检索结果-南通市图书馆

Effects of habitat configuration on biodiversity along gradients of forest cover on the Swiss plateau

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Forest Ecosystems 2024年第5期11卷 659-669页

作者： Yiwen pan Anna M.Hersperger Gang Ge Michael p.Nobis Key Laboratory of poyang Lake Environment and Resource Utilization Ministry of EducationSchool of Resources&EnvironmentNanchang UniversityNanchang330031China Swiss Federal Institute for Forest Snow and Landscape Research WSLZürcherstrasse 1118903BirmensdorfSwitzerland School of Life Sciences Nanchang UniversityNanchang330031China

The negative effects of habitat loss on biodiversity are undisputed,while the effect of habitat configuration,i.e.,the spatial arrangement of habitat area,has been debated for *** develop a more comprehensive understanding,it is important to know when and how configuration *** this study,we tested whether forest configuration influences the richness of species in groups characterized by varying shade tolerance in different ways and how such effects are related to habitat amount(i.e.,the percentage of forest cover)at the landscape *** on 104 survey plots(each measuring 1km^(2))of vascular plants on the Swiss plateau,and using two statistical approaches(i.e.,multiple regression and path analysis),we modeled the effects of habitat amount and configuration(measured as number of forest patches,total edge length,and proximity index)across all the plots and separately for three habitat amount classes:30%forest *** we modeled all plots together,we found that,after controlling for habitat amount,the forest configuration significantly affected species *** we considered the different habitat amount classes separately,most of the significant effects of habitat configuration on species richness occurred only for habitat amounts ofponse to forest configuration differed among species with different shade *** forest area waspatches and the total edge length on the species richness of light-demanding forest species were greater than the effect of habitat amount,whereas neither configuration metric affected the richness of shade-tolerant *** conclusion,our findings highlight the importance of configuration in landscapes with a small amount of *** the same time,they demonstrate that considering the confounding factors(*** traits)is important for understanding the effects of forest configuration on biodiversity and that genera

关键词： Forest plants Habitat amount Landscape fragmentation Species richness Swiss plateau

Exploring the size of Andean condor foraging groups along an altitudinal and latitudinal gradient in the Tropical Andes: Ecological and conservation implications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2024年第2期70卷 225-232页

作者： Diego Mendez Felix Hernan Vargas JoséHernan Sarasola pedro p.Oleaa Departamento de Ecologia Universidad Autonoma de MadridCalle Darwin 228049MadridSpain Museo Nacional de Historia Natural Calle 26 s/nCota CotaLa PazBolivia The peregrine Fund 5668 West Flying Hawk LaneBoiseID 83709USA Centro para el Estudio y Conservacion de Aves Rapaces en Argentina(CECARA) Universidad Nacional de La PampaAvda Uruguay 1516300 Santa RosaLa PampaArgentina Instituto de las Ciencias Ambientales y de la Tierra de La pampa(INCITAp-CONICET) Avda.Uruguay 1516300 Santa RosaLa PampaArgentina Centro de Investigacion en Biodiversidad y Cambio Global(CIBC-UAM) Universidad Autonoma de MadridMadridCalle Darwin 228049Madrid Snain

patterns of variation in the size of vulture foraging groups,and their ecological causes and consequences,remain litle explored despite strong links with the carrion recycling service that this key functional group *** documented the group size-frequency pattern of Andean con-dors Vultur gryphus gathered to feed on 42 equine carcasses experimentally placed in Bolivia,between 2012 and 2019,along an elevation range of 1,300-4,500 m *** on the location(altitude and latitude)of the foraging groups,we examined the relationship between their size and species'population parameters(size and trend),habitat conditions,and livestock carcass availability and *** utilized a high frequency(93%)of carcasses forming groups that ranged from 1 to 80 individuals(mean=25,median=18)and shaped a"lazy-J curve"typical pattern of size-frequency distribution whereby few groups(5,12%)were large(>55 individuals)and most(21,50%)were relatively small(p size related to altitude in that most larger groups formed at lower sites(below c.3,000 m asl),likely following an altitudinal gradient whereby larger groups are more likely to form around larger carcasses(i.e.,cattle),which are more likely to occur at lower *** of population size,group size could be an adaptive response of condors via local enhancement for improving individual scavenging *** information gaps on this topic still exist,thus we provide a set of questions to address them,especially amidst the unrestricted impacts of human activities that condition vulture survival globally.

