Structure of l-rhamnose isomerase in complex with l-rhamnopyranose demonstrates the sugar-ring opening mechanism and the role of a substrate sub-binding site

Abstractl-Rhamnose isomerase (l-RhI) catalyzes the reversible isomerization of l-rhamnose to l-rhamnulose. Previously determined X-ray structures of l-RhI showed a hydride-shift mechanism for the isomerization of substrates in a linear form, but the mechanism for opening of the sugar-ring is still unclear. To elucidate this mechanism, we determined X-ray structures of a mutant l-RhI in complex with l-rhamnopyranose and d-allopyranose. Results suggest that a catalytic water molecule, which acts as an acid/base catalyst in the isomerization reaction, is likely to be involved in pyranose-ring opening, and that a newly found substrate sub-binding site in the vicinity of the catalytic site may recognize different anomers of substrates

β-d-Altrose

The mol­ecule of the title compound, C6H12O6, [systematic name: (2R,3S,4R,5R,6R)-6-(hydroxy­meth­yl)oxane-2,3,4,5-tetrol] adopts a 4 C 1 chair conformation with the anomeric hydroxyl group in the equatorial position. All hydroxyl groups act as donors and acceptors in hydrogen bonding and the mol­ecule is involved in ten inter­molecular O—H⋯O inter­actions [O⋯O = 2.672 (5)–2.776 (4) Å] with eight neighbouring mol­ecules. Two independent O—H⋯O—H⋯ helices extending along the z axis are found in this structure

Examining Neutrino-Matter Interactions in the Cassiopeia A Supernova

Neutrino interactions with stellar material are widely believed to be fundamental to the explosion of massive stars. However, this important process has remained difficult to confirm observationally. We propose a new method to verify it using X-ray observations of the supernova remnant Cassiopeia A. The elemental composition in its Fe-rich ejecta that could have been produced at the innermost region of the supernova, where neutrinos are expected to interact, allows us to examine the presence of neutrino interactions. Here we demonstrate that the amount of Mn produced without neutrino nucleosynthesis processes (i.e., the $\nu$- and $\nu$p-process) is too small to explain the Mn/Fe mass ratio we measure (0.14--0.67\%). This result supports the operation of significant neutrino interactions in the Cassiopeia A supernova. If the observed Mn/Fe mass ratio purely reflects the production at the innermost region of the supernova, this would be the first robust confirmation of neutrino-matter interactions in an individual supernova. We further show that the Mn/Fe mass ratio has the potential to constrain supernova neutrino parameters (i.e., total neutrino luminosity, neutrino temperature). Future spatially-resolved, high-resolution X-ray spectroscopy will allow us to investigate the details of neutrino-supernova astrophysics through its signatures in elemental composition not only in Cassiopeia A but also in other remnants.Comment: 17 pages, 10 figures. Accepted for publication in Ap

Stream Mining for Network Management

Network management is an important issue in maintaining the Internet as an important social infrastructure. Finding excessive consumption of network bandwidth caused by P2P mass flows is especially important. Finding Internet viruses is also an important security issue. Although stream mining techniques seem to be promising techniques to find P2P and Internet viruses, vast network flows prevent the simple application of such techniques. A mining technique which works well with extremely limited memory is required. Also it should have a real-time analysis capability. In this paper, we propose a cache based mining method to realize such a technique. By analyzing the characteristics of the proposed method with real Internet backbone flow data, we show the advantages of the proposed method, i.e. less memory consumption while realizing realtime analysis capability. We also show the fact that we can use the proposed method to find mass flow information from Internet backbone flow data

Molecular basis for the dosing time-dependency of anti-allodynic effects of gabapentin in a mouse model of neuropathic pain

<p>Abstract</p> <p>Background</p> <p>Neuropathic pain is characterized by hypersensitivity to innocuous stimuli (tactile allodynia) that is nearly always resistant to NSAIDs or even opioids. Gabapentin, a GABA analogue, was originally developed to treat epilepsy. Accumulating clinical evidence supports the effectiveness of this drug for diverse neuropathic pain. In this study, we showed that the anti-allodynic effect of gabapentin was changed by the circadian oscillation in the expression of its target molecule, the calcium channel α2δ-1 subunit.</p> <p>Results</p> <p>Mice were underwent partial sciatic nerve ligation (PSL) to create a model of neuropathic pain. The paw withdrawal threshold (PWT) in PSL mice significantly decreased and fluctuated with a period length about 24 h. The PWT in PSL mice was dose-dependently increased by intraperitoneal injection of gabapentin, but the anti-allodynic effects varied according to its dosing time. The protein levels of α2δ-1 subunit were up-regulated in the DRG of PSL mice, but the protein levels oscillated in a circadian time-dependent manner. The time-dependent oscillation of α2δ-1 subunit protein correlated with fluctuations in the maximal binding capacity of gabapentin. The anti-allodynic effect of gabapentin was attenuated at the times of the day when α2δ-1 subunit protein was abundant.</p> <p>Conclusions</p> <p>These findings suggest that the dosing time-dependent difference in the anti-allodynic effects of gabapentin is attributable to the circadian oscillation of α2δ-1 subunit expression in the DRG and indicate that the optimizing its dosing schedule helps to achieve rational pharmacotherapy for neuropathic pain.</p

