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Hydrogeology and origin of waters of the Panyam Volcanic Line springs, Jos Plateau, Nigeria
No full textThe PVL springs are used for both domestic and agricultural purposes. The seepage from the springs has resulted in producing a large expanse of wetlands and is therefore intensively use for dry season farming. The aim of this study was to determine the hydrogeological, hydrochemical characteristics, origin and their suitability for domestic and irrigation. The hydrogeology of the springs was determined by field mapping. The physico-chemical parameters were determined in the field and by laboratory methods. For the cation and anion analysis the ICP-MS and the wet methods were employed respectively. The stable isotope composition of oxygen (δ18O) and hydrogen (δ2H) were analyzed by Isotope Ratio Mass Spectrometer. The hydrochemical analysis revealed that the PVL springs waters are generally neutral with an average pH value of 7.3. The average TDS and EC values are 127.8mg/l and 246µs/cm respectively. These values fall within fresh water class. The average Mg2+,Ca2+, Na+ and K+ cation concentration values are 16.3mg/l, 15.8mg/l, 10.8mg/l and 5.58mg/l respectively. The average anions concentration of HCO3-, SO4 and Cl- are 140mg/l, 8.6mg/l and 3.4mg/l respectively. Piper trilinear diagram show that the spring waters is predominantly Mg-Ca-HCO3 water type with potable qualities based on WHO drinking water standards. The sodium Adsorption Ratio (SAR) and Sodium Soluble Percentage (SSP) values range between 0.44 to 0.84 and 26.4 to 54% respectively and falls within irrigation quality standards. Stable isotope compositions of δ18O and δ2H ranges from -3.60/00 to -4.90/00 and -200/00 to -280/00 respectively falls within the meteoric water composition. This is further affirmed by the δ2H versus δ18O plot on the correlation diagram with Standard Meteoric Water Line
Relationship between seismicity and active faults in Thanh Hoa province detected by local seismic network
No full textThanh Hoa province belongs to the southwest part of Northwest Vietnam, which is considered a tectonically active region. In the area of Thanh Hoa province, there are three deep-seated tectonic faults, namely Son La-Bim Son, Song Ma, and Sop Cop. As predicted by scientists, these faults are capable of producing credible earthquakes that might be the strongest in the territory of Vietnam. Besides the three main seismogenic sources, in the province, there are other smaller active faults such as Thuong Xuan-Ba Thuoc and Thuong Xuan-Vinh Loc but the relationship of these faults with seismic activity is still rather blurred. This may due to the sparseness of the Vietnamese National Seismic Network which can not record adequately small earthquakes in the area. This paper presents new results of additional monitoring from a local seismic network using 12 Guralp - 6TD broadband seismometers that have been deployed in Thanh Hoa province since November 2009. We found that the Thanh Hoa area is not seismically quiet. The average number of earthquakes recorded by the network has reached 80 - 90 events per year and some of them have magnitude from ML 3.0 to 4.0.By integration of the earthquake epicenters derived from the local network and distribution of active faults, we can detect several earthquakes locating near the three active faults, not only along the main faults but also along its subsidiary faults. We focused on the active faults of Thuong Xuan-Ba Thuoc and Thuong Xuan-Vinh Loc by using the recent results of the gravity, seismic, and magnetotelluric data analyses. Several recorded earthquakes distribute along the two small faults and some of them reach magnitude 3.0 or greater on the ML scale. In this study, the Thuong Xuan-Vinh Loc is recognized as a seismogenic source. To identify seismic hazard potential caused by earthquakes generated from the active faults, segmentation of the Thuong Xuan - Ba Thuoc fault had been done based on geological and geomorphological indications and seismic activity, and then the peak ground acceleration was determined for each fault segment. Besides, a large number of earthquake epicenters do not have a good correlation with a specific fault, especially in the area of Thanh Hoa coastal plain, which is covered by thick layers of Neogene - Quaternary sediment. This shows that there may be hidden active faults in the area which are needed to study further
EXTRACTION AND BIOACTIVITY EVALUATION OF THE EXTRACTS FROM CLEISTOCALYX OPERCULATUS L. LEAVES
