927 research outputs found

    Theories of practice and geography

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    Recent developments in theories of practice have seen place and space taken explicitly into account. In particular, THEODORE SCHATZKI’s ‘site ontology’ offers distinctive but as yet under-explored means of engaging with human geographies. By giving ontological priority to practices as constitutive of the social, this kind of practice theory provides an integrative conceptual framework that enables the analysis of diverse phenomena in relation to each other, over space and time, as they are constituted through practices. This article develops an outline agenda for bringing theories of practice, and particularly SCHATZKI’s ‘site ontology’, together with geographical inquiry. We elucidate this agenda through consideration of three contemporary preoccupations in human geography, comprising emotion, materiality and knowledge

    Atomic quantum gases in Kagom\'e lattices

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    We demonstrate the possibility of creating and controlling an ideal and \textit{trimerized} optical Kagom\'e lattice, and study the low temperature physics of various atomic gases in such lattices. In the trimerized Kagom\'e lattice, a Bose gas exhibits a Mott transition with fractional filling factors, whereas a spinless interacting Fermi gas at 2/3 filling behaves as a quantum magnet on a triangular lattice. Finally, a Fermi-Fermi mixture at half filling for both components represents a frustrated quantum antiferromagnet with a resonating-valence-bond ground state and quantum spin liquid behavior dominated by continuous spectrum of singlet and triplet excitations. We discuss the method of preparing and observing such quantum spin liquid employing molecular Bose condensates.Comment: 4 pages, 1 figure. Missing affiliations adde

    Quelles technologies le CIRAD peut-il proposer pour redynamiser la filière cocotier ?

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    Le CIRAD-CP a été amené récemment à préconiser une réorientation des objectifs de la filière cocotier de plusieurs pays producteurs. Cette stratégie repose essentiellement sur une diversification accrue et une plus grande prise en compte des marché locaux, ce qui implique le développement de petites et moyennes unités de transformation sur les lieux de production. La mise en place de telles unités nécessite de pouvoir disposer de technologies pouvant être exploitées efficacement dans de tels contextes et permettant l'obtention de produits de qualité. Dans cette optique, une équipe pluri-disciplinaire du CIRAD a entrepris l'étude de deux procédés relevant des voies humides ou semi-humides : l'extraction après séchage friture, et l'extraction assistée par les enzymes. Les technologies développées sont décrites en détail, et leur adéquation avec les objectifs assignés fait l'objet d'une discussio

    The Heisenberg antiferromagnet on a triangular lattice: topological excitations

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    We study the topological defects in the classical Heisenberg antiferromagnet in two dimensions on a triangular lattice (HAFT). While the topological analysis of the order parameter space indicates that the defects are of Z2Z_2 type, consideration of the energy leads us to a description of the low--energy stationary points of the action in terms of ±\pm vortices, as in the planar XY model. Starting with the continuum description of the HAFT, we show analytically that its partition function can be reduced to that of a 2--dimensional Coulomb gas with logarithmic interaction. Thus, at low temperatures, the correlation length is determined by the spinwaves, while at higher temperatures we expect a crossover to a Kosterlitz--Thouless type behaviour. The results of recent Monte Carlo calculations of the correlation length are consistent with such a crossover.Comment: 9 pages, revtex, preprint: ITP-UH 03/9

    Exogenous application of platelet-leukocyte gel during open subacromial decompression contributes to improved patient outcome

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    Background: Platelet-leukocyte gel (PLG) is being used during various surgical procedures in an attempt to enhance the healing process. We studied the effects of PLG on postoperative recovery of patients undergoing open subacromial decompression (OSD). Methods: PLG was produced from platelet-leukocyte-rich plasma (P-LRP), prepared from a unit of whole blood. Forty patients were included in the study. Self-assessed evaluations, using the American Shoulder and Elbow Surgeons scoring system of activities of daily living (ADL), joint instability, pain levels, pain medications, and clinical evaluations for range of motion were conducted. Results: Platelet and leukocyte counts were significantly increased in the P-LRP compared to baseline counts. Treated patients demonstrated decreased visual analog scales for pain and used significantly less pain medication, had an improved range of motion during passive forward elevation, external rotation, external rotation with arm at 90 degrees abduction, internal rotation, and cross body adduction compared to control patients (p < 0.001). No differences in the instability score were observed between the groups. Furthermore, treated patients performed more ADL (p < 0.05). Conclusion: In the PLG-treated group, recovery was faster and patients returned earlier to daily activities and also took less pain medication than control subjects

