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

This study has been perfomed in order to verify the existence and location of vectors of Chagas disease in the entities of Guanajuato state to limit the territories and risk areas. Determining the infection of Trypanosoma cruzi in the vectors, evaluates the risk to human population. This research has been conducted evaluating the information of the labeled triatominos obtained by the field personnel of the Secretaria de Salud del estado de Guanajuato, and classified by the Laboratorio Estatal de Salud del Estado de Guanajuato. The information was obtained from 1998 to 2000 in the entities where work brigades are located and the reported abscence of vectors probably is due the absence of search on them. The index of infestation was not performed due the different search intensity across the territory and the sample method. Just the location of every studied specie to the collecting area was established. Triatoma mexicana, T. barberi, T. longipennis, T. pallidipennis y T. dimidiata, was present in 162 places of 25 entities of the states; at heighs of 870 to 2200 meters above sea level. Inside the house is the site where T. mexicana was present in a major frecuency, for T. barberi was the yard, for T. longipennis inside the house, as well as the T. pallidipennis and the ninphs, T. dimidiata which was collected once, did not reported collect site.

Today, Mexico faces a serious shortage of well-validated anthropometrics information; this has a strong bearing on the way labor elements are designed. The lack of reliable information impedes an adequate man-machine dimensional match, a factor that favors excessive fatigue, which in turn might result in serious damage to workers’ health. An initial logical step towards solving this problem is the gathering of anthropometrics information directly obtained from the Mexican working population. This report stems from a functional, anthropometrics study, that involved a sample of 509 male subjects, drawn from the working population in the shoemaking industry, at the city of Leon, Guanajuato. Thirty-seven anthropometrics, sociological and demographic features were measured or as sessed. The information so gathered was built into a database, which was in turn used as a base for the construction of a computerized mannequin. In generating this tool, a parametric method was applied using the standing height as the basic parameter. Both database and mannequin are meant as sources of guidance and help for designers. Relevant and properly validated information will be presented in a way that facilitates its consulting and handling. This, in turn will allow designers to create machines, tools and workspaces that incorporate ergonomic criteria.

In this this article structural formulas of clay minerals are determined from clays coming from the geologic localizations at Comonfort, Jerécuaro, Victoria and San Francisco del Rincón, in the state of Guanajuato, México. After applying, the Moore and Reynold’s method of chemical composition, it was deduced dioctahedral or trioctahedral type, layer charge origin and value, and the specific clay mineral from the analysis of the resulting formula. Two montmorillonites type minerals, a beidellite type and a vermiculite type mineral were obtained, and the last one showed a trend to be a part of the esmectite-vermiculite series.

Hans Reichenbach was the first philosopher to draw the distinction between “context of discovery and context of justification”, to distinguish between how scientific discoveries take place from how they are justified and accepted. Many philosophers (Reichenbach, Popper, Hempel, etc.) have argued that only justification is philosophically interesting, because in it there are methodological and epistemic issues involved. In this paper, it is argued that historical studies of scientific discoveries show that in the context of discovery there are relevant methodological and epistemic issues as well.

The variation in voluntary forage intake is undoubtedly the major dietary factor determining level and efficiency of ruminant production. This variation is bigger and least predictable for grazing ruminants. Range ruminant productivity and efficiency is relatively low due, partly, to intake limitations; productivity could probably be increased most by increasing intake. Distension of the reticulo-rumen wall is the primary intake regulation mechanism of low-quality roughages in range ruminants, digestibility and rate of ingest passage also affect voluntary intake. Body size and metabolic bodysize as well affect intake of grazing animals. Kind and amount of supplementation, forage availability, and grazing intensity have been related to voluntary forage intake.

Genomic sequentiation opens the possibility for searching genes related to diseases and behavior alterations. It should be interesting, using the genomic and proteomic tools, to investigate how patterns of behavior are inherited. Gene sequences and the structure and functions of the proteins confirm that we share the same molecules with the rest of the living organisms. These facts will change the vision that we have about us and other living creatures and should motivate to reflect about the relationship between bioethics and science.

Biological systems are able to generate magnetic fields. In spite of the fact that these fields are weak, now it is possible to detect them by means of sophisticated equipments and thus opens a new research field. Recent studies on this phenomenon reveal that the detection and analysis of the generated fields in organs such as the brain, heart, lungs, liver and other scan facilitate the diagnosis and treatment of illnesses among other possible applications.

Gene or haplotype analysis has revolutionized during the last decade the study of the population structure in populations. Presently, we can not only study the amount of genetic variation in a population but we can also infer the historical processes that are responsible for the observed genetic structure. This approach is supported by coalescence theory that studies gene and haplotype patterns of divergence under different assumptions not only related to population genetics but also with historical population demography. These innovations to the study of population structure have impact on at least two areas of evolutionary biology. The first one has to do with conservation aspects of regions where the studied species grow by producing conservation strategies as consequence of the historical processes that have affected populations. The second one is related to a species concept that takes into account these historical processes. In this work we present the results of an analysis that we have started in order to generate a conservation strategy of conifer forests in Mexico using as a model the species complex formed by P. montezumae and P. pseudostrobus. Our results show that fragmentation patterns, isolation by distance and events of range expansion have occurred in these species. They also show that introgresive hybridization is playing an important role on maintaining the structure seen particularly because it is asymmetric being more important from P. montezumae to P. pseudostrobus than from P. pseudostrobus to P. montezumae.

A descriptive, prospective and transversal type investigation was undertaken in order to identify the needs of the nursing labor market. The study shows the characteristics of the nursing labor market in the state of Guanajuato, referred to the potential and actual demands of this working force in the principal hiring institutions, their requirements on training skills and the potential working areas. The findings demonstrate a rising demand for the undergraduate nursing degree in the private health services institutions, civil associations, companies and educational services, it is worthwhile noting the demand for the specialization within the nursing field. The hiring perspectives in the studied institutions are focused towards general nurses and the undergraduate nursing degree. As far as the required profile by the DES-E of the University, the nursing graduates are up to the requirements.

The effect of feeding live water fleas (Daphnia pulex) and two dry feeds (Tetra-Bits and Sera) on growth of angel fish, Pterophyllum scalare, in the laboratory was evaluated over 60 days using 90 broods with an initial weight of 0.10 g applying the Specific growth rate, and Relative and Absolute growth tests. The Specific growth rate (mg/day) for the P. scalare broods receiving D. pulex was greastest (P<0.05) at 4.86 mg/day. Growth observed with Tetra-Bits and Sera was 3.58 mg/day and 3.35 mg/day, respectively. The effect of the feed on growth in terms of weight and size of the P. scalare broods was greater (P<0.05) in the organisms fed water fleas with a protein content of 52%. This lot obtained a final weight of 2.23 g, a length of 3.58 cm and a height of 2.77 cm. Individuals receiving Tetra-Bits reached an average weight of 0.84 g, a length of 2.60 cm and a height of 1.83 cm. The study group receiving Sera attained a final average weight of 0.716 g, a length of 2.28 cm and a height of 1.67 cm.