Improving Human Learning in The Classroom : Theories and Teaching Practices

25 cm;235 ha

Evaluación de las líneas de gallinas ponedoras Hy-Line CV-22® y Dekalb White® en un sistema de semipastoreo en Zamorano, Honduras

26 p.El estudio se realizó en la Unidad de Agricultura Orgánica de la Escuela Agrícola Panamericana Zamorano entre los meses de octubre de 2013 y julio de 2014. Se utilizaron 90 aves ponedoras de 33 semanas de edad, 43 aves de la línea Hy-Line CV-22® y 47 Dekalb White®. El objetivo fue evaluar la adaptabilidad de las líneas Hy-Line CV- 22® y Dekalb White® en un sistema de semipastoreo considerando las variables de postura (%), calidad física de huevo de mesa, consumo de alimento (g/ave), mortalidad (%) y peso corporal (kg/ave). Para la calidad física de huevo de mesa se evaluaron las categorías de huevo fresco y con diez días de almacenamiento en refrigeración y ambiente bajo los parámetros: peso de huevo (g), altura de albumina (mm), unidades Haugh, fuerza de quebradura (Instron), color de yema (escala de Roche) y grosor de cáscara (mm). La postura promedio para Hy-Line CV-22® fue de 82.8% y para Dekalb White® de 88.8% a la semana 66 de edad del ave. En el sistema de semipastoreo, la línea Hy-Line CV-22® obtuvo mejores resultados, en todas las condiciones, en las pruebas físicas de huevo en las categorías de peso de huevo (g), altura de albumina (mm), unidades Haugh y color (Roche 2000); la línea Dekalb White® fue superior en fuerza de quebradura (Instron) y grosor de cáscara (mm). Existió una disminución de calidad en cada una de las categorías evaluadas como peso del huevo (PH), altura de albumina (AA) y unidades Haugh (UH) en huevos con diez días de almacenamiento en ambiente y refrigerado con respecto a huevos fresco

Prevalence of asthma, atopy and bronchial hyperresponsiveness and their interrelation in a semi-rural area of Chile

OBJECTIVE: To assess the prevalence of asthma symptoms and their association with sensitisation to eight allergens and bronchial hyperresponsiveness (BHR) to methacholine. SETTING: A random sample of 1232 adults, aged 22 to 28 years, studied in a Chilean semi-rural area. DESIGN : A cross-sectional design for the purpose of this analysis. RESULTS: The prevalence of wheeze was 27.4% (95%CI 24.9-29.9) and waking with breathlessness 13.7% (95%CI 11.8-15.6), higher than the results of a multi-centre European study. Only 7.8% (95%CI 6.3-9.3) had a positive BHR (≤8 mg/ml) and 26.3% (95%CI 23.8-28.8) were atopic. The Youden index of asthma symptoms in non-atopic subjects varied from 0.184 to 0.259 when using BHR as gold standard for asthma, and increased from 0.379 to 0.504 among those with positive atopy. Only 4.5% reported asthma, and the Youden index was slightly higher in comparison to the asthma symptom groups. CONCLUSION: The prevalence of asthma symptoms in young adults was high, but o

Impact of specific sensitization on asthma and rhinitis in young Brazilian and Chilean adults

Background The pattern of associations and the attributable fractions (AF) of atopic conditions due to specific sensitizations vary between countries. Objective To assess the level of associations and AF between sensitization to five allergens and atopic conditions in two settings. Methods We studied 2063 Brazilians and 1231 Chileans of both sexes using representative samples selected at birth in the 1970s. Information on asthma and rhinitis was based on the European Community Respiratory Health Survey questionnaire. We assessed bronchial hyperresponsiveness (BHR) to methacholine and sensitization to Dermatophagoides pteronyssinus, cat, dog, grass blend and Alternaria alternata. Results The prevalence of sensitization to one or more allergens was 50% in Brazilians and 22% in Chileans. The level of associations varied according to the outcome used. Strong associations between sensitization and asthma, defined as wheeze or awakening with breathlessness at night and positive BHR, were found for each of the five allergens in Chileans [varying from odds ratio (OR) 3.24, 95% confidence interval (CI) 1.47, 7.15 for D. pteronyssinus to 8.44, 95% CI 3.82, 18.66 for cat], whereas the level of associations was restricted to D. pteronyssinus, cat and dog in Brazilians and was somewhat weaker (highest OR 3.90, 95% CI 2.80-5.44). The AF of sensitization on asthma was 54% in Brazil and 44% in Chile. D. pteronyssinus and cat made an independent contribution to asthma in the two samples. The patterns of associations between sensitization and rhino-conjunctivitis were similar to those for asthma. Conclusion The associations between sensitization, and asthma and rhinitis were high in Chile and moderately high in Brazil, but the AF were higher in Brazil, reflecting a higher prevalence of sensitization. In Brazil, dust mite had the greatest impact on atopic conditions while in Chile several allergens had an impact. Sensitization is as serious a problem in Chile and Brazil as in developed countries.National Fund for Scientific and Technological Development (FONDECYT)[1010572]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[2000/09508-7