Search results for: Nguyen Van Hung
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 454

Search results for: Nguyen Van Hung

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

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

Abstract:

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

Procedia PDF Downloads 186
123 Radio-Frequency Technologies for Sensing and Imaging

Authors: Cam Nguyen

Abstract:

Rapid, accurate, and safe sensing and imaging of physical quantities or structures finds many applications and is of significant interest to society. Sensing and imaging using radio-frequency (RF) techniques, particularly, has gone through significant development and subsequently established itself as a unique territory in the sensing world. RF sensing and imaging has played a critical role in providing us many sensing and imaging abilities beyond our human capabilities, benefiting both civilian and military applications - for example, from sensing abnormal conditions underneath some structures’ surfaces to detection and classification of concealed items, hidden activities, and buried objects. We present the developments of several sensing and imaging systems implementing RF technologies like ultra-wide band (UWB), synthetic-pulse, and interferometry. These systems are fabricated completely using RF integrated circuits. The UWB impulse system operates over multiple pulse durations from 450 to 1170 ps with 5.5-GHz RF bandwidth. It performs well through tests of various samples, demonstrating its usefulness for subsurface sensing. The synthetic-pulse system operating from 0.6 to 5.6 GHz can assess accurately subsurface structures. The synthetic-pulse system operating from 29.72-37.7 GHz demonstrates abilities for various surface and near-surface sensing such as profile mapping, liquid-level monitoring, and anti-personnel mine locating. The interferometric system operating at 35.6 GHz demonstrates its multi-functional capability for measurement of displacements and slow velocities. These RF sensors are attractive and useful for various surface and subsurface sensing applications. This paper was made possible by NPRP grant # 6-241-2-102 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.

Keywords: RF sensors, radars, surface sensing, subsurface sensing

Procedia PDF Downloads 282
122 Effects of Rumen Protozoa and Nitrate on Fermentation and Methane Production

Authors: S. H. Nguyen, L. Li, R. S. Hegarty

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Two experiments were conducted assessing the effects of presence or absence of rumen protozoa and dietary nitrate addition on rumen fermentation characteristics and methane production in Brahman heifers. The first experiment assessed changes in rumen fermentation pattern and in-vitro methane production post-refaunation and the second experiment investigated whether addition of nitrate to the incubation would give rise to methane mitigation additional to that contributed by defaunation. Ten Brahman heifers were progressively adapted to a diet containing coconut oil distillate 4.5% (COD) for 18 d and then all heifers were defaunated using sodium 1-(2-sulfonatooxyethoxy) dodecane (Empicol). After 15 d, the heifers were given a second dose of Empicol. Fifteen days after the second dosing, all heifers were allocated to defaunated or refaunated groups by stratified randomisation. On d 48, an oral dose of rumen fluid collected from unrelated faunated cattle was used to inoculate 5 heifers and form a refaunated group so that the effects of re-establishment of protozoa on fermentation characteristics could be investigated. Samples of rumen fluid collected from each animal using oesophageal intubation before feeding on d 48, 55, 62 and 69 were incubated for 23h in-vitro (experiment 1). On day 82, 2% of NO3 (as NaNO3) was included in in-vitro incubations (experiment 2) to test for additivity of NO3 and absence of protozoa effects on fermentation and methane production. It was concluded that increasing protozoal numbers were associated with increased methane production, with methane production rate significantly higher from refaunated heifers than from defaunated heifers 7, 14 and 21 d after refaunation. Concentration and proportions of major VFA, however, were not affected by protozoal treatments. There is scope for further reducing methane output through combining defaunation and dietary nitrate as the addition of nitrate in the defaunated heifers resulted in 86% reduction in methane production in-vitro.

Keywords: defaunation, nitrate, fermentation, methane production

Procedia PDF Downloads 519
121 Evaluation of Firearm Injury Syndromic Surveillance in Utah

Authors: E. Bennion, A. Acharya, S. Barnes, D. Ferrell, S. Luckett-Cole, G. Mower, J. Nelson, Y. Nguyen

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Objective: This study aimed to evaluate the validity of a firearm injury query in the Early Notification of Community-based Epidemics syndromic surveillance system. Syndromic surveillance data are used at the Utah Department of Health for early detection of and rapid response to unusually high rates of violence and injury, among other health outcomes. The query of interest was defined by the Centers for Disease Control and Prevention and used chief complaint and discharge diagnosis codes to capture initial emergency department encounters for firearm injury of all intents. Design: Two epidemiologists manually reviewed electronic health records of emergency department visits captured by the query from April-May 2020, compared results, and sent conflicting determinations to two arbiters. Results: Of the 85 unique records captured, 67 were deemed probable, 19 were ruled out, and two were undetermined, resulting in a positive predictive value of 75.3%. Common reasons for false positives included non-initial encounters and misleading keywords. Conclusion: Improving the validity of syndromic surveillance data would better inform outbreak response decisions made by state and local health departments. The firearm injury definition could be refined to exclude non-initial encounters by negating words such as “last month,” “last week,” and “aftercare”; and to exclude non-firearm injury by negating words such as “pellet gun,” “air gun,” “nail gun,” “bullet bike,” and “exit wound” when a firearm is not mentioned.

Keywords: evaluation, health information system, firearm injury, syndromic surveillance

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120 The Gap between Curriculum, Pedagogy, and National Standards of Vietnamese English Language Teacher Education

Authors: Thi Phuong Lan Nguyen

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Vietnamese English Language Teacher Education (ELTE) has been changing a lot in response to the rapidly evolving socio-economic context requirements. The Vietnamese government assigns the Ministry of Education and Training (MOET) primary tasks to have policy changes to prepare for ELTE development in the globalization and socialization process. Many educational policies have been made to develop ELTE, however, they seem not to address the new global or social demands. The issue is that there are still significant disparities between the national policy and the institutional implementation. This study is to investigate the alignment between ELTE institutional curriculum, pedagogies, and MOET standards. This study used a mixed-method with the data sources from policy documents, a survey, and 33 interviews conducted with the lecturers and administrators from eleven Vietnamese ELTE institutions. The data have been analysed to understand the gap between policy and practice. The initial findings are (i) a low alignment of curriculum and language proficiency standards and (ii) a moderate alignment between curriculum and future-career skills standards. Many pedagogical challenges have been found. In order to address these gaps, it is necessary for the curriculum to be standards-based designed. It is also vital for professional development in order to improve the quality teaching. The study offers multiple perspectives on a complex issue. The study is meaningful not only to educational governance, but also to teaching practitioners, English language researchers, and English language learners. The significance lies in its relevance to English teaching careers across all parts of Vietnam, it yet remains relevant to ELTE in other countries teaching English as a foreign language.

