36 research outputs found

    Port Flow Test System

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    Solar Turbines Gas Compressor Engineering Division of San Diego, California called upon the Mechanical Engineering students of California Polytechnic University, San Luis Obispo to provide recommendations for optimization of compressor end cap port design. Various sizes of compressors have end caps with numerous ports that exchange fluids between the inside and outside of the working fluid pressure vessel. Because so many ports must exist on the end caps, unusual flow paths are created to supply the appropriate location within the compressor. These flow paths commonly consist of a drilled inlet hole which intersects with a sudden expansion. The sudden expansion is deemed the “fly cut” because of its semicircular shape. Sudden expansions in general cause very high energy losses in fluid flow. This is one of the primary concerns when designing the compressor end cap port layout. Due to the unusual nature of the fly cuts found in Solar Turbines’ end caps, published information on the pressure losses for this particular flow path do not exist. For this reason, Solar Turbines were required to base their port design on the best information available, including: historical compressor design methods, conservative design analysis estimates, and computational fluid mechanics software. Of these options, the computational method could provide the best estimate but only if validated experimentally. In response to this problem, PreFlow Systems was formed and investigated the solution of designing, building, and testing a scaled experimental test apparatus. This report outlines the details involved in every aspect of the project, including: technical specifications and objectives, design conceptualization, engineering analysis, manufacturing, testing, and results. Each of these phases was crucial in creating the final flow test apparatus which simulated the gas port flow of Solar Turbines’ compressor end caps. This apparatus ultimately provided an experimental basis for concluding that computation fluid mechanics software is a reasonable aide in end cap port design

    Food Allergy in Youth: A Primer for Allied Health Professionals

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    Purpose: Many youth struggle with the physical, mental, and social burdens of food allergy. The exact cause of food allergies is unknown, but several theories exist such as the “couch potato theory”, “hygiene hypothesis”, “microflora theory”, and “alarmins” theory. This non-systematic literature review summarizes the problem of youth food allergy and provides guidance to allied health professionals. Method: A literature search of the relevant literature from years 2000 through 2017 was conducted using PubMed with the key words “food allergy”, “youth”, and “management”. Results: Youth with food allergy may experience anxiety, social isolation, bullying, and depression, in addition to life-threatening allergic reactions. Managing food allergies successfully requires a team approach and begins with accurate diagnosis and identification/avoidance of specific food protein triggers. Conclusions: Several federal laws exist to help protect food allergic youth from accidental exposure. Allied health professionals play important roles in helping adolescents avoid life-threatening reactions to food allergens

    Communication Preferences of Young Adults During "Do Not Drink" Water Emergencies

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    Background: Rapid, accurate communication between public health officials and the community members they serve is essential for public health protection and safety. "Do not drink" water advisories are public health emergencies that periodically occur in Northwest Ohio. The City of Toledo issued a "do not drink" advisory to approximately 400,000 residents in August 2014. Most families learned about the "do not drink" advisory from television news networks. However, communication preferences among young adults differ greatly from older generations. The purpose of this study was to identify young adult communication preferences during public health emergencies such as "do not drink" water advisories. Methods: A cross-sectional survey was used to gauge young adults' preferred method of communication during public health emergencies and to ask how they have learned about health advisories in the past. The questionnaire was administered electronically to 330 college students at a mid-size public institution in the Midwest. Results: A total of 291 surveys were collected (88% response rate). When asked "If you have experienced a "do not drink" advisory or other public health emergency, how did you hear about it?" the majority of students (69%) reported television news stations (38%) or Social Media/Facebook (31%). When asked "how would you like to be notified during a public health emergency such as a "do not drink" water advisory?" the majority (70%) preferred text messaging. Conclusions: Communicating rapidly with members of the community during public health emergencies is vital. Text messaging may be the best way to quickly disseminate critical information to young adults

    Trends in Resource Utilization by Children with Neurological Impairment in the United States Inpatient Health Care System: A Repeat Cross-Sectional Study

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    Jay Berry and colleagues report findings from an analysis of hospitalization data in the US, examining the proportion of inpatient resources attributable to care for children with neurological impairment

    Optimization of the Lucy Interplanetary Trajectory via Two-Point Direct Shooting

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    Lucy is NASAs next Discovery-class mission and will explore the Trojan asteroids in the Sun-Jupiter L4 and L5 regions. This paper details the design of Lucys interplanetary trajectory using a two-point direct shooting transcription, nonlinear programming, and monotonic basin hopping. These techniques are implemented in the Evolutionary Mission Trajectory Generator (EMTG), a trajectory optimization tool developed at NASA Goddard Space Flight Center. We present applications to the baseline trajectory design, Monte Carlo analysis, and operations

    Food biofortification : reaping the benefits of science to overcome hidden hunger

