检索结果-南通市图书馆

Extreme drought triggers parallel shifts in wood anatomical and physiological traits in upper treeline of the Mediterranean Andes

在线全文

学校读者我要写书评

暂无评论

Ecological Processes 2024年第1期13卷 132-143页

作者： Luiz Santini Jr. Dylan Craven Daigard Ricardo Ortega rodriguez Manolo Trindade Quintilhan Stephanie Gibson-Carpintero Cristina Aravena Torres Fidel A.Roig Ariel A.Mu?oz alejandro Venegas-Gonzalez Hémera Centro de Observación de la Tierra Universidad Mayor GEMA Center for Genomics Ecology and Environment Universidad Mayor Data Observatory Foundation ANID Technology Center Depart-ment of Forest Sciences ESALQ-University of Sao Paulo Department of Plant Biology Institute of Biology University of Campinas Instituto de Geografía Universidad Nacional Autónoma de México (UNAM) Argentine Institute of Nivology Glaciology and Environmental Sciences(IANIGLA CONICET ) Institute of Geography Pontificia Universidad Católica de Valparaíso Instituto de Ciencias Agroalimentarias Animales y Ambientales (ICA3) Universidad de O'Higgins

Background Treeline ecotones of Mediterranean ecoregions have been affected by the increasing intensity and severity of droughts. Even though the effect of droughts on forest dynamics has been widely documented, knowledge is relatively scarce of how extreme climate episodes affect the hydraulic structure and, therefore, the phys-iology of woody plants. The Mediterranean Andes have experienced an uninterrupted period of drought since 2010, including an extremely dry year in 2019 with approximately 80% rainfall deficit. Here, we investigated shifts in wood anatomical and physiological traits of Kageneckia angustifolia, an endemic treeline species, in response to this drought *** We evaluated the xylem plasticity of three K. angustifolia populations across their natural distribution(31–35° SL) based on anatomical(vessel structure and distribution) and physiological(intrinsic water-use efficiency) variables in the tree rings. We focused on the period 2000–2020 that corresponds to before the megadrought(2000–2007),(ii) megadrought(2008–2018) and(iii) hyperdrought(2019–2020). The variables were annualized and analyzed by linear mixed-effects *** Our results provide insights to the anatomical and physiological mechanisms underlying the resilience of treeline forests to persistent droughts in central Chile. We found that the extreme drought in 2019–2020 triggered shifts in vessel size and frequency that increased hydraulic safety. These significant shifts in vessel traits occurred in parallel with a decrease in pit aperture area and an increase in water-use efficiency, further increasing the resilience of K. angustifolia to extreme drought *** Our results revealed coordinated shifts in vessel size and frequency and water-use efficiency in response to the megadrought, thereby reducing vulnerability to hydraulic failure. The apparent resilience of K. angustifolia to extreme droughts suggests that this adaptation to drought stress may incre

关键词： Dendro-anatomy Kageneckia angustifolia Xylem vulnerability Drought Climate change

Factors affecting the spatial distribution and breeding habitat of an insular cliff-nesting raptor community

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2018年第2期64卷 173-181页

作者： Beneharo rodriguez Airam rodriguez Felipe SIVERIO Manuel SIVERIO Canary Islands' Ornithology and Natural History Group (GOHNIC) La Malecita s/n 38480 Buenavista del NorteTenerife Canary Islands Spain Department of Evolutionary Ecology Estacion Biologica de DoSana (CSIC)Avda. Americo Vespucio s/n Seville 41092 Spain

