88 research outputs found
Heterogeneity in behavioural response to pricing policies in the transition from motorcycles to private cars in motorcycle-based societies
No full textPricing instruments are widely seen as an effective tool for reducing the travel demand for private vehicles. In contrast to developed countries, the design of pricing policies in certain developing countries is more challenging, owing to the mixed use of private cars and motorcycles. This study argues for the existence of a transitional group of motorcycle users who will switch to being car users. An investigation of the behavioural responses to a pricing policy from private car users and motorcycle users is implemented in Ho Chi Minh City, Vietnam. A propensity score-matching technique is used to identify the transitional group. The results regarding the mode choice models for various pricing policies show similar responses between the transitional motorcycle users and car users. Such characteristics of the transitional group imply that ignorance of travellers' heterogeneity may cause significant bias, especially when modelling pricing policies.This research was financed by the Special Research Fund of Hasselt University.
Financial support in data collection: Ho Chi Minh City Institute for Development Studies (HIDS)
Author contribution: The authors confirm contribution to the paper as follows: study concept and design: Hoang Thuy Linh, Nguyen Hoang Tung, Vu Anh Tuan, Muhammad Adnan, and Tom Bellemans; data preparation, analysis, and interpretation of results: Hoang Thuy Linh; draft manuscript preparation: Hoang Thuy Linh, Nguyen Hoang Tung, and Muhammad Adnan. All authors reviewed the results and approved the final version of the manuscript
Emergency delivery of Vasopressin from an implantable MEMS rapid drug delivery device
No full textThesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2009.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student submitted PDF version of thesis.Includes bibliographical references.An implantable rapid drug delivery device based on micro-electro-mechanical systems (MEMS) technology was designed, fabricated and validated for the in vivo rapid delivery of vasopressin in a rabbit model. In vitro characterization of device performance found the device capable of reliably and reproducibly delivering 85% of its loaded drug solution. A comparison of intraperitoneal and subcutaneous injections of vasopressin in rabbits was performed to determine the implantation location for the device. Both routes of delivery were found to be viable implantation locations, and the less invasive subcutaneous site was chosen. Vasopressin was released from the subcutaneously implanted device in anesthetized rabbits and found to exert a measurable effect on blood pressure. The bioavailability of vasopressin delivered from the device was found to be 6.2% after one hour. Proof-of-concept experiments were also conducted to address long-term stability of drugs in the implanted device and wireless activation of the device. These experiments defined areas of future research for improvement of the device.by Hong Linh Ho Duc.Ph.D
Exploring the Spatial Transferability of FEATHERS – An Activity Based Travel Demand Model – For Ho Chi Minh City, Vietnam
No full textThis paper presents descriptive analyses to investigate the transferability of FEATHERS, an activity-based travel demand model developed for Flanders (Belgium), a region in a developed country to Ho Chi Minh City (Vietnam), a metropolitan area of a developing country using personal and household travel survey data. The transferability was tested by using indicators which represent individuals' activity and travel behaviors. The results confirm the transferability of FEATHERS modelling structure to Ho Chi Minh City (HCMC), but all sub-models require recalibration due to the different cultural settings between the two study areas. The differences in transport mode options, land use patterns and individuals' location choice preferences make transport mode and location choice the least transferable models. (C) 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the Conference Program Chairs.We would like to thank the JICA study team for their provision the data of METROS project.Linh, HT (corresponding author), UHasselt Univ Hasselt, Transportat Res Inst IMOB, B-3590 Diepenbeek, Belgium ; Univ Transport & Commun, Dept Civil Engn, Hanoi, Vietnam
Exploring Factors That Influence Gen Z Consumers’ Adoption of Metaverse and Brand Experience through Metaverse
