检索结果-南通市图书馆

Tree community composition,structure and diversity along an elevational gradient in an Andean forest of Northern Ecuador

引用

journal of Mountain Science 2021年第9期18卷 2315-2327页

作者： jIMÉNEZ-PAZ Rosa WORTHY Samantha j VALENcIA Renato PÉREZÁlvaro j REYNOLDS alex BARONE john A BURGESS Kevin S Laboratorio de Ecología de Plantas Escuela de Ciencias BiológicasFacultad de Ciencias Exactas y NaturalesPontificia Universidad Católica del EcuadorQuito 17-01-2184Ecuador Department of Biology College of Letters&SciencesColumbus State UniversityColumbusGeorgia 31907USA Herbario QcA Escuela de Ciencias BiológicasFacultad de Ciencias Exactas y NaturalesPontificia Universidad Católica del EcuadorQuito 17-01-2184Ecuador The Lovett School AtlantaGeorgia 30327USA

The Andean forests of northern Ecuador are known for their high levels of plant diversity relative to the area they ***,these forests grow on steep slopes that lead to dramatic habitat gradients across short *** extreme habitat gradients make the Andean forest ecosystem an excellent natural laboratory for understanding the effect of elevation on forest community diversity,structure and *** established 31 plots(50 m×5 m)which are divided between two elevational transects in the cloud forest of the Siempre Verde Reserve in the western foothills of the Andes Mountains of northern *** trees and tree ferns with a diameter at breast height(dbh)≥5 cm were measured and *** examined changes in community composition,structure,and diversity along and between the elevational transects and three elevational zones:low(2437–2700 m),middle(2756–3052 m),and high(3163–3334 m).We found four main trends associated with the elevational gradients at this site:(1)community composition differed between the two transects and among the three elevational zones according to N-MDS,ANOSIM,and percentage of shared species,with some species having limited distributions,(2)metrics of community structure showed opposite relationships with elevation,depending on the transect,with the only significant relationship(negative)found between basal area and elevation in the open trail transect,(3)alpha diversity,in general,peaked at mid-elevations,and(4)beta diversity consistently increased with distance between plots along *** complexity of changes in community composition,structure,and alpha diversity along elevation may be related to the heterogeneity of the environment on a local scale,such as topography,soil composition,and even human impact,or to dispersal limitation and should be investigated *** changes in community composition and the relatively high beta diversity found at this site exemplify the biological complexity of mon

关键词： Elevational gradient cloud forest Andes Structure composition Diversity

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

Molecular aspects of eye development and regeneration in the Australian redclaw crayfish,cherax quadricarinatus

引用

Aquaculture and Fisheries 2019年第1期4卷 27-36页

作者： Tomer Ventura Michael j.Stewart jennifer c.chandler Bronwyn Rotgans Abigail Elizur alex W.Hewitt Genecology Research centre Faculty of ScienceHealthEducation and EngineeringUniversity of the Sunshine CoastSunshine CoastQueensland 4556Australia Lions Eye Institute University of Western AustraliaPerthWestern Australia 6330Australia School of Medicine Menzies Institute for Medical ResearchUniversity of TasmaniaHobartTasmania 7005Australia

The compound eye evolved over 500 million years ago and enables mosaic vision in most arthropod *** molecular regulation of the development of the compound eye has been primarily studied in the fruit fly Drosophila ***,due to the nature of holometabolous insects halting growth after their terminal metamorphosis into the adult form,they lack the capacity to ***,unlike holometabolous insects,continue to grow during adulthood,achieved through regular shedding of their exoskeleton,in a cyclic process known as *** therefore offers crustaceans as a highly suitable model to study ocular regeneration in the adult arthropod *** have assessed the regenerative capacity of the retinal section of the cherax quadricarinatus(red-claw crayfish)eye,following ablation and successive post-metamorphic *** work then provides a transcriptomic description of the outer,pigmented retinal tissue(the ommatidia and lamina ganglionaris)and the basal,non-pigmented neuroendocrine ocular tissue(the X-organ Sinus Gland complex,hemiellipsoid body and optic nerve).Using comparative analysis,we identified all the transcripts in the *** ocular transcriptome that are known to function in compound eye development in *** and uniquely transcribed genes of the retina are described,suggesting proposed mechanisms that may regulate ocular regeneration in decapod *** research exemplifies the application *** holds as an optimal model to study the regulation of ocular *** in-depth transcriptomic analyses are now required,sampled throughout the regeneration process to better define the regulatory mechanism.

