Factors Leading to Different Viability Predictions for a Grizzly Bear Data Set

Population viability analysis programs are being used increasingly in research and management applications, but there has not been a systematic study of the congruence of different program predictions based on a single data set. We performed such an analysis using four population viability analysis computer programs: GAPPS, INMAT, RAMAS/AGE, and VORTEX. The standardized demographic rates used in all programs were generalized from hypothetical increasing and decreasing grizzly bear ( Ursus arctos horribilis ) populations. Idiosyncracies of input format for each program led to minor differences in intrinsic growth rates that translated into striking differences in estimates of extinction rates and expected population size. In contrast, the addition of demographic stochasticity, environmental stochasticity, and inbreeding costs caused only a small divergence in viability predictions. But, the addition of density dependence caused large deviations between the programs despite our best attempts to use the same density-dependent functions. Population viability programs differ in how density dependence is incorporated, and the necessary functions are difficult to parameterize accurately. Thus, we recommend that unless data clearly suggest a particular density-dependent model, predictions based on population viability analysis should include at least one scenario without density dependence. Further, we describe output metrics that may differ between programs; development of future software could benefit from standardized input and output formats across different programs.     

Risk-adequate motor underwriting of automated vehicles: a qualitative evaluation using German focus groups

The advent of automated vehicles is already taking place and will significantly disrupt the motor insurance industry. The shift from the human driver to the system as the driver cannot be reflected in the current insurance risk assessment. This call for an amendment of the insurance underwriting was discussed with German experts from both the primary insurance and reinsurance sector with their professional background on motor insurance. Based on the findings, we propose an alternative method to underwrite automated vehicles of level 4 & 5 using an enhanced telematics approach which considers new risk categories such as systems used and the transformed role of the driver as the general user of the automated vehicle.

     

The Use of Natural Systems to Remediate Groundwater: Department of Energy Experience at the Savannah River Site

Natural remediation is moving toward the forefront as engineers clean groundwater at the Savannah River Site (SRS), a major Department of Energy (DOE) installation near Aiken, South Carolina. This article reviews two successful, innovative remediation methods currently being deployed: biosparging to treat chlorinated solvents and phytoremediation to address tritium in groundwater. The biosparging system reintroduces oxygen into the groundwater and injects nutrient compounds for in‐situ remediation. The system has greatly reduced the concentrations of trichloroethylene (TCE) and vinyl chloride in wells downgradient from a sanitary landfill (SLF). Phytoremediation is an emerging technology that promises effective and inexpensive cleanup of certain hazardous wastes. Using natural processes, plants can break down, trap and hold, or transpire contaminants. This article discusses the use of phytoremediation to reduce the discharge of tritium to an on‐site stream at SRS. © 2002 Wiley Periodicals Inc. *     

Plants as biomarkers for monitoring heavy metal contaminants on landfill sites using sequential extraction and inductively coupled plasma atomic emission spectrophotometry (ICP-AES)

There have been a number of studies investigating metal uptake in plants on contaminated landfill sites, but little on their role as biomarkers to identify metal mobility for continuous monitoring purposes. Vegetation can be used as a biomonitor of site pollution, by identifying the mobilisation of heavy metals and by providing an understanding of their bioavailability. Plants selected were the common nettle (Uritica Dioica), bramble (Rubus Fruticosa) and sycamore (Acer Pseudoplatanus). A study of the soil fractionation was made to investigate the soil properties that are likely to influence metal mobility and a correlation exercise was undertaken to investigate if variations in concentration of metals in vegetation can reflect variations in concentration of the metals in soil. The soil was digested using aqua regia in a microwave closed vessel. The vegetation was digested using both microwave and a hydrogen peroxide-nitric acid mixture, refluxed on a heating block and a comparison made. The certified reference materials (CRMs) used were Standard Reference Material (SRM) 1547, peach leaves for vegetation (NIST) and for soil CRM 143R, sewage sludge-amended soil (BCR). The relative standard deviations (RSDs) were 2-6% for the analyses. Our findings show evidence of phytoextraction by some plants, (especially bramble and nettle), with certain plants, (sycamore) exhibiting signs of phytostabilisation. The evidence suggests that there is a degree of selectivity in metal uptake and partitioning within the plant compartments. It was also possible to correlate mobility phases of certain metals (Pb, Cu and Zn) using the soil and plant record. Zn and Cu exhibited the greatest potential to migrate from the roots to the leaves, with Pb found principally in the roots of ground vegetation. Our results suggest that analysis of bramble leaves, nettle leaves and roots can be used to monitor the mobility of Pb in the soil with nettle, bramble and sycamore leaves to monitor Cu and Zn.     

