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Bedrock outcropping in the accumulation zone of the largest glacier in mexico(Glaciar Norte of Citlaltépetl),as evidence of a possible accelerated extinction

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Journal of mountain Science 2023年第2期20卷 338-354页

作者： SOTO víctor Colegio de Geografía Facultad de EconomíaUniversidad VeracruzanaAv.Xalapa s/nObrero Campesina91020XalapaVer.México

The highest volcano in mexico,at the same time the third largest mountain in North America(Citlaltépetl,5610 m a.s.l.),is home to the largest glacier in the *** of the extinction of the popocatépetl glacier(5500 m a.s.l.)caused by eruptive activity,and the almost disappearance of the Iztaccíhuatl glaciers(5220 m a.s.l.)due to the lower elevation of the mountain,the Glaciar Norte of Citlatépetl has been the only glacier that has shown a certain degree of stability as a response to the altitude in which it is ***,as occurs in almost all glaciers on the planet,the retreat of its glacier terminus has been ***,during the last years the thickness of its upper part began to decrease rapidly until its bedrock was exposed for the first time in *** to its ecosystem importance and because it is the main glacier in mexico,as well as the only one in the world located at latitude 19°N,in this work its current dimensions are updated,as well as the local climatology that governs the current state of the glacier is pointed *** study was based on the analysis of high-resolution Sentinel-2 optical images,as well as through Sentinel-1 SAR images,with the support of climatological information from the study ***,the outcropping of the bedrock in the accumulation zone and the consequent horizontal retreat of the upper part of the glacier are documented;at the same time,the decrease in the thickness of the ice along it is *** rocky outcrop in the accumulation zone suggests that the flow dynamics of the ice towards the ablation zone will be considerably less,accelerating the retreat of the glacier ***,the ascent of the glacial front to 5102 m *** the modelled altitude of the equilibrium line to 5276 m *** reported as a warning signal in terms of snow catchment and mass balance;likewise,the decrease of 23%of its surface is also indicated regarding the surface reduction monitoring that has been done

关键词： Bedrock outcrop Citlaltépetl glacier Glacial accumulation zone Glacier retreat Glacial thickness

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Effects of Hedera helix *** on the understory early regeneration in an oak temperate forest in mexico City

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Ecological processes 2023年第1期12卷 438-449页

作者： Héctor Adrián jiménez-Hernández Leticia Bonilla-valencia Yuriana martínez-Orea mara Jessica Zamora-Almazan Francisco Javier Espinosa-García Silvia Castillo-Argüero Facultad de Ciencias Universidad Nacional Autónoma de MéxicoMexico CityMexico Instituto de Investigaciones en Ecosistemas y Sustentabilidad Universidad Nacional Autónoma de MéxicoMichoacánMexico

Background Hedera helix *** an invasive weed species introduced in several regions of the world,so it is relevant to study its effects on the plant community and the changes occurring after its *** established invaded(with/without removal of ***)and non-invaded(with/without removal of the understory)plots to compare some community attributes in an oak forest in mexico City and monitored them every 2 months for 1 year,taking soil samples to compare some edaphic variables between the *** invasive species negatively affect natural regenera-tion,seedlings of native species would be less abundant in plots invaded by *** than in the non-invaded *** invasive species modify the soil microbiota through exudates and often allelochemicals,soil chemical variables would differ between invaded and non-invaded *** The abundance of native species was lower in the invaded plots,but the richness and diversity of species were not statistically *** composition of the two invaded plots was similar to each other and more alike to that of the non-invaded *** species composition of the invaded plots was associated with soil potassium and phosphorus concentrations,whereas that of the non-invaded plots was more associated with soil nitrogen *** Following the removal of ***,several native species were registered,leading to a similar species composition as in the non-invaded plots,suggesting that some vegetation recovery can be expected following *** removal in 1 year.