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    Biofortification is a process of increasing the density of minerals and vitamins in a food crop through conventional plant breeding, genetic engineering, or agronomic practices (primarily use of fertilizers and foliar sprays). Biofortified staple food crops, when substituted consistently for non-biofortified staple food crops, can generate measurable improvements in human nutrition and health. This monograph describes the progress made in developing, testing, and disseminating biofortified staple food crops, primarily through the use of conventional plant breeding, summarizing the activities of two consortiums of inter-disciplinary collaborating institutions led the HarvestPlus program and the International Potato Center (CIP). We focus on laying out the evidence base proving the effectiveness and impact to date of biofortified crops. Results of a large number of nutritional bioavailability and efficacy trials are summarized (Chapter 2), crop development techniques and activities are presented and variety releases documented for a dozen staple food crops in low and middle income countries (LMICs) in Africa, Asia, and Latin America (Chapter 3), and strategies for promoting the uptake of specific biofortified crops are discussed, concurrent with policy advocacy to encourage key institutions to mainstream the promotion, and use of biofortified crops in their core activities (Chapters 4 and 5). Statistics will be presented on numbers of farm households adopting biofortified crops (Chapters 3 and 4), now available to farmers in 40 low and middle income countries (LMICs). Each section will outline the way forward on additional future activities required to enhance the development and impact the biofortification through conventional plant breeding. No biofortified staple food crop developed through transgenic techniques has been fully de-regulated for release to farmers in LMICs. Yet transgenic techniques hold the potential for a several-fold increase in the impact/benefits of biofortified crops. This potential is described in Chapter 6 which discusses developmental research already completed, including achieving higher densities of single nutrients than is possible with conventional breeding, combining multiple nutrient traits in single events, slowing down/reducing the level of degradation of vitamins after harvesting, and combining superior agronomic traits with nutrient traits in single events. A final chapter summarizes and discusses key questions and issues that will influence the ultimate mainstreaming of biofortified crops in food systems in LMICs and will allow maximization of the benefits of biofortification

    A collaborative analysis of land use and frog diversity across spatial scales

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    Amphibians are sensitive to changes in land use because they require both upland terrestrial habitat and aquatic wetland habitat to complete their life cycle. Our previous work demonstrates that land-use change including road density, development, and wetland area impact amphibian diversity. We build upon this previous work to examine the relative influences of these factors across different landscape scales. Incorporating scale within our model allows us to explore by which mechanism different factors impact amphibians (e.g. do roads increase roadkill in the immediate surrounding area or do they isolate populations at the larger scale?). North American amphibian monitoring program (NAAMP) compiles data from standardized roadside surveys of calling frogs and toads across the majority of the contiguous United States to examine the impacts of human activity on amphibian populations over time. In this study we used NAAMP call data from 18 eastern U.S. states and National Land Cover Data to address the following research questions 1) How is the impact of road length and landscape change mediated by distance from the habitat and 2) how do species differ in the relative influence of these effects over the landscape? We quantified landscape features (e.g., habitat types, wetland –forest connectivity, road density and arrangement) using a GIS program and calculated amphibian diversity estimates of each survey at six locations ranging from 300 meters (local scale, the core terrestrial habitat) to 10, 000 meters (associations should decline at this distance). This approached allows us to explore the relative influence of factors at the regional level to build a predictive model to answer our research questions. This project is supported by the National Science Foundation, Transforming Undergraduate Education in Science program coordinated by David Marsh and the National Center for Ecological Analysis and Synthesis.https://scholarscompass.vcu.edu/uresposters/1105/thumbnail.jp

    Transposable Element Proliferation and Genome Expansion Are Rare in Contemporary Sunflower Hybrid Populations Despite Widespread Transcriptional Activity of LTR Retrotransposons

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    Hybridization is a natural phenomenon that has been linked in several organismal groups to transposable element derepression and copy number amplification. A noteworthy example involves three diploid annual sunflower species from North America that have arisen via ancient hybridization between the same two parental taxa, Helianthus annuus and H. petiolaris. The genomes of the hybrid species have undergone large-scale increases in genome size attributable to long terminal repeat (LTR) retrotransposon proliferation. The parental species that gave rise to the hybrid taxa are widely distributed, often sympatric, and contemporary hybridization between them is common. Natural H. annuus × H. petiolaris hybrid populations likely served as source populations from which the hybrid species arose and, as such, represent excellent natural experiments for examining the potential role of hybridization in transposable element derepression and proliferation in this group. In the current report, we examine multiple H. annuus × H. petiolaris hybrid populations for evidence of genome expansion, LTR retrotransposon copy number increases, and LTR retrotransposon transcriptional activity. We demonstrate that genome expansion and LTR retrotransposon proliferation are rare in contemporary hybrid populations, despite independent proliferation events that took place in the genomes of the ancient hybrid species. Interestingly, LTR retrotransposon lineages that proliferated in the hybrid species genomes remain transcriptionally active in hybrid and nonhybrid genotypes across the entire sampling area. The finding of transcriptional activity but not copy number increases in hybrid genotypes suggests that proliferation and genome expansion in contemporary hybrid populations may be mitigated by posttranscriptional mechanisms of repression

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

    Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial

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    Background: Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events. Methods: The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≄18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627). Findings: Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29–146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0– 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25–1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39–1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65–1·60]; p=0·92). Interpretation: These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention
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