检索结果-南通市图书馆

Current Zoology 2020年第3期66卷 219-226页

作者： Levi J.Newediuk james f.Hare Department of.Biological Sciences University of ManitobaWinnipegManitobaCanada R3T 2N2

In grassland ecosystems,burrowing mammals create disturbances,providing habitat f.r animal species and increasing plant community *** investigated whether seedling assemblages on Richardson's ground squirrel Urocitellus richardsonii mounds result f.om seed rearrangement or environmental changes that f.vor germination of.certain species over *** test whether ground squirrels rearrange the seed bank by burrowing,we compared seed compositions among mounds,burrows,and undisturbed *** test whether ground squirrels change environmental conditions,we compared soil nitrate and bare ground cover on and of. *** also compared seedlings that germinated on mounds with seedlings that germinated on artif.cial disturbances f.om which we removed aboveground *** nitrate and bare ground cover were signif.cantly higher on mounds than artif.cial *** seed richness and abundance did not dif.er among mounds,burrows,and undisturbed soil,seedling richness was reduced on mounds relative to artif.cial *** disturbance f.vors seedlings that can capitalize on bare ground availability but are less able to immobilize nitrate,as opposed to perennial species that immobilize more nitrate but take longer to *** results suggest that Richardson's ground squirrels act as ecosystem engineers,although f.ture research f.llowing succession on ground squirrel mounds is necessary to understand how they inf.uence plant communities past the seedling stage.

关键词： burrowing disturbance ecosystem engineering Richardsons ground squirrel seed bank seedling species composition

Perceptual tolerance neighborhood-based similarity in content-based image retrieval and classif.cation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of.Intelligent Computing and Cybernetics 2012年第2期5卷 164-185页

作者： Amir H.Meghdadi james f.Peters Electrical and Computer Engineering University of ManitobaWinnipegCanada School of.Mathematics University of HyderabadHyderabadIndia

Purpose–The purpose of.this paper is to demonstrate the ef.ectiveness and advantages of.using perceptual tolerance neighbourhoods in tolerance space-based image similarity measures and its application in content-based image classif.cation and ***/methodology/approach–The proposed method in this paper is based on a set-theoretic approach,where an image is viewed as a set of.local visual *** method also includes a tolerance relation that detects the similarity between pairs of.elements,if.the dif.erence between corresponding f.ature vectors is less than a threshold 2(0,1).f.ndings–It is shown that tolerance space-based methods can be successf.lly used in a complete content-based image retrieval(CBIR)***,it is shown that perceptual tolerance neighbourhoods can replace tolerance classes in CBIR,resulting in more accuracy and less ***/value–The main contribution of.this paper is the introduction of.perceptual tolerance neighbourhoods instead of.tolerance classes in a new f.rm of.the Henry-Peters tolerance-based nearness measure(tNM)and a new neighbourhood-based tolerance-covering nearness measure(tcNM).Moreover,this paper presents a side–by–side comparison of.the tolerance space based methods with other published methods on a test dataset of.images.

关键词： Image similarity Nearness measure Distance measurement Content-based image retrieval(CBIR) Perceptual tolerance neighbourhoods Tolerance spaces Tolerances Measurement

In the f.rest vine Smilax rotundif.lia,f.ngal epiphytes show site-wide spatial correlation,while endophytes show evidence of.niche partitioning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

f.ngal Diversity 2015年第6期75卷 279-297页

作者： Christopher B.Zambell james f.White Graduate Program in Ecology&Evolution Rutgers UniversityNew BrunswickNJ 08901USA Department of.Plant Biology&Pathology 59 Dudley RoadNew BrunswickNJ 08901USA

Endophytic and epiphytic f.ngal assemblages f.om stems of.***,a shrubby vine,were studied in order to(1)quantif. dif.erences and the degree of.overlap between f.ngal communities of.both micro-habitats,and(2)examine whether f.ngal assemblages are spatially correlated at the local scale(tens to hundreds of.meters),in order to understand if.dispersal limitation may play a role in structuring these *** was conducted over 160 m of.growth along a f.rest *** communities showed low overlap(Bray-Curtis Similarity=0.22),with most species that were common in one habitat appearing rarely if.at all in the other,and only Aureobasidium pullulans showing high f.equency in *** assemblages proved to be spatially correlated along the 160 m length of.the transect,and even more so when adjacent pairs of.stems were considered as the unit of.comparison rather than individual *** assemblages showed no signif.cant spatial correlation along the ***,three species of.endophytes showed a pattern in which abundance of.colonies peaked at dif.erent heights on the *** boninense showed peak abundance at 3 cm f.om the stem *** sp.1 peaked at 33 cm f.om the stem *** isolates of.*** peaked at 63 cm f.om the stem *** was also f.und that positive correlative relationships were detected between endophyte-endophyte,and epiphyte-epiphyte ***-group interactions seemed to center around crossover species that were not entirely constrained within the surf.ce or interior.

