PubMed | Japan National Research Institute of Fisheries Science, Hakodate Junior College Hakodate, Tokyo Institute of Technology, University of Nice Sophia Antipolis and 5 more.
Type: | Journal: Frontiers in microbiology | Year: 2014
Harima Y.,Hiroshima University |
Sanada K.,Hiroshima University |
Patil R.,Hiroshima University |
Ooyama Y.,Hiroshima University |
And 2 more authors.
European Polymer Journal | Year: 2010
Monodisperse and isolated microspheres of poly(N-methylaniline) were successfully prepared through chemical polymerization of N-methylaniline by S2 O82 - in adipic acid containing poly(vinylpyrrolidone) (PVP). Mean diameters of the microspheres with smooth surfaces changed from 320 to 100 nm by increasing the reaction temperature from 25 to 75 °C. The concentration of PVP did not affect much the size of microspheres, but the increased PVP concentration led to longer induction times for the onset of dispersion polymerization. © 2010 Elsevier Ltd. All rights reserved.
Jiang X.,Nanjing Normal University |
Jiang X.,Hiroshima University |
Setodoi S.,Hiroshima University |
Fukumoto S.,Hiroshima University |
And 5 more authors.
Carbon | Year: 2014
An easy electrochemical technique is proposed to prepare electrochemically reduced graphene oxide (ERGO)/polyaniline (PANI) composites in a single step. The technique uses a two-electrode cell in which a separator soaked with an acid solution is sandwiched between graphene oxide (GO)/aniline films deposited on conductive substrates and an alternating voltage was applied to the electrodes. Successful preparations of ERGO/PANI composites were evidenced by characterizations due to UV-vis-NIR, FT-IR, XPS, XRD, and SEM measurements with free-standing films of ERGO/PANI obtained easily by disassembling the two-electrode cells. The ERGO/PANI films exhibited a high mechanical stability, flexibility, and conductivity (68 S cm-1 for the composite film containing 80% ERGO) with nanostructured PANI particles (smaller than 20 nm) embedded homogeneously between the ERGO layers. The two-electrode cells acted as electrochemical capacitors (ECs) after a sufficient voltage cycling and exhibited relatively large specific capacitances (195- 243 F g-1 at a scan rate of 100 mV s-1) with an excellent cycle life (retention of 83% capacitance after 20,000 charge-discharge cycles). Influences of the GO/aniline ratio, the sort of electrolytes, and the weight of the composite on the energy storage characteristics of ECs comprising the ERGO/PANI composites were also studied. © 2013 Elsevier Ltd. All rights reserved.
Harima Y.,Hiroshima University |
Setodoi S.,Hiroshima University |
Imae I.,Hiroshima University |
Komaguchi K.,Hiroshima University |
And 4 more authors.
Electrochimica Acta | Year: 2011
Graphene oxide (GO) cast on conductive substrates was electrochemically reduced in some organic solvents. The amount of electricity required for the almost complete reduction of GO was 2.0 C for 1 mg GO, corresponding to attaching of a one-electron reducible species to each benzene ring in graphene. The electrochemically reduced GO film gave an electrical conductivity of about 3 S cm -1 and exhibited a relatively high specific capacitance of 147.2 F g -1 in propylene carbonate. The electrochemical reduction of GO was feasible on Al foils as well. © 2011 Elsevier Ltd.
