1,349 research outputs found

    Shuttle antenna radome technology test program. Volume 2: Development of S-band antenna interface design

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    The effects of the Thermal Protection Subsystem (TPS) contamination on the space shuttle orbiter S band quad antenna due to multiple mission buildup are discussed. A test fixture was designed, fabricated and exposed to ten cycles of simulated ground and flight environments. Radiation pattern and impedance tests were performed to measure the effects of the contaminates. The degradation in antenna performance was attributed to the silicone waterproofing in the TPS tiles rather than exposure to the contaminating sources used in the test program. Validation of the accuracy of an analytical thermal model is discussed. Thermal vacuum tests with a test fixture and a representative S band quad antenna were conducted to evaluate the predictions of the analytical thermal model for two orbital heating conditions and entry from each orbit. The results show that the accuracy of predicting the test fixture thermal responses is largely dependent on the ability to define the boundary and ambient conditions. When the test conditions were accurately included in the analytical model, the predictions were in excellent agreement with measurements

    Alvira : comparative genomics of viral strains

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    The Alvira tool is a general purpose multiple sequence alignment viewer with a special emphasis on the comparative analysis of viral genomes. This new tool has been devised specifically to address the problem of the simultaneous analysis of a large number of viral strains. The multiple alignment is embedded in a graph that can be explored at different levels of resolution

    A Field-Test of Rhodamine B as a Biomarker in Raccoons

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    Rhodamine B is a dye that when ingested results in fluorescent bands in growing hair and whiskers of many mammals. Previous research at Wildlife Services’ (WS) National Wildlife Research Center (NWRC) found that rhodamine B is a successful biomarker in raccoon whiskers and that raccoons do not have a taste aversion to the dye when it comprises ≤ 3% of a bait. Our study assessed the ease of bait distribution, whisker collection, and evaluation of the biomarker for potential use in the Oral Rabies Vaccination (ORV) program administered by the WS National Rabies Management Program (NRMP). In collaboration with WS operations personnel from Ohio and Michigan, 750 fishmeal polymer baits each containing 150 mg of rhodamine B were hand distributed at NASA\u27s Plum Brook Station, Sandusky, Ohio in the summer of 2008. Four weeks after baits were distributed whiskers from 162 raccoons were collected. Wildlife Services biologists and technicians evaluated the whiskers for fluorescence using a handheld UV magnifying lamp. Biologists then sent the whiskers to the NWRC, Ft. Collins, Colorado for confirmation of fluorescence under a UV microscope. Results suggest a high level of agreement between the two methods of evaluation. Surveys completed by biologists confirmed that the ease of use, less invasive sampling techniques and promptness of results obtained through the use of rhodamine B are advantageous to the tetracycline biomarker presently used by the ORV program. All participants recommended further evaluation of rhodamine B for its inclusion in future efforts requiring biomarker evaluation

    Examination of BDNF Treatment on BACE1 Activity and Acute Exercise on Brain BDNF Signaling

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    Perturbations in metabolism results in the accumulation of beta-amyloid peptides, which is a pathological feature of Alzheimer’s disease. Beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) is the rate limiting enzyme responsible for beta-amyloid production. Obesogenic diets increase BACE1 while exercise reduces BACE1 activity, although the mechanisms are unknown. Brain-derived neurotropic factor (BDNF) is an exercise inducible neurotrophic factor, however, it is unknown if BDNF is related to the effects of exercise on BACE1. The purpose of this study was to determine the direct effect of BDNF on BACE1 activity and to examine neuronal pathways induced by exercise. C57BL/6J male mice were assigned to either a low (n = 36) or high fat diet (n = 36) for 10 weeks. To determine the direct effect of BDNF on BACE1, a subset of mice (low fat diet = 12 and high fat diet n = 12) were used for an explant experiment where the brain tissue was directly treated with BDNF (100 ng/ml) for 30 min. To examine neuronal pathways activated with exercise, mice remained sedentary (n = 12) or underwent an acute bout of treadmill running at 15 m/min with a 5% incline for 120 min (n = 12). The prefrontal cortex and hippocampus were collected 2-h post-exercise. Direct treatment with BDNF resulted in reductions in BACE1 activity in the prefrontal cortex (p < 0.05), but not the hippocampus. The high fat diet reduced BDNF content in the hippocampus; however, the acute bout of exercise increased BDNF in the prefrontal cortex (p < 0.05). These novel findings demonstrate the region specific differences in exercise induced BDNF in lean and obese mice and show that BDNF can reduce BACE1 activity, independent of other exercise-induced alterations. This work demonstrates a previously unknown link between BDNF and BACE1 regulation.Brock Library Open Access Publishing Fun

    Quasispecies structure and persistence of RNA viruses.

