1,635 research outputs found

    Social disruption stress exacerbates alpha-galactosylceramide-induced hepatitis in mice

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    Objective: Psychosocial stress has been suggested as a possible aggravating factor in liver diseases, however, the underlying mechanism has yet to be clarified. Recently, our research revealed that electric foot-shock stress aggravated NK1.1 Ag+ T cell-dependent a-galactosylceramide (alpha-GalCer)-induced hepatitis in mice via a mechanism mediated by endogenous glucocorticoids. In this study, we examined whether or not such aggravation could be applied to a psychosocially stressful situation, e.g. social disruption stress. Methods: Male wildtype C57BL/6 (B6) or B6 hepatitis virus type B surface antigen transgenic (HBs-tg) mice, a hepatitis B virus carrier mouse model, were exposed 3 times in 1 week to social disruption stress in which an 8-month-old aggressive male intruder was placed into their home cage (5 mice per group) for 2 h. Twelve hours after the final exposure to the stress, the wild-type and HBs-tg mice were intravenously injected with alpha-GalCer. Results:The stress-exposed wild-type mice exhibited significantly reduced thymus weight loss compared with the control animals. Moreover, this stress regimen led to a significant increase in serum alanine aminotransferase levels in both the wild-type and the HBs-tg mice, although the increase in the HBs-tg mice was higher than that in the wild-type mice. Conclusion: These findings demonstrated that, similar to electric foot-shock stress, social disruption stress exacerbated alpha-GalCer-induced hepatitis. Copyright (C) 2005 S. Karger AG, Basel

    Gauge Invariant Cutoff QED

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    A hidden generalized gauge symmetry of a cutoff QED is used to show the renormalizability of QED. In particular, it is shown that corresponding Ward identities are valid all along the renormalization group flow. The exact Renormalization Group flow equation corresponding to the effective action of a cutoff lambda phi^4 theory is also derived. Generalization to any gauge group is indicated.Comment: V1: 18 pages, 2 figures; V2: Discussions improved. Version accepted for publication in Physica Script

    Recursive representation of the torus 1-point conformal block

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    The recursive relation for the 1-point conformal block on a torus is derived and used to prove the identities between conformal blocks recently conjectured by R. Poghossian. As an illustration of the efficiency of the recurrence method the modular invariance of the 1-point Liouville correlation function is numerically analyzed.Comment: 14 pages, 1 eps figure, misprints corrected and a reference adde

    The effects of pressure dependent constitutive model to simulate concrete structures failure under impact loads

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    The main objective of this paper is to explore the effect of confining pressure in the compression and tension zone by simulating the behaviour of reinforced concrete/mortar structures subjected to the impact load. The analysis comprises the numerical simulation of the influences of high mass low speed impact weight dropping on concrete structures, where the analyses are incorporated with meshless method namely as Smoothed Particle Hydrodynamics (SPH) method. The derivation of the plastic stiffness matrix of Drucker-Prager (DP) that extended from Von-Mises (VM) yield criteria to simulate the concrete behaviour were presented in this paper. In which, the displacements for concrete/mortar structures are assumed to be infinitesimal. Furthermore, the influence of the different material model of DP and VM that used numerically for concrete and mortar structures are also discussed. Validation upon existing experimental test results is carried out to investigate the effect of confining pressure, it is found that VM criterion causes unreal impact failure (flexural cracking) of concrete structures

    Potential of an Asymmetrical Agitation in Industrial Mixing

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    Mixing is one of the most fundamental operations in chemical engineering. Stirred tanks are widely used in the manufacture of such materials as chemicals, paints, inks, electronics materials, ceramics, foods, pharmaceuticals and cosmetics. Suitable mixing is indispensable to the purpose achievement of a process. Eccentric mixing, in which an impeller installed at eccentric position in a vessel, is one of the traditional methods of promoting mixing. An asymmetrical flow which occurs in vessel is complicated, and it promotes mixing, distribution, and mass transfer. In this study, a new mixing method which eccentric mixing using a large type impeller which attracts attention in recent years is shown. The high performance of a large impeller can be combined with the advantages of an eccentric impeller by using the impeller at an eccentric position. The power consumption and mixing time for MAXBLEND, which is a type of large impeller, were investigated. The power consumption, P, and mixing time, θM, were measured under various eccentric conditions. The relation between the power number (Np) and Reynolds number (Re) and that between the dimensionless mixing time (nθM) and Re were investigated. When eccentric mixing is used industrially, we should be concerned about the horizontal load to a agitating shaft. The large oscillating horizontal load causes serious problems, such as the falling off of the impeller or the breakage of the motor, mechanical seal or gearbox. It is, therefore, important to understand the relation between these values and the impeller rotational speed when designing the mixing equipment and determining the operating conditions. In this study, the torque and horizontal load were measured in eccentric mixing under various eccentric conditions. The averages of both, the torque and the horizontal load, and their standard deviations, corresponding to the amplitude of fluctuation, were shown.Doi: 10.12777/ijse.5.2.73-80 [How to cite this article: Nishi, K., Enya, N., Sonoda, K., Misumi, R., Kaminoyama, M. (2013). Potential of an asymmetrical agitation in industrial mixing. International Journal of Science and Engineering, 5(2),73-80. Doi: 10.12777/ijse.5.2.73-80

