Evaluation and Comparison of 300-yd and 500-yd Shallow Water Run Tests as Predictors of Aerobic Power

The purposes of the study were to assess and compare the validity of both 300-yd and 500-yd shallow water run (SWR) tests to predict peak aerobic power (VO2peak). Subjects included 18 women and 18 men who performed a graded exercise treadmill test to predict VO2peak and then performed a 300-yd and 500-yd SWR for time. In addition to SWR times, other independent variables included age, gender, body weight, height, leg length, percent body fat, and 300-yd and 500-yd SWR heart rate and rating of perceived exertion. Correlation coefficients with measured VO2peak were r = -.84 and -.87 for the 300-yd and 500-yd SWR times, respectively. Multiple regression analyses revealed that prediction of VO2peak from 300-yd SWR time improved by including gender and body weight (R = .919; SEE = 0.360 L.min-1). Similarly, prediction of VO2peak improved from 500-yd SWR time by including gender, body weight, and leg length (R = .940; SEE = 0.316 L.min-1). Equations were also developed for use in pools of varying water depths. In conclusion, the 300-yd and 500-yd SWR tests can provide accurate and valid estimates of aerobic power

Estimation of body density in adolescent athletes

National samples of 141 male and 133 female highly-trained adolescent athletes were studied to derive anthropometric-based equations predicting body density. Anthropometric measures included skinfold thicknesses at seven sites, circum- ferences at 14 sites, and diameters at nine sites. Criterion measures of body density were determined by underwater weighing with corrections for residual lung vol- ume based on the oxygen dilution method. Variable selection procedures included factor analysis followed by forward-stepping regression and polynomial analysis. For both the male and female samples, two quadratic equations utilizing either the sum of three or seven skinfold measures were derived. Within the male sample, high validity coefficients (R = 0.81 - 0.82) and low standard errors (SEE = 0.0055 - 0.0056 g-ml !) were shown with these equations. Similar results were demon- strated with the equations for females (R = 0.82 and SEE = 0.0060 g-ml~ l). Cross- validation on independent samples of male (n = 66) and female (n = 46) adolescent athletes further confirmed these findings. In the cross-validation sample of males, predicted scores were highly correlated with actual body density (r = 0.86 - 0.87) and the total error of prediction ranged from 0.0057 to 0.0061 g-ml~ l. Among the females, these values were r = 0.82 - 0.83 and total error = 0.0058 to 0.0063 g*ml-1. These results indicate that within reasonable limits of error, the sum of three or seven skinfolds may be used to make estimates of the body density of adolescent male or female athlete

Assessing osteoporosis learning needs and preferences of exercise physiologists

Research has revealed substantial knowledge deficits regarding osteoporosis among various healthcare professionals, such as physicians, nurses, and physical therapists. However, no previous studies have addressed the levels of knowledge regarding osteoporosis among exercise physiologists working in a cardiopulmonary rehabilitation setting. It is essential that exercise physiologists have a thorough understanding of osteoporosis so they can ensure client safety and provide accurate information to the client and support group. The purpose of this project was to evaluate the levels of knowledge about osteoporosis among exercise physiologists working with clients who are at high risk for fragility fractures. Ninety-six exercise physiologists (female = 63 , male = 33) working in cardiopulmonary rehabilitation clinics throughout the United States were randomly selected and completed a three component survey, which included a 21-item osteoporosis knowledge test. The scores ranged from 11 to 20 with a mean score of 16.3 ± 1.7. Fifty percent of the respondents scored lower than 80% on the test. The major areas of knowledge deficit found were related to disease prevalence, nutritional relationships, and prevention. Additional findings suggest journal articles, websites, pamphlets, and presentations are the preferred methods for leaning among exercise physiologists. These findings are vital for guiding educational programs aimed at improving the osteoporosis related knowledge base of exercise professionals working with clients at high risk for fracture

Bifunctional catalytic electrode

The present invention relates to an oxygen electrode for a unitized regenerative hydrogen-oxygen fuel cell and the unitized regenerative fuel cell having the oxygen electrode. The oxygen electrode contains components electrocatalytically active for the evolution of oxygen from water and the reduction of oxygen to water, and has a structure that supports the flow of both water and gases between the catalytically active surface and a flow field or electrode chamber for bulk flow of the fluids. The electrode has an electrocatalyst layer and a diffusion backing layer interspersed with hydrophilic and hydrophobic regions. The diffusion backing layer consists of a metal core having gas diffusion structures bonded to the metal core

Thermoregulatory effects of caffeine ingestion during rest and exercise in men

Body temperatures and thermoregulatory responses were measured at rest and during submaximal exercise under normal ambient conditions in 11 aerobically-conditioned men (age = 29.2 +/- 6.2 yr, VO2(max) = 3.73 +/- 0.46 min(sup -1), relative body fat = 12.3 +/- 3.7 percent, mean +/- SD) with (CT) and without (NCT) the ingestion of 10 mg of caffeine per kg of body weight. Oxygen uptake (VO2), heart rate (HR), and rectal (T(sub re)) and mean skin (T-bar(sub sk)) temperatures were recorded for 100 minutes starting one minute after ingestion of caffeine or a placebo. Data were collected throughout 30 minutes of rest (sitting) and the following 70 minutes of sitting leg ergometer exercise using the same constant load (1,088 +/- 153 kgm/min) in both NCT and CT. The load resulted in a mean relative exercise intensity equal to approximately 68 percent of VO2(sub max). Skin heat conductance (H(sub sk)) and sweat rate were calculated. Two-way analysis of covariance revealed no significant (P greater than 0.05) differences between NCT and CT in VO2, HR, T(sub re), T-bar(sub sk), or H(sub sk). A dependent t-test indicated no significant difference between NCT and CT in sweat rate. Thus, a high level of caffeine ingestion has no detrimental effects on body temperatures and thermoregulatory responses during moderately heavy exercise in normal ambient conditions

Impact locations and damage to civil and military rotary-wing aircraft from wildlife strikes

Rotary-wing aircraft (e.g., helicopters and tilt-wing aircraft) are an important component of all U.S. military services and the U.S. civil aviation industry. Our analyses of wildlife strikes to military rotary-wing aircraft, both within the United States and during overseas deployments, as well as civil helicopters, have shown there are important patterns within wildlife strike data for flight operations conducted on airfields and during off-airfield missions. Birds accounted for 93% of the wildlife strikes where the animal was identified, and mammals (primarily bats) accounted for 7%. Wildlife impacted all parts of civil helicopters and military rotary-wing aircraft during strike events; however, specific areas were impacted by wildlife with a higher frequency compared to others. We recommend airframe manufacturers and maintenance personnel consider reinforcing and redesigning rotary-wing aircraft windscreens and main rotor systems to better withstand the impact of wildlife

Membrane with internal passages to permit fluid flow and an electrochemical cell containing the same

The invention provides an improved proton exchange membrane for use in electrochemical cells having internal passages parallel to the membrane surface, an apparatus and process for making the membrane, membrane and electrode assemblies fabricated using the membrane, and the application of the membrane and electrode assemblies to a variety of devices, both electrochemical and otherwise. The passages in the membrane extend from one edge of the membrane to another and allow fluid flow through the membrane and give access directly to the membrane for purposes of hydration

Detecting strain in birefringent materials using spectral polarimetry

A method, computer program product and system for analyzing multispectral images from a plurality of regions of birefringent material, such as a polymer film, using polarized light and a corresponding polar analyzer to identify differential strain in the birefringent material. For example, the birefringement material may be low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene, polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyvinylidene chloride, polyester, nylon, or cellophane film. Optionally, the method includes generating a real-time quantitative strain map