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new advances in hepatocellular carcinoma

World Journal of Hepatology 2016年第9期8卷 421-438页

作者： Sonia Pascual iván herrera Javier Irurzun Liver Unit Gastroenterology Department Interventional Radiological Unit Hospital General Universitario de Alicante03010 AlicanteSpain

AIM: To determine if gene-specific DnA methylation in prospectively collected blood samples is associated with later development of hepatocellular carcinoma(HCC).METHODS: Comparing genome-wide DnA methylation profiles using Illumina Human methylation 450 K arrays, we previously identified a list of loci that were differentially methylated between tumor and adjacent nontumor tissues. To examine if dysregulation of DnAmethylation patterns observed in tumor tissues can be detected in white blood cell(WBC) DnA, we conducted a prospective case-control study nested within a community-based cancer screening cohort in Taiwan with 16 years of follow up. We measured methylation levels in ninety-six loci that were aberrant in DnA methylation in HCC tumor tissues compared to adjacent tissues. Baseline WBC DnA from 159 HCC cases and 312 matched controls were bisulfite treated and assayed by Illumina Bead Array. We used the χ2 test for categorical variables and student's t-test for continuous variables to assess the difference in selected characteristics between cases and controls. To estimate associations with HCC risk, we used conditional logistic regression models stratified on the matching factors to calculate odds ratios(OR) and 95%CI. RESULTS: We found that high methylation level in cg10272601 in WnK2 was associated with increased risk of HCC, with an OR of 1.91(95%CI: 1.27-2.86). High methylation levels in both cg12680131 in TPO and cg22511877 in MYT1 L, however, were associated with decreased risk. The ORs(95%CI) were 0.59(0.39-0.87) and 0.50(0.33-0.77), respectively, for those with methylation levels of cg12680131 and cg22511877 above the median compared with those with levels below the median. These associations were still statistically significant in multivariable conditional logistic regression models after adjusting for hepatitis B virus infection and alcohol consumption. COnCLUSIOn: These findings support the measurement of methylation markers in WBC DnA as biomarke

关键词： DnA methylation Epigenetics Hepatitis B virus Hepatocellular carcinoma White blood cell DnA

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What is the prognosis of emphysematous pyelonephritis associated with extended-spectrum beta-lactamases producing microorganisms?

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Asian Journal of Urology 2022年第2期9卷 146-151页

作者： Joséiván Robles-Torres Marco Alberto Ocaña-Munguía JoséGustavo Arrambide-herrera Adrián Mauricio Martínez-Fernández Rodrigo Romero-Mata Lauro Salvador Gómez-Guerra Urology Department Hospital Universitario"Dr.Jose´Eleuterio Gonza´lez"Universidad Auto´noma de Nuevo LeonMonterreyNuevo LeonMexico

Objective:To describe the microbiological characteristics in emphysematous pyelonephritis(EPn),demonstrate the frequency of extended-spectrum beta-lactamase(ESBL)microorganisms,and determine if these microorganisms are associated with the prognosis of patients with ***:We conducted a retrospective study in patients with a diagnosis of EPn in a tertiary care hospital of the northeast region of Mexico during the period from January 2011 to January *** variables were analyzed to determine association with the presence of ESBL-producing *** significance was set with pnts were included;55(87.3%)of them were females,with a median age of 55(interquartile range:45-65)*** management was indicated in 38.1%;42.9%were treated with ureteral stent;12.7%with open or percutaneous drainage;15.8%with early nephrectomy;and 9.5%with delayed *** mortality was 13(20.6%)cases;23(36.5%)cases required admission to the intensive care *** most frequent microorganism isolated was Escherichia coli(n=34,53.9%).ESBL microorganisms were found in 31.7%of the *** significant association of ESBL was found with admission to the intensive care unit,or with increased ***:To our knowledge,this is the first study that evaluates ESBL microorganisms as a prognostic factor in *** factors associated with a poor prognosis in patients with EPn have been *** microbiological factors,specifically ESBL-producing bacteria,do not seem to influence in the prognosis of these patients.

