2,925 research outputs found

    Studies of CO oxidation on Pt/SnO2 catalyst in a surrogate CO2 laser facility

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    Samples of 1% Pt/SnO2 catalyst were exposed to a stoichiometric gas mixture of 1% CO and 1.2% O2 in helium over a range of flowrates from 5 to 15 sccm and temperatures from 338 to 394 Kelvin. Reaction rate constants for the catalytic oxidation of carbon monoxide and their temperature dependence were determined and compared with previous literature values

    Spacelab 3 flight experiment No. 3AFT23: Autogenic-feedback training as a preventive method for space adaptation syndrome

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    Space adaptation syndrome is a motion sickness-like disorder which affects up to 50 percent of all people exposed to microgravity in space. This experiment tested a physiological conditioning procedure (Autogenic-Feedback Training, AFT) as an alternative to pharmacological management. Four astronauts participated as subjects in this experiment. Crewmembers A and B served as treatment subjects. Both received preflight training for control of heart rate, respiration rate, peripheral blood volume, and skin conductance. Crewmembers C and D served as controls (i.e., did not receive training). Crewmember A showed reliable control of his own physiological responses, and a significant increase in motion sickness tolerance after training. Crewmember B, however, demonstrated much less control and only a moderate increase in motion sickness tolerance was observed after training. The inflight symptom reports and physiological data recordings revealed that Crewmember A did not experience any severe symptom episodes during the mission, while Crewmember B reported one severe symptom episode. Both control group subjects, C and D (who took antimotion sickness medication), reported multiple symptom episodes on mission day 0. Both inflight data and crew reports indicate that AFT may be an effective countermeasure. Additional data must be obtained inflight (a total of eight treatment and eight control subjects) before final evaluation of this treatment can be made

    Autogenic-feedback training: A preventive method for space adaptation syndrome

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    The progress made to date on the reduction of data for Spacelab 3 Shuttle experiment, No. 3AFT23 is reported. Four astronauts participated as subjects in this experiment. Crewmen A and B served as treatment subjects (i.e., received preflight training for control of their own motion sickness symptoms) and Crewmen C and D served as control (i.e., did not receive training). A preliminary evaluation of Autogenic Feedback Training (AFT) was made from visual inspections of graphs that were generated from the preflight and inflight and inflight physiological data which included: (1) Baseline rotating chair tests for all crewmen; (2) Posttraining rotating chair tests of treatment groups subjects; (3) Preflight data from Joint Integrated Simulations for all crewmen; and (4) Flight data for all crewmen during mission days 0 through 4, and mission day 6 for treatment subjects only. A summary of the findings suggested by these data is outlined

    Elevated cerebral spinal fluid biomarkers in children with mucopolysaccharidosis I-H.

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    Mucopolysaccharidosis (MPS) type-IH is a lysosomal storage disease that results from mutations in the IDUA gene causing the accumulation of glycosaminoglycans (GAGs). Historically, children with the severe phenotype, MPS-IH (Hurler syndrome) develop progressive neurodegeneration with death in the first decade due to cardio-pulmonary complications. New data suggest that inflammation may play a role in MPS pathophysiology. To date there is almost no information on the pathophysiologic changes within the cerebral spinal fluid (CSF) of these patients. We evaluated the CSF of 25 consecutive patients with MPS-IH. While CSF glucose and total protein were within the normal range, we found a significantly mean elevated CSF opening pressure at 24 cm H2O (range 14-37 cm H2O). We observed a 3-fold elevation in CSF heparan sulfate and a 3-8 fold increase in MPS-IH specific non-reducing ends, I0S0 and I0S6. Cytokine analyses in CSF of children with MPS-IH showed significantly elevated inflammatory markers including: MCP-1 SDF-1a, IL-Ra, MIP-1b, IL-8, and VEGF in comparison to unaffected children. This is the largest report of CSF characteristics in children with MPS-IH. Identification of key biomarkers may provide further insight into the inflammatory-mediated mechanisms related to MPS diseases and perhaps lead to improved targeted therapies

    A Conceptual Model for Predicting Areas with High Potential for Lake Trout Spawning Habitat in Yellowstone Lake

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    The presence of non-native lake trout (Salvelinus namaycush) has become a serious threat to native salmonid populations in many lakes throughout the West. Costly and time consuming suppression efforts have been undertaken by agencies in several of these systems with concern regarding their efficacy expressed by fisheries managers. Frequently, mature lake trout are interspersed with the native fishes, hindering removal efforts because of bycatch of fishes meant to be the beneficiary of suppression efforts. One method of improving suppression efforts that could reduce negative impacts on other species is to target areas where sexually mature lake trout congregate for spawning activities. Using theory that water movements within lakes influence habitat formation, parameters describing lake trout spawning habitat in published literature, and the capability of a GIS to mesh spatially-explicit geographical datasets, a conceptual lake trout spawning habitat model was developed for Yellowstone Lake. Important inputs to this model include detailed bathymetry of Yellowstone Lake, a sedimentation model that predicts erosion and deposition of particles within lake systems, and data on primary wind direction over the lake. The model predicts that 4.4 percent of the surface area of Yellowstone Lake has excellent potential, 8.9 percent has some potential, and 86.7 percent has no potential to contain lake trout spawning habitat. Additional data layers can be easily incorporated as new information becomes available on lake trout requirements for successful spawning. This model can be used to identify suitable spawning areas for monitoring and control, and has potential to be applied on other lakes experiencing lake trout invasion

