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Glyphosate Dissipation in Different Soils Under No-Till and Conventional Tillage

Pedosphere 2019年第6期29卷 773-783页

作者： Elena OKADA JoséLuis COSTA Francisco BEDMAR Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET) Balcarce 7620(Argentina Estación Experimental Agropecuaria Balcarce Instituto Nacional de Tecnología Agropecuaria(INTA)Balcarce 7620(Argentina facultad de ciencias agrarias Universidad Nacional de Mar del PlataBalcarce 7620(Argentina

Glyphosate is the most used herbicide in Argentina, accounting for 62% of the commercialized pesticides on the market. It is used as a weed controller in no-till systems, and it is also applied to various genetically modified crops ( e.g., soybean, corn, and cotton). Although it has a high solubility in water, it tends to adsorb and accumulate in agricultural soils. The main objectives of this work were to compare the dissipation of glyphosate and the accumulation of its metabolite aminomethylphosphonic acid (AMPA) over time in three soils from agricultural areas of Argentina under long-term management with no-till (NT) and conventional tillage (CT) practices. There were no differences in dissipation between NT and CT, indicating that the glyphosate-degrading microflora was not modified by the different tillage managements. Moreover, tillage practices did not alter the general soil properties;therefore, glyphosate bioavailability was not affected by NT or CT practice. Forty percent of the applied glyphosate was degraded within the first three days in all soils, indicating a fast initial dissipation rate. However, the dissipation rate considerably decreased over time, and the degradation kinetics followed a bi-exponential (or two-compartment) kinetic model. No differences were found between tillage practices. Dissipation was not related to the microbial activity measured as soil respiration. The fast decrease in the concentration of glyphosate at the beginning of the dissipation study was not reflected in an increase in the concentration of AMPA. The estimated half-lives for glyphosate ranged between 9 and 38 d. However, glyphosate bioavailability decreases over time, as it is strongly adsorbed to the soil matrix. This increases its residence time, which may lead to its accumulation in agricultural soils.

关键词： Aminomethylphosphonic acid Bioavailability Biodegradation Herbicide Metabolite Pesticide Two-compartment kinetic model

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Inference for a truncated positive normal distribution

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Applied Mathematics(A Journal of Chinese Universities) 2018年第2期33卷 163-176页

作者： Hector J.Gomez Neveka M.Olmos Hector Varela Heleno Bolfarine departamento de ciencias Matematicas y Ffsicas Facultad de IngenierlaUniversidad Catolica de TemucoTemucoChile departamento de Matematicas Facultad de Ciencias BasicasUniversidad de AntofagastaAntofagastaChile departamento de Estatfstica IMEUniversidade de Sao PauloSao PauloBrazil

The main object of this paper is to study an extension of the half normal distribution defined by adding a positive truncation to it. The new model is more flexible than the half-normal distribution and contains the half normal distribution as a special case. Properties of this distribution, such as moments, hazard function and entropy are studied and parameters estimation is dealt with by using inoinents and inaxiinuin likelihood. A real data application indicates good fit performance of the new model when compared to other competitors in litera- tures.

关键词： half-normal distribution maximum likelihood truncation

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Mineral dust resuspension under vibration: Onset conditions and the role of humidity

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Particuology 2020年第3期18卷 112-119页

作者： F.J.Balladore J.G.Benito R.O.Unac A.M.Vidales departamento de Mineria Facultad de Ciencias Fisico Matematicas y NaturalesUniversidad Nacional de San LuisChacabuco 917D5700HHWSan LuisArgentina INFAP CONICETDepartamento de FisicaFacultad de Ciencias Fisico Matematicas y NaturalesUniversidad Nacional de San LuisEjercito de los Andes 950D5700HHWSan LuisArgentina

The vibration of dusty surfaces inevitably causes re-entrainment of particles into the *** that movement of mineral dust particles deposited on a surface begins at a critical frequency (fc) and amplitude,an experimental laboratory study was conducted to determine the onset conditions for resuspension of a vibrated granular *** determined the resuspension state diagram as a function of frequency and amplitude of a sinusoidal vibration,the granulometry of the dust and the thickness of the soil *** mitigation effect of humidity was also *** frequencies ranged between 2.5 and 23 Hz when amplitudes were less than 12 *** results were independent of bed thickness and perturbation *** all particle sizes observed,fc decreased monotonically with A,contrasting with behavior observed for individual *** dry samples,fe for large size classes was markedly less when A was greater than 6 mm;while thefc for fine fractions only decreased once amplitudes reached 10 *** with wet granular soils demonstrated that wetting above an optimum humidity did not necessarily impede movement and caused *** study provides guidelines for managing resuspension of granular soils subjected to vibrations.

