1,415 research outputs found
Avionics for a Small Satellite
This paper discusses a small. seven and a half (7.5) inch diameter. satellite that NASA-JSC is developing as a technology demonstrator for an astronaut assistant free flyer. The Free Flyer is designed to off load flight crew work load by performing inspections of the exterior of Space Shuttle or International Space Station. The Free Flyer is designed to be operated by the flight crew thereby reducing the number of Extra Vehicle Activities (EVA) or by an astronaut on the ground further reducing crew work load. The paper focuses on the design constraint of a small satellite and the technology approach used to achieve the set of high performance requirements specified for the Free Flyer. Particular attention is paid to the processor card as it is the heart and system integration point of the Free Flyer
Nitrotyrosine Density of Rabbit Urinary Bladder Muscle and Mucosa Measured via Western Blotting and 96-Well Plate Analysis
Purpose. Nitrotyrosine was quantitated in rabbit bladder muscle and mucosa using two analytical systems: Western blotting analyses and a 96-well plate quantitative analysis kit. Materials and Methods. Rabbit bladder muscle and mucosa were obtained from control rabbits. For the Western analysis, the samples were loaded into a SDS page gel and then transferred to a PVDF membrane. The optical density was measured using a Kodak Scanner. Using the 96-well plate, the samples and standards were loaded, incubated with primary and secondary antibody, washed and vacuumed with 10x wash buffer three times between each incubation period. Stop buffer was added to the plate and the results were quantified via the plate reader. Results. For both muscle and mucosa tissue, the optical density readings were linear with tissue concentration; the concentration of nitrotyrosine in the mucosa was significantly higher than in the muscle. However, whereas the Western blot analysis is based on relative optical densities, the 96-well plate kit provides a truly quantitative analysis. Discussion. Mucosa tissue displayed a higher density of nitrotyrosine than did detrusor muscle tissue. This may well be due to the significantly higher metabolic activity of the mucosa compared to the muscle
Physical exercise training and coronary artery disease
Coronary artery disease (CAD) is a leading cause of death worldwide, despite improvements in medical and interventional therapies. Based on many studies in large cohorts, regular physical exercise training plays a central and indispensable role in both the primary and secondary prevention of CAD. Exercise training was shown to improve blood pressure control, lipid profile, glucose control, and enhance weight loss in obese patients. Moreover, exercise training not only affects clinical symptoms, it reduces CAD mortality and morbidity in addition to dietary, pharmacological and interventional treatments. Different kinds of exercise training (aerobic, interval, resistance training) have been studied and all are feasible, well tolerated, and beneficial in patients with CAD. Therefore, exercise training has the highest recommendation class (I) and level of evidence (A) in the European guidelines for patients with coronary artery disease. Nonetheless, exercise training is underutilized in patients with cardiac diseases and only a minority of eligible patients is referred to a cardiac rehabilitation or structured exercise training program by their physician
Chronic wasting disease detection and mortality sources in semi-protected deer population
Surveillance for wildlife diseases is essential for assessing population dynamics of ungulates, especially in free-ranging populations where infected animals are difficult to sample. Chronic wasting disease (CWD) is an emerging infectious disease of concern because of the potential for substantial negative effects on populations of cervids. Variability in the likelihood that CWD is detected could invalidate traditional estimators for prevalence. In some instances, deer located after death cannot be tested for infectious diseases, including CWD, because of lack of availability or condition of appropriate tissues. We used various methods to detect infectious diseases that could cause mortality for deer Odocoileus spp. residing in Wind Cave National Park, South Dakota, USA, and we report survival estimates for animals in this population. We included 34 monthly encounters of deer resightings and 67 mortalities. We tested live deer by tonsillar biopsy for CWD and estimated pooled prevalence (mean ± SE) at 5.6 ± 3.0% over the three-year study. Live deer potentially had exposure to several infectious diseases, including bluetongue, epizootic hemorrhagic disease, bovine viral diarrhea, West Nile virus, and malignant catarrhal fever, but no apparent morbidity or mortality from those diseases. We tested survival and influence of covariates, including age and sex, using known-fate analysis in Program MARK. Those data best supported a model with time-invariant encounter probability and an annual survival of 72.8%. Even without direct pressure from hunting within the park, average life expectancy in this population was 3.2 years. Only 68% of mortalities contained sufficient material for CWD sampling (because of predation and scavenger activity) and \u3e42% of these were CWD-positive. These findings underscore the possible biases in postmortem surveillance estimates of disease prevalence because of potential for subclinical infected animals to be removed by predators and not tested
Epoxidation of unsaturated esters
Eight isomeric 9,12-diunsaturated c₁₈ methyl esters and seven isomers from two series of positionally isomeric methyl octadecacis, cis-dienoates, ie. 18:2 (5c12c - 8c12c) and (6c9c - 6c11c) were epoxidised to furnish monounsaturated monoepoxy esters and diepoxy esters. The monoepoxides and diepoxides were separated in pure form by column and thin layer chromatography, A comparative study was made of the chromatographic (TLC and GLC) behaviour and the NMR spectra of the unsaturated epoxy esters. TLC gave some indication of the position and geometry of the epoxy group and the nature of the unsaturated centre. The geometry of the epoxy group and the olefinic or acetylenic nature of the unsaturated centre were also revealed by GLC. 220 MHz NMR spectra, recorded for all unsaturated epoxy esters and diepoxy esters, exhibited up to nine more or less resolved signals which showed the long range deshielding influences of the ester group, the unsaturated centre, and the epoxy group. These influences were noticeable even when five methylene groups separated the deshielding group and the proton under consideration. Even though the NMR spectra did not give a complete structural analysis of the epoxy esters, they nevertheless revealed the geometry of the epoxy group as well as the nature of the unsaturated centre. The epoxides were convened to vicinal diether derivatives the mass spectrometric examination of which allowed the unambiguous location of the epoxy group and therefore also of the original double bond. Melting points of the vicinal dihydroxy acids, derived from all the twenty-six unsaturated epoxy esters by acetolysis and hydrolysis, were determined. The melting point differences between the various Isomers reflected such structural features as the geometry and position of the alpha-diol group and of the accompanying unsaturated centre. Two diepoxy esters, methyl cis-6,7, cis-9,10-diepoxystearate and methyl cis-8,9, cis-12,13 diepoxystearate, were reacted with boron trifluoride etherate. Instead of the expected dioxo derivatives, various cyclic ethers were obtained. A minor study was concerned with the hydroboration of various unsaturated long chain esters. The intermediate organoboranes were subjected to oxida.tion, protonolysis and coupling reactions to give in good yields hydroxy, oxo and hydroperoxy esters as well as hydrogenated and coupled products
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