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Land Use of Nam Dinh Province in Response to Climate Change

Tran Thi Giang Huong, Nguyen Thi Vong, Bui Minh Tang

Received: 17-06-2015 / Accepted: 03-09-2015
Nam Dinh is a province that has competitive advantages of marine economy, but is strongly affected by climate change that leads to changes in the land use structure. In addition to surveys, collecting of information and study of land use patterns, map overlay method was used to investigate the change in land and the impact of climate change and to select suitable land use model in response to climate change. Based on analysis of B2 climate change scenario until 2020, it was estimated that flooding land and saline land area increase to 4.667,94 ha and 2.363,91ha, respectively. In order to adapt to to climate change due to flooding and salinization, Nam Dinh province should shift land use pattern of 2,310.59ha and flooded area and 2.216,09 ha salinized area, respectively.
Comparison of Spectral Clustering Algorithms for Gene Expression Data

Hoang Thi Thanh Giang, Nguyen Thi Thuy Hanh, Nguyen Hoang Huy

Received: 22-07-2015 / Accepted: 03-09-2015
Spectral clustering algorithms have been the most effective algorithms to divide genes into groups accordingto the degree of their expression similarity. Such a grouping may suggestthat the respective genes are correlated and/or co-regulated, and subsequently indicatesthat the genes could possibly share a common biological role. In this paper,three spectral clustering algorithms were investigated: unnormalized spectral clustering, normalized spectral clustering according to Shi and Malik (2000), and normalized spectral clustering according to Ng, Jordan and Weiss (2002). The algorithms were benchmarked against each other.The performance of the three clustering algorithms wasstudied on time series expressiondata using Dynamic TimeWarping (DTW) distance in order to measure similarity betweengene expression profiles. Four different cluster validation measures were usedto evaluate the clustering algorithms: Connectivity and Silhouette Index for estimatingthe quality of clusters, Jaccard Index for evaluating the stability of a clustermethod and Rand Index for assessing the accuracy. The results were analyzedby Friedman’s test. The performance of normalized spectral clustering according to Ng, Jordan and Weiss (2002)wasdemonstratedto be the best under the Silhouetteand Rand validation indices.
Effects of Housing Systems on Cortisol Concentration of The Gilfs Raised in Group

Nguyen Thi Phuong Giang, Han Quang Hanh, Vu Tien Viet Dung, Pham Kim Dang, Vu Dinh Ton

Received: 14-11-2016 / Accepted: 05-01-2017
The study was conducted to determine the effects of two housing systems on cortisol concentration of gilts. A total of 20 gilts F1 (Landrace x Yorkshire) gilts with similar body weight and age were randomly allotted into four pens of two group-housing systems (two pens with outdoor yards and the other two without yards, 5 gilts per pen). Saliva cortisol concentration on the days 1, 3, 7, 15, 30, 50, and 80 and plasma cortisol concentration on the days 1, 3, 15, 30,and50 of the gilts after grouping wasere determined by ELISA test and ECLIA (Electrochemiluminescence Immunoassay) using COBAS system, respectively. Results showed that there were no significant differencesin saliva and plasma cortisol concentration of the gilts between the two housing systems (P > 0.05). However, in each housing system, saliva cortisol concentrations on the days of grouping were significantly different (P < 0.05). Cortisol concentration of the gilts in both two housing systems waserehighest on the 1stday after grouping (0.58 µg/ dL in the pens with yard and 0.59 µg/ dL in ones without yard),; they weregradually decreased on the 3rdday (0.48 µg/ dL and 0.46 µg/ dL)and; then theywaserelowest and stable on the following days. Similarly, in each housing system, plasma cortisol concentration taken in the days 1, 3, 15, 30 and 50 after grouping were wassignificantly different from each other (P < 0.05). Plasma cortisol concentration waserehighest in the 1stday after mixing (7.38 µg/ dL in the pens with outdoor yard and 7.17 µg/ dL in the indoor pens), followed by the 3rdday (5.35 µg/ dL and 5.19 µg/ dL), then they were gradually decreased and stable in the following days. A positive correlation between plasma and saliva cortisol concentration was found (withr = 0.73).
Isolation and Evaluation of Antibiotic Activity of Endophytic Actinobacteria on May Chang Tree (Litsea cubeba) against Pathogenic Bacteria Causing Diseases on Common Carp and Tilapia