    Liouville Correlation Functions from Four-dimensional Gauge Theories

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    We conjecture an expression for the Liouville theory conformal blocks and correlation functions on a Riemann surface of genus g and n punctures as the Nekrasov partition function of a certain class of N=2 SCFTs recently defined by one of the authors. We conduct extensive tests of the conjecture at genus 0,1.Comment: 32 pages, 8 figures; v2: minor corrections, published versio

    Chironomidae (Diptera, Insecta) do reservatório de Furnas (MG) e sua relação com a qualidade da água.

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    Resumo: Com a crescente expansão da criação de peixes em tanques rede advinda da prática da aquicultura, alterações na qualidade da água e em todo o ecossistema relacionado podem ocorrer. Sabe-se que a ocorrência de larvas de certas espécies da família Chironomidae (Diptera) associada a variáveis físicas e químicas da água pode ser adotada como indicador de impactos. Este trabalho teve como principal objetivo levantar a fauna de Chironomidae presente na área profundal do entorno de tanques rede no Reservatório de Furnas (MG) e determinar sua relação com a qualidade da água. O sedimento de fundo foi coletado com o auxílio de uma draga de Ekman-Birge, em tréplicas, em seis pontos com 16 m de profundidade em média, sendo um ponto localizado em área sem produção aquícola e os demais em pontos com produção. Após a coleta, as amostras foram triadas em laboratório utilizando-se microscópio estereoscópico e as larvas foram montadas em lâmina para identificação taxonômica em nível de gênero. Ao todo, 765 indivíduos foram identificados, sendo em sua maioria da subfamília Chironominae. Os indivíduos foram enquadrados em grupos tróficos funcionais, onde se encontrou uma maior abundância de indivíduos coletores catadores indicando alta concentração de matéria orgânica no sistema. Abstract: With the increasing expansion of fish farming in cages arising from the practice of aquaculture, changes in water quality and all related ecosystem may occur. It is known that the occurrence of larvae of certain species of the family Chironomidae (Diptera) associated with physical and chemical parameters can be adopted as an indicator of impacts. This study aimed to raise the Chironomidae fauna present in the deep area around cages in Furnas Reservoir (MG) and to determine its relationship with water quality. The bottom sediment was collected with the aid of an Ekman-Birge dredge in rejoinders in six points of 16 m deep on average, with a point located in an area without aquaculture and other on points with production. After collection, the samples were screened in the laboratory using a stereoscopic microscope and larvae were mounted on slides for taxonomic identification at genus level. In all, 765 individuals were identified, mostly subfamily Chironominae. Individuals were classified into functional feeding groups, where they found a greater abundance of individuals collectors gatherers indicating high concentration of organic matter in the system

    Short distance behaviour of correlators in the 2D Ising model in a magnetic field

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    We study the spin-spin, spin-energy and energy-energy correlators in the 2d Ising model perturbed by a magnetic field. We compare the results of a set of high precision Montecarlo simulations with the predictions of two different approximations: the Form Factor approach, based on the exact S-matrix description of the model, and a short distance perturbative expansion around the conformal point. Both methods give very good results, the first one performs better for distances larger than the correlation length, while the second one is more precise for distances smaller than the correlation length. In order to improve this agreement we extend the perturbative analysis to the second order in the derivatives of the OPE constants.Comment: 46 pages, 10 figures, final version to appear in Nucl. Phys.

    Swift and Suzaku Observations of the X-Ray Afterglow from the GRB 060105

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    Results are presented of early X-ray afterglow observations of GRB 060105 by Swift and Suzaku. The bright, long gamma-ray burst GRB 060105 triggered the Swift Burst Alert Telescope (BAT) at 06:49:28 on 5 January 2006. The Suzaku team commenced a pre-planned target of opportunity observation at 19 ks (5.3 hr) after the Swift trigger. Following the prompt emission and successive very steep decay, a shallow decay was observed from T_0+187 s to T_0+1287 s. After an observation gap during T_0 +(1.5-3) ks, an extremely early steep decay was observed in T_0+(4-30) ks. The lightcurve flattened again at T_0+30 ks, and another steep decay followed from T_0+50 ks to the end of observations. Both steep decays exhibited decay indices of 2.3 - 2.4. This very early break, if it is a jet break, is the earliest case among X-ray afterglow observations, suggesting a very narrow jet whose opening angle is well below 1 degree. The unique Suzaku/XIS data allow us to set very tight upper limits on line emission or absorption in this GRB. For the reported pseudo-redshift of z=4.0+/-1.3 the upper limit on the iron line equivalent width is 50 eV.Comment: 8 pages, 5 figures, Accepted for publication in PASJ Suzaku Special Issue (vol. 58
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