Assessment of morphological vascular responses to exposure to cardiovascular risk factors in experimental animals requires ex vivo experiments that do not allow assessment of the time course of vascular alterations in individual subjects. We used a slit-lamp biomicroscope (resolution < 1 μm) to photograph the long posterior ciliary artery (LPCA) of the iris in conscious normotensive Wistar Kyoto rats (WKY, n=10) and spontaneously hypertensive rats (SHR, n=10) on normal-salt diet (NS) and in SHR (n=10) on high-salt diet (HS). The same segment along the LPCA was imaged in consecutive weekly imaging sessions and an imaging software was used to determine the wall to lumen (W/L) ratio. After 10 weeks, systolic blood pressure (SBP) did not change in WKY-NS, but increased significantly in SHR-NS and SHR-HS, (p < 0.05). The time course of the changes in W/L ratio of the LPCA mirrored the time course of the SBP changes. While W/L ratio did not change in WKY-RS, there was a significant increase in W/L ratio in SHR-NS and SHR-HS. Since the LPCA was not dilated pharmacologically the W/L ratio assessed in this study may reflect the combination of morphologic alterations and changes in vascular tone. In vivo imaging of the LPCA may allow assessment of the time course of morphological and functional vascular responses to hypertension in conscious rats.

In humans, it is thought that both central commands and peripheral feedback from sensory receptors contribute to the control of locomotion. An important problem that exists in human locomotion research is the interactions and balance between the individual contributions of the central (CNS) and peripheral (PNS) nervous systems to the control of muscles during movement are not fully understood. Applying external perturbations such as stretches, tendon taps, and electrical stimulation to the neuromuscular system during walking can help us learn more about how the response to afferent information is modulated during locomotion. To date, most of the research looking at modulation of the response during walking has investigated the soleus and quadriceps muscles. Very little research has focused on the hamstring muscles, which are important during walking, particularly during late swing. One reason for this is that it is difficult to detect H-reflexes in hamstrings following electrical stimulation of the sciatic nerve. The purpose of this study was to demonstrate a new sciatic nerve stimulation technique and use it to study the modulation of the response to afferent feedback during walking. This study consisted of two parts: 1) Establish the presence of an afferent mediated response (H-reflex) during prone lying in hamstrings muscles, and 2) Investigate the modulation of this afferent feedback during walking. Subjects underwent single and double pulse stimulations to the sciatic nerve during prone lying, followed by electrical stimulation at 12 different phases of the gait cycle. For each phase, stimulus response curves were created in which maximal direct (M-wave) and afferent mediated responses (H-reflex) could be determined. Maximal H-reflex (Hmax) was normalized to maximal M-wave (Mmax) to create an H:M ratio that was used to compare modulation of the responses between phases and subjects. Electrical stimulation of the sciatic nerve elicited detectable H-reflexes in biceps femoris during prone lying and walking. The modulation of the response to afferent feedback is not the same for all phases of the gait cycle, particularly in late swing when it has a higher amplitude than the rest of the gait cycle. This modulation was not simply related to background EMG as would be expected during isometric contractions. Thus, there must be both central and peripheral influences on the response. Understanding the control of human locomotion is important for developing rehabilitation programs for patients with lesions of the central nervous system such as stroke or spinal cord injury.

Sedentary behavior has been found to have independent and negative associations with several cardiometabolic risk factors while interrupting prolonged sedentary time may ameliorate these associations. College classrooms are a traditionally sedentary microenvironment and understudied setting for sedentary interventions. Introducing sit-stand desks into college classrooms may be an effective and sustainable approach to reduce classroom sedentary time of college students. The objective of this study was to test the efficacy of replacing seated desks with sit-stand desks in a college classroom on student’s classroom standing time and sit-stand transitions, as well as health-related and academic behaviors. We recruited 304 undergraduate college students taking one of 14 classes being taught in one of two small classrooms (25 seats per class) to participate. Using a cross-over design, each student’s classroom sitting and standing time were measured by self-report and objectively (direct observation via video camera surveillance) after having access to only seated desks or only sit-stand desks for six continuous weeks. A process evaluation survey was administered at the end of the study to explore student’s and instructor’s perceptions of the intervention and its impact on student engagement. The results suggest that students stood about 9.1% of class time on average when given access to sit-stand desks and about 1.95% of class time when using traditional seated desks, as measured by objective video surveillance data. There was no significant change in sit-stand transitions between sit-stand desks and seated desks. Students reported that a number of academic and health outcomes were favorably impacted as a result of using the sit-stand desks. Social acceptability appeared to be the biggest barrier to use of the sit-stand desks. Overall, students reported a desire to use sit-stand desks again in future classes. Students stood significantly more when provided access to sit-stand desks compared to seated desks. Sit-stand transitions were not significantly increased when sit-stand desks were implemented. Significantly more students reported improvements in academic and health related outcomes than students who reported declines in these areas as a result of using sit-stand desks. A majority of students reported they would use sit-stand desk again in the future and be supportive of adding sit-stand desks to other classrooms on campus. Sit-stand desks are a feasible environmental change in a college classroom to reduce student sedentary time.

