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An examination by GC×GC-TOFMS of organic molecules present inhighly degraded oils emerging from Caribbean terrestrial seeps of Cretaceous age

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Geoscience Frontiers 2019年第1期10卷 5-15页

作者： Alan G.Scarlett Ana Ibis Despaigne-diaz Simon A.Wilde Kliti Grice Western Australian Organic and Isotope Geochemistry Centre The Institute for Geoscience Research Curtin University Department of Applied Geology The Institute for Geoscience Research Curtin University

For our ancestors, oil seeps were both a fascination and a resource but as the planet's reserves of high quality low density oil becomes increasingly depleted, so there is now a renewed interest in heavier,biodegraded oils such as those encountered in terrestrial seeps. One such seep is Pitch Lake in the Caribbean island of Trinidad, which is the largest natural deposit of asphalt in the world. At the northern end of the Caribbean, oil emerges along a tectonic contact on the island on Cuba. The sources of the oils from these seeps are relatively recent and both are subject to intense weathering due to the tropical conditions. When analysed by gas chromatography(GC) both oils appear as unresolved complex mixtures(UCM) and show a very high degree of biodegradation thus presenting an analytical challenge. In this case study, these two Caribbean seep oils were analysed by comprehensive two dimensional GC with time of flight mass spectrometry(GC×GC-TOFMS) to expose many thousands of the individual compounds that comprise the UCM. The high chromatographic resolution of the GC×GC-TOFMS produced good quality mass spectra allowing many compounds including molecular fossil ‘biomarkers' to be identified. compound classes included diamondoid hydrocarbons, demethylated hopanes and secohopanes, mono-and tri-aromatic steroids. D-ring aromatised structures of the 8,14-seco-hopanes,including demethylated forms were present in both oils but further demethylation, probably at position C-25 during biodegradation, was only observed in the Pitch Lake oil. many polycyclic aromatic hydrocarbons(PAHs) were absent although the fungal-derived pentacyclic PAH perylene was present in both oils. The presence of the angiosperm biomarker lupane in the Pitch Lake oil constrained the age to the Late Cretaceous. The higher degree of biodegradation observed in the Cuban oil was likely due to relatively slow anaerobic processes whereas oil within Pitch Lake was probably subject to additional more rapid

关键词： Oil seep Biomarker Biodegradation GCxGC Diamondoids Aromatic steroids

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Resveratrol effects on neural connectivity during aging

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Neural Regeneration Research 2016年第7期11卷 1067-1068页

作者： Gonzalo Flores Rubén Antonio Vázquez-Roque Alfonso diaz Instituto de fisiología Benemerita Universidad autónoma de Puebla.14 Sur 6301PueblaMexico Departamento de Farmacia Facultad de Ciencias químicasbenemérita Universidad autónoma de PueblaPueblaMexico

Aging has been considered a natural process of any living *** rate of aging depends on many factors,including genetic and environmental *** this reason,many researchers in this field suggest that aging is an epigeneti... 详细信息

关键词： resveratrol connectivity older hippocampus neuronal metabolism cortical Aging cortex PPAR

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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

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A technical and socioeconomic approach to estimate forest residues as a feedstock for bioenergy in northern Mexico

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Forest Ecosystems 2019年第4期6卷 312-322页

作者： Guadalupe Carrasco-diaz Gustavo Perez-Verdin Jonathan Escobar-Flores ma.co Antonio marquez-Linares Instituto Politecnico Nacional CIIDIR Dgo.

Background: Forest residues can be a feasible alternative for converting energy into fuels, electricity, or *** to other second-generation bioenergy sources, they do not compete for food, are relatively cheap,abundant in forest-rich areas, and more importantly their energy balance is close to zero. Biomass estimations can help design energy strategies to reduce fossil fuels dependency. Because of the land property distribution in Mexico,biomass estimations should consider not only the physical availability, but also the willingness of landowners to extract such raw ***: This study presents a methodological approach for evaluating the potential use of forest residues as a feedstock to generate bioenergy in northern Mexico. Remote sensing and field forest inventory were used to estimate the quantity and distribution of forest residues. In addition, a discrete choice analysis evaluated landowners’ preferences towards bioenergy development, including the most important factors that influence their willingness to extract their products and the expected *** and conclusions: considering both physical and socio-economic aspects, results showed that about59,000 metric tons per year could be available in the study area. The vast majority of landowners surveyed are willing to extract forest residues, as long as they are presented with extraction plans with the highest income. However, many showed concerns about the environmental impacts this activity can have on soils,plants, and fauna. These results can help evaluate the potential of these resources for bioenergy development.

