检索结果-南通市图书馆

Early onset of a microcystin-producing cyanobacterial bloom in an agriculturally-influenced Great Lakes tributary

Journal of Oceanology and Limnology 2018年第4期36卷 1112-1125页

作者： Robert Michael L.McKAY Taylor TUTTLE Laura A.REITZ George S.BULLERJAHN william R.CODY Adam J.McDOwELL Timothy w.davis Department of Biological Sciences Bowling Green State University Bowling Green OH 43403 USA Aquatic Taxonomy Specialists Malinta OH 43535 USA City of Defiance Water Division Defiance OH 43512 USA NOAA Great Lakes Environmental Research Laboratory Ann Arbor MI USA

In late May 2016, a cyanobacterial harmful algal bloom(cHAB) was detected in the Maumee River, the largest tributary to Lake Erie, the southernmost lake of the Laurentian Great Lakes system. Testing on 31 May identified Planktothrix agardhii as the dominant cyanobacterium with cell abundance exceeding 1.7×10~9 cells/L and total microcystins(MC) reaching 19 μg/L MC-LR equivalents, a level over 10-fold higher than the 2015 revised U.S. Environmental Protection Agency(EPA) national health advisory levels for drinking water exposure to adults. Low river discharge coincident with negligible precipitation through the latter half of May coincided with an 80% decline in river turbidity that likely favored bloom formation by a low-light adapted P. agardhii population. Also contributing to the c HAB were high initial nutrient loads and an increase of the river temperature from 13℃ to 26℃ over this same period. The bloom persisted through 5 June with microcystins exceeding 22 μg/L MC-LR equivalents at the bloom peak. By 6 June, the river had returned to its muddy character following a rain event and sampling on 7 June detected only low levels of toxin(water systems located near the bloom origin. The elevated toxin production associated with this early onset bloom was without precedent for the Maumee River and an unique attribute of the c HAB was the high proportion of potentially-toxic genotypes. whereas Planktothrix spp. is common in lotic environments, and has been previously detected in the Maumee, blooms are not commonly reported. This early onset, microcystin-producing c HAB provided a rare opportunity to glean insights into environmental factors that promote bloom development and dominance by Planktothrix in lotic environments.

关键词： cyanobacteria microcystin Planktothrix qPCR river

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dog10K: an international sequencing effort to advance studies of canine domestication, phenotypes and health

引用

National Science Review 2019年第4期6卷 810-824页

作者： Elaine A.Ostrander Guo-Dong wang Greger Larson Bridgett M.von Holdt Brian w.davis Vidhya Jagannathan Christophe Hitte Robert K.wayne Ya-Ping Zhang National Human Genome Research Institute National Institutes of Health State Key Laboratory of Genetic Resources and Evolution Kunming Institute of Zoology Chinese Academy of Sciences Center for Excellence in Animal Evolution and Genetics Chinese Academy of Sciences Palaeogenomics and Bio-Archaeology Research Network School of Archaeology University of Oxford Department of Ecology and Evolutionary Biology Princeton University College of Veterinary Medicine and Biomedical Sciences Texas A&M University Institute of Genetics Vetsuisse Faculty University of Bern IGDR CNRS University of Rennes Department of Ecology and Evolutionary Biology University of CaliforniaLos Angeles the Dog10K Consortium

Dogs are the most phenotypically diverse mammalian species, and they possess more known heritable disorders than any other non-human mammal. Efforts to catalog and characterize genetic variation across well-chosen populations of canines are necessary to advance our understanding of their evolutionary history and genetic architecture. To date, no organized effort has been undertaken to sequence the world's canid populations. The Dog10 K Consortium(http://***10 ***) is an international collaboration of researchers from across the globe who will generate 20× whole genomes from 10 000 canids in 5 *** effort will capture the genetic diversity that underlies the phenotypic and geographical variability of modern canids worldwide. Breeds, village dogs, niche populations and extended pedigrees are currently being sequenced, and de novo assemblies of multiple canids are being constructed. This unprecedented dataset will address the genetic underpinnings of domestication, breed formation, aging, behavior and morphological variation. More generally, this effort will advance our understanding of human and canine health.

