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Variable exponent Hardy spaces associated with discrete Laplacians on graphs

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Science China Mathematics 2019年第1期62卷 73-124页

作者： Víctor Almeida jorge j.Betancor alejandro j.castro Lourdes Rodríguez-Mesa Departamento de Análisis Matemático Universidad de La Laguna Department of Mathematics Nazarbayev University

In this paper we develop the theory of variable exponent Hardy spaces associated with discrete Laplacians on infinite graphs. Our Hardy spaces are defined by square integrals, atomic and molecular decompositions. Also we study boundedness properties of Littlewood-Paley functions, Riesz transforms, and spectral multipliers for discrete Laplacians on variable exponent Hardy spaces.

关键词： graphs discrete Laplacian Hardy spaces variable exponent square functions spectral multipliers

Seasonal variation and host sex affect bat–bat fly interaction networks in the Amazonian savannahs

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Integrative Zoology 2024年第3期19卷 400-416页

作者： Paulo MEjIA Gustavo Lima URBIETA Bruna da Silva XAVIER Isaíjorge de castro joséjúlio DE TOLEDO Gustavo GRACIOLLI Lucio AndréVIANA DIAS William Douglas CARVALHO Programa de Pós-Graduação em Biodiversidade Tropical Universidade Federal do Amapá(UNIFAP)MacapáAPBrazil Programa de Pós-Graduação em Ecologia Instituto de BiologiaCentro de Ciências da SaúdeUniversidade Federal do Rio de Janeiro(UFRJ)Rio de JaneiroRJBrazil Laboratório de Mamíferos Instituto de Pesquisas Científicas e Tecnológicas do Estado do Amapá(IEPA)MacapáAPBrazil Programa de Pós-Graduação em Biologia Animal Laboratório de SistemáticaEcologia e Evolução(LSEE)Instituto de BiociênciasUniversidade Federal de Mato Grosso do Sul(UFMS)Campo GrandeMTBrazil Terrestrial Ecology Group(TEG-UAM) Departamento de EcologíaFacultad de CienciasUniversidad Autónoma de MadridMadridSpain Centro de Investigación en Biodiversidad y Cambio Global(CIBC-UAM) Universidad Autónoma de MadridMadridSpain

Bats are the second-most diverse group of mammals in the world,and bat flies are their main ***,significant knowledge gaps remain regarding these antagonistic interactions,especially since diverse factors such as seasonality and host sex can affect their network ***,we explore the influence of such factors by comparing species richness and composition of bat flies on host bats,as well as specialization and modularity of bat–bat fly interaction networks between seasons and adult host *** captured bats and collected their ectoparasitic flies at 10 sampling sites in the savannahs of AmapáState,northeastern region of the Brazilian *** female bats being more parasitized and recording greater bat fly species richness in the wet season,neither relationship was statistically *** pooled network could be divided into 15 compartments with 54 links,and all subnetworks comprised>12 *** total number of links ranged from 27 to 48(for the dry and wet seasons,respectively),and female and male subnetworks had 44 and 41 links,*** values were very low for the pooled network and for all *** results revealed higher bat fly species richness and abundance in the wet season,whereas specialization and modularity were higher in the dry ***,the subnetwork for female bats displayed higher specialization and modularity than the male ***,both seasonality and host sex contribute in different ways to bat–bat fly network *** studies should consider these factors when evaluating bat–bat fly interaction networks.

关键词： Amapá Amazon biome bat flies bats interaction networks

Synthesis of coral-like structures of Pr-Yb co-doped YIG: Structural,optical, magnetic and antimicrobial properties

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journal of Rare Earths 2024年第3期42卷 543-554,I0004页

作者： A.Fernandez Francisca P.Araujo Y.Guerra S.castro-Lopes j.Matilla-Arias Idglan S.de Lima Edson C.Silva-Filho josy A.Osajima F.Guerrero R.Pena-Garcia Federal University of Piau Graduate Program in Materials Science and EngineeringTeresinaPIBrazil Federal Rural University of Pernambuco Academic Unit of Cabo de Santo AgostinhoCabo de Santo AgostinhoPEBrazil Federal University of Piaui Department of PhysicTeresinaPBrazil Federal University of Pernambuco Graduate Program in Materials ScienceRecifePEBrazil University of Granma Departmentof Basic Sciences and Applied InformaticsFaculty of Technical SciencesBayamoCuba Federal University of Amazonas Department of PhysicManausAMBrazil Federal University of Pernambuco Department of PhysicRecifePEBrazil

