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The marbled eel has a distribution with great profitable, ecological and conservative values. Studies on the biology, population structure and phylogenetic of marbled eel are still incomplete. The research uses the large subunit ribosomal RNA (16S rRNA) of mitochondrial sequences to evaluate the genetic diversity populations of marbled eels living in the different ecosystems the regions in Central Vietnam. There are 7 polymorphic sites. 8 haplotypes, haplotype diversity (Hd) = 0.534 ± 0.079 and nucleotide diversity (π) = 99 x 10-3 were identified. The negative values are based on analysis of the neutrality tests, Strobeck’s S (S) values between individuals in populations = 0.00 to 1.000 and the genetic intraspecific distance between (Fst) individuals are in the population = 0.0000 – 0.0032 (mean = 0.0010). The individuals in the population signs of recent population expansion. A random pattern of genetic evolution with a high probability of occurrence of rare alleles as populations expand geographically has been found in the population. All marbled eels collected from Central Vietnam were genetically closely related. This result lays the foundation for the conservation strategy of the species germplasm resources and develops this species in Central Vietnam.

This study aimed to determine the effect of a commercial diet's protein level on the fry-to-fingerling stage. Thirty days-old fries having the initial length and weight of 18.25 ± 0.15 mm fish-1 and 0.036 ± 0.50 g fish-1 respectively have been used in this study. Diet having three protein levels i.e. 30% (trial 1 as control), 35% (trial 2), 40% (trial 3), and 45% (trial 4), respectively, have been used to evaluate the effect of protein, and each trial has been repeated three times. During the study, stocking density was allocated to 1000 fish per composite tank with a volume of 1 m3. After 30 days of rearing, the weight of fingerlings in trial 1 reached up to 1.50 ± 0.02 g fish-1 and it was recorded as 1.52 ± 0.01g for trial 2, these two were lower than that of trials 3 and 4, where fingerling weight was reported 1.69 ± 0.01 and 1.58g fish-1 respectively and obtained the best weight compared to others. The length of fingerlings at the end of the experimental period was also changed in different trials and it was recorded 47.12; 46.92; 50.97; and 48.89 mm fish-1 for trail 1, 2, 3, and 4 respectively, among the tested combinations lower fingerlings length was recorded for trial 2 (35% CP), but it is not significantly different for trial 1 and 2 and a significant difference (P < 0.05) was reported for trail 2, 3, and 4. The survival rate of fingerlings ranged from 67.27 to 72.33%. Meanwhile, the herd distribution coefficient variation (CVW) in the treatment using 40% protein (trial 3) was the highest at 72.33% (p < 0.05). The results of the study can be concluded that the level of protein has a significant effect on the various growth parameters of fingerlings.

This study was carried out to isolate and determine the Vibrio spp. from the Red drum fish (Sciaenops ocellatus) suffering from the hemorrhagic disease in Vietnam. In this study, 18 strains of Vibrio bacteria were identified from 27 samples of Red drum fish. The isolated bacterial strains were identified with the 16S rRNA sequencing method and checked for morphological, physiological, and biochemical characteristics by using the API 20E KIT. Results of the study revealed the presence of twelve strains of V. alginolyticus, three strains of V. fluvialis, and three strains of V. orientalis. All Vibrio strains have gene similarities with those on the Genbank ranging from 98.05 to 100%. The biochemical characteristics of these 18 isolates were similar and these are susceptible to tetracycline and doxycycline and entirely resistant to ampicillin, amoxicillin, and erythromycin.

This study aimed to identify the relationship between temperature, temperature-humidity index (THI), and the amount of dry matter food intake (DMI) by sheep. Twelve Phan Rang (Ninh Thuan province) sheep belonging to three age groups of 6, 9, and 12 months (4 heads of each age group) raised in Thua Thien Hue province were fed with natural grass for two seasons: hot season (April-August) and cold season (November-February). Daily temperature, humidity, and food intake were recorded. The results of the study revealed that temperature and THI were closely correlated (P

For a start-up company, besides creating intellectual property, protecting and maximizing economic benefits from those intellectual properties is a concerning issue for all businesses. However, the majority of start-ups are still not aware of the importance of intellectual property management. By analyzing the policies and legal regulations on intellectual property management for start-ups, this article will research the practical implementation of such policies and regulations, from that make recommendations to improve policies on intellectual property management. It will also propose solutions to help Vietnamese start-ups raise their awareness of the importance of building an appropriate intellectual property management strategy for their enterprise.

