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空間明示的個体ベース動的全球植生モデルを用いた気候変動下における非構造性炭水化物の生産が森林構造に与える影響の将来予測
No full textForest dynamics need to be considered when estimating the global carbon budget. The alteration of forest structure and function under a changing climate and expanding human activity could lead to a reduction of forest canopy cover and a spread of lower-biomass ecosystems in warm and dry regions. A non-structural carbohydrate (NSC) acts as a storage buffer between carbon supplied by assimilation and carbon consumed by respiration, reproduction, and pests. Estimation of NSC concentrations in a tree is very important for accurate projection of future forest dynamics. I developed a new NSC module for incorporation into a spatially explicit individual-based dynamic global vegetation model (SEIB-DGVM) to validate the simulated NSC dynamics with observations. NSC pools were simulated in three plant organs: leaves, trunk, and roots. The seasonal dynamics of the NSCs varied among plant species, and the sizes of the NSC pools inferred from observations differed between the boreal, temperate, and tropical climates. The NSC models were therefore validated for each of the three climatic regions at both point and global scales to assess the performance of the models. The modeled NSCs showed good agreement in seasonality with the observed NSCs at four sites – Canada (boreal), Austria and Switzerland (temperate), and Panama (tropical) – and in mean values for three climate zones derived from the global NSC dataset. I compared forest composition and biome type percentages in Asia, Europe, and North America under SSP scenarios between the new and previous models. In the new model, taller trees accumulate more NSCs, which slows their growth, resulting in lower mean tree height and DBH. Unlike the previous model, where taller trees dominated, the new model allows shorter trees to outcompete taller ones, creating a broader range of tree sizes, including more near-zero values. The new model also incorporates a carbon starvation mortality process. When carbon starvation is "switched on," tree density decreases, favoring taller tree growth while shortening tree lifespans due to increased vulnerability of shorter trees. The SEIB-DGVM-NSC improves simulations of vegetation distribution, GPP, and forest composition caused by the changes in NSC dynamics at global scales. This research advances understanding of NSC dynamics and their role in the terrestrial carbon cycle, particularly under climate chang
To Whom Does the Sea Belong? : Maritime Control by England and France before the Hundred Years’War
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The glymphatic system in oncology : from the perspective of a radiation oncologist
No full textThe brain and spinal cord, which constitute the central nervous system, were historically considered immune-privileged sites, as it was believed they lacked an equivalent to the systemic lymphatic system. However, in 2013, a pathway facilitating the clearance of waste products through the brain parenchyma via the perivascular space was proposed, garnering attention as the ‘glymphatic system’. Similar to the systemic lymphatic system, the glymphatic system plays a critical role in immune responses and has been implicated not only in Alzheimer’s disease and inflammatory brain disorders but also in conditions such as hydrocephalus and glaucoma, which are associated with cerebrospinal fluid circulation impairments. Recent studies have suggested that dysfunction of the glymphatic system may promote the progression of brain tumors and reduce the efficacy of immune responses and pharmacological therapies targeting tumors. Radiotherapy is a major treatment option for brain tumors; however, while it can enhance immune responses against tumors, it may also suppress these responses at the same time. Additionally, cranial irradiation has been suggested to impair the function of the glymphatic system. This review provides an overview of the structure and functional evaluation methods of the glymphatic system, summarizes the effects of its dysfunction on brain tumor treatment, and explores recent findings on the impact of radiation therapy on glymphatic system functioning. Lastly, it also explores the potential for radiation therapy strategies that account for their effects on the glymphatic system
Current status and challenges of municipalities in an era of population decline : Based on survey results of municipalities in Hokkaido
No full textThis article aims to provide an overview of the results of a survey and research on Regional policies in an era of population decline” conducted by us over a three-year period from 2022 together with the Hokkaido Development Association's Development Research Institute, in order to clarify how municipalities in Hokkaido are responding to policy issues in an era of population decline, and to consider the current situation and issues that emerge from the survey results. In the “Human Resources” section, first, it was empirically shown that most municipalities are struggling to secure human resources, and that it is particularly difficult to hire specialized staff. Secondly, the basic response to the shortage of specialized staff is to make up for the shortage with the current number of staff and to carry out business by outsourcing, assuming that the status of the administrative structure will be maintained. Thirdly, most municipalities are actively working to utilize external human resources to promote tourism and revitalize the region. In the “Policy” section, we asked about the utilization of the Grants for “Digital Garden City” Initiative and decarbonization policies. The number of municipalities utilizing the Grants was about 60% in the “digital implementation type” which had the largest number of applicants. It is worth noting that these local governments are utilizing the Support for the Introduction of Excellent Models (TYPE 1) and that it is common for them to create their plans with reference to the plans of other local governments. However, this does not only mean highly specialized human resources; for example, there appears to be a shortage of human resources to accept experts and advisors and to handle the day-to-day operation of new administrations launched with grant funding
Gennosuke Yokoyama's Theory of South American “Ishokumin”
No full text本稿は、横山源之助の南米移植民論に提示された移住者像を中心に、その南米移植民論を再検討するものである。第一章では、横山の社会・労働運動論と南米移植民論との関係、および横山の南米移植民論が提起した思想の経緯について検討する。労働運動の指導者たちに対する懐疑で、運動から離脱した横山は、日露戦争の勃発をきっかけに、「人民」の海外膨張を唱え始めた。その方向は南米大陸である。そして、横山の南米大陸に期待を寄せた理由の分析から、その南米移植民論には「生活難」の解決策と日本の移植民や経済膨張の一翼という二つの側面が同居していたこと、を明らかにした。第二章では、横山の南米移植民の展開について、彼の求めた移住者像を中心に論じる。日墨協同組合の事跡報告、および現地調査のもとにブラジル移植民活動の展開過程における問題点に触れ、その改善を求める横山が思い描き、また移住者に期待したのは、「同化の力」、永住意識、「独立自営事業」の経営志向、協同精神と移住者同士の組織化、の四点である。中でも、「独立自営事業」の経営志向、協同精神と移住者同士の組織化が横山の経済的ナショナリズム、つまり南米大陸での日本の商業貿易ないし経済産業の基盤の構築や拡大の構想と関わるところが、健全な移住者を求める彼のねらいだったこと、を指摘した。結論として、横山の思想上の転換点である南米移植民論は、その出発の段階から、日本の海外膨張と密接にかかわること、彼の南米移植民論の中に、従来の社会・労働問題解決の意図がなお存在しつつも、日露戦争後に芽生えた海外膨張という思想のベクトルに抑えられ、希薄化していったこと、を指摘した
