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Shimonoseki, Japan

Somamoto T.,Kyushu University | Kondo M.,National Fisheries University | Nakanishi T.,Nihon University | Nakao M.,Kyushu University
Developmental and Comparative Immunology | Year: 2014

Although many recent studies have suggested that CD4+ helper T cell (Th-cell) functions are well conserved among teleost fishes and mammals, there is little evidence that CD4+ Th-cells in fish are actually involved in both humoral and cell-mediated immunity during a secondary immune response. In the present study, adoptive transfer using clonal ginbuna crucian carp and crucian carp hematopoietic necrosis virus (CHNV) was used to investigate the functions of CD4+ cells during humoral and cell-mediated immunity. With regard to humoral immunity, transplanting CHNV-sensitized donor cells, containing CD4+ cells, into naive fish induced more rapid and stronger antibody production than by transplanting non-sensitized donor cells or sensitized donor cells lacking CD4+ cells. During cell-mediated immunity, no significant differences were found in recipients that received sensitized cells regardless of whether the donor cells contained CD4+ cells, although recipients that received both sensitized donor cells (with and without CD4+ cells) exhibited more efficient cell-mediated cytotoxicity than those that received non-sensitized donor cells. These findings suggest that inducing a secondary antibody response requires CD4+ cell help, and secondary cell-mediated immunity can be induced both by CD4+ cells and leukocytes other than CD4+ cells. © 2013 Elsevier Ltd. Source

Sasaki C.,Tokushima University | Wanaka M.,Tokushima University | Takagi H.,Tokushima University | Tamura S.,National Fisheries University | And 2 more authors.
Industrial Crops and Products | Year: 2013

Lignin extracted from steam-exploded bamboo has been used as resource material for the production of cured epoxy resins. In this study, 3 types of cured epoxy resin were prepared. The bamboo lignin extracted with methanol from steam-exploded bamboo (steam pressure 35. atm; steaming time 5. min) was epoxidized with epichlorohydrin and then cured with the general curing agent 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole (2E4MZ-CN) and bamboo lignin. General epoxy resin, cured with diglycidyl ether bisphenol A (DGEBA) and 2E4MZ-CN, was simultaneously synthesized as a petroleum-derived epoxy resin control. The mechanical and thermal properties of lignin-based epoxy resins were compared with petroleum epoxy resins. As indicated by their thermal decomposition properties (Td5), the lignin-based epoxy resins exceeded the dip-solder resistance (250-280 °C). Furthermore, lignin-based epoxy resin showed 70% of the flexural strength of the petroleum-based epoxy resin. © 2012 Elsevier B.V. Source

Nakane Y.,University of Tokyo | Suda Y.,National Fisheries University | Sano M.,University of Tokyo
Marine Biology | Year: 2013

To determine differences in fish assemblage structures between beach morphodynamic types on an exposed sandy shore, three beach types (reflective, intermediate, and dissipative) were sampled at Fukiagehama Beach, Kyushu Island, southern Japan, in May, August, and November 2006 and 2007. Distinct differences in physical conditions and the amount of major prey invertebrates, such as copepods, mysids, and amphipods, were recognized between the three beach types. The reflective beach was characterized mainly by turbulent swashes, coarse sediment, and a low abundance of major prey invertebrates. In contrast, the dissipative beach was characterized mostly by benign swashes, fine sediment, and a high abundance of prey invertebrates. The intermediate beach tended toward an intermediate condition between the reflective and dissipative beaches. The fish assemblage structures also differed clearly between the three beach types, with species and individual numbers being greatest on the dissipative beach and lowest on the reflective beach. A similarity index indicated differences in species composition of the assemblages between the beach types. Such differences arose primarily from the differential distributions of two dominant trophic groups, zooplankton (mostly copepods) and epibenthic crustacean (mainly mysids and amphipods) feeders, between the beach types, both groups tending to increase in species and individual numbers from the reflective beach to the dissipative beach. In addition, the mean standard length of all fish collected in each month tended to decrease toward the dissipative beach. These results suggested that beach types strongly influence sandy beach fish assemblage structures. © 2013 Springer-Verlag Berlin Heidelberg. Source

The research presented here evaluates the heat transfer coefficient of the contact interface of a thin liquid polymer film between a pair of columnar aluminum bodies with an initial temperature difference of approximately 160 K. We measured the unsteady temperature changes inside the columns. The heat transfer test was performed with three types of liquid polymers: squalane, oleic acid, and silicone oil. The heat transfer coefficient of the polymer films as a fitting parameter was obtained by ensuring the numerically computed time evolution of the columns’ temperature corresponded with the experimentally measured data. The interfacial heat transfer coefficients of the thin polymer films (mean thickness: 60 μm) for all three polymers used were 1.75 kW/m2·K, 2.75 kW/m2·K, and 4.10 kW/m2·K. The present estimating method for determining interfacial heat transfer coefficients was suitable for a material-polymer film-material contact model. The time evolution of the temperature at the contact surfaces was also effectively evaluated using the numerical simulation. © 2016 Elsevier Ltd Source

Ishida T.,National Fisheries University
Origins of Life and Evolution of Biospheres | Year: 2014

Understanding the generalized mechanisms of cell self-assembly is fundamental for applications in various fields, such as mass producing molecular machines in nanotechnology. Thus, the details of real cellular reaction networks and the necessary conditions for self-organized cells must be elucidated. We constructed a 2-dimensional cellular automata model to investigate the emergence of biological cell formation, which incorporated a looped membrane and a membrane-bound information system (akin to a genetic code and gene expression system). In particular, with an artificial reaction system coupled with a thermal system, the simultaneous formation of a looped membrane and an inner reaction process resulted in a more stable structure. These double structures inspired the primitive biological cell formation process from chemical evolution stage. With a model to simulate cellular self-organization in a 2-dimensional cellular automata model, 3 phenomena could be realized: (1) an inner reaction system developed as an information carrier precursor (akin to DNA); (2) a cell border emerged (akin to a cell membrane); and (3) these cell structures could divide into 2. This double-structured cell was considered to be a primary biological cell. The outer loop evolved toward a lipid bilayer membrane, and inner polymeric particles evolved toward precursor information carriers (evolved toward DNA). This model did not completely clarify all the necessary and sufficient conditions for biological cell self-organization. Further, our virtual cells remained unstable and fragile. However, the “garbage bag model” of Dyson proposed that the first living cells were deficient; thus, it would be reasonable that the earliest cells were more unstable and fragile than the simplest current unicellular organisms. © 2014, Springer Science+Business Media Dordrecht. Source

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