This study aims to determine how the levels of protein in commercial diets affect growth and survival rates of Siganus guttatus from the fry to fingerling stage. The experiment allocated 3 levels of protein in the diets: 35% (trial 1); 40% (trial 2) and 45% (trial 3) and each trial was repeated three times. The 30-day-old fry in this study had an initial length and weight of 18.25 ± 0.15 mm fish -1 and 0.036 ± 0.50 g fish -1 , respectively. In experimental setup, the stocking density was set to 1,000 fish m -3, and all the experimental fish were arranged in a composite tank with a volume of 1.0 m 3 . After 30 days of rearing, the weight of fingerlings in formula trial 1 reached 1.52 ± 0.01 g fish -1 , which was lower than that of trial 2, where fingerling weight was reported to be 1.69 ± 0.01 g fish -1 but was showed no difference from trial 3, which obtained a weight of 1.58 ± 0.08 g fish -1 . The length of fingerlings in trial 1 reached 36.92 ± 0.60 mm fish -1 , which was lower than that in trial 3 (45% CP) with lengths of 38.89 ± 0.43 mm fish -1, but not significantly different in trial 2 (40% CP) with a length of 37.97 ± 0.35 mm fish -1 . The survival rate of fingerlings ranged from 67.27 to 72.33%. Meanwhile, the herd distribution coefficient variation (CVw) in the treatment using 45% protein (trial 3) was the highest at 7.42% (p < 0.05).

In response to the long-term challenges of skills shortages and mismatches, many countries worldwide have made significant investments in STEM education. However, to obtain a comprehensive understanding of the progress of global research on the implementation of STEM education, it is essential to compile case studies on STEM education. Therefore, we conducted a bibliometric analysis of 750 publications from Scopus database to assess the bibliographic content of case studies on STEM education from 2006 to 2022. Our main findings show that the first case study on STEM education dates back to 2006, and research in this direction has grown enormously and continuously over the last five years (counting for 72.9%). The most influential articles in the field are cited mainly in the background citations section and help provide an initial perspective for readers to understand the insights discussed later in the study. The most popular journals publishing case studies in STEM education are of good quality, ranking highly in Scopus and Web of Science categories. The analysis results show three main research directions: STEM education in higher education, STEM education expands to STEAM, and STEM education activities in K12-education.

Students’ scientific research receives a lot of attention from universities and colleges. However, getting students to participate in research is not easy at all. As a result, the purpose of this research is to identify the factors that influence students’ participation in scientific research. The study was conducted for students at pedagogical universities in Vietnam. The study employed a quantitative approach and a survey sample of 298 students. Cronbach’s Alpha and Exploratory Factor Analysis (EFA) were used in the study to test and develop the scales. Furthermore, Multiple Linear Regression is used to determine the factors influencing students’ participation in scientific research. According to the findings of the study, three groups of factors influencing students’ participation in scientific research include internal factors, external factors, and student characteristics. The external factors have the greatest influence, while the internal factors have the least influence on students’ participation in scientific research.

Objective: This study was done to report the results of genetic diversity and toxic genes analysis of Vibrio pathogen isolated from white leg shrimp and marine fishes cultured in Thua Thien Hue province, Vietnam. Methods/statistical analysis: Pathogen Vibrio spp. were isolated from shrimps and fishes, and were identified by 16S rRNA sequencing. The presence of toxin genes in Vibrio spp. strains were determined through the presence of genes encoding toxic proteins (pirAvp, pir-Bvp, tlh, tdh and trh) based on specific primers for these genes. Genetic diversity of Vibrio strains was analysed by RAPD technique. Findings: A total of 120 Vibrio colonies from shrimps (with Acute Hepatopancreatic Necrosis Disease) and fishes (with hemorrhagic disease) cultured in Tam Giang lagoon in Thua Thien Hue, Vietnam were isolated. Of which, 14/54 strains from shrimps had pirAvp and pirBvp genes and 18/66 strains from fishes had tlh gene, and none of Vibrio strains had tdh and trh genes. Randomly amplified polymorphic DNA (RAPD) analysis of 36 Vibrio samples showed the 148 polymorphic DNA fragments from ten random primers. The genetic diversity is high within studied species. In there, V. parahaemolyticus has the highest diversity level (h=0.1645 and I=0.2695) while V. shilonii is lowest (h=0.0136) and I=0.0207). The degree of genetic differentiation among species is also high (Gst=0.4827). Genetic identity between V. parahaemolyticus and V. vulnificus (0.9545) is highest while between V. shilonii and V. harveyi (0.7416) is lowest. The dendrogram also showed that V. parahaemolyticus is closely related to V. vulnificus whereas V. shilonii and V. harveyi have large distance. Application/improvements: This study is aimed to provide scientific data as the basis for the study and production of rapid diagnostic kits in the future. Keywords: AHPND; Genetic diversity; RAPD; toxic genes; Vibrio; Vietnam