关键词： genomics genome-wide association studies(GwAS) breed selection variation evolution

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

提高输出电压的自耦变压器

引用

电子产品世界 1995年第7期 96-98页

作者： Dans w.davis,方 Maxim Integrated Products公司

利用小输入电压工作的升压直流-直流转换器,其最大击穿电压相应地只有5～6V。这就限制了这种器件可使用的最大输出电压。但是,只要加上一个自耦变压器,输出电压V_out就可增加一倍而不会超过该IC的击穿电压。

关键词：自耦变压器电力变压器输出电压单电池

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

AM500型采煤机维修的计算机应用

引用

煤矿自动化 1993年第4期 53-55页

作者： w.davis 忻元恺安德逊长壁公司服务部

AM500型采煤机我国曾从英国引进,使用效果良好。后由太原矿山机器厂引进技术并批量生产,希望本文能对该设备的维修提供有用的信息。

关键词：采煤机维修计算机应用

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Evolving technologies for growing,imaging and analyzing 3D root system architecture of crop plants

引用

Journal of Integrative Plant Biology 2016年第3期58卷 230-241页

作者： Miguel A.Pieros Brandon G.Larson Jon E.Shaff David J.Schneider Alexandre Xavier Falcao Lixing Yuan Randy T.Clark Eric J.Craft Tyler w.davis Pierre-Luc Pradier Nathanael M.Shaw Ithipong Assaranurak Susan R.Mc Couch Craig Sturrock Malcolm Bennett Leon V.Kochian USDA-ARS Robert Holley Center for Agriculture and Health538 Tower RoadIthacaNY 14580USA Department of Information Systems Institute of ComputingUniversity of CampinasAv.Albert Einstein1251CEP 13083-852CampinasSPBrazil Department of Plant Nutrition China Agricultural UniversityBeijing 100193China Department of Plant Breeding and Genetics Cornell UniversityIthacaNY 14853USA Centre for Plant Integrative Biology School of BiosciencesUniversity of NottinghamSutton BoningtonLE12 5RDUK College of Science King Saud UniversityRiyadh 11451Kingdom of Saudi Arabia

A plant＇s ability to maintain or improve its yield under limiting conditions,such as nutrient de ficiency or drought,can be strongly in fluenced by root system architecture（RSA）,the three-dimensional distribution of the different root types in the soil. The ability to image,track and quantify these root system attributes in a dynamic fashion is a useful tool in assessing desirable genetic and physiological root traits. Recent advances in imaging technology and phenotyping software have resulted in substantive progress in describing and quantifying RSA. we have designed a hydroponic growth system which retains the three-dimensional RSA of the plant root system,while allowing for aeration,solution replenishment and the imposition of nutrient treatments,as well as high-quality imaging of the root system. The simplicity and flexibility of the system allows for modi fications tailored to the RSA of different crop species and improved throughput. This paper details the recent improvements and innovations in our root growth and imaging system which allows for greater image sensitivity（detection of fine roots and other root details）,higher ef ficiency,and a broad array of growing conditions for plants that more closely mimic those found under field conditions.

