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Journal of China University of Geosciences 2008年第1期19卷 85-92页

作者： J A vargas-Guzmán Saudi Aramco Dhahran 31311 KSA

An analysis of statistical expected values for transformations is performed in this study to quantify the effect of heterogeneity on spatial geological modeling and evaluations. Algebraic transformations are frequently applied to data from logging to allow for the modeling of geological properties. Transformations may be powers, products, and exponential operations which are commonly used in well-known relations （e.g., porosity-permeability transforms）. The results of this study show that correct computations must account for residual transformation terms which arise due to lack of independence among heterogeneous geological properties. In the case of an exponential porosity-permeability transform, the values may be positive. This proves that a simple exponential model back-transformed from linear regression underestimates permeability. In the case of transformations involving two or more properties, residual terms may represent the contribution of heterogeneous components which occur when properties vary together, regardless of a pair-wise linear independence. A consequence of power- and product-transform models is that regression equations within those transformations need corrections via residual cumulants. A generalization of this result is that transformations of multivariate spatial attributes require multiple-point random variable relations. This analysis provides practical solutions leading to a methodology for nonlinear modeling using correct back transformations in geology.

关键词： reservoir static model intrinsic permeability non-Gaussian nonlinear residual moment cumulant unbiased simulation parameter.

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Galápagos land iguana(Conolophus subcristatus)as a seed disperser

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Integrative Zoology 2016年第3期11卷 207-213页

作者： Anna TRAVESET manuel NOGALES Pablo vargas Beatriz RUmEU Jens m.OLESEN Esporles Mallorca 07190Balearic IslandsSpain Island Ecology and Evolution Research Group(CSIC-IPNA) Instituto de Productos Naturales y Agrobiología38206 TenerifeCanary IslandsSpain Real Jardín Botánico(CSIC-RJB) Department of Biodiversity and ConservationPlaza de Murillo 228014 MadridSpain Centre for Functional Ecology Department of Life SciencesUniversity of CoimbraCalçada Martim de FreitasCoimbra 3000-456Portugal Institute of Bioscience Aarhus UniversityAarhusDenmark and 6Charles Darwin FoundationPuerto AyoraSanta CruzGalápagosQuitoEcuador

The role of the most common land iguana(Conolophus subcristatus)in the Galápagos Islands as an effective seed disperser is explored in this study.A total of 5705 seeds of 32 plant species were identified from 160 scats,4545 of which(80%)appeared visually *** trials of 849 seeds from 29 species revealed that at least 10 species remained viable after passing through the iguana’s gut,although only a small proportion of those seeds(4%)*** any case,we argue that *** exerts an important role on the 7 Galapagos islands where it occurs because of its abundance and capacity to ingest and disperse seeds at long *** results strongly suggest that the Galápagos *** plays an important role as a seed disperser of not only of native species but also some introduced plants in the Galápagos Islands.

关键词： Conolophus subcristatus Fernandina Island Galápagos Islands Saurochory seed dispersal

Global stability for multi-species Lotka-Volterra cooperative systems： One hyper-connected mutualistic-species

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International Journal of Biomathematics 2015年第3期8卷 215-223页

作者： Cruz vargas-De-Leon Unidad de medicina Experimental Hospital General de mexico"Dr. Eduardo Liceaga" DF 06726 Mexico

We propose two models of one hyper-connected mutualistic-species described by delay differential equations of Lotka-Volterra type. An hyper-connected model comprises a central species interacting with a number of peripheral species around it, that is to say, one animal species （pollinators or dispersers） that interacts with several plant species （flowering plants or fruit trees）, or several animal species that interact with one plant species. We derive a necessary and sufficient condition for the global asymptotic stability of the unique coexisting steady state of hyper-connected systems by means of novel Lyapunov functionals.

关键词： Lotka Volterra cooperative system discrete delays distributed delays Lyapunov functional global stability.

Adsorption of Toxic metals and Control of mosquitos-borne Disease by Lysinibacillus sphaericus:Dual Benefits for Health and Environment

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Biomedical and Environmental Sciences 2016年第3期29卷 187-196页

作者： Javier Edo.vargas Jenny Dussan Biological Sciences Universidad De Los AndesBogota 111711Colombia

Objective Assessment of the bacterium L. sphaericus as a dual-action candidate for biological control of mosquito-borne diseases and bioremediation of toxic metals. methods Larvae of the mosquito, C quinquefasciatus, were first evaluated for metal tolerance and then exposed to 5 ppm cadmium, chromium, arsenic, and lead in assays together with seven strains of L. sphaericus. A probit regression analysis was used to estimate the LCso of Cd, Cr, As, and Pb to C. quinquefosciatus. An analysis of covariance and multifactorial ANOVA examined the metal biosorption and larvicidal properties of the seven strains of L. sphaericus. Results We found that L. sphaericus adsorbed the toxic metal ions and was toxic against mosquito larvae. The L. sphoericus strain 111（3）7 resulted in a larvae mortality of over 80% for all the tested metals. This strain also exhibited the capacity to adsorb 76% of arsenic, 32% of lead, 25% of chromium, and 7% of cadmium. Conclusion This study found combined metal adsorption and larval toxicity associated with three strains of L. sphaericus [111（3）7, OT4b.31, and CBAm5]. This suggests that a combination of these strains shows strong dual potential for biological control of mosquitos in heavy metal-contaminated areas and remediate the heavy metal contamination as well.

