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1.
2.
Do Thi Thanh HUONG Vidya JAYASANKAR Safiah JASMANI Hisako SAIDO-SAKANAKA Andrew J. WIGGINTON Marcy N. WILDER 《Fisheries Science》2004,70(3):518-520
3.
Dominant sources of dietary carbon and nitrogen for shrimp reared in extensive rice-shrimp ponds 总被引:1,自引:0,他引:1
Michele A Burford Nigel P Preston Truong Hoang Minh Tran Thi Tuyet Hoa Stuart E Bunn & Vanessa M Fry 《Aquaculture Research》2004,35(2):194-203
Stable isotope analysis was used to determine the sources of dietary nitrogen (N) and carbon (C) for shrimp during the rearing phase in extensive rice‐shrimp ponds in My Xuyen and Gia Rai districts, Vietnam. Farm‐made feed was added as a food source in shrimp ponds in My Xuyen district, and based on stable isotope analyses, was generally a poor dietary source. The commercial formulated feed used in Gia Rai also appeared to contribute little directly to the nutritional needs of the shrimp. In contrast, the natural biota in all ponds appeared to contribute substantially. In particular, biota from beam trawls and benthic organic matter were the most likely sources of nutrition in My Xuyen ponds, while benthic organic matter was the main source in Gia Rai ponds. δ15N ratios in the natural biota in My Xuyen farms decreased over the growing season, suggesting increased N fixation in the case of the benthic organic matter reaching values as low as 1‰. This suggests N‐limitation in the ponds and that natural biota become increasingly dependent on N fixed by algae and/or other microorganisms. There is the potential to promote the growth of the plankton and hence, the other natural biota, by the judicious addition of fertilizer. 相似文献
4.
Nadezhda E. Ustyuzhanina Maria I. Bilan Andrey S. Dmitrenok Eugenia A. Tsvetkova Sofya P. Nikogosova Cao Thi Thuy Hang Pham Duc Thinh Dinh Thanh Trung Tran Thi Thanh Van Alexander S. Shashkov Anatolii I. Usov Nikolay E. Nifantiev 《Marine drugs》2022,20(6)
Fucosylated chondroitin sulfates (FCSs) FCS-BA and FCS-HS, as well as fucan sulfates (FSs) FS-BA-AT and FS-HS-AT were isolated from the sea cucumbers Bohadschia argus and Holothuria (Theelothuria) spinifera, respectively. Purification of the polysaccharides was carried out by anion-exchange chromatography on DEAE-Sephacel column. Structural characterization of polysaccharides was performed in terms of monosaccharide and sulfate content, as well as using a series of non-destructive NMR spectroscopic methods. Both FCSs were shown to contain a chondroitin core [→3)-β-d-GalNAc-(1→4)-β-d-GlcA-(1→]n bearing sulfated fucosyl branches at O-3 of every GlcA residue in the chain. These fucosyl residues were different in pattern of sulfation: FCS-BA contained Fuc2S4S, Fuc3S4S and Fuc4S at a ratio of 1:8:2, while FCS-HS contained these residues at a ratio of 2:2:1. Polysaccharides differed also in content of GalNAc4S6S and GalNAc4S units, the ratios being 14:1 for FCS-BA and 4:1 for FCS-HS. Both FCSs demonstrated significant anticoagulant activity in clotting time assay and potentiated inhibition of thrombin, but not of factor Xa. FS-BA-AT was shown to be a regular linear polymer of 4-linked α-L-fucopyranose 3-sulfate, the structure being confirmed by NMR spectra of desulfated polysaccharide. In spite of considerable sulfate content, FS-BA-AT was practically devoid of anticoagulant activity. FS-HS-AT cannot be purified completely from contamination of some FCS. Its structure was tentatively represented as a mixture of chains identical with FS-BA-AT and other chains built up of randomly sulfated alternating 4- and 3-linked α-L-fucopyranose residues. 相似文献
5.
Vittadini E Dickinson LC Lavoie JP Pham X Chinachoti P 《Journal of agricultural and food chemistry》2003,51(6):1647-1652
Molecular mobility of water was studied in a microbiological media containing complex and heterogeneous mixtures of cellulose, l-sorbose, and orange serum broth (OSB) using (2)H and (17)O high-resolution NMR. All mixtures showed Lorentian (17)O NMR spectra but complex (2)H NMR line shapes. Sorbose, when solubilized, caused line-narrowing where as cellulose-OSB mixtures showed wide peaks with flat plateaus. Presence of liquid or solvent water had a profound effect on a marked increase in T(2) relaxation time observed in sorbose-containing samples. (17)O NMR data were not composition dependent, while (2)H NMR data were highly sorbose dependent. 相似文献
6.
Aamir Lal Eui-Joon Kil Vo T. B. Thuy Chairina Fadhila Phuong T. Ho Hee-Seong Byun Hang T. Dao Ji-Kwang Kim Sukchan Lee 《Plant pathology》2020,69(6):1026-1033
Milk vetch dwarf virus (MDV) is an important member of the genus Nanovirus and is transmitted by the aphid Aphis craccivora. MDV has multiple single-stranded DNA genome components, each approximately 1 kb, and two or three alpha-satellite molecules. It mainly infects plants of the legume family Fabaceae. Recently, papaya (Carica papaya) collected in Yesan, South Korea, displaying symptoms of leaf yellowing and dwarfism, was identified as a new host for MDV. To examine the geographical distribution of MDV, papaya samples with symptoms were harvested in South Korea, Vietnam, and Taiwan in August 2018, along with tomato and pepper samples grown in adjacent fields in Vietnam. The results revealed the presence of MDV not only in papaya but also in pepper and tomato. This MDV infection in members of the Solanaceae family was confirmed by Southern blot hybridization performed using a PCR product of segment S as a probe. Based on sequence analysis of three MDV components (M, S, and C3), we verified the presence of three different isolates of MDV in these three countries and homology between sequences of isolates from papaya and from members of the Solanaceae from Vietnam. Taken together, our results clearly demonstrate MDV infection in Vietnam and Taiwan for the first time and confirm that MDV can infect economically important pepper and tomato. 相似文献
7.