This study investigates the ways in which understandings of gender, physicality and equality influenced policy and thus constructed the identities and experiences of female cadets during the 1976 integration of women into the United States Military Academy at West Point. Policy decisions and the way in which they were put into practice set the precedent for all subsequent female cadets and so it is important to explore their origins and early impact. West Point is an ideal setting in which to explore two historically masculinist institutions, sport and the military, during a time when the women's movement was cresting and the military was redefining itself in a new post-Vietnam voluntary military. An exploration of the changing gender dynamics as this elite male military institution became co-ed at a particular historical moment shows that physicality was more integral to the process of integrating women than actual military training was. This study is based on archival research conducted at the Special Collections and Archives of USMA and the personal accounts of female cadets who attended West Point from 1976-1980 to produce a qualitative picture of the integration of women into West Point. Focusing on military training, physical education, athletics, and covert training I found that women generally performed equally to men in military training yet struggled in certain aspects of physical training which seemed to validate those who doubted women's ability to be successful cadets. Women were also excluded from important physical activities because of "physiological differences," something that further served to separate them and construct them as "different" and "lesser." Based on the Academy's policy and practice with regard to physical training, along with a number of related matters, I conclude that while women were given equality in most respects, those in which they were not served to make them a second-class tier of cadet and soldier, judged not on combat and military skill and potential but rather on physical capabilities and attributes. As a consequence, even though West Point integrated women it did so in a way that served to protect the symbolic role of combat associated with masculinity.

This project examines mediated representations of marijuana users in film, advertisement, and sport. Situated within the recent Global Commission on Drugs denouncement of the War on Drugs, the rising medical marijuana movement, and the illegality of marijuana at the federal level in all fifty states, this project examines who gets to be a marijuana user in contemporary America. Using the tools of auto-ethnography, media analysis, genealogy, and narrative analysis this project deconstructs dominant conceptions about productive and unproductive bodies with a particular emphasis on the athletic body. How are we to understand a body that usually connotes exemplary health, and fitness when it uses a substance that is assumed to render the corporeal unproductive. In addition this project also explores how race and masculinity shape these understanding. A critical analysis of the narratives of five athletes- Michael Phelps, Tim Lincecum, Ricky Williams, Josh Howard, and Joakim Noah- provides the basis for deconstructing dominant understandings of the marijuana using body. This project seeks to generate new knowledge about the marijuana using body in order to help sick people obtain a helpful medicine and stop the imprisonment of non-violent drug offenders, who are disproportionately the poor and minorities.

PURPOSE: To compare: 1-the physiological profile of former athletes (Ath) and non-athletes (Non-Ath) upon college entrance, 2-PA levels in these groups, and 3-changes in physiological profile and PA level of former Ath and Non-Ath and females and males over the course of freshman year. Sixty-two college freshmen were tested during the initial weeks of the school year and again during the final weeks of the school year; the sample consisted of 32 former Ath (18 females and 14 males) and 30 Non-Ath (19 females and 11 males). METHODS: Body composition (BC) was assessed using the Bod Pod with a conversion of body density to body fat percentage (%BF) using the Siri equation. PA was assessed using the International Physical Activity Questionnaire (IPAQ), and 7 days of steps were counted using a pedometer. RESULTS: Upon entrance into college, Ath and Non-Ath had similar BC. Daily average number of steps was similar among the groups (Ath: 11212±2729steps; Non-Ath 11191±3735). However, median MET-minutes of weekly total PA (TPA) was higher in Ath (2737 METmin/wk) than Non-Ath (1613 METmin/wk). Over the course of freshmen year, there was a significantly larger drop in TPA for Ath (-1006±2126 MET-min/wk) than Non-Ath (140±2458 MET-min/wk). Overall, Ath had a higher fat free mass (p=0.046). The overall sample experienced unhealthy changes in BC, with a significant average weight gain of 1.81 kg±2.59 kg and a significant decline in daily steps. Males had a significantly larger decline in steps than females (-2374±3720 steps/day vs. -929±2596 steps/day). The overall sample also had a significant decrease in median TPA (2134 MET-min/wk to 1725 MET-min/wk). However there was a wide variation of changes in BC and PA; some had large changes while others had small or none. CONCLUSION: Generally, there were small but unhealthy changes in BC and decreases in PA during freshman year. Former athletes enter college with initially higher activity level when compared to Non-Ath; however this difference disappears by the end of freshmen year. The key is to determine factors that contribute to the large changes in certain individuals and to pinpoint factors that influence college students’ PA behavior.

