Search results for: Wong Man Ting
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 350

Search results for: Wong Man Ting

140 Effects of a Bioactive Subfraction of Strobilanthes Crispus on the Tumour Growth, Body Weight and Haematological Parameters in 4T1-Induced Breast Cancer Model

Authors: Yusha'u Shu'aibu Baraya, Kah Keng Wong, Nik Soriani Yaacob

Abstract:

Strobilanthes crispus (S. crispus), is a Malaysian herb locally known as ‘Pecah kaca’ or ‘Jin batu’ which have demonstrated potent anticancer effects in both in vitro and in vivo models. In particular, S. crispus subfraction (SCS) significantly reduced tumor growth in N-methyl-N-Nitrosourea-induced breast cancer rat model. However, there is paucity of information on the effects of SCS in breast cancer metastasis. Thus, in this study, the antimetastatic effects of SCS (100 mg/kg) was investigated following 30 days of treatment in 4T1-induced mammary tumor (n = 5) model. The response to treatment was assessed based on the outcome of the tumour growth, body weight and hematological parameters. The results demonstrated that tumor bearing mice treated with SCS (TM-S) had significant (p<0.05) reduction in the mean tumor number and tumor volume as well as tumor weight compared to the tumor bearing mice (TM), i.e. tumor untreated group. Also, there was no secondary tumor formation or tumor-associated lesions in the major organs of TM-S compared to the TM group. Similarly, comparable body weights were observed among the TM-S, normal (uninduced) mice treated with SCS and normal (untreated/control) mice (NM) groups compared to the TM group (p<0.05). Furthermore, SCS administration does not cause significant changes in the hematological parameters as compared to the NM group, which indicates no sign of anemia and toxicity related effects. In conclusion, SCS significantly inhibited the overall tumor growth and metastasis in 4T1-induced breast cancer mouse model suggesting its promising potentials as therapeutic agent for breast cancer treatment.

Keywords: 4T1-cells, breast cancer, metastasis, Strobilanthes crispus

Procedia PDF Downloads 123
139 A Hybrid Simulation Approach to Evaluate Cooling Energy Consumption for Public Housings of Subtropics

Authors: Kwok W. Mui, Ling T. Wong, Chi T. Cheung

Abstract:

Cooling energy consumption in the residential sector, different from shopping mall, office or commercial buildings, is significantly subject to occupant decisions where in-depth investigations are found limited. It shows that energy consumptions could be associated with housing types. Surveys have been conducted in existing Hong Kong public housings to understand the housing characteristics, apartment electricity demands, occupant’s thermal expectations, and air–conditioning usage patterns for further cooling energy-saving assessments. The aim of this study is to develop a hybrid cooling energy prediction model, which integrated by EnergyPlus (EP) and artificial neural network (ANN) to estimate cooling energy consumption in public residential sector. Sensitivity tests are conducted to find out the energy impacts with changing building parameters regarding to external wall and window material selection, window size reduction, shading extension, building orientation and apartment size control respectively. Assessments are performed to investigate the relationships between cooling demands and occupant behavior on thermal environment criteria and air-conditioning operation patterns. The results are summarized into a cooling energy calculator for layman use to enhance the cooling energy saving awareness in their own living environment. The findings can be used as a directory framework for future cooling energy evaluation in residential buildings, especially focus on the occupant behavioral air–conditioning operation and criteria of energy-saving incentives.

Keywords: artificial neural network, cooling energy, occupant behavior, residential buildings, thermal environment

Procedia PDF Downloads 132
138 Incorporating Lexical-Semantic Knowledge into Convolutional Neural Network Framework for Pediatric Disease Diagnosis

Authors: Xiaocong Liu, Huazhen Wang, Ting He, Xiaozheng Li, Weihan Zhang, Jian Chen

Abstract:

The utilization of electronic medical record (EMR) data to establish the disease diagnosis model has become an important research content of biomedical informatics. Deep learning can automatically extract features from the massive data, which brings about breakthroughs in the study of EMR data. The challenge is that deep learning lacks semantic knowledge, which leads to impracticability in medical science. This research proposes a method of incorporating lexical-semantic knowledge from abundant entities into a convolutional neural network (CNN) framework for pediatric disease diagnosis. Firstly, medical terms are vectorized into Lexical Semantic Vectors (LSV), which are concatenated with the embedded word vectors of word2vec to enrich the feature representation. Secondly, the semantic distribution of medical terms serves as Semantic Decision Guide (SDG) for the optimization of deep learning models. The study evaluate the performance of LSV-SDG-CNN model on four kinds of Chinese EMR datasets. Additionally, CNN, LSV-CNN, and SDG-CNN are designed as baseline models for comparison. The experimental results show that LSV-SDG-CNN model outperforms baseline models on four kinds of Chinese EMR datasets. The best configuration of the model yielded an F1 score of 86.20%. The results clearly demonstrate that CNN has been effectively guided and optimized by lexical-semantic knowledge, and LSV-SDG-CNN model improves the disease classification accuracy with a clear margin.

Keywords: convolutional neural network, electronic medical record, feature representation, lexical semantics, semantic decision

Procedia PDF Downloads 107
137 Spatial Comparative Analysis on Travels of Mackay in Taiwan

Authors: Shao-Chi Chien, Ying-Ju Chen, Chiao-Yu Tseng, Wan-Ting Lee, Yi-Wen Cheng

Abstract:

Dr. George Leslie Mackay arrived at Takoukang (now Port of Kaohsiung) in Taiwan on December 30, 1871. When Dr. Mackay dedicated at Taiwan for 30 years, he has been an important factor in such areas as preaching, medical and engaged in education. Many researchers have thoroughly studied Dr. Mackay's travels to understand his impact on the state of education, medicine and religion in Taiwan. In the 30-year period of hard work, Dr. Mackay's made outstanding influence on the church in Taiwan. Therefore, the present study will be the mission of the establishment of hospitals, schools, churches which preaching, education, and medicine whether there are related the number of comparisons to explore. According to The Diaries of George Leslie Mackay, our research uses the Geographic Information System (GIS) to map the location of Dr. Mackay's travel in Taiwan and compares it with today's local churches, hospitals, and schools whether there are related the number of comparisons to explore. Therefore, our research focuses on the whole of Taiwan, divided into missionary, medical and education as the main content of the three major parts. Additionally, use of point layer, the surface layer of the property table to establish, in-depth mission of Dr. Mackay's development in Taiwan and Today's comparison. The results will be based on the classification of three different colors pictures that the distance of Mackay's contribution of preaching, medicine, and education. Our research will be compared with the current churches, hospitals, schools and the past churches, hospitals, schools. The results of the present study will provide a reference for future research.

