Analyzing Temperature Effects on Mortality Within the R Environment: The Constrained Segmented Distributed Lag Parameterization

Here we present and discuss the R package modTempEff including a set of functions aimed at modelling temperature effects on mortality with time series data. The functions fit a particular log linear model which allows to capture the two main features of mortality- temperature relationships: nonlinearity and distributed lag effect. Penalized splines and segmented regression constitute the core of the modelling framework. We briefly review the model and illustrate the functions throughout a simulated dataset

Extinctions of aculeate pollinators in Britain and the role of large-scale agricultural changes

Pollinators are fundamental to maintaining both biodiversity and agricultural productivity, but habitat destruction, loss of flower resources, and increased use of pesticides are causing declines in their abundance and diversity. Using historical records we assessed the rate of extinction of bee and flower-visiting wasp species in Britain, from the mid 19th century to the present. The most rapid phase of extinction appears to be related to changes in agricultural policy and practice beginning in the 1920s, before the agricultural intensification prompted by the Second World War, often cited as the most important driver of biodiversity loss in Britain. Slowing of the extinction rate from the 1960s onwards may be due to prior loss of the most sensitive species and/or effective conservation programs

Global trends in infectious diseases at the wildlife–livestock interface

The role and significance of wildlife–livestock interfaces in disease ecology has largely been neglected, despite recent interest in animals as origins of emerging diseases in humans. Scoping review methods were applied to objectively assess the relative interest by the scientific community in infectious diseases at interfaces between wildlife and livestock, to characterize animal species and regions involved, as well as to identify trends over time. An extensive literature search combining wildlife, livestock, disease, and geographical search terms yielded 78,861 publications, of which 15,998 were included in the analysis. Publications dated from 1912 to 2013 and showed a continuous increasing trend, including a shift from parasitic to viral diseases over time. In particular there was a significant increase in publications on the artiodactyls–cattle and bird–poultry interface after 2002 and 2003, respectively. These trends could be traced to key disease events that stimulated public interest and research funding. Among the top 10 diseases identified by this review, the majority were zoonoses. Prominent wildlife–livestock interfaces resulted largely from interaction between phylogenetically closely related and/or sympatric species. The bird–poultry interface was the most frequently cited wildlife–livestock interface worldwide with other interfaces reflecting regional circumstances. This review provides the most comprehensive overview of research on infectious diseases at the wildlife–livestock interface to date

Glucose instability is associated with a high level of circulating p-selectin.

We have previously shown that glycemic instability, as measured by the coefficient of variation for fasting plasma glucose (CV-FPG), is an independent predictor of cardiovascular mortality in type 2 diabetes (1,2). The mechanisms, if any, underlying the association between long-term plasma glucose instability and vascular diseases are difficult to explain. In vitro studies with retinal capillary pericytes have shown that rapid glucose fluctuations in the culture medium induced cellular damage and death by apoptosis (3). Moreover, tubulointerstitial cells exposed to intermittent high glucose concentrations underwent changes in cellular growth, collagen synthesis, and cytokine secretion that were more severe than those observed in cells exposed to stable high-glucose concentrations (4). These data extrapolated

Growth curves of sorghum roots via quantile regression with P-splines

Plant roots are a major pool of total carbon in the planet and their dynamics are directly relevant to greenhouse gas balance. Composted wastes are increasingly used in agriculture for environmental and economic reasons and their role as a substitute for traditional fertilizers needs to be tested on all plant components. Here we propose a regression quantile approach based on P-splines to assess, quantify and compare the root growth patterns in two treatment groups respectively undergoing compost and traditional fertilization

Free fatty acids link metabolism and regulation of the insulin-sensitizing fibroblast growth factor-21

