31 research outputs found
Temperature sensitivity of soil enzymes along an elevation gradient in the Peruvian Andes
Soil enzymes are catalysts of organic matter depolymerisation, which is of critical importance for ecosystem carbon (C) cycling. Better understanding of the sensitivity of enzymes to temperature will enable improved predictions of climate change impacts on soil C stocks. These impacts may be especially large in tropical montane forests, which contain large amounts of soil C. We determined the temperature sensitivity (Q 10) of a range of hydrolytic and oxidative enzymes involved in organic matter cycling from soils along a 1900 m elevation gradient (a 10 °C mean annual temperature gradient) of tropical montane forest in the Peruvian Andes. We investigated whether the activity (V max) of selected enzymes: (i) exhibited a Q 10 that varied with elevation and/or soil properties; and (ii) varied among enzymes and according to the complexity of the target substrate for C-degrading enzymes. The Q 10 of V max for β-glucosidase and β-xylanase increased with increasing elevation and declining mean annual temperature. For all other enzymes, including cellobiohydrolase, N-acetyl β-glucosaminidase and phosphomonoesterase, the Q 10 of V max did not vary linearly with elevation. Hydrolytic enzymes that degrade more complex C compounds had a greater Q 10 of V max, but this pattern did not apply to oxidative enzymes because phenol oxidase had the lowest Q 10 value of all enzymes studied here. Our findings suggest that regional differences in the temperature sensitivities of different enzyme classes may influence the terrestrial C cycle under future climate warming
Predictors of additional intraocular pressure reduction in patients changed to latanoprost/timolol fixed combination
Beliefs, Barriers and Facilitators to Physical Activity in Bariatric Surgery Candidates
Background: Bariatric surgery candidates engage in less physical activity (PA) and spend longer periods in sedentary behaviour (SB) when compared to the general adult population. The aim of this study was to explore the beliefs about PA and perceived barriers and facilitators to PA in obese adults scheduled for bariatric surgery. Methods: Nineteen obese adults (15 females), with a mean (SD) age of 41.6 (12.1) years, weight of 119.2 (20.5) kg and body mass index of 41.6 (6.7) kg/m2 participated in a one-on-one in-depth qualitative interview before undergoing bariatric surgery. Data were analysed using inductive thematic analysis. Results: Most participants believed that engaging in regular PA confers important health benefits, however reported insufficient PA levels to obtain those benefits. The perceived barriers to PA reported by participants were both obesity related (e.g. bodily pain, physical limitation and self-presentational concerns) and non-obesity related (e.g. lack of motivation, environment and restricted resources). All participants stated weight loss to be the main perceived facilitator to PA, together with social factors, better time management and access to financial resources. Conclusions: In bariatric surgery candidates, many of the perceived barriers and facilitators to PA are not obesity related and are therefore unlikely to change as a result of bariatric surgery. This may explain why earlier research shows little change in PA or SB following surgery. It is likely that an approach that aims to address the barriers and facilitators identified in this study is needed to change the inactive lifestyle adopted in this population