Physiological and pathophysiological concentrations of fatty acids induce lipid droplet accumulation and impair functional performance of tissue engineered skeletal muscle

Fatty acids (FA) exert physiological and pathophysiological effects leading to changes in skeletal muscle metabolism and function, however, in vitro models to investigate these changes are limited. These experiments sought to establish the effects of physiological and pathophysiological concentrations of exogenous FA upon the function of tissue engineered skeletal muscle (TESkM). Cultured initially for 14 days, C2C12 TESkM was exposed to FA‐free bovine serum albumin alone or conjugated to a FA mixture (oleic, palmitic, linoleic, and α‐linoleic acids [OPLA] [ratio 45:30:24:1%]) at different concentrations (200 or 800 µM) for an additional 4 days. Subsequently, TESkM morphology, functional capacity, gene expression and insulin signaling were analyzed. There was a dose response increase in the number and size of lipid droplets within the TESkM (p < .05). Exposure to exogenous FA increased the messenger RNA expression of genes involved in lipid storage (perilipin 2 [p < .05]) and metabolism (pyruvate dehydrogenase lipoamide kinase isozyme 4 [p < .01]) in a dose dependent manner. TESkM force production was reduced (tetanic and single twitch) (p < .05) and increases in transcription of type I slow twitch fiber isoform, myosin heavy chain 7, were observed when cultured with 200 µM OPLA compared to control (p < .01). Four days of OPLA exposure results in lipid accumulation in TESkM which in turn results in changes in muscle function and metabolism; thus, providing insight ito the functional and mechanistic changes of TESkM in response to exogenous FA.</div

The roles of the formal and informal sectors in the provision of effective science education

For many years, formal school science education has been criticised by students, teachers, parents and employers throughout the world. This article presents an argument that a greater collaboration between the formal and the informal sector could address some of these criticisms. The causes for concern about formal science education are summarised and the major approaches being taken to address them are outlined. The contributions that the informal sector currently makes to science education are identified. It is suggested that the provision of an effective science education entails an enhanced complementarity between the two sectors. Finally, there is a brief discussion of the collaboration and communication still needed if this is to be effective

Teaching of Energy Issues: A debate proposal for a GLobal Reorientation

The growing awareness of serious difficulties in the learning of energy issues has produced a great deal of research, most of which is focused on specific conceptual aspects. In our opinion, the difficulties pointed out in the literature are interrelated and connected to other aspects (conceptual as well as procedural and axiological), which are not sufficiently taken into account in previous research. This paper aims to carry out a global analysis in order to avoid the more limited approaches that deal only with individual aspects. From this global analysis we have outlined 24 propositions that are put forward for debate to lay the foundations for a profound reorientation of the teaching of energy topics in upper high school courses, in order to facilitate a better scientific understanding of these topics, avoid many students' misconceptions and enhance awareness of the current situation of planetary emergency

Representational predicaments for employees: Their impact on perceptions of supervisors\u27 individualized consideration and on employee job satisfaction

A representational predicament for a subordinate vis-à-vis his or her immediate superior involves perceptual incongruence with the superior about the subordinate\u27s work or work context, with unfavourable implications for the employee. An instrument to measure the incidence of two types of representational predicament, being neglected and negative slanting, was developed and then validated through an initial survey of 327 employees. A subsequent substantive survey with a fresh sample of 330 employees largely supported a conceptual model linking being neglected and negative slanting to perceptions of low individualized consideration by superiors and to low overall job satisfaction. The respondents in both surveys were all Hong Kong Chinese. Two case examples drawn from qualitative interviews illustrate and support the conceptual model. Based on the research findings, we recommend some practical exercises to use in training interventions with leaders and subordinates. © 2013 Copyright Taylor and Francis Group, LLC

The establishment of short rotation willow coppice in mid Wales

SIGLEAvailable from British Library Document Supply Centre-DSC:DX198826 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Effects of pseudomonas syringae pv. morsprunorum strain C28, outer membrane and LPS preparations on cherry callus

Callus cultures were established from cherry (Prunus avium) cvs. Napoleon and Colt, respectively susceptible and resistant to race-1 strains of Pseudomonas syringae pv. morsprunorum, by growth on Schenk–Hildebrandt medium. On Napoleon callus, necrosis began earlier and proceeded more rapidly when inoculated with the virulent race-1 cherry isolate strain C28, than with mutants of diminished virulence derived from it, or with the virulent plum isolates D10 and D17. Colt tissue displayed poorer viability and showed susceptibility to strain C28 and the plum isolates. Callus from both sources was somewhat susceptible to the saprophytes P. aeruginosa NCIMB 8295 and P. fluorescens NCIMB 3756. Strain C28 grew on suspended Napoleon callus cells over a period of 3–4 days, causing leakage of UV-absorbing compounds and K+, with a concomitant rise in extracellular pH. P. fluorescens NCIMB 3756 showed no growth on suspended callus for 6 days. EDTA-extracted outer membrane (OM) from strain C28 caused leakage of UV absorbing material and K+, which was later reabsorbed, with little change in pH. The presence of OM suppressed the growth of a subsequent inoculum of strain C28, possibly due to complexation of the available Ca2+ and/or Mg2+ in the surrounding medium, by the component lipopolysaccharide (LPS). OM from the rough avirulent mutant strain C28-2 induced leakage of K+, but not of UV-absorbing material, and did not prevent the growth of subsequently inoculated strain C28. Smooth LPS from strain C28 did not cause leakage of K+ or of UV-absorbing material and did not prevent growth of C28. The relevance of these findings is discussed in relation to disease