Una investigación en las aulas de inglés como lengua extranjera en centros mejicanos: el asunto de acceso

This paper aims to contribute to the understanding of the process of gaining entry into Mexican English Language classrooms. After a very brief discussion of the basic concepts involved in the process of asking for permission to carry out research in educational settings, it then tells the story of our first-hand experience of gaining entry into public (and several private) preparatory schools in one city on the east coast of Mexico by starting at the top of the educational hierarchy at state level and working our way down into the actual English language classrooms. The paper finishes by raising some general issues that grew out of our anecdotal experience and that we claim may resonate or be helpful for other researchers approaching real EFL classrooms wishing to gain understanding of what is going on in practice in similar educational contexts.En este artículo queremos compartir nuestras experiencias sobre aspectos claves al hacer trabajo de campo en salones de lenguas extranjeras en contextos educativos en México. Particularmente nos centramos en el proceso de negociación de acceso y entrada a las aulas, tanto públicas como privadas, en donde se enseña/aprende el inglés como lengua extranjera. Desafortunadamente, en los estudios etnográficos que se han llevado a cabo en escuelas en México y que han sido publicados, este aspecto vital de la investigación cualitativa ha merecido, si acaso, una mínima descripción de qué y cómo se pudo, o no, conseguir el permiso. Reconocemos que, aunque cada contexto requiere de una aproximación única, creemos que nuestras experiencias resonarán y podrán ser de utilidad para nuevos investigadores en contextos similare

Conjugated linoleic acid reduces permeability and fluidity of adipose plasma membranes from obese Zucker rats

NOTICE: this is the author’s version of a work that was accepted for publication in Biochemical and Biophysical Research Communications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Biochemical and Biophysical Research Communications. July 2010; 398 (2): 199-204.Conjugated linoleic acid (CLA) is a dietary fatty acid frequently used as a body fat reducing agent whose effects upon cell membranes and cellular function remain unknown. Obese Zucker rats were fed atherogenic diets containing saturated fats of vegetable or animal origin with or without 1% CLA, as a mixture of cis(c)9,trans(t)11 and t10,c12 isomers. Plasma membrane vesicles obtained from visceral adi- pose tissue were used to assess the effectiveness of dietary fat and CLA membrane incorporation and its outcome on fluidity and permeability to water and glycerol. A significant decrease in adipose membrane fluidity was correlated with the changes observed in permeability, which seem to be caused by the incor- poration of the t10,c12 CLA isomer into membrane phospholipids. These results indicate that CLA supple- mentation in obese Zucker rats fed saturated and cholesterol rich diets reduces the fluidity and permeability of adipose membranes, therefore not supporting CLA as a body fat reducing agent through membrane fluidification in obese fat consumers

Garantir a validade de conteúdo na construção de instrumentos: O caso do Cenas para Processamento de Informação Social na Adolescência

The Scenes for Social Information Processing in Adolescence (SSIPA) proposes to evaluate several cognitive steps suggested by the social information processing model, in addition to considering emotional states that may interfere with such rational processing of information. Psychometric evaluation of this instrument points to its construct validity but very little information was given on its construction process so as to guarantee that, as claimed, it accurately reflects the adolescents’ unique social experiences. The current work presents detailed information on the three steps undertaken to develop the SSIPA: 1) three focus groups with a total of 23 adolescents and use of their verbalizations for item generation; 2) examination of the face validity of the items by 7 experts, who rated each item according to the content it was intended to evaluate, and 3) evaluation of test usability, understandability, and overall pertinence by a new sample of 23 adolescents. Focus groups and item evaluation procedures were considered optimal tools in helping to formulate items that surpass the initial acceptability threshold and accurately grasp the social information processing of adolescents, resulting in an innovative and psychometrically robust assessment instrument, potentially useful in clinical assessment and research.O Cenas para Processamento de Informação Social na Adolescência (SSIPA) propõe avaliar diversos passos cognitivos sugeridos pelo modelo de processamento de informação social, além de considerar estados emocionais que podem interferir com este processamento racional. A avaliação psicométrica deste instrumento aponta para a sua validade de constructo, mas muito pouca informação foi avançada acerca do seu processo de construção, de forma a garantir que reflete adequadamente, como se propõe, as experiências sociais únicas de adolescentes. Este trabalho apresenta informação detalhada acerca dos três processos que foram considerados para desenvolver o SSIPA: 1) três grupos focais com um total de 23 adolescentes e utilização das suas verbalizações para construção de itens; 2) análise da validade facial dos itens por 7 peritos, que avaliaram cada item de acordo com o conteúdo pretendido para cada item, e 3) avaliação da usabilidade, compreensibilidade e pertinência geral do instrumento numa nova amostra de 23 adolescentes. Os grupos focais e a avaliação dos itens constituíram ferramentas apropriadas para construir itens que cumprissem o princípio de aceitabilidade inicial e captassem com precisão o processamento de informação social de adolescentes, resultando num instrumento inovador e psicometricamente robusto, passível de utilização em contextos clínicos e de investigação

