Down and out or up and in? Polarization-based measures of the middle class for Latin America

This document presents a systematic review of empirical approaches to the identification and measurement of the middle class as the concept is used in the applied literature. It then presents an arguably less arbitrary definition of the middle class which is based on sound principles of distributional analysis and derived from income polarization measures. The document illustrates the differences between the existing approaches and the proposed methodology with a comparative analysis of the extent and evolution of the middle classes since the early 1990s in six Latin American countries. The polarization-based measurements of the middle class are shown to exhibit a greater degree of homogeneity in terms of some key socioeconomic characteristics than other measures employed in the literatureFil: Cruces, Guillermo Antonio. Universidad Nacional de La Plata. Facultad de Ciencias Económicas. Departamento de Ciencias Económicas. Centro de Estudios Distributivos Laborales y Sociales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Lopez Calva, Luis Felipe. Banco Mundial; Estados UnidosFil: Battistón, Diego Ezequiel. Universidad Nacional de La Plata. Facultad de Ciencias Económicas. Departamento de Ciencias Económicas. Centro de Estudios Distributivos Laborales y Sociales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin

Trade Costs and Job Flows: Evidence from Establishment-Level Data

We present evidence of the impact of input and output trade liberalization on establishment-level job flows. Using a longitudinal database containing the universe of manufacturing establishments in California from 1992 to 2004, we find that a decline in input or output trade costs causes job destruction in the least productive establishments, job creation in the most productive establishments, and an increase in the death likelihood of the least productive establishments. The evidence is consistent with predictions of models of trade with heterogeneous firms. We also show that input trade liberalization has larger effects on establishment-level job flows than output trade liberalization.Heterogeneous firms; Job flows; Trade costs

Analysis of genetic variability and mapping of point mutations in influenza virus by the RNase A mismatch cleavage method

We have applied the RNase A mismatch cleavage method to analyze genetic variability in RNA viruses by using influenza virus as a model system. Uniformly labeled RNA probes synthesized from a cloned hemagglutinin gene of a given viral strain were hybridized to RNA isolated from other strains of characterized or uncharacterized genetic composition. The RNA.RNA heteroduplexes containing a variable number of base mismatches were digested with RNase A, and the resistant products were analyzed by denaturing polyacrylamide gel electrophoresis. We show that many of these single base mismatches are cleaved by RNase A, generating unique and characteristic patterns of resistant RNA fragments specific for each of the different viral strains. Comparative analysis of the cleavage patterns allows a qualitative estimation of the genetic relatedness and evolution of field strains. We also show that cleavage by RNase A at single base mismatches can readily detect and localize point mutations present in monoclonal antibody-resistant variants. This method should have wide applications in the study of RNA viruses, not only for epidemiological analysis but also in some diagnostic problems, such as characterization of phenotypic mutants.This work was supported by National Institutes of Health Grant CA33021 awarded by the Nationa l Cancer Institute to M.P. and by grants from the Comision Asesora de Investigacion Cientificay Tecnica (Grant 608/438) and Fondo de Investigaciones Sanitarias to J.O. and J.A.M.C.L.-G. was a recipient of a NATO short-term post doctoral fellow-ship while on leave from the Centro Nacional de Microbiologia, Majadahonda, Madri

Plantas silvestres ornamentales comercializadas en los mercados de la flor de Tenancingo y Jamaica, México

En nuestro país se han adoptado todas aquellas especies ornamentales que son famosas en el mundo, incluyendo algunas representantes de México; sin embargo, todavía se tiene material genético ornamental con grandes posibilidades de insertase en el comercio de la horticultura ornamental. Debido a lo anterior, se elaboró un listado de plantas silvestres comercializadas en los mercados de la flor de Tenancingo, Estado de México y Jamaica, Distrito Federal, México. El trabajo se realizó durante la época de verano- otoño (21 de junio-21 de diciembre del 2007), en este periodo se visitó, cada 15 días durante seis meses el área de estudio con la finalidad de obtener ejemplares para su identificación taxonómica, se hicieron entrevistas y se registró: nombre común, lugar y fecha de recolecta, vendedor, lugar de comercialización y valor ornamental. La identificación taxonómica de las especies se realizó mediante el uso de claves disponibles en bibliografía. Como resultados se reportaron 131 especies silvestres, distribuidas en 42 familias y 93 géneros, donde Orchidaceae fue la más representativa a nivel de especies. En cuanto al valor ornamental de las especies se observó que es toda la planta la queproporciona el mayor valor ornamental con 41%. El 53% de las especies proviene del Estado de México. De todas las especies 3% están amenazadas y 2% en protección especial según la NOM-059- ECOL-2001

