Physical activity intensity and surrogate markers for cardiovascular health in adolescents

We examined the impact of physical activity (PA) on surrogate markers of cardiovascular health in adolescents. 52 healthy students (28 females, mean age 14.5±0.7years) were investigated. Microvascular endothelial function was assessed by peripheral arterial tonometry to determine reactive hyperemic index (RHI). Vagal activity was measured using 24h analysis of heart rate variability [root mean square of successive normal-to-normal intervals (rMSSD)]. Exercise testing was performed to determine peak oxygen uptake ( $$\dot{V}{\text{O}}_{{2{\text{ peak}}}}$$ ) and maximum power output. PA was assessed by accelerometry. Linear regression models were performed and adjusted for age, sex, skinfolds, and pubertal status. The cohort was dichotomized into two equally sized activity groups (low vs. high) based on the daily time spent in moderate-to-vigorous PA (MVPA, 3,000-5,200 counts.min−1, model 1) and vigorous PA (VPA, >5,200 counts.min−1, model 2). MVPA was an independent predictor for rMSSD (β=0.448, P=0.010), and VPA was associated with maximum power output (β=0.248, P=0.016). In model 1, the high MVPA group exhibited a higher vagal tone (rMSSD 49.2±13.6 vs. 38.1±11.7ms, P=0.006) and a lower systolic blood pressure (107.3±9.9 vs. 112.9±8.1mmHg, P=0.046). In model 2, the high VPA group had higher maximum power output values (3.9±0.5 vs. 3.4±0.5 Wkg−1, P=0.012). In both models, no significant differences were observed for RHI and $$\dot{V}{\text{O}}_{{ 2 {\text{ peak}}}}$$ . In conclusion, in healthy adolescents, PA was associated with beneficial intensity-dependent effects on vagal tone, systolic blood pressure, and exercise capacity, but not on microvascular endothelial functio

CFTR genotype and maximal exercise capacity in cystic fibrosis: a cross-sectional study

RATIONALE: Cystic fibrosis transmembrane conductance regulator (CFTR) is expressed in human skeletal muscle cells. Variations of CFTR dysfunction among patients with CF may present an important determinant of aerobic exercise capacity in CF. Previous studies on the relationship between CFTR genotype and aerobic exercise capacity are scarce and contradictory. OBJECTIVES: This study was designed to explore factors influencing aerobic exercise capacity, expressed as peak oxygen consumption (VO2peak) with a specific focus on CFTR genotype in children and adults with CF. METHODS: In an international, multicenter cross-sectional study we collected data on CFTR genotype and cardiopulmonary exercise tests (CPET) in patients with CF eight years and older. CFTR mutations were classified into functional classes I-V. RESULTS: The final analysis included 726 patients (45% females, age 8 to 61 years, FEV1 16 to 123 % predicted) from 17 CF centers in North America, Europe, Australia and Asia whom all had both valid maximal CPET and complete CFTR genotype data. Overall, patients exhibited exercise intolerance (VO2peak, 77.3±19.1 % predicted), but values were comparable among different CFTR classes. Using linear regression analysis adjusted for relevant confounders, lung function and body mass index, but not CFTR genotype were the main predictors of VO2peak. CONCLUSIONS: We conclude that lung disease severity and reduced nutritional status rather than CFTR genotypes are the major determinants of aerobic exercise capacity in patients with CF

Training-related modulations of the autonomic nervous system in endurance athletes: is female gender cardioprotective?

The risk of sudden death is increased in athletes with a male predominance. Regular physical activity increases vagal tone, and may protect against exercise-induced ventricular arrhythmias. We investigated training-related modulations of the autonomic nervous system in female and male endurance athletes. Runners of a 10-mile race were invited. Of 873 applicants, 68 female and 70 male athletes were randomly selected and stratified according to their average weekly training hours in a low (≤4h) and high (>4h) volume training group. Analysis of heart rate variability was performed over 24h. Spectral components (high frequency [HF] and low frequency [LF] power in normalized units) were analyzed for hourly 5min segments and averaged for day- and nighttime. One hundred and fourteen athletes (50% female, mean age 42±7years) were included. No significant gender difference was observed for training volume and 10-mile race time. Over the 24-h period, female athletes exhibited a higher HF and lower LF power for each hourly time-point. Female gender and endurance training hours were independent predictors of a higher HF and lower LF power. In female athletes, higher training hours were associated with a higher HF and lower LF power during nighttime. In male athletes, the same was true during daytime. In conclusion, female and male athletes showed a different circadian pattern of the training-related increase in markers of vagal tone. For a comparable amount of training volume, female athletes maintained their higher markers of vagal tone, possibly indicating a superior protection against exercise-induced ventricular arrhythmia

Lutheran Day School Operation: Financial Stewardship Implications

In addressing this problem as it faces Trinity Lutheran Church, the writer will survey other schools and determine the method that each congregation uses to fund the operation of its day school. My premise from the outset is that some of these day schools use the traditional means of funding through congregational offerings while others use member tuition as a major factor in the funding of their day schools. The purpose of this exercise is to evaluate the methods used and make application to Trinity for the best method of funding their day school operation