Keywords: alignment, curriculum, educational policy, English language teaching, pedagogy, standards

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119 Investor Psychology, Housing Prices, and Stock Market Response to Policy Decisions During the Covid-19 Recession in the United States

Authors: Ly Nguyen, Vidit Munshi

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During the Covid-19 recession, the United States government has implemented several instruments to mitigate the impacts and revitalize the economy. This paper explores the effects of the various government policy decisions on stock returns, housing prices, and investor psychology during the pandemic in the United States. A numerous previous literature studies on this subject, yet very few focus on the context similar to what we are currently experiencing. Our monthly data covering the period from January 2019 through July 2021 were collected from Datastream. Utilizing the VAR model, we document a dynamic relationship between the market and policy actions throughout the period. In particular, the movements of Unemployment, Stock returns, and Housing prices are strongly sensitive to changes in government policies. Our results also indicate that changes in production level, stock returns, and interest rates decisions influence how investors perceived future market risk and expectations. We do not find any significant nexus between monetary and fiscal policy. Our findings imply that information on government policy and stock market performance provide useful feedback to one another in order to make better decisions in the current and future pandemic. Understanding how the market responds to a shift in government practices has important implications for authorities in implementing policy to avoid assets bubbles and market overreactions. The paper also provides useful implications for investors in evaluating the effectiveness of different policies and diversifying portfolios to minimize systematic risk and maximize returns.

Keywords: Covid-19 recession, United States, government policies, investor psychology, housing prices, stock market returns

Procedia PDF Downloads 143
118 The Evaluation of Adjuvant Effects of CD154 in a Subunit Vaccine against Classical Swine Fever Virus

Authors: Yu-Chieh Chen, Li-Yun Wang, Chi-Chih Chen, Huy Hùng Đào, Ya-Mei Chen, Ming-Chu Cheng, Wen-Bin Chung, Hso-Chi Chaung, Guan-Ming Ke

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Many recent researches have demonstrated that CD154, a protein primarily expressed on activated T cell molecules, has potentially acted as a molecular adjuvant to improve the immunogenicity of subunit vaccines against viral infections. Classical swine fever (CSF) affects the swine industry worldwide that is one of the most devastating and highly contagious pig diseases. It is listed by the World Organization for Animal Health (OIE) as an infectious animal disease that must be reported. Although pigs vaccinated with subunit vaccines can be differentially diagnosed from those infected animals, subunit vaccines usually need adjuvants to enhance and elicit immune responses. In this study, CD154 was linked with CSFV E2 sequences and then expressed in CHO cells to produce the fusion protein as E2-CD154. The porcine specific CpG adjuvant was also used in one of the formulations. The specific pathogen-free pigs (SPF) at the age of 4-week-old were randomly separated into four groups, vaccinated with E2-CpG, E2-CD154, E2-CD154-CpG or the commercial Bayovac® CSF-E2 vaccine and boosted two weeks after primary vaccination. The results showed that the percentages of CD4+ and CD4+IL2+ in peripheral blood mononuclear cells (PBMC) in E2-CD154 vaccinated piglets seven days after primary vaccination were gained by 1-5% relative to the control group. In addition, the percentages of CD4+IFNγ+ T cells had slightly edged up 0.1-0.3% compared with the control group. Also, increased E2-specific IFNγ levels had edged up CD4+CD8+ T cells found in E2-CD154 and E2-CD154-CpG groups, particularly in the E2-CD154-CpG group. These results implicate that CD154 may enhance cellular immunity and synergistically act with species-specific CpG adjuvant as a dual-phase adjuvant. Therefore, the CD154 may be beneficial as a promising adjuvant in subunit vaccines.

Keywords: CD154, CpG adjuvant, cellular immunity, subunit vaccine, pig

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117 Empirical Examination of High Performance Work System, Organizational Commitment and Organizational Citizen Behavior: A Mediation of Model of Vietnam Organizations

Authors: Giang Vu, Duong Nguyen, Yuan-Ling Chen

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Vietnam is a fast developing country with highly economic growth, and Vietnam organizations strive to utilize high performance work system (HPWS) in reinforcing employee in-role performance. HPWS, a bundle of human resource (HR) practices, are composed of eight sets of HR practices, namely selective staffing, extensive training, internal mobility, employment security, clear job description, result-oriented appraisal, incentive reward, and participation. However, whether HPWS stimulate employee extra-role behaviors remains understudied in a booming economic context. In this study, we aim to investigate organizational citizenship behavior (OCB) in a Vietnam context and, as a central issue, disentangle how HPWS elicits in employee OCB. On the other hand, recently, a deliberation of so-called 'black-box' HPWS issue has explored the role of employee commitment, suggesting that organizational commitment is a compelling source of employee OCB. We draw upon social exchange theory to predict that when employees perceive the organizational investment, like HPWS, in heightening their abilities, knowledge, and motivation, they are more likely to pay back with commitment; consequently, they will take initiatives in OCB. Hence, we hypothesize an individual level framework, in which organizational commitment mediates the positive relationship between HPWS and OCB. We collected data on HPWS, organizational commitment, OCB, and demographic variables, all at line managers of Vietnamese firms in Hanoi and Hochiminh. We conclude with research findings, implications, and future research suggestions.

Keywords: high performance work system, organizational citizenship behavior, organizational commitment, Vietnam

Procedia PDF Downloads 263
116 Exploring the Effectiveness of End-Of-Life Patient Decision Add in the ICU

Authors: Ru-Yu Lien, Shih-Hsin Hung, Shu-Fen Lu, Ju-Jen Shie, Wen-Ju Yang, Yuann-Meei Tzeng, Chien-Ying Wang

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Background: The quality of care in intensive care units (ICUs) is crucial, especially for terminally ill patients. Shared decision-making (SDM) with families is essential to ensure appropriate care and reduce suffering. Aim: This study explores the effectiveness of an end-of-life decision support Patient Decision Aid (PDA) in an ICU setting. Methods: This study employed a cross-sectional research design conducted in an ICU from August 2020 to June 2023. Participants included family members of end-of-life patients aged 20 or older. A total of 319 participants. Family members of end-of-life patients received the PDA, and data were collected after they made medical decisions. Data collection involved providing family members with a PDA during family meetings. A post-PDA questionnaire with 17 questions assessed PDA effectiveness and anxiety levels. Statistical analysis was performed using SPSS 22.0. Results: The PDA significantly reduced anxiety levels among family members (p < 0.001). It helped them organize their thoughts, prepare for discussions with doctors, and understand critical decision factors. Most importantly, it influenced decision outcomes, with a shift towards palliative care and withdrawal of life-sustaining treatment. Conclusion: This study highlights the importance of family-centered end-of-life care in ICUs. PDAs promote informed decision-making, reduce conflicts, and enhance patient and family involvement. These tools align patient values and goals with medical recommendations, ultimately leading to decisions that prioritize comfort and quality of life. Implementing PDAs in healthcare systems can ensure that patients' care aligns with their values.

