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

One of the principal activities in the poultry industry is determine the sex of chickens of one day old. In this paper, we present a non-invasive technique to determine the sex of day-old chickens based on image processing algorithms. The technique analyzes morphometrical attributes from chicken using the slow and rapid growth of primary and secondary feathers patterns and linear discriminant analysis models. Based on the area formed with the superior points of each feather, the technique is capable to determine the sex of day-old chickens with an accuracy of 94.4%, providing a cheap, non-invasive, and high accurate technique that could be implemented onto a dedicated and automated system.

In our consideration, we studied the vibration analysis and dynamic responses of aHybrid Rayleigh-Van der Pol- Duffing oscillator. This system presented by one –degree-of - freedom containing the fifth order of nonlinear terms and an external force. To control the vibration of the main system, we applied the proportional derivative controller (PD). The average method used to obtain the approximate solution of the vibrating system. The stability of the system is investigated at the primary resonance case (   ). Numerically, we used Runge–Kutta of the fourth order to scrutinize the time histories of the system before and after using PD. For response curves, we investigated the performance of some chosen parameters of studied system. Finally, there is a good agreement between the approximate solution which obtained from the average method and the numerical one.

This study was to develop a radiation sterilized polypropylene/ethylene-propylene diene monomer (PP/EPDM) binary blends using melt blending and the mechanical properties of the blends were studied. The PP/EPDM binary blends were prepared in the ratios of 80:20, 60:40, 50:50, 40:60 and 20:80. The binary blends were then compressed for 12 minutes using the Hot and Cold Press machine and were cut into 1mm, 3mm and 6mm thickness for tensile test, impact test, hardness test and Fourier Transform Infrared Spectroscopy analysis. The results showed that higher EPDM content binary blends were more elastic and had better energy absorption compared to lower EPDM ratio binary blends. With the introduction of 100kGy radiation dose, the binary blends performed better in Young modulus with crosslinking formed within the molecules. Among the PP/EPDM binary blends, 20:80 PP/EPDM blends performed the best in both physical and mechanical properties. This binary blend was suitable for medical devices.

The main goals of this research are to determine customers’ requirements from hotels based on TripAdvisor and the technical capabilities to fulfill customers’ requirements. Latent Dirichlet Allocation (LDA) used in this research is the method to determine the customer requirements based on review from TripAdvisor. An output from the LDA method is used as input to Voice of Customer (VOC) in the quality function deployment (QFD). A hotel is selected to be a case study for implementing the integration of LDA and QFD. Questionnaires are distributed to the respondents for the purposes of filling the QFD. The absolute weight, relative weight, absolute importance and relative importance from the QFD with the highest scores are determined as the major capabilities to fulfill customers’ requirements. Suggestion given to the hotel based on output from the QFD. The suggestions for the hotel in this research were unannounced inspections and notes for list of problem to be solved immediately by the hotel.

This paper develops a more diverse and multi-dimensional agenda for understanding and researching urban verticality. Particularly, it argues for the emergence of skyscrapers, the technological inventions that made this possible, the impact of high-rise buildings on the urban context and their interaction with it. It also draws attention to sociological aspects in the perception of skyscrapers and both role/status in advertising. The external and internal essence of skyscrapers, their interconnection and confrontation are considered. At the end, the question of the fullness of vertical urbanism is assessed and studied, its existence is called into question and the necessary conditions for its emergence are considered.

La pandemia de COVID-19 no solo amenaza la salud física de las personas, sino que también podría afectar la salud mental, especialmente a los adultos mayores. Por lo tanto, este trabajo examinó los niveles de angustia psicológica, ansiedad, depresión y estrés al inicio de la pandemia y tras haber transcurrido seis meses, en una muestra de adultos mayores en México. Se aplicó una encuesta en el domicilio de cada adulto mayor, que recopiló información sobre edad, sexo y estado civil, además se incluyó la escala la escala de impacto de eventos revisada (IES-R) y la escala de depresión, ansiedad y estrés (DASS-21). La recolección de datos se realizó del 30 de marzo al 5 de abril y posteriormente del 30 de agosto al 5 de septiembre. En la primera medición, el 45.70% de los adultos mayores mostraron una angustia psicológica moderada-severa, 53.19% depresión moderada-severa; 64.90% ansiedad moderado-severo y 56.38% mostraron estrés moderado-severo. En la segunda medición el 53.12% mostró una angustia psicológica moderada-severa, 59.58% mostró depresión moderada-severa, 77.66% ansiedad moderada-severa y 67.75% estrés moderado-severo. Se identificó diferencia significativa en todos los parámetros evaluados al comparación la primera evaluación con respecto a la segunda. Por lo tanto, el brote de COVID-19 ha provocado alteraciones psicológicas considerables entre la muestra mexicana de adultos mayores examinada, empeorando tras transcurrir seis meses.

Con el objetivo de construir y validar un cuestionario que mide las normas sociales alimentarias (NSA) en escolares, se realizó un estudio instrumental y transversal. Mediante un muestreo aleatorio, se seleccionaron 494 niños de escuelas primarias. Se les aplicó un cuestionario validado por jueces para medir las NSA. En el análisis exploratorio se encontraron dos factores que explican el 27.85% del constructo: normas para reproducir (α=.774, r2=.893, p=.001) y normas para evitar (α=.446, r2=.729, p=.001), demostrando confiabilidad (α=.762, r2=.892, p=.001) de la prueba total. El análisis confirmatorio mostró que el modelo bifactorial presentó una mejor bondad de ajuste (GFI=.951, RMSEA=.059) que el modelo unifactorial (GFI=.943, RMSEA=.096). El cuestionario de la NSA compuesto por dos factores es válido y confiable para la población de niños en edad escolar en el noreste de México.

Esta investigación tuvo como objetivo identificar las variables que promueven y limitan la comunicación sobre sexualidad en padres de jóvenes sordos, así como el papel que desempeña la modalidad comunicativa y el género de quienes conforman la díada padre-hijo. Se trabajó con una muestra no probabílistica de 79 padres a quienes se les aplicó un instrumento de autoinforme para conocer sus características sociodemográficas y las de sus hijos, sus creencias sobre sexualidad, roles de género, expectativas, autoeficacia, comunicación sobre sexualidad, modalidad comunicativa y percepción del dominio de la Lengua de Señas Mexicana (LSM). Los resultados más importantes de esta investigación sugieren que el género juega un papel importante tanto en las expectativas como en la comunicación sobre sexualidad. El hecho de que los padres tengan el mismo género que sus hijos, favorece que no tengan expectativas negativas hacia la comunicación sobre sexualidad y también que aborden temas que suelen resultar incómodos como la masturbación y el cómo usar condón. Se discuten las implicaciones de los resultados de esta investigación en el diseño de programas de intervención dirigidos a esta población.

The confinement derived from the health contingency due to COVID 19 has brought with it an increase in psychological disorders such as stress, anxiety and insomnia. Despite the existence of action guidelines for each of the conditions, the presence of constant environmental factors does not allow a convenient evaluation and intervention. That is why this article aims to provide guidelines for evaluation and action from an ideographic perspective. The cognitive-behavioral techniques with more evidence are analyzed and a guide to evaluation instruments adapted to the Mexican context is provided. Finally, the emphasis is placed on the importance of individual analysis in the context of confinement for the adequate choice of intervention techniques.