Dictators, Ministerial Cronyism, and International Conflict

My dissertation examines an underexplored actor on the world stage: the personalist dictator. Personalist dictators are leaders that have consolidated all domestic power for themselves. Idi Amin, Joseph Stalin, Saddam Hussein, Pol Pot, and Benito Mussolini are all examples of these heads of states. Their names often live in infamy, etched in the history books with the blood they spilt. Although these regimes are usually remembered for the violence they exhibited within their own regimes, recent studies have found that these leaders also show a proclivity for conflict at the international level. In this dissertation, I ask, “Why are personalist dictators so conflict-prone?" To answer this question, I show how domestic institutions vary across autocracies in response to leaders’ incentives and how this variation can be used to explain the propensity of international conflict. In particular, I investigate the role that advisers play in conflict occurrence and outcomes. Often, leaders rely on individuals, such as defense ministers, to give them assessments on the potential outcomes of conflicts. Little attention has been paid to the effects these ministers have. However, if we believe that war may be the product of miscalculation of capabilities or resolve, then we might expect that states with less capable advisers are more likely to experience international conflict. Using this logic, I argue that personalist dictators are more likely to experience conflict, because they are more prone to employ incompetent advisers and ministers. My theoretical argument starts with the assumption that personalist dictators live in constant fear of being overthrown. In comparison to other leaders, the despot can expect that his removal will more likely end in a negative post-tenure fate: exile, imprisonment, or death. The reason for this propensity is that a personalist leader’s legitimacy is uniquely tied to personal traits. So long as the despot is living, he poses a threat to his successors. The extreme costs for removal and the proximity of the likely culprits result in the dictator’s regime being characterized by paranoia and mistrust. In order to protect himself, the personalist dictator surrounds himself with small, exclusive circles of crony advisers whose loyalty is ensured through bloodlines or long-standing friendships. In utilizing this lever, the dictator trades bureaucratic independence and competence for loyalty and survival. This loyalty-competency tradeoff results in a personalist leader’s inability to get accurate and honest assessments of his opponents from these advisers, making him more likely to underestimate his opponents, experience war (particularly ones in which his state is the weaker party), and incur worse conflict outcomes. After constructing an original cross-national dataset of over 1500 defense ministers from 1945 to 2005, and performing in-depth examinations of the Gamal Abdel Nasser and Saddam Hussein regimes, I provide evidence that personalist leaders are more likely to place cronies in advisory positions, and these advisers undermine the ability for personalist leaders to form accurate war-time assessments, leading to bargaining breakdowns, and subsequently, war

Notch ligation by Delta1 inhibits peripheral immune responses to transplantation antigens by a CD8⁺ cell–dependent mechanism

Notch signaling plays a fundamental role in determining the outcome of differentiation processes in many tissues. Notch signaling has been implicated in T versus B cell lineage commitment, thymic differentiation, and bone marrow hematopoietic precursor renewal and differentiation. Notch receptors and their ligands are also expressed on the surface of mature lymphocytes and APCs, but the effects of Notch signaling in the peripheral immune system remain poorly defined. The aim of the studies reported here was to investigate the effects of signaling through the Notch receptor using a ligand of the Delta-like family. We show that Notch ligation in the mature immune system markedly decreases responses to transplantation antigens. Constitutive expression of Delta-like 1 on alloantigen-bearing cells renders them nonimmunogenic and able to induce specific unresponsiveness to a challenge with the same alloantigen, even in the form of a cardiac allograft. These effects could be reversed by depletion of CD8⁺ cells at the time of transplantation. Ligation of Notch on splenic CD8⁺ cells results in a dramatic decrease in IFN-γ with a concomitant enhancement of IL-10 production, suggesting that Notch signaling can alter the differentiation potential of CD8⁺ cells. These data implicate Notch signaling in regulation of peripheral immunity and suggest a novel approach for manipulating deleterious immune responses

Regional sociocultural differences as important correlate of physical activity and sedentary behaviour in Swiss preschool children

Regional differences in physical activity in school-aged children and adults even within one country with the same political and health care system have been observed and could not be explained by sociodemographic or individual variables. We analysed whether such differences were already present in preschool children.; Swiss children from 84 childcare centres in five cantons (Aargau, Bern, Fribourg, Vaud, Zurich) comprising about 50% of the population of the country participated. Physical activity was quantified with accelerometers (ActiGraph, wGT3X-BT) and potential correlates were assessed with measurements at the childcare centre or questionnaires. Mixed regression models were used to test associations between potential correlates of total physical activity (TPA), moderate-to-vigorous physical activity (MVPA), light physical activity (LPA) or sedentary behaviour with a special focus on regional differences.; 394 of 476 children (83%) provided valid physical activity data (at least 2 weekdays and 1 weekend day with 10 h recording; mean age 3.9 ± 0.7 years, 54% boys) with 26% and 74% living in the French- and German-speaking parts of Switzerland, respectively. Days consisted of (mean ± standard deviation) 1.5 ± 0.5 h MVPA, 5.0 ± 0.6 h LPA, and 6.3 ± 0.8 h sedentary behaviour with an average of 624 ± 150 counts/min TPA. TPA and MVPA (but not sedentary behaviour or LPA) increased with age, were higher in boys and children with better motor skills. Despite controlling for individual characteristics, familial factors and childcare exposure, children from the French-speaking part of Switzerland showed 13% less TPA, 14% less MVPA, 6% less LPA and 8% more sedentary behaviour than German-speaking children.; Beside motor skills and non-modifiable individual factors, the regional sociocultural difference was the most important correlate of phyical activity and sedentary behaviour. Therefore, regionally adapted public health strategies may be needed