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

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Editorial de la Revista

In order to determine the effect of Potassium Sorbate on the cell cycle in root meristems of Allium cepa L. “onion” set three experimental groups were exposed to solutions of Potassium Sorbate at concentrations of 0.5, 1 and 2g /l, for 6, 7 and 8 hours each and a control group. Later the respective color in 2% Acetic orcein according to the technique of Tjio and Levan, observed with the compound microscope a total of 1500 meristematic cells in each of the treatments. The appropriate treatment results after 8 hours of exposure to the concentration of 2 g / L showed a decrease in mitotic index of 11.26%, while it increased the rate at 95.57% prophasic index. There were also alterations as chromosome breaks, anaphasic bridges and binucleated cells. The tests and analysis of variance showed significant differences between the different treatments, as confirmed by multiple comparison test of Duncan averages. It shows a probable genotoxic effect in the genetic material by Potassium Sorbate and an alteration in the cell cycle of meristems of A. cepa L., likewise, is found biosensor function of A. cepa L. in the study of substances that may affect the cell cycle.

Pepper is the most famous of spices used to flavor foods. It is one of the crops with the highest microbial population, and it is causing disease and decay of mostly processed foods. The aim of this study was to determine the effect of gamma radiation on microbial population, the physicalchemical and sensory evaluation in ground black pepper, treated with different doses alternatives, in order to obtain the optimal minimal dose that reduces microbial load to the recommended specifications, without significantly altering the physical-chemical and sensory. 500 g samples were irradiated in the Gammacell 220 (0, 4, 6 and 8 kGy). The initial dose rate was 5.82 kGy/h. Were performed the following analysis: microbiological (aerobic mesophiles, anaerobes, Enterobacteriaceae, Salmonella / Shigella, total coliforms, Escherichia coli, Staphylococcus aureus, Lancefield group D streptococci, Bacillus cereus, Clostridium sulfite reducer, molds and yeasts). Physico-chemical (total ash, ash insoluble in HCl, HCl-soluble extract, alcohol, ether extract and crude fiber. Sensory evaluation (color, odor and flavor by descriptive test). The methods were those recommended by the FDA, APHA, AOAC and NTP. At different doses tested, there were no differences in physical-chemical analysis and sensory. The minimum dose of 8 kGy was selected that reduced the population of aerobic plate in 5 log units of 9,8 x 106 to 4.0 x 10 UFC/g, dose of 4 kGy was sufficient to reduce the fungal population by 3 log units of 1,7 x 103 to <10 UFC/g , according to the specifications.

The relationships between big companies and the small and mid-size companies (SMEs) are an important and simultaneously controversial subject. With the advances of the globalisation processes, in particular from the economic policies that privilege the commercial opening, it is emphasized in the positive impacts of the direct foreign investment in the economic dynamics of the receiving countries. In that context, diverse studies focus to the analysis of the spillover of big companies (transnational and national) towards local SMEs and suppose that the increases of productivity of these last ones are related to the spillover knowledge from the big ones. Other investigations emphasize the asymmetric relations between the big companies and the SMEs, for such reason maintain that the impacts are more negative on the smaller companies and significantly does not exist technological and productive accumulation of learnings, abilities and capacities in the SMEs. Having as frame the debate from these studies, the work analyze which are the advantages and the difficulties that the SMEs face for the advantage of the spillover knowledge as well as which are the specific mechanisms for their accumulation. In order to illustrate the argumentations the experience in some mexican industries is taken like reference.

The present work is related to study the surface circulation in Callao and Miraflores bays using Princeton Ocean Model (POM) model, which is a set of equations and parameters that govern the ocean dynamics. POM was used to caracterize the circulation pattern in the study area, analyzing the main influence of wind stress and tide in the generation of currents and the effects occur because of the coastal morphology and the presence of the Island, these factors influence the results indicating a complexity in the ocean currents and the presence of vortices inside the bay of Callao, also tidal propagation manifests in the area of the port of Callao, generating currents ebb and flow. In this way, knowing the ocean circulation in the Callao and Miraflores bays, further studies can be made pollutant dispersion, wastewater discharges, accidental spills of substances, and also sediment transport studies produced by the presence of Rimac and Chillon rivers.

We present here the process of optical axis alignment of the neutrographic system with the optical axis of the neutron beam from window 4 of the nuclear reactor rP-10. This process is done with the aid of a radiographic technique, which facilitates locating the optical axis of the neutron beam in space by a photographic record, thus allowing for later alignment of the neutrograph. The high neutronic absorption coefficient of light chemical elements and the high contrast of materials with similar density are an advantage for applications. The neutrograph has a wide variety of applications, among them: the analysis of nuclear fuels, the detection of hydrogenated and organic materials, the detection of flaws in turbine blades, the detection of corrosion in aircraft components, quality control of ceramic materials, detection of drugs and explosive materials (used in the pyrotechnic and ammunition industry), the study of archaeological materials, the detection of lubricating films in bearing systems, as well as dynamic processes of lubrication and combustion, among others. in this work we present a variety of examples of applications with the reactor rP-10.

With the aim of providing updated agrometeorologic information to land workers, which would minimize or avoid losses caused by meteorological extreme agents such as droughts and floods or climate change related events, including also the harmful assaults of plagues or diseases to crops, the national service of meteorology and hydrology of Peru (senamhi) implemented a system for agrometeorologic alert. in this respect senami developed workshops for the development and training of farmers with the goal that they learn to use the information generated to make suitable decisions.

This work shows recent theoretical contributions in the area of competition and strategy which have been expressed by a mathematical model. Taking as its starting point the theory of decision making, so that may be used for empirical research. The development objective of the model is to explain the possible outcomes of the strategic management of a firm, having as theoretical base the theory of competition and strategy. Finally, using the model it is concluded that competitive advantage is not exploitable feature, but is the result of the deployment of skills that are imperative for the best performance and business, understanding the latter as the supply of attributes of customer value. In this sense, competitive advantage is a condition with extrinsic in relation to other competitors. Furthermore, it is considered that the quality that enables a company to get better returns is the distinctive competence, whose value is evaluated in the operation of the company.