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

In this essay I discuss an interpretation of the portraits of one the most important rulers of the Kaanuʔl dynasty of the Late Classic: Yuhknoʔm Yihch’aak K’ahk’, currently also known as “Jaguar Paw,” who ruled from 686 to 695 in Calakmul and died in 697. His portraits are found on a stela, three ball court panels, and a vessel that are inscribed with discourses that legitimized and immortalized him. To interpret these, I examine the text in each portrait and, if there is no nominal hieroglyph, I posit a possible reference to him. With his ties to central Mexico, Yuhknoʔm Yihch’aak K’ahk’ is portrayed wearing the patron god of the dynasty and generating the movement of the cosmos.

Given the potential risks and social consequences involved in normalizing racism through media representations, this article exposes colorist racism in advertising for food and child hygiene products in Mexico. Using descriptive statistics (n=50), we analyzed the patterns and the underlying rationale of the profiles of children who participated in auditions (castings) to determine the body-image representation of infants in advertising. We conclude that the representation of children’s bodies in advertising is based on greater body “whiteness” compared to representations of older people, a fact that potentially strengthens the normalization of colorist racism in Mexican society beginning at an early age.

This article is a phenomenological-hermeneutical approach to the anthropogenic myth found in the Popol Vuh. The first section exhibits the structure and meaning of mythical discourse. The second section sheds light on the idea of man implicit in the sacred book, for which the essential features and limitations of the men of clay and wood are exposed. Finally, the analysis is underpinned by its theme: the essence and the ultimate goal of the corn man. The thesis to be demonstrated is that man is a being created by and for the gods. The methodological approach on which our research is based is derived from both Mircea Eliade’s phenomenology of religion and Heidegger’s fundamental ontology.

The objective of this article is to analyze the meanings attributed to the train station located in Huixtla, based on people’s experiences coexisting with it currently and in the past. Through oral histories, narrative sources such as verbal and written testimonies, we can understand how this space is legitimized as a symbolized place. Thus, the station should be preserved as part of Huixtla residents’ collective memory, history, and identity.

El mundo experimenta hoy una desenfrenada carrera por el lucro y la acumulación; el despliegue del capitalismo en su forma neoliberal ha intensificado la explotación de la naturaleza y del ser humano, lo que genera la aceleración del calentamiento global y, a su vez, causa el cambio climático.

Review of Fútbol en Cuba. Entre el balón y “la pelota” en la comunidad global, from Miguel Lisbona Guillén. México: CIALC-UNAM/CIMSUR-UNAM, 2021.

Introduction: Colon cancer diagnosis is usually performed late; so, it is necessary to search for prevention options. In vivo models are an option for the evaluation of chemopreventive agents, which are based mainly on the induction and promotion of carcinogenesis; however, they take a long time. This work aimed to evaluate and propose a carcinogenesis model, with tumor manifestation in a short time to prove the efficacy of chemopreventive compounds. Method: Colon carcinogenesis was induced in three groups (n = 7) male BALB/c mice with azoxymethane (AOM) and dextran sodium sulfate (DSS). The damage was assessed 14 weeks after the induction. Protocols were: 1) P1: two AOM injections and two DSS cycles at 1.5 % for five days, with three resting days between cycles; 2) P2: one AOM injection and two DSS cycles at 2 % for seven days with five rest days, and 3) P3: one AOM injection and two DSS cycles at 2 % for four days, with four resting days. Negative control was used in parallel, P0: with one injection of saline solution and water ad libitum. Weight, disease activity index (DAI), survival, tumor incidence, lipids, and protein oxidation were determined. Results: P2 showed greater severity in the assessed signs (100 % tumor incidence, colon weight/length ratio 101.68 ± 2.99 mg/cm), with low survival (43 %). P1 depicted lower mortality (14 %) and 83 % tumor incidence, without a significant difference to P2. P3 developed the disease but to a lesser degree (33 % tumor incidence). Furthermore, the three protocols showed lipid oxidation (0.4-0.58 ng/μg of protein) and proteins oxidation (0.6-1 ng/μg of protein). The P1 and P3 induction protocols presented less mortality, weight loss, and acceptable DAI, a weight/length ratio higher than the negative control and presence of tumors. Discussion: The use of AOM (10mg/kg) combined with DSS (1.5-2 %) are suitable models to evaluate the carcinogenic effect of compounds of interest, inflammation signs, lipids and proteins oxidation and a survival number adequate to perform the statistical analysis leading to accurate conclusions. Therefore, P1 and P3 are protocols that can be used in chemoprevention assays with satisfactory results.

