Bird distributions relative to remotely sensed habitats in Great Britain: towards a framework for national modelling

This paper develops a comprehensive and objective picture of bird distributions relative to habitats across Britain. Bird species presence/absence data from an extensive field survey and habitat data from the remotely sensed UK Land Cover Map 2000 were analysed in 36,920 tetrads (2 kmx2 km) across Britain (a 65% sample of Britain's c. 240,000 km2). Cluster analysis linked birds to generalised landscapes based on distinctive habitat assemblages. Maps of the clusters showed strong regional patterns associated with the habitat assemblages. Cluster centroid coordinates for each bird species and each habitat were combined across clusters to derive individualised bird-habitat preference indices and examine the importance of individual habitats for each bird species. Even rare species and scarce habitats showed successful linkages. Results were assessed against published accounts of bird-habitat relations. Objective corroboration strongly supported the associations. Relatively scarce coastal and wetland habitats proved particularly important for many birds. However, extensive arable farmland and woodland habitats were also favoured by many species, despite reported declines in bird numbers in these habitats. The fact that habitat-specialists do not or cannot move habitat is perhaps a reason for declining numbers where habitats have become unsuitable. This study showed that there are unifying principles determining bird-habitat relations which apply and can be quantified at the national scale, and which corroborate and complement the cumulative knowledge of many and varied surveys and ecological studies. This 'generality' suggests that we may be able, reliably and objectively, to integrate and scale up such disparate studies to the national scale, using this generalised framework. It also suggests the potential for a landscape ecology approach to bird-habitat analyses. Such developments will be important steps in building models to develop and test the sustainable management of landscapes for birds.     

Road safe seniors: Screening for age-related driving disorders in inpatient and outpatient settings

Introduction

Older drivers are increasing in number and they often have health conditions that place them at high risk for motor-vehicle crashes (MVC). Screening is underutilized, and is rarely done in hospital settings.

Methods

A convenience sample of 755 older adults completed age related driving disorders screening at University of California, San Diego inpatient and outpatient health centers. Screening included three strength/frailty tests, two vision tests (acuity and fields), and two cognitive tests, based on AMA recommendations. The average age of participants was 72.5; 55.5% were male and 94% English-speaking; 17.8% of older adults failed at least one aspect of screening.

Results

In multivariate analysis, significant associations of failed status were age, male sex, selfrestrictions of driving, and inpatient screening locations. The screening identified one in six adults to be 'high-risk' for age related driving disorders. Screening was effective and feasible in both inpatient and outpatient settings.

Impact on industry

As the driving population ages, industry, government and health car providers need to plan for the management of driving impairments in older adults.     

A dynamic transmission model of eastern equine encephalitis virus

Eastern equine encephalitis virus (EEEV) is one of several arthropod-borne viruses (arboviruses) endemic to the United States. Interactions between arthropod (mosquito) vectors and avian amplification host populations play a significant role in the dynamics of arboviral transmission. Recent data have suggested the hypothesis that an increased rate of successful feeding on young-of-the-year (YOY) birds might play a role in the dynamics of EEEV transmission. To test this hypothesis, we developed a model to explore the effect of the interactions of the vectors and avian host populations on EEEV transmission. Sensitivity analyses conducted using this model revealed eleven parameters that were capable of disproportionately affecting the predicted level of EEEV infection in the vertebrate reservoir and vector populations. Of these, four parameters were related to the interaction of the vector with young-of-the-year birds. Furthermore, adult birds could not substitute for young-of-the-year in initiating and maintaining a predicted enzootic outbreak of EEEV. Taken together, the model predicted that young-of-the-year birds play a key role in establishing and maintaining enzootic outbreaks of EEEV.     

