Study on biogenic amines in various dry salted fish consumed in China     

WU Yanyan  CHEN Yufeng  LI Laihao  YANG Xianqing  YANG Shaoling  LIN Wanling  ZHAO Yongqiang  DENG Jianchao 《中国海洋大学学报(英文版)》2016,15(4):681-689

This study was carried out to investigate the biogenic amines（BAs）, physicochemical property and microorganisms in dry salted fish, a traditional aquatic food consumed in China. Forty three samples of dry salted fish were gathered from retail and wholesale markets and manufacturers, which had been produced in various regions in China. Cadaverine（CAD） and putrescine（PUT） were quantitatively the most common biogenic amines. About 14% of the samples exceeded the histamine content standards established by the FDA and/or EU. The highest histamine content was found in Silver pomfret（Pampus argenteus）(347.79 mg kg^-1). Five of forty three samples exceeded the acceptable content of TYR(100 mg kg^-1), and 23.26% of dried-salted fish contained high contents of biogenic amines(above 600 mg kg^-1). In addition, species, regions, pickling processes and drying methods made the physicochemical property, microorganisms and biogenic amines in dry salted fish to be different to some extents. The total plate count（TPC） was much higher than that of total halophilic bacteria in all samples. The biogenic amines, physicochemical property and microbiological counts exhibited large variations among samples. Furthermore, no significant correlation between biogenic amines and physicochemical property and TPC was observed. This study indicated that dry salted fish may still present healthy risk for BAs, depending on the processing methods, storage conditions among others.  相似文献   

Advanced glycation endproducts in 35 types of seafood products consumed in eastern China     

WANG Jing  LI Zhenxing  PAVASE Ramesh Tushar  LIN Hong  ZOU Long  WEN Jie  LV Liangtao 《中国海洋大学学报(英文版)》2016,15(4):690-696

Advanced glycation endproducts(AGEs) have been recognized as hazards in processed foods that can induce chronic diseases such as cardiovascular disease, diabetes, and diabetic nephropathy. In this study, we investigated the AGEs contents of 35 types of industrial seafood products that are consumed frequently in eastern China. Total fluorescent AGEs level and Nε-carboxymethyl-lysine(CML) content were evaluated by fluorescence spectrophotometry and gas chromatography-mass spectrometry(GC-MS), respectively. The level of total fluorescent AGEs in seafood samples ranged from 39.37 to 1178.3 AU, and was higher in canned and packaged instant aquatic products that were processed at high temperatures. The CML content in seafood samples ranged from 44.8 to 439.1 mg per kg dried sample, and was higher in roasted seafood samples. The total fluorescent AGEs and CML content increased when seafood underwent high-temperature processing, but did not show an obvious correlation. The present study suggested that commonly consumed seafood contains different levels of AGEs, and the seafood processed at high temperatures always displays a high level of either AGEs or CML.  相似文献   

Glacier changes in the eastern Nyainqêntanglha Range of Tibetan Plateau from 1975 to 2013     

JI Qin  YANG Tai-bao  HE Yi  CHEN Jie  WANG Kai 《山地科学学报》2016,13(4):682-692

Maritime-type glaciers in the eastern Nyainqêntanglha Range, located in the southeastern part of the Tibetan Plateau, are an important water source for downstream residents and ecological systems. To better understand the variability of glaciers in this region, we used the band ratio threshold(TM3/TM5 for the Landsat TM /ETM+ and TM4/TM6 for Landsat OLI) to extract glacier outlines in ~1999 and ~2013. After that, we also generated a series of glacier boundaries and monitored glacier variations in the past 40 years with the help of the Chinese Glacier Inventory data(1975) and Landsat TM, ETM+ and OLI data. The total glacier area decreased by 37.69 ± 2.84% from 1975 to 2013. The annual percentage area change(APAC) was ~1.32% a-1 and ~1.29% a-1 in the periods 1975-1999 and 1999-2013, respectively. According to the lag theory, the reaction time is probably about 10 years and we discuss the variations of temperature and precipitation between 1965 and 2011. Temperature and precipitation increased between 1965 and 2011 at a rate of 0.34°C /10 a and 15.4 mm/10 a, respectively. Extensive meteorological data show that the glacier shrinkage rate over the period may be mainly due to increasing air temperature, while the increasing precipitation partly made up for the mass loss of glacier ice resulting from increasing temperature may also lead to the low APAC between 1999 and 2013. The lag theory suggests that glacier shrinkage may accelerate in the next 10 years. Small glaciers were more sensitive to climate change, and there was a normal distribution between glacier area and elevation. Glaciers shrank in all aspects, and south aspects diminished faster than others.  相似文献   

