Minimum viable metapopulation size, extinction debt, and the conservation of a declining species.

A key question facing conservation biologists is whether declines in species' distributions are keeping pace with landscape change, or whether current distributions overestimate probabilities of future persistence. We use metapopulations of the marsh fritillary butterfly Euphydryas aurinia in the United Kingdom as a model system to test for extinction debt in a declining species. We derive parameters for a metapopulation model (incidence function model, IFM) using information from a 625-km2 landscape where habitat patch occupancy, colonization, and extinction rates for E. aurinia depend on patch connectivity, area, and quality. We then show that habitat networks in six extant metapopulations in 16-km2 squares were larger, had longer modeled persistence times (using IFM), and higher metapopulation capacity (lambdaM) than six extinct metapopulations. However, there was a > 99% chance that one or more of the six extant metapopulations would go extinct in 100 years in the absence of further habitat loss. For 11 out of 12 networks, minimum areas of habitat needed for 95% persistence of metapopulation simulations after 100 years ranged from 80 to 142 ha (approximately 5-9% of land area), depending on the spatial location of habitat. The area of habitat exceeded the estimated minimum viable metapopulation size (MVM) in only two of the six extant metapopulations, and even then by only 20%. The remaining four extant networks were expected to suffer extinction in 15-126 years. MVM was consistently estimated as approximately 5% of land area based on a sensitivity analysis of IFM parameters and was reduced only marginally (to approximately 4%) by modeling the potential impact of long-distance colonization over wider landscapes. The results suggest a widespread extinction debt among extant metapopulations of a declining species, necessitating conservation management or reserve designation even in apparent strongholds. For threatened species, metapopulation modeling is a potential means to identify landscapes near to extinction thresholds, to which conservation measures can be targeted for the best chance of success.     

The criminalization of human error in aviation and healthcare: A review

This review explores the social causes and psychological and organizational consequences of the criminalization of human error in aviation and healthcare. Increasing prevalence of criminal prosecution is seen as a threat to the health and safety of employees and entire safety–critical systems in many industries, but initiatives to counter or mitigate the trend are local and haphazard. Social causes such as a greater societal risk consciousness and intolerance of failure are examined, as well as organizational consequences for disclosure and incident reporting. Psychological consequences of the criminalization of human error are evaluated in terms of employee ill-health, an area that is under-investigated. The criminalization of professional mistakes seems to be an increasingly prevalent phenomenon at the intersection of safety work, sociology, criminology and legal as well as social justice. This paper reviews possible research directions into the criminalization of professional mistake in aviation and healthcare, in the hope of stimulating debate and eventually legitimating it as a topic of study in its own right.     

EQUILIBRIUM AND TRANSIENT GLOBAL WARMING SCENARIO IMPLICATIONS FOR WATER RESOURCES IN WALES1

ABSTRACT: A methodology has been developed to predict the responses of a range of water supply sources in Wales to global warming scenarios. Hydrologically effective rainfall is predicted from temperature and precipitation for each season based on site specific formulae developed using the Meteorological Office Rainfall and Evaporation Calculation System (MORECS) and UK Surface Water Archive databases. Comparisons are then made between the effects predicted for the scenarios established from equilibrium simulations and the new Hadley Centre High Resolution Model (UKHI) transient mode results. Though very different, both suggest increased stress on water resources late in the hydrological year.     

Recovery of crustacean zooplankton communities from acidification in Killarney Park,Ontario, 1971-2000: pH 6 as a recovery goal

Despite reductions in atmospheric SO4(2-) deposition and resultant decreases in surface water acidity, widespread biological recovery from acidification has not yet been documented. Temporal trends in crustacean zooplankton species richness (number of species) and composition were examined between 1971-2000 in 46 Killarney Park lakes, Ontario, Canada, to assess the degree of biological recovery in lakes with significant water quality improvements, i.e. pH now > 6, compared to 2 other groups: i) lakes which never acidified; and ii) lakes which are still acidified (pH < 6). Time trends in species richness could not be distinguished among the 3 groups of lakes, nor did changes in species richness indicate recovery. In contrast, the zooplankton community composition of lakes in which the pH increased to above 6, as measured by a multivariate index of species abundances, changed from a "damaged" state to one typical of neutral lakes. Some recovery in composition was also documented for the acidic lakes. While still acidic, the pH levels of these lakes have risen. The extent and pace of recovery in Killarney Provincial Park bodes well for the future of other acidified regions in North America and Europe.     

