306 research outputs found
First report of Longidorus mindanaoensis Coomans, De Ley, Jimenez and De Ley, 2012 (Nematoda: Longidoridae) from a mangrove forest in Vietnam
Longidorus mindanaoensis was recovered from a mangrove forest in Vietnam. The recovered population is in general morphological agreement with the type population, and the characters of pharyngeal bulb, i.e. the same unique pattern of pharyngeal glands nuclei as well as the lip region morphology, amphidial fovea shape and size and position of vulva corroborated its identity. Molecular studies of the recovered population using D2-D3 expansion segments of large subunit ribosomal DNA (LSU rDNA D2-D3) revealed the D2-D3 sequence of the recovered population is 99.6% similar to the sequence of the type population. A new morphometric range for body size was recorded for the species based upon present Vietnamese population, and the present study emphasized that the diversity of Longidorus spp. in Vietnam could be higher than previously assumed
The Impact of Foreign Direct Investment on Economic Growth: Evidence from Vietnam
The relationship between Foreign Direct Investment (FDI) and economic growth has long been a topic of great interest in the field of international development. Although this interest has provided rich insights into the impact of FDI on growth in developing countries, there are very few empirical analyses of the linkage in Vietnam compared to other developing countries. Therefore, this study investigates the impact of FDI inflows on economic growth in Vietnam over the period from 1990 to 2013 using time series analysis techniques that address the problem of nonstationarity. Specifically, the Unit root test and Cointegration approach are applied to ensure that the regressions are not spurious. The empirical results reveal that FDI inflows, domestic investment, trade openness and secondary education have positive impacts on economic growth whereas inflation rate is found to have negative effect on economic growth. In addition, the impact of government consumption on economic growth is negative and statistically insignificant. Ultimately, this paper suggests that Vietnamese government should improve regulations governing business activities by easing the process of business start-up, controlling price, enhancing public spending on education and training, and augmenting cooperation between training centers and Foreign-invested enterprises. Keywords: Foreign Direct Investment, economic growth, time series, unit root test, cointegration, Vietnam
Morphological diversity of Meloidogyne spp. from carrot (Daucus carota subsp. Sativus) in Vietnam
Carrot (Daucus carota subsp. Sativus) is known as one of the most widely cultivated and widely consumed vegetables in the world due to its nutritional and economic values. During a survey of nematodes parasites carrots from Vietnam, six populations of three species of root-knot nematodes, namely M. incognita, M. arenaria, and M. graminicola were found. The species specific primers were confirmed before morphological studies. By combining the morphology and morphometry of the females, males, and juveniles, this study provided useful references for classification of Meloidogyne on carrots in the future. Quantitative morphological studies reveal profound changes corresponding with the generation of morphological disparity at high taxonomic diversity. Especially, this study provided the first morphological and morphometric information of M. graminicola, that is known as aquatic root-knot nematodes, on carrots
Description of Geocenamus vietnamensis sp. n. (Nematoda : Merliniidae) from Vietnam
A new species of the genus Geocenamus was isolated from soil and root samples from the rhizosphere of Casuarina equisetifolia (Casuarinaceae) in Quang Nam province, Vietnam. This species is characterized by a round-to-hexagonal labial disc, the presence of a labial region, which is continuous or slightly offset from the body with six sectors, lateral sectors of first labial annulus being smaller than the submedian sectors, the presence of six to seven labial annules; the absence of deirids; stylet length 24 to 28 mu m long, body length 776 to 979 mu m long; lateral field with six to eight lateral lines, without areolation at mid-body and with areolation in outer bands at the tail region and a pointed tail terminus. Geocenamus vietnamensis n. sp. most closely resembles G. boghiae in having a non-sclerotized head framework and lacking a bursa in the males. It can be clearly distinguished from all other species of the genus Geocenamus by these characteristics. The combination of morphology, morphometric features, and phylogenetic trees, based on D2-D3 of 28S and ITS rDNA sequences, showed that this new species can be clearly separated from all other sequenced species. This record is the first for Geocenamus in Vietnam
Morphological and molecular characteristics of Pratylenchus haiduongensis sp. n., a new species of root-lesion nematodes associated with carrot in Vietnam
