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At least 127 records · Page 7Linked to original sources

Developing transmissible vaccines for animal infections

Many emerging and reemerging pathogens originate from wildlife, but nearly all wild species are unreachable using conventional vaccination, which requires capture of and vaccine administration to individual animals. By enabling immunization at scales sufficient to interrupt pathogen transmission, transmissible vaccines (TVs) that spread themselves through wildlife populations by infectious processes could potentially transform the management of otherwise intractable challenges to public health, wildlife conservation, and animal welfare. However, generating TVs likely requires modifying viruses that would be intended to spread in nature, which raises concerns ranging from technical feasibility, to safety and security risks, to regulatory uncertainties ( 1 , 2 ). We propose a series of commitments and strategies for vaccine development—beginning with a priori decisions on vaccine design and continuing through to stakeholder codevelopment [see supplementary materials (SM)]—that we believe increase the likelihood that the potential risks of vaccine transmission are outweighed by benefits to conservation, animal welfare, and zoonosis prevention.

Science↗

Testing the effectiveness of interactive training on sexual harassment and assault in field science

Fieldwork is a critical tool for scientific research, particularly in applied disciplines. Yet fieldwork is often unsafe, especially for members of historically marginalized groups and people whose presence in scientific spaces threatens traditional hierarchies of power, authority, and legitimacy. Research is needed to identify interventions that prevent sexual harassment and assault from occurring in the first place. We conducted a quasi-experiment assessing the impacts of a 90-min interactive training on field-based staff in a United States state government agency. We hypothesized that the knowledge-based interventions, social modeling, and mastery experiences included in the training would increase participants’ sexual harassment and assault prevention knowledge, self-efficacy, behavioural intention, and behaviour after the training compared to a control group of their peers. Treatment–control and pre-post training survey data indicate that the training increased participants’ sexual harassment and assault prevention knowledge and prevention self-efficacy, and, to a lesser extent, behavioural intention. These increases persisted several months after the training for knowledge and self-efficacy. While we did not detect differences in the effect of the training for different groups, interestingly, post-hoc tests indicated that women and members of underrepresented racial groups generally scored lower compared to male and white respondents, suggesting that these groups self-assess their own capabilities differently. Finally, participants’ likelihood to report incidents increased after the training but institutional reports remained low, emphasizing the importance of efforts to transform reporting systems and develop better methods to measure bystander actions. These results support the utility of a peer-led interactive intervention for improving workplace culture and safety in scientific fieldwork settings.

Scientific Reports↗

Tsunami mitigation and preparedness activities in California

Scenario planning and final results associated with the U.S. Geological Survey Science Application for Risk Reduction (SAFRR) tsunami project are providing great benefits to the ongoing tsunami risk-reduction efforts of the California Tsunami Preparedness and Hazard Mitigation Program. This program, led by the California Governor’s Office of Emergency Services and the California Geological Survey, works with coastal communities to improve tsunami preparedness and mitigation at the local level through various efforts, such as improving tsunami hazard analysis, establishing consistent evacuation communications and planning, and leveraging national risk-reduction efforts associated with the National Tsunami Hazard Mitigation Program. The recent 2010 Chilean and 2011 Tohoku tsunamis did not cause notable inundation of dry land in California, but dozens of harbors sustained damages totaling nearly $100 million (Wilson and others, 2012a). Estimates associated with the SAFRR distant tsunami scenario suggest socioeconomic and environmental losses could be even larger. Information gathered from these events and the SAFRR scenario is guiding the development and implementation of new strategies for emergency response, maritime planning, and land-use planning, including a reassessment of the tsunami threat along the California coast; scenario-specific, tsunami evacuation “playbook” maps and guidance in-harbor hazard maps and offshore safety zones for potential boat evacuation during future distant source events; “probability-based” products for land-use planning under the California Seismic Hazard Mapping Act; and an expansion of real-time and post-tsunami field reconnaissance teams and information sharing through a state-wide clearinghouse. The state tsunami program has benefitted greatly from participation in the SAFRR tsunami scenario process, and hopes to continue this relationship with the U.S. Geological Survey to help improve tsunami preparedness in California.

