370 research outputs found

    Coalition structure generation in cooperative games with compact representations

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    This paper presents a new way of formalizing the coalition structure generation problem (CSG) so that we can apply constraint optimization techniques to it. Forming effective coalitions is a major research challenge in AI and multi-agent systems. CSG involves partitioning a set of agents into coalitions to maximize social surplus. Traditionally, the input of the CSG problem is a black-box function called a characteristic function, which takes a coalition as input and returns the value of the coalition. As a result, applying constraint optimization techniques to this problem has been infeasible. However, characteristic functions that appear in practice often can be represented concisely by a set of rules, rather than treating the function as a black box. Then we can solve the CSG problem more efficiently by directly applying constraint optimization techniques to this compact representation. We present new formalizations of the CSG problem by utilizing recently developed compact representation schemes for characteristic functions. We first characterize the complexity of CSG under these representation schemes. In this context, the complexity is driven more by the number of rules than by the number of agents. As an initial step toward developing efficient constraint optimization algorithms for solving the CSG problem, we also develop mixed integer programming formulations and show that an off-the-shelf optimization package can perform reasonably well

    Characteristics of Interaction Between Teachers and Children in the First Term of Elementary School Classes: Focusing on the Differences in Goals that Teachers Emphasize in Japanese Language and Mathematics Classes

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    近年,幼児期と児童期の学びの接続が重視されている。幼児教育では,めざすべき姿へと向かう方向目標を重視し,小学校以上の教育では獲得すべき能力を明示化した到達目標を重視することが多い。小学校入門期に開講時間が多い国語科と算数科では,方向目標と到達目標の比重は異なる。そこで,本研究では,小学校入門期の国語科と算数科授業における教師と子どもの相互作用の実態を明らかにすることを目的とした。 新1年生の国語科と算数科の授業を約4か月間観察し,教師の言葉がけと子どもの発話内容との関連を分析した。結果,子どもの状況に応じて展開する国語科に対し,算数科では多くが到達目標に向かうという違いが明らかになった。また,教師による方向目標に即した言葉がけは,到達目標を達成し,かつ子どもの多様な学びにつながる可能性があることがわかった。本稿は,指導の実態と教科内容の側面から,子どもの学びの姿を明らかにしたものである。Recent studies examine how a smooth transition can be achieved from early childhood education to elementary school education. In early childhood education, direction targets are emphasized, and in elementary school, achievement goals are often emphasized. In elementary school, there is a difference in the balance between the achievement goals and the direction targets in Japanese language classes and mathematics classes. The purpose of this study is to clarify the characteristics in the interaction between teachers and first graders in these two classes. In this paper, we observed the Japanese language and mathematics classes for the first grade from April to July, and collected some episodes of the interactions between teachers and children. These episodes were categorized according to subjects into those that focused on achievement goals versus direction targets. As a result, it was found that there was a difference in interactions between teachers and children depending on the subjects and the type of achievement goal or direction target. In Japanese language classes, the interaction between teachers and children develops toward the goal according to the situation of children, while in mathematics classes, the interaction often develops toward achievement goals. When teachers talked to children in a way that gave them directions, they were more likely to learn a variety of knowledge and skills as well as content related to their achievement goals. The primary aspect of this paper was to clarify what children were learning at the beginning of elementary school from the perspectives of teacher-child interaction and subject content

    Adherence to 24-h Movement Guidelines and Depressive Status During the Coronavirus Disease Outbreak: A Cross-Sectional Japanese Survey

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    Objectives: The coronavirus disease 2019 (COVID-19) pandemic has affected people’s physical activity, sedentary behavior, and sleep. This study aimed to clarify the association between combining these factors, integrated as adherence to 24-h movement guidelines, and depressive status during the COVID-19 pandemic.Methods: At the end of October 2020, we sent self-administered questionnaires to 1,711 adults aged ≥18. We assessed physical activity, sedentary behavior, sleep duration, adherence to 24-h movement guidelines, depressive status, and confounding factors.Results: Of the 640 valid responses, 90 (14.1%) reported a depressive status. Multivariable odds ratios (95% confidence interval) of depressive status were 0.22 (0.07, 0.71) for all three recommendations of the 24-h movement guidelines and those who met none of the recommendations as reference. The number of guidelines met was associated with depressive status in a dose-response fashion.Conclusion: Meeting the 24-h movement guidelines was associated with a lower prevalence of depressive status during the COVID-19 pandemic. Adults should adhere to these guidelines to maintain their mental health during future quarantine life

