406 research outputs found
Reaction norms for age and size at maturity in response to temperature: A puzzle for life historians.
Ectotherms mature later at smaller size when growth rates are lowered by reductions in food quality but they mature later at larger sizes when growth rate is lowered by reductions in temperature. We argue that this general pattern has been neglected by life history theorists and suggest that an explanation for these strikingly different responses to two environmental cues might be found by considering correlations between the growth coefficient of the Bertalanffy equation and asymptotic size in a model for the evolution of age and size at maturity
Associations between fruit and vegetable intake, leisure-time physical activity, sitting time and self-rated health among older adults : cross-sectional data from the WELL study
BackgroundLifestyle behaviours, such as healthy diet, physical activity and sedentary behaviour, are key elements of healthy ageing and important modifiable risk factors in the prevention of chronic diseases. Little is known about the relationship between these behaviours in older adults. The purpose of this study was to explore the relationship between fruit and vegetable (F&V) intake, leisure-time physical activity (LTPA) and sitting time (ST), and their association with self-rated health in older adults.MethodsThis cross-sectional study comprised 3,644 older adults (48% men) aged 55-65 years, who participated in the Wellbeing, Eating and Exercise for a Long Life ("WELL") study. Respondents completed a postal survey about their health and their eating and physical activity behaviours in 2010 (38% response rate). Spearman\u27s coefficient (rho) was used to evaluate the relationship between F&V intake, LTPA and ST. Their individual and shared associations with self-rated health were examined using ordinal logistic regression models, stratified by sex and adjusted for confounders (BMI, smoking, long-term illness and socio-demographic characteristics).ResultsThe correlations between F&V intake, LTPA and ST were low. F&V intake and LTPA were positively associated with self-rated health. Each additional serving of F&V or MET-hour of LTPA were associated with approximately 10% higher likelihood of reporting health as good or better among women and men. The association between ST and self-rated health was not significant in the multivariate analysis. A significant interaction was found (ST*F&V intake). The effect of F&V intake on self-rated health increased with increasing ST in women, whereas the effect decreased with increasing ST in men.ConclusionThis study contributes to the scarce literature related to lifestyle behaviours and their association with health indicators among older adults. The findings suggest that a modest increase in F&V intake, or LTPA could have a marked effect on the health of older adults. Further research is needed to fully understand the correlates and determinants of lifestyle behaviours, particularly sitting time, in this age group
Daily metabolic expenditures: estimates from US, UK and polish time-use data
BACKGROUND: Behaviour has diverse economic, social and health consequences. Linking time spent in different daily activities to energy expenditure (EE) is one way of investigating the health and physiological consequences of behaviour and identifying targets to improve population health and well-being. METHODS: We estimated behaviour-related EE for respondents to time use surveys (TUS) from three countries: UK 2001, Poland 2012 and US 2003-13. The Harmonised Multinational Time Use Survey (MTUS) activity categories were matched to MET estimates from the 2011 Compendium of Physical Activities. We attach METs values to each successive activity in the TUS, together with both the original UK, Polish and US activity classifications and the 68-category MTUS activity classification. We used TUS estimates of activity durations across 24-h to estimate the Physical Activity Level (PAL) for respondents from the three countries and the average time spent and MET values for different activity categories. RESULTS: PAL values ranged from 1.59 in the US to 1.74 in Poland. The main sources of daily EE from PA were paid and unpaid work activities. Discretionary PA accounted for only a very small part (~ 3%) of adult daily energy expenditures. Using the harmonised MTUS 68-activity classification reduced the variability of the aggregate PAEE measure by ~ 20%, but the patterns of association between key demographics (age, sex, educational attainment) were unaffected. TUS data were further used to (1) identify sources of daily PA, and (2) assess adherence to physical activity guidelines (PAG) on a single-day basis. Estimated adherence levels were similar to those reported from other TUS as well as frequency based estimates. CONCLUSIONS: Comparative studies of energy expenditure based on harmonised time use activity categories could provide insight into the relative importance of different activities for energy expenditure across different countries and demographic groups. However, new observational studies combining TUS data with accelerometer, direct observation and other measures of activity intensity are required for more accurate MET assignments to activity categories in TUS
Colony-level differences in the scaling rules governing wood ant compound eye structure
