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

The intersection between the migratory processes of Michoacán men to the United States is described in relation to the representation of masculinity, using the theory of gender technologies by Teresa de Lauretis, as well as performativity and the constitution of gender subjects by Judith Butler. All of this based on the findings of a decade of qualitative research (2011-2021), which aimed to understand the constitution of male gender subjects in said migratory experience. In-depth interviews, focus groups and participant observation were conducted with Michoacán men on both sides of the border. It was coincidentally found that men become masculine subjects throughout their lives based on the representation of masculinity, which mandates the trinomial of work-earning-economic provision, forming a couple and being parents; elements that can be achieved through migration, given that the macrostructural opportunities of the United States conjure up the ghosts of unemployment and insufficient economic provision that can occur if they remain in their place of origin. However, migration also implies challenges of maintaining healthy relationships, exercising emotional transnational parenthood, promoting self-care, and addressing their subjective and physical well-being.

This work presents a new version of the Picard method, known as the boundary values problems Picard method (BVPP), to obtain an analytical approximate solution for a highly complex nonlinear differential equation that models the magnetohydrodynamic flow of blood through a porous channel. The proposed method is versatile and can produce compact and easily evaluated analytical expressions that accurately capture the scientific phenomena being studied, making it ideal for practical applications. BVPP transforms a differential equation into an integral equation and utilizes an iterative algorithm like that of the basic Picard method. However, unlike the basic method, BVPP allows for the selection of an appropriate initial function and involves several adjustable parameters that can be optimized to obtain a precise analytical approximate solution with minimal effort. Overall, BVPP represents a significant advancement in the analysis of complex nonlinear differential equations, particularly in the field of biomedical engineering.

The American history of horses was compiled and systematized, reviewing its embarking in Spain (1493) and their evolution in the Antilles, until the expedition of Hernán Cortés from Cuba (1519). Colonial documents and contemporary texts on the subject were consulted, applying a multidisciplinary approach. The Catholic Monarchs wanted to found a Spanish colony on American soil and thus paid for ships, sailors, settlers, and animals; their acquisition, embarking, and feeding during the transatlantic route were examined. Horses were more costly than other animals, and Crown officers came with their horses. Columbus intended to multiply domestic animals and therefore preferred to embark females. After a long journey (14 weeks), people and horses arrived sick and landed with haste at Hispaniola. Expeditions to the West Indies continued, and European animals kept coming.  Horses multiplied rapidly at the beginning of the sixteenth century and dispersed throughout the islands before the expedition of Hernán Cortés.

This study analyzes the geographic distribution of karst in Mexico, considering its continuity and some of itsphysical environment characteristics (geology, climate, vegetation, relief, and soils), karst conservation, and aquifers exploitation status. A cartographic analysis of spatial overlapping was conducted on the world karst aquifer map (WOKAM) and thematic maps of Mexico. 25.52% of the Mexican territory is composed of rocks partially soluble in water. Sedimentary rocks are the most abundant in Mexico's karst areas (92.76%), with mountain ranges and plains being the predominant relief forms and with Leptosols being the most abundant soils. A total of 248 karst aquifers out of 278 in Mexico are not overexploited. 14.95% of Mexico's karstic area is under some conservation category. Fivekarst zones, each with specific and distinctive characteristics, were identified in Mexico.

Water bodies' overexploitation, droughts, and the impact of climate change are reducing water availability for human activities. Due to the above, severe economic and social problems occur. Therefore, an essential task is to monitor the state of surface water bodies. For this, a fast, accurate, and economical alternative is doing so through remote sensing techniques using satellite remote sensors. These techniques help obtain information at a distance from a specific object on the earth's surface. The objective of this study was to review, using PRISMA method, the applications of remote sensors in monitoring water bodies to provide alternatives for using water indices. The modified normalized difference water index (MNDWI) and the automated water withdrawal index (AWEI) are the best suited options, because they are easy to construct and interpret; additionally, they have high precision.

The SARS-CoV-2 emergency and the covid-19 pandemic are a global public health phenomenon. The objective of this study was to analyze the time trends of covid-19 pandemic in Guanajuato and México. For the analysis, the public database of the National Epidemiological Surveillance System was used to show the indicators of covid-19 (monthly) corresponding to the Institute of Public Health of the State of Guanajuato and the rest of Mexico. Online graphs were designed with the counts; for comparisons, the rate ratio in semi-annual periods was chosen. Guanajuato showed a better performance at the beginning of the pandemic, but in January 2021 this trend seems to reverse. In later months the curves tend to be more similar between Guanajuato and the rest of Mexico. The explanations for this phenomenon may be the coordination of local actions, the biology of the pandemic itself, or vaccination plans.

Oaxaca has a denomination of origin for the production of mezcal. The methods for mezcal production are artisanal or industrial. Producers show interest in innovating in traditional mezcal production systems, aiming to make processes more efficient. In the present work, a methodology that considers a process going from the arrival of the agaves to the factory to the distillation stage is developed. For each stage of mezcal production, a material and energy balance were carried out, identifying the inputs and outputs to calculate the thermal energy involved in each stage of the process. The methodology was used to model the production process using a commercial software. From the analysis of results, areas of opportunity were identified where the modernization of processes can be integrated, focusing on the use of alternative energy sources and environmental conservation.

This research proposes a tool applicable to any productive sector that seeks to streamline the use and management of internal resources in an organization. The objective of this work is to minimize transport costs in the shipment of bottled purified drinking water in the face of variations in customer orders through the Vogel approximation logarithm. The method consisted of applying the following five points: 1) to collect internal and external information, 2) to analyze and purify information, 3) to simulate in software, 4) to interpret results, and 5) to propose solutions. Results determine that the minimum transportation cost for bottled water in presentations of 600 ml, 1000 ml, and 2000 ml were $150.6, $251.5, and $494 Mexican pesos, respectively; additionally, each product generates an ideal optimal route. It is concluded that the methodology allowed to generate relevant information for strategic decision making in the company based on current conditions.

The objective of this research is to determine the factors of social commerce that contribute to the purchase decision of millennial consumers from the state of Baja California, Mexico. This is a cross-sectional, descriptive, and correlational. A literature review conceptualizing social commerce (s-commerce) was conducted. For the sample size a 97% confidence and 4.2% error was used, which corresponds to the representativeness of the study population. A total of 667 questionnaires were applied to millennial consumers, and an exploratory factor analysis was performed. Results show four components that contribute to the purchase decision: (1) Attention and monitoring of the needs of the customer during and after the purchase, (2) Safe and efficient purchasing process, (3) Advertising strategies, and (4) Loyalty programs. It is concluded that millennials consider social networks a necessity and have a positive attitude towards purchases through s-commerce and advertising, they feel motivated by comments on social networks, and they consider the opinions of others. users before making the purchase.

This research presents the design of an application to detect covid-19 using convolutional neural networks and X-ray images in two scenarios (covid/Non-covid and covid/Normal/Pneumonia). To avoid overfitting online data augmentation, dropout, batch normalization, and Adam optimizer was used. The three-class network was used as a pre-trained model, tuning only the dense and output layers to obtain the binary model. Additionally, hyper-parameter optimization was used to get dropout probabilities, activation functions, and neurons. The learning rate was adjusted using callbacks to avoid local optimums. Networks were converted to TensorFlow.js format and embedded locally in a hybrid application using Ionic and Capacitor and were deployed through Firebase to help provide diagnostics. The application obtained an accuracy of 98.61% and 96.48% for two and three classes, respectively, achieving higher performance when compared to other proposals (offline models) in the literature and using fewer training parameters.