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    Viral quasispecies are closely related (but nonidentical) mutant and recombinant viral genomes subjected to continuous genetic variation, competition, and selection. Quasispecies structure and dynamics of replicating RNA enable virus populations to persist in their hosts and cause disease. We review mechanisms of viral persistence in cells, organisms, and populations of organisms and suggest that the critical interplay between host and viral influences (including in some cases the quasispecies organization) is the main driving force for long-term survival of viruses in nature

    Association of parenting practices to encourage or discourage physical activity with Hispanic preschool children's objectively measured physical activity

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    Oral Session - Determinants of physical activity in children and adolescents: no. O.002Conference Theme: Promoting Healthy Eating and Activity WorldwidePURPOSE: Assess the association of parenting practices (PP) to encourage or discourage physical activity (PA) with Hispanic 3-5 year old children’s objectively measured PA METHOD: Cross-sectional study of Hispanic parent-child dyads (n= 84) who reported their demographics and frequency of using PP that encourage (structure/encouragement) or discourage (promote inactive transport, promote screen time, psychological control, and safety concerns) child PA using verified scales. Children wore Actigraph GT3X accelerometers recording 15 second epochs for 7 days. Allowing for re-wears …postprin

    Psychometrics of new scales of parenting practices to encourage or discourage Hispanic preschool children's physical activity

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    Conference Theme: Promoting Healthy Eating and activity worldwidePoster - Personal and environmental determinants of physical activity in children and adolescents: abstract P077PURPOSE: Develop and assess the psychometrics of a new instrument for parenting practices (PP) that encourage or discourage physical activity (PA) in Hispanic preschool children. METHOD: Cross--‐sectional study of 240 Hispanic parents who reported their demographics and frequency of using PP that encourage (structure and encouragement) or discourage (promoting inactivity, psychological control, safety …postprin

    Childhood Obesity in Florida: A Narrative Review on Current Trends and Interventions

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    We examine current research on childhood obesity (CO) trends and intervention strategies in Florida. The fiscal, emotional, and health-related costs related to general obesity are staggering. Unfortunately, CO-related publicity, research, policy, and interventions have not been entirely successful in addressing the problem. Florida ranks 35thnationally in prevalence of CO. Data from the Centers for Disease Control and Prevention (CDC) 2013 report a statistically significant decrease in Florida\u27s rate of CO among 2-4 year-olds participating in Florida’s Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) from 2008-2011. Whereas Florida still has significant room for improvement on the issue of CO, its relatively low CO prevalence indicates a step in the right direction. Information provided herein provides valuable insight, resource information, and motivation to healthcare providers, particularly registered dietitian nutritionists (RDNs). As nutrition experts employed in various areas of society, RDNs are advantageously situated to contribute significantly to the CO solution. Florida appears to benefit from interdisciplinary collaborations among healthcare facilities, schools, faith-based organizations, governmental agencies, and grassroots programs that may play a major role in the current fight against CO

    Measuring diet in primary school children aged 8-11 years: validation of the Child and Diet Evaluation Tool (CADET) with an emphasis on fruit and vegetable intake.

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    Background/Objectives:The Child And Diet Evaluation Tool (CADET) is a 24-h food diary that measures the nutrition intake of children aged 3-7 years, with a focus on fruit and vegetable consumption. Until now CADET has not been used to measure nutrient intake of children aged 8-11 years. To ensure that newly assigned portion sizes for this older age group were valid, participants were asked to complete the CADET diary (the school and home food diary) concurrently with a 1-day weighed record. Subjects/Methods:A total of 67 children with a mean age of 9.3 years (s.d.: ± 1.4, 51% girls) participated in the study. Total fruit and vegetable intake in grams and other nutrients were extracted to compare the mean intakes from the CADET diary and Weighed record using t-tests and Pearson's r correlations. Bland-Altman analysis was also conducted to assess the agreement between the two methods. Results: Correlations comparing the CADET diary to the weighed record were high for fruit, vegetables and combined fruit and vegetables (r=0.7). The results from the Bland-Altman plots revealed a mean difference of 54 g (95% confidence interval: -88, 152) for combined fruit and vegetables intake. CADET is the only tool recommended by the National Obesity Observatory that has been validated in a UK population and provides nutrient level data on children's diets. Conclusions:The results from this study conclude that CADET can provide high-quality nutrient data suitable for evaluating intervention studies now for children aged 3-11 years with a focus on fruit and vegetable intake
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