Cá Hồng mỹ (Sciaenops ocellatus) là loài cá biển có giá trị kinh tế cao và là đối tượng nuôi phổ biến ở Việt Nam, nhưng bệnh xuất huyết lở loét do vi khuẩn V. alginolyticus đang là thách thức chính cho nghề nuôi loài cá này tại Thừa Thiên Huế. Nghiên cứu này xác định hoạt tính kháng vi khuẩn của cao chiết từ cây Diệp hạ châu (Phyllanthus amarus) đối với 5 chủng V. alginolyticus được xác định là tác nhân gây bệnh xuất huyết trên cá Hồng mỹ. Cao chiết ở các nồng độ 100–500 mg/mL đều có khả năng kháng vi khuẩn V. alginolyticus, cao nhất ở nồng độ 500 mg/mL với đường kính vòng kháng lớn nhất (p < 0,05). Nồng độ ức chế tối thiểu (MIC) dao động từ 6,25 đến 25 mg/mL; nồng độ tiêu diệt tối thiểu (MBC) dao động từ 25 đến 50 mg/mL; tỷ lệ MBC/MIC từ 2 đến 4. Nồng độ cao chiết từ 50 đến 2.000 mg/mL cũng an toàn đối với cá Hồng mỹ ở giai đoạn giống.

Anguilla marmorata is a species with high economic value and increasingly interested by organizations and scientists. So far, many of the eel's biological characteristics remain mysterious, and they are often classified according to morphological features such as pigmentation patches, number of vertebrae, ... It is even difficult to distinguish one individual from another in some species, especially in the larval stage. In this study, the Random amplification of polymorphic DNA (RAPD) molecular marker was used to evaluate the genetic diversity of 48 eels collected in Thua Thien Hue province. Results showed that the genetic diversity of individuals in the Eel population studied is quite high. With 8 random primers via PCR, 77 DNA tapes with 76 polymorphic tapes were obtained, the tape size ranged from 170-2,500 bp, in which primer S10 showed the highest diversity with an average Ho value of 0.563, followed by primer S8 (Ho = 0.558). The lowest diversity was in the OPD5 primer (Ho = 0.300). The OPG17 primer is the primer that produces the most polymorphic tapes (13/13 tapes) and the S3 primer for the least amplified tapes polymorphism (9/10 DNA tapes). The diversity coefficient in each random primer ranged from about 0.300 to 0.563, with an average of 0.433. The genetic variation in the Eel population is random. Genetic variation can be attributed mainly to different eel breeding conditions and origins. Genetic similarity coefficients among the Eels varied from 0.660 to 0.910 and were divided into two main groups in genetic similarity coefficient 0.660.

This study investigated the dietary component and morphology of the digestive tract of Anguilla marmorata during its yellow stages (non-migrants). Anguilla marmorata is also widely distributed, exploited and cultivated with high economic value. A total of 127 samples, ranging in total length from 17-108 cm and weight from 10-3200 g were collected from Thua Thien Hue, Vietnam. The structure of the gastrointestinal tract indicated that Anguilla marmorata has the typical characters of carnivorous fish such as a wide mouth, small teeth in bands; free tongue; short esophagus, stomach, and intestines made up of folds. The mouth size of Anguilla marmorata ranged from 1.81-6.6 cm and it increased with the body weight of fish. Anguilla marmorata is an animal-eating species with an RLG (relative length of the gut) ranging from 0.34 to 0.41 (RLG

Data were collected from 30 strains of Vibrio and sampled on different organs (brain, hemorrhagic site and digestive tract) of Sciaenops ocellatus infection. The results showed that the nucleotide sequences 16S rRNA region are highly similar to those of V. alginolyticus, V. azureus, V. fluvialis, V. natriengens and V. orientalis, which were published on Genbank and other, ranging from 98.05 to 100%. The digestive tract has the most common Vibrio strains (V. alginolyticus [16] V. azureus [7] and V. fluvialis). Thereout, 25 of 30 strains of Vibrio contained 1 to 3 toxin genes, except V. parahaemolyticus. Six parameters were used to measure the DNA polymorphism of 33 homologous DNA sequences in this Vibrio bacteria population. The results indicated that number of separate polymorphic sites (S), total number of mutant sites (Eta), number of haplotype (h), haplotype diversity (Hd), average number of nucleotide differences (k), nucleotide diversity (Pi) were 98 (S), 103 (Eta), 9 (h), 0.887 ± 0.032 (Hd), 25.789 (k) and 17.980 × 10–3 ± 0.003 (Pi), respectively (P Vibrio on 3 organs of fish (S. ocellatus) hemorrhagic are V. azureus (27,67%), V. alginolyticus (50%), V. orientalis (6,67%) and V. fluvialis (16,67%). Through this result, we found that the diversity of Vibrio species that appeared on the red drum was used in the 16S rRNA region and the presence of toxin genes in these Vibrio species.

