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Modeling of potential habitat suitability of Hippocamelus bisulcus: effectiveness of a protected areas network in Southern Patagonia

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Ecological Processes 2017年第1期6卷 296-309页

作者： Yamina Micaela Rosas Pablo LPeri alejandro huertas herrera Hernán Pastore Guillermo Martínez Pastur Laboratorio de Recursos Agroforestales Centro Austral de Investigaciones Científicas(CONICET)Houssay 200Ushuaia 9410Tierra del FuegoArgentina UNPA-INTA-CONICET.CC 332 Río Gallegos 9400Santa CruzArgentina Delegación Regional Patagonia Norte Administración de Parques NacionalesVicealmirante O’Connor 1188San Carlos de Bariloche 8400Río NegroArgentina

Introduction:Huemul(Hippocamelus bisulcus Molina)is the most threatened flag species of Southern Patagonia,where conservation efforts were not effective to avoid the retraction of its distribution *** quality modeling can assist to design better management strategies for regional conservation *** objective was to elaborate one habitat suitability map for huemul,defining the environmental characteristics at landscape level,and determining the distribution of the suitable habitat inside the current natural reserve ***:We used a database of 453 records and explored 40 potential explanatory variables(climate,topographic,and landscape variables including human-related ones)to develop one habitat suitability map using the Environmental Niche Factor Analysis(ENFA)for Santa Cruz province(Argentina).We combined the outputs in a GIS project using different shapes,including the current natural reserve ***:We defined the potential habitat for huemul,where forest edges and ecotone zones(e.g.,mainly alpine environments)were the most important environmental variables,as well as some forest types(e.g.,Nothofagus pumilio).Habitat losses were found in the extreme potential distribution areas(northern and southern areas),probably related to the increasing ranch *** current natural reserve network maintains approximately half of the huemul potential habitat in Santa Cruz province,where National Parks presented the similar conservation importance than the Provincial natural ***:Habitat suitability model for huemul can be used as a decision support system for new management strategies at different landscape levels to improve the current conservation efforts.

关键词： Nothofagus forests ENFA Habitat loss Conservation Species requirements

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The influence of canopy-layer composition on understory plant diversity in southern temperate forests

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Forest Ecosystems 2017年第2期4卷 154-166页

作者： Luciana Mestre Monica Toro-Manriquez Rosina Soler alejandro huertas-herrera Guillermo Martinez-Pastur Maria Vanessa Lencinas National Scientific and Technical Research Council (CONICET) Austral Center for Scientific Research (CADIC-CONICET) Houssay 200 9410 Ushuaia Tierradel Fuego Argentina

Background： Understory plants represents the largest component of biodiversity in most forest ecosystems and plays a key role in forest *** their importance, the influence of overstory-layer composition on understory plant diversity is relatively poorly understood within deciduous-evergreen broadleaved mixed *** aim of this work was to evaluate how tree overstory-layer composition influences on understory-layer diversity in three forest types（monospecific deciduous Nothofagus pumilio（Np）, monospecific evergreen Nothofagus betuloides（Nb）, and mixed ***（M） forests）, comparing also between two geographical locations（coast and mountain） to estimate differences at landscape ***： We recorded 46 plant species： 4 ferns, 12 monocots, and 30 ***-layer composition influences the herb-layer structure and diversity in two different ways： while mixed forests have greater similarity to evergreen forests in the understory structural features, deciduous and mixed were similar in terms of the specific composition of plant *** pure stands were the most diverse, meanwhile evergreen stands were least *** of exclusive species of mixed forest could represent a transition where evergreen and deciduous communities meet and ***, landscape has a major influence on the structure, diversity and richness of understory vegetation of pure and mixed forests likely associated to the magnitude and frequency of natural disturbances, where mountain forest not only had highest herb-layer diversity but also more exclusive ***： Our study suggests that mixed Nothofagus forest supports coexistence of both pure deciduous and pure evergreen understory plant species and different assemblages in coastal and mountain *** the mixture of canopy patch types within mixed stands will be important for conserving the natural patterns of understory plant composition in southern beech mixe