关键词： Abiotic stress digital root phenotyping mineral nutrition root system architecture

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Packaging and Performance of 980nm Broad Area Semiconductor Lasers

引用

电子与封装 2006年第3期6卷 6-14页

作者： XingshengLiu LawrenceC.Hughes MichaelH.Rasmussen Martin H.Hu Venkata A Bhagavatula Ronald w.davis Sean Coleman Rajaram Bhat Chung-En Zah Science ＆ Technology Center SP-PR-02-1 Corning NY 14831 U.S.A

High power broad area semiconductor lasers have found increasing applications in pumping of solid state laser systems and fiber amplifiers, frequency doubling, medical systems and material processing. Packaging including the assembly design, process and thermal management, has a significant impact on the optical performance and reliability of a high power broad area laser. In this paper, we introduce the package structures and assembling process of 980nm broad area lasers and report the performances including output power, thermal behavior and far *** will report two types of high power broad area laser assemblies. One is a microchannel liquid cooled assembly and the other is a conduction cooled CT-mount assembly .Optical powers of 15w and 10w were achieved from a 980nm broad area laser with a 120μm stripe width in a microchannel liquid cooled assembly and conduction cooled CT-mount assembly, respectively .Furthermore, a high power of 6.5 w out of fiber was demonstrated from a pigtailed, fully packaged butterfly-type module without TEC ( Thermoelectric cooler ).The measurement results showed that thermal management is the key in not only improving output power, but also significantly improving beam divergence and far field distribution. The results also showed that the die attach solder can significant impact the reliability of high power broad area lasers and that indium solder is not suitable for high power laser applications due to electromigration at high current densities and high temperatures.

关键词：半导体激光器封装性能电迁移激光组装测试

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

扬子克拉通东南缘新元古代陆缘弧型TTG的厘定及其构造意义

引用

地质学报 2014年第8期88卷 1461-1474页

作者：姜杨赵希林林寿发 Donald w.davis 邢光福李龙明段政中国地质调查局南京地质矿产研究所南京210016 Department of Earth and Environmental Sciences University of WaterlooCanadaN2L3G1 Geological Survey of Canada OttawaOntarioK1A0E8

在扬子克拉通东南缘的江山-绍兴结合带沿线多处出露新元古代深成杂岩,以往被认为是沿扬子克拉通和华夏地块碰撞缝合带侵入的板内型深成岩类。本文选择其中的浙江金华罗店中酸性深成杂岩进行了系统的岩石学、年代学和地球化学研究,提出... 详细信息

在扬子克拉通东南缘的江山-绍兴结合带沿线多处出露新元古代深成杂岩,以往被认为是沿扬子克拉通和华夏地块碰撞缝合带侵入的板内型深成岩类。本文选择其中的浙江金华罗店中酸性深成杂岩进行了系统的岩石学、年代学和地球化学研究,提出它们属TTG岩石组合,包括英云闪长岩-奥长花岗岩-花岗闪长岩组合(T1T2G1)和二长花岗岩-花岗岩组合(G2QM)两类,普遍以明显富集Rb、Ba、K、Pb等大离子亲石元素而强烈亏损Nb、Ta、Ti、P等高场强元素为特征,δCe为弱负异常或无异常,属典型的弧岩浆岩类。T1T2G1组合富钠贫钾,εNd(t)值=+2.6^+9.4,Mg#值为41.5~63.1,推断由玄武质俯冲板片脱水部分熔融而成,并受到地幔楔橄榄岩熔体的混染。G2QM组合与T1T2G1组合地球化学特征类似,但又明显富K2O(2.75%~5.08%)、LILE和LREE,低Mg#值(27.2~52.31)和εNd(t)值(+1.7^+2.0),应是T1T2G1源区继续部分熔融的产物,可能未受到明显的地幔楔橄榄岩混染。测得花岗闪长岩(G1)锆石SHRIMP U-Pb年龄为841±10Ma,奥长花岗岩(T2)锆石LA-ICPMS U-Pb年龄为793±13Ma,前人报道之花岗岩(G2)年龄为832±44Ma,结合上述地球化学特征,说明T1T2G1和G2QM组合是由新元古代古华南洋向扬子东南缘持续俯冲形成的。综合区域地质资料及前人研究结果,提出金华罗店与诸暨璜山、绍兴平水等地的深成杂岩共同构成了扬子克拉通东南缘一条长达200km的青白口纪(930~793Ma)陆缘弧型深成杂岩带,反映迟至793Ma前仍存在强烈的洋壳俯冲,扬子克拉通尚未与华夏地块发生碰撞拼合,且T1T2G1-G2QM组合的出现指示洋壳俯冲正处于早-中期阶段。