Preliminary studies on the dynamic prediction method of rainfall-triggered landslide   总被引：1，自引：0，他引：1  

Yue-li Chen  De-hui Chen  Ze-chun Li  Jun-bao Huang 《山地科学学报》2016,13(10):1735-1745

Rainfall-triggered landslides have posed significant threats to human lives and property each year in China. This paper proposed a meteorologicalgeotechnical early warning system GRAPES-LFM(GRAPES: Global and Regional Assimilation and Pr Ediction System; LFM: Landslide Forecast Model),basing on the GRAPES model and the landslide predicting model TRIGRS(Transient Rainfall Infiltration and Grid-based Regional Slope-Stability Model) for predicting rainfall-triggered landslides.This integrated system is evaluated in Dehua County,Fujian Province, where typhoon Bilis triggered widespread landslides in July 2006. The GRAPES model runs in 5 km×5 km horizontal resolution, and the initial fields and lateral boundaries are provided by NCEP(National Centers for Environmental Prediction) FNL(Final) Operational Global Analysis data. Quantitative precipitation forecasting products of the GRAPES model are downscaled to 25 m×25 m horizontal resolution by bilinear interpolation to drive the TRIGRS model. Results show that the observed areas locate in the high risk areas, and the GRAPES-LFM model could capture about 74% of the historical landslides with the rainfall intense 30mm/h. Meanwhile, this paper illustrates the relationship between the factor of safety(FS) and different rainfall patterns. GRAPES-LFM model enables us to further develop a regional, early warning dynamic prediction tool of rainfall-induced landslides.  相似文献   

Long-range precipitation forecasts using paleoclimate reconstructions in the western United States     

Christopher Allen CARRIER  Ajay KALRA  Sajjad AHMAD 《山地科学学报》2016,13(4):614-632

Long-range precipitation forecasts are useful when managing water supplies.Oceanicatmospheric oscillations have been shown to influence precipitation.Due to a longer cycle of some of the oscillations,a short instrumental record is a limitation in using them for long-range precipitation forecasts.The influence of oscillations over precipitation is observable within paleoclimate reconstructions;however,there have been no attempts to utilize these reconstructions in precipitation forecasting.A data-driven model,KStar,is used for obtaining long-range precipitation forecasts by extending the period of record through the use of reconstructions of oscillations.KStar is a nearest neighbor algorithm with an entropy-based distance function.Oceanic-atmospheric oscillation reconstructions include the El Nino-Southern Oscillation(ENSO),the Pacific Decadal Oscillation(PDO),the North Atlantic Oscillation(NAO),and the Atlantic Multi-decadal Oscillation(AMO).Precipitation is forecasted for 20 climate divisions in the western United States.A 10-year moving average is applied to aid in the identification of oscillation phases.A lead time approach is used to simulate a one-year forecast,with a 10-fold cross-validation technique to test the models.Reconstructions are used from 1658-1899,while the observed record is used from 1900-2007.The model is evaluated using mean absolute error(MAE),root mean squared error(RMSE),RMSE-observations standard deviation ratio(RSR),Pearson’s correlation coefficient(R),NashSutcliffe coefficient of efficiency(NSE),and linear error in probability space(LEPS) skill score(SK).The role of individual and coupled oscillations is evaluated by dropping oscillations in the model.The results indicate ’good’ precipitation estimates using the KStar model.This modeling technique is expected to be useful for long-term water resources planning and management.  相似文献   