关键词： Emphysematous pyelonephritis Extended spectrum betalactamase Mortality Intensive care unit admission

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Seroprevalence of viral and bacterial pathogens among malaria patients in an endemic area of southern Venezuela

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Infectious Diseases of Poverty 2023年第2期12卷 130-131页

作者： David A.Forero-Peña Fhabián S.Carrión-nessi Mary Lopez-Perez Marisol Sandoval-de Mora iván D.Amaya Ángel F.Gamardo Melynar Chavero Luisamy Figuera María V.Marcano natasha A.Camejo-Ávila Mariana Hidalgo Cariagne J.Arenas Myriam Arévalo-herrera Sócrates herrera Biomedical Research and Therapeutic Vaccines Institute Ciudad Bolivar Venezuela Internal Medicine Department “Ruiz y Páez” University Hospital Complex Ciudad Bolivar Venezuela “Dr. Francisco Battistini Casalta” Health Sciences School University of Oriente – Bolivar Nucleus Ciudad Bolivar Venezuela Department of Immunology and Microbiology Faculty of Health and Medical Sciences Centre for Medical Parasitology University of Copenhagen Copenhagen Denmark Immunoparasitology Laboratory Microbiology and Cell Biology Centre Venezuelan Institute for Scientific Research Miranda Venezuela Caucaseco Scientific Research Centre Cali Colombia

Background Malaria remains a leading public health problem ***-infections with other pathogens complicate its diagnosis and may modify the disease’s clinical course and *** in malaria clinical presentation with other infections and overlapping endemicity result in underdiagnosis of co-infections and increased ***,the aim of this study was to determine the seroprevalence of viral and bacterial pathogens among diagnosed malaria patients in malaria-endemic areas in *** A cross-sectional study was conducted on malaria patients attending three reference medical centres in Ciudad Bolivar,*** evaluation and laboratory tests for dengue virus(DEnV),chikungunya virus(CHIKV),viral hepatitis[hepatitis A virus(HAV),hepatitis B virus(HBV),and hepatitis C virus(HCV)],and leptospirosis(LEP)were performed by enzyme-linked immunosorbent *** exposure to these pathogens was defined by the presence of specific immunoglobulin(Ig)G,and co-infection or recent exposure(CoRE)was determined by the presence of specific IgM alone or IgM+*** analysis considered descriptive *** distribution was statistically evaluated using Kolmogorov–Smirnov test and the necessary comparison *** ratio(OR)for complications was determined according to CoRE presence with a 95%confidence interval(CI).Results A total of 161 malaria patients were studied,66%infected with Plasmodium vivax,27%with ***,and 7.5%harboured ***/*** mixed *** exposure to DEnV(60%)and CHIKV(25%)was *** was confirmed in 55 of the 161 malaria patients(34%)and were more frequent in ***(49%)than in ***(29%)and mixed malaria patients(25%)(OR=2.43,95%CI:1.39–4.25,P=0.018).The most frequent CoRE was DEnV(15%),followed by HAV(12%),HBV(6.2%),CHIKV(5.5%),and LEP(3.7%);HCV CoRE was *** malaria was significantly more frequent in patients with CoRE(56%)than those without CoR

关键词： Malaria Seroprevalence Co-infection Chikungunya Dengue Hepatitis Venezuela

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Serum levels of chemokines in adolescents with major depression treated with fluoxetine

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World Journal of Psychiatry 2020年第8期10卷 175-186页

作者： Francisco Rafael de la Peña Carlos Cruz-Fuentes Lino Palacios Manuel iván Girón-Pérez Emilio Medina-Rivero Maria Dolores Ponce-Regalado Samantha Alvarez-herrera Gilberto Pérez-Sánchez Enrique Becerril-Villanueva JoséLuis Maldonado-García María C Jiménez-Martínez Lenin Pavón Adolescent Clinic Clinical ServicesNational Institute of Psychiatry“Ramón de la Fuente”Mexico City 14370Mexico Department of Psychiatric Genetics Clinical Research BranchNational Institute of Psychiatry“Ramón de la Fuente”Mexico City 14370Mexico Universidad Autónoma de nayarit Laboratorio de InmunotoxicologíaBoulevard Tepic-Xalisco s/nCd de la Cultura Amado NervoTepic 63000Mexico Centro nayarita de Innovación y Transferencia de Tecnología A.C.Laboratorio nacional para la Investigación en Inocuidad Alimentaria-Unidad nayarit Calle Tres s/n.Cd IndustrialTepic 63000NayaritMexico Unidad de Desarrollo e Investigación en Bioprocesos Escuela Nacional de Ciencias BiológicasInstituto Politécnico NacionalUnidad Profesional Lázaro CárdenasMexico City 11340Mexico Departamento de Ciencias de Salud Centro Universitario de los AltosUniversidad de Guadalajara Av Rafael Casillas Aceves No.1200Tepatitlán de MorelosJalisco47610Mexico Laboratory of Psychoimmunology National Institute of Psychiatry“Ramón de la Fuente”Mexico City 14370Mexico Department of Immunology and Research Unit Institute of Ophthalmology“Conde de Valenciana Foundation”Mexico City 06800Mexico Department of Biochemistry Faculty of MedicineNational Autonomous University of MexicoMexico City 04510Mexico

