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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

Effect of Multipoint Heterogeneity on Nonlinear Transformations for Geological Modeling: Porosity-Permeability Relations Revisited

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j.urnal 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.

Guest Editorial: Power Systems with Increasing Renewable Penetration: Market, Operations, Planning and Regulation

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j.urnal of Modern Power Systems and Clean Energy 2021年第4期9卷 I0001-I0002页

作者： Antonio j.Conej. j.anhui Wang Angel Arcos vargas Ohio State University ColumbusOhioUSA Southern Methodist University DallasTexasUSA University of Seville SevilleSpain

Our goal in putting together this special section is to contribute to the conversation on control,operations,planning and regulation of power systems with increasing renewable *** a conversation will hopefully involve regulators,operators,producers,consumers,and the research *** hope that this special section will spur innovative ideas that will contribute to ensuring a secure,efficient,and environmentally friendly supply of electrical ener-gy,and to eventually achieve a carbon-free electricity *** special section includes 15 research articles on control,operations,regulation,planning,forecasting,and estimation of power systems with increasing renewable penetration.

关键词： Market operations eventually

Enhancement and Optimization of ATO Nano-crystalline Films Properties by the Addition of Acetylacetone as Modifier in the Sol-gel Process

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j.urnal of Wuhan University of Technology(Materials Science) 2015年第5期30卷 873-881页

作者： Galaviz-pérez j.A CHEN Fei SHEN Qiang vargas-garcía j.R 张联盟 State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Dept.of Materials and Metallurgical Eng. National Polytechnic Institute

Sb-doped Sn O2(ATO) thin films have been prepared using the spin coating method by selecting the proper amount of acetylacetone as solution modifier. All ATO powders and films exhibited the cassiterite rutile-like structure in a crystal size below 10 nm under all the experimental conditions and a nonpreviously reported crystal structure was observed at high acetylacetone loads. The acetylacetone molar ratio influenced notably the optical and electrical properties of ATO films. When prepared at an acetylacetone molar ratio of 4, ATO films exhibited optical transparencies above 90% in the visible region and above 40% in the UV region for thicknesses of 100 and 300 nm. Films in a thickness of 100 nm and at an annealing temperature of 650 ℃ accounted for a high transparency of 97% in the visible wavelength. Films prepared at an acetylacetone molar ratio of 4 exhibited an electric resistivity of 1.33×10-3 Ω·cm at an annealing temperature of 650 ℃. The optimal Sb content for ATO films was found to be 8 at%. The relationships among the properties of starting solutions, the experimental parameters, and properties of ATO films are discussed.

关键词： tin oxide films antimony doping acetylacetone optical transparency electric properties

Living donor liver transplantation for patients with advanced hepatocellular carcinoma

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Hepatoma Research 2020年第11期6卷 18-31页

作者： j.Michael Cullen Paola vargas Nicolas Goldaracena Department of Surgery University of VirginiaCharlottesvilleVA 22908USA Division of Transplantation Department of SurgeryUniversity of VirginiaCharlottesvilleVA 22908USA

Liver transplantation(LT)is the treatment of choice for patients with hepatocellular carcinoma(HCC)and underlying liver *** the organ scarcity,LT for patients with HCC have been restricted to those patients associated with the highest ***,many patients with extended criteria HCC can still benefit from LT,but due to deceased organ shortage,they are not offered that *** donor liver transplantation(LDLT)emerged as a successful strategy to overcome organ shortage around the world and as LDLT experience grows,this technique might offer the opportunity to expand the indications of LT to patients with advanced ***,since LDLT is not competing for deceased donor organs,many patients with extended criteria HCC who could still benefit from transplantation may have access to this treatment *** this review,we will discuss the role of LDLT for patients with advanced-stage HCC and how LDLT allows for safe expansion of HCC transplant criteria.

关键词： Living donor liver transplantation hepatocellular carcinoma liver transplantation transplant oncology clinical outcomes

Effect of different exogenous fatty acids on the cytosolic triacylglycerol content in bovine mammary cells

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Animal Nutrition 2019年第2期5卷 202-208页

作者： Einar vargas-Bello-Pérez j.an j.Loor Philip C Garnsworthy The University of Nottingham Sutton Bonington Campus Department of Veterinary and Animal Sciences Faculty of Health and Medical SciencesUniversity of Copenhagen Department of Animal Sciences and Division of Nutritional Sciences University of Illinois1207 West Gregory DriveUrbana

The obj.ctive of this study was to determine how cytosolic triacylglycerols(TAG) are stored in mammary cells and whether this depends on the individual chemical configuration of fatty acids(FA). This obj.ctive was accomplished by addition of different FA to a FA-free medium used to culture mammary alveolar cells-large T antigen cells(MAC-T). Treatments consisted of adding FA(palmitate, stearate, oleate, linoleate,rumenic acid [CLA], elaidate and vaccinate) solutions to the medium at 100, 200, 300 and 400 mmol/L concentrations for a 24-h incubation period. At the end of each incubation period, cytosolic TAG, DNA and protein contents were measured. Palmitate, vaccenate, linoleate and CLA increased(P j.sted for DNA content. Overall, effects on cytosolic TAG accumulation depended on individual FA structure(chain length, degree of saturation, and number and orientation of FA double bonds). In addition, the long-chain FA used in this study did not have a detrimental effect on MAC-T cells as indicated by cytosolic protein and DNA contents reflecting their biological role in lipid accumulation.

