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Local Fourier Analysis for Edge-Based Discretizations on Triangular Grids

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Numerical Mathematics(Theory,Methods and Applications) 2015年第1期8卷 78-96页

作者： carmen Rodrigo Francisco Sanz Francisco J.Gaspar Francisco J.Lisbona Department of Applied Mathematics University of ZaragozaC/Maria de Luna 350018ZaragozaSpain BIFI University of Zaragoza C/Pedro Cerbuna 1250009ZaragozaSpain Department of Applied Mathematics University of ZaragozaC/Pedro Cerbuna 1250009ZaragozaSpain

In this paper,we present a local Fourier analysis framework for analyzing the different components within multigrid solvers for edge-based discretizations on triangular *** different stencils associated with edges of different orientation in a triangular mesh make this analysis *** resulting tool is demonstrated for the vector Laplace problem discretized by mimetic finite difference *** from the local Fourier analysis,as well as experimentally obtained results,are presented to validate the proposed analysis.

关键词： Multigrid local Fourier analysis edge-based discretizations mimetic finite differences

Spatiotemporal patterns of burned areas,fire drivers,and fire probability across the equatorial Andes

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Journal of Mountain Science 2021年第4期18卷 952-972页

作者： Xavier ZAPATA-RiOS carmen LOPEZ-FABARA Abigail NAVARRETE Sandra TORRES-PAGUAY Miguel FLORES Department of Civil and Environmental Engineering Escuela Politecnica NacionalLadron de Guevara E11-253P.O.Box 17-01-2759QuitoEcuador Center for Research and Water Resources Studies(CIERHI) Escuela Politecnica NacionalLadron de Guevara E11-253P.O.Box 17-01-2759QuitoEcuador Faculty of Agricultural Sciences Universidad Central del EcuadorAv.UniversitariaP.O.Box 17-03-100QuitoEcuador Modeling Optimization and Inferential Statistics Group(MODES)Department of MathematicsEscuela Politecnica NacionalLadron de Guevara Ell-253P.O.Box 17-01-2759QuitoEcuador

Field-based fire studies in the equatorial Andes indicate that fires are strongly associated with biophysical and anthropogenic ***,fire controls and fire regimes at the regional scale remain ***,this paper describes spatial and temporal burned-area patterns,identifies biophysical and anthropogenic fire drivers,and quantifies fire probability across 6°of latitude and 3°of longitude in the equatorial *** spatial and temporal burned-area analysis was carried out based on 18 years(2001-2018)of the MCD64 A1 MODIS burned-area ***,topography,vegetation,and anthropogenic variables were integrated in a logistic regression model to identify the significance of explanatory variables and determine fire occurrence probability.A total of 5779 fire events were registered during the 18 years of this study,located primarily along the western cordillera of the Andes and spreading from North to ***-eight percent of these fires took place within two fire hotspots located in the northwestern and southwestern corners of the study ***-nine percent occurred during the second part of the year,between June and *** largest density of fires was primarily located on herbaceous vegetation and *** show that mean monthly temperature,precipitation and NDVI during the prefire season,the location of land cover classes such as forest and agriculture,distance to roads and urban areas,slope,and aspect were the most important determinants of spatial and temporal fire *** logistic regression model achieved a good accuracy in predicting fire probability(80%).Probability was higher in the southwestern and northern corners of the study area,and lower towards the north in the western and eastern piedmonts of the *** analysis contributes to the understanding of fires in mountains within the *** results here presented have the potential to contribute to fire management and control in the regi

关键词： MODIS MCD64A1 Spectral vegetation indices Pre-fire season NDVI and precipitation Remote sensing

Total Reflection X-Ray Fluorescence Analysis of Toxic Metals in Fish Tissues

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American Journal of Analytical Chemistry 2014年第12期5卷 805-811页

作者： Graciela Zarazúa Karina Girón-romero Samuel Tejeda carmen Carreno-De León Pedro Avila-Pérez Nuclear Technology Division National Institute for Nuclear ResearchOcoyoacacMexico Faculty of Science University of Mexico StateTlachaloyaMexico Technology Institute of Toluca MetepecMexico

