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

Maize (Zea mays L.) is one of the cereals with the largest area planted worldwide due to its importance in food and feed. There are many etiological agents that cause diseases in maize plants; however, Fusarium verticillioides (Sacc.) Nirenberg is one of the molds to which special attention has been paid to its wide distribution, especially in tropical and subtropical areas, their toxigenic capacity and endurance. For this reason, the incidence of F. verticillioides and the fumonisin content in white maize grains of eleven hybrids destined for human consumption from Guárico and Yaracuy, Venezuela, were evaluated.Method: The quantification of toxigenic species was done by direct sowing whole grains and disinfected with NaClO at 3.27%, on the malt salt agar medium, expressing the results as percentages of grains colonized by total molds and by potentially toxigenic species. The fumonisin content was quantified by the immunoaffinity method with fumonisin columns (B1 + B2).Results: No significant statistical differences were observed for the incidence of F. verticillioides and the concentration of fumonisins in the samples evaluated in both. The mycobiota associated with the corn kernels were Aspergillus flavus, A. Niger, A. ochraceus, A. terreus, Eurotium chevalieri, F. verticillioides, Penicillium spp. Alternaria sp and Curvularia sp. The highest average incidence of toxigenic molds was obtained by A. flavus (24.3%), F. verticillioides (14.6%) and Penicillium sp. (4.4%) in Yaracuy; however, in Guárico were F. verticillioides (16.7%) and Penicillium spp. (13.8%). The average concentration of fumonisins in Yaracuy and Guárico was 1.8 and 8.4 μg / g, respectively, exceeding the limit allowed for human consumption (1 μg / g).Discussion: Based on the low incidence of F. verticillioides and the low levels of fumonisins detected in hybrids D1B-348 (from Guárico) and D1B-246 (from Yaracuy), it is recommended to use them in the respective states, as a measure of control of the pathogen at the field level and avoid possible contamination with fumonisins.

Introduction. Plant extracts have been shown to have antimicrobial properties related to certain chemical compounds such as thymol, carvacrol, limonene, linalool and terpinene. The objective of this study was to determine the concentration of these compounds in the extracts of Larrea tridentata, Origanum vulgare, Artemisa ludoviciana and Ruta graveolens; as well as to evaluate the antimicrobial effect in Escherichia coli, Acinetobacter baumanii, Pseudomona sp and Staphylococcus aureus.Method. The extracts were obtained by simple distillation using ethyl alcohol as solvent, the chemical composition was evaluated by gas chromatography. The antimicrobial activity of each of the plant extracts was performed by well diffusion and disk diffusion methods.Results. The bacteria showed different degrees of sensitivity to the extracts, S. aureus inhibition of growth with the extract of O. vulgare and R. graveolens, while the bacterium Pseudomona sp. showed inhibition with the extract of A. ludoviciana, L. tridentate and O. vulgare.Discussion. The highest concentration of thymol and carvacrol was found in the extracts of O. vulgare and L. tridentata. The compound linalool was found in a higher proportion in O. vulgare and to a lesser extent in A. ludoviciana. Limonene was found in the extracts of O. vulgare and R. graveolens. Of the four plants evaluated, L. tridentata extract was better because it had the highest inhibition compared to the other extracts; and with an effect similar to the oils used as control. The disk diffusion technique allowed better observation of the inhibitory effects of the extracts and oils on each of the bacteria used in comparison to the well diffusion method.

This article documents and analyzes Traditional Knowledge (CT), uses and perceptions of birds by children in Reforma Agraria (RA) and Frontera Corozal (FC) communities located in the Lacandon area of Chiapas, Mexico. Both belong to the zone of influence of the Montes Azules Biosphere Reserve (REBIMA) and the second also to the Yaxchilán Natural Monument (MNY). Participatory activities were carried out in basic education schools consisting of questionnaires, interviews, sociodramas, elaboration of drawings and stories about birds, among others. The children recognize 42 species of birds (in RA) and 31 species in each of the two FC schools, and identify their use as pets, ornamental (feathers), edible, harbinger birds and in some cases medicinal. Their knowledge is based on their proximity to the jungle and the recurrent observation of their environment. Their perception of birdlife is positive. They feel a great attraction and appreciation because of their colors, songs and diversity. Currently, government institutions are making limited use of the opportunities around this knowledge that must be considered to support the conservation of these organisms and their ecological environment, increasingly incorporating a biocultural and intercultural approach in their activities.

