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Unintended consequences of rangeland conservation structures

2004年

作者： Waldron kenneth j.

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International Soil and Water Conservation Research 2021年第1期9卷 158-165页

作者： Mary H.Nichols j.remy R shaw William K.Brandau Southwest Watershed Research Center USDA-ARS2000 E.Allen Rd.TucsonAZ85719USA Colorado State University Department of Forest&Rangeland Stewardship Fort CollinsCO80523-1472USA University of Arizona Cooperative Extension Service(retired) SaffordAZ85551USA

By the 1930's vast areas of the western US were severely degraded by overgrazing and *** response,Congress authorized conservation work including the construction of erosion control and water storage,distribution,and conveyance *** of structures such as check dams,water spreaders,and contour berms were built during the 1930s and 40s to control water and sediment in an attempt to restore degraded ***,across most of the western US,these soil and water conservation measures were implemented without the benefit of local hydrologic data or technical design *** of the established conservation practices had been developed for humid regions and were untested for use in semiarid areas that are characterized by highly variable rainfall and flash *** a result,many structures proved ineffective and were subsequently *** in cases where structures were effective,many never received maintenance after their initial *** structurally compromised,abandoned and unmaintained structures continue to alter surface runoff patterns and can greatly exacerbate *** sites in Arizona,USA were selected to charac-terize the multi-decadal impacts of conservation *** have formed in 100%of contour berms(n=67)while 96%of water spreader berms(n=26)were *** failures in these structures has created concentrated flow paths that reorganized routing of runoff and sediment thus transforming sheetflow regimes to concentrated flow *** study emphasizes the unin-tended legacy impacts of soil and water conservation structures and highlights their role as a potential constraint on contemporary resource management.

关键词： Contour berm Erosion Human altered landscape Restoration Semiarid Water spreader

Daily high-dose aspirin does not lower APRI in the Aspirin-Myocardial Infarction Study

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The j.urnal of Biomedical Research 2020年第2期34卷 139-142页

作者： Shilpa Tiwari-Heckler ZGordon j.ang Yury Popov kenneth j.Mukamal Division of Gastroenterology and Hepatology Department of MedicineHarvard Medical SchoolBostonMA 02115USA Division of General Medicine Beth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMA 02115USA

Antiplatelet agents reduce liver fibrosis by inhibiting platelet activation and platelet-derived growth factor production. Previous cross-sectional epidemiological studies suggest that the use of aspirin is related to reduced liver fibrosis. The Aspirin-Myocardial Infarction Study(AMIS) aims to examine this relationship in a multicenter,randomized, double-blind and placebo-controlled trial. The existing clinical trial of aspirin was conducted to study the benefit of one gram aspirin daily among 4 524 individuals who had experienced at least one documented myocardial infarction. The aspartate aminotransferase(AST)-to-Platelet Ratio Index(APRI) was calculated at baseline and annually from the platelet count and AST levels. Participants in the AMIS trial had a mean baseline APRI of 0.34±0.36, and only 1% individuals had APRI scores higher than 1.0, a common cutoff for cirrhosis. The daily use of aspirin was associated with an increase, rather than a reduction of APRI, by 0.007 per year(95% CI0.002-0.015, P=0.12). The use of aspirin did not significantly affect platelet counts. In a sensitivity analysis of individuals with probable significant fibrosis at baseline(APRI≥0.7), the aspirin group had a sustained reduction in APRI over time, although this change was not significant compared to that in the placebo group. In the AMIS trial, the daily use of high-dose aspirin did not significantly affect APRI, a surrogate index of liver fibrosis. This study highlights the need for de novo clinical trials to investigate the potential benefit of antiplatelet agents on liver fibrosis.

