1,296 research outputs found
Effects of sitting on the respiratory pattern, mechanics and work of breathing in mechanically ventilated patients
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
Dynamics of aerosol size during inhalation : Hygroscopic growth of commercial nebulizer formulations
We thank the Elizabeth Blackwell Institute (EBI) for financial support through the EBI Early Career Research Fellowship awarded to AEH, and the EPSRC for financial support through a Leadership Fellowship awarded to JPR (grant reference EP/G007713/1). This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are creditedThe size of aerosol particles prior to, and during, inhalation influences the site of deposition within the lung. As such, a detailed understanding of the hygroscopic growth of an aerosol during inhalation is necessary to accurately model the deposited dose. In the first part of this study, it is demonstrated that the aerosol produced by a nebulizer, depending on the airflows rates, may experience a (predictable) wide range of relative humidity prior to inhalation and undergo dramatic changes in both size and solute concentration. A series of sensitive single aerosol analysis techniques are then used to make measurements of the relative humidity dependent thermodynamic equilibrium properties of aerosol generated from four common nebulizer formulations. Measurements are also reported of the kinetics of mass transport during the evaporation or condensation of water from the aerosol. Combined, these measurements allow accurate prediction of the temporal response of the aerosol size prior to and during inhalation. Specifically, we compare aerosol composed of pure saline (150 mM sodium chloride solution in ultrapure water) with two commercially available nebulizer products containing relatively low compound doses: Breath, consisting of a simple salbutamol sulfate solution (5 mg/2.5 mL; 1.7 mM) in saline, and Flixotide Nebules, consisting of a more complex stabilized fluticasone propionate suspension (0.25 mg/mL; 0.5 mM in saline. A mimic of the commercial product Tobi (60 mg/mL tobramycin and 2.25 mg/mL NaC1, pH 5.5-6.5) is also studied, which was prepared in house. In all cases, the presence of the pharmaceutical was shown to have a profound effect on the magnitude, and in some cases the rate, of the mass flux of water to and from the aerosol as compared to saline. These findings provide physical chemical evidence supporting observations from human inhalation studies, and suggest that using the growth dynamics of a pure saline aerosol in a lung inhalation model to represent nebulizer formulations may not be representative of the actual behavior of the aerosolized drug solutions. (C) 2014 Published by Elsevier B.V.Peer reviewe
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
Trials
BACKGROUND: An international workshop on population health intervention research (PHIR) was organized to foster exchanges between experts from different disciplines and different fields. This paper aims to summarize the discussions around some of the issues addressed: (1) the place of theories in PHIR, (2) why theories can be useful, and (3) how to choose and use the most relevant of them in evaluating PHIR. METHODS: The workshop included formal presentations by participants and moderated discussions. An oral synthesis was produced by a rapporteur to validate, through an expert consensus, the key points of the discussion and the recommendations. All discussions were recorded and have been fully transcribed. RESULTS: The following recommendations were generated through a consensus in the workshop discussions: (i) The evaluation of interventions, like their development, could be improved through better use of theory. (ii) The referenced theory and framework must be clarified. (iii) An intervention theory should be developed by a partnership of researchers and practitioners. (iv) More use of social theory is recommended. (v) Frameworks and a common language are helpful in selecting and communicating a theory. (vi) Better reporting of interventions and theories is needed. CONCLUSION: Theory-driven interventions and evaluations are key in PHIR as they facilitate the understanding of mechanisms of change. There are many challenges in developing the most appropriate theories for interventions and evaluations. With the wealth of information now being generated, this subject is of increasing importance at many levels, including for public health policy. It is, therefore, timely to consider how to build on the experiences of many different disciplines to enable the development of better theories and facilitate evidence-based decisions
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
Environmental quality determines finder-joiner dynamics in socially foraging three-spined sticklebacks (Gasterosteus aculeatus)
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