Keywords: George Leslie Mackay, geographic information system, spatial distribution, color categories analysis

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136 The Practice of Integrating Sustainable Elements into the Housing Industry in Malaysia

Authors: Wong Kean Hin, Kumarason A. L. V. Rasiah

Abstract:

A building provides shelter and protection for an individual to live, work, sleep, procreate or engage in leisurely activities comfortably. Currently, a very popular term related to building was often stated by many parties, which is sustainability. A sustainable building is environmental friendly, healthy to the occupants, as well as efficient in electricity and water. This particular research is important to any parties that are involved in the construction industry. This research will provide the awareness and acceptability of Malaysian public towards sustainable residential building. It will also provide the developers about which sustainable features that the people usually want so that the developers can build a sustainable housing that suits the needs of people. Then, propose solutions to solve the difficulties of implementing sustainability in Malaysian housing industry. Qualitative and quantitative research methods were used throughout the process of data collection. The quantitative research method was distribution of questionnaires to 100 Malaysian public and 50 individuals that worked in developer companies. Then, the qualitative method was an interview session with experienced personnel in Malaysian construction industry. From the data collected, there is increasingly Malaysian public and developers are aware about the existence of sustainability. Moreover, the public is willing to invest on sustainable residential building with minimum additional cost. However, there is a mismatch in between sustainable elements provided by developers and the public needs. Some recommendations to improve the progression of sustainability had been proposed in this study, which include laws enforcement, cooperation between the both government sector with private sector, and private sector with private sector, and learn from modern countries. These information will be helpful and useful for the future of sustainability development in Malaysia.

Keywords: acceptability, awareness, Malaysian housing industry, sustainable elements, green building index

Procedia PDF Downloads 334
135 Visual Simulation for the Relationship of Urban Fabric

Authors: Ting-Yu Lin, Han-Liang Lin

Abstract:

This article is about the urban form of visualization by Cityengine. City is composed of different domains, and each domain has its own fabric because of arrangement. For example, a neighborhood unit contains fabrics such as schools, street networks, residential and commercial spaces. Therefore, studying urban morphology can help us understand the urban form in planning process. Streets, plots, and buildings seem as urban fabrics, and they configure urban form. Traditionally, urban morphology usually discussed single parameter, which is building type, ignoring other parameters such as streets and plots. However, urban space is three-dimensional, instead of two-dimensional. People perceive urban space by their visualization. Therefore, using visualization can fill the gap between two dimensions and three dimensions. Hence, the study of urban morphology will strengthen the understanding of whole appearance of a city. Cityengine is a software which can edit, analyze and monitor the data and visualize the result for GIS, a common tool to analyze data and display the map for urban plan and urban design. Cityengine can parameterize the data of streets, plots and building types and visualize the result in three-dimensional way. The research will reappear the real urban form by visualizing. We can know whether the urban form can be parameterized and the parameterized result can match the real urban form. Then, visualizing the result by software in three dimension to analyze the rule of urban form. There will be three stages of the research. It will start with a field survey of Tainan East District in Taiwan to conclude the relationships between urban fabrics of street networks, plots and building types. Second, to visualize the relationship, it will turn the relationship into codes which Cityengine can read. Last, Cityengine will automatically display the result by visualizing.

Keywords: Cityengine, urban fabric, urban morphology, visual simulation

Procedia PDF Downloads 266
134 Impact of Water, Sanitation and Hygiene Interventions on Water Quality in Primary Schools of Pakistan

Authors: Jamil Ahmed, Li P. Wong, Yan P. Chua

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The United Nation's sustainable development goals include the target to ensure access to water and sanitation for all; however, very few studies have assessed school-based drinking water in Pakistan. The purpose of this study was to characterize water quality in primary schools of Pakistan and to characterize how recent WASH interventions were associated with school water quality. We conducted a representative cross-sectional study of primary schools in the Sindh province of Pakistan. We used structured observations and structured interviews to ascertain the school’s WASH conditions. Our primary exposures of interest were the implementation of previous WASH interventions in the school and the water source type. Outcomes of interest included water quality (measured by various chemical and microbiological indicators) and water availability at the school’s primary drinking water source. We used log-binomial regression to characterize how WASH exposures were associated with water quality outcomes. We collected data from 256 schools. Groundwater was the primary drinking water source at most schools (87%). Water testing showed that 14% of the school’s water had arsenic above the WHO recommendations, and over 50% of the water samples exceeded recommendations for both lead and cadmium. A majority of the water sources (52%) had fecal coliform contamination. None of the schools had nitrate contamination (0%), and few had fluoride contamination (5%). Regression results indicated that having a recent WASH intervention at the school was not associated with either arsenic contamination (prevalence ratio=0.97; 95% CI: 0.46-2.1) or with fecal coliform contamination (PR=0.88; 95% CI: 0.67-1.17). Our assessment unveiled several water quality gaps that exist, including high heavy metal and fecal contamination. Our findings will help various stakeholders to take suitable action to improve water quality in Pakistani schools.

Keywords: WASH interventions, water quality, primary school children, heavy metals

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133 Biosignal Recognition for Personal Identification

Authors: Hadri Hussain, M.Nasir Ibrahim, Chee-Ming Ting, Mariani Idroas, Fuad Numan, Alias Mohd Noor

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A biometric security system has become an important application in client identification and verification system. A conventional biometric system is normally based on unimodal biometric that depends on either behavioural or physiological information for authentication purposes. The behavioural biometric depends on human body biometric signal (such as speech) and biosignal biometric (such as electrocardiogram (ECG) and phonocardiogram or heart sound (HS)). The speech signal is commonly used in a recognition system in biometric, while the ECG and the HS have been used to identify a person’s diseases uniquely related to its cluster. However, the conventional biometric system is liable to spoof attack that will affect the performance of the system. Therefore, a multimodal biometric security system is developed, which is based on biometric signal of ECG, HS, and speech. The biosignal data involved in the biometric system is initially segmented, with each segment Mel Frequency Cepstral Coefficients (MFCC) method is exploited for extracting the feature. The Hidden Markov Model (HMM) is used to model the client and to classify the unknown input with respect to the modal. The recognition system involved training and testing session that is known as client identification (CID). In this project, twenty clients are tested with the developed system. The best overall performance at 44 kHz was 93.92% for ECG and the worst overall performance was ECG at 88.47%. The results were compared to the best overall performance at 44 kHz for (20clients) to increment of clients, which was 90.00% for HS and the worst overall performance falls at ECG at 79.91%. It can be concluded that the difference multimodal biometric has a substantial effect on performance of the biometric system and with the increment of data, even with higher frequency sampling, the performance still decreased slightly as predicted.