Introduction: The objective was to determine the relationship between the serum concentrations of Calcium (Ca2+), non-esterified fatty acids (NEFA), and insulin 10 days prepartum with losses in milk yield (MY) at 10 and 20 days of lactation.Method: Two hundred forty-three Holstein-Friesian cows (780 ± 36 kg PV, with more than two lactations) were sampled by coccygeal puncture several times before, during and after parturition.                       Results: When Ca2+ levels were low 10 days before parturition and were related to MY at 10 days postpartum, it was observed that 77.11% of the cows lost 2.20 kg of milk; while on day 20, 66.41% of the cows lost 1.40 kg animal-1 day-1. In contrast, when NEFA were high 10 days before calving and were related to MY, 67.40% of cows showed a risk of losing 0.80 kg, whereas at 20 days postpartum, 22.00% of cows lost approximately 0.90 kg cow-1 day-1. The determination of low prepartum insulin and MY on days 10 and 20 of lactation indicated that 6.02% of cows lost 0.80 and 0.70 kg of milk-1 animal-1 day-1 for days 10 and 20 of lactation.                       Conclusion: In conclusion, low blood levels of calcium, high levels of NEFA, and low insulin 10 days before parturition were associated with milk yield losses at 10 and 20 days after parturition. It was also observed that low calcium could cause greater milk losses than excesses of non-esterified fatty acids and serum low insulin concentrations.

The Laguna Region is the most important dairy region of Mexico. Currently are using various techniques to genetically evaluate the animal at an early age, allowing to select future breeding with desirable characteristics. Among related genes to milk production, are the Ob gene also called Leptin gene which acts on the central nervous system and peripheral tissues playing an important role in regulating modulation of appetite, body weight gain, increased metabolism energy and muscle anabolism. This study was performed to determine polymorphism restriction fragment length ACI I of Leptin gene in exon 2 and correlate it with the production parameters and milk quality. Blood sample of one hundred cows were collected on the dairy farm "Lacteos Florida" Francisco I. Madero municipality of Coahuila, Mexico with three status of milk production: high, medium and low. DNA extraction was performed by the modified method of Salting-Out. PCR of leptin gene was performed resulting in a fragment of 272 bp in length and was subjected to PCR-RFLP with the ACI I restriction enzyme and sequencing, correlating TT, CT and CC genotypes with groups of cows sampled high, medium, low producers respectively. Statistical analysis indicated that cows carrier the homozygous genotype (TT) have a significant effect (P <0.01) with respect to the characteristics of production and quality of milk since they had a higher feed intake, weight gain, and a high milk production compared to heterozygote (CT) and homozygote (CC) genotypes. The results show that molecular identification of Ob gene polymorphisms can be used as a tool for genetic selection in Holstein cattle.

Game theory is a mathematical tool that allows modeling the cooperation between rational and intelligent agents. In this paper, game theory is presented as an application that proposes cooperation scenarios within the supply chain (SC) for maintaining the balance concerning logistics costs that are paid by customers of a company that distributing grocery products. From Shapley value and Capacitated Vehicle Routing Problem (CVRP) application, the balanced costs distribution among all customers were obtained. Variables such as demand, distance between all customer nodes, load capacity and vehicle performance are considered. The results obtained allowed to achieve savings closer than 40% in relation to company current distribution costs.

In Mexico, the goat population is concentrated in extensive production systems in Mexico, with herds mainly formed by goats that the producers called Creoles, now accepted as a local name. The power of the goat dairy in the extensive production system, is through the grazing, but this alone cannot meet the nutritional needs of the goat. Therefore, if the producers want to increase the production of milk, it is necessary to supplement the grazing goat diet with grains. On this manner, some results report an increase in milk production in grazing ruminants supplemented with an integral diet. The aim of this study was to evaluate the effect on the production and composition of milk in grazing local goats supplemented with an integral feed. Two experiments were performed. The first, evaluated the effect of changing from a grazing system to intensive system, in order to challenge the goats to express their productive potential by providing them with an integral feed. In the second, it evaluated the effect in grazing local goat milk reproduction and composition, evaluating them with different levels of supplements used in experiment one. Data from milk production and chemical composition in milk of both experiments were analyzed using a repeated measure model. The information of body weight and body condition of the goats, were analyzed as a completely randomized design. An analysis of partial cost was realized in both experiments, in order to know the economic viability of the treatments. In experiment one, the concentration of fat in milk did not changed (p > 0.05) by effect of treatment, however, it did increase milk production (p ≤ 0.01) and concentration of protein and lactose (p ≤ 0.05) in intensive goats compared with grazing goats. In experiment two, the grain supplementation in grazing local goats with two levels (500 g d-1 and 1000 g d-1) did not change the concentration of fat in milk (p > 0.05), but increased body condition of goats and milk production (p ≤ 0.01) and protein and lactose (p ≤ 0.05) in comparison to local grazing goats. Thus, partial costs analysis indicated that the supplementation of grazing goats is not economically viable. For future references, further research is recommended under low-cost food and negotiation to improve prices for quality of milk.