关键词： condor andino fusion-fission dynamics group size scavenger social foraging vultures.

Adding Value to Crop production Systems by Integrating Forage Cover Crop Grazing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of plant Sciences 2024年第3期15卷 180-192页

作者： Robert B. Mitchell Daren D. Redfearn Kenneth p. Vogel Terry J. Klopfenstein Galen Erickson p. Stephen Baenziger Bruce E. Anderson mary E. Drewnoski Jay parsons Steven D. Masterson Marty R. Schmer Virginia L. Jin USDA-ARS Wheat Sorghum and Forage Research Unit University of Nebraska-Lincoln Lincoln NE USA Department of Agronomy and Horticulture University of Nebraska-Lincoln Lincoln NE USA Department of Animal Science University of Nebraska-Lincoln Lincoln NE USA Department of Agricultural Economics University of Nebraska-Lincoln Lincoln NE USA USDA-ARS Agroecosystem Management Research Unit University of Nebraska-Lincoln Lincoln NE USA

In addition to their value as cereal grains, wheat (Triticum aestivum L.) and triticale (× Triticosecale Wittmack) are important cool-season annual forages and cover crops. Yearling steer (Bos taurus) performance was compared in the spring following autumn establishment as for age cover crops after soybean [Glycine max (L.) Merr.] grain harvest. Replicated pastures (0.4 ha) were no-till seeded in three consecutive years into soybean stubble in autumn, fertilized, and grazed the following spring near Ithaca, NE, USA. Each pasture (n = 3) was continuously stocked in spring with four yearling steers (380 ± 38 kg) for 17, 32, and 28 d in 2005, 2006, and 2007, respectively. In 2005, average daily gain (ADG) for steers grazing triticale exceeded the ADG for wheat by 0.31 kghdp>-1p>dp>-1p>. In 2006, wheat ADG exceeded that for triticale by 0.12 kghdp>-1p>dp>-1p>. In 2007, steers grazing wheat lost weight, while steers grazing triticale gained 0.20 kghdp>-1p>dp>-1p>. Based on the 3-year average animal gains valued at $1.32 kgp>-1p>, mean net return ($ hap>-1p> yrp>-1p>) was $62.15 for triticale and $22.55 for wheat. Since these grazed cover crops provide ecosystem services in addition to forage, grazing could be viewed as a mechanism for recovering costs and adds additional value to the system. Based on this 3-year grazing trial, triticale was superior to wheat and likely will provide the most stable beef yearling performance across years with variable weather for the western Cornbelt USA.

关键词： Cover crops Soybean Triticale Wheat

Comparison of the Anatomy and Adaptability of Reconstructed Teeth with Natural Teeth:An Innovative Approach in Forensic Dentistry

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 Forensic Science and Medicine 2024年第1期10卷 47-54页

作者： Supraja S p M Tejaswi Ravikanth Manyam Mohan Kumar pasupuleti Swetha p Ramesh Kumar Budumuru Department of Oral and Maxillofacial pathology Vishnu Dental CollegeBhimavaramAndhra PradeshIndia Vishnu Dental College BhimavaramAndhra PradeshIndia Department of periodontics and Implantology Vishnu Dental CollegeBhimavaramAndhra PradeshIndia Department of Oral Medicine and Radiology Vishnu Dental CollegeBhimavaramAndhra PradeshIndia

