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Dynamic analysis of a predator-prey model of Gause type with Allee effect and non-Lipschitzian hyperbolic-type functional response

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International Journal of Biomathematics 2024年第1期17卷 81-112页

作者： liliana Puchuri Orestes Bueno Pontificia Universidad Catolica del Peri Av.Universitaria 1801 San MiguelLima 15088Peru Universidad del Pacifico Jr.Gral Luis Sanchez Cerro 2141 Jesus MariaLima 15072Peru

In this work,we study a predator-prey model of Gause type,in which the prey growth rate is subject to an Allee effect and the action of the predator over the prey is determined by a generalized hyperbolic-type functional response,which is neither differentiable nor locally Lipschitz at the predator *** kind of functional response is an extension of the so-called square root functional response,used to model systems in which the prey have a strong herd *** study the behavior of the solutions in the first quadrant and the existence of limit *** prove that,for a wide choice of parameters,the solutions arrive at the predator axis in finite *** also characterize the existence of an equilibrium point and,when it exists,we provide necessary and sufficient conditions for it to be a center-type *** fact,we show that the set of parameters that yield a center-type equilibrium,is the graph of a function with an open *** also prove that any center-type equilibrium is stable and it always possesses a supercritical Hopf *** particular,we guarantee the existence of a unique limit cycle,for small perturbations of the system.

关键词： Predator-prey models Gause models Allee effect non-differentiable functional response

Tracking the change in Spanish greenhouse gas emissions through an LMDI decomposition model:A global and sectoral approach

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Journal of Environmental Sciences 2024年第5期139卷 114-122页

作者： Paula fernández González María José Presno Manuel Landajo Department of Applied Economics University of OviedoAuda del Cristos/n 33011 OviedoSpain

The reduction of GHG emissions to reverse the greenhouse effect is one of the main challenges in this *** this paper we pursue two ***,we analyze the evolution of GHG emissions in Spain in 2008–2018,at both the global and sectoral levels,with the variation in emissions decomposed into a set of determining ***,we propose several actions specifically oriented to more tightly controlling the level of *** results showed a remarkable reduction(18.44%)in GHG emissions,mainly due to the intensity effect,but also to the production-per-capita *** detected somewhat different patterns among the various sectors *** the intensity effect was the most influential one in the agricultural,transport,and others sectors,the production-per-capita effect was predominant in the case of *** carbonization effect was revealed as crucial in the commerce *** above findings highlight the importance of the energy efficiency measures taken in recent years in the Spanish economy,also pointing to the need to deepen those strategies and to propose new measures that entail greater efficiency in *** efforts in areas like innovation,R&D,diffusion of more eco-friendly technologies,and a greater use of greener energies all prove to be essential reduction actions to fight the greenhouse effect.

关键词： LMDI Decomposition Spain GHG emissions

Fractal Fractional Order Operators in Computational Techniques for Mathematical Models in Epidemiology

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Computer Modeling in Engineering & Sciences 2024年第2期138卷 1385-1403页

作者： Muhammad Farman Ali Akgül Mir Sajjad Hashemi liliana Guran Amelia Bucur Institue of Mathematics Khwaja Fareed University of Enginnering and Information TechnologyRaheem Yar KhanPakistan Department of Computer Science and Mathematics Lebanese American UniversityBeirutLebanon Department of Mathematics Art and Science FacultySiirt UniversitySiirt56100Turkey Department of Mathematics Mathematics Research CenterNear East UniversityNicosiaTurkey Department of Computer Engineering Biruni UniversityIstanbul34010Turkey Department of Hospitality Services Babes-Bolyai UniversityCluj-Napoca400174Romania Department of Pharmaceutical Sciences Vasile Goldi竤Western University of AradArad310025Romania Department of Mathematics and Informatics Faculty of SciencesLucian Blaga University of SibiuSibiu550012Romania Department of Electronics and Communication Engineering Saveetha School of EngineeringSIMATSChennaiTamilnaduIndia

