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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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Open versus laparoscopic cholecystectomies in patients with or without type 2 diabetes mellitus in Spain from 2003 to 2013

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Hepatobiliary & Pancreatic Diseases International 2016年第5期15卷 525-532页

作者： JoséM de Miguel-Yanes Manuel Méndez-Bailón Rodrigo Jiménez-García Valentín Hernández-barrera Napoleón Pérez-Farinós Fernando Turégano Nuria Munoz-Rivas Ana López-de-Andrés Internal Medicine Department Hospital General Universitario“Gregorio Maranón”46Doctor Esquerdo28007MadridSpain Internal Medicine Department Hospital Clínico San CarlosCalle Profesor Martín Lagos28040MadridSpain Preventive Medicine and Public Health Department Health Sciences FacultyRey Juan Carlos UniversityAvenida de AtenasAlcorcón28292MadridSpain Spanish Agency of Alimentary Safety and Nutrition Ministry of HealthSocial Policy and Equality56Alcalá28071MadridSpain Internal Medicine Department Hospital Infanta Leonor80Avenida Gran Vía del Este28031MadridSpain Surgery Department Hospital General Universitario“Gregorio Maranón”46Doctor Esquerdo28007MadridSpain

BACKGROUND: This study aimed to compare the rates of open and laparoscopic cholecystectomies and outcomes in patients with or without type 2 diabetes mellitus (T2DM) in Spain from 2003 to 2013. METHODS: We collected all cases of open and laparoscopic cholecystectomies using national hospital discharge data and evaluated the annual cholecystectomy rates stratiifed by T2DM status. We analyzed tendency for in-hospital mortality (IHM). We also analyzed the impact of T2DM on IHM in patients who underwent cholecystectomies. RESULTS: We identiifed 611 533 cholecystectomies (71.3%laparoscopic) in the patients, in whom 78 227 (12.8%) patients had T2DM. The rates of open cholecystectomies were 3-fold higher (130.0/105 vs 41.1/105) in patients with T2DM than in those without T2DM, and the rate of laparoscopic cholecys-tectomies was almost 2-fold higher (195.2/105 vs 111.8/105) in patients with T2DM. The annual rate of laparoscopic pro-cedures showed an 11-year relative increase of 88.3% (from 117.0/105 to 220.3/105) in T2DM and 49.2% (from 79.2/105 to 118.2/105) in patients without T2DM (P CONCLUSION: The rate of cholecystectomy was higher in patients with T2DM, and laparoscopic cholecystectomy was p

关键词： diabetes mellitus cholecystectomy mortality in-hospital mortality

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Use of a combination strategy to improve neuroprotection and neuroregeneration in a rat model of acute spinal cord injury

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Neural Regeneration Research 2019年第6期14卷 1060-1068页

作者： Elisa García Roxana Rodríguez-barrera Vinnitsa Buzoianu-Anguiano Adrian Flores-Romero Emanuel Malagón-Axotla Marco Guerrero-Godinez Estefanía De la Cruz-Castillo Laura Castillo-Carvajal Monserrat Rivas-Gonzalez Paola Santiago-Tovar Ivis Morales Cesar Borlongan Antonio Ibarra Centro de Investigación en Ciencias de la Salud (CICSA) Facultad de Ciencias de la SaludUniversidad Anáhuac México Campus Norte Centro de Investigación del Proyecto CAMINA A.C. Unidad de Investigación Médica en Enfermedades Neurologicas Hospital Especialidades CMN Siglo XXI Unidad de Rehabilitación Osteoarticular.Instituto Nacional de Rehabilitación. Luis Guillermo Ibarra Ibarra Center of Excellence for Aging and Brain Repair Department of Neurosurgery and Brain RepairUniversity of South Florida Morsani College of Medicine

