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Flow hydrodynamics in embankment breach

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j.urnal of Hydrodynamics 2015年第6期27卷 835-844页

作者： ZHAO Gensheng VISSER paul j. REN Yankai UIj.TEWAAL Wim S.j. Department of Hydraulic Engineering Delft University of Technology Flanders Hydraulics Research Flemish Government Department of Mobility and Public Works

Breaching flow occurs during the breach development of the embankment, dike, earthen dam, landslide barrier, etc. and plays an import role in the breaching erosion as the driving force. According to the previous research, the breaching process can be classified into initiation phase, breach widening phase and breach deepening phase. Based on the breaching development classifications, the breaching flow can be seen as a special compound weir flow when the breach channel is in the relatively equilibrium condition. There were five physical flow models were designed in the hypothesis of rectangular shape and trapezoidal shape for the breach channel cross sections to study the breaching flow characteristics. The distributions of water level and velocity were measured and analysed in the breaching flows in overtopping condition and emerged condition. There were two helicoidal flows above the breach channel slopes and triangular hydraulic j.mp in the downstream of the breach channel in the overtopping condition and emerged condition. The hydraulic energy loss was calculated according to the breaching velocity and water level distribution in the upstream and downstream of the model. It is found that the test results of the breach flow physical model can be valuable to bring insight of the breaching process of embankment and make contributions to the validations and verifications of breach numerical models.

关键词： embankment breach physical model breaching flow helicoidal flow hydraulic j.mp

Sexual/aggressive behavior of wild yak(Bos mutus Prej.valsky1883) during the rut: influence of female choice

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Chinese Science Bulletin 2014年第22期59卷 2756-2763页

作者： paul j. Buzzard Donghua Xu Huan Li China Exploration & Research Society

Wild yaks(Bos mutus)ranged across the Tibetan Plateau in large herds before being forced to remote areas of the ***,little has been published about their behavioral *** present the first extensive study on wild yak behavior during the *** gathered data on activity budgets,aggressive/sexual behaviors,and the behavior of bulls inside and outside mixed groups during 11 days in 2010 and 9 days in *** ate less and were more social during the rut than during *** ate less than females and socialized more during the *** observed yaks for 234.25 h and recorded 2,078 aggressive/sexual *** bulls inspected and tended cows showing off their profiles during lateral displays,the most common type of indirect *** bulls inside mixed sex groups rested less and socialized more than bulls *** initiated intense intra-sexual competition and led at least 25 bulls on *** then incited fight frenzies of numerous bulls from inside and outside the groups before copulations,and fights could be *** discuss female choice selecting for large size and fighting ability in males,the similarity of yak and bison(genus Bison)behavior,and conservation implications.

关键词：攻击行为野牦牛发情期女性战斗能力青藏高原行为生态学社会化

Stress, hippocampal neurogenesis and cognition： functional correlations

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Frontiers in Biology 2016年第3期11卷 182-192页

作者： paul j. Lucassen Charlotte A. Oomen Centre for Neuroscienee Swammerdam Institute for Life Sciences University of Amsterdam Science Park 904 1098 XH Amsterdam The Netherlands Department of Molecular and Cellular Neurobiology Center for Neurogenomics and Cognitive ResearchNeuroscience Campus Amsterdam VU University Amsterdam De Boelelaan 1085 1081 HV Amsterdam The Netherlands

The brain of many species including humans, harbors stem cells that continue to generate new neurons up into adulthood. This form of structural plasticity occurs in a limited number of brain regions, i.e. the subventricular zone and the hippocampal dentate gyrus and is regulated by environmental and hormonal factors. In this minireview, we provide an overview of the effects of stress and glucocorticoid hormones on adult hippocampal neurogenesis and discuss how these effects may be relevant for cognitive function and possibly, brain disease. While its exact functional role remains elusive, adult neurogenesis has been implicated in learning and memory, fear and mood regulation and recently, adult-born neurons were found to be involved in specific cognitive functions such as pattern separation （i.e. the ability to form unique memory representations） and cognitive flexibility. The process of adult neurogenesis is influenced by several factors; whereas e.g. exercise stimulates, exposure to stress and stress hormones generally inhibit neurogenesis. Effects of acute, mild stress are generally short-lasting and recover quickly, but chronic or severe forms of stress can induce lasting reductions in adult neurogenesis. Some of the inhibitory effects of stress can be rescued by exercise, by allowing a period of recovery from stress, by drugs that target the stress system, or by some, but not all, antidepressants. Stress may, partly through its effects on adult neurogenesis, alter structure and plasticity of the hippocampal circuit. This can lead to subsequent changes in stress responsivity and aspects of memory processing, which may be particularly relevant for stress related psychopathology or brain diseases that involve perturbed memory processing.