关键词： Bioenergy Choice experiments Forest landowners Forest residues Remote sensing

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Global health disparities in vulnerable populations of psychiatric patients during the coVID-19 pandemic

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World Journal of Psychiatry 2021年第4期11卷 94-108页

作者： Ailyn diaz Ritika Baweja Jessica K Bonatakis Raman Baweja Department of Psychiatry and Behavioral Health Penn State University College of MedicineHersheyPA 17033United States

The coronavirus disease 2019 pandemic affects psychiatric patients disproportionately compared to the general *** this narrative review,we examine the impact of the pandemic on significant global health disparities affecting vulnerable populations of psychiatric patients:People of diverse ethnic background and color,children with disabilities,sexual and gender minorities,pregnant women,mature adults,and those patients living in urban and rural *** identified disparities cause worsened mental health outcomes placing psychiatric patients at higher risk for depression,anxiety and posttraumatic stress disorder *** psychiatric patients who are ethnic minorities display barriers to care,including collective trauma and structural *** and gender minorities with mental illness face discrimination and limited access to *** women with psychiatric diagnoses show higher exposure to domestic *** with disabilities face a higher risk of worsening *** adults with psychiatric problems show depression due to social *** patients who live in urban communities face pollutants and overcrowding compared to those living in rural communities,which face limited access to telehealth *** suggest that social programs that decrease discrimination,enhance communal resilience,and help overcome systemic barriers of care should be developed to decrease global health disparities in vulnerable population.

关键词： coVID-19 Pandemic Health disparities Global disparities Mental health disparities Access to care

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Preparation and characterization of phosphate-modified mesoporous TiO2 incorporated in a silica matrix and their photocatalytic properties in the photodegradation of congo red

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Frontiers of materials Science 2017年第3期11卷 250-261页

作者： Alberto ESTRELLA GONZALEZ maximiliano ASOMOZA Ulises ARELLANO Sandra CIPAGAUTA diaz Silvia SOLíS Department of Chemistry Metropolitan Autonomous University-lztapalapa P.O. Box 55-532 C.P. 09340 México City México

This study describes the development of mesostructured TiO2 photo- catalysts modified with PO4^3- to improve its specific surface area and reduce the recombination rate of the electron-hole pairs. The mesoporous photocatalyst was successfully incorporated into a high specific surface area silica matrix by the hydrolysis reaction of tetraethyl orthosilicate （TEOS）. Pluronic 123 and phosphoric acid were used as the directing agent for the structure of the mesoporous TiO2 and as a source of phosphorus, respectively, TiO2, P/TiO2, TiO2-SiO2 and P/TiO2-SiO2 materials were characterized by BET, XRD, TEM-EDS, FTIR and UV-vis DRS measurements. The photoactivity of TiO2-SiO2 nanocomposites containing 15 wt.% photocatalystJsilica was evaluated in the degradation reaction of anionic dyes with UV radiation. The proposed nanomaterials showed high potential for applications in the remediation of wastewater, being able to reuse in several cycles of reaction, maintaining its photoactivity and stability. The separation and recovery time of the material is reduced between cycles since no centrifugation or filtration processes are required after the photooxidation reaction.

关键词： photocatalysis phosphated TiO2 TiO2-SiO2 congo red dye

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Hilbert Space of Probability Density Functions Based on Aitchison Geometry

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Acta mathematica Sinica,English Series 2006年第4期22卷 1175-1182页

作者： J.J.EGOZCUE J.L.diaz-BARRERO V.PAWLOWSKY-GLAHN Applied mathematics Ⅲ Universitat Politàcnica de CatalunyaJordi Girona 1-3C208034BarcelonaSpain Applied mathematics Ⅲ Universitat Politàcnica de CatalunyaJordi Girona 13C208034BarcelonaSpain Informatics and Applied mathematics Universitat de GironaCampus MontiliviP417071GironaSpain

The set of probability functions is a convex subset of L1 and it does not have a linear space structure when using ordinary sum and multiplication by real constants. Moreover, difficulties arise when dealing with distances between densities. The crucial point is that usual distances are not invariant under relevant transformations of densities. To overcome these limitations, Aitchison＇s ideas on compositional data analysis are used, generalizing perturbation and power transformation, as well as the Aitchison inner product, to operations on probability density functions with support on a finite interval. With these operations at hand, it is shown that the set of bounded probability density functions on finite intervals is a pre-Hilbert space. A Hilbert space of densities, whose logarithm is square-integrable, is obtained as the natural completion of the pre-Hilbert space.

