A multi-objective optimization framework for surfactant-enhanced remediation of DNAPL contaminations

The occurrence of Dense Non-Aqueous Phase Liquid (DNAPL) contaminations in the subsurface is a threat for drinkwater resources in the western world. Surfactant-Enhanced Aquifer Remediation (SEAR) is widely considered as one of the most promising techniques to remediate DNAPL contaminations in-situ, be it with considerable additional costs compared to classical pump-and-treat remediations. A cost-effective design of the remediation set-up is therefore essential. In this work, a pilot SEAR test is executed at a DNAPL contaminated site in Belgium in order to collect data for the calibration of a multi-phase multi-component model. The calibrated model is used to assess a series of scenario-analyses for the full-scale remediation of the site. The remediation variables that were varied were the injection and extraction rate, the injection and extraction duration, and the surfactant injection concentrations. A constrained multi-objective optimization of the model was applied to obtain a Pareto set of optimal remediation strategies with different weights for the two objectives of the remediation: (i) the maximal removal of DNAPL and (ii) a total minimal cost. These Pareto curves can help decision makers to select an optimal remediation strategy in terms of cost and remediation efficiency. The Pareto front shows a considerable trade-off between the total remediation cost and the removed DNAPL mass.     

REST-Rossendorf expert system for surface and sorption thermodynamics

This paper presents a digitized version of a thermodynamic sorption database, implemented as a relational database with MS Access. It is mineral-specific and can therefore be used for additive models of complex solid phases such as rocks or soils. An integrated user interface helps users to access selected mineral and sorption data, to extract internally consistent data sets for sorption modeling, and to export them in formats suitable for other modeling software. Data records comprise mineral properties, specific surface area values, surface binding sites' characteristics, sorption ligand information, and surface complexation reactions. An extensive bibliography is included, providing links not only to the above listed data, but also to background information concerning surface complexation model theories, evidence for surface species, and sorption experimental techniques.     

Assessing risk and adaptation options to fires and windstorms in European forestry

Risks can generally be described as the combination of hazard, exposure and vulnerability. Using this framework, we evaluated the historical and future development of risk of fire and wind damage in European forestry at the national level. Fire risk is expected to increase, mainly as a consequence of an increase in fire hazard, defined as the Fire Weather Index in summer. Exposure, defined as forest area, is expected to increase slightly as a consequence of active afforestation and abandonment of marginal agricultural areas. Adaptation options to fire risk should therefore aim to decrease the vulnerability, where a change in tree species from conifers to broadleaves had most effect. Risk for wind damage in forests is expected to increase mainly as a consequence of increase in exposure (total growing stock) and vulnerability (defined by age class and tree species distribution). Projections of future wind climate indicate an increase in hazard (storminess) mainly over Western Europe. Adaptation options should aim to limit the increase in exposure and vulnerability. Only an increase in harvest level can stop the current build-up of growing stock, while at the same time it will lower vulnerability through the reduction of the share of old and vulnerable stands. Changing species from conifers to broadleaves helps to reduce vulnerability as well. Lowering vulnerability by decreasing the rotation length is only effective in combination with a high demand for wood. Due to data limitations, no forecast of future fire area or damaged timber amount by storms was possible.     

Molecular phylogeny and DNA barcoding of tropical eastern Pacific shallow-water gorgonian octocorals

The octocoral fauna inhabiting the shallow waters (<50 m) of the eastern Pacific has been the subject of renewed interest, and the taxonomy of the most important genera in the region has been reviewed and clarified. Many new species have been described, significantly increasing the known biological diversity of the region. Despite their importance as potential sister-groups of Caribbean octocorals, the phylogenetic relationships of eastern Pacific octocorals remain poorly studied. Here, using partial mitochondrial MutS and igr1-COI sequences, we provide a phylogenetic assessment of a broad sample of eastern Pacific shallow-water octocorals and investigate their phylogenetic relationships with Caribbean gorgonians. We corroborate the monophyly of Pacifigorgia, Leptogorgia and Eugorgia and provide evidence of a close relationship between Swiftia and Psammogorgia, currently placed in Plexauridae. In addition, the phylogenies obtained here provide insights into the historical biogeography and phylogenetic diversity of the eastern Pacific octocoral assemblages and on character evolution among this diverse faunal assemblage. Finally, we evaluate the classification power of DNA barcoding for identifying species of shallow-water eastern Pacific octocorals and assess the use of a nuclear intron (SRP54) to supplement traditional mitochondrial barcodes in this group of organisms.     