关键词： Lysinibacillus sphaericus Culex quinquefasciatus Entomopathogen Toxic metals Heath

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Linear Biseparating maps between Vector-valued Little Lipschitz Function Spaces

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Acta mathematica Sinica,English Series 2010年第6期26卷 1005-1018页

作者： A. JImENEZ-vargas Ya-Shu WANG Departamento de Algebra y Andlisis matemdtico Universidad de Almerla 04120 Almerla Spain Department of Applied mathematics National Sun Yet-Sen University 804 Kaohsinug Taiwan

In this paper we provide a complete description of linear biseparating maps between spaces lip0（X^a, E） of Banach-valued little Lipschitz functions vanishing at infinity on locally com-pact HSlder metric spaces X^a=（X,dx^a） with 0〈a〈***, it is proved that any linear bijection T ： lip0（X^a,E）→lip0（Y^a,F）satisfying that ｜｜Tf（y）｜｜F｜｜Tg（y）｜｜F= 0 for all y ∈ Y if and only if ｜｜f（x）｜｜E｜｜g（x）｜｜E=0 for all x E X, is a weighted composition operator of the form Tf（y） = h（y）（f（φ（y）））, where φ is a homeomorphism from Y onto X and h is a map from Y into the set of all linear bijections from E onto F. moreover, T is continuous if and only if h（y） is continuous for all y ∈ Y. In this case, φ becomes a locally Lipschitz homeomorphism and h a locally Lipschitz map from Y^a into the space of all continuous linear bijections from E onto F with the metric induced by the operator canonical norm. This enables us to study the automatic continuity of T and the existence of discontinuous linear biseparating maps.

关键词： linear biseparating map little Lipschitz function Banach-Stone theorem automatic continuity

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Impact of dietary supplementation of β-hydroxybutyric acid on performance, nutrient digestibility, organ development and serum stress indicators in early-weaned goat kids

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Animal Nutrition 2022年第2期9卷 16-22页

作者： mahmoud m.Abdelsattar Einar vargas-Bello-Pérez Yimin Zhuang Yuze Fu Naifeng Zhang Key Laboratory of Feed Biotechnology of the ministry of Agriculture and Rural Affairs Institute of Feed Research of Chinese Academy of Agricultural Sciences Department of Animal and Poultry Production Faculty of Agriculture South Valley University Department of Veterinary and Animal Sciences Faculty of Health and Medical Sciences University of Copenhagen Grùnnegardsvej 3

The objective of this study was to determine the effect of dietary supplementation of β-hydroxybutyric acid(BHBA) on performance, nutrient digestibility, organ development, and serum composition in earlyweaned goat kids. Sixty-four goat kids at 30 d of age were assigned to 4 treatments in a completely randomized design: 1) control(basal diet); 2) low(basal diet with 3 g/d per animal BHBA); 3) medium(basal diet with 6 g/d per animal BHBA; and 4) high(basal diet with 9 g/d per animal BHBA). Subsequently, 48(6 kids per treatment) goat kids were randomly selected and slaughtered at 60 and 90 d of age. Compared with the control group, BHBA at low and high doses increased body weight(P mproved organ development, especially at the lowest dose(P matter and crude protein increased with age(P mpared with the control group, serum ceruloplasmin increased(P m creatinine(P me but was not affected by BHBA. The serum total antioxidant capacity and superoxide dismutase decreased with the high dose of BHBA at 90 d of age(P m glutathione peroxidase and malondialdehyde increased with the high doses of BHBA(P mance, organ development, and health status against weaning stress. Whereas high doses of BHBA in the long term could negatively affect antioxidant status.