Relationships between exposure to polyhalogenated aromatic hydrocarbons and organochlorine pesticides and the risk for developing type 2 diabetes: a systematic review and a meta-analysis of exposures to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)

A systematic review was performed to evaluate the association between environmental exposures to polyhalogenated aromatic hydrocarbons (PHAHs) and organochlorine (OC) pesticides and the risk for type 2 diabetes (T2D). Searches of EMbase, Google Scholar, Medline, and Scopus were performed. Reports were included if they were original human studies whose design included a control group and if the sample size was larger than 10 participants per group. The articles were excluded if the type of diabetes was unknown or Type 1. Odds ratios (OR), 95% confidence intervals (CI), and modified Naranjo scores for the effects of environmental contaminants were determined for each study. Of the 35 eligible studies, six were included in the meta-analysis; these focused specifically on 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Meta-analysis of these studies showed no significant increased OR for the development of T2D from exposure to TCDD. However, subgroup analysis showed significant elevated OR for the development of T2D if exposure is repeated and accompanied by exposure to other persistent pesticides (OR?=?1.48; 1.10–1.90) but a decreased odds for T2D with exposure resulting from accidental exposure (OR?=?0.46; 0.39–0.52). Our results suggest that there are significant risks of developing T2D in populations with recurring exposures to TCDD in concert with other persistent chlorinated pesticides. A mean Naranjo score of 2.0 was determined for all 35 articles; this score was 2.5 when examining only TCDD studies and 2.1 when examining studies that looked only at T2D. Each of these Naranjo scores suggests a possible association between the prevalence of T2D and exposure to PHAHs or OC pesticides.     

Suburbanization and drought: A mixed methods vulnerability assessment in rainy Massachusetts

This paper presents evidence that water restrictions in suburbanizing eastern Massachusetts towns are becoming more common, controlling for climate. We then assess the relationship between these suburban droughts and residential development. Focusing on the suburbs of Boston, seven towns independent of the Boston water supply system were selected to represent differing levels of sprawl-style growth. Water restrictions are becoming more frequent in all of the towns studied, and models demonstrate that restrictions are increasing in duration, independent of climate. Interviews suggest that residential development is playing a central role in this increasing sensitivity to suburban drought, though other factors are also important. Long-term planning and integration of land-use planning and water management emerged as two key paths for attenuating the impacts of development.     

Symbiont shuffling during thermal bleaching and recovery in the sea anemone Entacmaea quadricolor

The sea anemone Entacmaea quadricolor simultaneously harbours multiple symbiont types from the genus Symbiodinium, while providing essential habitat for anemonefish. This anemone lives close to its upper thermal threshold and experiences bleaching under elevated temperature and light stress. Here, we determine whether E. quadricolor experienced a shuffling in the abundance of two genetically distinct symbiont types (Symbiodinium C25 and C3.25) during bleaching and recovery. Anemones were exposed to control (22.9 °C) or elevated temperature (28.5 °C) for 42 days, whereas for the following 75 days, all anemones were exposed to 22.9 °C. By day 47, a more pronounced bleaching occurred via symbiont expulsion in the elevated temperature treatment than the control, and the proportion of C25 to C25 + C3.25 increased by 6.2 and 13.2 % in the control and bleached anemones, respectively. The increased relative abundance of C25 to C3.25 after exposure to thermal stress may indicate that C3.25 performs poorly when temperature is elevated. Although no significant recovery in symbiont density was detected, a revival of the C3.25 genotype was found at day 117, which may indicate that it is either more competitive or has qualities that are beneficial to the symbiosis when thermal stress is no longer apparent. This work demonstrates the potential for this anemone species to shuffle its symbiont types in response to environmental change and could provide resilience during times of stress.     

Simulation-based optimization of in-stream structures design: rock vanes

We employ a three-dimensional coupled hydro-morphodynamic model, the Virtual Flow Simulator (VFS-Geophysics) in its Unsteady Reynolds Averaged Navier–Stokes mode closed with \(k-\omega\) model, to simulate the turbulent flow and sediment transport in large-scale sand and gravel bed waterways under prototype and live-bed conditions. The simulation results are used to carry out systematic numerical experiments to develop design guidelines for rock vane structures. The numerical model is based on the Curvilinear Immersed Boundary approach to simulate flow and sediment transport processes in arbitrarily complex rivers with embedded rock structures. Three validation test cases are conducted to examine the capability of the model in capturing turbulent flow and sediment transport in channels with mobile-bed. Transport of sediment materials is handled using the Exner equation coupled with a transport equation for suspended load. Two representative meandering rivers, with gravel and sand beds, respectively, are selected to serve as the virtual test-bed for developing design guidelines for rock vane structures. The characteristics of these rivers are selected based on available field data. Initially guided by existing design guidelines, we consider numerous arrangements of rock vane structures computationally to identify optimal structure design and placement characteristics for a given river system.