No full textCleistocalyx Operculatus L. was known as a natural resource of bioactivity compounds with high potential of anti-inflammatory, anti-bacterial, and antioxidant. In this study, two conventional extraction methods (maceration and liquid-solid extraction) at different extraction conditions (solvent concentration, extraction temperature and time, liquid-to-solid ratio, and number of extractions) were conducted. The extracts were analyzed for total phenolic content, anti-inflammatory activity, anti-bacterial, and antioxidant activity. Three parameters (liquid-solid ratio, extraction temperature, and time) were the important factors that affected on the extraction yield and antioxidant activity. The results showed that the highest values of the extraction yield and antioxidant activity were obtained at liquid-solid ratio of 5:1 (v/w – mL/g), extraction temperature and time of 50°C and 50 min, respectively. The antioxidant activity of the extract was confirmed by IC50 values (29.94 ± 2.34 μg/mL). Moreover, Cleistocalyx Operculatus L. extract shown an average anti-inflammatory activity (381.14 ± 5.48 μg/mL), while it did not exhibit anti-bacterial activity at 1,000 mg/L
GAS SENSING PROPERTIES OF NANOJUNCTION OF NETWORKED ZnO NANOWIRES UNDER THE CORRELATION BETWEEN OPERATING TEMPERATURE AND UV RADIATION
No full textThe networked ZnO nanowires (NWs) are synthesized by thermal evaporation at 900 oC, using a mixture of ZnO and graphite. The morphology, crystalline structure, and chemical composition of the NWs are evaluated by field-emission scanning electron microscopy, X-ray diffraction, and energy-dispersive spectrum. The NO2 gas-sensing properties of a networked ZnO NWs-based sensor are considered in a correlation between the operating temperature and UV radiation with various operating temperatures as well as UV intensities. The results reveal that the sensing properties of the UV-illuminated sensor measured at room temperature are comparable to those of the heated sensor. The results also indicate that the UV intensity affects strongly both the response and the sensing kinetic of the sensor at all operating temperatures. Furthermore, based on a systematic investigation of the sensing performance of the sensor under both UV illumination and thermal activation, a model to explain the role of UV illumination is also proposed
To study impact level of dominat parameters and propose estimate methodology for wave transmission efficiency of unconventional complex pile submerged breakwater
Full text linkThis article proposes semi-empirical equations to estimate wave transmission coefficient through submerged complex with solid pile breakwater based on theories of random wave energy conservation of perpendicular wave transmission incorporated with physical hydraulic experiments in wave flume applied on both types of submerged breakwater with and without piles. These equations are able to describe interactions and energy dissipation process for each element of this complex structure which are foundation block and pile rows. Energy dissipation process depends on three major factors which are [relative submerge depth (Rc/Hm0), relative crest width (B/Hm0), wave slope at construction location (sm=Hm0/Lm)] and wave energy dissipation process through pile rows is determined by two major factors [relative submerged depth or submerged length of piles (Rc/Hm0), relative pile row width (Xb/Lm)].This article proposes semi-empirical equations to estimate wave transmission coefficient through submerged complex with solid pile breakwater based on theories of random wave energy conservation of perpendicular wave transmission incorporated with physical hydraulic experiments in wave flume applied on both types of submerged breakwater with and without piles. These equations are able to describe interactions and energy dissipation process for each element of this complex structure which are foundation block and pile rows. Energy dissipation process depends on three major factors which are [relative submerge depth (Rc/Hm0), relative crest width (B/Hm0), wave slope at construction location (sm=Hm0/Lm)] and wave energy dissipation process through pile rows is determined by two major factors [relative submerged depth or submerged length of piles (Rc/Hm0), relative pile row width (Xb/Lm)]
DNA barcoding for identification of some fish species (Carangidae) in Vietnam coastal area