New fractional operators, the COVID-19 model has been studied in this paper. By using different numericaltechniques and the time fractional parameters, the mechanical characteristics of the fractional order model areidentified. The uniqueness and existence have been established. Themodel’sUlam-Hyers stability analysis has beenfound. In order to justify the theoretical results, numerical simulations are carried out for the presented methodin the range of fractional order to show the implications of fractional and fractal *** applied very effectivenumerical techniques to obtain the solutions of themodel and simulations. Also, we present conditions of existencefor a solution to the proposed epidemicmodel and to calculate the reproduction number in certain state conditionsof the analyzed dynamic system. COVID-19 fractional order model for the case of Wuhan, China, is offered foranalysis with simulations in order to determine the possible efficacy of Coronavirus disease transmission in theCommunity. For this reason, we employed the COVID-19 fractal fractional derivative model in the example ofWuhan, China, with the given beginning conditions. In conclusion, again the mathematical models with fractionaloperators can facilitate the improvement of decision-making for measures to be taken in the management of anepidemic situation.

关键词： COVID-19 model fractal-fractional operator Ulam-Hyers stability existence and uniqueness numerical simulation

Identification and functional characterization of fish IL‑17 receptors suggest important roles in the response to nodavirus infection

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Marine Life Science & Technology 2024年第2期6卷 252-265页

作者： Carmen González‑fernández Miguel A.García‑Álvarez Alberto Cuesta Department of Cell Biology and Histology Faculty of BiologyUniversity of Murcia30100 MurciaSpain Laboratoire d’écotoxicologie Centre de Lyon-VilleurbanneINRAEUR RiverLy69625 VilleurbanneFrance

Th17 is a lymphocyte T helper(Th)subpopulation relevant in the control and regulation of the immune response characterized by the production of interleukin(IL)-*** crucial cytokine family acts through their binding to the IL-17 receptors(IL-17R),having up to six *** the biology of fish Th17 is well-recognized,the molecular and functional characterization of IL-17 and IL-17R has been ***,our aim was to identify and characterize the IL-17R repertory and regulation in the two main Mediterranean cultured fish species,the gilthead seabream(Sparus aurata)and the European sea bass(Dicentrarchus labrax).Our in silico results showed the clear identification of six members in each fish species,from IL-17RA to IL-17RE-like,with well-conserved gene structure and protein domains with their human *** of them showed wide and constitutive transcription in naïve tissues but with highest levels in mucosal tissues,namely skin,gill or *** leucocytes,T mitogens showed the strongest up-regulation in most of the il17 receptors though il17ra resulted in inhibition by most ***,in vivo nodavirus infection resulted in alterations on the transcription of il17 *** nodavirus infection led to some increments in the il17ra,il17rb,il17rc and il17rd transcripts in the susceptible European sea bass,many down-regulations were observed in the resistant gilthead *** data identify the presence and conservation of six coding IL-17R in gilthead seabream and European sea bass as well as their differential regulation in vitro and upon nodavirus infection.

关键词： Th17 cells IL-17 receptors Immunity Teleost fish Nodavirus(NNV) Aquaculture

The effect of slime accumulated in a long-term operating UASB using crude glycerol to treat S-rich wastewater

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Journal of Environmental Sciences 2024年第1期135卷 353-366页

作者： Xudong Zhou Eva fernández-Palacios Antoni DDorado Javier Lafuente Xavier Gamisans David Gabriel Key Laboratory of Urban Pollutant Conversion Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China GENOCOV Research Group Department of ChemicalBiological and Environmental EngineeringEscola d’EnginyeriaUniversitat Autònoma de Barcelona08193 BellaterraSpain Department of Mining Industrial and ICT EngineeringUniversitat Politècnica de CatalunyaAvinguda de les Bases de Manresa 61-7308242 ManresaSpain

