The VIII Region of Bio-Bio is a major fruit-growing area of Chile that makes intensive use of agricultural pesticides. The cytogenetic damage associated with exposure to mixtures of pesticides was evaluated by comparing peripheral blood lymphocyte micronucleus (MN) frequencies in a group of 64 female agricultural workers and 30 female controls. The exposed subjects worked during the spring and summer in thinning and pruning fruit trees and in harvesting and packing different fruits, such as raspberries, grapes, apples, and kiwis. They did not use any protective measures during their work activities. A significant increase in the frequency of binucleated cells with micronuclei (BNMN) was found in the exposed women as compared with the controls (36.94 +/- 14.47 vs. 9.93 +/- 6.17 BNMN/1000 BN cells; P < 0.001). The frequency of BNMN varied as a function of age in both the exposed and control groups, but no correlation was found between BNMN frequency and the duration of exposure. Also, smoking and other habits had no effect on MN frequency. Our study confirms that occupational exposure to pesticide mixtures results in cytogenetic damage.

Este trabajo presenta el diseño de una asignatura virtual de biología celular de pregrado y su implementación e la plataforma Moodle. Se analiza también el grado de satisfacción por de los estudiantes mediante la aplicación de un cuestionario de satisfacción. Un total de 223 alumnos participaron voluntariamente en la asignatura virtual y completaron el cuestionario. Esta información permitió determinar la percepción de los estudiantes sobre el entorno virtual. Los estudiantes tuvieron una positiva aceptación y valoración del curso virtual como complemento importante a la clase presencial. Además se observó participación más activa en el aula que se tradujo en un mejor rendimiento académico.

Problem-based learning using authentic material from the web was used to teach metabolism in a biochemistry course. In place of traditional lectures, students' analyzed health or nutrition articles from newspapers and magazines, which were debatable from a scientific point of view, following the principles of problem-based learning. A mixed method was used to assess the students' perception, use of sources of information and web services while performing the task, and changes in self-directed learning. Students' perception was particularly positive. The majority stated that the methodology helped them to apply knowledge to real life and that they learned about the topic analyzed by their group. The perception that problem-based learning promotes the ability to solve problems, critical thinking, and collaborative work is noteworthy. Tutors considered that teams identified the problem and concluded correctly, noticing students' enthusiasm and motivation. The methodology also promoted scientific reading. More importantly, a significant improvement in self-directed learning of the 2014 cohort was detected. This intervention suggests that this methodology is a valuable alternative to motive and promote self-learning; representing an opportunity to shift the focus of instruction from the teacher to the student. The design of the activity and materials are described in detail. Also, limitations and solutions are discussed.

Written tests improved after an intervention aiming to improve the teachers' skills to prepare such tests.

Las webquests son metodologías de enseñanza útiles para motivar a los alumnos durante el proceso de enseñanza-aprendizaje.Se elaboró un recurso basado en TICs denominado “Webquest: Genética Humana para estudiantes del área Biomédica” y se implementó para contenidos de Genética.Se demostró un alto grado de satisfacción en el uso del recurso, lo que indica la utilidad en incorporar  metodologías innovadoras mediante el uso de TICs en la docencia de pregrado.