Southern Vietnam Research Articles

Identifying opportunities and challenges of horticulture production: A case study of Tuong-Mango value chain in the southern Vietnam

This study’s primary objective is to determine the financial repercussions, including expenses, profits, and losses, that certain stakeholders in the Tuong-mango value chain face at various distribution stages. This was achieved through the utilisation of stakeholders cost-benefit value chain analysis. These individuals collectively contributed 849 sample observations to the dataset including 732 farmers, 10 cooperative, 32 collectors, 25 wholesalers, 30 retailers, 12 exporters and processors, and 08 grocery stores/fruit. The robust financial performance of the Tuong-mango value chain is attributable to its integrated economic efficiency, as evidenced by its over USD 1 billion in revenue and USD 98.2 million in net income. The marketing channels, specifically channels 1, 2, and 3, generate a total of USD 906.1 million in revenue, yielding a net profit of USD 81.9 million. The combined sales from domestic marketing channels 4 and 5 total USD 160 million, yielding a net profit of USD 16.2 million. The findings indicate that due to their limited scope and suboptimal grade 1, farmers are the most vulnerable link in the supply chain. This study proposes three strategies for augmenting quality, fostering technological advancement, and facilitating the spread of benefits. This study’s findings contribute to the existing literature on value chain analysis as it pertains to various tropical fruits and vegetables. The study provides empirical evidence supporting the utility of the value chain method in policy formulation.

Variations in soil carbon, nitrogen, and phosphorus concentrations and stoichiometry with stand age in Acacia hybrid plantations in Southern Vietnam

Abstract. Chau M, Quy N, Xu X, Hung B, Cuong LV, Ngoan T, Nguyen T. 2024. Variations in soil carbon, nitrogen, and phosphorus concentrations and stoichiometry with stand age in Acacia hybrid plantations in Southern Vietnam. Biodiversitas 25: 565-573. Soil Carbon (C), Nitrogen (N), and Phosphorus (P) contents are the three most critical soil nutrient elements required for plant growth and development, and their ecological stoichiometric ratios are significant indicators for understanding soil nutrient balance and cycling. This study was conducted to probe variations in the soil organic C (SC), total N (SN), and total P (SP) contents and stoichiometry at five soil depths (0-20, 20-40, 40-60, 60-80, and 80-100 cm) in Acacia hybrid plantations of five different ages (2-, 4-, 6-, 8-, and 10-year-old plantations) in Langa-Dongnai Forestry Company, Southern Vietnam. The results showed that forest age and soil depth substantially impacted soil nutrient contents and their stoichiometric characteristics. The concentrations of SC, SN, and SP as well as C/N, C/P, and N/P ratios increased as the forest stand age increased. The contents of SC, SN, and SP reduced with soil depth, indicating an obvious soil “surface-aggregation” phenomenon. The nutrient restriction varied based on forest stand development, shifting from restricted nitrogen in the earlier growth periods of trees to restricted phosphorus in the later growth periods. The findings demonstrate that to resolve the issue of restricted availability of these nutrient indexes, additional nitrogen should be supplied during earlier growth periods and additional phosphorus during later growth periods. The results further emphasize the importance of understanding SC, SN, and SP interactions and nutritional limitations and provide relevant theoretical support for sustainable Acacia hybrid plantation management in the Southern region.

Understanding the Characteristics of Corporate Culture in Vietnam via Some Golden Periods in History

In the Vietnamese business heritage, there were several golden times during which beneficial elements emerged and became distinct features of company culture. Using the multidisciplinary method of History of Science - Cultural Studies, this article collects and organizes historical documents to sketch a historical and comparative analysis of the value hierarchy and strengths of Vietnamese corporate culture during its golden era. The findings demonstrate that, between the 17th and 18th centuries, unique human and cultural aspects in business activities emerged in the Southern Vietnam region of Vietnam, where merchants and other factors of Corporate culture was quite frequent. In the early years of the 20th century, Vietnam witnessed a business movement aimed at economic revival and cultural development for the noble goal of national revival. Corporate culture in Vietnam has been around for a long time, reflected in the intelligence, creativity, sensitivity, and quick adaptation of Vietnamese corporates and entrepreneurs.

