942 resultados para Bellingshausen Sea, central axis of trough, outer shelf


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Vol. for 1896 reprinted from The School Review, May, 1896.

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Mode of access: Internet.

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The central elements of the algebra of monodromy matrices associated with the Z(n) R-matrix are studied. When the crossing parameter w takes a special rational value w = n/N, where N and n are positive coprime integers, the center is substantially larger than that in the generic case for which the quantum determinant provides the center. In the trigonometric limit, the situation corresponds to the quantum group at roots of unity. This is a higher rank generalization of the recent results by Belavin and Jimbo. (c) 2004 Elsevier B.V. All rights reserved.

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This paper discusses how the UK government has reconfigured its regulation of English local authorities by moving from direct oversight to using an indirect independent agency as a vehicle of meta-governance. This theme is discussed through two strands: first, by examining how several factors eroded central government's capacity to directly regulate councils. The second strand examines the strategies used by the Audit Commission, an independent agency, to assert its authority over councils and how its hegemony is sustained by facilitating and participating in horizontal and vertical networks across government, specialist policy and stakeholders' communities. © Blackwell Publishing Ltd. 2006.

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Objective: Pharyngeal stimulation can induce remarkable increases in the excitability of swallowing motor cortex, which is associated with short-term improvements in swallowing behaviour in dysphagic stroke patients. However, the mechanism by which this input induces cortical change remains unclear. Our aims were to explore the stimulus-induced facilitation of the cortico-bulbar projections to swallowing musculature and examine how input from the pharynx interacts with swallowing motor cortex. Methods: In 8 healthy subjects, a transcranial magnetic stimulation (TMS) paired-pulse investigation was performed comprising a single conditioning electrical pharyngeal stimulus (pulse width 0.2 ms, 240 V) followed by cortical TMS at inter-stimulus intervals (ISI) of 10-100 ms. Pharyngeal sensory evoked potentials (PSEP) were also measured over the vertex. In 6 subjects whole-brain magnetoencephalography (MEG) was further acquired following pharyngeal stimulation. Results: TMS evoked pharyngeal motor evoked potentials were facilitated by the pharyngeal stimulus at ISI between 50 and 80 ms (Δ mean increase: 47±6%, P<0.05). This correlated with the peak latency of the P1 component of the PSEP (mean 79.6±8.5 ms). MEG confirmed that the equivalent P1 peak activities were localised to caudolateral sensory and motor cortices (BA 4, 1, 2). Conclusions: Facilitation of the cortico-bulbar pathway to pharyngeal stimulation relates to coincident afferent input to sensorimotor cortex. Significance: These findings have mechanistic importance on how pharyngeal stimulation may increase motor excitability and provide guidance on temporal windows for future manipulations of swallowing motor cortex. © 2004 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

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Inadequate blood flow to an organ, ischaemia, may lead to both local and remote tissue injury characterized by oedema, increased microvascular permeability to protein and degradation of connective tissue components. This damage is probably caused by the accumulation and inappropriate activation of neutrophils which occurs when the tissue is reperfused. To test this hypothesis a number of in vitro models of the sequential stages of ischaemia/reperfusion injury were examined. Methods were initially developed to examine the adhesion of neutrophils to monolayers of a cultured endothelial cell line (ECV304) after periods of hypoxia and reoxygenation. Neutrophil migration in response to factors secreted by the treated endothelial cells was then assessed. The genesis of an inappropriate oxidative burst by the neutrophil upon exposure to endothelial chemoattractants and adhesion molecules was also measured. Finally to appraise how tissue function might be affected by endothelial cell hypoxia the contractility of vascular smooth muscle was examined. Neutrophil adhesion to ECV304 cells, which had been hypoxic for 4 hours and then reoxygenated for 30 minutes, was significantly increased. This response was probably initiated by reactive oxygen species (ROS) generated by the endothelial cells. Blockage of their production by allopurinol reduced the heightened adhesion. Similarly removal of ROS by superoxide dismutase or catalase also attenuated adhesion. ROS generation in turn caused the release of a soluble factor (s) which induced a conformational change on the neutrophil surface allowing it to bind to the intercellular adhesion molecule 1 (ICAM-1) on the endothelial cell. Soluble factor (s) from hypoxia/reoxygenated endothelial cells also had a powerful neutrophil chemoattractant ability. When neutrophils were exposed to both hypoxic/reoxygenated endothelial cells and the soluble factor (s) released by them a large oxidative burst was elicited. This response was greatest immediately after reoxygenation and one hour later was diminishing suggesting at least one of the components involved was labile. Analysis of the supernatant from hypoxic/reoxygenated endothelial cell cultures and studies using inhibitors of secretion suggested platelet activating factor (PAF) may be a major component in this overall sequence of events. Lesser roles for IL-8, TNF and LTB4 were also suggested. The secretory products from hypoxia/reoxygenated endothelial cells also affected smooth muscle contractility having an anti-vasoconstrictor or relaxation property, similar to that exerted by PAF.

