[1] Many debris flows initiate in steep channels (>20 degrees), yet studies have focused on lower-gradient streams where failure is controlled by water height above channel deposits. Multiple debris flows in a steep channel in Ohya landslide, central Japan, were linked to infilling processes (i.e., freeze-thaw and dry ravel) and partial saturation of accumulated sediment. Because of very active geomorphic processes in this catchment, 39 debris flows were observed in the past 6 yr. Pre-and post event imagery indicates selective transport of finer materials during most debris flows that comprise saturated and unsaturated flows; however, fluvial sediment processes, important in relation to debris flow initiation in gentler channels, were minimal. Critical conditions for the movement of such unsaturated materials are derived by equating shear stress with solid friction of the channel bed.
Bacterial iodate (IO 3؊ ) reduction is poorly understood largely due to the limited number of available isolates as well as the paucity of information about key enzymes involved in the reaction. In this study, an iodatereducing bacterium, designated strain SCT, was newly isolated from marine sediment slurry. SCT is phylogenetically closely related to the denitrifying bacterium Pseudomonas stutzeri and reduced 200 M iodate to iodide (I ؊ ) within 12 h in an anaerobic culture containing 10 mM nitrate. The strain did not reduce iodate under the aerobic conditions. An anaerobic washed cell suspension of SCT reduced iodate when the cells were pregrown anaerobically with 10 mM nitrate and 200 M iodate. However, cells pregrown without iodate did not reduce it. The cells in the former category showed methyl viologen-dependent iodate reductase activity (0.31 U mg ؊1 ), which was located predominantly in the periplasmic space. Furthermore, SCT was capable of anaerobic growth with 3 mM iodate as the sole electron acceptor, and the cells showed enhanced activity with respect to iodate reductase (2.46 U mg ؊1 ). These results suggest that SCT is a dissimilatory iodate-reducing bacterium and that its iodate reductase is induced by iodate under anaerobic growth conditions.
This paper aims to present an illustrative case study on the economic impacts of transport infrastructure disruptions caused by the hypothetical Tokai-Tonankai earthquakes in Japan. We formulate a spatial computable general equilibrium (SCGE) model, which integrates a transportation model that can estimate two types of interregional flows of freight movement and passenger trips. The case study shows the impacts of transportation disruptions and the importance of network redundancy with transport-related economic losses corresponding to several scenarios from disasters and network levels of development.Spatial computable general equilibrium model, catastrophic earthquakes, transport-related losses,
The stereoselective synthesis of tetracyclic intermediate, the indoline spiroaminal 3 for neoxaline (1) and oxaline (2), has been accomplished. The key step of the stereoselective synthesis of 3 was the Lewis acid mediated transcyclization of 4 to the diaminal 18, and the tungstate-catalyzed oxidation of 18 to obtain the nitrone 19, which easily cyclizes to the indoline spiroaminal framework 3. [structure: see text]
This article describes the determination of the absolute configurations of the guadinomines, which are novel cyclic guanidyl natural products that are inhibitors of the type III secretion system (TTSS) of bacteria. Any compound that interrupts the TTSS of bacteria is potentially an ideal anti-infectious drug. The reliable asymmetric synthesis of guadinomines has revealed their absolute configurations, which could not have been defined without this synthetic approach. Our report not only describes the asymmetric total synthesis of the title compounds, but also demonstrates the novel concise synthesis of tri-substituted piperazinone cores as optically pure forms. The novel feature of our method is an intramolecular S(N)2 cyclization that uses PPh(3) and I(2) to construct the unique 5-membered cyclic guanidine substructure.
This paper presents a framework for assessing the economic impact of disruption in transportation that can relate the physical damage to transportation networks to economic losses. A spatial computable general equilibrium (SCGE) model is formulated and then integrated with a transportation model that can estimate the traffic volumes of freight and passengers. Economic equilibrium under a disruption in the transportation network is computed subject to the condition that the adjustment of labor and capital inputs is restricted; the model reflects slow adjustment of these linked to the state of recovery. As a case study, the model reviews the large Niigata-Chuetsu earthquake of 2004. Considering the damage to the transportation infrastructure, the model indicates the extent of the economic losses arising from the earthquake distributed over regions as a consequence of the intra-and interregional trade in a regional economy. The results show that 20% of the indirect losses occur in the Niigata region directly affected by the earthquake, whereas 40% of the total losses are experienced in the Kanto region and non-negligible losses reach rather remote zones of the country such as Okinawa.
With the aid of an in silico method, α-glucosidase inhibitors with far more potent activities than salacinol (1), a potent natural α-glucosidase inhibitor isolated from an Ayurvedic traditional medicine Salacia reticulata, have been developed.
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