Ageing of brazilwood dye in wool – a chromatographic and spectrometric study

Brazilwood was used in this work to dye wool mordanted with different amounts of copper(II) sulfate, alum and iron(II) sulfate. Two different dyeing methods were used: premordanting (MD) and simultaneous mordanting (M+D) procedures. In order to evaluate the influence of the mordant ion in the brazilein chromophore photodegradation, samples were subjected to artificial light ageing. Color measurements were made and, for the first time, LC-DAD-ESI-MS was used for chromophore analysis of the dyed fibers before and after light exposure. Mordant ion quantification was done after fiber acid digestion, by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and flame atomic absorption spectroscopy (FAAS). Mordant metal ion, mordant bath concentration and dyeing procedure were found to have strong influence in the wool fiber hues. Color variation was more pronounced in the alum dyed samples. Overall, mordant quantification showed that the amount of metal ions found in the fibers is very small when compared to the original concentrations of the dyeing bath, being Cu the ion with greater affinity for the wool fibers. MD dyeing procedure yielded fibers with larger amounts of mordant metal ions and higher chromophore peak areas. Higher amounts of brazilein were extracted from wool mordanted with copper(II) sulfate. Finally, chromatographic analysis of the brazilwood dyed samples before and after light exposure resulted in the detection of Type C compound as an outcome of the photodegradation process.     

Scientific Skills as Core Competences in Medical Education: What do medical students think?

Background: Scientific excellence is one of the most fundamental underpinnings of medical education and its relevance is unquestionable. To be involved in research activities enhances students' critical thinking and problem-solving capacities, which are mandatory competences for new achievements in patient care and consequently to the improvement of clinical practice. Purposes: This work aimed to study the relevance given by Portuguese medical students to a core of scientific skills, and their judgment about their own ability to execute those skills. Methods: A cross-sectional study was conducted on students attending the first, fourth and sixth years of medical course in the same period. An assessment istrument, exploring the importance given by Portuguese medical students to scientific skills in high school, to clinical practice and to their own ability to execute them, was designed, adapted and applied specifically to this study. Results: Students' perceptions were associated with gender, academic year, previous participation in research activities, positive and negative attitudes toward science, research integration into the curriculum and motivation to undertake research. The viewpoint of medical students about the relevance of scientific skills overall, and the ability to execute them, was independently associated with motivation to be enrolled in research. Conclusions: These findings have meaningful implications in medical education regarding the inclusion of a structural research program in the medical curriculum. Students should be aware that clinical practice would greatly benefit from the enrollment in research activities. By developing a solid scientific literacy future physicians will be able to apply new knowledge in patient care.     

Science curricula design: analysis of authors’ ideological and pedagogical principles

The study analyses the extent to which the sociological message transmitted by the Official Pedagogic Discourse of the curriculum for Portuguese middle schools contains the ideological and pedagogical principles of its authors. The research is epistemologically and sociologically grounded, placing particular emphasis on Bernstein theory of pedagogic discourse. The ideological principles underlie broad educational aims and the pedagogical principles underlie characteristics of the pedagogic practice. Data was obtained through a semi‐structured interview with the authors and documental analysis of their publications. The results suggest that the authors were distinct in the ideological and pedagogical principles they valued and that discontinuities were evident between those principles and the curriculum message. These results are discussed and their consequences in terms of scientific learning are explored.     

Student perspectives of imaging anatomy in undergraduate medical education

Radiological imaging is gaining relevance in the acquisition of competencies in clinical anatomy. The aim of this study was to evaluate the perceptions of medical students on teaching/learning of imaging anatomy as an integrated part of anatomical education. A questionnaire was designed to evaluate the perceptions of second‐year students participating in a clinical anatomy course over three consecutive academic years. A principal component analysis was used to evaluate the dimensionality of the questionnaire. The variables were summarized using frequencies, mean, median, 25th percentile, 75th percentile, minimum, and maximum. The results demonstrated that students felt the teaching of imaging anatomy influenced learning in the clinical anatomy course (mean = 4.5, median = 5.0) and subsequent clinical courses (mean = 4.4, median = 4.0). Regarding the imaging techniques used in the demonstration of anatomical structures, computed tomography (median = 5.0) and magnetic resonance imaging (median = 5.0) were highly rated. Students suggested the use of additional support material (37.6%) and favored a more practical approach. In conclusion, the results of this work highlight the value of imaging anatomy in learning human anatomy. Students' comments pointed out a need to focus teaching/learning programs toward a more practical rather than theoretical approach as well as a need to provide a better fit between sectional anatomy and clinical cases using imaging anatomy. In order to provide an optimal learning environment to students, it also seems important to create improved media material as an additional resource tool. Anat Sci Educ. © 2013 American Association of Anatomists.     

