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Focuses on the concept of satellite settlements in relation to working environment in Steptoe City, Nevada. Characteristics of satellite settlements; Existence of neighborhoods in company towns; Role of marginal neighborhood on socioeconomic system.

The article reports that documents relating to the safety of the proposed nuclear-waste repository at Yucca Mountain in Nevada may have been falsified. A hydrologist at the U.S. Geological Survey (USGS), who was studying how water flowed through the mountain, faked documentation on the times and dates at which certain geological samples were taken from the site. The water data are crucial because the repository's safety depends heavily on how wet it is likely to get inside, and on how long it takes for water to escape from the mountain rock into surrounding river systems.

Context: Topographic ruggedness has been examined in thousands of ecological studies and is a popular variable for characterizing habitat selection. Despite widespread adoption, ruggedness metrics are often applied uncritically and require systematic and thorough testing using both artificial landscapes and real-world applications. Objectives: In this paper we introduce a technique that removes the correlation of topographic ruggedness with curvature in order to more accurately represent fine-scale surface ruggedness. Methods: We test our modified version of several ruggedness metrics against traditional ruggedness metrics using three ideal ruggedness criteria in artificial landscapes. We further tested our modified ruggedness measures using 449 real mountain ranges in Nevada, USA. Using desert bighorn sheep as a case study, we tested both modified and uncorrected ruggedness measures and slope in a multiscale context in order to examine habitat selection by female bighorn sheep. Results: The modified versions of the metrics passed all three criteria of the ideal ruggedness test and was able to accurately capture surface ruggedness. Modified versions of ruggedness differed from uncorrected versions by containing fewer highly rugged cells along ridgelines and drainages. Habitat relationships of desert bighorn sheep with ruggedness were scale-dependent, such that female sheep selected for steep slopes at fine spatial scales and ruggedness at moderate spatial scales. Conclusions: We demonstrate that there are three components to ruggedness: elevation variation, aspect diversity, and surface ruggedness representing first, second, and third generation ruggedness indices. Our technique for removing underlying topographic variation provides an improved mapping of surface ruggedness and augments the other two generations of ruggedness metrics. [ABSTRACT FROM AUTHOR]

The energy equation is an expression of the first law of thermodynamics or the law of conservation of energy. According to the first law of thermodynamics, the externally applied work to a system is equal to the sum of dissipation energy and Helmholtz free energy of the system. However, most of the currently available stress–dilatancy relationships are based on the energy equation of Taylor-Cam Clay type, which hypothesizes that the applied plastic work is equal solely to the frictional dissipation energy. The Helmholtz free energy has been completely neglected. Recently, observed from acoustic experiments, it has been recognized that Helmholtz free energy can be caused by deformation mechanisms other than friction between particles. Thus, it is necessary to include additional terms in the energy equation in order to correctly model the stress-dilatancy behavior. This paper addresses the issue regarding the balance of this energy equation. Analyses of experimental results are presented. Specific forms of the frictional energy and Helmholtz free energy are proposed. The proposed energy equation is verified with the experimental data obtained from Silica sand, Ottawa sand, and Nevada sand. [ABSTRACT FROM AUTHOR]

Underground gold mines in Nevada are exploiting increasingly deeper ore bodies comprised of weak to very weak rock masses. The Rock Mass Rating (RMR) classification system is widely used at underground gold mines in Nevada and is applicable in fair to good-quality rock masses, but is difficult to apply and loses reliability in very weak rock mass to soil-like material. Because very weak rock masses are transition materials that border engineering rock mass and soil classification systems, soil classification may sometimes be easier and more appropriate to provide insight into material behavior and properties. The Unified Soil Classification System (USCS) is the most likely choice for the classification of very weak rock mass to soil-like material because of its accepted use in tunnel engineering projects and its ability to predict soil-like material behavior underground. A correlation between the RMR and USCS systems was developed by comparing underground geotechnical RMR mapping to laboratory testing of bulk samples from the same locations, thereby assigning a numeric RMR value to the USCS classification that can be used in spreadsheet calculations and geostatistical analyses. The geotechnical classification system presented in this paper including a USCS-RMR correlation, RMR rating equations, and the Geo-Pick Strike Index is collectively introduced as the Weak Rock Mass Rating System (W-RMR). It is the authors' hope that this system will aid in the classification of weak rock masses and more usable design tools based on the RMR system. More broadly, the RMR-USCS correlation and the W-RMR system help define the transition between engineering soil and rock mass classification systems and may provide insight for geotechnical design in very weak rock masses. [ABSTRACT FROM AUTHOR]