Background:Forensic tooth reconstruction is the technique of reconstructing the morphology of a missing tooth from the intra-alveolar morphology of dental sockets from skeletal *** and Objectives:The aim and objective of the study are to compare and investigate whether the anatomy and adaptability of reconstructed teeth simulate with the natural tooth and to investigate whether the dental materials have potential in reconstruction of *** and Methods:An in vitro experimental study was undertaken on a human *** to the Fédération Dentaire Internationale,charting will be done based on the number of teeth *** entire study will be conducted in three phases using dental *** 1 comprised preparation for negative replica,where an impression will be taken,phase 2 comprised preparation of a positive replica or cast,and phase 3 comprised tooth reconstruction using the flowable ***:The specimen tooth(which had been taken from its socket)and the newly constructed tooth were compared,and when the length of the newly constructed root was measured using digital vernier calipers,there was a disparity of 0.5-1 *** cone-beam computed tomography radiographs demonstrated the necessary ***:The present study demonstrated that dental information can be obtained even when teeth are absent postmortem by making an attempt to recreate the teeth using dental materials while documenting the intra-alveolar anatomy of the dental root socket.

关键词： Adaptability anatomy reconstruction teeth

Convergent plate boundary environments for formation of≥3800 Ma mafic-ultramafic assemblages(Isua area,Greenland):Implications for early global geodynamics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2024年第3期15卷 119-136页

作者： Allen p.Nutman Clark R.L.Friend Vickie C.Bennett School of Earth Atmospheric and Life SciencesUniversity of WollongongWollongongNSW 2522Australia Glendale TiddingtonOxon OX92LQUK Research School of Earth Sciences Australian National UniversityCanberraACT 2601Australia

In the gneiss terrane on the south side of the Eoarchean Isua supracrustal belt,ultramafic rocks with relict abyssal peridotite mineralogy(Bennett et al.,2002;Friend et al.,2002;Nutman et al.,2007;Rollinson,2007;van de Löcht et al.,2020),layered gabbros with cumulate ultramafic rocks,basalts and associated siliceous sedimentary rocks were tectonically-imbricated,prior to and during intrusion of ca.3800 Ma *** with3800 Ma basalts in the Outer Arc Group of the nearby Isua supracrustal belt,the composition of all these mafic rocks(e.g.,Th-Hf-Nb systematics,high Th/Yb,Ba/Nb,Ba/Yb ratios and negative Nb and Ti anomalies)shows affinity with modern suprasubduction rocks whose genesis involved fluid fluxing of the upper ***,the majority of these samples have Ba/Nb and Ba/Yb values less than in modern island arc magmas,but similar to many backarc basin magmas(e.g.,pearce and Stern,2006).It is unknown whether these ca.3800 Ma mafic rocks are,(i)arc rocks where the Ba/Nb and Ba/Yb signatures reflect lower surficial Ba in Eoarchean oceanic settings,or(ii)in direct comparison with phanerozoic suites,these signatures reflect a back-arc setting with interplay between fluid fluxing and decompressional *** tectonic intercalation of upper mantle with lower and upper crustal rocks,combined with the fluid-fluxing influences seen in chemistry of all the mafic rocks is best accommodated in a compressional Eoarchean convergent plate boundary setting within a mobile-lid *** stagnant lid scenarios of crust formation,if operative,must have co-existed or alternated with mobile-lid regimes by 3800 Ma.

关键词： Eoarchean Fluid-fluxing plate tectonics Suprasubduction Crustal evolution

protein glycation:a wolf in sweet sheep’s clothing behind neurodegeneration

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第5期19卷 975-976页

作者： Ana B.Uceda Francisco Leal-pérez Miquel Adrover Institut Universitari d’Investigacióen Ciències de la Salut(IUNICS) Institut d’InvestigacióSanitària Illes Balears(IdISBa) Departament de Química Universitat de les Illes BalearsCtraPalma de MallorcaSpain

At the beginning of the 16th century,paracelsus coined the maxim:“the dose makes the poison”.This principle can be applied to all living organisms,including organs and *** brain and its glial and neuronal cells are ... 详细信息

关键词： organs sheep sweet

Structural build-up model for three-dimensional concrete printing based on kinetics theory

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

Frontiers of Structural and Civil Engineering 2024年第7期18卷 998-1014页

作者： prabhat Ranjan pREM p.S.AMBILY Shankar KUMAR Greeshma GIRIDHAR Dengwu JIAO Advanced Materials Laboratory CSIR-Structural Engineering Research CentreChennai 600113India Department of Architecture and Civil Engineering City University of Hong KongHong Kong 999077China

