591 research outputs found

    Dual solid cryogens for spacecraft refrigeration Patent

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    Dual solid cryogens for spacecraft refrigeration insuring low temperature cooling for extended period

    Design and construction of an engineering model solid cryogen refrigerator for infrared detector cooling at 50 deg K

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    Design and construction of prototype spacecraft cryogenic refrigerator for infrared detector coolin

    The Food Education Project: Teaching Nutrition through Environmental Awareness

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    This paper examines a 300-hour fieldwork internship that took place during a summer semester at a local non-profit called the Food Education Project (FEP). FEP provided a practical and hands- on opportunity, which allowed for the knowledge gained over the past two years at the University of San Francisco’s Public Health Program to be put to public health practice. The experience was invaluable for the author’s professional and personal growth. The paper will explore the prevalence of obesity and type II diabetes in the nation’s youth today. Second, a literature review will be conducted to examine the relevance of in school interventions to combat obesity and type II diabetes. Next, a description of the Food Education Project’s staff will be provided as well as various programmatic ways in which FEP is trying to address the obesity epidemic. The importance of a grass roots level organization and what makes FEP unique is explored. A project will be described where the author further researched the validity of the program, and sought to examine if FEP was having a positive and helpful impact for their students. From here, competencies that were put forth from the Master’s of Public Health Program at the University of San Francisco will be addressed and acknowledged in how they related to the author’s experience. Relevant and useful coursework will be recognized and final thoughts on the author’s experience during these 300 hours

    Mediating effects of the relationship between school-based professionals' role, knowledge, and self-efficacy as related to non-suicidal self-injury

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    Non-suicidal self-injurious (NSSI) behaviors are on the rise among school aged children and adolescents. The current research study assessed school-based professionals' general knowledge of NSSI behaviors and perceived self-efficacy in working with students that engage in NSSI behaviors. Direct experience working with students that engage in NSSI behaviors and familiarity with various mental health disorders served as mediators. Familiarity with various mental health disorders served as a significant predictor for most professionals when examining their general knowledge scores and perceived self-efficacy. Direct experience with NSSI behaviors proved to be a weak mediator in the current study. Findings suggest that school-based professionals, overall, do not hold a considerable amount of knowledge regarding NSSI behaviors or confidence in their ability to work with students that engage in NSSI behaviors. Specific areas for training and interventions are identified based upon study findings. The study emphasizes that school-based professionals are not required nor expected to have all the right answers. However, school-based professionals are encouraged to develop multidisciplinary teams to create action plans that address mental health issues in their schools

    Development of dual solid cryogens for high reliability refrigeration system

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    High reliability solid cryogen refrigeration system consists of a container initially filled with a solid cryogen which is coupled thermally to an infrared detector by means of a link of high thermal conductivity extending from a heat exchanger within the cryogen container

    Identifying and Forecasting Potential Biophysical Risk Areas within a Tropical Mangrove Ecosystem Using Multi-Sensor Data

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    Mangroves are one of the most productive ecosystems known for provisioning of various ecosystem goods and services. They help in sequestering large amounts of carbon, protecting coastline against erosion, and reducing impacts of natural disasters such as hurricanes. Bhitarkanika Wildlife Sanctuary in Odisha harbors the second largest mangrove ecosystem in India. This study used Terra, Landsat and Sentinel-1 satellite data for spatio-temporal monitoring of mangrove forest within Bhitarkanika Wildlife Sanctuary between 2000 and 2016. Three biophysical parameters were used to assess mangrove ecosystem health: leaf chlorophyll (CHL), Leaf Area Index (LAI), and Gross Primary Productivity (GPP). A long-term analysis of meteorological data such as precipitation and temperature was performed to determine an association between these parameters and mangrove biophysical characteristics. The correlation between meteorological parameters and mangrove biophysical characteristics enabled forecasting of mangrove health and productivity for year 2050 by incorporating IPCC projected climate data. A historical analysis of land cover maps was also performed using Landsat 5 and 8 data to determine changes in mangrove area estimates in years 1995, 2004 and 2017. There was a decrease in dense mangrove extent with an increase in open mangroves and agricultural area. Despite conservation efforts, the current extent of dense mangrove is projected to decrease up to 10% by the year 2050. All three biophysical characteristics including GPP, LAI and CHL, are projected to experience a net decrease of 7.7%, 20.83% and 25.96% respectively by 2050 compared to the mean annual value in 2016. This study will help the Forest Department, Government of Odisha in managing and taking appropriate decisions for conserving and sustaining the remaining mangrove forest under the changing climate and developmental activities