    IL-18 with IL-2 protects against Strongyloides venezuelensis infection by activating mucosal mast cell–dependent type 2 innate immunity

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    C57BL/6 (B6) and B6 background STAT6−/− mice pretreated with IL-18 plus IL-2 showed prominent intestinal mastocytosis and rapidly expelled implanted adult worms of the gastrointestinal nematode Strongyloides venezuelensis. In contrast, identically pretreated mast cell–deficient W/Wv mice failed to do so. Thus, activated mucosal mast cells (MMC) are crucial for parasite expulsion. B6 mice infected with S. venezuelensis third-stage larvae (L3) completed parasite expulsion by day 12 after infection, whereas IL-18−/− or IL-18Rα−/− B6 mice exhibited marked impairment in parasite expulsion, suggesting a substantial contribution of IL-18–dependent MMC activation to parasite expulsion. Compared with IL-18−/− or IL-18Rα−/− mice, S. venezuelensis L3–infected STAT6−/− mice have poorly activated MMC and sustained infection; although their IL-18 production is normal. Neutralization of IL-18 and IL-2 further reduces expulsion in infected STAT6−/− mice. These results suggest that collaboration between IL-18–dependent and Th2 cell–dependent mastocytosis is important for prompt parasite expulsion

    The roles of stress-activated Sty1 and Gcn2 kinases and proto-oncoprotein homologue Int6/eIF3e in responses to endogenous oxidative stress during histidine starvation

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    In fission yeast, Sty1 and Gcn2 are important protein kinases regulating gene expression in response to amino acid starvation. The translation factor subunit eIF3e/Int6 promotes the Sty1-dependent response by increasing the abundance of Atf1, a transcription factor targeted by Sty1. While Gcn2 promotes expression of amino acid biosynthesis enzymes, the mechanism and function for Sty1 activation and Int6/eIF3e involvement during this nutrient stress is not understood. Here we show that mutants lacking sty1+ or gcn2+ display reduced viabilities during histidine depletion stress in a manner suppressible by the antioxidant, N-acetyl cysteine, suggesting that these protein kinases function to alleviate endogenous oxidative damage generated during nutrient starvation. Int6/eIF3e also promotes cell viability by a mechanism involving stimulation of the Sty1 response to oxidative damage. In further support of these observations, microarray data suggests that, during histidine starvation, int6Δ increases the duration of Sty1-activated gene expression linked to oxidative stress due to the initial attenuation of Sty1-dependent transcription. Moreover, loss of gcn2 induces the expression of a new set of genes not activated in wild-type cells starved for histidine. These genes encode heatshock proteins, redox enzymes and proteins involved in mitochondrial maintenance, in agreement with the idea that oxidative stress is imposed onto gcn2Δ cells. Furthermore, the early Sty1 activation promotes a rapid Gcn2 activation on histidine starvation. These results suggest that Gcn2, Sty1, and Int6/eIF3e are functionally integrated and cooperate to respond to oxidative stress that is generated during histidine starvation

    Subaru Hyper Suprime-Cam Survey for An Optical Counterpart of GW170817

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    We perform a zz-band survey for an optical counterpart of a binary neutron star coalescence GW170817 with Subaru/Hyper Suprime-Cam. Our untargeted transient search covers 23.623.6 deg2^2 corresponding to the 56.6%56.6\% credible region of GW170817 and reaches the 50%50\% completeness magnitude of 20.620.6 mag on average. As a result, we find 60 candidates of extragalactic transients, including J-GEM17btc (a.k.a. SSS17a/DLT17ck). While J-GEM17btc is associated with NGC 4993 that is firmly located inside the 3D skymap of GW170817, the other 59 candidates do not have distance information in the GLADE v2 catalog or NASA/IPAC Extragalactic Database (NED). Among 59 candidates, 58 are located at the center of extended objects in the Pan-STARRS1 catalog, while one candidate has an offset. We present location, zz-band apparent magnitude, and time variability of the candidates and evaluate the probabilities that they are located inside of the 3D skymap of GW170817. The probability for J-GEM17btc is 64%64\% being much higher than those for the other 59 candidates (9.3×1032.1×101%9.3\times10^{-3}-2.1\times10^{-1}\%). Furthermore, the possibility, that at least one of the other 59 candidates is located within the 3D skymap, is only 3.2%3.2\%. Therefore, we conclude that J-GEM17btc is the most-likely and distinguished candidate as the optical counterpart of GW170817.Comment: 14 pages, 9 figures. Accepted for publication in PASJ (Publications of the Astronomical Society of Japan

    Surgical Results in T2N0M0 Nonsmall Cell Lung Cancer Patients With Large Tumors 5 cm or Greater in Diameter: What Regulates Outcome?