California↗

Volcano and Earthquake Monitoring Plan for the Yellowstone Volcano Observatory, 2006-2015

To provide Yellowstone National Park (YNP) and its surrounding communities with a modern, comprehensive system for volcano and earthquake monitoring, the Yellowstone Volcano Observatory (YVO) has developed a monitoring plan for the period 2006-2015. Such a plan is needed so that YVO can provide timely information during seismic, volcanic, and hydrothermal crises and can anticipate hazardous events before they occur. The monitoring network will also provide high-quality data for scientific study and interpretation of one of the largest active volcanic systems in the world. Among the needs of the observatory are to upgrade its seismograph network to modern standards and to add five new seismograph stations in areas of the park that currently lack adequate station density. In cooperation with the National Science Foundation (NSF) and its Plate Boundary Observatory Program (PBO), YVO seeks to install five borehole strainmeters and two tiltmeters to measure crustal movements. The boreholes would be located in developed areas close to existing infrastructure and away from sensitive geothermal features. In conjunction with the park's geothermal monitoring program, installation of new stream gages, and gas-measuring instruments will allow YVO to compare geophysical phenomena, such as earthquakes and ground motions, to hydrothermal events, such as anomalous water and gas discharge. In addition, YVO seeks to characterize the behavior of geyser basins, both to detect any precursors to hydrothermal explosions and to monitor earthquakes related to fluid movements that are difficult to detect with the current monitoring system. Finally, a monitoring network consists not solely of instruments, but requires also a secure system for real-time transmission of data. The current telemetry system is vulnerable to failures that could jeopardize data transmission out of Yellowstone. Future advances in monitoring technologies must be accompanied by improvements in the infrastructure for data transmission. Overall, our strategy is to (1) maximize our ability to provide rapid assessments of changing conditions to ensure public safety, (2) minimize environmental and visual impact, and (3) install instrumentation in developed areas.

Scientific Investigations Report↗

Emergency management response to a warning-level Alaska-source tsunami impacting California: Chapter J in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

This chapter is directed towards two audiences: Firstly, it targets nonemergency management readers, providing them with insight on the process and challenges facing emergency managers in responding to tsunami Warning, particularly given this “short fuse” scenario. It is called “short fuse” because there is only a 5.5-hour window following the earthquake before arrival of the tsunami within which to evaluate the threat, disseminate alert and warning messages, and respond. This action initiates a period when crisis communication is of paramount importance. An additional dynamic that is important to note is that within 15 minutes of the earthquake, the National Oceanic and Atmospheric Administration (NOAA) and the National Weather Service (NWS) will issue alert bulletins for the entire Pacific Coast. This is one-half the time actually presented by recent tsunamis from Japan, Chile, and Samoa. Second, the chapter provides emergency managers at all levels with insights into key considerations they may need to address in order to augment their existing plans and effectively respond to tsunami events. We look at emergency management response to the tsunami threat from three perspectives:“Top Down” (Threat analysis and Alert/Warning information from the Federal agency charged with Alert and Warning) “Bottom Up” (Emergency management’s Incident Command approach to responding to emergencies and disasters based on the needs of impacted local jurisdictions) “Across Time” (From the initiating earthquake event through emergency response) We focus on these questions: What are the government roles, relationships, and products that support Tsunami Alert and Warning dissemination? (Emergency Planning and Preparedness.) What roles, relationships, and products support emergency management response to Tsunami Warning and impact? (Engendering prudent public safety response.) What are the key emergency management activities, considerations, and challenges brought out by the SAFRR tsunami scenario? (Real emergencies) How do these activities, considerations, and challenges play out as the tsunami event unfolds across the “life” of the event? (Lessons)

California↗

Analysis of local slopes at the InSight landing site on Mars

To evaluate the topography of the surface within the InSight candidate landing ellipses, we generated Digital Terrain Models (DTMs) at lander scales and those appropriate for entry, descent, and landing simulations, along with orthoimages of both images in each stereopair, and adirectional slope images. These products were used to assess the distribution of slopes for each candidate ellipse and terrain type in the landing site region, paying particular attention to how these slopes impact InSight landing and engineering safety, and results are reported here. Overall, this region has extremely low slopes at 1-meter baseline scales and meets the safety constraints of the InSight lander. The majority of the landing ellipse has a mean slope at 1-meter baselines of 3.2°. In addition, a mosaic of HRSC, CTX, and HiRISE DTMs within the final landing ellipse (ellipse 9) was generated to support entry, descent, and landing simulations and evaluations. Several methods were tested to generate this mosaic and the NASA Ames Stereo Pipeline program dem_mosaic produced the best results. For the HRSC-CTX-HiRISE DTM mosaic, more than 99 % of the mosaic has slopes less than 15°, and the introduction of artificially high slopes along image seams was minimized.

