A Symbiosis of Access: Proliferating STEM PhD Training in the U.S. from 1920–2010

Minerva - Over the course of the 20th century, unprecedented growth in scientific discovery was fueled by broad growth in the number of university-based scientists. During this period the American...     

Comparison of methods for determining power generated on a rope-braked cycle ergometer during low-intensity exercise

This study compares the instrumentation and analysis techniques used when determining the power expended pedalling a rope-braked ergometer manufactured by Monark (Sweden) during a low intensity test. Power values were generated by eight subjects. The instrumentation consisted of load cells to measure the rope brake forces, a tachometer to measure the flywheel velocity and instrumented pedal cranks manufactured by Schoberer Rad Messtechnik (SRM). The subjects pedalled a rope-braked ergometer at 60 rev min^-1, against a resistance of 3 kg, for 5 minutes. Three different measurements of the mean power were recorded and these were compared with the value given by Monark. The SRM cranks provided two sets of results using different software packages supplied with the cranks. SRM standard software is used for taking measurements during training and cycle races over long time periods. An additional piece of software is provided by SRM called Ptnew, which gives readings of torque and pedal cadence over periods up to 30 seconds. Using the values supplied by Monark each subject generated 180 W of power. The mean power for the eight subjects, measured using the SRM cranks, was 170.36 W (SD 4.11) using the alternative SRM software (Ptnew) over a 30 second period and 173.68 W (SD 2.21) using the standard SRM software. From the direct measurement of the brake forces and flywheel velocity the mean power across the eight subjects was 148.90 W (SD 5.89). The SRM cranks measure the input power, whereas the direct measurement system measures the power output excluding mechanical losses. These values give a figure for the mechanical efficiency for the roped-braked ergometer of 88%. It was found that Monark overestimates the power generated by the subjects when compared with both the SRM systems and the direct measurement instrumentation.     

Gender and ethnic differences in perceptions of equal opportunity climate and job outcomes of US Army Reserve component personnel

We examined equal opportunity climate (EOC) perceptions of reserve component personnel in the US Army (n = 949). We expected that gender and ethnic group membership would influence perceptions of the equal opportunity climate; and that gender and ethnic group membership would moderate the relationship between equal opportunity climate perceptions and ratings of job satisfaction, organizational commitment and workgroup effectiveness. Consistent with our hypothesis, we found the women and minorities perceptions regarding the equal opportunity climate were less favorable than White men. We also found that both gender and ethnicity moderated the relationship between equal opportunity climate perceptions and job outcomes of these groups. Our findings suggest that different groups are sensitive to particular aspects of EOC (e.g., harassment or discrimination) and that these sensitivities affect job-related outcomes.