Iron nanoparticles synthesized using green methods with native plant extracts exhibit beneficial physicochemical properties. This synthesis method is an effective and sustainable alternative for treating heavy metal-contaminated water. In this study, the lead removal capacity of iron nanoparticles produced through green synthesis, employing Condaliopsis obtrusively extract as a stabilizing agent, was evaluated. Synthesis was conducted by varying the initial concentration of ferric chloride (0.75 M, 0.125 M) and pH (8, 11). The coprecipitation method was used to produce magnetite nanoparticles, and the morphological characterization was conducted by scanning electron microscopy (SEM) and atomic force microscopy (AFM), yielding diameters ranging from 20 to 40 nm. This synthesis approach resulted in a 41.5% yield, providing 1.2 g of purified nanoparticles per batch from an initial volume of 50 mL A superficial area of 105.47 m2/g was calculated using the Brunauer-Emmet-Teller (BET) method, indicating a mesoporous structure. Based on the results, the optimal conditions for nanoparticle synthesis are an iron concentration of 0.75 M and a pH of 11. The adsorption tests showed a removal percentage of 99% for Pb 2+, indicating that the nanoparticles are suitable for water remediation
Este estudio evaluó la eficacia de diferentes dispositivos para la vitrificación de embriones bovinos producidos in vitro, comparando sistemas abiertos y cerrados en términos de supervivencia y calidad embrionaria. Se analizaron 761 ovocitos bovinos procedentes de matadero, que fueron madurados, fecundados y cultivados en condiciones in vitro hasta el estadio de blastocisto y vitrificados en los siguientes dispositivos: Cryotop, OPS, Cryotip y CVM. La supervivencia se midió mediante la reexpansión del blastocele y la eclosión a las 48 h post-vitrificación. La reexpansión del blastocele fue similar entre los dispositivos: CVM (90,36%), Cryotip (87,11%), Cryotop (91,10%) y OPS (90,61%), sin diferencias significativas (p≥0,05), la tasa de eclosión mostró diferencias significativas (p≤0,05): Cryotop (85,63%) y OPS (85,37%) superaron a Cryotip (78,70%), mientras que CVM presentó un valor intermedio (82,60%). El índice de apoptosis no mostró diferencias significativas entre los dispositivos: CVM (2,63%), Cryotip (2,27%), Cryotop (2,46%) y OPS (2,25%) (p≥0,05). Tanto los sistemas abiertos como los cerrados son eficaces para preservar la viabilidad de los embriones bovinos; la elección del sistema puede depender de factores prácticos y económicos, ya que todos mantuvieron una calidad embrionaria comparable, lo que reafirma la importancia de optimizar los protocolos para mejorar la crioconservación en biotecnología reproductiva.
No existen estudios sobre el valor nutricional y fitoquímico del fruto de Isolatocereus dumortieri. El objetivo de este estudio fue evaluar el valor nutricional y nutracéutico del fruto de I. dumortieri recolectado en Naxthéy, Ixmiquilpan, Hidalgo, México. Se realizó la caracterización ecológica y edáfica de los sitios de recolección. Los frutos fueron cosechados aleatoriamente en estado de madurez de consumo, para determinar sus características nutricionales y compuestos antioxidantes. Esta cactácea crece en matorrales desértico aluviales, sin actividad antrópica directa. Los frutos presentaron un alto contenido de carbohidratos, fibra, proteína, potasio, magnesio y cobre en comparación con otras cactáceas comerciales. Además, podrían ser usados como una fuente potencial de compuestos nutracéuticos por su alto contenido de betalaínas (16.16 mg/100 g) y compuestos fenólicos (290.23 mg de EAG/100 g). Se encontró alta actividad antioxidante en los frutos, la técnica FRAP reportó 37.59 mM de equivalentes de Trolox (ET) por 100 g de pulpa fresca (p.f.), mientras que los ensayos de eliminación de radicales ABTS y DPPH reportaron 31.14 y 21.70 mM de ET/100 g, respectivamente. En conclusión, los frutos de I. dumortieri son una promisoria fuente de nutracéuticos y podrían ser empleados en la formulación de alimentos funcionales.
