392 research outputs found
Key Factors Influencing Customer Satisfaction and Intention to Reuse Food Ordering Apps
This empirical study aims to identify and evaluate the crucial factors that influence customer satisfaction and their intention to reuse a food ordering app (FOA) in Ho Chi Minh City (HCMC), Vietnam. A data sample of 413 observations from customers who used the FOA was used to test hypotheses using a quantitative technique and a structural linear model. The results indicated that among the four key factors, performance expectancy, price value, and online reviews had direct and indirect effects on customersâ continued intention to use the FOA. By contrast, hedonic motivation only had an indirect effect. Satisfaction level was the mediating factor that affected customersâ continuance intention. This study provided insights into the online service and how the key factors affected customersâ satisfaction level towards the intention to reuse the FOA. When the management of the online providing service improves the key factors â performance expectancy, hedonic motivation, price value, and online reviews â they will improve the level of satisfaction towards the intention to reuse the FOA of customers in HCMC. The management of food companies should refer to this research model for restructuring and improving their business to satisfy the needs and wants of their target customers in the competitive market
Musculoskeletal Pain and Work-related Risk Factors among Waste Collectors in Hanoi, Vietnam: A Cross-sectional Study
BACKGROUND: Musculoskeletal disorders (MSDs) are prevalent among waste collectors (WCs) in developing countries.
AIM: This study aimed to investigate the prevalence of MSDs and the factors associated with the risk of persistent musculoskeletal pain among WCs in Hanoi, Vietnam.
METHODS: A cross-sectional survey was utilized to study 468 WCs in 2017. The Ărebro Musculoskeletal Pain Questionnaire and a questionnaire on demographic and work conditions were used to collect data. Descriptive and multivariate logistics regression analyzes were applied at a significance level of 0.05 to examine the factors related to the risk of persistent pain.
FINDINGS: About 74.4% of the participants of this study experienced MSDs in at least one body region and 9.4% reported MSDs in all 10 body sites. The lower back was reported to be the most affected followed by the neck and shoulders. The risk of persistent musculoskeletal pain was significantly associated with age (odds ratio (OR) = 2.31, confidence interval (CI) = 1.05â5.09), gender (OR = 3.29, CI = 1.28â8.44), work hours (OR = 2.35, CI = 1.12â4.92), work shift (OR = 0.48, CI = 0.26â0.92), duration of poor postures of the neck (OR = 0.31, CI = 0.13â0.76), bent back (OR = 0.4 CI = 0.18â0.92) and for medial rotation (OR = 3.01, CI = 1.42â6.36), carrying heavy objects (OR = 2.94, CI = 1.15â7.48), and experience of work dissatisfaction (OR = 3.31, CI = 1.46-7.52), stress (OR = 7.14, CI = 3.14â16.24), or anxiety (OR = 6.37, CI = 3.07â13.21).
CONCLUSIONS: High prevalence of MSDs among WCs and its association with self-assessed unfavorable work postures and work-related stress implies the need of mechanical and social support at work for WC to prevent the development of MSDs and persistent pain
Genetic diversity of two successive generations of selection in bighead catfish (Clarias macrocephalus) populations
Selective programs associated with domestication can improve fish production but also can have an impact on broodstockâs genetic diversity. In this study, the genetic diversity of original sources (G0) from wild and cultured bighead catfish populations, as well as the two successive generations (G1 and G2) subjected to selection experiments, was assessed. G0 wild adults were collected in Ca Mau conservation area and G0 cultured fish were from a hatchery in Can Tho. The G1 fish included pure crosses and crossbreeds of G0, while G2 was the offspring of the selected G1. Fin clips from 27 to 29 individuals of each fish group were randomly sampled for genetic analysis. The amplification results using six ISSR primers showed that the genetic diversity was relatively higher in G0 (effective number of alleles Ne from 1.43 to 1.49; heterozygosity He from 0.265 to 0.290) than in G1 (Ne = 1.32±0.04; He = 0.201±0.023) and G2 (Ne = 1.34±0.04; He = 0.216±0.023). Genetic differences increased between the original populations and the descending generations. To reduce the detrimental impacts of low genetic diversity in domesticated bighead catfish in the Mekong Delta, it is recommended that broodstock in later generations should be produced in a larger..
