检索结果-南通市图书馆

Simultaneous Periodic Orbits Bifurcating from Two Zero-Hopf Equilibria in a Tritrophic Food Chain Model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Applied Mathematics and Physics 2013年第7期1卷 31-38页

作者： Vctor Castellanos Jaume Llibre Ingrid Quilantan departament de Matemátiques Universitat Autónoma de Barcelona Barcelona Catalonia Spain División Académica de Ciencias Básicas UJAT Km 1 Carretera Cunduacán-Jalpa de Méndez Cunduacán Tabasco México

We are interested in the coexistence of three species forming a tritrophic food chain model. Considering a linear grow for the lowest trophic species or prey, and a type III Holling functional response for the middle and highest trophic species (first and second predator respectively). We prove that this model exhibits two small amplitud periodic solutions bifurcating simultaneously each one from one of the two zero-Hopf equilibrium points that the model has adequate values of its parameters. As far as we know, this is the first time that the phenomena appear in the literature related with food chain models.

关键词： Periodic Orbit Averaging Theory Zero-Hopf Bifurcation Population Dynamics

Optimal Parameters for in Vitro development of the Fungus Hydrocarbonoclastic Penicillium sp.

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Chemical Engineering and Science 2013年第4期3卷 19-29页

作者： Marcia Eugenia Ojeda-Morales Miguelángel Hernández-Rivera JoséGabriel Martínez-Vázquez Yolanda Córdova-Bautista Yuridia Evelin Hernández-Cardeno División Académica de Ingenieria y Arquitectura Universidad Juarez Autonoma de TabascoCunduacanMéxico Facultad de Salud y Ciencias A.F. Universidad SEKSantiagoChile

México has extensive areas that have been impacted by oil spills for several decades. Current bioremediation technologies mostly used microorganisms to decontaminate sites with hydrocarbons. This research evaluated the conditions for the optimal development of the strain of a hydrocarbonoclastic fungus, which was found in samples of soil contaminated with 4.0 × 105 mg·kg-1 of Total Petroleum Hydrocarbons (TPH). A completely randomized experimental design with a 3 × 3 × 4 factor arrangement was used: three levels of temperature (T1 = 29℃, T2 = 35℃ and T3 = 40℃), three of pH (pH1 = 3.5, pH2 = 5.0 and pH3 = 6.0) and four nutrients (N1 = Urea, N2 = Triple-17, N3 = Nitrophoska-Blue and N4 = Pure-Salts). Total fungi were isolated from the sampled soil and were sown in a combined carbon medium for hydrocarbonoclastic fungi and a strain was selected to be adapted to a liquid mineral medium. The selected strain was classified as Penicillium sp. Analyses of variance and mean tests were performed, using the SPSS-11.0 statistical software. The microorganisms showed the highest population growth in the treatment N2pH2T1, which reached a value of 2.1 × 106 CFU·mL-1 in a biorreactor. To reach it, by bioaugmentation, the same development of Penicillium sp. in a conditioned soil would allow to implement a bioremediation strategy with great potential to retrieve soil contaminated with hydrocarbons both in tabasco and in general in Mexico.

关键词： Hydrocarbon degraders Optimal Growth Penicillium sp. Hydrocarbonoclastic

Potential Effects on Human Health of Hydrogen Sulfide Exposure in a Place in Southeast of Mexico

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Ecology 2016年第1期6卷 47-54页

作者： Manuel Muriel-García Rosa María Cerón-Bretón julia Griselda Cerón-Bretón Instituto Mexicano del Petróleo Ciudad del Carmen México Facultad de Quimica Universidad Autónoma del Carmen Ciudad del Carmen México

Ambient concentrations of H2S were determined by modeling the H2S emissions dispersion for three sites located in the surroundings of oil and gas maritime terminal at the southeast of Mexico. Hazard quotient is reported for different age groups. Paraiso City in tabasco State reported the highest values for over 19 years old group (0.49). It was concluded that there was no threat to human health due to H2S emissions derived from the maritime terminal for the studied sites.

