205 research outputs found
Formation and contraction of a microfilamentous shell in saponin-permeabilized platelets.
Comparison of the effects of phorbol 12-myristate 13-acetate and prostaglandin E1 on calcium regulation in human platelets
Lowering pH in blood platelets dissociates myosin phosphorylation from shape change and myosin association with the cytoskeleton.
The relationship between stress fiber-like structures and nascent myofibrils in cultured cardiac myocytes.
The Alexander-Orbach conjecture holds in high dimensions
We examine the incipient infinite cluster (IIC) of critical percolation in
regimes where mean-field behavior has been established, namely when the
dimension d is large enough or when d>6 and the lattice is sufficiently spread
out. We find that random walk on the IIC exhibits anomalous diffusion with the
spectral dimension d_s=4/3, that is, p_t(x,x)= t^{-2/3+o(1)}. This establishes
a conjecture of Alexander and Orbach. En route we calculate the one-arm
exponent with respect to the intrinsic distance.Comment: 25 pages, 2 figures. To appear in Inventiones Mathematica
Pupil response hazard rates predict perceived gaze durations
We investigated the mechanisms for evaluating perceived gaze-shift duration. Timing relies on the accumulation of endogenous physiological signals. Here we focused on arousal, measured through pupil dilation, as a candidate timing signal. Participants timed gaze-shifts performed by face stimuli in a Standard/Probe comparison task. Pupil responses were binned according to âLonger/Shorterâ judgements in trials where Standard and Probe were identical. This ensured that pupil responses reflected endogenous arousal fluctuations opposed to differences in stimulus content. We found that pupil hazard rates predicted the classification of sub-second intervals (steeper dilation =âLongerâ classifications). This shows that the accumulation of endogenous arousal signals informs gaze-shift timing judgements. We also found that participants relied exclusively on the 2nd stimulus to perform the classification, providing insights into timing strategies under conditions of maximum uncertainty. We observed no dissociation in pupil responses when timing equivalent neutral spatial displacements, indicating that a stimulus-dependent timer exploits arousal to time gaze-shifts
Language attitudes, linguistic authority and independence in 21st century Catalonia
peer-reviewedIn a context of increasing linguistic and cultural diversity and political uncertainty in Catalonia, this article reports on a research project which set out to explore the attitudes of members of independence organisations operating in the city of Girona toward the Catalan and Spanish languages. This study approaches language attitudes through the theoretical lens of linguistic authority, in particular, the concepts of anonymity and authenticity. The data, gathered from six focus groups, provide an insight on the nature of linguistic authority in contemporary Catalonia. Two themes emerge in the informantsâ discussion of Catalan and Spanish: âtwenty-first Century Catalanismeâ and âEmbracing Linguistic Diversityâ. The comments of the respondents indicate that, against the backdrop of the independence process in the region, bilingualism and multilingualism have become highly valued in the territory. In addition, this study suggests that a fuller understanding of the situation in Catalonia may be facilitated by qualitative approaches, which explore attitudes in-depth
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