检索结果-南通市图书馆

Three-dimensional light structure of an upland Quercus stand post-tornado disturbance

Journal of Forestry Research 2020年第1期31卷 141-153页

作者： Kevin G.Willson lauren E.Cox Justin l.Hart daniel C.Dey Department of Geography University of AlabamaTuscaloosaAL 35487USA Department of Environmental Science Policyand ManagementUniversity of CaliforniaBerkeleyCA 94720USA Northern Research Station USDA Forest ServiceColumbiaMO 65211USA

light is the most common limiting factor in forest plant communities,influencing species composition,stand structure,and stand productivity in closed canopy *** vertical light structure is relatively simple under a closed canopy because most light is captured by overstory ***,wind disturbance events create canopy openings from local to landscape scales that increase understory light intensity and vertical light structural *** studied the effects of an EF-1 tornado on horizontal and vertical(***-dimensional)light structure within a Quercus stand to determine how light structure changed with increasing disturbance *** used a two-tiered method to collect photosynthetic photon flux density at 4.67 m and 1.37 m above the forest floor to construct three-dimensional light structure across a canopy disturbance severity gradient to see if light intensity varied with increasing tornado *** indicate that increased canopy disturbance closer to the tornado track increased light penetration and light structure heterogeneity at lower forest *** light intensity correlated with increased sapling density that was more randomly distributed across the plot and had shifted light capture higher in the stand *** penetration through the overstory was most strongly correlated with decreased stem density in the two most important tree species(based on relative dominance and relative density)in the stand,Quercus alba l.(r=-0.31)and Ostrya virginiana(Mill.)***(r=-0.27,plight penetration was most affected by these two *** managers are increasingly interested in patterning silvicultural entries on natural disturbances,they must understand residual stand and light structures that occur after natural disturbance *** providing spatial light data that quantifies light structure post-disturbance,managers can use these results to improve planning required for long-term man

关键词： Photosynthetic photon flux density Midstory Blowdown Heterogeneity

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

Disturbance history,species diversity,and structural complexity of a temperate deciduous forest

引用

Journal of Forestry Research 2020年第2期31卷 397-414页

作者： Jonathan D.Goode Carson R.Barefoot Justin l.Hart daniel C.Dey Department of Geography University of AlabamaTuscaloosaAL 35487USA Northern Research Station USDA Forest ServiceColumbiaMO 65211USA

Stand structural complexity enhancement is an increasingly popular management objective,especially on public *** stand structures are hypothesized to support a relatively high degree of native forest diversity and be more resistant and resilient to *** structures are characterized by the presence of deadwood and heterogeneity of tree-size classes and tree *** little is known about how discrete disturbance events affect structural complexity and compositional diversity in Quercus-dominated stands at fine spatial scales(***).We established 200.05 ha fixed-radius plots on the Sipsey Wilderness of William *** National Forest in northern Alabama to quantify woody plant species composition and *** were mapped on each plot to quantify overstory structural complexity and compositional *** extracted two cores from all canopy Quercus spp.C 5 cm diameter at breast height to quantify age,recruitment pulses,and reconstruct canopy disturbance *** species diversity in the sampled area was 1.75 for trees,2.08 for saplings,and 1.69 for *** alba had the greatest basal area,and Ostrya virginiana had the highest *** stand exhibited a reverse J-shaped distribution with a q-factor of *** oldest Quercus dated to 1795,and the largest recruitment pulse occurred in the *** mean return interval for intermediateseverity disturbance was 38 *** we documented no relationships between disturbance frequency and compositional diversity at the neighborhood scale(0.05 ha),less frequent disturbance was associated with higher structural complexity(r^2=0.258,p=0.026)at the neighborhood *** suggest that localized disturbance increases species diversity and structural complexity,but these processes are manifest at the stand level and not at the neighborhood *** conclude that the spatial variability(***,shape,orientation,microsite conditions)is likel

关键词： Canopy gap Quercus(oak) Stand development Succession

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

A pentaploid-based linkage map of the ancestral octoploid strawberry Fragaria virginiana reveals instances of sporadic hyper-recombination

