Gluon Radiation off Hard Quarks in a Nuclear Environment: Opacity Expansion

We study the relation between the Baier-Dokshitzer-Mueller-Peigne-Schiff (BDMPS) and Zakharov formalisms for medium-induced gluon radiation off hard quarks, and the radiation off very few scattering centers. Based on the non-abelian Furry approximation for the motion of hard partons in a spatially extended colour field, we derive a compact diagrammatic and explicitly colour trivial expression for the N-th order term of the kt-differential gluon radiation cross section in an expansion in the opacity of the medium. Resumming this quantity to all orders in opacity, we obtain Zakharov's path-integral expression (supplemented with a regularization prescription). This provides a new proof of the equivalence of the BDMPS and Zakharov formalisms which extends previous arguments to the kt-differential cross section. We give explicit analytical results up to third order in opacity for both the gluon radiation cross section of free incoming and of in-medium produced quarks. The N-th order term in the opacity expansion of the radiation cross section is found to be a convolution of the radiation associated to N-fold rescattering and a readjustment of the probabilities that rescattering occurs with less than N scattering centers. Both informations can be disentangled by factorizing out of the radiation cross section a term which depends only on the mean free path of the projectile. This allows to infer analytical expressions for the totally coherent and totally incoherent limits of the radiation cross section to arbitrary orders in opacity.Comment: 22 pages, LaTeX, eps-figures included, typos corrected, Comment on (5.13) added, to appear in NP

Identity ambiguity and the promises and practices of hybrid e-HRM project teams

The role of IS project team identity work in the enactment of day-to-day relationships with their internal clients is under-researched. We address this gap by examining the identity work undertaken by an electronic human resource management (e-HRM) 'hybrid' project team engaged in an enterprise-wide IS implementation for their multi-national organisation. Utilising social identity theory, we identify three distinctive, interrelated dimensions of project team identity work (project team management, team 'value propositions' (promises) and the team's 'knowledge practice'). We reveal how dissonance between two perspectives of e-HRM project identity work (clients' expected norms of project team's service and project team's expected norms of themselves) results in identity ambiguity. Our research contributions are to identity studies in the IS project management, HR and hybrid literatures and to managerial practice by challenging the assumption that hybrid experts are the panacea for problems associated with IS projects

'Mamlukisation' between social theory and social practice: an essay on reflexivity, state formation, and the late medieval sultanate of Cairo

This working paper is a reflexive essay that tries to think with and beyond one of the basic assumptions upon which the field of late medieval Syro-Egyptian ‘Mamluk’ studies is built: the idea that all late medieval Syro-Egyptian objects of study are by default first and foremost connected, circumscribed and distinguished by some agency of dominant military slavery, of Mamluk-ness. Acknowledging that there may be different ways to pursue such an epistemological exercise, this essay opts for re-imagining the historical agency of what traditionally tends to be subsumed under the phenomenon of the Mamluk state. It is argued that the notions of state in modern research and of dawla in contemporary texts remain an issue of related analytical confusion. Engaging with this confusion in the generalising fashion of a historical sociology of late medieval Syro-Egyptian political action, this essay proposes an alternative analytical model that is inspired by Michael Chamberlain’s prioritisation of social practices of household reproduction and by Timothy Mitchell’s related understanding of the state as a structural effect of practices of social differentiation. The proposed model sees sultanic political order —the state— as process, in constant flux as the structural effect and structuring embodiment of constantly changing practices of social reproduction, of elite integration and of political distinction, in contexts that range between multipolar and unipolar social organisation at and around Cairo’s court and its military elites. The essay ends with summarily suggesting from this model how the socio-culturally structured and structuring memories of dynastic political order that had remained politically dominant for most of the thirteenth and fourteenth centuries were all but obliterated in the fifteenth century by a new layer of particularly ‘Mamluk’ socio-political meaning

Autonomy and autonomy disturbances in self-development and psychopathology: research on motivation, attachment, and clinical process

Self-determination theory (SDT) maintains that the adequate support and satisfaction of individuals' psychological needs for autonomy, competence, and relatedness promotes the gradual unfolding of individuals' integrative tendencies, as manifested through intrinsic motivation, internalization, identity development, and integrative emotion regulation. At the same time, the thwarting of these same psychological needs and the resultant need frustration is presumed to evoke or amplify a variety of psychopathologies, many of which involve autonomy disturbances. We begin by defining what autonomy involves and how socializing agents, particularly parents, can provide a nurturing (i.e., need-supportive) environment, and we review research within the SDT literature that has shed light on various integrative tendencies and how caregivers facilitate them. In the second part of this chapter, we detail how many forms of psychopathology involve autonomy disturbances and are associated with a history of psychological need thwarting. We especially focus on internally controlling regulation in internalizing disorders; impairments of internalization in conduct disorders and antisocial behavior; and fragmented self-functioning in borderline and dissociative disorders. The role of autonomy support as an ameliorative factor in treatment settings is then discussed among other translational issues. Finally we highlight some implications of recognizing the important role of basic psychological needs for both growth-related and pathology-related processes

