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

The effect of the addition of bocashi or sheep manure, mixed with 50% of synthetic fertilizers was evaluated in green tomato. Physiological variables, biomass production, fruit yield, and mineral foliar content, nutritive value and antioxidant capacity of the fruit were studied. The biomass and the yield of the fruit do not present differences between the treatments, except for the root biomass. The accumulation of N was greater in the foliage of plants with sheep manure + chemical fertilization 50% (SM-ChF 50%), the transpiration rate was higher, and the stomatal conductance was lower. The accumulation of P and K did not vary between treatments. The contents of fat, Ca, K, Fe, and total phenols were higher in fruits with SM-ChF 50%. The addition of organic fertilizer with 50% chemical fertilization equals yields and improves the quality of the green tomato (P. ixocarpa).

In this research an estimation of the evaporation discharges from shallow groundwater in the Salar de Pedernales basin is made, using the lysimeter methodology. The analysis performed shows values between 1400 L·s-1 and 1900 L·s-1 with an uncertainty of error of 5% with respect to the average and between 11% and 47% in relation to the minimum and maximum values which can be compared by other studies where different tools have been used to calculate evaporation, such as: chamber, numerical model, water balance, Bowen relationships, Eddy correlations, and evaporation curves vs. altitude. The results confirm that lysimeters are appropriate tools for the determination of soil evapotranspiration and evaporation from shallow groundwater, whose components are key in the hydrology of endorheic basins, arid and semi-arid zones, for the management of protected natural spaces such as salt flats, waterholes, fertile plains, and bofedales.

The first part of this research presents an optimized model for rectangular caps or footings supported on a group of piles to obtain the minimum surface in plant (optimal area) bearing an axial load and two moments on the X and Y axis due to a column. The present research shows the optimal design (minimum cost) for pile caps. This model considers that the caps are perfectly rigid, and the piles are articulated at the junction of the caps with the piles and, therefore, the piles transmit only vertical load. The methodology used to obtain the design of the caps considers that all the piles transmit the same vertical load; this only works when the column transmits axial load but not moments. Also, five types of caps supported on a group formed by two, three, four, five and six piles are shown to demonstrate the accuracy of the model presented in this document

This paper shows an optimized model for rectangular pile caps, or footings, supported on a group of piles to obtain the minimum surface area in plant, supporting an axial load and two moments in the direction of the X and Y axis due to a column. This model assumes that the caps are perfectly rigid, and the piles are articulated at the junction of the caps with the piles; therefore, the piles transmit only vertical load. The methodology normally used to obtain the surface area of the caps is proposed in accordance to the distribution of the piles, taking the specifications set by the building codes into account. Also, five types of caps supported on a group formed by two, three, four, five and six piles are shown to demonstrate the accuracy of the model presented.

Oil pipeline networks require periodic inspection to detect damages that can generate oil leakage in natural and human environments. These damages can be caused by geological hazard and interference from third party. In order to detect these damages, low-cost techniques that consider both the oil pipeline networks and the environment are required. In this paper, the aerodynamic analysis of an unmanned aerial vehicle (UAV) with Eppler 748 sailplane airfoil (wingspan of 1.635 m) is presented. The UAV can include a small infrared camera for monitoring oil leakage of a pipeline network using the infrared radiation related to oil. A computational fluid dynamics (CFD) model of the UAV is developed to predict its lift and drag coefficients as a function of the Reynolds number and the angle of attack (AoA). The air velocity profile around UAV is estimated with the CFD simulations. In addition, a scale model (1:6.5) of the UAV is fabricated using a 3D printer, which is tested employing a subsonic wind tunnel. For the UAV with AoA of 0, the drag and lift coefficients obtained with the CFD model have a similar behavior with respect to those measured through the subsonic wind tunnel. The designed UAV could be used for low-cost inspections of damages in oil pipeline networks in comparison with the use of helicopters or light aircraft.