An up-flow anaerobic sludge blanket(UASB)reactor targeting sulfate reduction was operated under a constant TOC/S-SO2-4ratio of 1.5±0.3 g C/g S for 639 days using crude glycerol as carbon source.A filamentous and fluffy flocculant material,namely slime-like substances(SLS),was gradually accumulated in the bioreactor after the cease of methanogenic *** accumulation of SLS was followed by a decrease in the removal efficiencies and a deterioration in the *** characteristics of SLS were investigated to explore the causes of its formation and the effect of SLS on the UASB *** showed that glycerol fermentation and sulfate reduction processes taking place in the reactor were mainly accomplished in the bottom part of the UASB reactor,as the sludge concentration in the bottom was *** accumulation of SLS in the UASB reactor caused sludge flotation that further led to biomass washout,which decreased the sulfate and glycerol removal *** activity tests performed with granular sludge(GS),slime-covered granular sludge(SCGS)and SLS showed that there was no difference between GS and SLS in the mechanism of glycerol fermentation and sulfate ***,the specific sulfate reduction rate of GS was higher than that of SLS,while SLS showed a higher glycerol fermentation rate than that of *** different rates in GS and SLS were attributed to the higher relative abundances of fermentative microorganisms found in SLS and higher relative abundances of sulfate reducing bacteria(SRB)found in GS.

关键词： Sludge flotation Granular sludge Slime-like substances Glycerol fermentation Sulfate reduction Removal efficiency

On-Line Photoinduced Fluorescence for Carbamazepine Determination after Multivariate Optimization

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American Journal of Analytical Chemistry 2019年第11期10卷 513-527页

作者： Cecilia Henestrosa Cecilia Peralta Leslie Aragó n liliana ferná ndez Gimena Acosta Área de Farmacotecnia Ética y Legislación FarmacÉutica San Luis Argentina Instituto de Química de San Luis (INQUISAL-CONICET) San Luis Argentina Área de Gestión en Calidad y Salud San Luis Argentina Área de Química Analítica Facultad de Química Bioquímica y Farmacia Universidad Nacional de San Luis Chacabuco y Pedernera San Luis Argentina

This work presents a simple and sensitive flow injection fluorimetric method for the determination of carbamazepine (CBZ) in pharmaceutical samples. It is based on the fluorescence signal measurement of the product generated by photoinduced (λex = 251 nm;λem = 434 nm) using a flow injection manifold containing an online homemade photoreactor. In order to optimize the experimental setup, the variable conditions were studied using a multivariate optimization method, thus finding the set of optimum parameters according to the evaluated responses (sensitivity and sampling frequency) and minimizing the number of experiments performed. Under optimal experimental conditions, linear relationship with good correlation coefficient (0.9956) was found between the fluorescence intensity and CBZ concentration in the range of 0.13 - 40 μg·mL-1. The limit of detection was 0.04 μg·mL-1. The precision of the method was satisfactory;the values of relative standard deviations were better than 4.36%. The proposed method was validated and successfully applied to the determination of CBZ in pharmaceuticals with good accuracy;being the recovery values from 89.45% - 112.20%.

关键词： Online Photoinduced Fluorescence Multivariate Optimization Carbamazepine Pharmaceutical Samples

Role of climatic variability in shaping intraspecific variation of thermal tolerance in Mediterranean water beetles

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Insect Science 2024年第1期31卷 285-298页

作者： Susana Pallarés David Garoffolo Belén Rodríguez David Sánchez-fernández Department of Zoology University of SevilleSevilleSpain Faculty of Biology Department of Ecology and HydrologyUniversity of MurciaCampus EspinardoMurciaSpain

The climatic variability hypothesis(CVH)predicts that organisms in more thermally variable environments have wider thermal breadths and higher thermal plasticity than those from more stable ***,due to evolutionary trade-offs,taxa with greater absolute thermal limits may have little plasticity of such limits(trade-off hypothesis).The CVH assumes that climatic variability is the ultimate driver of thermal tolerance variation across latitudinal and altitudinal gradients,but average temperature also varies along such *** explored intraspecific variation of thermal tolerance in three typical Mediterranean saline water beetles(families Hydrophilidae and Dytiscidae).For each species,we compared two populations where the species coexist,with similar annual mean temperature but contrasting thermal variability(continental *** population).We estimated thermal limits of adults from each population,previously acclimated at 17,20,or 25℃.We found species-specific patterns but overall,our results agree with the CVH regarding thermal ranges,which were wider in the continental(more variable)*** the two hydrophilid species,this came at the cost of losing plasticity of the upper thermal limit in this population,supporting the trade-off hypothesis,but not in the dytiscid *** results support the role of local adaptation to thermal variability and trade-offs between basal tolerance and physiological plasticity in shaping thermal tolerance in aquatic ectotherms,but also suggest that intraspecific variation of thermal tolerance does not fit a general pattern among aquatic *** such intraspecific variation could lead to inaccurate predictions of the vulnerability of aquatic insects to global warming.