Keywords: electrocardiogram, phonocardiogram, hidden markov model, mel frequency cepstral coeffiecients, client identification

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132 Finite Element Analysis of the Lumbar Spine after Unilateral and Bilateral Laminotomies and Laminectomy

Authors: Chih-Hsien Chen, Yi-Hung Ho, Chih-Wei Wang, Chih-Wei Chang, Yen-Nien Chen, Chih-Han Chang, Chun-Ting Li

Abstract:

Laminotomy is a spinal decompression surgery compatible with a minimally invasive approach. However, the unilateral laminotomy for bilateral side decompression leads to more perioperative complications than the bilateral laminotomy. Although the unilateral laminotomy removes the least bone tissue among the spinal decompression surgeries, the difference of spinal stability between unilateral and bilateral laminotomy and laminectomy is rarely investigated. This study aims to compare the biomechanical effects of unilateral and bilateral laminotomy and laminectomy on the lumbar spine by finite element (FE) simulation. A three-dimensional FE model of the lumbar spine (L1–L5) was constructed with the vertebral body, discs, and ligaments, as well as the sacrum was constructed. Three different surgical methods, namely unilateral laminotomy, bilateral laminotomy and laminectomy, at L3–L4 and L4–L5 were considered. Partial pedicle and entire ligamentum flavum were removed to simulate bilateral decompression in laminotomy. The entire lamina and spinal processes from the lower L3 to upper L5 were detached in the laminectomy model. Then, four kinds of loadings, namely flexion, extension, lateral bending and rotation, were applied on the lumbar with various decompression conditions. The results indicated that the bilateral and unilateral laminotomy both increased the range of motion (ROM) compared with intact lumbar, while the laminectomy increased more ROM than both laminotomy did. The difference of ROM between the bilateral and unilateral laminotomy was very minor. Furthermore, bilateral laminotomy demonstrated similar poster element stress with unilateral laminotomy. Unilateral and bilateral laminotomy are equally suggested to bilateral decompression of lumbar spine with minimally invasive technique because limited effect was aroused due to more bone remove in the bilateral laminotomy on the lumbar stability. Furthermore, laminectomy is the last option for lumbar decompression.

Keywords: minimally invasive technique, lumbar decompression, laminotomy, laminectomy, finite element method

Procedia PDF Downloads 148
131 Investigating Malaysian Prereader’s Cognitive Processes when Reading English Picture Storybooks: A Comparative Eye-Tracking Experiment

Authors: Siew Ming Thang, Wong Hoo Keat, Chee Hao Sue, Fung Lan Loo, Ahju Rosalind

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There are numerous studies that explored young learners’ literacy skills in Malaysia but none that uses the eye-tracking device to track their cognitive processes when reading picture storybooks. This study used this method to investigate two groups of prereaders’ cognitive processes in four conditions. (1) A congruent picture was presented, and a matching narration was read aloud by a recorder; (2) Children heard a narration telling about the same characters in the picture but involves a different scene; (3) Only a picture with matching text was present; (4) Students only heard the reading aloud of the text on the screen. The two main objectives of this project are to test which content of pictures helps the prereaders (i.e., young children who have not received any formal reading instruction) understand the narration and whether children try to create a coherent mental representation from the oral narration and the pictures. The study compares two groups of children from two different kindergartens. Group1: 15 Chinese children; Group2: 17 Malay children. The medium of instruction was English. An eye-tracker were used to identify Areas of Interest (AOI) of each picture and the five target elements and calculate number of fixations and total time spent on fixation of pictures and written texts. Two mixed factorial ANOVAs with the storytelling performance (good, average, or weak) and vocabulary level (low, medium, high) as between-subject variables, and the Areas of Interests (AOIs) and display conditions as the within-subject variables were performedon the variables.

Keywords: eye-tracking, cognitive processes, literacy skills, prereaders, visual attention

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130 Flipped Classroom in Bioethics Education: A Blended and Interactive Online Learning Courseware That Enhances Active Learning and Student Engagement

Authors: Molly Pui Man Wong

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In this study, a blended and interactive e-learning Courseware that our team developed will be introduced, and our team’s experiences on how the e-learning Courseware and the flipped classroom benefit student learning in bioethics in the medical program will be shared. This study is a continuation of the previously established study, which provides a summary of the well-developed e-learning Courseware in a blended learning approach and an update on its efficiency and efficacy. First, a collection of animated videos capturing selected topics of bioethics and related ethical issues and dilemma will be introduced. Next, a selection of problem-based learning videos (“simulated doctor-patient role play”) with pop-up questions and discussions will be further discussed. Our recent findings demonstrated that these activities launched by the Courseware strongly engaged students in bioethics education and enhanced students’ critical thinking and creativity, which were consistent with the previous data in the preliminary studies. Moreover, the educational benefits of the online art exhibition, art jamming, and competition will be discussed, through which students could express bioethics through arts and enrich their learning in medical research in an interactive, fun, and entertaining way, strengthening their interests in bioethics. Furthermore, online survey questionnaires and focus group interviews were conducted. Consistent with the preliminary studies, our results indicated that implementing the e-learning Courseware with a flipped classroom in bioethics education enhanced both active learning and student engagement. In conclusion, our Courseware not only reinforces education in art, bioethics, and medicine but also benefits students in understanding and critical thinking in socio-ethical issues and serves as a valuable learning tool in bioethics teaching and learning.

Keywords: bioethics, courseware, e-learning, flipped classroom

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129 The Implementation of Teaching and Learning Quality Assurance System at the Chaoyang University of Technology for Academic Year 2013-2015

Authors: Ting Hsiang Chang

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Nowadays in Taiwan, higher education, which was previously more emphasized on teaching-oriented approaches, has gradually shifted to an approach more focusing on students learning outcomes. With student employment rate as an important indicator for University Program Evaluation periodically held by the Ministry of Education, it becomes extremely critical for a university to build up a teaching and learning quality assurance system to bridge the gap between learning and practice. Teaching and Learning Quality Assurance System has been built and implemented at Chaoyang University of Technology for years and has received substantial results. By employing various forms of evaluation and performance appraisals, the effectiveness of teaching and learning can consistently be tracked as a means of ensuring teaching and learning quality. This study aims to explore the evaluation system of teaching and learning quality assurance system at the Chaoyang University of Technology by means of content analysis. The study contents the evaluation reports on the teaching and learning quality assurance at the Chaoyang University of Technology in the Academic Year 2013-2015. The quantitative results of the assessment were analyzed using the five-point Likert Scale. Quality assurance Committee meetings were further held for examining and discussions on the results. To the end, the annual evaluation report is to be produced as references used to improve approaches in both teaching and learning. The findings indicate that there is a respective relationship between the overall teaching evaluation items and the teaching goals and core competencies. In addition, graduates’ feedbacks were also collected for further analysis to examine if the current educational planning is able to achieve the university’s teaching goal and cultivation of core competencies.

