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Concept: Interval finite element


Purpose: The Ironman (IM) triathlon is a popular ultra endurance competition, consisting of a 3.8km swimming, 180.2km cycling, and a 42.2km run. The aim of this study was to investigate predictors of IM race time, comparing echocardiographic findings, anthropometric measures, and training characteristics.Methods: Amateur IM athletes (ATHL) participating in the Zurich IM race in 2010 were included. Participants were examined the day before the race by a comprehensive echocardiographic examination. Moreover, anthropometric measurements were obtained the same day. During the 3 months before the race, each IM-ATHL maintained a detailed training diary. Recorded data were related to total Ironman race time.Results: Thirty-eight Ironman finishers (average age 38±9 years, 32 male [84%]) were evaluated. Average total race time was 684±89 minutes. For right ventricular fractional area change (average: 45±7%, Spearman-ρ=-0.33; p=0.05) a weak correlation with race time was observed. Race performance exhibited stronger associations with percent body fat (15.2±5.6%, ρ=0.56; p=0.001), speed in running training (11.7±1.2 km/h, ρ=-0.52; p=0.002), and left ventricular myocardial mass index (98±24 g/m, ρ=-0.42; p=0.009). The strongest association was found between race time and right ventricular end-diastolic area (22±4 cm, ρ=-0.64; p<0.0001). In multivariate analysis, right ventricular end-diastolic area (beta=-16.7, 95% confidence interval: -27.3-[-6.1]; p=0.003) and percent body fat (beta=6.8, 95% confidence interval: 1.1-12.6; p=0.02) were independently predictive of Ironman race time.Conclusions: In amateur IM-ATHL, RV end-diastole area and percent body fat were independently related to race performance. RV end-diastolic area was the strongest predictor of race time. The role of the RV in endurance exercise may thus be more important than previously thought and needs to be further studied.

Concepts: Heart, Interval finite element, Anthropometry, Right ventricle, Ventricle, Left ventricle, Bulbus cordis, Primitive ventricle


BACKGROUND:: Pesticide poisoning rates remain high among farmworkers despite programs aimed at reducing pesticide exposure. METHODS:: A cross-sectional study was conducted among 187 Hispanic farmworkers in North Carolina. Farmworkers were interviewed to determine the association between pesticide safety training and knowledge about pesticides and use of personal protective equipment (PPE). RESULTS:: Use of PPE was higher among farmworkers who reported wearing gloves reduced the harmful effects of pesticides (adjusted odds ratio, 5.73; 95% confidence interval, 2.20-14.92) and those who received pesticide safety training at the extension office or growers association (adjusted odds ratio, 44.62; 95% confidence interval, 3.96-503.33). CONCLUSION:: Some farmworkers are still not using PPE. Evaluation of Environmental Protection Agency Worker Protection Standards pesticide safety training and requirements for providing PPE are crucial to encourage farm workers to use PPE.

Concepts: Odds ratio, Interval finite element, Pesticide, Personal protective equipment, United States Environmental Protection Agency, Protection, Poison, Protective gear


Elevated foetal haemoglobin (HbF) levels are protective against some manifestations of sickle cell anaemia but the impact on retinopathy is unknown. We report on 123 children with HbSS, 10·6% of whom developed retinopathy. Independent of hydroxycarbamide, children with a HbF <15% had 7·1-fold (95% confidence interval, 1·5-33·6) higher odds of developing retinopathy. In children treated with hydroxycarbamide, those with retinopathy had lower HbF levels compared to children without retinopathy (9% vs. 16%; P = 0·005). We report a protective benefit of elevated HbF regarding retinopathy, and our data suggests induction of HbF with hydroxycarbamide may prevent retinopathy in children.

