230 research outputs found
Zooplankton from Can Giuoc River in Southern Vietnam
In this study, the variables of zooplankton and water quality were investigated in the Can Giuoc River, Southern Vietnam. Zooplankton was monitored in April and September 2015 at 5 sampling sites in the river. Some basic water quality parameters were also tested, including pH, total suspended solid (TSS), dissolved oxygen (DO), biological oxygen demand (BOD5), inorganic nitrogen (NH4+), dissolved phosphorus (PO43-), and coliform. The zooplankton biodiversity indices were applied for the water quality assessment.
The results showed that pH ranged from 6.7 to 7.6 during the monitoring. The TSSs were between 34–117 mg/L. The DO and BOD5 were from 0.6 to 3.8 mg/L and from 6.3 to 13.2 mg/L, respectively. The NH4+ and PO43- concentrations ranged from 0.44 to 3.23 and from 0.08 to 1.85 mg/L, respectively. The coliform number was between 9.3x103–9.3x104 MPN/100 mL. The zooplankton analyses showed that there were 31 species of coelenterates, rotatoria, oligochaetes, cladocerans, copepods, ostracods, mysidacea, and 8 larval types. Thereof, the species of copepods were dominant in the species number. The zooplankton density ranged from 9 500 to 23 600 individuals/m3 with the main dominant species of Moina dubia (Cladocera), Thermocyclops hyalinus, Acartia clausi, Oithona similis (Copepoda), and nauplius copepods. The biodiversity index values during the monitoring were from 1.47 to 1.79 characteristic of mesotrophic conditions of the aquatic environment. Besides, the species richness positively correlated with pH, TSS, DO, BOD5, NH4+, PO43-, and coliform, while the zooplankton densities got a positive correlation with DO, BOD5, NH4+, PO43-, and coliform. The results confirmed the advantage of using zooplankton and its indices for water quality assessment
Innovation and Productivity of Vietnamese Small and Medium Enterprises: Firm level panel data evidence
Innovation is considered as a driver of productivity at both country and firm level. However, the researches on the relationship between innovation and firm productivity in Vietnam are rare. Using Vietnam's SMEs survey in 2007 and 2009, this paper examines this relationship for the small and medium enterprises (SMEs). Cobb-Douglas production function and the fixed effect model are employed throughout the paper. We find that the presence of innovation has positive effects on firm productivity. In addition, this study also looks at the impact of firm size, firm location and manufacturing sector on the relationship between innovation and SMEs' productivity.
Keywords: innovation, productivity, SMEs Vietnam
JEL Classifications: D24; L60; O3
Isolation, screening antimicrobial activity and identification of fungi from marine sediments of the area Thanh Lan, Co To, Vietnam
Marine environment is rich in natural product resources, including marine microorganisms, especially fungi which are not only seen as a potential source of highly applicable bioactive substances but also can provide for science new chemical structures. The objective of this study is to isolate and screen fungal strains with antibacterial activity from the marine environment. Twenty five strains of fungi were isolated from marine sediments of Thanh Lan, Co To island and assessed on antibiotic activity against 7 tested microbial strains, including three Gram-negative bacteria (Escherichia coli ATCC25922, Pseudomonas aeruginosa ATCC27853, Salmonella enterica ATCC13076), three Gram-positive bacteria (Enterococcus faecalis ATCC29212, Stapphylococus aureus ATCC25923, Bacillus cereus ATCC 13245), and the yeast Candida albicans ATCC10231. The minimum inhibitory concentration (MIC) against the tested microorganisms was determined for the crude extracts obtained from the culture broths after ethyl acetate extraction and vacuum rotary evaporation. Three strains with the highest antimicrobial activity M26, M30 and M45 were capable of inhibiting 4 - 5 of the 7 tested microorganisms with MIC values from 64 to 256 μg/ml, depending on each tested strain. Morphological and phylogenetic investigations based on 18S rRNA gene sequences of the three selected strains showed that strains M26 and M30 belonged to the genus Penicillium, whereas strain M45 belonged to the genus Neurospora. The sequences of 18S rRNA gene of three strains M26, M30 and M45 were registered on GenBank database with accession numbers: MH673730, MH673731, MH673732, respectively. Research results showed that marine environment has a great potential in isolation of fungal strains for the search for antibacterial substances as well as other biologically active compounds
Preparation of Ti/TiO2-PANi electrodes by combining method of thermal treatment with polymerization processing and their electrochemical property
