928 research outputs found

    Advanced Educational Methods in the Department of Defense: Application of Case Theory and Computer-Assisted Instruction to Business Process Reengineering

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    The goal of this research was to create a computer-assisted instruction (CAI) prototype tutorial to teach the fundamental principles of integrated, computer-aided manufacturing definition activity modeling (IDEFO), a component of business process reengineering within the Department of Defense. To accomplish this, the authors evaluated current instructional material related to IDEFO, then adapted the material to a computerized learning environment using the Authorware Professional™ authoring software and a hybrid methodology which incorporated elements both of instructional design and software development. One of the most notable characteristics of this hybrid model was a series of iterations at each phase of development, which eliminated the need for retroactive modifications at successive development phases. The objectives for this study were accomplished by completing a literature review, identifying learning objectives and testing strategies, creating a prototype tutorial using authoring software, incorporating a case study, and then operationally testing the prototype. Analysis of this research is limited to a discussion of the results of a qualitative survey provided to evaluators of the prototype. In general, the results of the survey indicated acceptance of CAI as a method of instruction and provided recommendations for improving the tutorial

    Expanding Qualitative Research Interviewing Strategies: Zoom Video Communications

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    The proliferation of new video conferencing tools offers unique data generation opportunities for qualitative researchers. While in-person interviews were the mainstay of data generation in qualitative studies, video conferencing programs, such as Zoom Video Communications Inc. (Zoom), provide researchers with a cost-effective and convenient alternative to in-person interviews. The uses and advantages of face-to-face interviewing are well documented; however, utilizing video conferencing as a method of data generation has not been well examined. The purpose of this paper is to examine the specific attributes of Zoom that contribute to high quality and in-depth qualitative interviews when in person interviewing is not feasible. While video conferencing was developed to facilitate long-distance or international communication, enhance collaborations and reduce travel costs for business these same features can be extended to qualitative research interviews. Overall, participants reported that Zoom video conferencing was a positive experience. They identified strengths of this approach such as: (1) convenience and ease of use, (2) enhanced personal interface to discuss personal topics (e.g., parenting), (3) accessibility (i.e., phone, tablet, and computer), (4) time-saving with no travel requirements to participate in the research and therefore more time available for their family. Video conferencing software economically supports research aimed at large numbers of participants and diverse and geographically dispersed populations

    Glacier algae: a dark past and a darker future

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    “Glacier algae” grow on melting glacier and ice sheet surfaces across the cryosphere, causing the ice to absorb more solar energy and consequently melt faster, while also turning over carbon and nutrients. This makes glacier algal assemblages, which are typically dominated by just three main species, a potentially important yet under-researched component of the global biosphere, carbon, and water cycles. This review synthesizes current knowledge on glacier algae phylogenetics, physiology, and ecology. We discuss their significance for the evolution of early land plants and highlight their impacts on the physical and chemical supraglacial environment including their role as drivers of positive feedbacks to climate warming, thereby demonstrating their influence on Earth’s past and future. Four complementary research priorities are identified, which will facilitate broad advances in glacier algae research, including establishment of reliable culture collections, sequencing of glacier algae genomes, development of diagnostic biosignatures for remote sensing, and improved predictive modeling of glacier algae biological-albedo effects

    Epithelial cell-directed efferocytosis in the post-partum mammary gland is necessary for tissue homeostasis and future lactation

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    <p>Abstract</p> <p>Background</p> <p>Mammary glands harbor a profound burden of apoptotic cells (ACs) during post-lactational involution, but little is known regarding mechanisms by which ACs are cleared from the mammary gland, or consequences if this process is interrupted. We investigated AC clearance, also termed efferocytosis, during post-lactational remodeling, using mice deficient for MerTK, Axl, and Tyro3, three related receptor tyrosine kinases (RTKs) regulating macrophage-mediated efferocytosis in monocytes. MerTK expression, apoptosis and the accumulation of apoptotic debris were examined in histological sections of MerTK-deficient, Axl/Tyro3-deficient, and wild-type mammary glands harvested at specific time points during lactation and synchronized involution. The ability of primary mammary epithelial cells (MECs) to engulf ACs was assessed in culture. Transplant of MerTK-deficient mammary epithelium into cleared WT mammary fat pads was used to assess the contribution of WT mammary macrophages to post-lactational efferocytosis.</p> <p>Results</p> <p>ACs induced MerTK expression in MECs, resulting in elevated MerTK levels at the earliest stages of involution. Loss of MerTK resulted in AC accumulation in post-lactational MerTK-deficient mammary glands, but not in Axl and Tyro3-deficient mammary glands. Increased vascularization, fibrosis, and epithelial hyperproliferation were observed in MerTK-deficient mammary glands through at least 60 days post-weaning, due to failed efferocytosis after lactation, but did not manifest in nulliparous mice. WT host-derived macrophages failed to rescue efferocytosis in transplanted MerTK-deficient mammary epithelium.</p> <p>Conclusion</p> <p>Efferocytosis by MECs through MerTK is crucial for mammary gland homeostasis and function during the post-lactational period. Efferocytosis by MECs thus limits pathologic consequences associated with the apoptotic load following lactation.</p

