1,128 research outputs found

    AFLP analysis on genetic diversity and population structure of small yellow croaker Larimichthys polyactis

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    The population genetic structure and diversity of small yellow croaker Larimichthys polyactis in the Bohai Bay, Yellow Sea and East China Sea were analyzed using amplified fragment length polymorphism(AFLP). Ninety-one individuals were collected from six locations representing three stocks of small yellow croaker. A total of 218 putative loci were detected by 3 primer combinations, 148 of which were polymorphic (67.89%). The proportion of polymorphic loci and Nei’s genetic diversity for six populations ranged from 55.34 - 60.09%, and from 0.1244 - 0.1378. AMOVA analysis and pairwise FST revealedsignificant genetic differentiation among the three groups based on the breeding migration routes and over-wintering grounds, supporting separate stocks in this species. The result shows the migratorybehavior might be an important factor which influences the genetic structure of this species. The UPGMA tree also revealed the significant geographic structure in this species. Pattern of isolation bydistance was observed in this species, indicating that significant genetic differentiation among localities of small yellow croaker might be due to the geographic distance

    Flavonoid intake and the risk of age-related cataract in China’s Heilongjiang Province

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    Background/Objectives: Epidemiological evidence suggests that diets rich in flavonoids may reduce the risk of developing age-related cataract (ARC). Flavonoids are widely distributed in foods of plant origin and the objective of this study was to evaluate retrospectively the association between the intakes of the five flavonoid subclasses and the risk of ARC.  Subjects/Methods: A population-based case-control study (249 cases and 66 controls) was carried out in Heilongjiang province, which is located in the Northeast of China, and where intakes and availability of fresh vegetables and fruits can be limited. Dietary data gathered by food-frequency questionnaire (FFQ) were used to calculate flavonoid intake. Adjusted odds ratio (OR) and 95% confidence interval (CI) were estimated by logistic regression.  Results: No linear associations between risk of developing ARC and intakes of total dietary flavonoids, anthocyanidins, flavon-3-ol, flavanone, total flavones or total flavonols were found, but quercetin and isorhamnetin intake was inversely associated with ARC risk (OR 11.78, 95% CI: 1.62-85.84, P<0.05, and OR 6.99, 95% CI:1.12-43.44, P<0.05, quartile 4 vs quartile 1, respectively).  Conclusion: As quercetin is contained in many plant foods and isorhamnetin is only contained in very few foods, we concluded that higher quercetin intake may be an important dietary factor in the reduction of risk of age-related cataract

    Antioxidant properties of banana flower of two cultivars in China using 2,2-diphenyl-1-picrylhydrazyl (DPPH,) reducing power, 2,2’-azinobis-(3-ethylbenzthiazoline-6- sulphonate (ABTS) and inhibition of lipid peroxidation assays

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    In this study, the antioxidant properties of banana flower extracts (cvs. Baxijiao (AAA) and Paradisiaca (AAB)) were analysed by using several biochemical assays which include 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, reducing power, 2, 2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate (ABTS) radical scavenging activities and inhibition of lipid peroxidation in egg lecithin through the formation of thiobarbituric acid-reactive substances (TBARS). These assays have been extensively studied and generally accepted as models to characterize peroxidative damage in biomembranes. In the present study, the EC50 values were calculated using each method as listed above was used to compare the antioxidant efficiency of each banana flower extract. The phenol, flavonoid, vitamin E and saponin contents were also analyzed. Baxijiao flower extract revealed better antioxidant properties by presenting much lower EC50 values, particularly for reducing power. In addition, antioxidant concentrations (polyphenols and flavonoids) were found higher in this flower sample than those in the Paradisiaca sample. The results suggested that the Baxijiao flower could be a better resource either as a dietary supplement or as a food additive than the later one.Key words: Banana flower, antioxidant, scavenging effects, peroxidation

    Growth of GaSb and GaInAsSb layers for thermophotovoltaic cells by liquid phase epitaxy

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    GaSb based cells as receivers in thermophotovoltaic system have attracted great interest and been extensively studied in the recent 15 years. Although nowadays the manufacturing technologies have made a great progress, there are still some details need to make a further study. In this paper, undoped and doped GaSb layers were grown on n-GaSb (100) substrates from both Ga-rich and Sb-rich solutions using liquid phase epitaxy (LPE) technique. The nominal segregation coefficients k of intentional doped Zn were 1.4 and 8.8 determined from the two kinds of GaSb epitaxial layers. Additionally, compared with growing from Ga-rich solutions, the growing processes from Sb-rich solutions were much easier to control and the surface morphologies of epitaxial layers were smoother. Furthermore, in order to broaden the absorbing edge, Ga 1-xInxAsySb1-y quaternary alloys were grown on both GaSb and InAs substrates from In-rich solutions, under different temperature respectively

    The responses of evapotranspiration due to changes of LUCC under seawater intrusion in a coastal region

