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

Introduction: The Comarca Lagunera, located in the states of Coahuila and Durango, Mexico, is the region with the highest milk production in the country. In this region, dairy farms with agricultural areas for the production of forage crops are common, where excessive rates of manure are applied to the soil and nitrate contamination of groundwater has been reported; therefore, it is important to generate information on the manure available nitrogen (MAN) in a system of two crops per year.                       Method: A study was conducted with increasing doses of nitrogen (N), depending on the crop N requirement (CNR), using urea, corral manure (CM) and manure from the solid separator (SSM) as sources of N, in silage corn in spring and triticale in winter. The yield of the crops and the availability of N in both types of manure were evaluated.                       Results: Silage corn dry matter yield was similar in all treatments, from 13.9 to 15.5 t∙ha-1, except in the 133% CNR with SSM, which had the lowest yield. In triticale, the differences in yield were not significant. In corn, the dose of 428.6 kg∙ha-1 of total N with CM and 449.6 kg∙ha-1 of total N with SSM, had the same extraction of N (Nex) of 141.2 kg∙ha-1, equivalent to 185 kg∙ha-1 of N with urea fertilizer, which corresponds to 100% of the CNR. The above indicates an availability of N of 43.2% in CM and 41.1% in SSM. In the winter season, available N was 19.5% and 11.1% in CM and SSM, respectively.                       Conclusion: Available N from both types of manure provided enough of this nutrient for two forage crops. Values of available N were similar in both types of manure when estimated in the spring-summer season, but in autumn-winter the MAN was higher in the CM.

In order to evaluate the effect of three types of cooking (sautéed, boiled, and roasted) on content of the bioactive compounds, and antioxidant activity in tomato, four treatments were established: sautéed, boiled, roasted, and control (without application of some cooking method). Once the treatments were applied, the physiochemical properties such as total soluble solids (TSS), titratable acidity (TA), and pH were evaluated as well as the lycopene content, β-carotene, ascorbic acid, phenols and total flavonoids, and antioxidant activity in vitro by essays of 2-2-diphenil-1-picrylhydrazil (DPPH), and 2,2'-azino-bis (3-ethylbenzothiazolino-6-sulfonic acid) (ABTS). All the cooking methods increased the TSS and reduced the acidity of the fruit. By roasting, a higher concentration of ascorbic acid (58.10%) was retained, as compared to the control. A significant increased (P ≤ 0.05) was observed in the concentration of carotenoids, and phenolic compounds in tomatoes due to the effect of the treatment sautéed, therefore a greater antioxidant activity. An inhibition of DPPH● radicals was found of 17.92%, and an antioxidant activity expressed as Trolox equivalents of 25.97 µM per g of fresh weight, as a result of the ABTS test. The boiling treatment caused a lixiviation effect of the bioactive compounds in the cooking media; therefore a smaller concentration was found. Sautéed was a better cooking method for tomatoes to obtain a higher concentration of antioxidant compounds.

Introduction: Given the importance of the country's electricity industry for influencing most of the productive processes of the economy, the challenges in the changes in the energy market and the new regulations for producers, it is necessary, from the aspect of manufacturing to offer tools to improve the processes of electrical products, the quality of the service and increase the reliability of the system. The transformer is one of the most important elements in the electric power transmission system, manufacturing it with low quality standards represents important problems for both the final consumers and the system. The purpose of this work is to establish efficient operating conditions for the manufacture of electric coils, minimizing the variability of the dimensions and allowing a correct assembly of the components that make up the single-phase transformer.Method: Capacity analysis was used to evaluate the ability of the process to meet the specifications before and after the improvements, in addition, a 2k Factorial Experiments Design was developed that allowed to establish adequate operating conditions in the manufacturing process in addition to determine the influence of the tension of the wire and the dielectric paper supplier on the dimensional variables of the coil.Results: With the study it was found that the factors considered have significant influence on the dimensions of the coils, the high levels of each factor allowed to minimize the dimensions, thus it was possible to meet the specification limits, it was possible to improve the centering of the process of the variables of length and width of the coil by substantially increasing the capability indices of the process.Discussion or Conclusion: The statistical methods used in this work were an effective tool to study the process. 

Introduction: Desensitization to violence is the result of exposure to violence. It reduces the negative emotions in cognitive and physiological responses to violence and can even generate a positive response to it.Method: A mixed sequential method yielding a transactional analytic design for Exploratory Factor Analysis and Confirmatory Factor Analysis with a sample of 1720 participants of 25 different high schools and a juvenile detention center. Followed by convergent validity (as a criterion validity) with a different sample.Results: The EFA’s cumulative explained variance was 52% with a GFI of .98 with a three-factor model: sensitivity to violence, amusement with physical violence, and enjoyment of psychological violence. The CFA showed scores above .50 in Average Explained Variance in every factor, and an ideal model fit in every measure (CFI, AGFI, RMSEA, SRMR, and ECVI). The remaining factors are only those related with enjoying or amusement with violent behavior, indicating that the desensitization to violence is related not only with the normalization and legitimation of violence, but the increasing of the performance and amusement of it.Discussion or Conclusion: The scale of desensitization to violence for adolescents has adequate psychometric properties and can be a valuable instrument to generate intervention or prevention programs, especially for its intimate relationship with high scores in people interned because of their criminal behavior.