Enhancing discharge estimation from SWOT satellite data in a tropical tidal river environment

The Surface Water and Ocean Topography (SWOT) mission aims to provide essential data on river width, height and slope in order to estimate worldwide river discharge accurately. This mission offers a powerful tool for monitoring river discharge in dynamic coastal areas, like the Saigon-Dongnai estuary in Southern Vietnam. However, estimating discharge of tidally-influenced rivers using SWOT measurements can be challenging when hydraulic variables have the same order of magnitude as SWOT measurement errors. In this paper we present a methodology to enhance discharge estimation accuracy from SWOT measurements based on simulated SWOT products at the 200 meter node resolution and varying river reach size. We assess measurement error variability and its impact on discharge estimation by employing a Monte Carlo analysis. Our approach significantly improved discharge estimation in the Saigon tidal river, reducing RMSE from 1400 m3/s to 180 m3/s and increasing R² from 0.31 to 0.95. Notably, the percentage of Monte Carlo particles meeting the 30% rRMSE threshold rose from 0% to 79%. This study underscores the feasibility of obtaining reliable discharge estimates from SWOT data in complex coastal areas where hydraulic variables are of the same order of magnitude as SWOT errors. Additionally, the proposed methodology to improve discharge estimation from SWOT measurements is widely adaptable as it can be applied to similar regions and can be combined with any discharge estimation method.

Another new species of Dibamus Dumril & Bibron, 1839 (Squamata: Dibamidae) from Nui Chua National Park, Ninh Thuan Province, Vietnam.

A new species of dibamid lizard, Dibamus deimontis sp. nov., is described based on eight specimens collected from the highlands of Nui Chua Mountain within Nui Chua National Park, Ninh Thuan Province, southern Vietnam. Dibamus deimontis sp. nov. co-occurs with the recently described Dibamus tropcentr, but is recorded at higher elevations (670700 m a.s.l. vs. 200280 m a.s.l.), and in a different habitat and microhabitats than the previous species. Our study represents the first report on the near sympatric occurrence of two Dibamus species. The new species can be distinguished from other congeners by the following combination of characters: rostral, labial and nasal sutures incomplete; two to three postoculars; three to five scales on the posterior edge of infralabial; 2225 midbody scale rows; 193225 ventral scales; 4755 subcaudal scales; 115 presacral and 27 tail vertebrae (in a single male specimen examined); and maximum snout-vent length 136.2 mm. We suggest this species should be considered as Vulnerable (VU) following the IUCNs Red List categories. Our study brings the number of species in the genus Dibamus to 26; Dibamus deimontis sp. nov. is the eighth species of Dibamus recorded in Vietnam, and underlines the importance of the country as a local center of reptilian diversity in Southeast Asia.

Prevalence of autism spectrum disorder diagnosed according to DSM-5 criteria and associated factors in preschoolers in southern Vietnam.

