38 results match your criteria: "04510 Ciudad Universitaria[Affiliation]"

A model for anomalous transport of tracer particles diffusing in complex media in two dimensions is proposed. The model takes into account the characteristics of persistent motion that an active bath transfers to the tracer; thus, the model proposed here extends active Brownian motion, for which the stochastic dynamics of the orientation of the propelling force is described by scaled Brownian motion (sBm), identified by time-dependent diffusivity of the form D_{β}∝t^{β-1}, β>0. If β≠1, sBm is highly nonstationary and suitable to describe such nonequilibrium dynamics induced by complex media.

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Fractional and scaled Brownian motion on the sphere: The effects of long-time correlations on navigation strategies.

Phys Rev E

November 2023

Instituto de Física, Universidad Nacional Autónoma de México, Apdo. Postal 20-364, 01000, Ciudad de México, México.

We analyze fractional Brownian motion and scaled Brownian motion on the two-dimensional sphere S^{2}. We find that the intrinsic long-time correlations that characterize fractional Brownian motion collude with the specific dynamics (navigation strategies) carried out on the surface giving rise to rich transport properties. We focus our study on two classes of navigation strategies: one induced by a specific set of coordinates chosen for S^{2} (we have chosen the spherical ones in the present analysis), for which we find that contrary to what occurs in the absence of such long-time correlations, nonequilibrium stationary distributions are attained.

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Fano Combs in the Directional Mie Scattering of a Water Droplet.

Phys Rev Lett

January 2023

Facultad de Ciencias, Universidad Nacional Autónoma de México, Alcaldía Coyoacán, C.P. 04510 Ciudad Universitaria, Ciudad de México, México.

When light scatters off a sphere, it produces a rich Mie spectrum full of overlapping resonances. Single resonances can be explained with a quantum analogy and result in Fano profiles. However, the full spectrum is so complex that recognizable patterns have not been found, and is only understood by comparing to numerical simulations.

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The ribosome rescue pathways SsrA-SmpB, ArfA, and ArfB mediate tolerance to heat and antibiotic stresses in Azotobacter vinelandii.

FEMS Microbiol Lett

November 2022

Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos 62210, México.

Bacteria have a mechanism to rescue stalled ribosomes known as trans-translation consisting of SsrA, a transfer-messenger RNA (tmRNA), and the small protein SmpB. Other alternative rescue mechanisms mediated by ArfA and ArfB proteins are present only in some species. Ribosome rescue mechanisms also play a role in tolerance to antibiotics and various stresses such as heat.

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Genetic diversity, gene flow, and differentiation among wild, semiwild, and landrace chile pepper (Capsicum annuum) populations in Oaxaca, Mexico.

Am J Bot

July 2022

Centro de Investigaciones Interdisciplinarias en Ciencias y Humanidades, Universidad Nacional Autónoma de México, Torre II de Humanidades 4°, 5° y 6° pisos, Circuito Interior, C.P. 04510, Ciudad Universitaria, Ciudad de México, México.

Premise: Capsicum annuum (Solanaceae) was originally domesticated in Mexico, where wild (C. annuum var. glabriusculum) and cultivated (C.

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Ab initio studies of magnetism and topology in solid Pd-rich [Formula: see text]-PdSi alloys.

Sci Rep

March 2022

Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, 04510 Ciudad Universitaria, CDMX, Mexico.

In 1965 Duwez et al. reported having generated an amorphous, stable phase of palladium-silicon in the region 15 to 23 atomic percent, at.%, silicon.

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Chronic ∆-9-tetrahydrocannabinol administration delays acquisition of schedule-induced drinking in rats and retains long-lasting effects.

Psychopharmacology (Berl)

May 2022

Departamento de Psicología Básica I, Facultad de Psicología, Universidad Nacional de Educación a Distancia (UNED), C/ Juan del Rosal 10, Ciudad Universitaria, 28040, Madrid, Spain.

Rationale: Schedule-induced drinking (SID) is a behavioural phenomenon characterized by an excessive and repetitive drinking pattern with a distinctive temporal distribution that has been proposed as a robust and replicable animal model of compulsivity. Despite cannabis currently being the most widely consumed illicit drug, with growing interest in its clinical applications, little is known about the effects of ∆-9-tetrahydrocannabinol (THC) on SID.

Objectives: The effects of chronic and acute THC administration on SID acquisition, maintenance and extinction were studied, as were the effects of such administrations on the distinctive temporal distribution pattern of SID.

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Pro-inflammatory cytokine profile is present in the serum of Mexican patients with different stages of diabetic retinopathy secondary to type 2 diabetes.

BMJ Open Ophthalmol

June 2021

Research Unit, Microbiology and Ocular Proteomics Department, Instituto de Oftalmologia Fundacion Conde de Valenciana IAP, Mexico City, Mexico.

