Published: 2019-10-28

Nong Lam University students' perceptions of corporate social responsibility: A case study

Na Lo
Electronic version: 28 Oct 2019 | DOI: 10.52997/jad.1.05.2019
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Abstract

This study was conducted to assess students' perceptions of corporate social responsibility (CSR) and the impacts of those perceptions on their thinking and behavior. Structural equation modelling (SEM) was used to examine the proposed correlations by analysing the data collected from 787 students at Nong Lam University. Results showed that there were positive correlations from relatives, social activity participation, demographics, and self perception of students' perception of CSR. Besides, we also found that perception would positively affect students' thinking and behavior.

Evaluation of growth and development of some varieties of tomato (Lycopersicon esculentum Mill) under nethouse conditions in Chau Doc

Chuong V. Nguyen
Electronic version: 28 Oct 2019 | DOI: 10.52997/jad.2.05.2019
Abstract | PDF (260.1K)

Abstract

This study was carried out under nethouse conditions in Chau Doc city with 6 types of back tomatoes to select the potential ones suitable for the local ecological conditions. The objectives of this research were to: (i) Survey on growth parameters, fruit quality; (ii) evaluate the adaptability characteristics of black tomato varieties under nethouse conditions in Chau Doc city; (iii) Compare and select some of suitable black tomatoes under nethouse conditions in Chau Doc city. The results showed that some promising cultivars had an early harvest ranging from 90 days to 103 days such as Indigo Rose, Viagra Socola, black Russia, Cherry Chocolate, Black Baron and Savior. All cultivars had a plant structure well adapted to the local nethouse conditions in Chau Doc city. Variety Cherry Chocolate gained the highest fruit setting with 203. Viagra Socola, black Russia, Cherry Chocolate gained higher at over 4,0 tons/ 1.000m2. The lowest yield of the Black Baron was obtained at 2,83 tons/ 1.000 m2. The Savior was obtained at 7,05 tons/ 1.000 m2 with a relatively good fruit quality. The promising cultivars are Viagra Socola, Cherry Chocolate, black Russia and they need further research to evaluate into real field production.  

Evaluation of chemical composition and inhibitory effects of Hypochaeris radicata L. extracts on seed germination and growth of Echinochloa crus-galli L.

Men T. Tran, T. T. Nguyen, Khang T. Do, Ly H. Sam, & Yen D. H. Nguyen
Electronic version: 28 Oct 2019 | DOI: 10.52997/jad.3.05.2019
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Abstract

Allelopathy is a common plant-resistance mechanism in nature, this mechanism demonstrates the growth of this plant that may affect the growth and development of other nearby plant species through the production of secondary compounds. In this study, the allelopathic ability of ethanol extracts from Hypochaeris radicata L. on Echinochloa crus-galli L. was investigated in laboratory conditions. The extracts from stems of Hypochaeris radicata L. at the concentration of 5 mg/mL showed highest inhibition (73.33%) on seed germination of barnyard-grass (Echinochloa crus-galli L.). In this study, total polyphenol and flavonoids in Hypochaeris radicata L. were determined by spectrophotometry. Polyphenol and flavonoids present in all parts of the Hypochaeris radicata L. were investigated. The highest polyphenol content in leaves was 9.67 mg/g extract and the flavonoid content in roots was 29.56 mg/g extract. Phenolic acids in extracts from leaves, flowers, and roots were identified by HPLC. The results showed the presence of 7 phenolic acids including chlorogenic, syringic, vanillic, synapic, p-coumaric, benzoic and ellagic in the extracts. The findings highlighted that Hypochaeris radicata L. is a wild plant species with great potential for allelochemicals.

Effects of replacement of black soldier fly (Hermetia illucens) larvae meal in the diets on growth performance of discus fish (Symphysodon sp.)

Tu P. C. Nguyen, Tri N. Nguyen, Ha N. Nguyen, & Linh T. T. Nguyen
Electronic version: 28 Oct 2019 | DOI: 10.52997/jad.5.05.2019
Abstract | PDF (260.1K)

Abstract

This study was conducted to evaluate the replacement of fishmeal by black soldier fly larvae (Hermetia illucens) (BSF) meal, frozen beefheart, and commercial pellet on growth performance, survival rate, and feed utilization of discus fish (Symphysodon sp.). Discus juveniles were graded into small, medium and large size groups as block in a completely randomized block design. Five trial diets included frozen beefheart (T1), commercial feed for discus fish (T2) and three diets containing graded levels of BSF as replacements for protein from fishmeal of 0% (T3), 25% (T4), and 50% (T5). The results showed that TAN and nitrite levels in the beefheart treatment were higher than those in the other ones. Moreover, discus fish in treatment 1 had a higher growth rate and a lower feed conversion ratio than those in the other treatments. On the other hand, no statistically significant differences among the pellet treatments were observed for growth rates of discus's weight, length and height and feed conversion ratio (P > 0.05). Moreover, the results showed that discus fish in the two BSF treatments did not suffer from diseases and had higher survival rates than those in the other treatments.

