Myocardial tissue characterization: histological and pathophysiological correlation

Cardiovascular magnetic resonance imaging (CMR) has become the gold standard not only for cardiac volume and function quantification, but for a key unique strength: non-invasive myocardial tissue characterization. Several different techniques, separately or in combination, can detect and quantify early and established myocardial pathological processes permitting better diagnosis, prognostication and tracking of therapy. The authors will focus on the histological and pathophysiological evidence of these imaging parameters in the characterization of edema, infarction, scar and fibrosis. In addition to laying out the strengths and weaknesses of each modality, the reader will be introduced to rapid developments in T1 and T2 mapping as well as the use of contrast-derived extracellular volume for quantification of diffuse fibrosis

Inner wellbeing: concept and validation of a new approach to subjective perceptions of wellbeing-India

© The Author(s) 2013. This article is published with open access at Springerlink.com. This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.This paper describes the conceptual development of a multi-domain, psychosocial model of 'Inner Wellbeing' (IWB) and assesses the construct validity of the scale designed to measure it. IWB expresses what people think and feel they are able to be and do. Drawing together scholarship in wellbeing and international development it is grounded in field research in marginalised, rural communities in the global South. Results from research in India at two points in time (2011 and 2013) are reported. At Time 1 (n = 287), we were unable to confirm an eight-factor, correlated model as distinct yet interrelated domains. However, at Time 2 (n = 335), we were able to confirm a revised, seven-factor correlated model with economic confidence, agency and participation, social connections, close relationships, physical and mental health, competence and self-worth, and values and meaning (five items per domain) as distinct yet interrelated domains. In particular, at Time 2, a seven-factor, correlated model provided a significantly better fit to the data than did a one-factor model.This work is supported by the Economic and Social Research Council/Department for International Development Joint Scheme for Research on International Development (Poverty Alleviation) grant number RES-167-25-0507 ES/H033769/1. Special thanks are due to Chaupal and Gangaram Paikra, Pritam Das, Usha Kujur, Kanti Minjh, Susanna Siddiqui, and Dinesh Tirkey

How large should whales be?

The evolution and distribution of species body sizes for terrestrial mammals is well-explained by a macroevolutionary tradeoff between short-term selective advantages and long-term extinction risks from increased species body size, unfolding above the 2g minimum size induced by thermoregulation in air. Here, we consider whether this same tradeoff, formalized as a constrained convection-reaction-diffusion system, can also explain the sizes of fully aquatic mammals, which have not previously been considered. By replacing the terrestrial minimum with a pelagic one, at roughly 7000g, the terrestrial mammal tradeoff model accurately predicts, with no tunable parameters, the observed body masses of all extant cetacean species, including the 175,000,000g Blue Whale. This strong agreement between theory and data suggests that a universal macroevolutionary tradeoff governs body size evolution for all mammals, regardless of their habitat. The dramatic sizes of cetaceans can thus be attributed mainly to the increased convective heat loss is water, which shifts the species size distribution upward and pushes its right tail into ranges inaccessible to terrestrial mammals. Under this macroevolutionary tradeoff, the largest expected species occurs where the rate at which smaller-bodied species move up into large-bodied niches approximately equals the rate at which extinction removes them.Comment: 7 pages, 3 figures, 2 data table

Simplified Waterproofing of Aerogels

A relatively simple silanization process has been developed for waterproofing or rewaterproofing aerogels, xerogels, and aerogel/tile composites, and other, similar low-density, highly microporous materials. Such materials are potentially attractive for a variety of applications especially for thermal-insulation panels that are required to be thin and lightweight. Unfortunately, such materials are also hydrophilic and tend to collapse after adsorbing water from the air. Hence, an effective means of waterproofing is necessary to enable practical exploitation of aerogels and the like. Older processes for waterproofing aerogels are time-consuming, labor-intensive, and expensive, relative to the present process. Each of the older processes includes a number of different chemical treatment steps, and some include the use of toxic halogenated surface-modifying compounds, pressures as high as hundreds of atmospheres, and/or temperatures as high as 1,000 C

Widespread association between the ericoid mycorrhizal fungus Rhizoscyphus ericae and a leafy liverwort in the maritime and sub-Antarctic

