±Genetic structure of the oak wilt vector beetle Platypus quercivorus: inferences toward the process of damaged area expansion

<p>Abstract</p> <p>Background</p> <p>The ambrosia beetle, <it>Platypus quercivorus</it>, is the vector of oak wilt, one of the most serious forest diseases in Japan. Population genetics approaches have made great progress toward studying the population dynamics of pests, especially for estimating dispersal. Knowledge of the genetic structuring of the beetle populations should reveal their population history. Using five highly polymorphic microsatellite loci, 605 individuals from 14 sampling sites were assessed to infer the ongoing gene flow among populations as well as the processes of expansion of damaged areas.</p> <p>Results</p> <p>Population differentiation (<it>F</it>_ST= 0.047, <it>G'</it>_ST= 0.167) was moderate and two major clusters were detected by several methods, dividing the samples into north-eastern and south-western populations, a similar genetic divergence was reported in host oak trees. Within the north-eastern populations, the subgroups mostly corresponded to differences in the collection period. The genetic characteristics of the population might have changed after 2 years due to the mixing of individuals between populations with enhanced migration related to population outbreaks. Because isolation by distance was detected for whole populations and also within the north-eastern populations, migration was considered to be limited between neighbouring populations, and most populations were suggested to be in genetic equilibrium of genetic drift and gene flow. Recent bottlenecks were found in some populations with no geographical bias; however, they were all from newly emerged oak wilt forests. The emergence of oak wilt should have induced intense fluctuations in the beetle population size.</p> <p>Conclusions</p> <p>Because the genetic boundaries coincide, we suggest that the geographical structuring of the beetle was formed by co-evolution with the host species. Our findings indicate the oak wilt expansion process.</p

大学生の成長の考察

大学の大衆化に伴い、大学入学者の基礎学力低下と並んで学習意欲の欠如および目的意識の希薄さが深刻化しており、大学全入学時代を迎え、問題の更なる顕在化が目前に迫っている。本論は、そうした環境下において大学の使命である学生の成長をいかに実現するかという現実の課題を取り上げる。研究の方法論に関する特徴の第1は、大学特に大学生を巡る諸問題について、互いに接触が少ない大学及び高等学校の関係者による共同討議である。具体的には、「高大連携で考える研究会」を設けて、意見交換並びに実態調査を行い、その成果を踏まえた。第2は、経営学分野におけるいくつかの新しい知見に着眼して、大学並びに学生が置かれている現状を分析し、いくつかの提言に結びつけようと試みた。経営学的アプローチとして、ステークホルダー論、顧客満足・顧客価値論、未来傾斜原理、学習地図といった論点を盛り込んだ。本論の構成は、次の通りである。まず第1部では、上述した経営学の視点による学生の飛躍的成長に向けた現状分析並びに課題と若干の提言を取り扱う。第2部では、「高大連携で考える研究会」の活動概要並びに得られた成果を報告する。第3部は全体の資料編であり、第1部で展開した各論の裏づけとなる各種資料並びに第2部で報告した研究会で用いた討論資料類を収録する。得られた知見は、次の3点である。第1に、大学をめぐる各種ステークホルダーの相互関係性を顧客連鎖の視点で整理したうえで、学生を主要な顧客として位置づけ、学生の戦略実現を大学が提供する教育サービスの最大の目的と指摘した。第2に、学生が未来に対していだく絶望感と渇望感を統一的に把握し、未来傾斜原理と組織内地図の視点から学生の成長を促進する要因を明らかにした。第3に、学生の成長を促進するうえで、内生要因と外生要因を整理して、学生の成長を促進する要因を明らかにした。学生の成長を促進するうえで、特に顧客である学生に対して教育サービスを提供する基本方針の確立、組織構成員としての自覚、自己の位置づけと居場所・自己評価・目標の発見と並んで、動機付けときっかけに対する具体的配慮・学生との信頼感の醸成の重要性の3点を指摘した点が重要である

Improvement in the productivity of xylooligosaccharides from waste medium after mushroom cultivation by hydrothermal treatment with suitable pretreatment

The effective xylooligosaccharides (XOs) production from the waste medium after mushroom cultivation (WM) was investigated. The WM contains rich nutrients (protein, etc.) which induce Maillard reaction with reducing sugars under hydrothermal conditions. To improve the productivity of XOs, the suitable pretreatment combined with washing and grinding was investigated, and subsequently hydrothermal treatment was demonstrated with batch type and continuous flow type reactor. The washing pretreatment with hot water of 60 degrees C was effective to remove nutrients from the WM, and it led to prevent brownish discoloration on the hydrothermal treatment. On the basis of experimental data, industrial XOs production processes consisting of the pretreatment, hydrothermal treatment and purification step was designed. During the designed process, 2.3 kg-dry of the purified XOs was produced from 30 kg-wet of the WM (15% yield as dry basis weight). Theoretical yield of XOs attained to 48% as xylan weight in the WM.ArticleBioresource Technology. 101(15):6006-6011 (2010)journal articl

Joint Observation of the Galactic Center with MAGIC and CTA-LST-1

MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes (IACTs), designed to detect very-high-energy gamma rays, and is operating in stereoscopic mode since 2009 at the Observatorio del Roque de Los Muchachos in La Palma, Spain. In 2018, the prototype IACT of the Large-Sized Telescope (LST-1) for the Cherenkov Telescope Array, a next-generation ground-based gamma-ray observatory, was inaugurated at the same site, at a distance of approximately 100 meters from the MAGIC telescopes. Using joint observations between MAGIC and LST-1, we developed a dedicated analysis pipeline and established the threefold telescope system via software, achieving the highest sensitivity in the northern hemisphere. Based on this enhanced performance, MAGIC and LST-1 have been jointly and regularly observing the Galactic Center, a region of paramount importance and complexity for IACTs. In particular, the gamma-ray emission from the dynamical center of the Milky Way is under debate. Although previous measurements suggested that a supermassive black hole Sagittarius A* plays a primary role, its radiation mechanism remains unclear, mainly due to limited angular resolution and sensitivity. The enhanced sensitivity in our novel approach is thus expected to provide new insights into the question. We here present the current status of the data analysis for the Galactic Center joint MAGIC and LST-1 observations