Sport activity in adolescence: associations with health perceptions and experimental behaviours

Despite the relevance of this research topic from a public health perspective, there is currently a lack of objective data on European adolescents' sport activity, notably the associations between their sport habits and their health attitudes and behaviours, which may have important consequences both in terms of somatic (cardiovascular) health and mental health. The objective of the present study was to determine the direction and strength of the associations between the frequency of sport and health variables; in particular, perceptions of health, self image, substance use and experimental behaviours. Data were collected as part of the 1993 Swiss Multicentric Adolescent Survey on Health. In this survey, anonymous self-administered questionnaires were distributed to a national representative sample of 10 000 in-school adolescents (15-20 years of age). Univariate analyses explored the relationships between the level of sport activity and health variables; then logistic regression analyses examined the strength of these relationships. According to the results, half of the sample do sports more than twice a week, boys more often as part of a sports club. Differences between non-athletic and athletic adolescents describe the latter as having less somatic complaints, more confidence in their future health, a better body image, a lesser tendency to attempt suicide, a higher frequency of use of the car seat belt, and a lower use of tobacco, wine and marijuana. Links between the frequency of sport activity and the locus of control related to health, general satisfaction with life or sexual behaviours are less strong. It must be noticed that the cross-sectional data collection precludes the establishment of a causal relationship between exercise and health behaviours. However, the existing links underline the coexistence of positive health characteristics and sport activity, suggesting that an incitement to get involved in physical activity may be a necessary component of a comprehensive prevention approach among adolescent

Protective effect of tomato-oleoresin supplementation on oxidative injury recoveries cardiac function by improving β-adrenergic response in a diet-obesity induced model

The system redox imbalance is one of the pathways related to obesity-related cardiac dysfunction. Lycopene is considered one of the best antioxidants. The aim of this study was to test if the tomato-oleoresin would be able to recovery cardiac function by improving \u3b2-adrenergic response due its antioxidant effect. A total of 40 animals were randomly divided into two experimental groups to receive either the control diet (Control, n = 20) or a high sugar-fat diet (HSF, n = 20) for 20 weeks. Once cardiac dysfunction was detected by echocardiogram in the HSF group, animals were re- divided to begin the treatment with Tomato-oleoresin or vehicle, performing four groups: Control (n = 6); (Control + Ly, n = 6); HSF (n = 6) and (HSF + Ly, n = 6). Tomato oleoresin (10 mg lycopene/kg body weight (BW) per day) was given orally every morning for a 10-week period. The analysis included nutritional and plasma biochemical parameters, systolic blood pressure, oxidative parameters in plasma, heart, and cardiac analyses in vivo and in vitro. A comparison among the groups was performed by two-way analysis of variance (ANOVA). Results: The HSF diet was able to induce obesity, insulin-resistance, cardiac dysfunction, and oxidative damage. However, the tomato-oleoresin supplementation improved insulin-resistance, cardiac remodeling, and dysfunction by improving the \u3b2-adrenergic response. It is possible to conclude that tomato-oleoresin is able to reduce the oxidative damage by improving the system\u2019s \u3b2-adrenergic response, thus recovering cardiac function

Sport activity in adolescence: associations with health perceptions and experimental behaviours

Despite the relevance of this research topic from a public health perspective, there is currently a lack of objective data on European adolescents' sport activity, notably the associations between their sport habits and their health attitudes and behaviours, which may have important consequences both in terms of somatic (cardiovascular) health and mental health. The objective of the present study was to determine the direction and strength of the associations between the frequency of sport and health variables; in particular, perceptions of health, self image, substance use and experimental behaviours. Data were collected as part of the 1993 Swiss Multicentric Adolescent Survey on Health. In this survey, anonymous self-administered questionnaires were distributed to a national representative sample of 10,000 in-school adolescents (15-20 years of age). Univariate analyses explored the relationships between the level of sport activity and health variables; then logistic regression analyses examined the strength of these relationships. According to the results, half of the sample do sports more than twice a week, boys more often as part of a sports club. Differences between non-athletic and athletic adolescents describe the latter as having less somatic complaints, more confidence in their future health, a better body image, a lesser tendency to attempt suicide, a higher frequency of use of the car seat belt, and a lower use of tobacco, wine and marijuana. Links between the frequency of sport activity and the locus of control related to health, general satisfaction with life or sexual behaviours are less strong. It must be noticed that the cross-sectional data collection precludes the establishment of a causal relationship between exercise and health behaviours. However, the existing links underline the coexistence of positive health characteristics and sport activity, suggesting that an incitement to get involved in physical activity may be a necessary component of a comprehensive prevention approach among adolescents

Experimental investigation of the influence of supply temperature and supply pressure on the performance of a two axial groove hydrodynamic journal bearing

