Arctic coralline algae elevate surface pH and carbonate in the dark

Red coralline algae are projected to be sensitive to ocean acidification, particularly in polar oceans. As important ecosystem engineers, their potential sensitivity has broad implications, and understanding their carbon acquisition mechanisms is necessary for making reliable predictions. Therefore, we investigated the localized carbonate chemistry at the surface of Arctic coralline algae using microsensors. We report for the first time carbonate ion concentration and pH measurements ([CO ]) at and above the algal surface in the microenvironment. We show that surface pH and [CO ] are higher than the bulk seawater in the light, and even after hours of darkness. We further show that three species of Arctic coralline algae have efficient carbon concentrating mechanisms including direct bicarbonate uptake and indirect bicarbonate use via a carbonic anhydrase enzyme. Our results suggest that Arctic corallines have strong biological control over their surface chemistry, where active calcification occurs, and that net dissolution in the dark does not occur. We suggest that the elevated pH and [CO ] in the dark could be explained by a high rate of light independent carbon fixation that reduces respiratory CO release. This mechanism could provide a potential adaptation to ocean acidification in Arctic coralline algae, which has important implications for future Arctic marine ecosystems

The existence region and composition of a polymer-induced liquid precursor phase for dl-glutamic acid crystals

The existence region of a polymer-induced liquid precursor (PILP) phase for crystals of an organic compound (DL-glutamic acid, Glu) was determined for the first time in the phase diagram of the Glu–polyethyleneimine–water–ethanol system. The existence region and the amount of PILP phase relative to the thermodynamically stable crystal phase were very small. Other phases detected in the phase diagram were coacervates, homogenous mixtures, and crystals obtained via a clear solution. The PILP phase is rich in the polymeric additive, which helps to explain the long induction period of PILP before crystallization occurs. Volume measurements indicated that its amount is {1 vol%, showing that this precursor phase is only a minor component

Improving nutrient and water use efficiency of IGNISCUM® – a new bioenergy crop

The new cultivars IGNISCUM Candy® and IGNISCUM Basic® of the Sakhalin Knotweed (Fallopia sachalinensis, Fam. Polygonaceae) are new bioenergy crops, which are characterized by a high annual biomass. The objectives of our study are to investigate (i) the water consumption; (ii) the interrelations between nutrient supply, biomass production, and transpiration; and (iii) the optimization of the biomass production

Multi-island single-electron devices from self-assembled colloidal nanocrystal chains

We report the fabrication of multi-island single-electron devices made by lithographic contacting of self-assembled alkanethiol-coated gold nanocrystals. The advantages of this method, which bridges the dimensional gap between lithographic and NC sizes, are (1) that all tunnel junctions are defined by self-assembly rather than lithography and (2) that the ratio of gate capacitance to total capacitance is high. The rich electronic behavior of a double-island device, measured at 4.2 K, is predicted in detail by combining finite element and Monte Carlo simulations with the standard theory of Coulomb blockade with very few adjustable parameters.Comment: 4 page

Effects of nitrogen and phosphate fertilization on leaf nutrient content, photosynthesis, and growth of the novel bioenergy crop <i>Fallopia sachalinensis</i> cv. ‘Igniscum Candy‘

The aim of the study was to determine the effects of nitrogen and phosphate fertilization on the growth performance of the novel bioenergy crop Fallopia sachalliensis cv. ‘Igniscum Candy’ (Polygonaceae). In a controlled pot experiment various nitrogen (0, 50, 150, 300 kg N ha-1) and phosphate (20, 40, 80 kg P ha-1) fertilizer amounts were applied to measure the effect on the biomass, height, leaf area and nitrogen and phosphate use efficiency. Furthermore, ecophysiological processes (chlorophyll content, chlorophyll fluorescence, gas exchange) were measured with non-destructive methods. The application of nitrogen correlated positively with biomass production, while phosphate fertilization did not show a significant effect on plant growth or ecophysiological parameters. The leaf nitrogen contents were significantly correlated with the nitrogen applications, while the leaf phosphate contents did not show a correlation with the P fertilizations, but increased with the leaf nitrogen contents. A significant linear correlation between the measured SPAD values and chlorophyll contents as well as with the leaf nitrogen contents could be determined. Under the influence of the nitrogen fertilization, net photosynthesis increased from 3.7 to 6.6 μmol m-2 s-1. The results of this experiment demonstrated that nitrogen fertilization has an overall positive correlation with leaf nutrient content, photosynthesis, and overall growth of the bioenergy crop Fallopia sachalinensis var. Igniscum Candy