624 research outputs found

    Some stationary properties of a QQ-ball in arbitrary space dimensions

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    Introducing new physically motivated ans\"{a}tze, we explore both analytically and numerically the classical and absolute stabilities of a single QQ-ball in an arbitrary number of spatial dimensions DD, working in both the thin and thick wall limits.Comment: 35 pages, 32 figures; added references, corrected typo

    On the Lieb-Thirring constants L_gamma,1 for gamma geq 1/2

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    Let Ei(H)E_i(H) denote the negative eigenvalues of the one-dimensional Schr\"odinger operator Hu:=uVu, V0,Hu:=-u^{\prime\prime}-Vu,\ V\geq 0, on L2(R)L_2({\Bbb R}). We prove the inequality \sum_i|E_i(H)|^\gamma\leq L_{\gamma,1}\int_{\Bbb R} V^{\gamma+1/2}(x)dx, (1) for the "limit" case γ=1/2.\gamma=1/2. This will imply improved estimates for the best constants Lγ,1L_{\gamma,1} in (1), as $1/2<\gamma<3/2.Comment: AMS-LATEX, 15 page

    The distinctiveness of employment relations within multinationals: political games and social compromises within multinationals’ subsidiaries in Germany and Belgium

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    This work makes a theoretical contribution to our understanding of the strategic mechanisms that enable subsidiary management and union agency to exploit ambiguities in the subnational competitive context impacting labour flexibility-security concerns. In so doing, the article contributes to the distinctiveness of employment relations through scrutiny of the internal regime competition that fosters political games in MNCs. Studying the dynamics, we identify the set of structuring conditions governing political games, and explain why some workplace regimes generate social compromises whilst others do not. We reveal a set of strategic conditions (i.e. technology, embeddedness and MNC control) upon which compromise is built in six German and Belgian subsidiaries of four MNCs. Our analysis suggests that subsidiary control modes through expatriates and local embeddedness act as key mechanisms through which the effects of wider strategic drivers influence the form of social compromise

    Necessary and sufficient conditions for existence of bound states in a central potential

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    We obtain, using the Birman-Schwinger method, a series of necessary conditions for the existence of at least one bound state applicable to arbitrary central potentials in the context of nonrelativistic quantum mechanics. These conditions yield a monotonic series of lower limits on the "critical" value of the strength of the potential (for which a first bound state appears) which converges to the exact critical strength. We also obtain a sufficient condition for the existence of bound states in a central monotonic potential which yield an upper limit on the critical strength of the potential.Comment: 7 page

    Gender- and age-related differences in clinical presentation and management of outpatients with stable coronary artery disease

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    &lt;br&gt;Introduction: Contemporary generalizable data on the demographics and management of outpatients with stable coronary artery disease (CAD) in routine clinical practice are sparse. Using the data from the CLARIFY registry we describe gender- and age-related differences in baseline characteristics and management of these patients across broad geographic regions.&lt;/br&gt; &lt;br&gt;Methods: This international, prospective, observational, longitudinal registry enrolled stable CAD outpatients from 45 countries in Africa, Asia, Australia, Europe, the Middle East, and North, Central, and South America.&lt;/br&gt; &lt;br&gt;Results: Baseline data were available for 33 280 patients. Mean (SD) age was 64 (10.5) years and 22.5% of patients were female. The prevalence of CAD risk factors was generally higher in women than in men. Women were older (66.6 vs 63.4 years), more frequently diagnosed with diabetes (33% vs 28%), hypertension (79% vs 69%), and higher resting heart rate (69 vs 67 bpm), and were less physically active. Smoking and a history of myocardial infarction were more common in men. Women were more likely to have angina (28% vs 20%), but less likely to have undergone revascularization procedures. CAD was more likely to be asymptomatic in older patients perhaps because of reduced levels of physical activity. Prescription of evidence-based medication for secondary prevention varied with age, with patients ≥ 75 years treated less often with beta blockers, aspirin and angiotensin-converting enzyme inhibitors than patients &#60; 65 years.&lt;/br&gt; &lt;br&gt;Conclusions: Important gender-related differences in clinical characteristics and management continue to exist in all age groups of outpatients with stable CAD.&lt;/br&gt

    Spontaneous alloying in binary metal microclusters - A molecular dynamics study -

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    Microcanonical molecular dynamics study of the spontaneous alloying(SA), which is a manifestation of fast atomic diffusion in a nano-sized metal cluster, is done in terms of a simple two dimensional binary Morse model. Important features observed by Yasuda and Mori are well reproduced in our simulation. The temperature dependence and size dependence of the SA phenomena are extensively explored by examining long time dynamics. The dominant role of negative heat of solution in completing the SA is also discussed. We point out that a presence of melting surface induces the diffusion of core atoms even if they are solid-like. In other words, the {\it surface melting} at substantially low temperature plays a key role in attaining the SA.Comment: 15 pages, 12 fgures, Submitted to Phys.Rev.

    A New Relativistic High Temperature Bose-Einstein Condensation

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    We discuss the properties of an ideal relativistic gas of events possessing Bose-Einstein statistics. We find that the mass spectrum of such a system is bounded by μm2M/μK,\mu \leq m\leq 2M/\mu _K, where μ\mu is the usual chemical potential, MM is an intrinsic dimensional scale parameter for the motion of an event in space-time, and μK\mu _K is an additional mass potential of the ensemble. For the system including both particles and antiparticles, with nonzero chemical potential μ,\mu , the mass spectrum is shown to be bounded by μm2M/μK,|\mu |\leq m\leq 2M/\mu _K, and a special type of high-temperature Bose-Einstein condensation can occur. We study this Bose-Einstein condensation, and show that it corresponds to a phase transition from the sector of continuous relativistic mass distributions to a sector in which the boson mass distribution becomes sharp at a definite mass M/μK.M/\mu _K. This phenomenon provides a mechanism for the mass distribution of the particles to be sharp at some definite value.Comment: Latex, 22 page

    Stress, ageing and their influence on functional, cellular and molecular aspects of the immune system

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    The immune response is essential for keeping an organism healthy and for defending it from different types of pathogens. It is a complex system that consists of a large number of components performing different functions. The adequate and controlled interaction between these components is necessary for a robust and strong immune response. There are, however, many factors that interfere with the way the immune response functions. Stress and ageing now consistently appear in the literature as factors that act upon the immune system in the way that is often damaging. This review focuses on the role of stress and ageing in altering the robustness of the immune response first separately, and then simultaneously, discussing the effects that emerge from their interplay. The special focus is on the psychological stress and the impact that it has at different levels, from the whole system to the individual molecules, resulting in consequences for physical health
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