Effect of benzo[a]pyrene on detoxification and the activity of antioxidant enzymes of marine microalgae     

Chen Shen  Jingjing Miao  Yun Li  Luqing Pan 《中国海洋大学学报(英文版)》2016,15(2):303-310

The objective of this study was to examine the effect of benzo[a]pyrene(Ba P) on the detoxification and antioxidant systems of two microalgae,Isochrysis zhanjiangensis and Platymonas subcordiformis.In our study,these two algae were exposed to Ba P for 4 days at three different concentrations including 0.5 μg~(L-1)(low),3 μg~(L-1)(mid) and 18 μg~(L-1)(high).The activity of detoxification enzymes,ethoxyresorufin O-deethylase(EROD) and glutathione S-transferase(GST) increased in P.subcordiformis in all Ba P-treated groups.In I.zhanjiangensis,the activity of these two enzymes increased at the beginning of exposure,and then decreased in the groups treated with mid-and high Ba P.The activity of antioxidant enzyme superoxide dismutase(SOD) increased in I.zhanjiangensis in all Ba P-treated groups,and then decreased in high Ba P-treated group,while no significant change was observed in P.subcordiformis.The activity of antioxidant enzyme catalase(CAT) increased in I.zhanjiangensis and P.subcordiformis in all Ba Ptreated groups.The content of malondialdehyde(MDA) in Isochrysis zhanjiangensis increased first,and then decreased in high Ba P-treated group,while no change occurred in P.subcordiformis.These results demonstrated that Ba P significantly influenced the activity of detoxifying and antioxidant enzymes in microalgae.The metabolic related enzymes(EROD,GST and CAT) may serve as sensitive biomarkers of measuring the contamination level of Ba P in marine water.  相似文献   

Development of three multiplex PCR primer sets for ark shell (<Emphasis Type="Italic">Scapharca broughtonii</Emphasis>) and their validation in parentage assignment     

Ning Li  Qi Li  Lingfeng Kong  Hong Yu 《中国海洋大学学报(英文版)》2016,15(2):311-317

Scapharca broughtonii is a commercially important and over-exploited species. In order to investigate its genetic diversity and population structure, 43 novel polymorphic microsatellites were isolated and characterized. The number of alleles per locus ranged from 3 to 22 with an average of 6.93, and the observed and expected heterozygosities varied between 0.233 and 1.000, and 0.250 and 0.953, with an average of 0.614 and 0.707, respectively. Three highly informative multiplex PCRs were developed from nine of those microsatellites for S. broughtonii. We evaluated and validated these multiplex PCRs in 8 full-sib families. The average polymorphism information content (PIC) was 0.539. The frequency of null alleles was estimated as 3.13% of all the alleles segregation based on a within-family analysis of Mendelian segregation patterns. Parentage analysis of real offspring demonstrated that 100% of all offspring were unambiguously allocated to a pair of parents based on 3 multiplex sets. Those 43 microsatellite loci with high variability will be helpful for the analysis of population genetics and conservation of wild stock of S. broughtonii. The 3 sets of multiplex PCRs could be an important tool of pedigree reconstruction, population genetic analysis and brood stock management.  相似文献   

Numerical study on inter-tidal transports in coastal seas     

Xinyan Mao  Wensheng Jiang  Ping Zhang  Shizuo Feng 《中国海洋大学学报(英文版)》2016,15(3):379-388

Inter-tidal(subtidal) transport processes in coastal sea depend on the residual motion, turbulent dispersion and relevant sources/sinks. In Feng et al.(2008), an updated Lagrangian inter-tidal transport equation, as well as new concept of Lagrangian in- ter-tidal concentration(LIC), has been proposed for a general nonlinear shallow water system. In the present study, the LIC is nu- merically applied for the first time to passive tracers in idealized settings and salinity in the Bohai Sea, China. Circulation and tracer motion in the three idealized model seas with different topography or coastline, termed as ‘flat-bottom', ‘stairs' and ‘cape' case, re- spectively, are simulated. The dependence of the LIC on initial tidal phase suggests that the nonlinearities in the stairs and cape cases are stronger than that in the flat-bottom case. Therefore, the ‘flat-bottom' case still meets the convectively weakly nonlinear condi- tion. For the Bohai Sea, the simulation results show that most parts of it still meet the weakly nonlinear condition. However, the de- pendence of the LIS(Lagrangian inter-tidal salinity) on initial tidal phase is significant around the southern headland of the Liaodong Peninsula and near the mouth of the Yellow River. The nonlinearity in the former region is mainly related to the complicated coast- lines, and that in the latter region is due to the presence of the estuarine salinity front.  相似文献   

