Accuracy of the Cosmed K5 portable calorimeter

Purpose The purpose of this study was to assess the accuracy of the Cosmed K5 portable metabolic system dynamic mixing chamber (MC) and breath-by-breath (BxB) modes against the criterion Douglas bag (DB) method. Methods Fifteen participants (mean age±SD, 30.6±7.4 yrs) had their metabolic variables measured at rest and during cycling at 50, 100, 150, 200, and 250W. During each stage, participants were connected to the first respiratory gas collection method (randomized) for the first four minutes to reach steady state, followed by 3-min (or 5-min for DB) collection periods for the resting condition, and 2-min collection periods for all cycling intensities. Collection periods for the second and third methods were preceded by a washout of 1–3 min. Repeated measures ANOVAs were used to compare metabolic variables measured by each method, for seated rest and each cycling work rate. Results For ventilation (VE) and oxygen uptake (VO2), the K5 MC and BxB modes were within 2.1 l/min (VE) and 0.08 l/min (VO2) of the DB (p≥0.05). Compared to DB values, carbon dioxide production (VCO2) was significantly underestimated by the K5 BxB mode at work rates ≥150W by 0.12–0.31 l/min (p\u3c0.05). K5 MC and BxB respiratory exchange ratio values were significantly lower than DB at cycling work rates ≥100W by 0.03–0.08 (p\u3c0.05). Conclusion Compared to the DB method, the K5 MC and BxB modes are acceptable for measuring VE and VO2 across a wide range of cycling intensities. Both K5 modes provided comparable values to each other

Exaggerated blood pressure response to maximal exercise in endurance-trained individuals

D ue to the fact that hypertension is a major health problem in the United States, the early detection and treatment of hypertension is a topic of paramount importance. Recent studies 2-4have suggested that an exaggerated blood pressure response to maximal exercise may be useful in detecting persons who are prone to developing hypertension in later years. Jette et a12reviewed the literature and concluded that hyperresponders face a 2-to 10-fold greater likelihood of developing future hypertension. In addition, several groups at risk for hypertension, including African-Americans, borderline hypertensives, and individuals with a parental history of hypertension, have been shown to exhibit this type of response.2J5It is possible that by observing the cardiovascular system's response to exercise, one may uncover latent tendencies towards hypertension that are not evident at rest. Unfortunately, few studies have examined the maximal blood pressure response to exercise in trained and untrained individuals. An early study by Ekblom et al('found that after 16 weeks of endurance training, NOVEMBER 1996-VOL. 9, NO. 11, PART 1 there was a 20 mm Hg increase in maximal systolic blood pressure in a group of eight subjects. Similarly, a subsequent study7 reported that trained individuals had higher maximal blood pressure values than untrained subjects. However, other researchers have reported no difference in the maximal blood pressure response before and after endurance trainingx and between trained and untrained subjects.g Thus, the role of training state in determining the blood pressure response to dynamic exercise remains controversial. If endurance-trained persons show an exaggerated blood pressure response to exercise, as preliminary studies suggest, '-s it would have important implications. Since it is well established that aerobic training reduces the risk of developing hypertension, '[" this finding would indicate that an exaggerated blood pressure response is not a valid prognostic test to indicate the likelihood of future hypertension in this population. Therefore, the purpose of this study is to compare the blood pressure responses to a maximal, graded exercise test between trained and untrained subjects. We hypothesized that physically-active subjects would demonstrate a smaller blood pressure response to maximal exercise than inactive subjects. METHODS Subjects The subjects for this study were 31 (27 men and 4 women) untrained subjects and 26 (22 men and 4 women) well-trained endurance athletes. All subjects were normotensive (blood pressure < 140/90 mm Hg) and were free of overt cardiovascular disease. None of the subjects was a smoker and was taking any medication. Endurance-trained athletes were either competitive runners, road cyclists, or triathletes, and had been training a minimum of 2 years prior to the study. Untrained subjects had not engaged in any regular exercise programs in the preceding year. Following a verbal and written explanation of the procedures and potential risks involved in this study, subjects signed an informed consent approved by the Institutional Review Board. Additionally, subjects were requested to complete a questionnaire on parental history of hypertension.1' Body composition was evaluated from the threesite skinfold thickness method.12Percent body fat ('ZO Fat) and lean body mass (LBM) were subsequently estimated from the sum of the skinfold measurements. Physical characteristics of the subjects are presented in Testing Procedures Prior to the testing,subjectswere familiarized with the exercise protocol. Subjects refrained from food intake and caffeinatedand alcoholic beverages for at least 4 h prior to the tests. A stationary pendulum-style cycle ergometer (Model 868, Monark, Sweden) was used for the maximum oxygen uptake (~Oz max) tests. The cycle ergometer was chosen in a

