Effects of long-term Wuqinxi exercise on working memory in older adults with mild cognitive impairment.

PURPOSE: Although physical exercise may improve memory in older adults, whether the Chinese traditional fitness exercise Wuqinxi improves working memory and delays cognitive deterioration in older adults with mild cognitive impairment (MCI) has not been assessed in randomized controlled experiments. METHODS: Fifty older adults with MCI based on their Montreal Cognitive Assessment scores were randomized to either a Wuqinxi exercise group or a non-exercise control group. The exercise group engaged in Wuqinxi once a week for 60 min each session for 40 weeks. Participants in the control group received no intervention and maintained their regular living habits. The n-back paradigm was used to measure changes in working memory before and after Wuqinxi exercise. RESULTS: In the 0-back task, the response speed of older adults with MCI who participated in Wuqinxi was faster than that of older adults with MCI in the non-exercise control group (P = 0.031); there was no significant difference in accuracy between the two groups (P > 0.05). In the 1-back and 2-back tasks, there was no significant difference in response times or in accuracy between the two groups (P > 0.05). CONCLUSIONS: In this randomized controlled study, participation in long-term Wuqinxi delayed the deterioration of working memory in older adults with MCI, suggesting that this exercise may be an effective intervention to delay or prevent the progression of MCI to Alzheimer's disease.

The interplay between cognitive tasks and vision for upright posture balance in adolescents.

BACKGROUND: The control of an upright stance in humans is important in medicine, psychology, and physiology. The maintenance of upright stance balance depends not only on sensory information from proprioceptive, vestibular, cutaneous, and visual sources but also on cognitive resources. The present study investigated the effects of cognitive tasks while standing with eyes open on upright stance balance in adolescents. We hypothesized that performing a cognitive task while standing with eyes open would increase body sway among these adolescents and that the upright posture would thus become less stable. METHODS: A static balance assessment system comprising a force platform connected to a computer was used to evaluate the stability of the upright stance among 21 healthy adolescents under six conditions: no cognitive task, a relatively easy cognitive task, or the same cognitive task made more difficult, with each task being performed while the eyes were open and again while the eyes were closed. The participants performed mental calculations as fast as possible by subtracting either 3 or 18 from a random three-digit number continuously, for the simple cognitive task or the difficult cognitive task, respectively. Each calculation was completed within 10 s. The evaluation indexes used to measure upright posture stability were the root mean square (RMS) of the total body sway in the mediolateral and anteroposterior directions, the mean velocity (MV) value of the total body sway, and the Romberg quotient (RQ) of these values. RESULTS: The RMS (p < 0.01) and MV (p < 0.01) values of the upright posture sway were lower when participants performed no cognitive task and their eyes were open than when their eyes were closed. When their eyes were open, compared with no cognitive task, the values of the measures evaluating upright posture sway were higher, meaning the stance was less stable, while performing either the simple or the more difficult cognitive task (RMS: simple task, p < 0.01; difficult task, p < 0.05; MV: simple task, p < 0.01; difficult task, p < 0.01) although no significant differences were detected for the RMS or MV values between the simple and more difficult cognitive tasks. The RQs for both the RMS and the total MV values of the upright posture sway during performance of the difficult cognitive task were significantly lower than when the participants performed no task. CONCLUSION: Performance of a cognitive task significantly reduced the upright posture balance in adolescents during eyes open although increased task difficulty did not show a greater effect. The interference between the performance of a cognitive task and the visual control of an upright stance may be attributable in part to cognitive and visual processing streams competing for common central resources, consistent with the Multiple Resource Theory of information processing.

[Emission Characteristics and Ozone Formation Potential of VOCs from a Municipal Solid Waste Composting Plant].

In Beijing, the chemical composition and component concentrations of volatile organic compounds (VOCs) were investigated during the municipal solid waste composting process using a portable gas chromatograph coupled with a mass spectrometer. The contributions of VOCs to the ozone formation potential were computed using the maximum incremental reactivity (MIR) scale and the propylene-equivalent concentration scale. The results showed that the concentrations of waste discharge in the sorting room, the first fermentation workshop, the second fermentation workshop, the compost product workshop, and the plant boundary were 10302.1, 15484.1, 929.9, 4693.6 and 370.4 µg·m-3, respectively. The main VOCs of the municipal solid waste composting plant were ethanol, limonene, and acetone. The propylene-equivalent concentrations of waste discharge in the sorting room, the first fermentation workshop, the second fermentation workshop, the compost product workshop, and the plant boundary were 25875.7, 4087.9, 378.0, 747.7 and 296.8 µg·m-3, whereas the O3 formation potentials computed using the MIR scale were 26979.3, 21168.3, 1469.3, 6439.6 and 455.8 µg·m-3. Reducing pollution by controlling the VOCs emission of waste discharge in the sorting room and the first fermentation workshop is important and can decrease the ozone formation potential. Given the accuracy and accessibility of the method, the MIR scale is more suitable for calculating the ozone formation potential of VOCs emitted from the municipal solid waste composting plant.

[Odor Emission Characteristics from Biochemical Treatment Facilities of Kichen Waste in China].

Xining, Ningbo and Beijing were closen as the representative cities about biochemical treatment of kichen waste. The treatment facilities of these cities were investigated and set as the sampling points. The main compositions and the material contents were analyzed by GC/MS, the odor concertration was obtained by the Triangle odor bag method. The results showed that oxygenated hydrocarbons including alcohol, aldehyde, ketone, ester were higher than others in the odor gases, however, the largest contribution to odor pollution were sulfocompounds and the 2nd materials were terpenes; According to the research of the three enterprises, ethyl alcohol, limonene, sulfuretted hydrogen, methyl mercaptan, dimethyl sulfide, dimethyl disulfide, acetaldehyde and ethyl acetate were likely to be considered as the typical odorants from the biochemical treatment facilities of kichen waste.