The thixotropic structural build-up is crucial in extrusion-based three-dimensional(3D)concrete *** paper uses a theoretical model to predict the evolution of static and dynamic yield stress for printed *** model employs a structural kinetics framework to create a time-independent constitutive link between shear stress and shear *** model considers flocculation,deflocculation,and chemical hydration to anticipate structural *** reversible and irreversible contributions that occur throughout the build-up,breakdown,and hydration are defined based on the proposed structural ***,detailed parametric studies are conducted to evaluate the impact of model *** is revealed that the proposed model is in good agreement with the experimental results,and it effectively characterizes the structural build-up of 3D printable concrete.

关键词： structural build-up rheology thixotropy 3D printable concrete kinetics theory ultra high performance concrete

Electron kinetic effects in back-stimulated Raman scattering bursts driven by broadband laser pulses

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Matter and Radiation at Extremes 2024年第4期9卷 54-67页

作者： Q.K.Liu L.Deng Q.Wang X.Zhang F.Q.Meng Y.p.Wang Y.Q.Gao H.B.Cai S.p.Zhu Graduate School China Academy of Engineering PhysicsBeijing 100088China Institute of Applied physics and Computational Mathematics Beijing 100094China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230026China Shanghai Institute of Laser plasma Shanghai 201800China HEDpS Center for Applied Physics and TechnologyPeking UniversityBeijing 100871China School of physics Zhejiang UniversityHangzhou 310027China

We examine electron kinetic effects in broadband-laser-driven back-stimulated Raman scattering(BSRS)bursts using particle-in-cell *** bursts occur during the nonlinear stage,causing reflectivity spikes and generating large numbers of hot ***-duration simulations are performed to observe burst events,and a simplified model is developed to eliminate the interference of the broadband laser’s random intensity *** the simplified model,we isolate and characterize the spectrum of electron plasma *** spectrum changes from a sideband structure to a turbulence-like structure during the burst.A significant asymmetry in the spectrum is *** asymmetry is amplified and transferred to electron phase space by high-intensity broadband laser pulses,leading to violent vortex-merging and generation of hot *** proportion of hot electrons increases from 6.76%to 14.7%during a single violent burst *** demonstrate that kinetic effects profoundly influence the BSRS evolution driven by broadband lasers.

关键词： scattering kinetic simplified

Numerical analysis of high‑speed railway slab tracks using calibrated and validated 3D time‑domain modelling

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Railway Engineering Science 2024年第1期32卷 36-58页

作者： A.F.Esen O.Laghrouche p.K.Woodward D.Medina‑pineda Q.Corbisez J.Y.Shih D.p.Connolly Institute for High‑Speed Rail and System Integration University of LeedsLeeds LS29JTUK Institute for Infrastructure and Environment Heriot-Watt UniversityEdinburgh EH144ASUK Alstom Transport Saint‑OuenFrance Birmingham Centre for Railway Research and Education University of BirminghamBirmingham B152TTUK

Concrete slabs are widely used in modern railways to increase the inherent resilient quality of the tracks,provide safe and smooth rides,and reduce the maintenance *** this paper,the elastic performance of a novel slab trackform for high-speed railways is investigated using three-dimensional finite element modelling in *** is then compared to the performance of a ballasted ***,slab and ballasted track models are developed to replicate the full-scale testing of track *** the models are calibrated with the experimental results,the novel slab model is developed and compared against the calibrated slab track *** slab and ballasted track models are then extended to create linear dynamic models,considering the track geodynamics,and simulating train passages at various speeds,for which the Ledsgard documented case was used to validate the *** travelling at low and high speeds are analysed to investigate the track deflections and the wave propagation in the soil,considering the issues associated with critical *** train loading methods are discussed,and the most practical approach is retained and ***,correlations are made between the geotechnical parameters of modern high-speed rail and conventional *** is found that considering the same ground condition,the slab track deflections are considerably smaller than those of the ballasted track at high speeds,while they show similar behaviour at low speeds.

关键词： High-speed railways Slab track New ballastless track Ballasted track Critical speeds Finite element modelling Calibration of numerical models