Diuron (DCMU; 3-(3,4-dichlorophenyl)-1,1-dimethylurea) concentrations were analyzed at 24 sites along shorelines of Ishigaki and Iriomote Islands in September 2019. The diuron ranged from <0.6 to 32 ng l-1. Slightly high as 19 l-1 observed a fishing port mooring point for boats Ishigaki, respectively, implying contamination likely antifouling paints boats. A slightly concentration (14 l-1) was ...

Mercury methylation and demethylation rates were measured in periphyton biofilms growing on submerged plants from a shallow fluvial lake located along the St. Lawrence River (Quebec, Canada). Incubations were performed in situ within macrophytes beds using low-level spikes of (199)HgO and Me(200)Hg stable isotopes as tracers. To determine which microbial guilds are playing a role in these proce...

Fragments of thalli of the liverwort, Sphaerocarpos donnellii Aust., inoculated into liquid medium containing sucrose and mineral salts, attain a much greater dry weight after 9 days growth in continuous white light than in darkness. Light causes this difference by increasing the rate of growth of the plants. This growth response is mediated by the pigment systems of photosynthesis and phytochr...

The position and interaction of cytochrome b with the electron transport chain in green plant photosynthesis has remained obscure. Levine et al. (13) and Levine and Gorman (12) first demonstrated the presence of cytochrome b. in the photosynthetic electron transport chain. Their results (12, 13), showing that photosystem II reduced cytochrome b, but that it was oxidized by PS I' in a DCMU-insen...

Frank Terjung and Karlheinz M aier Department of physics, Carl von Ossietzky-University Oldenburg, D-26111 Oldenburg, Germany Z. Naturforsch. 53c, 27-32 (1998); received October 9/October 31, 1997 Delayed Fluorescence, Energy Quenching, Pisum sativum , Xanthophyll Cycle Delayed chlorophyll fluorescence decay measurements on the second time scale were ap­ plied to investigate the state of photos...

The mechanism whereby light effects polyphenol oxidation was examined with Vicia faba chloroplast membranes known to contain a bound latent polyphenol oxidase. Results obtained with the inhibitors 3-(3',4'-dichlorophenyl)-1,1-dimethylurea (DCMU) and 2,5-dibromo-3-methyl-6-idopropyl-p-benzoquinone (DBMIB) indicated an involvement of the non-cyclic electron transport pathway in the light-dependen...