Concepts: Hemoglobin, Fetus, Red blood cell, Interval finite element, Sickle-cell disease, Blood proteins, Fetal hemoglobin, Sickle


Housing security is an important determinant of mental ill health. We used a quasinatural experiment to evaluate this association, comparing the prevalence of mental ill health in the United Kingdom before and after the government’s April 2011 reduction in financial support for low-income persons who rent private-sector housing (mean reduction of approximately £1,220 ($2,315) per year). Data came from the United Kingdom’s Annual Population Survey, a repeated quarterly cross-sectional survey. We focused our analysis on renters in the private sector, disaggregating data between an intervention group receiving the government’s Housing Benefit (n = 36,859) and a control group not receiving the Housing Benefit (n = 142,205). The main outcome was a binary measure of self-reported mental health problems. After controlling for preexisting time trends, we observed that between April 2011 and March 2013, the prevalence of depressive symptoms among private renters receiving the Housing Benefit increased by 1.8 percentage points (95% confidence interval: 1.0, 2.7) compared with those not receiving the Housing Benefit. Our models estimated that approximately 26,000 (95% confidence interval: 14,000, 38,000) people newly experienced depressive symptoms in association with the cuts to the Housing Benefit. We conclude that reducing housing support to low-income persons in the private rental sector increased the prevalence of depressive symptoms in the United Kingdom.

Concepts: Epidemiology, Disease, Statistics, Illness, United Kingdom, Interval finite element, Mental disorder, Constitutional monarchy


Emulsified isoflurane is a novel intravenous anesthetic, which is a lipid emulsion of isoflurane. As some drugs have a QTc-prolongation effect which can increase a risk of arrhythmia, this study was to evaluate the effects of emulsified isoflurane on the QTc interval. This was a single-center, randomized, single-blind, non-comparative study. Subjects were randomly allocated to receive an intravenous bolus injection of 22.63, 38.26, or 49.73 mg/kg emulsified isoflurane, respectively. Standard 12-lead electrocardiograms were recorded before administration and at 28 timepoints after administration. Blood samples and the end-tidal isoflurane concentrations were collected for pharmacokinetic analysis. The primary target variable was the QTcF change from baseline at each time point. A two-sided 90% confidence interval (CI) was calculated for a QTcF change from baseline at each timepoint. The maximal 90% CIs of the mean QTcF from the baseline for 22.63, 38.26 and 49.73mg/kg emulsified isoflurane were 2.52-21.18 ms, 15.66-35.90 ms, and 17.65-40.71 ms, respectively. Non-significant relationship was observed between QTcF and the plasma concentration (or the end-tidal isoflurane concentration). Single intravenous dose of emulsified isoflurane of the anticipated therapeutic dose or supra-therapeutic doses was associated with a potential dose-dependent and non-concentration-related QTc-prolongation effect.

Concepts: Pharmacology, Cardiology, Cardiac electrophysiology, QT interval, Interval finite element, Pharmacokinetics, Bolus, Dosage forms


The etiology of endometriosis is poorly understood, and few modifiable risk factors have been identified. Dairy foods and some nutrients can modulate inflammatory and immune factors, which are altered in women with endometriosis. We investigated whether intake of dairy foods, nutrients concentrated in dairy foods, and predicted plasma 25-hydroxyvitamin D (25(OH)D) levels were associated with incident laparoscopically confirmed endometriosis among 70,556 US women in Nurses' Health Study II. Diet was assessed via food frequency questionnaire. A score for predicted 25(OH)D level was calculated for each participant. During 737,712 person-years of follow-up over a 14-year period (1991-2005), 1,385 cases of incident laparoscopically confirmed endometriosis were reported. Intakes of total and low-fat dairy foods were associated with a lower risk of endometriosis. Women consuming more than 3 servings of total dairy foods per day were 18% less likely to be diagnosed with endometriosis than those reporting 2 servings per day (rate ratio = 0.82, 95% confidence interval: 0.71, 0.95; P(trend) = 0.03). In addition, predicted plasma 25(OH)D level was inversely associated with endometriosis. Women in the highest quintile of predicted vitamin D level had a 24% lower risk of endometriosis than women in the lowest quintile (rate ratio = 0.76, 95% confidence interval: 0.60, 0.97; P(trend) = 0.004). Our findings suggest that greater predicted plasma 25(OH)D levels and higher intake of dairy foods are associated with a decreased risk of endometriosis.