Soil salinity threatens agricultural productivity, especially in regions such as La Ciénega de Chapala, Michoacán, where salinity problems generate important economic losses. In this study, 100 hectares of bare soil were evaluated in the municipality of Villamar, Michoacán, to identify the ionic composition and classify the soil according to different salinity indices. A simple random sampling was performed, and the following chemical parameters were determined in the saturation paste extract: Ca2+, Mg2+, Na+, K+, CO32-, HCO3-, Cl-, SO42-, pH, electrical conductivity (EC), evaporated dry residue, and calcined dry residue. EC, Sodium Adsorption Ratio (SAR), and Exchangeable Sodium Percent (ESP) were used for classification. Spatial interpolation maps using triangulated irregular networks (TIN) allowed visualization of the distribution of both ESP and SAR. The predominant ions were Na+ and SO42-, with 21.45 and 15.83 mEq/L, respectively. EC was positively correlated with Total Dissolved Solids, and the ionic strength was high. Between 50 and 60% of the samples were classified as non-sodium. High spatial heterogeneity was identified, 43% of the property was classified as high in salinity, low in sodium, however, the southern zone is the most affected.
This paper analyzes the status of legal regulation of the use of glyphosate in Mexico. To achieve this purpose, its use has been debated in constitutional obligations to human rights to health, the environment, and access to drinking water. Glyphosate is an agrochemical compound used as a main substance in the formulation of pesticides having a low toxicological level, and it is currently the most widely used herbicide worldwide. It is well known that many international organizations have reported that the use of glyphosate does not represent harm to health, if it is used properly and, in the concentration indicated in the regulations. However, glyphosate inhibits enzymatic production which is the key factor to the aromatic amino acid biosynthesis needed for vegetation growth, having a negative effect on the environment. Researchers have suggested an important risk to health by indirect glyphosate exposure, such as water and food polluted with glyphosate residues, which could develop diseases or health conditions such as skin irritations, gastrointestinal disorders, endocrine or hematological disrupters, etc. In Mexico, there are reports about the presence of glyphosate in food, particularly 30% of tortillas production in Mexico City presents glyphosate residues. For this reason, the Mexican government has decided to eliminate the use of glyphosate in crop fields by 2024.
Linoleic and α-linolenic acids are essential fatty acids for animals and humans that must be provided in their diet. Several sources have been studied, however production by cyanobacterium Nostoc muscorum has not been thoroughly studied. We aim to evaluate the effect of mixotrophic culture on biomass and lipid content, and subsequently to characterize and quantify the fatty acids present in N. muscorum. The individual and interactive effects of three culture conditions (glycerol concentration, acetate concentration and culture time) on biomass and lipid production by N. muscorum were investigated through a three factor, three-level Box-Behnken experimental design of response surface methodology for process optimization. Glycerol and acetate addition proved to have a synergetic effect on growth of N. muscorum which caused an increased in biomass and lipid production at tenth day of culture compared to the control culture. Moreover, the fatty acid profile showed a high percentage of polyunsaturated fatty acids, especially linoleic (52.64%) and α-linolenic (33.34%), suggesting possible applications for nutraceutical and feed industries.
Entre la dieta base de los rumiantes en México se encuentra el ensilaje de maíz, que constituye de 35 a 50% de la dieta diaria; sin embargo, uno de los principales problemas en su proceso de elaboración es la contaminación por hongos fitopatógenos, entre los que se encuentran reportados los géneros: Aspergillus spp., Fusarium spp., Penicillium spp., Cladosporium spp., Trichothecium roseum., Geotruchum spp., Altenaria spp., Scopulariopsis spp. y Mucor spp. Algunos de estos hongos tienen la capacidad de producir micotoxinas que causan enfermedades y muerte, tanto en humanos como en animales. El objetivo de este estudio fue identificar los hongos presentes en los ensilados de maíz, producidos en municipios de Aguascalientes, Zacatecas, Guanajuato y Jalisco. El muestreo se realizó durante noviembre-diciembre del 2022 y abril-mayo del 2023, utilizando la técnica “W” en cada uno de los ensilajes, el análisis de las muestras se realizó en la Universidad Autónoma Agraria Antonio Narro, Saltillo, Coahuila México. En este estudio se aislaron e identificaron morfológica y molecularmente las especies Fusarium moniliforme, F. chlamydosporum, F. oxysporum, Aspergillus fumigatus, A. flavus, Geotrichum galactomyces, Monascus purpureus, M. ruber, confirmando su presencia como contaminantes del ensilaje de maíz.