Heat Stress Affects Seed Set and Grain Quality of Vietnamese Rice Cultivars during Heading and Grain Filling Period
Environmental stress trigger a variety of rice plant response, ranging from alters seed set, grain yield and grain quality during flowering and grain filling stage. Efforts are required to improve our understanding of the impact of heat stress on rice production, which are essential strategies in rice cultivation. This article investigated the seed set, yield components and grain yield of Vietnamese rice cultivars (Indica germplasm) under high temperature environment during the flowering and grain filling stage. Six rice cultivars, including popular cultivars and new cultivars of Cuu Long Delta Rice Research Institute, and one popular extraneous cultivar with differences in maturing time, were grown in pots at high temperature (HT) and natural temperature condition as control (CT). All rice cultivars were subjected to the high temperature starting from the heading stage to the harvest maturity, applied by greenhouse effect. The greenhouse has about 25 cm window opening on 3 sides for air ventilation. The seed set rate of the heat-sensitive rice genotypes decreased significantly under HT, leading to a significant reduction in grain yield. The lowest seed set was recorded in âOM4900â (44.3%) and âOM18â (39.9%) under high temperature environment. The lower yield in all rice cultivars at an elevated temperature resulted in a dramatic decrease of filled grains and contributed to a loss of 1000-grain weight. ââOM892â is a potential rice cultivar for heat tolerant breeding program due to the seed set percentage was above 80% in both HT and CT conditions. High temperature during the grain filling stage resulted in a decreased amylose and increased chalkiness for all OM cultivars
Contaminant spreading by natural convection in a box
In this paper the spreading of a contaminant accompanied  with natural convection in a box is numerically simulated. The box may be  considered as a cooking room or a working place where some sources of heat  and contaminant are in the simultaneous action. The box floor is supposed to  be divided into several domains with different boundary conditions for  temperature or heat flux. Here the purpose of the simulation is to  understand the contaminant spreading process in the box under the influence  of a convective motion. The model can be also applied for an enclosure with  separated parts differentially heated by the sunlight on its boundaries. A  good knowledge of this process is very useful for setting an efficient  ventilation scheme. In this paper the finite difference method based on the  Samarski scheme with ADI technique is applied for numerical simulation. Here  the box floor is divided into two domains of equal sizes but with different  temperature or heat flux. The contaminant source locates in the middle of  the box bottom. The simulation shows that over the part of the floor where  temperature or heat flux is greater the contaminant concentration is lager.  That result is in the accordance with the experiment done in the framework  of this~investigation
Factors affecting to digital skills and adaptability of students in the context of digital transformation at the Ho Chi Minh city University of Technology and Education
The article focuses on analyzing the factors affecting students' digital skills and adaptability in the context of digital transformation. The study identified influencing factors: Environment, Behavior, Individuals, Teachers, Time of use, and access. However, the results of an online survey of 1.282 students of the Ho Chi Minh City University of Technology and Education (HCMUTE) with Cronbach's Alpha test method, EFA analysis, correlations, and regression analysis, showed that there are 3/5 factors identified in the hypothesis that affect digital skills and adaptability of HCMUTE students in the context of digital transformation, specifically: behavior (Beta = 0.177, Sig. = 0.000); individuals (Beta = 0.181, Sig. = 0.027); teacher (Beta = 0.547, Sig. = 0.000). Besides, the environment does not affect digital skills and adaptability (KNSKNTU) due to Beta = 0.017 and Sig.=0.384>0.05. Sig does not involve usage and access time factors. >0.05 in the table Correlations not be further analyzed in the regression model. The research results are expected to help provide a more objective view of the reality of digital adoption and student adaptability in the digital transformation context at HCMUTE