Space Science Reviews↗

Incorporating uncertainty into mercury-offset decisions with a probabilistic network for National Pollutant Discharge Elimination System permit holders: An interim report

This interim report describes an alternative approach for evaluating the efficacy of using mercury (Hg) offsets to improve water quality. Hg-offset programs may allow dischargers facing higher-pollution control costs to meet their regulatory obligations by making more cost effective pollutant-reduction decisions. Efficient Hg management requires methods to translate that science and economics into a regulatory decision framework. This report documents the work in progress by the U.S. Geological Survey’s Western Geographic Science Center in collaboration with Stanford University toward developing this decision framework to help managers, regulators, and other stakeholders decide whether offsets can cost effectively meet the Hg total maximum daily load (TMDL) requirements in the Sacramento River watershed. Two key approaches being considered are: (1) a probabilistic approach that explicitly incorporates scientific uncertainty, cost information, and value judgments; and (2) a quantitative approach that captures uncertainty in testing the feasibility of Hg offsets. Current fate and transport-process models commonly attempt to predict chemical transformations and transport pathways deterministically. However, the physical, chemical, and biologic processes controlling the fate and transport of Hg in aquatic environments are complex and poorly understood. Deterministic models of Hg environmental behavior contain large uncertainties, reflecting this lack of understanding. The uncertainty in these underlying physical processes may produce similarly large uncertainties in the decisionmaking process. However, decisions about control strategies are still being made despite the large uncertainties in current Hg loadings, the relations between total Hg (HgT) loading and methylmercury (MeHg) formation, and the relations between control efforts and Hg content in fish. The research presented here focuses on an alternative analytical approach to the current use of safety factors and deterministic methods for Hg TMDL decision support, one that is fully compatible with an adaptive management approach. This alternative approach uses empirical data and informed judgment to provide a scientific and technical basis for helping National Pollutant Discharge Elimination System (NPDES) permit holders make management decisions. An Hg-offset system would be an option if a wastewater-treatment plant could not achieve NPDES permit requirements for HgT reduction. We develop a probabilistic decision-analytical model consisting of three submodels for HgT loading, MeHg, and cost mitigation within a Bayesian network that integrates information of varying rigor and detail into a simple model of a complex system. Hg processes are identified and quantified by using a combination of historical data, statistical models, and expert judgment. Such an integrated approach to uncertainty analysis allows easy updating of prediction and inference when observations of model variables are made. We demonstrate our approach with data from the Cache Creek watershed (a subbasin of the Sacramento River watershed). The empirical models used to generate the needed probability distributions are based on the same empirical models currently being used by the Central Valley Regional Water Quality Control Cache Creek Hg TMDL working group. The significant difference is that input uncertainty and error are explicitly included in the model and propagated throughout its algorithms. This work demonstrates how to integrate uncertainty into the complex and highly uncertain Hg TMDL decisionmaking process. The various sources of uncertainty are propagated as decision risk that allows decisionmakers to simultaneously consider uncertainties in remediation/implementation costs while attempting to meet environmental/ecologic targets. We must note that this research is on going. As more data are collected, the HgT and cost-mitigation submodels are updated and the uncertainties may be reduced. Subsequently, the value of using a probabilistic framework for estimating and explicitly stating these uncertainties within a decisionmaking process can be estimated when new data are collected. Future work includes the design and implementation of a Bayesian network decision support system (BN-DSS) to produce mitigation scenarios for offset-project evaluation in the Cache Creek watershed. The decisionmaker, a wastewater-treatment plant, is expected to evaluate potential Hg-offset programs in terms of changes in HgT load changes, MeHg-production potential, project cost, and other suitability criteria. Subsequently, scenarios can be analyzed by performing sensitivity analyses and ranking environmental and economic uncertainties in terms of the decisionmaker’s preferences and risk choices. Such an analysis allows decisionmakers and stakeholders to explore various scenarios and predict the consequences of different stated preferences over outcomes.