Clear sky models can be used as a reference for sizing solar technology applications and for solar irradiance forecasting purposes. Properly defining the parameters of each clear sky model implies knowing the altitude, latitude, longitude, as well as various climatic characteristics of the study site, which makes its implementation difficult. Derived from the above, in this work a new easy-calibration methodology was developed to obtain a functional clear sky model for any day of the year and any geographical location. By proposing calibration coefficients obtained from only a couple of DNI measurements, and without taking into account the geographical characteristics or climatic conditions of the study site, the developed clear sky model was tested in a global context using a period of 11 years (2010-2020) with databases of 71 solarimetric stations, obtaining an average RMSD that ranges between 6.48% (arid climate) to 7.97% (equatorial climate). In addition, the developed model was compared with a variety of clear sky models to determine the percentage of accuracy of these against clear and non-clear sky days, thus demonstrating that the accuracy of the proposed model can be superior in different scenarios.
This research is the result of observing the performance phenomenon of family businesses (FBs) in relation to the formal education level of participating members of their administration, aiming to establish a relationship between both variables. This study was conducted through the design of a survey as a measurement instrument, with a reliability of α = 0.741, applied to a sample of n = 280 companies, using statistical hypothesis tests: 1) One-way ANOVA, 2) Student's t-test for a single sample, and 3) Hypothesis testing with two samples for verification. It was found that companies whose average educational level is high do not necessarily have better performance expectations in a Mexican urban area with low economic growth, due to the phenomenon of migration at an early age. It is important to emphasize that the data collected for the purpose of this research were obtained in the locality of Jerez, in the state of Zacatecas; therefore, its results can only be generalized to locations with similar social, economic, and demographic conditions.
El sector lechero es uno de los más importantes del país; pese a su importancia y a la alta demanda de productos de origen animal, esta industria se asocia a la contaminación ambiental debido a la acumulación de gases de efecto invernadero y a la producción de residuos. El objetivo es evaluar estrategias de diversificación en la cadena de valor de leche-queso, que permita producir alimentos a la par de gestionar la biomasa residual de los procesos para obtener productos con alto valor agregado y que, contribuyan aumentar la rentabilidad y reducir el riesgo en las unidades de producción con la hipótesis de que la diversificación de productos tradicionales como queso y leche complementados con la gestión sostenible de los residuos para generar productos con alto valor agregado como biogás y suero de leche en polvo contribuyen a aumentar el nivel de ingreso y a reducir el riesgo en la producción para elevar la competitividad del sector. Se encontró que la tendencia de los precios de los productos con valor agregado fue mayor en comparación con los precios de los productos tradicionales y los portafolios sin diversificación presentaron menor rentabilidad y mayor riesgo en contraste con los portafolios diversificados.
The aim of this research is to analyze the application of the principle of proportionality–progressivity to the tax rates established by local Mexican governments on biological assets, assessing their impact on the tax burden regression of small, medium, and large enterprises that carry out economic activities in agriculture. The Suits index was applied to measure the progressivity and regressivity of taxes applied to agribusinesses through a critical hermeneutic analysis of the tax burden by biological assets. The study concludes that most of the taxes on biological assets of the state tax system are progressive, and two of them are highly regressive. This study contributes to the understanding of state tax structures in agriculture, highlighting disparities across Mexico’s 32 state governments. The originality of the study provides the method to measure the progressivity-regressivity of taxes.
The stress suffered by other animal species has not been considered in many situations of interaction with humans. Captive animals in zoos have constant interactions with their keepers, their doctors and with visitors. The objective of our study was to better understand the influence of visitors on the stress of captive animals. Like others around the world, the Zoo in Leon, Guanajuato, Mexico, closed its doors to visitors during the COVID-19 pandemic. We took advantage of this period to measure hair cortisol in mammals after months without visitors and months after visitors returned. Samples were taken whenever there was an opportunity for handling. Our results did not show a significant difference when considering all specimens sampled, however, we found that primates were significantly more stressed in the absence of visitors, as opposed to the rest of the animals who showed more stress with the presence of visitors, although not significantly. This supports the hypothesis that some animals have an adaptation to the presence of the public and even, in the case of primates, interaction with humans could become a beneficial factor.