PURPOSE: This study compared measures of physical activity (PA) taken from the 7- day Physical Activity Recall (PAR) and the International Physical Activity Questionnaire (IPAQ) with those obtained from the NL 2000 (NL) and Lifecorder (LC) accelerometers in entering, college freshmen. METHODS: 47 males and 64 females (overall age =18.5±.3 yrs, wt. = 68.7±14.4 kg, and BMI = 23.7 ±4.9) volunteered and signed an informed consent form. All subjects wore the NL for 7 days, and half wore the LC as well. After the 7 days the subjects completed the PAR and IPAQ. RESULTS: There was a strong agreement between accelerometers with PAEE expressed in kcal/wk (r = 0.958, p= 0.000). However, the NL recorded significantly higher values (p= 0.0001) for PAEE than the LC (Md= 2705 vs. 2120). Both PAR kcal/wk and IPAQ kcal/wk were significantly related to the NL kcal/wk, r = 0.275 (p= 0.004) and r= 0.430 (p= 0.000), respectively. In addition, there were no significant differences in overall PAEE between the NL and PAR (p= 0.148) or the NL and IPAQ (p= 0.198). However, both the PAR and IPAQ reported more PAEE as energy expenditure exceeded 3000 kcal/wk. PAR moderate and vigorous MET-min/wk were not significantly related to LC moderate (p= 0.411) and vigorous MET-min/wk (p= 0.204), respectively. In addition, there were significant differences in MET-min/wk between the PAR and LC for moderate (p= 0.019) and vigorous (p= 0.000) activity. PAR reported relatively the same PAEE at lower amounts of moderate intensity exercise, but reported more PAEE as energy expenditure increased. PAR systematically reported more vigorous PAEE across the full range of energy expenditure. CONCLUSION: The accelerometers correlated highly and were in close agreement with one another. In first year freshmen, both surveys provided overall estimates of PAEE that were significantly related to objective measures of PA. However, at high levels of energy expenditure, the questionnaires captured more of the vigorous PA that the accelerometers could not monitor.

PURPOSE: To compare: 1-the physiological profile of former athletes (Ath) and non-athletes (Non-Ath) upon college entrance, 2-PA levels in these groups, and 3-changes in physiological profile and PA level of former Ath and Non-Ath and females and males over the course of freshman year. Sixty-two college freshmen were tested during the initial weeks of the school year and again during the final weeks of the school year; the sample consisted of 32 former Ath (18 females and 14 males) and 30 Non-Ath (19 females and 11 males). METHODS: Body composition (BC) was assessed using the Bod Pod with a conversion of body density to body fat percentage (%BF) using the Siri equation. PA was assessed using the International Physical Activity Questionnaire (IPAQ), and 7 days of steps were counted using a pedometer. RESULTS: Upon entrance into college, Ath and Non-Ath had similar BC. Daily average number of steps was similar among the groups (Ath: 11212±2729steps; Non-Ath 11191±3735). However, median MET-minutes of weekly total PA (TPA) was higher in Ath (2737 METmin/wk) than Non-Ath (1613 METmin/wk). Over the course of freshmen year, there was a significantly larger drop in TPA for Ath (-1006±2126 MET-min/wk) than Non-Ath (140±2458 MET-min/wk). Overall, Ath had a higher fat free mass (p=0.046). The overall sample experienced unhealthy changes in BC, with a significant average weight gain of 1.81 kg±2.59 kg and a significant decline in daily steps. Males had a significantly larger decline in steps than females (-2374±3720 steps/day vs. -929±2596 steps/day). The overall sample also had a significant decrease in median TPA (2134 MET-min/wk to 1725 MET-min/wk). However there was a wide variation of changes in BC and PA; some had large changes while others had small or none. CONCLUSION: Generally, there were small but unhealthy changes in BC and decreases in PA during freshman year. Former athletes enter college with initially higher activity level when compared to Non-Ath; however this difference disappears by the end of freshmen year. The key is to determine factors that contribute to the large changes in certain individuals and to pinpoint factors that influence college students’ PA behavior.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 8 uppsatser.

Includes abstract. / Includes bibliographical references (p. 139-178). / This thesis examines the regulation of muscle function following exercise-induced muscle damage (EIMD), in an attempt to determine whether regulation occurs primarily in the muscle (neuromuscular) or further upstream. Upstream regulation has been hypothesized to occur in the lower brain structures, but one may assume that the efferent output to the muscle should be guided by the motor and pre-motor cortex alongside other associated cortical areas.