Numerical Simulation of Nutrient and Phytoplankton Dynamics in Guangxi Coastal Bays, China

The increasing riverine pollutants have resulted in nutrient enrichment and deterioration of water quality in the coastal water of Guangxi Province, China. However, the quantitative relationship between nutrient loads and water quality responses, which is crucial for developing eutrophication control strategies, is not well studied. In this study, the riverine fluxes of nutrients were quantified and integrated with nutrient cycling and phytoplankton dynamics by using box models for Guangxi coastal bays. The model concepts and biogeochemical equations were the same; while most model parameters were specific for each bay. The parameters were calibrated with seasonal observations during 2006–2007, and validated with yearly averaged measurements in 2009. The general features of nutrient and phytoplankton dynamics were reproduced, and the models were proved feasible under a wide range of bay conditions. Dissolved inorganic nitrogen was depleted during the spring algal bloom in Zhenzhu Bay and Fangcheng Bay with relatively less nutrient inputs. Phosphorus concentration was high in spring, which decreased then due to continuous phytoplankton consumption. Chlorophyll-a concentration reached its annual maximum in summer, but was the minimum in winter. Eutrophication was characterized by both an increase in nutrient concentrations and phytoplankton biomass in Lianzhou Bay. Either about 80% reduction of nitrogen or 70% reduction of phosphorus was required to control the algal bloom in Lianzhou Bay. Defects of the models were discussed and suggestions to the environmental protection of Guangxi coastal bays were proposed.

NUMERICAL SIMULATION OF THE IMPACT OF LATENT HEAT FLUX ANOMALY IN THE TROPICAL WESTERN PACIFIC ON PRECIPITATION OVER SOUTH CHINA IN JUNES

Based on composite analysis and numerical simulations using a regional climate model(RegCM3), this paper analyzed the impact of the LHF anomaly in the tropical western Pacific on the precipitation over the south of China in June. The results are as follows.(1) Correlation analysis shows that the SC precipitation in June is negatively correlated with the LHF of the tropical western Pacific in May and June, especially in May. The SC precipitation in June appears to negatively correlate with low-level relative vorticity in the abnormal area of LHF in the tropical western Pacific.(2) The LHF anomaly in the tropical western Pacific is a vital factor affecting the flood and drought of SC in June. A conceptual model goes like this: When the LHF in the tropical western Pacific is abnormally increased(decreased), an anomalous cyclone(anticyclone) circulation is formed at the low-level troposphere to its northwest. As a result, an anomalous northeast(southwest) air flow affects the south of China, being disadvantageous(advantageous) to the transportation of water vapor to the region. Meanwhile, there is an anomalous anticyclone(cyclone) at the low-level troposphere and an anomalous cyclone(anticyclone) circulation at the high-level troposphere in the region, which is advantageous for downdraft(updraft) there. Therefore a virtual circulation forms updraft(downdraft) in the anomalous area of LHF and downdraft(updraft) in the south of China, which finally leads to the drought(flood) in the region.

Review of Maritime Transportation Air Emission Pollution and Policy Analysis

The study of air emission in maritime transportation is new, and the recognition of its importance has been rising in the recent decade. The emissions of CO2, SO2, NO2 and particulate matters from maritime transportation have contributed to climate change and environmental degradation. Scientifically, analysts still have controversies regarding how to calculate the emissions and how to choose the baseline and methodologies. Three methods are generally used, namely the 'bottom up' approach, the 'top down' approach and the STEEM, which produce very different results, leading to various papers with great uncertainties. This, in turn, results in great difficulties to policy makers who attempt to regulate the emissions. A recent technique, the STEEM, is intended to combine the former two methods to reduce their drawbacks. However, the regulations based on its results may increase the costs of shipping companies and cause the competitiveness of the port states and coastal states. Quite a few papers have focused on this area and provided another fresh perspective for the air emission to be incorporated in maritime transportation regulations; these facts deserve more attention. This paper is to review the literature on the debates over air emission calculation, with particular attention given to the STEEM and the refined estimation methods. It also reviews related literature on the economic analysis of maritime transportation emission regulations, and provides an insight into such analysis. At the end of this paper, based on a review and analysis of previous literature, we conclude with the policy indications in the future and work that should be done. As the related regulations in maritime transportation emissions are still at their beginning stage in China, this paper provides specific suggestions on how China should regulate emissions in the maritime transportation sector.

Identification of a Long-Chain Fatty Acid Elongase from Nannochloropsis sp. Involved in the Biosynthesis of Fatty Acids by Heterologous Expression in Saccharomyces cerevisiae

The marine microalga Nannochloropsis sp.contains various elongases and desaturases that are critical for biosynthesis of polyunsaturated fatty acids.A full-length cDNA encoding a long-chain fatty acid elongase,named Ns FAE,was cloned from Nannochloropsis sp..The open reading frame of Ns FAE(GenBank accession no.MF680548)consisted of 1068 bp and encoded a predicted protein of 355 amino acids with molecular mass 38.8 k Da.The deduced polypeptide showed 43%–44%identity to fatty acyl elongases from other algae.RT-PCR experiments indicated that the Ns FAE gene exhibited the highest expression in Nannochloropsis sp.at 72 h(i.e.,during the third growth stage)and the expression was significantly lower in the other four growth stages.Plasmid p Ns FAE-CRISPR and a recombinant DNA fragment(ADH1p-Ns FAE-CYCt)were transformed into Saccharomyces cerevisiae strain BY4742 using the CRISPR-Cas system.Yeast transformants containing Ns FAE produced three fatty acids not normally present in wild-type BY4742-linoleic acid,linolenic acid and eicosadienoic acid-indicating that Ns FAE encodes a functional elongase enzyme.