Open-File Report↗

An approach to urban waterway assessment using holistic values and reciprocity

Current aquatic ecosystem assessment methods and tools often focus on physical, chemical, and biological indicators of ecosystem health. This approach to ecosystem assessment is not always straightforward to execute in urban environments and ignores potential connectivity between social and environmental outcomes. During a workshop at the Symposium on Urbanization and Stream Ecology in Brisbane, Australia in 2023 (SUSE6), we developed an approach to urban aquatic ecosystem assessment that incorporates a holistic perspective. Specifically, our approach considers both environmental (biological, chemical, and physical integrity) and social (community connection, human safety, resource use) values of urban waterways. This approach is inclusive of Indigenous perspectives, such as the concept of reciprocity, whereby consideration of both the environment and society leads to a healthy ecosystem. To highlight how this holistic assessment approach could be used, we present real-world examples that included assessing both environmental and societal values informed by reciprocity or balanced perspectives. This approach can be broadly applied and adapted to specific aquatic ecosystem conditions and projects, providing an inclusive, community-centered approach for assessing the health of waterways in urban environments.

Freshwater Science↗

Understanding knowledge and perceptions of bats among residents of Fort Collins, Colorado

As regional urbanization increases in Colorado, so do interactions between humans and wildlife. Where previous habitat has been reduced due to urbanization and development, a few bat species that easily adapt to new environments now roost in homes and buildings (Kunz and Reynolds, 2003). Bats frequently serve as reservoirs of disease that have potential health consequences for humans and other mammals (Messenger and others, 2003). As bat use of buildings becomes more frequent, the incidences of bat/human contact and the risk of spreading disease also increase. In Colorado, rabies is most common in the big brown bat (Eptesicus fuscus) Pape and others, 1999), the most ubiquitous species of urban-dwelling bat in the United States (Barbour and Davis, 1969) and the most common species submitted for rabies testing in Colorado (Pape and others, 1999). An in-depth knowledge of the big brown bat - including its ecology, habitat and movements, and aspects of disease transmission - and of its interactions with humans is essential for making informed management decisions regarding this species. To balance the competing priorities of species preservation and public safety, natural resource managers and public health professionals must be able to accurately estimate citizens' knowledge, perceptions, and perceived risks regarding the bat species that use human dwellings and harbor diseases potentially dangerous to humans. A recently completed five-year ecological study (2001-2005) on bats inhabiting buildings in Fort Collins, Colo., has provided much information on the basic epidemiology of rabies and on the ecology of the local bat population (Davis, Rudd, and Bowen, 2007; Ellison and others, 2007; Neubaum, Douglas, and others, in press; Neubaum, O'Shea, and Wilson, 2006; Neubaum, Wilson, and O'Shea, 2007; O'Shea, Ellison, and Stanley, 2004; Pearce and O'Shea, 2007; Pearce and others, in press; Shankar and others, 2004; Shankar and others, 2005; Wimsatt and others 2005). Research investigating the human dimensions of bats and bat/rabies relationships, however, has been very limited (Gibbins and others, 2002; Liesener and others, 2006). Herein, we report the results of a study to evaluate perceptions and knowledge of bats and rabies among residents of Fort Collins, Colo. The study resulted from collaborations between U.S. Geological Survey (USGS) bat ecologists of the Trust Species and Habitats branch, and social scientists of the Policy Analysis and Science Assistance branch, both of the USGS Fort Collins Science Center (FORT).

Open-File Report↗

Community clusters of tsunami vulnerability in the US Pacific Northwest

Many coastal communities throughout the world are threatened by local (or near-field) tsunamis that could inundate low-lying areas in a matter of minutes after generation. Although the hazard and sustainability literature often frames vulnerability conceptually as a multidimensional issue involving exposure, sensitivity, and resilience to a hazard, assessments often focus on one element or do not recognize the hazard context. We introduce an analytical framework for describing variations in population vulnerability to tsunami hazards that integrates ( i ) geospatial approaches to identify the number and characteristics of people in hazard zones, ( ii ) anisotropic path distance models to estimate evacuation travel times to safety, and ( iii ) cluster analysis to classify communities with similar vulnerability. We demonstrate this approach by classifying 49 incorporated cities, 7 tribal reservations, and 17 counties from northern California to northern Washington that are directly threatened by tsunami waves associated with a Cascadia subduction zone earthquake. Results suggest three primary community groups: ( i ) relatively low numbers of exposed populations with varied demographic sensitivities, ( ii ) high numbers of exposed populations but sufficient time to evacuate before wave arrival, and ( iii ) moderate numbers of exposed populations but insufficient time to evacuate. Results can be used to enhance general hazard-awareness efforts with targeted interventions, such as education and outreach tailored to local demographics, evacuation training, and/or vertical evacuation refuges.

