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General Perspective (general + perspective)

Distribution by Scientific Domains

Humanities and Social Sciences	50%

Selected Abstracts

Computational significance of transient dynamics in cortical networks

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2008
Daniel Durstewitz
Abstract Neural responses are most often characterized in terms of the sets of environmental or internal conditions or stimuli with which their firing rate are correlated increases or decreases. Their transient (nonstationary) temporal profiles of activity have received comparatively less attention. Similarly, the computational framework of attractor neural networks puts most emphasis on the representational or computational properties of the stable states of a neural system. Here we review a couple of neurophysiological observations and computational ideas that shift the focus to the transient dynamics of neural systems. We argue that there are many situations in which the transient neural behaviour, while hopping between different attractor states or moving along ,attractor ruins', carries most of the computational and/or behavioural significance, rather than the attractor states eventually reached. Such transients may be related to the computation of temporally precise predictions or the probabilistic transitions among choice options, accounting for Weber's law in decision-making tasks. Finally, we conclude with a more general perspective on the role of transient dynamics in the brain, promoting the view that brain activity is characterized by a high-dimensional chaotic ground state from which transient spatiotemporal patterns (metastable states) briefly emerge. Neural computation has to exploit the itinerant dynamics between these states. [source]

The Participant's Dilemma: Bringing Conflict and Representation Back In

INTERNATIONAL JOURNAL OF URBAN AND REGIONAL RESEARCH, Issue 3 2010
DEBBIE BECHER
Abstract Innovations in democratic participation involving small-scale, long-term focused governing bodies have increased citizen influence in poor American urban neighborhoods. Scholars have described these emerging forms of participation as essentially cooperative in spirit and directly democratic in nature. I argue that the new participatory regimes continue to involve social processes of representation and conflict inherent to more traditional forms of engagement. Participants move dynamically between cooperation and conflict and between participating as individuals and representing constituencies. This article presents a careful study of how a single decision developed and was implemented in such a participatory experiment, the American Street Empowerment Zone in Philadelphia, Pennsylvania, USA, between 1994 and 2008. Archival and interview data support the general perspective shared by articles in this symposium , that participation involves dynamic movement between conflict and cooperation. This article suggests that the durability of the participatory regime depends not on the level of conflict but on how participants move between displaying identification with either government or their community constituents. This article uses the concept of intermediation to describe this kind of dynamism and to reflect the flexibility a participatory structure must nurture to endure. Résumé Les innovations en matière de participation démocratique qui impliquent des organes de gouvernement ,uvrant à petite échelle et à long terme ont accru l'influence des habitants dans les quartiers urbains pauvres américains. D'après certains auteurs, ces formes nouvelles de participation sont, dans l'esprit, essentiellement coopératives et, par nature, directement démocratique. Il est exposé ici que les nouveaux régimes participatifs font encore intervenir des processus sociaux de représentation et de conflit propres à des formes d'engagement plus traditionnelles. Les participants oscillent de manière dynamique entre coopération et conflit, et entre participation en tant qu'individus et représentation collective. Cet article présente une étude minutieuse de la manière dont une décision a étéélaborée et mise en ,uvre dans le cadre d'une expérience participative de ce type, ,American Street Empowerment Zone'à Philadelphie (Pennsylvanie), de 1994 à 1998. Des données issues d'archives et d'entretiens corroborent la perspective générale commune aux articles de ce symposium: la participation implique un mouvement dynamique entre conflit et coopération. L'article suggère que la pérennité du régime participatif dépend, non pas du niveau de conflit, mais de la façon dont les participants alternent dans leur manifestation d'une identification soit au gouvernement soit aux membres de leur communauté. Le concept d'intermédiation est utilisé pour décrire cette forme de dynamique et pour traduire la souplesse que doit garder une structure participative pour perdurer. [source]

MULTIPLE FACILITIES, STRATEGIC SPLITTING AND VERTICAL STRUCTURES: STABILITY, GROWTH AND DISTRIBUTION RECONSIDERED,

THE MANCHESTER SCHOOL, Issue 5 2006
DAN COFFEY
This paper explores comparative cost structures when large firms split operations between separate production facilities in a way that puts pressure on wage rates and worker effort levels: one example of a ,divide and rule' strategy. It differentiates horizontal structures of this kind based on requirements for stability in a context of growing aggregate production vis-à-vis wages and effort. The analysis is formulated within a more general perspective that also considers vertical structures. It considers the implications for contemporary policy debates on desirable industrial forms, and concludes with a discussion of factors that might limit the scope for policies intended to promote industrial stability and redistribution via existing production networks. [source]

Food Process Engineering: The Last 25 Years and Challenges Ahead

COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 2 2003
S. Bruin
ABSTRACT In the first part of this contribution, an overview is given of some of the main developments in food process engineering in the last 25 years of the 20th century. This overview is, of course, colored by the personal experience of the authors, but a sincere effort was made to maintain a general perspective. Topics that will be briefly discussed are: progress in understanding how to control food microstructure formation during processing, separation processes, conversion processes and stabilization processes, progress in flavor technology and understanding of flavor retention during processing and release. In the 2nd part, in our view, the most exiting future developments are briefly discussed. The major items here are: processing requirements for functional foods, integrated process design approaches, application of novel,fields'in food processes,,precision'processing, supply chain approaches to food manufacturing, and more. [source]