Coral-like structures of the Y_(3-x)Pr_(x)Fe_(5-y)Yb_(y)O_(12),(0.00 ≤ x ≤ 0.04, 0.00 ≤ y ≤ 0.02) compound were synthesized using the sol-gel method. Structural investigation certified the YIG cubic crystal structure formation, without any secondary phase. It is shown that, the relatively large ionic radius of the dopant cations results in an expansion of the lattice parameter, variations in the Iona-O-Iondangle, Iona-O,Iond-O and Ionc-O bond distances and decrease in the average crystallite size. Fourier transform infrared(FTIR) and Raman measurements are essential to testify the single-phase formation of YIG crystal structure and are observed changes in the stretching and vibrational modes, respectively. The morphological study, energy dispersive spectroscopy(EDS) spectra and textural properties show corallike structures, peaks associated with Pr^(3+) and Yb^(3+) atoms and the effect of dopants on surface area,diameter, and pore volume, respectively. The optical analysis from diffuse reflectance spectra witnessed an increase in the optical gap band, a decrease in Urbach energy and blue shift in the charge transfer,correlated with the expansion of the unit cell due to the dopant's insertion in the YIG structure. A typical ferrimagnetic behavior is exhibited by the Y_(3-x)Pr_(x)Fe_(5-y)Yb_(y)O_(12)compound. The saturation magnetization(M_(s)), cubic anisotropy constant(K_(1)) and coercive field(H_(c)) increase with the Pr^(3+)cations content, as consequence of their magnetic nature and distribution around of Fe^(3+)ions due to the coexistence with the Yb^(3+). Finally, for the first time, antibacterial tests by mean of the direct contact method were performed for YIG co-doped with Pr^(3+)and Yb^(3+)and it is shown that, relatively high dosages of Pr^(3+) cations favored the activity against S. aureus, therefore, a new biological property for YIG doped with rare earths is presented.

关键词： Yttrium iron garnet(YIG) Coral-like structures Rare earths Band gap energy Magnetic properties Antimicrobial properties

On Lagrange-Projection Schemes for Shallow Water Flows Over Movable Bottom with Suspended and Bedload Transport

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Numerical Mathematics(Theory,Methods and Applications) 2023年第4期16卷 1087-1126页

作者： Alessia Del Grosso Manuel j.castro Díaz Christophe Chalons Tomás Morales de Luna UniversitéParis-Saclay UVSQCNRSLaboratoire de Mathématiques de Versailles78000VersaillesFrance Dpto.de Análisis Matemático Facultad de CienciasUniversidad de MálagaCampus de Teatinos S/N29081 MálagaSpain

In the present work we aim to simulate shallow water flows over movable bottom with suspended and bedload *** order to numerically approximate such a system,we proceed step by *** start by considering shallow water equations with non-constant density of the mixture ***,the Exner equation is included to take into account bedload sediment ***,source terms for friction,erosion and deposition processes are ***,observe that the sediment particle could go in suspension into the water or being deposited on the *** the numerical scheme,we rely on well-balanced Lagrange-projection *** particular,since sediment transport is generally a slow process,we aim to develop semi-implicit schemes in order to obtain fast *** Lagrange-projection splitting is well-suited for such a purpose as it entails a decomposition of the(fast)acoustic waves and the(slow)material waves of the ***,in subsonic regimes,an implicit approximation of the acoustic equations allows us to neglect the corresponding CFL condition and to obtain fast numerical schemes with large time step.

关键词： Shallow water flows movable bottom erosion-deposition processes Lagrangeprojection schemes implicit-explicit schemes

Experimental Study on Split-Ring Resonators with Different Slit Widths

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journal of Electromagnetic Analysis and Applications 2013年第9期5卷 366-370页

作者： Pedro j.castro joaquim j.Barroso joaquim P.Leite Neto Associated Plasma Laboratory National Institute for Space Research—INPESao Jose dos CamposBrazil

Metamaterial one-dimensional periodic structures are composed of split-ring resonators, which can display electric permittivity and magnetic permeability simultaneously negative, are studied experimentally. In the present study, each resonator is made up of two concentric circular copper rings patterned on a substrate of kapton, with slits diametrically opposite each other and with the line of the splits along the longitudinal direction of the periodic array containing seven split rings evenly spaced. The experiments consist in inserting the metamaterial slab into a square waveguide of side length 6 mm, corresponding to a cutoff frequency of 25 GHz. Transmission bands due to magnetic and electrical responses are identified for slits with aperture widths of 1 mm and 2 mm, centered at 5.67 and 6.12 GHz frequencies, respectively, values well below the 25 GHz frequency cutoff, so characterizing a medium with negative permeability and permittivity.

关键词： Metamaterials Split-Ring Resonators Magnetic Response Electric Response Left-Handed Transmission Band

Non-Genotoxic *** to Their Risk Assessment

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Biomedical and Environmental Sciences 1993年第1期6卷 71-80页

作者： j.A.castro.M.I.DIAZGOMEZ G.D.castro CentrodeInvestigacionesToxicologicasCitefa/ConicetZufriategui43801603VillaMartelli-BuenosAiresArgentina. CentrodeInvestigacionesToxicologicasCitefa/ConicetZufriategui43801603VillaMartelli-BuenosAiresArgentina.