    Carbon Sequestration in Managed Temperate Coniferous Forests Under Climate Change

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    Management of temperate forests has the potential to increase carbon sinks and mitigate climate change. However, those opportunities may be confounded by negative climate change impacts. We therefore need a better understanding of climate change alterations to temperate forest carbon dynamics before developing mitigation strategies. The purpose of this project was to investigate the interactions of species composition, fire, management, and climate change in the Copper–Pine Creek valley, a temperate coniferous forest with a wide range of growing conditions. To do so, we used the LANDIS-II modelling framework including the new Forest Carbon Succession extension to simulate forest ecosystems under four different productivity scenarios, with and without climate change effects, until 2050. Significantly, the new extension allowed us to calculate the net sector productivity, a carbon accounting metric that integrates aboveground and belowground carbon dynamics, disturbances, and the eventual fate of forest products. The model output was validated against literature values. The results implied that the species optimum growing conditions relative to current and future conditions strongly influenced future carbon dynamics. Warmer growing conditions led to increased carbon sinks and storage in the colder and wetter ecoregions but not necessarily in the others. Climate change impacts varied among species and site conditions, and this indicates that both of these components need to be taken into account when considering climate change mitigation activities and adaptive management. The introduction of a new carbon indicator, net sector productivity, promises to be useful in assessing management effectiveness and mitigation activities

    Resistance to the antimicrobial agent fosmidomycin and an FR900098 prodrug through mutations in the deoxyxylulose phosphate reductoisomerase gene (dxr)

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    There is a pressing need for new antimicrobial therapies to combat globally important drug-resistant human pathogens, including Plasmodium falciparum malarial parasites, Mycobacterium tuberculosis, and Gram-negative bacteria, including Escherichia coli. These organisms all possess the essential methylerythritol phosphate (MEP) pathway of isoprenoid biosynthesis, which is not found in humans. The first dedicated enzyme of the MEP pathway, 1-deoxy-d-xylulose 5-phosphate reductoisomerase (Dxr), is inhibited by the phosphonic acid antibiotic fosmidomycin and its analogs, including the N-acetyl analog FR900098 and the phosphoryl analog fosfoxacin. In order to identify mutations in dxr that confer resistance to these drugs, a library of E. coli dxr mutants was screened at lethal fosmidomycin doses. The most resistant allele (with the S222T mutation) alters the fosmidomycin-binding site of Dxr. The expression of this resistant allele increases bacterial resistance to fosmidomycin and other fosmidomycin analogs by 10-fold. These observations confirm that the primary cellular target of fosmidomycin is Dxr. Furthermore, cell lines expressing Dxr-S222T will be a powerful tool to confirm the mechanisms of action of future fosmidomycin analogs

    Clustering of Socioeconomic, Behavioural, and Neonatal Risk Factors for Infant Health in Pregnant Smokers

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    Background: Tobacco smoking is a major cause of morbidity and mortality, including during pregnancy. Although effective ways of promoting smoking cessation during pregnancy exist, the impact of these interventions has not been studied at a national level. We estimated the prevalence of smoking throughout pregnancy in the Netherlands and quantified associations of maternal smoking throughout pregnancy with socioeconomic, behavioural, and neonatal risk factors for infant health and development. Methodology/Principal Findings: Data of five national surveys, containing records of 14,553 Dutch mothers and their offspring were analyzed. From 2001 to 2007, the overall rate of smoking throughout pregnancy fell by 42% (from 13. 2% to 7. 6%) mainly as a result of a decrease among highly educated women. In the lowest-educated group, the overall rate of smoking throughout pregnancy was six times as high as in the highest-educated group (18. 7% versus 3. 2%). Prenatal tobacco smoke exposure was associated with increased risk of extremely preterm (≤28 completed weeks) (OR 7. 25; 95% CI 3. 40 to 15. 38) and small-for-gestational age (SGA) infants (OR 3. 08; 95% CI 2. 66 to 3. 57). Smoking-attributable risk percents in the population (based on adjusted risk ratios) were estimated at 29% for extremely preterm births and at 17% for SGA outcomes. Infants of smokers were more likely to experience significant alcohol exposure in utero (OR 2. 08; 95%CI 1. 25 to 3. 45) and formula feeding in early life (OR 1. 91; 95% CI 1. 69 to 2. 16). Conclusions: The rates of maternal smoking throughout pregnancy decreased significantly in the Netherlands from 2001 to 2007. If pregnant women were to cease tobacco use completely, an estimated 29% of extremely preterm births and 17% of SGA infants may be avoided annually. © 2009 Lanting et al
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