Trinh Thi Trang, Kim Van Van, Truong Dinh Hoai, Nguyen Thanh Hai, Nguyen Van Giang, Nguyen Ngoc Tuan

Received: 02-11-2016 / Accepted: 28-12-2016
Tilapia and common carp are two main cultured species with high annual production annually in freshwater aquaculture in northern Vietnam. , hHowever, there are serious problems caused by bacterial infection. The use of antibiotics is not sufficient to mitigate outbreaks of the diseases due to antibiotic resistance of the causal agentsrate are increasing. Therefore, antimicrobial compounds are potential as a new approach to overcome the challenges of antibiotic resistance. The aim of this study is to isolate and evaluate antibiotic activity of endophytic actinobacteria from May Chang tree (Litsea cubeba) against three pathogenic bacterial species Aeromonas hydrophila GL14, Aeromonas caviaeHD60 và S. agalactiaeHY10. The results showed that 9/32 (28,2%) endophytic actinobacteria isolates could inhibit at least one target pathogenic bacteria. Three isolates MTR711, MTR622 and MTL121 showed the highest antibacterial response with minimium inhibitory concentration (MIC) ranged from 93,3 to 300,0 µl/mL, amongst these the lowest value is for MTR711 and MTR622 without significant difference. When combining three individual actinobacteria mentioned above for fractional inhibitory concentration (FIC) test, the synergistic effect was found for the pair of MTR711-MTR622 against three pathogenic bacteria chosen in this study with ∑FIC ≤0,5. The combination of two actinobacteria MTR711 and MTR622 improved bacterial inhibitory effect at least 4 times compared to individual treatment. The results are motivating enough to conduct further studies on use of endophytic actinobacteria for treating pathogenic bacteria in aquatic animals.
SIMULATING YIELD RESPONSE OF MAIZE TO CLIMATE CHANGE WITH AQUACROP MODEL IN NORTHWEST VIETNAM

Le Thi Giang, Nguyen DinhCong

Received: 02-06-2016 / Accepted: 15-11-2016
Maize has become the second most important crop after rice in Vietnam, particularlyit is main cash crop for farmers intheNorthwest region. To seek a solutionforadapting to climate change, the impact of climate change onmaize production needs to be analyzed. The AquaCrop model was usedhereto predict maize yield inresponse toclimate change. The model was calibrated and validated for maize production at field scale in Muong Lum commune, Yen Chau district, Son La province duringtheperiod of 2008 - 2012.The AquaCrop model application under climate change scenario B2 shows that maize yield hasapositive response to climate change with apredicted increase of 2.2% in 2100 compared totheperiod of 2008 - 2012. It recommends that maize production can be continued in the study area.
EFFECTOF TRICHODERMA sp. TC1 AND ITS EXTRACT ON GROWTH INHIBITION AND AFLATOXIN PRODUCTION OF Aspergillus flavusAND Aspergillus parasiticus

Nguyen Thi Thanh Thuy, Luu Thi Phuong Thao, Vu Quynh Huong, Nguyen Van Giang

Received: 20-04-2016 / Accepted: 10-08-2016
Aflatoxins are toxic carcinogenic secondary metabolites produced predominantly by two fungi: Aspergillus flavusand Aspergillus parasiticus. These fungi are a health risk and are responsible for losses and contamination of processed foods and feeds. It is very important to find methods to inhibit the growth of A. flavus andA. parasiticus,and degrade aflatoxin. In laboratory conditions, the Percentages of Inhibition of Radial Growth (PIRG %) of Trichodermasp. TC1 against A. flavusLA21 and A. parasiticusNG10 after 7 days’ dual culture were 63.51% and 60.22%, respectively. However, the use of Trichodermasp.TC1mycelium has restrictions in agricultural products due to the risks of consuming the substrate and degrading the products’ quality. Therefore, its extracts are more preferred in application. In the PD media, when up to 4% Trichodermasp. TC1 extract was added, the biomass rate for A. flavusLA21 and A. parasiticusNG10 reduced to 74.00% and 60.30%, respectively, after 5 days of incubation. The toxin levels of corn samples deliberately infected by aflatoxin producing fungi were negatively correlated with sprayed on Trichoderma sp. TC1 extract. Seven days after spraying the extract 4%, the aflatoxin in samples from more than 60 ppb at the initial time reduced down to 16 ppb for A. flavusLA21 and 21.33 ppb for A. parasiticus NG10.
Molecular Characterization of Mycosphaerella berkeleyiCausing Late Leaf Spot of Groundnut in Nghe An

