Aircraft and road traffic noise exposure and children's mental health

There have been few studies examining noise and psychological disorders in children and the results are equivocal. The objective of this study was to examine exposure–effect relationships between aircraft and road traffic noise exposure and children's mental health. We conducted a cross-national, cross-sectional study assessing 2844 pupils, aged 9–10, from 89 schools around three major airports in the Netherlands, Spain and United Kingdom matched within country for socio-economic position. We selected children on the basis of exposure to external aircraft and road traffic noise exposure. The Strengths and Difficulties Questionnaire (SDQ) assessed child mental health, including emotional problems, conduct disorder, hyperactivity, peer problems and prosocial behaviour. Aircraft noise exposure was significantly associated with an increased score on the hyperactivity subscale (pooled B estimate 0.013 CI 0.007–0.019) after full adjustment. Road traffic noise was significantly associated with lower scores on the conduct problems subscale maintained after full adjustment (pooled B estimate 0.010 95%CI −0.020 to −0.001). There was no association between either aircraft or road traffic noise exposure and the SDQ total score. The hyperactivity results have been found in a previous UK study and may indicate that high aircraft noise exposure exacerbates hyperactivity symptoms in children although this finding requires further replication.     

Child restraint use and parental perceptions of comfort

Objective: Suboptimal child restraint use includes incorrect and/or inappropriate restraint use and increases the risk of injury. Comfort has been suggested as an important factor impacting on optimal use of restraints by children. This article aims to examine the relationships between parent reported comfort and restraint misuse and age-appropriate restraint choice.

Methods: This is an analysis of data from a cross sectional observation study of child restraint use in New South Wales. Logistic regression was used to model the relationship between parent-reported comfort and restraint misuse and age-appropriate restraint choice.

Results: There was no significant relationship between either parent-reported comfort and restraint misuse or parent-reported comfort and age-appropriate restraint choice.

Conclusions: Parent perceptions of comfort of children in child restraints do not appear to be associated with incorrect child restraint use or age appropriate restraint choice. It is possible that the actual comfort of the child may be related to incorrect use but this remains to be tested. Further investigation of the relationship between parent-perceived comfort and the actual comfort of the child, as well as the impact of child comfort on optimal child restraint use is warranted.     

An integrated climate change assessment for the Northeast United States

The papers in this Special Issue are the primary technical underpinnings for the Northeast Climate Impacts Assessment (NECIA), an integrated regional-scale assessment of projected climate change, impacts and options for mitigation and adaptation across the US Northeast. The consequences of future pathways of greenhouse gas emissions on projected climate and impacts across climate-sensitive sectors is assessed by using downscaled projections from three global climate models under both higher (Alfi) and lower (B1) emissions scenarios. The findings illustrate that near-term reductions in emissions can greatly reduce the extent and severity of regionally important impacts on natural and managed ecosystems and public health in the latter half of this century, and increase the feasibility that those impacts which are now unavoidable can be successfully managed through adaptation.     

The infrabuccal pellet piles of fungus-growing ants

Fungus-growing ants (Attini) live in an obligate mutualism with the fungi they cultivate for food. Because of the obligate nature of this relationship, the success of the ants is directly dependent on their ability to grow healthy fungus gardens. Attine ants have evolved complex disease management strategies to reduce their gardens exposure to potential parasitic microbes, to prevent the establishment of infection in their gardens, and to remove infected garden sections. The infrabuccal pocket, a filtering device located in the oral cavity of all ants, is an integral part of the mechanisms that leaf-cutter ants use to prevent the invasion and spread of general microbial parasites and the specific fungal-garden parasite Escovopsis. Fungus-growing ants carefully groom their garden, collecting general debris and pathogenic spores of Escovopsis in their infrabuccal pocket, the contents of which are later expelled in dump chambers inside the nest or externally. In this study we examined how a phylogenetically diverse collection of attine ants treat their infrabuccal pellets. Unlike leaf-cutters that deposit their infrabuccal pellets directly in refuse piles, ants of the more basal attine lineages stack their infrabuccal pellets in piles located close to their gardens, and a separate caste of workers is devoted to the construction, management, and eventual disposal of these piles.     

Global Warming and the Species Richness of Bats in Texas

General circulation models provide predictions for global climate under scenarios of increased atmospheric CO₂. Climate change is expected to lead directly to changes in distributions of vegetation associations. Distribution of animals will also change to the extent that animals rely on vegetation for food or shelter. Bat species in Texas appear to be restricted, in part, by the availability of roosts. We used geographic information systems and the Holdridge vegetation-climate association scheme to model the effect of climate change on bat distributions and species richness in Texas. Habitat characteristics for each species were identified from the literature and included vegetation, topography, and availability of caves. We assumed caves and topography to be fixed relative to climate. Vegetation changes were predicted from the Holdridge vegetation-climate association scheme. The redistribution of bats following climate change was predicted based on the new locations of suitable habitat characteristics. Under conditions of global warming tropical forests were predicted to expand into Texas; tree-roosting bats were sensitive to this change in vegetation. Cavity-roosting bats were less affected by changes in vegetation, but, where response was predicted, ranges decline.     

Social grouping and maternal behaviour in feral horses (<Emphasis Type="Italic">Equus caballus</Emphasis>): the influence of males on maternal protectiveness

The risk of infant injury or mortality influences maternal behaviour, particularly protectiveness. Mares are found in bands with a single stallion or bands with more than one stallion in which paternity is less certain. We investigated maternal behaviour in relation to band type. Mares in bands with more than one stallion were more protective of their foals, particularly when stallions and foals approached one another. The rate of aggression between the stallion and foal was a significant predictor of maternal protectiveness, and mare protectiveness was significantly correlated with reduced reproductive success in the subsequent year. Mares that changed band types with a foal at foot, or had their band type experimentally altered, were more protective of their foal in multi-stallion bands than they were in single-stallion bands. Equids are unusual amongst ungulates in that infanticide and feticide have been reported. Both occur where paternity has been uncertain, and equid social structure is similar to other species in which infanticide has been reported. Stallions benefit from infanticide as the mare has greater reproductive success in the subsequent year. Stallion aggression is a significant modifier of mare behaviour and maternal effort, probably due to the risk of infanticide.     

Alternative Non-market Value-Elicitation Methods: Are the Underlying Preferences the Same?

We advocate a more formal structural approach for comparing WTP for non-market or pre-test-market goods conveyed by fundamentally different preference elicitation mechanisms. Seven independent samples of respondents were asked to value the identical good. Elicitation methods include one actual purchase and six widely used hypothetical choice formats. Using a common underlying indirect utility function (and stochastic structure) allows data for different elicitation methods to be used independently, compared pair-wise (as in much of the earlier literature) or pooled across all samples in one unified model with heteroscedasticity across elicitation methods. Our differences in estimated WTP for the individual models are typical of earlier findings. However, pooled-data models that allow for heteroscedasticity reveal that while there are substantial differences in the amount of noise in the different samples, a common underlying systematic component of the preference structure cannot be rejected for at least four (and possibly five) of these seven elicitation methods.