4,779 research outputs found
Thermodynamics of Heat Shock Response
Production of heat shock proteins are induced when a living cell is exposed
to a rise in temperature. The heat shock response of protein DnaK synthesis in
E.coli for temperature shifts from temperature T to T plus 7 degrees,
respectively to T minus 7 degrees is measured as function of the initial
temperature T. We observe a reversed heat shock at low T. The magnitude of the
shock increases when one increase the distance to the temperature , thereby mimicking the non monotous stability of proteins at low
temperature. Further we found that the variation of the heat shock with T
quantitatively follows the thermodynamic stability of proteins with
temperature. This suggest that stability related to hot as well as cold
unfolding of proteins is directly implemented in the biological control of
protein folding. We demonstrate that such an implementation is possible in a
minimalistic chemical network.Comment: To be published in Physical Review Letter
Charles Tilly as a Theorist of Nationalism
This paper considers Charles Tilly as an important but underappreciated theorist of nationalism. Tilly’s theory of nationalism emerged from the “bellicist” strand of his earlier work on state-formation and later incorporated a concern with performance, stories, and cultural modeling. Yet despite the turn to culture in Tilly’s later work, his theory of nationalism remained state-centered, materialist, and instrumentalist—a source of both its power and its limitations
CD105 (Endoglin) exerts prognostic effects via its role in the microvascular niche of paediatric high grade glioma
Paediatric high grade glioma (pHGG) (World Health Organisation astrocytoma grades III and IV) remains poor prognosis tumours, with a median survival of only 15 months following diagnosis. Current investigation of anti-angiogenic strategies has focused on adult glioblastoma multiforme (GBM) with phase III trials targeting vascular endothelial growth factor continuing. In this study we investigated whether the degree of vascularity correlated with prognosis in a large cohort of pHGG (n = 150) and whether different vessel markers carried different prognostic value. We found that CD105 (endoglin) had a strongly significant association with poor prognosis on multivariate analysis (p = <0.001). Supervised hierarchical clustering of genome wide gene expression data identified 13 genes associated with differential degrees of vascularity in the cohort. The novel angiogenesis-associated genes identified in this analysis (including MIPOL-1 and ENPP5) were validated by realtime polymerase chain reaction. We also demonstrate that CD105 positive blood vessels associate with CD133 positive tumour cells and that a proportion of CD105 positive vessel cells demonstrates co-positivity for CD133, suggesting that the recently described phenomenon of vasculogenic mimicry occurs in pHGG. Together, the data suggest that targeting angiogenesis, and in particular CD105, is a valid therapeutic strategy for pHGG
Political Regimes and Sovereign Credit Risk in Europe, 1750-1913
This article uses a new panel data set to perform a statistical analysis of political regimes and sovereign credit risk in Europe from 1750 to 1913. Old Regime polities typically suffered from fiscal fragmentation and absolutist rule. By the start of World War I, however, many such countries had centralized institutions and limited government. Panel regressions indicate that centralized and?or limited regimes were associated with significant improvements in credit risk relative to fragmented and absolutist ones. Structural break tests also reveal close relationships between major turning points in yield series and political transformations
A 'Performative' Social Movement: The Emergence of Collective Contentions within Collaborative Governance
The enmeshment of urban movements in networks of collaborative governance has been characterised as a process of co-option in which previously disruptive contentions are absorbed by regimes and reproduced in ways that do not threaten the stability of power relations. Applying a theoretical framework drawn from feminist philosopher Judith Butler this paper directs attention to the development of collective oppositional identities that remain embedded in conventional political processes. In a case study of the English tenants' movement, it investigates the potential of regulatory discourses that draw on market theories of performative voice to offer the collectivising narratives and belief in change that can generate the emotional identification of a social movement. The paper originates the concept of the ‘performative social movement’ to denote the contentious claims that continue to emerge from urban movements that otherwise appear quiescent
A comparative framework: how broadly applicable is a 'rigorous' critical junctures framework?
The paper tests Hogan and Doyle's (2007, 2008) framework for examining critical junctures. This framework sought to incorporate the concept of ideational change in understanding critical junctures. Until its development, frameworks utilized in identifying critical junctures were subjective, seeking only to identify crisis, and subsequent policy changes, arguing that one invariably led to the other, as both occurred around the same time. Hogan and Doyle (2007, 2008) hypothesized ideational change as an intermediating variable in their framework, determining if, and when, a crisis leads to radical policy change. Here we test this framework on cases similar to, but different from, those employed in developing the exemplar. This will enable us determine whether the framework's relegation of ideational change to a condition of crisis holds, or, if ideational change has more importance than is ascribed to it by this framework. This will also enable us determined if the framework itself is robust, and fit for the purposes it was designed to perform — identifying the nature of policy change
Power and the durability of poverty: a critical exploration of the links between culture, marginality and chronic poverty
Risks, alternative knowledge strategies and democratic legitimacy: the conflict over co-incineration of hazardous industrial waste in Portugal.
The decision to incinerate hazardous industrial waste in cement plants (the socalled
‘co-incineration’ process) gave rise to one of the most heated environmental
conflicts ever to take place in Portugal. The bitterest period was between 1997 and
2002, after the government had made a decision. Strong protests by residents,
environmental organizations, opposition parties, and some members of the
scientific community forced the government to backtrack and to seek scientific
legitimacy for the process through scientific expertise. The experts ratified the
government’s decision, stating that the risks involved were socially acceptable.
The conflict persisted over a decade and ended up clearing the way for a more
sustainable method over which there was broad social consensus – a multifunctional
method which makes it possible to treat, recover and regenerate most
wastes. Focusing the analysis on this conflict, this paper has three aims: (1) to
discuss the implications of the fact that expertise was ‘confiscated’ after the
government had committed itself to the decision to implement co-incineration and
by way of a reaction to the atmosphere of tension and protest; (2) to analyse the
uses of the notions of ‘risk’ and ‘uncertainty’ in scientific reports from both
experts and counter-experts’ committees, and their different assumptions about
controllability and criteria for considering certain practices to be sufficiently safe
for the public; and (3) to show how the existence of different technical scientific
and political attitudes (one more closely tied to government and the corporate
interests of the cement plants, the other closer to the environmental values of reuse
and recycling and respect for the risk perception of residents who challenged
the facilities) is closely bound up with problems of democratic legitimacy. This
conflict showed how adopting more sustainable and lower-risk policies implies a
broader view of democratic legitimacy, one which involves both civic movements
and citizens themselves
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