检索结果-南通市图书馆

Multi-stream join answering for mining significant cross-stream correlations

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2012年第2期6卷 131-142页

作者： robert GWADErA IBM Zurich research Laboratory Säumerstrasse 4CH-8803 RüschlikonSwitzerland

Sliding-window multi-stream join （SWMJ） is a fundamental operation for correlating information from dif- ferent streams. We provide a solution to the problem of as- sessing significance of the SWMJ result by focusing on the relative frequency of windows satisfying a given equijoin predicate as the most important parameter of the SWMJ re- suit. In particular, we derive a formula for computing the expected relative frequency of windows satisfying a given equijoin predicate that can be. evaluated in quadratic time in the window size given a proposed probabilistic model of the multi-stream. In experiments conducted on a daily rain- fall data set we demonstrate the remarkable accuracy of our method, which confirms our theoretical analysis.

关键词： probabilistic data streams stream summariza-tion stream sketch window aggregate queries

POLY (β-HYDrOXYALKANOATES): NATUrAL BIOCOMPATIBLE AND BIODEGrADABLE POLYESTErS PrODUCED BY BACTErIA

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 1989年第4期7卷 289-298页

作者： robert W. LENZ rICHArD A. GrOSS HELMUT BrANDL r. CLINTON FULLEr Department of Polymer Science and Engineering University of MassachusettsAmherstMA 01003USADepartment of ChemistryUniversity of Lowell1 University Ave.LowellMA 01854USAInstitute for Plant BiologyZollikerstrasse 1078008 ZurichSwitzerlandDepartment of BiochemistryUniversity of MassachusettsAmherstMA 01003USA

A wide variety of different types of microorganisms are known to produce intracellular energy and carbon storage products, which have been generally described as being poly (β-hydroxybutyrate), PHB, but which are, more often than not, copolymers containing different alkyl groups at the β-position. Hence, PHB belongs to the family ofpoly (β-hydroxyalkanoastes), PHA, all of which are usually formed as intracellular inclusions in bacteria under unbalanced growth conditions. recently, it became of industrial interest to evaluate these PHA polyesters as natural biodegradable and biocompatible plastics for a wide range of possible applications, such as surgical sutures or packaging containers. For industrial applications, the controlled incorporation of repeating units with different chain lengths into a series of copolymers is desirable in order to produce polyesters with a range of material properties because physical and chemical characteristics depend strongly on the polymer composition. Such 'tailor-made' copolymers can be produced under controlled growth conditions in that, if a defined mixture of substrates for a certain type of microorganisms is supplied, a well defined and reproducible copolymer is formed.

关键词： PHB POLY HYDrOXYALKANOATES NATUrAL BIOCOMPATIBLE AND BIODEGrADABLE POLYESTErS PrODUCED BY BACTErIA

Impact of exome sequencing in inflammatory bowel disease

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2013年第40期19卷 6721-6729页

作者： Christopher J Cardinale Judith r Kelsen robert N Baldassano Hakon Hakonarson Center for Applied Genomics Children’s Hospital of PhiladelphiaAbramson Research Center Suite 1216PhiladelphiaPA 19104United States Division of Gastroenterology Hepatologyand NutritionDepartment of PediatricsChildren’s Hospital of PhiladelphiaPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPA 19104United States

Approaches to understanding the genetic contribution to inflammatory bowel disease(IBD)have continuously evolved from family-and population-based epidemiology,to linkage analysis,and most recently,to genome-wide association studies(GWAS).The next stage in this evolution seems to be the sequencing of the exome,that is,the regions of the human genome which encode *** GWAS approach has been very fruitful in identifying at least 163 loci as being associated with IBD,and now,exome sequencing promises to take our genetic understanding to the next *** this review we will discuss the possible contributions that can be made by an exome sequencing approach both at the individual patient level to aid with disease diagnosis and future therapies,as well as in advancing knowledge of the pathogenesis of IBD.