A PCR based method to detect Russula spp. in soil samples and Limodorum abortivum roots in Mediterranean environments

Aim of study. Orchidaceae has the largest number of species of any family in the plant kingdom. This family is subject to a high risk of extinction in natural environments, such as natural parks and protected areas. Recent studies have shown the prevalence of many species of orchids to be linked to fungal soil diversity, due to their myco-heterotrophic behaviour. Plant communities determine fungal soil diversity, and both generate optimal conditions for orchid development. Area of study. The work was carried out in n the two most important natural parks in Alicante (Font Roja and Sierra Mariola), in South-eastern of Spain. Material and Methods. We designed a molecular tool to monitor the presence of Russula spp. in soil and orchids roots, combined with phytosociological methods. Main results. Using a PCR-based method, we detected the presence in the soil and Limodorum abortivum orchid roots of the mycorrhizal fungi Russula spp. The species with highest coverage was Quercus rotundifolia in areas where the orchid was present. Research highlights. We present a useful tool based on PCR to detect the presence of Russula spp. in a natural environment. These results are consistent with those obtained in different studies that linked the presence of the mycorrhizal fungi Russula spp. in roots of the species Limodorum and the interaction between these fungal species and Quercus ilex trees in Mediterranean forest environments.This research was funded by the Spanish Ministry of Science and Innovation Grant AGL2008-00716/AGR and the Instituto Alicantino de Cultura Juan Gil-Albert

Editorial: Regulation and coordination of the different DNA damage responses and their role in tissue homeostasis maintenance

descripción no proporcionada por scopu

Competencias de los educadores físicos en su último año de formación: desde la teoría de la auto-eficacia

El presente trabajo de investigación trata el tema sobre las “Competencias percibidas de los Educadores Físicos en su último año de formación: desde la teoría de la auto-eficacia”. Tiene como propósito adaptar una escala para valorar las competencias docentes, en el contexto de las escuelas de formación profesional en México. Identificar las principales competencias que los estudiantes perciben al finalizar su carrera profesional y aquellas que los estudiantes perciben con menor grado de dominio desde la auto-eficacia. Se describen algunos estudios e investigaciones que tratan el tema de las competencias y de la auto-eficacia. También se menciona de manera especial a Albert Bandura padre y creador de la teoría de la auto-eficacia. Se presenta información sobre el origen de la auto-eficacia, como ha ido evolucionando y su adaptación (en este caso) en los educadores físicos Se presentan algunos criterios para la evaluación del desempeño docente, provenientes de aquellas competencias en educación que este ha adquirido a través del tiempo. Para lograr esta finalidad, en un primer momento se muestran los argumentos presentes que influyen sobre estas competencias y se identifican sus características principales; en un segundo apartado se apunta hacia la definición de las competencias, de la autoevaluación y de la auto-eficacia en una aproximación hacia las competencias docentes. Asimismo, se describen los criterios para desarrollar la evaluación en el contexto que plantean los nuevos desafíos para los sistemas educativos actuales, y también se expresan algunas consideraciones finales

IN VITRO EQUIVALENCE STUDY OF DIFFERENT DOSES OF CARBAMAZEPINE REFERENCE TABLETS USING USP APPARATUSES 2 AND 4

Objective: To perform an in vitro equivalence study of two doses of carbamazepine reference tablets sold in the local market under hydrodynamic conditions of USP Apparatus 4, a dissolution apparatus that better simulates the human gastrointestinal tract. Results were compared with dissolution official conditions using USP Apparatus 2. Methods: Dissolution profiles of both formulations were carried out with an automated USP Apparatus 2 at 75 rpm and 900 ml of dissolution medium. USP Apparatus 4 with laminar flow at 16 ml/min and 22.6 mm cells were used. 1% lauryl sulfate aqueous solution at 37.0±0.5 °C was used as dissolution medium. Spectrophotometric determination of drug at 285 nm was carried out during 60 min. Dissolution profiles were compared with model-independent and-dependent approaches. Results: When comparing dissolution profiles of low vs. high dose similar profiles were found (f2>50) in each dissolution apparatus, however, when the same dose was compared, USP 2 vs. USP 4, opposite results were obtained. Comparison of mean dissolution time and dissolution efficiency data corroborates these results. Weibull function was the best mathematical model that described the in vitro dissolution performance of carbamazepine. No significant differences were found in Td values (low vs. high dose) but opposite results were also found with USP 2 vs. USP 4. Conclusion: Equivalent dissolution performance of two doses of carbamazepine reference tablets were found in each USP dissolution apparatus. The main problem identified in this comparative study is the low dissolution rate and extent found with USP Apparatus 4. More research on this field is necessary for all available doses of reference drug products since the quality of generic formulations depends on the quality of references