引用

Horticulture Research 2020年第1期7卷 1796-1810页

作者： Thomas M.Davis Yilong Yang lise l.Mahoney daniel C.Frailey Department of Agriculture Nutritionand Food SystemsUniversity of New HampshireDurhamNH 03824USA

The first high-resolution genetic linkage map of the ancestral octoploid(2n=8x=56)strawberry species,Fragaria virginiana,was constructed using segregation data obtained from a pentaploid progeny *** novel mapping population of size 178 was generated by crossing highly heterozygous *** hybrid“lB48”as a paternal parent with diploid(2n=2x=14)Fragaria vesca“Hawaii 4”.The lB48 linkage map comprises 6055 markers genotyped on the Axiom®IStraw90 strawberry SNP *** map consists of 28 linkage groups(lGs)organized into seven homoeology groups of four lGs each,and excludes a small 29th lG of undefined *** member of each homoeology group was assignable to an“A”subgenome associated with ancestral diploid Fragaria vesca,while no other subgenomes were *** an intriguing discrepancy within homoeology group VI,synteny comparisons with the previously published Fragaria×ananassa DA×MO linkage map revealed substantial *** initial map construction,examination of crossover distributions revealed that six of the total 5162(=29 chromosomes/individual×178 individuals)chromosomes making up the data set exhibited abnormally high crossover counts,ranging from 15 to 48 crossovers per chromosome,as compared with the overall mean of 0.66 crossovers per *** of these six hyper-recombinant(HypR)chromosomes occurred in a different lG and in a different *** calculated upon exclusion of the six HypR chromosomes,the canonical(i.e.,broadly representative)lB48 map had 1851 loci distributed over a total map length of 1873 cM,while their inclusion increased the number of loci by 130,and the overall map length by 91 *** of these hyper-recombinant chromosomes points to the existence of a sporadically acting mechanism that,if identified and manipulable,could be usefully harnessed for multiple purposes by geneticists and breeders.

关键词： Fragaria straw linkage

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

Vacuum promotes metabolic shifts and increases biogenic hydrogen production in dark fermentation systems

引用

Frontiers of Environmental Science & Engineering 2016年第3期10卷 513-521页

作者： Haifa RAJHI daniel PUYOl Mirna C. MARTiNEZ Emiliano E. DlAZ Jose l. SANZ Department of Molecular Biology University Autonoma of Madrid Madrid 28049 Spain Section of Chemical Engineering University Autonoma of Madrid Madrid 28049 Spain MYGEN laboratory Cantoblanco Madrid 28049 Spain

The successful operation of any type of hydrogen-producing bioreactor depends on the performance of the microorganisms present in the system. Both substrate and partial gas pressures are crucial factors affecting dark fermentation metabolic pathways. The main objective of this study was to evaluate the impact of both factors on hydrogen production using anaerobic granular sludge as inoculum and, secondly, to study the metabolic shifts of an anaerobic community subjected to low partial gas pressures. With this goal in mind, seven different wastewater （four synthetic media, two industrial waste- water, and one domestic effluent） and the effect of applying vacuum on the systems were analyzed. The application of vacuum promoted an increase in the diversity of hydrogen-producing bacteria, such as Clostridium, and promoted the dominance of acetoclasticover hydrogenotrophic methanogens. The application of different media promoted a wide variety of metabolic pathways. Nevertheless, reduction of the hydrogen partial pressure by application of vacuum lead to further oxidation of reaction intermediates irrespective of the medium used, which resulted in higher hydrogen and methane production, and improved the COD removal. Interestingly, vacuum greatly promoted biogenic hydrogen production from a real wastewater, which opens possibilities for future application of dark fermentation systems to enhance biohydrogen yields.

关键词： dark fermentation biohydrogen wastewaters vacuum

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

Reproduction and beyond,kisspeptin in ruminants

引用

Journal of Animal Science and Biotechnology 2015年第3期6卷 264-268页

作者： Joseph A.daniel Chad D.Foradori Brian K.Whitlock James l.Sartin Department of Animal Science Berry College Department of Anatomy Physiology & PharmacologyAuburn University Department of large Animal Clinical Sciences University of Tennessee

