Mortality in relation to changes in physical activity in middle-aged to older Chinese: An 8-year follow-up of the Guangzhou Biobank Cohort Study

BackgroundPhysical activity (PA) is generally encouraged. Studies from developed countries in the West have shown that maintenance of adequate PA or increasing PA are associated with lower mortality risk. It is unclear whether these associations apply to an older Chinese population. Hence, we examined the changes in PA prospectively among a middle-aged and older Chinese population over an average of 4 years and explored their subsequent mortality risks.MethodsMetabolic equivalent scores of PA among participants in the Guangzhou Biobank Cohort Study were calculated. Participants were divided into 3 groups related to PA level, and changes in PA were classified into 9 categories. Information on vital status and causes of death from March 2008 to December 2012 (the first repeated examination) until December 31, 2017, was obtained via record linkage with the Death Registry.ResultsOf 18,104 participants aged 61.21 ± 6.85 years (mean ± SD), 1461 deaths occurred within 141,417 person-years. Compared to participants who maintained moderate PA, those who decreased PA from moderate or high levels to a low level had increased risks for all-cause mortality (hazard ratio (HR) = 1.47, 95% confidence interval (95%CI): 1.11–1.96). Participants who maintained a high level of PA (HR = 0.83, 95%CI: 0.70–0.98) or increased PA from low to high levels (HR = 0.71, 95%CI: 0.52–0.97) showed lower all-cause mortality risks. Those who maintained low PA levels showed a higher all-cause mortality risk, whereas those who increased their PA levels showed a non-significantly lower risk. Similar results were found for cardiovascular disease risk.ConclusionEven at an older age, maintaining a high PA level or increasing PA from low to high levels results in lower mortality risks, suggesting that substantial health benefits might be achieved by maintaining or increasing engagement in adequate levels of PA. The increased risk of maintaining a low PA level or decreasing PA to a low level warrants the attention of public health officials and clinicians.     

Exploring reading-spelling connection as locus of dyslexia in Chinese

This paper advances the argument that in learning to read/spell Chinese characters and words, it is important for learners to understand the role of the component parts. These constituents consist of phonetic and semantic radicals, or bujians, made up of clusters of strokes in their proper sequence. Beginning readers/spellers need to be sensitive to the positional hierarchy and internal structure of these constituent parts. Those Chinese children diagnosed with developmental dyslexia tend to have more difficulties in spelling Chinese characters and in writing to dictation than in reading. A lexical decision study with two groups of tertiary students differing in their Chinese language ability was carried out to test their efficiency in processing real and pseudo characters as a function of printed frequency of the characters, and the consistency of their component semantic radicals. There is some evidence that even for adult readers differing in their Chinese language ability, lexicality, frequency of characters and the consistency of the semantic radicals affect accurate and rapid character identification. Suggestions for research and teaching approaches are made to enhance the analysis and synthesis of the phonetic and semantic radicals to promote efficient reading and spelling in Chinese.     

Robust stabilization of uncertain time-delay systems containing nonlinear saturating actuators

The robust stabilization problem for a class of uncertain linear time-delay systems containing sector saturating actuator is considered in this paper. The uncertain time-delay systems under consideration are described by state differential equations with time-varying unknown-but-bounded uncertain parameters and delayed state. The delay is assumed to be constant bounded but unknown. The new criterion of delay-dependent robust stabilizability for uncertain time-delay systems is presented and the corresponding robust memoryless state feedback controller is derived in terms of the solutions of several linear matrix inequalities (LMIs). Numerical example is presented to illustrate the obtained results. Project supported by the Natural Science Key Foundation of China (NSFC: 69934030) and the Excellent (Youth) Teacher for Teaching and Research Award Foundation in Institutions of China.     

Effects of arch-support orthoses on ground reaction forces and lower extremity kinematics related to running at various inclinations

ABSTRACT

While foot orthoses are commonly used in running, little is known regarding biomechanical risk potentials during uphill running. This study investigated the effects of arch-support orthoses on kinetic and kinematic variables when running at different inclinations. Sixteen male participants ran at different inclinations (0°, 3° and 6°) when wearing arch-support and flat orthoses on an instrumented treadmill. Arch-support orthoses induced longer contact time, larger initial ankle dorsiflexion, maximum ankle eversion, and knee sagittal range of motion (RoM) (p < 0.05). As incline slopes increased, vertical impact peak and loading rate, stride length, and ankle coronal RoM decreased, but contact time, stride frequency, initial ankle dorsiflexion and inversion, maximum dorsiflexion, initial knee flexion, and ankle sagittal RoM increased (p < 0.05). Furthermore, knee sagittal RoM was lowest when running at an inclination of 3°. The interaction effect indicated that in arch-support condition, participants running at 6° induced higher maximum ankle eversion than running at 0° (p < 0.05), while no differences were found in flat orthosis condition. These findings suggest that the use of arch-support orthoses would influence running biomechanics that is related to injury risks. Running at higher inclination led to more alterations to biomechanical variables than at lower inclination.     