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder that has become a significant concern in pediatric mental health due to its rising prevalence in recent years. Despite this increase, the prevalence of ASD and its associated risk factors remain poorly understood. This study aims to elucidate the prevalence of ASD and its associated risk factors among preschool children in southern Vietnam. This prospective study was conducted from June 2021 to December 2022 and included 9,397 children (4,813 boys and 4,584 girls) aged 24 to 72 months, attending 41 kindergartens in southern Vietnam. Diagnoses of ASD were made by qualified pediatric psychiatrists using DSM-5 criteria. Data on ASD-related variables were collected through a structured questionnaire administered by trained preschool teachers. Univariate logistic regression analysis was employed to identify associations between independent variables and the prevalence of ASD, followed by multivariate logistic regression models to control for potential confounders. The overall prevalence of ASD among children aged 24 to 72 months attending preschool in southern Vietnam was found to be 1.2% (1 in 84 children). The prevalence rates in central, subcentral, and suburban areas were 2.00%, 0.6%, and 1%, respectively. Significant risk factors for ASD identified through multivariate regression analysis included age (24 to 30 months) with an odds ratio (OR) of 5.35 (95% CI: 2.84-10.10), male gender (OR=2.55, 95% CI: 1.68-3.86), maternal exposure to pesticides (OR=4.62, 95% CI: 1.84-11.61), maternal stress or psychological trauma during pregnancy (OR=2.3, 95% CI: 1.1-5.4). ASD represents a significant pediatric psychiatric issue in southern Vietnam, with a higher incidence than previously reported. Some of the identified risk factors are potentially preventable, suggesting that targeted interventions could reduce the incidence of ASD.

Emerging Enterovirus A71 Subgenogroup B5 Causing Severe Hand, Foot, and Mouth Disease, Vietnam, 2023.

We report on a 2023 outbreak of severe hand, foot, and mouth disease in southern Vietnam caused by an emerging lineage of enterovirus A71 subgenogroup B5. Affected children were significantly older than those reported during previous outbreaks. The virus should be closely monitored to assess its potential for global dispersal.

Notes on the Courtship and Captive Reproduction of the Southern Vietnam Box Turtle, Cuora picturata, at the Turtle Conservation Center in Cuc Phuong National Park, Vietnam.

Endemic to only three known provinces in South Central Vietnam, Cuora picturata have faced extensive collection pressures for the food, medicinal, and pet trades. Further exacerbating their decline is the lack of protected areas where wild populations exist, with only one known population occurring within a protected area. With threats to wild populations persisting, the development of an assurance colony has been prioritized for C. picturata. The Asian Turtle Program of Indo-Myanmar Conservation has been operating the Turtle Conservation Center (TCC) in Cuc Phuong National Park since 1998. From 2020 to 2022, 24 C. picturata were acquired by the TCC from the illegal trade. With no ideal repatriation plan, these animals provided an opportunity for developing a captive assurance colony at the TCC to safeguard the species from extinction. As semi-aquatic species, box turtles in the genus Cuora are a unique group that shows variations in habitat use and behavior between species. Herein, we documented some specific courtship behaviors not yet described for C. picturata, providing insight into the unique reproductive behaviors of this species.

Paralebeda prokopenkoi — new lappet moth species from southern Laos, Vietnam, and Cambodia (Lepidoptera: Lasiocampidae)

In this paper, we describe Paralebeda prokopenkoi sp. nov., a new species from southern Laos, Vietnam, and Cambodia. This species is a sister species to Paralebeda lucifuga (Swinhoe, 1892) which was described from Singapore. The new species differs externally by the more elongate forewings. Additionally, the uncorrected COI p-distance between P. prokopenkoi sp. nov. and P. lucifuga is 2.61–3.90%.

Advertisement calls from species of the Limnonectes hascheanus-limborgi complex (Anura: Dicroglossidae) from Peninsular Malaysia.

Limnonectes hascheanus and Limnonectes limborgi are two very similar-looking and closely related species and are sometimes referred to as the Limnonectes hascheanus-limborgi complex (Inger & Stuart 2010). Inger & Stuart (2010) tackled the systematics of the complex and confirmed the status of L. limborgi as a distinct species and not a junior synonym to L. hascheanus by providing molecular data and morphological characters of its distinctiveness. The geographic ranges of the two species were also reported to be distinct where L. hascheanus is mainly restricted to the southern part of the Thai-Malay Peninsula while L. limborgi is distributed from southern Myanmar north into northern Thailand and Laos before curving around into central Laos, northeastern Thailand, Cambodia, and southern Vietnam (Inger & Stuart 2010).