关键词： Ivy Invasive plant mechanical control Diversity Species composition

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A regionalized IO-model to value seasonal recreational ecosystem services in a mountain National park in Spain

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Journal of mountain Science 2022年第1期19卷 211-227页

作者： víctor mARTIN BARROSO mónica de CASTRO-pARDO pascual FERNÁNDEZ mARTÍnez João C.AZEvEDO Department of Applied Economics I and history and economic institutions Faculty of Law and Social SciencesUniversidad Rey Juan CarlosCampus of VicálvaroTulipanMóstoles 28933Spain Department of Financial and Actuarial Economics and Statistics-Statistics and Operational Research Complutense University of MadridCampus of SomosaguasPozuelo de Alarcon 28223Spain Centro de Investigação de montanha Instituto Politécnico de BragançaCampus de Santa ApolóniaBragança 5300-253Portugal

Recreational Ecosystem Services(RES)are among the most frequently evaluated ecosystem *** are seen as a major opportunity for sustainable development in areas of high ecological value resulting from the presence of emblematic species,habitats or scenery,often integrated in conservation areas,in particular in mountain areas affected by depopulation,rising environmental risks and ***,the assessment of RES has been based on Contingent valuation and Choice Experiments,methods with limitations related to their ***,Input-Output(IO)models provide a very accurate and effective way of valuation of RES with regional information regarding interindustry *** data on nature tourist expenditure may be only available annually,tourism inflows have a strong seasonal behavior,which impacts the profitability of several local economic *** this paper,we firstly constructed a novel regionalized IO-model based on Cross-Industry Location Quotients using employment data and,secondly,based on monte Carlo simulation,we estimated nature tourist expenditure monthly using data on nature tourism *** method allowed for a more precise RES evaluation,estimating direct,indirect and induced monthly economic impacts of nature-based *** method was applied to the Ordesa and monte perdido(Omp)National park in the Spanish *** estimate the average tourist expenditure,we collected and analyzed spending on commerce,hospitality and restaurants,leisure,and transport of 385 *** suggest that using a regionalized IO model leads to a considerable reduction of over-estimation of the economic impact of tourist expenditure estimated by conventional *** into consideration the direct,indirect and induced effects of tourist expenditure in 2016-2018,the total annual output effect in the Omp National park amounted to€208.8 million,while the total income effect amounted to€86.29 ***,a total of

关键词： Input-Output monte Carlo Simulation Location quotients Recreational Ecosystem Services Nature tourism Sustainable mountain development

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phylogeny,genetics,and the partial life cycle of Oncomegas wageneri in the Gulf of mexico

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Current Zoology 2020年第3期66卷 275-283页

作者： Andrés mARTInez-AQUINO víctor m.vIDAL-mARTInez F.Sara CECCARELLI Oscar mENDEZ Lilia C.SOLER-jimEnez m.Leopoldina AGUIRRE-mACEDO Facultad de Ciencias Universidad Autonoma de Baja CaliforniaCarretera Transpeninsular 3917Fraccionamiento PlayitasEnsenadaBaja California 22860Mexico Laboratorio de patologia Acuatica Departamento de Recursos del MarCentro de Investigacion y de Estudios Avanzados del Instituto Politecnico NacionalUnidad MeridaCordemexCarretera Antigua a Progreso Km.6MeridaYucatan 97310Mexico Departamento de Biologia de la Conservacion CONACYT-Centro de Investigacion Cientifica y de Educacion Superior de EnsenadaCarretera Ensenada-TjuanaEnsenadaBaja California 22860Mexico Laboratorio de Hidrobiologia Facultad de Biologia-XalapaUniversidad VeracruzanaCircuito Gonzalo Aguirre Beltran S/N Zona UniversitariaXalapaVeracruz 91090Mexico

Despite the diversity and ecological importance of cestodes,there is a paucity of studies on their life stages(i.e.,complete lists of intermediate,paratenic,and definitive hosts)and genetic *** example,in the Gulf of mexico(Gom)98 species of cestodes have been reported to date;however,data on their intraspecific genetic variation and population genetic studies are *** trypanorhynch cestode,Oncomegas wageneri,is found(among other places)off the American Western Atlantic Coast,including the Gom,and has been reported as an adult from stingrays and from several teleost species in its larval form(as plerocerci).This study represents the first report of 2 previously unregistered definitive hosts for ***,namely the Atlantic sharpnose shark Rhizoprionodon terraenovae and the southern stingray Hypanus *** this work,partial sequences of the 28S(region D1-D2)ribosomal DNA were analyzed to include *** within an eutetrarhynchoid phylogenetic *** *** individuals(which included plerocerci and adults)were recovered as monophyletic and Oncomegas celatus was identified as the sister species of ***,population genetic analyses of *** from the southern Gom were carried out using DNA sequences of the mitochondrial cytochrome c oxi-dase subunit 1(COI)gene,which reflected high genetic variation and a lack of genetic structure among the 9 oceanographic sampling *** on these results,*** is panmictic in the southern *** extensive sampling along the species entire distribution is necessary to make more accurate inferences of population genetics of ***.