The Food Collection Species (EAR) are the set of foods (herbs, fruits, seeds, flowers and animals) that grow naturally and are part of the diet of different cultural groups. These foods allow the conservation of biodiversity, offer the possibility of diversifying the consumption of food and have healthier diets. Mexico is one of the countries with the greatest biological and cultural diversity: biocultural, which has originated the creation and conservation of biocultural kitchens. Of these, rural people, indigenous communities and women cooks, who reproduce their food practices and appropriate their natural riches through them, are primarily guardians. The biocultural kitchens are the essence of the preservation of the food culture. The analysis of this is relevant because through it the common dietary patterns are determined. The present investigation analyzes the alimentary culture between the settlers of Todos Santos Almolonga from the Biocultural Heritage focus, which contributes to the permanence of the consumption of 23 EAR; as well as the assessment and perception. The study was qualitative with mixed methods, for this a survey was carried out to 59 domestic units, two routes to the collection areas, 9 semi-structured interviews were applied, informal talks and activities were carried out to prepare local stews with the EAR The surveys, interviews, field notes and field diary were coded. It was found that there is a food culture based on the consumption of EAR, which is found in families that are engaged in field activities (52.5%), are those who mainly conserve local knowledge, produce-collect and present the highest consumption of collection food. There are two forms of access to these foods: by direct harvesting given their proximity and access and by commercial exchange for their remoteness or laborious harvesting. The forms of consumption of the EAR are primarily raw, roasted and boiled. The two factors that contribute most to the EAR are present in the diet of the inhabitants are: the sociocultural factor, reinforces the part of the collective identity and social fabric, and the health factor, where the population identified its importance from the nutritional, wellness and in the prevention of diseases. In the community, the sociocultural factor in the consumption of EARs on the economic criterion that is the dominant discourse in recent times and that downplays the entire cultural construction and view of indigenous peoples and communities was highlighted.

In a breeding program for strawberry (Fragaria × ananassa) it is important to have a methodology to evaluate the genetic integrity of the plant in all the stages of increase, from different criteria, such as morphological, physiological and molecular; for this purpose one of the most appropriate tools are the Simple Sequence Repeats (SSR`s) molecular markers, since they allow, for example, identifying populations with a reduced genetic diversity, revealing genealogies, knowing the degree of relatedness between individuals, providing solid elements in the defense of intellectual property, evaluation of the purity of the plant material, identification of somaclonal variation and to avoid the mixture of plant material in germplasm banks. In this sense the objective of this study was to obtain the genetic fingerprint of strawberry varieties CP0201, CP0204, CP0615, CPLE7 developed at Colegio de Postgraduados and variety Festival developed at Florida, US, with the use of nine microsatellite (SSR`s) loci. The process included the DNA extraction from strawberry leaf tissue, as well as the amplification by means of PCR of the SSR`s loci grouped in multiplex reactions. The PCR products were separated by capillary electrophoresis and their size in base pairs was determined with the GeneMapper® v. 4 software. From the allele frequencies distance matrices were calculated the Jaccard and Dice coefficients. 63 different alleles were found, each pair of primers amplified between 3 and 12 alleles. The markers that presented the highest number of alleles were EMFn181 (11 alleles) and EMFv104 (12 alleles). The genetic fingerprint of each variety was generated. Differences between the CP0615, CPLE7 and Festival were found based on their allelic profiles; CP0204 and CP0201 had a similar genetic fingerprint, since they are related through their female parent; the allelic diversity index within the populations ranged from 3.96 to 5.93. The varieties had a low uniformity index due to the high level of polymorphism of the markers used.