关键词： Bayes' theorem Fourier coefficients Haar basis Aitchison distance Simplex Least squares approximation

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Residents'perception of sustainable tourism in protected mountain areas:the case of Asturias

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Journal of Mountain Science 2022年第12期19卷 3597-3614页

作者： maGADAN-diaz marta RIVAS-GARCIA Jesus I. Faculty of Business and communication Universidad Internacional de La RiojaAvda.de la Paz 137Logrono 26o06Spain

Spain is the country with the most Biosphere Reserves in the world,52,and Asturias,with 7,ranks first among the single-province Autonomous *** tourist interest in these natural spaces is increasing,but little or nothing is known about how the residents of these natural spaces perceive the tourist *** main objective of this research was to evaluate the residents’perceived changes in protected mountain areas in Asturias concerning the environmental,sociocultural,and economic dimensions related to tourism activity with survey methods and various quantitative *** findings obtained were the following:firstly,there were significant differences between the residents’sociodemographic characteristics and their perceptions of tourism impacts;secondly,there were positive relationships between the residents’perceived tourism economic,environmental and sociocultural impacts and their general attitude towards tourism development;and thirdly,the more positive the residents’attitude towards tourism development,the more likely residents actively support its further *** findings indicate the willingness of residents to get involved and participate in the tourism activity,so policymakers should implicate residents in decisionmaking on local tourism *** conclusion,long-term monitoring of residents’evolution of their perceptions and attitudes is necessary to achieve sustainable tourism development.

关键词： Sustainable tourism Tourists’perception Survey method Regression analysis Asturias

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Loop-Shaping Based control for Switch Mode DC-DC Power converters

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Journal of Power and Energy Engineering 2020年第10期8卷 66-83页

作者： ma Guadalupe Ortiz-Lopez Luis Humberto diaz-Saldierna Diego Langarica-cordoba Jesus Leyva-Ramos Universidad Politecnica de San Luis Potosí San Luis Potosí Mexico Instituto Potosino de Investigación Cientifica y Tecnologica San Luis Potosí Mexico Universidad Autonoma de San Luis Potosi San Luis Potosí Mexico

Renewable energy sources require switching regulators as an interface to a load with high efficiency, small size, proper output regulation, and fast transient response. Moreover, due to the nonlinear behavior and switching nature of DC-DC power electronic converters, there is a need for high-performance control strategies. This work summarized the dynamic behavior for the three basic switch-mode DC-DC power converters operating in continuous conduction mode, i.e. buck, boost, and buck-boost. A controller was designed using loop-shaping based on current-mode control that consists of two feedback loops. A high-gain compensator with wide bandwidth was used in the inner current loop for fast transient response. A proportional-integral controller was used in the outer voltage loop for regulation purposes. A procedure was proposed for the parameters of the controller that ensures closed-loop stability and output voltage regulation. The design-oriented analysis was applied to the three basic switch-mode DC-DC power converters. Experimental results were obtained for a switching regulator with a boost converter of 150 W, which exhibits non-minimum phase behavior. The performance of the controller was tested for voltage regulation by applying large load changes.

关键词： Renewable Energy Sources Loop-Shaping control Power Electronic converters Current-Mode control

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Performance Analysis of a High-Order Discontinuous Galerkin Method Application to the Reverse Time Migration

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communications in computational Physics 2012年第2期11卷 660-673页

作者： Caroline Baldassari Helene Barucq Henri Calandra Bertrand Denel Julien diaz INRIA Bordeaux Research Center Project Team Magique3DAvenue de l’universite64013 Pau CedexFrance. Lma CNRS UMR 5142Universite de PauAvenue de l’universite64013 Pau CedexFrance TOTAL Avenue Larribau64000 PauFrance

This work pertains to numerical aspects of a finite element method based discontinuous *** study focuses on the Interior Penalty Discontinuous Galerkin method(IPDGM)because of its high-level of flexibility for solving the full wave equation in *** assess the performance of IPDGMthrough a comparison study with a spectral element method(SEM).We show that IPDGM is as accurate as *** addition,we illustrate the efficiency of IPDGM when employed in a seismic imaging process by considering two-dimensional problems involving the Reverse Time Migration.

关键词： Interior penalty discontinuous Galerkin method spectral element method reverse time migration seismic imaging process

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