Data were collected from 30 strains of Vibrio and sampled on different organs (brain, hemorrhagic site and digestive tract) of Sciaenops ocellatus infection. The results showed that the nucleotide sequences 16S rRNA region are highly similar to those of V. alginolyticus, V. azureus, V. fluvialis, V. natriengens and V. orientalis, which were published on Genbank and other, ranging from 98.05 to 100 %. The digestive tract has the most common Vibrio strains (V. alginolyticus [16] V. azureus [7] and V. fluvialis). Thereout, 25 of 30 strains of Vibrio contained 1 to 3 toxin genes, except V. parahaemolyticus. Six parameters were used to measure the DNA polymorphism of 33 homologous DNA sequences in this Vibrio bacteria population. The results indicated that number of separate polymorphic sites (S), total number of mutant sites (Eta), number of haplotype (h), haplotype diversity (Hd), average number of nucleotide differences (k), nucleotide diversity (Pi) were 98 (S), 103 (Eta), 9 (h), 0.887 ± 0.032 (Hd), 25.789 (k) and 17.980x10-3 ± 0.003 (Pi), respectively (P < 0,05). The G+C content above 1434 sites positions of nucleotide sequences accounted for 0.542. The phylogenetic tree showed that these strains are divided into six groups. As observed, the appearance of isolated Vibrio on 3 organs of fish (S. ocellatus) hemorrhagic are V. azureus (27,67 %), V. alginolyticus (50 %), V. orientalis (6,67 %) and V. fluvialis (16,67 %). Through this result, we found that the diversity of Vibrio species that appeared on the red drum was used in the 16S rRNA region and the presence of toxin genes in these Vibrio species.

In Vietnam, the giant mottle eel Anguilla marmorata is the most widely distributed species and being exploited for seed in aquaculture as well as for human consumption. This study aims to investigate the basic nutritional components of the fish. The eels were collected from six locations of Thua Thien Hue province, with weights from 5 to 3200 g. In addition, the content of lipid in skin and tissue was also examined. The results show that eel flesh has a relatively high nutritional value. The water, protein, lipid, and total sugar content of the fish meat is 60.4 ± 0.94%, 19.54 ± 4.31%, 18.2 ± 1.02%, and 1.34 ± 0.34 (mg/g), respectively. The nutritional components of the eel have a good correlation with the weight according to the equation: Y = a × ln (W) + b (where W is the weight of eels; Y is the content of nutritional components; a is the correlation coefficient b is a constant) with r > 0.9. The lipid content of the fish skin is higher than that of muscle and meat.

Data were collected from 30 strains of Vibrio and sampled on different organs (brain, hemorrhagic site and digestive tract) of Sciaenops ocellatus infection. The results showed that the nucleotide sequences 16S rRNA region are highly similar to those of V. alginolyticus, V. azureus, V. fluvialis, V. natriengens and V. orientalis, which were published on Genbank and other, ranging from 98.05 to 100 %. The digestive tract has the most common Vibrio strains (V. alginolyticus [16] V. azureus [7] and V. fluvialis). Thereout, 25 of 30 strains of Vibrio contained from 1 to 3 toxin genes, except for V. parahaemolyticus. Six parameters were used to measure the DNA polymorphism of 33 homologous DNA sequences in this Vibrio bacteria population. The results indicated that the number of separate polymorphic sites (S), the total number of mutant sites (Eta), the number of haplotype (h), the haplotype diversity (Hd), the average number of nucleotide differences (k), the nucleotide diversity (Pi) were 98 (S), 103 (Eta), 9 (h), 0.887 ± 0.032 (Hd), 25.789 (k) and 17.980x10-3 ± 0.003 (Pi), respectively (P < 0,05). The G+C contentover 1434 sites positions of nucleotide sequences accounted for 0.542. The phylogenetic tree showed that these strains are divided into six groups. As observed, the appearance of isolated Vibrio on 3 organs of fish (S. ocellatus) which are hemorrhagic include V. azureus (27,67 %), V. alginolyticus (50 %), V. orientalis (6,67 %) and V. fluvialis (16,67 %). Through this result, it is found that the diversity of Vibrio species that appeared on the red drum was used in the 16S rRNA region and the presence of toxin genes in these Vibrio species.