Planning STI/HIV prevention among refugees and mobile populations: situation assessment of Sudanese refugees

This article reflects an investigation of knowledge, attitudes and behaviours and HIV/STI prevalence of Sudanese refugees and Ethiopian sex workers in 1992. It represents one of the earliest such investigations within an African refugee population. The investigation took place in the Dimma refugee settlement in south-western Ethiopia and study participants included Sudanese refugee men and women and Ethiopian female sex workers. Methods used for this investigation included focus group discussions, behavioural surveys and serologic testing. The main outcome measures of the investigation were HIV/STI knowledge, attitudes and behaviours and biological markers for HIV, syphilis and herpes simplex 2. The study findings indicate that in the early 1990s, knowledge about AIDS and condom use was low among Sudanese refugee women and not one reported having ever used a condom. Furthermore, sexual contact between refugee men and sex workers was frequent during the time of this study and the prevalence of HIV and other STIs was high. The results confirm a widely held assumption that highly mobile and transient populations in Africa are susceptible to STIs and HIV, in large part due to their knowledge, attitudes and behaviours.     

Reconstructing human contributions to accidents: the new view on error and performance

PROBLEM: How can human contributions to accidents be reconstructed? Investigators can easily take the position a of retrospective outsider, looking back on a sequence of events that seems to lead to an inevitable outcome, and pointing out where people went wrong. This does not explain much, however, and may not help prevent recurrence. METHOD AND RESULTS: This paper examines how investigators can reconstruct the role that people contribute to accidents in light of what has recently become known as the new view of human error. The commitment of the new view is to move controversial human assessments and actions back into the flow of events of which they were part and which helped bring them forth, to see why assessments and actions made sense to people at the time. The second half of the paper addresses one way in which investigators can begin to reconstruct people's unfolding mindsets. IMPACT ON INDUSTRY: In an era where a large portion of accidents are attributed to human error, it is critical to understand why people did what they did, rather than judging them for not doing what we now know they should have done. This paper helps investigators avoid the traps of hindsight by presenting a method with which investigators can begin to see how people's actions and assessments actually made sense at the time.     

Modeling of road traffic noise and estimated human exposure in Fulton County, Georgia, USA

Environmental noise is a major source of public complaints. Noise in the community causes physical and socio-economic effects and has been shown to be related to adverse health impacts. Noise, however, has not been actively researched in the United States compared with the European Union countries in recent years. In this research, we aimed at modeling road traffic noise and analyzing human exposure in Fulton County, Georgia, United States. We modeled road traffic noise levels using the United States Department of Transportation Federal Highway Administration Traffic Noise Model implemented in SoundPLAN?. After analyzing noise levels with raster, vector and fa?ade maps, we estimated human exposure to high noise levels. Accurate digital elevation models and building heights were derived from Light Detection And Ranging survey datasets and building footprint boundaries. Traffic datasets were collected from the Georgia Department of Transportation and the Atlanta Regional Commission. Noise level simulation was performed with 62 computers in a distributed computing environment. Finally, the noise-exposed population was calculated using geographic information system techniques. Results show that 48% of the total county population [N=870,166 residents] is potentially exposed to 55 dB(A) or higher noise levels during daytime. About 9% of the population is potentially exposed to 67 dB(A) or higher noises. At nighttime, 32% of the population is expected to be exposed to noise levels higher than 50 dB(A). This research shows that large-scale traffic noise estimation is possible with the help of various organizations. We believe that this research is a significant stepping stone for analyzing community health associated with noise exposures in the United States.