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The p75 neurotrophin receptor:at the crossroad of neural repair and death

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Neural Regeneration Research 2015年第5期10卷 721-725页

作者： rick B.Meeker Kimberly S.Williams Department of Neurology University of North Carolina Curriculum in Neurobiology University of North Carolina

The strong repair and pro-survival functions of neurotrophins at their primary receptors, TrkA, TrkB and TrkC, have made them attractive candidates for treatment of nervous system injury and disease. However, difficulties with the clinical implementation of neurotrophin therapies have prompted the search for treatments that are stable, easier to deliver and allow more precise regula- tion of neurotrophin actions. Recently, the p75 neurotrophin receptor （p75wrR） has emerged as a potential target for pharmacological control of neurotrophin activity, supported in part by stud- ies demonstrating 1） regulation of neural plasticity in the mature nervous system, 2） promotion of adult neurogenesis and 3） increased expression in neurons, macrophages, microglia, astro- cytes and/or Schwann cells in response to injury and neurodegenerative diseases. Although the receptor has no intrinsic catalytic activity it interacts with and modulates the function of TrkA, TrkB, and TrkC, as well as sortilin and the Nogo receptor. This provides substantial cellular and molecular diversity for regulation of neuron survival, neurogenesis, immune responses and pro- cesses that support neural function. Upregulation of the p75^NTR under pathological conditions places the receptor in a key position to control numerous processes necessary for nervous system recovery. Support for this possibility has come from recent studies showing that small, non-pep- tide p75^NTR ligands can selectively modify pro-survival and repair functions. While a great deal remains to be discovered about the wide ranging functions of the p75^NTR, studies summarized in this review highlight the immense potential for development of novel neuroprotective and neu- rorestorative therapies.

关键词： injury plasticity neurodegenerative disease brain therapy neuron microglia neuralprogenitor

Segmentation and classification of high resolution imagery for mapping individual species in a closed canopy,deciduous forest

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Science China(Technological Sciences) 2006年第Z1期49卷 128-139页

作者： Timothy A.Warner James B.McGraw rick Landenberger Department of Geology and Geography West Virginia UniversityMorgantown WV 26506-6300USA Biology Department West Virginia UniversityMorgantown WV 26506USA

In this paper we investigate the use of a shadow-based delineation program for identifying segments in imagery of a closed canopy, deciduous forest, in West Virginia, USA, as a way to reduce the noise associated with per-pixel classification in forested environments. Shadows typically cluster along the boundaries of trees and therefore can be used to provide a network of nodes for the delineation of segments. A minimum cost path algorithm, where cost is defined as the cumulative sum of brightness values traversed along the connecting route, was used to connect shadow clumps. To test this approach, a series of classifications was undertaken using a multispectral digital aerial image of a six hectare test site and a minimum cost path segmentation. Three species were mapped: oaks, red maple and yellow poplar. The accuracy of an aspatial maximum likelihood classification (termed PERPIXEL classification) was 68.5%, compared to 74.0% for classification using the mean vector of the segments identified with the minimum cost path algorithm (MEAN_SEG), and 78% when the most common class present in the segment is assigned to the entire segment (POSTCLASS_SEG). By comparison, multispectral classification of the multispectral data using the field-mapped polygons of individual trees as segments, produced an accuracy of 82.3% when the mean vector of the polygon was used for classification (MEAN_TREE), and 85.7% when the most common class was assigned to the entire polygon (POSTCLASS_TREE). A moving window-based post-classification majority filter (POSTCLASS_MAJ5BY5) produced an intermediate accuracy value, 73.8%. The minimum cost path segmentation algorithm was found to correctly delineate approximately 28% of the trees. The remaining trees were either segmented, aggregated, or a combination of both segmented and aggregated. Varying the threshold that was used to discriminate shadows appeared to have little effect on the number of correctly delineated trees, or on the overall accu

关键词： remote sensing, digital forestry, image classification, segmentation.

