Application of a predictive safety model in a combustion testing environment

A predictive safety model for accident prevention and system failure, called Continuous Hazard Tracking and Failure Prediction Methodology, is applied at the Marshall Space Flight Center's promoted combustion test chamber. It combines the underlying principles of work sampling, control charts, and multivariate analysis. The sampling is performed to observe the occurrence of conditions which may be becoming hazardous in a given system. These building blocks of hazards, which we have called dendritics, could result in an accident, system malfunction, or unacceptable risk conditions. The data collected is plotted to generate the appropriate control chart, which depends on the characteristics of the given system and the protection desired. Based on the pattern of the control chart, a system ‘under control’ is not disturbed whereas a system ‘out of control’ is investigated for potential conditions becoming hazardous. Then appropriate steps are taken to eliminate or control these conditions in order to maintain a desired safety status of the system. The continuously running characteristic of this model allows for the verification that the corrective measures taken to ameliorate the ‘out of control’ conditions were satisfactory or whether more proactive action is required. The results provided by the predictive model were validated with historical safety data.     

Historical perspectives on contemporary human–environment dynamics in southeast Africa

The human communities and ecosystems of island and coastal southeast Africa face significant and linked ecological threats. Socioecological conditions of concern to communities, governments, nongovernmental organizations, and researchers include declining agricultural productivity, deforestation, introductions of non-native flora and fauna, coastal erosion and sedimentation, damage to marine environments, illegal fishing, overfishing, waste pollution, salinization of freshwater supplies, and rising energy demands, among others. Human–environment challenges are connected to longer, often ignored, histories of social and ecological dynamics in the region. We argue that these challenges are more effectively understood and addressed within a longer-term historical ecology framework. We reviewed cases from Madagascar, coastal Kenya, and the Zanzibar Archipelago of fisheries, deforestation, and management of human waste to encourage increased engagement among historical ecologists, conservation scientists, and policy makers. These case studies demonstrate that by widening the types and time depths of data sets we used to investigate and address current socioecological challenges, our interpretations of their causes and strategies for their mitigation varied significantly.     

Balancing Forest‐Regeneration Probabilities and Maintenance Costs in Dry Grasslands of High Conservation Priority

Abstract: Abandonment of agricultural land has resulted in forest regeneration in species‐rich dry grasslands across European mountain regions and threatens conservation efforts in this vegetation type. To support national conservation strategies, we used a site‐selection algorithm (MARXAN) to find optimum sets of floristic regions (reporting units) that contain grasslands of high conservation priority. We sought optimum sets that would accommodate 136 important dry‐grassland species and that would minimize forest regeneration and costs of management needed to forestall predicted forest regeneration. We did not consider other conservation elements of dry grasslands, such as animal species richness, cultural heritage, and changes due to climate change. Optimal sets that included 95–100% of the dry grassland species encompassed an average of 56–59 floristic regions (standard deviation, SD 5). This is about 15% of approximately 400 floristic regions that contain dry‐grassland sites and translates to 4800–5300 ha of dry grassland out of a total of approximately 23,000 ha for the entire study area. Projected costs to manage the grasslands in these optimum sets ranged from CHF (Swiss francs) 5.2 to 6.0 million/year. This is only 15–20% of the current total estimated cost of approximately CHF30–45 million/year required if all dry grasslands were to be protected. The grasslands of the optimal sets may be viewed as core sites in a national conservation strategy.     

The development of point-of-use water filters as sampling devices in bioforensics: extent of microbial sorption and elution

The foundational idea for this project is that household faucet-mounted water filters may be used as bioforensic sampling devices to detect the extent of a potential bioagent release in domestic water supplies. An optimized eluent solution was determined experimentally by quantifying recoveries of microorganisms from point-of-use (POU) drinking water filters. The optimized extraction protocol was then used in mock bioagent release experiments to determine the feasibility of POU filters as bioforensic sampling devices. Bacillus atrophaeus spores, Escherichia coli and PP7 virus were exposed to filters and the number of attached organisms was determined by enumerating the unattached organisms on selective agar media. Subsequently, the filters were eluted and the percent of extracted organisms was determined based on the number of attached organisms. Two popular brands of carbon block filters retained 92%-99% of representative virus, spore and vegetative bacteria. In back-flush elutions of single filters, the most efficient eluent was identified as a combination of 1% peptone and 1% Tween-80, and extraction recovered 25.4% (+/-17.5%) of attached E. coli, 20.4% (+/-3.6%) of B. atrophaeus spores, and 9.4% (+/-5.2%) of PP7 virions (+/- standard deviations). In bioagent release studies in which filters were challenged with 100 agents mL(-1), greater than 99% of the spores were retained by the filters, and the percent of attached spores that were recovered ranged from 10.4% at day 0 to 4.3% five days after the release event (averaged from five separate experiments). In contrast, E. coli, Salmonella typhimurium and PP7 virus were rapidly inactivated in the chlorinated tap water, indicating their improbable survival in chlorinated water supplies. It is therefore concluded that household water filters can be used as microbial sampling devices for bioforensic applications in the event of a bioagent release in domestic drinking water supplies.     

Foraging behavior and habitat use by the Southern Giant Petrel on the Patagonian Shelf

We explored the at-sea behavior and marine habitat use of the Southern Giant Petrel breeding in Patagonia, Argentina by means of satellite telemetry. Adult breeders showed a wide distribution over the Patagonian Shelf, using 74% of its surface. The maximum distance traveled from the colonies was 683 km, but on average birds moved no more than 200 km further away from their colony. Important marine areas were located in the shelf break, middle shelf and coastal waters. Areas of activity by sex overlap between 35 and 94%. Females foraged primarily away from the coast and males mainly on coastal areas. Both sexes were capable of flying up to 4,000 km but most of the foraging trips were of less than 200 km. Our results emphasize the importance of the Patagonian Shelf as foraging habitat for pelagic seabirds and contribute to international efforts to identify and protect a network of marine sites.