Keywords: shared decision-making, patient decision aid, end-of-life care, intensive care unit, family-centered care

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115 Study of the Effect of the Contra-Rotating Component on the Performance of the Centrifugal Compressor

Authors: Van Thang Nguyen, Amelie Danlos, Richard Paridaens, Farid Bakir

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This article presents a study of the effect of a contra-rotating component on the efficiency of centrifugal compressors. A contra-rotating centrifugal compressor (CRCC) is constructed using two independent rotors, rotating in the opposite direction and replacing the single rotor of a conventional centrifugal compressor (REF). To respect the geometrical parameters of the REF one, two rotors of the CRCC are designed, based on a single rotor geometry, using the hub and shroud length ratio parameter of the meridional contour. Firstly, the first rotor is designed by choosing a value of length ratio. Then, the second rotor is calculated to be adapted to the fluid flow of the first rotor according aerodynamics principles. In this study, four values of length ratios 0.3, 0.4, 0.5, and 0.6 are used to create four configurations CF1, CF2, CF3, and CF4 respectively. For comparison purpose, the circumferential velocity at the outlet of the REF and the CRCC are preserved, which means that the single rotor of the REF and the second rotor of the CRCC rotate with the same speed of 16000rpm. The speed of the first rotor in this case is chosen to be equal to the speed of the second rotor. The CFD simulation is conducted to compare the performance of the CRCC and the REF with the same boundary conditions. The results show that the configuration with a higher length ratio gives higher pressure rise. However, its efficiency is lower. An investigation over the entire operating range shows that the CF1 is the best configuration in this case. In addition, the CRCC can improve the pressure rise as well as the efficiency by changing the speed of each rotor independently. The results of changing the first rotor speed show with a 130% speed increase, the pressure ratio rises of 8.7% while the efficiency remains stable at the flow rate of the design operating point.

Keywords: centrifugal compressor, contra-rotating, interaction rotor, vacuum

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114 Factors Associated with Depression: Insights from a Cross-Sectional Study among University Students in Vietnam

Authors: Diep The Tai, Huynh Phuong Thao, Tran Cong Luan, Nguyen Thi Hong Huong, Truong Thi Xuan Lien

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Backgrounds: Depression is a prevalent mental health concern among university students. This cross-sectional study explores the factors associated with depression among university students in Vietnam. Methods: In 2022, a web-based survey was conducted among 2,304 students from different universities across North, Central, and South Vietnam. The Pearson chi-squared test was used to analyze the statistical associations between socio-demographic factors, depression levels, and social media addiction. Results: The results showed that 33,9% of freshmen experienced severe depression, with higher rates among females (69,8%) than males (30,2%). Health field students had the highest proportion of severe depression (52%). Social media addiction was prevalent among freshmen (29%) and health students (54,4%). Factors such as family infections, study pressure, hometown, studying in public places, and social media addiction were strongly linked to higher depression levels. However, spending more time communicating with friends and studying at home had a protective effect against depression. Notably, social media addiction was significantly associated with increased depression levels. Conclusion: The study highlights the influence of family COVID-19 infections, academic pressures, studying in public places, hometown, social media addiction, and lack of social interactions on depression levels. It underscores the importance of comprehensive approaches to address depression, promote resilience, and provide support to students during future outbreaks.

Keywords: Depression, social media addiction, mental health, university students, Vietnam

Procedia PDF Downloads 43
113 Thermal Effects on Wellbore Stability and Fluid Loss in High-Temperature Geothermal Drilling

Authors: Mubarek Alpkiray, Tan Nguyen, Arild Saasen

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Geothermal drilling operations contain numerous challenges that are encountered to increase the well cost and nonproductive time. Fluid loss is one of the most undesirable troublesome that can cause well abandonment in geothermal drilling. Lost circulation can be seen due to natural fractures, high mud weight, and extremely high formation temperatures. This challenge may cause wellbore stability problems and lead to expensive drilling operations. Wellbore stability is the main domain that should be considered to mitigate or prevent fluid loss into the formation. This paper describes the causes of fluid loss in the Pamukoren geothermal field in Turkey. A geomechanics approach integration and assessment is applied to help the understanding of fluid loss problems. In geothermal drillings, geomechanics is primarily based on rock properties, in-situ stress characterization, the temperature of the rock, determination of stresses around the wellbore, and rock failure criteria. Since a high-temperature difference between the wellbore wall and drilling fluid is presented, temperature distribution through the wellbore is estimated and implemented to the wellbore stability approach. This study reviewed geothermal drilling data to analyze temperature estimation along the wellbore, the cause of fluid loss and stored electric capacity of the reservoir. Our observation demonstrates the geomechanical approach's significant role in understanding safe drilling operations on high-temperature wells. Fluid loss is encountered due to thermal stress effects around the borehole. This paper provides a wellbore stability analysis for a geothermal drilling operation to discuss the causes of lost circulation resulting in nonproductive time and cost.

Keywords: geothermal wells, drilling, wellbore stresses, drilling fluid loss, thermal stress

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112 Factors Affecting Access to Education: The Experiences of Parents of Children Who Are Deaf or Hard of Hearing

Authors: Hanh Thi My Nguyen

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The purpose of this research is to examine the experiences of parents of children who are deaf or hard of hearing in supporting their children to access education in Vietnam. Parents play a crucial role in supporting their children to gain full access to education. It was widely reported that parents of those children confronted a range of problems to support their children to access education. To author’s best knowledge, there has been a lack of research exploring the experiences of those parents in literature. This research examines factors affecting those parents in supporting their children to access education. To conduct the study, qualitative approach using a phenomenological research design was chosen to explore the central phenomena. Ten parents of children who were diagnosed as deaf or hard of hearing and aged 6-9 years were recruited through the support of the Association of Parents of Children with Hearing Impairment. Participants were interviewed via telephone with a mix of open and closed questions; interviews were audio recorded, transcribed and thematically analysed. The research results show that there are nine main factors that affected the parents in this study in making decisions relating to education for their children including: lack of information resources, perspectives of those parents on communication approaches, the families’ financial capacity, the psychological impact on the participants after their children’ diagnosis, the attitude of family members, attitude of school administrators, lack of local schools and qualified teachers, and current education system for the deaf in Vietnam. Apart from those factors, the lack of knowledge of the participants’ partners about deaf education and the partners’ employment are barriers to educational access and successful communication with their child.