Full text linkCarangidae family has got about 148 species belonging to 32 genera. In Vietnam, Carangidae is of high commercial value and playing an important role in the ecosystem. In the context Vietnam has received yellow card for seafood since Nov. 2017 by the EU, in which one of the main reasons was related to the restriction of traceability. In this study, DNA barcoding technique of mitochondrial cytochrome oxidase I (COI) gene was used to classify 56 specimens of Carangidae from three coastal areas (Northern, Central and Southern) in Vietnam to evaluate the effectiveness compared to the morphological classification method. Results showed that 21 species belonging to 16 genera were determined by the COI barcode while 18 species (16 genera) were determined when using morphological method. Seriola quinqueradiata and Trachinotus anak were newly recorded in Vietnam. From 56 sequences with 660 bp of mtDNA (COI), total 27 haplotypes were detected; haplotype diversity (h) and nucleotide diversity (π) were 0.903 ± 0.00060 and 0.14%, respectively. The DNA barcodes of COI gene of 21 species in Carangidae which were developed in this study could be used as a basis for comparison and traceability of their products. In addition, the results showed the high potentiality in using COI barcode to identify Carangidae fish in Vietnam
CHẤT LƯỢNG MÔI TRƯỜNG NƯỚC VÙNG CỬA SÔNG BA LẠT
No full textBa Lat estuary is the large mouth of the Red river; every year, the Ba Lat estuary receives million cubic meters of water before the water is dissolved in the sea. Therefore, polluted materials in the water from the continent are also transported to the sea through the estuary. However, the volume of the water pouring into the sea varies with the season. In this paper, the water quality at Ba Lat estuary (Red river) was surveyed in July 2017 representing the Southwest wind season (rainy season) and in October 2017 representing the Northeast wind season (dry season). The research results show that the values of chemical parameters of water at Ba Lat estuary changed according to the season: the average temperature of water in the rainy season was 2.5oC higher than in the dry season; average pH in the rainy season (7.45 ± 0.36) was higher than that in the dry season (7.01 ± 0.17). Parameters such as conductivity, salinity, NO3-N, NH3-N, PO4-P, total grease, Fe and Zn in the dry season were 1.22–2.92 times higher than in the rainy season. Concentration of some nutrition (including NO3-N; NH3-N; PO4-P and SiO3-Si), heavy metals (Fe, Zn), and total grease in the water were high, in which NO3-N ranged from 0.565 mg/l to 1.129 mg/l; NH3-N ranged from 0.139 mg/l to 6.16 mg/l, 1.53 to 4.47 times higher than the standard of Vietnam. PO4-P ranged from 0.16 mg/l to 0.82 mg/l, which was 2 to 3.14 times higher than the standard. SiO3-Si ranged from 3.49 mg/l to 5.31 mg/l. Iron concentration in the water was 2.2 to 9.7 times higher than the standard and not different between the two seasons. Zn ranged from 0.64 mg/l to 2.56 mg/l, 1.28 to 5.12 times higher than the standard. Total grease ranged from 2.8 mg/l to 7.0 mg/l, 5.6 to 14 times higher than the standard. Other parameters such as DO, BOD5, Fe, SiO3-Si in the Northeast wind season were 1.01 to 1.35 times lower than in the Southwest wind season. In particular, DO ranged from 3.75 mg/l to 4.99 mg/l, lower than the QCVN 10-MT: 2015 standard and the DO was not suitable for the growth and development of aquatic life. Iron concentration ranged from 2.172 mg/l to 2.209 mg/l, 4.3 to 4.4 times higher than the standard. Water quality also varies with the space, most notably in electrical conductivity, salinity and grease. In particular, the salinity and conductivity tend to increase gradually from the river to the sea, the total oil and grease reached the highest point at BL7 in both phases, and NO3-N in phase 2 reached the highest value at BL6 to BL11.Vùng bãi bồi, cửa sông ven biển là vùng chuyển tiếp giữa lục địa và biển. Tại vùng cửa sông, tính chất vật lý và hóa học của môi trường nước luôn luôn biến động theo mùa và theo thủy triều, do đó, việc đánh giá chất lượng nước của khu vực cửa sông theo mùa là cần thiết để xác định sự biến động của chất lượng nước theo thời gian. Vùng cửa sông Ba Lạt hàng năm tiếp nhận hàng triệu khối nước từ sông Hồng đổ ra biển, cùng với sự vận chuyển của dòng nước, các chất ô nhiễm từ lục địa theo sông được đưa ra biển, tuy nhiên lượng nước từ sông đổ ra biển của các mùa có sự khác biệt nhau tương đối lớn. Do đó, trong nghiên cứu này, chúng tôi tiến hành khảo sát và đánh giá chất lượng môi trường nước tại cửa sông Ba Lạt theo mùa: mùa gió Tây Bắc (đại diện cho mùa khô) và mùa gió Đông Nam (đại diện cho mùa mưa). Kết quả nghiên cứu cho thấy rằng, các thông số thủy lý hóa học của nước như pH, nhiệt độ, độ dẫn, độ muối, độ đục, DO, BOD5, COD và các kim loại nặng thay đổi theo mùa. Các muối dinh dưỡng như NH4+, PO43- đã cao hơn so tiêu chuẩn của vùng nuôi trồng thủy sản và bảo tồn thủy sinh của QCVN 10- MT: 2015. Trong đó NH4+ cao hơn từ 1,9 đến 2 lần, còn PO43- thì cao hơn từ 5 đến 10 lần so với QCVN 10 - MT: 2015. Nồng độ Cd và Zn trong nước tại một số điểm nghiên cứu đã cao hơn so với quy chuẩn QCVN 10- MT: 2015 với mục đích nuôi trồng thủy sản và bảo tồn thủy sinh. Dầu tổng số trong nước cao hơn so với QCVN 10: MT - 2015 từ 5,6 đến 14 lần
Efficiency of ITS1-5.8S-ITS2 region in identifying Cordyceps species