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    The paper provides a coherent pattern identification analysis of the impacts of coastal land use and land cover (LULC) on evapotranspiration (ET) under the impact of seawater intrusion. The study applied the Landsat satellite data to characterize the LULC at Laizhou Bay, Shandong Province, China. Then, the ET and heat fluxes were estimated using the surface energy balance algorithm for land model with two-time phase thermal infrared band images and regional surface parameters. This allowed for the eventual linkage of seawater intrusion to land use/cover changes (LUCC) and ET variations over time. The case study discussed in this paper carried out a coastal landscape dynamics assessment using multi-source and multi-sensor remote sensing technologies. The results are: (1) due to its distance from the sea, the vegetation index (modified soil-adjusted vegetation index, MSAVI) gradually increases with the gradual increase of land use grade (Uindex); (2) there are a variety of types of relational patterns between parameters (LST, G(n), MSAVI, and Uindex) and ET (positive, negative, and no relationship); and (3) seawater intrusion significantly affected the spatial pattern of LUCC, which evidently affected the spatial distribution of ET. The spatial distribution pattern and change characteristics of ET were formed by double driving forces of seawater intrusion and LUCC under the background effects of regional climate.The paper provides a coherent pattern identification analysis of the impacts of coastal land use and land cover (LULC) on evapotranspiration (ET) under the impact of seawater intrusion. The study applied the Landsat satellite data to characterize the LULC at Laizhou Bay, Shandong Province, China. Then, the ET and heat fluxes were estimated using the surface energy balance algorithm for land model with two-time phase thermal infrared band images and regional surface parameters. This allowed for the eventual linkage of seawater intrusion to land use/cover changes (LUCC) and ET variations over time. The case study discussed in this paper carried out a coastal landscape dynamics assessment using multi-source and multi-sensor remote sensing technologies. The results are: (1) due to its distance from the sea, the vegetation index (modified soil-adjusted vegetation index, MSAVI) gradually increases with the gradual increase of land use grade (Uindex); (2) there are a variety of types of relational patterns between parameters (LST, G(n), MSAVI, and Uindex) and ET (positive, negative, and no relationship); and (3) seawater intrusion significantly affected the spatial pattern of LUCC, which evidently affected the spatial distribution of ET. The spatial distribution pattern and change characteristics of ET were formed by double driving forces of seawater intrusion and LUCC under the background effects of regional climate

    Nitrate contamination of drinking water: relationship with HPRT variant frequency in lymphocyte DNA and urinary excretion of N-nitrosamines.

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    We studied peripheral lymphocyte HPRT variant frequency and endogenous nitrosation in human populations exposed to various nitrate levels in their drinking water. Four test populations of women volunteers were compared. Low and medium tap water nitrate exposure groups (14 and 21 subjects) were using public water supplies with nitrate levels of 0.02 and 17.5 mg/l, respectively. Medium and high well water nitrate exposure groups (6 and 9 subjects) were using private water wells with mean nitrate levels of 25 and 135 mg/l, respectively. Higher nitrate intake by drinking water consumption resulted in a dose-dependent increase in 24-hr urinary nitrate excretion and in increased salivary nitrate and nitrite levels. The mean log variant frequency of peripheral lymphocytes was significantly higher in the medium well water exposure group than in the low and medium tap water exposure groups. An inverse correlation between peripheral lymphocyte labeling index and nitrate concentration of drinking water was observed. Analysis of N-nitrosamine in the urine of 22 subjects by gas chromatography-mass spectrometry revealed the presence of N-nitrosopyrrolidine in 18 subjects. Analysis of the mutagenicity of well water samples showed that a small number of the well water samples were mutagenic in the Ames Salmonella typhimurium test after concentration over XAD-2 resin. In conclusion, consumption of drinking water, especially well water, with high nitrate levels can imply a genotoxic risk for humans as indicated by increased HPRT variant frequencies and by endogenous formation of carcinogenic N-nitroso compounds from nitrate-derived nitrite

    Protein 3D Graph Structure Learning for Robust Structure-based Protein Property Prediction

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    Protein structure-based property prediction has emerged as a promising approach for various biological tasks, such as protein function prediction and sub-cellular location estimation. The existing methods highly rely on experimental protein structure data and fail in scenarios where these data are unavailable. Predicted protein structures from AI tools (e.g., AlphaFold2) were utilized as alternatives. However, we observed that current practices, which simply employ accurately predicted structures during inference, suffer from notable degradation in prediction accuracy. While similar phenomena have been extensively studied in general fields (e.g., Computer Vision) as model robustness, their impact on protein property prediction remains unexplored. In this paper, we first investigate the reason behind the performance decrease when utilizing predicted structures, attributing it to the structure embedding bias from the perspective of structure representation learning. To study this problem, we identify a Protein 3D Graph Structure Learning Problem for Robust Protein Property Prediction (PGSL-RP3), collect benchmark datasets, and present a protein Structure embedding Alignment Optimization framework (SAO) to mitigate the problem of structure embedding bias between the predicted and experimental protein structures. Extensive experiments have shown that our framework is model-agnostic and effective in improving the property prediction of both predicted structures and experimental structures. The benchmark datasets and codes will be released to benefit the community

    Segmentation of sales for a mobile phone service through CART classification tree algorithm

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    The work consisted of detailing the CRISP-DM method in order to identify optimal groups of customers who are more likely to migrate from a prepaid to postpaid option in order to formulate an improvement plan for in call management by sorting the database. Classification models were applied to analyze the characteristics generated by the purchase of the different services. The CART Classification Tree algorithm. As a result, groups differentiated by probabilities of sales success (migrate from a prepaid to postpaid plan) were found, segments that reflect particular needs and characteristics to design marketing actions focused on the objective of increasing the effectiveness rate, contact information, and sales increase
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