Genetic characteristics in four farmed tilapia (Oreochromis niloticus) populations evaluated by microsatellite markers

Ha T. T. Tran, Trang T. Vu, Nam P. Nguyen, Nhat H. Pham, Diep H. Nguyen, & Giang T. H. Luu
Electronic version: 28 Oct 2019 | DOI: 10.52997/jad.7.05.2019
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Abstract

In this study, genetic characteristics of four tilapia strains including NOVIT4, 13th GIFT generation, China and Philippine have been investigated by analysis the genotype at 6 microsatellite loci. The results showed that all loci present abundant polymorphism with the total of 51 alen, in which, locus named GM 139 and UNH 995 were highest polymorphism, 14 and 11 alen respectively. A deficiency in expected heterozygosity has been appeared in all tilapia strains with the Ho was lower than He values and 17/24 loci was significant departure from Hardy-Weinberg (P < 0,05). Fst ranged from 0.012 to 0.025 that showed no large difference between all populations. However, the AMOVA result showed the genetic diversity at molecular level among individuals in the same population and between individuals were high, 36,69% and 61,00% respectively. The results of this study can be very useful in term of giving the genetic information of four tilapia strains in the selective breeding program.

Identification of the tolerant capacity to aquatic environment factors (temperature, pH and dissolved oxygen) of Asian bumblebee catfish (Pseudomystus siamensis Regan, 1913)

Binh T. T. Vu, Truc T. T. Nguyen, Tuan V. Vo, Tu V. Nguyen, & Chau M. Pham
Electronic version: 28 Oct 2019 | DOI: 10.52997/jad.6.05.2019
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Abstract

Asian bumblebee catfish (Pseudomystus siamensis) belongs to Bagridae family and is an economic value ornamental species. However, biological characteristics of this fish species have been rarely reported in the literature. A study to identify tolerant capacity to aquatic environment factors (incipient lethal temperature (ILT) and incipient lethal pH (ILpH) and oxygen threshold) of Asian bumblebee catfish at three developmental stages namely embryo, hatchling and ten-day post hatching (dph) was carried out from July 2018 to January 2019 at the Experimental Farm for Aquaculture of Fisheries Faculty - Nong Lam University in HCM City. The results showed that the incipient upper and lower lethal temperatures (IULT and ILLT) were 32.5oC and 22.3oC for embryos, 36.7oC and 18.7oC for hatchlings, and 38.6oC and 15.9oC for 10 dph fish, respectively. The incipient upper and lower lethal pHs (IULpH and ILLpH) were 10.7 and 4.4 for embryos, 10.2 and 3.7 for hatchlings, and 10.2 and 3.8 for 10 dph fish, respectively. The oxygen thresholds of the catfish at the three stages were 4.7, 1.1 and 1.0 mg O2/L, respectively. The Asian bumblebee catfish at post hatching stages appears to tolerate to unfavorable environmental factors compared to embryonic one. The study results would be an important scientific base for researches on seed production and conservation of the fish in the future.

Genotype by environment interaction for growth and survival rate in black tiger shrimp (Penaeus monodon) in generation 4

Sang V. Nguyen, Luan T. Nguyen, & Nhien V. Tran
Electronic version: 28 Oct 2019 | DOI: 10.52997/jad.4.05.2019
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Abstract

Genotype by environment interaction for growth rate in G1 of the same selection program has been published. However, there is no repeated figure in later generations for confirming and well-planning the design of selection program for further improvement. The experiment was conducted using selective population of generation 4 with 97 families tested in 3 environments. Growth (body weight) and survival rate at harvest weight were recorded and evaluated. There was no genotype by environment interaction for both traits with high genetic correlations of the same traits tested between ponds in the Central and in the South of Vietnam of 0.80 and 0.83, respectively. There was also no genotype by environment interaction for growth rate between ponds in the South of Vietnam and bio-security indoor tank with high genetic correlation of 0.91. These results indicated that the number of testing environments would be reduced to save the operation cost for a breeding program. Estimated genetic response was from moderate to high for growth trait corresponding to moderate to high heritabilities (0.20 - 0.45) and high for survival rate corresponding to high heritabilities (0.34 - 0.45).

Cloning, expressing and purification of recombinant C-terminal PMT of Pasteurella multocida

Hung K. Vu, Thinh T. Nguyen, Hang T. T. Trinh, Thuy T. T. Nguyen, Truong X. Nguyen, Anh T. T. Do, & Giang T. T. Nguyen
Electronic version: 28 Oct 2019 | DOI: 10.52997/jad.8.05.2019
Abstract | PDF (260.1K)

Abstract

Pasteurella multocida strains produce heat-stable toxin Pasteurella Multocida Toxin (PMT) which is the main virulence factor causing pasteurellosis in pigs. Therefore, PMT protein is considered as a promising candidate to study recombinant vaccine against pasteurellosis in pigs. In this study, we cloned the nucleotide sequence coding C-terminal fragment of PMT (tPMT-780), from acid amine 506 to acid amine 1285, into pRSET-A vector and expressed it on Escherichia coli BL21 bacteria. The SDS-PAGE result showed that tPMT-C780 was well-expressed by IPTG 1mM induction and determined to be insoluble protein, therefore it was purified by denaturation method using Ni-NTA beads. The protein elution samples contained only one protein band similar with the size of tPMT-C780 and positively reacted with PMT-specific antibody. These results suggested that we were successful in expressing and purifying C-terminal protein of PMT toxin, tPMT-C780. This is the primary material for further studies to produce recombinant vaccine against pasteurellosis in pigs.

