Ecoregions of the Conterminous United States: Evolution of a Hierarchical Spatial Framework

A map of ecological regions of the conterminous United States, first published in 1987, has been greatly refined and expanded into a hierarchical spatial framework in response to user needs, particularly by state resource management agencies. In collaboration with scientists and resource managers from numerous agencies and institutions in the United States, Mexico, and Canada, the framework has been expanded to cover North America, and the original ecoregions (now termed Level III) have been refined, subdivided, and aggregated to identify coarser as well as more detailed spatial units. The most generalized units (Level I) define 10 ecoregions in the conterminous U.S., while the finest-scale units (Level IV) identify 967 ecoregions. In this paper, we explain the logic underpinning the approach, discuss the evolution of the regional mapping process, and provide examples of how the ecoregions were distinguished at each hierarchical level. The variety of applications of the ecoregion framework illustrates its utility in resource assessment and management.     

Little by little,inch by inch: Project expansion assessments in the Papua New Guinea mining industry

Social impact assessment (SIA) has traditionally been practiced as an ex-ante predictive tool in the context of regulatory approval by government agencies. This model of SIA developed by Burdge and others is based on ‘greenfields’ development, of a new project going in to areas where there are no, or relatively few, similar types of development. The International Principles of SIA signalled a conceptual shift in the practice of SIA where greater emphasis is placed on the assessment and management of social issues across the life-cycle of developments. In addition forms of cumulative impact assessment have been developed for contexts where more than one project is likely to impact on populations or communities. With these changes to the traditional models of impact assessment there is a need to clarify how and when dedicated phases of ‘assessment’ might be undertaken over the life-cycle of a development. In the context of the mining industry, SIAs are increasingly required by governments for incremental increases in the size or impact of these operations. This paper reviews the development and application of Project Expansion Assessments (PEAs) for two large-scale mining operations in Papua New Guinea. It argues that a different set of assumptions need to underlie the model of IA for such assessments, with more emphasis on trajectories rather than baselines, a critical evaluation and attribution of effects, and the incorporation of adaptive management tools into the process.     

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.     

PCN BASED METAL PARTITIONING IN URBAN SNOWMELT,RAINFALL/RUNOFF,AND RIVER FLOW SYSTEMS1

ABSTRACT: Drawing an analogy between the popular Soil Conservation Service curve number (SCS‐CN) method based infiltration and metal sorption processes, a new partitioning curve number (PCN) approach is suggested for partitioning of heavy metals into dissolved and particulate bound forms in urban snowmelt, rainfall/runoff, and river flow environments. The parameters, the potential maximum desorption, ψ, and the PCN analogous to the SCS‐CN parameters S and CN, respectively, are introduced. Under the condition of snowmelt, PCN (or ψ) is found to generally rely on temperature, relative humidity, pH, and chloride content; during a rainstorm, ψ is found to depend on the alkalinity and the pH of the rainwater; and in the river flow situation, PCN is found to generally depend on the temperature, pH, and chloride content. The advantage of using PCN instead of the widely used partitioning parameter, K_d, is found to lie in the PCN's efficacy to distinguish the adsorption (or sorption) behavior of metals in the above snowmelt, rainfall/runoff, and river flow situations, analogous to the hydrological behavior of watersheds.     

Second-trimester levels of maternal urinary gonadotropin peptide in down syndrome pregnancy

Urinary gonadotropin peptide (UGP; β-core fragment), a major metabolite of human chorionic gonadotropin (hCG), was shown recently to be markedly elevated in Down syndrome pregnancy between 19 and 22 weeks of gestation. To confirm and extend this finding, we obtained maternal urine and matching maternal serum samples from 14 cases of Down syndrome and six other aneuploidies between 17 and 21 weeks of gestation. UGP was measured in all these samples and in 91 singleton control urines. Results were corrected for urinary creatinine level and expressed as multiples of the control median (MOM). hCG levels were assayed in all serum samples from the cases and compared with previously established reference values. The median UGP level in Down syndrome cases was 5.34 MOM (range 2.71–12.57); 88 per cent of the values were above the 95th centile of control levels after modelling. The median maternal serum hCG level for the same cases was 2.20 MOM (range 0.84–3.40); 36 per cent of the values were above the 95th centile. The level of UGP in every case including all other aneuploidies was higher than the comparable maternal serum hCG level. Elevated UGP measurements are strongly associated with fetal Down syndrome during the second trimester and could contribute to improved Down syndrome screening protocols that are more accessible and less expensive than are currently available.     