关键词： Landscape Understory communities Understory structure Forest structure Nothofagus Conservation

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Forage offering and seasonal intake comparisons to evaluate European rabbit threat in Nothofagus forests of southern Patagonia

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Ecological Processes 2022年第1期11卷 604-617页

作者： alejandro huertas herrera Mónica Toro‑Manríquez Laura Borrelli María Vanessa Lencinas Guillermo Martínez Pastur Centro de Investigación en Ecosistemas de la Patagonia(CIEP) Camino Baguales s/n Km 4CoyhaiqueChile Ulterarius Consultores Ambientales y Científicos Ltda. Ignacio Serrano 420CoyhaiqueChile Instituto Nacional de Tecnología Agropecuaria(INTA) EEA BarilocheModesta Victoria 44508400 San Carlos de BarilocheRío NegroArgentina Laboratorio de Recursos Agroforestales Centro Austral de Investigaciones Científicas(CADIC)Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET)Houssay 2009410 UshuaiaTierra del FuegoArgentina.

Background:The European rabbit(Oryctolagus cuniculus L.1758)was introduced into different regions of the world,generating significant trade‑offs that critically impacted native ***,we evaluate the rabbit’s forage intakes in three vegetation types(forests,shrublands,and grasslands)along the four seasons in a temperate forest landscape in Southern Patagonia and discuss the potential threats over native *** formulated the following questions:(i)what is the forage offer at each vegetation type?(ii)what is the rabbit’s forage intake and how it varied across the seasons along the year?and(iii)which vegetation types and plant life forms were more used according to the rabbit’s forage intakes?Methods:We censused understory vegetation to characterize the forage offer at each vegetation type and determined seasonal dietary intakes using microhistological analysis of *** plant species identified in the field were grouped according to life form classes(tree regeneration,shrubs,forbs,graminoids,orchids,ferns,bryophytes,and hemiparasites).Data were analysed through uni‑and multi‑variate analyses,determining relationships between forage offer and the rabbit’s forage ***:Forage intakes revealed changes in plant life form consumption across vegetation types,where intake pressure was considerably different for tree regeneration(p=0.001),graminoids(p=0.001),and hemiparasites(p=0.001).Besides,significant changes in consumption among seasons were detected for shrubs(p=0.001),ferns(p=0.030),and hemiparasites(p=0.002).Although many species play an important role in the rabbit’s forage intake networks(e.g.,Chiliotrichum diffusum,Holcus lanatus),the strongest intake linkages were found in exotic grasses(e.g.,Poa pratensis and Festuca sp.),native hemiparasites(e.g.,Misodendrum sp.),native shrubs(e.g.,Empetrum rubrum),and native trees(e.g.,Nothofagus sp.).The summer and autumn seasons presented higher intake compared to the winter and spring seasons.F

关键词： Forest ecology Oryctolagus cuniculus Plant-animal interaction Vegetation type Herbivory Habitat use

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Knowledge arising from long-term research of variable retention harvesting in Tierra del Fuego: where do we go from here?

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Ecological Processes 2019年第1期8卷 318-333页

作者： Guillermo J.Martínez Pastur Yamina M.Rosas Mónica Toro Manríquez alejandro huertas herrera Juan A.Miller Juan M.Cellini Marcelo D.Barrera Pablo L.Peri María V.Lencinas Centro Austral de Investigaciones Científicas(CADIC) Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET)Houssay 200(9410)UshuaiaTierra del FuegoArgentina Universidad Nacional de la Plata(UNLP) Calle 7 e/47 y 48(1900)La PlataBuenos AiresArgentina Instituto Nacional de Tecnología Agropecuaria(INTA) Universidad Nacional de la Patagonia Austral(UNPA)Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET)cc 332(9400)Río GallegosSanta CruzArgentina