BACKGROUnD Major depressive disorder(MDD)is a global health issue that affects 350 million people of all *** between 2%and 5.6%of affected individuals are adolescents,research on young patients is *** inflammatory response contributes to the onset of depression,and in adult MDD patients,symptom severity has been linked to chemokine *** To determine the differences in circulatory levels of chemokines in healthy volunteers(HVs)and adolescents with MDD,and assess the changes induced by fluoxetine *** The 22 adolescents with MDD were monitored during the first 8 wk of clinical follow-up and clinical psychiatric evaluation was done using the Hamilton depresión rating scale(HDRS).The serum levels of monocyte chemoattractant protein-1(MCP-1),macrophage inflammatory protein(MIP)-1α,MIP-1β,interleukin(IL)-8,interferon gamma-induced protein(IP)-10,and eotaxin were measured in patients and *** In all cases,significant differences were detected in circulating chemokine levels between patients before treatment and HVs(Pnes decreased at 4 wk,but only MCP-1 and IL-8 significantly differed(Pn 0 wk and 4 *** the patients,all chemokines rose to their initial concentrations by 8 wk vs 0 wk,but only IP-10 did so significantly(Pnts experienced a significant decrease in HDRS scores at 4 wk(Pnd 8 wk(Pnsumption of fluoxetine,patients had significantly higher chemokine levels,even after considering the improvement in HDRS *** high levels of eotaxin,IP-10,and IL-8 partially explain certain aspects that are affected in MDD such as cognition,memory,and learning.

关键词： Adolescents Major depression Chemokine Fluoxetine Interferon gammainduced protein-10

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Improving antibiotic prescribing in the emergency department for uncomplicated community-acquired pneumonia

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World Journal of Emergency Medicine 2020年第4期11卷 199-205页

作者： Rebekah Shaw Erica Popovsky Alyssa Abo Marni Jacobs nicole herrera James Chamberlain AndreaHahn Division of Pediatrics Children’s National Health SystemWashingtonDCUSA Division of Emergency Medicine Children’s National Health SystemWashingtonDCUSA Department of Pediatrics George Washington University School of Medicine and Health SciencesWashingtonDCUSA Division of Biostatistics and Epidemiology Children’s National Health SystemWashingtonDCUSA Division of Infectious Diseases Children’s National Health SystemWashingtonDCUSA

BACKGROUnD:The Pediatric Infectious Disease Society(PIDS)and Infectious Disease Society of America(IDSA)published an evidence-based guideline for the treatment of uncomplicated communityacquired pneumonia(CAP)in children,recommending aminopenicillins as the first-line *** guideline compliance with 10%–50%of patients admitted to the hospital receiving narrow-spectrum antibiotics has been reported.A new clinical practice guideline(CPG)was implemented in our emergency department(ED)for uncomplicated *** aim of this study was to examine baseline knowledge and ED provider prescribing patterns pre-and post-CPG ***:Prior to CPG-implementation,an anonymous case-based survey was distributed to evaluate knowledge of the current PIDS/IDSA guideline.A retrospective chart review of patients treated in the ED for CAP from January 2015 to February 2017 was performed to assess prescribing patterns for intravenous(iv)antibiotics in the ED at Children’s national Health System pre-and post-CPG ***:ED providers were aware of the PIDS/IDSA guideline recommendations,with 86.4%of survey responders selecting ampicillin as the initial antibiotic of ***,only 41.2%of patients admitted to the hospital with uncomplicated CAP pre-CPG received ampicillin(Pno statistically signifi cant increase in ampicillin prescribing post-CPG(P=0.40).COnCLUSIOnS:Providers in the ED are aware of the PIDS/IDSA guideline regarding the first-line therapy for uncomplicated CAP;however,this knowledge does not translate into clinical *** of a CPG in isolation did not significantly change prescribing patterns for uncomplicated CAP.

