Stabilization in degenerate parabolic equations in divergence form and application to chemotaxis systems

summary:This paper presents a stabilization result for weak solutions of degenerate parabolic equations in divergence form. More precisely, the result asserts that the global-in-time weak solution converges to the average of the initial data in some topology as time goes to infinity. It is also shown that the result can be applied to a degenerate parabolic-elliptic Keller-Segel system

子どもを持ち仕事を続ける夫婦が執る育児・家事行動に関する研究(その1)

With recent increase in the employment rate of women, the numbers of women working after marriage and having babies are increasing. For management of their work and family life, the husband\u27s cooperation is indispensable. Studies on fathers have been recently increasing, but they are still are insufficient compared to those on mothers. In this study, we investigated the involvement of couples and their task share in childcare and housework using questionnaires of 135 couples whose children were cared for in 3 nurseries in Toyama Prefecture, and analyzed differences in recognition between fathers and mothers. Of the women in their 30s who cared for their children, the traditional concept of GENDER (husband dominance, man- dominance, work for men and housework for women) was considered to be wrong m 31.9% partially right in 59.3% largely right in 7.4%, and right in 1.5%. Their working types were part-time jobs (26.2%), self-employment (11.1%), and full-time jobs (62.2%). After day nurseries, some women asked their mother-in-law or own mother to care for their children, and a small number of mother utilized prolonged care in the nurseries. Husbands were found to be more involved in playing and chatting with children, cuddling, sending the children to the nurseries and collecting, and shopping than in order childcare and household work, but none of them reached the levels that their wives expected.近年, 女性の就業承が高まり, 結婚・出産後も継続して働く,人,が増えている.そのような中で女性が仕事と家庭をうまく両立させていくためには, 夫の協力が不可欠である.最近, 父親研究が脚光を浴びはじめたものの, 母親研究ほど十分には行なわれていない.本研究は, 富山県内3ヶ所の保育施設に子どもを預けている135組の夫婦の日常から両者の育児・家事への関わりと分担の実像を探り, それに対する両者間の認識について調査し, 分析したものである.その結果, 現在子育て中の30代の女性は, 『ジェンダー』(伝統的性別認識による夫中心, 男性上位, 男は仕事・女は家庭)に対する考え方について, 「全然思わない」と答えた人が31.9%, 「いくらかそう思う」人が59.3%, 「かなりそうだと思う」人が7.4%, 「全くそうだと思う」1.5%であった.母親の就業形態は, パート勤務が26.2%, 自営業が11.1%, フルタイム勤務の人が62.2%あり, この人たちは, 保育所終了後は夫の母や実家の母に子どもを見てもらっており, 少数だが延長保育を利用している人もあった.夫の育児・家事に関わる行動では, 子どもの遊びの相手や話し相手, 抱っこ, 保育園の送り迎えと買い物に比較的多く関わりが見られたものの, 妻の期待するレベルまでにはどの項目も到達していない状況にあることが分かった

Evolutionary loss of thermal acclimation accompanied by periodic monocarpic mass flowering in Strobilanthes flexicaulis

While life history, physiology and molecular phylogeny in plants have been widely studied, understanding how physiology changes with the evolution of life history change remains largely unknown. In two closely related understory Strobilanthes plants, the molecular phylogeny has previously shown that the monocarpic 6-year masting S. flexicaulis have evolved from a polycarpic perennial, represented by the basal clade S. tashiroi. The polycarpic S. tashiroi exhibited seasonal thermal acclimation with increased leaf respiratory and photosynthetic metabolism in winter, whereas the monocarpic S. flexicaulis showed no thermal acclimation. The monocarpic S. flexicaulis required rapid height growth after germination under high intraspecific competition, and the respiration and N allocation were biased toward nonphotosynthetic tissues. By contrast, in the long-lived polycarpic S. tashiroi, these allocations were biased toward photosynthetic tissues. The life-history differences between the monocarpic S. flexicaulis and the polycarpic S. tashiroi are represented by the “height growth” and “assimilation” paradigms, respectively, which are controlled by different patterns of respiration and nitrogen regulation in leaves. The obtained data indicate that the monocarpic S. flexicaulis with the evolutionary loss of thermal acclimation may exhibit increased vulnerability to global warming

Tree hazards compounded by successive climate extremes after masting in a small endemic tree, Distylium lepidotum , on subtropical islands in Japan