The specific spatial distribution and habitat association--strongly influenced by environmental fac- tors or competitive interactions--are major issues in ecology and conservation. We located and georeferenced nesting sites of five cliff-nesting raptors （Egyptian vulture Neophron percnopterus [a locally extinct species], common buzzard Buteo buteo, osprey Pandion haliaetus, common kes- trel Falco tinnunculus, Barbary falcon Falco peregrinus pelegrinoides）, and common raven Corvus corax on one of the most biodiverse hotspot within the Canary Islands （Teno, Tenerife）. We used generalized linear models to evaluate the factors affecting abundance, richness, and intra- and interspecific interactions. Raptor abundance increased with slope, shrub-covered area, and habitat diversity, and decreased with altitude, and forested and grassed areas. Richness increased with slope and decreased with altitude. Threatened species （osprey, Barbary falcon, and raven） occu- pied cliffs farther away from houses and roads, and more rugged areas than the non-threatened species. The models suggested that the probability of cliff occupation by buzzards, falcons, and rav- ens depended only on inter-specific interactions. Buzzard occupation increased with the distance to the nearest raven and kestrel nests, whereas falcons and ravens seek proximity to each other. Teno holds between 75% and 100% of the insular breeding populations of the most endangered species （osprey and raven）, indicating the high conservation value of this area. Our study suggests that the preservation of rugged terrains and areas of low human pressure are key factors for raptor conservation and provide basic knowledge on the community structure and habitat associations to develop appropriated management actions for these fragile island populations.

关键词： Canary Islands competitive interactions human disturbances habitat threatened species.

Inexpensive and flexible nanographene-based electrodes for ubiquitous electrocardiogram monitoring

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

npj Flexible Electronics 2019年第1期3卷 100-105页

作者： Francisco J.Romero Encarnacion Castillo Almudena Rivadeneyra alejandro Toral-Lopez Markus Becherer Francisco G.Ruiz Noel rodriguez Diego P.Morales Pervasive Electronics Advanced Research Laboratory University of Granada18071 GranadaSpain Department of Electronics and Computer Technology University of Granada18071 GranadaSpain Institute for Nanoelectronics Technische Universität München80333 MunichGermany Biochemistry and Electronics as Sensing Technologies Group University of Granada18071 GranadaSpain

Flexible electronics is one of the fundamental technologies for the development of electronic skin,implant wearables,or ubiquitous *** this context,graphene-derived materials have attracted great interest due to their unique properties to fulfill the demands of these *** we report a simple one-step method for the fabrication of electrophysical electrodes based on the photothermal production of porous nanographene structures on the surface of flexible polyimide *** approach constitutes an inexpensive alternative to the commercial medical electrodes,leading to a lower and much more stable skin–electrode contact resistance and providing comparable signal *** technology has been framed inside the IoT paradigm through the development of a denoising and signal classification clustering algorithm suitable for its implementation in wearable *** experiments have shown promising achievements regarding noise reduction,increasing the crest factor~3.7 dB,as well as for the over 90%heart rate-monitoring accuracy.

关键词： ubiquitous IoT electrodes

Characterization of Gromov Hyperbolic Short Graphs

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

Acta Mathematica Sinica,English Series 2014年第2期30卷 197-212页

作者： José Manuel rodriguez Departamento de Matemticas Universidad Carlos III de MadridAvenida de la Universidad 30

To decide when a graph is Gromov hyperbolic is,in general,a very hard *** this paper,we solve this problem for the set of short graphs（in an informal way,a graph G is r-short if the shortcuts in the cycles of G have length less than r）：an r-short graph G is hyperbolic if and only if S9r（G）is finite,where SR（G）：=sup{L（C）：C is an R-isometric cycle in G}and we say that a cycle C is R-isometric if dC（x,y）≤dG（x,y）＋R for every x,y∈C.

关键词： Short graph Gromov hyperbolicity Gromov hyperbolic graph infinite graphs geodesics

Effects of medium-and long-distance running on cardiac damage markers in amateur runners:a systematic review,meta-analysis,and metaregression

在线全文

学校读者我要写书评

暂无评论

Journal of Sport and Health Science 2021年第2期10卷 192-200页

作者： Jacobo A.Rubio-Arias Luis Andreu Luis Manuel Martinez-Aranda alejandro Martinez-rodriguez Pedro Manonelles Domingo J.Ramos-Campo Faculty of Sport Catholic University of San Antonio(UCAM)Murcia 30107Spain LFE Research Group Department of Health and Human PerformanceFaculty of Physical Activity and Sport Science-INEFUniversidad Politecnica de MadridMadrid 28040Spain International Chair of Sports Medicine Catholic University of San Antonio(UCAM)Murcia 30107Spain Neuroscience of Human Movement Research Group(Neuromove) Catholic University of San Antonio(UCAM)Murcia 30107Spain Faculty of Sciences University of AlicanteAlicante 03690Spain