    Streamlined preparation of genomic DNA in agarose plugs for pulsed-field gel electrophoresis

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    Genome analysis using pulsed-field gel electrophoresis (PFGE) has been used in applications ranging from typing bacterial strains to radiobiology to cancer research. While methods for running PFGE have been significantly improved since its invention, the method for preparing chromosomal DNA itself has remained essentially unchanged. This limits the applicability of PFGE, especially when analyses require many samples. We have streamlined sample preparation for routine applications of PFGE through the use of deep-well 48-well plates. Besides saving time, our protocol has the added advantage of reducing the volume of expensive reagents. Our improved protocol enables us to reduce throughput time and simplify the procedure, facilitating wider application of PFGE-based analyses in the laboratory

    Microbial genomics amidst the Arctic crisis

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    The Arctic is warming – fast. Microbes in the Arctic play pivotal roles in feedbacks that magnify the impacts of Arctic change. Understanding the genome evolution, diversity and dynamics of Arctic microbes can provide insights relevant for both fundamental microbiology and interdisciplinary Arctic science. Within this synthesis, we highlight four key areas where genomic insights to the microbial dimensions of Arctic change are urgently required: the changing Arctic Ocean, greenhouse gas release from the thawing permafrost, 'biological darkening' of glacial surfaces, and human activities within the Arctic. Furthermore, we identify four principal challenges that provide opportunities for timely innovation in Arctic microbial genomics. These range from insufficient genomic data to develop unifying concepts or model organisms for Arctic microbiology to challenges in gaining authentic insights to the structure and function of low-biomass microbiota and integration of data on the causes and consequences of microbial feedbacks across scales. We contend that our insights to date on the genomics of Arctic microbes are limited in these key areas, and we identify priorities and new ways of working to help ensure microbial genomics is in the vanguard of the scientific response to the Arctic crisis

    Smoking Enhances Risk for New External Genital Warts in Men

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    Repeat episodes of HPV-related external genital warts reflect recurring or new infections. No study before has been sufficiently powered to delineate how tobacco use, prior history of EGWs and HIV infection affect the risk for new EGWs. Behavioral, laboratory and examination data for 2,835 Multicenter AIDS Cohort Study participants examined at 21,519 semi-annual visits were evaluated. Fourteen percent (391/2835) of men reported or were diagnosed with EGWs at 3% (675/21,519) of study visits. Multivariate analyses showed smoking, prior episodes of EGWs, HIV infection and CD4+ T-lymphocyte count among the infected, each differentially influenced the risk for new EGWs

    Three Dimensional Distorted Black Holes

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    We present three-dimensional, {\it non-axisymmetric} distorted black hole initial data which generalizes the axisymmetric, distorted, non-rotating [Bernstein93a] and rotating [Brandt94a] single black hole data developed by Bernstein, Brandt, and Seidel. These initial data should be useful for studying the dynamics of fully 3D, distorted black holes, such as those created by the spiraling coalescence of two black holes. We describe the mathematical construction of several families of such data sets, and show how to construct numerical solutions. We survey quantities associated with the numerically constructed solutions, such as ADM masses, apparent horizons, measurements of the horizon distortion, and the maximum possible radiation loss (MRLMRL).Comment: 23 pages, 12 figures, accepted for publication in Classical and Quantum Gravit

    Physical and Mental Health of Transgender Older Adults: An At-Risk and Underserved Population

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    Purpose: This study is one of the first to examine the physical and mental health of transgender older adults and to identify modifiable factors that account for health risks in this underserved population. Design and Methods: Utilizing data from a cross-sectional survey of lesbian, gay, bisexual, and transgender older adults aged 50 and older (N = 2,560), we assessed direct and indirect effects of gender identity on 4 health outcomes (physical health, disability, depressive symptomatology, and perceived stress) based on a resilience conceptual framework. Results: Transgender older adults were at significantly higher risk of poor physical health, disability, depressive symptomatology, and perceived stress compared with nontransgender participants. We found significant indirect effects of gender identity on the health outcomes via fear of accessing health services, lack of physical activity, internalized stigma, victimization, and lack of social support; other mediators included obesity for physical health and disability, identity concealment for perceived stress, and community belonging for depressive symptomatology and perceived stress. Further analyses revealed that risk factors (victimization and stigma) explained the highest proportion of the total effect of gender identity on health outcomes. Implications: The study identifies important modifiable factors (stigma, victimization, health-related behaviors, and social support) associated with health among transgender older adults. Reducing stigma and victimization and including gender identity in nondiscrimination and hate crime statutes are important steps to reduce health risks. Attention to bolstering individual and community-level social support must be considered when developing tailored interventions to address transgender older adults’ distinct health and aging needs
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