关键词： Risk assessment H2S Air Pollution Southeast of Mexico

Ischemic Stroke Secondary to Dissection of the Internal Carotid Artery: A Case Report and a Brief Review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Case Reports in Clinical Medicine 2022年第8期11卷 313-320页

作者： César Hayashi-Mercado Reynaldo Ramírez Chacón Leonardo Ramírez Iñ iguez Carlos Humberto Rodríguez Gómez Abelardo Alexander Aguilar West Natsuo Hayashi-Mercado The American British Cowdray Medical Center Mexico City México Hospital Regional de Pemex Villahermosa México Centro de Especialidades Medicas Dr. Julián Manzur Oca&#241 a ISSET Tabasco City México Ecodiagnostica Managua Nicaragua UABC Tijuana México

Background: Internal carotid artery (ICA) dissections generally occur when a tear occurs in the intima-media layer, either of traumatic or spontaneous origin. In this scenario, multifocal cerebral thrombosis may be a clear consequence of untreated ICA dissection. The incidence of internal carotid artery dissection in the US is estimated to be 1.72 per 100,000 population per year. Objective: To make a brief review of the literature and to explain, through a clinical case, the scenario of multiple ischemic cerebrovascular events is associated with the dissection of the internal carotid artery, in a young patient with no relevant history. Presentation of the Case: A 46-year-old female patient, with no significant history, who came to the emergency service presenting loss of strength in the right pelvic limb, disordered language, and difficulty walking for 3 hours, in the neurological examination evidence of decreased tendon reflexes and loss of strength of the right side of the body. Imaging studies show compromise of the M2 and M3 segments of the left middle cerebral artery, as well as multiple areas of associated ischemia in this hemisphere. Additional studies identify concomitant left ICA dissection. Based on the findings, it was decided to perform a thrombectomy of the affected area, as well as subsequent placement of a stent in the area of dissection. In the control angioTC study, revascularization of the M2 and M3 segments was observed, and in the follow-up of the patient, complete recovery of the symptoms was observed, with muscle strength, tendon reflexes, and preserved language functions. Conclusions: The ischemic cerebrovascular event is a frequent pathological entity in the emergency service;in the scenario of a young patient as mentioned above, it is important to take into consideration the different causes of this pathology. We are obliged to familiarize ourselves with the different imaging modalities for an adequate diagnostic approach, as well as the treatment methods according to the time of evolutio

关键词： Ischemic Stroke Dissection Internal Carotid Artery

A Review of Geothermal Type-Curves with Damage Effect: A Case of Practical Apply to a Mexican Geothermal Field

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Geosciences 2012年第3期3卷 591-600页

作者： Siomara López-Blanco Alfonso Aragón-Aguilar Víctor Arellano-Gómez Georgina Izquierdo-Montalvo Sócrates Santoyo-Gutiérrez Abel Hernández-Ochoa Instituto de Investigaciones Eléctricas Reforma 113 Col. Palmira Cuernavaca Morelos México universidad Popular de la Chontalpa Carr. Cárdenas-Huimanguillo km. 2.0 Cárdenas Tabasco México

A review of the art state was developed about the inflow relationships and their application for reservoir characterization. The theoretical development of the methodology for determining the damage effect using type-curves of the inflow relationships was shown. We show the process followed for achieve the geothermal type-curve affected with damage for reservoirs with mean salinities of 30000 ppm and temperatures up to 350℃. This type-curve was applied using measurement production data in a Mexican geothermal field. According with the obtained results is shown that the methodology for determining the damage effect using production measurements is a sure alternative for the damage effect calculation. It was used an alternative methodology in order to validate the damage presence and the obtained results were consistent. Last thing shows that both methodologies can be combined as a confident manner.