Conventional gravity inversion techniques have limited ability to quantify structural uncertainty in geologic models. In this paper, a stochastic framework is proposed that directly incorporates fault-related and density-related uncertainty into the inversion process. The approach uses Monte Carlo simulation to generate model realizations and the gradual deformation method to further refine models to match observed data. To guarantee that model realizations are structurally restorable, fault displacements are generated using a kinematic modeling approach in which fault model properties such as the number of faults, location, dip, slip, and orientation are considered uncertain. Using a synthetic case study problem, a reference gravity field was inverted to generate a suite of posterior model realizations. Analysis of the posterior models was used to create a fault probability map as well as quantify the distribution of slip and dip of faults in three zones of deformation. Uncertainty in density values was found to be greatly reduced in the top 250 m depth, suggesting limited sensitivity to deeper sources in this example. Following the synthetic case study problem, the inversion approach was applied to a field-observed gravity profile in Dixie Valley, Nevada, and the inversion results were compared to a previously published forward gravity model. By generating a suite of posterior models, structural uncertainty can be better assessed to make more informed decisions in a host of subsurface modeling problems. [ABSTRACT FROM AUTHOR]

The susceptibility of Alloy 22 (N06022) to crevice corrosion may depend on environmental and metallurgical variables. This paper summarizes the current findings regarding the effect of many of these variables, such as pH, other inhibitive species and types of crevicing material, geometry, and applied torque. There are still contradictory results regarding the effect of metallurgical factors such as the presence of weld seams. Crevice corrosion stifling and arrest must be considered in evaluating the life expectancy of components made of Alloy 22. [ABSTRACT FROM AUTHOR]

In this paper, we present an analysis using unsupervised machine learning (ML) to identify the key geologic factors that contribute to the geothermal production in Brady geothermal field. Brady is a hydrothermal system in northwestern Nevada that supports both electricity production and direct use of hydrothermal fluids. Transmissive fluid-flow pathways are relatively rare in the subsurface, but are critical components of hydrothermal systems like Brady and many other types of fluid-flow systems in fractured rock. Here, we analyze geologic data with ML methods to unravel the local geologic controls on these pathways. The ML method, non-negative matrix factorization with k-means clustering (NMFk), is applied to a library of 14 3D geologic characteristics hypothesized to control hydrothermal circulation in the Brady geothermal field. Our results indicate that macro-scale faults and a local step-over in the fault system preferentially occur along production wells when compared to injection wells and non-productive wells. We infer that these are the key geologic characteristics that control the through-going hydrothermal transmission pathways at Brady. Our results demonstrate: (1) the specific geologic controls on the Brady hydrothermal system and (2) the efficacy of pairing ML techniques with 3D geologic characterization to enhance the understanding of subsurface processes. [ABSTRACT FROM AUTHOR]