Ngo Thi Mai Vi, Ha Giang, Tran Thi Nhu Hoa, Nguyen Van Vien

Received: 05-09-2016 / Accepted: 30-10-2016
This study identified the ITS (Internal Transcribed Spacer) sequence of 11 groundnut late leaf spot fungal isolates collected from Vietnam, mainly from Nghe An province in 2013. The ITS sequences of the 11 isolates were identical among them and highly identical (99.7 and 100%) with two available isolates of Mycosphaerella berkeleyi onthe GenBank. Rep-PCR technique (Repetitive sequence primed PCR) with 3 sets of primers designed on the repetitive sequences of bacterial genome including the repetitive extragenic palindromic (REP) sequence, enterobacterial repetitive intergenic consensus (ERIC) and BOX element, was used to investigate the genetic diversity of 33 M. berkeleyi isolates.PCR using BOX primers (BOX-PCR) produced polymorphic bands from tested fungal isolates. Rep-PCR analysis proved that fungal populations in Nghe An were of low genetic diversity. There was no correlation between Rep-PCR defined fugal groups with the origin of the isolates (location of sampling, groundnut cultivars) and morphological characteristics of the isolates (color and size of cultures)
Causes of Farmers Who Abandon Star-Apple “Lo Ren” Productionwith Global GAP Standard in Chau Thanh District, Tien Giang Province

Tran Quoc Nhan, Nguyen Thi Hong Tham, Nguyen Thi Thuy Hang

Received: 20-07-2016 / Accepted: 16-09-2016
This study aimedto investigate thesocio-economic status offarm households growing star-apple “Lo Ren”according to Global GAP standard and clarifythe reasons for GAP adoption and abandonment after obtainingGlobal GAP standardcertification. A total of 54 star-apple growers who appliedGAP and 53 independent growers residing in Chau Thanh district of Tien Giang province were selected for primary data collection. Descriptive statitics and T-Test methods were employed to analyze the collected data related to GAP adoption and abandonment. Regardless of the benefits of GAP practices, such as reduced fertilizer and pesticide application and safety for environment, the abandon of GAP star apple growing was attributed to the uncertainty of market and unstable selling prices. Thus, only those farmers with higher education level, better economic condition and highexpectation for higher selling price of GAP-certified product engagedin growing star apple using GAP..
Study on Alternative Methods to Green Malachite in Treatment of Ichthyophthirius multifiliis

