Introducción a la genética en la enseñanza secundaria y bachillerato : I. Contenidos de enseñanza y conocimientos de los alumnos

In this paper an analysis is made of some of the causes which can hinder the students' learning of genetics at Secondary Leve1 (12-17 years). This research study highlights the need of introducing changes in content at syllabus design level, and shows that students have a slight knowledge of heredity, although the basic tenets are very often wrong, even before they have their first contact with the subject as academic content at school

Alternativas a la enseñanza de la genética en Educación Secundaria

En este artículo se analizan algunas referencias importantes para la enseñanza de la genética en la ESO. Considerando que los estudiantes aprenden a partir de lo que ya saben, se examinan sus concepciones cuando inician sus contactos académicos con la herencia biológica, se aportan criterios para seleccionar y secuenciar los contenidos relacionados con la localización, la transmisión y los cambios de la herencia biológica y se analizan las características que podrían tener las actividades de enseñanza para favorecer el aprendizaje de los estudiantes.In this paper we analyse some important issues related with teaching Genetics in secondary school. Starting from the premise that students' learning is based on prior knowledge, we examine the students' ideas on the location, transmission and changes in biological inheritance, before starting their first academic course on Genetics. Taking into account such knowledge, we establish several criteria for selecting and sequencing the teaching contents and analyse any characteristics that the learning activities might have to improve students' knowledge of Genetics

Introducción a la genética en la enseñanza secundaria y bachillerato : II. ¿Resolución de problemas o realización de ejercicios?

In this paper we analize the level of knowledge students have at different educational levels (15-18 years), about some basic concepts related to genetic inheritance. The strategies developed by students when solving, successfully, genetic problems have also been studied. The results show the difficulties in learning through problem-solving activities. Consequently, very often, their posings (even those of cause-effect approach) allow them to find the right solution by applying the correspondent algorithm. As a conclusion, some suggestions to change the students' position on genetic problems are presented

High intensity interval training exercise-induced physiological changes and their potential influence on metabolic syndrome clinical biomarkers: a meta-analysis

Abstract: Background: Despite the current debate about the effects of high intensity interval training (HIIT), HIIT elicits big morpho-physiological benefit on Metabolic Syndrome (MetS) treatment. However, no review or meta-analysis has compared the effects of HIIT to non-exercising controls in MetS variables. The aim of this study was to determine through a systematic review, the effectiveness of HIIT on MetS clinical variables in adults. Methods: Studies had to be randomised controlled trials, lasting at least 3 weeks, and compare the effects of HIIT on at least one of the MetS clinical variables [fasting blood glucose (BG), high-density lipoprotein (HDL-C) triglyceride (TG), systolic (SBP) or diastolic blood pressure (DBP) and waist circumference (WC)] compared to a control group. The methodological quality of the studies selected was evaluated using the PEDro scale. Results: Ten articles fulfilled the selection criteria, with a mean quality score on the PEDro scale of 6.7. Compared with controls, HIIT groups showed significant and relevant reductions in BG (− 0.11 mmol/L), SBP (− 4.44 mmHg), DBP (− 3.60 mmHg), and WC (− 2.26 cm). Otherwise, a slight increase was observed in HDL-C (+ 0.02 mmol/L). HIIT did not produce any significant changes in TG (− 1.29 mmol/L). Conclusions: HIIT improves certain clinical aspects in people with MetS (BG, SBP, DBP and WC) compared to people with MetS who do not perform physical exercise. Plausible physiological changes of HIIT interventions might be related with large skeletal muscle mass implication, improvements in the vasomotor control, better baroreflex control, reduction of the total peripheral resistance, increases in excess post-exercise oxygen consumption, and changes in appetite and satiety mechanisms

Interdigitated ring electrodes: Theory and experiment

The oxidation of potassium ferrocyanide, K_4Fe(CN)_6, in aqueous solution under fully supported conditions is carried out at interdigitated band and ring electrode arrays, and compared to theoretical models developed to simulate the processes. Simulated data is found to fit well with experimental results using literature values of diffusion coefficients for Fe(CN)_6^(4-) and Fe(CN)_6^(3-). The theoretical models are used to compare responses from interdigitated band and ring arrays, and the size of ring array required to approximate the response to a linear band array is investigated. An equation is developed for the radius of ring required for a pair of electrodes in a ring array to give a result with 5% of a pair of electrodes in a band array. This equation is found to be independent of the scan rate used over six orders of magnitude

Efecto de la vitamina e en la alimentación del pavo en la acumulación tisular y estabilidad oxidativa.

El presente trabajo pretende evaluar la efectividad de las formas naturales de vitamina E en la acumulación tisular de tocoferol, así como en la estabilidad oxidativa in vivo y postmortem. El único factor de diferenciación fue el tipo de vitamina E (natural vs sintética) y concentración (Baja: 40 ppm y alta: 120 ppm) en el pienso. Adicionalmente se produjo un grupo control sin vitamina E añadida en el pienso. Se ha observado una relación dosisrespuesta lineal en la concentración de tocoferol en el plasma de los pavos, así como una tendencia (P=0.139) hacia una mayor concentración en los animales que recibieron la vitamina E en forma natural.. Existe una relación entre la concentración de tocoferol y de Metamioglobina en el músculo en el día 9 de almacenamiento refrigerado, evidenciándose una mayor efectividad de la forma natural. Se ha observado una menor concentración de ácidos grasos saturados en el grupo control y el de bajo nivel de suplementación. Asimismo, existe una tendencia hacia una menor concentración d estos ácidos grasos en los animales que reciben la forma natural de vitamina E (P=0,0658)

Photoelectron recoil in CO in the x-ray region up to 7 keV

Carbon 1s photoelectron spectra of CO molecules in gas phase were recorded in the tender x-ray energy range, from 2.3 to 6.9 keV. The intensity ratios of individual peaks from ν=0 to 3 within the vibrational progression of the C 1s photoelectron spectrum were determined at the various photon energies and are shown to be strongly affected by the photoelectron recoil effect. The experimental vibrational intensity ratios are compared with theoretical predictions at different levels of accuracy. Developments of the recoil model, using generalized Franck-Condon factors, rovibrational coupling, Morse potential energy curves, and accurate angular averaging are presented and applied to the analysis of the experimental results

Not all shellfish "allergy" is allergy!

The popularity of shellfish has been increasing worldwide, with a consequent increase in adverse reactions that can be allergic or toxic. The approximate prevalence of shellfish allergy is estimated at 0.5-2.5% of the general population, depending on degree of consumption by age and geographic regions. The manifestations of shellfish allergy vary widely, but it tends to be more severe than most other food allergens