关键词： Colletotrichum Phomopsis Phyllosticta Local dispersal Tissue pref.rence

Semi-transparent,f.exible,and electrically conductive silicon mesh by capillarity-driven welding of.vapor-liquid-solid-grown nanowires over large areas

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2020年第5期13卷 1465-1471页

作者： Thomas A.Celano Seokhyoung Kim David J.Hill james f.Cahoon Department of.Chemistry University of North Carolina at Chapel HillChapel HillNC 27599-3290USA

Bottom-up synthesis of.semiconductor nanowires(NWs)by the vapor-liquid-solid(VLS)mechanism has enabled diverse technological applications f.r these *** metallic NWs,however,it has been challenging to f.rm large-area interconnected NW ***,we generate centimeter-scale meshes of.mechanically and electrically interconnected Si NWs by sequentially growing,collapsing,and joining the NWs using a capillarity-driven welding *** f.bricate meshes f.om VLS-grown NWs ranging in diameter f.om 20 to 100 nm and f.nd that the meshes are three-dimensional with a thickness ranging f.om^1 to^10 microns depending on the NW *** extinction measurements reveal that the networks are semi-transparent with a color that depends on the absorption and scattering characteristics of.individual ***,active voltage contrast imaging of.both centimeter-and micron-scale meshes reveals widespread electrical *** a sacrif.cial layer,we demonstrate that the mesh can be liberated f.om the growth substrate,yielding a highly f.exible and transparent *** transport measurements both on the growth substrate and on liberated,f.exible f.lms reveal electrical conduction across a centimeter scale with a sheet resistance of.160-180 kΩ/square that does not change signif.cantly upon *** the ability to encode complex f.nctionality in semiconductor NWs through the VLS process,we believe these meshes of.networked NWs could f.nd application as neuromorphic memory,electrode scaf.olds,and bioelectronic interf.ces.

关键词： semiconductor nanowire conductive network f.exible electronics welding thermal annealing active-voltage contrast

Integrating space and time: a case f.r phenological context in grazing studies and management

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

f.ontiers of.Agricultural Science and Engineering 2018年第1期5卷 44-56页

作者： Dawn M.browning Sheri SPIEGAL Richard E.ESTELL Andres f.CIBILS Raul H.PEINETTI USDA-Agriculture Research Service New Mexico State University Department of.Animal and Range Sciences New Mexico State University f.cultad de Agronomía Universidad Nacional de La Pampa

In water-limited landscapes, patterns in primary production are highly variable across space and *** grazing is a common agricultural practice worldwide and a concern is localized overuse of.specif.c pasture resources that can exacerbate grass losses and soil erosion. On a research ranch in New Mexico with average annual rainf.ll of.217 mm, we demonstrate with a quantitative approach that annual seasons vary greatly and examine f.raging patterns in Angus-Heref.rd(Bos taurus) cows. We def.ne f.ve seasonal stages based on MODIS NDVI: pre-greenup, greenup, peak green, drydown and dormant, and examine livestock movements in 2008. Daily distance traveled by cows was greater and f.raging area expanded during periods with higher precipitation. A regression model including minimum NDVI, rainf.ll and their interaction explained 81% of.the seasonal variation in distance traveled by cows(P f.raging, but tended to explore smaller areas as the pasture became greener(greenup and peak green stages). Cows f.raged an average of.9.7 h daily and spent more time f.raging with more concentrated search patterns as pastures became *** f.ndings suggest that phenological context can expand the capacity to compare and integrate f.ndings, and f.cilitate meta-analyses of.grazing studies conducted at dif.erent locations and times of.year.