Truong Dinh Hoai, Nguyen Van Tuyen, Nguyen Thi Huong Giang, Pham Thi Lam Hong

Received: 19-12-2015 / Accepted: 20-09-2016
The mixture of Green Malachite (MG) and formalin is the most effective chemical used to treat Ichthyophthirius multifiliis and other prasites infecting fish.However, MG was prohibited to usein aquaculture due to its potential risks to the environment, animal and human health. The prohibited use of MG has caused many difficulties to treat this parasite and other aquatic diseases. This study was conducted to examine a new, environmental friendly, safe and effectively method alternative to MG. Formalin 25 ppm (F25) was combined with a high oxidizing PHA (15% peracetic acid, 25% hydrogen peroxideand 25% acetic acid) at different concentrations of 1, 3, 5, 7, 10 ppm (PHA1, PHA3, PHA5, PHA7, PHA10) and the mixture was used to experimentally treat theronts (in vitro), and mature Ichthyophthirius multifiliis (trophonts) parasitized on Grass carp (in vivo), following with comparison to mixture of Green malachite and formalin (F25 + G0.25). The in vitrotest results show that the mixtureof F25 + PHA10 could kill 96.5% theronts within 48h. For in vivotest, treatments were conducted 72h post infection. After 10 days of experimental treatment, the control group (infected without treatment) had a high mortality rate (85.56%).In contrast, the F25 + G0.25 showed high efficiency in controlling this parasite with 94.43% fish survival. The mixtures F + PHA were effective to mitigate mortality rate compared to the control group, in which the mixture of F25 + PHA10 resulted in highest survival rate (92.23%), following with low prevalence and infection intensity, 5.13 and 1.81 parasites/sample at 40 x magnification, respectively. In addition, Ichthyophthirius multifiliis exhibited changes in morphology and moving behaviour. Results of following 10 days post treatment showed that fish treated with F25 + PHA10 recoveredeffectively, stopped mortality and probably created immunity against this parasite.
Effectsof Endophytic Bacterial Inoculationon Cassava Growth and Yield on Acid Sulphate Soil

Ly Ngoc Thanh Xuan, Le Van Dang, Ngo Ngoc Hung

Received: 07-03-2016 / Accepted: 15-07-2016
The objective of the present study was to evaluatethe effectof inoculation of three endophytic bacterial strains on cassavagrowth and yield cultivated on acid sulphate soil in Hau Giang. The endophytic bacterial strains, Burkholderiaacidipaludis, Burkholderia cenocepaciaandBurkholderia pyrrocinia,were isolated from roots and stems of cassava plantscultivated in acid sulphate soilsin theMekong delta. The greenhouse experiment wasconducted at Can Tho University during wet season2014- 2015 and on farmer’sfield in HauGiang in the dry season 2015. The results showed that all threestrains Burkholderia pyrrociniaincreased number of tuber roots, diameter and cassava yield.The combination of 60 kg N ha-1and Burkholderia pyrrociniagave the highest rootyield comparable to90 kg N ha-1ofchemical fertilizer application. The inoculation with endophytic bacteriasave 30 kg N ha-1applied to the cassava.
Biological Characteristics of The Stem Borer Bactra venosana Zeller (Lepidoptera: Tortricidae) on Sedge

Nguyen Pham Hung, Nguyen Van Chi, Do Xuan Dat, Nguyen Nam Hai, The Thanh Nam, Pham Thi Vuong, Ho Thi Thu Giang

Received: 22-07-2015 / Accepted: 01-12-2015
The sedge stem borer Bactra venosanaZeller isconsidered as one of themajor pestsonsedge. The studywas carried out to examine the biological characteristics of B. venosanaunder semi-natural conditions (green house)int Nga Son, Thanh Hoa. Themean developmental time was from 55.82 ± 0.90 days, 44.57 ± 0.87 days and 33.07 ± 0.82 days at 21.83 ± 0.74oC, 25.89 ± 0.89oC and 29.83 ± 0.71oC, respectively.The number of eggs laid by a female was 69.13 eggs at 25.4oC and 91.93%RH. The egg hatching percentage was high 84,1-90,1%. Male adult longevity was significantly shorter than thefemales.
Evaluating The Growth and Yield of Oyster Mushroom Strains (Pleurotusspp.) Cultured on Rice Straw

Nguyen Thi Bich Thuy, Nguyen Thi Lam Hai, Nguyen Thi Luyen, Tran Dong Anh, Nguyen Van Giang, Nguyen Thi Ngoc