    Atomic Fermi gas in the trimerized Kagom\'e lattice at the filling 2/3

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    We study low temperature properties of an atomic spinless interacting Fermi gas in the trimerized Kagom\'e lattice for the case of two fermions per trimer. The system is described by a quantum spin 1/2 model on the triangular lattice with couplings depending on bonds directions. Using exact diagonalizations we show that the system exhibits non-standard properties of a {\it quantum spin-liquid crystal}, combining a planar antiferromagnetic order with an exceptionally large number of low energy excitations.Comment: 4 pages & 4 figures + 2 tables, better version of Fig.

    A partnership in Nebraska with the Humane Society

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    Perhaps service-learning continues to grow as an effective pedagogy in colleges of education because it offers everyone involved an opportunity to put words into action. With the news full of stories of bullying and school shootings, teachers and teacher candidates look for someone to help them make sense of what feels to be a growing trend of cruelty. Perhaps it is a natural reaction for teachers to want to do something positive in the face of brutality. Perhaps our wanting to be proactive corresponds to whatever drew us to education in the first place. Regardless of the cause, four literacy professors used the vehicle of service-learning to challenge their graduate and undergraduate students to consider issues of bullying, brutality and cruelty

    Cognitive and emotional effects of carotid stenosis.

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    PRINCIPLES: Patients with carotid artery stenosis (CAS) are at risk of ipsilateral stroke and chronic compromise of cerebral blood flow. It is under debate whether the hypo-perfusion or embolism in CAS is directly related to cognitive impairment. Alternatively, CAS may be a marker for underlying risk factors, which themselves influence cognition. We aimed to determine cognitive performance level and the emotional state of patients with CAS. We hypo-thesised that patients with high grade stenosis, bilateral stenosis, symptomatic patients and/or those with relevant risk factors would suffer impairment of their cognitive performance and emotional state. METHODS: A total of 68 patients with CAS of ≥70% were included in a prospective exploratory study design. All patients underwent structured assessment of executive functions, language, verbal and visual memory, motor speed, anxiety and depression. RESULTS: Significantly more patients with CAS showed cognitive impairments (executive functions, word production, verbal and visual memory, motor speed) and anxiety than expected in a normative sample. Bilateral and symptomatic stenosis was associated with slower processing speed. Cognitive performance and anxiety level were not influenced by the side and the degree of stenosis or the presence of collaterals. Factors associated with less co-gnitive impairment included higher education level, female gender, ambidexterity and treated hypercholesterolemia. CONCLUSIONS: Cognitive impairment and increased level of anxiety are frequent in patients with carotid stenosis. The lack of a correlation between cognitive functioning and degree of stenosis or the presence of collaterals, challenges the view that CAS per se leads to cognitive impairment

    Peculiarities of the function of cardiomyocytes in patients with ischemic heart disease associated with diabetes mellitus type 2

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    The functional activity of myocardium in patients with type 2 diabetes mellitus(T2DM) and coronary heart disease (CAD) was studied. The study included patients with CAD with T2DM as representatives of the main group, the comparison group consisted of patients with univariant course of ischemic heart disease without violation of carbohydrate metabolism. Contractile activity of the myocardium was evaluated by the inotroic reaction of isolated trabeculae of patients according to the Protocol tests "Post-rest" and "Ekstrasistoliei test". As a result, it was found that rhythm-inotropic myocardial response in patients with comorbid pathology persists to a greater extent than in the one-dimensional flow of CAD
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