Introduction: Since the beginning of the XXI century, several authors affirm that open business models (OBM) enable an organization to be more effective in creating as well as capturing value and are a prerequisite for successful co-development partnerships. As a result of both trends, the rising development costs and shorter product/service lifecycles, companies are finding it increasingly difficult to justify investments in innovation. The OBM solve both trends, underscoring the terms: “industry ecosystem” and/or “collaborative business model”. Not only it changes the innovation process but it also modifies organizations themselves by reconfiguring value chains and networks. For the firms, it creates a heuristic logic, based on the current business model and technology to extend them with strategy, to the development of innovation to create value and increasing revenues and profits. It emphasizes the external communities with governance as valuable resources with several roles that promote corporate competitiveness.  So, for a specialized sector with high technology such as the information technologies sector of metropolitan zone of Guadalajara (ITSMZG), we posed the next research question:  Which are the determinant factors of the OBM as an empirical model to be applied at the ITSMZG?Method: As you see, this research is aimed to pose, the determinant factors of the OBM as an empirical model to be applied at the ITSMZG.This is a documentary study to select the main variables among specialists in ITSMZG practicing the OBM process using analytic hierarchy process (AHP) and Delphi’s Panel to contrast the academic terms with the specialists experience. It´s a descriptive, exploratory, correlational, cross-sectional, qualitative-quantitative study to obtain a final  questionnaire in Likert scale, with reliability tested through a pilot survey (Cronbach’s Alpha>0.75), applied during Jan. 2015-May 2016 to the total population asked: 600 specialists of ITSMZG (150 IT teachers and 150 representatives of consulting firms as “consultant part”; 290 IT SME CEO and 10 IT LE CEO as the “decision-making part”, since 1 year in the market,  80% with bachelor degree, 20% with postgrade, 20% women and 80% men).  It was designed a first-order structural equation modeling (SEM) as a confirmatory factor analysis (CFA) technique, using the EQS 6.1 software to analyse the OBM underlying variables, to determine a final empirical model.Results: The result is an empirical OBM based on 5 main factors: business management BMG (10 variables/76 indicators), strategy (STR, 3 variables/14 indicators), technology (TEC, 3 variables/24 indicators), new entrepeneurships (NWE , 3 variables /7indicators) and open innovation orientation (OIO, 3 variables/18 indicators), empirically proved for the ITSMZG.               Conclusion.  Although the final empirical OBM has a significant positive effect among its variables, also showed different levels of factor loadings, meaning opportunities to improve the model for the ITSMZG.

Introduction:  Energy balance trial allows to carefully allocating any inputs for field production of the crop as well as, dosing precisely the amount of energy required for each process, thus determining the efficiency when energy transformation inside the crop is required for a certain task.                       Method: Castor oil plant (Ricinus communis L.) as an energetic crop was field drillet and cultural practices were undertaken for crop growth and at harvest, the whole plant was collected where each constituent was tested for its energy concentration. Thus, to reach for an energy balance calculation; bilological energy figures from higuerilla plant were compared with technical and physical energy application for crop cultivation and processing.                       Results: Entire energy applied for crop growth is 28% higher that energy obtained from higuerilla plant. Also, biomass of whole castor oil plant except seeds generates twice energy than oil from seeds, so whole crop harvesting has to be promoted.                       Conclusion: Oil from sedes should de used as biomaterial, since there is a positive balance by 15%.

The need to influence how to intervene the historic center of Puebla to improve living conditions and social cohesion in the neighborhood of San Jose, leads us to build a methodological proposal multidisciplinary approach that is an intervention model. Thus, should analyze policies, strategies and impact generated by urban rehabilitation projects implemented by the government in the Historical Center and mainly emphasize the role of community participation in the protection, rescue and conservation of their neighborhoods. This research concern leads to theoretical reflection and study of the art of sustainable urban regeneration, of great importance in the international arena and provides guidelines to analyze the feasibility of different types of intervention (conservation, renewal, regeneration, etc.) made partial and fragmented in the early twentieth century way: social, cultural, economic, urban and environmental. As a result a comprehensive model of sustainable urban regeneration as a major improvement action, able to recover these historic spaces in the fields is formulated. In this sense, participatory management will contribute to strengthening the proposed rehabilitation strategies at neighborhood to ensure social integration and improving the quality of life in the neighborhood of San José.