Received: 09-06-2017 / Accepted: 12-12-2017
Oyster mushroom (Pleurotus spp.) is a delicious edible fungus with high nutritional and medicinal values. Itcontains all essential amino acids and several polysaccharides.Five strains of oyster mushroom werecultivated on rice straw sterilized at 121oC for 100 min and on rice straw piled for6-7 days at 60-70oC. The results showed that of5 oyster mushroom strains, PN1 showed the highest growth rate. In addition, sterilized straw was the most suitable material for the growth of PN1 with bio-efficiency at 73.8%. For further investigation, PN1 was cultured on a mixture of different materials including straw and some agricultural wastes such as cotton seed hull, sawdust, husk, and rice bran. It showed that the mix(in percent) with straw (84), cotton seed hull (10), rice bran (5) and CaCO3(1)was the best medium for the mycelial growth and fruitingbody yield and the bio-efficiency of PN1reached 77.4%.
Effect of Lime Applicationon Changes in Soil Exchangeable Calcium and Sodiumand Yieldof Ricein Saline- Acid Sulfate Soil

Le Van Dang, Tran Ngoc Huu, Ngo Ngoc Hung

Received: 05-07-2017 / Accepted: 19-03-2018
The study aimed at investigating the effect of lime (CaO) application on the change ofsoil exchangeable calium and sodium and yields of 3 rice varieties in salineacid sulphatesoil at Long My district, Hau Giang province. The field experiment was arranged in 3x2 factorial designs: three rice varieties and two lime rates. Results showed that the application of CaO increased soil exchangeable Caandsoil EC buty reducedsoil exchangeable Na in the 0-20cm soil layer. Thissoil improvement brought about highergrain yield through increasedpanicle number/m2 and grain number/panicle. Under soilsalinitycondition at early crop season, grain yield of OM 5451 and OM 8017 washigher than that of OM 4900. The trial result showed damage from salinityinstrusion during wet season 2017 has been reducedandprofit obtained from the trial was higher than that of farmer practicewith VnD3,158,000 per ha. It is recommended to use OM 5451 or OM 8017 varieties and applyimg CaO at 1.0 t/ha for salt-affectedsoils inLong My,Hau Giang.
Sustainable Poverty Reduction for Ethnic MinorityMigrants to the Central Highlands: A review on some Theorical and Practical Issues

Tran Huong Giang, Mai Lan Phuong, Ho Ngoc Ninh

Received: 28-02-2023 / Accepted: 18-04-2023
The Party and State aim to improve the material and spiritual life of ethnic minorities by promoting sustainable poverty alleviation in their communities. However, the Central Highlands region has witnessed a high influx of free migration, which has exacerbated poverty-related issues. Thus, this study seeked to examine existing theories and practices that address poverty reduction among ethnic minorities migrating to the Central Highlands. Through a review of domestic and international studies, the research results have generalized some theories on sustainable poverty alleviation for ethnic minority migrants.By doing so, we can provide a scientific basis for refining and enhancing sustainable poverty reduction policies that cater to the unique needs of ethnic minorities in the Central Highlands.
Analyzing Awareness of Swine Breeding Farms Toward Circular Waste Management in Hanoi

Nguyen Thi Huong Giang, Tran Cong Chinh, Ngo The An

Received: 21-12-2022 / Accepted: 18-04-2023
The study analyzed the awareness of swine breeding farms toward circular waste management in Hanoi. There were 177 swine breeding farms participated in the survey. The questionnaire for the survey was developed based on the basis of theories of behavioral psychology, especially the theory of Planned Behavior. The research results provided an overall picture of farmers’ perspectives on swine waste recycling. In addition, the study also used chi-square test and Fisher’s Extract test to compute the significant difference among farmers’ perspectives according to the main demographic factors, particularly age, education, gender, location, social relations, farm land ownership, and farming scale. From the results, the study proposed specific policy recommendations for promoting swine waste recycling toward a circular economy in the study area.
Management of Vegetable Production Adopting Vietgap Protocol in Dong Anh District, Hanoi

Nguyen Thi Duong Nga, Tran Trong, Pham Thi To Dieu, Nguyen Thi Ly, Giang Huong, Nguyen Thi Huyen Trang