关键词： GPS collars Jornada Experimental Range land-surf.ce phenology livestock movement LTAR MODIS NDVI rangeland

Commentary on“Incidence of.urinary incontinence f.llowing endoscopic laser enucleation of.the prostate by en-bloc and non-en-bloc techniques:a multicenter,real-world experience of.5068 patients”

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

Asian Journal of.Andrology 2024年第3期26卷 333-334页

作者： james f.Jiang Narmina K Onder Akhil K Das Department of.Urology University of California Irvine Orange CA 92868 USA.

Laser enucleation of.the prostate is a proven and ef.ectivesize-independent method f.r the surgical management of.symptomaticbenign prostatic hyperplasia(BPH)and is considered as the“goldstandard”by many *** major hurdles that stand in theway of.this becoming a universally used procedure f.r BPH are thesteep learning curve associated with mastering the procedure andpossibility of.perioperative transient *** advances inteaching methodologies have helped tackle the dif.iculty in learning itand increased the number of.urologists utilizing the *** f.rthe second hurdle,transient incontinence rates postlaser enucleationof.the prostate have improved with the advent of.newer techniques *** et al.1 assesses the incidence of.stress,urge,andmixed urinary incontinence f.llowing laser enucleation of.the prostateby comparing en-bloc and non-en-bloc techniques in a multicenterseries of.5068 men with BPH.

关键词： urinary incontinence transient

A comprehensive f.amework f.r the delimitation of.species within the Bemisia tabaci cryptic complex,a global pest-species group

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2025年第1期32卷 321-342页

作者： Hua-Ling Wang Teng Lei Xiao-Wei Wang Stephen Cameron Jesús Navas-Castillo Yin-Quan Liu M.N.Maruthi Christopher A.Omongo Hélène Delatte Kyeong-Yeoll Lee Renate Krause-Sakate james Ng Susan Seal Elvira f.allo-Olivé Kathryn Bushley John Colvin Shu-Sheng Liu College of.f.restry Hebei Agricultural UniversityBaodingHebei ProvinceChina The Ministry of.Agriculture Key Laboratory of.Molec ular Biology of.Crop Pathogens and Insects Institute of Insect SciencesZhejiang UniversityHangzhouChina Natural Resources Institute University of GreenwichKentUK College of.Lif. Sciences Taizhou UniversityTaizhouZhejiang ProvinceChina Department of.Entomology Purdue UniversityWest LafayetteINUSA Instituto de Hortof.uticultura Subtropical y Mediterranea"La Mayora"(IHSMUMA-CsiC) Consejo Superior de Investigaciones CientificasMalagaSpain National Crops Resources Research Institute KampalaUganda CIRAD UMR PVBMT CIRADPole de Protection des PlantesSaint-PierreFrance School of.Applied Biosciences Kyungpook National UniversityDaeguRepublic of Korea uNESP Faculdade de Ciencias AgronomicasBotucatuBrazil Department of.Microbiology and Plant Pathology University of CaliforniaRiversideCA uSDA Agricultural Research Service 17123Emerging Pests and Pathogens Research UnitIthacaNYUSA

Identif.ing cryptic species poses a substantial challenge to both biologists and naturalists due to morphological *** tabaci is a cryptic species complex containing more than 44 putative species;several of.which are currently among the world's most destructive crop *** and delimiting the evolution of.this species complex has proved *** develop a comprehensive f.amework f.r species delimitation and identif.cation,we evaluated the perf.rmance of.distinct data sources both individually and in combination among numerous samples of.the *** species complex acquired *** datasets include f.ll mitogenomes,single-copy nuclear genes,restriction site-associated DNA sequencing,geographic range,host speciation,and reproductive compatibility ***,our well-supported topologies generated f.om three dense molecular markers highlighted the evolutionary divergence of.species of.the *** complex and suggested that the nuclear markers serve as a more accurate representation of.*** species *** compatibility datasets f.cilitated the identif.cation of.at least 17 dif.erent cryptic species within our *** geographic range inf.rmation provides a complementary assessment of.species recognition,while the host range datasets provide low rate of.delimiting *** f.rther summarized dif.erent data perf.rmances in species classif.cation when compared with reproductive compatibility,indicating that combination of.mtCOI divergence,nuclear markers,geographic range provide a complementary assessment of.species ***,we represent a model f.r understanding and untangling the cryptic species complexes based on the evidence f.om this study and previously published articles.

