Singaporean and Taiwanese pre-service teachers' beliefs and their attitude towards ICT: A comparative study

Teachers' epistemological and pedagogical beliefs and their attitude about ICT are identified as the second-order barrier for the integration of ICT into classrooms. In this paper, we report the findings obtained from our recent survey and conducted among Singaporean and Taiwanese pre-service teachers (N=108). The results indicate that the teachers' epistemological beliefs were generally relativistic. They were also inclined to believe rather strongly the constructivist notion of teaching. The profile we obtained in this study seems to suggest that pre-service teachers from Singapore and Taiwan are holding beliefs that are congruent to the education reform efforts. However, the teachers' attitude about ICT use does not seem to relate to their epistemological and pedagogical beliefs. The findings suggest that further effort needs to be taken in order to foster more productive use of ICT to support constructivism-oriented teaching. These results need to be verified with further study

Students\u27 Views on General Education: Insights Gained from the Narratives of Chinese Students in Hong Kong

The General University Requirements (GUR) is a component of the new 4-year undergraduate program at The Hong Kong Polytechnic University (PolyU). This study examined students’ views and experiences of the GUR using a qualitative methodology. Written comments of 240 freshmen, sophomores, and senior-year students with reference to open-ended questions on their memorable experiences in the GUR study were collected. The qualitative findings suggested that students generally had positive views on the GUR in terms of its widely adopted active and experiential learning pedagogy, useful and attractive contents, caring teaching staff, and rich learning outcomes. Challenges were also identified for further improvement of the GUR

Off-policy Q-learning: set-point design for optimizing dual-rate rougher flotation operational processes

Rougher flotation, composed of unit processes operating at a fast time scale and economic performance measurements known as operational indices measured at a slower time scale, is very basic and the first concentration stage for flotation plants. Optimizing operational process for rougher flotation circuits is extremely important due to high economic profit arising from the optimality of operational indices. This paper presents a novel off-policy Q-learning method to learn theoptimal solution to rougher flotation operational processes without the knowledge of dynamics of unit processes and operational indices. To this end, first, the optimal operational control (OOC) for dual-rate rougher flotationprocesses is formulated. Second, H∞ tracking control problem is developed to optimally prescribe the set-points for the rougher flotation processes. Then, a zero-sum game off-policy Q-learning algorithm is proposed to find theoptimal set-points by using measured data. Finally, simulation experiments are employed to show the effectiveness of the proposed method

Evaluation of Glucosidase Inhibitory and Cytotoxic Potential of Five Selected Edible and Medicinal Ferns

Purpose: To evaluate the glucosidase inhibitory and cytotoxic activities of five selected edible and medicinal ferns, namely, Blechnum orientale, Davallia denticulata, Diplazium esculentum, Nephrolepis biserrata, and Pteris vittata.Methods: The aqueous extracts of the five ferns were prepared by water extraction at 90 ºC for 1 h. Antiglucosidase assay was used to determine the effect of each extract on yeast alpha-glucosidase activity in vitro. Cytotoxicity was evaluated using methylthiazol tetrazolium assay on chronic myelogenous leukaemia cell line (K562). The phenolic, hydroxycinnamic acid, flavonoid and proanthocyanidin contents of the extracts were also determined.Results: The α-glucosidase inhibitory activity of D. esculentum (half maximal effective concentration, EC50 = 6.85 μg/ml) was considerably stronger than that of myricetin (EC50 = 53.21 μg/ml). B. orientale, D. esculentum, N. biserrata, and P. vittata were cytotoxic to K562 cells. P. vittata had the strongest cytotoxicity, although it was less potent than 5-fluorouracil. D. denticulata had the highest phenolic, hydroxycinnamic acid and flavonoid contents of all the extracts while B. orientale had the highest proanthocyanidin content.Conclusion: Among the five ferns evaluated, D. esculentum is a potential source of an antidiabetic agent and is recommended for further investigation in this regard. All the fern extracts, except D. denticulata, exhibited dose-dependent cytotoxicity against K562 cells.Keywords: Medicinal fern, α-Glucosidase inhibition, Cytotoxicity, Blechnum orientale, Davallia denticulata, Diplazium esculentum, Nephrolepis biserrata, Pteris vittat

