Identifying biologically meaningful hot-weather events using threshold temperatures that affect life-history

Increases in the frequency, duration and intensity of heat waves are frequently evoked in climate change predictions. However, there is no universal definition of a heat wave. Recent, intense hot weather events have caused mass mortalities of birds, bats and even humans, making the definition and prediction of heat wave events that have the potential to impact populations of different species an urgent priority. One possible technique for defining biologically meaningful heat waves is to use threshold temperatures (T thresh ) above which known fitness costs are incurred by species of interest. We set out to test the utility of this technique using T thresh values that, when exceeded, affect aspects of the fitness of two focal southern African bird species: the southern pied babbler Turdiodes bicolor (T thresh = 35.5°C) and the common fiscal Lanius collaris (T thresh = 33°C). We used these T thresh values to analyse trends in the frequency, duration and intensity of heat waves of magnitude relevant to the focal species, as well as the annual number of hot days (maximum air temperature > T thresh ), in north-western South Africa between 1961 and 2010. Using this technique, we were able to show that, while all heat wave indices increased during the study period, most rapid increases for both species were in the annual number of hot days and in the maximum intensity (and therefore intensity variance) of biologically meaningful heat waves. Importantly, we also showed that warming trends were not uniform across the study area and that geographical patterns in warming allowed both areas of high risk and potential climate refugia to be identified. We discuss the implications of the trends we found for our focal species, and the utility of the T thresh technique as a conservation tool

Advanced glycation end products:An emerging biomarker for adverse outcome in patients with peripheral artery disease

AbstractPatients with peripheral artery disease (PAD) suffer from widespread atherosclerosis. Partly due to the growing awareness of cardiovascular disease, the incidence of PAD has increased considerably during the past decade. It is anticipated that algorithms to identify high risk patients for cardiovascular events require being updated, making use of novel biomarkers. Advanced glycation end products (AGEs) are moieties formed non-enzymatically on long-lived proteins under influence of glycemic and oxidative stress reactions. We elaborate about the formation and effects of AGEs, and the methods to measure AGEs. Several studies have been performed with AGEs in PAD. In this review, we evaluate the emerging evidence of AGEs as a clinical biomarker for patients with PAD

Evaluating complex mine ventilation operational changes through simulations

Increasing the profitability of the mining industry is contingent on its ability to improve operational efficiency. Mine ventilation networks typically represent 25-50% of a mine’s energy consumption and, therefore, exhibits scope for optimisation. Ventilation networks comprise numerous complex integrated airways, branches and ventilation fans. The most effective way to optimise and evaluate them is computer-aided simulations. However, no framework exists to clarify exactly how operational changes in ventilation networks should be evaluated. In this study, a scalable method was developed, implemented and analysed. The case study validation resulted in satisfying key performance indicators of both service delivery and operational energy costs, thereby increasing operational efficiency. The significance of the novel method is that it allows for improved operational decisions on mine ventilation networks. The value of the method was illustrated by the adoption of the method by the case study mining personnel to form the new norm of their procedures and standards

Abnormal Nailfold Capillaroscopy Is Common in Patients with Connective Tissue Disease and Associated with Abnormal Pulmonary Function Tests

Objective. To assess the presence of a systemic sclerosis (SSc) pattern on nailfold capillary microscopy (NCM) in patients with Raynaud phenomenon (RP) and to explore its association with abnormal pulmonary function tests (PFT). Methods. NCM patterns were assessed in 759 consecutive patients with RP. Patterns were classified as normal (n = 354), nonspecific (n = 159), or SSc pattern (n = 246). Abnormal PFT was defined as forced vital or diffusion capacity <70%. Patients were classified as primary RP (n = 245), or secondary: no definite diagnosis (n = 391), SSc (n = 40), primary Sjogren syndrome (pSS; n = 30), systemic lupus erythematosus (SLE; n = 30), mixed connective tissue disease (MCTD; n = 7), rheumatoid arthritis (RA; n = 15). Results. An SSc pattern on NCM was frequently observed in most patients with a definite diagnosis: SSc (88%), pSS (33%), SLE (17%), MCTD (71%), and RA (13%). In patients without definite diagnosis, 17% had a normal NCM pattern, 35% nonspecific, and 48% SSc pattern. Abnormal PFT was more frequent in patients with an SSc pattern (35.9% vs 19.5%, p = 0.002), even when corrected for SSc diagnosis (p = 0.003). Absence of an SSc pattern had high negative predictive value (88%); positive predictive values were low. Conclusion. SSc pattern on NCM is common in patients with RP, and in those with connective tissue diseases other than SSc. It is associated with a higher prevalence of abnormal PFT, independent of the presence of an SSc diagnosis. Although these data need validation in a prospective setting, they underline the importance of NCM in RP and putative value to stratify the risk of pulmonary involvement in early stages of disease

A parameterization of flow separation over subaqueous dunes

Flow separation plays a key role in the development of dunes, and modeling the complicated flow behavior inside the flow separation zone requires much computational effort. To make a first step toward modeling dune development at reasonable temporal and spatial scales, a parameterization of the shape of the flow separation zone over two-dimensional dunes is proposed herein, in order to avoid modeling the complex flow inside the flow separation zone. Flow separation behind dunes, with an angle-of-repose slip face, is characterized by a large circulating leeside eddy, where a separation streamline forms the upper boundary of the recirculating eddy. Experimental data of turbulent flow over two-dimensional subaqueous bed forms are used to parameterize this separation streamline. The bed forms have various heights and height to length ratios, and a wide range of flow conditions is analyzed. This paper shows that the shape of the flow separation zone can be approximated by a third-order polynomial as a function of the distance away from the flow separation point. The coefficients of the polynomial can be estimated, independent of flow conditions, on the basis of bed form shape at the flow separation point and a constant angle of the separation streamline at the flow reattachment point. \ud \u

Engineering of lipid-coated PLGA nanoparticles with a tunable payload of diagnostically active nanocrystals for medical imaging

Polylactic-co-glycolic acid (PLGA) based nanoparticles are biocompatible and biodegradable and therefore have been extensively investigated as therapeutic carriers. Here, we engineered diagnostically active PLGA nanoparticles that incorporate high payloads of nanocrystals into their core for tunable bioimaging features. We accomplished this through esterification reactions of PLGA to generate polymers modified with nanocrystals. The PLGA nanoparticles formed from modified PLGA polymers that were functionalized with either gold nanocrystals or quantum dots exhibited favorable features for computed tomography and optical imaging, respectively.National Heart, Lung, and Blood Institute (Programs of Excellence in Nanotechnology (PEN) Award, Contract #HHSN268201000045C))National Institutes of Health (U.S.) (R01 EB009638)National Institutes of Health (U.S.) (R01 CA155432)National Institutes of Health (U.S.) (K99 EB012165)Netherlands Organization for Scientific Research ((NWO) ECHO.06.B.047