Nothofagus pumilio forests in Tierra del Fuego are the southernmost forests in the world,where extreme climate conditions represent a challenge to attain sustainable forest *** forestry was proposed as an alternative to increase the species conservation in managed ***,we synthetized results related to the implementation of a variable retention harvesting based on a combination of aggregate patches and dispersed retention during the last 18 years comparing with other silviculture proposals(e.g.,shelterwood cuts)and control treatments(primary unmanaged forests).We summarized the results for(i)sawmill operations,(ii)timber yield,(iii)overstory stability,(iv)forest structure,(v)microclimate and natural cycles,(vi)natural regeneration dynamics(flowering,seeding,foraging,recruitment,growth,and mortality),and(vii)biodiversity(mammals,understory plants,mistletoes,birds,arthropods,mosses,lichens,and fungi).In general,aggregate patches maintained forest structure and micro-environmental variables,and slightly increased biodiversity and forest reproduction variables compared to unmanaged primary *** the contrary,dispersed retention decreased forest structure variables and greatly increased biodiversity(richness and abundance)when it was compared to unmanaged primary *** conditions are influenced by variable retention harvesting,but direction and magnitude of the effect depend and differ according to retention *** this,biodiversity taxa greatly differed among groups depending on retention *** general,the species assemblages in aggregate patches were similar to those found in primary unmanaged forests,while they were significantly modified in the dispersed *** occurred due to(i)local extinction of some original species,(ii)the introduction of native species from the surrounding environments,or(iii)the invasion of exotic *** silvicultural method has been a useful tool to conserve biodiversity and ec

关键词： Aggregate patches Dispersed retention Biodiversity conservation Long-term sustainability Timber production

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The reaction electronic flux in chemical reactions

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Science China Chemistry 2011年第12期54卷 1982-1988页

作者： CERON María Luisa ECHEGARAY Eleonora GUTIRREZ-OLIVA Soledad herrera Barbara TORO-LABB alejandro Laboratorio de Química Teorica Computacional(QTC) Facultad de Química Pontificia Universidad Catolica de Chile

The mechanism of a chemical reaction can be characterized in terms of chemical events that take place during the *** events are bond weakening/breaking and/or bond strengthening/*** reaction electronic flux(REF),a concept that identifies and rationalizes the electronic activity taking place along the reaction coordinate,has emerged recently as a powerful tool for characterizing the mechanism of chemical reactions.A quantitative theory introducing new descriptors for characterizing reaction mechanisms is presented in detail and three illustrative examples are *** nucleophilic substitution reactions the REF indicates that bond breaking or forming events may be leading the electronic activity whereas in the methanol decomposition reaction by copper oxide,the REF allows to discover that consecutive electronic reductions of copper together with bond breaking processes control the course of the reaction.

关键词： reaction mechanisms chemical potential conceptual DFT reaction electronic flux (REF)

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Synthesis of activated carbons from black sapote seeds,characterization and application in the elimination of heavy metals and textile dyes

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Chinese Journal of Chemical Engineering 2020年第2期28卷 613-623页

作者： Alejandra Alicia Peláez-Cid Vincent Romero-Hernández Ana María herrera-González alejandro Bautista-Hernández Oscar Coreno-Alonso Facultad de Ingeniería Benemérita Universidad Autónoma de PueblaMexico Instituto de Ciencias Básicas e Ingeniería Universidad Autónoma del Estado de HidalgoMexico División de Ingenierías Universidad de GuanajuatoMexico

Many different techniques may be used to remove industrial pollutants from wastewater. Adsorption using activated carbon has been reported to be an effective method. This work proposes the use of a vegetable residue(black sapote seeds) as a raw material for its synthesis. These carbons were chemically activated using phosphoric acid and carbonized at 673 and 873 K. Adsorption isotherms were constructed for the textile dyes on the carbons, and this data was treated using Langmuir’s equation to quantitatively describe the adsorption process. The synthesized carbons were characterized using FTIR, EA, SEM, Nitrogen adsorption(specific surface areas of 879 and 652 m2·g-1), and their points of zero charge(2.1 and 2.3). It was possible to adsorb both heavy metals and textile dyes present in aqueous solutions and wastewaters using these activated carbons. Heavy metals were adsorbed almost completely by both carbons. Cationic dyes where adsorbed(58–59.8 mg·g-1) in greater amounts compared to anionic dyes(10–58.8 mg·g-1). The amount of anionic dyes adsorbed increased almost 30% by changing the pH of the solutions. One of the carbons was thermally regenerated on three occasions without losing its adsorption capacity and it was proved in a flow system.