Keywords: core competencies, teaching and learning quality assurance system, teaching goals, university program evaluation

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128 An Energy-Balanced Clustering Method on Wireless Sensor Networks

Authors: Yu-Ting Tsai, Chiun-Chieh Hsu, Yu-Chun Chu

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In recent years, due to the development of wireless network technology, many researchers have devoted to the study of wireless sensor networks. The applications of wireless sensor network mainly use the sensor nodes to collect the required information, and send the information back to the users. Since the sensed area is difficult to reach, there are many restrictions on the design of the sensor nodes, where the most important restriction is the limited energy of sensor nodes. Because of the limited energy, researchers proposed a number of ways to reduce energy consumption and balance the load of sensor nodes in order to increase the network lifetime. In this paper, we proposed the Energy-Balanced Clustering method with Auxiliary Members on Wireless Sensor Networks(EBCAM)based on the cluster routing. The main purpose is to balance the energy consumption on the sensed area and average the distribution of dead nodes in order to avoid excessive energy consumption because of the increasing in transmission distance. In addition, we use the residual energy and average energy consumption of the nodes within the cluster to choose the cluster heads, use the multi hop transmission method to deliver the data, and dynamically adjust the transmission radius according to the load conditions. Finally, we use the auxiliary cluster members to change the delivering path according to the residual energy of the cluster head in order to its load. Finally, we compare the proposed method with the related algorithms via simulated experiments and then analyze the results. It reveals that the proposed method outperforms other algorithms in the numbers of used rounds and the average energy consumption.

Keywords: auxiliary nodes, cluster, load balance, routing algorithm, wireless sensor network

Procedia PDF Downloads 252
127 Hierarchical Porous Carbon Composite Electrode for High Performance Supercapacitor Application

Authors: Chia-Chia Chang, Jhen-Ting Huang, Hu-Cheng Weng, An-Ya Lo

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This study developed a simple hierarchical porous carbon (HPC) synthesis process and used for supercapacitor application. In which, mesopore provides huge specific surface area, meanwhile, macropore provides excellent mass transfer. Thus the hierarchical porous electrode improves the charge-discharge performance. On the other hand, cerium oxide (CeO2) have also got a lot research attention owing to its rich in content, low in price, environmentally friendly, good catalytic properties, and easy preparation. Besides, a rapid redox reaction occurs between trivalent cerium and tetravalent cerium releases oxygen atom and increase the conductivity. In order to prevent CeO2 from disintegration under long-term charge-discharge operation, the CeO2 carbon porous materials were was integrated as composite material in this study. For in the ex-situ analysis, scanning electron microscope (SEM), X-ray diffraction (XRD), transmission electron microscope (TEM) analysis were adopted to identify the surface morphology, crystal structure, and microstructure of the composite. 77K Nitrogen adsorption-desorption analysis was used to analyze the porosity of each specimen. For the in-situ test, cyclic voltammetry (CV) and chronopotentiometry (CP) were conducted by potentiostat to understand the charge and discharge properties. Ragone plot was drawn to further analyze the resistance properties. Based on above analyses, the effect of macropores/mespores and the CeO2/HPC ratios on charge-discharge performance were investigated. As a result, the capacitance can be greatly enhanced by 2.6 times higher than pristine mesoporous carbon electrode.

Keywords: hierarchical porous carbon, cerium oxide, supercapacitor

Procedia PDF Downloads 96
126 Thermal Performance of an Air-Water Heat Exchanger (AWHE) Operating in Groundwater and Hot-Humid Climate

Authors: César Ramírez-Dolores, Jorge Wong-Loya, Jorge Andaverde, Caleb Becerra

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Low-depth geothermal energy can take advantage of the use of the subsoil as an air conditioning technique, being used as a passive system or coupled to an active cooling and/or heating system. This source of air conditioning is possible because at a depth less than 10 meters, the subsoil temperature is practically homogeneous and tends to be constant regardless of the climatic conditions on the surface. The effect of temperature fluctuations on the soil surface decreases as depth increases due to the thermal inertia of the soil, causing temperature stability; this effect presents several advantages in the context of sustainable energy use. In the present work, the thermal behavior of a horizontal Air-Water Heat Exchanger (AWHE) is evaluated, and the thermal effectiveness and temperature of the air at the outlet of the prototype immersed in groundwater is experimentally determined. The thermohydraulic aspects of the heat exchanger were evaluated using the Number of Transfer Units-Efficiency (NTU-ε) method under conditions of groundwater flow in a coastal region of sandy soil (southeastern Mexico) and air flow induced by a blower, the system was constructed of polyvinyl chloride (PVC) and sensors were placed in both the exchanger and the water to record temperature changes. The results of this study indicate that when the exchanger operates in groundwater, it shows high thermal gains allowing better heat transfer, therefore, it significantly reduces the air temperature at the outlet of the system, which increases the thermal effectiveness of the system in values > 80%, this passive technique is relevant for building cooling applications and could represent a significant development in terms of thermal comfort for hot locations in emerging economy countries.

Keywords: convection, earth, geothermal energy, thermal comfort

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125 Finite Element Analysis of Resonance Frequency Shift of Laminated Composite Beam

Authors: Cheng Yang Kwa, Yoke Rung Wong

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Laminated composite materials are widely employed in automotive, aerospace, and other industries. These materials provide distinct benefits due to their high specific strength, high specific modulus, and ability to be customized for a specific function. However, delamination of laminated composite materials is one of the main defects which can occur during manufacturing, regular operations, or maintenance. Delamination can bring about considerable internal damage, unobservable by visual check, that causes significant loss in strength and stability, leading to composite structure catastrophic failure. Structural health monitoring (SHM) is known to be the automated method for monitoring and evaluating the condition of a monitored object. There are several ways to conduct SHM in aerospace. One of the effective methods is to monitor the natural frequency shift of structure due to the presence of defect. This study investigated the mechanical resonance frequency shift of a multi-layer composite cantilever beam due to interlaminar delamination. ANSYS Workbench® was used to create a 4-plies laminated composite cantilever finite element model with [90/0]s fiber setting. Epoxy Carbon UD (230GPA) Prepreg was chosen, and the thickness was 2.5mm for each ply. The natural frequencies of the finite element model with various degree of delamination were simulated based on modal analysis and then validated by using literature. It was shown that the model without delamination had natural frequency of 40.412 Hz, which was 1.55% different from the calculated result (41.050 Hz). Thereafter, the various degree of delamination was mimicked by changing the frictional conditions at the middle ply-to-ply interface. The results suggested that delamination in the laminated composite cantilever induced a change in its stiffness which alters its mechanical resonance frequency.