European integration and the social science of EU studies: the disciplinary politics of a subfield

This article takes the 50th anniversary of the Treaty of Rome as an opportunity to reflect upon half a century of academic discourse about the EU and its antecedents. In particular, it illuminates the theoretical analysis of European integration that has developed within political science and international studies broadly defined. It asks whether it is appropriate to map, as might be tempting, the intellectual 'progress' of the field of study against the empirical evolution of its object (European integration/the EU). The argument to be presented here is that while we can, to some extent, comprehend the evolution of academic thinking about the EU as a reflex to critical shifts in the 'real world' of European integration ('externalist' drivers), it is also necessary to understand 'internalist' drivers of theoretical discourse on European integration/the EU. The article contemplates two such 'internalist' components that have shaped and continue to shape the course of EU studies: scholarly contingency (the fact that scholarship does not proceed with free agency, but is bound by various conditions) and disciplinary politics (the idea that the course of academic work is governed by power games and that there are likely significant disagreements about best practice and progress in a field). In terms of EU studies, the thrust of disciplinary politics tends towards an opposition between 'mainstreaming' and 'pluralist versions' of the political science of EU studies. The final section explores how, in the face of emerging monistic claims about propriety in the field, an effective pluralist political science of the EU might be enhanced

Neural correlates of enhanced visual short-term memory for angry faces: An fMRI study

Copyright: © 2008 Jackson et al.Background: Fluid and effective social communication requires that both face identity and emotional expression information are encoded and maintained in visual short-term memory (VSTM) to enable a coherent, ongoing picture of the world and its players. This appears to be of particular evolutionary importance when confronted with potentially threatening displays of emotion - previous research has shown better VSTM for angry versus happy or neutral face identities.Methodology/Principal Findings: Using functional magnetic resonance imaging, here we investigated the neural correlates of this angry face benefit in VSTM. Participants were shown between one and four to-be-remembered angry, happy, or neutral faces, and after a short retention delay they stated whether a single probe face had been present or not in the previous display. All faces in any one display expressed the same emotion, and the task required memory for face identity. We find enhanced VSTM for angry face identities and describe the right hemisphere brain network underpinning this effect, which involves the globus pallidus, superior temporal sulcus, and frontal lobe. Increased activity in the globus pallidus was significantly correlated with the angry benefit in VSTM. Areas modulated by emotion were distinct from those modulated by memory load.Conclusions/Significance: Our results provide evidence for a key role of the basal ganglia as an interface between emotion and cognition, supported by a frontal, temporal, and occipital network.The authors were supported by a Wellcome Trust grant (grant number 077185/Z/05/Z) and by BBSRC (UK) grant BBS/B/16178

Seeing More than Orange: Organizational Respect and Positive Identity Transformation in a Prison Context

This paper develops grounded theory on how receiving respect at work enables individuals to engage in positive identity transformation and the resulting personal and work-related outcomes. A company that employs inmates at a state prison to perform professional business-to-business marketing services provided a unique context for data collection. Our data indicate that inmates experienced respect in two distinct ways, generalized and particularized, which initiated an identity decoupling process that allowed them to distinguish between their inmate identity and their desired future selves and to construct transitional identities that facilitated positive change. The social context of the organization provided opportunities for personal and social identities to be claimed, respected, and granted, producing social validation and enabling individuals to feel secure in their transitional identities. We find that security in personal identities produces primarily performance-related outcomes, whereas security in the company identity produces primarily well-being-related outcomes. Further, these two types of security together foster an integration of seemingly incompatible identities—”identity holism”—as employees progress toward becoming their desired selves. Our work suggests that organizations can play a generative role in improving the lives of their members through respect-based processes

Artificial and Natural Genetic Information Processing

Conventional methods of genetic engineering and more recent genome editing techniques focus on identifying genetic target sequences for manipulation. This is a result of historical concept of the gene which was also the main assumption of the ENCODE project designed to identify all functional elements in the human genome sequence. However, the theoretical core concept changed dramatically. The old concept of genetic sequences which can be assembled and manipulated like molecular bricks has problems in explaining the natural genome-editing competences of viruses and RNA consortia that are able to insert or delete, combine and recombine genetic sequences more precisely than random-like into cellular host organisms according to adaptational needs or even generate sequences de novo. Increasing knowledge about natural genome editing questions the traditional narrative of mutations (error replications) as essential for generating genetic diversity and genetic content arrangements in biological systems. This may have far-reaching consequences for our understanding of artificial genome editing