In order to reduce flood risk, river management policies advise floodplain restoration and the recreation of water retention areas. These measures may also offer opportunities for the restoration of speciesrich floodplain habitats through rewetting and the restoration of flood dynamics. The potential to enhance biodiversity in such flood restoration areas is, however, still subject to debate. In this paper we investigate whether flooding along a small altered lowland river can contribute to the potential and realised species richness of semi-natural meadows. We compare the seed bank and vegetation composition of flooded and non-flooded semi-natural meadows and test the hypothesis that flooding contributes to an input of diaspores into the meadow seed banks, thereby promoting seed density and potential species richness. Furthermore we hypothesise that, where habitat conditions are suitable, flooding leads to a higher realised species richness. Results showed that seed densities in flooded meadows were significantly higher than in non-flooded meadows. The seed banks of flooded meadows also contained a higher proportion of exclusively hydrochorous species. However, the seed bank species richness, as well as the species richness realised in the vegetation did not differ significantly between flooded and non-flooded meadows. Finally, the seed bank and standing vegetation of flooded sites showed larger differences in species composition and Ellenberg nitrogen distribution than non-flooded sites. From these results we conclude that, although flooding does contribute to the density and composition of the seed bank, most imported seeds belong to only a few species. Therefore, it is unlikely that flooding substantially enhances the potential species richness. Furthermore, even if new species are imported as seeds into the seed bank, it seems unlikely that they would be able to establish in the standing vegetation. However, it is unclear which factors impede the establishment of imported species in the vegetation. The implications of our findings for flood meadow restoration are discussed.

The tricarboxylate carrier has recently been purified from rat liver mitochondria by three distinct scientific groups using different methods. A 37-38-kDa protein has been prepared by silca gel 60 chromatography by our group (Claeys and Azzi, 1989; Glerum et al., 1990). The specific citrate transport activity of this preparation is not significantly different from that measured in mitochondria and it is inhibitable by 1,2,3-benzenetricarboxylic acid. Bisaccia et al. (1990) have reported the isolation of a 30-kDa protein by Celite 535 chromatography, and Kaplan's group (Kaplan et al., 1990) have isolated a 32.5-kDa protein by Matrex Orange, Matrex Blue, and Affi-Gel chromatography. Peptide mapping has failed to support any structural homologies between the 37-38-kDa and the 30-32.5-kD proteins. The 38-kD protein is N-terminally blocked. The peptides obtained by several cleavage procedures have been partially sequenced. Their sequence information has been used to obtain different cDNA clones by a dual approach, the polymerase chain reaction and screening of a lambda ZAP cDNA library. The largest cDNA which could be isolated is 2,986 bp in length and contains a 1071-bp-long open reading frame and an unusually long 3' untranslated region, both of which have been completely sequenced. The protein sequence of the carrier from the first in-frame methionine is 322 amino acids in length and exhibits a molecular mass of 35,546. Comparison of the protein sequence to the sequences of the four members of the mitochondrial carrier protein family (ADP/ATP carrier, phosphate carrier, 2-oxoglutarate/malate carrier, and uncoupling protein) does not reveal significant similarity (cf. Walker et al., 1987). A tripartite internal homology, which is a characteristic of these proteins, is not present in the sequence of the tricarboxylate carrier protein. The mRNA for the tricarboxylate carrier is expressed in rat liver and brain, but not in rat heart.

The tricarboxylate carrier from rat liver mitochondria has been purified and reconstituted into phospholipid vesicles. Its activity has been characterized by both a radioactive citrate uptake assay and a coupled enzymatic assay. A K , of 40 pM and a V,,, of 1.56 pmol x min-' x mg-' have been determined for the carrier. Cholesterol levels of between 5 -10% of total lipid content are shown to cause a decrease in carrier activity.The inner mitochondrial membrane contains a specific tricarboxylic acid transporter which catalyzes the electroneutral exchange (1 : 1) of a tricarboxylate [citrate, threo-D,(+)-isocitrate, cis-aconitate] for another tricarboxylate, a dicarboxylate (malate or succinate) or phosphoenolpyruvate [l]. This carrier takes part in several important metabolic processes including fatty acid and cholesterol biosynthesis, gluconeogenesis and the shuttling of reducing equivalent across the mitochondrial inner membrane [2].Recent evidence indicates that the tricarboxylate carrier plays an important role in rapidly growing tumour cells, which show a deregulated cholesterol biosynthesis [3]. These cells have an elevated cholesterol content in all cellular membranes, including the mitochondrial membranes. These cell lines have also been shown to have a much higher activity of the citrateisocitrate carrier. The consequence of this elevated activity is a net export of citrate (the carbon source for the synthesis of cholesterol) from mitochondria, and truncation of the Krebs cycle.The citrate carrier has recently been purified from several mammalian species. We isolated the carrier from bovine liver mitochondria using a silica gel 60 column. As judged from SDS/polyacrylamide gel electrophoresis, the purified carrier had a molecular mass of 37 kDa [4]. The tricarboxylate carrier from rat liver, as purified by Bisaccia et al., showed a molecular mass of 30 kDa [5]. Here, we present the purification of the citrate carrier from rat liver mitochondria, using a procedure similar to that used to purify the transporter from bovine liver. The carrier activity was identified after reconstitution of the protein into liposomes, both without and enriched in cholesterol, by measuring the radioactive exchange equilibrium. Activity was also measured by following the exchange of citrate for isocitrate in an indirect enzymatic assay [6]. MATERIALS AND METHODS MaterialsChemicals used for the isolation and reconstitution of the tricarboxylate carrier were obtained as described previouslyCorrespondence to A. Azzi, Institut fur Biochemie und Molekularbiologie, Universitat Bern, Biihlstrasse 28, CH-3012 Bern, Switzerland Abbreviations. PtdCho, phosphatidylcholine; PtdEtn, phosphatidylethanolamine.[4]. In addition, phophatidylcholine (PtdCho) and cholesterol were from Sigma and phosphatidylethanolamine (PtdEtn) from Avanti Polar lipids. The chemicals for the enzymatic assay (isocitrate, isocitrate dehydrogenase and NADP') were from Sigma.Isolation of the carrier Rat liver mitochondria were prepared according to Pedersen et al. [7...

Using airborne drones to monitor water quality in inland, transitional or coastal surface waters is an emerging research field. Airborne drones can fly under clouds at preferred times, capturing data at cm resolution, filling a significant gap between existing in situ, airborne and satellite remote sensing capabilities. Suitable drones and lightweight cameras are readily available on the market, whereas deriving water quality products from the captured image is not straightforward; vignetting effects, georeferencing, the dynamic nature and high light absorption efficiency of water, sun glint and sky glint effects require careful data processing. This paper presents the data processing workflow behind MapEO water, an end-to-end cloud-based solution that deals with the complexities of observing water surfaces and retrieves water-leaving reflectance and water quality products like turbidity and chlorophyll-a (Chl-a) concentration. MapEO water supports common camera types and performs a geometric and radiometric correction and subsequent conversion to reflectance and water quality products. This study shows validation results of water-leaving reflectance, turbidity and Chl-a maps derived using DJI Phantom 4 pro and MicaSense cameras for several lakes across Europe. Coefficients of determination values of 0.71 and 0.93 are obtained for turbidity and Chl-a, respectively. We conclude that airborne drone data has major potential to be embedded in operational monitoring programmes and can form useful links between satellite and in situ observations.

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