关键词： Sequencing Exome Genetics Inflammatory bowel disease

Visualization of atomic scale reaction dynamics of supported nanocatalysts during oxidation and ammonia synthesis using in-situ environmental(scanning) transmission electron 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

Journal of Energy Chemistry 2021年第6期30卷 281-290,I0007页

作者： Michael r.Ward robert W.Mitchell Edward D.Boyes Pratibha L.Gai The York Nanocentre University of YorkYork YO105DDUK Department of Physics University of YorkYork YO105DDUK Department of Electronic Engineering University of YorkYork YO105DDUK Department of Chemistry University of YorkYork YO105DDUK

reaction dynamics in gases at operating temperatures at the atomic level are the basis of heterogeneous gas-solid catalyst reactions and are crucial to the catalyst *** noble metal nanocatalysts such as platinum are of interest in fuel cells and as diesel oxidation catalysts for pollution control,and practical ruthenium nanocatalysts are explored for ammonia *** and graphitic carbons are of interest as supports for the *** considerable literature on the catalytic processes on graphite and graphitic supports,reaction dynamics of the nanocatalysts on the supports in different reactive gas environments and operating temperatures at the single atom level are not well *** we present real time in-situ observations and analyses of reaction dynamics of Pt in oxidation,and practical ru nanocatalysts in ammonia synthesis,on graphite and related supports under controlled reaction environments using a novel in-situ environmental(scanning) transmission electron microscope with single atom *** recording snapshots of the reaction dynamics,the behaviour of the catalysts is *** images reveal single metal atoms,clusters of a few atoms on the graphitic supports and the support *** all play key roles in the mobility,sintering and growth of the *** experimental findings provide new structural insights into atomic scale reaction dynamics,morphology and stability of the nanocatalysts.

关键词： In-situ visualization Atomic scale reaction dynamics In-situ environmental scanning transmission electron microscopy with single atom resolution Supported nanoparticles Ammonia synthesis Oxidation reactions

Quo vadis carbocatalysis?

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2021年第10期30卷 219-227,I0007页

作者： robert Schlögl Max-Planck-Institut für Chemische Energiekonversion Stiftstr.34-3645470 Mülheim an der RuhrGermany Fritz-Haber Institut der Max-Planck-Gesellschaft Faradayweg 4-614195 BerlinGermany

Prologue The rich scientific heritage of Dangsheng Su contains as substantial fraction his contributions to the field of catalysis with nanostructured carbon *** from microstructural analysis it became quickly clear that the richness of morphological and hence surface electronic variations in this class of materials should be suitable for the development of a science base for heterogeneous catalysis.

关键词： materials. catalysis. catalysis

Digital imaging approaches for phenotyping whole plant nitrogen and phosphorus response in Brachypodium distachyon

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2014年第8期56卷 781-796页

作者： richard Poiré Vincent Chochois Xavier r.r.Sirault John P.Vogel Michelle Watt robert T.Furbank CSIrO Plant Industry High resolution Plant Phenomics Centre CSIRO Plant Industry USDA-ArS Western regional research Center

This work evaluates the phenotypic response of the model grass （Brachypodium distacbyon （L.） P. Beauv.） to nitrogen and phosphorus nutrition using a combination of imaging techniques and destructive harvest of shoots and roots. reference line Bd21-3 was grown in pots using 11 phosphorus and 11 nitrogen concentrations to establish a dose-response curve. Shoot biovolume and biomass, root length and biomass, and tissue phosphorus and nitrogen concentrations increased with nutrient concentration. Shoot biovolume, estimated by imaging, was highly correlated with dry weight （r2 〉 0.92） and both biovolume and growth rate responded strongly to nutrient availability. Higher nutrient supply increased nodal root length more than other root types. Photochemical efficiency was strongly reduced by low phosphorus concentrations as early as 1 week after germination, suggesting that this measurement may be suitable for high throughput screening of phosphorus response. In contrast, nitrogen concentration had little effect on photochemical efficiency. Changes in biovolume over time were used to compare growth rates of four accessions in response tonitrogen and phosphorus supply. We demonstrate that a time series image-based approach coupled with mathematical modeling provides higher resolution of genotypic response to nutrient supply than traditional destructive techniques and shows promise for high throughput screening and determina- tion of genomic regions associated with superior nutrient use efficiency.