Methods for estimating juvenile survival of wildlife populations often rely on intensive data collection efforts to capture and uniquely mark individual juveniles and observe them through time. Capturing juveniles in a time frame sufficient to estimate survival can be challenging due to narrow and stochastic windows of opportunity. For many animals, juvenile survival depends on postnatal parental care (e.g., lactating mammals). When a marked adult gives birth to, and provides care for, juvenile animals, investigators can use the adult mark to locate and count unmarked juveniles. Our objective was to leverage the dependency between juveniles and adults and develop a framework for estimating reproductive rates, juvenile survival, and detection probability using repeated observations of marked adult animals with known fates, but imperfect detection probability, and unmarked juveniles with unknown fates. Our methods assume population closure for adults and that no juvenile births or adoptions take place after monitoring has begun. We conducted simulations to evaluate methods and then developed a field study to examine our methods using real data consisting of a population of mule deer in a remote area in central Nevada. Using simulations, we found that our methods were able to recover the true values used to generate the data well. Estimates of juvenile survival rates from our field study were 0.96, (95% CRI 0.83–0.99) for approximately 32-day periods between late June and late August. The methods we describe show promise for many applications and study systems with similar data types, and our methods can be easily extended to unmanned aerial platforms and cameras that are already commercially available for the types of images we used. Supplementary materials accompanying this paper appear online. [ABSTRACT FROM AUTHOR]

Copyright of Fire Ecology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purpose of this paper is to describe the development, actions, and evaluation of a university-based, transdisciplinary coalition so that the model may be replicated in other university or multidisciplinary systems. The University of Nevada Las Vegas (UNLV) Mental and Behavioral Health Coalition addresses Nevada's workforce shortages through multi-disciplinary faculty collaboration among seven training programs at UNLV that produce mental health professionals. The coalition's collaborative approach to solution-generating work has served as a catalyst for professional integration in the community as a whole. [ABSTRACT FROM AUTHOR]

Copyright of Mine Water & the Environment is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article focuses on the links between the chronic fatigue syndrome (CFS) and the XMRV virus, according to Judy Mikovits, viral immunologist at the Whittemore Peterson Institute for Neuro-Immune Disease (WPI) in Reno, Nevada. It explores the criticism on Mikovits' findings as well as the support she receives from patients with CFS. It explores the efforts of researchers and public-health officials to find out if XMRV virus could be spread by blood products.

Stress corrosion cracking (SCC) is one of the most common corrosion-related causes of premature failure of metal structural components. This paper presents an assessment of the performance of titanium alloys (titanium grade 7 for the drip shield and grade 29 for the structural support), which may be subjected to SCC under proposed U.S. nuclear waste repository environments. The threshold stresses for SCC initiation, SCC crack propagation rates, and the threshold stress intensity factors for titanium grades 7, 28, and 29 are discussed. [ABSTRACT FROM AUTHOR]

The U.S. Department of Energy (DOE) has indicated that it may use Alloy 22 as the waste package outer container material for the potential high-level waste repository at Yucca Mountain, Nevada. Additionally, a drip shield, made of titanium grade 7 and titanium grade 29, may extend the length of the emplacement drifts to enclose the top and sides of the emplaced waste package. Localized corrosion in the form of crevice corrosion could be one degradation process that may adversely affect the waste package performance. This paper will summarize the work conducted to evaluate the effects of environmental conditions relevant to the potential Yucca Mountain repository, metallurgical states (e.g., mill-annealed and welded plus solution annealed), and similar and dissimilar metal crevices on the crevice corrosion susceptibility of Alloy 22. This work also evaluates crevice corrosion propagation behavior resulting from contact with Alloy 22 or titanium grade 7. [ABSTRACT FROM AUTHOR]

This paper presents the general corrosion model used by the Yucca Mountain Project to account for general corrosion degradation of the Alloy 22 waste package outer barrier. The general corrosion rates were determined from mass-loss measurements of specimens exposed to repository-relevant solutions at 60°C and 90°C for about five years. An Alloy 22 general corrosion temperature dependence was obtained from short-term polarization resistance measurements and found to be consistent with values quoted in the literature. Uncertainty in mass-loss data and model fitting was evaluated and incorporated into the resultant Alloy 22 general corrosion model. [ABSTRACT FROM AUTHOR]