Surface-Related Multiple Elimination on High-Resolution Geopulse Profile

A geopulse seismic system was implemented to obtain new information on underlying strata beneath the Yellow River Delta. However, owing to the shpping of sea floor and shallow water （ 〈 25 m）, free surface-related multiples are conflicted with the flat primaries, which may instruct the interpreters in a wrong way and make wrong conclusions. Owing to the variation of multiple periods, standard anti-multiple techniques may lose their power, such as predictive deconvolution. Surface-related multiple elimination methods are introduced to attenuate the multiples based on the underlying waveequation principles. The results justified the method on the single-channel geopulse profile, revealing the real nature of the subsurface.

Topographic features around Zhongshan Station,southeast of Prydz Bay

Considering the complex topographic features of the southeast of Prydz Bay where China's Zhongshan Station is located,three types of geomorphologic units can be identified,i.e., submarine slopes,canyons,and terrains.The major topographic features in the study area are the submarine canyon and trough system outside the calving ice front of Dalk Glacier.A 3.8 km×80 m fissure is found on the submarine terrain at Zhongshan Anchorage,which,once triggered by geological hazards such as earthquakes and ice falls,would be a threat to the usage and maintenance of the anchorage.

EVOLUTION OF MOIST POTENTIAL VORTICITY DURING A WARM-ZONE HEAVY RAINFALL EVENT IN THE PEARL RIVER DELTA

First,based on routine meteorological data,the synoptic characteristics of a heavy warm-sector rainfall that occurred on June 13,2008 in the Pearl River Delta were analyzed.Second,a mesoscale numerical model,Weather Research and Forecasting(WRFV2.2),was used to simulate the heavy rainfall. Diagnostic analyses were done of moist potential vorticity(MPV)for its horizontal components(MPV2) and vertical components(MPV1)based on the simulation results of WRFV2.2 to identify the mechanism of the rainfall development.The results showed that the heavy rainfall occurred when there were high MPV1 in the upper levels and low MPV1 and high MPV2 in the lower levels.Disturbances of high MPV1 in the upper levels came from the southwest or northwest,those of low MPV1 in the lower levels came from the southwest,and those of high MPV2 came from the south.Disturbances of low MPV1 at low levels were the direct cause of convective instability.Enhanced vertical shear of meridional wind led to increased MPV2 at lower levels,strengthened baroclinicity,and active warm and wet flows.These distributions of MPV helped to trigger the release of unstable energy and produce warm-sector heavy rainfall.As it integrates the evolution of dynamic and thermal fields,MPV is able to reveal the development of this heavy rainfall effectively.

Cloning and expression of prion protein encoding gene of flounder (Paralichthys olivaceus)

The prion protein (PrP) encoding gene of flounder (Paralichthys olivaceus) was cloned. It was not interrupted by an intron. This gene has two promoters in its 5' upstream, indicating that its transcription may be intensive, and should have an important function. It was expressed in all 14 tissues tested, demonstrating that it is a house-keeping gene. Its expression in digestion and reproduction systems implies that the possible prions of fish may transfer horizontally.

ESTABLISHMENT OF THE OCEAN DYNAMIC SYSTEM WITH FOUR SUB-SYSTEMS AND THE DERIVATION OF THEIR GOVERNING EQUATION SETS

Based on their differences in physical characteristics and time-space scales,the ocean motions have been divided into four types in the present paper：turbulence,wave-like motion,eddy-like motion and circulation.Applying the three-fold Reynolds averages to the governing equations with Boussinesq approximation,with the averages defined on the former three sub-systems,we derive the governing equation sets of the four sub-systems and refer to their sum as ＂the ocean dynamic system＂.In these equation sets,the interactions among different motions appear in two forms：the first one includes advection transport and shear instability generation of larger scale motions,and the second one is the mixing induced by smaller scale motions in the form of transport flux residue.The governing equation sets are the basis of analytical/numerical descriptions of various ocean processes.

Pharmacophore modeling and virtual screening for the discovery of new fatty acid amide hydrolase inhibitors

A predictive pharmacophore model has been generated from a series of diverse fatty acid amide hydrolase(FAAH)inhibitors and the optimal pharmacophore model applied in virtual screening.The pharmacophore model was based on a training set of 21 compounds carefully selected from the published literatures.The optimal model Hypo-1 included four features(two hydrogen-bond acceptor units,one aromatic hydrophobic unit and one aromatic ring unit)and two excluded volumes.Cross-validation of the model confirmed that Hypo-1 was not generated by chance correlation.A large test set of 55 compounds showed that Hypo-1 performed well in classifying highly active and less active FAAH inhibitors.Superimposition analysis of the FAAH X-ray crystal structure and the pharmacophore Hypo-1 further validated the adequacy of the model.Virtual screening generated a total of 976 hits from the Zinc Natural Products database,a hit rate of 1.04%and enrichment of 83.89.The acceptable hit rate further supports the use of Hypo-1 as a 3D query tool for virtual screening.

风暴在长江三角洲侵蚀和沉积物向南输运中的控制作用

Densely populated coasts are vulnerable to storm damage. Episodic storm-induced redistribution of coastal sediment is known to have major geological and ecological implications [1,2], but little is known about storm-driven delta erosion and longshore sediment transport. The Yangtze (Changjiang) Delta and Zhejiang–Fujian coasts (Fig. S1 online) are among the world’s largest coastal depositional systems, and play an important role in supporting China’s socioeconomic development [3,4].