关键词： Resuspension Vibration Granular soil Mineral dust Critical frequency Humidity

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Effect of full-fat sunflower or flaxseed seeds dietary inclusion on performance,egg yolk fatty acid profile and egg quality in laying hens

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Animal Nutrition 2020年第2期6卷 179-184页

作者： yandy J.Aguillón-Páez Laura A.Romero Gonzalo J.Diaz facultad de ciencias Agropecuarias Universidad de CundinamarcaFusagasugá252211Colombia facultad de Medicina Veterinaria y de Zootecnia Universidad Nacional de ColombiaBogotá111321Colombia

A study was conducted to evaluate the effect of the dietary inclusion of full-fat flaxseed of full-fat sunflower seeds on performance parameters,egg quality parameters and egg yolk fatty acid profile in laying hens.A total of 150 Babcock Brown hens at 27 weeks of age were distributed in 3 experimental treatments,as follows:T1,control;T2,diet containing 13.5% full-fat whole flaxseed seeds;and T3,diet containing 13.5% full-fat ground sunflower *** and water were provided ad libitum and the experiment lasted for 8 *** significant differences were found on egg quality parameters,but total egg production and rate of lay were significantly(P yolk saturated,monounsaturated,polyunsaturated,omega-6(n-6) and omega-3(n-3) fatty acids were observed,as well as in the n-6:n-3 *** results show that the dietary inclusion of 13.5% flaxseed full-fat seeds significantly increases the n-3 polyunsaturated fatty acid(PUFA) content in the eggs and lowers the n-6:n-3 ratio without affecting performance *** of full-fat sunflower seeds increases the n-6 PUFA content but affects total egg production and rate of *** studies are needed to determine the level of inclusion of full-fat sunflower seeds that does not affect performance.

关键词： Flaxseed Sunflower Polyunsaturated fatty acid Laying hens Egg quality Performance

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Mountain invasions on the way:are there climatic constraints for the expansion of alien woody species along an elevation gradient in Argentina?

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Journal of Plant Ecology 2016年第4期9卷 380-392页

作者： Paula A.Tecco Ana I.Pais-Bosch Guillermo Funes Paula I.Marcora Sebastián R.Zeballos Marcelo Cabido Carlos Urcelay Instituto Multidisciplinario de BiologíaVegetal(CONICET-UNC) Velez Sarsfield 1611.Córdoba 5000Argentina facultad de ciencias Exactas Físicas y Naturales Universidad Nacional de CórdobaVelez Sarsfield 299Córdoba 5000Argentina facultad de ciencias agrarias Universidad Nacional de Catamarca.Maestro Quiroga 51Catamarca 4700Argentina

Aims Increasing evidence worldwide indicates that high mountain regions are not immune to invasion by alien ***,we aimed to address whether three major woody invaders of low-mountain areas are constrained to lower altitudes due to climatic restrictions or just by low propagule *** hypothesize that the increasing climatic harshness towards higher altitudes restricts seedling establishment and survival of these woody invaders and thus their potential for altitudinal *** The study was carried out in the Sierras Grandes Mountains,Córdoba,central Argentina(32°50′S,64°90′W).We addressed the hypothesis with an experimental approach,dissociating the effect of the environmental gradient from that of propagule pressure,by discarding the influence of seed *** translocated seeds of Gleditsia triacanthos L.,Ligustrum lucidum *** Pyracantha angustifolia(Franch.)*** the altitudinal gradient(from 900 to 2700 m asl).Seven sites were selected along the altitudinal gradient,spaced every 200-400 *** plots(4×4 m)were selected within each altitudinal site and excluded from livestock;100 seeds of each species were sown within each plot(6300 seeds in total).Seedling emergence and survival was monitored during two growing seasons and soil temperature and moisture was recorded as *** field experiment was complemented with lab *** Findings Climate along this altitudinal gradient might be least restrictive at mid elevations,as a result of the intersection between opposite soil temperature and moisture *** seeds germinated along the whole altitudinal gradient and seedlings successfully established and over-wintered well above their current altitudinal distribution(up to 2200 m for Ligustrum and 2400 m for Gleditsia and Pyracantha).Additional lab assays confirmed field patterns and gave some insights into contrasting regeneration strategies between these invaders that might help to overcome stochastic e

