The Influence of Proximity to a National Forest on Emotions and Fire-Management Decisions

Because American national forests are managed for all citizens, it is important that researchers explore the differences and similarities between citizens living both near and far from publicly managed land. We surveyed residents living at various distances from nationally managed land to collect resident perceptions of different forest fire-management techniques, to determine public preferences for these techniques, and to examine the motivations behind these preferences. Participants both close to and far away from national forests tended to favor a multipronged approach to fire management by preferring the use of a combination of two or more fire-management techniques. There were no significant differences by proximity in participants’ self-rated emotions, types of fire-management techniques preferred, or the reasons and rationales for their preferred fire-management technique(s), indicating that the proximity variable may not be as significant as previously thought.     

Biogeochemical consequences of a changing Arctic shelf seafloor ecosystem

Unprecedented and dramatic transformations are occurring in the Arctic in response to climate change, but academic, public, and political discourse has disproportionately focussed on the most visible and direct aspects of change, including sea ice melt, permafrost thaw, the fate of charismatic megafauna, and the expansion of fisheries. Such narratives disregard the importance of less visible and indirect processes and, in particular, miss the substantive contribution of the shelf seafloor in regulating nutrients and sequestering carbon. Here, we summarise the biogeochemical functioning of the Arctic shelf seafloor before considering how climate change and regional adjustments to human activities may alter its biogeochemical and ecological dynamics, including ecosystem function, carbon burial, or nutrient recycling. We highlight the importance of the Arctic benthic system in mitigating climatic and anthropogenic change and, with a focus on the Barents Sea, offer some observations and our perspectives on future management and policy.     

Multiscale satellite and spatial information and analysis framework in support of a large-area forest monitoring and inventory update

Many countries undertake a national forest inventory to enable statistically valid monitoring in support of national and international reporting of forest conditions and change. Canada’s National Forest Inventory (NFI) program is designed to operate on a 10-year remeasurement cycle, with an interim report produced at the 5-year mid-point. The NFI is a sample-based inventory, with approximately 18,850 2 ×2-km photo plots across the country, distributed on a 20×20-km grid of sample points; these photo plots are the primary data source for the NFI. Capacity to provide annual monitoring information is required to keep policy and decision makers apprised of current forest conditions. In this study, we implemented a multistage monitoring framework and used a Moderate Resolution Imaging Spectroradiometer (MODIS) change product to successfully identify 78% of the changes in forest cover area that were captured with a Landsat change detection approach. Of the NFI photo plots that were identified by both the Landsat and MODIS approaches as having changes in forest cover, the proportion of change area within the plots was similar (R ²?=?0.78). Approximately 70% of the Landsat-derived change events occupied less than 40% of a single MODIS pixel, and more than 90% of the change events of this size were successfully detected with the MODIS product. Finally, MODIS estimates of the proportion of forest cover change at the NFI photo plot level were comparable to change estimates for the ecoregions as a whole (R ²?=?0.95). High-temporal, low-spatial resolution imagery such as MODIS, in combination with other remotely sensed data sources, can provide information on disturbance events within a national forest inventory remeasurement cycle, thereby satisfying the interim information needs of policy and decision makers as well as the requirements of national and international reporting commitments.     

Enhanced degradation of benzo[a]pyrene by Mycobacterium sp. in conjunction with green alga

Previous work in this laboratory has confirmed that the bacteria Mycobacterium sp. strain RJGII.135 and Sphingomonas yanoikuyae strain B1 and the green alga Selanastrum capricornutum strain UTEX 1648 degrade benzo[a]pyrene (BaP) to various BaP intermediates. S. capricornutum was first grown with BaP for 4 days. The organic extract of this media was then introduced into separate cultures of strain RJGII.135 and strain B1; separate cultures were grown with BaP for comparison. Cultures grown with BaP and those grown with the algal/BaP extract showed similar mineralization patterns. The quantity of total metabolites formed was greater in bacterial cultures grown with the algal/BaP extract than those grown with BaP alone. For strain RJGII.135, only 27% of the original BaP remained in cultures grown with the algal/BaP extract; 59% remained in cultures grown with BaP. For strain B1, only 6% of the original BaP remained in cultures grown with the algal/BaP extract; 38% remained in cultures grown with BaP. These results indicate that strategies utilizing organisms together may be necessary in being able to degrade large, recalcitrant polycyclic aromatic hydrocarbons (PAHs) such as BaP.     

Affirmative action programs: an organizational justice perspective

Affirmative Action Programs (AAPs) are becoming increasingly common in the workplace. Typically their effectiveness has been assessed by the number of women and minorities hired and promoted. A neglected, but important measure of effectiveness is how AAPs are perceived by employees. When employees perceive that AAPs violate notions of fairness, negative attitudes and behaviors may occur and lead to decreased organizational performance. A model of perceived AAP fairness is presented using an organizational justice perspective. An initial (partial) test of the model is conducted and avenues for future research are discussed.     

Fetoscopic myelomeningocoele closure: Is the scientific evidence enough to challenge the gold standard for prenatal surgery?