Full text linkCordyceps genus is a well-known traditional medicine worldwide. It contains abundant physiological active compounds that were demonstrated to perform benefit in reducing progression of cancer as well as protecting human health. Accurately classifying species in this genus is essential in order to prevent commercial counterfeit medicines. Nowadays, a taxonomic classification of species based on DNA sequences can overcome the existed limitation in identifying by using only morphological characteristics of this genus. DNA barcodes are standard short genomic regions that are universally present in target lineages and has sufficient sequence variation to discriminate species in the genus. A variety of loci has been suggested as DNA barcodes for plants, including genes and non-coding regions in the nuclear and plastid genomes such as psbA-trnH, matK, rbcL, and ITS. Thus, the objective of this study was to identify selected species of Cordyceps genus using DNA barcodes. Seven strains of Cordyceps were collected. Total DNA extraction and purification, PCR amplification and DNA sequencing were performed with standard chemicals and kits. The candidate ITS1-5.8S-ITS2 region was amplified and sequenced. Data were analyzed using Bioedit 7.2.6 and MEGA 7 softwares. Analysis of seven obtained DNA barcode sequences of collected samples revealed that the ITS1-5.8S-ITS2 region provided high species discriminating power for Cordyceps genus. Accordingly, phylogenetic trees based on this DNA barcode exhibited six samples had closed relationship to Cordyceps militaris, while another specimen was the nearest neighbor to Cordyceps sinensis with average similarities at 99.82% and 99.81%, respectively. Our results support the identification of valuable medicinal plant species within Cordyceps genus
Drought stress - related functional characterization of transcription factor GmNAC085 in soybean
Full text linkStudies on soybean GmNAC085 transcription factor revealed that the gene expression in plants was induced by water shortage treatments and its overexpression in the model plant Arabidopsis displayed improved plant tolerance characteristics towards drought stress. In this study, we continued analyzing the biological functions of GmNAC085 using transgenic soybean system overexpressing GmNAC085 gene, by targeting at a number of plant physiological features and biochemical activities in response to limited water growing condition. Compared to the wild-type, the transgenic line demonstrated that it possessed stress tolerance characters, including enhanced elongation of taproot, minimized reduction of shoot growth, lower intracellular H2O2 content and stronger peroxidase enzyme activity under drought condition. The results of this study therefore suggest the transgenic plants had better drought tolerance and the GmNAC085 plays important role in aiding plants to cope with water deficit condition, probably via regulating the growth of roots and shoots, and activities of reactive-oxygen-species- scavenging enzymes
. In vitro propagation of the new orchid Dendrobium trankimianum T. Yukawa
Full text linkDendrobium trankimianum T. Yukawa is a beautiful, endemic orchid of Vietnam, a new species with a first - published description in 2004. It is very rare and expected to be added to the IUCN Red List status - CR. In vitro studies of orchid D. trankimianum T. Yukawa were conducted in order to conserve and increase the genetic pool of this precious wild orchid species. The results showed that full-strength MS medium supplemented with 2.0 mg/L BA and 0.5 mg/L NAA (10.24 PLBs/explant; 90.11% explants formed PLBs) or full-strength MS medium supplemented with 1.5 mg/L TDZ and 0.5 mg/L NAA (14.11 PLBs/explant; 92.06% explants formed PLBs) were the most suitable for protocorm formation. For subculture, suitable growth of shoots were obtained on full-strength MS medium supplemented 1.5 mg/L BA (22.35 shoots/explant; shoots length of 1.96 cm) and full-strength MS medium supplemented with 60 g ripe banana per liter (25.11 shoots/explant; shoots length of 2.12 cm). The shoots in vitro were transferred to half-strength MS supplemented with different concentrations of IAA, IBA and NAA to investigate root formation. The best rooting occurred at 0,5 mg/L NAA (7.91 roots/shoot; root length of 4.01 cm; 98.51% root formation). The plantlets with uniform growth were planted on different substrate: Eco clean soil, Coconut fiber, Fern fiber, 50% Rice husk in combination with 50% Eco clean soil for research the most suitable substrate. After 60 days of transplantion and acclimatization, the result showed that Fern fiber was suitable substrate for plantlet growth in a nursery garden (8.0 roots/ explant; root length of 5.5 cm; survival rate of 93.29%)