关键词： Antibiotics Community-acquired pneumonia Emergency department Pediatrics

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Male age and strain affect ejaculate quality in the Mexican fruit fly

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Insect Science 2018年第4期25卷 703-711页

作者： Mariana herrera-Cruz Solana Abraham nicolas nuSez-Beverido norma Flores-Estevez Martha Reyes-Hernandez Mayvi Alvarado Diana P6rez-Staples Catedra COnACYT- Facultad de Medicina y Cirugia Universidad Autonoma 'Benito Juarez' de Oaxaca Oaxaca Mexico Laboratorio de Investigaciones Ecoetologicas de Moscas de la Fruta y sus Enemigos naturales (LIEMEn) PROIMI Tucuman Argentina COnICET Argentina InBIO TECA Universidad Veracruzana Xalapa Veracruz Mexico Instituto de neuroetologia Universidad Veracruzana Xalapa Veracruz Mexico

Aging in all organisms is inevitable. Male age can have profound effects on mating success and female reproduction, yet relatively little is known on the effects of male age on different components of the ejaculate. Furthermore, in mass-reared insects used for the Sterile Insect Technique, there are often behavioral differences between mass-reared and wild males, while differences in the ejaculate have been less studied. The ejaculate in insects is composed mainly of sperm and accessory gland proteins. Here, we studied how male age and strain affected （i） protein quantity of testes and accessory glands, （ii） the biological activity of accessory gland products injected into females, （iii） sperm viability, and （iv） sperm quantity stored by females in wild and mass-reared Anastrepha ludens （Diptera： Tephritidae）. We found lower protein content in testes of old wild males and lower sperm viability in females mated with old wild males. Females stored more sperm when mated to young wild males than with young mass-reared males. Accessory gland injections of old or young males did not inhibit female remating. Knowledge of how male age affects different ejaculate components will aid our understanding on investment of the ejaculate and possible postcopulatory consequences on female behavior.

关键词： accessory glands age Anastrepha ludens mass-rearing sperm Tephritidae

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A novel mortality risk score for emphysematous pyelonephritis:A multicenter study of the Global Research in the Emphysematous Pyelonephritis group

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Current Urology 2024年第1期18卷 55-60页

作者： Hegel Trujillo-Santamaría José iván Robles-Torres Jeremy Yuen-Chun Teoh Yiloren Tanidir José Gadú Campos-Salcedo Edgar iván Bravo-Castro Marcelo Langer Wroclawski W.S.Yeoh Santosh Kumar Juan Eduardo Sanchez-nuñez José Enrique Espinoza-Aznar Deepak Ragoori Saeed Bin Hamri Ong Teng Aik Cecil Paul Tarot-Chocooj Anil Shrestha Mohamed Amine Lakmichi Mateus Cosentino-Bellote Luis Gabriel Vázquez-Lavista Boukary Kabre Ho Yee Tiong José Gustavo Arrambide-herrera Lauro Salvador Gómez-Guerra Umut Kutukoglu Joao Arthur Brunhara Alves-Barbosa Jorge Jaspersen Christian Acevedo Francisco Virgen-Gutiérrez Sumit Agrawal Hugo Octaviano Duarte-Santos Chai Chu Ann Daniele Castellani Vineet Gahuar Department of Urology Hospital CovadongaCórdobaMéxico Department of Urology Hospital Universitario"Dr.José Eleuterio Gonzalez"MonterreyMéxico Department of Surgery S.H.Ho Urology CentrePrince of Wales HospitalThe Chinese University of Hong KongHong KongChina Department of Urology Marmara University School of MedicineIstanbulTurkey Department of Urology Hospital Central MilitarMéxico CityMéxico Department of Urology Hospital Israelita Albert EinsteinBP-a Beneficência Portuguesa de Sao PauloSao PauloBrazil Faculdade de Medicina do ABC Santo AndréBrazil Department of Urology University Surgical ClusterNational University HospitalSingaporeSingapore Department Urology Christian Medical CollegeVelloreTamilnadIndia Department Urology Hospital General de México"Dr.Eduardo Liceaga"México CityMéxico Department of Urology Hospital Regional de Alta Especialidad de la Peninsula de YucatánMéridaMéxico Department Urology Asian Institute of Nephrology and UrologyHyderabadIndia Department Urology King Abdulaziz National Guard HospitalRiyadhSaudi Arabia Division of Urology Department of SurgeryUniversity of MalayaKuala LumpurMalaysia Department of Urology Central Military HospitalMexico CityMexico national Academy of Medical Sciences Bir Hospital and B&B HospitalGwarko LalitpurNepal Department of Urology University Hospital Mohammed theⅥ^(th)of MarrakeshMarrakeshMorocco Department of Urology Federal University of ParanáSchool of MedicineHospital das ClínicasCuritibaBrazil Department of Urology Hospital Médica SurMexico CityMexico Department of Urology Hospital Yalgado Ouedraogo OuagadougaKadiogoBurkina Faso Department of Urology Hospital Das Clínicas da Universidade de Sao PauloSao PauloBrazil Department of Urology AIIMSBhubaneshwarIndia Department of Urology Hospital Municipal Dr.Moysés Deutsch(M'Boi Mirim)Sao PauloBrazil Department of Urology Azienda Ospedaliero-Universitaria Ospedali Riuniti di AnconaPolytechnic University of Le Marche RegionAnconaItaly Department of Minim

