The effect of pitch type on ground reaction forces in the baseball swing

Coaches have identified the batter's weight shift as a critical component for promoting proper timing and balance in a baseball swing. Analysing the weight shift through maximum horizontal (Fx) and vertical (Fz) ground reaction forces (GRFs) of professional batters (N = 29; height = 185 +/- 6 cm; mass = 92 +/- 9 kg), the purpose of this study was to compare GRFs among swings against fastballs and changeups. General linear models were used to compare three conditions of interest: successful results against fastballs, successful results against changeups, and unsuccessful results against changeups. Batters had a similar loading mechanism and initial weight transfer from back foot to front foot regardless of pitch type, but peak front foot GRFx and GRFz occurred with significantly different magnitudes and at significantly different times, depending on the pitch type and hit result. Peak front foot GRFs were greater for successful swings against fastballs compared to both successful and unsuccessful swings against changeups. Peak front foot GRFs of unsuccessful swings against changeups occurred, on average, 15-20 ms earlier than successful swings against changeups and 30-35 ms earlier than successful swings against fastballs, quantifying how a changeup can disrupt the coordination of a hitter's weight shift.     

The Nature and Role of Thought Experiments in Solving Conceptual Physics Problems

This study describes the possible variations of thought experiments in terms of their nature, purpose, and reasoning resources adopted during the solution of conceptual physics problems. A phenomenographic research approach was adopted for this study. Three groups of participants with varying levels of physics knowledge—low, medium, and high level—were selected in order to capture potential variations. Five participants were selected within each level group and the study was conducted with fifteen participants in total. Think aloud and retrospective questioning strategies were used throughout the individually conducted problem solving sessions to capture variations in the participants’ thinking processes. The analysis of the data showed that thought experiments were actively used cognitive tools by participants from all there levels while working on the problems. Four different thought experiment structures were observed and categorized as limiting case, extreme case, simple case, and familiar case. It was also observed that participants conducted thought experiments for different purposes such as prediction, proof, and explanation. The reasoning resources behind the thought experiment processes were classified in terms of observed facts, intuitive principles, and scientific concepts. The results of the analysis suggested that thought experiments used as a creative reasoning tool for scientists can also be a productive tool for students. It was argued that instructional practices enriched with thought experiments and related practices not only reveal hidden elements of students’ reasoning but also provide students opportunities to advance their inquiry skills through thought experimentation processes.     

Emotional outcomes of e-learning adoption during compulsory online education

Education and Information Technologies - Information on the emotional outcomes of e-learning system use and emotional aspects of user experience in higher education is quite limited. Accordingly,...     

Psychological Flexibility,Coronavirus Anxiety,Humor and Social Media Addiction During COVID-19 Pandemic in Turkey

Psychological flexibility is associated with psychological health and affected by various factors. The aim of the present study is to examine the role of coronavirus anxiety, humor and social media addiction on psychological flexibility during the COVID-19 pandemic in Turkey. Variables were measured with online self-report surveys and data were gathered from December 2020 to January 2021 in Turkey. The sample consisted of 376 people (295 female, M?=?29.88, SD?=?11.05). The relationships between the variables were tested with path analysis using structural equation modelling (SEM). According to results, the constructed model showed that COVID-19 anxiety significantly and directly increased social media addiction (β?=?.17, p?<?.01), decreased coping humor (β?=?-.11, p?<?.05) and decreased psychological flexibility indirectly through social media addictions (β?=?-.08, p?<?.01). Humor coping significantly and directly increased psychological flexibility (β?=?.25, p?<?.01), and social media addiction significantly and directly decreased psychological flexibility (β?=?-.31, p?<?.01). Findings indicated that psychological flexibility is influenced by coronavirus anxiety, social media addiction and humor coping.  Supporting humor coping and reducing anxiety and problematic social media use would be helpful to enhance psychological flexibility of individuals during the pandemic.

     

Assessing measurement invariance of Turkish “Central Examination for Secondary Education Institutions” for visually impaired students

Educational Assessment, Evaluation and Accountability - Studies that focus on measurement invariance are of significant importance in proving the validation of high-stake tests, and in order to...     

Some Reflections on Hagiology with Reference to the Early Mawlawī-Christian Relations in the Light of the Manāqib al-cārifīn

Abstract

Hagiographic sources are of particular value for the study of social life in historical societies. They reflect contemporary social discourses such as how to deal with members of different religious or ethnic groups or social classes. A prime Muslim example of this genre is the Persian Manāqib al-?ārifīn (Feats of the Knowers of God) of the Mawlawī-Dervish A?mad-i Aflākī written in Konya in the eighth/fourteenth century. It is dedicated to the life and deeds of the masters of the emerging brotherhood of the Mawlawiyya. This community was of outstanding importance in urban central and western Asia Minor in the eighth/fourteenth century, both as an institution of the urban middle classes and as an effective missionary, and was thus an important protagonist in the process of Islamisation. After some methodological considerations on the genre of hagiography, the article will address the issue of missionary strategies of the early Mawlawiyya on the basis of the Manāqib al-?ārifīn.     

EFFECTS OF A MULTIFOCUSED PREVENTION PROGRAM ON PRESCHOOL CHILDREN'S COMPETENCIES AND BEHAVIOR PROBLEMS

This study was designed to assess the effectiveness of a multifocused (child‐, teacher‐ and parent‐focused) prevention program for Romanian preschoolers, targeting social–emotional competence development, as well as reduction of behavior problems. Fourteen classrooms were randomly assigned to the intervention and control conditions. Subsequent hierarchical linear analyses indicated that intervention‐group children performed better on experimental tasks measuring emotion knowledge and social problem‐solving strategies, and received higher assessments by their teachers and parents on measures of social–emotional competencies and externalizing problems. These results indicate that a prevention program combining intervention strategies for both high‐ and low‐risk children is effective across a wide range of adaptive and maladaptive behaviors. Moreover, a short four‐session parent group training employed to attract parent participation elicited an acceptable overall attendance rate (54%), indicating the sustainability of parent intervention in the context of community‐based interventions.