Since the completion of the Management of Myelomeningocoele Study, maternal-fetal surgery for spina bifida has become a valid option for expecting parents. More recently, multiple groups are exploring a minimally invasive approach and recent outcomes have addressed many of the initial concerns with this approach. Based on a previously published framework, we attempt to delineate the developmental stage of the surgical techniques. Furthermore, we discuss the barriers of performing randomized controlled trials comparing two surgical interventions and suggest that data collection through registries is an alternative method to gather high-grade evidence.     

Relationships between soil and runoff phosphorus in small Alberta watersheds

Field-scale relationships between soil test phosphorus (STP) and flow-weighted mean concentrations (FWMCs) of dissolved reactive phosphorus (DRP) and total phosphorus (TP) in runoff are essential for modeling phosphorus losses, but are lacking. The objectives of this study were (i) to determine the relationships between soil phosphorus (STP and degree of phosphorus saturation (DPS)) and runoff phosphorus (TP and DRP) from field-sized catchments under spring snowmelt and summer rainfall conditions, and (ii) to determine whether a variety of depths and spatial representations of STP improved the prediction of phosphorus losses. Runoff was monitored from eight field-scale microwatersheds (2 to 248 ha) for 3 yr. Soil test phosphorus was determined for three layers (0 to 2.5 cm, 0 to 5 cm, and 0 to 15 cm) in spring and fall and the DPS was determined for the surface layer. Average STP (0 to 15 cm) ranged from 3 to 512 mg kg(-1), and DPS (0 to 2.5 cm) ranged from 5 to 91%. Seasonal FWMCs ranged from 0.01 to 7.4 mg L(-1) DRP and from 0.1 to 8.0 mg L(-1) TP. Strong linear relationships (r2=0.87 to 0.89) were found between the site mean STP and the FWMCs of DRP and TP. The relationships had similar extraction coefficients, intercepts, and predictive power among all three soil layers. Extraction coefficients (0.013 to 0.014) were similar to those reported for other Alberta studies, but were greater than those reported for rainfall simulation studies. The curvilinear DPS relationship showed similar predictive ability to STP. The field-scale STP relationships derived from natural conditions in this study should provide the basis for modeling phosphorus in Alberta.     

The study of age influence on human bone lead metabolism by using a simplified model and X-ray fluorescence data

Long term lead metabolism in the human body has never been fully understood due to the lack of human data in this area. The technological improvement of bone lead measurement systems has made bone lead data of substantial populations available. In this study, a set of X-ray fluorescence bone lead data was used to test Leggett's lead metabolism model (R. W. Leggett, Environ. Health Perspect., 1993a, 101, 598-616), especially the model of metabolism in bone. The data set includes the bone lead concentration of 539 occupationally exposed workers, of whom 327 were measured twice in five years. The bone lead concentrations of both cortical bone (tibia) and trabecular bone (calcaneus) were obtained by Cd-109 gamma-ray induced XRF measurement. The histories of blood lead concentration for these workers were used to regulate the input file of the model. The results show that the bone lead concentrations predicted by Leggett's model greatly underestimate the measured values, especially for older workers. This data set was then organized into five age groups. A new simplified model was applied to estimate the lead transfer rates between blood and lead compartments for these age groups. The original transfer rates and the new transfer rates are compared, and the differences are discussed. When the transfer rates derived from measured bone lead data were put into the input file of the model to replace the existing parameters, the predicted values were much closer to the measured values for both cortical bone and trabecular bone.     

DNA Heat Treatment for Improving qPCR Analysis of Human Adenovirus in Wastewater

PCR inhibitory substances in complex sample matrices can cause false negatives or under-estimation of target concentration. This study assessed DNA heat treatment for reducing inhibition during qPCR analysis of human adenovirus (HAdV) in wastewater samples. Inhibition was reduced by heat treating DNA, where mean HAdV concentration was increased by 0.71 log₁₀ GC/L (and up to 3.04 log₁₀ GC/L in one case), and replicate variability and false negatives were reduced. DNA heat treatment should be further investigated for improving reliability of HAdV concentration estimates in water, which can support more accurate assessment of health risks associated with viral pathogen exposure.     

Modelling the long-term dynamics of radiocaesium in closed lakes

During the years after the Chernobyl accident the radioceasium activity concentration in most contaminated aquatic ecosystems decreased markedly. Lakes with no permanent inflows and outflows (closed lakes), however, still present a radioecological problem which is expected to continue for some time. In this paper, a mechanistic model for the long-term prediction of radiocaesium behaviour in closed lakes is developed. The model of Prokhorov (Radiokhimiya (Radiochemistry) 11 (1969) 317) was modified to describe the effects of bottom sediment bioturbation, surface runoff from the catchment and suspended solids formation and sedimentation. The model input parameters are the effective diffusion coefficient in bottom sediments, depth of the completely mixed layer, the distribution coefficient in the sediment-water system, the runoff coefficient, sedimentation rate, and deposition density. Values of all these parameters can be independently estimated or measured in a short-term experiment. Given negligible runoff and sedimentation, the dynamics of radiocaesium in lake water is described by a simple equation with only one unknown parameter. This allows us to make long-term predictions on the basis of a series of measurements carried out during the relatively short period. The model was tested against 137Cs activity concentrations measured between 1993 and 1999 in Svyatoe lake in the Bryansk region of Russia. Calculated and measured activity concentrations are in good agreement.