关键词： barcode Cyclopsetta chittendeni population genetics Hypanus americanus Oncomegas Rhizoprionodon terraeno-vae 28S rDNA(D1-D2)

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Effect of initial microstructure on austenite formation kinetics in high-strength experimental microalloyed steels

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International Journal of minerals,metallurgy and materials 2015年第12期22卷 1304-1312页

作者： Edgar López-martínez Octavio vázquez-Gómez Héctor Javier vergara-Hernández Bernardo Campillo Faculty of Chemistry Metallurgical Engineering Department Autonomous National University of Mexico National Council for Science and Technology metallurgy Science postgraduate programme Morelia Institute of Technology Institute of physical Sciences Autonomous National University of Mexico

Austenite formation kinetics in two high-strength experimental microalloyed steels with different initial microstructures comprising bainite-martensite and ferrite-martensite/austenite microconstituents was studied during continuous heating by dilatometric analysis. Austenite formation occurred in two steps：（1） carbide dissolution and precipitation and （2） transformation of residual ferrite to austenite. Dilatometric analysis was used to determine the critical temperatures of austenite formation and continuous heating transformation diagrams for heating rates ranging from 0.03°C.s^-1 to 0.67°C.s^-1. The austenite volume fraction was fitted using the Johnson-mehl-Avrami-Kolmogorov equation to determine the kinetic parameters k and n as functions of the heating rate. Both n and k parameters increased with increasing heat- ing rate, which suggests an increase in the nucleation and growth rates of austenite. The activation energy of austenite formation was determined by the Kissinger method. Two activation energies were associated with each of the two austenite formation steps. In the first step, the austenite growth rate was controlled by carbon diffusion from carbide dissolution and precipitation; in the second step, it was controlled by the dissolution of residual ferrite to austenite.

关键词： non-isothermal kinetics microalloyed steel austenite heating dilatometry

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Freeze-thaw cycles and associated geomorphology in a post-glacial environment:current glacial,paraglacial,periglacial and proglacial scenarios at pico de Orizaba volcano,mexico

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Journal of mountain Science 2024年第6期21卷 1954-1977页

作者： víctor SOTO Carlos m.WELSH R. Kenji YOSHIKAWA Hugo DELGADO GRANADOS Centro de Ciencias de la Tierra Universidad VeracruzanaCircuito Gonzalo Aguirre BeltránS/NZona Universitaria91090XalapaMéxico Water and Environmental Research Center University of Alaska FairbanksFairbanksAlaska 99775USA Instituto de Geofísica Universidad Nacional Autónoma de MéxicoCiudad de México 04150México Department of Earth and Environmental Sciences Ludwig Maximilians UniversitätMunich 80333Germany

The glacial history of pico de Orizaba indicates that during the Last Glacial maximum,its icecap covered up to~3000 m asl;due to the air temperature increasing,its main glacier has retreated to 5050 m *** retraction of the glacier has left behind an intense climatic instability that causes a high frequency of freeze-thaw cycles of great intensity;the resulting geomorphological processes are represented by the fragmentation of the bedrock that occupies the upper parts of the *** is a notable lack of studies regarding the fragmentation and erosion occurring in tropical high mountains,and the associated geomorphological risks;for this reason,as a first stage of future continuous research,this study analyzes the freezing and thawing cycles that occur above 4000 m asl,through continuous monitoring of surface ground *** results allow us to identify and characterize four zones:glacial,paraglacial,periglacial and *** was found that the paraglacial zone presents an intense drop of temperature,of up to~9℃ in only sixty *** rock fatigue and intense freeze-thaw cycles that occur in this area are responsible for the high rate of rock disintegration and represent the main factor of the constant slope dynamics that occur at the *** activity decreases,both in frequency and intensity,according to the distance to the glacier,which is where the temperature presents a certain degree of stability,until reaching the proglacial zone,where cycles are almost non-existent,and therefore there is no gelifraction *** geomorphological processes have resulted in significant alterations to the mountain slopes,which can have severe consequences in terms of risk and water.

