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Structural Processes (structural + process)
Selected AbstractsArginine-induced conformational change in the c -ring/a -subunit interface of ATP synthaseFEBS JOURNAL, Issue 9 2008Thomas Vorburger The rotational mechanism of ATP synthases requires a unique interface between the stator a subunit and the rotating c -ring to accommodate stability and smooth rotation simultaneously. The recently published c -ring crystal structure of the ATP synthase of Ilyobacter tartaricus represents the conformation in the absence of subunit a. However, in order to understand the dynamic structural processes during ion translocation, studies in the presence of subunit a are required. Here, by intersubunit Cys,Cys cross-linking, the relative topography of the interacting helical faces of subunits a and c from the I. tartaricus ATP synthase has been mapped. According to these data, the essential stator arginine (aR226) is located between the c -ring binding pocket and the cytoplasm. Furthermore, the spatially vicinal residues cT67C and cG68C in the isolated c -ring structure yielded largely asymmetric cross-linking products with aN230C of subunit a, suggesting a small, but significant conformational change of binding-site residues upon contact with subunit a. The conformational change was dependent on the positive charge of the stator arginine or the aR226H substitution. Energy-minimization calculations revealed possible modes for the interaction between the stator arginine and the c -ring. These biochemical results and structural restraints support a model in which the stator arginine operates as a pendulum, moving in and out of the binding pocket as the c -ring rotates along the interface with subunit a. This mechanism allows efficient interaction between subunit a and the c- ring and simultaneously allows almost frictionless movement against each other. [source] Marking Difference and Negotiating Belonging: Refugee Women, Volunteering and EmploymentGENDER, WORK & ORGANISATION, Issue 3 2010Frances Tomlinson Refugee women occupy a position at a neglected point of intersection of many categories of difference. This article draws on a study of pathways from voluntary work into paid employment for refugee women in the UK and reveals how they drew on these markers of difference to express and explain their experiences of exclusion or belonging. Their accounts are considered alongside those of organizational representatives, who drew on vocabularies of equality and diversity to construct refugee women as organizational outsiders or insiders. The article explores the interplay between the active agency of refugee women in negotiating the possibilities of belonging and the effect of discursive practices and structural processes that tend to perpetuate their outsider status. It concludes by briefly considering the relevance of these findings to current controversies concerning the impact of policies of managing diversity and multiculturalism on combating inequality and discrimination. [source] Tracing Differentiation in Gendered Leadership: An Analysis of Differences in Gender Composition in Top Management in Business, Politics and the Civil ServiceGENDER, WORK & ORGANISATION, Issue 1 2002Lis Højgaard The aim of this article is to discuss the relationship between the gendering of leadership positions and sector-specific structures within politics, business and the civil service in Denmark in the context of differences between the Nordic countries and other western countries. The analysis is based on data from a survey of top male and female leaders within the three sectors. The theoretical point of departure of this article is constructivist. It looks at gender as constituted by actions in social space, orchestrated by structural processes and a symbolic order of gender. This constitutes a cultural discourse on gender reflected in gender conventions in society and in a range of possibilities of gender positioning. Expressions of this are discussed in the analysis of the patterns of difference in structural conditions for women and men in leadership positions to be found within the three sectors. The structural conditions encompass access conditions and conditions for gendered positioning and are analysed on the basis of data on social background, education, career course, family, children and distribution of housework. The analysis shows that there is a correlation between gender composition of leadership and possibilities of gendered positioning within a sector. The results are finally discussed as possible expressions of an egalitarian culture. [source] One-dimensional thermal modelling of Acadian metamorphism in southern Vermont, USAJOURNAL OF METAMORPHIC GEOLOGY, Issue 6 2000T. R. Armstrong One-dimensional thermal (1DT) modelling of an Acadian (Devonian) tectonothermal regime in southern Vermont, USA, used measured