with a high degree of migratory connectivity, but could arise if species use isotopically similar resources at different locations. Wood warbler carbon isotope ratios are more depleted than typical for African-Eurasian migrants and are compatible with use of moist lowland forest. The very limited variance in these ratios indicates specialisation on isotopically restricted resources, which may drive the similarity in wood warbler populations' stable isotope ratios and increase susceptibility to environmental change within its wintering grounds. House martins were previously considered to primarily use moist montane forest during the winter, but this seems unlikely given the enriched nature of their carbon isotope ratios. House martins use a narrower isotopic range of resources than the common swift, indicative of increased specialisation or a relatively limited wintering range; both factors could increase house martins' vulnerability to environmental change. The marked variance in isotope ratios within each common swift population contributes to the lack of population specific signatures and indicates that the species is less vulnerable to environmental change in sub-Saharan Africa than our other focal species. Our findings demonstrate how stable isotope research can contribute to understanding avian migrants' winter ecology and conservation status

    Reconciliation Revisited: Handling Multiple Optima when Reconciling with Duplication, Transfer, and Loss

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    Phylogenetic tree reconciliation is a powerful approach for inferring evolutionary events like gene duplication, horizontal gene transfer, and gene loss, which are fundamental to our understanding of molecular evolution. While duplication–loss (DL) reconciliation leads to a unique maximum-parsimony solution, duplication-transfer-loss (DTL) reconciliation yields a multitude of optimal solutions, making it difficult to infer the true evolutionary history of the gene family. This problem is further exacerbated by the fact that different event cost assignments yield different sets of optimal reconciliations. Here, we present an effective, efficient, and scalable method for dealing with these fundamental problems in DTL reconciliation. Our approach works by sampling the space of optimal reconciliations uniformly at random and aggregating the results. We show that even gene trees with only a few dozen genes often have millions of optimal reconciliations and present an algorithm to efficiently sample the space of optimal reconciliations uniformly at random in O(mn[superscript 2]) time per sample, where m and n denote the number of genes and species, respectively. We use these samples to understand how different optimal reconciliations vary in their node mappings and event assignments and to investigate the impact of varying event costs. We apply our method to a biological dataset of approximately 4700 gene trees from 100 taxa and observe that 93% of event assignments and 73% of mappings remain consistent across different multiple optima. Our analysis represents the first systematic investigation of the space of optimal DTL reconciliations and has many important implications for the study of gene family evolution.National Science Foundation (U.S.) (CAREER Award 0644282)National Institutes of Health (U.S.) (Grant RC2 HG005639)National Science Foundation (U.S.). Assembling the Tree of Life (Program) (Grant 0936234

    Prognostic and Mechanistic Potential of Progesterone Sulfates in Intrahepatic Cholestasis of Pregnancy and Pruritus Gravidarum

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    A challenge in obstetrics is to distinguish pathological symptoms from those associated with normal changes of pregnancy, typified by the need to differentiate whether gestational pruritus of the skin is an early symptom of intrahepatic cholestasis of pregnancy (ICP) or due to benign pruritus gravidarum. ICP is characterized by raised serum bile acids and complicated by spontaneous preterm labor and stillbirth. A biomarker for ICP would be invaluable for early diagnosis and treatment and to enable its differentiation from other maternal diseases. Three progesterone sulfate compounds, whose concentrations have not previously been studied, were newly synthesized and assayed in the serum of three groups of ICP patients and found to be significantly higher in ICP at 9-15 weeks of gestation and prior to symptom onset (group 1 cases/samples: ICP n = 35/80, uncomplicated pregnancy = 29/100), demonstrating that all three progesterone sulfates are prognostic for ICP. Concentrations of progesterone sulfates were associated with itch severity and, in combination with autotaxin, distinguished pregnant women with itch that would subsequently develop ICP from pruritus gravidarum (group 2: ICP n = 41, pruritus gravidarum n = 14). In a third group of first-trimester samples all progesterone sulfates were significantly elevated in serum from low-risk asymptomatic women who subsequently developed ICP (ICP/uncomplicated pregnancy n = 54/51). Finally, we show mechanistically that progesterone sulfates mediate itch by evoking a Tgr5-dependent scratch response in mice. Conclusion: Our discovery that sulfated progesterone metabolites are a prognostic indicator for ICP will help predict onset of ICP and distinguish it from benign pruritus gravidarum, enabling targeted obstetric care to a high-risk population. Delineation of a progesterone sulfate-TGR5 pruritus axis identifies a therapeutic target for itch management in ICP

    COVID-19 publications: Database coverage, citations, readers, tweets, news, Facebook walls, Reddit posts

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    © 2020 The Authors. Published by MIT Press. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1162/qss_a_00066The COVID-19 pandemic requires a fast response from researchers to help address biological, medical and public health issues to minimize its impact. In this rapidly evolving context, scholars, professionals and the public may need to quickly identify important new studies. In response, this paper assesses the coverage of scholarly databases and impact indicators during 21 March to 18 April 2020. The rapidly increasing volume of research, is particularly accessible through Dimensions, and less through Scopus, the Web of Science, and PubMed. Google Scholar’s results included many false matches. A few COVID-19 papers from the 21,395 in Dimensions were already highly cited, with substantial news and social media attention. For this topic, in contrast to previous studies, there seems to be a high degree of convergence between articles shared in the social web and citation counts, at least in the short term. In particular, articles that are extensively tweeted on the day first indexed are likely to be highly read and relatively highly cited three weeks later. Researchers needing wide scope literature searches (rather than health focused PubMed or medRxiv searches) should start with Dimensions (or Google Scholar) and can use tweet and Mendeley reader counts as indicators of likely importance
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