Chemical rationales: another triplet for chemical thinking

ABSTRACT

One of the central goals of modern science and chemistry education is to develop students’ abilities to understand complex phenomena, and productively engage in explanation, justification, and argumentation. To accomplish this goal, we should better characterise the types of reasoning that we expect students to master in the different scientific disciplines. This analysis is needed to support the design of instructional tasks, teaching strategies, and assessments that foster those ways of thinking. This essay contributes in this direction by characterising the major types of rationales built and applied by experts when analysing chemical systems and processes. The term ‘chemical rationale’ is used to refer to any product of reasoning that uses chemical knowledge to build explanations, justifications or arguments. Three main types of rationales are identified and discussed: Phenomenological, Mechanical, and Structural. Difficulties associated with learning how to build each type of rationale are highlighted, and implications for research and practice of this other chemistry ‘triplet’ are discussed.     

TENSIONS IN THE THIRD SPACE: LOCATING RELEVANCY IN PRESERVICE SCIENCE TEACHER PREPARATION

In this paper, we build on growing conversations centered around indigenous knowledge and its parity with various ways of knowing nature including traditional ecological knowledge, indigenous ways of living in nature, a Japanese way of knowing seigo-shizen, and Eurocentric sciences. We situate our discussion in Philippine postcolonial realities, where categorical boundaries are blurred, and any attempt to create culturally relevant preservice science teacher preparation will create confusions and tensions between/among/within abovementioned discourses. The Philippines is a highly colonized country—physically, for more than 300 hundred years, and mentally, after our colonizers have long gone. The marks of colonization are still present in our consciousness, in our current local knowledge, and in our ways of living with nature. In the attempt to create a “third space” for culturally relevant science teacher preparation, tensions are highlighted and categorical boundaries are troubled. Where is science? Which one is indigenous or neo-indigenous? Which one is Filipino? Which one is foreign? Which one is ours? Which one is borrowed? These tensions and insights are highlighted through analysis of narratives drawn from interviews with and written outputs of prospective science teachers, as they attempted to make sense of the local knowledge of residents of a rural coastal village in the Philippines during Community Immersion, a community-centered, early field experience in science teacher preparation.     

A test of genetic algorithms in relevance feedback

There have been recent applications of genetic algorithms to information retrieval, mostly with respect to relevance feedback. Nevertheless, they are yet to be evaluated in a way that allows them to be compared with each other and with other relevance feedback techniques. We here implement the different genetic algorithms that have been applied in the literature together with some of our own variations, and evaluate them using the residual collection method described by Salton in 1990 for the evaluation of relevance feedback techniques. We compare the results with those of the Ide dec-hi method, which is one of the traditional methods that yields the best results.     

Promotion of autonomy for participation in physical activity: a study based on the trans-contextual model of motivation

The aim of this study was to analyse the effects of a school-based intervention to promote physical activity, utilising the postulates of the trans-contextual model of motivation. The study examined two separate classes of elementary school students (mean age 11.28?years), one of which served as the control group (n?=?26) and the other as the experimental group (n?=?21). The intervention in the experimental group consisted of showing videos related to physical activity participation, conducting discussions and doing tasks related to the content presented in the videos and conducting family discussions. Autonomy support from teachers, peers and parents; motivation in physical education and leisure time physical activity; the different variables of theory of planned behaviour; and physical activity, were measured before and after the intervention. Results showed an increase in teacher autonomy support, identified regulation in physical education, autonomy support from parents and peers, integrated and identified regulation in leisure time physical activity, control, subjective norm, intention and physical activity in the experimental group. Furthermore, this increase resulted in post-intervention differences across groups in such variables. Results are discussed in relation to the important role of families in the promotion of physical activity participation.     

Bone mass,bone mineral density and muscle mass in professional golfers

The aim of this study was to determine the effects of long-term professional golf participation on whole-body and regional bone mass and density. Dual-energy X-ray absorptiometry was performed on 15 male professional golfers and 18 sedentary individuals, matched for sex, race, age (29 ± and 25 ± 1 years, respectively), body mass (79 ± 2 and 74 ± 2 kg), height (1.78 ± 0.01 and 1.77 ± 0.02 m) and percent body fat (20 ± 2 and 21 ± 2%; mean ± s _χ). We found that long-term professional golf participation is not associated with significant increments in regional or whole-body bone mass or density. Neither the lumbar spine nor the femoral neck showed any noticeable enhancement of bone mass in professional golfers compared with controls from the same population. The only effect of professional golf participation on regional body composition was a 9% increase in muscle mass in the dominant arm (P ? 0.05).     