Pharmacokinetic characteristics of L-valyl-ara-C and its implication on the oral delivery of ara-C

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Acta Pharmacologica Sinica 2007年第2期28卷 268-272页

作者： Eun-pa CHEON Hyo-kyung HAN College of Pharmacy Chosun UniversityGwangju 501-759Korea

Aim:To evaluate the pharmacokinetic characteristics of L-valyl-ara-C,apeptidomimetic prodrug of ***:After the synthesis of L-valyl-ara-C,the in vitro stability of L-valyl-ara-C was examined in various biological *** pharmacokinetic profiles of ara-C and L-valyl-ara-C were also evaluated ***:The degradation of L-valyl-ara-C was negligible in fresh plasmaand also in the presence of plasmin over a 2 h incubation ***,L-valyl-ara-C appeared to be stable in the leukemia cell homogenates,andsubsequently,it was far less cytotoxic than the parent,ara-C in AML2 and *** chemical hydrolysis of L-valyl-ara-C was rather accelerated in *** an oral administration of L-valyl-ara-C,the appearance of ara-Cwas observed in plasma although the systemic exposure of the prodrug was muchhigher than that of *** bioavailability of ara-C was about 4% via ***:The amide bond of L-valyl-ara-C was stable againstthe enzymatic hydrolysis,and the utility of L-valyl-ara-C as an oral delivery sys-tem of ara-C appeared to be limited by its low metabolic conversion to ara-C in rats.

关键词： ara-C L-valyl-ara-C prodrug pharmacokinetics rats

Nanobubble generation and its applications in froth flotation(part IV):mechanical cells and specially designed column flotation of coal

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Mining Science and Technology 2010年第5期20卷 641-671页

作者： FAN Maoming TAO Danie HONAKER rick LUO Zhenfu Department of Mining Engineering University of Kentucky Lexington KY 40506 USA CPT Eriez Manufacturing Co Erie PA 16514 USA School of Chemical Engineering and Technology China University of Mining & Technology Xuzhou 221116 China

Coal is the world's most abundant fossil *** froth flotation is a widely used cleaning process to separate coal from mineral *** of coarse coal particles,ultrafine coal particles and oxidized coal particles is well known to be difficult and *** this paper,the nanobubbles' effects on the flotation of the varying particle size,particle density and floatability coal samples were evaluated using a bank of pilot scale flotation cells,a laboratory scale and a pilot scale specially designed flotation *** parameters evaluated during this study include the flow rate ratio between the nanobubble generator and the conventional size bubble generator,the superficial air velocity,collector dosage,frother concentration,flotation feed rate,feed solids concentration,feed particle size,and the superficial wash water flow rate,*** results show that the use of nanobubbles in a bank of mechanical cells flotation and column flotation increased the flotation recovery by 8%～27% at a given product *** increased the flotation rate constants of 600～355,355～180,180～75,and 75～0 microns size coal particles by 98.0%,98.4%,50.0% and 41.6%,*** separation selectivity index was increased by up to 34%,depending on the flotation feed characteristics and the flotation conditions.

关键词： coal froth flotation cavitation nanobubble flotation kinetics

Key Techniques in Real Time Digital Simulation for Closed-loop Testing of HVDC Systems

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CSEE Journal of Power and Energy Systems 2017年第2期3卷 125-130页

作者： Yi Zhang Hui Ding rick Kuffel RTDS Technologies Inc. WinnipegManitobaCanada

This paper introduces several key techniques in realtime digital simulation for closed-loop testing of high voltage direct current(HVDC)systems,including line commutated converter(LCC)HVDC valve group models,modular multilevel converter(MMC)HVDC models,phase domain frequency dependent transmission line models,and switchable filter *** issues such as background,algorithms,implementations,applications,and validation of these models are *** techniques represent the most advanced technology in modelling HVDC systems on a real time *** models have been implemented on the RTDS Simulator,a comprehensive real time power system digital simulation tool.

关键词： HVDC real time simulation

Nanobubble generation and its application in froth flotation (part I): nanobubble generation and its effects on properties of microbubble and millimeter scale bubble solutions

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Mining Science and Technology 2010年第1期20卷 1-19页

作者： FAN Maoming TAO Daniel HONAKER rick LUO Zhenfu Department of Mining Engineering University of Kentucky Lexington KY40506 USA CPT Eriez Manufacturing Co. Erie PA 16514 USA School of Chemical Engineering and Technology China University of Mining & Technology Xuzhou 221116 China

A special nanobubble generation system has been developed for evaluating the effect of nanobubble on froth flotation. In this study, an eight-factor five-level Central Composite Experimental Design was conducted for investigating eight important parameters governing the median size and the volume of nanobubbles. These process parameters included surfactant concentration, dissolved oxygen (O2) content, dissolved carbon dioxide gas (CO2) content, pressure drop in cavitation tube nozzle, particle concentration, particle concentration, slurry temperature and the time interval after nanobubble generation. The properties, stability and uniformity of nanobubbles were investigated. The study of the produced nanobubble’s effects on the characteristics of microbubble solutions and millimeter scale bubble solutions was performed in a 50.8 mm column.