Munehara H.,Hakodate University |
Horita M.,Hokkaido University of Science |
Kimura-Kawaguchi M.R.,Hokkaido University of Science |
Yamazaki A.,Hokkaido University of Science
Ecology and Evolution | Year: 2016
Two natural, hemiclonal hybrid strains were discovered in three Hexagrammos species. The natural hybrids, all of which were females that produced haploid eggs containing only the Hexagrammos octogrammus genome (maternal ancestor; hereafter Hoc), generated F1 hybrid-type offspring by fertilization with haploid sperm of Hexagrammos agrammus or Hexagrammos otakii (paternal species; Hag and Hot, respectively). This study was performed to clarify the extent of diversification between the two hybrids and the maternal ancestor. Genealogical analysis using mtDNA revealed that all 38 Hoc/Hot hybrids formed a branch (Branch I) with 18 of the 33 Hoc/Hag hybrids. No haplotype sharing was observed with the maternal ancestor. Further, microsatellite DNA analysis suggested that the members of Branch I shared the same hemiclonal genome set. The results suggested that Hoc/Hot hybrids originated by anomalous hybridization, or "host switching," between Hoc/Hag and Hot, and not from interspecific hybridization between Hoc and Hot. The remaining 9 of 11 Hoc/Hag haplotypes and all of the 27 Hoc haplotypes were mixed within the genealogical tree, as if they had originated from multiple mutations. However, Hoc/Hag could also mate with Hoc. Although offspring from this host switch (Backcross-Hoc) have the same genome as normal Hoc, a part of their genome retains genetic factors capable of producing hemiclones. Consequently, when a descendant of a BC-Hoc hybrid mates with Hag males, a new hemiclone lineage will arise. Multiple haplotype revival through host switching from a single mutation in hybrids is another possible hypothesis for the observed mixing of Hoc/Hag haplotypes within the mtDNA genealogical tree. © 2016 Published by John Wiley & Sons Ltd.
Yoshimizu M.,Hakodate University
Fish Pathology | Year: 2016
The first outbreak of bacterial kidney disease (BKD) of salmonids occurred in the autumn of 1973 in Hokkaido, Japan. Subsequently, outbreaks of BKD were confirmed in Hokkaido and main land of Japan. Most of the cases were caused by imported eyed eggs of coho salmon Oncorhynchus kisutch. In this review, pathogenicity of the causative agent R. salmoninarum (Rs), culture methods of Rs, serological and Rs specific gene detection methods for diagnoses, disease signs of infected fish, and distribution of BKD in Japan are described. Also, preventive measures of vertical transmission and control methods of BKD are introduced. © 2016 The Japanese Society of Fish Pathology.
Yoshida A.,Hakodate University |
Sakurazawa S.,Hakodate University
2012 IEEE/SICE International Symposium on System Integration, SII 2012 | Year: 2012
Locomotion is the most important characteristic of living matter. To clarify the factor makes observers find out autonomy in locomotion of living organism is significant from the perspective of artificial intelligence or emergence. In considering physical basis of autonomy of locomotion, we have to remark following three biotic features; 'unidirectional movement generated from asymmetric architecture', 'mismatch between objects of apparent locomotion and of endogenous internal activity in the relation of the parts to the whole' and 'homeostasis as motive force of internal activity.' In previous study, we have implemented these features to an autonomous distributed robot consisting of several identical modules, which are connected in a linear arrangement and behave in order to resolve the strain of one-self each other. The results of the experiments changing delay time to resolve the strain and the resolving speed showed that the robot shows wide variety of unidirectional locomotion under specific conditions. Therefore, to understand the meaning of the specific conditions, in this study, we logged change of load and angle for each module during the locomotion. Then, we could find that propagations of load and angle change were occurred during long distance locomotion. This means that postponing and passing outstanding problem to neighbors generate large winding propagation and causes baseless locomotion, which is possible to give autonomy. © 2012 IEEE.
Imazai K.-I.,Hakodate University
Shinrigaku Kenkyu | Year: 2015
The labor tribunal system, whieh is a form of alternative dispute resolution rather than a type of lawsuit, requires both parties' agreements to settle disputes and maintains a high settlement rate. As most of parties involved in the system are said to expect that labor problems should be settled fairly, it is assumed that they will readily accept the results of fair procedures. However, it seems that laborers who submit claims for compensation have a different concept of justice than employers or company employees in charge of settlements and this determines the attitudes toward the results. This study conducted a survey of participants in the labor tribunal system, and suggest that laborers attribute the validity of this system's results directly to judges, while company representatives attribute it to the procedure conducted by the judges.
