University of Tsukuba

About: University of Tsukuba is a education organization based out in Tsukuba, Ibaraki, Japan. It is known for research contribution in the topics: Population & Gene. The organization has 36352 authors who have published 79483 publications receiving 1934752 citations. The organization is also known as: Tsukuba daigaku & Tsukuba University.

The Effects of Prosocial Video Games on Prosocial Behaviors: International Evidence From Correlational, Longitudinal, and Experimental Studies:

Abstract: Although dozens of studies have documented a relationship between violent video games and aggressive behaviors, very little attention has been paid to potential effects of prosocial games. Theoretically, games in which game characters help and support each other in nonviolent ways should increase both short-term and long-term prosocial behaviors. We report three studies conducted in three countries with three age groups to test this hypothesis. In the correlational study, Singaporean middle-school students who played more prosocial games behaved more prosocially. In the two longitudinal samples of Japanese children and adolescents, prosocial game play predicted later increases in prosocial behavior. In the experimental study, U.S. undergraduates randomly assigned to play prosocial games behaved more prosocially toward another student. These similar results across different methodologies, ages, and cultures provide robust evidence of a prosocial game content effect, and they provide support for the General Learning Model.

Optimized geometries and electronic structures of graphyne and its family

Abstract: The optimized geometries of carbon allotropes related to graphite, called graphyne, graphdiyne, graphyne-3, and graphyne-4, as well as their electronic band structures were calculated using a full-potential linear combination of atomic orbitals method in the local-density approximation. These carbon allotropes consist of hexagons connected by linear carbon chains. The bond length of a hexagon is a little longer than that of the bond that links a hexagon to the outside carbon. Furthermore, part of the linear carbon chain is composed of acetylenic linkages (---C\ensuremath{\equiv}C---) rather than cumulative linkages (=C=C=). The binding energies are 7.95 eV/atom for graphyne and 7.78 eV/atom for graphdiyne, and the optimized lattice lengths are 6.86 \AA{} for graphyne and 9.44 \AA{} for graphdiyne. These materials are semiconductors with moderate band gaps. The band gap occurs at the M point or \ensuremath{\Gamma} point depending on the number of acetylenic linkages that are contained between the nearest-neighboring hexagons. The effective masses are very small for both conduction and valence bands.

Kakusan4 and Aminosan: two programs for comparing nonpartitioned, proportional and separate models for combined molecular phylogenetic analyses of multilocus sequence data.

Abstract: Proportional and separate models able to apply different combination of substitution rate matrix (SRM) and among-site rate variation model (ASRVM) to each locus are frequently used in phylogenetic studies of multilocus data A proportional model assumes that branch lengths are proportional among partitions and a separate model assumes that each partition has an independent set of branch lengths However, the selection from among nonpartitioned (ie, a common combination of models is applied to all-loci concatenated sequences), proportional and separate models is usually based on the researcher’s preference rather than on any information criteria This study describes two programs, ‘Kakusan4’ (for DNA sequences) and ‘Aminosan’ (for amino-acid sequences), which allow the selection of evolutionary models based on several types of information criteria The programs can handle both multilocus and single-locus data, in addition to providing an easy-to-use wizard interface and a noninteractive command line interface In the case of multilocus data, SRMs and ASRVMs are compared at each locus and at all-loci concatenated sequences, after which nonpartitioned, proportional and separate models are compared based on information criteria The programs also provide model configuration files for MRBAYES, PAUP*, PHYML, RAXML and Treefinder to support further phylogenetic analysis using a selected model When likelihoods are optimized by Treefinder, the best-fit models were found to differ depending on the data set Furthermore, differences in the information criteria among nonpartitioned, proportional and separate models were much larger than those among the nonpartitioned models These findings suggest that selecting from nonpartitioned, proportional and separate models results in a better phylogenetic tree Kakusan4 and Aminosan are available at http://wwwfifthdimensionjp/ They are licensed under GNU GPL Ver2, and are able to run on Windows, MacOS X and Linux

Silent information regulator 2 potentiates Foxo1-mediated transcription through its deacetylase activity

Abstract: Longevity regulatory genes include the Forkhead transcription factor FOXO and the NAD-dependent histone deacetylase silent information regulator 2 (Sir2). Genetic studies demonstrate that Sir2 acts to extend lifespan in Caenorhabditis elegans upstream of DAF-16, a member of the FOXO family, in the insulin-like signaling pathway. However, the molecular mechanisms underlying the requirement of DAF-16 activity in Sir2-mediated longevity remain unknown. Here we show that reversible acetylation of Foxo1 (also known as FKHR), the mouse DAF-16 ortholog, modulates its transactivation function. cAMP-response element-binding protein (CREB)-binding protein binds and acetylates Foxo1 at the K242, K245, and K262 residues, the modification of which is involved in the attenuation of Foxo1 as a transcription factor. Conversely, Sir2 binds and deacetylates Foxo1 at residues acetylated by cAMP-response element-binding protein-binding protein. Sir2 is recruited to insulin response sequence-containing promoter and increases the expression of manganese superoxide dismutase and p27kip1 in a deacetylase-activity-dependent manner. Our findings establish Foxo1 as a direct and functional target for Sir2 in mammalian systems.