Concepts: Vitamin D, Epidemiology, Nutrition, Milk, Calcium, Vitamin, Interval finite element, Prediction interval


The research was designed to determine if the Mahalanobis Taguchi System (MTS) applied to the delirium evidence based bundle could detect medical patterns in retrospective data sets. The methodology defined the evidence based bundle as a multi-dimensional system that conformed to a parameter diagram. The mahalanobis distance (MD) was calculated for the retrospective healthy observations and the retrospective unhealthy observations. Signal to noise ratios (SNR) were calculated to determine the relative strength of detection of twenty three delirium pre-indicators. The research discovered that sufficient variation in the CAM-ICU assessment, the standard for delirium assessment, would benefit from knowledge of how different the MD is from the healthy average. The sensitivity of the detection system was 0.89 with a 95% confidence interval of between 0.84 and 0.92. The specificity of the detection system was 0.93 with a 95% confidence interval between 0.90 and 0.95. The MTS applied to the delirium evidence based bundle could detect medical patterns in retrospective data sets. The implication of this research to biomedical research is an automated decision support tool for the delirium evidence based bundle providing an early detection capability needed today.

Concepts: Health care, Scientific method, Medicine, Health, Epidemiology, Interval finite element, Knowledge, Statistical inference


This systematic review included 12 studies that compared the well-being of Para and Olympic sport athletes. Meta-analyses revealed that Para athletes, compared with Olympic sport athletes, had lower levels of self-acceptance, indicated by athletic identity, d = 0.47, 95% confidence interval (CI) [0.77, 0.16], and body-image perceptions, d = 0.33, 95% CI [0.59, 0.07], and differed from Olympic sport athletes in terms of their motivation, indicated by a greater mastery-oriented climate, d = 0.74, 95% CI [0.46, 1.03]. Given an inability to pool the remaining data for meta-analysis, individual standardized mean differences were calculated for other dimensions of psychological and subjective well-being. The results have implications for professionals and coaches aiming to facilitate the well-being needs of athletes under their care. Future research would benefit from incorporating established models of well-being based on theoretical rationale combined with rigorous study designs.

Concepts: Statistics, Evidence-based medicine, Systematic review, Olympic Games, Interval finite element, Educational psychology, Normal distribution, Meta-analysis


Growth differentiation factor-15 (GDF-15) is a member of the TGF-β cytokine superfamily that is widely expressed and may be induced in response to tissue injury. Elevations in GDF-15 may identify a novel pathway involved in loss of kidney function among patients with CKD. Among participants in the Clinical Phenotyping and Resource Biobank (C-PROBE) study and the Seattle Kidney Study (SKS), we tested whether kidney tissue expression of GDF15 mRNA correlates with circulating levels of GDF-15 and whether elevations in circulating GDF-15 are associated with decline in kidney function. In matching samples of 24 patients with CKD from the C-PROBE study, circulating GDF-15 levels significantly correlated with intrarenal GDF15 transcript levels (r=0.54, P=0.01). Among the 224 C-PROBE and 297 SKS participants, 72 (32.1%) and 94 (32.0%) patients, respectively, reached a composite end point of 30% decline in eGFR or progression to ESRD over a median of 1.8 and 2.0 years of follow up, respectively. In multivariable models, after adjusting for potential confounders, every doubling of GDF-15 level associated with a 72% higher (95% confidence interval, 1.21 to 4.45; P=0.003) and 65% higher (95% confidence interval, 1.08 to 2.50; P=0.02) risk of progression of kidney disease in C-PROBE and SKS participants, respectively. These results show that circulating GDF-15 levels strongly correlated with intrarenal expression of GDF15 and significantly associated with increased risk of CKD progression in two independent cohorts. Circulating GDF-15 may be a marker for intrarenal GDF15-related signaling pathways associated with CKD and CKD progression.

Concepts: Kidney, Gene expression, Function, Cellular differentiation, Interval finite element, Confidence interval, Normal distribution, Expression


For those at risk for cold-related injury, frostbite contributes significant morbidity through loss of limbs and digits. Frostbite injury generally affects distal extremities first and spreads proximally as the time of exposure increases. The Hennepin score is a tool to quantify injury and tissue loss of frostbite injury, similar to TBSA calculators in burn patients. Application of the Hennepin score allows for a clear picture of the effect of treatment through calculation of a salvage rate. The authors found high reliability between raters using the Hennepin score worksheet, suggesting consistency with applying the score to frostbite injury and outcomes (intraclass correlation, 0.93; confidence interval, 0.88-0.97). The Hennepin score allows for a standard means to accurately measure injury and outcomes, which will aid in the study of treatment outcomes of frostbite injuries.

Concepts: Statistics, Measurement, Interval finite element, Injuries, Injury, Confidence interval, Normal distribution, The Score