关键词： liver fibrosis aspirin APRI antiplatelet AMIS

Accumulation sequence of Chinese loess and climatic records of Greenland ice core during the last 130 ka

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Chinese Science Bulletin 1995年第15期40卷 1272-1276页

作者：安芷生孙东怀张小曳周卫建 S.C.Porter j.shaw 张代州 Xi'an Laboratory of Loess and Quaternary Geology. Chinese Academy of Sciences. Xi'an 710061 China Quaternary Research Centre. University of Washington. Seattle. USA Geomagnetism Laboratory. University of Liverpool UK Department of Geophysics. Peking University. Beij.ng 100871 China

The present winter climate of continental China is associated with cold air *** cold air forming Siberian high pressure comes from the Northern Barents *** Kara Sea and Northern Atlantic Ocean (fig.1). in other words,... 详细信息

关键词： winter monsoon GRIP core and Chinese loess.

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社会选择及个人价值

社会选择及个人价值

Predicting the mode of flow in pneumatic conveying systems—A review

1974年

作者： kenneth j. Arrow 汤慎之译

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Particuology 2008年第5期6卷 289-300页

作者： Mark G.j.nes kenneth C.Williams Centre for Bulk Solids and Particulate Technologies School of EngineeringUniversity of NewcastleNewcastle 2308Australia

An initial prediction of the particulate mode of flow in pneumatic conveying systems is beneficial as this knowledge can provide clearer direction to the pneumatic conveying design process. There are three general categories of modes of flow, two dense flows： fluidised dense phase and plug flow, and dilute phase oniy. Detailed in this paper is a review of the commonly used and available techniques for predicting mode of flow. Two types of predictive charts were defined： basic particle parameter based （e.g. particle size and density） and air-particle parameter based （e.g. permeability and de-aeration）. The basic particle techniques were found to have strong and weak areas of predictive ability, on the basis of a comparison with data from materials with known mode of flow capability. It was found that there was only slight improvement in predictive ability when the particle density was replaced by loose-poured bulk density in the basic parameter techniques. The air-particle-parameter-based techniques also showed well-defined regions for mode of flow prediction though the data set used was smaller than that for the basic techniques. Also, it was found to be difficult to utilise de-aeration values from different researchers and subsequently, an air-particle-based technique was developed which does not require any de-aeration parameter in its assessment.

关键词： Pneumatic conveying Mode of flow Dense phase Permeability De-aeration

Forecast future disasters using hydro-meteorological datasets in the Yamuna river basin,Western Himalaya:Using Markov Chain and LSTM approaches

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Artificial Intelligence in Geosciences 2024年第1期5卷 114-136页

作者： Pankaj.Chauhan Muhammed Ernur Akiner Raj.b shaw Kalachand Sain Wadia Institute of Himalayan Geology DehradunUttarakhand248001India Graduate School of Media and Governance Keio University5322 EndoFujisawa 252-0882KanagawaJapan Akdeniz University Vocational School of Technical SciencesDepartment of Environmental Protection TechnologiesAntalyaTurkey

This research aim to evaluate hydro-meteorological data from the Yamuna River Basin,Uttarakhand,India,utilizing Extreme Value Distribution of Frequency Analysis and the Markov Chain *** method assesses persistence and allows for combinatorial probability estimations such as initial and transitional *** hydrologic data was generated(in-situ)and received from Uttarakhand j.l Vidut Nigam Limited(Uj.NL),and meteorological data was acquired from NASA’s archives MERRA-2 product.A total of sixteen years(2005-2020)of data was used to foresee daily Precipitation from 2020 to ***-2 products are utilized as observed and forecast values for daily Precipitation throughout the monsoon season,which runs from j.ly to *** Chain and Long Short-Term Memory(LSTM)findings for 2020,2021,and 2022 were observed,and anticipated values for daily rainfall during the monsoon season between j.ly and *** to test findings,the artificial intelligence technique cannot anticipate future regional meteorological formations;the correlation coefficient R^(2) is around *** to the randomly verified precipitation data findings,the Markov Chain model has a success rate of 79.17 *** results suggest that extended return periods should be a warning sign for drought and flood risk in the Himalayan *** study gives a better knowledge of the water budget,climate change variability,and impact of global warming,ultimately leading to improved water resource management and better emergency planning to the establishment of the Early Warning System(EWS)for extreme occurrences such as cloudbursts,flash floods,landslides hazards in the complex Himalayan region.

