Effect of Tai Chi Training on Dual-Tasking Performance That Involves Stepping Down among Stroke Survivors: A Pilot Study

Descending stairs demands attention and neuromuscular control, especially with dual-tasking. Studies have demonstrated that stroke often degrades a survivor’s ability to descend stairs. Tai Chi has been shown to improve dual-tasking performance of healthy older adults, but no such study has been conducted in stroke survivors. This study investigated the effect of Tai Chi training on dual-tasking performance that involved stepping down and compared it with that of conventional exercise among stroke survivors. Subjects were randomized into Tai Chi (n=9), conventional exercise (n=8), and control (n=9) groups. Those in the former two groups received 12-week training. Assessments included auditory Stroop test, stepping down test, and dual-tasking test involving both simultaneously. They were evaluated before training (time-1), after training (time-2), and one month after training (time-3). Tai Chi group showed significant improvement in the auditory Stroop test from time-1 to time-3 and the performance was significantly better than that of the conventional exercise group in time-3. No significant effect was found in the stepping down task or dual-tasking in the control group. These results suggest a beneficial effect of Tai Chi training on cognition among stroke survivors without compromising physical task performance in dual-tasking. The effect was better than the conventional exercise group. Nevertheless, further research with a larger sample is warranted

Structure-function study of maize ribosome-inactivating protein: implications for the internal inactivation region and the sole glutamate in the active site

Maize ribosome-inactivating protein is classified as a class III or an atypical RNA N-glycosidase. It is synthesized as an inactive precursor with a 25-amino acid internal inactivation region, which is removed in the active form. As the first structural example of this class of proteins, crystals of the precursor and the active form were diffracted to 2.4 and 2.5 Å, respectively. The two proteins are similar, with main chain root mean square deviation (RMSD) of 0.519. In the precursor, the inactivation region is found on the protein surface and consists of a flexible loop followed by a long α-helix. This region diminished both the interaction with ribosome and cytotoxicity, but not cellular uptake. Like bacterial ribosome-inactivating proteins, maize ribosome-inactivating protein does not have a back-up glutamate in the active site, which helps the protein to retain some activity if the catalytic glutamate is mutated. The structure reveals that the active site is too small to accommodate two glutamate residues. Our structure suggests that maize ribosome-inactivating protein may represent an intermediate product in the evolution of ribosome-inactivating proteins. © 2007 The Author(s).published_or_final_versio

The C-terminal fragment of the ribosomal P protein complexed to trichosanthin reveals the interaction between the ribosome-inactivating protein and the ribosome

Ribosome-inactivating proteins (RIPs) inhibit protein synthesis by enzymatically depurinating a specific adenine residue at the sarcin-ricin loop of the 28S rRNA, which thereby prevents the binding of elongation factors to the GTPase activation centre of the ribosome. Here, we present the 2.2 Å crystal structure of trichosanthin (TCS) complexed to the peptide SDDDMGFGLFD, which corresponds to the conserved C-terminal elongation factor binding domain of the ribosomal P protein. The N-terminal region of this peptide interacts with Lys173, Arg174 and Lys177 in TCS, while the C-terminal region is inserted into a hydrophobic pocket. The interaction with the P protein contributes to the ribosome-inactivating activity of TCS. This 11-mer C-terminal P peptide can be docked with selected important plant and bacterial RIPs, indicating that a similar interaction may also occur with other RIPs

The impact of compassion from others and self-compassion on psychological distress, flourishing, and meaning in life among university students

Objectives: Research shows that compassion from others and from the self may enable university students to face, overcome, and bounce back from adversity and generate a greater sense of thriving and meaning in life. However, the underlying processes are largely unknown. The present study aimed to examine the associations of compassion with psychological distress, flourishing, and meaning in life among university students and explore the mechanisms underlying these associations. Methods: A total of 536 Hong Kong university students completed questionnaires measuring their experiences of compassion from others, self-compassion, resilience, psychological distress, flourishing, and meaning in life. Results: Serial mediation analyses showed that compassion from others was associated positively with self-compassion, which was, in turn, linked to greater resilience and consequently lower levels of psychological distress and higher levels of flourishing and meaning in life. Conclusions: Our findings reveal the associations of compassion from others and self-compassion with the well-being and life meaning of university students. The findings highlight the importance of being open and receptive to love and kindness from others. The findings also point to the importance of developing a caring attitude toward oneself

Palladium(II)-Catalyzed othro-C–H-Benzoxylation of 2-Arylpyridines by Oxidative Coupling with Aryl Acylperoxides

A palladium(II)-catalyzed ortho-benzoxylation of 2-arylpyridines with aryl acylperoxides was developed. With pyridyl as directing group, the benzoxylation reaction exhibits remarkable regioselectivity and excellent functional group tolerance, providing the products in up to 87% yield