Differential organ growth during development is essential for adults to maintain the correct proportions and achieve their characteristic shape. Organs scale with body size, a process known as allometry that has been studied extensively in a range of organisms. Such scaling rules, typically studied from a limited sample, are assumed to apply to all members of a population and/or species. Here we study scaling in the compound eyes of workers of the wood ant, Formica rufa, from different colonies within a single population. Workers' eye area increased with body size in all the colonies showing a negative allometry. However, both the slope and intercept of some allometric scaling relationships differed significantly among colonies. Moreover, though mean facet diameter and facet number increased with body size, some colonies primarily increased facet number whereas others increased facet diameter, showing that the cellular level processes underlying organ scaling differed among colonies. Thus, the rules that govern scaling at the organ and cellular levels can differ even within a single population
Electrodeposition and characterisation of CdS thin films using thiourea precursor for application in solar cells
CdS thin films have been successfully electrodeposited on glass/FTO substrates using acidic and aqueous solution of CdCl2.xH2O and thiourea (SC(NH2)2). The electrodeposition of CdS thin films were carried out potentiostatically using a 2-electrode system. The prepared films were characterised using X-ray diffraction (XRD), Raman spectroscopy, Scanning electron microscopy (SEM), Atomic force microscopy (AFM), Photoelectrochemical (PEC) cell measurements, Electrical resistivity measurements and UV-Vis spectrophotometry to study their structural, compositional, morphological, electrical and optical properties, respectively. The structural studies show that the as-deposited and annealed CdS layers are polycrystalline with hexagonal crystal structure and preferentially oriented along (200) planes. The optical studies indicate that the ED-CdS layers have direct bandgaps in the range (2.53-2.58) eV for the as-deposited and (2.42-2.48) eV after annealing at 400oC for 20 minutes in air. The morphological studies show the good coverage of the FTO surface by the CdS grains. The average grain sizes for the as-deposited and annealed layers were in the range (60-225) nm. These grains or clusters are made out of smaller nano crystallites with the sizes in the range ~(11-33) nm. The electrical resistivity shows reduction as thickness increases. The resistivity values for the as-deposited and annealed layers were in the range (0.82-4.92)×105 Ωcm. The optimum growth voltage for the CdS thin films was found to be at the cathodic potential of 797 mV with respect to the graphite anode. No visible precipitations of elemental S or CdS particles were observed in the deposition electrolyte showing a stable bath using thiourea during the growth
Efficacy and cost-effectiveness of intensive short-term dynamic psychotherapy for treatment resistant depression: 18-month follow-up of the Halifax depression trial
Background
Depressed patients with chronic and complex health issues commonly relapse; therefore, examining longer-term outcomes is an important consideration. For treatment resistant depression (TRD), the post-treatment efficacy of time-limited Intensive Short-Term Dynamic Psychotherapy (ISTDP) has been demonstrated but longer-term outcomes and cost-effectiveness are unclear.
Method
In this superiority trial, 60 patients referred to Community Mental Health Teams (CMHT) were randomised to 2 groups (ISTDP=30 and CMHT=30). The primary outcome was Hamilton Depression Rating scale (HAM-D) scores at 18 months. Secondary outcomes included Patient Health Questionnaire (PHQ-9) depression scores and dichotomous measure remission. A health economic evaluation examined mental health costs with quality-adjusted life years (QALYs).
Results
Statistically significant treatment differences in depression previously found at 6 months favouring ISTDP were maintained at 18-month follow-up. Group differences in depression were in the moderate to large range on both the observer rated (Cohen's d = .64) and self-report measures (Cohen's d = .70). At 18 months follow-up the remission rate in ISTDP patients was 40.0%, and 23.4% had discontinued antidepressants. Health economic analysis suggests that ISTDP was more cost-effective than CMHT at 18 months. Probabilistic analysis suggests that there is a 64.5% probability of ISTDP being cost-effective at a willingness to pay for a QALY of $25,000 compared to CMHT at 18 months.
Limitations
Replication of these findings is necessary in larger samples and future cost analyses should also consider indirect costs.
Conclusions
ISTDP demonstrates long-term efficacy and cost-effectiveness in TRD
Associations between community programmes and policies and children’s physical activity: the Healthy Communities Study
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146309/1/ijpo12426.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146309/2/ijpo12426_am.pd
Sedentary Activity Associated With Metabolic Syndrome Independent of Physical Activity
This study examined the association between objectively measured sedentary activity and metabolic syndrome among older adults
A Youth Compendium of Physical Activities: Activity Codes and Metabolic Intensities
A Youth Compendium of Physical Activities (Youth Compendium) was developed to estimate the energy costs of physical activities using data on youth only
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