Defined as the mechanism that companies own to manage the use of business analysis resources so as to distinguish and analyze competitive information, corporate governance is a relevant factor for the deployment of the intelligence function. The purpose of this paper is to study the relationship that exists between corporate governance and competitive intelligence in tourism services companies in an important tourist area of Mexico. This is a descriptive and correlational study, with a quantitative approach including the review of scientific literature, the critical analysis of data, the processing and systematization of these data, and the verification of the hypothesis proposed by Spearman's rho correlation coefficient. The results indicate that the process of competitive intelligence in these companies is positively influenced by corporate governance, with a positive linear relationship between both variables.

The present study aims to investigate the psychometric results proposed by Schaufeli and collaborators for the Maslach Burnout Inventory-Student Survey. The total sample comprised 1222 participants; all of them are students of a degree in Physical Education and Human Motricity offered at the Autonomous University of Chihuahua, Mexico, with a mean age of 20.67 years (SD = 1.91). The sample was randomly divided into two parts to be able to carry out parallel studies that would corroborate and verify the results obtained. The factorial structure of the questionnaire was analyzed with confirmatory factor analysis. Psychometric analysis showed that a three-factorial structure was viable and adequate. The structure of the three factors (exhaustion, cynicism and efficiency), attending to substantive and statistic criteria, showed adequate indicators of validity and reliability adjustment. In addition, the factor analysis conducted with subsamples indicated the presence of strong evidence of factor structure stability.

Adolescent Pregnancy (AP) is more frequent among young people who do not enjoy full access to human rights and life opportunities. A quantitative study was developed in Querétaro based on the application of a multipurpose questionnaire with 321 high school students, in order to understand the association between the Prospective of Adolescent Pregnancy (PAP) with family relationships and the educational expectations of this young population. It was identified that 30% of men and 20% of women find it possible to experience an AP. Besides, in this group was present a reminiscence of traditional gender expectations on their families. The main factors of protection against the PAP are: prioritizing a high educational level (OR = 3.25 [CI: 1.06 - 9.98]), feeling loved by their families (OR = 2.47 [CI: 1.36 - 4.50]), and having people to talk with about sexuality (OR = 2.40 [CI: 1.31 - 4.38]). The findings call for strengthening initiatives to accompany decision-making processes in adolescence, with public policies that expand their life options from gender equality.

Children's eating habits are characterized by a high consumption of high-calorie foods with low nutritional value. The aim of this study was to modify the quality of the lunch that schoolchildren brought from home. With a follow-up of eight weeks, an intervention group (IG) and a control group (CG) were formed with children in elementary school (1st and 2nd grade) with an average age of 6.85 ± 0.60. The strategy consisted of teaching nutrition education to the IG. Anthropometric measurements were taken in both groups, and the food that the children brought for lunch was observed for three non-consecutive days. At the end of the intervention, in the IG the fruit/vegetable consumption increased (p = 0.024), whereas it decreased in the CG (p = 0.014). The consumption of sugary drinks decreased in the IG (p = 0.008), while in the CG it remained (p = 1.000). In conclusion, an increase in the consumption of healthy foods and a decrease in industrialized beverages were observed; however, it is recommended to increase the intervention time to obtain a more significant result.

Fabaceae dominate the forests of southeastern Mexico: in the Peninsula of Yucatanthe jabín (Piscidia piscipula L.) is the dominant tree species. However, its management is poorly documented. Therefore, the objective of this work was to describe aspects of its management under nursery conditions. For this, the emergence of seedlings was evaluated after the scarification of seeds in hydrochloric acid solutions and in water at 100 °C, against others without scarification. The seedlings obtained were fertilized with the NPK (Nitrogen, Phosphorus and Potassium) formulas (17-17-17, 46-00-00 and 18-46-00) and a white control. Seedling emergence was registered for 20 days and its growth for one month, recording height and diameter. Data analysis was performed with the Kruskal Wallis non-parametric method applied in both experiments. The results did not show statistical differences between scarification treatments; the height was favored by the NPK formulas 17-7-17 and 18-46-00, whereas the largest diameter was obtained with the NPK 46-00-00 formula. This indicates that, statistically, scarification does not influence seedling emergence and that the fertilization of jabín seedlings should contain more nitrogen and phosphorous.