564 research outputs found
Cosmological Multi-Black Hole Solutions
We present simple, analytic solutions to the Einstein-Maxwell equation, which
describe an arbitrary number of charged black holes in a spacetime with
positive cosmological constant . In the limit , these
solutions reduce to the well known Majumdar-Papapetrou (MP) solutions. Like the
MP solutions, each black hole in a solution has charge equal
to its mass , up to a possible overall sign. Unlike the limit,
however, solutions with are highly dynamical. The black holes move
with respect to one another, following natural trajectories in the background
deSitter spacetime. Black holes moving apart eventually go out of causal
contact. Black holes on approaching trajectories ultimately merge. To our
knowledge, these solutions give the first analytic description of coalescing
black holes. Likewise, the thermodynamics of the solutions is
quite interesting. Taken individually, a black hole is in thermal
equilibrium with the background deSitter Hawking radiation. With more than one
black hole, because the solutions are not static, no global equilibrium
temperature can be defined. In appropriate limits, however, when the black
holes are either close together or far apart, approximate equilibrium states
are established.Comment: 15 pages (phyzzx), UMHEP-380 (minor referencing error corrected
Designing multiplayer games to facilitate emergent social behaviours online
This paper discusses an exploratory case study of the design of games that facilitate spontaneous social interaction and group behaviours among distributed individuals, based largely on symbolic presence 'state' changes. We present the principles guiding the design of our game environment: presence as a symbolic phenomenon, the importance of good visualization and the potential for spontaneous self-organization among groups of people. Our game environment, comprising a family of multiplayer 'bumper-car' style games, is described, followed by a discussion of lessons learned from observing users of the environment. Finally, we reconsider and extend our design principles in light of our observations
Entrepreneurial sons, patriarchy and the Colonels' experiment in Thessaly, rural Greece
Existing studies within the field of institutional entrepreneurship explore how entrepreneurs influence change in economic institutions. This paper turns the attention of scholarly inquiry on the antecedents of deinstitutionalization and more specifically, the influence of entrepreneurship in shaping social institutions such as patriarchy. The paper draws from the findings of ethnographic work in two Greek lowland village communities during the military Dictatorship (1967â1974). Paradoxically this era associated with the spread of mechanization, cheap credit, revaluation of labour and clear means-ends relations, signalled entrepreneurial sonsâ individuated dissent and activism who were now able to question the Patriarchâs authority, recognize opportunities and act as unintentional agents of deinstitutionalization. A âdifferentâ model of institutional change is presented here, where politics intersects with entrepreneurs, in changing social institutions. This model discusses the external drivers of institutional atrophy and how handling dissensus (and its varieties over historical time) is instrumental in enabling institutional entrepreneurship
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Developing the concept of society: Institutional domains, regimes of inequalities and complex systems in a global era
This article develops the concept of society to meet the challenge of cross-border and global processes. Global processes have made visible the inadequacy of interpreting the concept of society as if it were a nation-state, since there is a lack of congruence of institutional domains (economy, polity, civil society, violence) and regimes of inequality (class, gender, ethnicity). The article engages with two strands of intellectual heritage in sociological analysis of society as a macro concept: the differentiation of institutions and the relations of inequality. The concepts of society and societalisation are developed by hybridising these two approaches rather than selecting only one or the other. To achieve this, the concept of system is developed by drawing on complexity science. This enables the simultaneous analysis of differentiated institutional domains (economy, polity, violence, civil society) and multiple regimes of inequality without reductionism. In turn, this facilitates the fluent theorisation of variations in the temporal and spatial reach of social systems
Acetylcholine turnover in an autoactive molluscan neuron
1. We have studied acetylcholine (ACh) turnover at the cholinergic synapse between an identified motoneuron, the salivary burster (SB), and the muscle cells of the salivary duct (SD) in the terrestrial mollusk Limax maximus.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44284/1/10571_2004_Article_BF00710939.pd
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'Open Marxism' against and beyond the 'Great Enclosure'? Reflections on How (Not) to Crack Capitalism
