336 research outputs found

    Angular Power Spectrum in Modular Invariant Inflation Model

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    We propose a scalar potential of inflation, motivated by modular invariant supergravity, and compute the angular power spectra of the adiabatic density perturbations that result from this model. The potential consists of three scalar fields, S, Y and T, together with two free parameters. By fitting the parameters to cosmological data at the fixed point T=1, we find that the potential behaves like the single-field potential of S, which slowly rolls down along the minimized trajectory in Y. We further show that the inflation predictions corresponding to this potential provide a good fit to the recent three-year WMAP data, e.g. the spectral index n_s = 0.951. The TT and TE angular power spectra obtained from our model almost completely coincide with the corresponding results obtained from the \LambdaCDM model. We conclude that our model is considered to be an adequate theory of inflation that explains the present data, although the theoretical basis of this model should be further explicated.Comment: 8 pages, 8 figures and 1 tabl

    Passive Oral Immunization by Egg Yolk Immunoglobulin (IgY) to Vibrio cholerae Effectively Prevents Cholera

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    In an attempt to prepare egg yolk immunoglobulin (IgY) to treat and prevent cholera, hens were immunized by a mixture of heat- or formalin-killed Vibrio cholerae O1 and O139 organisms, or by the recombinant cholera toxin B subunit (CTB). The IgYs were partially purified from egg yolk and orally administered to suckling mice before or after challenge with live O1 or O139 cells. The anti-O1 and O139 IgYs and the mixture of either IgY with anti-CTB IgY significantly protected the occurrence of cholera caused by both O1 and O139 infection. Since large amounts of IgY can be prepared very easily and at low cost, this seems to be a useful procedure for preventing and treating cholera

    Antibody and Cytokine Responses in Helicobacter pylori-Infected Various Mouse Strains

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    Helicobacter pylori (H. pylori) infection in the stomach is etiologically closely associated with chronic active gastritis, peptic ulcer, gastric cancer and gastric mucosa-associated lymphoid tissue lymphoma. In this study, we examined the antibody responses and cytokine profiles of three strains of mice (BALB/c, C3H/He, and C57BL/6) infected with H. pylori. Following this, correlations between host-immune reactions and intensity of inflammation were analyzed. H. pylori (ATCC43504) was intragastrically administered once a week to the mice from 4 weeks of age, and they were sacrificed at the ages of 4 and 7 months. In these mice, we examined the histology of the stomach, antibody titers against H. pylori, and serum levels of cytokines (IL-4, IL-10, TNF-alpha, IL-2 and Interferon-gamma). In BALB/c mice, inflammation of the stomach was minimal. Inflammation was observed in 63.6% of C57BL/6 mice and 33.3% of C3h/He mice. In C57BL/6 and C3H/He mice, all the cytokines tended to increase. In contrast, BALB/c mice were inactive in cytokine production except for IL-2. Two C3H/He mice developed severe inflammation with lymph follicles; one showed a response largely typical of Th-1, and the other showed a response largely typical of Th-2. Although a definite correlation was not shown between Th-1/Th-2 response evaluated by cytokine production and intensity of inflammation, it appears that in H. pylori-induced inflammation both cell-mediated (Th-1) and humoral (Th-2) immunity play a role in pathogenesis.</p

    Lipid profiles of Helicobacter pylori and Helicobacter mustelae grown in serum-supplemented and serum-free media.

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    Many of Helicobacter species have been found to have novel cholesteryl glucosides (CGs). To study the biosynthetic mechanism of CGs, the lipid profiles of H. pylori and H. mustelae grown in serum-supplemented and cholesterol-restricted serum-free media were investigated. In contrast to the serum-supplemented state, helicobacters had less CGs in the serum-free state; a trace amount of CGs and no CG was detected in H. pylori and H. mustelae, respectively. The proportion of total and individual phospholipid also showed significant alteration. Unknown lipids which did not contain phosphate and sugar were detected in the serum-free state, but not in the serum-supplemented state. The CGs were found to be distributed mainly in the membrane fractions, and one of the unknown lipids was found exclusively in the cytosol fraction. Based on these data, it is apparent that the CGs of helicobacters are synthesized by de novo uptake of cholesterol from the media. The unknown lipids detected in the serum-free state may be storage lipids, appearing in response to depletion of nutrients, especially cholesterol, or other factors in the media.</p

    Evaluation of roller arrangement of sphere by omnidirectional integral value

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    Roller arrangement problem is a sphere conveyance problem of driving rollers. In this research, the roller arrangement problem, viewed as an evaluation function, is thought of as mean of roller kinetic energy with respect to the sphere direction. Furthermore, theoretically, we derive the function, and find the contact point such that the evaluated value is minimal.The 2022 International Conference on Artificial Life and Robotics (ICAROB 2022), January 20-23, 2022, on line, Oita, Japa

    The Critical Point of Average Grain Size in Phonon Thermal Conductivity of Fine-Grained Undoped Lead Telluride

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    Undoped PbTe was melted at 1123 K, ball milled (BM) at rotation speeds from 90 to 180 rpm and hot pressed (HP) at 147 MPa and 650 K. Milling at 120 rpm produced the minimum phonon thermal conductivity of 1.29 W m−1 K−1 and average grain size of 0.80 µm. Phonon thermal conductivity was constant from coarse grain size to fine grain size of 1 µm and decreased suddenly at 0.80 µm. This tendency of phonon thermal conductivity corresponded to theoretical calculations with grain boundary scattering. However, the observed critical point of 1 µm was much larger than the calculated value of 0.03 µm. There was a significant inverse relationship between phonon thermal conductivity and FWHM of X-ray diffraction peaks. The low phonon thermal conductivity was associated with not only grain boundary scattering but high internal strain

    Immune Reactions Against Elongation Factor 2 Kinase: Specific Pathogenesis of Gastric Ulcer from Helicobacter pylori Infection

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    Helicobacter pylori (H. pylori) infection is a definite causative factor for gastric ulcers (GUs). In the present study we detected a specific antigen of gastric epithelial cells (HGC-27) using cell ELISA, which was recognized by the sera of GU patients (n = 20) but not in patients with chronic gastritis (CG; n = 20) or in healthy volunteers (HC; n = 10). This antigen was over-expressed by a stressful (heat-stressed) environment, and was identified as elongation factor 2 kinase (EF-2K) by western blotting. The GU patients' lymphocytes stimulated by H. pylori specifically disrupted heat-stressed HGC-27 cells in a cytotoxic assay. In flow cytometry, the effector cells (lymphocytes) from GU patients were significantly differentiated to T helper type 1 lymphocyte (Th1) and cytotoxic T lymphocyte (CTL) as opposed to those from CG patients. The target cells (HGC-27) expressed EF-2K and MHC-class I together with costimulatory molecules from heat stress. This antigen specific immune mechanism could have a prominent role in the pathogenesis of GU
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