富山大学・富生命博甲第126号・NGUYEN QUANG LINH・2020/09/28・★論文非公開★

Data were collected from 30 strains of Vibrio and sampled on different organs (brain, hemorrhagic site and digestive tract) of Sciaenops ocellatus infection. The results showed that the nucleotide sequences 16S rRNA region are highly similar to those of V. alginolyticus, V. azureus, V. fluvialis and V. orientalis which is published on Genebank, ranging from 98.05 to 100 %. The digestive tract has the most common Vibrio strains (V. alginolyticus, V. azureus and V. fluvialis). Thereout, 25 of 30 strains of Vibrio contained 1 to 3 toxin genes, except V. parahaemolyticus. Six parameters were used to measure the DNA polymorphism of 33 homologous DNA sequences in this Vibrio bacteria population. The results indicated that number of separate polymorphic sites (S), total number of mutant sites (Eta), number of haplotype (h), haplotype diversity (Hd), average number of nucleotide differences (k), nucleotide diversity (Pi) were 98 (S), 103 (Eta), 9 (h), 0.887 ± 0.032 (Hd), 25.789 (k) and 17.980x10-3 ± 0.003 (Pi), respectively (P < 0,05). The G+C content above 1434 sites positions of nucleotide sequences accounted for 0.542. The phylogenetic tree showed that these strains are divided into six groups. As observed, the appearance of isolated Vibrio on 3 organs of fish (S. ocellatus) hemorrhagic are V. azureus (27,67 %), V. alginolyticus (50 %), V. orientalis (6,67 %) and V. fluvialis (16,67 %). Through this result, we found that the diversity of Vibrio species that appeared on the red drum was used in the 16S rRNA region and the presence of toxin genes in these Vibrio species.

In this study, we isolated thirty strains of Vibrio from three different organs (brain, hemorrhagic site and digestive system) of Sciaenops ocellatus disease. The results showed that nucleotide sequences 16S rRNA region are highly, similar to those of V. alginolyticus, V. azureus, V. fluvialis and V. orientalis is published on Genebank, ranging from 98.05 to 100 %. The digestive system has the most common Vibrio strains (V. alginolyticus, V. azureus and V. fluvialis). Thereout, We found 25/30 strains of Vibrio containing from 1 to 3 toxin genes. None of V. parahaemolyticus present. Six parameters were used to measure the DNA polymorphism of thirty-three homologous DNA sequences in this Vibrio bacteria population. The results indicated that, number of separate polymorphic sites (S), total number of mutant sites (Eta), number of haplotype (h), haplotype diversity (Hd), average number of nucleotide differences (k), nucleotide diversity (Pi) were 98 (S) 103 (Eta), 9 (h), 0.887±0.032 (Hd), 25.789 (k) and 17.980x10-3±0.003 (Pi), respectively (P < 0,05). The G+C content above 1434 sites positions of nucleotide sequences accounts for 0.542The phylogenetic tree showed that these strains are divided into six groups. As observed, the appearance of isolated Vibrio on 3 organs of fish (S. ocellatus) hemorrhagic are V. azureus (27,67 %), V. alginolyticus (50 %), V. orientalis (6,67 %) and V. fluvialis (16,67 %). Through this result, we found that the diversity of Vibrio species that appeared on the red drum was used in the 16S rRNA region and the presence of toxin genes in these Vibrio species.Keywords: Sciaenops ocellatus, TDH, TRH, TLH, ToxR, Toxin gene, Vibrio.

The giant mottled eel Anguilla marmorata is a species of great economic, ecological, and conservative values in the Southeast Asian region. The research aims to conservation and evaluation of the genetic diversity of A. marmorata populations living in Thua Thien Hue (TTH), Vietnam. The sequencing of the barcode region of the cytochrome c oxidase subunit 1 gene was carried out for 48 individuals of A. marmorata elvers, which were collected from five different ecosystem regions. The sequences were analyzed using various genetic, phylogenetic, and population analyses to assess their variability. A total of 20 polymorphic sites and 17 haplotypes were identified. Extremely low fixation (Fst = -0.073 – 0.003; < 0.05) was found for A. marmorata populations in the region. The populations showed signs of recent populations’ expansion, besides negative Tajima’s D test, Fu’s Fs, Fu and Li’s D* and F* test values. The genetic evolution of eel occurs in a randomized pattern over a large population, with the likelihood of rare alleles appearing in the population. In TTH (Viet Nam) territories, we indicated the five areas for conservation units with moderate eels’ populations’ diversity.