Hokkaido University

About: Hokkaido University is a education organization based out in Sapporo, Hokkaidô, Japan. It is known for research contribution in the topics: Catalysis & Population. The organization has 53925 authors who have published 115403 publications receiving 2651647 citations. The organization is also known as: Hokudai & Hokkaidō daigaku.

A detailed linkage map of medaka, Oryzias latipes: comparative genomics and genome evolution.

Abstract: We mapped 633 markers (488 AFLPs, 28 RAPDs, 34 IRSs, 75 ESTs, 4 STSs, and 4 phenotypic markers) for the Medaka Oryzias latipes, a teleost fish of the order Beloniformes. Linkage was determined using a reference typing DNA panel from 39 cell lines derived from backcross progeny. This panel provided unlimited DNA for the accumulation of mapping data. The total map length of Medaka was 1354.5 cM and 24 linkage groups were detected, corresponding to the haploid chromosome number of the organism. Thirteen to 49 markers for each linkage group were obtained. Conserved synteny between Medaka and zebrafish was observed for 2 independent linkage groups. Unlike zebrafish, however, the Medaka linkage map showed obvious restriction of recombination on the linkage group containing the male-determining region (Y) locus compared to the autosomal chromosomes.

Controls on iron(III) hydroxide solubility in seawater: The influence of pH and natural organic chelators

Abstract: Iron solubilities of Fe(III) hydroxide in coastal and oceanic waters and in the ultraviolet (UV)-irradiated seawaters over a pH range of 5.7-8.2 at 20°C were determined by a sim:Dle filtration (0.025 pm) involving y-activity measurement of 59Fe. At pH ranges of 5.7-7.2 (coastal water) and of 5.7-7.6 (oceanic water), only the Fe(OH),+ species is significant. The calculated solubility products, log*&,, for coastal and oceanic waters were 4.8-5.0 and 4.4-4.6, respectively. The solubilities within the pH range of 7.8-8.2 are relatively independent of pH and aging time. Solubility in the oceanic water was about one order of magnitude lower than that in the coastal water, and UV irradiation reduced solubility to 40.1 r-I solubility minima (0.15-0.2 nM) occur at a depth of 50-200 m. These results suggest that natural organic Fe(III) chelators exist in significant concentrations and control the dissolved iron concentration in seawaters.

Discounting Delayed and Probabilistic Monetary Gains and Losses by Smokers of Cigarettes

Abstract: Rationale: Nicotine dependence has been associated with impulsivity and discounting delayed/uncertain outcomes. Objectives: This study had two main objectives: (1) to examine the relationship between the number of cigarettes consumed per day and the degree to which delayed and uncertain monetary gains and losses are discounted by smokers, and (2) to determine the relationship between the estimated dose of nicotine intake per day and the degree to which four types of discounting occur. Methods: Twenty seven habitual smokers and 23 never smokers participated in this experiment. They were required to choose between immediate and delayed monetary rewards (or losses), or between guaranteed and probabilistic rewards (or losses). Results: The degree to which delayed monetary gains were discounted was significantly and positively correlated with both the number of cigarettes smoked and the estimated dose of nicotine intake per day. Conversely, there was no relationship between smoking and the remaining three types of discounting. Also, mild smokers in our sample did not differ from never smokers in discounting monetary gains or losses. Conclusions: In general, our results suggest that both the frequency of nicotine self-administration, as well as the dosage, are positively associated with greater delay discounting of gains. One neuropsychopharmacological explanation for this effect is that chronic nicotine intake may induce neuroadaptation of the neural circuitry involved in reward processing.

The Second Survey of the Molecular Clouds in the Large Magellanic Cloud by NANTEN. I. Catalog of Molecular Clouds

Abstract: The second survey of the molecular clouds in the Large Magellanic Cloud in 12CO ( -->J = 1?0) was carried out by NANTEN. The sensitivity of this survey is twice as high as that of the previous NANTEN survey, leading to a detection of molecular clouds with -->MCO 2 ? 104 M?. We identified 272 molecular clouds, 230 of which are detected at three or more observed positions. We derived the physical properties, such as size, line width, and virial mass, of the 164 GMCs that have an extent more than the beam size of NANTEN in both the major and minor axes. The CO luminosity and virial mass of the clouds show a good correlation of -->Mvir LCO1.1 ? 0.1, with a Spearman rank correlation of 0.8, suggesting that the clouds are in nearly virial equilibrium. Assuming the clouds are in virial equilibrium, we derived an XCO-factor of ~ -->7 ? 1020 cm?2 (K km s?1)?1. The mass spectrum of the clouds is fitted well by a power law of -->Ncloud(> MCO) MCO?0.75 ? 0.06 above the completeness limit of -->5 ? 104 M?. The slope of the mass spectrum becomes steeper if we fit only the massive clouds, e.g., -->Ncloud(> MCO) MCO?1.2 ? 0.2 for -->MCO ? 3 ? 105 M?.