California, Oregon, Washington↗

The past is the key to the future

A new major frontier of geological research, which was initiated in the 1970's, involves predicting future geologic trends or events through study of the present and past, rather than trying to understand the past, often using what one knows about the present. Like most scientific frontiers, this one began from practical considerations—environmental concerns. The lack of formal recognition of this frontier results from fragmentation among many Federal agencies and highly focused mission-oriented programs ( e.g. , earthquake prediction, CO 2 , nuclear-energy safety, etc.). Most programs aim to predict only the next 50–100 years, but much longer periods of the past need to be studied to do this. Nuclear-waste disposal has sometimes been considered in terms of the next million years, a period of time permitting significant and broad geologic changes. Decreasing public interest in environmental concerns relegates many questions from the realm of applied research back to that of basic research. Most of these questions are so fascinating, however, that the frontier is still worth pursuing. Such questions include whether a phenomenon will or will not take place and the rates at which it can develop ( e.g. , how fast do rifts form, how fast can a caldera event begin, and how quickly can a glacial maximum arrive?). Common elements of all studies include the historic record, trends in the Quaternary, analogues in various periods of the geologic time scale, and allowance for phenomena never experienced before. Other examples of studies include the Cretaceous as a period of a climatic extreme, an especially interesting time period; establishing the amount of paleocloudiness, a particularly challenging and important research area; acid rain as a possible new phenomenon. Geochemistry has much to contribute to this frontier science.

Geochimica et Cosmochimica Acta↗

Assessing locations susceptible to shallow landslide initiation during prolonged intense rainfall in the Lares, Utuado, and Naranjito municipalities of Puerto Rico

Hurricane Maria induced about 70 000 landslides throughout Puerto Rico, USA, including thousands each in three municipalities situated in Puerto Rico's rugged Cordillera Central range. By combining a nonlinear soil-depth model, presumed wettest-case pore pressures, and quasi-three-dimensional (3D) slope-stability analysis, we developed a landslide susceptibility map that has very good performance and continuous susceptibility zones having smooth, buffered boundaries. Our landslide susceptibility map enables assessment of potential ground-failure locations and their use as landslide sources in a companion assessment of inundation and debris-flow runout. The quasi-3D factor of safety, F 3 , showed strong inverse correlation to landslide density (high density at low F 3 ). Area under the curve (AUC) of true positive rate (TPR) versus false positive rate (FPR) indicated success of F 3 in identifying head-scarp points (AUC = 0.84) and source-area polygons (0.85 ≤ AUC ≤ 0.88). The susceptibility zones enclose specific percentages of observed landslides. Thus, zone boundaries use successive F 3 levels for increasing TPR of landslide head-scarp points, with zones bounded by F 3 at TPR = 0.75, very high; F 3 at TPR = 0.90, high; and the remainder moderate to low. The very high susceptibility zone, with 118 landslides km −2 , covered 23 % of the three municipalities. The high zone (51 landslides km −2 ) covered another 10 %.

Puerto Rice↗

Ultrahigh resolution topographic mapping of Mars with MRO HiRISE stereo images: Meter-scale slopes of candidate Phoenix landing sites