Keywords: access to education, deaf, hard of hearing, parents experience

Procedia PDF Downloads 111
111 Variations in the Angulation of the First Sacral Spinous Process Angle Associated with Sacrocaudal Fusion in Greyhounds

Authors: Sa'ad M. Ismail, Hung-Hsun Yen, Christina M. Murray, Helen M. S. Davies

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In the dog, the median sacral crest is formed by the fusion of three sacral spinous processes. In greyhounds with standard sacrums, this fusion in the median sacral crest consists of the fusion of three sacral spinous processes while it consists of four in greyhounds with sacrocaudal fusion. In the present study, variations in the angulation of the first sacral spinous process in association with different types of sacrocaudal fusion in the greyhound were investigated. Sacrums were collected from 207 greyhounds (102 sacrums; type A (unfused) and 105 with different types of sacrocaudal fusion; types: B, C and D). Sacrums were cleaned by boiling and dried and then were placed on their ventral surface on a flat surface and photographed from the left side using a digital camera at a fixed distance. The first sacral spinous process angle (1st SPA) was defined as the angle formed between the cranial border of the cranial ridge of the first sacral spinous process and the line extending across the most dorsal surface points of the spinous processes of the S1, S2, and S3. Image-Pro Express Version 5.0 imaging software was used to draw and measure the angles. Two photographs were taken for each sacrum and two repeat measurements were also taken of each angle. The mean value of the 1st SPA in greyhounds with sacrocaudal fusion was less (98.99°, SD ± 11, n = 105) than those in greyhounds with standard sacrums (99.77°, SD ± 9.18, n = 102) but was not significantly different (P < 0.05). Among greyhounds with different types of sacrocaudal fusion the mean value of the 1st SPA was as follows: type B; 97.73°, SD ± 10.94, n = 39, type C: 101.42°, SD ± 10.51, n = 52, and type D: 94.22°, SD ± 11.30, n = 12. For all types of fusion these angles were significantly different from each other (P < 0.05). Comparing the mean value of the1st SPA in standard sacrums (Type A) with that for each type of fusion separately showed that the only significantly different angulation (P < 0.05) was between standard sacrums and sacrums with sacrocaudal fusion sacrum type D (only body fusion between the S1 and Ca1). Different types of sacrocaudal fusion were associated with variations in the angle of the first sacral spinous process. These variations may affect the alignment and biomechanics of the sacral area and the pattern of movement and/or the force produced by both hind limbs to the cranial parts of the body and may alter the loading of other parts of the body. We concluded that any variations in the sacrum anatomical features might change the function of the sacrum or surrounding anatomical structures during movement.

Keywords: angulation of first sacral spinous process, biomechanics, greyhound, locomotion, sacrocaudal fusion

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110 Production of Hydrophilic PVC Surfaces with Microwave Treatment for its Separation from Mixed Plastics by Froth Floatation

Authors: Srinivasa Reddy Mallampati, Chi-Hyeon Lee, Nguyen Thanh Truc, Byeong-Kyu Lee

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Organic polymeric materials (plastics) are widely used in our daily life and various industrial fields. The separation of waste plastics is important for its feedstock and mechanical recycling. One of the major problems in incineration for thermal recycling or heat melting for material recycling is the polyvinyl chloride (PVC) contained in waste plastics. This is due to the production of hydrogen chloride, chlorine gas, dioxins, and furans originated from PVC. Therefore, the separation of PVC from waste plastics is necessary before recycling. The separation of heavy polymers (PVC 1.42, PMMA 1.12, PC 1.22 and PET 1.27 g/cm3 ) from light ones (PE and PP 0.99 g/cm3) can be achieved on the basis of their density. However it is difficult to separate PVC from other heavy polymers basis of density. There are no simple and inexpensive techniques to separate PVC from others. If hydrophobic the PVC surface is selectively changed into hydrophilic, where other polymers still have hydrophobic surface, flotation process can separate PVC from others. In the present study, the selective surface hydrophilization of polyvinyl chloride (PVC) by microwave treatment after alkaline/acid washing and with activated carbon was studied as the pre-treatment of its separation by the following froth flotation. In presence of activated carbon as absorbent, the microwave treatment could selectively increase the hydrophilicity of the PVC surface (i.e. PVC contact angle decreased about 19o) among other plastics mixture. At this stage, 100% PVC separation from other plastics could be achieved by the combination of the pre- microwave treatment with activated carbon and the following froth floatation. The hydrophilization of PVC by surface analysis would be due to the hydrophilic groups produced by microwave treatment with activated carbon. The effect of optimum condition and detailed mechanism onto separation efficiency in the froth floatation was also investigated.

Keywords: Hydrophilic, PVC, contact angle, additive, microwave, froth floatation, waste plastics

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109 Modeling of the Dynamic Characteristics of a Spindle with Experimental Validation

Authors: Jhe-Hao Huang, Kun-Da Wu, Wei-Cheng Shih, Jui-Pin Hung

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This study presented the investigation on the dynamic characteristics of a spindle tool system by experimental and finite element modeling approaches. As well known facts, the machining stability is greatly determined by the dynamic characteristics of the spindle tool system. Therefore, understanding the factors affecting dynamic behavior of a spindle tooling system is a prerequisite in dominating the final machining performance of machine tool system. To this purpose, a physical spindle unit was employed to assess the dynamic characteristics by vibration tests. Then, a three-dimensional finite element model of a high-speed spindle system integrated with tool holder was created to simulate the dynamic behaviors. For modeling the angular contact bearings, a series of spring elements were introduced between the inner and outer rings. The spring constant can be represented by the contact stiffness of the rolling bearing based on Hertz theory. The interface characteristic between spindle nose and tool holder taper can be quantified from the comparison of the measurements and predictions. According to the results obtained from experiments and finite element predictions, the vibration behavior of the spindle is dominated by the bending deformation of the spindle shaft in different modes, which is further determined by the stiffness of the bearings in spindle housing. Also, the spindle unit with tool holder shows a different dynamic behavior from that of spindle without tool holder. This indicates the interface property between tool holder and spindle nose plays an dominance on the dynamic characteristics the spindle tool system. Overall, the dynamic behaviors the spindle with and without tool holder can be successfully investigated through the finite element model proposed in this study. The prediction accuracy is determined by the modeling of the rolling interface of ball bearings in spindles and the interface characteristics between tool holder and spindle nose. Besides, identifications of the interface characteristics of a ball bearing and spindle tool holder are important for the refinement of the spindle tooling system to achieve the optimum machining performance.