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    金沢大学医学部附属病院呼吸器外科Background: We assessed the surgical results along with the clinical and biological features of nonsmall-cell lung cancer (NSCLC) patients with localized large tumors. Methods: The study population consisted of 86 NSCLC patients who underwent complete resection of tumors 5 cm or larger in diameter in stage IB (T2N0M0). We immunohistochemically assessed the expression of angiostatin and endostatin. Results: The median tumor size was 6.0 cm (range, 5 to 14 cm). The operative procedures used were lobectomy in 71 cases, bilobectomy in 8 cases, and pneumonectomy in 11 cases. Fifty patients (58.1%) relapsed during the mean follow-up period of 33.6 ± 4.5 months. The median disease-free interval was 9 months. Of 44 recurrent patients whose disease-free interval could be identified, 25 patients (56.8%) relapsed within 12 months after the operation. The overall 5- and 10-year survival rates were 42.0% and 24.2%, respectively. Multivariate analysis showed that the degree of pleural involvement and angiostatin expression within the tumor were independent prognostic indicators. The endostatin expression within tumors also had a weaker relationship with outcome. Conclusions: Long-term surgical results were poor and early relapse was common in this cohort. In addition to pleural involvement, the tumor-induced expression of angiostatin and endostatin merit further investigation to gain possible insights into selection of patients who will benefit from surgery as the first line treatment. © 2006 The Society of Thoracic Surgeons

    Full-Length Sequence of Mouse Acupuncture-Induced 1-L (Aig1l) Gene Including Its Transcriptional Start Site

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    We have been investigating the molecular efficacy of electroacupuncture (EA), which is one type of acupuncture therapy. In our previous molecular biological study of acupuncture, we found an EA-induced gene, named acupuncture-induced 1-L (Aig1l), in mouse skeletal muscle. The aims of this study consisted of identification of the full-length cDNA sequence of Aig1l including the transcriptional start site, determination of the tissue distribution of Aig1l and analysis of the effect of EA on Aig1l gene expression. We determined the complete cDNA sequence including the transcriptional start site via cDNA cloning with the cap site hunting method. We then analyzed the tissue distribution of Aig1l by means of northern blot analysis and real-time quantitative polymerase chain reaction. We used the semiquantitative reverse transcriptase-polymerase chain reaction to examine the effect of EA on Aig1l gene expression. Our results showed that the complete cDNA sequence of Aig1l was 6073 bp long, and the putative protein consisted of 962 amino acids. All seven tissues that we analyzed expressed the Aig1l gene. In skeletal muscle, EA induced expression of the Aig1l gene, with high expression observed after 3 hours of EA. Our findings thus suggest that the Aig1l gene may play a key role in the molecular mechanisms of EA efficacy

    Anti-cancer stem cell activity of the Src inhibitor dasatinib in thyroid cancer cells

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    Although the prognosis of differentiated thyroid cancer (DTC) is good, those of poorly-differentiated and undifferentiated thyroid cancers (PDTC and UDTC) are poor. Recent preclinical studies have suggested that the Src inhibitor dasatinib is active in thyroid cancer cell lines. We conducted the present study in an attempt to clarify the antitumor activity of dasatinib in PDTC and UDTC. The expression levels of c-Src, phosphorylated Srcs (p-SrcY416 and p-SrcY527), focal adhesion kinase (FAK), and phosphorylated FAK (p-FAKY861) were immunohistochemically investigated in a case-control series (15 cases of PDTC or UDTC vs. 29 control cases of DTC). The PDTC cell line KTC-1 and UDTC cell line KTC-2 were used to investigate the anticell growth and anti-cancer stem cell (CSC) activities of dasatinib. The combined effects of dasatinib and the taxane paclitaxel on anti-cell growth and anti-CSC activities were also tested. c-Src and p-FAKY861 expression levels were significantly higher, while those of p-SrcY416 were slightly higher in PDTC and UDTC than in DTC. Dasatinib inhibited cell growth in association with G1-S cell cycle retardation and increased apoptosis in both cell lines. Dasatinib significantly decreased the proportion of CSCs and more than additively enhanced the anti-cell growth activity of paclitaxel. The results of this study suggest that the Src signaling pathway is activated more in PDTC and UDTC than in DTC. The Src inhibitor dasatinib exhibited anti-cell growth and anti-CSC activities. Furthermore, it more than additively enhanced the anti-cell growth activity of paclitaxel
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