Background:Emphysematous pyelonephritis(EPn)is a necrotizing infection of the kidney and the surrounding tissues associated with considerable *** aimed to formulate a score that classifies the risk of mortality in patients with EPn at hospital *** and methods:Patients diagnosed with EPn between 2013 and 2020 were retrospectively *** from 15 centers(70%)were used to develop the scoring system,and data from 7 centers(30%)were used to validate *** and mułtivariable logistic regression analyses were performed to identify independent factors related to *** operating characteristic curve analysis was performed to construct the sconng system and calculate the risk of mortality.A standardized regression coefficient was used to quantify the discriminating power of each factor to convert the individual coefficients into *** area under the curve was used to quantify the scoring system *** 8-point scoring system for the mortality risk was created(range,0-7).Results:In total,570 patients were included(400 in the test group and 170 in the validation group).Independent predictors of mortality in the multivariable logistic regression were included in the scoring system:quick Sepsis-related Organ Failure Assessment score≥2(2 points),anemia,paranephric gas extension,leukocyte count>22,000/pL,thrombocytopenia,and hyperglycemia(1 point each).The mortality rate wasnd 100%for scores *** area under the Curve was 0.90(95%confidence interval,0.84-0.95)for test and 0.91(95%confidence interval,0.84-0.97)for the validation ***:Our score predicts the risk of mortality in patients with EPn at presentation and may help clinicians identify patients at a higher risk of death.

关键词： Emphysematous pyelonephritis Mortality Prognosis

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Mitochondrial phylogeography and molecular evolution of the rhodopsin visual pigment in troglobitic populations of Astyanax mexicanus(De Filippi,1853)

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Zoological Research 2023年第4期44卷 761-775页

作者： Marco A.A.Garduño-Sánchez Vladimir de Jesus-Bonilla Silvia Perea Ramses Miranda-Gamboa Andrea herrera-García Mauricio de la Maza Benignos Claudia Patricia Ornelas-García Colección nacional de Peces Departamento de ZoologíaInstituto de BiologíaUniversidad Nacional Autónoma de MéxicoCiudad de MéxicoC.P.04510México Posgrado en Ciencias Biológicas Colección Nacional de PecesDepartamento de ZoologíaInstituto de BiologíaUniversidad Nacional Autónoma de MéxicoCiudad de MéxicoC.P.04510México Licenciatura en Ciencias Forenses Facultad de MedicinaUniversidad Nacional Autónoma de MéxicoCiudad UniversitariaCoyoacánMéxico CityC.P.04510México Instituto de Energías Renovables Universidad Nacional Autónoma de MéxicoTemixcoMorelos C.P.62580Mexico Facultad de Ciencias Biológicas Universidad Autónoma de Nuevo LeónCiudad UniversitariaSan Nicolás de los GarzaNuevo LeónC.P.66450México

