Effects of Resistance Training Status on Exercise Patterns and Body Composition Among Younger and Older Adults

As individuals age, percent body fat tends to increase and lean muscle mass decreases, which may limit the ability to engage in higher intensity exercise. Moderate to vigorous physical activity has been shown to improve body composition, but it is unclear whether exercise patterns, such as amount of moderate and high intensity exercise performed, are impacted by resistance training status in younger and older adults. PURPOSE: To examine whether resistance trained and untrained younger and older adults differ on duration of high, moderate, and low intensity exercise and percent body fat (%BF). METHODS: Younger (23.8 ± 0.4 years) and older (68.5 ± 1.2 years) healthy adults were categorized into 4 groups based on resistance training status: young resistance trained (YT: n = 22), young not resistance trained (YNT: n = 16), old resistance trained (OT: n = 17), and old not resistance trained (ONT: n = 20). Resistance trained participants had been training ≥ 2X per week, for the past ≥ 6 months. Participants completed a survey to assess the intensity and duration of exercise, and a dual x-ray absorptiometry (DEXA) scan was used to determine %BF. The survey asked how many minutes/hours per week participants engaged in high intensity exercise (e.g., jogging, hiking), moderate intensity exercise (e.g., light bicycling, walking briskly), and low intensity exercise (e.g., slow walking, easy yoga). Responses were coded as 1 = none, 2 = 30-60 minutes, 3 = 1-2 hours, 4 = 2-3 hours, 5 = 3-5 hours, and 6 = more than 5 hours. ANOVAs were used to determine group differences for each variable, p ≤ 0.05. Data are reported as mean ± SE. RESULTS: Group differences emerged for high and moderate intensity exercise (p \u3c 0.05), but not for low intensity (p \u3e 0.05). For high intensity, YT (3.64 ± 0.31) was significantly higher than YNT and ONT (YNT: 1.63 ± 0.37, p \u3c 0.001; ONT: 1.55 ± 0.33, p \u3c 0.001), and OT (2.82 ± 0.36) was significantly higher than YNT and ONT (YNT: p = 0.022; ONT: p = 0.010). For moderate intensity, YT (4.91 ± 0.31) was significantly higher than YNT and ONT (YNT: 2.40 ± 0.38, p \u3c 0.001; ONT: 3.52 ± 0.32, p = 0.003), and OT (4.77 ± 0.35) was significantly greater than YNT and ONT (YNT: p \u3c 0.001; ONT: p = 0.011). Also for moderate intensity, ONT was significantly greater than YNT (p = 0.025). For %BF, YT (25.06 ± 2.1%) was significantly lower than YNT and ONT (YNT: 33.55 ± 1.87%, p = 0.001; ONT: 36.47 ± 1.28%, p \u3c 0.001), and OT (29.37 ± 1.11%) was significantly lower than ONT (p = 0.003). All other group comparisons were not different (p \u3e 0.05). CONCLUSION: The older resistance trained individuals did not differ from the younger trained participants on exercise patterns or percent body fat, suggesting the enduring positive effects of resistance training as individuals age. These resistance trained individuals also performed more moderate and high intensity exercise than non-resistance trained groups, likely contributing to their favorable body composition. Funded by Texas American College of Sports Medicine Student Research Development Award to H. Kendall, J. Mettler, and L. Kipp, and Thesis Fellowship Award to H. Kendall

