404 research outputs found

    Improved Measurement of the Pseudoscalar Decay Constant fDsf_{D_{s}}

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    We present a new determination of the Ds decay constant, f_{Ds} using 5 million continuum charm events obtained with the CLEO II detector. Our value is derived from our new measured ratio of widths for Ds -> mu nu/Ds -> phi pi of 0.173+/- 0.021 +/- 0.031. Taking the branching ratio for Ds -> phi pi as (3.6 +/- 0.9)% from the PDG, we extract f_{Ds} = (280 +/- 17 +/- 25 +/- 34){MeV}. We compare this result with various model calculations.Comment: 23 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    Lead exposure in adult males in urban Transvaal Province, South Africa during the apartheid era

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    Human exposure to lead is a substantial public health hazard worldwide and is particularly problematic in the Republic of South Africa given the country’s late cessation of leaded petrol. Lead exposure is associated with a number of serious health issues and diseases including developmental and cognitive deficiency, hypertension and heart disease. Understanding the distribution of lifetime lead burden within a given population is critical for reducing exposure rates. Femoral bone from 101 deceased adult males living in urban Transvaal Province (now Gauteng Province), South Africa between 1960 and 1998 were analyzed for lead concentration by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Of the 72 black and 29 white individuals sampled, chronic lead exposure was apparent in nearly all individuals. White males showed significantly higher median bone lead concentration (ME = 10.04 µg·g−1), than black males (ME = 3.80 µg·g−1) despite higher socioeconomic status. Bone lead concentration covaries significantly, though weakly, with individual age. There was no significant temporal trend in bone lead concentration. These results indicate that long-term low to moderate lead exposure is the historical norm among South African males. Unexpectedly, this research indicates that white males in the sample population were more highly exposed to lead

    First Observation of τ3πηντ\tau\to 3\pi\eta\nu_{\tau} and τf1πντ\tau\to f_{1}\pi\nu_{\tau} Decays

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    We have observed new channels for τ\tau decays with an η\eta in the final state. We study 3-prong tau decays, using the ηγγ\eta\to\gamma\gamma and \eta\to 3\piz decay modes and 1-prong decays with two \piz's using the ηγγ\eta\to\gamma\gamma channel. The measured branching fractions are \B(\tau^{-}\to \pi^{-}\pi^{-}\pi^{+}\eta\nu_{\tau}) =(3.4^{+0.6}_{-0.5}\pm0.6)\times10^{-4} and \B(\tau^{-}\to \pi^{-}2\piz\eta\nu_{\tau} =(1.4\pm0.6\pm0.3)\times10^{-4}. We observe clear evidence for f1ηππf_1\to\eta\pi\pi substructure and measure \B(\tau^{-}\to f_1\pi^{-}\nu_{\tau})=(5.8^{+1.4}_{-1.3}\pm1.8)\times10^{-4}. We have also searched for η(958)\eta'(958) production and obtain 90% CL upper limits \B(\tau^{-}\to \pi^{-}\eta'\nu_\tau)<7.4\times10^{-5} and \B(\tau^{-}\to \pi^{-}\piz\eta'\nu_\tau)<8.0\times10^{-5}.Comment: 11 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    Factor structure and factorial invariance of the strengths and difficulties questionnaire among children of prisoners and their parents

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    Parental imprisonment has been linked to a variety of adverse psychological outcomes for children and adolescents. The Strengths and Difficulties Questionnaire (SDQ) has been widely used to assess behavioural and emotional difficulties among 7-17 year olds in the general population and more recently has been utilised among samples of children of prisoners. Previous research has variously tested traditional one-, three- and five- factor solutions to the SDQ, and more recently one bifactor solution has been examined. Based on a sample of children of prisoners (N = 724) and their non-imprisoned parent or caregiver (N = 658), the aim of the present study was to simultaneously compare nine alternative factor structures, including previously tested models and alternative bifactor solutions. Tests of factorial invariance and composite reliability were also performed. The five-factor model was found to provide the best fit for the data. Tests of factorial invariance revealed that the five-factor model provided an equally acceptable, but not identical fit, among boys and girls. Composite reliability scores were low for the Conduct Problems and Peer Problems subscales. The utility of the SDQ in measuring psychological functioning in response to parental imprisonment is discussed

    Nothing Lasts Forever: Environmental Discourses on the Collapse of Past Societies

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    The study of the collapse of past societies raises many questions for the theory and practice of archaeology. Interest in collapse extends as well into the natural sciences and environmental and sustainability policy. Despite a range of approaches to collapse, the predominant paradigm is environmental collapse, which I argue obscures recognition of the dynamic role of social processes that lie at the heart of human communities. These environmental discourses, together with confusion over terminology and the concepts of collapse, have created widespread aporia about collapse and resulted in the creation of mixed messages about complex historical and social processes