Iman Tahmasbian Zhihong Xu Kadum Abdullah Jun Zhou Roya Esmaeilani Thi Thu Nhan Nguyen Shahla Hosseini Bai 《Journal of Soils and Sediments》2017,17(8):2091-2103
Purpose
The main objective of this study was to examine the potential of using hyperspectral image analysis for prediction of total carbon (TC), total nitrogen (TN) and their isotope composition (δ13C and δ15N) in forest leaf litterfall samples.Materials and methods
Hyperspectral images were captured from ground litterfall samples of a natural forest in the spectral range of 400–1700 nm. A partial least-square regression model (PLSR) was used to correlate the relative reflectance spectra with TC, TN, δ13C and δ15N in the litterfall samples. The most important wavelengths were selected using β coefficient, and the final models were developed using the most important wavelengths. The models were, then, tested using an external validation set.Results and discussion
The results showed that the data of TC and δ13C could not be fitted to the PLSR model, possibly due to small variations observed in the TC and δ13C data. The model, however, was fitted well to TN and δ15N. The cross-validation R2 cv of the models for TN and δ15N were 0.74 and 0.67 with the RMSEcv of 0.53% and 1.07‰, respectively. The external validation R2 ex of the prediction was 0.64 and 0.67, and the RMSEex was 0.53% and 1.19 ‰, for TN and δ15N, respectively. The ratio of performance to deviation (RPD) of the predictions was 1.48 and 1.53, respectively, for TN and δ15N, showing that the models were reliable for the prediction of TN and δ15N in new forest leaf litterfall samples.Conclusions
The PLSR model was not successful in predicting TC and δ13C in forest leaf litterfall samples using hyperspectral data. The predictions of TN and δ15N values in the external litterfall samples were reliable, and PLSR can be used for future prediction.8.
Downy mildews cause considerable damage to maize (Zea mays L.) worldwide, particularly in the tropical Asia. We have evaluated a set of 42 tropical/sub-tropical maize inbred lines
developed in different countries in Asia (India, Thailand and Philippines), and Mexico, for analysing the genetic variability
for resistance to sorghum downy mildew [Peronosclerospora sorghi; SDM] and Rajasthan downy mildew [P. heteropogoni; RDM]. Experiments were carried out in replicated trials under artificial infection in field conditions against SDM and RDM
at Mandya in Karnataka, India, and Udaipur in Rajasthan, India, respectively, during 1999 and 2000. The study resulted in
identification of five inbred lines offering consistent and strong resistance to both SDM and RDM, while several inbred lines
revealed resistance only to RDM. It was also revealed that the SDM-resistant inbreds are invariably resistant to RDM, while
the RDM-resistant inbreds might show differential responses to the SDM. The maize inbred lines identified in this study with
broad-spectrum resistance to downy mildews could be potentially useful for basic and applied research work on downy mildews
in tropical Asia.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
9.
基于SRTM_DEM的泾河流域特征信息提取研究 总被引:2,自引:0,他引:2
流域特征信息的提取对于水文地理信息分析、模拟技术和水文模型建立具有重要意义。基于STRM_DEM数据,在ArcGIS9.3环境下,提取泾河流域坡度、坡向等地形特征,以及河网、流域边界和面积等水文要素,并划分子流域。分析表明,当闽值取5000(40.5km^2)时,生成的流域河网能够较好地反映该地区水系。根据河网分级、低级集水区域生成结果和流域地形特征,可划分为32个子流域,为流域分布式水文模型的构建提供了基础地理信息。SRTM_DEM提取泾河和部分支流流域面积误差均较小,说明提取结果与实际非常接近。结果表明,SRTM_DEM数据和ArcGIS9.3提取流域特征信息方便快捷,具有较高的精度和准确性,应用前景广阔。 相似文献
10.
Elena V. Girich Anton N. Yurchenko Olga F. Smetanina Phan Thi Hoai Trinh Ngo Thi Duy Ngoc Mikhail V. Pivkin Roman S. Popov Evgeny A. Pislyagin Ekaterina S. Menchinskaya Ekaterina A. Chingizova Shamil S. Afiyatullov Ekaterina A. Yurchenko 《Marine drugs》2020,18(12)
Low molecular weight secondary metabolites of marine fungi Aspergillus flocculosus, Aspergillus terreus and Penicillium sp. from Van Phong and Nha Trang Bays (Vietnam) were studied and a number of polyketides, bis-indole quinones and terpenoids were isolated. The structures of the isolated compounds were determined by 1D and 2D NMR and HR-ESI-MS techniques. Stereochemistry of some compounds was established based on ECD data. A chemical structure of asterriquinone F (6) was thoroughly described for the first time. Anthraquinone (13) was firstly obtained from a natural source. Neuroprotective influences of the isolated compounds against 6-OHDA, paraquat and rotenone toxicity were investigated. 4-Hydroxyscytalone (1), 4-hydroxy-6-dehydroxyscytalone (2) and demethylcitreoviranol (3) have shown significant increasing of paraquat- and rotenone-treated Neuro-2a cell viability and anti-ROS activity. 相似文献