FT-IR and MAS NMR analysis of montmorillonite K10 supported MF2 reagents and their activity as catalysis /

ZnF2, CdF2, and CUF2 have been adsorbed onto the surface of montmorillonite K10, and the infrared and 19F, 27 AI, and 29Si MAS NMR spectra of the reagents over a range of loadings have been obtained. CUF2 was observed to attack the Si02 layer and form the complex CuSiF6, Zn F2 tends to attack the aluminium oxide layer, in which Zn isomorphously replaces AI, and forms AIF3 and AIF4 - complexes. All the spectroscopic evidence ruled out the formation of any AI-F and/or Si-F free species as CdF2 is adsorbed on the surface of montmorillonite K10. The reactivity of MF2-K10 reagents towards Friedel-Crafts benzylation of benzene with benzyl chloride varied from one reagent to another. ZnF2-K10 was observed to be the most reactive and CUF2 was the least reactive.

3D movement and muscle activity patterns in a violin bowing task

Objective: Overuse injuries in violinists are a problem that has been primarily analyzed through the use of questionnaires. Simultaneous 3D motion analysis and EMG to measure muscle activity has been suggested as a quantitative technique to explore this problem by identifying movement patterns and muscular demands which may predispose violinists to overuse injuries. This multi-disciplinary analysis technique has, so far, had limited use in the music world. The purpose of this study was to use it to characterize the demands of a violin bowing task. Subjects: Twelve injury-free violinists volunteered for the study. The subjects were assigned to a novice or expert group based on playing experience, as determined by questionnaire. Design and Settings: Muscle activity and movement patterns were assessed while violinists played five bowing cycles (one bowing cycle = one down-bow + one up-bow) on each string (G, D, A, E), at a pulse of 4 beats per bow and 100 beats per minute. Measurements: An upper extremity model created using coordinate data from markers placed on the right acromion process, lateral epicondyle of the humerus and ulnar styloid was used to determine minimum and maximum joint angles, ranges of motion (ROM) and angular velocities at the shoulder and elbow of the bowing arm. Muscle activity in right anterior deltoid, biceps brachii and triceps brachii was assessed during maximal voluntary contractions (MVC) and during the playing task. Data were analysed for significant differences across the strings and between experience groups. Results: Elbow flexion/extension ROM was similar across strings for both groups. Shoulder flexion/extension ROM increaslarger for the experts. Angular velocity changes mirrored changes in ROM. Deltoid was the most active of the muscles assessed (20% MVC) and displayed a pattern of constant activation to maintain shoulder abduction. Biceps and triceps were less active (4 - 12% MVC) and showed a more periodic 'on and off pattern. Novices' muscle activity was higher in all cases. Experts' muscle activity showed a consistent pattern across strings, whereas the novices were more irregular. The agonist-antagonist roles of biceps and triceps during the bowing motion were clearly defined in the expert group, but not as apparent in the novice group. Conclusions: Bowing movement appears to be controlled by the shoulder rather than the elbow as shoulder ROM changed across strings while elbow ROM remained the same. Shoulder injuries are probably due to repetition as the muscle activity required for the movement is small. Experts require a smaller amount of muscle activity to perform the movement, possibly due to more efficient muscle activation patterns as a result of practice. This quantitative multidisciplinary approach to analysing violinists' movements can contribute to fuller understanding of both playing demands and injury mechanisms .

Relationships among adolescent substance use, leisure boredom, and physical activity

This study was a secondary analysis of data drawn from the Youth Leisure Study. The purpose of the study was to: a) explore the relationships among physical activity, leisure boredom, and various substance use variables; b) determine if leisure boredom moderated the relationship among physical activity and substance use variables; and c) create a foundation of knowledge with which to educate adolescents and educators of the importance of adopting and maintaining a healthy lifestyle early in life (i.e., free from unhealthy behaviours such as substance use and physical inactivity). Studies examining relationships among physical activity and substance are limited and, in the past, have yielded inconsistent results. The interaction of leisure boredom with physical activity intensity variables, including both team and individual pursuits were tested using moderated hierarchical regression procedures. Six measures of physical activity were used as independent variables, including, frequency of high, medium, and low intensity individual and team physical activities. Various types of substance use, including, tobacco, marijuana, and alcohol use, binge drinking, and drunkenness were used as dependent variables. The results for this study indicated that frequency of physical activity intensity was a consistent, positive predictor of alcohol use and binge drinking, but not tobacco use, marijuana use, or drunkenness. Leisure boredom was found to be a highly significant predictor of tobacco use, however, it was not a moderator of relationships among physical activity intensity and substance use variables. The implications for the study findings, are discussed further, and suggestions for future research are presented.

The Moderating Effects of Appearance Commentary on the Relationship Between Weight Status and Physical Activity Participation in Female College Students

When looked at individually, overweight status and a higher frequency of negative appearance commentary (AC) are associated with lower physical activity (PA) levels. However, the combined effect has yet to be examined. The purpose of this study was to examine if the frequency of AC moderated the relationship between weight status and PA in college-aged females. No significant differences in PA levels (F(1,99)=2.41, p=.12) were found between the Never Overweight and Previously/Presently Overweight groups. Significant correlations existed for both negative AC (r=-.30, p=.00) and positive AC (r=.20, p=.05) with PA participation. AC did not significantly moderate the relationship between weight status and PA (F(2,95)=.65, p=.52, R2 adjusted=.13) as the interaction term did not account for any additional increase in variance (ΔR2=.01). Overall, AC frequency does not moderate the relationship between weight status and PA; other predictor variables should be explored.

Is Pride a Vice or a Virtue? Associations to Well-Being and Physical Activity

The first objective of the present study was to determine patterns of association between authentic and hubristic fitness-related pride to outcomes of well-being and leisure-time physical activity (LTPA). A second objective was to examine motivation as a potential mediator of these relationships. Participants (N = 119) were young adults who completed self-report questionnaires at two time points separated by 4-weeks. Authentic and hubristic pride were associated with well-being and LTPA at Time 1 and Time 2. Changes in pride were associated with changes in well-being but not LTPA. Results of the mediation analyses highlight the role of more autonomous motives, specifically intrinsic motivation, as important mediators between pride and well-being. Motivation did not mediate the relationship between pride and LTPA. Overall, both authentic and hubristic pride seem to be important in the promotion of well-being More research is needed to elucidate the relationship between pride and LTPA.