检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

高性能云审计及其应用

国外科技新书评介 2015年第3期 18-18页

作者： Keesook j. hart 张进兴不详中国科学院空间科学与应用研究中心

近几年，云计算正在革命性地改变着技术的所有方面，为用户提供较佳的可扩展性与灵活性和更高的成本效益。用多级别安全服务器联合保证以支持跨领域服务的云计算安全已经成为了当前的主要挑战。为了保证云服务与云资源的安全，云审计技... 详细信息

近几年，云计算正在革命性地改变着技术的所有方面，为用户提供较佳的可扩展性与灵活性和更高的成本效益。用多级别安全服务器联合保证以支持跨领域服务的云计算安全已经成为了当前的主要挑战。为了保证云服务与云资源的安全，云审计技术与快速响应任务机制应运而生，它将满足服务级别需求，如：可用性水平、适用性、安全性、性能等。本书旨在通过集中介绍云安全、云审计及高性能计算相关技术与研究，为建立云计算标准提供参考，并向读者展示一个较为完整与详实的云计算知识。

关键词：审计技术性能计算安全服务器计算安全应用成本效益可扩展性任务机制

Post-ablation surveillance in Barrett's esophagus: A review of the literature

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World journal of Gastroenterology 2016年第17期22卷 4297-4306页

作者： Matthew W Stier Vani j Konda john hart Irving Waxman Department of Internal Medicine The University of Chicago Medicine Division of Gastroenterology Department of Medicine The University of Chicago Medicine Department of Pathology The University of Chicago Medicine

Barrett’s esophagus (BE) is a pre-malignant condition affecting up to 15% of patients with gastroesophageal reflux disease. Neoplastic Barrett’s mucosa is defined as harboring high grade dysplasia or intra-mucosal cancer, and carries a high risk of progression to esophageal adenocarcinoma. The rising incidence of Barrett’s lesions along with the high morbidity of surgical approaches has led to the development of numerous validated endoscopic techniques capable of eradicating neoplastic mucosa in a minimally invasive manner. While there has been widespread adoption of these techniques, less is known about optimal surveillance intervals in the post-therapy period. This is due in part to limitations in current surveillance methods, questions about durability of treatment response and the risk of subendothelial progression. As we are now able to achieve organ sparing eradication of superficial neoplasia in BE, we need to also then focus our attention on how best to manage these patients after eradication is achieved. Implementing optimal surveillance practices requires additional understanding of the biology of the disease, appreciation of the limits of current tools and treatments, and exploration of the role of adjunctive technologies. The aim of this article is to provide a comprehensive review of current literature surrounding post-ablation surveillance in neoplastic BE.

关键词： Barrett’ s esophagus Endotherapy Post-ablation surveillance Neoplastic Radiofrequency ablation Endoscopic mucosal resection

Quantitative study on pollen-based reconstructions of vegetation history from central Canada

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2008年第8期51卷 1081-1088页

作者： hart Catherina VETTER Mary SAUCHYN David Department of Biology University of ReginaS4S 0A2Canada Prairie Adaptation Research Collaborative SK S4S 7J7Canada Department of GeographyUniversity of ReginaS4S 0A2Canada

Based on high-resolution pollen records from lake cores in central Canada, the present study instructed pollen taxa assignations in ecosystem groups and modern analogue technique, reported major results of quantitativ... 详细信息

关键词： sedimentary pollen surface pollen modern analogue technique ecosystem paleovegetation past 1000 years

Multi-scale drivers of soil resistance predict vulnerability of seasonally wet meadows to trampling by pack stock animals in the Sierra Nevada,USA

在线全文

学校读者我要写书评

暂无评论

Ecological Processes 2020年第1期9卷 364-377页

作者： joy S.Baccei Mitchel P.McClaran Tim j.Kuhn Stephen C.hart Environmental Systems Graduate Group University of CaliforniaMercedCA 95343USA UC Merced Vernal Pools and Grassland Reserve UC Merced Natural Reserve SystemMercedCA 95343USA School of Natural Resources and the Environment University of ArizonaTucsonAZ 85721USA Resources Management and Science Yosemite National ParkEl PortalCA 95318USA Department of Life&Environmental Sciences and Sierra Nevada Research Institute University of CaliforniaMercedCA 95343USA.