The concentration of Cr, Ni, Cu, Zn, Hg and Pb, considered like toxic, was evaluated in fish tissues by means the total reflection X-Ray Fluorescence technique (TXRF). Grass carp (Ctenopharygodon idella) samples were collected from six regions of the Tepuxtepec Dam which was used as a water reservoir and fish production for the local population. Fish tissues: gills, liver, kidney and muscle were analyzed in triplicate using a TXRF spectrometer “TX-2000 Ital Structures” with a Si(Li) detector and a resolution of 140 eV (FWHM) at Mn Kα and Mo tube (40 kV, 30 mA) with 17.4 KeV excitation energy. The mean concentration of metals in tissues decrease in the sequence: Kidney ≈ Gills > Liver > Muscle;the range of concentration for Zn was 26.68 - 816.67 mg/Kg followed by Cu: 1.18 - 35.81 mg/Kg, Cr: 1.10 - 9.30 mg/Kg, Ni: 0.40 - 3.80 mg/Kg, Pb: <0.02 - 1.92 mg/Kg and Hg: <0.03 - 1.97 mg/Kg. Chromium and mercury concentrations slightly exceed the limits for fish proposed by FAO/WHO and Mexican Legislation for human consumption in the edible parts of fish from each one of the regions of the Tepuxtepec Dam. The results show that metal accumulation in herbivorous carp tissues was higher in regions 1, 2 and 3 than the others, which could be due to the influence of Lerma River, one of the most polluted rivers of Mexico.

关键词： Metals Fish Tissues TXRF

Early performance of two tropical dry forest species after assisted migration to pine-oak forests at different altitudes:strategic response to climate change

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Journal of Forestry Research 2020年第4期31卷 1215-1223页

作者： Pilar Angélica Gómez-Ruiz Cuauhtémoc Sáenz-romero Roberto Lindig-Cisneros Catedrática CONACYT Centro de Investigaciónde Ciencias Ambientales CICAFacultad de Ciencias NaturalesUniversidad Autónoma del CarmenCiudad del CarmenCampecheMexico Instituto de Investigaciones Agropecuarias y Forestales Universidad Michoacana de San Nicolás de Hidalgo(IIAFUMSNH)MoreliaMexico Instituto de Investigaciones en Ecosistemas y Sustentabilidad(IIES) Universidad Nacional Autónoma de MéxicoCampus MoreliaMoreliaMexico

Assisted migration has been proposed as a strategy for adaptive management of forest species in response to expected effects of climate change,but it is controversial for several *** dry forests are among the most threatened ecosystems in the *** Mexico,historically,land-use change and deforestation have been decreasing forest cover,and climate change is shifting the potential distribution of different forest types,exacerbating the risk of local *** altitudinal migration could be a feasible strategy for reducing local extinctions in response to climate change and lack of landscape *** objective was to evaluate survival and growth of Albizia plurijuga and Ceiba aesculifolia,two tropical deciduous forests species in *** transplanted 4-month-old seedlings to experimental raised beds at three altitudes(2100,2400 and 2700 m a.s.l.),exceeding their upper regional limit of distribution(2000 m a.s.l.).We also tested seed germination at each *** monitored the experiment for 10 *** both species,as altitude increased and cold weather was more prevalent,plant performance *** species,differences in individual growth were significant among *** survival was 18.5%for *** and 24.5%for *** species had higher survival and better growth at lower altitude,and no seedling emergence at any *** conclude that assisted migration can be implemented for each species by an upward attitudinal shift within,and not exceeding,400 m beyond their present upper altitudinal limit of *** results indicate that for many species that show altitudinal gradients at regional scales,unless current climate conditions change,the potential to establish outside their range is minimal.

关键词： Albizia plurijuga Ceiba aesculifolia Climate change Fabaceae Forest management Mitigation strategy Range expansion

Inventory and action plan for PFOS and related substances in Suriname as basis for Stockholm Convention implementation

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Emerging Contaminants 2020年第1期6卷 421-431页

作者： Victorine Pinas carmen Van Dijk Roland Weber Institute for Graduate Studies and Research Anton de Kom University of Suriname ParamariboSuriname Ministry of Agriculture Animal Husbandry and FisheriesParamariboSuriname POPs Environmental Consulting 73527Schw€abisch GmündGermany