OBJECTIVE—Fibroblast growth factor (FGF)-21 improves insulin sensitivity and lipid metabolism in obese or diabetic animal models, while human studies revealed increased FGF-21 levels in obesity and type 2 diabetes. Given that FGF-21 has been suggested to be a peroxisome proliferator–activator receptor (PPAR) –dependent regulator of fasting metabolism, we hypothesized that free fatty acids (FFAs), natural agonists of PPAR, might modify FGF-21 levels. RESEARCH DESIGN AND METHODS—The effect of fatty acids on FGF-21 was investigated in vitro in HepG2 cells. Within a randomized controlled trial, the effects of elevated FFAs were studied in 21 healthy subjects (13 women and 8 men). Within a clinical trial including 17 individuals, the effect of insulin was analyzed using an hyperinsulinemic-euglycemic clamp and the effect of PPAR activation was studied subsequently in a rosiglitazone treatment trial over 8 weeks. RESULTS—Oleate and linoleate increased FGF-21 expression and secretion in a PPAR-dependent fashion, as demonstrated by small-interfering RNA–induced PPAR knockdown, while palmitate had no effect. In vivo, lipid infusion induced an increase of circulating FGF-21 in humans, and a strong correlation between the change in FGF-21 levels and the change in FFAs was observed. An artificial hyperinsulinemia, which was induced to delineate the potential interaction between elevated FFAs and hyperinsulinemia, revealed that hyperinsulinemia also increased FGF-21 levels in vivo, while rosiglitazone treatment had no effect. CONCLUSIONS—The results presented here offer a mechanism explaining the induction of the metabolic regulator FGF-21 in the fasting situation but also in type 2 diabetes and obesity

Relationship between soluble CD40 ligand and gamma-glutamyltransferase concentrations in non-drinking, young type 1 diabetic individuals

Aims: To assess the association between circulating levels of soluble CD40 ligand (sCD40L), an emerging cardiovascular risk factor, and \u3b3-glutamyltransferase (GGT) activity concentrations in Type 1 diabetic subjects. Methods: Plasma concentrations of sCD40L and GGT activity, a marker of liver dysfunction, were measured in 54 non-smoking, non-drinking, young Type 1 diabetic patients, who were free of diagnosed cardiovascular disease. Results: When participants were grouped according to tertiles of GGT, plasma sCD40L concentrations steadily increased across GGT tertiles (P = 0.007 for trend). Similarly, plasma sCD40L concentrations were positively correlated with plasma GGT levels in the whole group of participants (r = 0.532; P < 0.0001). In multivariate linear regression analysis, plasma GGT activity levels were positively associated with sCD40L (standardized beta coefficient = 0.342; P = 0.027) independently of age, gender, diabetes duration, glycated haemoglobin, total cholesterol and systolic blood pressure. Further adjustment for the presence of diabetic retinopathy and microalbuminuria did not appreciably attenuate this association. Conclusions: Our findings suggest that there is a strong, graded, relationship between plasma GGT activity and sCD40L concentrations in non-smoking, non-drinking, young Type 1 diabetic individuals. This association appears to be independent of numerous confounding factors. Further studies are required to confirm the reproducibility of these results

Elevated Serum Uric Acid Concentrations Independently Predict Cardiovascular Mortality in Type 2 Diabetic Patients

OBJECTIVE\u2014 There is limited information on whether increased serum uric acid levels are independently associated with cardiovascular mortality in type 2 diabetes. We assessed thepredictive role of serum uric acid levels on all-cause and cardiovascular mortality in a large cohort of type 2 diabetic individuals.RESEARCH DESIGN AND METHODS\u2014 The cohort included 2,726 type 2 diabetic outpatients, who were followed for a mean period of 4.7 years. The independent association of serum uric acid levels with all-cause and cardiovascular mortality was assessed by Cox proportional hazards models and adjusted for conventional risk factors and several potential confounders.RESULTS\u2014 During follow-up, 329 (12.1%) patients died, 44.1% (n = 145) of whom from cardiovascular causes. In univariate analysis, higher serum uric acid levels were significantly associated with increased risk of all-cause (hazard ratio 19 [95% CI 1.12\u20131.27], P < 0.001) and cardiovascular (1.25 [1.16 \u20131.34], P < 0.001) mortality. After adjustment for age, sex, BMI, smoking, hypertension, dyslipidemia, diabetes duration, A1C, medication use (allopurinol or hypoglycemic, antihypertensive, lipid-lowering, and antiplatelet drugs), estimated glomerular filtration rate, and albuminuria, the association of serum uric acid with cardiovascular mortalityremained statistically significant (1.27 [1.01\u20131.61], P = 0.046), whereas the association of serum uric acid with all-cause mortality did not.CONCLUSIONS\u2014 Higher serum uric acid levels are associated with increased risk of cardiovascular mortality in type 2 diabetic patients, independent of several potential confounders, including renal function measures