2,031 research outputs found

    On the construction of QED using ERG

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    It has been known for some time that a smooth momentum cutoff is compatible with local gauge symmetries. In this paper we show concretely how to construct QED using the exact renormalization group (ERG). First, we give a new derivation of the Ward identity for the Wilson action using the technique of composite operators. Second, parameterizing the theory by its asymptotic behavior for a large cutoff, we show how to fine-tune the parameters to satisfy the identity. Third, we recast the identity as invariance of the Wilson action under a non-linear BRST transformation.Comment: 18 pages, LaTeX2e; added appendix A to improve sects. 2 and 4; added ref. 1

    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

    Evidence for Carrier-Induced High-Tc Ferromagnetism in Mn-doped GaN film

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    A GaN film doped with 8.2 % Mn was grown by the molecular-beam-epitaxy technique. Magnetization measurements show that this highly Mn-doped GaN film exhibits ferromagnetism above room temperature. It is also revealed that the high-temperature ferromagnetic state is significantly suppressed below 10 K, accompanied by an increase of the electrical resistivity with decreasing temperature. This observation clearly demonstrates a close relation between the ferromagnetism with extremely high-Tc and the carrier transport in the Mn-doped GaN film.Comment: 9 pages, 3 figure

    On the Design and Development of a Zigbee-Based Multimodal Input-Output Monitoring-Actuating System

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    The monitoring of a physically challenged patient’s activities is a crucial and difficult task for the medical professionals. The design and development of a multimodal- input and output wireless system with two sensors and three actuators that can be used for just monitoring or for both monitoring and stimulating are discussed in this research. Touch and tilt sensors at the input part of the system attached to Zigbee modules communicate in a wireless manner with voice, vibration and light actuators connected to Zigbee modules at the output part. The hardware and the software parts are designed and integrated in such a way that a new sensor at the input or a new actuator at the output can be included or excluded based on the needs of the patient. It is shown how to design and develop sensors. In an application programming interface communication mode, 3 XBee series 1 modules send and receive data in a wireless manner. The prototype of the system was tested with promising results in the case of the patients with inattention disorder. This system can be used for monitoring the activities of a patient and also for actuating certain stimulus in the patient side in case of necessity

    Distribution of Connectin (Titin) and Transverse Tubules at Myotendinous Junctions

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    The ends of muscle fibers form many longitudinal projections which are further divided into numerous processes and attach to the collagen fibrils of tendons to form myotendinous junctions (MTJs). Immunocytochemical and electron microscopic observations on pectoralis muscles of the chicken revealed the presence of an elastic filamentous protein, connectin (titin), within the terminal sarcomere on the side adjacent to the terminal Z bands, and the absence of connectin and myosin and the presence of actin at the apical sarcoplasmic region of MTJ processes between the terminal Z band and the MTJ sarcolemma. Intermediate voltage electron microscopy showed that T tubules in the terminal sarcomere were absent at the level of the A-I junction on the MTJ side in the rat vastus intermedius, and at the level of the terminal Z band or under the MTJ subsarcolemmal densities in the chicken pectoralis

    High-energy spectroscopic study of the III-V nitride-based diluted magnetic semiconductor Ga1−x_{1-x}Mnx_{x}N

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    We have studied the electronic structure of the diluted magnetic semiconductor Ga1−x_{1-x}Mnx_{x}N (xx = 0.0, 0.02 and 0.042) grown on Sn-doped nn-type GaN using photoemission and soft x-ray absorption spectroscopy. Mn LL-edge x-ray absorption have indicated that the Mn ions are in the tetrahedral crystal field and that their valence is divalent. Upon Mn doping into GaN, new state were found to form within the band gap of GaN, and the Fermi level was shifted downward. Satellite structures in the Mn 2pp core level and the Mn 3dd partial density of states were analyzed using configuration-interaction calculation on a MnN4_{4} cluster model. The deduced electronic structure parameters reveal that the pp-dd exchange coupling in Ga1−x_{1-x}Mnx_{x}N is stronger than that in Ga1−x_{1-x}Mnx_{x}As.Comment: 6pages, 10figures. To be published to Phys. Rev.

    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
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