Within the framework of the Stockholm Convention implementation in Suriname,the first inventory of perfluorooctane sulfonic acid(PFOS)has been *** major stocks of PFOS are firefighting foams with minor stocks in pesticides(ant baits)and possibly *** inventory of firefighting foams assessed the import,current stocks and major use sites and recent *** amount of PFOS and potentially PFOS containing firefighting foams are stored at the military base,the oil company and small firefighting departments throughout the *** total amount of stored PFAS firefighting foam in Suriname is estimated to be at least 275.6 tonnes,where the major stockpile of 206 tonnes is at the oil storage *** some of these foams PFOS content is confirmed and for others it is not clear if the foam contains PFOS or other per-or polyfluorinated alkylated substances(PFAS).The upper estimate of PFOS content is 4133 kg in these ***,PFOS or other PFAS has also been discovered in fire extinguishers in *** total amount of PFOS related substance EtFOSA imported with the pesticide sulfluramid was 75 *** imports were banned in 2014 and is controlled.A considerable amount of synthetic carpets are in stores even produced before 2003 where main use of PFOS from 3 M took place possibly containing PFOS related substances.A compilation of potentially PFOS contaminated sites has been *** contaminated sites result from firefighting foam use,dumpsites and sulfluramid *** airport where firefighting foam was applied is above a major drinking water reservoir,where an urgent assessment is *** to the lack of analytical capacity for PFOS and precursors,drinking water,firefighting foam or impacted carpets,could not been *** action plan for the control of PFOS and other PFAS has been developed considering the synergy of the Stockholm Convention and the Strategic Approach to International Chemicals Management(SAI

关键词： POPs Firefighting foam Sulfluramid Contaminated sites PFAS SAICM synergy

Characterisation of human non-proliferative diabetic retinopathy using the fractal analysis

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International Journal of Ophthalmology(English edition) 2015年第4期8卷 770-776页

作者： Stefan Tǎlu Dan Mihai Cǎlugǎru carmen Alina Lupascu Discipline of Descriptive Geometry and Engineering Graphics Department of AET Faculty of Mechanical Engineering Technical University of Cluj-Napoca Discipline of Ophthalmology Department of Surgical Specialties and Medical Imaging Faculty of Medicine Iuliu Hatieganu University of Medicine and Pharmacy Cluj-Napoca Department of Mathematics and Informatics University of Palermo

· AIM: To investigate and quantify changes in the branching patterns of the retina vascular network in diabetes using the fractal analysis method.·METHODS: This was a clinic-based prospective study of 172 participants managed at the Ophthalmological Clinic of Cluj-Napoca, Romania, between January 2012 and December 2013. A set of 172 segmented and skeletonized human retinal images, corresponding to both normal(24 images) and pathological(148 images)states of the retina were examined. An automatic unsupervised method for retinal vessel segmentation was applied before fractal analysis. The fractal analyses of the retinal digital images were performed using the fractal analysis software Image J. Statistical analyses were performed for these groups using Microsoft Office Excel2003 and Graph Pad In Stat software.·RESULTS: It was found that subtle changes in the vascular network geometry of the human retina are influenced by diabetic retinopathy(DR) and can be estimated using the fractal geometry. The average of fractal dimensions D for the normal images(segmented and skeletonized versions) is slightly lower than the corresponding values of mild non-proliferative DR(NPDR) images(segmented and skeletonized versions).The average of fractal dimensions D for the normal images(segmented and skeletonized versions) is higher than the corresponding values of moderate NPDR images(segmented and skeletonized versions). The lowestvalues were found for the corresponding values of severe NPDR images(segmented and skeletonized versions).· CONCLUSION: The fractal analysis of fundus photographs may be used for a more complete understanding of the early and basic pathophysiological mechanisms of diabetes. The architecture of the retinal microvasculature in diabetes can be quantitative quantified by means of the fractal *** abnormalities on retinal imaging may elucidate early mechanistic pathways for microvascular complications and distinguish patients with DR from health

关键词： diabetic retinopathy fractal fractal dimension retinal image analysis retinal microvasculature

Risk factors for antenatal depression: A review

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World Journal of Psychiatry 2021年第7期11卷 325-336页

作者： M carmen Míguez M Belén Vázquez Department of Clinical Psychology and Psychobiology Faculty of PsychologyUniversity of Santiago de CompostelaSantiago de Compostela 15782Spain

Depression is the most prevalent mental disorder in pregnancy, and yet it is lessstudied than postpartum depression despite the consequences it may have onboth the pregnant woman and her offspring. Therefore, it would be important toknow which risk factors may favour the appearance of antenatal depression inorder to carry out appropriate prevention interventions. The aim of the presentreview was to identify the main risk factors of antenatal depression. We searchedin databases PubMed and PsycINFO for articles published about the factorsassociated with antenatal depression from January 2010 through December *** literature review identified three main groups of antenatal depression riskfactors: sociodemographic, obstetric, and psychological. First, among thesociodemographic variables, the low level of studies and the economic incomeclearly stood out from the rest. Then, not having planned the pregnancy was themain obstetric variable, and finally, the main psychological risk factors werehaving a history of psychological disorders and/or depression as well aspresenting anxiety, stress, and/or low social support during pregnancy. Thisreview shows that the antenatal depression is affected by multiple factors. Mostcan be identified at the beginning of the pregnancy, and some are risk factorspotentially modifiable through appropriate interventions, such as psychologicalfactors. For this reason, it is important to carry out a good screening for depressionduring pregnancy and consequently, be able to prevent its appearance ortreat it if necessary.