关键词：陆缘弧型TTG岩石组合新元古代金华罗店钦杭结合带扬子克拉通东南缘

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

电缆调制解调器遥遥领先

引用

中文信息 1998年第5期 91-92页

作者： Andrew w.davis,John w.iRza,陈久强 wainhouse ConSulting Group Massachusetts Arlington Sygnus Technology 管理主任总裁

经过测试,电缆调制解调器比模拟调制解调器或ISDN提供更快的网络访问速度。

关键词：调制解调器 ISDN 电缆

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Physical and chemical processes promoting dominance of the toxic cyanobacterium Cylindrospermopsis raciborskii

引用

Chinese Journal of Oceanology and Limnology 2011年第4期29卷 883-891页

作者： Michele A. BURFORD Timothy w. davis Australian Rivers Institute Griffith University Nathan Qld. 4111 Australia

The freshwater cyanobacterium, Cylindrospermopsis raciborskii （woloszyflska） Seenayya and Subba Raju is a common species in lakes and reservoirs globally. In some areas of the world it can produce cytoand hepatotoxins （cylindrospermopsins, saxitoxins）, making blooms of this species a serious health concern for humans. In the last 10 15 years, there has been a considerable body of research conducted on the ecology, physiology and toxin production of this species and this paper reviews these studies with a focus on the cylindrospermopsin （CYN）-producing strains. C. raciborskii has low light requirements, close to neutral buoyancy, and a wide temperature tolerance, giving it the capacity to grow in many lentic waterbodies. It also has a flexible strategy with respect to nitrogen （N） utilisation; being able to switch between utilising fixed and atmospheric N as sources of N fluctuate. Additionally this species has a high phosphate （DIP） affinity and storage capacity. Like many cyanobacteria, it also has the capacity to use dissolved organic phosphorus （DOP）. Changes in nutrient concentrations, light levels and temperature have also been found to affect production of the toxin CYN by this species. However, optimal toxin production does not necessarily occur when growth rates are optimal. Additionally, different strains of C. raciborskii vary in their cell quota of CYN, making it difficult to predict toxin concentrations, based on C. raciborskii cell densities. In summary, the ecological flexibility of this organism means that controlling blooms of C. raciborskii is a difficult undertaking. However, improved understanding of factors promoting the species and toxin production by genetically capable strains will lead to improved predictive models of blooms.

关键词： cyanobacteria freshwater algal toxins nutrients light temperature

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Focal therapy for localized prostate cancer:is there a “middle ground” between active surveillance and definitive treatment?

引用

Asian Journal of Andrology 2019年第1期21卷 37-44页

作者： Cihan H Demirel Muammer Altok John w.davis Department of Urology The University of Texas MD Anderson Cancer CenterHoustonTexas 77030USA.

In recent years,it has come a long way in the diagnosis,treatment,and follow-up of prostate *** this,it was argued that definitive treatments could cause overtreatment,particularly in the very low,low,and favorable risk *** alternative treatment and follow-up methods are being considered for this group of patients,active surveillance is seen as a good alternative for patients with very low and low-risk groups in this ***,it has become necessary to find other alternatives for patients in the favorable risk group or patients who cannot adopt active *** the light of technological developments,the concept of focal therapy was introduced with the intensification of research to treat only the lesioned area instead of treating the entire organ for prostate lesions though there are not many publications about many of them *** to the initial results,it was understood that the results could be good if the appropriate focal therapy technique was applied to the appropriate ***,focal therapies have begun to find their"middle ground"place between definitive therapies and active follow-up.

关键词： focal therapy multiparametric magnetic resonance imaging prostate biopsy prostate cancer prostatic neoplasms

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：