In the Comarca Lagunera the area estimated of pecan (Carya illinoensis) is 9,208 ha-1, with an approximate yield of 1, 459 t of pecan ha-1. Varieties predominants in the Comarca Lagunera are Wichita and Western. When the demand for nutrients in the plants cannot be covered, they depend directly on the stored compounds. One of the most demanding nutrients by plants for their growth and development is nitrogen (N), the lack of this nutritive element can lead to low growth. It´s necessary to know the influence of climate variables (temperature, irradiation and relative humidity) on nitrogen percentage stored in the biomass of two varieties cultivated in the study area (Western and Wichita) in order to contribute to agronomical management. The objective of this research was to observe the variation of the N content in the trunk and to develop a mathematical function that describes its behavior from the environmental variables (temperature, relative humidity, and irradiation). The study was conducted in the experimental field of the Universidad Agraria Antonio Narro Unidad Laguna. Four trees of approximately 30 years of each variety were selected. Cores were extracted monthly for one year (July 2016 to June 2017). The content of total N was determined through gas analyzer, the biomass was estimated by through of allometric equations. An analysis of variance of two factors (month and variety) was performed to observe the difference between the N percentage in the trunk in the different months. The relationship of the environmental variables with the N percentage in the trunk was determined through multiple linear regression. The percentage of N was not affected by the factors (month and variety). The average monthly temperature was the variable that most affected the total N content in the trunk of the tree, in comparison with the relative humidity and irradiation. No significant difference was found between the sampling months and the varieties (Western and Wichita). The prediction of the percentage of N is less precise due to the size of the trunk of the tree. Pecan tends to increase the N percentage when low temperatures are recorded. The stored compounds can fluctuate at any time due to their plasticity.                       

From the end of the 1990’s and the beginning of the 2000’s, Latin American region experienced the largest female labor force participation growth in the world.  Recent literature (Camou, 2015; Chioda, 2016; Gasparini & Marchionni, 2015; Klasen, 2018; Serrano, Gasparini, Marchionni, & Gluzmann, 2018) conclude that marriage and fertility trends, economic growth and education as important determinants, but agree to the need to analyze women preferences and social factors also as contributing elements.  This study contributes to the literature by studying these two factors in the region, from the viewpoint of Akerlof & Kranton’s (2000) Identity Economic Theory, and Welzel’s (2013b) Emancipative Values Theory.  Exploiting World Values Survey data and European Values Study, this investigation developed a probabilistic regression model where women’s preference towards egalitarian views as workingwoman is analyzed as Women’s Identity, and social constraints upon gender equality is analyzed integrating a Women’s Emancipative Values indicator. This work also compares Latin American countries results with OECD countries to note differences between the groups.  We conclude that Women’s Identity and Women’s Emancipative Value are strong positive statistically significant determinants of FLFP.  When compared with OECD countries, we also conclude that women in the two groups of countries share similar self views as workingwoman, but Latin America still has social constraints at play that are limiting FLFP in the region.

Introduction: The main objective is to know the joint influence of business management practices, innovation and entrepreneurship on the performance of entrepreneurial firms in the state of Guanajuato, Mexico.Method: The methodological design was quantitative, explanatory, observational and transversal, where a sample of 304 young entrepreneurs was obtained. A structural equation model (SEM) was developed through the statistical software Mplus v.7.0. STATA v.12 was used to analyze the data. As for the SEM goodness and adjustment indexes (c2=1656.156 gl= 921; CFI = 0.914 y TLI=0.908; RMSEA= .05) they were absolutely acceptable (Jöreskog & Sörbom, 1981; Muthén & Muthén, 1998-2007; Rigdon, 1996).Results: According to the findings found in the research, it is proven that management practices and business entrepreneurship have a positive and significant influence on innovation, entrepreneurship and the performance of the entrepreneurial firm. In the same way, innovation has a positive and significant influence on business entrepreneurship. Likewise, innovation, business entrepreneurship and the performance of the firm have a positive and significant influence as mediating variables between business management practices and production performance, both financial and non-financial, of entrepreneurial firms.Discussion or Conclusion: A model is proposed that allows to guarantee the success of the entrepreneurial firms through the entrepreneurial performance of the entrepreneurial firms. In this way, the findings are relevant and of great value since currently there are not enough investigations that are focused on the analyzed variables.

Suicide is considered a public health problem that has increased exponentially, so identify a population on suicide risk as well as associated factors, is essential for prevention in the adolescent population. This study analyzed the influence of self-esteem, hopelessness and sociodemographic factors affect the presence of suicidal risk in adolescents; for this, was worked with a total of 74 participants, men and women with an age range of 15 to 18 years, from a non-clinical population classified into two groups: with and without suicide risk, in equal number and characteristics of age and sex. The Scale of Suicidal Risk of Plutchik (1989; 1998), the scale of Self-Esteem of González-Arratia (2011) and the scale of Desesperanza de Córdoba, Rosales and Eguiluz (2005) were applied. It was found that exist a significant positive relationship between suicidal risk and hopelessness and inverse with self-esteem. Regarding the type of family, single-parent family participants scored higher in suicidal risk and in hopelessness. From the binary logistic regression model, it was obtained that the variable that predicts suicide risk is hopelessness, followed by self-esteem. No differences are reported between men and women in any of the evaluated variables. Therefore, it’s concluded that hopelessness increases the probability of suicidal risk, that’s why it’s essential to include it in future empirical studies, as well as models of prevention and intervention in adolescents.