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31.
Long-term synaptic enhancement in the hippocampus has been suggested to cause deficits in spatial performance. Synaptic enhancement has been reported after hippocampal kindling that induced repeated electrographic seizures or afterdischarges (ADs) and after long-term potentiation (LTP) defined as synaptic enhancement without ADs. We studied whether repeated stimulations that gave LTP or ADs resulted in spatial performance deficits on the radial arm maze (RAM) and investigated the minimal number of ADs required for such deficits. Three experimental groups were run as follows: (1) 5 hippocampal ADs in 1 d (5-AD group), (2) 10 hippocampal ADs in 2 d (10-AD group), and (3) 12 -frequency primed-burst stimulations (PBSs) in 2 d in order to induce LTP without ADs (LTP group). Each experimental group was run together with a control group during the same time period. Rats were first trained in a spatial task on a radial arm maze with four of the eight arms baited, then given control or experimental treatment, and maze performance was tested in the first week (1-4 d) and fourth week (22-25 d) after treatment. Basal dendritic population excitatory postsynaptic potentials (pEPSPs) and medial perforant path (MPP)-evoked dentate gyrus population spike and polysynaptic CA1 excitation were recorded before and after experimental and control treatment. Spatial memory errors, in particular reference memory errors, were significantly higher in the 10-AD kindled group than any other group on the first and fourth week after treatment. Spatial memory errors were not significantly different in the 5-AD and LTP groups as compared with any control groups at any time. Basal dendritic pEPSP in CA1 was enhanced for about 1 wk after 12 PBSs, 10 ADs, or 5 ADs, while the dentate gyrus population spike and CA1 polysynaptic excitation evoked by MPP was increased for up to 4 wk after 10 ADs, but not 12 PBSs. Thus, distributed alteration of multiple synaptic transmission in the entorhinal-hippocampal circuit, but not LTP at the basal dendritic synapses in CA1, may disrupt spatial performance after 10 hippocampal ADs.  相似文献   
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The influence of estradiol on learning and memory is dependent on a number of factors. The effects of physiological levels of estradiol on the acquisition of a spatial working memory task mediated by the prefrontal cortex (PFC) and the hippocampus were examined in Experiment 1. Ovariectomized Long-Evans rats received daily injections of estradiol or vehicle were tested on the win-shift version of the radial arm maze. A high dose of estradiol benzoate (5 microg) enhanced acquisition of the task, whereas a low dose of estradiol (0.3 microg) increased the number of errors committed over 17 days of testing. Experiment 2 was conducted to examine site-specific influences of estradiol on spatial working memory in well-trained rats. Saline and estradiol cyclodextrin (0.1 and 0.9 microg) were infused into the prelimbic region of the PFC or dorsal hippocampus 40 min prior to testing on the win-shift task. Infusions of estradiol into both brain areas attenuated saline-infusion disruptions in working memory. Specifically, the higher dose of estradiol facilitated working memory when infused into the PFC, whereas the lower dose of estradiol facilitated performance when infused into the dorsal hippocampus. Moreover, working memory was significantly impaired 24 h after infusions of estradiol into the dorsal hippocampus but not the PFC. These data provide further evidence for the notion that estradiol can dose-dependently alter memory processes and suggest that facilitation or disruptions of working memory by estradiol are site- and time-specific.  相似文献   
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The widespread development of comprehensive community initiatives that aim to improve community health is driven by the need to change the systems charged with delivering the services and creating the policies related to a variety of health outcomes. Georgia's Family Connection initiative is the nation's largest statewide network of community collaboratives for health, with collaboratives operating in 159 counties. Data on community context, collaborative processes, engagement in systems change, and changes in programs and activities implemented, gathered consistently at the collaborative level over 3 years, will be used to answer the following questions. How do community contexts and the structure and processes of collaboratives affect implementation of systems change? How do systems changes affect intermediate outcomes such as the type of programs offered in a community? Longitudinal change in systems change and program implementation is described and significant predictors of between‐collaborative variation in longitudinal change for each outcome are identified.  相似文献   
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Contemporary discussion concerning institutions focus on, and mostly accept, the Searlean view that institutional objects, i.e. money, borders and the like, exist in virtue of the fact that we collectively represent them as existing. A dissenting note has been sounded by Smit et al. (Econ Philos 27:1–22, 2011), who proposed the incentivized action view of institutional objects. On the incentivized action view, understanding a specific institution is a matter of understanding the specific actions that are associated with the institution and how we are incentivized to perform these actions. In this paper we develop the incentivized action view by extending it to institutions like property, promises and complex financial organisations like companies. We also highlight exactly how the incentivized action view differs from the Searlean view, discuss the method appropriate to such study and discuss some of the virtues of the incentivized action view.  相似文献   
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Stan Chu Ilo 《Heythrop Journal》2012,53(6):1005-1025
This essay is a critical theological and pastoral study of the Working Document of the Second African Synod. The article engages the articles in the document which deal with the theme of reconciliation. This essay begins by exploring the Christological and ecclesiological foundations for an African theology of reconciliation as found in the working document. While engaging the significant aspects of the working document which relate to articulating an African theology of reconciliation, this essay shows the limitations of the document in its historical and cultural analysis of the situation in Africa. Drawing from a phenomenological hermeneutical engagement with African history, cultural grammar, and Christ‐centered African Christian imagination, the essay widens the scope of theological engagement with the task of reconciliation in Africa. It does a theological aesthetics of reconciliation in Africa, by integrating diverse cultural, ontological, and Christological symbols within the African world on vital participation and vital union. Through the inculturation of vital participation as analogous to Trinitarian Communion, the essay shows how the Church in Africa can deal with the ever‐revolving cycle of violence, conflicts, and divisions in the churches and political institutions which have all hampered the mission of building relationship and God's kingdom in Africa. The essay concludes by recommending four pastoral approaches through which the Catholic Church in Africa can be both a reconciled community and an instrument for reconciliation in Africa.  相似文献   
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The objective of the present study was to examine the joint effects of stress, coping, and coping resources in predicting depressive symptoms. A community sample comprising 194 people aged 65 and older was interviewed. Task-oriented coping and emotion-oriented coping both appeared to be directly related to depressive symptoms. In addition, emotion-oriented coping moderated the impact of stress to varying degrees, depending on the amount of stress experienced. Coping resources (social support and coping self-efficacy) also were directly related to depressive symptoms. Furthermore, coping self-efficacy appeared to be related to the kind of coping strategies used. Respondents with higher coping self-efficacy used more task-oriented coping and less emotion-oriented coping. These findings suggest that it is advisable to include coping resources when studying stress-coping processes. Developing prevention and intervention programs aimed at teaching people adaptive coping strategies and helping them to build up their coping resources seems advisable.  相似文献   
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We summarize a recent search for quantum reality. The full anhomomorphic logic of coevents for an event set is introduced. The quantum integral over an event with respect to a coevent is defined. Reality filters such as preclusivity and regularity of coevents are considered. A quantum measure that can be represented as a quantum integral with respect to a coevent is said to 1-generate that coevent. This gives a stronger filter that may produce a unique coevent called the “actual reality” for a physical system. What we believe to be a more general filter is defined in terms of a double quantum integral and is called 2-generation. It is noted that ordinary measures do not 1 or 2-generate coevents except in a few simple cases. Various general results are stated.  相似文献   
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