Spinal cord injury is a very common pathological event that has devastating functional consequences in patients. In recent years, several research groups are trying to find an effective therapy that could be applied in clinical practice. In this study, we analyzed the combination of different strategies as a potential therapy for spinal cord injury. Immunization with neural derived peptides(INDP), inhibition of glial scar formation(dipyridyl: DPY), as well as the use of biocompatible matrix(fibrin glue: FG) impregnated with bone marrow mesenchymal stem cells(MSCs) were combined and then its beneficial effects were evaluated in the induction of neuroprotection and neuroregeneration after acute SCI. Sprague-Dawley female rats were subjected to a moderate spinal cord injury and then randomly allocated into five groups: 1) phosphate buffered saline; 2) DPY; 3) INDP + DPY; 4) DPY+ FG; 5) INDP + DPY + FG + MSCs. In all rats, intervention was performed 72 hours after spinal cord injury. Locomotor and sensibility recovery was assessed in all rats. At 60 days after treatment, histological examinations of the spinal cord(hematoxylin-eosin and Bielschowsky staining) were performed. Our results showed that the combination therapy(DPY+ INDP + FG+ MSCs) was the best strategy to promote motor and sensibility recovery. In addition, significant increases in tissue preservation and axonal density were observed in the combination therapy group. Findings from this study suggest that the combination theapy(DPY+ INDP + FG + MSCs) exhibits potential effects on the protection and regeneration of neural tissue after acute spinal cord injury. All procedures were approved by the Animal Bioethics and Welfare Committee(approval No. 178544; CSNBTBIBAJ 090812960)on August 15, 2016.

关键词： fibrin glue mesenchymal stem cells glial scar protective autoimmunity neural derived peptides neural regeneration

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Characterization and Classification of Agricultural Production Systems in the Galapagos Islands (Ecuador)

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Agricultural Sciences 2021年第5期12卷 481-502页

作者： Víctor barrera Álvaro Monteros-Altamirano Marilú Valverde Luis Escudero Joanna Allauca Angélica Zapata Estación Experimental Santa Catalina Instituto Nacional de Investigaciones Agropecuarias (INIAP) Quito Ecuador Researchers at the Centro de Bioconocimiento y Desarrollo Agrario CBDA Galapagos INIAP San Cristobal Island GalapagosEcuador

The low level of agricultural productivity within the production systems in the insular region of Galapagos is caused by the lack of sustainable technologies accordingly to the insular conservation regime. As a consequence, producers face low productivity and economic losses, which result in low levels of incomes and hasten the change from agricultural to tourist activities. With consequent abandonment of productive lands, the presence of invasive species and pathogens has become a growing threat to the biodiversity of the Galapagos National Park. For this reason, it is necessary to generate and disseminate technologies adapted to the prevalent production systems in the islands. Primary data were collected through face-to-face surveys in a sample of 208 producers from 4 islands during the period from July to November 2018. Multivariate analyses (principal components and cluster) were applied to characterize and classify typical agricultural production systems. The results show three types of systems, differentiated mainly by the technology used in the management of agricultural production, that influence the yields of crops and of animal products such as beef and milk, which cannot satisfy the demand for food on the islands, which has created the dependence on imports to cover the production gap. The definition of the types of agricultural production systems can help in identifying sustainable production alternatives that integrate local social and environmental needs. This is one of the very few technical descriptions of farms on the islands and should be used by policymakers to plan interventions.

关键词： Agricultural Productivity Types of Systems Biodiversity Multivariate Analysis

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四足机器人仿生腿结构特性及其控制系统研究

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机械设计与制造 2018年第A1期 150-153页

作者：黄林考谭跃刚 David Nicolas Torres barrera 赵东升武汉理工大学机电工程学院湖北武汉430000

针对四足机器人整机对单个支撑腿的要求,对机械腿结构特性和控制系统展开研究。基于对四足动物腿部生理结构分析,提出具有两个主动关节和一个被动关节的四足机器人仿生腿结构,并完成运动学特性分析。通过分析仿生四足机器人控制系统功... 详细信息

针对四足机器人整机对单个支撑腿的要求,对机械腿结构特性和控制系统展开研究。基于对四足动物腿部生理结构分析,提出具有两个主动关节和一个被动关节的四足机器人仿生腿结构,并完成运动学特性分析。通过分析仿生四足机器人控制系统功能与性能要求,提出具有开放性、模块化和结构紧凑特点的仿生四足机器人控制系统方案,基于DSP设计并实现仿生腿控制系统。实验证明仿生腿结构合理,控制系统稳定可靠且具有良好的扩展性,仿生腿系统可作为下层模块集成到仿生四足机器人系统。

关键词：四足机器人仿生腿控制系统结构特性

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Gamma Irradiation Effect on Nylon 6-12 Modification under Argon Atmosphere

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材料科学与工程（中英文B版） 2012年第4期2卷 247-254页