Kisspeptin （Kp） is synthesized in the arcuate nucleus and preoptic area of the hypothalamus and is a regulator of gonadotropin releasing hormone in the hypothalamus. In addition, Kp may regulate additional functions such as increased neuropeptide Y gene expression and reduced proopiomelanocortin （POMC） gene expression in sheep. Other studies have found a role for Kp to release growth hormone （GH）, prolactin and luteinizing hormone （lH） from cattle, rat and monkey pituitary cells. Intravenous injection of Kp stimulated release lH, GH, prolactin and follicle stimulating hormone in some experiments in cattle and sheep, but other studies have failed to find an effect of peripheral injection of Kp on GH release. Recent studies indicate that Kp can stimulate GH release after intracerebroventricular injection in sheep at doses that do not release GH after intravenous injection. These studies suggest that Kp may have a role in regulation of both reproduction and metabolism in sheep. Since GH plays a role in luteal development, it is tempting to speculate that the ability of Kp to release GH and lH is related to normal control of reproduction.

关键词： Growth hormone leptin luteinizing Neuropeptide Y POMC

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

Observation of a single protein by ultrafast X-ray diffraction

引用

light(Science & Applications) 2024年第1期13卷 80-90页

作者： Tomas Ekeberg Dameli Assalauova Johan Bielecki Rebecca Boll Benedikt J.Daurer lutz A.Eichacker linda E.Franken Davide E.Galli luca Gelisio lars Gumprecht laura H.Gunn Janos Hajdu Robert Hartmann Dirk Hasse Alexandr Ignatenko Jayanath Koliyadu Olena Kulyk Ruslan Kurta Markus Kuster Wolfgang lugmayr Jannik lübke Adrian P.Mancuso Tommaso Mazza Carl Nettelblad Yevheniy Ovcharenko daniel E.Rivas Max Rose Amit K.Samanta Philipp Schmidt Egor Sobolev Nicusor Timneanu Sergey Usenko daniel Westphal Tamme Wollweber lena Worbs Paul lourdu Xavier Hazem Yousef Kartik Ayyer Henry N.Chapman Jonas A.Sellberg Carolin Seuring Ivan A.Vartanyants Jochen Küpper Michael Meyer Filipe R.N.C.Maia laboratory of Molecular Biophysics Department of Cell and Molecular BiologyUppsala UniversityHusargatan 3(Box 596)SE-75124 UppsalaSweden Deutsches Electronen-Synchrotron DESY Notkestrasse 8522607 HamburgGermany European XFEl Holzkoppel 422869 SchenefeldGermany Diamond light Source Harwell Science&Innovation CampusDidcot OX110DEUK University of Stavanger Centre Organelle ResearchRichard-Johnsensgate 44021 StavangerNorway leibniz Institute for Experimental Virology(HPI) Centre for Structural Systems BiologyNotkestraße 8522607 HamburgGermany Dipartimento di Fisica“Aldo Pontremoli” Universitàdegli Studi di Milanovia Celoria 1620133 MilanoItaly Center for Free-Electron laser Science DESY22607 HamburgGermany Plant Biology Section School of Integrative Plant ScienceCornell UniversityIthacaNY 14853USA PNSensor GmbH Otto-Hahn-Ring 6D-81739 MünchenGermany Biomedical and X-Ray Physics Department of Applied PhysicsAlbaNova University CenterKTH Royal Institute of TechnologySE-10691 StockholmSweden ElI Beamlines/IoP Institute of Physics AS CR v.v.i.Na Slovance 218221 Prague 8Czech Republic Multi-User CryoEM Facility Centre for Structural Systems BiologyNotkestr.8522607 HamburgGermany University Medical Center Hamburg-Eppendorf(UKE) Martinistrasse 5220246 HamburgGermany The Hamburg Center for Ultrafast Imaging Universität HamburgLuruper Chaussee 14922761 HamburgGermany Department of Physics Universität HamburgLuruper Chaussee 14922761 HamburgGermany Department of Chemistry and Physics La Trobe Institute for Molecular ScienceLa Trobe UniversityMelbourneVIC 3086Australia Division of Scientific Computing Science for Life LaboratoryDepartment of Information TechnologyUppsala UniversityBox 337SE-75105 UppsalaSweden European Molecular Biology laboratory c/o DESYNotkestrasse 8522607 HamburgGermany Department of Physics and Astronomy Uppsala UniversityBox 516SE-75120 UppsalaSweden Max Planck Institute for the Structure and Dynamics of Matter Luruper Chaussee 14922761 HamburgGe

