Use of noise attenuation modeling in managing missile motor detonation activities

The Sound Intensity Prediction System (SIPS) and Blast Operation Overpressure Model (BOOM) are semiempirical sound models that are employed by the Utah Test and Training Range (UTTR) to predict whether noise levels from the detonation of large missile motors will exceed regulatory thresholds. Field validation of SIPS confirmed that the model was effective in limiting the number of detonations of large missile motors that could potentially result in a regulatory noise exceedance. Although the SIPS accurately predicted the impact of weather on detonation noise propagation, regulators have required that the more conservative BOOM model be employed in conjunction with SIPS in evaluating peak noise levels in populated areas. By simultaneously considering the output of both models, in 2001, UTTR detonated 104 missile motors having net explosive weights (NEW) that ranged between 14,960 and 38,938 lb without a recorded public noise complaint. Based on the encouraging results, the U.S. Department of Defense is considering expanding the application of these noise models to support the detonation of missile motors having a NEW of 81,000 lb. Recent modeling results suggest that, under appropriate weather conditions, missile motors containing up to 96,000 lb NEW can be detonated at the UTTR without exceeding the regulatory noise limit of 134 decibels (dB).     

Complying with Executive Order 13148 using the Enterprise Environmental Safety And Occupational Health Management Information System

All U.S. Department of Defense (DoD) facilities are required under Executive Order (EO) 13148, "Greening the Government through Leadership in Environmental Management," to establish quality-based environmental management systems (EMSs) that support environmental decision-making and verification of continuous environmental improvement by December 31, 2005. Compliance with EO 13148 as well as other federal, state, and local environmental regulations places a significant information management burden on DoD facilities. Cost-effective management of environmental data compels DoD facilities to establish robust database systems that not only address the complex and multifaceted environmental monitoring, record-keeping, and reporting requirements demanded by these rules but enable environmental management decision-makers to gauge improvements in environmental performance. The Enterprise Environmental Safety and Occupational Health Management Information System (EESOH-MIS) is a new electronic database developed by the U.S. Air Force to manage both the data needs associated with regulatory compliance programs across its facilities as well as the non-regulatory environmental information that supports installation business practices. The U.S. Air Force, which has adopted the Plan-Do-Check-Act methodology as the EMS standard that it will employ to address EO 13148 requirements.     

Fetal karyotype following ascertainment of fetal anomalies by ultrasound

Data pooled from contributors to a Registry for Cytogenetic Abnormalities and PKU (ReCAP) shows an unbalanced chromosome abnormality rate of 27 per cent (29 fetuses) for 107 fetuses with ultrasonically diagnosed fetal anomalies. Of the abnormal, 12 were trisomic, 6 were monosomy X and 6 were structural abnormalities, 4 were mosaics and one triploid.     

Observations on shell deformities,ultrastructure, and increment formation in the bay scallop Argopecten irradians

Shell morphology and ultrastructure were examined in the bay scallop Argopecten irradians, cultured in recirculating seawater systems under various conditions of feeding, lighting, and handling. On a unialgal diet of Thalassiosira pseudonana, scallop growth ranged from 120 to 183 m d^-1 at 20°C in the laboratory, about two-thirds of the growth rate found in the field. However, shell deposited in the laboratory differed from that in the field in several ways. In the field, scallops formed costae as an unpigmented, corrugated marginal shell layer; shell deposited in the laboratory lacked this layer and was therefore darker. Also, microstructure of the exterior shell surface of field scallops was coarsely granular, while that of cultured scallops was relatively smooth. Excessive handling of scallops in the laboratory resulted in marginal thickening of valves, a deformity which was completely arrested by a change from daily to weekly handling. Scallops cultured in the same tank with oysters developed shell-thickening on the interior of the valves. It is postulated that shell abnormalities in bivalves result from disruption of complex behavioral processes associated with shell deposition and may be elicited by a variety of natural and experimental irritants. Under natural lighting regimes and optimal conditions for growth, scallops deposited exactly one shell increment per day, but under continuous lighting, deposition of growth increments often became aphasic. In one 28-d experiment, there was a strong correlation between number of growth increments formed and increase in shell height, suggesting that shell ridge formation occurred intermittently, rather than daily, when shell growth rates fell below approximately 150 m d^-1.     

Testing the robustness of management decisions to uncertainty: Everglades restoration scenarios.