A recent study identified a fungal isolate from the Antarctic leafy liverwort Cephaloziella varians as the ericoid mycorrhizal associate Rhizoscyphus ericae. However, nothing is known about the wider Antarctic distribution of R. ericae in C. varians, and inoculation experiments confirming the ability of the fungus to form coils in the liverwort are lacking. Using direct isolation and baiting with Vaccinium macrocarpon seedlings, fungi were isolated from C. varians sampled from eight sites across a 1875-km transect through sub- and maritime Antarctica. The ability of an isolate to form coils in aseptically grown C. varians was also tested. Fungi with 98–99% sequence identity to R. ericae internal transcribed spacer (ITS) region and partial large subunit ribosomal (r)DNA sequences were frequently isolated from C. varians at all sites sampled. The EF4/Fung5 primer set did not amplify small subunit rDNA from three of five R. ericae isolates, probably accounting for the reported absence of the fungus from C. varians in a previous study. Rhizoscyphus ericae was found to colonize aseptically-grown C. varians intracellularly, forming hyphal coils. This study shows that the association between R. ericae and C. varians is apparently widespread in Antarctica, and confirms that R. ericae is at least in part responsible for the formation of the coils observed in rhizoids of field-collected C. varians

Comparing methods for estimating patient‐specific treatment effects in individual patient data meta‐analysis

Meta-analysis of individual patient data (IPD) is increasingly used to synthesize data from multiple trials. IPD meta-analysis offers several advantages over meta-analyzing aggregate data, including the capacity to individualize treatment recommendations. Trials usually collect information on many patient characteristics. Some of these covariates may strongly interact with treatment (and thus be associated with treatment effect modification) while others may have little effect. It is currently unclear whether a systematic approach to the selection of treatment-covariate interactions in an IPD meta-analysis can lead to better estimates of patient-specific treatment effects. We aimed to answer this question by comparing in simulations the standard approach to IPD meta-analysis (no variable selection, all treatment-covariate interactions included in the model) with six alternative methods: stepwise regression, and five regression methods that perform shrinkage on treatment-covariate interactions, that is, least absolute shrinkage and selection operator (LASSO), ridge, adaptive LASSO, Bayesian LASSO, and stochastic search variable selection. Exploring a range of scenarios, we found that shrinkage methods performed well for both continuous and dichotomous outcomes, for a variety of settings. In most scenarios, these methods gave lower mean squared error of the patient-specific treatment effect as compared with the standard approach and stepwise regression. We illustrate the application of these methods in two datasets from cardiology and psychiatry. We recommend that future IPD meta-analysis that aim to estimate patient-specific treatment effects using multiple effect modifiers should use shrinkage methods, whereas stepwise regression should be avoided

Weight management: a comparison of existing dietary approaches in a work-site setting

<b>OBJECTIVES:</b> (1) To compare the effectiveness a 2512 kJ (600 kcal) daily energy deficit diet (ED) with a 6279 kJ (1500 kcal) generalized low-calorie diet (GLC) over a 24 week period (12 weeks weight loss plus 12 weeks weight maintenance). (2) To determine if the inclusion of lean red meat at least five times per week as part of a slimming diet is compatible with weight loss in comparison with a diet that excludes lean red meat. DESIGN: Randomized controlled trial. <b>SETTING:</b> Large petrochemical work-site. <b>PARTICIPANTS:</b> One-hundred and twenty-two men aged between 18 and 55 y. <b>MAIN OUTCOME MEASURES:</b> Weight loss and maintenance of weight loss. <b>INTERVENTION:</b> Eligible volunteers were randomized to one of the four diet=meat combinations (ED meat, ED no meat, GLC meat, GLC no meat). One-third of subjects in each diet/meat combination were randomized to an initial control period prior to receiving dietary advice. All subjects attended for review every 2 weeks during the weight loss period. For the 12 week structured weight maintenance phase, individualized energy prescriptions were re-calculated for the ED group as 1.4 (activity factor)x basal metabolic rate. Healthy eating advice was reviewed with subjects in the GLC group. All subjects were contacted by electronic mail at 2 week intervals and anthropometric and dietary information requested. <b>RESULTS:</b> No difference was evident between diet groups in mean weight loss at 12 weeks (4.3 (s.d. 3.4) kg ED group vs 5.0 (s.d. 3.5) kg GLC group, P=0.34). Mean weight loss was closer to the intended weight loss in the 2512 kJ (600 kcal) ED group. The dropout rate was also lower than the GLC group. The inclusion of lean red meat in the diet on at least five occasions per week did not impair weight loss. Mean weight gain following 12 weeks weight maintenance was þ1.1 (s.d. 1.8) kg, P<0.0001. No differences were found between groups. <b>CONCLUSIONS:</b> This study has shown that the individualized 2512 kJ (600 kcal) ED approach was no more effective in terms of weight loss than the 6279 kJ (1500 kcal) GLC approach. However the ED approach might be considered preferable as compliance was better with this less demanding prescription. In terms of weight loss the elimination of red meat from the diet is unnecessary. The weight maintenance intervention was designed as a low-input approach, however weight regain was significant and weight maintenance strategies require further development