Green roofs runoff coefficient: different time-scale approaches to estimate its value

info:eu-repo/semantics/publishedVersio

Extensive green roofs: different time approaches to runoff coefficient determination

Stormwater runoff in green roofs (GRs) is represented by the runoff coefficient, which is fundamental to assess their hydraulic performance and to design the drainage systems downstream. Runoff coefficient values in newly installed GR systems should be estimated by models that must be feasible and reproduce the retention behavior as realistically as possible, being thus adjusted to each season and climate region. In this study, the suitability of a previously developed model for runoff coefficient determination is assessed using experimental data, and registered over a 1 year period. Results showed that the previously developed model does not quite fit the experimental data obtained in the present study, which was developed in a distinct year with different climate conditions, revealing the need to develop a new model with a better adjustment, and taking into consideration other variables besides temperature and precipitation (e.g., early-stage moisture conditions of the GR matrix and climate of the study area). Runoff coefficient values were also determined with different time periods (monthly, weekly, and per rain event) to assess the most adequate approach, considering the practical uses of this coefficient. The monthly determination approach resulted in lower runoff coefficient values (0–0.46) than the weekly or per rain event (0.017–0.764) determination. When applied to a long-term performance analysis, this study showed no significant differences when using the monthly, weekly, or per rain event runoff, resulting on a variation of only 0.9 m3 of annual runoff. This indicates that the use of monthly values for runoff coefficient, although not suitable for sizing drainage systems, might be used to estimate their long-term performance. Overall, this pilot extensive GR of 0.4 m2 presented an annual retention volume of 469.3 L, corresponding to a retention rate of 89.6%, in a year with a total precipitation of 1089 mm. The assessment of different time scales for runoff coefficient determination is a major contribution for future GR performance assessments, and a fundamental decision support tool.info:eu-repo/semantics/publishedVersio

Green roofs runoff coefficient: different time-scale approaches to estimate its value

The high impermeabilization in densely populated areas brings numerous problems concerning stormwater management, mainly when intense precipitation events occur. This is frequent in the beginning of the winter/rainy season in the Mediterranean region, namely in Portugal. Implementation of nature-based solutions in general, and green roofs in particular, can minimize the damages caused by such events in urban areas. The reduction of stormwater runoff in Green Roofs (GR), can be estimated with the runoff coefficient, a parameter that assesses their hydraulic performance and contributes to the design of the drainage systems downstream. Due to their natural characteristics, GR have variable performance throughout the year and so models used to determine runoff coefficients should reproduce this behaviour as realistically as possible, adjusted to each season and climate region. In this study, monthly runoff coefficient determination, using experimental data, was assessed through the use of a previous developed model. Runoff coefficient was also determined using different time periods (monthly, weekly and per rain events) to assess the most adequate approach, considering the practical uses of this coefficient. The monthly determination approach resulted in lower runoff coefficient values, than the weekly or per rain-event determination. However, when applied to a long-term performance analysis, this study showed no significant differences when using the monthly, weekly or per rain-event runoff. Furthermore, the results revealed the need to improve the model for extensive Green Roofs determination, taking into consideration other variables besides temperature and precipitation (e.g. early-stage moisture conditions of the GR matrix). The assessment of different time scales for runoff coefficient determination is a major contribution for GR future performance assessment, and a fundamental decision support tool.info:eu-repo/semantics/publishedVersio