Effects of different evaluative feedback on students’ self-efficacy in learning

Two studies examined the effects of four types of teachers’ evaluative feedback on Chinese students’ self-efficacy in English vocabulary acquisition. In Study 1, a random sample of Grade 8 students (N = 79) learned prefixes and received either formative or summative feedback after failure in test. The results showed that students who received summative feedback showed a larger decrease in their self-efficacy than those who received formative feedback. In Study 2, a random sample of Grade 7 students (N = 77) went through similar procedures as in Study 1 except that students received either self-referenced or norm-referenced feedback. The results showed that self-referenced feedback was more beneficial to students’ self-efficacy than norm-referenced feedback. The influences of teachers’ evaluation and feedback on students’ self-efficacy are discussed.     

Students’ use of asynchronous discussions for academic discourse socialization

Our universities are becoming increasingly diverse at the same time as online asynchronous discussions (OADs) are emerging as the most important forum for computer mediated communication (CMC) in distance education. But there is shortage of studies that explore how graduate students from different ethnic, linguistic and cultural backgrounds use OADs for academic discourse socialization. This article discusses a qualitative study conducted to address these issues. Language socialization and community of practice theories informed the study. Analyses of surveys, interviews, and Blackboard postings from seven hybrid courses reveal that participants perceived OADs highly positively and used them as a virtual community for academic and professional discourse socialization and appropriation. Findings also suggest that students experienced some frustrations and disappointments regarding professorial presence and grading. We discuss these findings, show how academic and professional discourse socialization occurs in asynchronous virtual reality, and draw implications for further research and practice.     

Does the gender of the teacher matter in the teaching of reading literacy? Teacher gender and pupil attainment in reading literacy in Hong Kong

A study of 148 primary school teachers and 4867 Grade 4 pupils in Hong Kong found no support for the proposal that boys learn to read better when taught by men teachers. In fact, it was found that both boys and girls learnt better when taught by women. Responses to a teacher questionnaire indicate significant differences in the preferred patterns of teaching favoured by male and female teachers. Responses from men teachers suggest they are more authoritarian, prefer to control pupils' learning, engage pupils in whole-class reading and like to read passages aloud while pupils follow the text. Responses from women teachers suggest they prefer to teach reading in groups, to group pupils according to reading ability, set tasks that suit pupils' stage of learning, allocate more time for pupils to read books and use the school library and encourage pupils to discover for themselves the meaning of new vocabulary encountered in text. The implications of these findings are discussed.     

FROM “EXPLORING THE MIDDLE ZONE” TO “CONSTRUCTING A BRIDGE”: EXPERIMENTING IN THE SPIRAL BIANSHI MATHEMATICS CURRICULUM

The spiral bianshi curriculum, an improvement on bianshi teaching developed by Gu (2000) and in line with Marton’s theory of variation (Marton & Booth, 1997), was tried out in a primary school in Hong Kong. This improved theoretical framework for the spiral bianshi curriculum comprises four types of bianshi problems—the inductive bianshi, the broadening bianshi, the deepening bianshi, and the applicative bianshi. Based on this framework, the research team developed a set of teaching materials on the three topics of division of fraction, speed, and volume. The materials were tried out in 21 Primary 6 classes (a total of 686 students) in a school. The effect was compared with a reference group using standard textbook materials in Hong Kong. A series of instruments, pre-tests, and post-tests were administered to gauge the effects on students’ performance in solving routine and non-routine problems, as well as the affective outcomes including self-concept, attitude towards learning mathematics, approaches to learning, and conceptions of mathematics. The intervention effects of the experimental design were examined by hierarchical regression analysis. The research reveals that students using spiral bianshi teaching materials performed significantly better than their counterparts using standard textbook materials. However, no significant differences were identified among affective learning outcome variables despite the positive results on cognitive learning outcomes. The findings indicate that spiral bianshi curriculum has high potential in enhancing students’ learning effectiveness. However, further studies are needed to map its strengths in detail.     

Direction dependence of displacement time for two-fluid electroosmotic flow

Electroosmotic flow that involves one fluid displacing another fluid is commonly encountered in various microfludic applications and experiments, for example, current monitoring technique to determine zeta potential of microchannel. There is experimentally observed anomaly in such flow, namely, the displacement time is flow direction dependent, i.e., it depends if it is a high concentration fluid displacing a low concentration fluid, or vice versa. Thus, this investigation focuses on the displacement flow of two fluids with various concentration differences. The displacement time was determined experimentally with current monitoring method. It is concluded that the time required for a high concentration solution to displace a low concentration solution is smaller than the time required for a low concentration solution to displace a high concentration solution. The percentage displacement time difference increases with increasing concentration difference and independent of the length or width of the channel and the voltage applied. Hitherto, no theoretical analysis or numerical simulation has been conducted to explain this phenomenon. A numerical model based on finite element method was developed to explain the experimental observations. Simulations showed that the velocity profile and ion distribution deviate significantly from a single fluid electroosmotic flow. The distortion of ion distribution near the electrical double layer is responsible for the displacement time difference for the two different flow directions. The trends obtained from simulations agree with the experimental findings.