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Search Results: 1 - 10 of 764 matches for " Pui-Woon Yap "
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Production of Cyclodextrin Glycosyltransferase (CGTase) by Bacillus lehensis S8 using Sago Starch as Carbon Source
Pui-Woon Yap,Arbakariya B. Ariff,Kwan-Kit Woo,Siew-Ling Hii
Journal of Biological Sciences , 2010,
Abstract: Production of cyclodextrin glycosyltransferase (CGTase) is influenced by the reaction of the CGTase-producing strain towards various types of substrates. Variations in environmental factors such as concentrations of carbon and nitrogen sources possess significant effects on CGTase production. The present study was conducted with the prime purpose to optimise the cultivation medium in enhancing the CGTase production by a locally isolated alkalophilic Bacillus sp. The CGTase fermentation processes were performed in 250 mL Erlenmeyer flasks containing 200 mL of production medium with continuous shaking at 200 rpm and 37°C. Optimisation process was conducted by using change-a-factor-at-a-time method. From the study, an indigenous Malaysian carbon source, i.e., sago starch was found capable in improving the CGTase production with the CGTase yield of 18452 U g-1 at 0.1% w/v of starch. In addition to that, by using yeast extract as the sole nitrogen source in the medium, the CGTase excretion by the isolate is greatly enhanced as compared to the basal medium which employed two types of nitrogenous compounds. The optimised growth medium that has been successfully developed for high level of CGTase production by using the locally isolated Bacillus lehensis in 250 mL Erlenmeyer flask is comprised of (% w/v): 0.1% sago starch, 1% yeast extract, 1% sodium carbonate, 0.009% magnesium sulphate and 0.1% di-potassium hydrogen phosphate.
Spatial analysis of tuberculosis in four main ethnic communities in Taiwan during 2005 to 2009  [PDF]
Pui-Jen Tsai
Open Journal of Preventive Medicine (OJPM) , 2011, DOI: 10.4236/ojpm.2011.13017
Abstract: The aim of the present study was to assess spatial features of tuberculosis prevalence and their relationships with four main ethnic communities in Taiwan. Methods of spatial analysis were clustering pattern determination (such as global version of Moran’s test and local version of Gi*(d) statistic), using logistic regression calculations to identify spatial distributions over a contiguous five years and identify significant similarities, discriminant analysis to classify variables, and geographically weighted regression (GWR) to determine the strength of relationships between tuberculosis prevalence and ethnic variables in spatial features. Tuberculosis demonstrated decreasing trends in prevalence in both genders during 2005 to 2009. All results of the global Moran’s tests indicated spatial heterogeneity and clusters in the plain and mountainous Aboriginal townships. The Gi*(d) statistic calculated z-score outcomes, categorized as clusters or non-clusters, at at 5% significance level. According to the stepwise Wilks’ lambda discriminant analysis, in the Aborigines and Hoklo communities townships with clusters of tuberculosis cases differentiated from townships without cluster cases, to a greater extent than in the other communities. In the GWR models, the explanatory variables demonstrated significant and positive signs of parameter estimates in clusters occurring in plain and mountainous aboriginal townships. The explanatory variables of both the Hoklo and Hakka communities demonstrated significant, but negative, signs of parameter estimates. The Mainlander community did not significantly associate with cluster patterns of tuberculosis in Taiwan. Results indicated that locations of high tuberculosis prevalence closely related to areas containing higher proportions of the Aboriginal community in Taiwan. This information is relevant for assessment of spatial risk factors, which, in turn, can facilitate the planning of the most advantageous types of health care policies, and implementation of effective health care services.
Implementation of the Whole Language in Hong Kong Kindergartens: The Teachers’ Perceptive  [PDF]
Pui Lee Liu
Open Journal of Modern Linguistics (OJML) , 2013, DOI: 10.4236/ojml.2013.33023
Abstract:

The whole language approach is an important language theory in the West. In recent years, many kindergartens in Hong Kong have been implementing the whole language approach. To understand how this western educational concept is being implemented in the Chinese society, this research aims to investigate the current practices of teachers implementing the Whole Language Approach in Hong Kong. The study employed a combination of quantitative and qualitative methods with data collected through questionnaires and interviews. 138 questionnaires were sent to experienced teachers. A total of six teachers were interviewed, and they were all experienced. Findings indicate that most of the kindergarten teachers have the basic understanding of the whole language approach. However, it finds that many teachers cannot fully implement the meaning of the whole language approach in it entirely. Further training for teachers is needed.

