Time filter

Source Type

Horak P.,Institute of Ecology and Earth science | Sild E.,Institute of Ecology and Earth science | Sepp T.,Institute of Ecology and Earth science
Journal of Experimental Biology | Year: 2010

Carotenoid and melanin pigments in the plumage of birds are hypothesized to be sensitive to oxidative stress. We manipulated oxidative status of captive greenfinches (Carduelis chloris L.) by the administration of buthionine sulfoximine (BSO), a selective inhibitor of the synthesis of glutathione (GSH), an intracellular antioxidant. Half of the birds in the treated group, as well as in the control group, also received dietary carotenoid (lutein) supplementation. BSO treatment reduced erythrocyte GSH levels and caused oxidative damage as indicated by the increased concentration of plasma malondialdehyde (MDA), an end product of lipid peroxidation. BSO treatment also reduced the brightness (i.e. increased blackness) of the tips of tail feathers grown during the experiment. These results show that a low systemic GSH level is required for development of eumelanin plumage coloration and that such a low GSH level is also potentially dangerous for the organism. Carotenoid supplementation increased plasma carotenoid levels and chroma of the yellow parts of the feathers grown during the experiment. However, carotenoid supplementation did not reduce plasma MDA levels. Manipulation of GSH did not affect plasma carotenoids or carotenoid-based plumage coloration. These findings argue against the antioxidant function of lutein in vivo and carotenoid signaling of antioxidant status. © 2010. Published by The Company of Biologists Ltd.

Ehrlich U.,Tallinn University of Technology | Reimann M.,Tallinn University | Reimann M.,Institute of Ecology and Earth science
International Conference on Energy, Environment, Devices, Systems, Communications, Computers, EEDSCC'11 | Year: 2011

The article discusses the resource utilisation conflict at the example of Jagala Waterfall, which is the highest and greatest natural waterfall in Estonia. There are plans to build a hydro-power plant there, which would conduct most of the water past the waterfall to the power plant's turbines, reducing significantly the nature values of the waterfall. The authors carried out a contingent valuation (CV) study to identify the monetary equivalent of non-market values related with Jagala waterfall in the natural state.

Preusser F.,University of Stockholm | Muru M.,Institute of Ecology and Earth science | Rosentau A.,Institute of Ecology and Earth science
Geochronometria | Year: 2014

Different post-IR Infrared Stimulated Luminescence (IRSL) approaches are applied to sediments from a Holocene coastal foredune sequence on Ruhnu Island in the eastern Baltic Sea. The comparison of De-values and ages determined by the different approaches is complimented by fading and bleaching experiments. The fading experiments imply strong fading of IRSL (50°C) signals and no fading of any of the post-IR IRSL signals, but this is not confirmed by the determined De-values. In fact, post-IR IRSL (150°C) De-values agree within errors with those calculated for IRSL (50°C). From the bleaching experiments it is inferred that the higher values observed for post-IR IRSL at more elevated stimulation temperatures (225°C/290°C) are likely related to either thermal transfer and/or slow-to-bleach components within the signal. For the dating of the Holocene foredune sequence of Ruhnu Island, the post-IR IRSL (150°C) approach is preferred and these agree with the limited independent age control available from radiocarbon dating. Accordingly, the sequence formed between ca. 7.0 ka and 2.5 ka ago. © 2013, Versita Warsaw and Springer-Verlag Wien.

Loading Institute of Ecology and Earth science collaborators
Loading Institute of Ecology and Earth science collaborators