No full textMetaverse is an all-encompassing digital ecosystem that comprises numerous virtual worlds. Nowadays, Metaverse platforms are utilized globally for social interactions, work-related tasks, leisure activities, and online shopping. Furthermore, fashion brands now recognize immersive Metaverse technology\u27s great potential and focus on reaching more consumers and expanding market share through Metaverse. However, it is unclear if other brands should invest in building a solid presence in Metaverse. Limited studies have investigated how these fashion-related factors influence brand experience, brand awareness, brand attitude, and purchase intention on Metaverse retail platforms. Therefore, this study aimed to explore the Technology Acceptance Model (TAM) and fashion-related factors that influence the adoption of Metaverse for online apparel shopping among Gen Z consumers and to examine how the use of Metaverse enhances their brand experience, brand awareness, brand attitude, and purchase intention toward fashion brands. Based on TAM theory, it is hypothesized that TAM-related factors—perceived usefulness, ease-of-use, and enjoyment of a fashion brand’s Metaverse—positively influence brand experience, brand awareness, and brand attitude to provide a greater purchase intention on a fashion brand\u27s Metaverse. This study expanded the application of TAM by incorporating fashion-related factors—fashion innovativeness and fashion involvement—as possible antecedents, brand experience, and brand awareness in the model. Data were collected via a Qualtrics survey from a sample of college students (birth years range from 1997 to 2012 as Gen Z) from a large Midwestern university. Participants were recruited for this study using a convenience sample method. Of 747 students invited to participate in the survey, 171 responded to provide a response rate of 22.89%. Completed responses used for data analysis were 165 (22%).Preliminary and main analyses included normality using Q-Q scatterplots, reliability checks using Cronbach’s alpha coefficient principal component analysis, correlation analysis, and multiple regression. SPSS version 29.0 was used for this analysis. Findings from this study showed perceived enjoyment was positively related to brand awareness, brand experience, brand attitude, and purchase intention toward the fashion brand. Meanwhile, perceived usefulness significantly affected fashion’s brand experience and purchase intention. Additionally, perceived ease of use was shown to be positively related to brand attitude. Regarding fashion-related factors, fashion involvement was positively related to brand experience and brand attitude. Surprisingly, no significant relationship was found between fashion innovativeness and brand experience, brand awareness, brand attitude, and purchase intention regarding the fashion brand. Both brand experience and brand awareness of fashion brands are positively related to attitude toward brands and purchase intention for brands. A positive attitude toward the brand ultimately leads to greater purchase intention. This study elucidated the predictive power of the TAM model to explain the consumers’ acceptance of Metaverse and its impact on the brand\u27s relationship. Based oiin these findings, this study provides valuable managerial insights for fashion brands on Metaverse. Fashion brands on Metaverse should create virtual products that closely resemble their real-life counterparts in terms of features, functionalities, and details such as price, delivery, and promotion, or align with real-world collections. Meanwhile, fashion brands on Metaverse should incorporate its platform with entertaining features to attract users and create an immersive experience. Moreover, retailers on Metaverse should focus on building a strong community on its platform
Spatiotemporal variability of annual and seasonal rainfall time series in Ho Chi Minh city, Vietnam
No full textAbstract
This study analyzed spatial and temporal patterns of rainfall time series from 14 proportionally distributed stations in Ho Chi Minh City for the period 1980–2016. Both parametric and nonparametric approaches, specifically, linear regression, the Mann–Kendall test and Sen's slope estimator, were applied to detect and estimate the annual and seasonal trends after using original and notched boxplots for the preliminary interpretation. The outcomes showed high domination of positive trends in the annual and seasonal rainfall time series over the 37-year period, but most statistically significant trends were observed in the dry season. The results of trend estimation also indicated higher increasing rates of rainfall in the dry season compared to the rainy season at most stations. Even though the total amount of annual rainfall is mainly contributed by rainfall during the rainy season, the pronounced increment in the dry season can be a determining factor of possible changes in annual rainfall. Additionally, the interpolated results revealed a consistently increasing trend in the southeastern parts of the study area (i.e., Can Gio district), where annual rainfall was by far the lowest intensity compared to other regions.</jats:p
Screening of endophytes from rubber trees (hevea brasiliensis) for biological control of Corticium salmonicolor