关键词： Long chain fatty acid Mammary cells Trans fatty acid Triacylglycerol accumulation Vaccenic acid

Nucleocytoplasmic Gynodioecy

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Applied Mathematics 2013年第12期4卷 1658-1668页

作者： R. Doroteo j. A. vargas CIIDIR-Oaxaca Instituto Politécnico Nacional Xoxocotlán México Departamento de Ciencias Básicas Instituto Tecnológico de Oaxaca Oaxaca México

We study the evolution of a gynodioecious species under mixed-mating through a nucleocytoplasmic male sterility model. We consider two cytoplasmic types and a nuclear locus with two alleles. Here, the interaction between one cytoplasmic type and a recessive nuclear male-sterility factor gives rise to only one female genotype, while the remaining types correspond to hermaphroditic plants. We include two fitness paramaters: the advantageous female fitness t of females relative to that of hermaphrodites;and a silent and dominant cost of restoration, that is, a diminished fitness for plants carrying a dominant restorer gene relative to that of hermaphrodites. The parameter related to the cost of restoration is assumed to be present on outcrossing male fertility only. We find that every population converges to a stable population. We also determine the nature of the attracting stable population, which could be a nucleocytoplasmic polymorphism, a nuclear polymorphism or another population with some genotypes absent. This depends on the position of t with respect to critical values expressed in terms of the other parameters and also on the initial population.

关键词： Population Genetics Gynodioecy Dynamical System Nucleocytoplasmic Interaction Matrix of Linear Forms

Population dynamics of three lizard species from the genus Sceloporus:short-term changes in demographic parameters

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Integrative Zoology 2019年第6期14卷 542-560页

作者： Selene vargas-GARCÍA Víctor ARGAEZ Israel SOLANO-ZAVALETA j.j.ime ZÚÑIGA-VEGA Graduate Program in Biological Sciences National Autonomous University of MexicoUniversity CityMexico CityMéxico Department of Ecology and Natural Resources Faculty of SciencesNational Autonomous University of MexicoUniversity CityMexico CityMéxico.

Most demographic studies focus on numerical changes that occur within populations across ***,typically studies at an interannual scale do not provide information on the particular times of the year(particular months or seasons)when rates of survival,recruitment,or migration increase or decrease due to physiological,behavioral or ecological *** monthly or seasonal changes in demographic parameters may lead to substantial variations in population *** this study,we collected capture-mark-recapture data on 3 species of lizards of the genus Sceloporus(Sceloporus torquatus,Sceloporus grammicus and Sceloporus megalepidurus)found in ecologically similar habitats to examine potential changes in demographic rates among 3 different climatic seasons:rainy,cold-dry and warm-dry *** tested different hypotheses about the effect of these seasons on survival,recruitment of new adults,and temporary *** found that during the season with severe thermal constraints,the cold-dry season,survival of *** decreased *** also detected a considerable increase in the recruitment rate of *** during the rainy season,when these lizards are establishing territories and finding *** contrast,we found no evidence of intra-annual changes in the rate of temporary *** addition,we calculated abundance and population growth rates for each species and for each *** study represents a significant contribution to the understanding of intra-annual demographic variation in lizards.

关键词： abundance recruitment Sceloporus lizards survival temporary emigration

Inflow and outflow permeability tests in a very soft clay under low stresses

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j.urnal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3270-3283页

作者： j.W.S.vargas F.A.B.Danziger F.R.Lopes T.Lunne Federal University of Rio de j.neiro Rio de JaneiroBrazil Norwegian Geotechnical Institute OsloNorway

In situ inflow and outflow permeability tests with the BAT probe at SarapuíII soft clay test site are presented.A description of the BAT permeability test is provided,discussing its advantages and shortcomings,especially in the case of very soft clays under low *** pressures were monitored during probe installation and were found to be slightly lower than piezocone u2 pore pressures,consistent with the position of the *** role of filter tip saturation was investigated after the usual saturation procedure provided an unsatisfactory pore pressure response during probe *** show that the vacuum saturation procedure provides adequate response during installation and increases the reliability of the coefficient of permeability determination in early *** inflow and outflow tests yielded similar results,indicating that careful execution of the test can lead to good test repeatability regardless of the loading *** sequences of alternated inflow and outflow tests have yielded similar results,indicating that soil reconsolidation and filter clogging were negligible in the tests *** are presented concerning the relationship between index parameters and the in situ coefficient of permeability for SarapuíII clay,which plot outside the range of existing databases.

关键词： Permeability test Soft clay BAT probe Inflow and outflow tests