The main purpose of this article is to provide an in-depth discussion of John Hollowayâs recent book, Crack Capitalism. To this end, the paper offers a detailed account of the key strengths and weaknesses of Hollowayâs version of âopen Marxismâ. The analysis is divided into two parts. The first part focuses on six significant strengths of Crack Capitalism: (1) its insistence upon the importance of autonomous forms of agenda-setting for both individual and collective emancipation; (2) its emphasis on the ordinary constitution of social struggles; (3) its fine-grained interpretation of the socio-ontological conditions underlying human agency; (4) its processual conception of radical social transformation; (5) its recognition of the elastic, adaptable, and integrative power of capitalism; and (6) its proposal for an alternative critical theory, commonly known as âopen Marxismâ or âautonomous Marxismâ. The second part of the study examines the principal weaknesses of Crack Capitalism: (1) the counterproductive implications of the preponderance of negativity, owing to a one-sided concern with critique, cracks, and crises; (2) conceptual vagueness; (3) an overuse of poetic and metaphorical language; (4) the absence of a serious engagement with the question of normativity; (5) a lack of substantive evidence; (6) a residual economic reductionism; (7) a simplistic notion of gender; (8) the continuing presence of various problematic âismsâ; (9) the misleading distinction between âdoingâ and âlabourâ; (10) a reductive understanding of capitalism; (11) an unrealistic view of society; and (12) socio-ontological idealis
Modernization and Its Discontents
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67022/2/10.1177_000276427702100208.pd
Computational and mathematical approaches to societal transitions
After an introduction of the theoretical framework and concepts of transition studies, this article gives an overview of how structural change in social systems has been studied from various disciplinary perspectives. This overview first leads to the conclusion that computational and mathematical approaches and their practical form, modeling, up till now, have been almost absent in the research and theorizing of structural change or transitions in social systems. Second, this review of the social science literature suggests numerous theoretical constructs relevant for transition modeling. Relevant concepts include the conceptualization of the micro-to-macro link, the importance of explaining both stability and change, quantitative and qualitative definitions of structural change, the use of dichotomies, synchronic and diachronic reasoning in explaining structural change, definitions of basic patterns of social change, the conceptualization of resistance to change and intentional and normative aspects of social change. This article employs these theoretical concepts to describe and discuss the models presented in this special issue in order to develop an understanding of what exactly entails a computational or mathematical approach to societal transitions
âEither Everyone Was Guilty or Everyone Was Innocentâ: The Italian Power Elite, Neopatrimonialism, and the Importance of Social Relations
Rarely does the Byzantine world of football administration get exposed as clearly as during the 2006 calciopoli scandal. This scandal laid bare the interpersonal relationships of football administrators at the top three Italian menâs football clubs: Juventus, Inter, and AC Milan. This article draws on the media leaks that revealed the inner workings of those working within football to argue that the football clubs are pyramids of power for club presidents that allows them to operate within the Italian power elite. This is done through interpersonal clientelistic networks that operate within a neopatrimonial system. Theoretically, this article draws on four main concepts: C. Wright Millsâs concept of the Power Elite, Lomnitzâs model of âPyramids of Power,â Eisenstadtâs notion of neopatrimonialism, and Maussâs utilization of the gift. Power is exercised through quid pro quo relationships, with certain key individuals operating as brokers to the flow of favors throughout the network
Grounds for engagement: Dissonances and overlaps at the intersection of contemporary civilizations analysis and postcolonial sociology
This article elucidates grounds for engagement between two fields of the social sciences engaged in critique of Eurocentrism: contemporary civilizations analysis and postcolonial sociology. Between the two fields there are both evident dissonances and points of potential dialogue and engagement. The article identifies three areas of high contention: divergent perceptions of essentialism, commitments to transformative politics and evaluations of the paradigm of multiple modernities. Despite extensive theoretical and normative differences, a notional intersection of the two fields is outlined in the form of three conceptual and methodological shifts. The first is a displacement of ideal typology. The second move is the most original. âIntercivilizational encountersâ and âintracivilizational encountersâ are re-cast as âintercivilizational engagementâ. The goal is the demarcation of a discrete position based on a strong version of interaction that goes further than the notion of intercivilizational encounters recently re-developed in civilizational analysis. To illustrate potential grounds for engagement on this point, the article reviews the historiography of âconnected historiesâ and the insights of relational historians. Finally, the article urges for a nuanced definition of âregionâ and deeper appreciation of the multiplicity of regionalisms as a meeting point for both fields of critique of Eurocentrism
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