Received: 01-04-2024 / Accepted: 12-06-2024
Vegetable productin adopting VietGAP protocol are significant for sustainable development and provide safe food for consumers. This study aimed to evaluate the current situation and propose some solutions to strengthen the management of vegetable production adopting VietGAP in Dong Anh district, Hanoi city. Primary data were collected through interviews with 90 vegetable farming households adopting VietGAP process, leaders of vegetable production and trading cooperatives, and local officials. Results show that the public sector (District People's Committee and relevant departments) has fully implemented production management activities, and farmer households have adopted VietGAP practices, but there were still gaps in implementation. Difficulties and challenges for management of vegetable production adopting VietGAP were identified. Several solutions to strengthen management of vegetable production adoptingVietGAP in Dong Anh district were proposed accordingly.
Reproductive Performance and Egg Quality of Na Tau Ducks

Nguyen Thi Vinh, Tran Bich Phuong, Nguyen Thi Phuong, Nguyen Van Thong, Nguyen Thi Phuong Giang, Ha Xuan Bo, Nguyen Hoang Thinh, Pham Kim Dang

Received: 12-12-2023 / Accepted: 24-06-2024
The study was conducted to evaluate reproductive performace and egg quality of Na Tau ducks raised at Faculty of Animal Science, Vietnam National University of Agriculture. A total of 105 Na Tau ducks (15 males and 90 females)was used to estimate laying age and weight; egg yield; FCR and egg quality parameters. Na Tau ducks had laying ages at 141.67 days; the weight of the ducks when laying was 1978.02g. The laying rate in the period of 1-38 weeksreached 63.91%; egg yield reached 170 eggs/hen/38 weeks of laying; and FCR was 3.56 kg of feed/10 eggs.The egg weight and Haugh units were70.04g and 72.11, respectively. Na Tau duck eggs contained 28.21% dry matter, 12.15% protein, 14.7% lipids, 1.04% Ash, and453.67mg/100g of cholesterol concentration. The highest non-essential amino acid content in Na Tau duck egg was Glu (3.6 g/100g), followed by Asp (2.4 g/100g) while the highest concentrated essentialamino acid was Leu (2.27 g/100g). The rate of embryonated eggs,hatching rate/embryonated eggs and the rate of type 1 ducks was 89.21%, 68.45%, 90.66%, respectively.
Detection of Avian Poxvirus in Duck Flocks Raised in Hung Yen and Ninh Binh Province

TranThi Huong Giang, Nguyen Van Giap, Le Thi Trinh, Huynh Thi My Le

Received: 28-11-2023 / Accepted: 12-06-2024
This study aimed to detect the presence of avian poxvirus in ducks raised in Hung Yen and Ninh Binh provinces. Some ducks showing nodular hyperplasia lesions on the beak and around the eyes were discovered in three flocks of ducks raised in the Van Lam district, Hung Yen, and Gia Vien district, Ninh Binh during May - June 2023. Diagnosis using polymerase chain reaction (PCR) method showed that 3 pooled samples taken from suspected infected ducks representing flocks at each collection farm were positive for the viral genome of poxvirus. The results of partial sequencing of the gene encoding core protein 4b showed that the nucleotide similarity between the 3 poxvirus strains in this study ranged from 99.60-100%. The results of phylogenetic tree analysis also revealed that the virus strains in this study belonged to the A5 subgroup and showed a close genetic relationship with the APV_D2 virus strain (GenBank code MT877437) reported in India in 2021 and strain APV_XL (GenBank code KJ192189) recorded in China in 2014.
Reproductive Performance and Egg Quality ofVan Linh chickens raised at Vietnam National University of Agriculture

Duong Thu Huong, Nguyen Thi Chau Giang, Nguyen Van Thong, Nguyen Khanh Toan, Pham Van Son, Nguyen Hoang Thinh

Received: 11-12-2023 / Accepted: 23-05-2024
The study was carried out to determine reproductive performance and egg quality of Van Linh chicken from 17 to 40 weeks raised at the Faculty of Animal Science, Vietnam National University of Agriculture. A total of 40 hens and 6 roosters were randomly divided into 2 groups to monitor reproductive performance, feed consumption per ten eggs, egg quality and egg hatching rate. The results showed that Van Linh chickens attained sexual maturity at 120 days of age and the highest of laying egg rate at 193 days of age. In theperiod from 17-40 weeks of age, the egg yield was 66.93 eggs/hen, laying rate was 39.81%, feedconsumption/10 eggs was 3.24kg. The eggs of Van Linh chickens had an average weight of 43.81 g/egg, morphological index of 1.33; Haugh unit was 80.12. The rate of fertile eggs, hatched/fertile eggsand the rate of type I chicks/hatched eggswere 83.17; 86.98 and 90.48% respectively.
Preliminary detection of Gyrovirus Galga 1 in chickens farmed in Thai Nguyen province