作者： Carmina Menchaca Griselda Demesa Anabel Santiaguillo Gonzalo Martinez-barrera Hetor Lopez-Valdivia Hetor Carrasco Jorge Uruchurtu Centro de Investigacion en Ingenieria y Ciencias Aplicadas （CIICAp） Universidad Aut6noma del Estado de Morelos Cuernavaca Morelos Mexico Laboratorio de Investigacion y Desarrollo de Materiales Avanzados （LIDMA） Facultad de Quimica Universidad Aut6noma del Estado de Mexico Edo. de Mexico Mexico Sintesis y Caracterizacion de Materiales Instituto Nacional de lnvestigaciones Nucleares Edo. de Mexico Mexico

Nylon is an important industrial material, and gamma irradiation is used for material modification. In this work, different gamma radiation dose were applied to crystalline fibres of nylon 6-12 at room temperature under argon atmosphere. Post-radiation effect was also studied, to know the effects of time. Some physical properties were measured obtaining the degree of modification with respect to the applied dose. X-ray values showed increment on the crystallinity and crystal size with dose increase up to 300 kGy. Brill Transition can be appreciated as a result of the in-situ X-ray with temperature study. Thermal analyses and AFM roughness measurements corroborate the modifying mechanisms in terms of the applied dose. For 15 and 50 kGy re-polymerization and crosslinking are the main mechanisms. Increment in the melting point at 15 kGy occurs, returning at 50 kGy to the original value. For 100 to 300 kGy the chain scission is the dominant mechanism because the melting point is lower than the original one. Both mechanisms take place in the amorphous zone.

关键词：改性尼龙辐射效应氩气保护伽玛辐射剂量原子力显微镜 γ射线辐照粗糙度测量

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Morphometric Analysis on Shape Transition during Growth of the Red Snapper (<em>Lutjanus campechanus</em>, Poey, 1860)

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Open Journal of Marine Science 2018年第4期8卷 407-430页

作者： Elvia Teresa Mendoza-barrera María Eugenia Vega-Cendejas Monica Améndola-Pimenta Rossanna Rodríguez-Canul Departamento de Recursos del Mar. Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN)-Unidad Mérida. Carr. Mérida Yucatán México

The red snapper Lutjanus campechanus (Poey, 1860) has a high commercial value that sustains an important fishery in Mexico. In this study, the patterns in morphological variations from early juvenile to adult stages were assessed by geometric methods (GM) in 194 organisms. Changes in shape were more evident and rapid in the early juvenile stage and decreased during adulthood. The principal components analysis of shape (Relative Warp Analysis, or RWA) identified size and body depth as the main sources of variance associated to both juvenile and adult organisms. The outline of the head and the tail showed the most noticeable differences following the ontogenic pathway visualized by thin-plate splines indicating that the ontogenetic pathway of the upper half and the lower half of the dorsal head profile (DHP) are in relatively opposite directions than those from the tail that bends ventrally. The Two-Block Partial Least Square analysis (2B-PLS) and their CR coefficients showed that the two modules had a moderate linear trend (p = 0.001). Although the blocks have morphological changes at different rates, there is a moderate synchrony in growth by modules. This study is the first to report the use of geometrical morphometry in L. campechanus in Mexico.

关键词： Lutjanus campechanus Ontogeny Shape Integration 2B-PLS CR Coefficient

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A Novel Process Using Ion Exchange Resins for the Coproduction of Ethyl and Butyl Acetates

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Green and Sustainable Chemistry 2018年第3期8卷 221-246页

作者： Nydia Ileana Guzman barrera Cecile Bories Jerome Peydecastaing Caroline Sablayrolles Emeline Vedrenne Carlos Vaca-Garcia Sophie Thiebaud-Roux Laboratoire de Chimie Agro-industrielle(LCA) Universite de ToulouseINRAINPTToulouseFrance

Before proposing an innovative process for the coproduction of ethyl and butyl acetates, the individual syntheses of ethyl acetate and butyl acetate by two different routes were first studied. These syntheses involved the reaction of ethanol or n-butanol with acetic acid or acetic anhydride in the presence of ion exchange resins: Amberlyst 15, Amberlyst 16, Amberlyst 36 and Dowex 50WX8. Kinetic and thermodynamic studies were performed with all resins. The lowest activation energy (Ea) value was obtained with Dowex 50WX8, which was identified as the best-performing resin, able to be reused at least in four runs without regeneration. The presence of water-azeotropes during the synthesis of ethyl acetate makes its purification difficult. A new strategy was adopted here, involving the use of ethanol and acetic anhydride as the starting material. In order to minimize acetic acid as co-product of this reaction, a novel two-step process for the coproduction of ethyl and butyl acetates was developed. The first step involves the production of ethyl acetate and its purification. Butyl acetate was produced in the second step: n-butanol was added to the mixture of acetic acid and the resin remaining after the first-step distillation. This process yields ethyl acetate and butyl acetate at high purity and shows an environmental benefit over the independent syntheses by green metrics calculation and life cycle assessment.

