Assessing PAH and PCB emissions from the relocation of harbour sediments using equilibrium passive samplers

Large-scale dredging of contaminated sediments is taking place in the harbor of Oslo, Norway. The dredged sediment masses are transferred into a confined aquatic disposal facility (CAD) in a natural 70-m deep basin within the Oslofjord. Currently there is no established method to determine how much dissolved contaminants are released during relocation and deposition of these sediments. For this reason we tested the use of equilibrium passive samplers consisting of 55 microm thin polyoxymethylene (POM-55) for studying the release of freely dissolved and thus bioavailable PAHs and PCBs at the disposal site, and found this to be a suitable method. In order to use POM-55 for monitoring PCBs, it was necessary to measure their POM-55/water partition coefficients, which was also presented as part of this study. Elevated turbidity (average 4.1 mg l(-1)) was observed at one side of the basin where no natural sill exists. Analysis of POM-55 at this location before and after deposition revealed that there was an increase in freely dissolved concentrations (C(W,free)) during deposition by a factor 37.5 for PAHs and a factor of 2.9 for PCBs. In addition, during deposition phenanthrene-to-anthracene aqueous concentration ratios at this location (values of 3-4) were more similar to those of the deposited sediments (approximately 2) than to those of the CAD water prior to deposition (approximately 14). This was not observed for the other locations where a natural sill exists at approximately 30 m water depth. The POM-55 equilibrium passive samplers are here shown to be useful tools for measuring and understanding the dynamics involved in the release of dissolved contaminants during sediment relocation.     

Land cover dynamics in the Simien Mountains (Ethiopia), half a century after establishment of the National Park

Regional Environmental Change - The Simien Mountains house several endangered and endemic wildlife species and provide important ecosystem services. Despite its regional environmental importance,...     

Effects of preference heterogeneity among landowners on spatial conservation prioritization

The participation of private landowners in conservation is crucial to efficient biodiversity conservation. This is especially the case in settings where the share of private ownership is large and the economic costs associated with land acquisition are high. We used probit regression analysis and historical participation data to examine the likelihood of participation of Danish forest owners in a voluntary conservation program. We used the results to spatially predict the likelihood of participation of all forest owners in Denmark. We merged spatial data on the presence of forest, cadastral information on participation contracts, and individual‐level socioeconomic information about the forest owners and their households. We included predicted participation in a probability model for species survival. Uninformed and informed (included land owner characteristics) models were then incorporated into a spatial prioritization for conservation of unmanaged forests. The choice models are based on sociodemographic data on the entire population of Danish forest owners and historical data on their participation in conservation schemes. Inclusion in the model of information on private landowners’ willingness to supply land for conservation yielded at intermediate budget levels up to 30% more expected species coverage than the uninformed prioritization scheme. Our landowner‐choice model provides an example of moving toward more implementable conservation planning.     

A Shift Toward Building with Nature in the Dredging and Port Development Industries: Managerial Implications for Projects in or Near Natura 2000 Areas

Building with Nature is a new approach to designing water infrastructure, one that seeks to realize socioeconomic project goals in harmony with the environment. The Dutch dredging industry is promoting its application in the Netherlands, but similar concepts are emerging internationally. The Working with Nature concept has been developed under the auspices of the World Association for Waterborne Transport Infrastructure, Engineering with Nature by the US Army Corps of Engineers, and Flanders Bays 2100 by a group of Belgian dredging companies and international consultants. The research discussed in this article focuses on the feasibility of implementing the Building with Nature approach in the context of EU Natura 2000 governance. The initial expectation of the industry was that Natura 2000 regulations would obstruct innovative Building with Nature attempts. The empirical evidence points to a shift toward Building with Nature have taken place on the governance and project levels, and the goals of Natura 2000 and Building with Nature converging in practice. Using specific project-level variables identified by researchers, guidance for project development in Natura 2000 areas was proposed. We conclude by discussing the implications of the research results for the dredging industry dealing with Natura 2000 regulations in Europe and similar overarching nature regulations elsewhere.     

Pregnancy outcome after transcervical cvs with a flexible biopsy forceps: Evaluation of risk factors

The pregnancy outcome of 1936 women who had transcervical chorionic villus sampling (CVS) with a flexible biopsy forceps was evaluated. Follow-up until 4 weeks after delivery was 99.4 per cent. Various patient- and procedure-related risk factors for spontaneous loss (fetal or neonatal death) were analysed using stepwise logistic regression analysis. The overall spontaneous loss rate was 4.5 per cent. Factors found to be significantly associated with spontaneous loss were quantity of villi ≤ 15 mg (relative risk (RR) 2.13), a history of first-trimester miscarriage (RR 1.87) or delivery between 16 and 27 weeks (RR 3.87), cervical culture positive for anaerobes (RR 4.52) or group B streptococcus (RR 3.62), post-procedural bleeding >3 days (RR 1.99), and multiple insertions (RR 2.64). Significant differences in loss rates between individual operators were found. A learning effect was not present. There were no infants born with terminal transversal limb anomalies in our series.     

Model consideration for the origin of life

In an attempt to understand the origin of living systems we encounter the following problems: How can we conceive the origin of the first self-reproducing forms, and by means of what stimuli could a constant increase in the complexity of such forms commence? How can a translation apparatus for genetic information develop? One cannot that such an apparatus for the synthesis of enzymes can function alone without the interference of enzymes themselves, which, however, could only become available after the construction of the apparatus itself. What stimulus mechanism is conceivable that leads to the division of the genetic apparatus into a replication system, and an enzyme-synthesis system?The main problem therefore, is not the search for basic theoretical concepts. It is not a question which can be answered by means of specific experiments. One should rather explore the principal possibilities of how molecules combine to produce more and more complicated functional units. We look for the fundamental structural changes in the organizational systems and the driving forces initiating these developments. Questions concerning the detailed chemical realization are of secondary importance. In trying to solve the puzzle of how the genetic apparatus is gradually built up as complex aggregates of molecules, we consider a consistent causal chain of simple and transparent physicochemical model steps.