765 research outputs found

    Reconstructing events with missing transverse momentum at the LHC and its application to spin measurement

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    In this article we discuss the measurement of spin at the LHC, in events with two unknown four-momenta. Central to this problem is the identification of spin-dependent kinematic variables and the construction of a statistical test that can distinguish between different spin hypotheses. We propose a method for reconstructing kinematic variables that depend upon the unknown momenta. The method is based upon a probabilistic reconstruction of each event, given the masses of the final and intermediate states and the cross-section of the assumed hypothesis. We demonstrate that this method can distinguish between two spin hypotheses for a specific process, even after mass uncertainties and Standard Model backgrounds are taken into account. We compare our method with another that only utilises the observable momenta of each event. We will show that our method permits an improved discrimination between hypotheses, with a reduced probability of error.Comment: 20 pages, 13 figures. Minor changes to text, references adde

    Draft genome sequence of Colletotrichum acutatum sensu lato (Colletotrichum fioriniae)

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    In addition to its economic impact, Colletotrichum acutatum sensu lato is an interesting model for molecular investigations due to the diversity of host-determined specialization and reproductive lifestyles within the species complex. The pathogen Colletotrichum fioriniae forms part of this species complex and causes anthracnose in a wide range of crops and wild plants worldwide. Some members of this species have also been reported to be entomopathogenic. Here, we report the draft genome sequence of a heterothallic reference isolate of C. fioriniae (strain PJ7). This sequence provides a range of new resources that serve as a useful platform for further research in the field

    Antigenic and genetic characterization of a divergent African virus, Ikoma lyssavirus

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    In 2009, a novel lyssavirus (subsequently named Ikoma lyssavirus, IKOV) was detected in the brain of an African civet (Civettictis civetta) with clinical rabies in the Serengeti National Park of Tanzania. The degree of nucleotide divergence between the genome of IKOV and those of other lyssaviruses predicted antigenic distinction from, and lack of protection provided by, available rabies vaccines. In addition, the index case was considered likely to be an incidental spillover event, and therefore the true reservoir of IKOV remained to be identified. The advent of sensitive molecular techniques has led to a rapid increase in the discovery of novel viruses. Detecting viral sequence alone, however, only allows for prediction of phenotypic characteristics and not their measurement. In the present study we describe the in vitro and in vivo characterization of IKOV, demonstrating that it is (1) pathogenic by peripheral inoculation in an animal model, (2) antigenically distinct from current rabies vaccine strains and (3) poorly neutralized by sera from humans and animals immunized against rabies. In a laboratory mouse model, no protection was elicited by a licensed rabies vaccine. We also investigated the role of bats as reservoirs of IKOV. We found no evidence for infection among 483 individuals of at least 13 bat species sampled across sites in the Serengeti and Southern Kenya

    Evaluating Coastal Landscape Response to Sea-Level Rise in the Northeastern United States - Approach and Methods

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    The U.S. Geological Survey is examining effects of future sea-level rise on the coastal landscape from Maine to Virginia by producing spatially explicit, probabilistic predictions using sea-level projections, vertical land movement rates (due to isostacy), elevation data, and land-cover data. Sea-level-rise scenarios used as model inputs are generated by using multiple sources of information, including Coupled Model Intercomparison Project Phase 5 models following representative concentration pathways 4.5 and 8.5 in the Intergovernmental Panel on Climate Change Fifth Assessment Report. A Bayesian network is used to develop a predictive coastal response model that integrates the sea-level, elevation, and land-cover data with assigned probabilities that account for interactions with coastal geomorphology as well as the corresponding ecological and societal systems it supports. The effects of sea-level rise are presented as (1) level of landscape submergence and (2) coastal response type characterized as either static (that is, inundation) or dynamic (that is, landform or landscape change). Results are produced at a spatial scale of 30 meters for four decades (the 2020s, 2030s, 2050s, and 2080s). The probabilistic predictions can be applied to landscape management decisions based on sea-level-rise effects as well as on assessments of the prediction uncertainty and need for improved data or fundamental understanding. This report describes the methods used to produce predictions, including information on input datasets; the modeling approach; model outputs; data-quality-control procedures; and information on how to access the data and metadata online

