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

In Mexico, the management of drinking water by community it provides a wide range of institutional arrangements based on the cooperation of users. This makes it a substantive element in suburban and rural areas water supply. This article presents the case of the Committee of drinking water of Tlaltepango, San Pablo del Monte, Tlaxcala, México, who for more than six decades has supplied water to its users. The objective was to analyze the elements of cooperation supporting their self-management using the principles of design by Elinor Ostrom. Therefore, interviews were carried out with members of the commission and direct observations in the field. It was verified that the community has developed specific rules that maintain cooperating of the users. So, in general, complies with the principles of design. In that sense, it can be taken as a model of teaching for the rest of the local suppliers of drinkable water of San Pablo del Monte.

The closed urbanism in the medium-sized cities and metropolitan areas in Mexico, despite being exclusive residential enclaves that suppose qualities on better levels of life and security in the Metropolitan Zone of the south of Tamaulipas, present locations of risk and high levels of fragmentation along with the expanded growth of the region, generating important changes in the urban and affecting the social and cultural. Due to this, by means of the urban spatial analysis of the formal, structural and functional variables, we intend to characterize the physical-spatial phenomenon according to the particularities that distinguish them from the rest of the local open urbanizations.

Introduction: In Mexico, there is an unmet demand for sheep meat. To remedy this, it is necessary to study production systems and determine the factors affecting them. The objectives of this study were 1) to evaluate the effect of birth year (BY), type of birth (TB), lambing season (LS), lamb sex (LSX) and parity number (PN) on growth characteristics of pre-and postweaning of Pelibuey lambs and 2) to estimate the relationship among pre and postweaning growth characteristics.Method: The study was retrospective observational with productive data of a sheep farm located in Tabasco, Mexico. The dataset include records from 389 Pelibuey ewes corresponding 941 lambs and 629 lambing. The statistical model included fixed effects of BY (2005 to 2008), TB (single and multiple), LS (dry, rainy and windy), LSX (female and male), PN (primiparous and multiparous), and as well as random effects dam within BY and experimental error. Partial correlation coefficients of Pearson for all response variables were analized. The pre-weaning dependent variables were: weight at birth (BW), average daily gain of adjusted pre-weaning weight to 60 (ADG1) and adjusted weight at weaning to 60 d of age (WWa). Postweaning dependent variables were: average daily gain of adjusted postweaning weight (ADG2) and adjusted final weight to 106 d (FWa). The final weight corresponds to the last weight recorded in productive records, taken at an average age of 165±49 d.Results: With exception of TB and LS on ADG2 and FWa, all independent variables affected (P≤0.05) the preweaning dependent variables. TB and LS affected the preweaning lamb performance (P<0.01). Single lambs had higher BW, ADG1 and WWa (P < 0.01) compared with multiple lambs. The lambs born in rainy and windy had higher BW (P≤0. 05), born in dry and rains had greater ADG1 and those born in dry showed greater WWa (P < 0.01) with respect to other LS. Male lambs had higher BW, WWa, ADG1, FWa and ADG2 than females (P≤0.05). Lambs from multiparous ewes had better growth performance than lambs from primiparous ewes (P<0.01) with exception of ADG2 (P>0.05). The correlation coefficients more high (P < 0.01) were observed between ADG1 with WWa and ADG2 with FWa. The correlation coefficients ranged from 0.27 to 0.88 between the dependent variables studied (P < 0.01).Conclusion: The YB affected all preweaning and postweaning variables. However, was not detected a year where all pre and postweaning variables were higher or lower than other BY. The single lambs had better preweaning performance than the multiple. In the dry season the BW of the lambs was lower with respect to other LS. In windy, the lambs had less ADG1 and WWa compared to other LS. Male lambs were higher in their preweaning performance with respect to females. Lambs from multiparous ewes had greater pre-weaning performance. In postweaning performance, ADW2 and FWa were not affected by the TB and LS. ADG2 was affected by PN. The BW, ADG1, WWa and ADG2 had a positive relationship with FWa.

