2,098 research outputs found

    Quantum Chinos Game: winning strategies through quantum fluctuations

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    We apply several quantization schemes to simple versions of the Chinos game. Classically, for two players with one coin each, there is a symmetric stable strategy that allows each player to win half of the times on average. A partial quantization of the game (semiclassical) allows us to find a winning strategy for the second player, but it is unstable w.r.t. the classical strategy. However, in a fully quantum version of the game we find a winning strategy for the first player that is optimal: the symmetric classical situation is broken at the quantum level.Comment: REVTEX4.b4 file, 3 table

    Quantum dynamics of a model for two Josephson-coupled Bose--Einstein condensates

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    In this work we investigate the quantum dynamics of a model for two single-mode Bose--Einstein condensates which are coupled via Josephson tunneling. Using direct numerical diagonalisation of the Hamiltonian, we compute the time evolution of the expectation value for the relative particle number across a wide range of couplings. Our analysis shows that the system exhibits rich and complex behaviours varying between harmonic and non-harmonic oscillations, particularly around the threshold coupling between the delocalised and self-trapping phases. We show that these behaviours are dependent on both the initial state of the system as well as regime of the coupling. In addition, a study of the dynamics for the variance of the relative particle number expectation and the entanglement for different initial states is presented in detail.Comment: 15 pages, 8 eps figures, accepted in J. Phys.

    Second record of Pseudimares aphrodite H. Asp?ck et U. Asp?ck, 2009 (Neuroptera, Myrmeleontidae)

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    Some adults of Pseudimares aphrodite H. Asp?ck et U. Asp?ck, 2009 were observed and photographed while attracted by light in Southern Morocco, in August 2009 and 2011. Only the typus of this species, a male, was known previously from South Morocco too. Moreover the genus Pseudimares Kimmins, 1933 is perhaps the most enigmatic taxon among Neuroptera Myrmeleontidae. Its second species Pseudimares iris Kimmins, 1933 from Southern Iran is known also only in the type series, a male and a female. What little information we know about Pseudimares is reporte

    Systemic Effects Induced by Hyperoxia in a Preclinical Model of Intra-abdominal Sepsis

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    Supplemental oxygen is a supportive treatment in patients with sepsis to balance tissue oxygen delivery and demand in the tissues. However, hyperoxia may induce some pathological effects. We sought to assess organ damage associated with hyperoxia and its correlation with the production of reactive oxygen species (ROS) in a preclinical model of intra-abdominal sepsis. For this purpose, sepsis was induced in male, Sprague-Dawley rats by cecal ligation and puncture (CLP). We randomly assigned experimental animals to three groups: control (healthy animals), septic (CLP), and sham-septic (surgical intervention without CLP). At 18 h after CLP, septic (n = 39), sham-septic (n = 16), and healthy (n = 24) animals were placed within a sealed Plexiglas cage and randomly distributed into four groups for continuous treatment with 21%, 40%, 60%, or 100% oxygen for 24 h. At the end of the experimental period, we evaluated serum levels of cytokines, organ damage biomarkers, histological examination of brain and lung tissue, and ROS production in each surviving animal. We found that high oxygen concentrations increased IL-6 and biomarkers of organ damage levels in septic animals, although no relevant histopathological lung or brain damage was observed. Healthy rats had an increase in IL-6 and aspartate aminotransferase at high oxygen concentration. IL-6 levels, but not ROS levels, are correlated with markers of organ damage. In our study, the use of high oxygen concentrations in a clinically relevant model of intra-abdominal sepsis was associated with enhanced inflammation and organ damage. These findings were unrelated to ROS release into circulation. Hyperoxia could exacerbate sepsis-induced inflammation, and it could be by itself detrimental. Our study highlights the need of developing safer thresholds for oxygen therapy