Anousack Sormixay, Dong Van Hieu, Dinh Thi ThuyDuong, MaiThi Ngan, TranThi Huong Giang

Received: 28-03-2024 / Accepted: 23-05-2024
The study aimedto determine the ocurrence of Gyrovirus in chickens raised inseveral districts in Thai Nguyen province. A total of 42 pooled samples were collected from chickens with symptoms such as stunting, drooping, and diarrheaat svarious farms in Phu Binh, Phu Luong, and Vo Nhai districts of Thai Nguyen province from March to August 2023. Resultsof Polymerase chain reaction(PCR)showed that the positiveratefor chicken Gyrovirus virus was 17.65%, 28.57%, and 27.27% collected from Phu Binh, Phu Luong, and Vo Nhai districts, respectively. The partial sequencing of the gene encoding the VP2 protein revealed that the field virus strainsin chickens showing drooping and stunted behavior belonged to the Gyrovirus galga 1 and weregeneticallyclose to the ChineseGyrovirusstrain (2014) and BrazilianGyrovirus strain(2019). The results of this studysupplementthe presence of Gyrovirus galga1 in chickens as a basis for future in-depth research on Gyrovirus.
Labour Migration Andiimpacts of the COVID-19 Pandemic on Migrant Workers in Viet Nam: A Review

Tran Thi Anh Nguyet, Le Thi Hoa Sen, Hoang Dung Ha, Dang Ngoc Thi Giang, Do Thi Hang

Received: 01-08-2023 / Accepted: 26-01-2024
Labour migration is a livelihood strategy that contributes to increasing income and improving the lives of migrant workers. Labour migration is increasingly common in developing countries. In Vietnam, in 2019 the country had 6.4 million migrant workers, accounting for 7.3% of the total population. Therefore, when the Covid-19 pandemic broke out, migrant workers were severely affected by losing jobs and income, falling into psychological stress and reduced quality of life. Although the Covid-19 pandemic was over the consequences of the Covid-19 pandemic still take a lot of time to overcome. Therefore, this article aimed to describe the impact of the Covid-19 pandemic on migrant workers in Vietnam by analysing domestic research results. The results of the article can be considered by concerned policymakers and governments to issue policies for migrant workers in the new context when the Covid-19 pandemic gone by. From there, lessons can be drawn for coping with other types of shocks that may occur in the future.
Factors Influencing Land use Change in Hung Yen Province

Le Thi Lan, Tran Quoc Vinh, Pham Quy Giang

Received: 03-01-2024 / Accepted: 26-01-2024
The objective of this study was to identify and evaluate factors influencing land use changes in Hung Yen province. The data were analyzed using descriptive statistics, correlation analysis, exploratory factor analysis, and regression analysis. Results from the investigation of land use status show that in Hung Yen province, there were 3 types of land that changed tremendously during 10-year period (2012-2022), including rice land, perennial cropland, and construction land. The study has identified 04 main factors influencing land use changes in the province, i.e. (i) State policy on land use management, (ii) Economy, (iii) Infrastructure development and (iv) Location. In particular, the State's policy on land use management factor exerted the greatest impact on land use changes in Hung Yen province. The finding of the study is an important practical basis for local authorities on orientations in the process of rational land use and sustainable protection of land resources.
Assessment of Genetic Diversity of Bombyx moriBased on Coi Sequences

Tran Thi Binh Nguyen, Nguyen Thi Nhai, Ho Viet Duc, Nguyen Duc Duy, Pham Thu Giang, Nguyen Hoang Thinh, Nguyen Thi Nhien, Nguyen Huu Duc