No full text28 leaves and living-tissue samples of rubber tree (Hevea brasiliensis) were collected from Ho Chi Minh City, Binh Phuoc province and Binh Duong province (Viet Nam). We isolated and screened endophytes that have potential application as agents for biocontrol of Corticium salmonicolor, the agent of Pink Disease in rubber trees. As a result, 21 strains of endophytic bacteria and 14 strains of endophytic fungi were isolated. Antagonistic activity of the endophytes towards C. salmonicolor was checked by using a dual culture. Testing results showed that: T9, T15 and T16 strains have inhibited C. salmonicolor. T9 and T16 strains showed result that 100% of inhibiting C. salmonicolor at the concentration of 1:1. In the test of ability to kill C. salmonicolor, T9 and T16 strains showed that they could kill C. salmonicolor
after 3 sprays of bacterial filtrate. T9 and T6 strains, which were identified by biochemical methods, have similar characteristics to Bacillus thuringiensis
Bioinspired synthesis of Ag/AgCl nanoparticles from Aganonerion Polymorphum leaves: Boosted antibacterial potential
No full textThe use of plant extracts (mainly polyphenols) as both reducing and stabilizing agents has opened up new scopes in AgNPs biosynthesis. A lack of comprehensive studies on the possibility of Aganonerion Polymorphum (AP) leaves extract prompts an updated synthesis of Ag/AgCl nanoparticles, thanks to the rich source of chlorine in the AP leaves extract, to illuminate the positive effect of AgCl in antibacterial systems. Ag/AgCl nanoparticles were efficiently synthesized using AP leaf extract, serving as both a natural reducing and stabilizing agent. The highest concentrations of polyphenols (2.55 mg/g) and ascorbic acid (2.89 µg/mL) were extracted under optimal conditions (at 70°C for 1.5 hours), acting as the phytochemicals for metal ion reduction to form Ag/AgCl nanoparticles under sunlight, observed by absorbance bands at the wavelength of 400 - 500nm. XRD showed a highly crystalline face-centered cubic structure of Ag and AgCl, and EDX indicated the presence of Ag and Cl. TEM revealed spheres with a nanosize of 15 - 20nm. The zeta potential confirmed the long-term stability of the Ag/AgCl in aqueous solution (-8.7mV). As-prepared Ag/AgCl demonstrated an excellent antibacterial ability against five bacteria, as indicated by their inhibition zone (average diameter > 9.3mm) and minimum inhibitory concentration (MIC, 16.6 μg/mL). This study proposes a green and sustainable strategy for synthesizing Ag/AgCl nanoparticles, employing AP leaf extract as a natural reducing and stabilizing agent under ambient temperature conditions. The synthesized Ag/AgCl nanoparticles exhibited potent antibacterial activity against both Gram-positive and Gram-negative bacteria. Notably, the presence of AgCl further enhanced their efficacy, expanding their potential for advanced antibacterial applications
Studying the impact factors of climate change on agricultural land use in Phong Dien district, Thua Thien Hue province
No full textMany factors influence agricultural land, in particular, climate change show the most significant and serious effect on agricultural land in Phong Dien district. This study applied Binary Logistic analysis, using the SPSS software, on data collected through state agencies, fieldwork and interviews. The study has identified the impact of climate change on agricultural land by several factors; the most significant influence is derived from temperature and other extreme weather factors. In addition, the elements of rainfall, wind, and cold air also have a substantial impact on agricultural land causing serious consequences such as damage, loss of construction quality, overload of water supply and drainage systems, landslides, damage to infrastructure systems, etc. Some adaptive solutions to counteract the effects of climate change on agricultural land include changing crop structure, upgrading facilities, raising awareness of officials, and peo-ple about climate change.Công tác sử dụng đất nông nghiệp chịu ảnh hưởng từ rất nhiều yếu tố. Trong đó, yếu tố tác động của biến đổi khí hậu gây ảnh hưởng lớn và nghiêm trọng nhất đối với việc sử dụng đất nông nghiệp nói chung và trên địa bàn huyện Phong Điền nói riêng. Nghiên cứu đã sử dụng phân tích Binary Logistic trên phần mềm SPSS từ các số liệu thu thập được qua các cơ quan nhà nước, thực địa, phỏng vấn. Từ đó, nghiên cứu đã xác định được tác động của biến đổi khí hậu đến sử dụng đất nông nghiệp thông qua các yếu tố: Gây ảnh hưởng lớn nhất là yếu tố nhiệt độ và yếu tố cực đoan khác; ngoài ra, các yếu tố lượng mưa, chế độ gió và không khí lạnh cũng tác động không nhở vào việc sử dụng đất nông nghiệp . Các yếu tố này gây ra các hậu quả nghiêm trọng như làm hư hại, giảm chất lượng công trình, làm quá tải hệ thống cấp thoát nước, làm sạt lở, hư hại hệ thống cơ sở hạ tầng… Nghiên cứu đã đề xuất được một số giải pháp thích ứng của biến đổi khí hậu đến việc sử dụng đất nông nghiệp như thay đổi cơ cấu cây trồng, nâng cấp cơ sở vật chất, nâng cao nhận thức của cán bộ và người dân về biến đổi khí hậu
Evaluating the potential anti-Methicillin-Resistant Staphylococcus Aureus (MRSA) activities from extracts of Eleutherine subaphylla Gagnep.