    Exosomes in head and neck cancer. Updating and revisiting

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    Exosomes have gone from being considered simple containers of intracellular waste substances to be considered important carriers of cellular signals. Its broad capacity to promote tumour growth, both in situ and metastatic, has greatly intensified scientific research on them. In the same way and depending on its content, its tumour suppressive properties have opened a window of light and hope in the fight against cancer. In the present review we try to gather in a simple and understandable way the most relevant knowledge to date on the role of exosomes in oral squamous cell carcinoma, helping to understand their process of formation, release and activity on the tumour microenvironment

    K0-Sigma+ Photoproduction with SAPHIR

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    Preliminary results of the analysis of the reaction p(gamma,K0)Sigma+ are presented. We show the first measurement of the differential cross section and much improved data for the total cross section than previous data. The data are compared with model predictions from different isobar and quark models that give a good description of p(gamma,K+)Lambda and p(gamma,K+)Sigma0 data in the same energy range. Results of ChPT describe the data adequately at threshold while isobar models that include hadronic form factors reproduce the data at intermediate energies.Comment: 4 pages, Latex2e, 4 postscript figures. Talk given at the International Conference on Hypernuclear and Strange Particle Physics (HYP97), Brookhaven National Laboratory, USA, October 13-18, 1997. To be published in Nucl. Phys. A. Revised version due to changes in experimental dat

    Effect of age on exercise capacity and cardiac reserve in patients with pulmonary atresia with intact ventricular septum after biventricular repair

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    OBJECTIVESIn patients with pulmonary atresia with intact ventricular septum (PAIVS), biventricular repair is considered to be the optimal treatment option in the absence of significant right ventricular (RV) hypoplasia. However, long-term clinical outcome studies are limited. We evaluated exercise capacity and cardiac function during pharmacological stress in children and young adults with PAIVS after biventricular repair.METHODSTen PAIVS patients after biventricular repair, with a median age of 12 years (range 9-42 years), underwent a cardiopulmonary exercise test, dobutamine stress magnetic resonance imaging (DS-MRI) and delayed contrast enhancement (DCE) MRI.RESULTSThe patients' ages negatively correlated with exercise capacity (r = -0.72, P = 0.01) as well as left (LV) and RV stroke volume (SV) response to pharmacological stress (r = -0.72, P = 0.02; and r = -0.64, P = 0.04; respectively), Furthermore, older age was associated with decreased RV E/A volume ratio and increased pulmonary late diastolic forward flow percentage (r = 0-0.65, P = 0.04, r = 0.66, P = 0.03, respectively). RV E/A volume ratio positively correlated with RV-SV response to DS-MRI (r = 0.77, P = 0.009). and O(2)-pulse during physical stress correlated with biventricular SV response to DS-MRI. No RV or LV ventricular myocardial fibrosis was detected.CONCLUSIONSIn PAIVS patients after biventricular repair exercise capacity and cardiac reserve decrease with age. These findings appear to be related to impaired diastolic RV function and decreased RV filling, indicating that the function of the relatively small RV deteriorates with tim

    Form factors and photoproduction amplitudes

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    We examine the use of phenomenological form factors in tree level amplitudes for meson photoproduction. Two common recipes are shown to be fundamentally incorrect. An alternate form consistent with gauge invariance and crossing symmetry is proposed.Comment: To be published in PR

    How to Educate Entrepreneurs?

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    Entrepreneurship education has two purposes: To improve students’ entrepreneurial skills and to provide impetus to those suited to entrepreneurship while discouraging the rest. While entrepreneurship education helps students to make a vocational decision its effects may conflict for those not suited to entrepreneurship. This study shows that vocational and the skill formation effects of entrepreneurship education can be identified empirically by drawing on the Theory of Planned Behavior. This is embedded in a structural equation model which we estimate and test using a robust 2SLS estimator. We find that the attitudinal factors posited by the Theory of Planned Behavior are positively correlated with students’ entrepreneurial intentions. While conflicting effects of vocational and skill directed course content are observed in some individuals, overall these types of content are complements. This finding contradicts previous results in the literature. We reconcile the conflicting findings and discuss implications for the design of entrepreneurship courses
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