关键词： Ocular development Regeneration compound eye crustacean cherax quadricarinatus Transcriptome

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

Effect of host-cocoon mass on adult size in the secondary hyperparasitoid wasp, Pteromalus semotus （Hymenoptera： Pteromalidae）

引用

Insect Science 2012年第3期19卷 383-390页

作者： jeffrey A. Harvey alex Gumovsky Rieta Gols Netherlands Institute of Ecology Department of Terrestrial Ecology Wageningen The Netherlands Schmalhausen Institute of Zoology Kiev Ukraine Laboratory of Entomology Plant Science Group Wageningen University Wageningen The Netherlands

Parasitoids have long proven to be model organisms in studying resourcerelated constraints on immature development. Here we examine the relationship between host cocoon （= pupal） size in the gregarious endoparasitoid wasp, cotesia glomerata, and development time and adult size in the solitary idiobiont hyperparasitoid, Pteromalus semotus. Little is known about the biology or ecology of this ecto-hyperparasitoid species, although it is one of the major secondary hyperparasitoids of c. glomerata. The size of the adult wasp covaried with the size of the host cocoon at parasitism. Moreover, female wasps were larger than male wasps for a given cocoon size. Adult wasps have remarkably long life-spans, 3 months on average. Longevity did not significantly differ with sex. We also examined how larvae of P. semotus exclude other potential competitors. P. semotus is protandrous, with females taking significantly longer to complete their development than males. In experiments where several eggs of P. semotus were placed on individual pupae of c. glomerata, newly hatched hyperparasitoid larvae moved rapidly over the surface of the host and destroyed the eggs of any conspecifics by biting them before they would initiate feeding on host tissues. Our results are discussed in relation to those with other studies with solitary ichneumonid idiobiont hyperparasitoids of c. glomerata.

关键词： cotesia glomerata growth idiobiont longevity protandry trade-off

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

Family Forest Owners’ Motivation to control Understory Vegetation: Implications for consulting Forestry

引用

Open journal of Forestry 2013年第4期3卷 99-103页

作者： alex c. Londeau Thomas j. Straka School of Agricultural Forest and Environmental Sciences Clemson University Clemson USA

Forest vegetation management has evolved as a recognized component of intensive forest management practice. It involves the management of competing vegetation necessary to obtain the high yields expected in modern forest plantations via control of interfering plants that influence regeneration outcome, impact timber stand development, and limit native plant and wildlife diversity. It includes cultural control, fire control, mechanical control, biological control, and chemical control. The public perception of forest vegetation management, especially chemical control, is sometimes negative due to health and environmental concerns. It is an important tool in the forest management alternatives available to consulting foresters managing family forest lands (the vast majority of private forest land in the United States). We report on a study that addresses the motivations of family forest owners that implement forest vegetation management practices and the motivation of those who chose not to implement after forester recommendations to do so. For those who do implement forest vegetation management, improvement of wildlife habitat and increased timber growth was the main motivation. For those who did not, cost was the main concern. Size of forest holding plays a major role in determining who will practice intensive forestry.

关键词： Forest Vegetation Management chemical control Family Forest Owners consulting Forestry

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

calcite twinning strain variations across the Proterozoic Grenville orogen and Keweenaw-Kapuskasing inverted foreland,USA and canada

引用

Geoscience Frontiers 2017年第6期8卷 1357-1384页

作者： john P.craddock Suzanne D.craddock alex Konstantinou Andrew R.c.Kylander-clark David H.Malone Geology Department Macalester CollegeSt.PaulMN 55105USA School of Earth Sciences and Environmental Sustainability Northern Arizona UniversityFlagstaffAZUSA cyprus Hydrocarbons company NicosiaCyprus Department of Earth Science University of CaliforniaSanta BarbaraCA 93106USA Department of Geography-Geology Illinois State UniversityNormalIL 61790-4400USA