Gauging the societal impacts of natural disasters using a capability approach

There is a widely acknowledged need for a single composite index that provides a comprehensive picture of the societal impact of disasters. A composite index combines and logically organizes important information policy‐makers need to allocate resources for the recovery from natural disasters; it can also inform hazard mitigation strategies. This paper develops a Disaster Impact Index (DII) to gauge the societal impact of disasters on the basis of the changes in individuals’ capabilities. The DII can be interpreted as the disaster impact per capita. Capabilities are dimensions of individual well‐being and refer to the genuine opportunities individuals have to achieve valuable states and activities (such as being adequately nourished or being mobile). After discussing the steps required to construct the DII, this article computes and compares the DIIs for two earthquakes of similar magnitude in two societies at different levels of development and of two disasters (earthquake and wind storm) in the same society.     

OHP02 gravity wave campaign in relation to optical turbulence

Herein we present a campaign dedicated to the detection and the characterization of Gravity Waves (GW) in the Earth’s atmosphere in relation to the generation of Optical Turbulence (OT). The observations took place in France from 17 to 24 July 2002 at the Haute Provence Observatory (OHP) and simultaneously at the Sirene Observatory, some 20 km apart. From both sites, several balloons were launched that measured the classical PTU-Wind profiles and additionally the structure constant of the temperature field vertical profiles. A Generalized Scidar (GS) technique was implemented at the 1.93 m-diameter OHP telescope, providing profiles every minute. From our observations, a significant amount of GW activity was observed at both sites, but without clear evidence of correlation between the two sites. It seems from our observations that a wide spectrum of GW is present at a given altitude and that this could result in a lack of correlation between observations made from two sites 20 km apart. Most GW are non-stationary with long horizontal wavelengths (λ ∼ 100–200 km), kilometric vertical wavelengths (λ ~ 0.5–2 km) and long intrinsic period (T ~ 2–15 h). They belong in the category of “hydrostatic rotating or non-rotating waves”. Layers of optical turbulence detected by balloons and the Scidar technique correlate well with regions of GW activity. The U.S. Government’s right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged.     

Evaluating portable infrared spectrometers for measuring the silica content of coal dust

Miners face a variety of respiratory hazards while on the job, including exposure to silica dust which can lead to silicosis, a potentially fatal lung disease. Currently, field-collected filter samples of silica are sent for laboratory analysis and the results take weeks to be reported. Since the mining workplace is constantly moving into new and often different geological strata with changing silica levels, more timely data on silica levels in mining workplaces could help reduce exposures. Improvements in infrared (IR) spectroscopy open the prospect for end-of-shift silica measurements at mine sites. Two field-portable IR spectrometers were evaluated for their ability to quantify the mass of silica on filter samples loaded with known amounts of either silica or silica-bearing coal dust (silica content ranging from 10-200 μg/filter). Analyses included a scheme to correct for the presence of kaolin, which is a confounder for IR analysis of silica. IR measurements of the samples were compared to parallel measurements derived using the laboratory-based U.S. Mine Safety and Health Administration P7 analytical method. Linear correlations between Fourier transform infrared (FTIR) and P7 data yielded slopes in the range of 0.90-0.97 with minimal bias. Data from a variable filter array spectrometer did not correlate as well, mainly due to poor wavelength resolution compared to the FTIR instrument. This work has shown that FTIR spectrometry has the potential to reasonably estimate the silica exposure of miners if employed in an end-of-shift method.     

Monitoring of Particle Mass and Number in Urban Air

Measurements of aerosol particles in the air of an urban area in the UK have been made. Ambient air was sampled and the particulates measured after passing through a size selective PM₁₀ inlet. Particle mass was measured using a Tapered Element Oscillating Microbalance (TEOM). Particle number and size distributions were obtained using an Electrical Aerosol Analyser (EAA) and an Aerodynamic Particle Sizer (APS). Measurements were also made of local meteorological parameters. Fine particle number concentrations were found to show better temporal agreement, including diurnal variation, with particle mass concentrations than the coarser particle number concentrations.