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Az elmúlt két évtized folyamán a menedzserek megtanultak a megújult szabályok szerint játszani. Tudatosították, hogy a vállalatuk eredményes navigálásához folyamatosan figyelniük és adaptálniuk kell a legújabb módszereket, elméleteket. Jelen tanulmányával a szerző ezt a folyamatot kívánja segíteni, valamint arra az alapvető kérdésre keresi a választ, hogy érdemes-e a rendkívül gyorsan változó világban hosszabb távú célok meghatározásával foglalkozni, és ha igen, akkor mire összpontosítsák a vállalatok erőfeszítéseiket. Milyen részletezettséggel, milyen módon határozzák meg az elképzeléseiket úgy, hogy közben megőrizzék a vállalat flexibilitását, a változások idején nélkülözhetetlen agilitást. A szerző arra vállalkozik, hogy feltárja a stratégiai paradigmaváltás fejlődését, a termelési stratégia, az operations management központi meghatározó szereppé válását, valamint áttekintse a termelési és szolgáltatási rendszervezetés (OM) elveinek, eszközeinek, módszereinek fejlődését, kölcsönhatását, összefüggéseit. _______ Change of paradigm has taken place in strategic planning. Fight for position turned into a fight of movement. Companies strive to achieve individual, not copyable organizational performance, as well as to realize their business strategies by means of value generating, proactive approach. Operative management now placed in the focus of production strategy is becoming the compass, the driving force of leadership. The management of production and service systems has grown into independent scientific disciplines. It yielded such principles, tools and methods which are present as world-renowned blueprints (scientific tools) in the field of maintaining and developing corporate performance. In the present study the author specifies and discusses the tools of operative management as criteria of value generation aiming at quality and cost efficiency. He analyses the backto- back character, interrelationship of quality, TQM (Total Quality Management), TPS (Toyota Production System) and JIT (Just in Time). He examines the effects thereof on corporate performance where significant and strong relationship can be demonstrated in case there is an ability to plan and develop new products. The current new OM (Operations Management) techniques increasingly rely upon the quality of human resources, the permanent improvement of procedures as well as focusing on tight cooperation with suppliers/customers. Supply chain management, core competence management, service management now represent a “new generation” of the OM methods, processes, serving at the same time as basis and starting point for expectable future techniques as well.

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Subduction zone magmatism is an important and extensively studied topic in igneous geochemistry. Recent studies focus on from where arc magmas are generated, how subduction components (fluids or melts) are fluxed into the source of the magmas, and whether or how the subduction components affect partial melting processes beneath volcanic arcs at convergent boundaries. ^ At 39.5°S in the Central Southern Volcanic Zone of the Andes, Volcano Villarrica is surrounded by a suite of Small Eruptive Centers (SEC). The SECs are located mostly to the east and northeast of the stratovolcano and aligned along the Liquine-Ofqui Fault Zone, the major fracture system in this area. Former studies observed the geochemical patterns of the SECs differ distinctively from those of V. Villarrica and suggested there may be a relationship between the compositions of the volcanic units and their edifice sizes. This work is a comprehensive geochemical study on the SECs near V. Villarrica, using a variety of geochemical tracers and tools including major, trace and REE elements, Li-Be-B elements, Sr-Nd-Pb isotopes and short-lived isotopes such as U-series and 10Be. In this work, systematic differences between the elemental and isotopic compositions of the SECs and those of V. Villarrica are revealed and more importantly, modeled in terms of magmatic processes occurring at continental arc margins. Detailed modeling calculations in this work reconstruct chemical compositions of the primary magmas, source compositions, compositions and percentages of different subduction endmembers mixed into the source, degrees of partial melting and different time scales of the SECs and V. Villarrica, respectively. Geochemical characteristics and possible origins of the two special SECs—andesitic Llizan, with crustal signatures, and Rucapillan, to the northwest toward the trench, are also discussed in this work. ^