The University of the Ryukyus , abbreviated to Ryūdai , is a national university of Japan in Okinawa Prefecture. It is located in the Senbaru neighborhood of the town of Nishihara, with its campus bordering both the village of Nakagusuku and the city of Ginowan. It is the westernmost national university of Japan and the largest public university in Okinawa Prefecture. Wikipedia.
Dobata S.,University of Ryukyus
Proceedings. Biological sciences / The Royal Society | Year: 2012
Colonies of eusocial Hymenoptera, such as ants, bees and wasps, have long been recognized as candidates for the study of genomic imprinting on the grounds of evolutionary conflicts that arise from close interactions among colony members and relatedness asymmetry owing to haplodiploidy. Although a general kinship theory of genomic imprinting predicts its occurrence under various circumstances of the colony life cycle, new theoretical approaches are required to account for the specifics of real colonies based on recent advances in molecular-level understanding of ants and honeybees. Using a multivariate quantitative genetic model, we examined the potential impact of genomic imprinting on genes that determine the carrier female's propensity to develop into the queen caste. When queen overproduction owing to the increased propensity comes at a colony-level cost, the conflict between maternally and paternally inherited genes in polyandrous (queen multiple mating) colonies favours genomic imprinting. Moreover, we show that the genomic imprinting can occur even under monandry (queen single mating), once incorporating the costs differentially experienced by new males and new queens. Our model predicts the existence of imprinted 'genetic royal cheats' with patriline-specific expression in polyandrous colonies, and seems consistent with the paternal effect on queen determination in monandrous Argentine ants. Source
Oda I.,University of Ryukyus
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013
We consider a coupling of conformal gravity to the classically scale-invariant B-L extended standard model which has been recently proposed as a phenomenologically viable model realizing the Coleman-Weinberg mechanism of breakdown of the electroweak symmetry. As in a globally scale-invariant dilaton gravity, it is also shown in a locally scale-invariant conformal gravity that without recourse to the Coleman-Weinberg mechanism, the B-L gauge symmetry is broken in the process of spontaneous symmetry breakdown of the local scale invariance (Weyl invariance) at the tree level and as a result the B-L gauge field becomes massive via the Higgs mechanism. As a bonus of conformal gravity, the massless dilaton field does not appear and the parameters in front of the non-minimal coupling of gravity are completely fixed in the present model. This observation clearly shows that the conformal gravity has a practical application even if the scalar field does not possess any dynamical degree of freedom owing to the local scale symmetry. © 2013 Elsevier B.V. Source
University of Ryukyus | Date: 2013-09-06
TROPICAL TECHNOLOGY CENTER Ltd. and University of Ryukyus | Date: 2010-04-06
A therapeutic agent comprising fucoxanthin or fucoxanthinol as an active component is disclosed. The therapeutic agent is effective and high clinical utility for medical treatment and prevention of virus-associated malignancy such as adult T-cell leukemia and Burkitt lymphoma.
Okinawa Research Center Co. and University of Ryukyus | Date: 2013-08-09
The object of the invention is to provide a method of manufacturing a fraction containing nobiletin and tangeretin at high concentrations, which is excellent in terms of safety, economic efficiency, and the potential for industrialization. The object is achieved by a method of manufacturing a composition containing nobiletin and tangeretin, comprising (1-1) a step of treating citrus fruit with hot water to obtain a hot water-treated product; (1-2) a step of drying the hot water-treated product to obtain a dried product; (1-3) a step of treating the dried product with a solvent capable of dissolving nobiletin and tangeretin to obtain a nobiletin and tangeretin solution; (3) a step of concentrating and/or drying the nobiletin and tangeretin solution to obtain a nobiletin and tangeretin concentrate; and (4) a step of treating the nobiletin and tangeretin concentrate with a dilute alkali to obtain a composition containing nobiletin and tangeretin as an insoluble component, and by a composition containing nobiletin and tangeretin at high concentrations manufactured by the method.