关键词： Geothermal Reservoir Inflow Performance Relationships Type-Curves Damage Effect Well Production Mass Flow Rate Output Curves

Rhinoplasty in Cleft Lip and Palate

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Case Reports in Clinical Medicine 2023年第11期12卷 439-446页

作者： Enrique Hernandez Vidal Enrique Hernandez del Moral Omar Hernandez del Moral Erick Daniel Hernandez del Moral juan Daniel Madera Brito Erik Ramos Garcia Crystell Guadalupe Guzmán-Priego Institute of High Specialty in Ear Nose Throat and Surgery of Head and Neck Villahermosa Mexico Cardiometabolism Laboratory Academic Division of Health Sciences Juarez Autonomous University of Tabasco Villahermosa México

Various surgical techniques and approaches have been described to repair cleft nose deformities. It is necessary to consider that since it is a congenital deformity, surgical management must consider the patient’s growth process, as well as the healing itself from the surgery. The present study aims to evaluate an alternative solution to secondary rhinology, aesthetic, and functional alterations to unilateral or bilateral cleft lift palate to minimize deformities and ensure good results. 11 patients were studied between 1995 to 2002, ten male and one female. In 8 cases, the patients had a history of cleft lip and palate on the left side, 2 patients with cleft lift palate on the right, and 1 patient with bilateral cleft lip and palate. 100% of the patients increased their naso-labial angle. This improved their appearance and structure, starting from a preoperative arithmetic mean of 39 degrees to a postoperative arithmetic mean of 96 degrees. Such intervention increased the naso-labial angle by 57 degrees. At the base of the nose, it was possible to improve the inclination of the alar line (line B) in 10 of the cases with a variation of 2 to 3 mm in relation to the perpendicular line A and only one case remained with the same inclination.

关键词： Cleft Lip and Palate Naso-Labial Angle Inclination Appearance

Alkaloids, Limonoids and Phenols from Meliaceae Species decrease Survival and Performance of <i>Hypsipyla Grandella</i>Larvae

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2012年第7期3卷 988-994页

作者： julián Pérez-Flores Sanford D. Eigenbrode Luko Hilje-Quiroz CATIE Turrialba Costa Rica Colegio de Postgraduados-Campus tabasco H. Cárdenas Tabasco México University of Idaho PSES Department Moscow Idaho USA 3CATIE Turrialba Costa Rica.

Meliaceae plants are distinguished by the attack of the shootborer Hypsipyla grandella and also for the occurrence of limonoids, alkaloids and phenolic compounds. Such compounds extracted from leaves of Meliaceae species Cedrela odorata L., Swietenia macrophylla King, Khaya senegalensis, Toona ciliata, and C. odorata grafted onto T. ciliata plants, were tested on C. odorata leaf disks to determine their effects on survival and performance of H. grandella larvae. Larval survival was assessed 2, 10 and 25 days after starting the bioassays. Leaf consumption and weight gain per larva, days to pupa and to adult stages, pupal weight and length, and moth wing appearance were assessed for larval performance. The three compunds from the four Meliaceae species and the grafted combination affected (P ≤ 0.02) larval leaf consumption, weight gain, time to pupa and to adult stages, wing development and larval survival of H. grandella. Pupa weight (P = 0.78, F = 0.72, d.f. = 18, 160) and length (P = 0.48, F = 0.98, d.f. = 18, 160) were similar regardless of the coumpound used. Limonoid reduced larval survival on the three dates of evaluation. Alkaloids decreased leaf consumption, weight gain of larvae and time needed to reach pupa and adult stages. Alkaloids from T. ciliata and phenols from C. odorata were the best coumpounds to reduce leaf consumption and weight gain. Alkaloids from the grafted plants caused 20% of H. grandella adults to form abnormal wings.

关键词： Leaf Extracts Cedrela Swietenia Khaya Toona Shootborer

Vasorelaxant activity of extracts obtained from Apium graveolens:Possible source for vasorelaxant molecules isolation with potential antihypertensive effect

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2013年第10期3卷 776-779页

作者： Vergara-Galicia Jorge Jimenez-Ramirez Luis Angel Tun-Suarez Adrian Aguirre-Crespo Francisco Salazar-Gomez Anuar Estrada-Soto Samuel Sierra-Ovando Angel Hernandez-Nunez Emmanuel Division of Health Sciences University of Quintana rooChetumalQuintana Ron.Mexico department of Biotechnology Polytechnic University of the State of MorelosJiutepecMorelosMexico College of Pharmacy.University of the State of Morelos CuernavacaMorelosMexico Division of Health Sciences.juarez autonomous University of tabasco VillahermosaTabascoMexico School of Engineering University of YucatanMeridaYucatanMexico

