Monsoon mixing cycles in the Bay of Bengal: A year-long subsurface mixing record

Based on the first year-long record of mixing collected in the eastern central Bay of Bengal, we quantify the role that subsurface turbulent heat fluxes play in upper-ocean cooling brought on by southwest (SW) and northeast (NE) monsoons. During the NE (dry, or winter) monsoon, atmospheric and subsurface turbulent heat fluxes each contribute about 50% of the net sea surface cooling. During the SW (wet, or summer) monsoon, the atmospheric heat flux varied widely due to “active” and “break” cycles of the monsoon intraseasonal oscillations, but had a net positive seasonal average. The subsurface turbulent heat flux during the SW monsoon led to surface cooling at rates more than three times greater than those measured during the NE monsoon. Since the seasonally averaged atmospheric heat flux was positive, subsurface mixing accounted for nearly all of the cooling during the SW monsoon. During the transition between the NE and SW monsoons, subsurface heat flux was near zero, and atmospheric heating rapidly warmed the sea surface. Following the SW monsoon, passage of Tropical Storm Hudhud led to O(1) m2 s–1 rates of turbulence diffusivity and strong subsurface heat flux, accounting for roughly half of the 1.4°C surface cooling that occurred over a 60-hour period

Is health-related quality of life associated with the risk of low-energy wrist fracture: a case-control study

<p>Abstract</p> <p>Background</p> <p>Some risk factors for low-energy wrist fracture have been identified. However, self-reported measures such as health-related quality of life (HRQOL) have not been examined as potential risk factors for wrist fracture. The aims of this study were to compare HRQOL prior to a low-energy wrist fracture in elderly patients (≥ 50 years) with HRQOL in age- and sex-matched controls, and to explore the association between HRQOL and wrist fracture after adjusting for known risk factors for fracture such as age, weight, osteoporosis and falls.</p> <p>Methods</p> <p>Patients with a low-energy wrist fracture (n = 181) and age- and sex-matched controls (n = 181) were studied. Shortly after fracture (median 10 days), patients assessed their HRQOL before fracture using the Short Form 36 (SF-36). Statistical tests included <it>t </it>tests and multivariate logistic regression analysis.</p> <p>Results</p> <p>Several dimensions of HRQOL were significantly associated with wrist fracture. The direction of the associations with wrist fracture varied between the different sub-dimensions of the SF-36. After controlling for demographic and clinical variables, higher scores on <it>general health </it>(odds ratio (OR) = 1.31, 95% confidence interval (CI) = 1.10–1.56), <it>bodily pain </it>(OR = 1.18, 95% CI = 1.03–1.34) and <it>mental health </it>(OR = 1.39, 95% CI = 1.09–1.79) were related to an increased chance of being a wrist fracture patient rather than a control. In contrast, higher scores on <it>physical role limitation </it>(OR = 0.87, 95% CI = 0.79–0.95) and <it>social function </it>(OR = 0.65, 95% CI 0.53–0.80) decreased this chance. Significant associations with wrist fracture were also found for living alone (OR = 1.91, 95% CI 1.07–3.4), low body mass index (BMI) (OR = 0.92, 95% CI 0.86–0.98), osteoporosis (OR = 3.30, 95% CI 1.67–6.50) and previous falls (OR = 2.01, 95% CI 1.16–3.49).</p> <p>Conclusion</p> <p>Wrist fracture patients perceive themselves to be as healthy as the controls before fracture. Our data indicate that patients with favourable and unfavourable HRQOL measures may be at increased risk of wrist fracture.</p

Factors associated with disease evolution in Greek patients with inflammatory bowel disease

BACKGROUND: The majority of Crohn's disease patients with B1 phenotype at diagnosis (i.e. non-stricturing non-penetrating disease) will develop over time a stricturing or a penetrating pattern. Conflicting data exist on the rate of proximal disease extension in ulcerative colitis patients with proctitis or left-sided colitis at diagnosis. We aimed to study disease evolution in Crohn's disease B1 patients and ulcerative colitis patients with proctitis and left-sided colitis at diagnosis. METHODS: 116 Crohn's disease and 256 ulcerative colitis patients were followed-up for at least 5 years after diagnosis. Crohn's disease patients were classified according to the Vienna criteria. Data were analysed actuarially. RESULTS: B1 phenotype accounted for 68.9% of Crohn's disease patients at diagnosis. The cumulative probability of change in disease behaviour in B1 patients was 43.6% at 10 years after diagnosis. Active smoking (Hazard Ratio: 3.01) and non-colonic disease (non-L2) (Hazard Ratio: 3.01) were associated with behavioural change in B1 patients. Proctitis and left-sided colitis accounted for 24.2%, and 48.4% of ulcerative colitis patients at diagnosis. The 10 year cumulative probability of proximal disease extension in patients with proctitis and left-sided colitis was 36.8%, and 17.1%, respectively (p: 0.003). Among proctitis patients, proximal extension was more common in non-smokers (Hazard Ratio: 4.39). CONCLUSION: Classification of Crohn's disease patients in B1 phenotype should be considered as temporary. Smoking and non-colonic disease are risk factors for behavioural change in B1 Crohn's disease patients. Proximal extension is more common in ulcerative colitis patients with proctitis than in those with left-sided colitis. Among proctitis patients, proximal extension is more common in non-smokers

A simple approximation for larval retention around reefs

Estimating larval retention at individual reefs by local scale three-dimensional flows is a significant problem for understanding, and predicting, larval dispersal. Determining larval dispersal commonly involves the use of computationally demanding and expensively calibrated/validated hydrodynamic models that resolve reef wake eddies. This study models variation in larval retention times for a range of reef shapes and circulation regimes, using a reef-scale three-dimensional hydrodynamic model. It also explores how well larval retention time can be estimated based on the "Island Wake Parameter", a measure of the degree of flow turbulence in the wake of reefs that is a simple function of flow speed, reef dimension, and vertical diffusion. The mean residence times found in the present study (0.48–5.64 days) indicate substantial potential for self-recruitment of species whose larvae are passive, or weak swimmers, for the first several days after release. Results also reveal strong and significant relationships between the Island Wake Parameter and mean residence time, explaining 81–92% of the variability in retention among reefs across a range of unidirectional flow speeds and tidal regimes. These findings suggest that good estimates of larval retention may be obtained from relatively coarse-scale characteristics of the flow, and basic features of reef geomorphology. Such approximations may be a valuable tool for modeling connectivity and meta-population dynamics over large spatial scales, where explicitly characterizing fine-scale flows around reef requires a prohibitive amount of computation and extensive model calibration