An experimental study of the influence of oil supply temperature and supply pressure on the performance of a 100mm plain journal bearing with two axial grooves located at ±90º to the load line was carried out. The hydrodynamic pressure at the mid-plane of the bearing, temperature profiles at the oil-bush and oil-shaft interfaces, bush torque, oil flow rate, and the position of the shaft were measured for variable operating conditions. Shaft rotational speed ranged from 1000 to 4000rpm and two different values of applied load were tested (2kN and 10kN). The supply temperature ranged from 35 to 50ºC, whereas the oil supply pressure range was 70kPa to 210kPa. Bearing performance is strongly dependent on the supply conditions. It was found that the existence of the downstream groove significantly affects the temperature profile at the oil-bush interface except for the low load, low feeding pressure cases, where the cooling effect of the upstream groove is significant. Feeding temperature has a strong effect on the minimum film thickness. The increase in maximum temperature is significantly lower than the corresponding increase in supply temperature. Increases in supply pressure lead to a significant rise in oil flow rate but have little effect on the maximum temperature and power-loss, except in the case of the lightly-loaded bearing. Shaft temperature was found to be close to the bearing maximum temperature for low applied loads, being significantly smaller than this value for high loads. The mean shaft temperature is only significantly higher than the outlet temperature at high shaft speeds

GSK-3β Function in Bone Regulates Skeletal Development, Whole-Body Metabolism, and Male Life Span

Glycogen synthase kinase 3 β (GSK-3β) is an essential negative regulator or “brake” on many anabolic-signaling pathways including Wnt and insulin. Global deletion of GSK-3β results in perinatal lethality and various skeletal defects. The goal of our research was to determine GSK-3β cell-autonomous effects and postnatal roles in the skeleton. We used the 3.6-kb Col1a1 promoter to inactivate the Gsk3b gene (Col1a1-Gsk3b knockout) in skeletal cells. Mutant mice exhibit decreased body fat and postnatal bone growth, as well as delayed development of several skeletal elements. Surprisingly, the mutant mice display decreased circulating glucose and insulin levels despite normal expression of GSK-3β in metabolic tissues. We showed that these effects are due to an increase in global insulin sensitivity. Most of the male mutant mice died after weaning. Prior to death, blood glucose changed from low to high, suggesting a possible switch from insulin sensitivity to resistance. These male mice die with extremely large bladders that are preceded by damage to the urogenital tract, defects that are also seen type 2 diabetes. Our data suggest that skeletal-specific deletion of GSK-3β affects global metabolism and sensitizes male mice to developing type 2 diabetes. (Endocrinology 154: 3702–3718, 2013

Mouse nuclear myosin I knock-out shows interchangeability and redundancy of myosin isoforms in the cell nucleus.

Nuclear myosin I (NM1) is a nuclear isoform of the well-known "cytoplasmic" Myosin 1c protein (Myo1c). Located on the 11(th) chromosome in mice, NM1 results from an alternative start of transcription of the Myo1c gene adding an extra 16 amino acids at the N-terminus. Previous studies revealed its roles in RNA Polymerase I and RNA Polymerase II transcription, chromatin remodeling, and chromosomal movements. Its nuclear localization signal is localized in the middle of the molecule and therefore directs both Myosin 1c isoforms to the nucleus. In order to trace specific functions of the NM1 isoform, we generated mice lacking the NM1 start codon without affecting the cytoplasmic Myo1c protein. Mutant mice were analyzed in a comprehensive phenotypic screen in cooperation with the German Mouse Clinic. Strikingly, no obvious phenotype related to previously described functions has been observed. However, we found minor changes in bone mineral density and the number and size of red blood cells in knock-out mice, which are most probably not related to previously described functions of NM1 in the nucleus. In Myo1c/NM1 depleted U2OS cells, the level of Pol I transcription was restored by overexpression of shRNA-resistant mouse Myo1c. Moreover, we found Myo1c interacting with Pol II. The ratio between Myo1c and NM1 proteins were similar in the nucleus and deletion of NM1 did not cause any compensatory overexpression of Myo1c protein. We observed that Myo1c can replace NM1 in its nuclear functions. Amount of both proteins is nearly equal and NM1 knock-out does not cause any compensatory overexpression of Myo1c. We therefore suggest that both isoforms can substitute each other in nuclear processes

Forward pi^0 Production and Associated Transverse Energy Flow in Deep-Inelastic Scattering at HERA

Deep-inelastic positron-proton interactions at low values of Bjorken-x down to x \approx 4.10^-5 which give rise to high transverse momentum pi^0 mesons are studied with the H1 experiment at HERA. The inclusive cross section for pi^0 mesons produced at small angles with respect to the proton remnant (the forward region) is presented as a function of the transverse momentum and energy of the pi^0 and of the four-momentum transfer Q^2 and Bjorken-x. Measurements are also presented of the transverse energy flow in events containing a forward pi^0 meson. Hadronic final state calculations based on QCD models implementing different parton evolution schemes are confronted with the data.Comment: 27 pages, 8 figures and 3 table