To examine whether beta-adrenergic desensitization occurs after prolonged exercise, echocardiograms, heart rate responses to isoproterenol, plasma catecholamines, and circulating lymphocyte beta-adrenergic receptors were examined in 10 sedentary normal subjects at rest and after brief (10 min) and exhaustive (mean duration 95 min) cycle exercise. Resting end-diastolic volume and ejection fraction were significantly reduced after exercise (from 120 +/- 34 to 100 +/- 26 ml and from 60 +/- 0.4 to 54 +/- 0.6%, respectively; both P < 0.05). The amount of isoproterenol needed to increase heart rate 15 and 25 beats/min increased in a dose- (exercise duration) related fashion, and the increase in amount of isoproterenol needed after prolonged exercise was closely related to the decrease in ejection fraction (r2 = 0.67, P = 0.004). Circulating lymphocyte beta-receptor density and affinity, agonist binding, and adenylylcyclase levels were unchanged with prolonged exercise. In conclusion, prolonged exercise in sedentary normal subjects resulted in reduced cardiac chronotropic responsiveness to isoproterenol that was not reflected in peripheral lymphocyte beta-adrenergic-receptor downregulation.
This paper discusses a K−12/university collaboration in which students participated in a four-day scenario-based summer STEM (science, technology, engineering, and mathematics) camp aimed at making difficult scientific concepts salient. This scenario, Jumpstart STEM−CSI: Chocolate Science Investigation (JSCSI), used open-and guided-inquiry methods to generate meaningful student engagement for 33 rising 8th through 12th graders. This paper presents curriculum for the scenario; reports results from postevent survey data regarding students' self-reported gains in science motivation, science confidence, science knowledge, and students' associations with scientificallyminded social niches; and illustrates how a scenario can incorporate the use of skills and knowledge from many disciplines and make them relevant to student learning, providing a context for STEM literacy. Implications for science educators are discussed.
This article reports on a case study which compares a group of police officers hired by a large metropolitan police department during a recent five-year period (n = 190) with a group of all applicants (n = 1,545) for a recent recruit class. The study, examining age, gender, race, residence and military experience finds that many of the characteristics appear with nearly the same frequency in both groups. However, notably, there are differences in the frequencies in the populations of the two groups as to age, education, number of white females and numbers of black females. [Article copies available for a fee from The Haworth Document Delivery Service: 1-800-342-9678. E-mail address: getinfo@ haworthpressinc.com ]Each time manpower needs dictate, law enforcement agencies engage in the ritual ''hiring process'' which they have devised to select the men and women who will police the citizens of our communities. Regardless of the size or location of the department, the hiring process which the department uses will likely have many things in common with hiring processes used by Downloaded by [University of Waterloo] at 07:54 03 November 2014
Police departments are slowly but steadily moving to increase the educational requirements for sworn officers. Additionally, some departments are beginning to consider raising the age requirements. This study examines the impact which raising the age and/or educational requirements could have on the selection of women and minority officers through a case study of the Indianapolis Police Department (IPD). Findings from an analysis of hiring practices in the IPD over a five year period are discussed, and the effects that raising the age and/or educational requirements would have on the traditional pool of successful applicants are described, with particular attention to the possible exclusionary effect on women and minorities.
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