Human fascioliasis emergence in southern Asia: Complete nuclear rDNA spacer and mtDNA gene sequences prove Indian patient infection related to fluke hybridization in northeastern India and Bangladesh

Fascioliasis is a snail-borne zoonotic disease with impact on the development of human subjects and communities. It is caused by two liver-infecting fasciolid trematode species, the globally-distributed Fasciola hepatica and the Africa/Asia-restricted but more pathogenic, larger F. gigantica. Fasciola gigantica is the cause of endemicity in livestock throughout the warm lowlands from Pakistan to southeastern Asia since old times. Human fascioliasis is emerging in this region at present, with an increase of patient reports. Complete sequences of rDNA ITS-1 and ITS-2 spacers and mtDNA nad1 and cox1 genes were obtained from fasciolid eggs found in the endoscopic bile aspirate from a patient of Arunachal Pradesh, northeastern India. Egg measurements, pronounced ITS heterozygosity, and pure F. gigantica mtDNA haplotypes demonstrate an infection by a recent F. gigantica-like hybrid. Sequence identities and similarities with the same DNA markers found in livestock from Bangladesh prove the human-infecting fasciolid to present identical ITSs and nad1 haplotypes and only one silent transversion in cox1 when compared to a widely-spread combined haplotype in animals. In northeastern India and Bangladesh, human fascioliasis emergence appears linked to increasing livestock prevalences due to: ruminant importation from other countries because of the increasing demand of rapidly growing human populations; numerous livestock movements, including transborder corridors, due to the uncontrolled small-scale household farming practices; and man-made introduction of F. hepatica with imported livestock into an area originally endemic for F. gigantica leading to frequent hybridization. Sequences, phylogenetic trees, and networks indicate that the origins of intermediate/hybrid fasciolids and factors underlying human infection risk differ in eastern and western South Asia. The emergence scenario in southern China and Vietnam resembles the aforementioned of northeastern India and Bangladesh, whereas in Pakistan it is linked to increasing monsoon rainfall within climate change combined with an impact of an extensive irrigation system. Past human-guided movements of pack animals along the western Grand Trunk Road and the eastern Tea-Horse Road explain the F. gigantica mtDNA results obtained. Physicians should be aware about these emerging scenarios, clinical pictures, diagnostic techniques and treatment. Government authorities must appropriately warn health professionals, ensure drug availability and improve livestock control.

Potential usage of fly ash and nano silica in high-strength concrete: Laboratory experiment and application in rigid pavement

High-strength concrete (HSC) using supplementary cementitious material of 30% fly ash (FA) and various nano silica (NS) contents were investigated in this study. FA and NS are waste materials collected from local thermal plants and rice husk ash in Southern Vietnam, respectively. Different concentrations of NS at 0%, 0.5%, 1.0%, and 1.5% were incorporated into the base mixture in place of cement and FA. The water-to-binder ratio of 0.32 was constant for all the mixtures. Results indicated that the combination binder of cement, FA, and NS satisfied the setting time as pure cement binder. The slump test value was in the range of 30–40 mm by adjusting the superplasticzer. Mechanical properties of HSC were studied at various curing ages of 3, 7, 28, and 56 days, including compressive strength, flexural strength, elastic modulus, and abrasion resistance. Results indicated that 1% NS can be considered as optimum content for preparing an HSC mixture, which showed the best mechanical properties. Furthermore, a good correlation between compressive strength and flexural strength was obtained from the results. Finally, rigid pavement calculation revealed that the addition of 1% NS resulted in a reduction in the thickness of the concrete slab by 30 mm (around 10.7%) compared to non-NS concrete. These findings suggest that incorporating nano-silica into concrete can lead to thinner concrete slabs with improved performance characteristics.

