The Chinese rare minnow (Gobiocypris rarus) as an in vivo model for endocrine disruption in freshwater teleosts: a full life-cycle test with diethylstilbestrol

Chinese rare minnow (Gobiocypris rarus), a freshwater teleost,. was exposed to diethylstilbestrol (DES) at 0.05, 0.5, 1 and 5 mug/L from fertilized eggs for up to mature period under flow-through condition. Several endpoints that related to development, reproductive fitness and transgenerational effects were evaluated. It was found that body length and body weight were significantly reduced and vitellogenin (Via) levels were significantly increased for fish exposed to DES. Histological examination showed that the sex ratios of F-0 fish skewed to female and about 2% of the fish exposed to 0.05 mug/L DES developed testes-ova. The reproductive success, as determined from data on egg production, was reduced in female fish exposed to 0.05, 0.5, 1 and 5 mug/L DES. The lowest-observed-effect concentrations (LOEC) for chances of sex ratios, reproductive success and histology alteration of F-0 are 0.05 mug/L. In the offspring, transgenerational effects on egg hatching rate. egg fertilization and Vtg levels of juvenile individuals were not observed. However. survival of F, generation fry significantly declined. The analysis of sex steroid levels revealed a significant decrease of testosterone (T) in the whole body homogenates (WBH) of male progeny and somewhat elevation of estradiol (E-T) in the WBH of female offspring. These findings indicate that exposure to DES causes a variety of developmental, reproductive and transgenerational effects. (C) 2004 Elsevier B.V. All rights reserved.

PHYSICAL MODEL FOR SMALL SCALE SANDWAVES MIGRATION IN NORTH GULF OF SOUTH CHINA SEA

The aim of this paper is to investigate the mechanism of small scale sand-wave migration. According to the environmental characteristic of the north gulf of South China Sea, a quasi-3D mechanics model has been built for simulating the small scale sand wave migration. The calculation results are shown to be consistent with the observed data in the trough of sand ridge. Considering the effect of environmental actions and sand wave features, we develop an effective formula to predict sand-wave migration. It is indicated that the physical models should be used to predict the migration of the small scale sand-wave, which is rarely dominated by wave activity.

Ten Years of the Relative Risk Model and Regional Scale Ecological Risk Assessment

It has been 10 years since the publication of the relative risk model (RRM) for regional scale ecological risk assessment. The approach has since been used successfully for a variety of freshwater, marine, and terrestrial environments in North America, South America, and Australia. During this period the types of stressors have been expanded to include more than contaminants. Invasive species, habitat loss, stream alteration and blockage, temperature, change in land use, and climate have been incorporated into the assessments. Major developments in the RRM have included the extensive use of geographical information systems, uncertainty analysis using Monte Carlo techniques, and its application to retrospective assessments to determine causation. The future uses of the RRM include assessments for forestry and conservation management, an increasing use in invasive species evaluation, and in sustainability. Developments in risk communication, the use of Bayesian approaches, and in uncertainty analyses are on the horizon.

A data-model fusion approach for upscaling gross ecosystem productivity to the landscape scale based on remote sensing and flux footprint modelling

Chinese Academy of Sciences ; National Science Foundation of China [41071059]; National Key Technology R&D Program of China [2008BAK50B06-02]; National Basic Research Program of China [2010CB950900, 2010CB950704]; Natural Sciences and Engineering Research Council of Canada

A novel nanometer-scale "gold electrode-molecular wires-silver" junction: An efficient test bed for electrochemical investigation of electron transportation through molecular wires in self-assembled monolayers

A novel "gold electrode-molecular wires-silver" junction was facilely fabricated for electrochemical study on the electron transportation through molecular wires. Rapid electron transportation through this sandwich-like structure was indeed observed by cyclic voltammograms and ac impedance measurements. Since rather reproducible and reliable results are easily available by electrochemical techniques, it would be an efficient and reliable test bed for electrochemical investigation of charge transportation through molecular wires in self-assembled monolayers on electrodes.