RESUMEN
Anthropogenic activities have altered the geomorphological and ecological conditions of the Nakdong River Estuary (NRE) dramatically over the last century. The objectives of this study were to classify NRE sub-environments and to identify their unique ecological functions. The first step in classification was the establishment of 14 a priori sub-environmental groups based on landscape factors. Surface sediments obtained for these groups were analyzed for factors related to grain size and organic matter. Based on the results, the NRE was divided into two primary estuarine environment divisions: (1) a mixed marine and terrestrial environment influenced primarily by land; and (2) a principally marine environment influenced primarily by the ocean. Using multivariate analysis, we subdivided these primary estuarine divisions into six sub-environments, including Sub-1 and -2 in the former and Sub-3, -4, -5, and -6 in the latter.
Asunto(s)
Estuarios , Sedimentos Geológicos/análisis , Ecología , Ecosistema , Análisis Multivariante , República de Corea , RíosRESUMEN
Tidal current survey as well as geochemical and benthic foraminiferal analyses of sediment cores were conducted in an abalone farm and a Zostera bed to understand the degree to which the abalone farm facilities installed along a channel in a shallow sea affect the benthic environment and ecology. In the abalone farm, Ammonia beccarii-Pseudoparrella naraensis-Elphidium somaense-Rosalina globularis-Trochammina hadai and P. naraensis-E. somaense-A. beccarii-T. hadai assemblages appeared owing to an increase in the total nitrogen content from the biodeposits. The Zostera bed consisted of A. beccarii-P. naraensis-Buccella frigida-T. hadai assemblage owing to the gradual expansion of a brackish shallow-water environment by the rapidly decreasing current speed, and it may have flourished. Moreover, the total sulfur, Zn, Cr, and Cu contents in the sediments decreased remarkably more than those of the pre-abalone farming did, caused by the vigorous activity of Zostera marina physiology.
Asunto(s)
Acuicultura , Foraminíferos/química , Zosteraceae , Animales , Bahías , Monitoreo del Ambiente , Sedimentos Geológicos/química , República de Corea , Agua de Mar/química , Contaminantes Químicos del AguaRESUMEN
We describe synthesis and evaluation of a series of cyclic urea derivatives with hydroxylethylamine isostere. Modification of P3, P1, and P2' and combination of SAR display a >100-fold increase in potency with good cellular activity (IC(50)=0.15microM) relative to the previously reported compound 3.