1,407 research outputs found

    Neutron Correlations in the Decay of the First Excited State of 11Li

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    The decay of unbound excited 11Li was measured after being populated by a two-proton removal from a 13B beam at 71 MeV/nucleon. Decay energy spectra and Jacobi plots were obtained from measurements of the momentum vectors of the 9Li fragment and neutrons. A resonance at an excitation energy of ∼1.2 MeV was observed. The kinematics of the decay are equally well fit by a simple dineutron-like model or a phase-space model that includes final state interactions. A sequential decay model can be excluded

    Mapping Trachoma in the Solomon Islands: Results of Three Baseline Population-Based Prevalence Surveys Conducted with the Global Trachoma Mapping Project.

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    PURPOSE: We sought to complete the baseline trachoma map of the Solomon Islands by establishing prevalences of active trachoma and trichiasis in the provinces of Choiseul, Western, Rennell-Bellona, and Temotu. METHODS: Using the standardized methodology developed for the Global Trachoma Mapping Project, we conducted cross-sectional community-based surveys from September to November 2013. Choiseul and Western provinces were each mapped as separate evaluation units (EUs); Rennell-Bellona and Temotu were combined to form a third EU. RESULTS: A total of 9819 individuals were sampled for inclusion, with 9224 (93.3%) consenting to examination, of whom 4587 (46.3%) were female. Survey teams visited 82 villages, and surveyed 2448 households. Two EUs had prevalences of trachomatous inflammation - follicular (TF) in 1-9-year-olds over the 10% threshold at which WHO recommends mass distribution of azithromycin for at least 3 years (Western 20.4%, 95% confidence interval, CI 15.6-26.3%; Rennell-Bellona/Temotu 22.0%, 95% CI 18.5-26.0%). Choiseul had a TF prevalence of 6.1% (95% CI 4.1-8.6%), and met the criterion for a single round of mass antibiotic distribution before re-survey. The adjusted prevalences of trichiasis in those aged 15+ years were 0.0% (95% CI 0.0-0.2%) in Choiseul, 0.16% (95% CI 0.0-0.5%) in Western, and 0.10% (95% CI 0-0.3%) in Rennell-Bellona/Temotu provinces. All three EUs require implementation of the facial cleanliness and environmental improvement components of the trachoma elimination strategy. CONCLUSION: Active trachoma is prevalent in the Solomon Islands. However, there is little evidence of the blinding complications of trachoma being a public health problem there. Further research into the explanation for this phenomenon is warranted

    A declining CD4 count and diagnosis of HIV-associated Hodgkin lymphoma: do prior clinical symptoms and laboratory abnormalities aid diagnosis?

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    BACKGROUND: The incidence of Hodgkin lymphoma (HL) among HIV-infected individuals remains unchanged since the introduction of combination antiretroviral therapy (cART). Recent epidemiological data suggest that CD4 count decline over a year is associated with subsequent diagnosis of HL. In an era of economic austerity monitoring the efficacy of cART by CD4 counts may no longer be required where CD4 count>350 cells/µl and viral load is suppressed (350 may not have delayed diagnosis

    A New Species of Boubou (Malaconotidae: Laniarius) from the Albertine Rift

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    We describe Laniarius willardi, a new species of boubou shrike (Malaconotidae) from the Albertine Rift of Africa. The most conspicuous, distinguishing morphological feature of the species is a gray to blue-gray iris. This and external morphometric data indicate that L. willardi is diagnosable from other black or sooty boubous. Further, L. willardi is genetically diagnosable, and its closest relative is the Mountain Sooty Boubou (L. poensis camerunensis) from Cameroon. The Crimson-breasted Bush-shrike (L. atrococcineus) and the Lowland Sooty Boubou (L. leucorhynchus) are together the sister clade to L. willardi—L.p. camerunensis. Laniarius willardi and the geographically codistributed L. p. holomelas differ by 11.5% in uncorrected sequence divergence, and elevational data taken from museum specimens suggest the possibility of elevational segregation of the species at ∼2,000 m, withL. willardi occurring at lower elevations. Our broad sampling of black and sooty boubou taxa indicate that (1) races of Mountain Sooty Boubou (L. poensis) do not form a monophyletic clade; (2) L. p. camerunensismay represent multiple, nonsister lineages; and (3) at least one race of Fülleborn\u27s Black Boubou (L. fuelleborni usambaricus) is genetically distinct from other races of that species

