Ocean University of China

About: Ocean University of China is a education organization based out in Qingdao, China. It is known for research contribution in the topics: Population & Sea surface temperature. The organization has 27604 authors who have published 27886 publications receiving 440181 citations. The organization is also known as: Zhōngguó Hǎiyáng Dàxué & OUC.

Haemolysins in Vibrio species

Abstract: Many Vibrio species are pathogenic to humans, and/or marine vertebrates and invertebrates. The pathogenic species produce various virulence factors including enterotoxin, haemolysin, cytotoxin, protease, lipase, phospholipase, siderophore, adhesive factor and/or haemagglutinins. Haemolysin, which is an exotoxin that lyses erythrocyte membranes with the liberation of haemoglobin, is arguably the most widely distributed toxin among pathogenic vibrios and exerts various roles in the infection process. Haemolysins act on erythrocytes membranes thus lysing the cells which leads to the freeing up of the iron-binding proteins namely haemoglobin, transferrin and lactoferrin. This iron can then be picked up by various siderophores, and is subsequently taken up through receptors in the cell membrane. In many cases, the pore-forming activity of haemolysin is not restricted to erythrocytes, but extends to a wide range of other cell types including mast cells, neutrophils, and polymorphonuclear cells, and enhances virulence by causing tissue damage. There are four representative haemolysin families in Vibrio spp., including the TDH (thermostable direct haemolysin) family, the HlyA (E1 Tor haemolysin) family, the TLH (thermolabile haemolysin) family and the d-VPH (thermostable haemolysin) family. Some haemolysins, for example, TDH of Vibrio parahaemolyticus and HlyA of Vibrio cholerae have been studied extensively, and are closely associated with virulence. However, the role of some haemolysins, e.g. TLH and d-VPH are unclear, and await the outcome of further research. 2. INTRODUCTION

Nutrient budgets for large Chinese estuaries

Abstract: . Chinese rivers deliver about 5–10% of global freshwater input and 15–20% of the global continental sediment to the world ocean. We report the riverine fluxes and concentrations of major nutrients (nitrogen, phosphorus, and silicon) in the rivers of the contiguous landmass of China and Korea in the northeast Asia. The rivers are generally enriched with dissolved inorganic nitrogen (DIN) and depleted in dissolved inorganic phosphate (PO43−) with very high DIN: PO43− concentration ratios. DIN, phosphorus, and silicon levels and loads in rivers are mainly affected by agriculture activities and urbanization, anthropogenic activities and adsorption on particulates, and rock types, climate and physical denudation intensity, respectively. Nutrient transports by rivers in the summer are 3–4 times higher than those in the winter with the exception of NH4+. The flux of NH4+ is rather constant throughout the year due to the anthropogenic sources such as the sewer discharge. As nutrient composition has changed in the rivers, ecosystems in estuaries and coastal sea have also changed in recent decades. Among the changes, a shift of limiting nutrients from phosphorus to nitrogen for phytoplankton production with urbanization is noticeable and in some areas silicon becomes the limiting nutrient for diatom productivity. A simple steady-state mass-balance box model was employed to assess nutrient budgets in the estuaries. The major Chinese estuaries export