关键词： Beta-hydroxybutyric acid Goat kid Acute-phase protein response Weaning stress Antioxidant capacity

Root Secretion of Phytochemicals in Arabidopsis Is Predominantly Not Influenced by Diurnal Rhythms

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molecular Plant 2010年第3期3卷 491-498页

作者： Dayakar V. Badri Victor m. Loyola-vargas Corey D. Broeckling Jorge m. Vivanco Center for Rhizosphere Biology Colorado State University Fort Collins CO 80523 USA 30 Col. Chuburna de Hidalgo Merida Yucatan Mexico

Root-secreted phytochemicals mediate multiple interactions in the rhizosphere. The root exudation process can be altered by various biotic factors, including pathogenic and non-pathogenic microbes, and abiotic factors like temperature and soil moisture. It has been suggested that root secretion of specific flavonoids is influenced by diurnal rhythms （by light or dark） but a comprehensive analysis of the overall secretion of phytochemicals in response to diurnal rhythms has not been studied. In this study, we analyzed the effect of light/dark cycles on root exudation profiles using Arabidopsis as a model plant. Our results reveal that the root secretion of phytochemicals is partly regulated by the diurnal light cycle and follows two main patterns of secretion：（1） the large majority of phytochemicals in the exudates showed no diurnal pattern in their secretion, and （2） a few compounds showed a diurnal pattern in their secretion： three compounds increased in secretion only under light; two compounds increased in secretion only while it was dark; and two compounds increased in secretion during the transition from dark to light. Root-specific ABC transporters have been implicated in root exudation; an analysis of the gene expression patterns of ABC transporters in the roots of Arabidopsis at specific time points revealed that none of the ABC transporters followed a diurnal expression pattern, suggesting that they are expressed constantly during the day and night. Similarly, we analyzed the expression in roots of genes involved in secondary metabolite biosynthesis and found that some of the genes involved in phenylpropanoid and glucosinolate biosynthesis （i.e. 4-coumarate-CoA ligases （4CL1 and 4CL2）, flavonol synthases （FSl and FS2）, and CYP79B3） followed distinct diurnal expression patterns. Overall, we have discovered that while root exudation of the majority of phytochemicals is constitutive, the secretion of a few compounds follows a diurnal rhythm, which is in accor

关键词： Arabidopsis diurnal rhythm root exudates ABC transporters secondary metabolite biosynthesis.

Construction of Dulac functions for mathematical models in population biology

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International Journal of Biomathematics 2015年第3期8卷 135-154页

作者： Osvaldo Osuna Cruz vargas-De-Leon Instituto de Fisica y matematicas Universidad MichoacanaEdif. C-3 Cd. Universitaria CP 58040 Morelia Michoacan Mexico Unidad de medicina Experimental Hospital General de Mexico "Dr. Eduardo Liceaga" DF 06726 Mdxieo

In this paper, we present a method for constructing a Dulac function for mathematical models in population biology, in the form of systems of ordinary differential equations in the plane.

关键词： Population models epidemic models chemostat models Dulac function nonexistence of periodic orbits.

Significance of long non-coding RNA AGPG for the metabolism of esophageal cancer

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Cancer Communications 2020年第7期40卷 313-315页

作者： Rebecca Elizabeth vargas Wenqi Wang Department of Developmental and Cell Biology University of CaliforniaIrvineCalifornia92697USA

Over the years,thousands of long non-coding RNAs(lncRNAs)have been identified to be exclusively expressed in specific cancer types and for their unique functions in *** has led to an increasing interest in elucidating the vital roles[1]and underlying mechanism[2,3]of such non-coding genome in driving cancerous phenotypes.A number of studies have pinpointed the key functions of lncRNAs in diverse biological events including chromatin interactions,transcriptional regulation,RNA processing,mRNA stabilization,signal transduction,and metabolic regulation;highlighting their essential roles in both physiology and diseases such as cancer[4].

关键词： metabolism esophageal cancer

Relative toxicity of three wheat herbicides to two species of Coccinellidae

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Insect Science 2010年第5期17卷 434-438页

作者： J. P. michaud German vargas Department of Entomology Kansas State University Hays Kansas USA

On the High Plains of the USA, herbicides specific for broad-leaf weeds are regularly applied to winter wheat in the early spring, sometimes late enough to coincide with the colonization of fields by cereal aphids and their natural enemies. We tested the toxicity of three such herbicides, Ally （Dupont）, Rave （Syngenta） and 2,4-D ester （generic）, to neonate larvae of two coccinellid species important in cereal aphid biocontrol, Coleomegilla maculata DeGeer and Hippodamia convergens Gurrin-mrneville. Topical treatment of larvae with 2,4-D resulted in 25% and 60% mortality in the two species, respectively, with surviving C. maculata larvae experiencing a 5% increase in developmental time. No significant effects were noted for the other two materials, save for a 2.5% increase in developmental time for C. maculata larvae exposed to Rave. No material caused significant mortality in either species when larvae were fed on prey （Schizaphis graminum Rondani） treated with herbicide 24 h earlier, although 2,4-D reduced developmental time slightly in C. maculata. When herbicide applications are delayed enough in spring to coincide with aphid activity in wheat, farmers can reduce the risk of disrupting biological control by selecting an alternative to 2,4-D.

关键词： 2,4-D Coleomegilla maculata dicamba Hippodamia convergens Schizaphis graminum thifensulfuron methyl