Objective:To investigate the vasorelaxant effect of organic extracts from Apium graveolens(A.graveolens)which is a part of a group of plants subjected to pharmacological and phytochemical study with the purpose of offering it as an ideal source for obtaining lead compounds for designing new therapeutic agents with potential vasorelaxant and antihypertensive effects.Methods:An ex vivo method was employed to assess the vasorelaxant activity.This consisted of using rat aortic rings with and without endothelium precontracted with norepinephrine.Results:All extracts caused concentration-dependent relaxation in precontracted aortic rings with and without endothelium;the most active extracts were Dichloromethane and Ethyl Acetate extracts from A.graveolens.These results suggested that secondary metabolites responsible for the vasorelaxant activity belong to a group of compounds of medium polarity.Also,our evidence showed that effect induced by dichloromethane and ethyl acetate extracts from A.graveolens is mediated probably by calcium antagonism.Conclusions:A.graveolens represents an ideal source for obtaining lead compounds for designing new therapeutic agents with potential vasorelaxant and antihypertensive effects.

关键词： Aortic ring Apium graveolens Medicinal plant Vasorelaxant

The domestication of Cucurbita argyrosperma as revealed by the genome of its wild relative

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Horticulture Research 2021年第1期8卷 1287-1300页

作者： Josue Barrera-Redondo Guillermo Sanchez-de la Vega Jonas A.Aguirre-Liguori Gabriela Castellanos-Morales Yocelyn T.Gutierrez-Guerrero Xitlali Aguirre-Dugua Erika Aguirre-Planter Maud I.Tenaillon Rafael Lira-Saade Luis E.Eguiarte departamento de Ecologia Evolutiva Instituto de EcologiaUniversidad Nacional Autonoma de MexicoCircuito Exterior s/n Anexo al Jardin Botanico04510 Ciudad de MexicoMexico department of Ecology and Evolutionary Biology University of CaliforniaIrvineCA 92697USA departamento de Conservacion de la Biodiversidad El Colegio de la Frontera SurVillahermosaCarretera Villahermosa‐Reforma km 15.5 Rancheria El Guineo 2ªseccion86280 VillahermosaTabascoMexico Genetique Quantitative et Evolution-Le Moulon Universite Paris-SaclayInstitut National de Recherche pour l’Agriculturel’Alimentation et l’EnvironnementCentre National de la Recherche ScientifiqueAgroParisTechGif-sur-Yvette 91190France UBIPRO Facultad de Estudios Superiores IztacalaUniversidad Nacional Autonoma de MexicoAv.de los Barrios#1Col.Los Reyes IztacalaTlalnepantlaEdo.de Mex 54090Mexico

despite their economic importance and well-characterized domestication syndrome,the genomic impact of domestication and the identification of variants underlying the domestication traits in Cucurbita species(pumpkins and squashes)is currently lacking.Cucurbita argyrosperma,also known as cushaw pumpkin or silver-seed gourd,is a Mexican crop consumed primarily for its seeds rather than fruit flesh.This makes it a good model to study Cucurbita domestication,as seeds were an essential component of early Mesoamerican diet and likely the first targets of human-guided selection in pumpkins and squashes.We obtained population-level data using tunable Genotype by Sequencing libraries for 192 individuals of the wild and domesticated subspecies of C.argyrosperma across Mexico.We also assembled the first high-quality wild Cucurbita genome.Comparative genomic analyses revealed several structural variants and presence/absence of genes related to domestication.Our results indicate a monophyletic origin of this domesticated crop in the lowlands of Jalisco.We found evidence of gene flow between the domesticated and wild subspecies,which likely alleviated the effects of the domestication bottleneck.We uncovered candidate domestication genes that are involved in the regulation of growth hormones,plant defense mechanisms,seed development,and germination.The presence of shared selected alleles with the closely related species Cucurbita moschata suggests domestication-related introgression between both taxa.

关键词： Cucurbita likely pump