关键词： altitudinal gradient exotic species Gleditsia triacanthos Ligustrum lucidum Pyracantha angustifolia seedling establishment

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On the intraspecific variability in basal metabolism and the food habits hypothesis in birds

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Current Zoology 2010年第6期56卷 759-766页

作者： F. BOZINOVIC P. SABAT Center for Advanced Studies in Ecology and Biodiversity LINC-Globaland Departamento de EcologíaFacultad de Ciencias BiológicasPontificia Universidad Católica de Chile Center for Advanced Studies in Ecology and Biodiversity LINC-Globaland Departamento de EcologíaFacultad de Ciencias BiológicasPontificia Universidad Catolica de Chile departamento de ciencias Ecológicas Facultad de CienciasUniversidad de Chile

The food habits hypothesis （FHH） stands as one of the most striking and often-cited interspecific patterns to emerge from comparative studies of endothermic energetics. The FHH identifies three components of diet that potentially produce variability in mass-independent BMR, i.e. food quality, food availability, and food predictability or environmental productivity. The hypothesis predicts that species with diets of low energy content and/or low digestibility should evolve low mass-independent BMRs. The effects of food habits on BMR have been widely investigated at the interspecific level, but the variation between individuals and populations has been largely ignored. Our focus is to compare predictions derived from interspecific studies with data collected from within-species studies to explore the mechanisms and functional significance of adaptive responses predicted by the food-habits hypothesis among birds. We conclude that if BMR is correlated with daily energy expenditure, then organisms that can lower BMR will reduce daily energy expenditure and hence, food requirements. Birds that lower BMR in stressful environments may increase survival. Nevertheless, the mechanism （s） by which birds eating a low quality diet reduce BMR and whether lower BMR affects fitness remain to be determined [Current Zoology 56 （6）： 759-766, 2010].

关键词： Intraspecific comparisons Avian energetics Food habits hypothesis Diet Basal metabolic rate

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Impact of chitosan-based nanocarriers on cytoskeleton dynamics:Current status and challenges

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BIOCELL 2022年第4期46卷 885-891页

作者： M.CAROLINA DI SANTO AGUSTINA ALAIMO ANA PAULA DOMÍNGUEZ RUBIO OSCAR E.PÉREZ departamento de Química Biológica Facultad de Ciencias Exactas y NaturalesUniversidad de Buenos AiresBuenos AiresArgentina Instituto de Química Biológica de la facultad de ciencias Exactas y Naturales Consejo Nacional de Investigaciones Científicas y Técnicas(IQUIBICENCONICET)Buenos AiresArgentina

Chitosan-based nanocarriers(CS-NCs)show a promising role in improving drugs and bioactive compounds delivery for ***,the effects exerted by CS-NCs at the cellular level,including their recognition and uptake,have not been fully investigated *** factors,including size,shape,concentration,and surface chemistry of CS-NCs,play an important role in determining the types of intracellular signals *** mechanism of uptake and the involvement of the cytoskeleton during the CS-NCs endocytosis variates among the different cell types as well as further effects observed inside *** the present work,we discuss the effects induced by CS-NCs per se on the cytoskeleton,a key component in cell architecture and *** focus of this report is made on tumoral and normal biological models in which CS-NCs could differentially affect the cell *** recent years reports regarding the impact of CS-NCs on cytoskeleton dynamics and the current techniques for its evaluation are summarized and *** mechanisms underlying cytoskeletal impact after cell exposure to CS-NCs is critical for the design of safest value-added formulations in the biomedical ***,this revision points out some interesting aspects of cytoskeletal changes and cell death encompassing anti-tumoral effects.

关键词： Cytoskeletal dynamics Cellular uptake Endocytosis Nanocarriers Chitosan Bioactive compounds

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Assessment of Technical and Economic Impacts of EV User Behavior on EV Aggregator Smart Charging

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Journal of Modern Power Systems and Clean Energy 2020年第2期8卷 356-366页

作者： Jean-Michel Clairand Javier Rodriguez-Garcia Carlosalvarez-Bel the facultad de Ingenieria y ciencias Agropecuarias Universidad de las Americas-Ecuador170122 QuitoEcuador the Institute for Energy Engineering Universitat Politecnica de Valencia46022 ValenciaSpain

The increase in global electricity consumption has made energy efficiency a priority for ***,there has been a focus on the efficient integration of a massive penetration of electric vehicles(EVs)into energy *** study presents an assessment of various strategies for EV *** this analysis,the smart charging methodology proposed in a previous study is *** smart charging technique employs charging power rate modulation and considers user *** adopt several strategies,this study simulates the effect of these actions in a case study of a distribution system from the city of Quito,*** actions are simulated,and the EV aggregator costs and technical conditions are evaluated.