We report the calcite twinning strain results of a traverse across the Grenville orogen from Parry Sound,Ontario(NW)to ***,New York(SE),including the younger,adjacent Ordovician Taconic *** four carbonates(marbles,calcite veins,Ordovician limestone)were collected resulting in 68 strain analyses on mechanically twinned calcite(n=2337 grains)across the central Gneiss Belt(cGB;3 samples),the central Metasedimentary Belt(cMB;27 samples),the central Granulite Terrane(cGT;Adirondack's;13 samples)and the Ottawan Orogenic Lid(OOL;11 samples).Twinning strains in the greenschist-grade OOL marbles preserve N-S shortening and U-Pb titanite ages(~1150 Ma;n=4)document these marbles formed during the Shawinigan(1190-1140 Ma)part of the Grenville *** northwest to southeast,the Ottawan(1095-1020 Ma)twinning strain is dominantly a layerparallel shortening fabric oriented N-S(Parry Sound),then becomes parallel to the Grenville thrust direction(NW-SE)across the cMB to the Adirondack Highlands where the sub-horizontal shortening strain becomes margin-parallel(SW-NE).Within the regional sample suite there are two areas studied in detail,the Bancroft shear zone(n=11)and a roadcut on the southeast side of the Adirondack Mountains(***,NY;n=8).Marbles from the Bancroft shear zone contain calcite grains with 2 sets of twin lamellae(e_1 and e_2).The better-developed e_1 sets(n=406)record a horizontal fabric oriented NW-SE whereas the younger e_2 lamellae(n=146)preserve a margin-parallel(SW-NE)horizontal *** the e_1 and e_2 strains record an overprint vertical shortening strain(NEV),perhaps related to extensional orogenic *** also report an Ottawan orogen-aged granoblastic mylonite(1093 Ma,U-Pb zircon;1102 Ma Ar-Ar biotite)in the Keweenaw thrust hanging wall 500 km inboard of the Grenville front and interpret the relations of Grenville-Keweenaw far-field dynamics.

关键词： Orogenic belts Strain Proterozoic

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

Nitric oxide-mediated S-nitrosylation of IAA17 protein in intrinsically disordered region represses auxin signaling

引用

journal of Genetics and Genomics 2023年第7期50卷 473-485页

作者： Hongwei jing Xiaolu Yang Ryan j.Emenecker jian Feng jian Zhang Marcelo Rodrigues Alves de Figueiredo Patarasuda chaisupa R.clay Wright alex S.Holehouse Lucia c.Strader jianru Zuo State Key Laboratory of Plant Genomics Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China University of chinese Academy of Sciences Beijing 100049China Department of Biology Duke UniversityDurhamNC 27008USA Department of Neurobiology Duke University Medical CenterDurhamNC 27710USA Department of Biochemistry and Molecular Biophysics Washington University School of MedicineSt.LouisMO 63110USA center for Biomolecular condensates(cBc) Washington University in St.LouisSt.LouisMO 63130USA Department of Biological Systems Engineering Virginia TechBlacksburgVA 24061USA The Translational Plant Sciences center(TPSc) Virginia TechBlacksburgVA 24061USA cAS center for Excellence in Molecular Plant Sciences Chinese Academy of SciencesBeijing 100101China

The phytohormone auxin plays crucial roles in nearly every aspect of plant growth and *** signaling is activated through the phytohormone-induced proteasomal degradation of the Auxin/INDOLE-3-AcETIc AcID(Aux/IAA)family of transcriptional ***,many auxin-modulated physiological processes are also regulated by nitric oxide(NO)that executes its biological effects predominantly through protein S-nitrosylation at specific cysteine ***,little is known about the molecular mechanisms in regulating the interactive NO and auxin ***,we show that NO represses auxin signaling by inhibiting IAA17 protein *** induces the S-nitrosylation of cys-70 located in the intrinsically disordered region of IAA17,which inhibits the TIR1-IAA17 interaction and consequently the proteasomal degradation of *** accumulation of a higher level of IAA17 attenuates auxin ***,an IAA17^(c70W)nitrosomimetic mutation renders the accumulation of a higher level of the mutated protein,thereby causing partial resistance to auxin and defective lateral root *** together,these results suggest that S-nitrosylation of IAA17 at cys-70 inhibits its interaction with TIR1,thereby negatively regulating auxin *** study provides unique molecular insights into the redox-based auxin signaling in regulating plant growth and development.