    Autogenic-feedback training as a treatment for airsickness in high-performance military aircraft: Two case studies

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    The purpose of this paper is to present a detailed description of the physiological and performance responses of two military pilots undergoing a treatment for motion sickness. The treatment used, Autogenic-Feedback Training (AFT), is an operant conditioning procedure where subjects are taught to control several of their autonomic responses and thereby suppress their motion sickness symptoms. Two male, active duty military pilots (U.S. Navy and U. S. Marine Corps), ages 30 and 35, were each given twelve 30-minute training sessions. The primary criterion for success of training was the subject's ability to tolerate rotating chair motion sickness tests for progressively longer periods of time and at higher rotational velocities. A standardized diagnostic scale was used during motion sickness to assess changes in the subject's perceived malaise. Physiological data were obtained from one pilot during tactical maneuvers in an F-18 aircraft after completion of his training. A significant increase in tolerance to laboratory-induced motion sickness tests and a reduction in autonomic nervous system (ANS) response variability was observed for both subjects after training. Both pilots were successful in applying AFT for controlling their airsickness during subsequent qualification tests on F-18 and T-38 aircraft and were returned to active duty flight status

    Assessment of the Water Quality in the Salt River Prior to Its Impoundment in Anderson and Spencer Counties, Kentucky

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    Monthly water samples were taken and analyzed to determine the water quality of the Salt River in Anderson and Spencer counties Kentucky prior to the river\u27s impoundment. Sediments from the area watershed were analyzed to total acid digestion, barium chloride extraction, and aqueous extraction methods. Rainwater and runoff water were collected and analyzed for major cations and anions from two sites in the watershed. The Salt River at Taylorsville is characterized by hard water with high levels of calcium (33.5-74.8 mg/1), bicarbonate (136-236 mg/l), specific conductance (200-535 μmhos/cm), and sulfate (16.5-71.5 mg/l). Nitrates (0.6-5.7 mg/l), phosphates (0.2-2.4 mg/l), sodium (3.2-20.3 mg/l), and potassium (1.3-5.6 mg/l), are moderate. Iron, manganese, copper, and nitrites are less than 0.5 mg/1. Suspended solids in the river (4.0-l ,684.0 mg/l) are highly variable and directly related to fluctuations in discharge. Sediments from the Salt River Basin are high in potassium (12.4-213.3 mg/g) and iron (23.4-135.1 mg/g), with moderate levels of calcium (0.8-45.7 mg/g), sodium (4.5-10.5 mg/g), magnesium (3.2-6.3 mg/g), and phosphate (1.3-15.3 mg/g). Approximately 10% of the total ionic composition of these sediments is exchangeable and may be extracted with barium chloride. Calcium (309-3,292 μg/g), was the most readily adsorbed cation, with lower levels of potassium (17.6-490.5 μg/g), sodium (12.9-458.1 μg/g), and magnesium (89.4-266.2 μg/g). In the aqueous extractions, calcium (18-486 μg/g), potassium (16.6-69.5 μg/g), sodium (11.1-30.8 μg/g), and magnesium (6.6-68.7 μg/g) comprised about 10% of the exchangeable fraction. Ranges of rainwater ions from the Salt River Basin were: sulfate (8.3-27.8 mg/l), calcium (0.3-10.7 mg/l), potassium (0.4-15.4 mg/l), sodium (0.0-0.7 mg/l), and magnesium (0.1-2.8 mg/l). Ionic composition and sediment yield of runoff water was variable and was related to magnitude of rainfall and runoff sampler placement. Ranges for selected constituents at the two samplers near Taylorsville were: suspended solids (44.0-8,808.0 mg/l), potassium (1.1-84.0 mg/l), magnesium (l.5-7.1 mg/l), calcium (9.5-33.0 mg/l), and sodium (0.6-3.0 mg/l). Calcium and bicarbonate in the Salt River originate from weathering of calcite, although mole ratios of these two ions greater than 1:2 suggest that weathering of magnesium carbonates also contributes bicarbonate to the water. Carbonate equilibrium calculations using field pH and ionic strength suggest calcium is at saturation in the Salt River. High levels of sulfate in rainwater indicate some of this anion may be introduced into the area watershed by atmospheric precipitation

    Autogenic-feedback training: A countermeasure for orthostatic intolerance

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    NASA has identified cardiovascular deconditioning as a serious biomedical problem associated with long-duration exposure to microgravity in space. High priority has been given to the development of countermeasures for this disorder and the resulting orthostatic intolerance experienced by crewmembers upon their return to the 1g norm of Earth. The present study was designed to examine the feasibility of training human subjects to control their own cardiovascular responses to gravitational stimulation (i.e., a tilt table). Using an operant conditioning procedure, Autogenic-Feedback Training (AFT), we would determine if subjects could learn to increase their own blood pressure voluntarily
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