Practical Work in Science Education: Study of Different Contexts of Pedagogic Practice

Research in Science Education - The study investigates differentiated teaching practices of practical work in distinct social contexts and with different experienced teachers, at the level of the...     

Knowledge,Belief, and Science Education

This article intends to show that the defense of “understanding” as one of the major goals of science education can be grounded on an anti-reductionist perspective on testimony as a source of knowledge. To do so, we critically revisit the discussion between Harvey Siegel and Alvin Goldman about the goals of science education, especially where it involves arguments based on the epistemology of testimony. Subsequently, we come back to a discussion between Charbel N. El-Hani and Eduardo Mortimer, on the one hand, and Michael Hoffmann, on the other, striving to strengthen the claim that rather than students’ belief change, understanding should have epistemic priority as a goal of science education. Based on these two lines of discussion, we conclude that the reliance on testimony as a source of knowledge is necessary to the development of a more large and comprehensive scientific understanding by science students.     

Continental Drift: A Discussion Strategy for Secondary School

The paper describes a discussion strategy for secondary schoolstudents. The strategy focus the various dimensions of Science, especially the internal sociological and philosophicaldimensions. Students are expected to learn more about Science, namely the role of controversy for scientific progress.The article contains key questions for the students and guidelines for the teacher and also an analysis of the strategyin terms of the construction of Science and of learning processes.     

Scoring mode and age-related effects on youth soccer teams’ defensive performance during small-sided games

ABSTRACT

This study aimed to examine the scoring mode (line goal, double goal or central goal) and age-related effects on the defensive performance of youth soccer players during 4v4 small-sided games (SSGs). Altogether, 16 male players from 2 age groups (U13, n = 8, mean age: 12.61 ± 0.65 years; U15, n = 8, 14.86 ± 0.47 years) were selected as participants. In six independent sessions, participants performed the three SSGs each during 10-min periods. Teams’ defensive performance was analysed at every instant ball possession was regained through the variables: ball-recovery type, ball-recovery sector, configuration of play and defence state. Multinomial logistic regression analysis used in this study revealed the following significant main effects of scoring mode and age: (1) line goal (vs. central goal) increased the odds of regaining possession through tackle and in the defensive midfield sector, and decreased the odds of successful interceptions; (2) double goal (vs. central goal) decreased the odds of regaining possession through turnover won and with elongated playing shapes; (3) the probability of regaining possession through interception significantly decreased with age. Moreover, as youth players move forward in age groups, teams tend to structurally evolve from elongated playing shapes to flattened shapes and, at a behavioural level, from defending in depth to more risky flattened configurations. Overall, by manipulating the scoring mode in SSGs, coaches can promote functional and coadaptive behaviours between teams not only in terms of configurations of play, but also on the pitch locations that teams explore to regain possession.     

Conceptions of the Nature of Science and Technology: a Study with Children and Youths in a Non-Formal Science and Technology Education Setting

This study investigated some of the aspects that characterise the understanding of the Nature of Science (NOS) and Nature of Technology (NOT) of 20 children and youths from different countries who perform scientific and technological activities in a non-formal teaching and learning setting. Data were collected using a questionnaire and semistructured interviews. A categorical instrument was developed to analyse the participants’ conceptions of the following subjects: (1) the role of the scientist, (2) NOS and (3) NOT. The results suggest that the participants had naïve conceptions of NOS that are marked by empirical and technical-instrumental views. They characterised NOT primarily as an instrumental apparatus, an application of knowledge and something important that is part of their lives. They exhibited a stereotypical understanding of the role of the scientist (development of methods, demonstration of facts, relationship with technological devices, etc.).