Keywords: contact stiffness, dynamic characteristics, spindle, tool holder interface

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108 High Aspect Ratio Sio2 Capillary Based On Silicon Etching and Thermal Oxidation Process for Optical Modulator

Authors: Nguyen Van Toan, Suguru Sangu, Tetsuro Saito, Naoki Inomata, Takahito Ono

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This paper presents the design and fabrication of an optical window for an optical modulator toward image sensing applications. An optical window consists of micrometer-order SiO2 capillaries (porous solid) that can modulate transmission light intensity by moving the liquid in and out of porous solid. A high optical transmittance of the optical window can be achieved due to refractive index matching when the liquid is penetrated into the porous solid. Otherwise, its light transmittance is lower because of light reflection and scattering by air holes and capillary walls. Silicon capillaries fabricated by deep reactive ion etching (DRIE) process are completely oxidized to form the SiO2 capillaries. Therefore, high aspect ratio SiO2 capillaries can be achieved based on silicon capillaries formed by DRIE technique. Large compressive stress of the oxide causes bending of the capillary structure, which is reduced by optimizing the design of device structure. The large stress of the optical window can be released via thin supporting beams. A 7.2 mm x 9.6 mm optical window area toward a fully integrated with the image sensor format is successfully fabricated and its optical transmittance is evaluated with and without inserting liquids (ethanol and matching oil). The achieved modulation range is approximately 20% to 35% with and without liquid penetration in visible region (wavelength range from 450 nm to 650 nm).

Keywords: thermal oxidation process, SiO2 capillaries, optical window, light transmittance, image sensor, liquid penetration

Procedia PDF Downloads 455
107 Anatomically-Based Oropharyngeal Rehabilitation for the Patients with Obstructive Sleep Apnea Using a Multilevel Approach

Authors: Hsin-Yu Lin, Ching-Hsia Hung

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Obstructive sleep apnea (OSA) is characterized by a complete or partial obstruction of the upper airway during sleep. The vulnerable sites of upper airway collapses are consequences of sleep state-dependent reductions in tone in specific pharyngeal dilators. Clinical examinations reveal multilevel collapses of the upper airway among the patients with OSA. Therefore, an anatomically-based oropharyngeal rehabilitation should comprise a multilevel approach, including retropalatal, retroglossal, hypopharyngeal, temporomandibular, and facial levels, all of which involve different muscle groups and contribute to multifunctional interaction and coordination, such as swallowing, breathing, and phonation. The purpose of the study was to exam the effects of this rehabilitation program with a multilevel approach. In this study, fifteen subjects with newly diagnosed moderate or severe OSA (Apnea-Hypopnea-Index≥15) were randomized into an intervention group and control group. The intervention group (N=8) underwent a 12-week-intervention of a hospital-based rehabilitation program, while the control group (N=7) was kept on the waiting list. The 12-week-intervention comprised an anatomically based multilevel approach. The primary outcome was Polysomnography (PSG) data, and the secondary outcome was oropharyngeal and respiratory muscle function. In the intervention group, Apnea-Hypopnea-Index significantly improved (46.96±19.45 versus 32.78±10.78 events/h, p=0.017) compared with control group (35.77±17.49 versus 42.96±17.32 events/h, p=0.043). While the control group remained no change, the intervention group demonstrated other PSG outcomes significantly improvement, including arousal index (46.04±18.9 versus 32.98±8.35/h, p=0.035), mean SpO2 (92.88±2.1 versus 94.13±1.46%, p=0.039). Besides, the intervention group demonstrated significant improvement in oropharyngeal and respiratory muscle function compared to the control group. This anatomically-based oropharyngeal rehabilitation with a multilevel approach can be proven as a non-invasive therapy for patients with OSA.

Keywords: obstructive sleep apnea, upper airway, oropharyngeal rehabilitation, multilevel approach

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106 Improvement of Healthcare Quality and Psychological Stress Relieve for Transition Program in Intensive Care Units

Authors: Ru-Yu Lien, Shih-Hsin Hung, Shu-Fen Lu, Shu-I Chin, Wen-Ju Yang, Wan Ming-Shang, Chien-Ying Wang

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Background: Upon recovery from critical condition, patients are normally transferred from the intensive care units (ICUs) to the general wards. However, transferring patients to a new environment causes stressful experiences for both patients and their families. Therefore, there is a necessity to communicate with the patients and their families to reduce psychological stress and unplanned return. Methods: This study was performed in the general ICUs from January 1, 2021, to December 31, 2021, in Taipei Veteran General Hospital. The patients who were evaluated by doctors and liaison nurses transferred to the general wards were selected as the research objects and ranked by the Critical Care Transition Program (CCTP). The plan was applied to 40 patients in a study group and usual care support for a control group of 40 patients. The psychological condition of patients was evaluated by a migration stress scale and a hospital anxiety and depression scale. In addition, the rate of return to ICU was also measured. Results: A total of 63 patients out of 80 (78.8%) experienced moderate to severe degrees of anxiety, and 42 patients (52.6%) experienced moderate to severe degrees of depression before being transferred. The difference between anxiety and depression changed more after the transfer; moreover, when a transition program was applied, it was lower than without a transition program. The return to ICU rate in the study group was lower than in the usual transition group, with an adjusted odds ratio of 0.21 (95% confidence interval: 0.05-0.888, P=0.034). Conclusion: Our study found that the transfer program could reduce the anxiety and depression of patients and the associated stress on their families during the transition from ICU. Before being transferred out of ICU, the healthcare providers need to assess the needs of patients to set the goals of the care plan and perform patient-centered decision-making with multidisciplinary support.

Keywords: ICU, critical care transition program, healthcare, transition program

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105 Comparison of Catalyst Support for High Pressure Reductive Amination

Authors: Tz-Bang Du, Cheng-Han Hsieh, Li-Ping Ju, Hung-Jie Liou

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Polyether amines synthesize by secondary hydroxyl polyether diol play an important role in epoxy hardener. The low molecular weight product is used in low viscosity and high transparent polyamine product for the logo, ground cover, especially for wind turbine blade, while the high molecular weight products are used in advanced agricultures such as a high-speed railway. High-pressure reductive amination process is required for producing these amines. In the condition of higher than 150 atm pressure and 200 degrees Celsius temperature, supercritical ammonia is used as a reactant and also a solvent. It would be a great challenge to select a catalyst support for such high-temperature alkaline circumstance. In this study, we have established a six-autoclave-type (SAT) high-pressure reactor for amination catalyst screening, which six experiment conditions with different temperature and pressure could be examined at the same time. We synthesized copper-nickel catalyst on different shaped alumina catalyst support and evaluated the catalyst activity for high-pressure reductive amination of polypropylene glycol (PPG) by SAT reactor. Ball type gamma alumina, ball type activated alumina and pellet type gamma alumina catalyst supports are evaluated in this study. Gamma alumina supports have shown better activity on PPG reductive amination than activated alumina support. In addition, the catalysts are evaluated in fixed bed reactor. The diamine product was successfully synthesized via this catalyst and the strength of the catalysts is measured. The crush strength of blank supports is about 13.5 lb for both gamma alumina and activated alumina. The strength increases to 20.3 lb after synthesized to be copper-nickel catalyst. After test in the fixed bed high-pressure reductive amination process for 100 hours, the crush strength of the used catalyst is 3.7 lb for activated alumina support, 12.0 lb for gamma alumina support. The gamma alumina is better than activated alumina to use as catalyst support in high-pressure reductive amination process.