关键词： Ion Exchange Resins Esterification Ethyl Acetate Butyl Acetate Coproduction Life Cycle Assessment

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Role of Transparent Exopolymer Particles on Phytoplankton Dynamics in a Subtropical Estuary,Cananeia-Iguape(Sp,Brazil)

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Open Journal of Marine Science 2012年第1期2卷 25-32页

作者： Jose Juan barrera-Alba Gleyci Aparecida Oliveira Moser Sonia Maria Flores Gianesella Flávia Marisa Prado Saldanha-Correa Departamento de Biologia Marinha Universidade Federal do Rio de JaneiroRio de JaneiroBrazil Faculdade de Oceanografia Universidade do Estado do Rio de JaneiroRio de JaneiroBrazil Instituto Oceanográfico Universidade de Sao PauloSao PauloBrazil

Transparent Exopolymer Particles (TEP) has a known crucial role in vertical fluxes of carbon in the ocean and has been intensively studied in the last decade. Nevertheless, few studies have considered horizontal fluxes of TEP. These fluxes arise prominently between estuaries and the coast, where its importance is associated to the predominant horizontal transport. This is due both to the low density of the TEP agglomerate generated in low density waters of continental origin, and to the fact that the main component of the advective transport at estuarine regions is the horizontal one. In this study, the significance of TEP in the particulate matter exchange between estuary and coast was analyzed in the estuarine lagoon system of Cananéia-Iguape (southeast coast of Brazil). TEP, total seston (TS), organic seston (OS) and chlorophyll a (Chl.a) were analyzed over complete tidal cycles, during the dry and rainy seasons both at spring and neap tides. Horizontal fluxes and net transport rates of these variables were also calculated. TEP concentrations (max. 4991 μg Xeq/L) were almost one order of magnitude higher during the rainy season. TEP horizontal transport rates as high as 1.8 g Xeq. m/s were observed at the northern inlet of the system. In terms of particulate carbon, it represents 32.7 g TEP-C m/s or 4% of the OS transport rates. Our study quantifies the advective transport of TEP and their importance in particulate matter exchange between a subtropical estuarine system and the adjacent coastal region. Our results contribute to the knowledge of exopolimer particles dynamics in subtropical estuarine systems, and their relationship to phyto-plankton biomass and particulate matter.

关键词： Cananéia-Iguape Estuarine Lagoon System Phytoplankton Biomass Carbon Flux

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A Review on Cr(Ⅵ) Adsorption Using Inorganic Materials

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American Journal of Analytical Chemistry 2013年第7期4卷 8-16页

作者： Claudia Rosales-Landeros Carlos Eduardo barrera-Díaz Bryan Bilyeu Víctor Varela Guerrero Fernando Urena Núnez Unidad El Rosedal Centro Conjunto de Investigación en Química SustentableUAEM-UNAMTolucaMéxico Department of Chemistry Xavier University of LouisianaNew OrleansUSA Instituto Nacional de Investigaciones Nucleares OcoyoacacMéxico

Chromium compounds are widely used in electroplating, metal finishing, magnetic tapes, pigments, leather tanning, wood protection and electronic and electrical equipment. Hexavalent chromium is a highly toxic metal and produces health damages. The most soluble, mobile and toxic forms of hexavalent chromium in soils are chromate and dichromate and the chromium distribution is also controlled by redox processes, its adsorption decreases with increasing pH and when competing dissolved anions are present. Several techniques have been developed to remove Cr(VI) from wastewater but these techniques have disadvantages such as high cost, non-selective, pH dependence, etc. The use of low cost sorbents has been investigated as a replacement for current costly methods;natural materials with a high adsorption capacity for heavy metals can be obtained. Modification of the sorbents can improve adsorption capacity. This paper includes some techniques for remove Cr(VI) with clays, silica and zeolites from aqueous solutions, some of the treated adsorbents show good adsorption capacities.

关键词： Sorption Hexavalent Chromium Clay Silica Zeolites

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