关键词： Nutrients uptake phenomics photosynthesis root shootCitation: Poire r, Chochois V, Sirault Xrr, Vogel JP, Watt M, Furbank rT(2o14) Digital imaging approaches for phenotyping whole plantnitrogen and phosphorus response in Brachypodium distachyon.

Full noncontact laser ultrasound:first human data

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2019年第1期8卷 11-21页

作者： Xiang Zhang Jonathan r.Fincke Charles M.Wynn Matt r.Johnson robert W.Haupt Brian W.Anthony Department of Mechanical Engineering Massachusetts Institute of Technology77 Massachusetts Ave.CambridgeMA 02139USA Institute for Medical Engineering&Science Massachusetts Institute of Technology45 Carleton St.CambridgeMA 02142USA Lincoln Laboratory Massachusetts Institute of Technology244 Wood StreetLexingtonMA 02421USA

Full noncontact laser ultrasound(LUS)imaging has several distinct advantages over current medical ultrasound(US)technologies:elimination of the coupling mediums(gel/water),operator-independent image quality,improved repeatability,and volumetric *** light-based ultrasound utilizing tissue-penetrating photoacoustics(PA)generally uses traditional piezoelectric transducers in contact with the imaged tissue or carries an optical fiber detector close to the imaging *** PA,the LUS design presented here minimizes the optical penetration and specifically restricts optical-to-acoustic energy transduction at the tissue surface,maximizing the generated acoustic source *** an appropriate optical design and interferometry,any exposed tissue surfaces can become viable acoustic sources and *** operates analogously to conventional ultrasound but uses light instead of piezoelectric ***,we present full noncontact LUS results,imaging targets at~5 cm depths and at a meterscale standoff from the target *** results demonstrating volumetric imaging and the first LUS images on humans are presented,all at eye-and skin-safe optical exposure *** progression of LUS imaging from tissue-mimicking phantoms,to excised animal tissue,to humans in vivo is shown,with validation from conventional ultrasound *** LUS system design insights and results presented here inspire further LUS development and are a significant step toward the clinical implementation of LUS.

关键词： laser piezoelectric image

Identification and Analysis of Genetic Diversity Structure Within Pisum Genus Based on Microsatellite Markers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2009年第3期8卷 257-267页

作者： ZONG Xu-xiao rebecca Ford robert r redden GUAN Jian-ping WANG Shu-min Institute of Crop Sciences/National Key Facility for Crop Gene resources and Genetic Improvement Chinese Academy of Agricultural Sciences Beijing 100081 P.R. China BioMarka Faculty of Land and Food Resources University of Melbourne Melbourne 3010 Australia Australian Temperate Field Crops Collection Grains Innovation Park Department of Primary Industries Private Bag 260 Horsham 3401 Australia

To assesse the genetic diversity among wild and cultivated accessions of 8 taxonomic groups in 2 species, and 5 subspecies under Pisum genus, and to analyze population structure and their genetic relationships among various groups of taxonomy, the study tried to verify the fitness of traditionally botanical taxonomic system under Pisum genus and to provide essential information for the exploration and utilization of wild relatives of pea genetic resources. 197 Pisum accessions from 62 counties of 5 continents were employed for SSr analysis using 21 polymorphic primer pairs in this study. Except for cultivated field pea Pisum sativum ssp. sativum var. sativum （94 genotypes）, also included were wild relative genotypes that were classified as belonging to P. fulvum, P. sativum ***, P. sativum ssp. asiaticum, P. sativum ssp. transcaucasicum, P. sativum ssp. elatius var. elatius, P. sativum ssp. elatius var. pumilio and P. sativum ssp. sativum var. arvense （103 genotypes）. The PCA analyses and 3-dimension PCA graphs were conducted and drawn by NTSYSpc 2.2d statistical package. Nei78 genetic distances among groups of genetic resources were calculated, and cluster analysis using UPGMA method was carried out by using Popgene V1.32 statistical package, the dendrogram was drawn by MEGA3.1 statistical package. Allelic statistics were carried out by Popgene V1.32. The significance test between groups of genotypes was carried out by Fstat V2.***.3.2 statistical package. 104 polymorphic bands were amplified using 21 SSr primer pairs with unambiguous unique polymorphic bands. 4.95 alleles were detected by each SSr primer pair in average, of which 65.56% were effective alleles for diversity. PSAD270, PSAC58, PSAA18, PSAC75, PSAA175 and PSAB72 were the most effective SSr pairs. SSr alleles were uniformly distributed among botanical taxon units under Pisum genus, but significant difference appeared in most pairwise comparisons for genetic diversity between taxon unit based

