Optimization of a monitoring network for sulfur dioxide

In this study, we develop and apply a methodology to reduce an existing monitoring network to find an optimal configuration of a smaller network. We use a criterion based on locally weighted regression with two different weight functions. The methodology is applied to the Dutch national SO2 network and offers the possibility to include different politically relevant options in the model by weight criteria. Because full enumeration of all monitoring networks is impossible, a combinatorial search algorithm is applied to find a (sub)optimal solution. If different (optimal) monitoring networks result from different criteria, then the best can be selected.     

First world-wide interlaboratory study on polybrominated diphenylethers (PBDEs)

The first world-wide interlaboratory study on PBDEs, organised between November 1999 and April 2000, involved five biological samples, two sediments and two standard solutions. These materials were sent to 26 participants in nine different countries. Results were returned from 18 laboratories. The results reported for BDE 47 were acceptable with a range of relative standard deviations (Rsd) of 17-40%. Results for the BDEs 99 (Rsd 25-77%), BDE 100 (Rsd 19-48%), 153 (Rsd 30-48%) and 154 (Rsd 25-43%) showed that a further improvement of these analyses is needed. The BDE 209 analysis is not under the control of the participating laboratories. The data reported for the biota samples were very variable and for the two sediments Rsd values of 48% and 78% were obtained. It is recommended that analysts pay more attention to the special requirements for the BDE 209 analysis such as avoiding exposure to intensive light and exposure for too long times to too high temperatures.     

Simple nomenclature for chlorinated camphenes and dihydrocamphenes from which structural information can be directly deduced

The systematic nomenclature for chlorinated camphenes and dihydrocamphenes is rather complicated and confusing. Therefore, a simple structure-related nomenclature is proposed for these compounds, which is based on the same logic as was recently used for the chlorinated bornanes, bomenes and bornadienes. Although final IUPAC rules for the systematic nomenclature for camphenes and dihydrocamphenes have not yet been presented, the present nomenclature can be used for retrieving the correct conformation without the help of extensive tables or computer programmes, and vice versa. When the final IUPAC rules will be presented, the present nomenclature can easily be adjusted, if necessary     

Inter‐organisational communication in civil–military cooperation during complex emergencies: a case study in Afghanistan1

This paper seeks to contribute to an improved information management and exchange between humanitarian organisations and military agents in complex emergencies. To do so, a theoretical information management process model was developed and applied to the case of information management between International Security Assistance Force troops and humanitarian organisations such as Cordaid, DACAAR and the International Office for Migration in Kabul, Afghanistan. Based on this analysis the main shortcomings and problems in each stage of the information management process were identified. These include a lack of structured information databases, the absence of identification of information needs, and an over‐classification of documents by the military. Using a logical framework analysis, six major improvement tactics were developed, including the creation of more overlap in rotations of personnel, the specification of aims and tasks regarding information management, the improvement of skills and competences of personnel involved, and the introduction of regular joint civil–military evaluations.     

A network approach to prioritize conservation efforts for migratory birds

Habitat loss can trigger migration network collapse by isolating migratory bird breeding grounds from nonbreeding grounds. Theoretically, habitat loss can have vastly different impacts depending on the site's importance within the migratory corridor. However, migration-network connectivity and the impacts of site loss are not completely understood. We used GPS tracking data on 4 bird species in the Asian flyways to construct migration networks and proposed a framework for assessing network connectivity for migratory species. We used a node-removal process to identify stopover sites with the highest impact on connectivity. In general, migration networks with fewer stopover sites were more vulnerable to habitat loss. Node removal in order from the highest to lowest degree of habitat loss yielded an increase of network resistance similar to random removal. In contrast, resistance increased more rapidly when removing nodes in order from the highest to lowest betweenness value (quantified by the number of shortest paths passing through the specific node). We quantified the risk of migration network collapse and identified crucial sites by first selecting sites with large contributions to network connectivity and then identifying which of those sites were likely to be removed from the network (i.e., sites with habitat loss). Among these crucial sites, 42% were not designated as protected areas. Setting priorities for site protection should account for a site's position in the migration network, rather than only site-specific characteristics. Our framework for assessing migration-network connectivity enables site prioritization for conservation of migratory species.     

Modeling Ethylene Bisdithiocarbamate Efficacy Potential in the Presence of a Zoospore Attractant

A common class of fungicides are the ethylene bisdithiocarbamates (EBDCs) which decompose into ethylene bis-isothiocyanate sulfide (EBIS). EBIS is the primary fungitoxic component which is effective on various life stages of oomycete fungi, including zoospores (primary infection agents of oomycete fungal diseases). It is hypothesized that increased fungicide effectiveness can occur if zoospores are attracted to the toxicant (site of fungicide deposition) through chemotaxis using zoospore attractants (ZAs). Several probe studies proved this hypothesis when a ZA was formulated with EBDC products. A highly effective zoospore attractant is isovaleraldehyde (IVA), but IVA is volatile and dissipates rapidly in the environment. Therefore, various precursors for IVA and EBIS were studied to characterize the transient production and decline of EBIS and IVA from precursor material. First-order kinetic material balances and a stochastic modeling tool are created to fully exploit the conditions when the overlap of EBIS and IVA is maximized. A metric is proposed (measure of the overlap of fungicide and ZA residue) as an indirect measure of the potential for preventative fungicide efficacy when ZAs are included within the formulation. Therefore, fungicide formulations containing a ZA can be designed through model deployment that considers the production and decline patterns of both the fungicide and ZA, and the daily environmental dew cycle responsible for achieving the maximum concentration overlap when zoospores are the most infectious (e.g., mobile in the presence of dew) for enhanced crop disease control. It is found that the poly-IVA produrg investigated provides the maximum overlap of EBIS and IVA residues for many different EBDC formulations investigated. This modeling approach, and the examples provided for EBIS and IVA material balances, can be expanded for different fungicides and ZAs allowing for cause/effect to be inferred from multiple interacting factors, and formulations can be designed for optimal release characteristics that maximize the overlap of fungitoxic material and zoospore attractant.     

Mediterranean alien harmful algal blooms: origins and impacts

Environmental Science and Pollution Research - Harmful algal blooms (HABs) are mostly phytoplankton blooms, which have detrimental environmental and socioeconomic impacts. The Mediterranean Sea due...