Background:To finish an endurance race,athletes perform a vigorous effort that induces the release of cardiac damage *** are several factors that can affect the total number of these markers,so the aim of this review was to analyze the effect of endurance running races on cardiac damage markers and to identify the factors that modify the levels of segregation of these cardiac damage ***:A systematic search of PubMed,Web of Science,and the Cochrane Library databases was *** analysis included studies where the acute effects of running races on cardiac damage markers(troponin I and troponin T)were analyzed,assessing the levels of these markers before and after the ***:The effects of running races on troponin I(mean difference=0.0381 ng/mL)and troponin T(mean difference=0.0256 ng/mL)levels were *** ages(R^(2)=14.4%,p=0.033)and body mass indexes(R^(2)=14.5%,p=0.045)of the athletes had a significant interaction with troponin *** addition,gender,mean speed,time to finish the race,and type of race can affect the level of cardiac damage ***:Endurance running races induce the release of cardiac-damage markers that remain elevated for at least 24 h after the *** addition,young male athletes with high body mass indexes who perform races combining long duration and moderate intensity(i.e.,marathons)release the highest levels of cardiac damage *** should take into consideration these results in the diagnosis and treatment of patients admitted to the hospital days after finishing endurance running races.

关键词： Endurance races Troponin I Troponin T Ultra-endurance

Small-signal Model for Dual-active-bridge Converter Considering Total Elimination of Reactive Current

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2021年第2期9卷 450-458页

作者： Juan Ramon rodriguez-rodriguez Nadia Maria Salgado-Herrera Jacinto Torres-Jimenez Nestor Gonzalez-Cabrera David Granados-Lieberman Martin Valtierra-rodriguez the Universidad Nacional Autonoma de Mexico Facultad de IngenieriaDepto.Energia Electri-ca.Av.Universidad 3000Col.UNAM CUCoyoacanCDMXMexico the Instituto de Energias Renovables Universidad Nacional Autonoma de MexicoPriv.Xochicalco s/nCol.Centro.TemixcoMorelosMexico the Instituto Tec-nologico Superior de Irapuato Carretera Irapuato-Silao km 12.5.IrapuatoGuanajuatoMexico the Universidad Autonoma de Queretaro Campus San Juan del RioRio Moctezuma 249San Juan del RioQueretaroMexico

Emerging technologies such as electric vehicles,solid-state transformers,and DC transformers are implemented using the closed-loop bi-directional dual-active-bridge(DAB)*** this context,it is necessary to have average models that provide an efficient way of tuning the proportional integral(PI)compensator parameters for large-and small-signal *** present a novel small-signal model(SSM)for DAB converter with a single closed-loop PI controller and the total elimination of reactive current(IQ=0).The method applies a modulation technique for IQ=0 and introduces a composite function in the controller while reducing the original nonlinear switching model,which allows to decrease the order of the transfer function and analyze the closed-loop *** proposed SSM is analyzed using different response time,load,and DC voltage *** simulation and experimental results demonstrate the ease of implementation and effectiveness of the proposed model with respect to other SSM techniques.

关键词： Small-signal model(SSM) dual-active-bridge(DAB)converter reactive current elimination proportional integral(PI)control

Automatic Bone Surface Restoration for Markerless Computer-Assisted Orthopaedic Surgery

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2022年第1期35卷 85-90页

作者： Xue Hu Ferdinando rodriguez y Baena Mechatronics in Medicine Laboratory Imperial College LondonLondonUK

An automatic markerless knee tracking and registration algorithm has been proposed in the literature to avoid the marker insertion required by conventional computer-assisted knee surgery,resulting in a shorter and less invasive surgical ***,such an algorithm considers intact femur geometry *** bone surface modification is inevitable due to intra-operative *** mismatched correspondences will degrade the reliability of registered target *** solve this problem,this work proposed a supervised deep neural network to automatically restore the surface of processed *** network was trained on a synthetic dataset that consists of real depth captures of a model leg and simulated realistic femur *** to the evaluation on both synthetic data and real-time captures,the registration quality can be effectively improved by surface *** improvement in tracking accuracy is only evident over test data,indicating the need for future enhancement of the dataset and network.

