Segmental sequencing of kinetic energy in a computer-simulated golf swing

The concept of the transfer of kinetic energy (KE) sequentially through the human body from proximal to distal segments is an influential concept in biomechanics literature. The present study develops this area of research through investigation of segmental sequencing of the transfer of KE by means of computer simulation. Using a musculoskeletal computer model previously developed by the authors, driven using three-dimensional kinematic data from a single elite male golfer, combined inverse and forward dynamics analyses enabled derivation of KE. Rigid body segments of torso, hips, arms and clubhead were examined in line with previous literature. Using this method a driver swing was compared to a 7 iron swing. Findings showed a high level of correlation between driver and iron peak KE and timing of peak KE relative to impact. This seems to indicate equivalent trunk and arms linear velocity, thus force applied, for an iron shot and a driver shot. There were highly significant differences between KE output for body segments for both clubs. In addition, peak KE magnitudes increased sequentially from proximal to distal segments during swing simulations for both the driver and 7 iron. This supports the principle of the summation of speed. However, timing of peak KE was not sequential from proximal to distal segments, nor did segments peak simultaneously. Rather, arms peaked first, followed by hips, torso and club. This seems to indicate a subjective optimal coordination of sequencing.

Assessment of student learning: Evolution of objectives in engineering education and the consequences for assessment

The focus of objectives of engineering education has evolved from knowledge to skills. This is a logical consequence of the changing demands of employers of graduated engineers. This change is referred to as a paradigm shift in engineering education. It is therefore not surprising that the views on assessment of student learning are changing as well. In this paper the relation between the demands and the educational objectives are reviewed. Consequently, the implications for assessment are discussed. Assessment is introduced as a feedback procedure. It is discussed that in fact four different feedback pathways can be identified. Finally, the relation between educational methods and their relation to assessment is discussed in detail. As an example, the problems in assessment of group work are discussed.     

Validity of a Tympanic Thermometer and Thermal Imaging Camera for Measuring Core and Skin Temperature during Exercise in the Heat

ABSTRACT

This study compared criterion to minimally invasive, practical measures of core (T_c) and skin (T_sk) temperature during 30 min of moderate-intensity cycle exercise in a heat chamber (35°C, 60% rH). T_c was monitored using a core temperature pill (T_c(Pill)) and tympanic thermometer (T_c(Tymp)) during rest, exercise, and recovery in 15 participants. T_sk was monitored using hard-wired skin thermistors attached to a data logger (T_sk(T)) and a thermal imaging camera (T_sk(IR)) in 11 participants. T_c measurement resulted in no significant difference (p > 0.05), a mean bias of 0.1°C, coefficient of variation (CV%) of 1.0%, and correlation of r = 0.74 between devices. T_sk measurement resulted in a significant difference (p = 0.01), a mean bias of 0.6°C, CV% of 2.3%, and correlation of r = 0.61 between devices. T_c(Tymp) demonstrated acceptable agreement with T_c(Pill); however, caution is advised when using T_sk(IR) to give accurate measures of T_sk during exercise.     

Coherence,contradiction, and the development of school science identities

This study demonstrates the potential for collaborative research among participants in local settings to effect positive change in urban settings characterized by diversity. It describes an interpretive case study of a racially, ethnically, and socioeconomically diverse eighth grade science classroom in an urban magnet school in order to explore why some of the students did not achieve at high levels and identify with school science although they were both interested in and knowledgeable about science. The results of this study indicated that structural issues such as the school's selection process, the discourses perpetuated by teachers, administrators, and peers regarding “who belongs” at the school, and negative stereotype threat posed obstacles for students by highlighting rather than mitigating the inequalities in students' educational backgrounds. We explore how a methodology based on the use of cogenerative dialogues provided some guidance to teachers wishing to alter structures in their classrooms to be more conducive to all of their students developing identities associated with school science. Based on the data analysis, we also argue that a perspective on classrooms as communities of practice in which learning is socially situated rather than as forums for competitive displays, and a view of students as valued contributors rather than as recipients of knowledge, could address some of the obstacles. Recommendations include a reduced emphasis on standardized tasks and hierarchies, soliciting unique student contributions, and encouraging learning through peripheral participation, thereby enabling students to earn social capital in the classroom. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 47: 1209–1228, 2010     