No full textMethicillin-Resistant Staphylococcus Aureus (MRSA) is a significant cause of infections in hospitals and communities worldwide. Staphylococcus aureus is classified as a high-alert antimicrobial-resistant organism. Currently, alongside advancements in medicine, naturally occurring compounds with bioactive properties have garnered the attention of the scientific community due to their safety, low side effects, and potential as sustainable, promising alternatives. This study evaluated the antimicrobial activity of extracts of Eleutherine subaphylla Gagnep, against Methicillin-Resistant Staphylococcus Aureus (MRSA). The results indicated that the n-hexane extract exhibited the highest antibacterial efficacy against MRSA (28.00 ± 0.86mm). The n-hexane extract demonstrated a Minimum Inhibitory Concentration (MIC) of 31.25 µg/mL against MRSA. By combining column and thin-layer chromatography, a crystalline compound, ES02, was isolated and purified, demonstrating the most substantial resistance to MRSA. Based on 1H-NMR spectral data, the structure of compound ES02 was identified as eleutherol. The results of this study reported bioactive compounds from Eleutherine subaphylla Gagnep. had the potential to be further applied against antibiotic-resistant bacteria
Comparison of Triglyceride-Glucose Index Indices and Fatty Liver Index in Predicting Metabolic Dysfunction-Associated Fatty Liver Disease: A Cross-Sectional Study Conducted in Vietnam
No full textBackground and Aims: Metabolic dysfunction-associated fatty liver disease (MAFLD) is increasingly prevalent and linked to liver and cardiometabolic complications. Although liver biopsy remains the diagnostic gold standard, its invasiveness limits routine use, and imaging modalities show variable accuracy. Non-invasive indices such as triglyceride-glucose (TyG), triglyceride glucose-body mass index (TyG-BMI), triglyceride glucose-waist circumference (TyG-WC), and the fatty liver index (FLI) are recommended for screening, yet their performance in Vietnam remains unclear. This study evaluated and compared these indices in Vietnamese adults. Methods: A cross-sectional study was conducted at the Health Screening Department, University Medical Center Ho Chi Minh City (September 2024–January 2025). After exclusions, 290 adults undergoing routine check-ups with abdominal ultrasound were included. Clinical and laboratory data were collected to calculate TyG, TyG-BMI, TyG-WC, and FLI, and their diagnostic performance for MAFLD was compared using logistic regression and receiver operating characteristic (ROC) analysis, with area under the ROC curve (AUROC) and 95% confidence intervals (CIs). Results: Of 290 participants, 32.76% were diagnosed with MAFLD. Patients with MAFLD were older, more frequently male, and had higher body mass index (BMI), waist circumference (WC), blood pressure (BP), metabolic comorbidities, and abnormal biochemical parameters compared with non-MAFLD. The highest diagnostic performance was observed with TyG-BMI and FLI, both showing area under the receiver operating characteristic curve (AUROC) = 0.89, followed by TyG-WC (0.88) and TyG (0.82). In gender-stratified analysis, indices performed better in females; TyG-BMI achieved the highest AUROC of 0.91, comparable to FLI (0.90). Conclusions: TyG, TyG-BMI, TyG-WC, and FLI demonstrated excellent and comparable diagnostic accuracy for MAFLD, with superior performance in women. These indices represent practical, non-invasive tools for MAFLD screening in both clinical and community settings
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