Evaluation of the performance of different atmospheric chemical transport models and inter-comparison of nitrogen and sulphur deposition estimates for the UK

An evaluation has been made of a number of contrasting atmospheric chemical transport models, of varying complexity, applied to estimate sulphur and nitrogen deposition in the UK. The models were evaluated by comparison with annually averaged measurements of gas, aerosol and precipitation concentrations from the national monitoring networks. The models were evaluated in relation to performance criteria. They were generally able to satisfy a criterion of ‘fitness for purpose’ that at least 50% of modelled concentrations should be within a factor of two of measured values. The second criterion, that the magnitude of the normalised mean bias should be less than 20%, was not always satisfied. Considering known uncertainties in measurement techniques, this criterion may be too strict. Overall, simpler models were able to give a good representation of measured gas concentrations whilst the use of dynamic meteorology, and complex photo-chemical reactions resulted in a generally better representation of measured aerosol and precipitation concentrations by more complex models. The models were compared graphically by plotting maps and cross-country transects of wet and dry deposition as well as calculating budgets of total wet and dry deposition to the UK for sulphur, oxidised nitrogen and reduced nitrogen. The total deposition to the UK varied by ±22–36% amongst the different models depending on the deposition component. At a local scale estimates of both dry and wet deposition for individual 5 km × 5 km model grid squares were found to vary between the different models by up to a factor of 4.This work was funded by the Department for the Environment, Food and Rural Affairs. Additional support was provided by the Joint Environmental Program, the Natural Environment Research Council and the Environment Agency.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.atmosenv.2015.08.00

Exploring psychological need satisfaction from gambling participation and the moderating influence of game preferences

Psychological needs are satisfied through leisure participation, which in turn influences subjective well-being. The present study explored the psychological needs reported to be satisfied through gambling participation and examined associations between need satisfaction, game preferences and subjective well-being. A heterogeneous, self-selected sample of 1446 participants was recruited, through the Internet gambling provider Kindred Group Plc, for an online questionnaire survey. Five psychological need dimensions of gambling were identified, using exploratory and confirmatory factor analyses on calibration and validation samples, respectively: mastery, detachment, self-affirmation, risk and excitement, and affiliation. Challenge and mastery need satisfaction was higher for poker than for sports betting, horse racing, slots or casino table games; both self-affirmation and affiliation were also higher for poker than for sports betting and slots. By comparison, detachment was higher for slots than for sports gambling. While there were no significant variations in stress levels between the different forms of gambling, happiness ratings were lower for slots compared with sports betting and poker. This study provides insight into how distinctive patterns of play may satisfy different psychological needs and provides preliminary insights into how gambling patterns may prove adaptive or maladaptive as leisure choices

A review of the occurrence of inter‐colony segregation of seabird foraging areas and the implications for marine environmental impact assessment

Understanding the determinants of species’ distributions is a fundamental aim in ecology and a prerequisite for conservation but is particularly challenging in the marine environment. Advances in bio‐logging technology have resulted in a rapid increase in studies of seabird movement and distribution in recent years. Multi‐colony studies examining the effects of intra‐ and inter‐colony competition on distribution have found that several species exhibit inter‐colony segregation of foraging areas, rather than overlapping distributions. These findings are timely given the increasing rate of human exploitation of marine resources and the need to make robust assessments of likely impacts of proposed marine developments on biodiversity. Here we review the occurrence of foraging area segregation reported by published tracking studies in relation to the density‐dependent hinterland (DDH) model, which predicts that segregation occurs in response to inter‐colony competition, itself a function of colony size, distance from the colony and prey distribution. We found that inter‐colony foraging area segregation occurred in 79% of 39 studies. The frequency of occurrence was similar across the four seabird orders for which data were available, and included species with both smaller (10–100 km) and larger (100–1000 km) foraging ranges. Many predictions of the DDH model were confirmed, with examples of segregation in response to high levels of inter‐colony competition related to colony size and proximity, and enclosed landform restricting the extent of available habitat. Moreover, as predicted by the DDH model, inter‐colony overlap tended to occur where birds aggregated in highly productive areas, often remote from all colonies. The apparent prevalence of inter‐colony foraging segregation has important implications for assessment of impacts of marine development on protected seabird colonies. If a development area is accessible from multiple colonies, it may impact those colonies much more asymmetrically than previously supposed. Current impact assessment approaches that do not consider spatial inter‐colony segregation will therefore be subject to error. We recommend the collection of tracking data from multiple colonies and modelling of inter‐colony interactions to predict colony‐specific distributions

An investigation of the role of microsomal oxidative metabolism in the in vivo genotoxicity of 1,2-dichloroethane

In vitro studies have demonstrated that two different metabolic pathways, glutathione conjugation mediated by the glutathione S-transferases and microsomal oxidation, may be involved in the genotoxicity and carcinogenicity of 1,2-dichloroethane (DCE). To evaluate the importance of microsomal oxidative metabolism in the bioactivation of DCE in vivo, male B6C3F1 mice were pretreated with piperonyl butoxide (PIB), an inhibitor of microsomal oxidative metabolism, and the effect of this pretreatment on the extent of hepatic DNA damage produced by DCE was determined 4 hr after DCE administration. The in vivo genotoxicity of 2-chloroethanol, a product of the microsomal oxidative metabolism of DCE, was also investigated. Hepatic DNA damage was measured with a sensitive, alkaline DNA unwinding assay for the presence of single-strand breaks and alkali-labile lesions in DNA. Pretreatment of mice with PIB to inhibit microsomal oxidative metabolism significantly potentiated the hepatic DNA damage observed 4 hr after aa single, 200-mg/kg, ip dose of DCE. Treatment of mice with single, ip doses of 2-chloroethanol as high as 1.2 mmol/kg failed to produce any evidence of single-strand breaks and/or alkali-labile lesions in hepatic DNA. When diethyl maleate (DEM) was used to deplete hepatic glutathione levels prior to administration of 2-chloroethanol, the acute hepatotoxicity of 2-chloroethanol was potentiated but again there was no evidence of hepatic DNA damage. These results indicate that microsomal, oxidative metabolism of DCE to 2-chloroethanol and/or 2 chloroacetaldehyde is not responsible for the hepatic DNA damage observed in these studies after DCE administration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25803/1/0000366.pd