15,845 results match your criteria: "Ciudad universitaria[Affiliation]"

A system is called antifragile when damage acts as a constructive element improving the performance of a global function. In this paper, we analyze the emergence of antifragility in the movement of random walkers on networks with modular structures or communities. The random walker hops considering the capacity of transport of each link, whereas the links are susceptible to random damage that accumulates over time.

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Non-nematicity of the filamentary phase in systems of hard minor circular arcs.

Phys Rev E

October 2024

Departamento de Física Teórica de la Materia Condensada, Instituto de Física de la Materia Condensada (IFIMAC), Instituto de Ciencias de Materiales "Nicolás Cabrera," Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco, E-28049 Madrid, Spain.

This work further investigates an aspect of the phase behavior of hard circular arcs whose phase diagram has been recently calculated by Monte Carlo numerical simulations: the non-nematicity of the filamentary phase that hard minor circular arcs form. Both second-virial density-functional theory and further Monte Carlo numerical simulations find that the positional one-particle density function undulates in the direction transverse to the axes of the filaments while further Monte Carlo numerical simulations find that the mobility of the hard minor circular arcs across the filaments occurs via a mechanism reminiscent of the mechanism of diffusion in a smectic phase: the filamentary phase is not a {"modulated" ["splay(-bend)"]} nematic phase.

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Effect of texturization on microbial inactivation in UV-C treated orange juice: Predictive modeling and analysis of Alicyclobacillus acidoterrestris physiological and morphological changes.

Int J Food Microbiol

January 2025

Instituto de Tecnología de Alimentos y Procesos Químicos (ITAPROQ), CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Industrias, Ciudad Universitaria, Avenida Intendente Güiraldes 2160 (C1428EGA), Ciudad Autónoma de Buenos Aires, Argentina. Electronic address:

UV-C light is an alternative for preserving clear fruit-based drinks, replacing existing thermal treatments that degrade product quality and are ineffective against some microorganisms, including Alicyclobacillus acidoterrestris, a spoiling agent of concern in the juice sector. Texturizing agents are essential since consumers' preferences for these products strongly depend on the mouthfeel. However, the complexity of the treated texturized system may have an essential influence on UV-C effectiveness.

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Correction to: Aromaticity in cyanuric acid.

J Mol Model

November 2024

Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, circuito exterior s/n, ciudad universitaria, Coyoacán, 04510, México City, Mexico.

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Airborne microplastic pollution detected in the atmosphere of the South Shetland Islands in Antarctica.

Chemosphere

November 2024

Instituto Antártico Argentino (IAA/DNA), 25 de Mayo N° 1143, San Martín (1650), Buenos Aires, Argentina.

Plastic pollution has emerged as a growing environmental concern, affecting even the most remote regions of the planet as the Antarctic continent, endangering its ecosystem and contributing to climate change. In this context, a continuous atmospheric microplastics monitoring study was conducted at Carlini Argentine Antarctic Station located in the southwest of 25 de Mayo (King George) Island (South Shetlands). Passive samplers were installed at three locations throughout the station, chosen based on the intensity of human activity and proved to be effective in collecting atmospheric particles over a one-year study period.

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Parasites of veterinary importance of ornamental fish commercialized in Mexico.

Vet Parasitol Reg Stud Reports

November 2024

Departamento de Medicina y Zootecnia de Abejas, Conejos y Organismos Acuaticos, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Ciudad Universitaria, Circuito de la Investigación Científica s/n, 04510, Mexico.

Article Synopsis
  • * A total of 631 fish were surveyed, revealing 66 species of parasites in marine fish and 22 species in freshwater fish, with certain monogeneans being particularly prevalent.
  • * The researchers found a link between poor biosecurity practices in aquarium management and higher parasite prevalence, suggesting that improving these practices could enhance fish health and support the ornamental fish trade's sustainability in Mexico.
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Gray fox (Urocyon cinereoargenteus) identified as a new intermediate host for Sarcocystis neurona.