Population Genetics of Bowhead Whales (Baleana mysticetus) in the Western Arctic

Bowhead whales (Balaena mysticetus) in the Bering, Chukchi, and Beaufort seas experienced a severe reduction as a result of commercial whaling in the 19th century. Since the cessation of commercial whaling, the population has recovered to a size that is approaching pre-whaling estimates. Inupiat and Yupik communities in northern and western Alaska hunt these Western Arctic (WA) bowheads along their migratory path during spring and fall. This hunting is regulated by the International Whaling Commission. Recent but preliminary analysis of available genetic data (207 whales and 10 microsatellite markers) raised the question of the presence of multiple, genetically distinct populations within the WA bowheads. Here we re-examined this question on the basis of a study of 414 whales and 22 newly developed microsatellite loci. We identified widespread departures from Hardy-Weinberg equilibrium; however, we were unable to detect significant evidence of multiple genetic populations within the WA bowheads that could explain this Hardy-Weinberg disequilibrium, particularly when compared to the strength of evidence for differentiation between WA bowheads and other populations from distant regions such as the Okhotsk Sea and eastern Canada. There was conclusive evidence of genetic differentiation among the three regions. The statistical rejection of panmixia within the WA improves our understanding of bowhead whale biology, and the lack of evidence for multiple populations within the WA enables risk-averse management of aboriginal hunting of Western Arctic bowhead whales.La population de baleines boréales (Balaena mysticetus) des mers de Béring, de Tchoukotka et de Beaufort a enregistré un grave déclin en raison de la pêche commerciale à la baleine au XIXe siècle. Depuis que la pêche commerciale à la baleine a cessé, la population de baleines boréales a connu un certain essor au point où elle approche maintenant les estimations de la taille qu’elle avait avant la pêche commerciale à la baleine. Les collectivités Inupiat et Yupik du nord et de l’ouest de l’Alaska chassent les baleines boréales de l’ouest de l’Arctique le long de leur voie de migration au printemps et à l’automne. La chasse est réglementée par l’International Whaling Commission. Des analyses récentes, bien que préliminaires, des données génétiques disponibles (207 baleines et 10 marqueurs microsatellites) ont soulevé la question de la présence de multiples populations génétiquement distinctes au sein de la population de baleines boréales de l’ouest de l’Alaska. Ici, nous avons réexaminé cette question en fonction de l’étude de 414 baleines et de 22 locis microsatellites nouvellement mis au point. Nous avons remarqué d’importantes déviations de l’équilibre de Hardy-Weinberg; toutefois, nous n’avons pas pu trouver de preuve significative de populations génétiques multiples au sein des baleines boréales de l’ouest de l’Alaska qui pourrait expliquer ce déséquilibre de Hardy-Weinberg, plus particulièrement en comparaison avec la force de la preuve de différenciation entre les baleines boréales de l’ouest de l’Arctique et d’autres populations de régions distantes telles que la mer d’Okhotsk et l’est du Canada. Il y avait des preuves concluantes de différenciation génétique entre les trois régions. Le rejet statistique de la panmixie au sein de l’ouest de l’Arctique améliore notre compréhension de la biologie des baleines boréales, et le manque de preuves de populations multiples dans l’ouest de l’Arctique donne lieu à la gestion de l’aversion au risque de la chasse à la baleine boréale de l’ouest de l’Arctique par les Autochtones

Hypertension in mice lacking 11beta-hydroxysteroid dehydrogenase type 2

Deficiency of 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) in humans leads to the syndrome of apparent mineralocorticoid excess (SAME), in which cortisol illicitly occupies mineralocorticoid receptors, causing sodium retention, hypokalemia, and hypertension. However, the disorder is usually incompletely corrected by suppression of cortisol, suggesting additional and irreversible changes, perhaps in the kidney. To examine this further, we produced mice with targeted disruption of the 11β-HSD2 gene. Homozygous mutant mice (11β-HSD2(–/–)) appear normal at birth, but ∼50% show motor weakness and die within 48 hours. Both male and female survivors are fertile but exhibit hypokalemia, hypotonic polyuria, and apparent mineralocorticoid activity of corticosterone. Young adult 11β-HSD2(–/–) mice are markedly hypertensive, with a mean arterial blood pressure of 146 ± 2 mmHg, compared with 121 ± 2 mmHg in wild-type controls and 114 ± 4 mmHg in heterozygotes. The epithelium of the distal tubule of the nephron shows striking hypertrophy and hyperplasia. These histological changes do not readily reverse with mineralocorticoid receptor antagonism in adulthood. Thus, 11β-HSD2(–/–) mice demonstrate the major features of SAME, providing a unique rodent model to study the molecular mechanisms of kidney resetting leading to hypertension. J. Clin. Invest. 103:683–689 (1999

Artificial drainage of peatlands: hydrological and hydrochemical process and wetland restoration

Peatlands have been subject to artificial drainage for centuries. This drainage has been in response to agricultural demand, forestry, horticultural and energy properties of peat and alleviation of flood risk. However, the are several environmental problems associated with drainage of peatlands. This paper describes the nature of these problems and examines the evidence for changes in hydrological and hydrochemical processes associated with these changes. Traditional black-box water balance approaches demonstrate little about wetland dynamics and therefore the science of catchment response to peat drainage is poorly understood. It is crucial that a more process-based approach be adopted within peatland ecosystems. The environmental problems associated with peat drainage have led, in part, to a recent reversal in attitudes to peatlands and we have seen a move towards wetland restoration. However, a detailed understanding of hydrological, hydrochemical and ecological process-interactions will be fundamental if we are to adequately restore degraded peatlands, preserve those that are still intact and understand the impacts of such management actions at the catchment scale