Prospective intervention trial of a screening protocol to identify fetal trisomy 18 using maternal serum alpha-fetoprotein,unconjugated oestriol,and human chorionic gonadotropin

Two prenatal centres in New England, routinely using a screening protocol for fetal Down syndrome that included maternal serum alpha-fetoprotein (AFP), unconjugated oestriol (uE3), and human chorionic gonadotropin (hCG) measurements in combination with maternal age, adopted a separate screening protocol for trisomy 18. That protocol identified a pregnancy as being at high risk when AFP, uE3, and hCG measurements all fell at or below specified cut-offs (0.75, 0.60, and 0.55 multiples of the median, respectively), regardless of maternal age. Among the first 19 491 women screened, 98 (0.5 per cent) were found to have values which placed them in the high-risk category. Four of these women were subsequently found not to be pregnant. In two others, samples from non-pregnant individuals were found to have been incorrectly submitted for analysis in place of the samples from the pregnant women. All of the remaining 92 women were counselled and offered amniocentesis and fetal karyotyping. Eighty-eight (96 per cent) accepted. Karyotypes or birth outcomes were available on all 92 pregnancies. Six cases of trisomy 18 and one case of Turner syndrome were identified by karyotype. One case of trisomy 18 was identified for every 14 unaffected pregnancies offered amniocentesis. In the present prospective study, an estimated 85 per cent of the cases of trisomy 18 were identified. However, given the small number ofcases (six), the 95 per cent confidence interval for the detection rate is broad (40–95 per cent).     

Desertification,and climate change: the case for greater convergence

Poor knowledge of links between desertification and globalclimate change is limiting funding from the Global Environment Facility foranti-desertification projects and realization of synergies between theConvention to Combat Desertification (CCD) and the FrameworkConvention on Climate Change (FCCC). Greater convergence betweenresearch in the two fields could overcome these limitations, improve ourknowledge of desertification, and benefit four areas of global climate changestudies: mitigation assessment; accounting for land cover change in thecarbon budget; land surface-atmosphere interactions; and climate changeimpact forecasting. Convergence would be assisted if desertification weretreated more as a special case in dry areas of the global process of landdegradation, and stimulated by: (a) closer cooperation between the FCCCand CCD; (b) better informal networking between desertification and globalclimate change scientists, e.g. within the framework of theIntergovernmental Panel on Climate Change (IPCC). Both strategies wouldbe facilitated if the FCCC and CCD requested the IPCC to provide ascientific framework for realizing the synergies between them.     

Second-trimester levels of maternal serum unconjugated oestriol and human chorionic gonadotropin in pregnancies affected by fetal anencephaly and open spina bifida

Unconjugated oestriol (uE3) and human chorionic gonadotropin (hCG) levels were determined in second-trimester maternal serum (MS) samples from 21 pregnancies associated with fetal anencephaly and 15 pregnancies associated with fetal open spina bifida. Each measurement was expressed as a multiple of the median (MoM) for unaffected pregnancies for each completed week of gestation. In pregnancies associated with anencephaly, the median value for MSuE3 was very low (0–17 MoM, range <0·12–0·33 MoM), suggesting a functional defect in the fetal adrenal prior to 20 weeks' gestation; the median value for MShCG was also low (0–73 MoM), although not to the same extent as for MSuE3. A biological explanation for the hCG result is not apparent. In pregnancies associated with open spina bifida, the MSuE3 and MShCG values were unremarkable, consistent with a lack of involvement of these open fetal defects in the synthesis and secretion of uE3 and hCG.