Aim: It's been reported that pro-inflammatory cytokines are elevated in patients with diabetic retinopathy (DR); this may contribute to the pathophysiology of the disease. The aim of this study is to measure the concentration of various inflammatory cytokines from the main CD4+ T helper inflammatory responses in blood serum from Mexican patients with DR in different stages using cytometric bead array (CBA) technology and correlate them with the presence and severity of DR in order to find possible DR biomarkers that serve as diagnostic or therapeutic predictors.

Methods: 64 subjects were included in the study, 16 in the control group, 16 in the type 2 diabetes mellitus no DR (NDR) group, 16 in the non-proliferative DR (NPDR) group and 16 in the proliferative DR (PDR) group.

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Seeds Reduce Anxiety-Like Behavior, Lipids, and Overweight in Mice.

Molecules

May 2021

Laboratorio de Neurofarmacología de Productos Naturales, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, 14370 Mexico City, Mexico.

Overweight, obesity, and psychiatric disorders are serious health problems. To evidence the anxiolytic-like effects and lipid reduction in mice receiving a high-calorie diet and seeds in a nonpolar extract (SBHX, 30 and 300 mg/kg), animals were assessed in open-field, hole-board, and elevated plus-maze tests. SBHX (3 and 10 mg/kg) potentiated the pentobarbital-induced hypnosis.

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More than 100 years ago, Robert Millikan demonstrated the quantization of the electron using charged, falling droplets, but the statistical analysis on many falling droplets did not allow a direct visualization of the quantization of charge. Instead of letting the droplets fall, we have used optical levitation to create a single droplet version of Millikan's experiment where the effects of a single electron removal can be observed by the naked eye and measured with a ruler. As we added charges to the levitated droplet, we observed that its equilibrium position jumped vertically in quantized steps.

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Histidine Self-assembly and Stability on Mineral Surfaces as a Model of Prebiotic Chemical Evolution: An Experimental and Computational Approach.

Orig Life Evol Biosph

June 2021

Laboratorio de Evolución Química, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria Coyoacán, C.P. 04510, Ciudad de México, México.

The abiotic synthesis of histidine under experimental prebiotic conditions has proven to be chemically promising and plausible. Within this context, the present results suggest that histidine amino acid may function as a simple prebiotic catalyst able to enhance amino acid polymerization. This work describes an experimental and computational approach to the self-assembly and stabilization of DL-histidine on mineral surfaces using antigorite ((Mg, Fe)SiO(OH)), pyrite (FeS), and aragonite (CaCO) as representative minerals of prebiotic scenarios, such as meteorites, and subaerial and submarine hydrothermal systems.

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Taenia hydatigena larvae vesicular concentrate reduces the egg shedding of Haemonchus contortus associated with the overexpression of abomasal cytokines in lambs.

Vet Parasitol

April 2021

Departamento de Ciencias Biológicas, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Km. 2.5 Carretera Cuautitlán-Teoloyucan S/N, 54714, Cuautitlán Izcalli, Edo. de México, Mexico. Electronic address:

The expression patterns of some cytokines were compared by RT-qPCR between lambs with and without Taenia hydatigena larvae vesicular concentrate (ThLVC) administration and subsequent infection with Haemonchus contortus. Lambs that received ThLVC prior to infection with H. contortus showed lower (p < 0.

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Dear enemy effect in the Mexican volcano mouse Neotomodon alstoni: Implications of sex in the agonistic behaviour among neighbours.

Behav Processes

December 2020

Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, km 1.5 Carretera Tlaxcala-Puebla S/N. 90070, Tlaxcala, Mexico. Electronic address:

Two opposite phenomena have been found in territorial animals, the "dear enemy'' and the "nasty neighbour'', which refer to individuals that show less aggression toward neighbours than toward strangers and vice versa. However, the need to maintain territory should differ for males and females because sexual reproduction is the result of the different adaptive strategies of the sexes. In this study, we explore territorial behaviour in the context of dear-enemy and nasty neighbour effects in the Mexican volcano mouse (Neotomodon alstoni).

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NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics.

Ecology

November 2020

Departamento de Ecologia, Instituto deBiociências, Laboratório de Ecologia Espacial e Conservação (LEEC), Universidade Estadual Paulista (UNESP), Rio Claro, São Paulo, 13506-900, Brazil.

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown.

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Stray dogs in the tropical state of Chiapas, Mexico, harbour atypical and novel genotypes of Toxoplasma gondii.

Int J Parasitol

January 2020

Laboratorio de Inmunología Experimental, Instituto Nacional de Pediatría, Insurgentes Sur 3700-C, Colonia Insurgentes-Cuicuilco, Delegación Coyoacán, C.P. 04530 Ciudad de México, Mexico. Electronic address:

Genotyping of Toxoplasma gondii remains a relevant topic of study, since genotypes can be related to the presentation and severity of toxoplasmosis. To date, 292 restriction fragment length polymorphism genotypes have been described around the world. Serosurveys in southeastern Mexico have documented exposure in over 70% of people and certain animals.