Factors affecting to digital skills and adaptability of students in the context of digital transformation at the Ho Chi Minh city University of Technology and Education
The article focuses on analyzing the factors affecting students' digital skills and adaptability in the context of digital transformation. The study identified influencing factors: Environment, Behavior, Individuals, Teachers, Time of use, and access. However, the results of an online survey of 1.282 students of the Ho Chi Minh City University of Technology and Education (HCMUTE) with Cronbach's Alpha test method, EFA analysis, correlations, and regression analysis, showed that there are 3/5 factors identified in the hypothesis that affect digital skills and adaptability of HCMUTE students in the context of digital transformation, specifically: behavior (Beta = 0.177, Sig. = 0.000); individuals (Beta = 0.181, Sig. = 0.027); teacher (Beta = 0.547, Sig. = 0.000). Besides, the environment does not affect digital skills and adaptability (KNSKNTU) due to Beta = 0.017 and Sig.=0.384>0.05. Sig does not involve usage and access time factors. >0.05 in the table Correlations not be further analyzed in the regression model. The research results are expected to help provide a more objective view of the reality of digital adoption and student adaptability in the digital transformation context at HCMUTE
Arsenate reductase gene from Pityrogramma calomelanos L. enhances tolerance to arsenic in tobacco
Arsenic (As) contamination in soil, water and air is an alarming issue worldwide and has serious effects on human health and environment. Arsenic is a naturally occurring element found in rocks, soil, and water, and exposure to high levels of arsenic can lead to a range of health problems. The effects of arsenic contamination can also be felt in the environment, as it can harm plants and animals and disrupt ecological systems. The major purpose of this study was to produce transgenic plants with improved tolerance to and accumulation of arsenic via transformation of arsenate reductase gene (ArsC) into tobacco genome. Transgenic plants were screen by PCR and southern blot. Further, their tolerance and accumulation to arsenic were evaluated. In the result, we have cloned, characterized, and transformed the ArsC gene from Pityrogramma calomelanos L. (PcArsC). Its phylogenetic analysis revealed 99% homology to ArsC gene in GenBank (accession number X80057.1). Moreover, Southern blot analysis showed that ArsC gene was integrated into the tobacco genome as a single-copy. These single-copy transgenic lines showed much higher tolerance to and accumulation of As than wild type, with no other phenotypes observed. These results demonstrated that Pityrogramma calomelanos ArsC gene can improve arsenic tolerance and accumulation in transgenic tobacco lines. Thus, using Pityrogramma calomelanos L. ArsC gene for genetic engineering has potential implications in the decontamination of arsenic-containing soil
First investigation of the prevalence of parvoviruses in slaughterhouse pigs and genomic characterization of Ungulate copiparvovirus 2 in Vietnam
Chemical composition and antibacterial activities of essential oils from fruits of Melicope pteleifolia (Champ. Ex Benth.) T.G. Hartley grown in Lam Dong Province, Vietnam
In the present study, chemical composition and antibacterial properties of essential oil obtained from the aerial parts of the Melicope pteleifolia (Champ. ex Benth.) T.G Hartley in Dalat were evaluated. Essential oil was isolated through hydro-distillation. Twenty-nine constituents comprising 100% of the essential oil were characterized by gas chromatography/mass spectrometry (GC-MS) techniques. The major compounds in the essential oil were (+)-Sabinene (34.73%), Cis-α-bergamotene (13.15%), Z-α-trans-bergamotol (5.28%), ÎČ-mycrene (4.98%), and 1,3,6-octatriene, 3,7-dimethyl-(4.71%). Antibacterial activities of Melicope pteleifolia essential oil were investigated against Gram-positive and-negative bacteria. Results showed significant activities against Streptococcus pyogenes and Escherichia coli using an agar well diffusion method. The application of this essential oil in preventing and eliminating bacteria could be useful in fields as medicine and cosmetics.
- âŠ