Improvements in heat tolerance induced by interval running training in the heat and in sweat clothing in cool conditions

To compare the effectiveness of training in heat and in sweat clothing in cool conditions on improving heat tolerance, two groups of active subjects (n = 6 in each) performed an interval running heat-tolerance test before and after a 7-day experimental treatment. On each treatment day the subjects attempted to complete 4 x 15 min interval treadmill running periods (a 7.5 s effort every 30 s, on 15 km h-1, 15% grade; the same exercise format as the heat-tolerance test), which were interspersed with 5-min recovery periods (total time each day = 80 min). Group 1 (heat) ran in shorts, socks and shoes in hot humid conditions, and Group 2 (sweat clothing) ran in cool conditions dressed in shorts, socks and T-shirt covered by a polyester-cotton tracksuit, over which was worn 100% nylon spray-proof pants and jacket (cotton lined) with an acrylic cloth bobble hat (beanie) on the head. Both groups displayed changes typical of heat acclimatization over the 7-day period, with significant decreases in final rectal temperature (Tr) and heart rate (HR) being evident, but no change in sweat loss. Mean skin temperature (Tsk) was similar in both groups during the training sessions (heat group: 34.8-35.7 degrees C; sweat clothing group 34.9-35.5 degrees C). After the heat-tolerance test, both groups had significantly lower Tr, Tsk and HR values than before, and sweating sensitivity (g m-2 h-1 degrees C rise in Tr) was significantly increased. There was only one significant difference between the two groups (Tsk, 20th min value). It was concluded that training in sweat clothing in cool conditions can provide the same improvements in heat tolerance as training in hot humid conditions where a fixed exercise intensity and duration are used.     

Somatotype and longevity of former university athletes and nonathletes

A longitudinal study was conducted on 398 athletes and 369 nonathletes who were born before 1920 and attended Michigan State University. The subjects were compared to determine if intercollegiate athletic competition accounts for significant variation in longevity when considered with somatotype. Because some of the subjects were still alive at the time of the study, the BMDP Statistical Software was used to do a survival analysis with covariates. Preliminary comparisons considered the differences in somatotype between athletes and nonathletes. Two sample t-tests indicated that athletes were more mesomorphic and less ectomorphic (p less than .05) than nonathletes. When comparing the relationship between somatotype and longevity, the pooled data of athletes and nonathletes indicated that endomorphs were shorter lived than the other three comparison groups. When only the athletes were considered, similar results were found. However, the nonathlete group exhibited differences only between the mesomorphic and endomorphic groups. The endomorphs were shorter lived. Longevity was examined by using the Cox proportional hazards regression method with somatotype and athlete/nonathlete status as covariates. Somatotype, by itself, was found to be significantly related to longevity, (p less than .001). Athletic status was not significantly related to longevity, either by itself or when entered into the model with somatotype.     

A causal analysis relating previous achievement,attitudes, discourse,and intervention to achievement in biology and chemistry

This study described the relationship of 38 variates to achievement in high school biology and chemistry classes. Forty-four teachers prepared audio tape recordings of discussions throughout a nine-month period. Equal-sized groups received treatment consisting of wait time feedback and/or supportive intervention, a form of peer coaching. Other variables were initial measures, which included the variates of class size and previous science grade, pre- and posttest scores on student attitudes and perceptions, and prediscourse and discourse analyses, which included the variates of wait times, actions, and response durations. While previous research has shown that wait time feedback and supportive intervention are effective means of changing teacher behavior, the results of the present study revealed that previous student achievement and the attitudes of students accounted for 70% of the variation in the final examination scores (New York State Regents) on the basis of only the first three weeks of data collection on the variables assessed. Generally, little emphasis on higher-level thinking, wait time, or problem solving was found at the beginning of the school year, and only minimal changes resulted from the application of the treatment variables. Pressures for content coverage and preparation for externally imposed statewide examinations that emphasize memory-level learning augured against the changes that the independent variables were designed to produce.     

A Brief History of Item Theory Response

How did early work of Binet and Thurstone foreshadow item response theory? What connections to work in other areas are not widely recognized? What are current application trends?