Complete discrepancy between abnormal fetal karyotypes predicted by QF-PCR rapid testing and karyotyped cultured cells in a first-trimester CVS

A chorion villus sample (CVS) biopsied at 11 weeks' gestation for raised nuchal translucency, revealed monosomy X (presumptive 45,X karyotype) by QF-PCR for rapid aneuploidy testing for chromosomes 13, 18, 21, X and Y. Long-term culture gave the karyotype: 47,XY,+ 21[66]/49,XYY,+ 21,+ 21 [22]. This discrepancy prompted redigestion of the combined residual villus fragments from the original QF-PCR assay. The repeat QF-PCR assay identified the presence of trisomy 21 and a Y chromosome consistent with a 47,XY,+ 21 karyotype. A double non-disjunction event early in embryogenesis in a 47,XY,+ 21 conceptus with subsequent cell lineage compartmentalisation of the three observed cell lines (45,X; 47,XY,+ 21 and 49,XYY,+ 21,+ 21) would account for these results. This is the first reported case to describe complete discrepancy at diagnosis between abnormal karyotypes detected by QF-PCR rapid aneuploidy testing and a cultured karyotype in the same CVS. Copyright © 2006 John Wiley & Sons, Ltd.     

How Stable are Public Responses to Changing Local Environments? A 'Before' and 'After' Case Study of River Restoration

This paper considers the stability of public responses to an urban river restoration scheme on the River Skerne, Darlington, UK, by comparing the results from surveys of local residents carried out before and after scheme implementation. This case study provides evidence of strong and generally consistent positive responses to the proposals and implemented scheme to return the straightened and channelized river to a more natural condition although support was more qualified after than before implementation. Although the scheme design and construction costs were high, nearly two-thirds regarded the scheme as value for money. Exploratory contingent valuation results on whether or not local residents were prepared to pay for the scheme were broadly stable over the two surveys.     

Fugacity models of indoor exposure to volatile chemicals

A method of calculating the atmospheric concentration of a volatile chemical in confined volumes is presented and illustrated which uses the fugacity concept to simplify the manipulation of the various transport and reaction terms. The method is particularly suitable for estimating exposure to chemicals which may be released by evaporation into a house, work place, or partially confined outdoor environment in which there are several volumes (eg. rooms) with known ventilation characteristics. Illustrative calculations are presented.     

Volatilization of contaminants from suspended sediment in a water column during dredging

Remedial dredging of contaminated bed sediments in rivers and lakes results in the suspension of sediment solids in the water column, which can potentially be a source for evaporation of hydrophobic organic compounds (HOCs) associated with the sediment solids. Laboratory experiments were conducted in an oscillating grid chamber to simulate the suspension of contaminated sediments and flux to air from the surface of the water column. A contaminated field sediment from Indiana Harbor Canal (IHC) and a laboratory-inoculated University Lake (UL) sediment, Baton Rouge, LA, were used in the experiments, where water and solids concentration and particle size distribution were measured in addition to contaminant fluxes to air. A transient model that takes into account contaminant desorption from sediment to water and evaporation from the water column was used to simulate water and sediment concentrations and air fluxes from the solids suspension. In experiments with both sediments, the total suspended solids (TSS) concentration and the average particle diameter of the suspended solids decreased with time. As expected, the evaporative losses were higher for compounds with higher vapor pressure and lower hydrophobicity. For the laboratory-inoculated sediment (UL), the water concentrations and air fluxes were high initially and decreased steadily implying that contaminant release to the water column from the suspended solids was rapid, followed by evaporative decay. For the field sediments (IHC), the fluxes and water concentrations increased initially and subsequently decreased steadily. This implied that the initial desorption to water was slow and that perhaps the presence of oil and grease and aging influenced the contaminant release. Comparison of the model and experimental data suggested that a realistic determination of the TSS concentration that can be input into the model was the most critical parameter for predicting air emission rates.     

Predicting Airborne Particle Levels Aboard Washington State School Buses

School buses contribute substantially to childhood air pollution exposures yet they are rarely quantified in epidemiology studies. This paper characterizes fine particulate matter (PM(2.5)) aboard school buses as part of a larger study examining the respiratory health impacts of emission-reducing retrofits.To assess onboard concentrations, continuous PM(2.5) data were collected during 85 trips aboard 43 school buses during normal driving routines, and aboard hybrid lead vehicles traveling in front of the monitored buses during 46 trips. Ordinary and partial least square regression models for PM(2.5) onboard buses were created with and without control for roadway concentrations, which were also modeled. Predictors examined included ambient PM(2.5) levels, ambient weather, and bus and route characteristics.Concentrations aboard school buses (21 mug/m(3)) were four and two-times higher than ambient and roadway levels, respectively. Differences in PM(2.5) levels between the buses and lead vehicles indicated an average of 7 mug/m(3) originating from the bus's own emission sources. While roadway concentrations were dominated by ambient PM(2.5), bus concentrations were influenced by bus age, diesel oxidative catalysts, and roadway concentrations. Cross validation confirmed the roadway models but the bus models were less robust.These results confirm that children are exposed to air pollution from the bus and other roadway traffic while riding school buses. In-cabin air pollution is higher than roadway concentrations and is likely influenced by bus characteristics.     