Effect of bioactive peptides (BPs) on the development of Pacific white shrimp (<Emphasis Type="Italic">Litopenaeus vannamei</Emphasis> Boone, 1931)     

Guangjun Wang  Ermeng Yu  Zhifei Li  Deguang Yu  Haiying Wang  Wangbao Gong 《中国海洋大学学报(英文版)》2016,15(3):495-501

The present study was conducted to evaluate the feasibility of replacing fish meal (FM) with bioactive peptides (BPs) in diet of white shrimp (Litopenaeus vannamei). The changes in growth performance, body composition, non-specific immunity, and water quality were examined after the shrimp were fed four diets, in which 0% (control), 33.3%, 66.7% and 100% of FM was replaced by BPs, respectively. The groups were designated as Con, 1/3BPs, 2/3BPs, and 3/3BPs. A total of 720 shrimp with an initial body weight of 1.46 ± 0.78 g were fed the experimental diets for 56 days. The results revealed that: 1) the weight gain rate (WGR) in 1/3BPs, 2/3BPs, and 3/3BPs was significantly higher than that in Con (P < 0.05), while no significant difference was found on survival rate and feed conversion ratio (FCR); 2) the whole-body crude protein (CP) and crude lipids (CL) were significantly different among groups, while there was no significant difference between crude ash and phosphorus contents; 3) the levels of acid phosphatase (ACP), lysozyme (LZM), superoxide dismutase (SOD), phenol oxidase (PO) and bactericidal activity increased significantly with the inclusion of BPs; 4) in terms of water quality, no significant difference was found in pH and dissolved oxygen among diets during the whole experimental period. Moreover, even though nitrite and ammonium levels tended to increase with time, there was no significant difference among groups. The results indicated that BPs is an applicable alternative of protein source, which can substitute FM in the diets of L. vannamei; it is able to effectively promote growth performance and improve immunity. Moreover, BPs in the diets had no negative impact on water quality.  相似文献   

Approximate optimal tracking control for near-surface AUVs with wave disturbances     

Qing Yang  Hao Su  Gongyou Tang 《中国海洋大学学报(英文版)》2016,15(5):789-798

This paper considers the optimal trajectory tracking control problem for near-surface autonomous underwater vehicles (AUVs) in the presence of wave disturbances. An approximate optimal tracking control (AOTC) approach is proposed. Firstly, a six-degrees-of-freedom (six-DOF) AUV model with its body-fixed coordinate system is decoupled and simplified and then a nonlinear control model of AUVs in the vertical plane is given. Also, an exosystem model of wave disturbances is constructed based on Hirom approximation formula. Secondly, the time-parameterized desired trajectory which is tracked by the AUV’s system is represented by the exosystem. Then, the coupled two-point boundary value (TPBV) problem of optimal tracking control for AUVs is derived from the theory of quadratic optimal control. By using a recently developed successive approximation approach to construct sequences, the coupled TPBV problem is transformed into a problem of solving two decoupled linear differential sequences of state vectors and adjoint vectors. By iteratively solving the two equation sequences, the AOTC law is obtained, which consists of a nonlinear optimal feedback item, an expected output tracking item, a feedforward disturbances rejection item, and a nonlinear compensatory term. Furthermore, a wave disturbances observer model is designed in order to solve the physically realizable problem. Simulation is carried out by using the Remote Environmental Unit (REMUS) AUV model to demonstrate the effectiveness of the proposed algorithm.  相似文献