On the Origin of the Symbol “Dragon” from the Zoonym “Crocodile” in the Cultures of Ancient Southern China and Vietnam

The author explores the origin of the symbol “dragon” in the cultures of ancient Southern China and Vietnam from the “crocodile”, puts forward the hypothesis that the ancient ethnonym and toponym “Yue” 越, (modern Vietnam) come from the Chinese zoonym ‘crocodile’ 鳄鱼 èyú. Other sources are the words “yue” 岳 ‘mountain’, “yue” 钺 ‘great battle axe’ and “yue” 月 ‘moon’. The Vietnamese word âu ‘seagull’, isomorphic to the Chinese word 鸥 ‘ōu’, is also involved in the semiotic analysis. Correlation of the Chinese letter from “jiaguwen” to “kaishu” (with the mention of the Vietnamese “ty-nom” and the letter of the state “Dian”) with historical and modern reality contributes to the objectification of the Chinese-Vietnamese world, the possibility of studying it using philological knowledge. The article also provides a comparison of the Chinese classification of nature by Zhou Qu-fei with the system of Carl Linnaeus and the earlier classification of Conrad Gesner, and develops the idea of the economy of nature.

The Ethnoarchaeology of Restaurants in Southern Vietnam: Fish Stew Culinary Practices and Organic Residues in Earthenware Cooking Pots

ABSTRACT Ethnoarchaeological studies of food and culinary practices are typically conducted in communities and households that still practice traditional ways of food preparation and consumption. This article presents ethnoarchaeological research in small, contemporary restaurants in Vietnam that serve cá kho tộ, a braised caramelized fish stew prepared in earthenware cooking pots. Comparative reference samples of pottery were collected from the restaurants for organic residue analysis, and the results were compared with residue analysis of pottery sherds recovered from archaeological sites in Southern Vietnam. The results contribute novel insights to both ancient and present-day culinary practices in the region and to the study of open earthenware pots and pottery sherds with interior surface charred residues.

"Gian đạo sĩ" and the trend of "Orthodoxization" of endogenous religions in Southern Vietnam

Southern Vietnam became the "good land" of Chinese immigrant groups since the late 17th century after the Ming Dynasty was overthrown by the Manchu Qing army. A part of those political refugees were members of South China folk religious sects, who used religion and religious movements as a means to gather a large number of insurgents to “fight against Qing and restore Ming” in order to realize their political intentions. This spirit of “restoring the old dynasty” influenced patriotic scholars with feudal ideology in Vietnam, who were in a similar situation when confronting the invading French colonialists, thereby transforming into the awareness of “fighting against the French and restoring the Vietnamese emperor". They were deeply influenced by the Confucian spirit of "patriotism and respect for the monarch" and were determined to embrace the religious flag with the nuances of Confucianism - Buddhism - Taoism and local traditions to gather insurgents, who fought against invaders and restored the kingship of the natives. It is the ambiguous transformation process between Confucian scholars and Taoist priests. Especially, in the context of strict surveillance and brutal repression by contemporary authorities, they were considered "gian đạo sĩ" fiercely resisting authorities. Since then, the trend of "Orthodoxization" has appeared to shape them into monks who do not care about politics, or at least submit to serve the government. Using research methods (tactics) of analyzing written documents, field surveys, ethnographic fieldwork, and logical analysis, the article analyzes the phenomenon of "gian đạo sĩ" in Southern Vietnam’s endogenous religions and also clarifies the "Orthodoxization" trend of the popular belief of Ngũ Công Vương Phật from the late 19th to early 20th century, thereby introducing an interesting cultural phenomenon in contemporary Southern Vietnam’s social life.

Application of Homemade Percussion Instruments into Nursery Rhymes in Music Activities for Preschool Children: A Case of Can Tho City: Southern Vietnam

As recycled materials have increased inexorably in recent years, using daily waste products to make homemade percussion instruments has emerged as a topic of interest in music education. This article details six homemade percussion instruments (including a small drum, coconut shell, two shaking instruments, castanets, and claves) and how to use them in children’s songs, especially nursery rhymes that originated in Southern Vietnam. An experiment using these instruments in music activities for preschool children in Can Tho City was conducted with feasible outcomes and positive feedback.