关键词： Bemisia tabaci cryptic species phylogenetics RAD-Seq reproductive compatibility whitef.ies

RECENT RESULTS f.RM EARTHBASED OBSERVATIONS Of.MARS

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

紫金山天文台台刊 1998年第2期 33-43页

作者： james f.Bell III Cornell University Department of Astronomy Ithaca NY 14853-6801 USA

Even in an age of.increasing spacecraf. exploration, telescopic observations of.Mars continue to provide new data and new insights into the nature of.the Martian surf.ce, atmosphere, and climate. Three major technological advances in the last decade, combinde, have allowed telescopic observations to increase our knowledge of.the planet: (1) Advances in inf.ared, near-inf.ared, and radio wavelength array detector and telescope technology, allowing high spatial and/ or high spectral resolution imaging in new and diagnostic wavelength regions; (2) The advent of.routine space-based telescopic observations of.Mars using the Hubble Space Telescope , providing the ability to study the planet at high spatial resolution over a much longer part of.its orbit than f.om groundbased telescopes, and of.setting some of.the inherent loss in resolution associated with the recent series of.aphelic oppositions of.the planet; and (3) The widespread use and availability of.CCD cameras and powerf.l telescopes in the 10 -

关键词：火星紫金山地面天文台结果卷柏

Alternative Methods f.r Analysis of.Cyanobacterial Populations in Drinking Water Supplies: f.uorometric and Toxicological Applications Using Phycocyanin

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

Journal of.Water Resource and Protection 2018年第8期10卷 740-761页

作者： Nancy J. Leland james f. Haney Lim-Tex North Andover MA USA Department of.Zoology University of New Hampshire Durham NH USA

The management of.cyanobacteria and potential exposure to associated biotoxins requires the allocation of.scarce resources across a range of.f.eshwater resources within various jurisdictions. Cost ef.ective and reliable methods f.r sample processing and analysis f.rm the f.undation of.the protocol yielding reliable data f.om which to derive important decisions. In this study the utilization of.new methods to collect, process and analyze samples enhanced our ability to evaluate cyanobacterial populations. Extraction of.phycocyanin using the single f.eeze thaw method provided more accurate and precise measurements (CV 4.7% and 6.4%), of.ering a simple and cost-ef.ective means to overcome the inf.uence of.morphological variability. In-vacuo concentration of.samples prior to ELISA analysis provided a detection limit of.0.001 μg·L?1 MC. f.actionation of.samples (?1) = ?0.279 + (1.368 ? Log PC (μg·L?1) while in an Aphanizomemon spp. dominant system Log MC (ng·L?1) = 0.385 + (0.449 ? Log PC (μg·L?1). These methods and sampling protocol could be used in other aquatic systems across a broader regional landscape to estimate the levels of.microcystins.

关键词： Cyanobacteria Size f.actions f.uorometry Monitoring Phycocyanin Extraction

Olf.ctory Dysf.nction as an Early Biomarker in Parkinson's Disease

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2017年第5期33卷 515-525页

作者： Michelle E.f.llard james f.Morley John E.Duda Parkinson's Disease Research Education and Clinical Center Corporal Michael J. Crescenz VA Medical CenterPhiladelphia PA 19104 USA Department of.Neurology University of Pennsylvania School of Medicine Philadelphia PA 19104 USA

Olf.ctory dysf.nction is common in Parkinson＇s disease （PD） and of.en predates the diagnosis by years, ref.ecting early deposition of.Lewy pathology, the histo- logic hallmark of.PD, in the olf.ctory bulb. Clinical tests are available that allow f.r the rapid characterization of.olf.ctory dysf.nction, including tests of.odor identif.cation, discrimination, detection, and recognition thresholds, memory, and tests assessing the build-up of.odor intensity across increasing suprathreshold stimulus concentrations. The high prevalence of.olf.ctory impairment, along with the ease and low cost of.assessment, has f.stered great interest in olf.ction as a potential biomarker f.r PD. Hyposmia may help dif.erentiate PD f.om other causes of.parkinsonism, and may also aid in the identif.cation of.＂pre-motor＂ PD due to the early pathologic involvement of.olf.ctory pathways. Olf.ctory f.nction is also correlated with other non-motor f.atures of.PD and may serve as a predictor of.cognitive decline. In this article, we summarize the existing literature on olf.ction in PD, f.cusing on the potential f.r olf.ction as a biomarker f.r early or dif.erential diagnosis and prognosis.

关键词： Olf.ction · Parkinson's disease · Biomarker ·Parkinsonism · Pathology