Physical activity profile of old order Amish, Mennonite, and contemporary children

Purpose: This study explored the influence of modernity on the physical activity behaviors (e.g., intensity and timing) of children. Methods: Children aged 8-13 yr living a traditional lifestyle (Old Order Amish [OOA], n = 68; Old Order Mennonite [OOM], n = 120) were compared with children living a contemporary lifestyle (rural Saskatchewan [RSK], n = 132; urban Saskatchewan [USK], n = 93). Physical activity was objectively assessed for seven consecutive days using Actigraph 7164 accelerometers. Custom software was used to reduce the raw accelerometer data into standardized outcome variables. Results: On weekdays, there were group differences in moderate physical activity between all lifestyle groups (OOA > OOM > USK > RSK). On the weekend, the group differences in moderate physical activity persisted between, but not within, lifestyle groups (OOA = OOM > USK = RSK). During school hours, all groups had similar activity and inactivity periods; however, they differed in magnitude, with the OOA and OOM being both more sedentary and more active. In comparison with the children in school, the OOA and the OOM children had 44% lower sedentary time out of school compared with only 15% lower for RSK and USK children. Conclusions: Although cross sectional, these data suggest that contemporary/modern living is associated with lower levels of moderate-and vigorous-intensity physical activity compared with lifestyles representative of earlier generations. Analyzing the physical activity and inactivity patterns of traditional lifestyle groups such as the OOA and the OOM can provide valuable insight into the quantity and quality of physical activity necessary to promote health. Copyright © 2010 by the American College of Sports Medicine

Effect of exercise training on glucose tolerance, in vivo insulin sensitivity, lipid and liproprotein concentrations in middle-aged men with mild hypertriglyceridemia

The effects of 9 weeks of aerobic exercise training with maintenance of stable body weight upon insulin sensitivity and upon glucose, lipid, and lipoprotein concentrations were studied in 10 middle-aged men with mild hypertriglyceridemia. Following training, mean maximum oxygen consumption improved from 33.5 +/- 1.9 to 39.3 +/- 1.9 mL/kg/min ( +/- SEM), (P P P P P P 2. Serum cholesterol levels declined from 211 +/- 8.9 to 193 +/- 11.9 mg/dL (P < 0.01), and the ratio of HDL-cholesterol to total cholesterol was improved. This study demonstrates that exercise training at a level of intensity feasible for many middle-aged men has beneficial effects on several factors that have been associated with an increased risk of cardiovascular disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25746/1/0000306.pd

Wing pathology of white-nose syndrome in bats suggests life-threatening disruption of physiology

White-nose syndrome (WNS) is causing unprecedented declines in several species of North American bats. The characteristic lesions of WNS are caused by the fungus Geomyces destructans, which erodes and replaces the living skin of bats while they hibernate. It is unknown how this infection kills the bats. We review here the unique physiological importance of wings to hibernating bats in relation to the damage caused by G. destructans and propose that mortality is caused by catastrophic disruption of wing-dependent physiological functions. Mechanisms of disease associated with G. destructans seem specific to hibernating bats and are most analogous to disease caused by chytrid fungus in amphibians