Las palmeras de la CDMX se encuentran en proceso de declinación y muerte y, a la fecha, se han identificado distintos agentes bióticos que incentivan el problema. El diagnóstico de desórdenes abióticos no ha tenido la misma atención, a pesar de que estos pueden predisponer el ataque de otros agentes en las plantas y ocasionar su muerte. Con estas bases, el presente estudio tuvo como objetivo identificar desórdenes asociados a varias palmas de la ciudad. Se realizaron muestreos de síntomas inciertos en 50 sitios (35 transectos de 200 m, nueve de longitud variable, de los cuales se localizaron palmas con tres diferentes categorías de salud y otros seis puntos en donde se sospechó la presencia de agentes abióticos). Por palma, se midió el diámetro normal a 1.30 m sobre el nivel del suelo, altura total y ancho del camellón de plantación, y en los nueve transectos de longitud variable, también se colectaron muestras de suelo de las palmas con diferente categoría de salud y se determinó el grado de compactación del suelo (bajo o alto). En laboratorio, se determinó el pH (relación 1:2.5) y la conductividad eléctrica. La necrosis apical de foliolos se asoció con las altas temperaturas y la baja precipitación. Se encontraron pHs extremos (4.8 a 7.4), con un promedio de 6.4, valores de conductividad que oscilaron de 0.39 a 4.0 dS m-1, con un promedio de 1.62 dS m-1, grado de compactación de bajo a alto (de <20 a >60 golpes para alcanzar una profundidad de 20 cm) y espacio de crecimiento limitado (5.37 m en los sitios de longitud variable y 6.34 m en promedio en los transectos de 200 m). Finalmente, se detectaron síntomas típicos de deficiencia de potasio. Todos estos factores y otros no estudiados podrían estar actuando sinérgicamente en la predisposición de las palmas al ataque de agentes bióticos (enfermedades e insectos). Para priorizar su importancia individual y, en conjunto, se requiere de más investigación.
Las microalgas cultivadas en fotobiorreactores (FBR) se utilizan para producir biocombustibles renovables (biodiésel, bioetanol, biogás y biohidrógeno) por su capacidad de poder producir 20-50% lípidos del peso seco de la biomasa, además para producir bienes y diseño de servicios. El modelado del FBR mediante el modelo Droop, o Droop Model, se ha utilizado para describir la dinámica y la limitación de sustratos en este bioproceso. Así, muchos procesos de producción de microalgas en FBR están normalmente controlados mediante controladores clásicos todo/nada sin considerar el modelo sistema. Debido a la importancia de mantener el/los sustrato(s) dentro de valores determinados para maximizar la productividad, en este estudio, abordamos el problema de regulación de la concentración de sustrato en el FBR mediante la implementación numérica de un nuevo controlador no lineal en la dinámica de un FTB basado el modelo Droop. La respuesta de la dinámica no lineal del sistema a lazo abierto ante diferentes tasas de dilución (D=0.5,1.0,1.5 ,2.0 1/d) fue estable y controlable y la influencia del parámetro cinético K_q en las concentraciones biomasa, quota y sustrato en el FBR fueron más sensible a diferencia de los parámetros cinéticos ρ_m, K_m, μ_m en el modelo de Droop. El controlador propuesto se compara con un controlador clásico Proporcional-Integral PI. Los resultados del desempeño de los controladores fueron evaluados numéricamente mediante el índice de desempeño ITSE frente a diferentes perturbaciones. Como resultado, se encuentra que el controlador propuesto presento un mejor desempeño para diferentes cambios de los valores de referencia de la concentración de sustrato.
En el sur de Tamaulipas, México, en parcelas de sorgo (≈170 ha), se observaron hojas con lesiones irregulares-semicirculares color café rojizo-oscuro paralelas a la nervadura de la hoja. El objetivo de esta investigación fue identificar el agente causal y evaluar la incidencia y severidad en el sorgo. A los 22 días después de la siembra (DDS), se colectaron muestras foliares y se prepararon laminillas en laboratorio para la identificación del patógeno con claves taxonómicas. A los 27 DDS, se evaluó la incidencia y severidad por planta y por estrato en el sorgo comercial CROPLAN-8240. Para la incidencia, se estimó la presencia o ausencia de enfermedad. Para severidad, se estableció una escala visual, de cinco clases: 1, 5, 50, 80 y 100 % de lámina foliar dañada. El patógeno se identificó como Microdochium sorghi. La incidencia fue de 100 % y el daño mayor se presentó en las etapas de V3-V5. La enfermedad se observó con mayor frecuencia en el estrato inferior (96 %), seguido del medio (78 %) y superior (56 %). M. sorghi con humedad relativa alta (>85 %) puede convertirse en un patógeno que afecta severamente la producción de sorgo en condiciones cálidas subhúmedas, presentándose con mayor incidencia en etapa vegetativa del cultivo.