Keywords: high pressure reductive amination, copper nickel catalyst, polyether amine, alumina

Procedia PDF Downloads 194
104 Understanding the Influence of Cross-National Distances on Tourist Expenditure

Authors: Wei-Ting Hung

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Inbound tourist expenditure might not only have influenced by individual tourist characteristics but may also be affected by nationality characteristics. The cross national distance effects on tourist consumption behavior should be incorporated in the analytical framework. Additionally, the often used factor analysis, cluster analysis and regression analysis overlook the hierarchical tourist consumption data structure and may lead to misleading results. The objectives of the present study were twofold. First, we propose a multilevel model that takes individual and cross-national differences into account under a hierarchical framework. Second, we further sought to determine the types of cross-national differences affecting tourist expenditure. Thus, this study incorporates the individual tourist effects and cross national distance effects simultaneously, uses the data of 2010 Annual Survey Report on Visitors’ Expenditure and Trends in Taiwan to investigate the determinants of inbound tourist expenditure. Multilevel analysis was used to investigate the influence of individual tourist effects and cross national distance effects on inbound tourist expenditure. The empirical results show that cross national distance plays a crucial role in tourist consumption behavior. Our findings also indicate age and income have positive influence on tourism expenditure., whereas education and gender do not have significant impact. Regarding macro-level factors, geographic and cultural differences exhibited significant positive relationships on tourism expenditure, while economic differences did not. Based on the above empirical results, it is suggested that tour operators should take tourists’ individual attributes, particularly their income and age, into consideration when arranging tours. In addition, nationality holds sway over tourists’ consumption behavior, of which geographic and cultural differences are the two major factors at play. The empirical results of this study serve as practical suggestions for tourism marketing strategies and policy implications for government policies.

Keywords: cross national distance, inbound tourist, multilevel analysis, tourist expenditure

Procedia PDF Downloads 320
103 Effect of Golden Oyster Mushroom (Pleurotus citrinopileatus) Powder on Physiochemical, Antioxidative, and Sensory Properties of Noodles

Authors: Giap Pham Ngoc Tram, Tran Hong Quan, Tran Tieu Yen, Nguyen Phung Tien

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The use of natural ingredients to enhance the nutritional and sensory properties of food products has gained significant interest in recent years. This study focuses on the effect of Golden oyster mushroom powder (GOMP) on the physiochemical, antioxidative, and sensory properties of noodles. The aim of this study is to investigate the influence of GOMP on the nutritional, antioxidant, and sensory properties of noodles. The study determined the color, moisture, total ash, protein, total phenolic, flavonoid contents, water activity, and antioxidant activity of GOMP and noodles. The incorporation of GOMP at levels of 5-15% increased the ash, protein, flavonoid, and total phenolic contents of the noodles. It also enhanced their antioxidant activities, as evidenced by improved DPPH radical scavenging activity and metal chelating activity. However, the incorporation of GOMP resulted in a decrease in the L* and b* values of the noodles. Furthermore, the GOMP-enriched noodles exhibited a lower cutting force compared to the control. This study highlights the potential of GOMP as a nutritional and antioxidant ingredient in noodle preparation. It adds to the existing literature by providing evidence of the positive effects of GOMP on the nutritional and functional properties of noodles. The researchers collected data on the physiochemical properties, nutritional contents, and antioxidant activities of GOMP and noodles. Statistical analysis was then performed to assess the differences between the control and GOMP-enriched noodles. The results of this study demonstrate that the inclusion of GOMP at the amount of 5-15% can increase the nutritional and antioxidant properties of noodles without significantly impacting sensory attributes.

Keywords: oyster mushroom, noodles, antioxidant activity, phytochemical, sensory property

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102 Cement Bond Characteristics of Artificially Fabricated Sandstones

Authors: Ashirgul Kozhagulova, Ainash Shabdirova, Galym Tokazhanov, Minh Nguyen

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The synthetic rocks have been advantageous over the natural rocks in terms of availability and the consistent studying the impact of a particular parameter. The artificial rocks can be fabricated using variety of techniques such as mixing sand and Portland cement or gypsum, firing the mixture of sand and fine powder of borosilicate glass or by in-situ precipitation of calcite solution. In this study, sodium silicate solution has been used as the cementing agent for the quartz sand. The molded soft cylindrical sandstone samples are placed in the gas-tight pressure vessel, where the hardening of the material takes place as the chemical reaction between carbon dioxide and the silicate solution progresses. The vessel allows uniform disperse of carbon dioxide and control over the ambient gas pressure. Current paper shows how the bonding material is initially distributed in the intergranular space and the surface of the sand particles by the usage of Electron Microscopy and the Energy Dispersive Spectroscopy. During the study, the strength of the cement bond as a function of temperature is observed. The impact of cementing agent dosage on the micro and macro characteristics of the sandstone is investigated. The analysis of the cement bond at micro level helps to trace the changes to particles bonding damage after a potential yielding. Shearing behavior and compressional response have been examined resulting in the estimation of the shearing resistance and cohesion force of the sandstone. These are considered to be main input values to the mathematical prediction models of sand production from weak clastic oil reservoir formations.

Keywords: artificial sanstone, cement bond, microstructure, SEM, triaxial shearing

Procedia PDF Downloads 135
101 Study of the Hysteretic I-V Characteristics in a Polystyrene/ZnO-Nanorods Stack Layer