关键词： Bone surface reconstruction Computer assisted orthopedic surgery Markerless femur tracking

The regional employment implications of a net-zero economy in Costa Rica under uncertainty

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2023年第6期14卷 988-999页

作者： Maria JoséSAUMA CHACON alejandro MATARRITA VALVERDE Bernardo ZUNIGA ALVARADO Monica rodriguez-ZUNIGA Jairo QUIROs-TORTOS Luis ViCTOR-GALLARDO Pauline SCHAAL Paula CUBILLOS Thierry DUPLAN Matthieu ROBIN Slim DALI Universidad de Costa Rica San Jose 11501-2060Costa Rica Agence Frangaise de Developpement Paris 75598 France

This study estimates job creation from Costa Rica's transition to net-zero emissions by 2050,contrasting it with a business-as-usual scenario(BAU)using employment multipliers from Costa Rica's input-output *** model is soft-linked with a bottom-up technology-rich regional model of the CLEW sectors in Costa Rica.A robust decision-making-inspired approach is taken to assess the effects of uncertainty on the *** study addresses a literature gap in modeling subnational employment while accounting for long-term uncertainty and allows to identify economic activities affected by the transformation,so that policies regarding a just transition can be properly developed and stakeholders incentivized to take active participation in the *** baseline assumptions,a net-zero economy would have 135 thousand more jobs by 2050 than the BAU,equivalent to 7%of the employed population in ***-related jobs would triple by mid-21st century,and regions capitalizing on renewables would perceive the highest *** considering uncertainty,the net jobs range between 35-750 *** net positive outcomes in terms of jobs are feasible,global governance should focus efforts on policies that enhance these.

关键词： Decarbonization Environmental policy Input-output Employment multipliers Costa Rica

Near shore seismic movements induced by seaquakes using the boundary element method

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

Earthquake Engineering and Engineering Vibration 2017年第3期16卷 571-585页

作者： alejandro Rodríguez-Castellanos Manuel Carbajal-Romero Norberto Flores-Guzmán J.Efraín Rodríguez-Sánchez Andriy Kryvko instituto mexicano del petróleo eje central lázaro cárdenas 152Gustavo A.MaderoDistrito FederalMéxico escuela superior de ingeniería mecánicay eléctrica instituto politécnico nacionalupalmEdif.5Av.Instituto Politécnico Nacional S/NCol.LindavistaGustavo A.MaderoDistrito FederalMéxico escuela superior de ingeniería mecánicay eléctrica instituto politécnico nacionalunidad profesional azcapotzalcoDistrito FederalMéxico centro de investigación en matemáticas jalisco s/nmineral de valencianaguanajuatoMéxico

This study quantifies seismic amplifications in near-shore arising from seaquakes. Within the Boundary Element Method, boundary elements are used to irradiate waves and force densities obtained for each element. Huygens′ Principle is implemented since the diffracted waves are constructed at the boundary from which they are radiated, which is equivalent to Somigliana′s theorem. Application of boundary conditions leads to a system of integral equations of the Fredholm type of second kind and zero order. Several numerical configurations are analyzed： The first is used to verify the present formulation with ideal sea floor configurations to estimate seismic amplifications. With the formulation verified, simple slope configurations are studied to estimate spectra of seismic motions. It is found that P-waves can produce seismic amplifications from 1.2 to 3.9 times the amplitude of the incident wave. SV-waves can generate seismic amplifications up to 4.5 times the incident wave. Another relevant finding is that the highest amplifications are at the shore compared to the ones at the sea floor.

关键词： seismic amplifications seaquake earthquake elastic waves boundary element method near shore cities