The objectives of this paper are twofold: first, to report our estimates of the meter‐to‐decameter‐scale topography and slopes of candidate landing sites for the Phoenix mission, based on analysis of Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images with a typical pixel scale of 3 m and Mars Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) images at 0.3 m pixel −1 and, second, to document in detail the geometric calibration, software, and procedures on which the photogrammetric analysis of HiRISE data is based. A combination of optical design modeling, laboratory observations, star images, and Mars images form the basis for software in the U.S. Geological Survey Integrated Software for Imagers and Spectrometers (ISIS) 3 system that corrects the images for a variety of distortions with single‐pixel or subpixel accuracy. Corrected images are analyzed in the commercial photogrammetric software SOCET SET (® BAE Systems), yielding digital topographic models (DTMs) with a grid spacing of 1 m (3–4 pixels) that require minimal interactive editing. Photoclinometry yields DTMs with single‐pixel grid spacing. Slopes from MOC and HiRISE are comparable throughout the latitude zone of interest and compare favorably with those where past missions have landed successfully; only the Mars Exploration Rover (MER) B site in Meridiani Planum is smoother. MOC results at multiple locations have root‐mean‐square (RMS) bidirectional slopes of 0.8–4.5° at baselines of 3–10 m. HiRISE stereopairs (one per final candidate site and one in the former site) yield 1.8–2.8° slopes at 1‐m baseline. Slopes at 1 m from photoclinometry are also in the range 2–3° after correction for image blur. Slopes exceeding the 16° Phoenix safety limit are extremely rare.

Journal of Geophysical Research E: Planets↗

Land-Use Portfolio Modeler, Version 1.0

Natural hazards pose significant threats to the public safety and economic health of many communities throughout the world. Community leaders and decision-makers continually face the challenges of planning and allocating limited resources to invest in protecting their communities against catastrophic losses from natural-hazard events. Public efforts to assess community vulnerability and encourage loss-reduction measures through mitigation often focused on either aggregating site-specific estimates or adopting standards based upon broad assumptions about regional risks. The site-specific method usually provided the most accurate estimates, but was prohibitively expensive, whereas regional risk assessments were often too general to be of practical use. Policy makers lacked a systematic and quantitative method for conducting a regional-scale risk assessment of natural hazards. In response, Bernknopf and others developed the portfolio model, an intermediate-scale approach to assessing natural-hazard risks and mitigation policy alternatives. The basis for the portfolio-model approach was inspired by financial portfolio theory, which prescribes a method of optimizing return on investment while reducing risk by diversifying investments in different security types. In this context, a security type represents a unique combination of features and hazard-risk level, while financial return is defined as the reduction in losses resulting from an investment in mitigation of chosen securities. Features are selected for mitigation and are modeled like investment portfolios. Earth-science and economic data for the features are combined and processed in order to analyze each of the portfolios, which are then used to evaluate the benefits of mitigating the risk in selected locations. Ultimately, the decision maker seeks to choose a portfolio representing a mitigation policy that maximizes the expected return-on-investment, while minimizing the uncertainty associated with that return-on-investment. The portfolio model, now known as the Land-Use Portfolio Model (LUPM), provided the framework for the development of the Land-Use Portfolio Modeler, Version 1.0 software (LUPM v1.0). The software provides a geographic information system (GIS)-based modeling tool for evaluating alternative risk-reduction mitigation strategies for specific natural-hazard events. The modeler uses information about a specific natural-hazard event and the features exposed to that event within the targeted study region to derive a measure of a given mitigation strategy`s effectiveness. Harnessing the spatial capabilities of a GIS enables the tool to provide a rich, interactive mapping environment in which users can create, analyze, visualize, and compare different

Techniques and Methods↗

Characterization of seismic hazard and structural response by energy flux

Seismic safety of structures depends on the structure's ability to absorb the seismic energy that is transmitted from ground to structure. One parameter that can be used to characterize seismic energy is the energy flux. Energy flux is defined as the amount of energy transmitted per unit time through a cross-section of a medium, and is equal to kinetic energy multiplied by the propagation velocity of seismic waves. The peak or the integral of energy flux can be used to characterize ground motions. By definition, energy flux automatically accounts for site amplification. Energy flux in a structure can be studied by formulating the problem as a wave propagation problem. For buildings founded on layered soil media and subjected to vertically incident plane shear waves, energy flux equations are derived by modeling the buildings as an extension of the layered soil medium, and considering each story as another layer. The propagation of energy flux in the layers is described in terms of the upgoing and downgoing energy flux in each layer, and the energy reflection and transmission coefficients at each interface. The formulation results in a pair of simple finite-difference equations for each layer, which can be solved recursively starting from the bedrock. The upgoing and downgoing energy flux in the layers allows calculation of the energy demand and energy dissipation in each layer. The methodology is applicable to linear, as well as nonlinear structures. ?? 2000 Published by Elsevier Science Ltd.

