50 research outputs found
植物生態學實習地としての九重山彙
本文は植物學殊に植物生態學に趣味を有し, 實地観察によりて其智識を瀾澤ならしめんとする人達のために, 其手引草にもと思つて, 自分等が調査して得た材料を綴つて見たものである。そして茲に附記せねばならぬ事は, 吾々の此山を調査するに當り, 鶴田竹田營林署長, 安藤森營林署長, 岩永森林主事, 小野大分縣種畜場長, 工藤久佳町郵便局長諸氏が大なる好意と便宜とを與へられた事で, 此機會に於て之に對して感謝の意を衷するのは, 吾々の愉快なる義務だと信する
福岡縣新宮濱に於ける砂丘植物群落とその土壌要素との關係
1) 新宮濱の砂丘植物群落は高潮線より僅々200米内外の間に明かに異つた三つの帶状群落を區別することが出來る。2) 第一は前砂丘植物群落であり, 第二は梢中生的傾向のある好砂砂丘植物群落で, 第三はクロマツを主とする砂丘林である。3) 砂層内の鹽分はその採集地點が内方に向ふにつれて急減し, 高潮線よりの距離と含鹽量との關係は雙曲線型曲線で表はすことが出來るものの如くである。4) それぞれの群落の生育地砂層内の鹽分分布には特有の型があり, 前砂丘植物群落では地表・地下共に鹽分濃度高く, 梢中生的傾向を持つ好砂砂丘植物群落では地表は鹽分濃度は地表下含度に比し割合に大である。砂丘林の部分では地表・地下共に低濃度で植物群落の區分と土壤に於ける含鹽状態區分とは大體一致を認めることが出來た。5) 土壤の酸度によつても大體鹽分によつたと同樣の三區分が出來る樣である。6) 隨つて土壤の鹽分と酸度とは本砂丘の植物群落の成立上重要なる役割を演じ居るものの如くである
Neuroinflammation in Parkinson's Disease and Related Disorders: A Lesson from Genetically Manipulated Mouse Models of α-Synucleinopathies
Neuroinflammation in Parkinson's disease (PD) is a chronic process that is associated with alteration of glial cells, including astrocytes and microglia. However, the precise mechanisms remain obscure. To better understand neuroinflammation in PD, we focused on glial activation in α-synuclein (αS) transgenic and related model mice. In the majority of αS transgenic mice, astrogliosis was observed concomitantly with accumulation of αS during the early stage of neurodegeneration. However, microglia were not extensively activated unless the mice were treated with lipopolysaccharides or through further genetic modification of other molecules, including familial PD risk factors. Thus, the results in αS transgenic mice and related model mice are consistent with the idea that neuroinflammation in PD is a double-edged sword that is protective in the early stage of neurodegeneration but becomes detrimental with disease progression
Anti-Prion Activity of Brilliant Blue G
BACKGROUND: Prion diseases are fatal neurodegenerative disorders with no effective therapy currently available. Accumulating evidence has implicated over-activation of P2X7 ionotropic purinergic receptor (P2X7R) in the progression of neuronal loss in several neurodegenerative diseases. This has led to the speculation that simultaneous blockade of this receptor and prion replication can be an effective therapeutic strategy for prion diseases. We have focused on Brilliant Blue G (BBG), a well-known P2X7R antagonist, possessing a chemical structure expected to confer anti-prion activity and examined its inhibitory effect on the accumulation of pathogenic isoforms of prion protein (PrPres) in a cellular and a mouse model of prion disease in order to determine its therapeutic potential. PRINCIPAL FINDINGS: BBG prevented PrPres accumulation in infected MG20 microglial and N2a neural cells at 50% inhibitory concentrations of 14.6 and 3.2 µM, respectively. Administration of BBG in vivo also reduced PrPres accumulation in the brains of mice with prion disease. However, it did not appear to alleviate the disease progression compared to the vehicle-treated controls, implying a complex role of P2X7R on the neuronal degeneration in prion diseases. SIGNIFICANCE: These results provide novel insights into the pathophysiology of prion diseases and have important implications for the treatment
INVESTIGATIONS ON THE RELATION BETWEEN PLANTS AND THEIR SURROUNDING CONDITIONS BY THE QUANTITATIVE METHOD. V. MEASURING OF DIMENTION OF LEAFINTERCELLULARSPACES ON SEVERAL SPECIES OF PLANTS AND ITS ECOLOGICAL SIGNIFICANCE