Vet Parasitol Reg Stud Reports

November 2024

United States Department of Agriculture, Agricultural Research Service, Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, Beltsville, MD 20705-2350, USA.

The protozoan Sarcocystis neurona can cause severe disease in horses, marine mammals, and several other animal species in North America. The Virginia opossum (Didelphis virginiana) is its definitive host, and the raccoon (Procyon lotor) has been considered its primary intermediate host in the USA. Although canids have not previously been identified as important intermediate hosts for this parasite, we here report several natural cases in the gray fox (Urocyon cinereoargenteus).

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We present an experiment investigating the rotational Doppler effect using a single trapped ion excited by two copropagating vortex laser beams. The setup isolates the azimuthal gradients of the fields, eliminating longitudinal and curvature effects. We provide a detailed characterization of the phenomenon by deterministically positioning a single ion across the beams and measuring fluorescence spectra with sharp "dark resonances" whose features depend on the angular velocity of the ion and the difference of optical orbital angular momentum between the two beams.

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Maternal Perceptions and Feeding Practices Associated with Infant Nutritional Status.

Matern Child Health J

November 2024

Faculty of Biological Sciences, Universidad Autónoma de Nuevo León, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolás de los Garza, Monterrey, 66450, México.

Article Synopsis
  • Malnutrition in early childhood can lead to long-term health issues, including obesity, with this study focusing on how maternal perceptions and feeding practices influence infant nutrition in northeastern Mexico.
  • The research assessed 192 mother-infant pairs, revealing that 38% of infants were overweight/obese while 7% were underweight, and identified key maternal factors like low self-efficacy and inaccurate weight perceptions affecting infant nutritional status.
  • Findings suggest that many mothers lack knowledge about proper feeding practices, with longer sleep duration linked to underweight infants and critical inaccuracies in maternal perceptions of their child’s weight for both underweight and overweight/obese infants.
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Predicting bacterial transcription factor binding sites through machine learning and structural characterization based on DNA duplex stability.

Brief Bioinform

September 2024

Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México, Unidad Académica del Estado de Yucatán, Carretera Sierra Papacal, Mérida 97302, Yucatán, México.

Transcriptional factors (TFs) in bacteria play a crucial role in gene regulation by binding to specific DNA sequences, thereby assisting in the activation or repression of genes. Despite their central role, deciphering shape recognition of bacterial TFs-DNA interactions remains an intricate challenge. A deeper understanding of DNA secondary structures could greatly enhance our knowledge of how TFs recognize and interact with DNA, thereby elucidating their biological function.

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Article Synopsis
  • The -representability problem aims to determine if a given -body matrix can be derived from a corresponding -body density matrix through contraction, which is crucial for finding a system's exact ground state.
  • Understanding the complete conditions for -representability is complicated due to the exponential growth of constraints with the size of the system, making it impractical for larger applications.
  • The study introduces a hybrid quantum-stochastic algorithm to replace traditional -representability checks, utilizing adaptive unitary evolution and a simulated annealing process to efficiently assess and improve the quality of -body matrices from various quantum models.
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Bonding properties and crystal packing in β-(SeCl) derived from Hirshfeld Atom Refinement.

Acta Crystallogr C Struct Chem

December 2024

Universidad Nacional Autónoma de México, Instituto de Química, Ciudad Universitaria, Ciudad de México, 04510, Mexico.

Article Synopsis
  • The article discusses binary chalcogen halogen compounds, focusing on selenium tetrachloride, which forms a unique ionic structure rather than a simple molecular form.
  • It details the tetrameric arrangement of this compound, known as tetra-μ-chlorido-dodecachloridotetraselenium, which is formed by complexes of ions.
  • The research employs advanced techniques like Hirshfeld Atom Refinement, deformation density analysis, electron localization function (ELF), and Quantum Theory of Atoms in Molecules (QTAIM) to examine bonding characteristics and electron distribution in the tetramer.
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The sperm ability to fertilize involves the regulation of ATP levels. Because inside cells, ATP is complexed with Mg ions, changes in ATP levels result in changes in intracellular Mg concentration ([Mg]), which can be followed using intracellular Mg sensors such as Mag-520. In this work, we tested conditions known to decrease sperm ATP such as starvation and capacitation.

