1,660 research outputs found
Social disruption stress exacerbates alpha-galactosylceramide-induced hepatitis in mice
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
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
The effects of pressure dependent constitutive model to simulate concrete structures failure under impact loads
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
Recursive representation of the torus 1-point conformal block
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
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
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
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.
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
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.
- …