The idea of using ultrashort X-ray pulses to obtain images of single proteins frozen in time has fascinated and inspired *** was one of the arguments for building X-ray free-electron *** to theory,the extremely intense pulses provide sufficient signal to dispense with using crystals as an amplifier,and the ultrashort pulse duration permits capturing the diffraction data before the sample inevitably *** was first demonstrated on biological samples a decade ago on the giant *** then,a large collaboration has been pushing the limit of the smallest sample that can be *** ability to capture snapshots on the timescale of atomic vibrations,while keeping the sample at room temperature,may allow probing the entire conformational phase space of *** we show the first observation of an X-ray diffraction pattern from a single protein,that of Escherichia coli GroEl which at 14 nm in diameter is the smallest biological sample ever imaged by X-rays,and demonstrate that the concept of diffraction before destruction extends to single *** the pattern,it is possible to determine the approximate orientation of the *** experiment demonstrates the feasibility of ultrafast imaging of single proteins,opening the way to single-molecule time-resolved studies on the femtosecond timescale.

关键词： smallest intense ultrafast

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

Depression among elderly Chinese-Canadian immigrants from China's Mainland

引用

Chinese Medical Journal 2004年第5期117卷 677-683页

作者： daniel W.l.lai University of Calgary

Background This study examined the prevalence of depressive symptoms among elderly immigrants from China's Mainland to Canada and the impact of various psychosocial factors as predictors of the number of depressive symptoms reported by the elderly Chinese immigrants Methods The participants were 444 elderly immigrants who migrated from China's Mainland to Canada They were a part of a random sample of 2272 elderly Chinese living in the communities and took part in a face-to-face interview to answer questions in an orally administrated questionnaire The depressive symptoms of the participants were measured by a Chinese version of the Geriatric Depression Scale Data obtained from the 444 elderly Chinese immigrants was analyzed to assess the impact of various psychosocial factors on the number of depressive symptoms that they reported Results The findings indicated that 23 2% of the elderly immigrants were assessed to have some depressive symptoms When other predicting variables were adjusted, elderly immigrants with more chronic illnesses, less positive attitude towards ageing, poorer physical health, less adequate financial situation, lower level of ethnic identification as Chinese, more service barriers, lower level of life satisfaction, shorter length of residency in Canada and those who lived alone tended to have more depressive symptoms Conclusions The findings indicate that the prevalence rate of depressive symptoms among our elderly immigrant sample is higher than the one reported in a general elderly population While further research is recommended to examine the reasons for such a difference, culturally appropriate health services, including health promotion programs, should be promoted to reduce mental health disparities

关键词： elderly Chinese depression elderly immigrants mental health Geriatric Depression Scale

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

Using SWAT to simulate crop yields and salinity levels in the North Fork River Basin,USA

引用

International Journal of Agricultural and Biological Engineering 2015年第3期8卷 110-124页

作者： Aaron R.Mittelstet daniel E.Storm Art l.Stoecker Department of Biosystems and Agricultural Engineering Oklahoma State UniversityStillwaterOklahoma 74078USA Department of Agricultural Economics Oklahoma State UniversityStillwaterOklahoma 74078USA

Crop yields and salinity levels in the North Fork of the Red River(North Fork River)basin,located in southwestern Oklahoma and the Texas Panhandle,were analyzed based on the diverse climate in the *** irrigation water is a major problem in the *** Elm Fork Creek flows through salt deposits,making the creek and its receiving stream,the North Fork River,too saline to use for *** greatly reduces the number of hectares that can be utilized for agricultural crops within the basin.A baseline SWAT model was setup,calibrated and validated to simulate streamflow and wheat and cotton *** SWAT model and a regression equation were used to analyze variable weather impacts on crop yields and salinity *** the weather generator WXGEN and 58 years of observed weather data,ten 50-year weather datasets were *** from the weather generator was input into the calibrated SWAT model to simulate wheat and dryland and irrigated cotton yields for the ten weather *** an empirical relationship between ionic strength and streamflow,salinity levels were *** the crop yields varied greatly from year to year,the yields were not significantly different over the 50-year simulation *** electrical conductivity(EC,expressed in decisiemens per meter or dS/m)at the US Geological Survey gage station just downstream of the salt deposits was significantly different with levels ranging from 40 to 65 dS/*** the water in the Elm Fork is much too saline to use for irrigation,the water in the North Fork River may be used as long as the flow rates in the river are greater than 0.60 m3/*** order to optimize the available cropland,a salinity control must be installed upstream of the salt deposits on the Elm Fork Creek.

