Publications by authors named "Ding-Ding Shao"

This is the first study to investigate the rate of mercury (Hg) biomagnification in the aquaculture pond ecosystem of the Pearl River Delta (PRD), China, by analyzing total mercury (THg) and methyl mercury (MeHg) concentrations in various species of fish at different trophic levels (TLs). Species representing a gradient of trophic positions in the aquaculture pond food chains were chosen for analyzing THg and MeHg concentrations. In this study, there were two kinds of the aquaculture pond food chains: (1) omnivorous (fish feeds, zooplankton, grass carp [Ctenopharyngodon idellus], and bighead carp [Aristichthys nobilis]) and (2) predatory (zooplankton, mud carp [Cirrhina molitorella], and mandarin fish [Siniperca kneri]).

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To study the influence of mariculture on mercury (Hg) speciation and distribution in sediments and cultured fish around Hong Kong and adjacent mainland China waters, sediment samples were collected from six mariculture sites and the corresponding reference sites, 200-300 m away from the mariculture sites. Mariculture activities increased total mercury, organic matter, carbon, nitrogen and sulfur concentrations in the surface sediments underneath mariculture sites, possibly due to the accumulation of unconsumed fish feed and fish excretion. However, methylmercury (MeHg) concentrations and the ratio of MeHg to THg (% MeHg) in sediments underneath mariculture sites were lower than the corresponding reference sites.

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Surface and core sediments collected from six fish farms in Hong Kong and from reference sites were investigated for the enrichment and sources of polycyclic aromatic hydrocarbons (PAHs). Moderately high SigmaPAH16 levels (123-947 ng g(-1), mean: 450 ng g(-1)) were found in the surface aquaculture sediments. In comparison with the sediments from the reference sites, the average enrichment percentage of total organic carbon (TOC) and PAHs in surface sediments were 21.

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Article Synopsis
  • - The study investigated the levels and sources of polycyclic aromatic hydrocarbons (PAHs) in sediment samples from fifteen freshwater fishponds and six mariculture rafts in the Pearl River Delta, revealing total PAH concentrations from 52.7 to 717 ng g(-1), with an average of 184 ng g(-1).
  • - Marine sediments had significantly higher PAH levels, particularly high molecular weight and carcinogenic PAHs, compared to freshwater sediments.
  • - Principal component analysis showed that PAHs in freshwater sediments mainly came from the combustion of coal, wood, and vehicle emissions, while vehicle emissions and coal combustion were predominant sources in marine sediments.
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Objective: To clone and express a homologue of human macrophage migration inhibitory factor (MIF) from P. falciparum 3D7--PfMIF.

Methods: The nucleotide sequence of PfMIF was found through blast P.

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Developing a polyepitope vaccine which contains diverse antigenic types is a promising strategy to cope with the problem of malaria variation and diversity. However, arranging the peptides to produce the most effective immunogenicity remains a hurdle. In an attempt to develop an effective complex antigenic gene vaccine, we constructed a polyepitope library by randomly assembling epitopes using the epitope shuffling technique.

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