To effectively manage large natural reserves, resource managers must prepare for future contingencies while balancing the often conflicting priorities of different stakeholders. To deal with these issues, managers routinely employ models to project the response of ecosystems to different scenarios that represent alternative management plans or environmental forecasts. Scenario analysis is often used to rank such alternatives to aid the decision making process. However, model projections are subject to uncertainty in assumptions about model structure, parameter values, environmental inputs, and subcomponent interactions. We introduce an approach for testing the robustness of model-based management decisions to the uncertainty inherent in complex ecological models and their inputs. We use relative assessment to quantify the relative impacts of uncertainty on scenario ranking. To illustrate our approach we consider uncertainty in parameter values and uncertainty in input data, with specific examples drawn from the Florida Everglades restoration project. Our examples focus on two alternative 30-year hydrologic management plans that were ranked according to their overall impacts on wildlife habitat potential. We tested the assumption that varying the parameter settings and inputs of habitat index models does not change the rank order of the hydrologic plans. We compared the average projected index of habitat potential for four endemic species and two wading-bird guilds to rank the plans, accounting for variations in parameter settings and water level inputs associated with hypothetical future climates. Indices of habitat potential were based on projections from spatially explicit models that are closely tied to hydrology. For the American alligator, the rank order of the hydrologic plans was unaffected by substantial variation in model parameters. By contrast, simulated major shifts in water levels led to reversals in the ranks of the hydrologic plans in 24.1-30.6% of the projections for the wading bird guilds and several individual species. By exposing the differential effects of uncertainty, relative assessment can help resource managers assess the robustness of scenario choice in model-based policy decisions.     

Mutualism as reciprocal exploitation: African plant-ants defend foliar but not reproductive structures

The foundation of many plant-ant mutualisms is ant protection of plants from herbivores in exchange for food and/or shelter. While the role of symbiotic ants in protecting plants from stem- and leaf-feeding herbivores has been intensively studied, the relationship between ant defense and measures of plant fitness has seldom been quantified. We studied ant aggression, damage by herbivores and seed predators, and fruit production among Acacia drepanolobium trees occupied by four different acacia-ant species in an East African savanna. Levels of ant aggression in response to experimental disturbance differed strongly among the four species. All four ant species recruited more strongly to new leaf growth on host plants following disturbance, while recruitment to developing fruits was on average an order of magnitude lower. Host plants occupied by more aggressive ant species suffered significantly less vegetative damage from leaf-feeding insects, stem-boring beetles, and vertebrate browsers than host plants occupied by less aggressive ant species. However, there were no differences among fruiting host plants occupied by different ant species in levels of seed predation by bruchid seed predators. Fruit production on host trees was significantly correlated with tree stem diameter but not with the identity of resident ants. Our results demonstrate that defense of host plants may differ substantially among ant species and between vegetative and reproductive structures and that fruit production is not necessarily correlated with high levels of aggression by resident ants.     

Comparison of methods used to calculate typical threshold values for potentially toxic elements in soil

The environmental quality of land can be assessed by calculating relevant threshold values, which differentiate between concentrations of elements resulting from geogenic and diffuse anthropogenic sources and concentrations generated by point sources of elements. A simple process allowing the calculation of these typical threshold values (TTVs) was applied across a region of highly complex geology (Northern Ireland) to six elements of interest; arsenic, chromium, copper, lead, nickel and vanadium. Three methods for identifying domains (areas where a readily identifiable factor can be shown to control the concentration of an element) were used: k-means cluster analysis, boxplots and empirical cumulative distribution functions (ECDF). The ECDF method was most efficient at determining areas of both elevated and reduced concentrations and was used to identify domains in this investigation. Two statistical methods for calculating normal background concentrations (NBCs) and upper limits of geochemical baseline variation (ULBLs), currently used in conjunction with legislative regimes in the UK and Finland respectively, were applied within each domain. The NBC methodology was constructed to run within a specific legislative framework, and its use on this soil geochemical data set was influenced by the presence of skewed distributions and outliers. In contrast, the ULBL methodology was found to calculate more appropriate TTVs that were generally more conservative than the NBCs. TTVs indicate what a “typical” concentration of an element would be within a defined geographical area and should be considered alongside the risk that each of the elements pose in these areas to determine potential risk to receptors.     

Detecting pigments from colourful eggshells of extinct birds

The known chemical basis of diverse avian eggshell coloration is generated by the same two classes of tetrapyrrole pigments in most living birds. We aimed to extend the evolutionary scope of these patterns by detecting pigments from extinct birds’ eggs. In our samples biliverdin was successfully extracted from subfossil shell fragments of the blue-green egg-laying upland moa Megalapteryx didinus, while protoporphyrin was extracted from the beige eggs of two other extinct moa species. Our data on pigment detection from eggshells of other extant paleognath birds, together with published information on other modern lineages, confirm tetrapyrroles as ubiquitous and conserved pigments contributing to diverse eggshell colours throughout avian evolution.