522 research outputs found

    Moduli trapping mechanism in modular flavor symmetric models

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    We discuss how the moduli in modular flavor symmetric models dynamically select enhanced symmetry points at which the residual modular symmetry renders extra matter fields massless. The moduli dynamics non-perturbatively produces the extra matter particles, which gives (time-dependent) effective potential that traps the moduli to enhanced symmetry points. We show analytic estimates of particle production rate consistent with numerical results, and the dynamics of moduli based on the analytic estimates.Comment: 35 pages, 14 figure

    The competitiveness of domestic rice production in East Africa: A domestic resource cost approach in Uganda

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    The rapid increase of rice imports in sub-Saharan Africa under the unstable situation in the world rice market during the 2000s has made it an important policy target for the countries in the region to increase self-sufficiency in rice in order to enhance food security. Whether domestic rice production can be competitive with imported rice is a serious question in East African countries that lie close, just across the Arabian Sea, to major rice exporting countries in South Asia. This study investigates the international competitiveness of domestic rice production in Uganda in terms of the domestic resource cost ratio. The results show that rainfed rice cultivation, which accounts for 95% of domestic rice production, does not have a comparative advantage with respect to rice imported from Pakistan, the largest supplier of imported rice to Uganda. However, the degree of non-competitiveness is not serious, and a high possibility exists for Uganda’s rainfed rice cultivation to become internationally competitive by improving yield levels by applying more modern inputs and enhancing labour productivity. Irrigated rice cultivation, though very limited in area, is competitive even under the present input-output structure when the cost of irrigation infrastructure is treated as a sunk cost. If the cost of installing irrigation infrastructure and its operation and maintenance is taken into account, the types of irrigation development that are economically feasible are not large-scale irrigation projects, but are small- and microscale projects for lowland rice cultivation and rain-water harvesting for upland rice cultivation

    B-Cell-Activating Factor Affects the Occurrence of Thyroid Autoimmunity in Chronic Hepatitis C Patients Treated with Interferon Alpha

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    Chronic hepatitis C (CHC) patients frequently suffer from thyroid disorders during interferon therapy. However, the mechanism remains unclear. In this study, we investigated the association between serum B-cell-activating factor belonging to the TNF family (BAFF) levels and the presence of antithyroid peroxidase antibody (anti-TPO) in CHC patients treated with pegylated interferon alpha and ribavirin combination therapy. Six months after the therapy, anti-TPO antibody was detected in 10 (males, 1; females, 9) of 50 patients. The mean age of these patients was higher than that of the anti-TPO-negative patients (61 yr versus 55 yr). Before treatment, the serum BAFF levels of the anti-TPO-positive patients were higher than those of the anti-TPO-negative patients. After starting therapy, the serum BAFF levels of both the anti-TPO-positive and -negative patient groups were elevated. Our findings suggest that the serum BAFF concentration before therapy can predict the risk of thyroid autoimmunity in elderly female patients with CHC

    Year-round observations of sea-ice drift and near-inertial internal waves in the Northwind Abyssal Plain, Arctic Ocean

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    The Tenth Symposium on Polar Science/Ordinary sessions: [OM] Polar Meteorology and Glaciology, Thu. 5 Dec. / 2F Auditorium , National Institute of Polar Researc
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