Epidemiological studies support the idea that most human cancers are related to chemicals present in the human environment. In turn, chemicals are believed to cause cancer via either genotoxic or non-genotoxic mechanisms. There were described in literature several simple, rapid and inexpensive short term tests to reasonably predict the genotoxic nature of chemicals but in contrast, there is no reliable test or battery of tests available to predict the carcinogenicity of non-genotoxic compounds and this poses a major problem to their risk assessment. In addition, there are conflictive opinions about risk assessment needs for both classes of carcinogens. Some workers believe that for non-genotoxic carcinogens, thresholds for exposure can be drawn while others do not. In this review, the reasons behind both of these opinions and the present hypotheses about the mechanism of action of non-genotoxic carcinogens are described and analyzed in relation to future needs.

关键词： Non-Genotoxic Carcinogens.Approaches to Their Risk Assessment

Crohn's disease presenting as acute gastrointestinal hemorrhage

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World journal of Gastroenterology 2016年第16期22卷 4073-4078页

作者： Amareshwar Podugu Kanwarpreet Tandon Fernando j.castro Department of Gastroenterology Cleveland Clinic Florida

Severe gastrointestinal (GI) hemorrhage is a rare complication of Crohn’s disease (CD). Although several surgical and non-surgical approaches have been described over the last 2 decades this complication still poses significant diagnostic and therapeutic challenges. Given the relative infrequency of severe bleeding in CD, available medical literature on this topic is mostly in the form of retrospective case series and reports. In this article we review the risk factors, diagnostic modalities and treatment options for the management of CD presenting as GI hemorrhage.

关键词： Crohn’ s disease Recurrence Gastrointestinal hemorrhage Biologic agents Risk factors

Using Delphi and fuzzy DEMATEL for analyzing the intertwined relationships of the barriers of university technology transfer: Evidence from a developing economy

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International journal of Innovation Studies 2020年第3期4卷 85-104页

作者： Renissa S.Quinones june Anne A.Caladcad Celbert M.Himang Hubert G.Quinones Charena j.castro Shirley Ann A.Caballes Dharyll Prince M.Abellana Eula Margareth Y.jabilles Lanndon A.Ocampo Technology Research Center Cebu Technological UniversityCorner M.J.Cuenco Ave.&R.Palma St.Cebu City6000Philippines Graduate School Cebu Technological UniversityCorner M.J.Cuenco Ave.&R.Palma St.Cebu City6000Philippines Department of Industrial Engineering Cebu Technological UniversityCorner M.J.Cuenco Ave.&R.Palma St.Cebu City6000Philippines

Universities are highly responsible for knowledge creation and technology ***,university technology transfer(UTT)is considered a challenge in bringing innovative technologies for commercialization and community ***,identifying the barriers and their complex interrelationships that hinder the successful implementation of UTT provides a better understanding of the process,which may be considered as inputs to crucial decision-making *** this approach is highly relevant in the domain field,it remains a point of departure in the current *** paper addresses this gap by holistically determining the UTT barriers and their intertwined *** the Delphi method and the fuzzy decision-making trial and evaluation laboratory(DEMATEL)to carry out this objective,a case study in a state university in the Philippines is presented in this *** show that lack of resources has the strongest causal relationship among the 24 UTT ***,poor marketing/technical/negotiation skills of technology transfer office obtained the highest impacts received and is categorized as the main net *** findings are intended to guide various stakeholders in understanding the influence of barriers in the formulation of strategies and initiatives to carry out effectively the UTT process.

关键词： University technology transfer Barriers Causal relationships Delphi DEMATEL Fuzzy set theory

The role of BRCA 1 and BRCA2 in prostate cancer

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Asian journal of Andrology 2012年第3期14卷 409-414,I0006页

作者： Elena castro Rosalind Eeles Oncogenetics Team The Institute of Cancer Research Sutton SM2 5NG UK Academic Urology Unit The Royal Marsden NH Foundation Trust London SW3 6J J UK

One of the strongest risk factors for prostate cancer is a family history of the disease. Germline mutations in the breast cancer predisposition gene 2 （BRCA2） are the genetic events known to date that confer the highest risk of prostate cancer （8.6-fold in men ≤ 65 years）. Although the role of BRCA2 and BRCA1 in prostate tumorigenesis remains unrevealed, deleterious mutations in both genes have been associated with more aggressive disease and poor clinical outcomes. The increasing incidence of prostate cancer worldwide supports the need for new methods to predict outcome and identify patients with potentially lethal forms of the disease. As we present here, BRCA germline mutations, mainly in the BRCA2gene, are one of those predictive factors. We will also discuss the implications of these mutations in the management of prostate cancer and hypothesize on the potential for the development of strategies for sooradic cases with similar characteristics.

关键词： BRCA1 BRCA2 prostate cancer