장광현 교수

The expression of inducible nitric oxide synthase (iNOS) is a critical factor in both normal physiological functions and the pathogenesis of disease. This study was undertaken to determine the molecular mechanism by which nitric oxide (NO) exerts negative feedback regulation on iNOS gene expression. Isolated rat hepatocytes stimulated with cytokines exhibited a marked increase in NO production as well as iNOS mRNA and protein levels, which were significantly reduced by pretreatment of the NO don

SUMMARY 1. We analysed the vulnerability of a number of cladoceran species ( Bosmina longirostris , B. fatalis , Diaphanosoma brachyurum , Ceriodaphnia reticulata , Daphnia ambigua and D. pulex ) to predation by Mesocyclops leuckarti in the laboratory. 2. The prey species represented a wide range of body size, morphology, and swimming behaviour. To compare vulnerability, we measured the efficiency of capture and ingestion of each prey species by Mesocyclops . We also measured the rate at which p

The seasonal succession and cyclomorphosis of Bosmina longirostris and Bosmina fatalis (also known as Sinobosmina fatalis) were investigated in the shallow eutrophic Lake Suwa from 1996 to 1999. Two different invertebrate predators, cyclopoid copepods and Leptodora kindtii, co-existed with Bosmina in the lake. A pattern of seasonal succession of the two species was apparent, with B. fatalis dominant in summer and B. longirostris in spring and fall. The two species also showed different seasonal

Spatial distribution and the diet composition of Asplanchna species were studied in 18 water bodies in Matsuyama, Japan. The abundance of Asplanchna and other rotifers, crustaceans, phytoplankton and microbial plankton, together with basic environmental parameters, were determined between October and December 2006, and the distribution and diet composition of Asplanchna species were estimated. Three species of Asplanchna, A. herricki, A. priodonta and A. girodi were found in the present study, b

Abstract Predation by cyclopoid copepods is an important factor affecting zooplankton communities in freshwater habitats. Experiments provide strong evidence of the role of selective predation by cyclopoid copepods in structuring zooplankton communities. To assess the predation impact of a cyclopoid copepod, Mesocyclops pehpeiensis , we conducted a mesocosm experiment using 20‐l polyethylene tanks in which the density of the predator and the food available to herbivorous zooplankton varied. M. p

Summary 1. We assessed the impact of predation by the invertebrate predator Leptodora kindtii on Bosmina longirostris and B. fatalis , which show seasonal and reciprocal succession patterns in Lake Suwa, in a mesocosm experiment using 20‐L tanks with or without the predator under different food conditions. We also analysed morphological responses of the two Bosmina species to the predator in the tanks. 2. Bosmina fatalis dominated B. longirostris regardless of predator presence under high food d

ABSTRACT We examined the feeding habit of pond smelt (Hypomesus transpacificus nipponesis) and its impact on the zooplankton community in Lake Suwa, Japan, from May to December 2001. Stomach contents were analyzed, and prey importance and the prey selectivity index were estimated from the stomach contents of fish and prey density in the lake. Results showed that herbivorous zooplankters the cladoceran Bosmina fatalis and the calanoid copepod Eodiaptomus jaonicus were the most important prey item

For the sustainable use of lake ecosystem services—water resources, aquatic habitats for biodiversity conservation, and aesthetic values as waterfront space—ecosystem health assessments using biota are implemented as important national environmental monitoring projects. Zooplankton play a key role as an important linkage in the material circulation as secondary producers in lake ecosystems. At the same time, they influence the composition and biomass of other communities through biological inter

Saemangeum Reservoir in South Korea is an estuarine system enclosed by a dyke construction, where seawater inflow and retained water outflow are managed by the opening/closing of sluice gates installed in the southern part of the dyke. An exchange of the reservoir water can cause spatiotemporal fluctuations in the salinity and trophic state, which are major drivers determining variation in the composition of biological communities in estuarine systems. Here, we investigated the seasonal and spat