Microplastic inclusion in birch tree roots.

In this pilot study, microplastic beads (5-50 µm) were tagged with fluorescent dye and introduced to the soil of potted Betula pendula Roth. (silver birch) saplings during the growing season. After five months, root samples were examined using fluorescence- and confocal laser scanning microscopy. This paper presents the first documented indication of the incorporation of microplastic into root tissues of woody plants and discusses the phytoremediation potential of birch in soil with microplastic contamination.

Towards Insect-Friendly Road Lighting-A Transdisciplinary Multi-Stakeholder Approach Involving Citizen Scientists.

(1) The project "Tatort Streetlight" implements an insect-friendly road light design in a four year before-after, control-impact (BACI) approach involving citizen scientists. It will broaden the stakeholder interests from solely anthropogenic perspectives to include the welfare of insects and ecosystems. Motivated by the detrimental impacts of road lighting systems on insects, the project aims to find solutions to reduce the insect attraction and habitat fragmentation resulting from roadway illumination. (2) The citizen science approach invites stakeholders to take part and join forces for the development of a sustainable and environmentally friendly road lighting solution. Here, we describe the project strategy, stakeholder participation and motivation, and how the effects of the alternative road luminaire and lighting design can be evaluated. (3) The study compares the changes in (a) insect behavior, (b) night sky brightness, and (c) stakeholder participation and awareness. For this purpose, different experimental areas and stakeholders in four communities in Germany are identified. (4) The project transfers knowledge of adverse effects of improperly managed road illumination and interacts with various stakeholders to develop a new road lighting system that will consider the well-being of street users, local residents, and insects.

Density functional theory study of the binding of glycine, proline, and hydroxyproline to the hydroxyapatite (0001) and (0110) surfaces.

In view of the importance of the hydroxyapatite/collagen composite of both natural bone tissue and in synthetic biomaterials, we have investigated the interaction of three constituent amino acids of the collagen matrix with two major hydroxyapatite surfaces. We have employed electronic structure techniques based on the density functional theory to study a range of different binding modes of the amino acids glycine, proline, and hydroxyproline at the hydroxyapatite (0001) and (0110) surfaces. We have performed full geometry optimizations of the hydroxyapatite surfaces with adsorbed amino acid molecules to obtain the optimum substrate/adsorbate structures and interaction energies. The calculations show that the amino acids are capable of forming multiple interactions with surface species, particularly if they can bridge between two surface calcium ions. The binding energies range from 290 kJ mol(-1) for glycine on the (0001) surface to 610 kJ mol(-1) for hydroxyproline on the (0110) surface. The large adsorption energies are due to a wide range of interactions between the adsorbate and surface, including proton transfer from the adsorbates to surface OH or PO(4) groups. Hydroxyproline binds most strongly to the surfaces, but all three amino acids should be good sites for the nucleation and growth of the hydroxyapatite (0110) surface at the collagen matrix.

The interaction of dolomite surfaces with metal impurities: a computer simulation study.

This study investigates the behaviour of selected, morphologically important surfaces of dolomite (CaMg(CO3)2), using computational modelling techniques. Interatomic potential methods have been used to examine impurity substitution at cationic sites in these surfaces. Environmentally prevalent cations were studied to this end, namely Ni2+, Co2+, Zn2+, Fe2+, Mn2+ and Cd2+, all of which are also found as end-member carbonate minerals. Solid-solution substitution was investigated and showed that Cd and Mn will substitute from their end-member carbonate phase at either dolomite cation site. Mn is found to preferentially substitute at Mg sites, in agreement with experimental findings. For Ni2+, Co2+ and Zn2+, the magnitude of substitution energies is approximately equal for all surfaces, with the exception of the (1014) surface. However, for the larger cations, a far greater disparity in substitution energies is observed. At a stepped surface, analogous substitutions were performed and it was found that substitution energies for all impurity cations were reduced, indicating that uptake is more viable during growth. The predominant surface, the (1014), was solvated with a monolayer of water in order to investigate the influence of hydration on substitution energetics. The addition of water changes the relative preference for substitution of the different cations. Under aqueous conditions, the substitution energy is determined by three competing factors, the relative importance of which cannot be predicted without this type of computational investigation.