210,546 research outputs found

    Hippocampus-dependent emergence of spatial sequence coding in retrosplenial cortex.

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    Retrosplenial cortex (RSC) is involved in visuospatial integration and spatial learning, and RSC neurons exhibit discrete, place cell-like sequential activity that resembles the population code of space in hippocampus. To investigate the origins and population dynamics of this activity, we combined longitudinal cellular calcium imaging of dysgranular RSC neurons in mice with excitotoxic hippocampal lesions. We tracked the emergence and stability of RSC spatial activity over consecutive imaging sessions. Overall, spatial activity in RSC was experience-dependent, emerging gradually over time, but, as seen in the hippocampus, the spatial code changed dynamically across days. Bilateral but not unilateral hippocampal lesions impeded the development of spatial activity in RSC. Thus, the emergence of spatial activity in RSC, a major recipient of hippocampal information, depends critically on an intact hippocampus; the indirect connections between the dysgranular RSC and the hippocampus further indicate that hippocampus may exert such influences polysynaptically within neocortex

    Negotiating Relationally: The Dynamics of the Relational Self In Negotiations

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    Although negotiation research is thriving, it has been criticized as having an arelational bias—emphasizing autonomy, competition, and rationality over interdependence, cooperation, and relationality. In this article, we advance a new model of relationality in negotiation. Drawing on research in social psychology, we describe the construct of relational self-construals (RSC) and present a temporal model of RSC and negotiation. After delineating the conditions through which RSC becomes accessible in negotiation and conditions that inhibit its use, we discuss how RSC affects negotiators\u27 pre-negotiation psychological states, early and later tactics, and negotiation outcomes. We illustrate a number of distinct relational dynamics that can occur based on the dyadic composition of RSC, each of which brings distinct benefits and costs to the negotiation table. Implications for the science and practice of negotiation are discussed

    Architecture of the chromatin remodeler RSC and insights into its nucleosome engagement.

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    Eukaryotic DNA is packaged into nucleosome arrays, which are repositioned by chromatin remodeling complexes to control DNA accessibility. The Saccharomyces cerevisiae RSC (Remodeling the Structure of Chromatin) complex, a member of the SWI/SNF chromatin remodeler family, plays critical roles in genome maintenance, transcription, and DNA repair. Here, we report cryo-electron microscopy (cryo-EM) and crosslinking mass spectrometry (CLMS) studies of yeast RSC complex and show that RSC is composed of a rigid tripartite core and two flexible lobes. The core structure is scaffolded by an asymmetric Rsc8 dimer and built with the evolutionarily conserved subunits Sfh1, Rsc6, Rsc9 and Sth1. The flexible ATPase lobe, composed of helicase subunit Sth1, Arp7, Arp9 and Rtt102, is anchored to this core by the N-terminus of Sth1. Our cryo-EM analysis of RSC bound to a nucleosome core particle shows that in addition to the expected nucleosome-Sth1 interactions, RSC engages histones and nucleosomal DNA through one arm of the core structure, composed of the Rsc8 SWIRM domains, Sfh1 and Npl6. Our findings provide structural insights into the conserved assembly process for all members of the SWI/SNF family of remodelers, and illustrate how RSC selects, engages, and remodels nucleosomes

    Pressure Evolution of the Ferromagnetic and Field Re-entrant Superconductivity in URhGe

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    Fine pressure (PP) and magnetic field (HH) tuning on the ferromagnetic superconductor URhGe are reported in order to clarify the interplay between the mass enhancement, low field superconductivity (SC) and field reentrant superconductivity (RSC) by electrical resistivity measurements. With increasing PP, the transition temperature and the upper critical field of the low field SC decrease slightly, while the RSC dome drastically shifts to higher fields and shrinks. The spin reorientation field HRH_{\rm R} also increases. At a pressure P1.8P\sim 1.8 GPa, the RSC has collapsed while the low field SC persists and may disappear only above 4 GPa. Via careful (P,H)(P, H) studies of the inelastic T2T^2 resistivity term, it is demonstrated that this drastic change is directly related with the PP dependence of the effective mass which determines the critical field of the low field SC and RSC on the basis of triplet SC without Pauli limiting field.Comment: 5 pages, 6 figures, to appear in Journal of the Physical Society of Japa

    Transcranial magnetic stimulation disrupts the perception and embodiment of facial expressions

