Predictors of Physical Activity Levels in University Physical Education Implementing Sport Education.

By adopting Sport Education into the university context, this study examined how lesson content and teacher interaction contribute to university students' physical activity levels during physical education lessons. Following a continuing professional development workshop, a 10-week Sport Education season was designed collaboratively and implemented at a university, taking into account the university's facilities. This study used the momentary time sampling tool, System for Observing Fitness Instruction Time, in which eight teachers and 202 students (72% male) were videotaped in 156 lessons. The data on physical activity levels, lesson content, and teacher behavior were collected and analyzed. The student-participants engaged in an average of 38.77 (±18.78) moderate-to-vigorous physical activity (MVPA) minutes which did not meet the recommendation of 50% lesson time. Findings of hierarchical linear regression indicated that knowledge (ß = 0.29) and general content (ß = 0.29) contributed to the sitting physical activity while skill practices (ß = 0.25) and gameplay (ß = 0.38) predicted the MVPA. Practical implications of utilizing the features of Sport Education in boosting the intensity of activities are discussed, especially team affiliation, formal competition, and record keeping. Further investigations are proposed on the interaction of gameplay content and teacher behavior with larger sample size.

Introduction of a hydrogen bond between phylloquinone PhQ(A) and a threonine side-chain OH group in photosystem I.

The phylloquinone acceptor PhQ(A) in photosystem I binds to the protein through a single H-bond to the backbone nitrogen of PsaA-L722. Here, we investigate the effect of this H-bond on the electron transfer (ET) kinetics by substituting threonine for PsaA-L722. Room temperature spin-polarized transient EPR measurements show that in the PsaA-L722T mutant, the rate of PhQ(A)(-) to F(X) ET increases and the hyperfine coupling to the 2-methyl group of PhQ(A) is much larger than in the wild type. Molecular dynamics simulations and ONIOM type electronic structure calculations indicate that it is possible for the OH group of the Thr side chain to form an H-bond to the carbonyl oxygen atom, O(4) of the phylloquinone, and that this results in an increase in the 2-methyl hyperfine couplings as observed in the transient EPR data. The Arrhenius plot of the PhQ(A)(-) to F(X) ET in the PsaA-L722T mutant suggests that the increased rate is probably the result of a slight change in the electronic coupling between PhQ(A)(-) and F(X). The strong deviation from Arrhenius behavior observed at ∼200 K can be reproduced using a semiclassical model, which takes the zero-point energy of the mode coupled to the ET into account. However, since the change in slope of the Arrhenius plot occurs at the protein glass transition temperature, it is argued that it could be the result of a change in the protein relaxation dynamics at this temperature rather than quantum mechanical effects.