关键词： Pisum genus SSr genetic diversity botanical taxonomy gene pool

Serum vitamin D content is associated with semen|parameters and serum testosterone levels in men

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2021年第1期23卷 52-58页

作者： Inari M Ciccone Elaine MF Costa Juliana r Pariz Thiago A Teixeira Joel r Drevet Parviz Gharagozloo robert J Aitken Jorge Hallak Androscience Science and Innovation Center in Andrology and High-Complex Clinical and Andrology LaboratorySao Paulo 04534-011Brazil Division of Urology University of Sao PauloSao Paulo 05403-000Brazil Men's Health Study Group Institute for Advanced StudiesUniversity of Sao PauloSao Paulo 05508-060Brazil Division of Endocrinology University of Sao PauloSao Paulo 05403-000Brazil School of Medicine Urology DepartmentFederal University of AmapaMacapa 68903-419Brazil Faculty of Medicine GReD LaboratoryUniversity Clermont Auvergne49Bd Frangois-Mitterrand-CS 6003263001 Clermont-Ferrand CedexFrance Cell0xess LLC EwingNJ 08628USA School of Environmental and Life Sciences Priority Research Centre for Reproductive SciencesUniversity of NewcastleCallaghanNSW 2308Australia reproductive Toxicology Unit Department of PathologyUniversity of Sao PauloSao Paulo 05403-000Brazil

The present study aimed to evaluate the influence of serum vitamin D levels on semen quality and testosterone *** is a crosssectional study conducted at Androscience,Science and Innovation Center in Andrology and High-Complex Clinical and Andrology Laboratory in Sao Paulo,Brazil,with 508 male patients,aged 18-60 years,from 2007 to *** parameters and serum sexual hormones were correlated with serum vitamin D concentrations in 260 men selected by strict selection *** were divided into normozoospermic group(NZG,n=124)and a group with seminal abnormalities(SAG,n=136).Evaluation included complete physical examination,past medical history,habits and lifestyle factors,two complete seminal analysis with sperm functional tests,serum levels of 25-hydroxy-vitamin D_(3)(25(OH)VD_(3)),total and free testosterone,luteinizing hormone(LH),follicle-stimulating hormone(FSH),sex hormone-binding globulin(SHBG),total cholesterol,homeostatic model assessment of insulin resistance(HOMA-Ir)index,and *** mean concentration of 25(OH)VD_(3)was significantly lower in the SAG(Prrelated with all baseline seminal parameters and total testosterone *** addition,serum vitamin D_(3)concentration was found to be positively correlated with sperm concentration(β=2.103;Pr of spermatozoa with progressive motility(β=2.069;P=0.003),total number of motile spermatozoa(β=2.571;P=0.015),and strict morphology(β=0.056;P=0.006),regardless of other *** is the first comparative study to address the issue of serum vitamin D_(3)content between normozoospermic patients and those with sperm *** clearly demonstrates a direct and positive relationship between serum vitamin D level and overall semen quality,male reproductive potential,and testosterone levels.

关键词： male infertility semen quality sexual hormones sperm motility testosterone vitamin D deficiency