Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

The objective of this work was to characterize Trichoderma isolates based on morphological and cultural characters, their vegetative compatibility and molecular variability. Morphological descriptions were made from microscopic observations of microcultures, according to Rifai, Gams and Bissett. The vegetative compatibility relationships were macroscopically evaluated, and the type of reaction (compatible or incompatible) was determined. The genetic variability of isolates was determined by using the RAPD technique; with the results generated, a dendrogram was constructed based on Jaccard’s similarity coefficient and the analyses carried out using FreeTree software. The isolates exhibited similar morphological characteristics, however, they presented differences in the coloration of the colonies and the morphometry of fungal structures. The isolates showed vegetative compatibility with the species Trichoderma viride, Trichoderma asperellum and Trichoderma atroviride, as among them, which shows the genetic closeness between these genotypes. The eleven RAPD primers generated a total of 92 reproducible bands. Of them, 65 were polymorphic, for 70.7 % polymorphism; only OPH-19 showed 100 % polymorphism. The cluster analysis by UPGMA showed intraspecific variability, forming four groups. Specific individual bands were detected for isolates T.13, T.17, T.75 and T.78, important for designing specific primers for authentication, protection and monitoring in productive systems.

The need to investigate and evaluate the alternative of producing triticale in Mexico, to later incorporate it into the agri-food chain for human consumption is important, due to its good protein content (around 20 % more than wheat), added to the better balance of amino acids and its grain is richer in phosphorus than wheat grain. The objective of this research was to identify lines of triticales (X. Triticosecale Wittmack) based on the physical and chemical properties of the grain with value for the food industry. Twenty elite lines of spring triticales from the CIMMYT (Centro Internacional de Mejoramiento de Maíz y Trigo) research program were evaluated. The study was carried out in 2018 in Celaya, Guanajuato, Mexico, the experiment was randomized in a completely randomized experimental design with six repetitions, each experimental unit was each line, the variables measured were: thousand grain weight (PMG) hectoliter weight (PH), humidity, ashes, fat, fiber, protein and carbohydrates were determined in the food analysis laboratory of TecNM-Roque. The results showed statistical differences between lines; higher contents of PMG (45.85 g), PH (78.8 Kg hL-1) were found in L-18 and L-20 respectively, in fat, fiber, carbohydrate proteins the lines L-17, L-18 and L-20 obtained higher averages, in ash 75 % of the lines showed values lower than 2.0 %.

Solution-processing is a low-cost solution method to preparea variety of organic or inorganic thin films. For metal oxide compounds, a solution-processing solution of an organometallic compound is frequently used as a precursor to be spin coated, followed by a thermal annealing to form metal oxide. In this work, vanadium oxide powders are obtained from a simple acid-base reaction, and then they are dispersed in isopropyl alcohol to form a solution for spin-coating. Different amount of cobalt salt are also added together with VOx into isopropyl alcohol to form VOx:Co2+ solutions. After thermal annealing at 200 °C, continuous transparent thin films are obtained. Optical, structural, morphological and chemical binding energies of those films are analyzed. It is found that amorphous VO2:Co2+ compound is formed in those films with V:Co atomic ratios between 6.6:1 and 1.6:1. Optical absorption onsets of those films are around 2.3 eV. An interesting interconnected porous morphology is observed when the atomic ratio of V:Co is around 4.9:1. It is concluded that porous amorphous cobalt doped vanadium oxide thin films can be obtained from a spin-coating process at low annealing temperature from a simple solution without any complex agent.

Protein quality maize (QPM) combines the protein quality of the opaque-2 (o2) mutant with a vitreous endosperm. These characteristics have allowed breeding programs worldwide to produce QPM genotypes that help alleviate malnutrition of people in developing countries from Africa, Asia and Latin America with a cereal-based diet. However, the development of these materials has been inefficient due to the limited knowledge about the molecular basis of the conversion of the soft o2 endosperm into a vitreous phenotype in QPM. This conversion has been associated with an increase in small protein bodies rich in 27 kDa γ-zein, the synthesis of starch with a higher proportion of amylose and short-intermediate amylopectin chain branches that favors the compaction of the starch granules, as well as alterations in the amyloplast envelope that favors the interaction between starch granules and protein bodies. Additional studies about the mechanisms involved in the modification of the endosperm in QPM will contribute to produce materials with good agronomic characteristics and protein quality.