Potential good reduction of degree 2 rational maps
Diane Yap
Mathematics , 2012,
Abstract: We give a complete characterization of degree two rational maps with potential good reduction over local fields. We show this happens exactly when the map corresponds to an integral point in the moduli space. We detail an algorithm by which to conjugate any degree two rational map corresponding to an integral point in the moduli space into a map with unit resultant. The local fields result is used to solve the same problem for fields over a principal ideal domain. Some additional results are given for degree 2 rational maps over the rationals.
Biodiesel from Plant Resources—Sustainable Solution to Ever Increasing Fuel Oil Demands  [PDF]
Md Enamul Hoque, Lu Pui Gee
Journal of Sustainable Bioenergy Systems (JSBS) , 2013, DOI: 10.4236/jsbs.2013.33023
Abstract:
The demand for fuel oil is ever increasing with the advance of the modern world, whereas worldwide reserves of fossil oils are diminishing at an alarming rate. However, there exist large stockpiles of vegetable oil feedstocks that could be exploited to produce fuel oil, called biodiesel with the aid of biotechnology. Initially, the biodiesel produced from vegetable oil did not attract much attention because of its high cost. However, the recent increase in petroleum prices and the uncertainties of petroleum availability led to the renewal of interest in biodiesel production from such sustainable resources (i.e., vegetable oil feedstocks). This research focuses on the production of biodiesel from plant resources, and further investigates the influences of key process parameters, such as the molar ratio of methanol to oil, catalyst concentration, reaction temperature, reaction period and stirring speed on the biodiesel yield. This investigation is to determine the optimum process parameters for maximum biodiesel yield. The biodiesel was produced from three vegetable oil feedstocks, namely palm, soybean and sunflower oil via a transesterification process. It was observed that all the process parameters significantly influenced the biodiesel yield. The maximum biodiesel yields for palm, sunflower and soybean oil feedstocks were found to be 87.5%, 83.6% and 80.2%, respectively at optimum condition. The results suggest that through proper optimization of the process parameters the biodiesel yields could be maximized. In conclusion, the production of biodiesel from plant resources would be regarded as a sustainable solution to the ever increasing demand of fuel oils.
Pen Pals Are Now in Your Finger Tips— A Global Collaboration Online Project to Develop Writing Skills  [PDF]
Woon Wern Lie, Melor Md Yunus
Creative Education (CE) , 2018, DOI: 10.4236/ce.2018.915188
Abstract: Many Malaysian students have an aversion towards writing. This study explores the potential of using an online material entitled, PenPal Schools, in the English as Second Language (ESL) classroom to develop writing skill with peers around the world via an online collaborative project. A research was carried out to provide insights into the aspects of PenPal Schools that are useful in developing writing skills and to find out the potential of this material as a teaching and learning tool in writing lessons. Thirty 12-year-old primary school students from Cheras, Selangor were chosen as the participants based on their March 2018 school based assessment writing results together?with May 2018 school based midterm writing results to avoid any biasness. After the March test, they were required to join PenPal Schools and take part in the online collaborative project. The research used mixed-method design where quantitative data from pre-and post-tests and responses from semi-structured?interviews were used to measure the outcome. The post test result reflected the improvement in their writing skill and it hadfound out that this educational website could make the writing lessons become more interesting as they could communicate and learn with peers around the world, particularly native speakers. This positive engagement in a dynamic and collaborative classroom is hoped to shed new light?on the era of 4.0 education.
Characterization of the Optical Properties of Heavy Metal Ions Using Surface Plasmon Resonance Technique  [PDF]
Yap Wing Fen, W. Mahmood Mat Yunus
Optics and Photonics Journal (OPJ) , 2011, DOI: 10.4236/opj.2011.13020
Abstract: The aim of this research is to characterize the optical properties of heavy metal ions (Hg2+, Cu2+, Pb2+ and Zn2+) using surface plasmon resonance (SPR) technique. Glass cover slips, used as substrates were coated with a 50 nm gold film using sputter coater. The measurement was carried out at room temperature using Kretchmann SPR technique. When the air medium outside the gold film is changed to heavy metal ions solution, the resonance angle shifted to the higher value for all samples of heavy metal ions solution. By our developed fitting program (using Matlab software), the experimental SPR curves were fitted to obtain the refractive index of Hg2+, Cu2+, Pb2+ and Zn2+ ions solution with different concentrations. Both the real and imaginary part of refractive index of the heavy metal ions solution increased with the concentration. The results give the basic idea such that the SPR technique could be used as an alternative optical sensor for detecting heavy metal ions in solution.
