Pick a Number … Any Number?

A recent classroom revelation caused us to reconsider the adequacy of the instructions offered in our textbooks for one of our most elementary quantitative methods. Specifically, we found that many students were mystified concerning how to pick an initial objective function value when plotting an isoprofit line in order to graphically solve a linear programming problem. We observed that this seemingly insignificant issue was causing a surprising amount of wasted time, confusion, and even anxiety. Our experience indicated that students do not necessarily possess any consistent intuition for choosing an appropriate initial value. We confirmed this perception through informal experimentation. We reviewed several textbooks and found that most simply do not bother to address this issue. Therefore, we devised a simple, comprehensible method which we have taught our students to resolve or avoid this problem. Although we quickly found the method to be helpful for many students, we conducted an experiment to formally measure its effect.     

Social Guarantee Programme: principles for classroom procedure with students who have suffered failure at school – the Spanish educational system case

The article explores the Social Guarantee Programmes, one measure at attending to diversity within the Spanish educational system. It is an alternative measure that aims to break away from the organisational structure of Obligatory Secondary Education, seeking an organisational model and educational strategies that pursue satisfactory results through motivation, interest and the recovery of the student’s self‐esteem. The article presents the obtained results following ethnographic case study methodology. The research was performed in a secondary education school in a town in the province of Cadiz, Andalusia, Spain. The group chosen suffered significant learning difficulties and problems in adapting to schools. Our intention was to analyse and understand the relevant educational practices in the context of these programmes, since they were so innovative in nature.     

Effect of <Emphasis Type="SmallCaps">l</Emphasis>-Thyroxine on Micronuclei Frequency in Peripheral Blood Lymphocytes in Clinical and Experimental Conditions

The aim was to study the genotoxic effect of high concentration of thyroxine (T₄) in vivo in peripheral blood lymphocytes (PBL) of the patients suffering from thyroid disorders. The effect was compared by performing in vitro experiments with addition of increasing concentration of T₄ (0.125–1 µM) in whole blood samples from healthy donors. Cytokinesis-blocked micronuclei (CBMN) assay method was used to assess the DNA damage in the PBL. The study included 104 patients which were grouped as control (n = 49), hyperthyroid (n = 31) and hypothyroid (n = 24). A significant increase in micronuclei (MN) frequency was observed in hyperthyroid patients when compared with the hypothyroid and euthyroid group thereby suggesting increased genotoxicity in hyperthyroidism (p < 0.001). A significant increase in MN frequency was observed at T₄ concentration of 0.5 µM and above when compared to lower T₄ concentrations (0.125 and 0.25 µM) and basal in in vitro experiments (p = 0.000). The results indicate that the T₄ in normal concentration does not exhibit the genotoxic effect, as observed in both the in vivo and in vitro experiments. The toxicity of T₄ increases at and above 0.5 μM concentration in vitro. Therefore acute T₄ overdose should be handled promptly and effectively so as to avoid the possible genotoxic effect of high concentration of T₄ in vivo.     

Turkish Prospective Chemistry Teachers’ Beliefs about Chemistry Teaching

Given the progressive loss of influence for the school relative to television in youngsters’ everyday lives, this article describes the procedure and the results of including cartoons in the physics curriculum in secondary education. Work was carried out intensively with a small group of pupils and sporadically with a larger group. In the first case, cartoons were used for identifying and discussing fictitious phenomena, problem‐solving, and assessment of the learning. In the second case, for identifying and discussing fictitious phenomena, a quasi‐experimental research design was followed. The results back the use of this didactic tool as an element for motivating and invigorating the classroom, for identifying the pupils’ alternative ideas and the assessment of their learning, as well as for a more critical way of watching television.