Optimization of alcoholic fermentation of custard apple juice by Saccharomyces cerevisiae using response surface methodology

Huan T. Phan, & Hien M. Nguyen
Electronic version: 28 Oct 2019 | DOI: 10.52997/jad.9.05.2019
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Abstract

In recent years, custard apple fruit has been applied in food processing with various products. The objective of this study was to valorize a fermented fruit drink from a Vietnamese local custard apple fruit by the alcoholic fermentation of the juice using Saccharomyces cerevisiae. Response surface methodology was used to describe dependency of soluble solid content, inoculum size of yeast and fermentation time on ethanol production during fermentation of custard apple juice by Saccharomyces cerevisiae SLS. The experiments were performed according to the central composite design with total soluble solid content ranging from 16 to 20oBrix, inoculum size of yeast from 1% to 3%, and fermentation time from 42 to 48 h. A quadratic model was developed to correlate the variables to the ethanol yield and sensory score. The results showed that a production of ethanol from the custard apple juice could be achieved reaching up to 5.1% (v/v) at optimum conditions of 19oBrix, 2% yeast and 44-h fermentation time. The model predictions agreed satisfactorily with the experimental values.  

Survey of ornamental plants functioned as medicinal plants at some ornamental gardens in Ho Chi Minh City and applying them in garden design

Tien T. M. Duong, & Phuc T. Le
Electronic version: 28 Oct 2019 | DOI: 10.52997/jad.11.05.2019
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Abstract

The objective of the study was to identify some of common ornamental plants functioned as medicinal plants. The study was carried out in Ho Chi Minh city, from September 2016 to June 2018, using some methods such as: survey, identification, statistics, and applying these plants in garden design with site analysis, computer aided design and drafting base on main idea. One hundred and twenty popular species belonging to 69 families with medicinal values were identified. Two cases for concept design, instant tree list, shrub and cover list were also proposed. The completed design drawings included function layout plan, master plan, sections and some details of garden, master perspective, detailed perspectives.

Estimating the economic value of absorbing and storing of carbon in dipterocarp forests in Ia Pa district, Gia Lai province

Trang T. Q. Nguyen, & Phuong T. B. Tran
Electronic version: 28 Oct 2019 | DOI: 10.52997/jad.10.05.2019
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Abstract

Dry dipterocarp forest is one of the ecosystems that features variety of rare plants and animals. The forest in Ia Pa district, Gia Lai province is declining owing to illegal logging and encroachment of forest land for cultivation. Forest degradation can reduce CO2 sequestration, contributing to increasing greenhouse gas emission and global warming. The study was carried out in the 4 quadrats (each 2,500 m2 = 50 x 50 m) in dry dipterocarp forest of Ia Pa district. In each quadrat, 5 sub-quadrats (each 25 m2 = 5 x 5 m) were set up, one at a central point and four at four corners of the quadrat, respectively. Based on the relationship between carbon stock and above ground biomass, we found that CO2 accumulation in dry dipterocarp forest was 105.6 tons/ha corresponding to the economic value of 12,299,760 VND/ha. Thus, it is necessary to improve forest quality towards sustainable management of dry dipterocarp forest ecosystem and increase the economic value of the forest with respect to environmental services.

Climate change vulnerability zoning for suburban districts of Ho Chi Minh City

Linh T. Vu, Loi K. Nguyen, Lam H. Vo, & Dung M. Ho
Electronic version: 28 Oct 2019 | DOI: 10.52997/jad.12.05.2019
Abstract | PDF (260.1K)

Abstract

The study aims to partition vulnerabilities caused by climate change in suburban districts of Ho Chi Minh City by integrating the use of AHP and GIS. The subjects used data collected from different departments, from surveys in the study area, and consulted with experts in the field of research to assess the weight of factors: Exposure, sensitivity and adaptability. After overlapping component maps, the results show that the high vulnerability to climate change in five suburban districts of Ho Chi Minh City by 2025 was dominated by Binh Chanh, Nha Be and Hoc Mon. Area of ​​35,865.57 ha (accounting for 22.84%). The low and medium damage was concentrated in Cu Chi and Can Gio (the respective area was 36,354.33 ha, equivalent to 23.16% and 84.762.27 ha, equivalent to 54%). In addition, the study proposes solutions to increase adaptation and mitigation of the impacts of climate change on the lives of people in the affected area.