Background:Meadow ecosystems have important ecological functions and support socioeconomic services,yet are subject to multiple stressors that can lead to rapid *** the Sierra Nevada of the western USA,recreational pack stock(horses and mules)use in seasonally wet mountain meadows may lead to soil trampling and meadow degradation,especially when soil water content is high and vegetation is ***:In order to improve the ability to predict meadow vulnerability to soil disturbance from pack stock use,we measured soil resistance(SR),which is an index of vulnerability to trampling disturbance,at two spatial scales using a stratified-random sampling *** then compared SR to several soil and vegetation explanatory variables that were also measured at the two spatial scales:plant community type(local scale)and topographic gradient class(meadow scale).Results:We found that local-scale differences in drivers of SR were contingent on the meadow scale,which is important because multiple spatial scale evaluation of ecological metrics provides a broader understanding of the potential controls on ecological processes than assessments conducted at a single spatial *** also found two contrasting explanatory models for drivers of SR at the local scale:(1)soil gravimetric water content effects on soil disaggregation and(2)soil bulk density and root mass influence on soil *** resistance was insufficient to sustain pack stock use without incurring soil deformation in wet plant communities,even when plant cover was maximal during a major ***:Our study provides new information on seasonally wet meadow vulnerability to trampling by pack stock animals using multi-scale drivers of SR,including the contrasting roles of soil disaggregation,friction,and *** work aims to inform meadow management efforts in the Sierra Nevada and herbaceous ecosystems in similar regions that are subject to seasonal soil saturation and livestock u

关键词： Hydrogeomorphic classification Hydrologic regime Pack stock Plant communities Soil properties Soil strength

A General Algorithm for Calculating Irreducible Brillouin Zones

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Computational Physics 2022年第2期31卷 495-515页

作者： jeremy j.jorgensen john E.Christensen Tyler j.jarvis Gus L.W.hart Department of Physics and Astronomy Brigham Young UniversityProvoUtah84602USA Department ofMathematics BrighamYoungUniversityProvoUtah84602USA

Calculations of properties of materials require performing numerical integrals over the Brillouin zone(BZ).Integration points in density functional theory codes are uniformly spread over the BZ(despite integration error being concentrated in small regions of the BZ)and preserve symmetry to improve computational *** points over an irreducible Brillouin zone(IBZ),a rotationally distinct region of the BZ,do not have to preserve crystal symmetry for greater *** freedom allows the use of adaptive meshes with higher concentrations of points at locations of large error,resulting in improved algorithmic *** have created an algorithm for constructing an IBZ of any crystal structure in 2D and *** algorithmuses convex hull and half-space representations for the BZ and IBZ to make many aspects of construction and symmetry reduction of the BZ *** algorithm is simple,general,and available as open-source software.

关键词： Brillouin zone irreducible Brillouin zone

海湾战争退伍军人的海马功能障碍:毒扁豆碱激发动脉自旋标记MR灌注成像的诊断价值

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

国际医学放射学杂志 2011年第6期 592-592页

作者： j.S.Spence D.M.Buhner j.hart C.M.Cullum M.M.Biggs 孙美丽 Departments of Radiology Division of NeuroradiologyInternal MedicineUniversity of Texas Southwestern Medical Center5323 Harry Hines BlvdDallasTX 75390-8874

目的利用动脉自旋标记(ASL)MR灌注成像和毒扁豆碱激发实验探讨海湾战争退伍军人病人的海马是否存在血流灌注异常。此次检查距他们进行首次单光子发射计算机体层摄影(SPECT)检查11年,距1991年海湾战争20年。材料与方法本研究经伦理委员... 详细信息

目的利用动脉自旋标记(ASL)MR灌注成像和毒扁豆碱激发实验探讨海湾战争退伍军人病人的海马是否存在血流灌注异常。此次检查距他们进行首次单光子发射计算机体层摄影(SPECT)检查11年,距1991年海湾战争20年。材料与方法本研究经伦理委员会批准,遵从HIPAA(有禁忌

关键词：自旋标记海马边缘系统灌注成像 MR 海湾战争动脉退伍军人

Physical Characteristics Explain Ball-Carrying Capability in Sub-Elite Rugby Union Players

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

journal of Science in Sport and Exercise 2023年第3期5卷 244-253页

作者： Alexander S.hart Robert M.Erskine Tom j.Mclaughlin David R.Clark School of Sport and Exercise Science Liverpool John Moores UniversityL33AF LiverpoolUK Ealing Trailfinders Rugby Club LondonUK Institute of Sport Exercise and HealthUniversity College LondonLondonUK