    Distance Dependence of Electron Transfer Kinetics for Azurin Protein Adsorbed to Monolayer Protected Nanoparticle Film Assemblies

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    The distance dependence and kinetics of the heterogeneous electron transfer (ET) reaction for the redox protein azurin adsorbed to an electrode modified with a gold nanoparticle film are investigated using cyclic voltammetry. The nanoparticle films are comprised of nonaqueous nanoparticles, known as monolayer-protected clusters (MPCs), which are covalently networked with dithiol linkers. The MPC film assembly serves as an alternative adsorption platform to the traditional alkanethiolate self-assembled monolayer (SAM) modified electrodes that are commonly employed to study the ET kinetics of immobilized redox proteins, a strategy known as protein monolayer electrochemistry. Voltammetric analysis of the ET kinetics for azurin adsorbed to SAMs of increasing chain length results in quasi-reversible voltammetry with significant peak splitting. We observed rate constants (k°ET) of 12−20 s−1 for the protein at SAMs of shorter alkanethiolates that decays exponentially (β = 0.9/CH2 or 0.8/Å) at SAMs of longer alkanethiolates (9−11 methylene units) or an estimated distance of 1.23 nm and is representative of classical electronic tunneling behavior over increasing distance. Azurin adsorbed to the MPC film platforms of increasing thickness results in reversible voltammetry with very little voltammetric peaks splitting and nearly negligible decay of the ET rate over significant distances up to 20 nm. The apparent lack of distance dependence for heterogeneous ET reactions at MPC film assemblies is attributed to a two-step mechanism involving extremely fast electronic hopping through the MPC film architecture. These results suggest that MPC platforms may be used in protein monolayer electrochemistry to create adsorption platforms of higher architecture that can accommodate greater than monolayer protein coverage and increase the Faradaic signal, a finding with significant implications for amperometric biosensor design and development

    Integrated Mapping of Yaws and Trachoma in the Five Northern-Most Provinces of Vanuatu.

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    Yaws and trachoma are targeted for eradication and elimination as public health problems. In trachoma-endemic populations mass administration of azithromycin can simultaneously treat yaws. We conducted a population-based prevalence survey in the five northernmost provinces of Vanuatu, where trachoma and yaws are suspected to be co-endemic. Clinical signs of trachoma were evaluated using the WHO simplified grading system, and skin examination with a serological rapid diagnostic test used to identify yaws. We enrolled 1004 households in 59 villages over 16 islands, and examined 3650 individuals of all ages for trachoma. The overall adjusted prevalence of trachomatous inflammation-follicular (TF) in 1-9 year-olds was 12.0% (95% Confidence Interval: 8.1-16.7%), and the overall adjusted prevalence of TT in those aged 15 years and greater was 0.04% (95% CI 0-0.14%). In multivariate analysis, the odds of children having TF was 2.6 (95% CI = 1.5-4.4) times higher in households with unimproved latrines, and independently associated with the number of children in the household (OR 1.3, 95% CI = 1.0-1.6 for each additional child). We examined the skin of 821 children aged 5-14 years. Two children had yaws, giving an estimated prevalence of active yaws in those aged 5-14 years of 0.2% (95% CI = 0.03-0.9%). Mass treatment with azithromycin is recommended in these provinces. Given the apparent low burden of yaws, integration of yaws and trachoma control programmes is likely to be useful and cost-effective to national programmes
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