Pratylenchus haiduongensis sp. n. is described as associated with carrot (Daucus carota subsp. sativus (Hoffm.) Schubl. & G. Martens) in Hai Duong Province, Vietnam. P. haiduongensis sp. n. is characterized by the lip region with three annuli and slightly separated from the body. Stylet knobs are rounded (never indented anteriorly). The lateral field includes four incisures, bearing areolation at the pharynx region and tail region and occasionally appears in the vulval region. Sometimes the appearances of oblique broken striaes divide the lateral field into five or six incisures. The ovary is distinct with one row of oocytes. Spermatheca is oval in shape with round central cavity, without sperm or reduced in some specimens. The postvuval uterine sac is long surpassing the vulva body diameter by 2 to 2.5 times (PUS = 31 to 65 mm). High vulva position with V = 66 to 75%. The tail shape can be subhemispherical with a smooth, slightly indented, broadly smooth, or cleft terminus observed in some specimens. The matrix code of P. haiduongensis sp. n. is: A2, B1, C4, D(1,3), E1, F(5,6), G(1,2), H(1,4); I(1,2,3,4), J1, K(1,2) according to Castillo and Vovlas (2007). The LSU-D2D3 segment and the ITS-rDNA region of this species were amplified and sequenced. The morphological characters and molecular phylogenetic analyses confirmed that this is a new species of the genus Pratylenchus in Vietnam
First report of Mesocriconema sphaerocephalum (Taylor, 1936) Loof, 1989 associated with carrot (Daucus carota subsp. Stativus) in Vietnam
Our study recorded the presence of Mesocriconema sphaeroce phalum on carrot in Hanoi city and Hai Duong province in Vietnam. This species was identified by morphometric, morphological characterizations, and molecular characterization of D2D3 of 28S rDNA sequence. To our knowledge, this is the first report of M. sphaerocephalum on carrot in Vietnam
First report of Xiphinema hunaniense Wang & Wu, 1992 (Nematoda : Longidoridae) in Vietnam
For the first time, a survey of plant-parasitic nematodes in the Central Highlands of Vietnam discovered a population of Xiphinema hunaniense Wang & Wu, 1992. The Vietnamese population of X. hunaniense is characterized by having an offset lip region, lack of anterior genital branch, vagina directed backward, and a digitate tail. Morphological features and morphometrics of this population are in agreement with the type population of X. hunaniense except for some variations. In addition, molecular characterization of this population and phylogenetic tree of 28S rDNA sequences of the genus are also provided
First report of Hemicriconemoides litchi associated with Piper sarmentosum and revision of the genus Hemicriconemoides in Vietnam
The taxonomic status of Hemicriconemoides litchi, H. mangiferae, and H. strictathecatus has been in debates for many years. In this study, a population of H. litchi collected from the rhizosphere of Piper sarmentosum is characterized using a combination of morphology and molecular data. Our results are in agreement with other authors to maintain the validity of H. litchi and provide sequences of H. litchi with correct names on GenBank. A revision on the genus Hemicriconemoides in Vietnam is also discussed
Anti-inflammatory activity of methyl ferulate isolated from Stemona tuberosa Lour
AbstractObjectiveTo evaluate the anti-inflammatory activity of methyl ferulate (MF) isolated from the roots of Stemona tuberosa (S. tuberosa) Lour (Stemonaceae) in lipopolysaccharide activated macrophage cells.MethodsMethanol extracts of a root powder of S. tuberosa were prepared for isolation of a potential anti-inflammatory agent using ultrasound extraction combined with repeated chromatography on silica gel. After the quantitative analyses, anti-inflammatory activity of the isolated compound was evaluated by measurement of cytokine release, NO generation, expression of cyclooxygenase-2 and phosphorylation of mitogen activated protein kinases including p38 and c-Jun NH2-terminal kinase using quantitative kits and Western blotting with specific antibodies.ResultsThe isolation process yielded a potential anti-inflammatory compound with a purity level of 99% determined by high performance liquid chromatography. The compound was identified as MF by using nuclear magnetic resonance. MF strongly inhibited the release of pro-inflammatory cytokines from macrophages, including IL-6, TNFα, IFNγ, yet it did not affect the anti-inflammatory cytokine IL-10. Phosphorylation of p38 and c-Jun NH2-terminal kinase were clearly reduced in MF-treated macrophages stimulated with lipopolysaccharide. cyclooxygenase-2 expression and NO generation by macrophages were also suppressed when the cells were treated with MF.ConclusionsThe data suggested that MF is a possible inhibitor of the mitogen activated phosphor kinase pathway and could be a potential anti-inflammatory agent isolated for the first time in medicinal plant S. tuberosa
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