Nakayama Y.,Hokkaido University |
Kuma K.,Hokkaido University |
Kuma K.,Hakodate University |
Fujita S.,Hokkaido University |
And 2 more authors.
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2010
Iron [dissolved Fe (D-Fe) and total dissolvable Fe (T-Fe)] and nutrient concentrations in the surface water of the Oyashio region (northwestern North Pacific) were measured before and during spring phytoplankton bloom (March to May in 2007). During the pre-bloom period (middle of March), we observed vertically uniform concentrations of iron (0.3-0.5nM [D-Fe] and 3-5nM [T-Fe]), macronutrients (10-15γM NO3+NO2, 1.0-1.5γM PO4 and 20-30γM Si(OH)4) and chlorophyll a (Chl-a, 0.3-0.4γg l-1) throughout the upper 125 to 150m due to vertical mixing during winter. Water temperature and salinity before the bloom were also vertically uniform with >5°C and S>33.5, the conditions of a modified Kuroshio warm-water (MKW) ring, higher than those of the Coastal Oyashio Water (COW). The cold COW (<2°C, S<33.2) intruded a few times into the surface during the bloom period with high iron (0.4-0.6nM [D-Fe] and 10-25nM [T-Fe]) and Chl-a (10-23γg l-1) concentrations. The high Chl-a observed in the COW is due to the higher original concentrations of iron and macronutrients in the COW than in the MKW. An incubation experiment conducted during a COW intrusion in early April resulted in robust phytoplankton growth and complete exhaustion of nutrients, indicating an adequate supply of bioavailable iron. This result is also consistent with robust in situ phytoplankton growth and Chl-a production due to the presence of high iron levels in the COW. The most important mechanisms transporting iron to the surface water, which would regulate the primary production during spring bloom in the Oyashio region, are the surface intrusions of iron- and nutrient-rich COW derived from vertical and lateral mixing processes and vertical mixing in MKW during winter and spring. © 2010 Elsevier Ltd.
PubMed | Bangladesh Agricultural University and Hakodate University
Type: | Journal: Frontiers in chemistry | Year: 2014
The common sea hare Aplysia kurodai is known to be a good source for the enzymes degrading seaweed polysaccharides. Recently four cellulases, i.e., 95, 66, 45, and 21 kDa enzymes, were isolated from A. kurodai (Tsuji et al., 2013). The former three cellulases were regarded as glycosyl-hydrolase-family 9 (GHF9) enzymes, while the 21 kDa cellulase was suggested to be a GHF45 enzyme. The 21 kDa cellulase was significantly heat stable, and appeared to be advantageous in performing heterogeneous expression and protein-engineering study. In the present study, we determined some enzymatic properties of the 21 kDa cellulase and cloned its cDNA to provide the basis for the protein engineering study of this cellulase. The purified 21 kDa enzyme, termed AkEG21 in the present study, hydrolyzed carboxymethyl cellulose with an optimal pH and temperature at 4.5 and 40C, respectively. AkEG21 was considerably heat-stable, i.e., it was not inactivated by the incubation at 55C for 30 min. AkEG21 degraded phosphoric-acid-swollen cellulose producing cellotriose and cellobiose as major end products but hardly degraded oligosaccharides smaller than tetrasaccharide. This indicated that AkEG21 is an endolytic -1,4-glucanase (EC 18.104.22.168). A cDNA of 1013 bp encoding AkEG21 was amplified by PCR and the amino-acid sequence of 197 residues was deduced. The sequence comprised the initiation Met, the putative signal peptide of 16 residues for secretion and the catalytic domain of 180 residues, which lined from the N-terminus in this order. The sequence of the catalytic domain showed 47-62% amino-acid identities to those of GHF45 cellulases reported in other mollusks. Both the catalytic residues and the N-glycosylation residues known in other GHF45 cellulases were conserved in AkEG21. Phylogenetic analysis for the amino-acid sequences suggested the close relation between AkEG21 and fungal GHF45 cellulases.