連続して生じる異常気象は樹木の衰退を加速させる --地球温暖化の森林への影響を高精度に予測する道を開く成果--. 京都大学プレスリリース. 2021-09-28.Ongoing global warming increases the frequency and severity of tropical typhoons and prolonged drought, leading to forest degradation. Simultaneous and/or successive masting events and climatic extremes may thus occur frequently in the near future. If these climatic extremes occur immediately after mass seed reproduction, their effects on individual trees are expected to be very severe because mass reproduction decreases carbohydrate reserves. While the effects of either a single climate extreme or masting alone on tree resilience/growth have received past research attention, understanding the cumulative effects of such multiple events remains challenging and is crucial for predicting future forest changes. Here, we report tree hazards compound by two successive climate extremes, a tropical typhoon and prolonged drought, after mass reproduction in an endemic tree species (Distylium lepidotum Nakai) on oceanic islands. Across individual trees, the starch stored within the sapwood of branchlets significantly decreased with reproductive efforts (fruit mass/shoot mass ratio). Typhoon damage significantly decreased not only the total leaf area of apical shoots but also the maximum photosynthetic rates. During the 5-month period after the typhoon, the mortality of large branchlets (8–10-mm diameter) increased with decreasing stored starch when the typhoon hit. During the prolonged summer drought in the next year, the recovery of total leaf area, stored starch, and hydraulic conductivity was negatively correlated with the stored starch at the typhoon. These data indicate that the level of stored starch within branchlets is the driving factor determining tree regrowth or dieback, and the restoration of carbohydrates after mass reproduction is synergistically delayed by such climate extremes. Stored carbohydrates are the major cumulative factor affecting individual tree resilience, resulting in their historical effects. Because of highly variable carbohydrate levels among individual trees, the resultant impacts of such successive events on forest dieback will be fundamentally different among trees

歯の形態形成に関与する新規遺伝子の解明

Tooth development is controlled by body plan during the fetal period, the generation of teeth from tooth germ is induced by the epithelial-mesenchymal interaction. Spatiotemporal regulation of tooth morphogenesis is supported by gene expression. Although many of the genes involved in tooth development are known, the molecular mechanism underlying tooth morphogenesis is not completely understood. For a comprehensive understanding of tooth development, the elucidation of unknown genes is necessary. In this study, to identify unknown genes involved in tooth development, we performed genome-wide analysis at each stage of tooth development and identified 17 genes with high levels of expression and large changes in expression. In addition, we performed qPCR and in situ hybridization analyses to elucidate the spatiotemporal regulation, such as the regulation that occurs around or in the entire tooth germ, enamel knots, epithelium, and mesenchyme. These results show that these characteristic genes may play important roles in each time period or region of tooth development, and the elucidation of the functions of these genes will lead to an integrated understanding of the process of tooth development.博士（医学）・甲第790号・令和3年3月15日発行元である日本再生歯科医学会の許諾を得て登録（2021年6月29日付）ジャーナル公式サイト（日本再生歯科医学会HP内）：http://www.jarde.jp/zasshi/e/18-2-1.htm

Rapid diagnosis of drug intoxication using novel NAGINATA TM gas chromatography/mass spectrometry software

In Japan, not only the classical stimulant, methamphetamine, but also a wide variety of illicit drugs and designer drugs are abused by juveniles. It is, however, difficult to screen these drugs in human urine due to the poor availability of high-quality standards. Therefore, it is important to develop a screening method that does not require the use of standard compounds. Furthermore, if we can obtain approximate drug concentrations in biological fluids by the first screening procedure, the subsequent treatment of the patient and forensic diagnosis can be carried out more rapidly and exact quantitative analysis performed more efficiently. We have devised a rapid screening method for the simultaneous semi-quantitative analysis of 30 abused drugs using gas chromatography/mass spectrometry (GC/MS) with a retention time locking technique. Based on this method, an 'abused drugs database' was constructed including retention time (RT), qualifier ion/target ion (QT) percentage and calibration curve (values of slope and intercept) using the novel GC/MS software, NAGINATA TM . We compared the analytical results obtained by this method using the constructed database with those from conventional methods in six forensic cases. The number of confirmed drugs and concentrations obtained by the established method was comparable with that obtained by conventional methods. We found a significant improvement in the time for data analysis, and qualitative and quantitative information about each drug was obtained without using standards. Therefore, this new screening procedure using NAGINATA TM has potential for the rapid identification of poisoning and should be useful in clinical and forensic toxicological analyses