561 research outputs found

    PROCESSING POLICY IN A PANDEMIC

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    The United States has no recent experience dealing with a large-scale pandemic such as COVID-19 that has clearly affected our entire culture, institutions, and way of life. This type of problem is not predictable, and its associated impacts are not easily estimated. As such, we conducted a quantitative comparison in terms of case count between the Navy’s response and the United States’ national response to the COVID-19 pandemic. We evaluated the timing and implementation of Navy versus national and state policies, and explored the patterns and lessons learned to benefit the Navy and Department of Defense in the future. Our study meets a substantial need to look at both entities' response from an objective standpoint and to critique those aspects that served to further benefit or hinder outcomes.Lieutenant Commander, United States NavyLieutenant Commander, United States NavyLieutenant Commander, United States Navy ReserveApproved for public release. Distribution is unlimited

    Suprasellar Epidermoid Cyst Originating from the Infundibulum: Case Report and Literature Review.

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    Epidermoid cysts account for a small fraction of intracranial brain tumors, most commonly found in the cerebellopontine angle and parasellar cisterns. Here we present a rare case of an epidermoid cyst located in the suprasellar region, specifically originating from the infundibulum. Only one additional case with an epidermoid cyst originating within the pituitary stalk has been previously reported in the literature. The patient in this case presented with headaches, diplopia and blurred vision without any endocrinopathy. The patient\u27s pre-operative evaluation was significant for pseudotumor cerebri, hyponatremia, obesity, and a history of smoking; post-operative course was significant for neurogenic diabetes insipidus

    Neuroimaging of a pilocytic astrocytoma with anaplastic features and diffusion tensor imaging characteristics

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    We report the magnetic resonance imaging findings of an adult patient with a biopsy-proven pilocytic astrocytoma with anaplastic features. Pilocytic astrocytomas rarely occur in adults, and presentation with anaplastic features such as rapid mitotic activity, hypercellularity, and atypia is particularly uncommon. Accurate neuroimaging diagnosis is essential, but differentiation from more malignant neoplastic lesions may be challenging. Diffusion tensor imaging may potentially provide information on cell proliferation, vascularity, and fiber destruction, which can have implications for treatment and prognosis. In this case, tractography and fractional anisotropy maps demonstrated displacement of adjacent parenchyma and relatively intact fractional anisotropy, which is more suggestive of a pilocytic rather than an anaplastic astrocytoma. However, in the presence of focal anaplasia, long-term monitoring will be necessary, since pilocytic astrocytomas with anaplastic features frequently recur

    A candidate gene analysis and GWAS for genes associated with maternal nondisjunction of chromosome 21

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    Human nondisjunction errors in oocytes are the leading cause of pregnancy loss, and for pregnancies that continue to term, the leading cause of intellectual disabilities and birth defects. For the first time, we have conducted a candidate gene and genome-wide association study to identify genes associated with maternal nondisjunction of chromosome 21 as a first step to understand predisposing factors. A total of 2,186 study participants were genotyped on the HumanOmniExpressExome-8v1-2 array. These participants included 749 live birth offspring with standard trisomy 21 and 1,437 parents. Genotypes from the parents and child were then used to identify mothers with nondisjunction errors derived in the oocyte and to establish the type of error (meiosis I or meiosis II). We performed a unique set of subgroup comparisons designed to leverage our previous work suggesting that the etiologies of meiosis I and meiosis II nondisjunction differ for trisomy 21. For the candidate gene analysis, we selected genes associated with chromosome dynamics early in meiosis and genes associated with human global recombination counts. Several candidate genes showed strong associations with maternal nondisjunction of chromosome 21, demonstrating that genetic variants associated with normal variation in meiotic processes can be risk factors for nondisjunction. The genome-wide analysis also suggested several new potentially associated loci, although follow-up studies using independent samples are required

    Four Levels of Hierarchical Organization, Including Noncovalent Chainmail, Brace the Mature Tumor Herpesvirus Capsid against Pressurization

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    SummaryLike many double-stranded DNA viruses, tumor gammaherpesviruses Epstein-Barr virus and Kaposi’s sarcoma-associated herpesvirus withstand high internal pressure. Bacteriophage HK97 uses covalent chainmail for this purpose, but how this is achieved noncovalently in the much larger gammaherpesvirus capsid is unknown. Our cryoelectron microscopy structure of a gammaherpesvirus capsid reveals a hierarchy of four levels of organization: (1) Within a hexon capsomer, each monomer of the major capsid protein (MCP), 1,378 amino acids and six domains, interacts with its neighboring MCPs at four sites. (2) Neighboring capsomers are linked in pairs by MCP dimerization domains and in groups of three by heterotrimeric triplex proteins. (3) Small (∼280 amino acids) HK97-like domains in MCP monomers alternate with triplex heterotrimers to form a belt that encircles each capsomer. (4) One hundred sixty-two belts concatenate to form noncovalent chainmail. The triplex heterotrimer orchestrates all four levels and likely drives maturation to an angular capsid that can withstand pressurization

    Comparing urban and wildland bear densities with a DNA-based capture-mark-recapture approach

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    California’s black bear (Ursus americanus) population has tripled over the last 3 decades, causing an increased incidence of human–bear conflicts, many of which now occur in urban areas. Consequently, it is imperative that bear managers have the ability to monitor population parameters in both wildland and urban environments to help manage bears. Capture-mark-recapture (CMR) methods using uniquely typed genetic samples (DNA) collected via hair-snares have been widely used to monitor bears in wildland areas. However, we are unaware of researchers applying this technique to bears occupying urban areas. We implemented a multi-year DNA-based CMR study to compare bear densities between an urban area and a nearby wildland area. We deployed hair-snares for 6 weekly capture occasions during June and July, 2011 and 2012. We uniquely typed DNA from snared hair follicles using 14 microsatellite loci and 2 sexing loci. We coupled unique identification with robust-design closed-capture models and model averaging in Program MARK to estimate abundance. We identified 41 and 62 individual bears on the urban and wildland study areas, with average densities of 3.8 and 1.8 bears/10 km2,respectively. Our data support the hypothesis that bears can occur at greater densities in urban areas. Based on these results, we recommend using DNA-based CMR methods to monitor populations of bears in urban areas, but we suggest increasing the density of sampling locations to account for greater bear densities. Furthermore, we contend that DNA-based CMR can also estimate survival, recruitment, rate of population change (λ), and identify movement patterns by incorporating additional survey years
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