关键词： Forecast disasters Western Himalaya Hydro-meteorological hazards LSTM Markov chain Yamuna river basin

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埃及神话

胶东区域成矿断裂带蚀变年龄研究及其矿床学意义

2018年

作者： (英)加里·j. 肖(Garry j. shaw)

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地学前缘 2017年第2期24卷 140-150页

作者：吕承训 Norbert H.MAERZ kenneth j.BOYKO 吕古贤邵鹤森密苏里科技大学地质科学与石油及地质工程学院美国密苏里州罗拉65401 中国地质科学院地质力学研究所北京100081 中国地质大学(北京)地球科学与资源学院北京100083

胶东金矿是中生代构造岩浆活化区岩浆期后中温热液蚀变脉状矿床。前人曾认为该类金矿属于壳源深融花岗岩-热液石英脉-蚀变岩型金矿。近期研究表明,胶东金矿围岩蚀变年龄的测定,对于矿床成因的研究有重要意义。为解决胶东区域断裂热液蚀... 详细信息

胶东金矿是中生代构造岩浆活化区岩浆期后中温热液蚀变脉状矿床。前人曾认为该类金矿属于壳源深融花岗岩-热液石英脉-蚀变岩型金矿。近期研究表明,胶东金矿围岩蚀变年龄的测定,对于矿床成因的研究有重要意义。为解决胶东区域断裂热液蚀变年龄问题,对胶东半岛主要断裂矿化蚀变带开展如下相关研究:(1)选择胶东地区各蚀变岩带普遍发育的黄铁绢英岩化蚀变岩带和强钾长石化蚀变岩带作为取样目标,进行区域对比;(2)该两类岩石中的蚀变矿物受到脆性断裂影响较小,能够得到蚀变阶段的稳定化学成分;(3)该两类岩石中的蚀变矿物发育有与蚀变同期的韧性变形,能够揭示蚀变阶段的构造应力应变状态。对样品中的钾长石和斜长石颗粒进行K-Ar法同位素年龄测试,获得蚀变岩同位素年龄数据。测试结果显示,胶东区域构造热液蚀变作用时期为(148.3±4.3)^(52.03±0.70)Ma,即早白垩世燕山晚期;同位素年龄自西向东逐渐变小,证明胶东西部地区的热液蚀变作用早于东部地区。通过分析已有的构造、热液成分和成矿物理化学参数等资料,结合本研究的最新成果,总结出区域成矿时代与成矿规律:胶东区域断裂蚀变系统中的构造附加静水压力、流体温度压力条件和成矿元素的分布与变化控制了热液蚀变成矿规律。上述地质特征显示,胶东金矿床是复成构造热液作用下的一种新型矿床类型。

关键词：胶东金矿 K-Ar同位素年龄黄铁绢英质蚀变岩带钾长石化蚀变岩带复成构造热液作用

Designing sgRNAs for CRISPR-BEST base editing applications with CRISPyweb 2.0

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Synthetic and Systems Biotechnology 2020年第2期5卷 99-102页

作者： Kai Blin Simon shaw Yaoj.n Tong Tilmann Weber The Novo Nordisk Foundation Center for Biosustainability Technical University of DenmarkKgs.LyngbyDenmark

CRISPR/Cas9 systems are an established tool in genome *** double strand breaks caused by the standard Cas9-based knock-out techniques can be problematic in some organisms,new systems were developed that can efficiently create knock-outs without causing double strand breaks to elegantly sidestep these *** recently published CRISPR-BEST base editor system for actinobacteria is built around a C to T or A to G base *** base editing systems however require additional constraints to be considered for designing the ***,we present an updated version of the interactive CRISPy-web single guide RNA design tool https://***/that was built to support“classical”CRISPR and now also CRISPRBEST workflows.

关键词： CRISPR Base editor sgRNA Webserver CRISPR-BEST Genome editing