Glass sponges arrest pumping in response to sediment: implications for the physiology of the hexactinellid conduction system

The hexactinellid sponge Rhabdocalyptus dawsoni propagates electrical signals to arrest its feeding current in response to mechanical stimuli and sediment. The deepwater habitat of other species of glass sponge, and the difficulty of working with the tissue in vitro have so far prevented confirmation of electrical signaling in other members of the Class. Here we show in laboratory experiments (ex situ) that mechanical and sediment stimuli trigger immediate arrest in R. dawsoni and in a second species of hexactinellid, Aphrocallistes vastus, suggesting that rapid signaling may be a general feature of glass sponge tissue. Further, responses of the two species differed, suggestive of underlying physiological differences in the conduction system. R. dawsoni and A. vastus were sensitive to sediment but arrests were often prolonged in R. dawsoni, whereas in A. vastus pumping resumed immediately following each arrest. Fine sediment (<25 μm) caused immediate arrests in R. dawsoni and A. vastus, but with a higher stimulus threshold in A. vastus. Large amounts of sediment triggered repeated arrests in both species, and prolonged exposure to sediment (over 4 h) caused a gradual reduction in pumping, with recovery taking up to 25 h. During recovery, both species of sponge carried out repeated arrests, which had a precise periodicity indicative of pacemaker activity. Scanning electron microscopy of the tissue of these specimens showed many chambers were clogged. The results suggest that the glass sponge conduction system generates arrest of the feeding current that prevent uptake of small amounts of sediment, and that each species has different threshold sensitivities. However, ongoing exposure to sediment can clog the filtration apparatus.     

Habitat biodiversity as a determinant of fish community structure on coral reefs

Increased habitat diversity is often predicted to promote the diversity of animal communities because a greater variety of habitats increases the opportunities for species to specialize on different resources and coexist. Although positive correlations between the diversities of habitat and associated animals are often observed, the underlying mechanisms are only now starting to emerge, and none have been tested specifically in the marine environment. Scleractinian corals constitute the primary habitat-forming organisms on coral reefs and, as such, play an important role in structuring associated reef fish communities. Using the same field experimental design in two geographic localities differing in regional fish species composition, we tested the effects of coral species richness and composition on the diversity, abundance, and structure of the local fish community. Richness of coral species overall had a positive effect on fish species richness but had no effect on total fish abundance or evenness. At both localities, certain individual coral species supported similar levels of fish diversity and abundance as the high coral richness treatments, suggesting that particular coral species are disproportionately important in promoting high local fish diversity. Furthermore, in both localities, different microhabitats (coral species) supported very different fish communities, indicating that most reef fish species distinguish habitat at the level of coral species. Fish communities colonizing treatments of higher coral species richness represented a combination of those inhabiting the constituent coral species. These findings suggest that mechanisms underlying habitat-animal interaction in the terrestrial environment also apply to marine systems and highlight the importance of coral diversity to local fish diversity. The loss of particular key coral species is likely to have a disproportionate impact on the biodiversity of associated fish communities.     

Bridging the legitimacy gap—translating theory into practical signposts for legitimate flood risk governance

Legitimacy is widely regarded as a founding principle of ‘good’ and effective governance, yet despite intense academic debate and policy discourse, the concept remains conceptually confusing and poorly articulated in practice. To bridge this gap, this research performed an interpretive thematic analysis of academic scholarship across public administration, public policy, law, political science, and geography. Four core themes were identified in relation to representative deliberation, procedural and distributive equity and justice, and socio-political acceptability, with numerous sub-themes therein. In an attempt to clarify conceptual confusion, this paper grounds these theoretical debates in the context of flood risk governance where numerous legitimacy dilemmas exist. A number of questions are presented as conceptual ‘signposts’ to encourage reflexive governance in the future. Thus, more broadly, we assert the importance of bringing legitimacy to the forefront of contemporary flood risk governance discourse and practice, moving beyond the realm of academic reflection.

     

Social justice in the context of adaptation to climate change—reflecting on different policy approaches to distribute and allocate flood risk management

Regional Environmental Change -