Distribution of 226Ra and 210Po Radionuclides in Different Phases of Soil and Estimation of Their Annual Change Rates for Some Agricultural Soils

Human activities, such as plant cultivation, enhance the activity concentrations (ACs) of radionuclides in the topsoil and have the potential to affect humans and the environment. The soil with a high radiation background not only acts as a source of continuous radiation exposure to humans but also as a medium of migration for the transfer of radionuclides to food crops. Some spectrometers can measure the AC of radionuclides in the soil, but long‐term variation of AC is difficult to investigate. Therefore, developing methods for predicting the AC of radionuclides in agricultural soil is an interesting topic that many studies have focused on. In this work, a simple method was introduced to estimate long‐term changes of some radioisotopes in the top layer of soil (0–20 cm). The estimation considered four major processes: fertilization, irrigation, vertical leaching, and plant uptake. The leaching rates () of radionuclides were predicted by their ACs in the soil water and the infiltration rate of water in the soil. The method was applied to the soils of five study fields in southern Vietnam, and the values of 226Ra were between 7.4 Bq·m−2·y−1 and 60 Bq·m−2·y−1, while the rates of 210Po were between 22.1 and 111 Bq·m−2·y−1. For long‐term assessment, it was found that 226Ra increases in sweat potato soil and tomato soil with annual rates (ΔC) of 0.99 Bq·kg−1·y−1 and 0.69 Bq·kg−1·y−1, respectively. The AC of 210Po was predicted to increase in some soils. The corresponding ΔC values for 210Po were 0.028 Bq·kg−1·y−1 in rice, 0.617 Bq·kg−1·y−1 sweet potato, and 0.099 Bq·kg−1·y−1 in tomato soils. The results imply that interventions are necessary to reduce the radioactivity accumulation in fields with high ΔC values. The effective methods can be changing the fertilizer types and the irrigation systems.

Subclinical Mastitis Affects Milk Yield and Quality in Smallholder Dairy Cow Farms in the Highlands and Southern Vietnam

Subclinical Mastitis Affects Milk Yield and Quality in Smallholder Dairy Cow Farms in the Highlands and Southern Vietnam

A 24 BP Indel Prolactin Gene Polymorphism and Its Association with Some Reproductive Traits in Color Dual-Purpose VLV Hens in Southern Vietnam

A 24 BP Indel Prolactin Gene Polymorphism and Its Association with Some Reproductive Traits in Color Dual-Purpose VLV Hens in Southern Vietnam

The Prominent Role of Hat Chap Cai Luong Arts in Tourist Attraction to Thoi Son Island, Tien Giang Province

The purpose of this article is to study and analyze the current development and utilization of cultural and artistic tourism products on Thoi Son Island, Tien Giang Province. The article focuses on evaluating the effectiveness of incorporating don ca tai tu music (a genre of chamber music in the traditional music of southern Vietnam) in serving tourism activities in recent times and identifying existing issues in the development process of these cultural and artistic tourism products. In addition to discussing the advantages and competitive capabilities of Thoi Son Island, the article also proposes suitable solutions for the development of cultural and artistic tourism products in the locality, particularly the application and promotion of the art of hat chap cai luong (one of the traditional theater opera plays in southern Vietnam) combined with storytelling for tourism purposes. The research methodology employed in the article combines both quantitative and qualitative approaches. The quantitative part of the research will concentrate on collecting data on tourist numbers, income from cultural and artistic tourism activities, and tourist satisfaction. The qualitative part will involve conducting interviews, surveys, and gathering opinions from experts and local residents to gain a better understanding of the issues related to cultural and artistic tourism products featuring cai luong singing on Thoi Son Island. The research findings indicate that incorporating the art of hat chap cai luong into tourism activities is effective. However, several issues have been identified that need to be addressed, such as diversifying cultural and artistic tourism products, protecting and promoting the local cultural values, and ensuring the ability to meet the future demand for cultural tourism products without causing harm.