Fractional calculus is becoming increasingly important nowadays in studying and understanding fundamental physical phenomena, both simple and complex, through the formulation of generalized models. In the present work, a treatment of non-integer order is developed for the study of the wave function that describes the accessible states of a one-dimensional particle confined in a finite well with finite and constant walls, using a conformable derivative in describing the temporal evolution of the states of the system and Caputo-Fabrizio fractional derivative in describing its spatial evolution. By plotting the complete fractional solution ψ(x,t) for given values of the Kernel indices α, β, γ, we recover the flat-wave front oscillations predicted by the integer-order calculation, whose superposition represents the particle state with uniform probability in all space. However, for another range of values of the indices of the integral transformation, damping effects are observed, which do not seem to have a quantum mechanical physical meaning in themselves, but they do have a special physical-mathematical interest since such effects are related to the nature of the Caputo-Fabrizio operator, which as a non-local operator saves memory, that is, non-local spatial effects entail long-range interactions in a physical region, so the generalized wave function obtained does not depend exclusively on a point in space but on a region of space. When calculating the probability density, the fractional wave function shows a definite parity when γ is unitary, just as expected for a symmetric potential well. The generalized model obtained by incorporating a greater number of free parameters can represent an appropriate alternative formulation in the description of the probabilistic behavior of simple and complex quantum mechanical systems. Palabras clave: Ecuación de Schrödinger fraccional; Derivada fraccionaria de Caputo, derivada fraccionaria de Caputo-Fabrizio, derivada general conformable de Khalil.
The present work reports a comparative study on CuO and 3.0% Mn-doped CuO nanofibers (NFs) produced by the electrospinning method. State-of-the-art characterization techniques such as Electron Energy Loss Spectroscopy (EELS) and X-Ray photoelectron Spectroscopy (XPS) have been employed to determine the multivalent states and elucidate their electronic structure at the Cu-L3,2 (2p) edge. The CASTEP code has been used to model CuO (P1) and Mn-doped (C 2/c) with the GGA-PBE functional on the supercomputing system with the Xeon10 module (10 nuclei). Structural characterization was done by using a CM 200 Philips Transmission Electron Microscope (TEM) and the chemical state of surfaces with ESCALAB 250Xi XPS Thermoscientific TM. The NFs present an indirect energy bandgap, Eg = 2.03 eV and 2.85 eV, respectively. The results show that the Cu-L3,2 edge presents degenerate states associated with Cu 2p - O and Cu 3d - O hybridization, indicated as Cu3+.
Se presentan los modelos clásicos de epidemiología (SIR y SEIR) de Kermack y McKendrick. Se introduce una variable de control correspondiente a la tasa de vacunación y se estudia la controlabilidad del modelo SEIR, así como un problema de control óptimo asociado y los efectos en las dinámicas de las poblaciones por medio de simulaciones numéricas. En particular se muestra que, a diferencia de la suposición usual, no es posible controlar la propagación de la enfermedad únicamente introduciendo la tasa de vacunación para individuos susceptibles. Esto evidencia que para evitar que aumente la población de individuos infectados es necesario considerar otras estrategias, por ejemplo, distanciamiento social, medidas sanitarias, etc.
One of the greatest risks to human and animal health are infectious diseases caused by pathogenic bacteria, as these microorganisms develop mechanisms of resistance to antimicrobials, as a consequence of the indiscriminate and prolonged use of antimicrobials. This makes the treatment of infectious diseases increasingly difficult, in addition to an increase in treatment costs. These disadvantages have led to the search for alternative therapies based on bioactive compounds such as tannins, and flavonoids. Thus, some plant-derived compounds have been used to counteract infectious diseases and other health disorders. This study aimed to identify polyphenols of purified extract from Purshia plicata, and evaluate the antioxidant potential and the response of in vitro antibacterial activity against pathogen microorganisms of clinical importance for humans and animals. An aqueous extraction was performed and the compounds were purified using liquid chromatography. The total polyphenolic content was measured employing the Folin Ciocalteu and butanol-HCI methods. The polyphenolic profile was identified by HPLC/ESI/MS. These compounds were screened for in vitro antibacterial activity using the agar diffusion method and antioxidant activity was determined by ABTS•+, DPPH•, and FRAP methods. The compounds showed effectiveness against Klebsiella sp, Escherichia coli, and Salmonella sp, and moderate inhibition against Staphylococcus aureus. The total hydrolyzable polyphenols content was 45.7 mg g-1; the total condensed polyphenols content was 27 mg g-1. The results of the antioxidant activity showed that IC50 was reached at 150 µgml-1, 250 µgml-1, and 150 µgml-1. Twelve compounds were identified by HPCL/ESI/MS, the most important being anthocyanins and ellagitannins. The polyphenolic compounds of P. plicata have the potential to be used as pharmacological products with antibacterial and antioxidant properties for the treatment of infectious diseases in animals and humans.