Cork processing wastewater treatment/valorisation by nanofiltration

Nanofiltration process for the treatment/valorisation of cork processing wastewaters was studied. A DS-5 DK 20/40 (GE Water Technologies) nanofiltration membrane/module was used, having 2.09 m(2) of surface area. Hydraulic permeability was determined with pure water and the result was 5.2 L.h(-1).m(-2).bar(-1). The membrane presents a rejection of 51% and 99% for NaCl and MgSO4 salts, respectively. Two different types of regimes were used in the wastewaters filtration process, total recycling mode and concentration mode. The first filtration regime showed that the most favourable working transmembrane pressure was 7 bar working at 25 degrees C. For the concentration mode experiments it was observed a 30% decline of the permeate fluxes when a volumetric concentration factor of 5 was reached. The permeate COD, BOD5, colour and TOC rejection values remained well above the 90% value, which allows, therefore, the concentration of organic matter (namely the tannin fraction) in the concentrate stream that can be further used by other industries. The permeate characterization showed that it cannot be directly discharged to the environment as it does not fulfil the values of the Portuguese discharge legislation. However, the permeate stream can be recycled to the process (boiling tanks) as it presents no colour and low TOC (< 60 ppm) or if wastewater discharge is envisaged we have observed that the permeate biodegradability is higher than 0.5, which renders conventional wastewater treatments feasible

UCP2 and ANT differently modulate proton-leak in brain mitochondria of long-term hyperglycemic and recurrent hypoglycemic rats

A growing body of evidence suggests that mitochondrial proton-leak functions as a regulator of reactive oxygen species production and its modulation may limit oxidative injury to tissues. The main purpose of this work was to characterize the proton-leak of brain cortical mitochondria from long-term hyperglycemic and insulininduced recurrent hypoglycemic rats through the modulation of the uncoupling protein 2 (UCP2) and adenine nucleotide translocator (ANT). Streptozotocin-induced diabetic rats were treated subcutaneously with twice-daily insulin injections during 2 weeks to induce the hypoglycemic episodes. No differences in the basal proton-leak, UCP2 and ANT protein levels were observed between the experimental groups. Mitochondria from recurrent hypoglycemic rats presented a decrease in proton-leak in the presence of GDP, a specific UCP2 inhibitor, while an increase in proton-leak was observed in the presence of linoleic acid, a proton-leak activator, this effect being reverted by the simultaneous addition of GDP. Mitochondria from longterm hyperglycemic rats showed an enhanced susceptibility to ANT modulation as demonstrated by the complete inhibition of basal and linoleic acid-induced proton-leak caused by the ANT specific inhibitor carboxyatractyloside. Our results show that recurrent-hypoglycemia renders mitochondria more susceptible to UCPs modulation while the protonleak of long-term hyperglycemic rats is mainly modulated by ANT, which suggest that brain cortical mitochondria have distinct adaptation mechanisms in face of different metabolic insults.The authors’ work is supported by the Fundação para a Ciência e a Tecnologia (FCT) (PTDC/SAU-NEU/103325/2008) co-funded by Fundo Europeu de Desenvolvimento Regional (FEDER) via Programa Operacional Factores de Competitividade (COMPETE). Susana Cardoso has a PhD fellowship from the Portuguese Foundation for Science and Technology (SFRH/BD/43968/2008)

Propolis microencapsulation by double emulsion solvent evaporation approach: Comparison of different polymeric matrices and extract to polymer ratio

Propolis, a heterogeneous matrix produced by honeybees, is an antioxidant amongst other valuable biological properties. Nevertheless, the practical application of propolis, especially for the food industry, is still limited due to its relative high hydrophilicity and strong/unpleasant taste and aroma. Accordingly, microencapsulation arises a potential alternative approach to protect propolis compounds while allowing to mask its unpleasant sensory properties. The purpose of this study was to microencapsulate propolis extracts in lipophilic polymer-carriers using alternative propolis extract to polymer ratios – 1/4, 1/2 and 3/4 – by double emulsion solvent evaporation approach. The product yield was higher than the previously reported in the literature (80.3 ± 3.7% versus 68%). The encapsulation efficiencies (considering the encapsulated antioxidants and phenolic compounds) were independent from the propolis extract to polymer ratio, for the studied lipophilic polymer-carriers. The results of this work provide promising approaches for the manufacture of propolis extracts-loaded microparticles for further incorporation in functional matrices.info:eu-repo/semantics/publishedVersio