Keywords: structural health monitoring, NDT, cantilever, laminate

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124 Language and Culture Exchange: Tandem Language Learning for University Students

Authors: Hebe Wong, Luz Fernandez Calventos

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Tandem language learning, a language exchange process based on the principles of autonomy and reciprocity, provides opportunities for interlocutors to learn each other’s language by communicating online or face-to-face. While much attention has been paid to the process and outcomes of tandem learning via email, little has been discussed about the effectiveness of face-to-face tandem learning on language and culture exchange for university students. The LACTS (Language and Culture Tandem Scheme), an 8-week project, was set up to study students’ perceptions of conducting tandem learning to assist their language and culture exchange. Students of both post-graduate and undergraduate programmes (N=103) from a Hong Kong SAR university were put in groups of 4 to 6 according to their availability and language preferences and met for an hour a week. While sample task sheets on a range of topics were provided to assist the language exchange, all groups were encouraged to take charge of their meeting format and choose their own topics. At the end of the project, a 19-item questionnaire, which included both open-and closed-ended questions investigating students’ perceptions of reciprocal teaching and cultural exchange, was administered. Thirty-minute individual interviews were conducted to elicit students’ views and experiences in the LACTS activities. Quantitative and qualitative data analysis showed that most students agreed that the project had enhanced their cultural awareness and helped create an inclusive and participatory learning environment. Significant differences were found in students’ confidence in speaking their targeted language after joining the scheme. The interviews also provided rich data on the variety of formats and leadership patterns in student-led meetings, which could shed light on student autonomy and future tandem language learning projects.

Keywords: autonomy, reciprocity, tandem language learning, university students

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123 Oxygen-Tolerant H₂O₂ Reduction Catalysis by Iron Phosphate Coated Iron Oxides

Authors: Chia-Ting Chang, Chia-Yu Lin

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We report on the decisive role of iron phosphate (FePO₄), formed in-situ during the electrochemical characterization, played in the electrocatalytic activity, especially its oxygen tolerance of iron oxides towards H₂O₂ reduction. Iron oxides studied including, Nanorod arrays (NRs) of β-FeOOH, γ-Fe₂O₃, α-Fe₂O₃, α-Fe₂O₃ nanosheets (α-Fe₂O₃NS), α-Fe₂O₃ nanoparticles (α-Fe₂O₃NP), were synthesized using chemical bath deposition. The nanostructure was controlled simply by adjusting the composition of precursor solution and reaction duration for CBD process, whereas the crystal phase was controlled by adjusting the annealing temperature. It was found that iron phosphate (FePO₄) was deposited in-situ onto the surface of this nanostructured α-Fe₂O₃ during the electrochemical pretreatment in the phosphate electrolyte, and both FePO₄ and α-Fe₂O₃ showed the activity in catalysing the electrochemical reduction of H₂O₂. In addition, the interaction/compatibility between deposited FePO₄ and iron oxides has a decisive effect on the overall electrocatalytic activity of the resultant electrodes; FePO₄ only showed synergetic effect on the overall electrocatalytic activity of α-Fe₂O₃NR and α-Fe2O₃NS. Both α-Fe₂O₃NR and α-Fe₂O₃NS showed two reduction peaks in phosphate electrolyte containing H₂O₂, one being pH-dependent and related to the electrocatalytic properties of FePO₄, and the other one being pH-independent and only related to the intrinsic electrocatalytic properties of α-Fe₂O₃NR and α-Fe₂O₃NS. However, all iron oxides showed only one pH-independent reductive peak in non-phosphate electrolyte containing H₂O₂. The synergesitic catalysis exerted by FePO₄ with α-Fe₂O₃NR or α-Fe₂O₃NS providing additional oxygen-insensitive active site for H₂O₂ reduction, which allows their applications to electrochemical detection of H₂O₂ without the interference of O₂ involving in oxidase-catalyzed chemical processes.

Keywords: H₂O₂ reduction, Iron oxide, iron phosphate, O₂ tolerance

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122 A Primary Care Diagnosis of Middle-Aged Men with Oral Cancer Who Underwent Extensive Resection and Flap Repair: A Case Report

Authors: Ching-Yi Huang, Pi-Fen Cheng, Hui-Zhu Chen, Shi Ting Huang, Heng-Hua Wang

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This is a case of oral cancer after extensive resection and modified right lateral neck lymph node dissection followed by reconstruction with a skin flap. The nursing period lasted From September 25 to October 3, 2017, through observation, interview, physical assessment, and medical record review, the author identified the following nursing problems: acute pain, impaired oral mucous membrane, and body image change. During the nursing period, the author provided individual and overall nursing care and established mutual trust through the use of empathy. Author listened and eased the patient's physical indisposition, such as wound pain, we use medications and acupuncture massage to relieve pain. However, for oral mucosa change caused by surgery, provide continuous and complete oral care and oral exercise training to improve oral mucosal healing and restore swallowing function. In the body-image changes, guided him to express his feeling after the body-image change, and enhanced support and from the family, and encouraged him to attend head and neck cancer survivor alliance which allowed the patient to accept the altered body image and reaffirm self-worth. Hopefully, through sharing this nursing experience will help to the nursing care quality of nursing care for oral cancer patients after extensive resection and modified right lateral neck lymph node dissection followed by reconstruction with a skin flap.