metamorphic pressures and temperatures and estimated metamorphic cooling ages based on published thermobarometric and geochronological studies to constrain thermal and tectonic input parameters. The area modelled lies within the Vermont Sequence of the Acadian orogen and includes: (i) a western domain containing garnet-grade pre-Silurian metasedimentary and metavolcanic rocks from the eastern flank of an Acadian composite dome structure (Rayponda,Sadawga Dome); and (ii) an eastern domain containing similar, but staurolite- or kyanite-grade, rocks from the western flank of a second dome structure (Athens Dome), approximately 10 km farther east. Using reasonable input parameters based on regional geological, petrological and geochronological constraints, the thermal modelling produced plausible P,T paths, and temperature,time (T ,t) and pressure,time (P,t) curves. Information extracted from P,T ,t modelling includes values of maximum temperature and pressure on the P,T paths, pressure at maximum temperature, predicted Ar closure ages for hornblende, muscovite and K-feldspar, and integrated exhumation and cooling rates for segments of the cooling history. The results from thermal modelling are consistent with independently obtained pressure, temperature and Ar cooling age data on regional metamorphism in southern Vermont. Modelling results provide some important bounding limits on the physical conditions during regional metamorphism, and indicate that the pressure contemporaneous with the attainment of peak temperature was probably as much as 2.5 kbar lower than the actual maximum pressure experienced by rocks along various particle paths. In addition, differences in peak metamorphic grade (garnet-grade versus staurolite-grade or kyanite-grade) and peak temperature for rocks initially loaded to similar crustal depths, differences in calculated exhumation rates, and differences in 40Ar/39Ar closure ages are likely to have been consequences of variations in the duration of isobaric heating (or ,crustal residence periods') and tectonic unroofing rates. Modelling results are consistent with a regional structural model that suggests west to east younging of specific Acadian deformational events, and therefore diachroneity of attainment of peak metamorphic conditions and subsequent 40Ar/39Ar closure during cooling. Modelling is consistent with the proposition that regional variations in timing and peak conditions of metamorphism are the result of the variable depths to which rocks were loaded by an eastward-thickening thrust-nappe pile rooted to the east (New Hampshire Sequence), as well as by diachronous structural processes within the lower plate rocks of the Vermont Sequence. [source] ARTICLES: REPRODUCTIVE TOURISM AND THE QUEST FOR GLOBAL GENDER JUSTICEBIOETHICS, Issue 7 2010ANNE DONCHIN ABSTRACT Reproductive tourism is a manifestation of a larger, more inclusive trend toward globalization of capitalist cultural and material economies. This paper discusses the development of cross-border assisted reproduction within the globalized economy, transnational and local structural processes that influence the trade, social relations intersecting it, and implications for the healthcare systems affected. I focus on prevailing gender structures embedded in the cross-border trade and their intersection with other social and economic structures that reflect and impact globalization. I apply a social connection model of responsibility for unjust outcomes and consider strategies to counter structural injustices embedded in this industry. The concluding section discusses policy reforms and proposals for collaborative action to preclude further injustices and extend full human rights to all. [source] Struggles Over the Shore: building the quay of Izmir, 1867,1875CITY & SOCIETY, Issue 1 2000Sibel Zandi-Sayek BEGINNING IN THE MID-NINETEENTH CENTURY, the urban landscape of the Ottoman seaport of Izmir, like other centers on the eastern Mediterranean, was profoundly transformed by the advent of modern forms of urban institutions and infrastructure. Studies dealing with these transformations have been so immersed in structural processes of European economic penetration that little has been known on the ways in which local actors participated in these changes and reworked them to address their own urban concerns and ambitions. Focusing on the remaking of the quay in Izmir, this essay explores how the project triggered discursive and practical struggles among Ottoman administrators, shore owners, local merchants, and a progressive elite, by transforming land tenure patterns and modes of handling trade and shipping on the shore. In doing so, it demonstrates how existing power relations and the complexity of the local urban context reshaped'and gave meaning to this urban modernization scheme. [Modernization, urban elite, public interest, Izmir, Turkey] [source] | ||||||||||