Received: 02-10-2023 / Accepted: 26-01-2024
The main goal of study was to use nucleotide sequencing of the cytochrome c oxidase 1 (COI) gene to assess the genetic diversity of 9 bivoltine breeds and 5 native Vietnamese silkworm breeds. DNA Sequencing was carried out using by chain termination method. Data were analyzed by Bioedit, DNAsp and MEGA X softwareThe results indicated 17 polymorphic nucleotide substitution sites when comparing the COI gene sequence of the 14 silkworm breeds in this study with the sequence AB737913.1 on GenBank. Only one polymorphic nucleotide site appeared when comparing the 14 breeds with each other. These silkworm breeds were divided into 2 haplotypes, with a main concentration in haplotype 1. The genetic classification tree shows that 13 out of the 14 studied silkworm breeds were distributed in branch 2, which is the common branch of Chinese and European silkworm breeds. This outcome provides initial information for breeders to strategically use molecular markers in the conservation, exploitation, and development of the genetic resources of silkworm.
Diversity and Distribution of Zoobenthos Community at Integrated Shrimp-mangrove Farms in Ca Mau Province

Au Van Hoa, Tran Trung Giang, Le Van Linh, Nguyen Thi Kim Lien, Vu Ngoc Ut

Received: 22-08-2023 / Accepted: 05-01-2024
The study was conducted to evaluate the distribution and diversity of zoobenthos species composition at integrated shrimp-mangrove farms in Ca Mau province. The sampling was taken monthly during 12 months, from January to December 2022. At each sampling, samples of zoobenthos were collected in 9 farms (3 farms/district) in three districts of Ca Mau province, including Dam Doi, Nam Can, Ngoc Hien. A total of 49 species were identified and they belonged to 43 genera, 4 classes and 3 phylums, including Molluscan, Annelida and Arthropods. The molluscan community was the most pre-dominant (28 species), followed by Annelida (15 species) and Arthropods (6 species). The number of mollusca species was higher than those of the others. Total zoobenthos abundance in each point varied from 16 to 30 species, with the mean ranging from 119 to 2,833 ind./m2. The species composition and abundance of Gastropoda were highest within the study area. The Gastropoda represented the highest number ranging from 2-15 species and density from 2-2,794 ind./m2in the study area. The shannon (H’) diversity index ranged from 0.6~1.4, indicating that the diversity richness of zoobenthos characterized by sampling sites and periods was low to moderate level. The species diversity of zoobenthos in Nam Can area was considerably lower compared to that in Dam Doi and Ngoc Hien areas..
Effects of Culture Conditions on Mycelial Growth and Fruiting Bodies of Trametes versicolorMushroom Tra-6 Strain

Tran Thu Ha, Nguyen Van Giang, Nguyen Duy Trinh, Nguyen Thi Phuong

Received: 03-10-2023 / Accepted: 25-12-2023
Turkey tail mushroom (Trametes versicolor) is a medicinal mushroom used as a health-promoting pharmaceutical, extending life, and adjuvant therapy for cancer patients. The mycelia and fruiting bodies of the Turkey tail mushroom contain various biologically active compounds such as polysaccharides, glucans, phenolics, flavonols, coumarins, isoflavonoids, triterpenoids, and sterols. This study was carried out to choose the optimal culture conditions, including culture pH, temperature, medium, and substrate composition, for the growth of the mycelia and fruiting bodies of the T. versicolor mushroom Tra-6 strain, collected in Lao Cai, Vietnam. The experimental factors were examined individually in a randomized complete block design. Research results show that the mycelia of the Turkey tail mushroom Tra-6 strain quickly grew on MCM and YEA media at pH 8 and 25 ± 1C. Sucrose, yeast extract, MgSO4.7H2O, KCl, and KH2PO4 were the optimal carbon, nitrogen, and mineral salt sources for this strain, respectively. Tra-6 strain had the ability to form fruiting bodies when growing on substrate from agricultural by-products. The highest yield of 44.4kg dry mushroom per ton of dry substrate was obtained on a substrate consisting of 55% sawdust, 24% crushed corncobs, 20% rice bran, and 1% CaCO3 powder.

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