Galactomannans (GM) are multifunctional polysaccharides made up of a β (1→4)-D-mannopyranose backbone with D-galactopyranose branches linked by α (1→6) glycosidic bonds. They are obtained from the endosperm of seeds of plants by different extraction methods. GM are natural products of carbon fixation through a series of large-scale biosynthetic pathways. The chemical modification of polysaccharides has been used as strategy to change structural characteristics and functional properties, as solubility, polarity, ionic charge, bioactivity, and others. Reported modifications of GM includes hydrolyzation, esterification, etherification, and addition of functional groups as sulphates or phosphates produced GM derivates with biological and technological application potential. Therefore, this review focuses on the synthetic routes and the analysis of the chemical structures of chemically modified GM.

Proteolysis during cheese ripening contributes to generation of biopeptides, and changes in sensory and textural characteristics. The aim of this work was to determine antioxidant capacity, as well as the changes in the sensorial and textural characteristics of cheese from Zacazonapan, during ripening (0, 30, 95 and 180 d). At 95 days, the extracts of evaluated cheeses presented the highest content of soluble protein. The degree of hydrolysis stood out at 95 (7.43 ± 0.34%) and 180 d (6.44 ± 0.31%). The DPPH free radical uptake was higher at 30 and 180 d (18.70 ± 0.48 and 19.92 ± 0.48%, respectively), while the highest oxygen radical absorption capacity (ORAC) was recorded at 180 d. Concerning the sensory characteristics, cheeses with 180 d presented attributes such as bitter residual taste, foot odor, hardness, pungency, ripened cheese flavor and porous appearance; its texture was hard and less elastic.

Introduction: Dynamic stability is the ability to preserve a static stable condition on a sustaining base after a dynamic transition, therefore, it is relevant in basketball due to changes in direction, acceleration and deceleration, a fact that affects both hearing impaired and non-hearing impaired athletes. Aim: To identify characteristics related to dynamicstability of lower limbs in basketball players with and without hearing impairment. Methods: Descriptive study in athletes with and without hearing impairment between 18 and 45 years of age from Valle del Cauca. Sociodemographic, clinicaland anthropometric variables, history, dynamic stability with the Y test, and core strength with the McGuill protocol were evaluated. Results: No significant differences were found in the dynamic stability variable in athletes with nor without hearing impairment, however, 2 athletes, with and  without hearing impairment obtained a composite abovethe average. For the core muscle resistance variable, longer times were obtained in the left lateral decubitus test than in the right lateral decubitus test, this being their dominant side. Conclusion: The diverse results invite us to maintain the principle of individualization in the evaluation and approachto athletes.

The intensity and distribution of the primary and scatter radiation that reaches the detectors in a Computed Tomography (CT) scanner has a direct impact in the clinical usability of the image reconstructed. The amount of radiation that reaches each detector depends on both the geometrical and material characteristics of the CT scanner, as well as the image acquisition parameters and patient characteristics. The purpose of this work is to determine the range of variation of total signal that reaches CT detectors in a computational simulation of a commercial CT scanner, using radiation transport Monte Carlo methods, as a study of the characteristics of a particular scanner configuration. The geometry was based on that of a commercially available CT scanner. The gadolinium oxysulfide detectors are separated by highly attenuating septa. In this exploratory study, two sets of monoenergetic beams were used, 45 keV and 80 keV. Scatter signal of the phantom is determined and the amount of primary signal that arrives to the detector is not evenly distributed on the module.

Tissue is primarily composed of elements such as hydrogen, carbon, oxygen, and nitrogen. Nitrogen has the largest neutron capture cross section among these elements. In a nitrogen neutron capture reaction (NNCR), an energetic proton is emitted, which quickly loses its energy along its track. It is expected that such released energy will be deposited within the tissue under consideration. Therefore, even though nitrogen only makes up approximately 3% of tissue by mass, its effect is significant and cannot be ignored. In this work, the neutron capture reaction by 14N is simulated using the GEANT4 toolkit to characterize the reaction in terms of kinematical quantities. In future work, we will be able to study the effects associated with the final state of the NNCR that might take place in tissue.

Physics instructors, especially those who are new to teaching, often have a strong background in their field but limited knowledge of educational theory. This work aims to address this issue by providing a summary of learning strategies utilized by students, along with their key advantages and disadvantages, in a clear and concise manner. The focus is on techniques that promote efficient time utilization and active thinking among students. In addition to summarizing various learning strategies, this work also offers recommendations and practical examples of how these strategies can be implemented in the classroom. The intention is to provide instructors with actionable insights that can enhance their teaching methods and improve student engagement and understanding. It is worth noting that while this work specifically focuses on physics education, the knowledge and strategies presented can be applied by instructors in other STEM (Science, Technology, Engineering, and Mathematics) fields as well. By incorporating these effective learning strategies into their teaching practices, instructors in various STEM disciplines can create a more engaging and productive learning environment for their students.