    Insight on genes affecting tuber development in potato upon <i>Potato spindle tuber viroid</i> (PSTVd) infection

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    Potato (Solanum tuberosum L) is a natural host of Potato spindle tuber viroid (PSTVd) which can cause characteristic symptoms on developing plants including stunting phenotype and distortion of leaves and tubers. PSTVd is the type species of the family Pospiviroidae, and can replicate in the nucleus and move systemically throughout the plant. It is not well understood how the viroid can affect host genes for successful invasion and which genes show altered expression levels upon infection. Our primary focus in this study is the identification of genes which can affect tuber formation since viroid infection can strongly influence tuber development and especially tuber shape. In this study, we used a large-scale method to identify differentially expressed genes in potato. We have identified defence, stress and sugar metabolism related genes having altered expression levels upon infection. Additionally, hormone pathway related genes showed significant up- or down-regulation. DWARF1/DIMINUTO, Gibberellin 7-oxidase and BEL5 transcripts were identified and validated showing differential expression in viroid infected tissues. Our study suggests that gibberellin and brassinosteroid pathways have a possible role in tuber development upon PSTVd infection

    Recent developments in genetics and medically assisted reproduction : from research to clinical applications

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    Two leading European professional societies, the European Society of Human Genetics and the European Society for Human Reproduction and Embryology, have worked together since 2004 to evaluate the impact of fast research advances at the interface of assisted reproduction and genetics, including their application into clinical practice. In September 2016, the expert panel met for the third time. The topics discussed highlighted important issues covering the impacts of expanded carrier screening, direct-to-consumer genetic testing, voiding of the presumed anonymity of gamete donors by advanced genetic testing, advances in the research of genetic causes underlying male and female infertility, utilisation of massively parallel sequencing in preimplantation genetic testing and non-invasive prenatal screening, mitochondrial replacement in human oocytes, and additionally, issues related to cross-generational epigenetic inheritance following IVF and germline genome editing. The resulting paper represents a consensus of both professional societies involved.Peer reviewe

    Ethanol production of semi-simultaneous saccharification and fermentation from mixture of cotton gin waste and recycled paper sludge

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    Ethanol production from the steam-exploded mixture of 75% cotton gin waste and 25% recycled paper sludge in various conditions was investigated by semi-simultaneous saccharification and fermentation (SSSF) consisting of a pre-hydrolysis and a simultaneous saccharification and fermentation (SSF). Four cases were studied: 24-h pre-hydrolysis + 48-h SSF (SSSF 24), 12-h pre-hydrolysis + 60-h SSF (SSSF 12), 72-h SSF, and 48-h hydrolysis + 24-h fermentation (SHF). The ethanol concentration, yield, and productivity of SSSF 24 were higher than those of the other operations. A model of SSF was used to simulate the data for four components in SSF. The analysis of the reaction rates of cellobiose, glucose, cell, and ethanol using the model and the parameters from the experiments showed that there was a transition point of the rate-controlling step at which the cell growth control in the initial 2 h was changed to the cellobiose reaction control in later period during ethanol production of SSF from the mixture

    Health disparities across the counties of Kenya and implications for policy makers, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016

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    Background The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016 provided comprehensive estimates of health loss globally. Decision makers in Kenya can use GBD subnational data to target health interventions and address county-level variation in the burden of disease. Methods We used GBD 2016 estimates of life expectancy at birth, healthy life expectancy, all-cause and cause-specific mortality, years of life lost, years lived with disability, disability-adjusted life-years, and risk factors to analyse health by age and sex at the national and county levels in Kenya from 1990 to 2016. Findings The national all-cause mortality rate decreased from 850·3 (95% uncertainty interval [UI] 829·8–871·1) deaths per 100 000 in 1990 to 579·0 (562·1–596·0) deaths per 100 000 in 2016. Under-5 mortality declined from 95·4 (95% UI 90·1–101·3) deaths per 1000 livebirths in 1990 to 43·4 (36·9–51·2) deaths per 1000 livebirths in 2016, and maternal mortality fell from 315·7 (242·9–399·4) deaths per 100 000 in 1990 to 257·6 (195·1–335·3) deaths per 100 000 in 2016, with steeper declines after 2006 and heterogeneously across counties. Life expectancy at birth increased by 5·4 (95% UI 3·7–7·2) years, with higher gains in females than males in all but ten counties. Unsafe water, sanitation, and handwashing, unsafe sex, and malnutrition were the leading national risk factors in 2016. Interpretation Health outcomes have improved in Kenya since 2006. The burden of communicable diseases decreased but continues to predominate the total disease burden in 2016, whereas the non-communicable disease burden increased. Health gains varied strikingly across counties, indicating targeted approaches for health policy are necessary
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