Characteristics of macroalgal vegetation along the coasts of Yashiro and Heigun islands, western Seto Inland Sea, Japan : especially, on the vertical distribution patterns of species of Sargassum and Ecklonia

瀬戸内海西部の伊予灘と広島湾の島嶼（屋代島，平郡島）で，大型褐藻のホンダワラ類（ヒバマタ目ホンダワラ科）とクロメ（コンブ目レッソニア科）により形成される藻場の特性を調べた。対象とした藻場は，自然岩礁域およびそれに付帯する礫集積域に形成されているものが8か所，投石による人工礁に形成されているものが3か所であり，ライントランセクト法により植生の垂直構造を明らかにし，そこにみられる法則性と環境要因との関係について考察した。調査では計85種の海藻を確認し，そのうちホンダワラ類についてはヒジキ，ノコギリモク，アカモク，ジョロモク，ホンダワラ等の計14種をみとめた。総じて，ホンダワラ類は潮間帯から水深4m 程度までで優占し，クロメは14mを下限にホンダワラ類より深所まで分布した。しかし，平郡島南岸や屋代島南岸では，浅所の岩盤上部にクロメ，その下部の漂砂影響域や礫集積域にホンダワラ類が生育し，植生の垂直構造が逆転している場合もみとめられた。人工礁上では，おおむね自然岩礁・礫集積域と類似した植生が形成されていたが，特に屋代島北岸（広島湾側）では深所で沈積浮泥の影響がみとめられ，クロメの生育は不良であるか植生から欠落していた。藻場の環境特性と植生の関係を解析した結果，平均水深が浅い藻場ではホンダワラ類の平均被度が大きくなり，海底傾斜が大きい藻場ではクロメの平均被度が大きくなる傾向がみとめられた。Characteristics of macroalgal beds composed of sargassaceous plants (Fucales, Phaeophyta) and Ecklonia kurome (Laminariales, Phaeophyta) were surveyed at Yashiro and Heigun islands in the western Seto Inland Sea (Iyo-nada Sea and Hiroshima Bay areas). The surveyed macroalgal beds were located on 8 natural rocky or boulder shores and 3 subtidal stone-built artificial reefs. A transect was set at each bed between the upper and lower limits of the macroalgal vegetation to investigate vertical distribution patterns of the constituent species. Eighty-five macroalgal species were recognized in total, and among those, 14 sargassaceous species, such as Sargassum fusiforme, S. macrocarpum, S. horneri, S. fulvellum and Myagropsis myagroides, were found. In general, sargassaceous plants were dominant from the intertidal to 4 m depth, and E. kurome distributed in deeper zones than sargassaceous plants, down to 14 m at the deepest. However, in some beds on the southern coasts of the islands, this vertical pattern was reversed. Ecklonia grows on rocky substrata which was stable and free from the effects of sand action, though sargassaceous plants grow on boulders distributed in zones deeper than the Ecklonia zones. On artificial reefs, similar vegetation with those on natural substrata was established. On reefs of the northern coast of Yashiro Is. (Hiroshima Bay area), however, sedimentation on substrata prevented the growth of Ecklonia. In the correlation analysis between physical characteristics and vegetation of the beds, there is a tendency that mean coverage of sargassaceous plants of the beds is higher as the mean depth of the beds becomes shallower, and that mean coverage of Ecklonia is higher as the slope of the beds becomes steeper.本現地調査は，農林水産省プロジェクト研究「地球温暖化が水産分野に与える影響評価と適応技術の開発」（平成22―24年度）および水産庁「藻場・干潟の炭素吸収源評価と吸収機能向上技術の開発」（平成23，24年度）の一環として実施し，とりまとめにあたってはJSPS科研費25450267の助成を受けたものである

Patent Analyses of Manufacture of Industrial Robot and Machine Tools: FANUC LTD.

本稿の目的は. 日本の産業用ロボットの海外売上とロボット関連の同内特許出願件数を牽引しているファナックの特許出願状況と発明の広がりを特許書誌情報から分析し，出願や権利に対する考えや意識の移り変わりを析出することである。出願や登録に関係する考えや意識をできるだけノイズが入らないように抽出するため，ファナックのみが出願人となっている自社単独特許出願について出願数や発明にかかる研究規模，同際特許分類，審査請求率，登録件数等の経年変化を検討した。さらに共同特許出願の相手先と関係する発明の内容から，同業種での技術交流，異業種との製品開発，大学等の公的機関との共同研究開発の状況を調べた