2,686 research outputs found

    Complication after Embolization of Internal Iliac Artery by Gelatin Sponge Powder

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    A case is reported of muscular atrophy of the buttock and advanced and permanent neuropathy following embolization of the internal iliac artery by gelatin sponge powder. We discuss and review the risk of complications by embolic material and the method of embolization

    Mechanism of the declining process of forest caused by the deposition of acid fog on forest canopies and the regeneration of the forest.

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    私達は、丹沢大山においてガス、エアロゾル、雨、霧、林内雨、樹幹流等の採取・分析を行った。関東平野に面するモミの樹冠には多量の汚染物質が沈着しているが、これはエーロゾルやガスの乾性沈着と霧の沈着の影響による。それぞれの寄与を見積もると、大山中腹ではガスの乾性沈着の影響が最も大きく、次いで霧水、粗大粒子、降雨の順であった。霧の発生頻度は標高の上昇と共に高くなるが、大気汚染物質の沈着量も同様であり、標高が高い地域の樹冠ほど霧を介した大気汚染物質の影響が大きい。丹沢山塊における微量ガス成分の濃度分布調査を行った結果、硝酸ガス等の濃度は大山より低いが大差無く、斜面方角依存性は小さいことが分かった。丹沢山塊では大気汚染物質の影響が大山とおよそ同レベルであり、その影響は標高の高い南東斜面の樹冠で顕著であり、ブナ衰退の斜面方角依存性には霧の影響が示唆された。大気汚染物質の植物影響を調べるため、ブナ苗木へのpH3の酸性霧曝露実験を行ったところ、葉の成長が悪くなり、落葉時期が早まった。酸性霧による同様な影響はモミについても見られるが、モミについての衰退メカニズムとしてまずワックス層が破壊され、続いて細胞壁を構成する糖鎖の架橋の機能を持つ2価のカルシウムイオンが水素イオンとイオン交換してはずれ、架橋が解けてカルシウムイオン、ホウ酸イオン、糖鎖が溶脱する。ブナについては蛍光顕微鏡を使って膜に結合したカルシウム濃度を調べたところ、酸の曝露により明らかに濃度減少することが示され、これによる耐性の減少が示唆された。以上のことから、大気汚染物質によりブナやモミの成長は抑制され、さらには枯れる可能性が高いこと、大気汚染物質の影響は大気汚染物質濃度だけでなく、霧の発生頻度、風向等に左右されるので植生の地形的環境に大きく依存することが明らかになった。In the mountain slope of Mt.Oyama, fog is frequently formed and pH of fogwater is low for nitric acid formed from NOx. The concentration of fog components becomes high when LWC is low, and acid fog events with fog water pH lower than 3.5 occurs for about 20% of fog duration there every year. It has been observed that the throughfall amount increased with the altitude for the contribution of fog, and the fog deposition may be dominated by the fog formation frequency and the deposition rate of fog droplets depending on the wind velocity. Deposited hydrogen ion via fog droplets is exchanged with metal ions in the cells in the leaves, and the concentrations of metal ions, calcium, magnesium, and potassium ions, in the throughfall is large for the leaching. In order to clarify the influence of acid fog on fir and beech, their seedlings were treated with simulated acid fog (SAF) at pH 3 and pH 5 prepared with a mixed solution of nitric acid, ammonium sulfate, sodium chloride with a molar ratio of 2:1:1 in a mobile fog chamber. The growth of the seedlings treated with the SAF at pH 3 had been reduced in plant height, stem diameter, the number of leaves, and dry matter production. Furthermore, the exposure to the SAF at pH 3 during growth phase induced early falling of leaves, and the falling rate were nearly 2 times greater than that at control. The laboratory experiment of the application of the simulated acid fog on their leaves also showed a large leaching of metal ions, and the leaching amount increased with the decreasing pH of the simulated fog solution. Not only the field observation but also laboratory experiments show the large effect of acid depositions on the trees.平成15年度~平成18年度科学研究費補助金(基盤研究(A))(課題番号:15201008)第3章-1 大気汚染物質の樹冠への沈着第3章-2 苗木の擬似酸性霧への応答第3章 参考文

    Characterisation of major histocompatibility complex class I genes in Japanese Ranidae frogs.

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    The major histocompatibility complex (MHC) is a key component of adaptive immunity in all jawed vertebrates, and understanding the evolutionary mechanisms that have shaped these genes in amphibians, one of the earliest terrestrial tetrapods, is important. We characterised MHC class I variation in three common Japanese Rana species (Rana japonica, Rana ornativentris and Rana tagoi tagoi) and identified a total of 60 variants from 21 individuals. We also found evolutionary signatures of gene duplication, recombination and balancing selection (including trans-species polymorphism), all of which drive increased MHC diversity. A unique feature of MHC class I from these three Ranidae species includes low synonymous differences per site (d S) within species, which we attribute to a more recent diversification of these sequences or recent gene duplication. The resulting higher d N/d S ratio relative to other anurans studied could be related to stronger selection pressure at peptide binding sites. This is one of the first studies to investigate MHC in Japanese amphibians and permits further exploration of the polygenetic factors associated with resistance to infectious diseases

    Le problème de l\u27intersubjectivité chez Merleau-Ponty

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    寿命伸長のベイズモデリングとその応用

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    Open House, ISM in Tachikawa, 2011.7.14統計数理研究所オープンハウス(立川)、H23.7.14ポスター発
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