关键词： Freeze-Thaw Gelifraction mountain mechanical erosion periglacial geomorphology postglacial scenarios

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Landscape Analysis for pav1 Infection in Lobsters panulirus argus from the Artisanal Fishery of the Eastern Coast of Yucatan, mexico

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Open Journal of marine Science 2016年第3期6卷 386-394页

作者： Ruth A. pérez-Campos Oswaldo Huchim-Lara Silvia Salas maría Liceaga-Correa Héctor Hernández-Nuñez Cristina pascual-jiménez pascual-jiménez Rossanna Rodríguez-Canul Laboratorio de Inmunología y Biología molecular Mérida Yucatán México Laboratorio de pesquerías Mérida Yucatán México Laboratorio de percepción Remota y Sistemas de Información Geográfica Centro de Investigación y de Estudios Avanzados del IPN-Mérida (CINVESTAV-IPN) Merida Mexico Universidad Nacional Autónoma de méxico Facultad de Ciencias Unidad Académica Sisal Sisal Mexico

panulirus argus virus 1 (pav1) is considered a major threat to spiny lobsters panulirus argus. In this study Geospatial analysis was used to analyze pav1 distribution in an artisanal fishery of spiny lobster panulirus argus population from the north coast of the Yucatan peninsula. Adult and sub-adult p. argus and seabed coverage data were collected from thirty artisanal fishing sites. Five seabed coverage types were identified: seagrass;sand/seagrass mixture;sand only;coral/sand mixture;and seaweed. No juveniles were examined. Of the 358 collected lobsters, pav1 was identified in four organisms (three sub-adults and one adult) from two fishing sites (termed A & B), both found in a seagrass coverage area. Overall prevalence was of 1.12%. prevalence was of 20% (2/10) at one site and of 12.6% (2/16) at the other.

关键词： panulirus argus pav1 Geospatial Analysis Artisanal Fishery Seagrass

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proteomic dynamics revealed sex-biased responses to combined heat-drought stress in marchantia

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Journal of Integrative plant Biology 2024年第10期66卷 2226-2241页

作者： Sara Guerrero víctor Roces Lara García-Campa Luis valledor mónica meijón Department of Organisms and Systems BiologyFaculty of Biology/BiotechnologyInstitute of AsturiasUniversity of OviedoOviedoAsturias 33071Spain

Recent studies have documented plant responses to climate change extensively, particularly to single-stress exposures. However, critical factors for stress survival, such as sexual differentiation,are not often considered. The dioicous marchantia polymorpha stands as an evolutionary milestone,potentially preserving ancestral traits from the early colonizers. In this study, we employed proteomic analyses complemented with physiological monitoring to investigate combined heat and drought responses in Tak-1(male) and Tak-2(female)accessions of this liverwort. Additionally, targeted transcriptomics was conducted using different natural populations from contrasting *** findings revealed sex-biased dynamics among natural accessions, particularly evident under control conditions and during early stress responses. Although Tak-2 exhibited greater diversity than Tak-1 under control conditions, male accession demonstrated distinct and more rapid stress sensing and signaling. These differences in stress response appeared to be strongly related to sex-specific plasticity influenced by geoclimatic origin. Furthermore, we established distinct protein gene ages and genomic distribution trends, underscoring the importance of protein diversification over time. This study provides an evolutionary perspective on sexual divergence and stress emergence employing a systems biology approach, which allowed for the establishment of global and sex-specific interaction networks in the stress response.