Introduction: Sugarcane is an essential agricultural product for bioethanol production in Mexico. The discovery of both the bacterial community associated with this crop and the soil status is a decisive step towards understanding how microorganisms influence crop productivity. Culture enrichment allows for the identification of the biodiversity of biological samples. The objective of this research was to identify the bacterial biodiversity related with two complex carbohydrate sources (starch and cellulose) in soils sown with sugarcane in the Papaloapan Basin in Oaxaca, Mexico via a metagenomic approach.                    Method: Soil content was analyzed chemically. Liquid LB, LB-starch and LB-1% carboximetilcellulose media were inoculated with 2 g soil and cultured at 180 rpm, 37°C for 48 h. The biomass was collected and the 16S rDNA gene was amplified and a library was constructed which was analyzed by sequencing.Results: N, K and Zn content of organic matter showed higher values than average, as opposed to P and Na, which were lower than average. In the library, 35 OTUs related to Clostridium, Bacillus, Enterococcus, Lysinibacillus and Citrobacter genera were found which could contain genes for breaking cellulose and starch.Discussion or Conclusion: This is the first approach to identify the diversity related to starch and cellulose hydrolysis in the Papaloapan region, where the principal genera detected were Clostridium, Bacillus, Enterococcus, Citrobacter and Lysinibacillus in a soil moderately rich in organic matter.

Introduction: This article introduces the utilization of denim waste, obtained from local denim companies located in the city of Saltillo, state of Coahuila, Mexico, as a material for thermal insulation for dwellings. The material was shaped into panels, ensuring their functionality in such a way that dwelling residents may experience a reduction in their use of electricity by means of an insulating system that can withstand extreme outdoor temperatures, therefore, generating greater physical comfort for the dweller.Method: Each prototype was exposed to the heat produced by a set of incandescent light bulbs placed directly over the external surfaces. They were monitored for 22 hours and the heat absorption, both in their outer and inner surface, was carefully recorded with the use of thermocouples. The final temperature results were registered by using a thermographic camera.Results: The panels presented a variation of thermal efficiency of up to 66 %, compared to materials such as the CEB (Compressed Earth Block) and up to 75 % compared with the concrete block, the difference in temperature results between the panels was affected by factors like the thickness and quantity of the used material. These values allowed the selection of the most suitable panel considering that the thermal delay time was up to 20 % more efficiently, allowing to choose the panel that was displayed to have better performance.Conclusion: The insulation developed with denim waste proved capable of withstanding extreme temperature conditions. Such findings may translate into improved living conditions, for the residents of Saltillo, with the promise of better indoor temperatures. The resulting material can help maintain cooler indoor temperatures in the summer, and warmer during the winter. Also, the prototypes consume less energy resources because they´re produced from waste that is not used in any other area today and reduce pollution by the excessive industrial scrap.

In order to satisfy his needs, the man has to appropriate the nature. Of the two opposing modes of appropriation, the peasant and the agroindustrial, the least degrading is the first, in addition to being the most important because the volume of food produced, work generated and ecological advantages. Due the relevance of this appropriation mode, the objective was to show the ecological, social and economic relevance of the peasant appropriation mode, and the characteristics that propitiate the agroindustrial trend. The study was carried out in the communities of San Lucas Tulcingo and La Magdalena Yancuitlalpan of Tochimilco municipality in Puebla, Mexico, selected by the landscapes pattern (altitude gradients) the area with amaranth and corn seeded and the type of technology. The Peasant Production Unit (PPU) was analyzed, which is based on the sowing of amaranth and corn. The research techniques were the survey and the direct observation. A stratified random sampling was performed, resulting in a sample of 74 producers. A Peasantry Index (CI) was constructed based on nine attributes. A logistic regression was applied by the Wald method (forward) to determine the indicators with the greatest influence on the Peasantry Index (CI). The results of the nine attributes show that the two localities are classified in the mode of peasant appropriation. San Lucas Tulcingo presented greater use of fossil energy by the use of agricultural machinery, while in La Magdalena Yancuitlalpan the peasant mode employs more family labor. Both, the energy source and the labor force, showed association with the peasantry index according to the variable selection procedure,  the forward Wald method. It is concluded that the PPU of San Lucas Tulcingo presented a Peasantry Index of 0.327 (tending to the agroindustrial), and those of La Magdalena Yancuitlalpan of 0.298, but both conserved their mode of peasant appropriation. The difference is in the main source of energy used; fossil energy and family work energy, respectively.

