Steady and transient conjugate heat transfer modelling of IGBTS subjected to liquid cooling by a membrane heat sink for rolling

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.A 3-D modeling technology based on Conjugate Heat Transfer (CHT) is developed to demonstrate numerically the thermal and hydrodynamic capabilities of a liquid cooled heat sink equipped with six high power semi-conductor modules of IGBT type. Calculated results are validated against experiments for three types of heat dissipating situations, where the diodes and transistors within the modules are heated simultaneously and separately. The CHT modeling is carried out with the commercially available software STAR-CCM+ from CDAdapco. The modeling accounts for all thin materials of the thermal stack of the six IGBT modules, the thermal compound, the aluminum based heat sink with surface enlargements and turbulent coolant flow. Encouraged by the agreement regarding numerical and experimental steady state results, a transient modeling practice is developed for the entire system. The transient modeling enables accurate and controlled studies of the thermal impedances of step responses that are often challenging to achieve in a laboratory. The novelty is the ability to return accurate time relaxation factors between heat sink and water for the whole system. Moreover, the transient results of the step responses are used to derive equivalent circuit models of Foster type. To that end, so-called H and Y models are devised and optimized that are able to predict essential mechanisms of the thermal cross talk of diodes and transistors. Such models are important in the daily work to provide swift and accurate results of the temperature response and life length analysis of dimensioning load cycles pertinent to rolling stock applications.cf201

A pilot controlled trial of a cognitive dissonance-based body dissatisfaction intervention with young British men

This pilot study evaluated a body image intervention for men, Body Project M. Seventy-four British undergraduate men took part in two 90-min intervention sessions, and completed standardised assessments of body image, bulimic pathology, and related outcomes at baseline, post-intervention, and 3-month follow-up. Fifty-three other men completed the questionnaires as an assessment-only control group. Per-protocol analysis showed that Body Project M improved men’s dissatisfaction with body fat and muscularity, body appreciation, muscularity enhancing behaviours, appearance comparisons, and internalization (ds = 0.46 - 0.80) at post-intervention. All except dissatisfaction with muscularity and internalization were sustained at 3-month follow-up. No effects were found for bulimic pathology. Post-intervention effects for dissatisfaction with muscularity and internalization only were retained under intention-to-treat analysis. Participants were favourable towards the intervention. This study provides preliminary evidence for the acceptability and post-intervention efficacy of Body Project M. Further development of the intervention is required to improve and sustain effects

Turkish Accession and Defining the Boundaries of Nationalism and Supranationalism: Discourses in the European Commission

The European Union in general and the European Commission in particular are characterised by supranational governance. The enlargement policy gives the Commission the opportunity to export and promote supranational norms and define the boundaries of Europe as a supranational polity through the conditionality of membership and intensive contact with the candidate countries. This article analyses the discourses of the Commission on Turkey and gives us insights into how well Turkey fits the supranational model in the eyes of Commission officials. It demonstrates how the boundaries of supranationalism are set and even challenged by the prospects of Turkey’s accession

Young men’s minimisation of their body dissatisfaction

Objective: To examine men’s body dissatisfaction qualitatively. Design: Forty-two British men aged 18–45 years took part in a two-session group intervention across 12 groups. The intervention was designed to improve body dissatisfaction by engaging them in a critique of the appearance ideal through written and behavioural exercises. Main outcome measures/results: Analysis of the topics discussed during the intervention generated two core themes. Theme 1 showed that, in general, men minimised the existence of their own body dissatisfaction while (somewhat surprisingly) outlining the ubiquity and potency of the appearance ideal for men in general. Theme 2 involved men reporting the problematic impact of body dissatisfaction in their lives (despite earlier minimisation), such as social avoidance, strict eating and supplement regimes, or difficulty in situations where the body was exposed. Conclusion: The results stress the need to acknowledge that men experience a range of impacts of body dissatisfaction beyond clinical presentations (such as disordered eating) that influence their everyday lives, while also recognising that they tend to minimise this dissatisfaction in conversation. These findings have important implications for advocacy and interventions to improve men’s body dissatisfaction

Syndecan-4 Is Essential for Development of Concentric Myocardial Hypertrophy via Stretch-Induced Activation of the Calcineurin-NFAT Pathway

Sustained pressure overload leads to compensatory myocardial hypertrophy and subsequent heart failure, a leading cause of morbidity and mortality. Further unraveling of the cellular processes involved is essential for development of new treatment strategies. We have investigated the hypothesis that the transmembrane Z-disc proteoglycan syndecan-4, a co-receptor for integrins, connecting extracellular matrix proteins to the cytoskeleton, is an important signal transducer in cardiomyocytes during development of concentric myocardial hypertrophy following pressure overload. Echocardiographic, histochemical and cardiomyocyte size measurements showed that syndecan-4−/− mice did not develop concentric myocardial hypertrophy as found in wild-type mice, but rather left ventricular dilatation and dysfunction following pressure overload. Protein and gene expression analyses revealed diminished activation of the central, pro-hypertrophic calcineurin-nuclear factor of activated T-cell (NFAT) signaling pathway. Cardiomyocytes from syndecan-4−/−-NFAT-luciferase reporter mice subjected to cyclic mechanical stretch, a hypertrophic stimulus, showed minimal activation of NFAT (1.6-fold) compared to 5.8-fold increase in NFAT-luciferase control cardiomyocytes. Accordingly, overexpression of syndecan-4 or introducing a cell-permeable membrane-targeted syndecan-4 polypeptide (gain of function) activated NFATc4 in vitro. Pull-down experiments demonstrated a direct intracellular syndecan-4-calcineurin interaction. This interaction and activation of NFAT were increased by dephosphorylation of serine 179 (pS179) in syndecan-4. During pressure overload, phosphorylation of syndecan-4 was decreased, and association between syndecan-4, calcineurin and its co-activator calmodulin increased. Moreover, calcineurin dephosphorylated pS179, indicating that calcineurin regulates its own binding and activation. Finally, patients with hypertrophic myocardium due to aortic stenosis had increased syndecan-4 levels with decreased pS179 which was associated with increased NFAT activation. In conclusion, our data show that syndecan-4 is essential for compensatory hypertrophy in the pressure overloaded heart. Specifically, syndecan-4 regulates stretch-induced activation of the calcineurin-NFAT pathway in cardiomyocytes. Thus, our data suggest that manipulation of syndecan-4 may provide an option for therapeutic modulation of calcineurin-NFAT signaling

Mechanisms of leukocyte migration across the blood–retina barrier

Immune-mediated inflammation in the retina is regulated by a combination of anatomical, physiological and immuno-regulatory mechanisms, referred to as the blood–retina barrier (BRB). The BRB is thought to be part of the specialised ocular microenvironment that confers protection or “immune privilege” by deviating or suppressing destructive inflammation. The barrier between the blood circulation and the retina is maintained at two separate anatomical sites. These are the endothelial cells of the inner retinal vasculature and the retinal pigment epithelial cells on Bruch’s membrane between the fenestrated choroidal vessels and the outer retina. The structure and regulation of the tight junctions forming the physical barrier are described. For leukocyte migration across the BRB to occur, changes are needed in both the leukocytes themselves and the cells forming the barrier. We review how the blood–retina barrier is compromised in various inflammatory diseases and discuss the mechanisms controlling leukocyte subset migration into the retina in uveoretinitis in more detail. In particular, we examine the relative roles of selectins and integrins in leukocyte interactions with the vascular endothelium and the pivotal role of chemokines in selective recruitment of leukocyte subsets, triggering adhesion, diapedesis and migration of inflammatory cells into the retinal tissue