Evolution, radiation and chemotaxonomy of Lamellodysidea, a demosponge genus with anti-plasmodial metabolites

Sponges of the family Dysideidae (Dictyoceratida) are renowned for their diversity of secondary metabolites, and its genus Lamellodysidea, particularly Lamellodysidea herbacea, is the most studied taxon biochemically. Despite its importance, the taxonomic status of L. herbacea—whether it is a distinct species or a species complex—has never been assessed. Recent biochemical profiling revealed anti-plasmodial activity of brominated compounds in Lamellodysidea of the Pacific. Here, we present a comparative chemotaxonomic and molecular analysis of selected Dysideidae from the Pacific and the Indian Ocean (New Caledonia, Great Barrier Reef, Fiji, Mayotte, Guam, Palau). We investigated the phylogenetic relationships between the populations and assessed their bioactive (PBDE) compounds in order to unravel the taxonomic status of this commercially important group of sponges and assessed patterns of dispersal and biochemical variation. The molecular phylogeny was based on the internal transcribed ribosomal spacer and compared against a PBDE phylogeny for several specimens. Molecular data revealed a diversity of Indo-Pacific L. herbacea populations, also reflected by different PBDE compound profiles. Molecular and biochemical data also revealed a Lamellodysidea species new to science. Several specimens misidentified as Lamellodysidea were detected based on their position on different clades in the molecular phylogeny and their production of different halogenated compounds (brominated vs. chlorinated). The direct comparison of molecular and biochemical data also provided evidence for the occurrence of a host switch event and support for the theory that abiotic factors, such as sedimentation, affect the chemical constituents produced in L. herbacea.     

The concept of ecological debt: some steps towards an enriched sustainability paradigm

In this paper, we elaborate on the concept of ecological debt. Starting from the enriching environmental justice perspectives, this grass-roots concept has to offer to sustainability discourse, a broad conceptual discussion is presented resulting in a working definition for ecological debt. In elaborating on this definition, we try both to accommodate these enriching perspectives and to offer a more robust conceptualisation that is applicable in international sustainability discourse. Also, a scientifically sound methodology is presented which allows quantifying different aspects of ecological debt. Finally, both the conceptual analysis as well as the quantification method is applied to the case of climate change.     

Modelling the long-term soil response to atmospheric deposition at intensively monitored forest plots in Europe

The dynamic soil chemistry model SMART was applied to 121 intensive forest monitoring plots (mainly located in western and northern Europe) for which both element input (deposition) and element concentrations in the soil solution were available. After calibration of poorly known parameters, the model accurately simulated soil solution concentrations for most plots as indicated by goodness-of-fit measures, although some of the intra-annual variation especially in nitrate and aluminium concentrations could not be reproduced. Model evaluations of two emission-deposition scenarios (current legislation and maximum feasible reductions) for the period 1970-2030 show a strong reduction in sulphate concentrations between 1980 and 2000 in the soil due to the high reductions in sulphur emissions. However, current legislation hardly reduces future nitrogen concentrations, whereas maximum feasible reductions reduces them by more than half. Maximum feasible reductions are also more effective in increasing pH and reducing aluminium concentrations, mostly below ‘critical’ values.     

Die Regulation der Blutgerinnung

The patency of the vascular tree as well as thrombus formation are achieved by the interactions of several components of the circulating blood and the vessel wall. Circulating glycoproteins (coagulation factors), cellular elements of the blood (platelets), the fibrinolytic system, the endothelium of the vasculature and inhibitors that are present in the blood stream are involved in the maintainance of the subtle balance between anti-coagulant and pro-coagulant forces. Regulation of the activity of thrombin represents a key event in this process.