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Conceptual Discussion (conceptual + discussion)
Selected AbstractsElements of a neurobiological theory of hippocampal function: the role of synaptic plasticity, synaptic tagging and schemasEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2006R. G. M. MorrisArticle first published online: 8 JUN 200 Abstract The 2004 EJN Lecture was an attempt to lay out further aspects of a developing neurobiological theory of hippocampal function [Morris, R.G.M., Moser, E.I., Riedel, G., Martin, S.J., Sandin, J., Day, M. & O'Carroll, C. (2003) Phil. Trans. R. Soc. Lond. B Biol. Sci., 358, 773,786.] These are that (i) activity-dependent synaptic plasticity plays a key role in the automatic encoding and initial storage of attended experience; (ii) the persistence of hippocampal synaptic potentiation over time can be influenced by other independent neural events happening closely in time, an idea with behavioural implications for memory; and (iii) that systems-level consolidation of memory traces within neocortex is guided both by hippocampal traces that have been subject to cellular consolidation and by the presence of organized schema in neocortex into which relevant newly encoded information might be stored. Hippocampal memory is associative and, to study it more effectively than with previous paradigms, a new learning task is described which is unusual in requiring the incidental encoding of flavour,place paired associates, with the readout of successful storage being successful recall of a place given the flavour with which it was paired. NMDA receptor-dependent synaptic plasticity is shown to be critical for the encoding and intermediate storage of memory traces in this task, while AMPA receptor-mediated fast synaptic transmission is necessary for memory retrieval. Typically, these rapidly encoded traces decay quite rapidly over time. Synaptic potentiation also decays rapidly, but can be rendered more persistent by a process of cellular consolidation in which synaptic tagging and capture play a key part in determining whether or not it will be persistent. Synaptic tags set at the time of an event, even many trivial events, can capture the products of the synthesis of plasticity proteins set in train by events before, during or even after an event to be remembered. Tag,protein interactions stabilize synaptic potentiation and, by implication, memory. The behavioural implications of tagging are explored. Finally, using a different protocol for flavour,place paired associate learning, it is shown that rats can develop a spatial schema which represents the relative locations of several different flavours of food hidden at places within a familiar space. This schema is learned gradually but, once acquired, enables new paired associates to be encoded and stored in one trial. Their incorporation into the schema prevents rapid forgetting and suggests that schema play a key and hitherto unappreciated role in systems-level memory consolidation. The elements of what may eventually mature into a more formal neurobiological theory of hippocampal memory are laid out as specific propositions with detailed conceptual discussion and reference to recent data. [source] ,GLOCAL' MOVEMENTS: PLACE STRUGGLES AND TRANSNATIONAL ORGANIZING BY INFORMAL WORKERSGEOGRAFISKA ANNALER SERIES B: HUMAN GEOGRAPHY, Issue 2 2009Ilda Lindell ABSTRACT. This paper investigates the scalar practices of collectively organized informal workers and the political implications of such practices. It illustrates how the studied group organizes across scales , hence, a ,glocal movement', and stresses the importance of an analysis that integrates these multiple scales of collective organizing, as they may have a bearing on each other. In so doing, it contests a common tendency to analytically privilege one or other scale of resistance and agency. In particular, I argue that networking across scales may be of significance for local struggles and thus play a role in local politics. The transnational activities of the studied group assist it in challenging local power relations and dominant place projects that repress informal livelihood activities. This paper comprises a conceptual discussion of notions of scale, of conceptions of the spatialities and scales of resistance as well as of place, followed by an empirical illustration that refers to an association of informal vendors in Maputo, Mozambique, and its international connections. The analysis is based on interviews with vendors, leaders of the association and with the international partners of the association. [source] Studying Contemporary Constitutionalism: Memory, Myth and HorizonJCMS: JOURNAL OF COMMON MARKET STUDIES, Issue 1 2010HANNES HANSEN-MAGNUSSON This article proposes to apply a praxeological approach to study contemporary constitutionalism. The approach is conceptualized following critical constructivist research on constitutionalism that focuses on experience and expectation when studying the contested meaning of norms in international relations. It argues that the concept of memory offers an important view on the language-based concept of experience which extends beyond the confines of behavioural approaches that study habitual change with regard to norms. The article offers a conceptual discussion of approaches to constitutionalism, emphasizing the distinction between modern and contemporary constitutionalism and their respective foci on regulatory versus cultural practices, introduces a praxeological dimension of horizons and elaborates on political memory and myth as concepts of functional memory. [source] Assigning priority to environmental policy interventions in a heterogeneous worldJOURNAL OF POLICY ANALYSIS AND MANAGEMENT, Issue 1 2003Paul J. Ferraro Failure to consider costs as well as benefits is common in many policy initiatives and analyses, particularly in the environmental arena. Economists and other policy scientists have demonstrated that integrating both cost and benefit information explicitly into the policy process can be vital to ensuring that scarce funds go as far as they can toward achieving policy objectives. The costs of acquiring and analyzing such information, however, can be substantial. The objective of this paper is to help policy analysts and practitioners identify the conditions under which integrating cost and benefit information is likely to be vital to effective decisionmaking, and the conditions under which failing to use both cost and benefit data would result in little, if any, loss in efficiency. These points are illustrated through a conceptual discussion and an empirical analysis of a conservation initiative in the United States. © 2003 by the Association for Public Policy Analysis and Management. [source] Validation and advantages of FAWSETS perfusion measurements in skeletal muscleNMR IN BIOMEDICINE, Issue 4 2005Kenneth I. Marro Abstract This work discusses the strengths, limitations and validity of a novel arterial spin labeling technique when used specifically to measure perfusion in limb skeletal muscle. The technique, flow-driven arterial water stimulation with elimination of tissue signal (FAWSETS), offers several advantages over existing arterial spin labeling techniques. The primary goal of this study was to determine the perfusion signal response to changes in net hind limb flow that were independently verifiable. The range of perfusate flow was relevant to skeletal muscle during mild to moderate exercise. Localized, single voxel measurements were acquired from a 5,mm-thick slice in the isolated perfused rat hind limb at variable net flow rates. The results show that the perfusion signal is linearly proportional to net hind limb flow with a correlation coefficient of 0.974 (p,=,0.0013). FAWSETS is especially well suited for studies of skeletal muscle perfusion, where it eliminates the need to compensate for magnetization transfer and arterial transit time effects. A conceptual discussion of the basic principles underlying these advantages is presented. Copyright © 2005 John Wiley & Sons, Ltd. [source] Rank and health: a conceptual discussion of subjective health and psychological perceptions of social statusPSYCHOTHERAPY AND POLITICS INTERNATIONAL, Issue 1 2006Pierre Morin Abstract The social dimensions of health and illness have been studied extensively from a materialistic angle. The nonmaterial or subjective factors of social experience affecting health have only recently received some attention. This paper introduces a new multidimensional concept of rank, which includes social dimensions as well as nonmaterially based elements of emotional, psychological, and spiritual strength. It proposes that rank is an important addition to the current literature of socioeconomic inequality and health and examines its relevance for the discussion of how social status inequalities affect people's global health. It suggests that rank as a signifier of power contributes to feelings of powerlessness and leads to worsened health outcomes. This paper suggests that perceived rank may play a role in the socioeconomic status (SES) effect on self-reported health. It presents a new conceptual and therapeutic model to address issues of rank-based discrimination in health care. Copyright © 2006 John Wiley & Sons, Ltd. [source] | ||||||||||