Controlling Chemotherapy-Induced Nausea and Vomiting with Neurokinin-1 Receptor Antagonists in Patients on AC-Based Chemotherapy—Are We There Yet?  [PDF]
Kevin Yap, Cassandra Leong, Alexandre Chan
Journal of Cancer Therapy (JCT) , 2012, DOI: 10.4236/jct.2012.31012
Abstract: Chemotherapy-induced nausea and vomiting (CINV) are distressing side effects of chemotherapy. Neurokinin-1 receptor antagonists (NK1-RAs) have been incorporated in the contemporary management of CINV. However, clinical studies on NK1-RAs have shown mixed results in reducing CINV risk. Most studies focused on the use of aprepitant (APR) and casopitant (CAS) in breast cancer patients receiving AC-type (doxorubicin and cyclophosphamide) chemotherapy. In this study, we compared the study design and clinical efficacies of these NK1-RAs in reducing CINV risk. Among the selected eight studies, 4 APR Randomized Controlled Trials (RCTs), 2 APR Observational Studies (OSs) and 2 CAS RCTs were identified. Patient-related characteristics such as the proportion of females (60.0% - 100.0%), age (46.5 - 59.5 years), histories of motion (5.6% - 47.0% in NK1-RA arms) and morning sicknesses (14.2% - 45.0% in NK1-RA arms) and types of antiemetic regimens; as well as chemotherapy-related characteristics such as the proportion of patients on AC chemotherapy (15.0% - 100.0%) varied greatly. In terms of efficacies, both APR and CAS improved overall CR and vomiting in majority of the studies. None of the studies, however, demonstrated that NK1-RA could provide adequate nausea control. To conclude, NK1-RAs are effective in improving vomiting and overall CR, but not useful in controlling nausea or attaining CC, the ideal CINV endpoint. A shift in paradigm is needed for future CINV research. As healthcare providers continue to strive for optimum CINV control in their patients, we hope this review can help them make better informed clinical decisions.
Face Recognition in the Presence of Expressions  [PDF]
Xia Han, Moi Hoon Yap, Ian Palmer
Journal of Software Engineering and Applications (JSEA) , 2012, DOI: 10.4236/jsea.2012.55038
Abstract: The purpose of this study is to enhance the algorithms towards the development of an efficient three dimensional face recognition system in the presence of expressions. The overall aim is to analyse patterns of expressions based on techniques relating to feature distances compare to the benchmarks. To investigate how the use of distances can help the recognition process, a feature set of diagonal distance patterns, were determined and extracted to distinguish face models. The significant finding is that, to solve the problem arising from data with facial expressions, the feature sets of the expression-invariant and expression-variant regions were determined and described by geodesic distances and Euclidean distances. By using regression models, the correlations between expressions and neutral feature sets were identified. The results of the study have indicated that our proposed analysis methods of facial expressions, was capable of undertaking face recognition using a minimum set of features improving efficiency and computation.
Reducing Fuel Consumption Using Flywheel Battery Technology for Rubber Tyred Gantry Cranes in Container Terminals  [PDF]
Kai Hou Tan, Yap Fook Fah
Journal of Power and Energy Engineering (JPEE) , 2017, DOI: 10.4236/jpee.2017.57002
Abstract: Flywheel Energy Storage System (FESS) is used as an energy regeneration system to help with reducing peak power requirements on RTG cranes that are used to load or unload container ships. Nevertheless, with the use of FESS, Port Operator can deploy undersized generator for new RTG as this will further reduce fuel consumption. This paper presents the investigation of the amount of energy and fuel consumption that can be reduced in Rubber Tyred Gantry (RTG) cranes in container terminals by the use of simulation. In addition, Variable Speed Generator is integrated to the simulation-hybridized RTG. Simulation results reveal that the total energy saving exceeded 30% relatively to conventional RTG. A hardware-in-loop system is introduced for the purpose of validating the simulation results. The hardware components procured include a FESS, a Variable Frequency Drive (VFD) and brake resistors.
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