Authors: You-Lin Wu, Yi-Hsing Sung, Shih-Hung Lin, Jing-Jenn Lin

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Performance improvement in optoelectronic devices such as solar cells and photodetectors has been reported when a polymer/ZnO nanorods stack is used. Resistance switching of polymer/ZnO nanocrystals (or nanorods) hybrid has also gained a lot of research interests recently. It has been reported that high- and low-resistance states of a metal/insulator/metal (MIM) structure diode with a polystyrene (PS) and ZnO hybrid as the insulator layer can be switched by applied bias after a high-voltage forming process, while the same device structure merely with a PS layer does not show any forming behavior. In this work, we investigated the current-voltage (I-V) characteristics of an MIM device with a PS/ZnO nanorods stack deposited on fluorine-doped tin oxide (FTO) glass substrate. The ZnO nanorods were grown by a hydrothermal method using a mixture of zinc nitrate, hexamethylenetetramine, and DI water. Following that, a PS layer was deposited by spin coating. Finally, the device with a structure of Ti/ PS/ZnO nanorods/FTO was completed by e-gun evaporated Ti layer on top of the PS layer. Semiconductor parameters analyzer Agilent 4156C was then used to measure the I-V characteristics of the device by applying linear ramp sweep voltage with sweep sequence of 0V → 4V → 0V → 3V → 0V → 2V → 0V → 1V → 0V in both positive and negative directions. It is interesting to find that the I-V characteristics are bias dependent and hysteretic, indicating that the device Ti/PS/ZnO nanorods/FTO structure has ferroelectricity. Our results also show that the maximum hysteresis loop height of the I-V characteristics as well as the voltage at which the maximum hysteresis loop height of each scan occurs increase with increasing maximum sweep voltage. It should be noticed that, although ferroelectricity has been found in ZnO at its melting temperature (1975℃) and in Li- or Co-doped ZnO, neither PS nor ZnO has ferroelectricity at room temperature. Using the same structure but with a PS or ZnO layer only as the insulator does not give and hysteretic I-V characteristics. It is believed that a charge polarization layer is induced near the PS/ZnO nanorods stack interface and thus causes the ferroelectricity in the device with Ti/PS/ZnO nanorods/FTO structure. Our results show that the PS/ZnO stack can find a potential application in a resistive switching memory device with MIM structure.

Keywords: ferroelectricity, hysteresis, polystyrene, resistance switching, ZnO nanorods

Procedia PDF Downloads 282
100 Kernel-Based Double Nearest Proportion Feature Extraction for Hyperspectral Image Classification

Authors: Hung-Sheng Lin, Cheng-Hsuan Li

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Over the past few years, kernel-based algorithms have been widely used to extend some linear feature extraction methods such as principal component analysis (PCA), linear discriminate analysis (LDA), and nonparametric weighted feature extraction (NWFE) to their nonlinear versions, kernel principal component analysis (KPCA), generalized discriminate analysis (GDA), and kernel nonparametric weighted feature extraction (KNWFE), respectively. These nonlinear feature extraction methods can detect nonlinear directions with the largest nonlinear variance or the largest class separability based on the given kernel function. Moreover, they have been applied to improve the target detection or the image classification of hyperspectral images. The double nearest proportion feature extraction (DNP) can effectively reduce the overlap effect and have good performance in hyperspectral image classification. The DNP structure is an extension of the k-nearest neighbor technique. For each sample, there are two corresponding nearest proportions of samples, the self-class nearest proportion and the other-class nearest proportion. The term “nearest proportion” used here consider both the local information and other more global information. With these settings, the effect of the overlap between the sample distributions can be reduced. Usually, the maximum likelihood estimator and the related unbiased estimator are not ideal estimators in high dimensional inference problems, particularly in small data-size situation. Hence, an improved estimator by shrinkage estimation (regularization) is proposed. Based on the DNP structure, LDA is included as a special case. In this paper, the kernel method is applied to extend DNP to kernel-based DNP (KDNP). In addition to the advantages of DNP, KDNP surpasses DNP in the experimental results. According to the experiments on the real hyperspectral image data sets, the classification performance of KDNP is better than that of PCA, LDA, NWFE, and their kernel versions, KPCA, GDA, and KNWFE.

Keywords: feature extraction, kernel method, double nearest proportion feature extraction, kernel double nearest feature extraction

Procedia PDF Downloads 291
99 A Study on the Relationships among Teacher Empowerment, Professional Commitment and School Effectiveness

Authors: S. C. Lin, W. F. Hung, W. W. Cheng

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Teacher empowerment was regarded as investing teachers with the right to participate in the determination of school goals and policies and to exercise professional judgment about what and how to teach. Professional commitment was considered as a person’s belief in and acceptance of the values of his or her chosen occupation or line of work, and a willingness to maintain membership in that occupation. An effective school has been defined as one in which students’ progress further than might be expected from consideration of its intake. An effective school thus adds extra value to its students' outcomes, in comparison with other schools serving similar intakes. A number of literature from various countries explored that teacher empowerment and professional commitment significantly influenced school effectiveness. However, there lacked more empirical studies to examine the relationships among them. Hence, this study was to explore the relationships among teacher empowerment, professional commitment and school effectiveness in junior high schools in Taiwan. Samples were seven hundred and five junior high school teachers selected from Taichung City, Changhua County and Nantou County. Questionnaire was applied to collect data. Data were analyzed by using descriptive statistics, t-test, one-way ANOVA, Pearson’s product-moment correlation, and multiple regression analysis. The findings of this study were as follows: First, the overall performances of teachers’ perceptions of teacher empowerment, teacher professional commitment and school effectiveness were above average. Second, the teachers’ perceptions of teacher empowerment were significant different in gender, designated duty, and school size. Third, the teachers’ perceptions of teacher professional commitment were significant different in gender, designated duty, and school size. Fourth, the teachers’ perceptions of school effectiveness were significant different in designated duty. Fifth, teacher empowerment was mid-positively correlation by teacher professional commitment. Sixth, there was mid-positively correlation between teacher empowerment and school effectiveness. Seventh, there was mid-positively correlation between teacher professional commitment and school effectiveness. Eighth, Teacher empowerment and professional commitment could significantly predict school effectiveness. Based on the findings of this study, the study proposed some suggestions for educational authorities, schools, teachers, and future studies as well.

Keywords: junior high school teacher, teacher empowerment, teacher professional commitment, school effectiveness

Procedia PDF Downloads 428
98 Construction of Genetic Recombinant Yeasts with High Environmental Tolerance by Accumulation of Trehalose and Detoxication of Aldehyde

Authors: Yun-Chin Chung, Nileema Divate, Gen-Hung Chen, Pei-Ru Huang, Rupesh Divate

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Many environmental factors, such as glucose concentration, ethanol, temperature, osmotic pressure and pH, decrease the production rate of ethanol using yeast as a starter. Fermentation starters with high tolerance to various stresses are always demanded for brewing industry. Trehalose, a storage carbohydrate in cell wall of yeast, plays an important role in tolerance of environmental stress by preserving integrity of plasma membrane and stabilizing proteins. Furan aldehydes are toxic to yeast and the growth rate of yeast is significantly reduced if furan aldehydes were present in the fermentation medium. In yeast, aldehyde reductase is involved in the detoxification of reactive aldehydes and consequently the growth of yeast is improved. The aims of this study were to construct a genetic recombinant Saccharomyces cerevisiae or Pichia pastoris with furfural and HMF degrading and high ethanol tolerance capacities. Yeast strains were engineered by genetic recombination for overexpression of trehalose-6-phosphate synthase gene (tps1) and aldehyde reductase gene (ari1). TPS1 gene was cloned from S. cerevisiae by reverse transcription-polymerase chain reaction (RT-PCR) and then ligated with pGAPZαC vector. The constructed vector, pGAPZC-tps1, was transformed to recombinant yeasts strain with overexpression of ari1. The transformants with pGAPZC-tps1-ari1 were generated called STA (S. cerevisiae) and PTA (P. pastoris) with overexpression of tps1, ari1. PCR with tps1-specific primers and western blot with his-tag confirmed the gene insertion and protein expression of tps1 in the transformants, respectively. The neutral trehalase gene (nth1) of STA was successfully deleted and the novel strain STAΔN will be used for further study, including the measurement of trehalose concentration and ethanol, furfural tolerance assay.

