Strengths and weaknesses of microarray approaches to detect Pseudo-nitzschia species in the field

The planktonic diatom genus Pseudo-nitzschia contains several genetically closely related species. Some of these can produce domoic acid, a potent neurotoxin. Thus, monitoring programs are needed to screen for the presence of these toxic species. Unfortunately, many are impossible to distinguish using light microscopy. Therefore, we assessed the applicability of microarray technology for detection of toxic and non-toxic Pseudo-nitzschia species in the Gulf of Naples (Mediterranean Sea). Here, 11 species have been detected, of which at least 5 are potentially toxic. A total of 49 genus- and species-specific DNA probes were designed in silico against the nuclear LSU and SSU rRNA of 19 species, and spotted on the microarray. The microarray was tested against total RNA of monoclonal cultures of eight species. Only three of the probes designed to be species-specific were indeed so within the limits of our experimental design. To assess the effectiveness of the microarray in detecting Pseudo-nitzschia species in environmental samples, we hybridized total RNA extracted from 11 seasonal plankton samples against microarray slides and compared the observed pattern with plankton counts in light microscopy and with expected hybridization patterns obtained with monoclonal cultures of the observed species. Presence of species in field samples generally resulted in signal patterns on the microarray as observed with RNA extracted from cultures of these species, but many a-specific signals appeared as well. Possible reasons for the numerous cross reactions are discussed. Calibration curves for Pseudo-nitzschia multistriata showed linear relationship between signal strength and cell number.     

The Use of Electrokinetics for Hazardous Waste Site Remediation

The Superfund Innovative Technology Evaluation (SITE) program was authorized as part of the 1986 amendments to the Superfund legislation. It represents a joint effort between U.S. EPA’s Office of Research and Development and Office of Solid Waste and Emergency Response. The program is designed to assist and encourage the development of waste treatment technologies that would contribute to more solutions to our hazardous waste problems.

Recently, EPA, through the SITE program, issued a work assignment to assess the “stateof- the-art” of electroklnetically enhanced contaminant removal from soils. Prior research efforts, both laboratory and field, have demonstrated that electroosmosis has the potential to be effective In facilitating the removal of certain types of hazardous wastes from soils. Particularly encouraging results have been achieved with inorganics in fine-grained soils where more traditional removal alternatives are less effective.

Although the results of various studies suggest that electrokinetics is a promising technology, further testing Is needed at both the laboratory and field levels to fully develop this technology for site remediation. A conceptual test program Is presented based on best available data which incorporates system design and operating parameters used in previous applications of this technology In the use of electrokinetics treatment as a remediation technique at hazardous waste sites.     

Long-term declines of European insectivorous bird populations and potential causes

Evidence of declines in insect populations has recently received considerable scientific and societal attention. However, the lack of long-term insect monitoring makes it difficult to assess whether declines are geographically widespread. By contrast, bird populations are well monitored and often used as indicators of environmental change. We compared the population trends of European insectivorous birds with those of other birds to assess whether patterns in bird population trends were consistent with declines of insects. We further examined whether declines were evident for insectivores with different habitats, foraging strata, and other ecological preferences. Bird population trends were estimated for Europe (1990–2015) and Denmark (1990–2016). On average, insectivores declined over the study period (13% across Europe and 28% in Denmark), whereas omnivores had stable populations. Seedeaters also declined (28% across Europe; 34% in Denmark), but this assessment was based on fewer species than for other groups. The effects of insectivory were stronger for farmland species (especially grassland species), for ground feeders, and for cold-adapted species. Insectivory was associated with long-distance migration, which was also linked to population declines. However, many insectivores had stable populations, especially habitat generalists. Our findings suggest that the decline of insectivores is primarily associated with agricultural intensification and loss of grassland habitat. The loss of both seed and insect specialists indicates an overall trend toward bird communities dominated by diet generalists.     

A proposed Multi Criteria Analysis decision support tool for international environmental policy issues: a pilot application to emissions control in the international aviation sector

Policy making at the level of international environmental problems appears to lack a transparent, multi criteria based, decision support ‘tool’. This is due mainly to the highly political, volatile, and contextual nature of issues at this level. The environmental problem of how to regulate emissions from international civil aviation due to their transboundary nature, and the participation of international and domestic players, makes it a ‘wicked’ international environmental problem where policy making has proved problematic. This problem has been used as the basis for developing and pilot testing a tool for contributing to international policymaking, the Multi Criteria Decision Support System (MCDSS). This tool is based on simplifying and integrating key components of Multi Criteria Analysis with a Decision Support System. A preliminary application of the tool explored three options for progressing the reduction of aviation emissions. Testing was based on the allocation of weights to environmental, social, economic and institutional categories, which were each then internally weighted to reflect key criteria in the policy process. Finally, likely performances of each option, against the criteria, were evaluated against Likert scale measures. The outputs from each of these steps were combined to generate a summed best policy option. Conclusions have been drawn and they indicate that the tool is potentially useful especially in the initial stages of policy development. The MCDSS is not an alternative to the international policy process, but rather complements, and makes explicit key tradeoffs in, that process.