Anti-oxidative, metal chelating and radical scavenging effects of protein hydrolysates from blue-spotted stingray

Purpose: To evaluate protein hydrolysates and membrane ultrafiltration fractions of blue-spotted stingray for metal chelating and radical scavenging activities, as well as protection against oxidative protein damage.Methods: Stingray protein isolates were hydrolysed with alcalase, papain and trypsin for 3 h. Alcalase hydrolysate was fractionated by membrane ultrafiltration to yield < 3, 3 - 10 and > 10 kDa fractions. Peptide contents, iron and copper chelating activity, 2, 2'-azino-bis(3- ethylbenzothiazoline-6-sulphonic acid) (ABTS) and hydroxyl radical scavenging activities, and protection against oxidative protein damage were evaluated.Results: Three-hour alcalase hydrolysate (3AH) had the highest peptide content and the lowest half maximal effective concentration (EC50) for ABTS radical scavenging (793.9 μg/mL), hydroxyl radical scavenging (6.93 mg/mL), iron chelating (116.4 μg/mL) and copper chelating  activity (2136.9 μg/mL) among the hydrolysates. Among the fractions of 3AH, < 3 kDa fraction had the best iron chelating activity, 3 - 10 kDa fraction exhibited the highest ABTS radical scavenging activity, while > 10 kDa fraction showed the best copper chelating activity. The < 3 kDa and 3 - 10 kDa fractions had similar levels of hydroxyl radical scavenging activity to reduced glutathione. The protective effects of 3AH and < 3 kDa fraction against oxidative protein damage were comparable to that of reduced glutathione.Conclusion: Alcalase is the best protease for producing hydrolysates with metal chelating and antioxidant activities from stingray proteins. Alcalase hydrolysate, specifically its < 3 kDa fraction, has potential for future applications in antioxidant therapy and health food formulation

Antioxidant Activities of Methanol Extract and Solvent Fractions of Marine Macroalga, Avrainvillea erecta (Berkeley) A. Gepp and E.S. Gepp (Dichotomosiphonaceae)

Purpose: To determine the antioxidant activity of methanol extract (ME) and solvent fractions of Avrainvillea erecta as well as their total phenolic and flavonoid contents.Methods: The antioxidant activities of ME as well as its chloroform, butanol, and aqueous fractions (CF, BF and WF, respectively) of A. erecta were evaluated via 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO) and hydrogen peroxide (H2O2) scavenging assays as well as ferric reducing antioxidant power (FRAP) assay. Total phenolic and flavonoid contents were determined spectrophotometrically.Results: CF and BF possessed equally high DPPH scavenging activity with half-maximal effective concentration (EC50) of 535 and 532 mg/ml, respectively. CF had stronger NO scavenging activity (EC50 743 μg/mL) than ME and BF, although weaker compared with quercetin (EC50 279 μg/ml). CF also produced the highest FRAP value (451 μmol Fe2+/g) among all samples examined. Notably, H2O2 scavenging activity was only found in CF (EC50 387 μg/ml), which was as strong (p > 0.05) as that of gallic acid (EC50 456 μg/mL). BF had the highest total phenolic content while CF had the highest total flavonoid content.Conclusion: CF of A. erecta, which has the highest flavonoid content of all the extracts evaluated, is a potential source of natural antioxidants, especially hydrogen peroxide scavengers.Keywords: Antioxidant, Avrainvillea erecta, Flavonoid, Macroalga, Phenoli