The author has measured the dimensions of intercellularspaces of leafassue on several different ecological types of species and indicated in value in percent of the volume of tissue. In the measurement he made use of an improved method of NEGER\u27S using ALFRED J. AMSLER\u27S volumeter in measuring the volume of tissue. The results obtained concur with those of some other investigators in showing generally larger values in the leaves of mesophitic herbs than in the leaves of evergreen or deciduous trees or shrubs, and also larger values in shady leaves than in sunny ones belonging to the same or different species of plants. To conclude, the present method with the results obtained recommends itself for the purpose of quantitative studies of ecology regarding the intercelluler spaces of leaf tissue.1. 本研究は生態を異にする種々の植物の葉の組織の細胞間隙の廣さを數量的に測定し, その結果によつてそれ等の植物の有する生態學的意義を考察するの一助たらしめんとして行はれたものである。2. 著者は葉の組織の細胞間隙の廣さを數量的に測定する方法として數種の方法の得失を考察したる後生態學的研究の目的に最も適切と考へられる NEGER 氏の組織内水分注入法を採用した。3. この水分注人法によつて測定せる細胞間隙は一般に行はれる如く組織の全容積に對する%で表はしたが, その容積の測定法として著者は特に ALFRED J. AMSLER 會社製の水銀を媒劑とする測容計 (volumeter) を用ひて可成精密なる値を得ることが出來た。4. 著者は又實驗を進めるに先ちてあらかじめ二三の植物の葉に就いて水分注入法及び對照として行つた葉の組織の横斷面圖による直接的面積測定法によつて細胞間隙の%を計算したが兩者の數値はその傾向に於て全く一致した。即ちこれにより採用したる水分注入法による結果が相當信頼するに足るものであることを間接的に證明する一助を得た。5. 同種植物の陽地葉と陰地葉とにつき水分注入法によりその組織の細胞間隙を測定比較したる結果は從來の組織學的所見の結果と一致し, 概して陰地葉に於て陽地葉より大なる値を示した。6. しかるにスミレの葉に於てはその一般的傾向と反對でかへつて陽地葉に大なる値を得たのであり, こは生態學的に注意すぺきことである。7. 生態を異にする種々の植物の葉の組織の細胞間隙を測定したる結果は概して中生草本に於て最大なる値を示し, その内でも概して陰地生草本は陽地生のものに比し大なる値を示し, 又常緑濶葉樹及び薄質の落葉澗葉樹にては著しく小なる値を示したことは, 他の研究者の得たる研究結果の傾向と大體に於て一致した。8. 之れを要するに茲に採用したる方法による細胞間隙の測定は, 生態學的一研究方法として利用てし相當の效果を擧げ得るものと認められる
植物と外界との關係の數量的方法による研究. VII. : 森林生態學的見地より見たる特殊植物の構造及び生理作用の數量的研究
The author, who, for some years past, has been studying from several angles and in quantitative way the relation between plants and their surrounding conditions, has been able to deduce from time to time some results, which are of some significance from the view-point of forest ecology and which may help support the conception of so-called phytometer. The subject-matter of ecology, the interrelation of plants with their surrounding conditions, naturally require very careful treatment and is one perhaps that can only be approached with power of inventive conception. To meet such a requirement, very close observation and ample experiments based on exact measurements, such as we now see carried on in the fields of morphology and physiology may be essential. Just such quantit a tive studies in ecology are now being fast introduced into the field of forestry, thus giving ride to the conception of plant-indicators or phytometers. The conception of plant-indicators or phytometers is really one of wide application, and almost any feature of plant life may be regarded as admitting such conception. However, such feature as the variation in histological structure and also of physiological process of plant, as it may easily admit of quantitative treatment, may have the great likelihood of well developing such conception. Among some new facts of plant life which the author in his study has been able to observe and which may be found useful as phytometer, the value set to wavyness in the lateral walls of epidermal cells in the leaves of some special plants as Taraxacum albidum and the ratio of the value of absorption to that of transpiration may stand somewhat prominent. The author fully believes that such quantitative studies as he has carried on will go to add to the practical value of phytometer used in the field of forest ecology.植物生態學上に於て取扱ふ環境は純正植物生理學の取扱ふ環境に比し, 一層複雜であつて, その取扱ひに特別なる考慮考察を要する場合が多いことはすでに述べた如くであるが, その生態學的環境を正しく認識するためには植物と外界との相互關係を數量的に仔細に觀察することが第一に必要である。例へば SCHIMPER (76) が提出せる生理的乾燥なる概念は生理及び生態學的方面に於ける大なる警鐘ではあつたが, 自然界の實際的現象に於て果してどれ丈けその概念があてはまるかに就いては多くの疑問があつた。すでに HUBER (25), STOCKER (82, 83, 84) の詳細なる實驗的研究によつて, 泥炭濕地及び鹽性濕地の植物が生理的に決して乾燥状態にあるものでないことを明かにせるが如きは, 生態學的環境を理解するに當つて實驗的觀察の如何に重要なるかを雄辯に物語るものであらう。かくの如き研究的用意は一般農林學殊に造林學方面に於て植物生育地の環境を論ずる場合に當然準備さるべきもので, 特に指標植物或は Phytometer 等の利用を考慮に入れる場合に於ては, あらかじめ充分なる實驗的數量的根據による研究を必要とすることは勿論である