关键词： acclimation capacity aquatic insects climate change heat coma temperature supercooling point thermal plasticity

Green Photoluminescent Methodology for Aluminium Traces Quantification in 24-Hour Urine of Subjects with Different Exposition to Tobacco Smoke

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American Journal of Analytical Chemistry 2018年第10期9卷 514-528页

作者： Débora G. Santarossa María C. Talio liliana P. fernández Instituto de Química de San Luis (INQUISAL-CONICET) Chacabuco y Pedernera San Luis Argentina área de Química Analítica Facultad de Química Bioquímica y Farmacia Universidad Nacional de San Luis San Luis Argentina

The aim of this work has been to evaluate the aluminium (Al(III)) traces contents in 24-hour urine samples from subjects with different tobacco smoke expositions using a new methodology with 1,4-dihydroxy-9, 10-anthraquinone (Quinizarine, QZ) as a fluorosphore. Biological samples were tested using commercial reagent strips and clinical parameters. Al(III) was determined complexing with QZ followed by a solid phase extraction step using Nylon membranes as a solid support. The analyte was subsequently quantified by solid surface fluorescence (SSF, λem= 573, λexc= 490) with a detection limit of 0.88 μg L-1 and quantification limit of 2.69 μg L-1. The calibration curve was linear from 2.69 to 499.13 μg L-1 Al(III) (R2 = 0.9973). Urine samples were successfully analysed with an average recovery close to 100%. Solid phase extraction step showed efficacy to eliminate foreign ions and the highly fluorescent matrix own of urine. Results were validated by electrothermal atomic absorption spectrometry (ETAAS) with an adequate concordance. The new methodology has low operation cost with simple instrumentation and without organic solvent.

关键词： Tobacco Aluminium Traces 1 4-dihydroxy-9 10-anthraquinone (Quinizarine) Solid Phase Extraction Solid Surface Fluorescence Urine samples

Surfactant Enhanced Chemofiltration of Zinc Traces Previous to Their Determination by Solid Surphase Fluorescence

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American Journal of Analytical Chemistry 2011年第8期2卷 902-908页

作者： Mabel Vega Miriam Augusto María C. Talío liliana P. fernández 不详

Surfactant enhanced chemofiltration on Nylon membranes pre-treated with hexadecyltrimethylammonium bromide (HTAB) and eosin dye (eo) is proposed for zinc traces quantification by solid surphase spectro- fluorimetry (SSF, λexc = 532 nm;λem = 548 nm). Operational variables which have influence on quantitative retention of metal complex have been studied and optimized. At optimal experimental conditions, quantita- tive recovery was reached with a detection limit of 0.662 pg?L–1 and quantification limit of 2.20 pg?L–1. The calibration sensitivity was of 1.22 L?pg–1 for the new methodology with a linear range of 2.20 pg?L–1 to 779 pg?L–1 Zn (II). The tolerance levels of potential interfering ions were studied with good results. Recuperation studies were carried out by standard addition method applied to natural water samples (San Juan, Argentine) without previous treatment. The reproducibility (between-days precision) was also evaluated over 3 days by performing five determinations each day. CV% was 0.37. The performing obtained in sensitivity and selec- tivity thanks to chemofiltration step, converts the proposed methodology in an adequate alternative to con- ventional techniques for Zn (II) traces determination.

关键词： Zinc Traces Eosin Dye Surfactant Enhanced Chemofiltration Solid Surphase Fluorescence Natural Water Samples