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In this article, the nonadiabatic excited-state Molecular dynamics (NEXMD) package is linked with the SANDER package, provided by AMBERTOOLS. The combination of these software packages enables the simulation of photoinduced dynamics of large multichromophoric conjugated molecules involving several coupled electronic excited states embedded in an explicit solvent by using the quantum/mechanics/molecular mechanics (QM/MM) methodology. The fewest switches surface hopping algorithm, as implemented in NEXMD, is used to account for quantum transitions among the adiabatic excited-state simulations of the photoexcitation and subsequent nonadiabatic electronic transitions, and vibrational energy relaxation of a substituted polyphenylenevinylene oligomer (PPV3-NO2) in vacuum and methanol as an explicit solvent has been used as a test case.

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Article Synopsis
  • * Resveratrol was studied for its impact on amylin aggregation and the formation of extracellular vesicles in pancreatic β cells and hippocampal cells.
  • * The research found that resveratrol reduced amylin aggregation and the size of toxic exosomes, thereby lessening their harmful effects on neurons.
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Adults of the genus , Dubois, 1936 are parasites of fish-eating birds, mainly of the family Ardeidae, and are globally distributed. The genus currently comprises 35 species, although recent molecular evidence has shown that the diversity of the genus is underestimated since several candidate species have been recognized. In the Neotropical region of Mexico, at least 6 lineages have been detected with metacercaria stages recovered from unrelated fish hosts.

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Looking back to shape the future: Trajectories and resilience of social-ecological systems in the Global South.

Ambio

December 2024

Economics Research Institute, National Autonomous University of Mexico, Circuito Mario de la Cueva, Ciudad de la Investigación en Humanidades, C.P. 04510, Ciudad Universitaria, Mexico.

In complex Social-Ecological Systems (SES), the interplay between ecological and social components shapes trajectories that impact human well-being and ecosystem services. While SES dynamics have been studied in static conditions, there has been less attention to how said systems respond to shocks and stressors over time and space. This special issue presents a collection of articles that use diverse methodologies-ranging from system dynamics modeling to participatory approaches-to analyze past SES changes and discuss future scenarios.

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Fertility is a crucial aspect of dairy herd efficiency and sustainability. Among factors influencing fertility in dairy cattle, metabolic stress and systemic inflammation of animals are of main relevance, especially in the postpartum stage when ovarian activity begins and cows are inseminated. Our study aimed to infer the associations between milk infrared-predicted blood biomarkers of stress resilience and fertility traits, namely the interval from calving to first service (iCF), days open (DO), and the pregnancy rate at first service (PRF) in a multibreed population of 89,097 dairy cows.

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The Neurobehavioral State hypothesis.

Biosystems

January 2025

Department of Cognitive Neuroscience, Division of Neuroscience, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Coyoacán, 04510, Mexico City, Mexico. Electronic address:

Since the early attempts to understand the brain made by Greek philosophers more than 2000 years ago, one of the main questions in neuroscience has been how the brain perceives all the stimuli in the environment and uses this information to implement a response. Recent hypotheses of the neural code rely on the existence of an ideal observer, whether on specific areas of the cerebral cortex or distributed network composed of cortical and subcortical elements. The Neurobehavioral State hypothesis stipulates that neurons are in a quasi-stable state due to the dynamic interaction of their molecular components.

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Effects of metallic dust on Nile tilapia: Exploring the relationship between metal bioaccumulation, metallothionein levels, and oxidative stress responses.