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    Copyright © 2008 Society for Neuroscience and the authors. The The Journal of Neuroscience uses a Creative Commons Attribution-NonCommercial-ShareAlike licence: http://creativecommons.org/licenses/by-nc-sa/4.0/.Theories of embodied cognition propose that recognizing facial expressions requires visual processing followed by simulation of the somatovisceral responses associated with the perceived expression. To test this proposal, we targeted the right occipital face area (rOFA) and the face region of right somatosensory cortex (rSC) with repetitive transcranial magnetic stimulation (rTMS) while participants discriminated facial expressions. rTMS selectively impaired discrimination of facial expressions at both sites but had no effect on a matched face identity task. Site specificity within the rSC was demonstrated by targeting rTMS at the face and finger regions while participants performed the expression discrimination task. rTMS targeted at the face region impaired task performance relative to rTMS targeted at the finger region. To establish the temporal course of visual and somatosensory contributions to expression processing, double-pulse TMS was delivered at different times to rOFA and rSC during expression discrimination. Accuracy dropped when pulses were delivered at 60–100 ms at rOFA and at 100–140 and 130–170 ms at rSC. These sequential impairments at rOFA and rSC support embodied accounts of expression recognition as well as hierarchical models of face processing. The results also demonstrate that nonvisual cortical areas contribute during early stages of expression processing.Biotechnology and Biological Sciences Research Counci

    A Snapshot of Homelessness in the Bay Area

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    The Regional Steering Committee (RSC) has focused for over two decades on estimating the number of homeless people in each county and the region. We have often discussed the challenge of finding data to back the trends that providers see every day in shelters, housing and service centers. Early efforts centered on capturing a census of bed use and turn-aways. Statistical efforts using the AFDC-HAP program were done annually during the 1990's. With more wide-spread use of technology, and after substantial review of research methodologies, HUD began requiring that jurisdictions receiving federal funding for homeless assistance through the McKinney-Vento Homeless Assistance Act conduct a point-in-time (PIT) homeless count every two years. But how much do these PIT counts reflect what we see in our communities? And how do they fit with the other data we see, from HMIS, national studies, and other sources?The RSC has discussed completing the homeless census and evaluating the resulting data several times over the years. In June 2002, we discussed methodologies and the cost-effectiveness of counting the homeless. In May 2004, we looked into the value of HMIS in this effort. In November of the same year, HomeBase presented a briefing memo to the RSC on HUD's suggested methodologies for conducting homeless counts. In March 2005, April 2007, and March 2009, and January 2010 the RSC discussed the homeless count results for those years and provided feedback and impressions of the counts conducted in members' communities. In July 2007, we discussed methodologies for enumerating the homeless population. In 2012, HUD began requiring CoCs to conduct sheltered point-in-time counts in even-numbered years in addition to the existing biennial sheltered/unsheltered count; the RSC discussed approaches to sheltered point-in-time counts in that year. Most recently, in May of this year, we debriefed community processes for the 2013 point-in-time and housing inventory counts as well as plans for 2014. This memo provides an updated snapshot of homelessness in the Bay Area and other local communities based on point-in-time count data

    Refinement Types for TypeScript

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    We present Refined TypeScript (RSC), a lightweight refinement type system for TypeScript, that enables static verification of higher-order, imperative programs. We develop a formal core of RSC that delineates the interaction between refinement types and mutability. Next, we extend the core to account for the imperative and dynamic features of TypeScript. Finally, we evaluate RSC on a set of real world benchmarks, including parts of the Octane benchmarks, D3, Transducers, and the TypeScript compiler

    Single-ensemble-based eigen-processing methods for color flow imaging-Part I. the Hankel-SVD filter

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    Because of their adaptability to the slow-time signal contents, eigen-based filters have shown potential in improving the flow detection performance of color flow images. This paper proposes a new eigen-based filter called the Hankel-SVD filter that is intended to process each slow- time ensemble individually. The new filter is derived using the notion of principal Hankel component analysis, and it achieves clutter suppression by retaining only the principal components whose order is greater than the clutter eigen- space dimension estimated from a frequency-based analysis algorithm. To assess its efficacy, the Hankel-SVD filter was first applied to synthetic slow-time data (ensemble size: 10) simulated from two different sets of flow parameters that model: (1) arterial imaging (blood velocity: 0 to 38.5 cm/s, tissue motion: up to 2 mm/s, transmit frequency: 5 MHz, pulse repetition period: 0.4 ms) and 2) deep vessel imaging (blood velocity: 0 to 19.2 cm/s, tissue motion: up to 2 cm/s, transmit frequency: 2 MHz, pulse repetition period: 2.0 ms). In the simulation analysis, the post-filter clutter- to-blood signal ratio (CBR) was computed as a function of blood velocity. Results show that for the same effective stopband size (50 Hz), the Hankel-SVD filter has a narrower transition region in the post-filter CBR curve than that of another type of adaptive filter called the clutter- downmixing filter. The practical efficacy of the proposed filter was tested by application to in vivo color flow data obtained from the human carotid arteries (transmit frequency: 4 MHz, pulse repetition period: 0.333 ms, ensemble size: 10). The resulting power images show that the Hankel-SVD filter can better distinguish between blood and moving- tissue regions (about 9 dB separation in power) than the clutter-downmixing filter and a fixed-rank multi-ensemble- based eigen-filter (which showed a 2 to 3 dB separation). © 2006 IEEE.published_or_final_versio
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