Hypertrophy of mature xenopus muscle fibres in culture induced by synergy of albumin and insulin

The aim of this study was to investigate effects of albumin and insulin separately as well as in combination on mature muscle fibres during long-term culture. Single muscle fibres were dissected from m. iliofibularis of Xenopus laevis and attached to a force transducer in a culture chamber. Fibres were cultured in a serum-free medium at slack length (mean sarcomere length 2.3 μm) for 8 to 22 days. The medium was supplemented with (final concentrations): (1) bovine insulin (6 nmol/L or 200-600 nmol/L), (2) 0.2% bovine albumin or (3) 0.2% bovine albumin in combination with insulin (120 nmol/L). In culture medium with insulin, 50% of the muscle fibres became in-excitable within 7-12 days, whereas the other 50% were stable. Caffeine contractures of in-excitable muscle fibres produced 80.4±2.4% of initial peak tetanic force, indicating impaired excitation-contraction (E-C) coupling in in-excitable fibres. In the presence of albumin, all cultured muscle fibres were stable for at least 10 days. Muscle fibres cultured in medium with insulin or albumin exclusively did not hypertrophy or change the number of sarcomeres in series. In contrast, muscle fibres cultured with both albumin and insulin showed an increase in tetanic force and fibre cross-sectional area of 19.6±2.8% and 32.5±4.9%, respectively, (means±SEM.; P=0.007) after 16.3±1.7 days, whereas the number of sarcomeres in series remained unchanged. We conclude that albumin prevents muscle fibre damage and preserves E-C coupling in culture. Furthermore, albumin is important in regulating muscle fibre adaptation by a synergistic action with growth factors like insulin. © 2008 The Author(s)

Seduced by System: Edmund Burke's Aesthetic Embrace of Adam Smith's Philosophy

No abstract available

Between Commerce and Empire: David Hume, Colonial Slavery, and Commercial Incivility

Eighteenth-century Enlightenment thought has recently been reclaimed as a robust, albeit short-lived, cosmopolitan critique of European imperialism. This essay complicates this interpretation through a study of David Hume’s reflections on commerce, empire and slavery. I argue that while Hume condemned the colonial system of monopoly, war and conquest, his strictures against empire did not extend to colonial slavery in the Atlantic. This was because colonial slavery represented a manifestly uncivil institution when judged by enlightened metropolitan sensibilities, yet also a decisively commercial institution pivotal to the eighteenth-century global economy. Confronted by the paradoxical ‘commercial incivility’ of modern slavery, Hume opted for disavowing the link between slavery and commerce, and confined his criticism of slavery to its ancient, feudal and Asiatic incarnations. I contend that Hume’s disavowal of the commercial barbarism of the Atlantic economy is part of a broader ideological effort to separate the idea of commerce from its imperial origins and posit it as the liberal antithesis of empire. The implications of analysis, I conclude, go beyond the eighteenth-century debates over commerce and empire, and more generally pertain to the contradictory entwinement of liberalism and capitalism

Why Can't You All Just Get Along?: Effects of Political Conflict among Outgroups Pre-Analysis Plan

This document contains the motivation, theory, hypotheses, design, and analysis plan for a survey experiment regarding the effects of political conflict among outgroups. The study draws on balance theory from social psychology to make predictions about a) the consequences of political disputes among two social groups toward which an individual feels positively and b) the role of cognitive dissonance in mediating these effects. We randomly assign participants to one of four experimental conditions, separately manipulating the presence of political conflict and the opportunity to attribute the resulting dissonance to an unrelated source

Why Can\u27t You All Just Get Along?: Effects of Political Conflict among Outgroups Pre-Analysis Plan

This document contains the motivation, theory, hypotheses, design, and analysis plan for a survey experiment regarding the effects of political conflict among outgroups. The study draws on balance theory from social psychology to make predictions about a) the consequences of political disputes among two social groups toward which an individual feels positively and b) the role of cognitive dissonance in mediating these effects. We randomly assign participants to one of four experimental conditions, separately manipulating the presence of political conflict and the opportunity to attribute the resulting dissonance to an unrelated source

Replication Data for: Pigeonholing Partisans: Stereotypes of Party Supporters and Partisan Polarization

These are the replication files for Pigeonholing Partisans. They include the R scripts to conduct the analyses in the paper and online appendix and the datasets (as .dta files)

Involvement, Tate and me

The involvement construct has been explored in relation to products, services and leisure but not in an art museum context. The purpose of this paper is to address this theoretical gap by drawing on the marketing and leisure literature to understand members’ consumption of Tate using the involvement construct. Tate, a portfolio of four art museums in the UK has more than 90,000 members that receive a benefits package in return for a membership fee. Data were collected using an interpretive, qualitative approach. 59 face to face semi-structured interviews were conducted with Tate Members during spring 2008. The narratives expose the complexity in exploring the involvement construct and the analysis revealed six new involvement characteristics: 1) Centrality and Pleasure; 2) Desire to Learn; 3) Escapism: Spirituality and Creativity; 4) Sense of Belonging and Prestige; 5) Physical; and 6) Drivers of Involvement. These are discussed in the context of previous studies into museum consumption, services and leisure involvement literature. The authors discuss how these findings may be transferred to other settings and the managerial implications for marketers and membership managers are considered