Introduction: Oleoresins are extracts of oily nature from chilies, used as ingredients to provide flavor and aroma to many food products. However, they are thermolabile and very susceptible to quality losses during processing or storage, it being convenient to encapsulate their bioactive components before being used as food ingredients in order that their useful life is not affected.A methodology that allows to recommend the optimal storage conditions for dehydrated products is the proposed by Beristain and Azuara (1990). Where there is a zone of minimum integral entropy of the water molecules. In the minimum integral entropy, water is less available for deterioration reactions and the food retains its functional quality.Method: Habanero chili oleoresin (OCH) was encapsulated using the molecular inclusion technique with β-cyclodextrin (βCD) to protect it during storage. The molecular inclusion complex was prepared in the proportions 20:80 and 30:70 oleoresin: β-cyclodextrin, respectively, and stored for 5 weeks in a range of aw =0.103–0.765 at 25, 35 and 45 °C. The thermodynamic properties were analyzed to explain the effect of temperature and aw on the encapsulates stability.Results: The results showed that the inclusion complex in the 30-70 ratio is more stable than elaborated in the 20-80 ratio, being less hygroscopic, presenting a large zone of minimum integral entropy of around 0.3-0.6 aw and smaller ΔE values during storage at 25 ºC.Conclusion: According to the thermodynamic analyzes and the tests of the variation of ΔE, it was possible to obtain the adequate proportion of encapsulation (OCH-βCD), as well as to recommend the best conditions of temperature and humidity during storage, in order to avoid drastic changes in the color, product of the thermal degradation of carotenoids present in the samples.

The aim was to evaluate a DNA vaccine (INHA-DNA) and its recombinant peptide INHA-rec) against inhibin alpha (INHA) on the immune response and fertility in mice. Sixteen Balb/c mice were divided into two groups of 8 each and under a heterologous prime boost immunogenic scheme one group were inoculated with 100 μg of INHA-DNA and 14 d later with 100 μg of INHA-rec. The control group received saline solution. After the first birth, a booster was given with both antigens (INHA-DNA + INHA-rec). Immunization with 100 μg of INHA-DNA and INHA-rec induced high levels of anti-INHA antibody, as well as greater weight and size litter (P <0.05) compared to control. The mean fertility was similar between INHA (67%) and control (60%). In conclusion, the DNA vaccine and its recombinant antigen against INHA are capable of inducing immunity against INHA by increasing litter size without an apparent negative effect on fertility in mice.

Introduction:  The Peruvian technological MSMEs play a very important role for the economic and social development of the country in the medium and long term, however, the number of these in the country is limited, since currently non-technological MSMEs are predominant. Hence, the tough access to the use of technologies and knowledge management is one of the traits of this type of companies, which implies a low technological intensity production, not according to the emerging technological trends, thus promoting their scarce competitiveness and insertion into industry 4.0.                        Method: The aim of the present prospective study was to explore the possible futures of the Peruvian technological MSMEs by 2030, for this purpose -with the intervention of Peruvian and Mexican experts in MSMEs and prospective methodology- the key variables that will affect the future of those, were identified. scenarios were designed about their innovation processes and the betting scenario for 2030 was chosen. Likewise, with trend analysis, future technology-based business opportunities were identified for Peruvian MSMEs.Results: The prospective study made it possible to identify two determining variables for the future development of the Peruvian technological MSMEs, these variables are "Education in entrepreneurship" and "An articulated and systemic regulatory framework that promotes technological development and innovation". Finally, for the future construction of said variables, various actions were proposed.Discussion or Conclusion: The Peruvian MSMEs constitute a business conglomerate of great importance for the economic and social development of the country, but it is crucial that they become technology-based MSMEs. For this, it is necessary for Peru to design and implement a systemic and entrepreneurial framework according to the new technological trends based on the geographical diversity, biodiversity, and cultural richness of the country.

The assessment of the residual lifetime of in-service structural components requires knowledge of fracture toughness values; however, conventional test methods for measuring fracture toughness demand the removal of large material samples from components, which generally is impractical. Recently, the Small Punch Test (SPT) (which utilizes nonstandard miniature specimens) has been used as a practical and convenient alternative for evaluating fracture toughness characteristics of the material of components in service. The purpose of this research was to find a correlation between the SPT equivalent fracture strain εqf and the fracture toughness JIC of low-alloy cast steels coming from anchorages of a cable-stayed bridge, which is located in the Gulf of México. Fracture toughness was calculated from KIC experimental data from previous work and equivalent fracture strain εqf was obtained by SPT using specimens 10×10 mm2 squares of 0.5 mm thickness. From εqf and JIC results and corresponding low-alloy steel experimental data from literature, a linear correlation was proposed to estimate fracture toughness from SPT equivalent fracture strain for cast steels belonging to this study case.