Analyzing Learning About Conservation of Matter in Students While Adapting to the Needs of a School

We probed the impact of two teaching strategies, guided inquiry and argumentation, on students' conceptual understanding of the conservation of matter. Conservation of matter is a central concept in middle school science curriculum and a prerequisite upon which rests more complex constructs in chemistry. The results indicate that guided inquiry was particularly effective in improving students' conceptual understanding, as evidenced by pre/posttest results and by a skill analysis of in-depth interviews of student dyads. We also discuss how the challenges inherent to educational contexts can undermine the quality and limit the impact of empirical research carried out in many schools. We suggest how these challenges could be met in the emerging infrastructures for change called the Research Schools Network.     

In Search of Structures: How Does the Mind Explore Infinity?

When reasoning about infinite sets, children seem to activate four categories of conceptual structures: geometric (g-structures), arithmetic (a-structures), fractal-type (f-structures), and density-type (d-structures). Students select different problem-solving strategies depending on the structure they recognize within the problem domain. They naturally search for structures in challenging learning contexts. This tendency to search for structure might be a characteristic of human cognition and a necessary condition for human knowledge development. For example, specific fractal structures are intrinsic to concepts such as the numerical system that have been developed by the human race over a long period of time. When these structures are emphasized within teaching, they can facilitate the deep understanding of several basic concepts, in mathematics and beyond.     

Effect of a novel pedal design on maximal power output and mechanical efficiency in well-trained cyclists

In this study, we evaluated the effects of a novel pedal design, characterized by a downward and forward shift of the cleat fixing platform relative to the pedal axle, on maximal power output and mechanical efficiency in 22 well-trained cyclists. Maximal power output was measured during a series of short (5-s) intermittent sprints on an isokinetic cycle ergometer at cadences from 40 to 120 rev min(-1). Mechanical efficiency was evaluated during a submaximal incremental exercise test on a bicycle ergometer using continuous VO(2) and VCO(2) measurement. Similar tests with conventional pedals and the novel pedals, which were mounted on the individual racing bike of the participant, were randomized. Maximal power was greater with novel pedals than with conventional pedals (between 6.0%, s(x) = 1.5 at 40 rev min(-1) and 1.8%, s(x) = 0.7 at 120 rev min(-1); P = 0.01). Torque production between crank angles of 60 degrees and 150 degrees was higher with novel pedals than with conventional pedals (P = 0.004). The novel pedal design did not affect whole-body VO(2) or VCO(2). Mechanical efficiency was greater with novel pedals than with conventional pedals (27.2%, s(x) = 0.9 and 25.1%, s(x) = 0.9% respectively; P = 0.047; effect size = 0.9). In conclusion, the novel pedals can increase maximal power output and mechanical efficiency in well-trained cyclists.     

Antecedents of emotions in elite athletes: a cognitive motivational relational theory perspective

Cognitive motivational relational theory suggests that cognitive appraisals or core relational themes (a composite summary of appraisal components) represent the proximal determinants of athletes' emotions. Semistructured interviews with 12 current international athletes (1 woman and 11 men) ages 19 to 37 years (M age = 27 years, SD = 6.03), representing a range of sports (badminton, golf rugby union, athletics, archery, sailing, and snooker) explored the association between athletes' appraisals and emotions. Concurrent inductive and deductive content analyses suggested that primary and secondary appraisal components (goal relevance, goal congruence, ego-involvement, blame/credit, coping potential, future expectations) were associated with a range of emotions: anger anxiety, guilt, happiness, pride, relief sadness, and shame. A hierarchical content analysis provided some support for Lazarus' (1991) core relational themes. Limitations and applications of this study are discussed.     

Reliability of force-velocity relationships during deadlift high pull

This study aimed to evaluate the within- and between-session reliability of force, velocity and power performances and to assess the force-velocity relationship during the deadlift high pull (DHP). Nine participants performed two identical sessions of DHP with loads ranging from 30 to 70% of body mass. The force was measured by a force plate under the participants’ feet. The velocity of the ‘body + lifted mass’ system was calculated by integrating the acceleration and the power was calculated as the product of force and velocity. The force-velocity relationships were obtained from linear regression of both mean and peak values of force and velocity. The within- and between-session reliability was evaluated by using coefficients of variation (CV) and intraclass correlation coefficients (ICC). Results showed that DHP force-velocity relationships were significantly linear (R² > 0.90, p < 0.05). Within sessions and between sessions, mean and peak forces during DHP showed a strong agreement (CV < 3%, ICC > 0.94), mean and peak velocities showed a good agreement (CV < 9%, 0.78 < ICC < 0.92). It was concluded that DHP performance and its force-velocity relationships are highly reliable and can therefore be utilised as a tool to characterise individuals’ muscular profiles.     

The effects of an increased calorie breakfast consumed prior to simulated match-play in Academy soccer players

Dietary analysis of Academy soccer players highlights that total energy and carbohydrate intakes are less than optimal, especially, on match-days. As UK Academy matches predominantly kick-off at ～11:00?h, breakfast is likely the last pre-exercise meal and thus may provide an intervention opportunity on match-day. Accordingly, the physiological and performance effects of an increased calorie breakfast consumed ～135-min before soccer-specific exercise was investigated. English Premier League Academy soccer players (n?=?7) repeated a 90-min soccer match simulation on two occasions after consumption of habitual (B_hab; ～1100?kJ) or increased (B_inc; ～2100?kJ) energy breakfasts standardised for macronutrient contributions (～60% carbohydrates, ～15% proteins and ～25% fats). Countermovement jump height, sprint velocities (15-m and 30-m), 30-m repeated sprint maintenance, gut fullness, abdominal discomfort and soccer dribbling performances were measured. Blood samples were taken at rest, pre-exercise, half-time and every 15-min during exercise. Although dribbling precision (P?=?.522; 29.9?±?5.5?cm) and success (P?=?.505; 94?±?8%) were unchanged throughout all time-points, mean dribbling speed was faster (4.3?±?5.7%) in B_inc relative to B_hab (P?=?.023; 2.84 vs 2.75?m?s^?1). Greater feelings of gut fullness (67?±?17%, P?=?.001) were observed in B_inc without changes in abdominal discomfort (P?=?.595). All other physical performance measures and blood lactate and glucose concentrations were comparable between trials (all P?>?.05). Findings demonstrate that Academy soccer players were able to increase pre-match energy intake without experiencing abdominal discomfort; thus, likely contributing to the amelioration of energy deficits on match-days. Furthermore, whilst B_inc produced limited benefits to physical performance, increased dribbling speed was identified, which may be of benefit to match-play.     

Comparison of the peabody picture vocabulary test-revised and the McCarthy screening test

The relationship between the Peabody Picture Vocabulary Test-Revised (PPVT-R) and the McCarthy Screening Test (MST) was investigated with a sample of 39 Caucasian children from a semirural, Northeastern Ohio school district. The sample consisted of 23 males and 16 females, whose mean age was 62.3 months. Pearson product moment correlations were obtained between the measures, and correlated t-tests were completed. All of the subtests of the MST, excluding Numerical Memory and Leg Coordination, correlated positively and significantly with the PPVT-R. Discussion regarding the relationship found between the MST and the PPVT-R and that previously found between the McCarthy Scales of Children's Abilities (MSCA) and the PPVT-R is presented.