Purpose The aims of the present study were two-fold:(i)to investigate the relationship between physical characteristics and the game statistics associated with ball-carrying capability amongst sub-elite rugby union players,and(ii)to predict the level of change in these physical characteristics required to improve the associated game statistic via regression *** Thirty-eight senior professional players(forwards,n=22;backs,n=16)were assessed for body mass(BM),back squat(BS)single-repetition maximum(1RM)normalised to BM(1RM/BM),10 m sprint velocity(S10),10 m sprint momentum(SM10),and the game statistics from 22 games within the 2019/20 RFU Championship *** relationship between these measures and the predicted level of change in a physical measure required to improve the total number of the associated game statistic by one were assessed by Pearson’s correlation coefficient and simple regression *** In forwards,an~11.5%reduction in BM,an~11.8%improvement in BS 1RM/BM,or an~11.5%increase in S10 was required to improve the game statistics associated with ball-carrying *** backs,a~19.3%increase in BM or a~15.6%improvement in SM10 was *** These findings demonstrate that improvements in lower-body relative strength,acceleration performance,and position-specific alterations in body mass are required to maximise the ball-carrying capability and therefore match outcome of sub-elite rugby union players.

关键词： Speed Acceleration Momentum Strength Body mass

High-throughput quantification of microbial birth and death dynamics using fluorescence microscopy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Electrical and Electronic Engineering in China 2019年第1期7卷 69-81页

作者： Samuel F. M. hart David Skelding Adam j. Waite justin C. Burton Wenying Shou Fred Hutchinson Cancer Research Center SeattleWA 98109USA

Background: Microbes live in dynamic environments where nutrient concentrations fluctuate. Quantifying fitness in terms of birth rate and death rate in a wide range of environments is critical for understanding microbial evolution and ecology. Methods^ Here, using high-throughput time-lapse microscopy, we have quantified how Saccharomyces cerevisiae mutants incapable of synthesizing an essential metabolite (auxotrophs) grow or die in various concentrations of the required metabolite. We establish that cells normally expressing fluorescent proteins lose fluorescence upon death and that the total fluorescence in an imaging frame is proportional to the number of live cells even when cells form multiple layers. We validate our microscopy approach of measuring birth and death rates using flow cytometry, cell counting, and chemostat culturing. Results: For lysine-requiring cells, very low concentrations of lysine are not detectably consumed and do not support cell birth, but delay the onset of death phase and reduce the death rate compared to no lysine. In contrast, in low hypoxanthine, hypoxanthine-requiring cells can produce new cells, yet also die faster than in the absence of hypoxanthine. For both strains, birth rates under various metabolite concentrations are better described by the sigmoidal-shaped Moser model than the well-known Monod model, while death rates can vary with metabolite concentration and time. Conclusions: Our work reveals how time-lapse microscopy can be used to discover non-intuitive microbial birth and death dynamics and to quantify growth rates in many environments.

关键词： Saccharomyces cerevisiae fluorescence microscopy microbial growth birth rate death rate

Comparison of five video-assisted intubation devices by novice and expert laryngoscopists for use in the aeromedical evacuation environment

在线全文

学校读者我要写书评

暂无评论

Military Medical Research 2017年第2期4卷 61-69页

作者： Matthew C.Wallace SSgt Tyler Britton Robbie Meek Sharon Walsh-hart Col Todd E.Carter Steven j.Lisco University of Cincinnati Medical Center Department of Anesthesiology

Background: The critically ill or injured patient undergoing military medical evacuation may require emergent intubation. Intubation may be life-saving, but it carries *** novice or infrequent laryngoscopist has a distinct disadvantage because experience is critical for the rapid and safe establishment of a secured airway. This challenge is compounded by the austere environment of the back of an aircraft under blackout conditions. This study determined which of five different video-assisted intubation devices(VAIDs) was best suited for in-flight use by U.S. Air Force Critical Care Air Transport Teams by comparing time to successful intubation between novice and expert laryngoscopists under three conditions, Normal Airway Lights on(NAL), Difficult Airway Lights on(DAL) and Difficult Airway Blackout(DAB), using manikins on a standard military transport stanchion and the floor with a minimal amount of setup time and extraneous light ***: A convenience sample size of 40 participants(24 novices and 16 experts) attempted intubation with each of the 5 different video laryngoscopic devices on high-fidelity airway manikins. Time to tracheal intubation and number of optimization maneuvers used were recorded. Kruskal-Wallis testing determined significant differences between the VAIDs in time to intubation for each particular scenario. Devices with significant differences underwent pair-wise comparison testing using rank-sum analysis to further clarify the difference. Device assembly times, startup times and the amount of light emitted were recorded. Perceived ease of use was surveyed. Results: Novices were fastest with the Pentax AWS in all difficult airway scenarios. Experts recorded the shortest median times consistently using 3 of the 5 devices. The AWS was superior overall in 4 of the 6 scenarios tested. Experts and novices subjectively judged the Glide Scope Ranger as easiest to use. The light emitted by all the devices was less than the USAF-issued hea

关键词： simulation difficult airway novice expert military video laryngoscopy light emission