关键词： adult neurogenesis stem cells hippocampus stress memory pattern separation cognition

Scales of snow depth variability in high elevation rangeland sagebrush

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Frontiers of Earth Science 2017年第3期11卷 469-481页

作者： Molly E. TEDESCHE Steven R. FASSNACHT paul j. MEIMAN Watershed Science Department of Ecosystem Science and Sustainability Colorado State University Fort Collins CO 80523-1476 USA Intemational Arctic Research Center Water & Environmental Research Center Institute of Northern Engineering University of Alaska Fairbanks Fairbanks AK 99775 USA Cooperative Institute for Research in the Atmosphere Fort Collins CO 80523-1375 USA Natural Resources Ecology Laboratory Fort Collins CO 80523-1499 USA Abt. Kartographie GIS & Femerkundung Geographisches Institut Georg-August-Universitat Gottingen 37077 Gottingen Germany Rangeland Ecosystem Science Department of Forest and Rangeland Stewardship Colorado State University Fort Collins CO 80523 USA

In high elevation semi-arid rangelands, sage- brush and other shrubs can affect transport and deposition of wind-blown snow, enabling the formation of snowdrifts. Datasets from three field experiments were used to investigate the scales of spatial variability of snow depth around big mountain sagebrush （Artemisia tridentata Nutt.） at a high elevation plateau rangeland in North Park, Colorado, during the winters of 2002, 2003, and 2008. Data were collected at multiple resolutions （0.05 to 25 m） and extents （2 to 1000 m）. Finer scale data were collected specifically for this study to examine the correlation between snow depth; sagebrush microtopogra- phy, the ground surface, and the snow surface, as well as the temporal consistency of snow depth patterns. Vario- grams were used to identify the spatial structure and the Moran＇s I statistic was used to determine the spatial correlation. Results show some temporal consistency in snow depth at several scales. Plot scale snow depth variability is partly a function of the nature of individual shrubs, as there is some correlation between the spatial structure of snow depth and sagebrush, as well as between the ground and snow depth. The optimal sampling resolution appears to be 25-cm, but over a large area, this would require a multitude of samples, and thus a random stratified approach is recommended with a fine measurement resolution of 5-cm.

关键词： snow hydrology high elevation rangelands,spatial statistics variograms snow pack spatial variability,snow drifts

Robust Filtration Techniques in Geometrical Metrology and Their Comparison

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International j.urnal of Automation and computing 2013年第1期10卷 1-8页

作者： Shan Lou Wen-Han Zeng Xiang-Qian j.ang paul j. Scott EPSRC Centre for Innovative Manufacturing in Advanced Metrology University of Huddersfield

Filtration is one of the core elements of analysis tools in geometrical metrology. Filtration techniques are progressing along with the advancement of manufacturing technology. Modern filtration techniques are required to be robust against outliers, applicable to surfaces with complex geometry and reliable in whole range of measurement data. A comparison study is conducted to evaluate commonly used robust filtration techniques in the field of geometrical metrology, including the two-stage Gaussian filter, the robust Gaussian regression filter, the robust spline filter and morphological filters. They are compared in terms of four aspects： functionality, mathematical computation, capability and characterization parameters. As a result, this study offers metrologists a guideline to choose the appropriate filter for various applications.

关键词： Geometrical metrology robust Gaussian regression filter robust spline filter morphological filters surface roughness

Arthropod prey of imported fire ants （Hymenoptera： Formicidae） in Mississippi sweetpotato fields

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Insect Science 2013年第4期20卷 467-471页

作者： Tahir Rashid j.an Chen j.mes T. Vogt paul j. McLeod Aicorn State University Extension~Research Demonstration Farm & Tech Transfer Center Mound Bayou Mississippi USDA ARS Bio- logical Control of Pests Research Unit Stoneville Mississippi USDA FS Inventory & Analysis Knoxville Tennessee Department of Entomology University of Arkansas Fayetteville Arkansas United States

The red imported fire ants, Solenopsis invicta （Buren）, are generally considered pests. They have also been viewed as beneficial predators feeding on other insect pests of various agroecosystems. This study documents the foraging habits of fire ants in a sweetpotato field in Mississippi. Fire ant foraging trails connecting outside colonies to a sweetpotato field were exposed and foraging ants moving out of the field toward the direction of the colony were collected along with the solid food particles they were carrying. The food material was classified as arthropod or plant in origin. The arthropod particles were identified to orders. Fire ant foragers carried more arthropods than plant material. Coleoptera and Homoptera were the most abundant groups preyed upon. These insect orders contain various economically important pests of sweetpotato. Other maj.r hexapod groups included the orders Hemiptera, Diptera and Collembola. The quantity of foraged material varied over the season. No damage to sweetpotato roots could be attributed to fire ant feeding. Imported fire ant foraging may reduce the number of insect pests in sweetpotato fields.

关键词： foraging imported fire ant predation Solenops& invicta sweetpotato

Molecular biology and the diagnosis and treatment of liver diseases

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World j.urnal of Gastroenterology 1998年第3期4卷 5-11页

作者： Howard j. Worman, Feng Lin, Naoto Mamiya and paul j. Mustacchia

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ＭｏｌｅｃｕｌａｒｂｉｏｌｏｇｙａｎｄｔｈｅｄｉａｇｎｏｓｉｓａｎｄｔｒｅａｔｍｅｎｔｏｆｌｉｖｅｒｄｉｓｅａｓｅｓＨｏｗａｒｄＪ．Ｗｏｒｍａｎ，ＦｅｎｇＬｉｎ，ＮａｏｔｏＭａｍｉｙａａｎｄＰａｕｌＪ．ＭｕｓｔａｃｃｈｉａＳｕｂｊｅｃｔｈｅａｄｉｎｇ...

