Mitsubishi

About: Mitsubishi is a company organization based out in Tokyo, Japan. It is known for research contribution in the topics: Layer (electronics) & Signal. The organization has 53115 authors who have published 54821 publications receiving 870150 citations. The organization is also known as: Mitsubishi Group of Companies & Mitsubishi Companies.

Parthenogenetic activation of oocytes in c-mos-deficient mice

Abstract: IN Xenopus the c-mos proto-oncogene product (Mos) is essential for the initiation of oocyte maturation1, for the progression from meiosis I to meiosis II2,3 and for the second meiotic metaphase arrest, acting as an essential component of the cytostatic factor CSF4,5. Its function in mouse oocytes is unclear6–9, however, as is the biological significance of c-mos mRNA expression in testes1,10 and several somatic tissues1,10,11. We have generated c-mos-deficient mice by gene targeting in embryonic stem cells. These mice grew at the same rate as their wild-type counterparts and reproduction was normal in the males, but the fertility of the females was very low. The c-mos-deficient female mice developed ovarian teratomas at a high frequency. Oocytes from these females matured to the second meiotic metaphase both in vivo and in vitro, but were activated without fertilization. The results indicate that in mice Mos plays a role in the second meiotic metaphase arrest, but does not seem to be essential for the initiation of oocyte maturation, spermatogenesis or somatic cell cycle.

Chemical and isotopic evidence of thermochemical sulphate reduction by light hydrocarbon gases in deep carbonate reservoirs

Abstract: Large H2S accumulations in deep carbonate reservoirs have been attributed to thermochemical sulphate reduction. Although organic matter has been invoked as the reducing agent, individual reactants in specific environments have hitherto not been identified. Carbon isotope data reveal that light hydrocarbon gases have been effective reducing agents in some Palaeozoic foothill reservoirs of western Canada.

Parallel operation of voltage source inverters

Abstract: Parallel operating systems of voltage source inverters with other inverters or with the utility source are sensitive to disturbances from the load or other sources and can easily be damaged by overcurrent. Thus extremely careful attention should be given to the system design of parallel operating inverters. Types of system configuration, control methods, and means of protection against failure are summarized, and several methods are proposed. Features and problems of these systems are discussed. >

Isolation of chicken vasa homolog gene and tracing the origin of primordial germ cells.

Abstract: To obtain a reliable molecular probe to trace the origin of germ cell lineages in birds, we isolated a chicken homolog (Cvh) to vasa gene (vas), which plays an essential role in germline formation in Drosophila. We demonstrate the germline-specific expression of CVH protein throughout all stages of development. Immunohistochemical analyses using specific antibody raised against CVH protein indicated that CVH protein was localized in cytoplasm of germ cells ranging from presumptive primordial germ cells (PGCs) in uterine-stage embryos to spermatids and oocytes in adult gonads. During the early cleavages, CVH protein was restrictively localized in the basal portion of the cleavage furrow. About 30 CVH-expressing cells were scattered in the central zone of the area pellucida at stage X, later 45–60 cells were found in the hypoblast layer and subsequently 200–250 positive cells were found anteriorly in the germinal crescent due to morphogenetic movement. Furthermore, in the oocytes, CVH protein was predominantly localized in granulofibrillar structures surrounding the mitochondrial cloud and spectrin protein-enriched structure, indicating that the CVH-containing cytoplasmic structure is the precursory germ plasm in the chicken. These results strongly suggest that the chicken germline is determined by maternally inherited factors in the germ plasm.