The validity and reliability of a novel app for the measurement of change of direction performance

ABSTRACT

The aim of the present investigation was to analyze the validity and reliability of a novel iPhone app (CODTimer) for the measurement of total time and interlimb asymmetry in the 5 + 5 change of direction test (COD). To do so, twenty physically active adolescent athletes (age = 13.85 ± 1.34 years) performed six repetitions in the COD test while being measured with a pair of timing gates and CODTimer. A total of 120 COD times measured both with the timing gates and the app were then compared for validity and reliability purposes. There was an almost perfect correlation between the timing gates and the CODTimer app for the measurement of total time (r = 0.964; 95% Confidence interval (CI) = 0.95–1.00; Standard error of the estimate = 0.03 s.; p < 0.001). Moreover, non-significant, trivial differences were observed between devices for the measurement of total time and interlimb asymmetry (Effect size < 0.2, p > 0.05). Similar levels of reliability were observed between the timing gates and the app for the measurement of the 6 different trials of each participant (Timing gates: Intraclass correlation coefficient (ICC) = 0.651–0.747, Coefficient of variation (CV) = 2.6–3.5%; CODTimer: ICC = 0.671–0.840, CV = 2.2–3.2%). The results of the present study show that change of direction performance can be measured in a valid, reliable way using a novel iPhone app.     

A Comparison of Item Exposure Control Methods in Computerized Adaptive Testing

Two new methods for item exposure control were proposed. In the Progressive method, as the test progresses, the influence of a random component on item selection is reduced and the importance of item information is increasingly more prominent. In the Restricted Maximum Information method, no item is allowed to be exposed in more than a predetermined proportion of tests. Both methods were compared with six other item-selection methods (Maximum Information, One Parameter, McBride and Martin, Randomesque, Sympson and Hetter, and Random Item Selection) with regard to test precision and item exposure variables. Results showed that the Restricted method was useful to reduce maximum exposure rates and that the Progressive method reduced the number of unused items. Both did well regarding precision. Thus, a combined Progressive-Restricted method may be useful to control item exposure without a serious decrease in test precision.     

Psycho-physiological response in an automatic parachute jump

Parachute jump is an extreme activity that elicits an intense stress response that affects jumpers’ body systems being able to put them at risk. The present research analysed modifications in blood oxygen saturation (BOS), heart rate (HR), cortisol, glucose, lactate, creatine kinase (CK), muscles strength, cortical arousal, autonomic modulation, pistol magazine reload time (PMRT) and state anxiety before and after an automatic open parachute jump in 38 male Spanish soldiers (25.6 ± 5.9 years). A MANOVA with samples as a fixed factor and Effect Size (ES) were conducted. MANOVA showed (Wilks lambda = .225; F = 5.980; P = .000) a significantly increase in cortisol (6.2 ± 3.2 vs. 8.2 ± 4.3 nmol/l; P = .025; ES = .47), HR (75.0 ± 14.6 vs. 87.4 ± 17.3 bpm; P = .004; ES = .72), lactate (1.8 ± 1.2 vs. 4.4 ± 2.2 mmol · l^?1; P = .002; ES = 1.18), sympathetic nervous system and leg strength manifestation after the parachute jump. By contrary BOS, PMRT (55.6 ± 27.6 vs. 48.0 ± 16.7 s; P = .021; ES = .46) and somatic anxiety (SA), evaluated by CSAI2R questionnaire, decreased. An automatic parachute jump increased physiological and cortical response and decreased SA of participants. This stress response can affect the jumpers’ abilities and allow us to have a better understanding of the organism stress response and to improve training for both military and sport parachute jumps.     

Discovery of carbon-based strongest and hardest amorphous material

Carbon is one of the most fascinating elements due to its structurally diverse allotropic forms stemming from its bonding varieties (sp, sp² and sp³). Exploring new forms of carbon has been the eternal theme of scientific research. Herein, we report on amorphous (AM) carbon materials with a high fraction of sp³ bonding recovered from compression of fullerene C₆₀ under high pressure and high temperature, previously unexplored. Analysis of photoluminescence and absorption spectra demonstrates that they are semiconducting with a bandgap range of 1.5–2.2 eV, comparable to that of widely used AM silicon. Comprehensive mechanical tests demonstrate that synthesized AM-III carbon is the hardest and strongest AM material known to date, and can scratch diamond crystal and approach its strength. The produced AM carbon materials combine outstanding mechanical and electronic properties, and may potentially be used in photovoltaic applications that require ultrahigh strength and wear resistance.     

How cultural organizations’ size and funding influence innovation and performance: the case of museums

Our work pursues a twin aim. Firstly, we explore the influence of organizational size on innovations in museums as well as its impact on museums’ economic, market and social performance. Secondly, we analyse how the (public–private) funding of such organizations impacts innovation and performance. The empirical work is based on information from a survey of 491 museums (British, French, Italian and Spanish). We find that museum size does prove relevant in the commitment to engage in innovation but that public funding of museums does not encourage innovation. We also highlight the importance of the explanatory power of the type of funding on the performance of these cultural organizations. This research also reveals how organizational and technological innovations as well as innovation in value creation in museums enhance economic, market and social performance.