Keywords: genetic recombinant, yeast, ethanol tolerance, trehalase, aldehyde reductase

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97 Observed Changes in Constructed Precipitation at High Resolution in Southern Vietnam

Authors: Nguyen Tien Thanh, Günter Meon

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Precipitation plays a key role in water cycle, defining the local climatic conditions and in ecosystem. It is also an important input parameter for water resources management and hydrologic models. With spatial continuous data, a certainty of discharge predictions or other environmental factors is unquestionably better than without. This is, however, not always willingly available to acquire for a small basin, especially for coastal region in Vietnam due to a low network of meteorological stations (30 stations) on long coast of 3260 km2. Furthermore, available gridded precipitation datasets are not fine enough when applying to hydrologic models. Under conditions of global warming, an application of spatial interpolation methods is a crucial for the climate change impact studies to obtain the spatial continuous data. In recent research projects, although some methods can perform better than others do, no methods draw the best results for all cases. The objective of this paper therefore, is to investigate different spatial interpolation methods for daily precipitation over a small basin (approximately 400 km2) located in coastal region, Southern Vietnam and find out the most efficient interpolation method on this catchment. The five different interpolation methods consisting of cressman, ordinary kriging, regression kriging, dual kriging and inverse distance weighting have been applied to identify the best method for the area of study on the spatio-temporal scale (daily, 10 km x 10 km). A 30-year precipitation database was created and merged into available gridded datasets. Finally, observed changes in constructed precipitation were performed. The results demonstrate that the method of ordinary kriging interpolation is an effective approach to analyze the daily precipitation. The mixed trends of increasing and decreasing monthly, seasonal and annual precipitation have documented at significant levels.

Keywords: interpolation, precipitation, trend, vietnam

Procedia PDF Downloads 250
96 The Retinoprotective Effects and Mechanisms of Fungal Ingredient 3,4-Dihydroxybenzalacetone through Inhibition of Retinal Müller and Microglial Activation

Authors: Yu-Wen Cheng, Jau-Der Ho, Liang-Huan Wu, Fan-Li Lin, Li-Huei Chen, Hung-Ming Chang, Yueh-Hsiung Kuo, George Hsiao

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Retina glial activation and neuroinflammation have been confirmed to cause devastating responses in retinodegenerative diseases. The expression and activation of matrix metalloproteinase (MMP)-9 and inducible nitric oxide synthase (iNOS) could be exerted as the crucial pathological factors in glaucoma- and blue light-induced retinal injuries. The present study aimed to investigate the retinoprotective effects and mechanisms of fungal ingredient 3,4-dihydroxybenzalacetone (DBL) isolated from Phellinus linteus in the retinal glial activation and retinodegenerative animal models. According to the cellular studies, DBL significantly and concentration-dependently abrogated MMP-9 activation and expression in TNFα-stimulated retinal Müller (rMC-1) cells. We found the inhibitory activities of DBL were strongly through the STAT- and ERK-dependent pathways. Furthermore, DBL dramatically attenuated MMP-9 activation in the stimulated Müller cells exposed to conditioned media from LPS-stimulated microglia BV-2 cells. On the other hand, DBL strongly suppressed LPS-induced production of NO and ROS and expression of iNOS in microglia BV-2 cells. Consistently, the phosphorylation of STAT was substantially blocked by DBL in LPS-stimulated microglia BV-2 cells. In the evaluation of retinoprotective functions, the high IOP-induced scotopic electroretinographic (ERG) deficit and blue light-induced abnormal pupillary light response (PLR) were assessed. The deficit scotopic ERG responses markedly recovered by DBL in a rat model of glaucoma-like ischemia/reperfusion (I/R)-injury. DBL also reduced the aqueous gelatinolytic activity and retinal MMP-9 expression in high IOP-injured conditions. Additionally, DBL could restore the abnormal PLR and reduce retinal MMP-9 activation. In summary, DBL could ameliorate retinal neuroinflammation and MMP-9 activation by predominantly inhibiting STAT3 activation in the retinal Müller cells and microglia, which exhibits therapeutic potential for glaucoma and other retinal degenerative diseases.

Keywords: glaucoma, blue light, DBL, retinal Müller cell, MMP-9, STAT, Microglia, iNOS, ERG, PLR

Procedia PDF Downloads 104
95 The Transition from National Policy to Institutional Practice of Vietnamese English Language Teacher Education

Authors: Thi Phuong Lan Nguyen

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The English Language Teacher Education (ELTE) in Vietnam is rapidly changing to address the new requirements of the globalization and socialization era. Although there has been a range of investments and innovation in policy and curriculum, tertiary educators and learners do not engage in the enactment. It is vital to understand the practices at the tertiary education level. The study is to understand the higher education curriculum development policy, both in theory and in practice across four representatives of ELTE institutions in the North of Vietnam. The lecturers’ perceptions about the extent to which the enacted curriculum is aligned with national standards will be explored. Nineteen policy documents, seventy surveys, and twelve interviews with lecturers and instructional leaders across these four Vietnamese Northern ELTE institutions have been analyzed to investigate how the policy shape the practice. The two most significant findings are (i) a low level of alignment between curriculum and soft-skills standards of the graduates required by the Vietnamese Ministry of Education and Training (MOET) and (ii) incoherence between current national policy and these institutions’ implementation. In order to address these gaps, it is strongly recommended that curriculum needs to be further developed, focusing more on the institutional outcomes, MOET’s standards, and the social demands in times of globalization. More importantly, professional development in ELTE is vital for a range of curriculum and educational policy stakeholders. The study helps to develop the English teaching profession in Vietnam in a systematic way, from policymakers to implementers, and from instructors to learners. Its significance lies in its relevance to English teaching careers, particularly within the researcher’s specific context, yet also remains relevant to ELTE in other parts of Vietnam and in other EFL (English as a Foreign Language) countries.

Keywords: curriculum, English language teaching education, policy implementation, standard, teaching practice

Procedia PDF Downloads 205