Creating interaction in online learning: a case study

This paper uses the case‐study method to examine detailed data related to student and tutor usage of an asynchronous discussion board as an interactive communication forum during a first‐semester associate degree course in applied psychology at the City University of Hong Kong. The paper identifies ‘what works’ in relation to discussion board use, demonstrating how students might gradually create an online community of their own, but only if prompted in a timely and appropriate way by the course structure. It also identifies three distinct phases in online interaction and suggests these might, to some extent, be mediated by assessment tasks

Validation and reliability of the Physical Activity Scale for the Elderly in Chinese population

Objectives: Physical Activity Scale for the Elderly (PASE) is a widely used questionnaire in epidemiological studies for assessing the physical activity level of elderly. This study aims to translate and validate PASE in Chinese population. Design: Cross-sectional study. Subjects: Chinese elderly aged 65 or above. Methods: The original English version of PASE was translated into Chinese (PASE-C) following standardized translation procedures. Ninety Chinese elderly aged 65 or above were recruited in the community. Test-retest reliability was determined by comparing the scores obtained from two separate administrations by the intraclass correlation coefficient. Validity was evaluated by Spearman’s rank correlation coefficients between PASE and Medical Outcome Survey 36-Item Short Form Health Survey (SF-36), grip strength, single-leg-stance, 5 times sit-to-stand and 10-m walk. Results: PASE-C demonstrated good test-retest reliability (intraclass correlation coefficient  =0.81). Fair to moderate association were found between PASE-C and most of the subscales of SF-36 (rs=0.285 to 0.578, p<0.01), grip strength (rs=0.405 to 0.426, p<0.001), single-leg-stance (rs =0.470 to 0.548, p<0.001), 5 times sit-to-stand (rs =–0.33, p=0.001) and 10-m walk (rs =–0.281, p=0.007). Conclusion: PASE-C is a reliable and valid instrument for assessing the physical activity level of elderly in Chinese population

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

REGULATION OF CENTROMERE INTEGRITY BY SET2

Ph.DDOCTOR OF PHILOSOPHY (SOM

Nesting of 2D parts with complex geometry and material heterogeneity

published_or_final_versionabstractMechanical EngineeringMasterMaster of Philosoph

Chinese speakers' metalinguistic and processing representations of words and characters

published_or_final_versionPsychologyMasterMaster of Philosoph

Regulatory role of orexin on postnatal maturation of the central vestibular system in rats

Orexin is a hypothalamic neuropeptide which is associated with motor function in the vestibular nucleus (VN) complex. Deficiency of orexin in adult rats results in a sudden loss of muscle strength as in cataplexy and deterioration in the performance of vestibular-mediated behaviors. To evaluate whether early postnatal perturbation of orexinergic circuits in the VN exerts any effects on the vestibular-related behaviors, we perturbed the activities of orexin receptors in the VN of postnatal day (P) 1 rat by implanting polymer (Elvax) slices loaded with orexin, orexin receptor antagonist (SB334867) or agonist ([Ala11, D-Leu15]-orexin-B) onto the dorsal surface of VN for slow release of the drug to the underlying VN. Specific behavioral tests including negative geotaxis, surface righting, air righting, balanced beam, rotarod, tail suspension, and dead reckoning were performed on these rats at different postnatal ages. Improvement of vestibular-related behavior was observed in rats pretreated with orexin receptor antagonist, while derangement of vestibular-related behaviors were observed in rats pretreated with orexin or its agonist. Interestingly, perturbation delivered to the VN at P14 did not impose any effect on animals’ behavior, indicating the presence of a critical period of orexinergic perturbation. To ascertain the source of orexinergic projection, we conducted behavioral experiments in rats which had received stereotaxic injection of a designed shOrexin adeno-associated virus (AAV) into the lateral hypothalamus (LH) of rat pups at P4. The virus expresses designed shRNA cocktails which reduces orexin mRNA and protein expression by more than 2 folds as indicated in results of western blot and quantitative polymerase chain reaction. Similar alternation in vestibular behavior were also observed in the experiments of air righting, tail suspension and dead reckoning, thereby providing further evidence with regard to the role of orexin on functional maturation of the VN complex during postnatal development. Given that glutamatergic receptors at the VN constitutes to the coordination of motor function, we hypothesized that behavioral alternation upon early orexinergic perturbation may be associated with glutamatergic circuits in the VN. Significant decrease in protein levels of AMPA receptor subunit GluA1 and GluR2 as well as NMDA receptor GluR1 were observed in the medial vestibular nucleus (MVN) of P6 rats pretreated at P1 with orexin and its agonist. In addition, significant increase in spine density and maturation were observed in the MVN of P14 rats pretreated at P1 with orexin and its agonist. Such change in morphology of dendritic spine among MVN neurons may account for the delay in behavioral emergence of vestibular-related responses. Altogether, our findings indicate that orexin modulates the glutamatergic circuits within the VN, and thereby regulate the expression of vestibular behavior and dendritic spine morphology of the MVN neuron. These provide us insights for development of novel therapeutic approach in children patients suffered from cataplexy and vestibular disorder.published_or_final_versionBiological SciencesMasterMaster of Philosoph