This paper describes the use of lichen chemistry to assess airborne tungsten and cobalt in Fallon, Nevada, where a cluster of childhood leukemia has been on going since 1997. Lichens and their rock substrates were collected from Rattlesnake Hill within Fallon as well as from four different rock outcrops located north, east, south, and west of Fallon and at least 20 km away from the town center. In the lichens themselves, W and Co are significantly higher within Fallon than in the combined control site outside of Fallon. In the rock substrates of the lichens, no differences exist in W and Co. The W and Co differences in lichens cannot be attributed to substrate geochemistry. Fallon is distinctive in west central Nevada for high airborne W and Co, and given its cluster of childhood leukemia, it stands to reason that additional biomedical research is in order to test directly the leukogenicity of combined airborne W and Co. [ABSTRACT FROM AUTHOR]

Much of the academic literature dealing with state and local demography involves the development and evaluation of methods for estimating population. The focus on estimation methods is not surprising because they are used in many states to allocate resources. The quality control in regard to the validity and reliability afforded these methods by the traditional academic peer review process is important because, among other things, it serves to reduce the high potential for conflict that exists when resources are at stake. There are, however, methods being used by state and local demographers that have not been subject to peer review. While not necessarily un- sound, these "fugitive" methods serve to keep the potential for conflict high because of the uncertainty regarding their validity and reliability. This paper examines just such a situation in the form of a case study. It is a discussion of a regression model developed in Nevada following the 2000 census that led to conflict over its use to estimate the population of Clark County, Nevada in 2002. The discussion reveals statistical and methodological shortcomings in this model that lead to an alternative model not subject to these shortcomings. This example illustrates how this type of analysis and discussion can lead to a wider understanding of methods on the part of practitioners through the corrective process of academic peer review. It also suggests that states in which estimates are used to allocate resources would be well-served by subjecting new methods being considered for use to academic peer review before they are adopted. [ABSTRACT FROM AUTHOR]

Three-dimensional geophysical inversion modeling of gravity data has been performed to test the validity of a 3D geologic model constructed for the Bradys geothermal area. Geophysical modeling was implemented in three different ways: (1) fully unconstrained (i.e., no geologic data included); (2) constrained by the 3D geologic model using homogeneous rock unit densities, and (3) constrained by the 3D geologic model using heterogeneous rock unit densities. We show that the existing 3D geologic model of the Bradys area is broadly consistent with the gravity data. At a more detailed level, however, our analysis suggests that some adjustments to the Bradys 3D geologic model would improve agreement between the observed gravity and the calculated gravity response. The results of the geophysical inversion modeling are important as they serve as a guide to show where and how the boundaries of the 3D geologic model may need to be adjusted to address density excesses and deficiencies. A 3D geologic model that has been independently tested prior to drilling (using a method such as that described in this paper) will be more robust and have less uncertainty than those which have not been tested. Such an approach will facilitate a reduction in drilling risk, lead to more successful drilling programs, and provide valuable geologic input to improve the accuracy of reservoir models. [ABSTRACT FROM AUTHOR]

Wraparound is a widely-implemented team-based care coordination process for youth with serious emotional and behavioral needs. Wraparound has a positive evidence base; however, research has shown inconsistency in the quality of its implementation that can reduce its effectiveness. The current paper presents results of three studies used to examine psychometrics, reliability, and validity of a measure of wraparound fidelity as assessed during team meetings called the Team Observation Measure (TOM). Analysis of TOM results from 1,078 team observations across 59 sites found good overall internal consistency (α = 0.80), but constrained variability, with the average team rated as having 78 % of indicators of model adherent wraparound present, 11 % absent, and 11 % not applicable. A study of N = 23 pairs of raters found a pooled Kappa statistic of 0.733, indicating substantial inter-rater reliability. Higher agreement was found between external evaluators than for pairs of raters that included an external evaluator and an internal rater (e.g., supervisor or coach). A validity study found no correlation between the TOM and an alternate fidelity instrument, the Wraparound Fidelity Index (WFI), at the team level. However, positive correlations between mean program-level TOM and WFI scores provide support for TOM validity as a summative assessment of site- or program-level fidelity. