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

  After the growth of cells of strain YR-1 of Mucor circinelloides with naphthalene as sole carbon source, the presence of five different 1, 2-dihydroxi-1, 2-dihydro-naphthalenediol dehydrogenase activities were revealed by electrophoretic zymograms using (+)-cis-1(R), 2(s)-dihydroxi-1, 2-dihydronaphthalene as substrate and NADP+ as electron acceptor. The bands NDD1, NDD3 and NDD5 showing the highest intensity in the zymograms and by their relative electrophoretic mobilities, were purified to homogeneity by means of sequen­tial steps of electrophoresis-electroelution to know both, the molecular weight and the number of subunits that conform each activity band. The results show molecular weights of 98.64 kDa, 48.37 kDa and 102.45 kDa for the subunit of each protein band respectively. We conclude that these activities there are not enzymatic isoforms conformed by the same proteic subunit, the native enzymes have a homopolymeric structure and they do not share any protomeric subunit.

With the aim to study the relationships among stayability to 36 months of age with 14 type traits and first lactation milk yield in the Alpine breed, were used 1937 records of goats distributed in 155 flocks from the US American Dairy Goat Association. Data were analyzed using stepwise forward logistic regressions model. Flock effect resulted significant (p<0.01) and type traits that were significant (p<0.05) were rump width, rump angle, dairyness, stature, strength and fore udder attachment. Relationships founded in this study among the different traits, although not point out genetic relationships directly, suggest that some traits can be used in the indirect selection of longevity in dairy goats.

  Nowadays many industries want to replace synthetic dyes by natural, due to its harmful effects and the high contamination of the environment. Dactylopius coccus Costa (cochi­neal) is an insect to obtain natural products that are used as dyes. The aim of this study was to promote the application of cochineal and the products derivates of these insect, in the dyeing of cotton fabric and in the coloration of a lipstick bullet at the laboratory. Was applied to the aqueous extract of cochineal on cotton fabric, obtaining homogeneous colors, with average values in the CIELab scale of: 43.81±0.33 L*, 44.64±0.15 a* y -4.03±0.55 b*. It also was applied the carmine pigment in the elaboration of a lipstick bullet, was obtai­ned consistent color with the following average values on the CIELab scale: 13.25±3.62 L*, 4.80±1.41 a* y -0.23±0.84 b*.

A 5-months-old, commercial-crossbreed male lamb was remitted to post-morten study. The clinical history about of animal included: signs of severe abdominal distension, anorexia, poliaquiuria, straguria and prolonged urination posture, urine dribbling and blood-tinged urine. Necropsy revealed ascitis and a hemorrhagic fibrine membrane floating in approximately 8 litres of urine caused by a rupture of the urinary bladder in consequence of a total blockage of urethral lumen by multiple small stones localized in the sigmoid flexure of the animal. Obstructive urolithiasis is a common problem in the fed-flocks affecting between 20 % and 30 % of the animals. A diet with adequate mineral balance could reduce the health risk of formation of urinary stones.

A new method was developed with a GC/PTV/EI/MSMS system designed for the detection and quantification of 21 organochlorine pesticides in bovine fat: α-BHC, γ-BHC (lindane), β-BHC, δ-BHC, Heptachlor, Aldrin, Heptachlor epoxide, γ-chlordane, α-chlordane, Endosulfan I, p,p’- DDE, Dieldrin, Endrin, Endosulfan II, p,p’-DDD, Endrin aldehyde, p,p’-DDT, Endosulfan sulfate, Methoxychlor and Mirex, as a proposal for technological improvement in complying with the Mexican Official Norm NOM-004-ZOO-1994 based on the extraction methodology specified in the Mexican Official Norm NOM-021-ZOO-1995. A Gas Chromatography system was used with an ion trap analyzer and an automatic flow controller in the MS system’s hardware. Increasing the pressure inside the ion trap with high helium flows to optimize the selection of the precursor ion for each pesticide, and amplifying the signals of the product ions, achieved measurements of MSMS with sensitivity values superior to those of electronic capture detectors (ECD), provided correlation coefficient values of ≥0,990, and recovery values in bovine fat of between 60 % and 120 %, thus satisfying the requirements demanded by the Mexican Official Norm.

A preliminary analysis is presented of the results obtained in a quality evaluation of Advanced Mathematics I taught in the first semester of the major in Accounting at the Camajuani campus of the Municipal University. The results showed a growing interest among students and professors in increasing the quality of instruction in this subject in order to satisfy the growing demands of society on the University with respect to the formation ofprofessionals in the 21st century. The goal of describing the communal experience of the professors involved in the teaching of this subject and major was obtained by means of the techniques used in the internal self-evaluation of quality, with the intention of optimizing the teaching-learning process in the classroom.

  This paper describes an investigation of the density and distribution of phytoplankton and zoobenthic organisms carried out in the Zempoala Lake from 1998 to 1999. The data showed that the flora is made up of 29 species, distributed in eight categories. Of these the category of Bacillariophyceae showed the highest density and was also dominant in time and space as well. With regards to phytoplankton, the highest densities were found during spring, and according to the distribution of species, a seasonal succession was observed. With regards to benthic organisms, results showed that the abundance of these organisms during Fall and Winter was higher than during Spring and Summer, with a peak abundance of 10,612 org/m2, Oligoquetos were dominant along the coastline during almost all the year, while cladoceros were dominant in the deeper water, through the largest part of the time that sampling took place. The largest number of organism were found at sampling points seven and eight.

Las imágenes por resonancia magnética pesadas en difusión son ampliamente utilizadaspara el estudio de las estructuras cerebrales dentro de la materia blanca del cerebro. Sinembargo, recuperar las orientaciones de los axones puede ser susceptible a errores por elruido dentro de la señal. Una regularización espacial puede mejorar la estimación, perodebe ser realizada cuidadosamente dado que puede remover información espacial ó introducirfalsas orientaciones. En este trabajo se investigaron las ventajas de aplicar un filtroanisotrópico basado en simples y múltiples kerneles de orientación de manojos de axones.Para esto, hemos calculado kerneles locales de difusión basados en modelos de tensoresde difusión y multi tensores de difusión. Mostraremos los beneficios de nuestra propuestaen 3 tipos diferentes de imágenes obtenidas por resonancia magnética pesada en difusión:Datos sintéticos, imágenes humanas tomadas en vivo, y datos obtenidos de un fantasmasimulador de difusión.

This paper assesses the environmental education activities implemented in the Agronomy and Environmental Engineering Degrees at the University of Guanajuato. A survey pool was designed, tested and implemented on teachers responsible for subjects related to environmental education. Questions were asked about teaching and learning techniques, as well as jobs and tasks, practices and evaluation forms. These variables were evaluated by frequency and percentage. Teacher-centered education is promoted, and it is the teacher who outlines the course topics and asks for literature reviews; laboratory practice assists in the acquisition of the basics in the discipline, whereas in the case of Agronomy Engineering, field practice focuses on conservation of natural resources, and in the case of the Environmental Engineering, contextual visits are used; course evaluation is predominantly by testing. The paper concludes that the integration of environmental education is incipient, isolated and non-systematic at the level of the curricula.

In the present study, volatile compounds were recovered from the fresh leaves and stems ofcilantro (Coriandrum sativum L.) by two methods: Liquid-Solid Extraction (LSE) and SimultaneousDistillation-Extraction (SDE). The identification and quantification was done byGas Chromatography-Mass Spectrometry (GC-MS). Fourteen compounds were characterizedby LSE and GC-MS; whereas by SDE and GC-MS, they were twenty three compounds.The statistical analysis revealed significant quantitative differences (p ≤ 0,05) between theanalyzed techniques (LSE and SDE). In this work, the Simultaneous Distillation-Extractionshowed the greater identification and total concentration of volatile compounds. Aldehydes,monoterpenes, and alcohols comprised 78% of the volatile found for two methods, the restwere hydrocarbons. (E)-2-decenal was the most abundant compound in cilantro in bothextraction techniques.