This work solves the regulation and tracking trajectories tasks for four degrees of freedom anthropomorphic robot manipulators. Two controllers are considered: a Super-Twisting controller (ST) and a Proportional Derivative with dynamics compensation (PD+) control. This comparison is carried out through numeric simulation of the dynamic model in the presence of disturbances using Matlab-Simulink software. Also, the tuning procedure of each controller is shown, as well as the stability criteria used for each case. The tunning of the ST controller is done considering the effects produced by an unknown Lipschitz disturbance; this guarantees robustness against this kind of disturbance. The results of the ST controller show the rejection of the disturbance, allowing the correct trajectory tracking. An algorithm based on the inverse kinematics solution is used to generate trajectories and their interpretation in generalized coordinates corresponding to the manipulator’s joint positions obtained through the geometric approach. In addition, we show the workspace, the manipulator parameterization, and the manipulator dynamic model through the Euler-Lagrange motion equations.  

Introduction: The high prevalence of Diabetes Mellitus type 2 in Mexico has positioned diabetic retinopathy as the main cause of blindness in adults of productive age in Mexico. Therefore, the timely detection of this disease is a priority task for the public health system. This article studies the efficiency of a new algorithm for determining the shape of the Major Temporal Arcade of the retina, using image segmentation techniques and numerical modeling of curves.                          Method: The proposed methodology uses Gaussian Matched Filters that enhance the geometry of the blood vessels. Subsequently, the vascular structure is segmented by global thresholding of the enhanced image. Said segmentation is used as input to build a numerical model of the Superior and Inferior Temporal Arcades, using Spline functions.                Results: The performance evaluation was carried out using 136 images of  pixels. The automatic retinal vein segmentation algorithm using the GMF method obtained an Accuracy of 0.9852; the numerical modeling algorithm gave a result of 6.01 pixels for the metric Mean Distance to the Closest Point (MDCP). Another previous study reported 12.33 pixels. Regarding time, the method reported an average time of 10.65 seconds per image.                        Discussion: The proposed method was able to carry out the numerical modeling of temporal arches in fundus images efficiently. The results show that this method is an useful computational tool for the diagnosis of alterations in the anatomy of the eye.

Introduction: García, Rodríguez, Diaz, and Estrada (1988, p. 70) define the work team as “a highly organized social entity oriented towards the achievement of a common task” who recognize and value their "own functional roles" (Bejarano, 2019, p. 112). For Arrea (2016, p. 97), teamwork "is not an innate quality" and must be learned by applying rules. For Guerrero, Delgado. and Sánchez (2018), researchers and companies agree on the factors that promote teamwork. For their success, organizations need to base their operation on teamwork (Rojas, Jaimes and Valencia, 2018). Beal, Bohlen and Raudabaugh (1964), Shein (1973) and Hersey and Blanchard (1986) define the maturity of a team as the level of development it is in, and it is a function of combining the competencies of its members (Guerrero et al., 2018), measured using a scale to establish the degree of maturity (Guiridkian and Cassanelli, 2010). The S-curve, model functions that grow gradually at the beginning, accelerate in the middle of the period and end slowly, describes and predicts human, animal and product population growth (Aguilar et al., 2012 y Zartha et al., 2017) Method: The present study is quantitative with a descriptive cross-sectional design, which worked with an incidental sample, made up of 32 work teams from 25 manufacturing companies in the city of Chihuahua, whose central inclusion criterion was belonging to the production department. The objective of the study was to graphically develop the development process followed by the work teams, applying the logistic growth curve, with the R(t) equation (Guerrero, 2006), using the group maturity variable (Montanari and Pilatti, 2014), along with over time, relative to the 9 factors established by the Integral and Dynamic Model, applying its measurement instrument (Guerrero, 2013), its justification arises from the fact of having a graphic representation that shows the development of team maturity as a function of the time. Results: S curve was generated using the Group Maturity calculated values, by means of simple linear regression, to determine the time values, at the levels of the maturity scale. The location coefficients were determined, b = 82 and k = 0.26, and the percentages were defined for each development phase of the Integral and Dynamic Model, and their estimated times. Discussion and conclusions: The plotted curve coincides with the curve proposed by Katzenbach and Smith (1995). Using the generated S-curve, percentages were established and limits were defined for each phase of the Integral and Dynamic Model that a work team must go through, as well as the estimated times it may take in each phase.