Biomechanical differences between left- and right-handed baseball pitchers

Left-handed baseball pitchers are thought to have a number of theoretical advantages compared to right-handed pitchers; however, there is limited scientific research detailing differences in the pitching mechanics of right- and left-handed pitchers. Therefore, this study sought to understand whether any kinematic and kinetic differences existed between right- and left-handed baseball pitchers. A total of 52 collegiate pitchers were included in this study; 26 left-handed pitchers were compared to 26 age-, height-, weight- and ball velocity-matched right-handed pitchers. Demographic information, passive shoulder range of motion and kinematic and kinetic data were obtained for each pitcher participating in the study. Results indicated that left-handed pitchers did not have a glenohumeral internal rotation deficit as compared to right-handed pitchers. Kinematic analysis indicated that elbow flexion, horizontal glenohumeral abduction and wrist coronal plane motion were significantly different between the two study cohorts. It was also noted that left-handed pitchers had increased elbow varus moments. The findings of this study suggest that pitching coaches should be aware that there are biomechanical differences between left- and right-handed pitchers.     

The prevalence of behavior problems in deaf children

The appropriateness of the Behavior Problem Checklist for deaf children has been established in various studies. The objective of this study was to use the Behavior Problem Checklist to assess the prevalence of behavior problems in deaf children and to compare these results to earlier studies of behavior problems of hearing and hearing-impaired children. A lesser prevalence of behavior problems was found than in some earlier studies of deaf children. Results were somewhat more consistent with past findings regarding children with no hearing problems. Comparisons by sex found, as in earlier studies, that boys tended to evidence more behavior problems than girls.     

Introduction and training of students to use separate answer sheets: Effects on standardized test scores

Previous research has found conflicting evidence regarding how early children can effectively use separate answer sheets with achievement tests. This study looked at the effects of separate answer sheets on the California Achievement Test (CAT) scores of third, fourth, and fifth graders. The Mathematics Computation and the Reading Comprehension subtests of the CAT were used. Seventy-one classrooms were randomly assigned to have students record their answers on either: (a) their test booklets, (b) separate answer sheets, or (c) separate answer sheets after being given training in the use of separate answer sheets. The results were consistent across both subtests and grades; no response mode treatment effect was found. Further, no evidence of a treatment by ability interaction was found, which was contrary to previously reported research. The results of this study suggest that students can, as early as grade three, effectively use separate answer sheets without prior training.     

An Approach to Annual Assessment and Evaluation of University Faculty

An approach used to determine some university faculty annual raises is described. Faculty assessment information is covered first. Tabular summaries made from this information are also described. Then the annual evaluation procedure carried out by a faculty review team and the department head are described. The method used to determine faculty raise allocations is presented. Difficulties and limitations of the approach are mentioned throughout.     

Microliter-bioreactor array with buoyancy-driven stirring for human hematopoietic stem cell culture

This work presents the development of an array of bioreactors where finely controlled stirring is provided at the microliter scale (100–300 μl). The microliter-bioreactor array is useful for performing protocol optimization in up to 96 parallel experiments of hematopoietic stem cell (HSC) cultures. Exploring a wide range of experimental conditions at the microliter scale minimizes cost and labor. Once the cell culture protocol is optimized, it can be applied to large-scale bioreactors for stem cell production at the clinical level. The controlled stirring inside the wells of a standard 96-well plate is provided by buoyancy-driven thermoconvection. The temperature and velocity fields within the culture volume are determined with numerical simulations. The numerical results are verified with experimental velocity measurements using microparticle image velocimetry (μPIV) and are used to define feasible experimental conditions for stem cell cultures. To test the bioreactor array’s functionality, human umbilical cord blood-derived CD34⁺ cells were cultured for 7 days at five different stirring conditions (0.24–0.58 μm∕s) in six repeated experiments. Cells were characterized in terms of proliferation, and flow cytometry measurements of viability and CD34 expression. The microliter-bioreactor array demonstrates its ability to support HSC cultures under stirred conditions without adversely affecting the cell behavior. Because of the highly controlled operative conditions, it can be used to explore culture conditions where the mass transport of endogenous and exogenous growth factors is selectively enhanced, and cell suspension provided. While the bioreactor array was developed for culturing HSCs, its application can be extended to other cell types.     

Living Un/Grammatically in a Grammatical World: The Pedagogic World of Teachers and Students

In my work with preservice teachers I face daily a dilemma. My student-teachers come to me with an urgent practical agenda: What do I need to know in order to survive in the world of school? In effect they want me to tell them how to fit into a world that they assume is structured like a grammar, with traditions and conventions and rules and patterns. They are seeking ways to conform to the pedagogic world as it has been written, but I hope they will seek ways to transform the pedagogic world, always written and always in the process of being written. I hope my student-teachers will seek ways to write, actively and deliberately and imaginatively, the pedagogic world of students and teachers. I want them to learn to live un/grammatically, to challenge the ways in which the world has been written for them, to know that they are not only written by the world, but that they also write the world. I invite my students to write the unwritten sentences, the sentences that interrogate and subvert syntax and semantics, the sentences that create spaces where my students can live un/grammatically.