关键词： Arabidopsis thaliana Auxin Aux/IAA Nitric oxide S-nitrosylation Intrinsically disordered region

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

Triple the steady-state reaction rate by decorating the In_(2)O_(3)surface with SiO_(x)for cO_(2)hydrogenation

引用

journal of Energy chemistry 2024年第8期95卷 96-105,I0003页

作者： Hao Wang chun Yang Xiaoyan Yu Mingrui Wang Runze Yang Xiaowa Nie Ben Hang Yin alex c.K.Yip chunshan Song Guanghui Zhang Xinwen Guo State Key Laboratory of Fine chemicals Frontier Science Center for Smart MaterialsPSU-DUT Joint Center for Energy ResearchSchool of Chemical EngineeringDalian University of TechnologyDalian 116024LiaoningChina Department of chemistry the Chinese University of Hong KongHong Kong 999077China Paihau-Robinson Research Institute the MacDiarmid Institute for Advanced Materials and NanotechnologyVictoria University of WellingtonWellington 6012New Zealand Department of chemical and Process Engineering The University of CanterburyChristchurch 8041New Zealand

Indium oxide(In_(2)O_(3)),as a promising candidate for cO_(2)hydrogenation to c_(1) products,often suffers from sintering and activity decline,closely related to the undesirable structural evolution under reaction *** on the comprehension of the dynamic evolution,this study presents an efficient strategy to alleviate the agglomeration of In_(2)O_(3)nanoparticles by the surface decoration with highly dispersed silica species(SiO_(x)).Various structural characterizations combined with density functional theory calculations demonstrated that the sintering resulted from the over-reduction,while the enhanced stability originated from the anchoring effect of highly stable In-OSi bonds,which hinders the substantial formation of metallic In(In^(0))and the subsequent agglomeration.0.6Si/In_(2)O_(3)exhibited cO_(2)conversion rate of10.0 mmol g^(-1)h^(-1)at steady state vs.3.5 mmol g^(-1)h^(-1)on In_(2)O_(3)in cO_(2)*** steady-state activity was also achieved on Pd-modified *** to the traditional Pd/In_(2)O_(3)catalyst,the methanol production rate of Pd catalyst supported on 0.6Si/In_(2)O_(3)was enhanced by 23%,showing the potential of In_(2)O_(3)modified by SiO_(x)in serving as a platform *** work provides a promising method to design new In_(2)O_(3)-based catalysts with improved activity and stability in cO_(2)hydrogenation.

关键词： cO_(2)hydrogenation In_(2)O_(3)sintering Dynamic structural evolution Surface SiO_(x)modification DFT simulations

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

Depleted uranium oxide supported nickel catalyst for autothermal cO_(2)methanation in non-adiabatic reactor under induction heating

引用

journal of Energy chemistry 2023年第10期85卷 310-323,I0010页

作者： Lai Truong-Phuoc jean-Mario Nhut Loïc Vidal cuong Duong-Viet Sécou Sall corinne Petit christophe Sutter Mehdi Arab alex jourdan cuong Pham-Huu Institute of chemistry and Processes for Energy Environment and Health(ICPEES)ECPMUMR 7515 CNRS-University of Strasbourg25 rue Becquerel67087 Strasbourg Cedex 02France BlackLeaf SAS 210 rue Geiler de Kaysersberg67400 IllkirchFrance Institute of Materials Science of Mulhouse IS2MUMR 7361Universitéde Haute-AlsaceCNRS15rue Jean Starcky-BP 248868057 MulhouseFrance ORANO Tricastin Direction de La Recherche&DéveloppementSite du TRICASTIN BP 1626701 Pierrelatte CedexFrance

Undoped nickel-based catalysts supported on depleted uranium oxide allow one to carry out cO_(2)methanation process under extremely low reaction temperature under atmospheric pressure and powered by a contactless induction *** adjusting the reaction conditions,the catalyst is able to perform cO_(2)methanation reaction under autothermal process operated inside a non-adiabatic reactor,without any external energy *** autothermal process is possible thanks to the high apparent density of the UO_x which allows one to confine the reaction heat in a small catalyst volume in order to confine the exothermicity of the reaction inside the catalyst and to operate the reaction at equilibrium heat in-heat *** autothermal operation mode allows one to significantly reduce the complexity of the process compared to that operated using adiabatic reactor,where complete insulation is required to prevent heat disequilibrium,in order to reduce as much as possible,the heat exchange with the external *** catalyst displays an extremely high stability as a function of time on stream as no apparent *** is expected that such new catalyst with unprecedented catalytic performance could open new era in the field of heterogeneous catalysis where traditional supports show their limitations to operate catalytic processes under severe reaction conditions.

