Territorial Developments Based on Graffiti: a Statistical Mechanics Approach

We study the well-known sociological phenomenon of gang aggregation and territory formation through an interacting agent system defined on a lattice. We introduce a two-gang Hamiltonian model where agents have red or blue affiliation but are otherwise indistinguishable. In this model, all interactions are indirect and occur only via graffiti markings, on-site as well as on nearest neighbor locations. We also allow for gang proliferation and graffiti suppression. Within the context of this model, we show that gang clustering and territory formation may arise under specific parameter choices and that a phase transition may occur between well-mixed, possibly dilute configurations and well separated, clustered ones. Using methods from statistical mechanics, we study the phase transition between these two qualitatively different scenarios. In the mean-field rendition of this model, we identify parameter regimes where the transition is first or second order. In all cases, we have found that the transitions are a consequence solely of the gang to graffiti couplings, implying that direct gang to gang interactions are not strictly necessary for gang territory formation; in particular, graffiti may be the sole driving force behind gang clustering. We further discuss possible sociological -- as well as ecological -- ramifications of our results

Spelling dyslexia:a defict of the visual word form

A patient with spelling dyslexia read both words and text accurately but slowly and laboriously letter by letter. Her performance on a test of lexical decision was slow. She had great difficulty in detecting a 'rogue' letter attached to the beginning or end of a word--for example, ksong--or in parsing two unspaced words, such as applepeach. By contrast she was immune to the effects of interpolating extraneous coloured letters in a word, a manipulation that affects normal readers. Therefore it is argued that this patient had damage to an early stage in the reading process, to the visual word form itself

Elevation of plasma high-density lipoproteins inhibits development of experimental abdominal aortic aneurysms

Objective— Patients with abdominal aortic aneurysms have lower concentrations of high-density lipoproteins (HDLs), leading us to investigate whether increasing plasma HDLs could influence aneurysm formation. Methods and Results— Using the angiotensin II−induced hypercholesterolemic and the CaCl2-induced normocholesterolemic mouse model of AAA, we investigated the hypothesis that elevation of HDLs inhibits AAA. HDLs elevated before or at the time of AAA induction reduced AAA formation in both models but had no effect on early ruptures. Analysis of protein lysates from specific aortic segments demonstrated site-specific effects of HDLs on early signal transduction and cellular attrition. We found that HDLs reduced extracellular signal related kinases 1/2 activation in the suprarenal segment, while having no effect on p38 mitogen-associated protein kinase activation in any aortic segment and inhibiting c-Jun N-terminal kinase activation in all aortic segments. In addition, HDL elevation inhibited angiotensin II−induced apoptosis while inducing autophagy in the suprarenal segment of the aorta. Using Illumina gene array profiling we investigated the ability of HDL to modulate basal suprarenal aortic gene expression. Conclusion— Increasing plasma HDLs inhibit experimental AAA formation, independent of hypercholesterolemia via reduced extracellular signal related kinases 1/2 activation and alteration of the balance of cellular attrition. HDLs modulate genes involved in matrix remodelling, cell migration, and proliferation

Digital Artifacts as Institutional Attractors: A Systems Biology Perspective on Change in Organizational Routines

Track V: Innovative Trends in Information Systems ResearchInternational audienceDigital artifacts have become fundamental elements of organizational change. Such change is not frictionless, since routines and associated structures are deeply embedded- or institutionalized. Though, organizational institutionalism has been traditionally concerned with stability and change in routines and underlying structures, it has so far meagerly theorized the role of digital artifacts in balancing stability and change. To address this gap, we draw on systems biology to understand how introduction of new digital artifacts can influence routines in organizations. In particular, we approach digital artifacts as institutional attractors and examine the role of such attractors within gene regulatory networks. In this view institutional attractors become endogenous to sociomaterial systems and are keys to simultaneously promoting stability and inducing change. Just as attractors are implicated in changes to established gene regulatory networks within cells, so too are digital artifacts implicated in the efforts of institutional entrepreneurs to bring about change to organizational routines (behaviors). Based upon this analogous reasoning we outline elements of a research agenda and conclude with a discussion of methodological directions to deal with digitally induced endogenous sociomaterial change

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Complex pathologies of angiotensin II-induced abdominal aortic aneurysms*

Angiotensin II (AngII) is the primary bioactive peptide of the renin angiotensin system that plays a critical role in many cardiovascular diseases. Subcutaneous infusion of AngII into mice induces the development of abdominal aortic aneurysms (AAAs). Like human AAAs, AngII-induced AAA tissues exhibit progressive changes and considerable heterogeneity. This complex pathology provides an impediment to the quantification of aneurysmal tissue composition by biochemical and immunostaining techniques. Therefore, while the mouse model of AngII-induced AAAs provides a salutary approach to studying the mechanisms of the evolution of AAAs in humans, meaningful interpretation of mechanisms requires consideration of the heterogeneous nature of the diseased tissue

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