Bibliometric Evidence for a Hierarchy of the Sciences

The hypothesis of a Hierarchy of the Sciences, first formulated in the 19(th) century, predicts that, moving from simple and general phenomena (e.g. particle dynamics) to complex and particular (e.g. human behaviour), researchers lose ability to reach theoretical and methodological consensus. This hypothesis places each field of research along a continuum of complexity and "softness", with profound implications for our understanding of scientific knowledge. Today, however, the idea is still unproven and philosophically overlooked, too often confused with simplistic dichotomies that contrast natural and social sciences, or science and the humanities. Empirical tests of the hypothesis have usually compared few fields and this, combined with other limitations, makes their results contradictory and inconclusive. We verified whether discipline characteristics reflect a hierarchy, a dichotomy or neither, by sampling nearly 29,000 papers published contemporaneously in 12 disciplines and measuring a set of parameters hypothesised to reflect theoretical and methodological consensus. The biological sciences had in most cases intermediate values between the physical and the social, with bio-molecular disciplines appearing harder than zoology, botany or ecology. In multivariable analyses, most of these parameters were independent predictors of the hierarchy, even when mathematics and the humanities were included. These results support a "gradualist" view of scientific knowledge, suggesting that the Hierarchy of the Sciences provides the best rational framework to understand disciplines' diversity. A deeper grasp of the relationship between subject matter's complexity and consensus could have profound implications for how we interpret, publish, popularize and administer scientific research

Addressing the environmental, community and health impacts of resource development: Challenges across scales, sectors and sites

Work that addresses the cumulative impacts of resource extraction on environment, community, and health is necessarily large in scope. This paper presents experiences from initiating research at this intersection and explores implications for the ambitious, integrative agenda of planetary health. The purpose is to outline origins, design features, and preliminary insights from our intersectoral and international project, based in Canada and titled the “Environment, Community, Health Observatory” (ECHO) Network. With a clear emphasis on rural, remote, and Indigenous communities, environments, and health, the ECHO Network is designed to answer the question: How can an Environment, Community, Health Observatory Network support the integrative tools and processes required to improve understanding and response to the cumulative health impacts of resource development? The Network is informed by four regional cases across Canada where we employ a framework and an approach grounded in observation, “taking notice for action”, and collective learning. Sharing insights from the foundational phase of this five-year project, we reflect on the hidden and obvious challenges of working across scales, sectors, and sites, and the overlap of generative and uncomfortable entanglements associated with health and resource development. Yet, although intersectoral work addressing the cumulative impacts of resource extraction presents uncertainty and unresolved tensions, ultimately we argue that it is worth staying with the trouble

Quantum Tunneling in Nuclear Fusion

Recent theoretical advances in the study of heavy ion fusion reactions below the Coulomb barrier are reviewed. Particular emphasis is given to new ways of analyzing data, such as studying barrier distributions; new approaches to channel coupling, such as the path integral and Green function formalisms; and alternative methods to describe nuclear structure effects, such as those using the Interacting Boson Model. The roles of nucleon transfer, asymmetry effects, higher-order couplings, and shape-phase transitions are elucidated. The current status of the fusion of unstable nuclei and very massive systems are briefly discussed.Comment: To appear in the January 1998 issue of Reviews of Modern Physics. 13 Figures (postscript file for Figure 6 is not available; a hard copy can be requested from the authors). Full text and figures are also available at http://nucth.physics.wisc.edu/preprints

Addressing the environmental, community and health impacts of resource development: Challenges across scales, sectors and sites

Work that addresses the cumulative impacts of resource extraction on environment, community, and health is necessarily large in scope. This paper presents experiences from initiating research at this intersection and explores implications for the ambitious, integrative agenda of planetary health. The purpose is to outline origins, design features, and preliminary insights from our intersectoral and international project, based in Canada and titled the “Environment, Community, Health Observatory” (ECHO) Network. With a clear emphasis on rural, remote, and Indigenous communities, environments, and health, the ECHO Network is designed to answer the question: How can an Environment, Community, Health Observatory Network support the integrative tools and processes required to improve understanding and response to the cumulative health impacts of resource development? The Network is informed by four regional cases across Canada where we employ a framework and an approach grounded in observation, “taking notice for action”, and collective learning. Sharing insights from the foundational phase of this five-year project, we reflect on the hidden and obvious challenges of working across scales, sectors, and sites, and the overlap of generative and uncomfortable entanglements associated with health and resource development. Yet, although intersectoral work addressing the cumulative impacts of resource extraction presents uncertainty and unresolved tensions, ultimately we argue that it is worth staying with the trouble

Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics

A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based on simulations of the detector and physics processes, with particular emphasis given to the data expected from the first years of operation of the LHC at CERN