Keywords: oral cancer, acute pain, impaired oral mucous membrane, body image change

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121 Interpersonal Variation of Salivary Microbiota Using Denaturing Gradient Gel Electrophoresis

Authors: Manjula Weerasekera, Chris Sissons, Lisa Wong, Sally Anderson, Ann Holmes, Richard Cannon

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The aim of this study was to characterize bacterial population and yeasts in saliva by Polymerase chain reaction followed by denaturing gradient gel electrophoresis (PCR-DGGE) and measure yeast levels by culture. PCR-DGGE was performed to identify oral bacteria and yeasts in 24 saliva samples. DNA was extracted and used to generate DNA amplicons of the V2–V3 hypervariable region of the bacterial 16S rDNA gene using PCR. Further universal primers targeting the large subunit rDNA gene (25S-28S) of fungi were used to amplify yeasts present in human saliva. Resulting PCR products were subjected to denaturing gradient gel electrophoresis using Universal mutation detection system. DGGE bands were extracted and sequenced using Sanger method. A potential relationship was evaluated between groups of bacteria identified by cluster analysis of DGGE fingerprints with the yeast levels and with their diversity. Significant interpersonal variation of salivary microbiome was observed. Cluster and principal component analysis of the bacterial DGGE patterns yielded three significant major clusters, and outliers. Seventeen of the 24 (71%) saliva samples were yeast positive going up to 10³ cfu/mL. Predominately, C. albicans, and six other species of yeast were detected. The presence, amount and species of yeast showed no clear relationship to the bacterial clusters. Microbial community in saliva showed a significant variation between individuals. A lack of association between yeasts and the bacterial fingerprints in saliva suggests the significant ecological person-specific independence in highly complex oral biofilm systems under normal oral conditions.

Keywords: bacteria, denaturing gradient gel electrophoresis, oral biofilm, yeasts

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120 Our Shared Humanity: Bridging the Great Divide of Different Religions

Authors: Aida Raissi, Holly Wong, Elma Raissi

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Background: Connection is a primal need established during infancy and reiterated in many forms of social interaction. When we make connections with others we experience growth, continuity, and gain an understanding of the other’s sense of the world. Feeling socially connected to another individual or community has been shown to increase self-esteem, happiness, and meaning. However, feeling connected to another individual or a specific community may also decrease the motivation to seek connection with more distant individuals or communities. Furthermore, we allow ourselves to interact with those in other communities as apart from us, and in some cases, to dehumanize their existence. Objective: The aim of this project is to bridge the gap between different communities, specifically religious communities and foster feelings of connection as one with all members through the medium of art, specifically photography. Method: Members of all major faiths including Agnosticism, Atheism, Buddhism, Catholicism, Christianity, Ismaili, Jewish, Ja’far Shia, Sunni will be interviewed. Participants will be asked to partake in a brief interview of two parts: A. Answering two questions: 1. What are you most looking forward to in the future, and why? 2. What does religion mean to you? B. Having their picture taken. Our questions aim to elicit individual stories that together, show that we have more in common, than differences, despite our faiths. With the completion of the interviews, the responses will be compiled together and major themes will be identified. Impact: The resulting stories and corresponding individual pictures provide an excellent opportunity to encourage and inspire people to get to know those of other beliefs and values, participate in each other’s communities and develop a sense of oneness within our shared humanity. Knowledge translation: The personal stories, and the common themes they illustrate, will be shared with various audiences, including the general public, academia and targeted groups such as students. This will be done through displaying the photographs and responses at art galleries, conferences, in print and online.

Keywords: social justice, religion, connection, understanding, community

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119 A Cognitive Behavioural Therapy (CBT) Intervention Programme for Excessive Internet Use among Young Adults

Authors: Ke Guek Nee, Wong Siew Fan, Nigel V. Marsh

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Excessive use of the Internet has become a cause for concern in many countries, including Malaysia. Such behaviour is reported to be more prevalent amongst young adults who are reported to be spending large amount of time on the Internet. The present study has three objectives. First one is designing a manual-based Cognitive Behavioural Therapy (CBT) programme to reduce problematic Internet use among young adults in Malaysia. Second one is examining the effectiveness of a manual-based CBT programme at the pilot study stage. Thirdly, the programme focuses on reducing the level of stress and anxiety in problematic Internet users. We adopted CBT with single subject experimental design method. A total of six participants completed the entire program. They were asked to report their daily Internet use and software was installed on their devices to record actual use. The data collection involved three time frame measurements: T1 (baseline), T2 (immediately during the last session of the intervention sessions), and T3 (follow-up). Three scales were used to measure the effectiveness of the program: Depression, Anxiety, Stress Scales (DASS), Social Interaction Anxiety Scale (SIAS), and Problematic Internet Use Questionnaire (PIUQ). The results revealed that the intervention programme has significantly improved two dimensions of problematic Internet use which were obsession and control disorder. The participants’ mental health also showed a deduction in means scores for depression, anxiety and stress with depression showing the greatest improvement after the intervention programme. The participants’ social anxiety showed a slight deduction in means scores. We concluded that the intervention programme designed was effective. However, its limitations need to be addressed in future research.

Keywords: excessive internet use, cognitive behavioral thearapy (CBT), psychological well-being, young adults

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118 Characterization of White Spot Lesion Using Focused Ion Beam - Scanning Electron Microscopy

Authors: Malihe Moeinin, Robert Hill, Ferranti Wong

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Background: A white spot lesion (WSL) is defined as subsurface enamel porosity from carious demineralisation on the smooth surfaces of the tooth. It appears as a milky white opacity. Lesions shown an apparently intact surface layer, followed underneath by the more porous lesion body. The small pores within the body of the lesion act as diffusion pathway for both acids and minerals, so allowing the demineralisation of enamel to occur at the advancing front of the lesion. Objectives: The objective is to mapthe porosity and its size on WSL with Focused Ion Bean- Scanning Electron Microscopy (FIB-SEM) Method: The basic method used for FIB-SEM consisted of depositing a one micron thick layer of platinum over 25μmx 25μm of the interest region of enamel. Then, making a rough cut (25μmx 5μmx 20μm) with 3nA current and 30Kv was applied with the help of drift suppression (DS), using a standard “cross-sectional” cutting pattern, which ended at the front of the deposited platinum layer. Two adjacent areas (25μmx 5μmx 20μm) on the both sides of the platinum layer were milled under the same conditions. Subsequent, cleaning cross-sections were applied to polish the sub-surface edge of interest running perpendicular to the surface. The "slice and view" was carried out overnight for milling almost 700 slices with 2Kv and 4nA and taking backscattered (BS) images. Then, images were imported into imageJ and analysed. Results: The prism structure is clearly apparent on FIB-SEM slices of WSL with the dissolution of prism boundaries as well as internal porosity within the prism itself. Porosity scales roughly 100-400nm, which is comparable to the light wavelength (500nm). Conclusion: FIB-SEM is useful to characterize the porosity of WSL and it clearly shows the difference between WSL and normal enamel.