关键词： Activated carbons Black sapote seeds Heavy metal adsorption Textile dye adsorption Wastewater treatment

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Comment on "Vortex of Fluid Field as Viewed from Curvature" [Commun. Theor. Phys. 43 (2005) 604]

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Communications in Theoretical Physics 2010年第1期53卷 43-44页

作者： Blas herrera Gerard Fortuny Departament d'Enginyeria Informàtica i Matemàtiques Universitat Rovira i Virgili

Here, we make comments to the conclusions of the paper： LIU Shi-Da, Sill Shao-Ying, LIU Shi-Kuo, et al., ＂Vortex of Fluid Field as Viewed from Curvature＂ [Commun. Theor. Phys. 43 （2005） 604].

关键词： curvature vortex

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TWO NOVEL GRADIENT METHODS WITH OPTIMAL STEP SIZES

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Journal of Computational Mathematics 2021年第3期39卷 375-391页

作者： Harry Oviedo Oscar Dalmau Rafael herrera Centro de Investigacion en Matematicas CIMAT A.C.GuanajuatoGto.Mexico

In this work we introduce two new Barzilai and Borwein-like steps sizes for the classical gradient method for strictly convex quadratic optimization *** proposed step sizes employ second-order information in order to obtain faster gradient-type *** step sizes are derived from two unconstrained optimization models that involve approximate information of the Hessian of the objective function.A convergence analysis of the proposed algorithm is *** numerical experiments are performed in order to compare the efficiency and effectiveness of the proposed methods with similar methods in the ***,it is observed that our proposals accelerate the gradient method at nearly no extra computational cost,which makes our proposal a good alternative to solve large-scale problems.

关键词： Gradient methods Convex quadratic optimization Hessian spectral properties Steplength selection

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Identification of boundary surfaces in flows

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Applied Mathematics and Mechanics(English Edition) 2010年第9期31卷 1097-1104页

作者： B.herrera J.PALLARES Department d'Enginyeria Informàtica i Matematiques Universitat Rovira i VirgiliAvinguda Pasos Catalans 26Tarragona 43007Spain Department d'Enginyeria Mecànica Universitat Rovira i VirgiliAvinguda Pasos Catalans 26Tarragona 43007Spain

In this study, boundary surfaces of a flow field are defined as stream surfaces, on which the shear rates vanish, and a procedure is proposed to find them. The method, based on calculations using the velocity vector f... 详细信息

关键词： interracial surfaces structure of flow kinematics

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Human Interaction Dynamics for Its Use in Mobile Robotics:Impedance Control for Leader-follower Formation

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IEEE/CAA Journal of Automatica Sinica 2017年第4期4卷 696-703页

作者： Daniel herrera Flavio Roberti Marcos Toibero Ricardo Carelli Instituto de Automatica Universidad Nacional de San Juan-CONICET IEEE

A complete characterization of the behavior in human-robot interactions(HRI) includes both: the behavioral dynamics and the control laws that characterize how the behavior is regulated with the perception data. In this way, this work proposes a leader-follower coordinate control based on an impedance control that allows to establish a dynamic relation between social forces and motion error. For this, a scheme is presented to identify the impedance based on fictitious social forces, which are described by distance-based potential *** part of the validation procedure, we present an experimental comparison to select the better of two different fictitious force structures. The criteria are determined by two qualities: least impedance errors during the validation procedure and least parameter variance during the recursive estimation ***, with the best fictitious force and its identified impedance,an impedance control is designed for a mobile robot Pioneer 3AT,which is programmed to follow a human in a structured *** to results, and under the hypothesis that moving like humans will be acceptable by humans, it is believed that the proposed control improves the social acceptance of the robot for this kind of interaction.

关键词： Human modeling human-machine interaction impedance control robot dynamics social robotics

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