Development of a magnetic immunosorbent for on-chip preconcentration of amyloid �� isoforms: Representatives of Alzheimer��s disease biomarkers

Determination of amyloid β (Aβ) isoforms and in particular the proportion of the Aβ 1-42 isoform in cerebrospinal fluid (CSF) of patients suspected of Alzheimer’s disease might help in early diagnosis and treatment of that illness. Due to the low concentration of Aβ peptides in biological fluids, a preconcentration step prior to the detection step is often necessary. This study utilized on-chip immunoprecipitation, known as micro-immunoprecipitation (μIP). The technique uses an immunosorbent (IS) consisting of magnetic beads coated with specific anti-Aβ antibodies organized into an affinity microcolumn by a magnetic field. Our goal was to thoroughly describe the critical steps in developing the IS, such as selecting the proper beads and anti-Aβ antibodies, as well as optimizing the immobilization technique and μIP protocol. The latter includes selecting optimal elution conditions. Furthermore, we demonstrate the efficiency of anti-Aβ IS for μIP and specific capture of 5 Aβ peptides under optimized conditions using various subsequent analytical methods, including matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), capillary electrophoresis, microchip electrophoresis, and immunoblotting. Synthetic Aβ peptides samples prepared in buffer and spiked in human CSF were analyzed. Finally, on-chip immunoprecipitation of Aβ peptides in human CSF sample was performed.     

Analysis of author affiliation across four school psychology journals from 2000 to 2008: Where is the practitioner research?

Articles published between 2000 and 2008 in four major school psychology journals—School Psychology Review, Journal of School Psychology, Psychology in the Schools, and School Psychology Quarterly—were classified based on type (empirical or narrative) and on the primary and secondary authors' affiliations. Results showed that more than 90% of the primary and secondary authors were university affiliated with little difference across article type. Although more than 85% of school psychologists are practitioners, these results suggest that their contributions to these school psychology journals are limited because they account for less than 10% of the authors of articles. Discussion focuses on practitioners' involvement in the research base that is intended to inform their professional behaviors. © 2009 Wiley Periodicals, Inc.     

PRESERVICE ELEMENTARY TEACHERS’ GROWTH IN KNOWLEDGE OF MODELS IN A SCIENCE CAPSTONE COURSE

We used four different methods to determine the best means of assessing over 200 preservice elementary teachers’ growth in knowledge of models and their use in K-8 classrooms while participating in the Science Capstone course that focused on the unifying themes of models in science. Each assessment method probed a different aspect of models (from growth in scientific use to need for greater emphasis on the role and use of models) and each used a different method of gathering student responses (Likert-type responses to concept maps). We determined that growth in student knowledge was demonstrated by all instruments, but some instruments were more useful than others for determining preservice elementary teachers’ prior knowledge as well as growth in knowledge of models necessary for K-8 teachers.     

Using problem-based learning to increase computer self-efficacy in Taiwanese students

In Taiwan, teaching focuses around lecturing, with students having little opportunity to interact with each other. Problem-based learning (PBL) is a means of instruction where students learn the subject by being active participants in the pedagogical process, with the emphasis on problem-solving. In this study, the authors investigated whether PBL would enhance self-efficacy better than common lecturing with children who had little access to technology outside of school. Two sixth-grade computer classes, both with 32 students in each and both located in the mountainous regions of eastern Taiwan, served as participants. A quasi-experimental, non-equivalent control group design was used with one class utilizing PBL principles, while the other used traditional lecturing. A pre-/posttest was administered, using the General Self-Efficacy Scale with data analysis employing the Mann–Whitney test and Pearson Goodness-of-Fit. The results indicated that PBL is superior to lecturing, with respect to an increase in computer self-efficacy.     

Tools to support expository video capture and access

Video tends to be imbalanced as a medium. Typically, content creators invest enormous effort creating work that is then watched passively. However, learning tasks require that users not only consume video but also engage, interact with, and repurpose content. Furthermore, to promote learning across domains where content creators are not necessarily videographers, it is important that capture tools facilitate creation of interactive content. In this paper, we describe some early experiments toward this goal. Specifically, we describe a needfinding study involving interviews with amateur video creators as well as our experience with an early prototype to support expository capture and access. Our findings led to a system redesign that can incorporate a broad set of video-creation and interaction styles.