Keywords: white spot lesion, FIB-SEM, enamel porosity, porosity

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117 Developing an Intelligent Table Tennis Ball Machine with Human Play Simulation for Technical Training

Authors: Chen-Chi An, Jun-Yi He, Cheng-Han Hsieh, Chen-Ching Ting

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This research has successfully developed an intelligent table tennis ball machine with human play simulate all situations of human play to take the service. It is well known; an excellent ball machine can help the table tennis coach to provide more efficient teaching, also give players the good technical training and entertainment. An excellent ball machine should be able to service all balls based on human play simulation due to the conventional competitions are today all taken place for people. In this work, two counter-rotating wheels are used to service the balls, where changing the absolute rotating speeds of the two wheels and the differences of rotating speeds between the two wheels can adjust the struck forces and the rotating speeds of the ball. The relationships between the absolute rotating speed of the two wheels and the struck forces of the ball as well as the differences rotating speeds between the two wheels and the rotating speeds of the ball are experimentally determined for technical development. The outlet speed, the ejected distance, and the rotating speed of the ball were measured by changing the absolute rotating speeds of the two wheels in terms of a series of differences in rotating speed between the two wheels for calibration of the ball machine; where the outlet speed and the ejected distance of the ball were further converted to the struck forces of the ball. In process, the balls serviced by the intelligent ball machine were based on the received calibration curves with help of the computer. Experiments technically used photosensitive devices to detect the outlet and rotating speed of the ball. Finally, this research developed some teaching programs for technical training using three ball machines and received more efficient training.

Keywords: table tennis, ball machine, human play simulation, counter-rotating wheels

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116 A Pilot Study Assessing the Effectiveness of a Virtual Reality Intervention for Alleviating Pain and Anxiety in the Pediatric Emergency Room

Authors: Muqadis Shazia Rajpar, Lawrence Mitelberg, Rubaiat S. Ahmed, Jemer Garrido, Rukhsana Hossain, Sergey M. Motov

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Distraction techniques have been used as a means to reduce pain, anxiety, and stress in various healthcare settings to facilitate care and make visits less unpleasant. Using virtual reality (VR) in the pediatric emergency setting can be a valuable, effective, and safe non-pharmacological alternative to the current standard of care for pain and anxiety management in pediatric patients. Our pilot study aimed to evaluate the effectiveness of a VR-based intervention as an alternative distraction modality to alleviate pain and anxiety associated with pediatric emergency department (ED) visits and acute pain conditions. The pilot study period was from November 16 to December 9, 2022, for pediatric ED visits for pain, anxiety, or both. Patients were selected based on a novel VR protocol to receive the VR intervention with the administration of pre and post-intervention surveys concerning pain/anxiety ratings and pain scores (Wong-Baker FACES/NRS). Descriptive statistics, paired t-test, and a Fisher Exact Test were used for data analysis, assuming a p-value of 0.05 for significance. A total of 33 patients (21 females, 12 males), ages 5-20 (M = 10.5, SD = 3.43) participated in this study – 12 patients had pain, 2 patients had anxiety, and 19 patients had both pain and anxiety. There was a statistically significant decrease in post-intervention pain scores of less than one point on the rating scale (6.48 vs. 5.62, p < .001). There was a statistically significant reduction in the percentage of patients suffering from “considerable” or “great” pain after the VR intervention (51.6% to 42.3%, p < .001). Similarly, we noticed an increase in the number of patients with “slight” or “moderate” pain post–VR intervention (48.4% to 57.7%, p < .001). Lastly, we demonstrated a decrease in anxiety among patients after utilizing VR (63.6% vs. 36.4%, p < .001). To conclude, VR can alleviate pain and anxiety in pediatric patients and be a useful non-pharmacological tool in the emergency setting.

Keywords: anxiety, emergency room, pain management, pediatric emergency medicine, virtual reality

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115 IgA/λ Plasma Cell Myeloma with λ Light Chain Amyloidosis: A Case Report

Authors: Kai Pei Huang, Ting Chung Hung, Li Ching Wu

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Amyloidosis refers to a variety of conditions wherein amyloid proteins are abnormally deposited in organ or tissues and cause harm. Among the several forms of amyloidosis, the principal types of that in inpatient medical services are the AL amyloidosis (primary) and AA amyloidois (secondary). AL Amyloidois is due to deposition of protein derived from overproduction of immunoglobulin light chain in plasma cell myeloma. Furthermore, it is a systemic disorder that can present with a variety of symptoms, including heavy proteinemia and edema, heptosplenomegaly, otherwise unexplained heart failure. We reported a 78-year-old female presenting dysuria, oliguria and leg edema for several months. Laboratory data showed proteinuria (UPCR:1679.8), leukocytosis (WBC:16.2 x 10^3/uL), results of serum urea nitrogen (39mg/dL), creatinine (0.76 mg/dL), IgG (748 mg/dL.), IgA (635 mg/dL), IgM (63 mg/dL), kappa light chain(18.8 mg/dL), lambda light chain (110.0 mg/dL) and kappa/lambda ratio (0.17). Renal biopsy found amyloid fibrils in glomerular mesangial area, and Congo red stain highlights amyloid deposition in glomeruli. Additional lab studies included serum protein electrophoresis, which shows a major monoclonal peak in β region and minor small peak in gamma region, and the immunotyping studies for serum showed two IgA/λ type. We treated sample with beta-mercaptoethanol which reducing the polymerized immunoglobulin to clarify two IgA/λ are secreted from the same plasma cell clone in bone marrow. Later examination confirmed it existed plasma cell infiltration in bone marrow, and the immunohistochemical staining showed monotypic for λ light chain and are positive for IgA. All findings mentioned above reveal it is a case of plasma cell myeloma with λ Light Chain Amyloidosis.