关键词： Electric vehicle(EV) smart grid aggregator smart charging charging power modulation charging strategies

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Beyond habitat structure: Landscape heterogeneity explains the monito del monte (Dromiciops gliroides) occurrence and behavior at habitats dominated by exotic trees

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Integrative Zoology 2016年第5期11卷 413-421页

作者： Daniela A.SALAZAR Francisco E.FONTÚRBEL departamento de ciencias Ecológicas Facultad de CienciasUniversidad de ChileSantiagoChile Instituto de Biología Facultad de CienciasPontificia Universidad Católica de ValparaísoValparaísoChile

Habitat structure determines species occurrence and ***,human activities are altering natural habitat structure,potentially hampering native species due to the loss of nesting cavities,shelter or movement *** South American temperate rainforest is experiencing an accelerated loss and degradation,compromising the persistence of many native species,and particularly of the monito del monte(Dromiciops gliroides Thomas,1894),an arboreal marsupial that plays a key role as seed *** to compare 2 contrasting habitats(a native forest and a transformed habitat composed of abandoned Eucalyptus plantations and native understory vegetation),we assessed ***’occurrence using camera traps and measured several structural features(*** and bamboo cover,deadwood presence,moss abundance)at 100 camera ***plementarily,we used radio telemetry to assess its spatial ecology,aiming to depict a more complete *** abundance was the only significant variable explaining *** occurrence between habitats,and no structural variable explained its occurrence at the transformed *** were no differences in home range,core area or inter-individual *** the transformed habitats,tracked individuals used native and Eucalyptus-associated vegetation types according to their *** locations(and,hence,nesting sites)were located exclusively in native *** landscape heterogeneity resulting from the vicinity of native and Eucalyptus-associated vegetation likely explains *** occurrence better than the habitat structure itself,as it may be use Eucalyptus-associated vegetation for feeding purposes but depend on native vegetation for nesting.

关键词： behavior fleshy fruits southern Chile spatial ecology temperate rainforest

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Selection of Maize Genotypes with Tolerance to Osmotic Stress Associated with Salinity

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Agricultural Sciences 2016年第2期7卷 82-92页

作者： Mónica B. Collado Mónica B. Aulicino Miguel J. Arturi María del C. Molina Instituto Fitotécnico de Santa Catalina Facultad de Ciencias Agrarias y Forestales Universidad Nacional de La Plata Provincia de Buenos Aires Argentina CONICET

Thirteen different inbred lines in relation to the type of grain and life cycles were characterized by testing for osmotic stress associated with salinity. The identification of tolerant genotypes would be an effective strategy to overcome the saline stress. Osmotic stress reduces immediately the expansion of the roots and young leaves which determine a reduction in the size of the plant. A completely randomized design was adopted to test seedlings under controlled conditions of light and temperature. Two treatments were used: 0 mM NaCl (as control) and 100 mM NaCl. After 15 days of complete salinization, the seedlings were harvested and several morphological traits were measured. The morphological traits of growth were leaf growth (Ar1, Ar2, Ar3 and Ar4), dry masses of shoot and root (SDM and RDM, respectively). Also, traits associated with water economy were registered: leaf water loss (LWL) and relative water content (RWC). The morphological traits were expressed in relative terms, while the traits associated with the economy of water were expressed in absolute terms. Uni and multivariate techniques were applied to identify genotypes with divergent behaviors to osmotic stress tolerance. Also, a Tolerance Index was employed to identify superior genotypes. Four clusters were obtained after applying a Cluster Analysis and Principal Component Analysis (PCA). The genotypes were compared to each other with a test of DMS. The results obtained with different statistical techniques converged. Some variables presented a differential weight classification of genotypes. The morphological traits like RDM, SDM, Ar3, Ar4 and Ar5 were the most discriminating. Tolerance Index allowed to classify genotypes, thus SC2 and AD3 lines were that reached highest value of the index and therefore would be tolerant lines, while AF3 and LP3 had a low index and were seen as sensible.

关键词： Maize Salinity Osmotic Stress Tolerance Selection Index

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