关键词： abiotic stress land adaptation liverwort sex-biased response systems biology

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meckel's diverticulum diagnosis by video capsule endoscopy: A case report and review of literature

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World Journal of Clinical Cases 2018年第14期6卷 791-799页

作者： Diego García-Compeán Alan R jiménez-Rodríguez Angel N Del Cueto-Aguilera Gilberto Herrera-Quinones José A González-González Héctor J maldonado-Garza Gastroenterology Service and Department of Internal medicine Faculty of Medicine University Hospital "Dr. José E. González" Universidad Autónoma de Nuevo León Monterrey 64700 Nuevo León México

BACKGROUND meckel’s diverticulum （mD） occurs predominantly in chil-dren and adolescents. It is rarely diagnosed in adults. preoperative diagnosis is diffcult due to low sensitivity of the radiological imaging studies. The role of video capsule endoscopy （vCE） in the diagnosis of mD is unknown, and the endoscopic patterns are not defned. We will describe four of our cases of mD evaluated with vCE and make a review of the literature focusing on the endoscopic *** SUmmARYWe present four cases of mD confirmed by surgery. They were all adult males with ages going from 18 to 50 years, referred to our service from 2004 to 2018, due to obscure gastrointestinal bleeding （OGIB）. TheyGarcía-Compeán D et al . merckel’s diverticulum diagnosis by vCEhad a history of 1 mo to 10 years of overt and occult bleeding episodes. Laboratory blood test showed an iron-deficiency anemia from 4 to 9 g/dL of hemoglo-bin that required multiple hospitalizations and blood transfusions in all cases. Repeated upper digestive endoscopies and colonoscopies were negative. Small bowel was examined with vCE, which revealed double lumen images in all cases, one with polyps and three with circumferential ulcers in the diverticulum. However, based on vCE findings, preoperative diagnosis of mD was suggested only in two patients. Capsule was retain-ed in one patient, which was recovered with surgery. The anatomopathological report revealed ulcerated ectopic gastric mucosa in all *** is useful for the diagnosis of mD. However, endo-scopic characteristics must be recognized in order to establish preoperative diagnosis.

关键词： meckel’s diverticulum Endoscopic features video capsule endoscopy Wireless capsule endoscopy Review Case report

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Is the kafirin profile capable of modulating the ileal digestibility of amino acids in a soybean meal-sorghum diet fed to pigs?

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Animal Nutrition 2019年第2期5卷 124-129页

作者： víctor A.Balderrama-pérez JoséG.Gómez-Soto Tércia C.Reis de Souza Ericka R.Rodríguez Gerardo mariscal-Landín Facultad de Estudios Superiores Cuatitlán Universidad National Autónoma de MéxicoCuautitlan54714Mexico Facultad de Cientias Naturales Universidad Autónoma de QuerétaroQuerétaro76230Mexico Centro Nacional de Investigación Disciplinaria en Fisiología y mejoramiento Animal Instituto Nacional de Investigaciones Forestales Agrícolas y PecuariasAjuchitilan76380Mexico

The effects of kafirins on protein and amino acid ileal digestibility have not been evaluated in vivo in *** aim of this study was to determine the effects of protein profile on apparent ileal digestibility(AID)of amino acids. We used a sorghum hybrid with low tannin content(me hybrid was harvested from 2 different plots with different kafirin profile. Sorghum with greater content of total kafirins had less content of y-and al-kafirins and higher content of β-and a2-kafirins than that with lower content of total kafirins. Two sorghum-soybean meal(SBm) diets were formulated: 1) low kafirin(LK) content(32.2 g/kg) and 2) high kafirin(HK) content(48.1 g/kg). A control diet(maize-SBm) and a reference SBm-diet were also prepared. The reference diet was fed to all pigs following the experimental period and was used to estimate the AID of cereals by the difference method. 'T' cannulas were fixed in the distal ileum of 18 barrows(6 by treatment), divided into 2 groups of 9 pigs. The pigs were fed 2.5 times their maintenance requirement of digestible energy(110 kcal/kg BW00.75). The AID of dry matter,protein, amino acids, and energy of the experimental diets was measured;the AID of cereals(maize, LK sorghum and HK sorghum) was estimated by the difference method. The maize-SBm diet was more digestible than the sorghum-SBm diets, only with respect to valine(p valine in the maize-SBm diet was higher than that in sorghum-SBm diets. The changes in kafirin profile between the diets only affected the AID of threonine(p percentage units in LK diet compared with HK diet. Regarding the AID of cereals, maize exhibited greater AID than sorghum, with respect to valine(p p mparison of sorghum with LK and HK content showed that the AID of threonine and serine increased by 50.5(p percentage units(p pec:tively. The higher content of γ-kafirins in L

关键词： Amino acids Ileal digestibility Kafirin pig Sorghum

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