关键词： liver disease molecular biology viral hepatitis metabolic diseases recombinant DNA rational drug design gene therapy

Tobacco Transcription Factors NtMYC2a and NtMYC2b Form Nuclear Complexes with the Ntj.Z1 Repressor and Regulate Multiple j.smonate-lnducible Steps in Nicotine Biosynthesis

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Molecular Plant 2012年第1期5卷 73-84页

作者： Hong-Bo Zhang Marta T. Bokowiec paul j. Rushton Sheng-Cheng Han Michael R Timko Department of Biology University of Virginia Charlottesville VA 22904 USA College of Agronomy and Biotechnology Southwest University Chongqing 400715 China Department of Biology and Microbiology South Dakota State University Brookings SD 57007 USA College of Life Science Beijing NormalUniversity Beijing 100875 China

Biotic and abiotic stress lead to elevated levels of j.smonic acid （j.） and its derivatives and activation of the biosynthesis of nicotine and related pyridine alkaloids in cultivated tobacco （Nicotiana tabacum L.）. Among the j.- responsive genes is NtPMTla, encoding putrescine N-methyl transferase, a key regulatory enzyme in nicotine formation. We have characterized three genes （NtMYC2a, b, c） encoding basic helix-loop-helix （bHLH） transcription factors （TFs） whose expression is rapidly induced by j. and that specifically activate j.-inducible NtPMTla expression by binding a G-box motif within the NtPMTla promoter in in vivo and in vitro assays. Using split-YFP assays, we further show that, in the absence of j., NtMYC2a and NtMYC2b are present as nuclear complexes with the Ntj.Z1 repressor. RNA interference （RNAi）-mediated knockdown of NtMYC2a and NtMYC2b expression results in significant decreases in j.-inducible NtPMTla transcript levels, as well as reduced levels of transcripts encoding other enzymes involved in nicotine and minor alkaloid biosynthesis, in- cluding an 80-90% reduction in the level of transcripts encoding the putative nicotine synthase gene NtA662. In contrast, ectopic overexpression of NtMYC2a and NtMYC2b had no effect on NtPMTla expression in the presence or absence of exogenously added j.. These data suggest that NtMYC2a, b, c are required components of j.-inducible expression of multiple genes in the nicotine biosynthetic pathway and may act additively in the activation of j. responses.

关键词： COl1 j.smonate MYC2 nicotine tobacco.

Patient Characteristics, Safety, and Tolerability With Telaprevir Treatment for HCV in the Clinic:a Retrospective, Multicenter Study

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j.urnal of Clinical and Translational Hepatology 2014年第2期2卷 65-73页

作者： Steven L. Flamm paul j. Pockros Leif Bengtsson Mark Friedman Northwestern University Feinberg School of Medicine Chicago Illinois USA Scripps Clinic and Scripps Translational Science Institute La Jolla California USA Vertex Pharmaceuticals Incorporated Boston Massachusetts USA

Background and Aims: There is a paucity of information regarding similarities and differences between patients from the phase 3 studies of telaprevir and those receiving telaprevir in clinical practice. Methods: This retrospective chart review evaluated baseline characteristics and follow-up safety and tolerability data for patients with hepatitis C virus (HCV) infection treated with telaprevir and peginterferon alfa and ribavirin (PR) in clinical practice. Results: In total, 338 charts from patients at four academic and three community US treatment centers who received telaprevir and PR and had at least 12 weeks of follow-up data were included;62%were from academic centers and 38% were from community centers. Of the 338 patients, 269 completed 12 weeks of telaprevir and PR;32 discontinued due to adverse events. Mean age was 55 years;patients were predominantly white (79.3%) males (58.9%) with genotype 1a HCV infection (61.8%);35.5%were reported to have cirrhosis at baseline;and 55.3%previously received PR. Hypertension and depres-sion were the most common comorbidities. Patient charac-teristics outside the per-protocol minimum criteria used in the phase 3 studies of telaprevir were, e.g., hemoglobin, 9.2%;albumin, 5.3%;platelets, 11.5%;and neutrophil count, 5.6%. Adverse events occurred in 329/338 (97.3%) patients, with anemia, fatigue, nausea, and rash being the most common. Of 38 hospitalizations, 26 were deemed related to telaprevir and PR. Three patients died due to pneumonia, septic shock, and hepatorenal syndrome (n=1 each). Conclusions: These findings complement those reported from rigorous, randomized controlled studies with telaprevir-based treatment and provide a general assess-ment of similarities and/or differences between patients from the phase 3 studies of telaprevir and those treated with telaprevir in clinical practice.

关键词： Hepatitis C virus Combination drug therapy Protease inhibitors Liver diseases