Soil Dynamics and Earthquake Engineering↗

At the crossroads: Hazard assessment and reduction of health risks from arsenic in private well waters of the northeastern United States and Atlantic Canada

This special issue contains 12 papers that report on new understanding of arsenic (As) hydrogeochemistry, performance of household well water treatment systems, and testing and treatment behaviors of well users in several states of the northeastern region of the United States and Nova Scotia, Canada. The responsibility to ensure water safety of private wells falls on well owners. In the U.S., 43 million Americans, mostly from rural areas, use private wells. In order to reduce As exposure in rural populations that rely on private wells for drinking water, risk assessment, which includes estimation of population at risk of exposure to As above the EPA Maximum Contaminant Level, is helpful but insufficient because it does not identify individual households at risk. Persistent optimistic bias among well owners against testing and barriers such as cost of treatment mean that a large percentage of the population will not act to reduce their exposure to harmful substances such as As. If households are in areas with known As occurrence, a potentially large percentage of well owners will remain unaware of their exposure. To ensure that everyone, including vulnerable populations such as low income families with children and pregnant women, is not exposed to arsenic in their drinking water, alternative action will be required and warrants further research.

Maine, New Hampshire, Massachusetts, Connecticut, ↗

Large scale Wyoming transportation data: a resource planning tool

The U.S. Geological Survey Fort Collins Science Center created statewide roads data for the Bureau of Land Management Wyoming State Office using 2009 aerial photography from the National Agriculture Imagery Program. The updated roads data resolves known concerns of omission, commission, and inconsistent representation of map scale, attribution, and ground reference dates which were present in the original source data. To ensure a systematic and repeatable approach of capturing roads on the landscape using on-screen digitizing from true color National Agriculture Imagery Program imagery, we developed a photogrammetry key and quality assurance/quality control protocols. Therefore, the updated statewide roads data will support the Bureau of Land Management’s resource management requirements with a standardized map product representing 2009 ground conditions. The updated Geographic Information System roads data set product, represented at 1:4,000 and +/- 10 meters spatial accuracy, contains 425,275 kilometers within eight attribute classes. The quality control of these products indicated a 97.7 percent accuracy of aspatial information and 98.0 percent accuracy of spatial locations. Approximately 48 percent of the updated roads data was corrected for spatial errors of greater than 1 meter relative to the pre-existing road data. Twenty-six percent of the updated roads involved correcting spatial errors of greater than 5 meters and 17 percent of the updated roads involved correcting spatial errors of greater than 9 meters. The Bureau of Land Management, other land managers, and researchers can use these new statewide roads data set products to support important studies and management decisions regarding land use changes, transportation and planning needs, transportation safety, wildlife applications, and other studies.

Wyoming↗

The discourses of incidents: Cougars on Mt. Elden and in Sabino Canyon, Arizona

Incidents are relatively short periods of intensified discourse that arise from public responses to symbolically important actions by public officials, and an important part of the conflict that increasingly surrounds state wildlife management in the West. In an effort to better understand incidents as a facet of this conflict, we analyzed the discourses of two incidents in Arizona that were precipitated by the intended removal of cougars by managers in response to public safety concerns. We used newspaper content, 1999–2007, to elucidate seminal patterns of public discourses and discourse coalitions as well as differences in discursive focus between incident periods and background periods. Cougars were mentioned in newspaper articles 13–33 times more often during incidents compared with background periods. State wildlife agency commissioners and hunters were part of a discourse coalition that advocated killing cougars to solve problems, blamed cougars and those who promoted the animals’ intrinsic value and sought to retain power to define and solve cougar-related problems. Personnel from affected state and federal agencies expressed a similar discourse. Environmentalists, animal protection activists, and some elected officials were of a coalition that defined “the problem” primarily in terms of people’s behaviors, including behaviors associated with current institutional arrangements. This discourse advocated decentralizing power over cougar management. The discourses reflected different preferences for the allocations of power and use of lethal versus non-lethal methods, which aligned with apparent core beliefs and participants’ enfranchisement or disenfranchisement by current state-level management power arrangements.

Arizona↗