关键词： cO_(2)methanation Auto-methanation Induction heating Depleted uranium oxide Electrification process Operando DRIFTS

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

Thrust characteristics of nano-carbon/Al/oxygenated salt nanothermites for micro-energetic applications

引用

Defence Technology（防务技术） 2023年第12期30卷 55-69页

作者： Ahmed Fahd alex Baranovsky charles Dubois jamal chaouki Sherif Elbasuney Shady Shokry chemical Engineering Department Ecole Polytechnique de MontrealMontrealH3C 3A7Canada Energetic Materials and Nanotechnology Research center Technical Research CenterCairo11765Egypt Mechanical and Mechatronics Engineering Department University of WaterlooOntarioN2L 3G1Canada Head of Nanotechnology Research center Military Technical CollegeCairo11767Egypt Laser and Optoelectronics Research center Technical Research CenterCairo11765Egypt

combustion within small motors is key in the application-specific development of nanothermite-based micro-energetic systems. This study evaluates the performance of nanothermite mixtures in a converging-diverging nozzle and an open tube. Mixtures were prepared using nano-aluminum(n-Al),potassium perchlorate(KclO_(4)), and different carbon nanomaterials(cNMs) including graphene-oxide(GO), reduced GO, carbon nanotubes(cNTs) and nanofibers(cNFs). The mixtures were packed at different densities and ignited by laser beam. Performance was measured using thrust measurement,high-speed imaging, and computational fluid dynamics modeling, respectively. Thrust, specific impulse(ISP), volumetric impulse(ISV), as well as normalized energy were found to increase notably with cNM content. Two distinctive reaction regimes(fast and slow) were observed in combustion of low and high packing densities(20% and 55%TMD), respectively. Total impulse(IFT) and ISPwere maximized in the 5%GO/Al/KclO_4 mixture, producing 7.95 m N·s and 135.20 s respectively at 20%TMD, an improvement of 57%compared to a GO-free sample(5.05 m N·s and 85.88 s). cFD analysis of the motors over predicts the thrust generated but trends in nozzle layout and packing density agree with those observed experimentally;peak force was maximized by reducing packing density and using an open tube. The numerical force profiles fit better for the nozzle cases than the open tube scenarios due to the rapid nature of combustion. This study reveals the potential of GO in improving oxygenated salt-based nanothermites,and further demonstrates their applicability for micro-propulsion and micro-energetic applications.

关键词： Nanothermites Graphene oxide Reduced graphene oxide carbon nano material Oxygenated salts Laser ignition computational fluid dynamics

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

Effect of age and different doses of dietary vitamin E on breast meat qualitative characteristics of finishing broilers

引用

Animal Nutrition 2021年第1期7卷 163-167页

作者： Vivian Vieira Francielle O.Marx Lucas S.Bassi Marley c.Santos alexandre Oba Simone Gisele de Oliveira alex Maiorka Federal University of Paraná Curitiba80035-050Brazil State University of Londrina Londrina86055-900Brazil

The supplementation of vitamin E on broiler chicken diets is essential to the prevention of lipid oxidation reactions in the meat and improvement of meat *** objective of this study was to assess the effect of different doses of dietary vitamin E on breast meat quality of broiler chickens in the finishing *** doses of vitamin E were used(30,90,150,210,and 270 mg/kg feed)in broilers'diets from 42 to 54 d of age.A completely randomized design was conducted,followed by a split-plot,where the vitamin E dose was considered as the whole plot,and broilers'age at slaughter was the *** meat quality was assessed at 4 different ages(45,48,51,and 54 d old),using 50 birds per age,totaling 200 *** quality characteristics evaluated were:pH at 24 h post mortem,color(brightness,redness,and yellowness),water holding capacity,cooking loss,shear force,and lipid *** was no interaction between age and dose of vitamin E for meat quality characteristics(P>0.05).The age at slaughter had a quadratic effect(Pce value was higher in breast meat of birds slaughtered at later ages(Pct was *** increased linearly(Pcooking loss,and lipid *** this study,increasing vitamin E doses in the finishing period increased the brightness of broiler breast meat,whereas slaughtering at later ages resulted in greater meat pH and shear force value.

关键词： Alpha-tocopherol Broiler chicken Meat quality Oxidation Vitamin

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：