Making Connections - Envisioning Springfield\u27s North End

This work explores a service learning strategy in the context of the senior Urban Design Studio taught in the Department of Landscape Architecture and Regional Planning at the University of Massachusetts Amherst. The primary goal of this project is to stimulate a conversation in the neighborhoods of the North End, to develop green design strategies, to improve services and businesses for residents and the employees of local businesses, and to foster cultural engagement and interaction in the North End that will enhance the vibrancy, resilience, and quality of life of this urban community. Making connections - Envisioning Springfield\u27s North End proposes improved connectivity in a physical, cultural, and social sense will be key to attaining these goals and to engaging and synergizing individuals and community groups in the North End - residents, businesses, schools, churches, employers, and employees. Six sustainable learning and planning principles have emerged from this studio: 1. Input and interaction – Visioning workshops connect campus and community 2. Community-building art - Expression of place and people 3. Healthy living - Urban agriculture and education 4. Urban greenways – Abandoned railways and urban rivers and streams 5. Green infrastructure - Green streets as networks and structural framework 6. Sustainable urban form – Mixed use and pedestrian friendly neighborhood

Acoustic-Friction Networks and the Evolution of Precursory Rupture Fronts in Laboratory Earthquakes

We show that the mesoscopic and transport characteristics of networks follow the same trends for the same type of the shear ruptures in terms of rupture speed while also comparing the results of three different friction experiments.The classified fronts obtained from a saw cut Westerly granite fault regarding friction network parameters show a clear separation into two groups indicating two different rupture fronts. With respect to the scaling of local ruptures durations with the networks parameters we show that the gap is related to the possibility of a separation between slow and regular fronts

Driving and Driven Architectures of Directed Small-World Human Brain Functional Networks

Recently, increasing attention has been focused on the investigation of the human brain connectome that describes the patterns of structural and functional connectivity networks of the human brain. Many studies of the human connectome have demonstrated that the brain network follows a small-world topology with an intrinsically cohesive modular structure and includes several network hubs in the medial parietal regions. However, most of these studies have only focused on undirected connections between regions in which the directions of information flow are not taken into account. How the brain regions causally influence each other and how the directed network of human brain is topologically organized remain largely unknown. Here, we applied linear multivariate Granger causality analysis (GCA) and graph theoretical approaches to a resting-state functional MRI dataset with a large cohort of young healthy participants (n = 86) to explore connectivity patterns of the population-based whole-brain functional directed network. This directed brain network exhibited prominent small-world properties, which obviously improved previous results of functional MRI studies showing weak small-world properties in the directed brain networks in terms of a kernel-based GCA and individual analysis. This brain network also showed significant modular structures associated with 5 well known subsystems: fronto-parietal, visual, paralimbic/limbic, subcortical and primary systems. Importantly, we identified several driving hubs predominantly located in the components of the attentional network (e.g., the inferior frontal gyrus, supplementary motor area, insula and fusiform gyrus) and several driven hubs predominantly located in the components of the default mode network (e.g., the precuneus, posterior cingulate gyrus, medial prefrontal cortex and inferior parietal lobule). Further split-half analyses indicated that our results were highly reproducible between two independent subgroups. The current study demonstrated the directions of spontaneous information flow and causal influences in the directed brain networks, thus providing new insights into our understanding of human brain functional connectome

An Estimate of the Incidence of Prostate Cancer in Africa: A Systematic Review and Meta-Analysis

Prostate cancer (PCa) is rated the second most common cancer and sixth leading cause of cancer deaths among men globally. Reports show that African men suffer disproportionately from PCa compared to men from other parts of the world. It is still quite difficult to accurately describe the burden of PCa in Africa due to poor cancer registration systems.We systematically reviewed the literature on prostate cancer in Africa and provided a continentwide incidence rate of PCa based on available data in the regio