Ti/TiO2-PANi-electrodes were synthesized by combining method of thermal treatment of titanium substrate with chemical polymerization processing of aniline on which. Their morphological structure was observed by scanning electron microscopy. The presence of PANi and TiO2 were indicated by infrared spectra and X-ray diffraction, respectively. Their electrochemical properties were characterized by cyclic voltammetry and impedance spectroscopy. The results showed that their photoelectrochemical property with light on in 0.5 M H2SO4 indicating a n-conductor that depended on PANi thickness covered TiO2-layer among them the best one obtained by oxidative temperature of 500 oC for 30 minutes during thermal treatment of titanium substrate connected with an immersing into acidic aniline solution for only 8 min during polymerization
Impact of Vocational Education and Training On Decent Job Opportunities Regarding Information and Communication Technology
Vocational education and training plays a crucial part in the creation of decent job. The fast growth of information and communication technology (ICT) during the past ten years has increased work opportunities for laborers. This research uses the yearly labor force survey data to study the impact of vocational education and training on decent job opportunities for employees in the context of Vietnam's information and communication technology development. The logit model results indicate that the 2020 rate of decent jobs is still low, at approximately 25.6 percent. However, vocational education and training and the advancement of ICT positively affect decent job opportunities. This long-lasting impact affects laborers in various areas, regions, and industries. These findings suggest that vocational education and training and ICT must play a significant role in transitioning from precarious to more secure employment, so laborers must acquire professional knowledge and information technology skills
An insight into non-English major learners’ task engagement from a sociocultural perspective
Under the lens of a sociocultural view, this qualitative study was conducted with 83 non-English major learners at a university in the Mekong Delta to examine English learners’ task engagement. Twelve of them were further invited to be interviewed. Data were collected from class observations, learning journals, semi-structured interviews and stimulated recall. The study showed that the same task was performed differently by learners, and that the way learners implemented a given task was shaped by the negotiation between their personal and contextual factors because of their sense of agency in the situated sociocultural learning context. The study has acquired an increased insight into learners’ task engagement regarding their agency in the teaching and learning context of Vietnam from a sociocultural view
Self-injurious Behavior of Children with Autism in Vietnam: Across Sectional Study
This study explored self-injurious behaviour (SIB) of autistic children in Vietnam through a crosssectional
design. 60 informants, including 57 parents and 3 caregivers completed the questionnaire on
problem behaviour consisting of aggression, self-injury, stereotyping, property destruction, other
problem behaviours and their functions. Results revealed that children experienced all mentioned
problem behaviours, especially self-injurious behaviour. The topographies of self-injurious behaviour
of the children included head-hitting, head-scratching, head-banging, hair-pulling, face-hitting, facepuncturing
with a pen, ear-scratching, lip-picking, hand-biting, hand-scratching, hand-pinching, and
belly-scratching. The most common area of self-injurious behaviour is the head. The functions of these
problem behaviours were expressed in four types (social positive reinforcement, social negative
reinforcement, automatic positive reinforcement and automatic negative reinforcement). Social
positive reinforcement appeared as a prominent function. Out of these 57 children, 21 of them who
were autistic with self-injurious behaviour went through a functional behaviour assessment (FBA) in
which the four conditions known as attention, tangible items, escape from task/activities, automatic
stimulation were tested. The results of functional behaviour assessment (FBA) further indicated the
correspondence between the FAST-R and FBA outcome on function of problem behaviour, especially
self-injurious behaviour. The research concluded that the prominent function of these self-injurious
behaviours was social function. It means self-injurious behaviours usually occur within a condition of
social interaction, especially, in this present study, in the tangible condition. The antecedent of selfinjurious
behaviour is the removal of tangibles (e.g. food, preferred items). This paper contributes to
our knowledge of self-injurious behaviour of children with autism in Vietnam where empirical
research of this field was still very rare
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