Keywords: amyloidosis, immunoglobulin light chain, plasma cell myeloma, serum protein electrophoresis

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114 Understanding the Semantic Network of Tourism Studies in Taiwan by Using Bibliometrics Analysis

Authors: Chun-Min Lin, Yuh-Jen Wu, Ching-Ting Chung

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The formulation of tourism policies requires objective academic research and evidence as support, especially research from local academia. Taiwan is a small island, and its economic growth relies heavily on tourism revenue. Taiwanese government has been devoting to the promotion of the tourism industry over the past few decades. Scientific research outcomes by Taiwanese scholars may and will help lay the foundations for drafting future tourism policy by the government. In this study, a total of 120 full journal articles published between 2008 and 2016 from the Journal of Tourism and Leisure Studies (JTSL) were examined to explore the scientific research trend of tourism study in Taiwan. JTSL is one of the most important Taiwanese journals in the tourism discipline which focuses on tourism-related issues and uses traditional Chinese as the study language. The method of co-word analysis from bibliometrics approaches was employed for semantic analysis in this study. When analyzing Chinese words and phrases, word segmentation analysis is a crucial step. It must be carried out initially and precisely in order to obtain meaningful word or word chunks for further frequency calculation. A word segmentation system basing on N-gram algorithm was developed in this study to conduct semantic analysis, and 100 groups of meaningful phrases with the highest recurrent rates were located. Subsequently, co-word analysis was employed for semantic classification. The results showed that the themes of tourism research in Taiwan in recent years cover the scope of tourism education, environmental protection, hotel management, information technology, and senior tourism. The results can give insight on the related issues and serve as a reference for tourism-related policy making and follow-up research.

Keywords: bibliometrics, co-word analysis, word segmentation, tourism research, policy

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113 Effects of Bilateral Electroconvulsive Therapy on Autobiographical Memories in Asian Patients

Authors: Lai Gwen Chan, Yining Ong, Audrey Yoke Poh Wong

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Background. The efficacy of electroconvulsive therapy (ECT) as a form of treatment to a range of mental disorders is well-established. However, ECT is often associated with either temporary or persistent cognitive side-effects, resulting in the failure of wider prescription. Of which, retrograde amnesia is the most commonly reported cognitive side-effect. Most studies found a recalling deficit in autobiographical memories to be short-term, although a few have reported more persistent amnesic effects. Little is known about ECT-related amnesic effects in Asian population. Hence, this study aims to resolve conflicting findings, as well as to better elucidate the effects of ECT on cognitive functioning in a local sample. Method: 12 patients underwent bilateral ECT under the care of Psychological Medicine Department, Tan Tock Seng Hospital, Singapore. Participants’ cognition and level of functioning were assessed at four time-points: before ECT, between the third and fourth induced seizure, at the end of the whole course of ECT, and two months after the index course of ECT. Results: It was found that Global Assessment of Functioning scores increased significantly at the completion of ECT. Case-by-case analyses also revealed an overall improvement in Personal Semantic and Autobiographical memory two months after the index course of ECT. A transient dip in both personal semantic and autobiographical memory scores was observed in one participant between the third and fourth induced seizure, but subsequently resolved and showed better performance than at baseline. Conclusions: The findings of this study suggest that ECT is an effective form of treatment to alleviate the severity of symptoms of the diagnosis. ECT does not affect attention, language, executive functioning, personal semantic and autobiographical memory adversely. The findings suggest that Asian patients may respond to bilateral ECT differently from Western samples.

Keywords: electroconvulsive therapy (ECT), autobiographical memory, cognitive impairment, psychiatric disorder

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112 Rethinking the Air Quality Health Index: Harmonizing Health Protection and Climate Mitigation

Authors: Kimberly Tasha Jiayi Tang, Changqing Lin, Zhe Wang, Tze-Wai Wong, Md. Shakhaoat Hossain, Jian Yu, Alexis Lau

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Hong Kong has practiced a risk-based Air Quality Health Index (AQHI) system that sums hospitalization risks associated with short-term exposure to air pollu-tants. As an air pollution risk communication tool, it informs the public about the current air quality, anchoring around the World Health Organization's (WHO) 2005 Air Quality Guidelines (AQGs). Given the WHO's recent update in 2021, assessing how Hong Kong’s air quality risk communication can be en-hanced using these updated guidelines is essential. Hong Kong’s AQHI is lim-ited by solely focusing on short-term health risks, which could lead the public to underestimate cumulative health impacts. Therefore, we propose the intro-duction of a composite AQHI that reports both long-term and short-term health risks. Additionally, the WHO interim targets will be considered as anchor points for various health risk categories. Furthermore, with the increasing ozone levels in Hong Kong and Southern China due to improved NOx mitigation measures, it has been a challenging task in balancing health protection against climate mitigation. However, our findings present a promising outlook. Despite the rise in ozone levels, the combined health risks in Hong Kong and Guang-dong have seen a decline, largely due to reductions in NO2 and PM concentra-tions, both having significant health implications. By shifting from a concentra-tion-based approach to a health risk-based system like the AQHI, our study highlights the prospective of harmonizing health protection and climate mitiga-tion goals. This health-focused framework suggests that rigorous NOx controls can effective-ly serve both objectives in parallel.

Keywords: air quality management, air quality health index, health risk management, air pollution

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111 Recent Progress in the Uncooled Mid-Infrared Lead Selenide Polycrystalline Photodetector

Authors: Hao Yang, Lei Chen, Ting Mei, Jianbang Zheng

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Currently, the uncooled PbSe photodetectors in the mid-infrared range (2-5μm) with sensitization technology extract more photoelectric response than traditional ones, and enable the room temperature (300K) photo-detection with high detectivity, which have attracted wide attentions in many fields. This technology generally contains the film fabrication with vapor phase deposition (VPD) and a sensitizing process with doping of oxygen and iodine. Many works presented in the recent years almost provide and high temperature activation method with oxygen/iodine vapor diffusion, which reveals that oxygen or iodine plays an important role in the sensitization of PbSe material. In this paper, we provide our latest experimental results and discussions in the stoichiometry of oxygen and iodine and its influence on the polycrystalline structure and photo-response. The experimental results revealed that crystal orientation was transformed from (200) to (420) by sensitization, and the responsivity of 5.42 A/W was gained by the optimal stoichiometry of oxygen and iodine with molecular density of I2 of ~1.51×1012 mm-3 and oxygen pressure of ~1Mpa. We verified that I2 plays a role in transporting oxygen into the lattice of crystal, which is actually not its major role. It is revealed that samples sensitized with iodine transform atomic proportion of Pb from 34.5% to 25.0% compared with samples without iodine from XPS data, which result in the proportion of about 1:1 between Pb and Se atoms by sublimation of PbI2 during sensitization process, and Pb/Se atomic proportion is controlled by I/O atomic proportion in the polycrystalline grains, which is very an important factor for improving responsivity of uncooled PbSe photodetector. Moreover, a novel sensitization and dopant activation method is proposed using oxygen ion implantation with low ion energy of < 500eV and beam current of ~120μA/cm2. These results may be helpful to understanding the sensitization mechanism of polycrystalline lead salt materials.

Keywords: polycrystalline PbSe, sensitization, transport, stoichiometry

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