Cave-adapted animals provide a unique opportunity to study the evolutionary mechanisms underlying phenotypic,metabolic,behavioral,and genetic evolution in response to cave *** Mexican tetra(Astyanax mexicanus)is considered a unique model system as it shows both surface and cave-dwelling *** date,at least 33 different cave populations have been identified,with phylogenetic studies suggesting an origin from at least two independent surface lineages,thereby providing a unique opportunity to study parallel *** the present study,we carried out the most exhaustive phylogeographic study of *** to date,including cave and surface localities,using two mitochondrial markers(cytochrome b(cyt b)and cytochrome c oxidase subunit I(COI))and nuclear rhodopsin visual pigment(rho).Additionally,we inferred the molecular evolution of rho within the two contrasting environments(cave and surface)and across three geographic regions(Sierra de El Abra,Sierra de Guatemala,and Micos).In total,267 individuals were sequenced for the two mitochondrial fragments and 268 individuals were sequenced for the rho visual pigment from 22 cave and 46 surface *** results based on the mitochondrial data supported the two-lineage hypothesis,except for the Pachón and Chica caves,whose introgression has been largely *** Sierra de El Abra region depicted the largest genetic diversity,followed by the Sierra de Guatemala *** the phylogeographic patterns of rho,we recovered exclusive haplogroups for the Sierra de El Abra(Haplogroup I)and Sierra de Guatemala regions(Haplogroup iv).Moreover,a 544 bp deletion in the rho gene was observed in the Escondido cave population from Sierra de Guatemala,reducing the protein from seven to three intramembrane *** change may produce a loss-of-function(LOF)but requires further *** nonsynonymous(dn)and synonymous(dS)substitution rates(omega valuesω),our results revealed

关键词： Visual pigments Selection Cavefish Vision loss Loss of function

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Hydrogeochemical and isotopic assessment of the origin of nO_(3)^(−)and n-nH_(3)contents in the aquifer located in a closed lacustrine volcano-sedimentary basin in the metropolitan area of Mexico City

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Acta Geochimica 2024年第4期43卷 719-736页

作者： Jose ivan Morales-Arredondo Maria Aurora Armienta Hernandez Joel Edmundo Ortega-Gutierrez Elisa Cuellar Ramirez natural Resources Department Institute of GeophysicsNational Autonomous University of MexicoCiudad Universitaria No.3000Col.Copilco UniversidadCoyoacán Delegation04360 MexicoCDMXMexico Instituto Politecnico nacional ***án 55La Laguna Ticoman07340 MexicoCDMXMexico Benemérita Universidad Autónoma de Puebla Ciudad Universitaria Col.San ManuelPueblaPueMexico

To explain the presence and spatial distribution of nO_(3)^(−)and n-nH_(3)in the Aquifer of the Metropolitan Area of Mexico City(AMAMC),a hydrogeochemical and isotopic analysis using^(13)C DIC(as well as the stable isotopes^(18)O and^(2)H)in groundwater was *** aquifer is located in an old closed lacustrine volcano-sedimentary basin;some wells hosted in the semi-confined zone contain high n-nH_(3)concentrations,while others present nO_(3)^(−)contents in the recharge zones(hosted in an oxidizing environment).In this study,a change in the isotopic signature(primarily in^(18)O and^(2)H)was observed from the recharge zones to the basin center in some of the wells with high nO_(3)^(−)concentrations,this behavior can be attributed to evaporation during the incorporation of recently infiltrated *** addition,the results for^(13)C(along with ^(2) H)in wells with the highest n-nH_(3)concentrations exhibited an atypically broad range of *** indicated the occurrence of hydrogeochemical and/or biochemical processes in the aquifer(in an oxidizing or reducing environment),such as organic degradation,bacterial decomposition(primarily in the ancient Lake Texcoco and which acts as a natural sink for carbon,nitrogen,sulfur,and phosphorus),besides rock weathering and dissolution,which may be responsible for a very marked isotopic modification of the^(13)C(and,to a lesser extent,2 H).Methanotrophic bacterial activity and methanogenic activity may be related to n-nH_(3)removal processes by oxidation and residual water incorporation respectively,whereas the increase in the nO_(3)^(−)content in some wells is due to the recent contribution of poor-quality water due to contamination.

关键词： 18 O and^(13)C isotopes Iron Hydrogeochemical processes nitrate nitrogen species

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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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