Muscle coordination during breaststroke swimming: Comparison between elite swimmers and beginners

The present study aimed to compare muscle coordination strategies of the upper and lower limb muscles between beginners and elite breaststroke swimmers. Surface electromyography (EMG) of eight muscles was recorded in 16 swimmers (8 elite, 8 beginners) during a 25 m swimming breaststroke at 100% of maximal effort. A decomposition algorithm was used to identify the muscle synergies that represent the temporal and spatial organisation of muscle coordination. Between-groups indices of similarity and lag times were calculated. Individual muscle patterns were moderately to highly similar between groups (between-group indices range: 0.61 to 0.84). Significant differences were found in terms of lag time for pectoralis major (P < 0.05), biceps brachii, rectus femoris and tibialis anterior (P < 0.01), indicating an earlier activation for these muscles in beginners compared to elites (range: ?13.2 to ?3.8% of the swimming cycle). Three muscle synergies were identified for both beginners and elites. Although their composition was similar between populations, the third synergy exhibited a high within-group variability. Moderate to high indices of similarity were found for the shape of synergy activation coefficients (range: 0.63 to 0.88) but there was a significant backward shift (?8.4% of the swimming cycle) in synergy #2 for beginners compared to elites. This time shift suggested differences in the global arm-to-leg coordination. These results indicate that the synergistic organisation of muscle coordination during breaststroke swimming is not profoundly affected by expertise. However, specific timing adjustments were observed between lower and upper limbs.     

From Hard to Soft Governance in Multi‐level Education Systems

Decision‐making in educations systems has become more complex: while decentralisation has moved the locus of power to lower governance levels, the central level still is held responsible for the quality of outcomes. As a consequence, new steering strategies have emerged that tend to apply softer modes of governance as opposed to harder ones in the past. This article aims at shedding empirical and conceptual light on these new developments. It compares two national examples for soft modes of governance with a supra‐national one (the EU's Open Method of Co‐ordination OMC) and argues that OMC might be both a useful analytical lens to categorise new steering mechanisms and a possibly promising policy strategy at the national level.     

The Impact of School Improvement Grants on Student Outcomes: Findings From a National Evaluation Using a Regression Discontinuity Design

As part of the American Recovery and Reinvestment Act of 2009, the School Improvement Grants (SIG) program received more than $3 billion with the goal of substantially improving student achievement. The SIG program’s funding was to help states turn around the nation’s persistently lowest-achieving schools using one of four school intervention models—transformation, turnaround, restart, or closure. We used a regression discontinuity design and a large sample of schools from more than 20 states to evaluate the impact of implementing a SIG-funded intervention model on use of SIG-promoted practices and student outcomes. Our regression discontinuity design exploited cutoff values on the continuous variables used to define the SIG eligibility tiers to compare outcomes in schools that just met the eligibility cutoff for receiving SIG funding to outcomes in schools that just missed it. We found that SIG had no impact on any of the outcomes we examined, including math and reading test scores, high school graduation rates, and college enrollment rates. Using a correlational analysis, we found the turnaround model was associated with larger student achievement gains in math than the transformation model for grades 6 through 12.     

Positive and negative patterning in human classical skin conductance response conditioning

Three experiments on classical differential conditioning of the human skin conductance response to elemental and compound stimuli are reported. Subjects in Experiment 1 received both positive and negative patterning training, followed by either positive or negative patterning transfer tests on new stimuli. In positive patterning, a compound of two stimuli is reinforced and its elements are nonreinforced. In negative patterning, the elements are reinforced and the compound is nonreinforced. Subjects in Experiments 2 and 3 received either positive or negative patterning during training, followed by transfer tests on new stimuli. In Experiment 2, the transfer series began with new elements, after which their compound was presented; in Experiment 3, the new compound was presented first in the transfer series, and then the separate elements were administered. All three experiments provided evidence of the acquisition of positive patterning, while negative patterning was found only in Experiments 2 and 3. Positive patterning transferred to new stimuli, indicating that it was not attributable solely to summation of sub-threshold excitation conditioned to the elements on reinforced compound trials. This finding, coupled with the negative patterning found in Experiments 2 and 3, provided support for the unique cue hypothesis. It was concluded that the assumed unique cue constituted a learned “rule,” and that the actual elemental stimuli were neither perceptually nor otherwise modified during the conditioning process.     