关键词： Depression Antenatal Antenatal depression Pregnancy Risk factors Review

Changes in Mediterranean mesocarnivore communities along urban and ex-urban gradients

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Current Zoology 2015年第5期61卷 793-801页

作者： Mariano R. RECIO carmen M. ARIJA Sara CABEZAS-DIAZ Emilio VIRGOS School of Surveying University of Otago PO Box 56 Dunedin New Zealand Departamento de Biologia y Geologia Escuela de Ciencias Experimentales y Tecnologia. Universidad Rey Juan Carlos E-28933 Mostoles Madrid. Spain.

Urbanization causes wildlife habitat loss, fragmentation, and the replacement of specialist species by generalists and/or exotic taxa. Because mesocarnivores are particularly vulnerable to habitat modifications, the rapid expansion of urban areas and the increasing trend for ex-urban development occurring in Mediterranean ecosystems may be major drivers of change in mesocamivore communities. We combined camera trapping and sign surveys to quantify the richness and relative abundance of a set of wild and domestic mesocarnivores. We quantified these variables controlling for the gradient of urbanism, ex-urbanism, and other environmental variables in patches of natural vegetation in the region of Madrid （central Spain）, and a non-urbanized control area -220 km south of Madrid city. Using conditional autoregressive models （CAR） and model selection procedures, we found that urbanization influenced mesocarnivore community composition but this influence was not detrimental for all the species tested. Generalist carnivores such as the red fox Vulpes vulpes were more abundant in urban and ex-urban areas. Ex-urban development creates overlapping areas between wild and domestic species （such as the domestic cat Felis catus and the wildcat Felis silvestris） but contact between wild and domestic carnivores in natural areas is unlikely. Detection of species in the control area was very low. Therefore, the impact of urbanization in causing changes in mesocarnivore communities may be less than other factors such as illegal predator culling [Current Zoology 61 （5）： 793-801, 2015].

关键词： Urbanization Exurbanization Mesocamivores Mediterranean Domestic carnivores Wild camivores

Acoustic radiation force imaging sonoelastography for noninvasive staging of liver fibrosis

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World Journal of Gastroenterology 2009年第44期15卷 5525-5532页

作者： carmen Fierbinteanu-Braticevici Dan Andronescu Radu Usvat Dragos Cretoiu Cristian Baicus Gabriela Marinoschi Medical Clinic and Gastroenterology University Hospital050094 BucharestRomania Department of Cellular and Molecular Medicine "Carol Davila" University of Medicine and Pharmacy050094 BucharestRomania Department of Internal Medicine and Réseau d'Epidémiologie Clinique International Francophone (RECIF) Colentina Hospital020125 BucharestRomania Institute of Mathematical Statistics and Applied Mathematics 050711 BucharestRomania

AIM:To investigate the diagnostic accuracy of acoustic radiation force impulse (ARFI) imaging as a noninvasive method for the assessment of liver fibrosis in chronic hepatitis C (CHC) ***:We performed a prospective blind com-parison of ARFI elastography,APRI index and FibroMax in a consecutive series of patients who underwent liver biopsy for CHC in University Hospital Bucharest. His-topathological staging of liver fibrosis according to the METAVIR scoring system served as the reference. A to-tal of 74 patients underwent ARFI elastography,APRI index,FibroMax and successful liver biopsy. RESULTS:The noninvasive tests had a good correlation with the liver biopsy results. The most powerful test in predicting fibrosis was ARFI elastography. The diagnostic accuracy of ARFI elastography,expressedas area under receiver operating characteristic curve (AUROC) had a validity of 90.2% (95% CI AUROC = 0.831-0.972,P < 0.001) for the diagnosis of significant f ibrosis (F ≥ 2). ARFI sonoelastography predicted even better F3 or F4 fibrosis (AUROC = 0.993,95% CI = 0.979-1).CONCLUSION:ARFI elastography had very good accuracy for the assessment of liver fibrosis and was superior to other noninvasive methods (APRI Index,FibroMax) for staging liver fibrosis.

关键词： Elasticity imaging techniques Hepatitis C Liver biopsy Liver fibrosis