Role of Myosin Va in the Plasticity of the Vertebrate Neuromuscular Junction In Vivo

Background: Myosin Va is a motor protein involved in vesicular transport and its absence leads to movement disorders in humans (Griscelli and Elejalde syndromes) and rodents (e.g. dilute lethal phenotype in mice). We examined the role of myosin Va in the postsynaptic plasticity of the vertebrate neuromuscular junction (NMJ). Methodology/Principal Findings: Dilute lethal mice showed a good correlation between the propensity for seizures, and fragmentation and size reduction of NMJs. In an aneural C2C12 myoblast cell culture, expression of a dominant-negative fragment of myosin Va led to the accumulation of punctate structures containing the NMJ marker protein, rapsyn-GFP, in perinuclear clusters. In mouse hindlimb muscle, endogenous myosin Va co-precipitated with surface-exposed or internalised acetylcholine receptors and was markedly enriched in close proximity to the NMJ upon immunofluorescence. In vivo microscopy of exogenous full length myosin Va as well as a cargo-binding fragment of myosin Va showed localisation to the NMJ in wildtype mouse muscles. Furthermore, local interference with myosin Va function in live wildtype mouse muscles led to fragmentation and size reduction of NMJs, exclusion of rapsyn-GFP from NMJs, reduced persistence of acetylcholine receptors in NMJs and an increased amount of punctate structures bearing internalised NMJ proteins. Conclusions/Significance: In summary, our data show a crucial role of myosin Va for the plasticity of live vertebrate neuromuscular junctions and suggest its involvement in the recycling of internalised acetylcholine receptors back to th

Creating and Contesting Social Inequalities: Contemporary Readings

Creating and Contesting Social Inequalities: Contemporary Readings offers readings on a variety of topics, with a focus on the how of inequality. Rather than structuring the book topically, editors Carissa M. Froyum, Katrina Bloch, and Tiffany Taylor have organized the readings around social processes that reproduce and maintain inequality. This unique anthology includes social change readings throughout its entirety, rather than segmenting them at the end of the reader. It also features innovative data analysis exercises, reading questions, and social change projects. With its combination of generic processes, intersectionality, full incorporation of disabilities, global perspective, and data analysis exercises, Creating and Contesting Social Inequalities will challenge students to see themselves as agents in a system of inequality rather than passive learners. -- Provided by Amazon.comhttps://scholarworks.uni.edu/facbook/1390/thumbnail.jp

Gender composition and share of management: Tipping points in US workplaces, 1980–2005

This paper examines how concepts of gendered organizations, tokenism and the glass escalator affect women’s share of management. Specifically, we examine how the gender composition of workplaces affects women’s share of management in 195,534 workplaces using EEO-1 report data collected from the US Equal Employment Opportunity Commission from 1980 until 2005. The EEO-1 data allow us to explore the effects of gender composition on women’s share of management net of labor market change, industrial change, organizational determinants, and changes in workplace segregation using workplace-level data. We draw on past research to identify potential composition levels—tipping points—in which women have more or less share of management. Our findings suggest that across all compositions, ranging from women comprising less than 15% to over 85% of the workplace, larger percentages of the non-management women are associated with greater shares of women in management. Findings offer little support for the glass escalators hypothesis extended to workplaces, but once further contextualized, the findings do suggest that workplaces are gendered in such a way that tokenism works differently for men and women. Thus, our paper adds to the body of research on gender composition and further illustrates the need to determine under which conditions these social processes operate

Post-millennial local whiteness: racialism, white dis/advantage and the denial of racism

In the tumultuous early 21st century, vigorous appeals to whiteness in Britain are largely attributed to populist ethno-nationalism. This article offers a complementary critical account focusing on the use of ‘racialism’ as a purportedly non-invidious theoretical framework for describing racial differences and resultant societal impacts. Drawing on recent examples, especially the work of David Goodhart and Eric Kaufmann, I consider the deployment of racialism to characterise a benign white ethno-racial communalism based on ‘self-interest’ and a positive preference for ‘co-ethnics’ sharing common values. I suggest that racialist local whiteness is used to pursue two repudiatory projects: first, politically weakening black, Asian and minority ethnic groups by constituting white disadvantage; and second, disarming accounts of pervasive and systemic racism by naturalising racial stratification. Ultimately, I argue that an understanding of racialist local whiteness guards against the racial reification of populist nationalism and illuminates the deeper entrenchment of racism