Sci Total Environ

December 2024

Departamento de Ciências Fisiológicas (DCF), Centro de Ciências Biológicas e da Saúde (CCBS), Universidade Federal de São Carlos (UFSCar), 13565-905 São Carlos, São Paulo, Brazil. Electronic address:

Settleable atmospheric particulate matter (SePM), from steelmaking processes, contains a complex mixture of metals, metalloids, and metallic nanoparticles. The SePM is released airborne and disperses in water, representing a significant threat to aquatic life, particularly fish. This study investigated the effects of a sublethal and environmentally relevant concentration of SePM (1 g·L) for 96 h in the gill, liver, kidney, and white muscle of Nile tilapia (Oreochromis niloticus), employing exposure and effect biomarkers to test causality between metal accumulation and biochemical responses.

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Predicting radiotoxic effects after BNCT for brain cancer using a novel dose calculation model.

Phys Med

December 2024

División Física Computacional y Biofísica de las Radiaciones, Comisión Nacional de Energía Atómica (CNEA), Av. General Paz 1499, B1650KNA, San Martín, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Godoy Cruz 2270, C1425FQD, Ciudad Autónoma de Buenos Aires, Argentina. Electronic address:

Purpose: The normal brain is an important dose-limiting organ for brain cancer patients undergoing radiotherapy. This study aims to develop a model to calculate photon isoeffective doses (D) to normal brain that can explain the incidence of grade 2 or higher somnolence syndrome (SS⩾2) after Boron Neutron Capture Therapy (BNCT).

Methods: A D model was constructed to find the reference photon dose that equals the Normal Tissue Complication Probability (NTCP) of the absorbed dose from BNCT.

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Antiviral Potential and Chemical Composition of Wild Spreng. Populations (Asteraceae) from Córdoba, Argentina: Perspective on Population Variability.

Plants (Basel)

November 2024

Instituto de Virología "Dr. J. M. Vanella"-Argentina, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Enfermera Gordillo S/N, Ciudad Universitaria, Córdoba X5000HUA, Argentina.

Medicinal plants have been explored worldwide as potential alternatives for the prevention and treatment of different diseases, including viral infections. Spreng. (Asteraceae) is a native medicinal species widely used in South America.

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The use of Lufenuron 50-EC pesticide in oil palm crops affects water quality and aquatic life. This study investigated the adsorption of Lufenuron 50-EC from an aqueous solution using activated carbon derived from oil palm shells (OPSs). Activated carbon (AC) was prepared through physical and chemical activation processes in carbon dioxide environments, using potassium hydroxide (KOH) as a chemical activating agent.

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Dietary auxin may help patients to fight cancer.

Trends Plant Sci

November 2024

Instituto de Investigaciones Químico- Biológicas, Universidad Michoacana de San Nicolás de Hidalgo. Edificio A1', Ciudad Universitaria, Morelia, Michoacán, Mexico. Electronic address:

The phytohormone auxin (indole-3-acetic acid; IAA) increases the efficacy of cancer treatment. IAA is a universal molecule, being produced by bacteria, fungi, and plants. Therefore, incorporating IAA-rich products derived from microbes or plants, such as yoghurt, probiotics, microgreens, and fresh carrots into the diet may be promising for disease management.

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Assessing Process Conditions on Xylose Fermentation in Spathaspora passalidarum: Effects of pH, Substrate-to-Inoculum Ratio, Temperature, and Initial Ethanol Concentration.

Curr Microbiol

November 2024

Grupo de Procesos Biológicos en Ingeniería Ambiental (GPBIA), Facultad de Ingeniería y Ciencias Hídricas (FICH), Universidad Nacional del Litoral (UNL), Ciudad Universitaria CC 242 Paraje El Pozo, 3000, Santa Fe, Argentina.

Bioethanol represents a clean and renewable alternative to fossil fuels, offering a significant reduction in environmental impact. Second-generation ethanol (2G) is produced using lignocellulosic biomass, which presents additional challenges due to the presence of hemicellulose. The pentose sugars within hemicellulose cannot be efficiently metabolized by conventional yeast strains like Saccharomyces cerevisiae.

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