关键词： nanobubble cavitation Zeta potential microbubble froth flotation

Determination of velocity correction factors for real-time air velocity monitoring in underground mines

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International Journal of Coal Science & Technology 2017年第4期4卷 322-332页

作者： Lihong Zhou Liming Yuan rick Thomas Anthony Iannacchione Pittsburgh Mining Research Division Office of Mine Safetyand Health Research National Institute for OccupationalSafety and Health PO Box 18070 626 Cochrans Mill RoadPittsburgh PA 15236 USA University of Pittsburgh Pittsburgh PA USA

When there are installations of air velocity sensors in the mining industry for real-time airflow monitoring, a problem exists with how the monitored air velocity at a fixed location corresponds to the average air velocity, which is used to determine the volume flow rate of air in an entry with the cross-sectional area. Correction factors have been practically employed to convert a measured centerline air velocity to the average air velocity. However, studies on the recommended correction factors of the sensor-measured air velocity to the average air velocity at cross sections are still lacking. A comprehensive airflow measurement was made at the Safety Research Coal Mine, Bruceton, pa, using three measuring methods including single-point reading, moving traverse, and fixed-point traverse. The air velocity distribution at each measuring station was analyzed using an air velocity contour map generated with Surfer~. The correction factors at each measuring station for both the centerline and the sensor location were calculated and are discussed.

关键词： Underground mine Airflow measurement - Correction factor

Ultraviolet reflection enhances the risk of predation in a vertebrate

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Current Zoology 2013年第2期59卷 151-159页

作者： Ricarda MODARRESSIE IngolfE rick Theo C. M. BAKKER Institute for Evolutionary Biology and Ecology University of Bonn An der Immenburg 1 D-53121 Bonn Germany

Many animals are sensitive to ultraviolet light and also possess UV-reflective regions on their body surface. Individu- als reflecting UV have been shown to be preferred during social interactions such as mate choice or shoaling decisions. However, whether those body UV-reflections enhance also the conspicuousness to UV-sensitive predators and thereforeentail costs for its bearer is less well documented. Two size-matched three-spined sticklebacks Gasterosteus aculeatus, one enclosed in a UV-transmitting （UV＋） and another in a UV-blocking （UV-） chamber, were simultaneously presented to individual brown trout Salmo trutta. ＂yearlings＂. Brown trout of this age are sensitive to the UV part of the electromagnetic spectnun and are natural predators of three-spined sticklebacks. The stickleback that was attacked first as well as the subsequent number of attacks was recorded. Sticklebacks enclosed in the UV-transmitting chamber were attacked first significantly more often compared to stickle- backs enclosed in the UV-blocking chamber. Control experiments using neutral density filters revealed that this was more likely due to LrV having an influence on hue perception rather than brighmess discrimination. The difference in attack probability cor- responded to the difference in chromatic contrasts between sticklebacks and the experimental background calculated for both the UV＋ and UV- conditions in a physiological model of trout colour vision. UV reflections seem to be costly by enhancing the risk of predation due to an increased conspicuousness of prey. This is the first study in a vertebrate, to our knowledge, demonstrating direct predation risk due to UV wavelengths [Current Zoology 59 （2）： 151-159, 2013].

关键词： UV vision Brown trout Salmo trutta Ultraviolet reflection Three-spined stickleback Gasterosteus aculeatus Pre-dation risk

Comparative performance analysis of stroke correspondence search methods for stroke-order free online multi-stroke character recognition

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Frontiers of Computer Science 2014年第5期8卷 773-784页

作者： Wenjie ca1 Seiichi UCHIDA Hiroaki SAKOE Department of Advanced Information Technology Kyushu University Fukuoka-shi 819-0395 Japan

For stroke-order free online multi-stroke charac- ter recognition, stroke-to-stroke correspondence search be- tween an input pattern and a reference pattern plays an im- portant role to deal with the stroke-order variation. Although various methods of stroke correspondence have been pro- posed, no comparative study for clarifying the relative su- periority of those methods has been done before. In this pa- per, we firstly review the approaches for solving the stroke- order variation problem. Then, five representative methods of stroke correspondence proposed by different groups, includ- ing cube search （CS）, bipartite weighted matching （BWM）, individual correspondence decision （ICD）, stable marriage （SM）, and deviation-expansion model （DE）, are experimen- tally compared, mainly in regard of recognition accuracy and efficiency. The experimental results on an online Kanji char- acter dataset, showed that 99.17%, 99.17%, 96.37%, 98.54%, and 96.59% were attained by CS, BWM, ICD, SM, and DE, respectively as their recognition rates. Extensive discussions are made on their relative superiorities and practicalities.

关键词： cube search bipartite weighted matching indi-vidual correspondence decision stable marriage deviation-expansion model