    We make the road by walking: challenging conceptualisations of leisure time for children in poverty

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    In this article, we discuss a research project focusing on the ways in which children in poverty spend and experience their leisure time. We argue that the dominant conceptualisation of leisure time participation reduces poverty to a lack of social and cultural capital, marginalising poor children as passive objects of socialisation. Inspired by the interpretative paradigm of lifeworld orientation, three insights are identified throughout poor children’s experiences, which include the following: (1) challenging taken-for-granted divisions of time; (2) giving meaning to regimes of time as an on-going learning process; and (3) imagining a socially just future

    Investigating diversity of pathogenic microbes in commercial bait trade water

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    The recreational bait trade is a potential pathway for pathogen introduction and spread when anglers dump bait shop sourced water into aquatic systems. Despite this possibility, and previous recognition of the importance of the bait trade in the spread of aquatic invasive species (AIS), to date there has been no region wide survey documenting pathogens in retail bait shops. In this study, we analyzed 96 environmental DNA samples from retail bait shops around the Great Lakes region to identify pathogens, targeting the V4 hypervariable region of the 16S rRNA gene. Additionally, we used samples from one site in Lake Michigan as a comparison to pathogen diversity and abundance in natural aquatic systems. Our results identified nine different groups of pathogens in the bait shop samples, including those that pose risks to both humans and fish species. Compared to wild sourced samples, the bait shops had higher relative abundance and greater taxonomic diversity. These findings suggest that the bait trade represents a potentially important pathway that could introduce and spread pathogens throughout the Great Lakes region. Improving pathogen screening and angler outreach should be used in combination to aid in preventing the future spread of high risk pathogens

    The purpose of financial reporting: the case for coherence in the Conceptual Framework and standards

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    This paper proposes a basis for progress in the development of the conceptual framework (CF) as a foundation for developing accounting standards. This topic has gained increased prominence following the IASB's (2013) release of its Review of the Conceptual Framework for Financial Reporting (RCFFR) proposing changes to the CF. In this paper the broad socio-economic environment is seen as determining the primary purpose of General Purpose Financial Reporting (GPFR), which, in turn, establishes the high-level properties of a CF suitable to meet that primary purpose. This is to support market stability and efficiency through the provision of an account of the financial position and performance of an entity that accords with economic reality. The case is made that the primary purpose of a CF is to provide the principles for the development of accounting standards that will result in GPFR that is useful. This requires theoretical coherence. The CF should drive the standards and if standards depart from the CF principles, such departures should be justified. This proposal is consistent with the position adopted in the RCFFR. However, in contrast to the RCFFR, this paper accents the purposive approach and links the formation of standards directly to the CF. This approach implies that standards are subordinate to CF principles; therefore compliance with standards should not provide a basis for compromising the faithful representation of economic reality. From the purpose identified for GPFR, the paper argues for a default presumption in favour of Fair Value Accounting, a retreat from the asset/liability approach, and a re-casting of the income statement to focus on operational flows

    Genome-Wide Association Mapping in Arabidopsis Identifies Previously Known Flowering Time and Pathogen Resistance Genes

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    There is currently tremendous interest in the possibility of using genome-wide association mapping to identify genes responsible for natural variation, particularly for human disease susceptibility. The model plant Arabidopsis thaliana is in many ways an ideal candidate for such studies, because it is a highly selfing hermaphrodite. As a result, the species largely exists as a collection of naturally occurring inbred lines, or accessions, which can be genotyped once and phenotyped repeatedly. Furthermore, linkage disequilibrium in such a species will be much more extensive than in a comparable outcrossing species. We tested the feasibility of genome-wide association mapping in A. thaliana by searching for associations with flowering time and pathogen resistance in a sample of 95 accessions for which genome-wide polymorphism data were available. In spite of an extremely high rate of false positives due to population structure, we were able to identify known major genes for all phenotypes tested, thus demonstrating the potential of genome-wide association mapping in A. thaliana and other species with similar patterns of variation. The rate of false positives differed strongly between traits, with more clinal traits showing the highest rate. However, the false positive rates were always substantial regardless of the trait, highlighting the necessity of an appropriate genomic control in association studies