L. Aguilar-Santelises

Flavonoids and antioxidant activity of flowers of Mexican Crataegus spp.

Flavonoids and antioxidant activity of extracts of flowers from some Mexican accessions of Crataegus were studied using six accessions with the purpose of contributing to the knowledge of the nutraceutical properties of the accessions of the Germplasm Bank of the Universidad Autonoma Chapingo. Flavonoids were identified by HPLC–MS. Among the flavonoids, the quercetin 3-O-glucoside (3), quercetin 3-O-rhamnoside (4), quercetin 3-O-rhamnosyl-(1 → 6)-glucoside (2) and quercetin 3-O-rhamnosyl-(1 → 2)-[rhamnosyl-(1 → 6)]-glucoside (1) were assigned. Flavonoid content and radical scavenging activity explain some of the medicinal properties attributed to flowers of Mexican hawthorns.

STRATEGIES FOR TEACHING STATISTICS BASED ON COLLABORATIVE WORK AND PROBLEM SOLVING

Various strategies may be applied for teaching statistics. Lectures, equipment, teamwork and guidance are all important to help students to become capable of using statistics to analyse their own work and the results produced by others. Students following the second year from the Chemistry Pharmacology and Biology curricula (QFB) in the Faculty for Higher Studies Zaragoza (FES-Z), UNAM start becoming familiar with simple concepts and procedures, such as percentage, average, mean, median, standard deviation, standard error, confidence intervals and probability. They also learn to correctly elaborate standard curves and to interpret both graphically and statistically the results of their experiments. Our university provides wired and inalambric facilities for a wide and fast access to the institutional and public networks. The information can be accessed from various devices, like tablets, smartphones, personal and institutional computers. Thus, the students can connect, search, upload, download and interact in various ways through digital means. Our institution’s policy is to guarantee that limited access or insufficient knowledge of information and communication technologies (ICT) will not be a barrier for our students. Instead, they may benefit from state-of-the art digital communication systems and guided learning to use them properly [1]. The students receive files containing full information about experiments designed to answer specific questions. Then, by using their knowledge on statistical procedures and interpretation of results, they must describe, analyse and conclude if the experiments have been properly performed and what is the significance of the results. Teams of 4 or 6 students are formed in order to promote exchange of information, collaboration and discussion. Teachers are always following their progress, making comments and helping them to resolve their doubts [2]. This tutorial-guided students’ teamwork stimulates and promotes critical analysis of information and problem solving thinking [3]. Students’ capacity to develop critical thinking and proper application of statistics are both important qualities for a solid academic development.