Investigating a learning progression for energy ideas from upper elementary through high school

This study tests a hypothesized learning progression for the concept of energy. It looks at 14 specific ideas under the categories of (i) Energy Forms and Transformations; (ii) Energy Transfer; (iii) Energy Dissipation and Degradation; and (iv) Energy Conservation. It then examines students’ growth of understanding within each of these ideas at three levels of increasing conceptual complexity. The basic level of the model focuses on simple energy relationships and easily observable effects of energy processes; the intermediate level focuses on more complex energy concepts and applications; and the advanced level focuses on still more complex energy concepts, often requiring an atomic/molecular model to explain phenomena. The study includes results from 359 distractor‐driven, multiple‐choice test items administered to over 20,000 students in grades 4 through 12 from across the U.S. Rasch analysis provided linear measures of student performance and item difficulty on the same scale. Results largely supported a model of students’ growth of understanding that progresses from an understanding of forms and transformations of energy to energy transfer to conservation while also progressing along a separate dimension of cognitive complexity. An analysis of the current state of students’ understanding with respect to the knowledge identified in the learning progression showed that elementary level students perform well in comparison to expectations but that middle and high school students’ performance does not meet expectations. © 2017 Wiley Periodicals, Inc. J Res Sci Teach 55: 68–93, 2018     

Reliability and validity of a soccer passing test using the Footbonaut

The aim of this study was to investigate the reliability and validity of a soccer short passing test using the Footbonaut training system. Forty-eight young skilled soccer players and 31 lesser-skilled soccer players completed a test and a retest, each involving four sessions a day of a Footbonaut short passing test (FSPT). We found significant differences in mean execution times for skilled (mean [M]?=?2487, standard deviation [SD] ?=?155) and lesser-skilled players (M?=?2682, SD?=?176) but no significant difference in accuracy (M?=?74.13, SD?=?7.65; M?=?72.19, SD?=?8.13) between groups. The results from linear mixed-effects models show that there were no significant effects of repeated measurements on execution time. In contrast, we found an estimated increase of 0.86% in accuracy per session for both groups. In conclusion, the FSPT offers a reliable and valid method to differentiate young soccer players at different competitive levels, using execution time.     

‘Energy regions’: The transformative power of regional discourses on socio-technical futures

‘Guiding visions’ play an important role in the transition management approach as a central means of mobilizing social actors and the co-ordination of dispersed agency.‘Energy regions’ in Austria are an interesting example for the strategic promotion of such guiding visions in the context of regional development. We describe the case of Murau, an alpine district in which a strong actor network has been built around a vision of systematically exploiting renewable energy sources and at the same time saving the region from economic decay. The vision gained much authority and has been institutionalised at various levels of regional governance. It furthermore was supported by and played an important role for regime level attempts to influence socio-technical change.Development and social propagation of such visions are inherently political and contested processes involving much strategizing and anticipation of conflict. We describe particular discursive strategies applied in niches - such as the combination and translation of sentiments into localised visions and demonstrations of feasibility. These strategies can be understood as systematic attempts to support discursive shifts at regime level by means of local activities, and aim to modify rather durable power structures.We suggest ways to analyse such discursive practices in order to orient strategic action in the course of such processes: analysing ‘guiding visions’ and their interference with other emerging trends; extending analyses across spatial scales (e.g. translations) and across thematic fields (e.g. convergence of agendas); and focusing on processes of stabilisation, institutionalisation and mutually reinforcing developments.     

Connecting and Creating for Learning: Integrating Subject Matter Across the Curriculum and the School

In this article, the authors explore a growing awareness of problems and current developments in classroom and schoolwide research on subject matter integration. Schwab's four common places—including the learner, the teacher, the content, and the context—provide a framework for examining subject matter integration from a language arts perspective. Two lines of classroom-based research are examined that were conducted in response to the lack of integration within the curriculum: Explanation and Responsive Elaboration in Reading and Cognitive Strategies in Writing. As a result of these two lines of research, researchers became more aware of the importance of understanding the complexity of integrating process into content within the context of the classroom and the school. A major shift toward schoolwide integration in two Professional Development School settings is described that was created in response to these research findings. Teachers and researchers within specific contexts generated and implemented integrated instruction and curriculum content collaboratively. The authors conclude with emerging questions and principles for stimulating thinking among teachers and researchers who work toward furthering understanding of language and subject matter integration within specific contexts.     

Muscle coordination,activation and kinematics of world-class and elite breaststroke swimmers during submaximal and maximal efforts

The aims of this study were to describe muscular activation patterns and kinematic variables during the complete stroke cycle (SC) and the different phases of breaststroke swimming at submaximal and maximal efforts. Surface electromyography (sEMG) was collected from eight muscles in nine elite swimmers; five females (age 20.3 ± 5.4 years; Fédération Internationale de Natation [FINA] points 815 ± 160) and four males (27.7 ± 7.1 years; FINA points 879 ± 151). Underwater cameras were used for 3D kinematic analysis with automatic motion tracking. The participants swam 25 m of breaststroke at 60%, 80% and 100% effort and each SC was divided into three phases: knee extension, knee extended and knee flexion. With increasing effort, the swimmers decreased their SC distance and increased their velocity and stroke rate. A decrease during the different phases was found for duration during knee extended and knee flexion, distance during knee extended and knee angle at the beginning of knee extension with increasing effort. Velocity increased for all phases. The mean activation pattern remained similar across the different effort levels, but the muscles showed longer activation periods relative to the SC and increased integrated sEMG (except trapezius) with increasing effort. The muscle activation patterns, muscular participation and kinematics assessed in this study with elite breaststroke swimmers contribute to a better understanding of the stroke and what occurs at different effort levels. This could be used as a reference for optimising breaststroke training to improve performance.