6,094 research outputs found

    HRXRD study of the theoretical densities of novel reactive sintered boride candidate neutron shielding materials

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    Reactive Sintered Borides (RSBs) are novel borocarbide materials derived from FeCr-based cemented tungsten (FeCr-cWCs) show considerable promise as compact radiation armour for proposed spherical tokamak,[1],[2],[3],[4],[5]. Six candidate compositions (four RSBs, two cWCs) were evaluated by high-resolution X-ray diffraction (XRD), inductively coupled plasma (ICP), energy dispersive X-ray analysis (EDX) and scanning electron microscopy (SEM) to determine the atomic composition, phase presence, and theoretical density. RSB compositions were evaluated with initial boron contents equivalent to 25 at% 30 at%. All RSB compositions showed delamination and carbon enrichment in the bulk relative to the surface, consistent with non-optimal binder removal and insufficient sintering time. Phase abundance within RSBs derived from powder XRD was dominated by iron tungsten borides (FeWB/FeW2B2), tungsten borides (W2B5/WB) and iron borides. The most optimal RSB composition (B5T522W) with respect to physical properties and highest Ļ/Ļtheo had Ļtheo = 12.59 Ā± 0.01 g cm-3 for Ļ/Ļtheo = 99.3% and had the weigh-in and post-sintered W : B : Fe abundance closest to 1 : 1 : 1. This work indicates that despite their novelty, RSB materials can be optimized and in principle be processed using existing cWC processing routes

    Jobs, natural resources, and community resilience: A survey of southeast Alaskans about social and environmental change

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    As part of the Community and Environment in Rural America (CERA) project, researchers at the Carsey Institute surveyed 1,541 residents of the ten boroughs and unincorporated census areas in Southeast Alaska to better understand social and environmental change in the region and their implications for Alaskan community and families. The authors of this brief report that social problems in the extremely isolated region of Southeast Alaska such as crime and drug use are closely related to economic distress, particularly in small outlying communities

    A Study of Collaboration between the Defense Logistics Agency and the U.S. Agency for International Development in the Conduct of humanitarian Operations

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    Many organizations are finding it advantageous and often necessary to form collaborative alliances with strategic partners in order to solve collective problems and jointly work towards mutually desirable ends. This research examines a single case study of inter-agency coordination between the Defense Logistics Agency (DLA) and the U.S. Agency for International Development (USAID) and their involvement in humanitarian relief efforts. Pursuit of advancement through two collaboration models provided the framework of the research and contributed to the analysis of data. Resulting outcomes offer incentives for both organizations to develop stronger social networks assisting in a deeper understanding of the others organizational cultures and as well as urges operational collaboration across institutional lines

    Genome sequence of an alphaherpesvirus from a beluga whale (Delphinapterus leucas)

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    Beluga whale alphaherpesvirus 1 was isolated from a blowhole swab taken from a juvenile beluga whale. The genome is 144,144 bp in size and contains 86 putative genes. The virus groups phylogenetically with members of the genus Varicellovirus in subfamily Alphaherpesvirinae and is the first alphaherpesvirus sequenced from a marine mammal

    Genome sequence of a gammaherpesvirus from a common bottlenose dolphin (Tursiops truncatus)

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    A herpesvirus genome was sequenced directly from a biopsy specimen of a rectal lesion from a female common bottlenose dolphin. This genome sequence comprises a unique region (161,235 bp) flanked by multiple copies of a terminal repeat (4,431 bp) and contains 72 putative genes. The virus was named common bottlenose dolphin gammaherpesvirus 1

    Equine or porcine synovial fluid as a novel ex vivo model for the study of bacterial free-floating biofilms that form in human joint infections

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    Bacterial invasion of synovial joints, as in infectious or septic arthritis, can be difficult to treat in both veterinary and human clinical practice. Biofilms, in the form of free-floating clumps or aggregates, are involved with the pathogenesis of infectious arthritis and periprosthetic joint infection (PJI). Infection of a joint containing an orthopedic implant can additionally complicate these infections due to the presence of adherent biofilms. Because of these biofilm phenotypes, bacteria within these infected joints show increased antimicrobial tolerance even at high antibiotic concentrations. To date, animal models of PJI or infectious arthritis have been limited to small animals such as rodents or rabbits. Small animal models, however, yield limited quantities of synovial fluid making them impractical for in vitro research. Herein, we describe the use of ex vivo equine and porcine models for the study of synovial fluid induced biofilm aggregate formation and antimicrobial tolerance. We observed Staphylococcus aureus and other bacterial pathogens adapt the same biofilm aggregate phenotype with significant antimicrobial tolerance in both equine and porcine synovial fluid, analogous to human synovial fluid. We also demonstrate that enzymatic dispersal of synovial fluid aggregates restores the activity of antimicrobials. Future studies investigating the interaction of bacterial cell surface proteins with host synovial fluid proteins can be readily carried out in equine or porcine ex vivo models to identify novel drug targets for treatment of prevention of these difficult to treat infectious diseases

    Reviews

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    J.R.R. Tolkien: This Far Land. Robert Giddings. Reviewed by Jessica Yates. The Book of Lost Tales Part II. J.R.R. TOlkien. Reviewed by Sarah Beach. The Monsters and the Critics, and Other Essays. J.R.R. Tolkien. Reviewed by Thomas M. Egan. The Restitution of Man: C.S. Lewis and the Case Against Scientism. Michael D. Aeschliman. Reviewed by Nancy-Lou Patterson. The High Kings: Arthur\u27s Celtic Ancestors. Joy Chant. Reviewed by Nancy-Lou Patterson

    The Impact of a GenCyber Camp on In-service Teachersā€™ TPACK

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    The purpose of this study was to examine the impact of a GenCyber camp curriculum on teachersā€™ technology, pedagogy, and content knowledge (TPACK). The camp was designed to engage participants in developing the knowledge and skills to incorporate GenCyber Cybersecurity First Principles and GenCyber Cybersecurity Concepts (GenCyber, 2019) into their curriculums. Participants (37 middle and high school teachers from a variety of disciplines) attended one of two weeklong camps held at a Midwestern liberal arts university. Using the TPACK Self-Reflection and TPACK Self-Assessment Surveys, pre- and post-camp data were collected from participants. Findings indicate that participants demonstrated an increase in all domains of the TPACK framework from pre- to post-survey. The greatest increase was in Technological Pedagogy Knowledge (TPK) (0.57), followed by Pedagogical Content Knowledge (PCK) (0.51), and Technological Pedagogical Content Knowledge (TPACK) (0.46). GenCyber participants also demonstrated an average increase in pre- and post-test scores in all areas on the TPACK Self-Assessment Survey Results; however, individual results were mixed. The majority of participants (n=21), sixty percent, saw an increase in composite score from pre- to post, whereas 12 participants\u27 (34%) scores decreased from pre- to post, and two (6%) stayed the same. Findings indicate the GenCyber Camp provided in-service teachers with the knowledge and skills necessary to incorporate GenCyber Principles and Cybersecurity Concepts into their curriculum. Recommendations for teacher professional development on cybersecurity are made
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