O-Glycome beam search arrays for carbohydrate ligand discovery

O-glycosylation is a post-translational modification of proteins crucial to molecular mechanisms in health and disease. O-glycans are typically highly heterogeneous. The involvement of specific O-glycan sequences in many bio-recognition systems is yet to be determined due to a lack of efficient methodologies. We describe here a targeted microarray approach: O-glycome beam search that is both robust and efficient for O-glycan ligand-discovery. Substantial simplification of the complex O-glycome profile and facile chromatographic resolution is achieved by arraying O-glycans as branches, monitoring by mass spectrometry, focusing on promising fractions, and on-array immuno-sequencing. This is orders of magnitude more sensitive than traditional methods. We have applied beam search approach to porcine stomach mucin and identified extremely minor components previously undetected within the O-glycome of this mucin that are ligands for the adhesive proteins of two rotaviruses. The approach is applicable to O-glycome recognition studies in a wide range of biological settings to give insights into glycan recognition structures in natural microenvironments

Conformational analysis of the Streptococcus pneumoniae hyaluronate lyase and characterization of Its hyaluronan-specific carbohydrate-binding module

For a subset of pathogenic microorganisms, including Streptococcus pneumoniae, the recognition and degradation of host hyaluronan contributes to bacterial spreading through the extracellular matrix and enhancing access to host cell surfaces. The hyaluronate lyase (Hyl) presented on the surface of S. pneumoniae performs this role. Using glycan microarray screening, affinity electrophoresis, and isothermal titration calorimetry we show that the N-terminal module of Hyl is a hyaluronan-specific carbohydrate-binding module (CBM) and the founding member of CBM family 70. The 1.2 Å resolution x-ray crystal structure of CBM70 revealed it to have a β-sandwich fold, similar to other CBMs. The electrostatic properties of the binding site, which was identified by site-directed mutagenesis, are distinct from other CBMs and complementary to its acidic ligand, hyaluronan. Dynamic light scattering and solution small angle x-ray scattering revealed the full-length Hyl protein to exist as a monomer/dimer mixture in solution. Through a detailed analysis of the small angle x-ray scattering data, we report the pseudoatomic solution structures of the monomer and dimer forms of the full-length multimodular Hyl

Risk of self-harm after the diagnosis of psychiatric disorders in Hong Kong, 2000–10: a nested case-control study

Background Psychiatric disorders are established risk factors for self-harm. However, variation in risk of self-harm by specific psychiatric disorder, stratified by gender and age, is rarely examined using population representative samples. This study aims to investigate the risk of self-harm following the diagnosis of different psychiatric disorders based on inpatient records retrieved from the Hong Kong Clinical Data Analysis and Reporting System (CDARS). Method A cohort of 86,353 people with a first-recorded diagnosis of depression, alcohol abuse/dependence, personality disorders, bipolar disorders, anxiety disorders, schizophrenia, or substance abuse/dependence, along with 134,857 matched controls, were followed between 2000 and 2010. For each diagnostic category, a Cox proportional hazard regression model was fitted to estimate the adjusted hazard ratio (aHR) (95% confidence intervals) of associated self-harm, adjusting for gender, age, admission time, district of residence, and comorbidities. Outcomes The personality disorders and substance abuse/dependence groups had the highest self-harm incidences of 3,174 and 3,018 per 100,000 patient-years, respectively. The highest risk of self-harm was found in the substance abuse/dependence group (aHR, 9·6; 95% CI, 8·4-11·0), followed by the groups with personality disorders (3·7; 2·8-4·9) and alcohol abuse/dependence (3·2; 2·9-3·7). When stratified by gender and age, the highest risk was found in substance abuse/dependence group for both genders (female: aHR, 7·7; 95% CI, 6·0-9·8; male: 10·5; 95% CI, 8·9-12·4) and all age groups (adolescent: aHR, 9·6; 95% CI, 7·2-12·7; young: 10·2; 95% CI, 8·4-12·3; middle-aged: 11·2; 95% CI, 8·0-15·6; Elderly: 3·2; 95% CI, 1·7-6·1). Interpretation First-recorded diagnosis of psychiatric disorders were significantly associated with elevated risks of subsequent self-harm. The associations varied considerably by diagnostic categories across gender-age subgroups. This finding highlighted the needs to develop more efficient and targeted preventive measures in psychiatric care management. Specific attention should be paid to demographic characteristics linked to increased risk within the same diagnostic category