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A new species of Centruroides (Scorpiones, Buthidae) from Colima, Mexico.

C R Biol

February 2020

Facultad de Ciencias Químicas, Universidad de Colima, Km. 9 Carretera Colima-Coquimatlán, 28400 Coquimatlán, Colima, Mexico. Electronic address:

As part of an ongoing survey of scorpion diversity in Colima, Mexico, the isolated mountain Cerro Grande, part of the Biosphere Reserve Sierra de Manantlán, was investigated. Centruroides possanii sp. nov.

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Modelling and simulating Lenski's long-term evolution experiment.

Theor Popul Biol

June 2019

Goethe University, Institute of Mathematics, 60629 Frankfurt am Main, Germany. Electronic address:

We revisit the model by Wiser et al. (2013), which describes how the mean fitness increases over time due to beneficial mutations in Lenski's long-term evolution experiment. We develop the model further both conceptually and mathematically.

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Paraptosis in human glioblastoma cell line induced by curcumin.

Toxicol In Vitro

September 2018

Laboratorio de Investigación en Patología Experimental, México. Electronic address:

Curcumin is a polyphenol compound extracted from Curcuma longa plant, is a molecule with pleiotropic effects that suppresses transformation, proliferation and metastasis of malignant tumors. Curcumin can cause different kinds of cell death depending of its concentration on the exposed cell type. Here we show that exposure of the glioblastoma cell line A172 to curcumin at 50 μM, the IC50, causes morphological change characteristic of paraptosis cell-death.

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Progesterone inhibits the in vitro L3/L4 molting process in Haemonchus contortus.

Vet Parasitol

December 2017

Departamento de Ciencias Biológicas, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Km. 2.5 Carretera Cuautitlán-Teoloyucan S/N, 54714 Cuautitlán Izcalli, Mexico, Mexico. Electronic address:

We evaluated the direct effects of progesterone on the morphology, maturation and behavior of Haemonchus contortus larvae in vitro. The presence and location of possible progesterone receptors in these larvae were also determined. The addition of 8ng/mL of progesterone to larval cultures over 10days reduced larval enlargement, while the addition of 160ng/mL of the hormone increased the enlargement.

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Experimental transmission of Toxocara canis from Blattella germanica and Periplaneta americana cockroaches to a paratenic host.

Vet Parasitol

November 2017

Departamento de Ciencias Biológicas, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, México. Km 2.5 Cuautitlán-Teoloyucan, Col. San Sebastian Xhala, Cuautitlán Izcalli, Edo. de México. Electronic address:

The present study assessed the capacity of Blattella germanica and Periplaneta americana to disseminate and transmit infective phases of T. canis to rats, which were used as a model paratenic host. P.

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North American matsutake: names clarified and a new species described.

Mycologia

May 2018

e Herbario FCME (Hongos), Facultad de Ciencias , Universidad Nacional Autónoma de México, Avenida Universidad 3000, Circuito Exterior S/N Delegación Coyoacán , CP 04510 Ciudad Universitaria, CDMX , México.

Tricholoma matsutake, known widely as "matsutake," has great commercial and cultural significance in Japan. Because Japanese production is insufficient to meet the high domestic demand, morphologically similar mushrooms, thought by many to belong to T. magnivelare, are imported from western North America.

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Identification of DNA Methyltransferase Genes in Human Pathogenic Bacteria by Comparative Genomics.

Indian J Microbiol

June 2016

Departamento de Ingeniería de Sistemas Computacionales y Automatización, Instituto de Investigación en Matemáticas Aplicadas y Sistemas (IIMAS), Universidad Nacional Autónoma de México (UNAM), Escolar #300, 04510 Ciudad Universitaria, Distrito Federal Mexico.

DNA methylation plays an important role in gene expression and virulence in some pathogenic bacteria. In this report, we describe DNA methyltransferases (MTases) present in human pathogenic bacteria and compared them with related species, which are not pathogenic or less pathogenic, based in comparative genomics. We performed a search in the KEGG database of the KEGG database orthology groups associated with adenine and cytosine DNA MTase activities (EC: 2.

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The male of Megacormusgranosus (Gervais, 1844) with comments on its hemispermatophore (Scorpiones, Euscorpiidae).

Zookeys

May 2015

Laboratorio de Aracnología, Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México. Av. Universidad 3000, Circuito Exterior S/N, Delegación Coyoacán, C.P. 04510 Ciudad Universitaria, D.F. México.

The male of Megacormusgranosus is described for the first time and the female redescribed. A homology scheme proposed recently is applied to hemispermatophore structures. The specimens were collected in an oak forest from Pico de Orizaba Volcano at an average altitude of 2340 m.

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