关键词： salinity SWAT crop yield wheat modeling cotton modeling Red River

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

Carbon nanostructure morphology templates nanocomposites for phosphoproteomics

引用

Nano Research 2020年第2期13卷 380-388页

作者： Susy Piovesana daniel Iglesias Manuel Melle-Franco Slavo Kralj Chiara Cavaliere Michele Melchionna Aldo laganà Anna l.Capriotti Silvia Marchesan Piazzale A.Moro 5 Dipartimento di ChimicaSapienza Universitadi RomaRome 00185Italy Via l.Giorgieri 1 Dipartimento di Scienze Chimiche e FarmaceuticheUniversitd di TriesteTrieste 34127Italy CICECO University of AveiroAveiro 3810-193Portugal Jamova 39 Department for Materials SynthesisJozef Stefan InstituteLjubljana 1000Slovenia Via Monteroni Campus Ecotekne CNR NANOTECUniversity of SalentoLecce 73100Italy

Protein and peptide phosphorylation regulate numerous pathological processes,however,their characterization is challenging due to their low abundance and transient ***,nanomaterials are being developed to address this demanding *** particular,carbon nanostructures are attracting interest as scaffolds for functional nanocomposites,yet only isolated studies exist on the topic,and lttle is known on the effect of nanocarbon morphology on templating *** this work,we compared oxidized carbon nanotubes,graphene oxide,oxidized carbon nanohorns and oxidized graphitized carbon black,as scaffolds for magnetized *** nanomaterials were extensively characterized with experimental and in silico ***,they were applied to phosphopeptide enrichment from cancer cell lysates for NanoHPlC-MS/MS,with selectivity as high as nearly 90%and several-thousand identification ***,new insights emerged for the understanding and the design of nanocomposites for phosphoproteomics.

关键词： nanocomposites carbon nanotubes graphene oxide carbon nanohorns proteomics magnetic

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

leveraging Hazard,Exposure,and Social Vulnerability Data to Assess Flood Risk to Indigenous Communities in Canada

引用

International Journal of Disaster Risk Science 2021年第6期12卷 821-838页

作者： liton Chakraborty Jason Thistlethwaite Andrea Minano daniel Henstra daniel Scott Public Safety Canada.Ottawa.ON K1A OPS.Canada Department of Geography and Environmental Management.Faculty of En\imnmcnt.University of Waleiioo Waicrloo.ON N2A 0E9.Canada School of En\imnmcnt.Enterprise and De\elopmont.Faculty of Environment University of WaterlooWaterloo.ON N2L 3GICanada Department of Political Science University of Waterloo.Waterloo.ON N2L 3GL Canada

This study integrates novel data on 100-year flood hazard extents,exposure of residential properties,and place-based social vulnerability to comprehensively assess and compare flood risk between Indigenous communities living on 985 reserve lands and other Canadian communities across 3701 census ***-scale exposure of residential properties to fluvial,pluvial,and coastal flooding was estimated at the 100-year return period.A social vulnerability index(SVI)was developed and included 49 variables from the national census that represent demographic,social,economic,cultural,and infrastructure/community indicators of *** information system-based bivariate choropleth mapping of the composite SVI scores and of flood exposure of residential properties and population was completed to assess the spatial variation of flood *** found that about 81%of the 985 Indigenous land reserves had some flood exposure that impacted either population or residential *** analysis indicates that residential property-level flood exposure is similar between non-Indigenous and Indigenous communities,but socioeconomic vulnerability is higher on reserve lands,which confirms that the overall risk of Indigenous communities is *** suggest the need for more local verification of flood risk in Indigenous communities to address uncertainty in national scale analysis.

关键词： Canada Flood risk assessment Indigenous communities Social vulnerability

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

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：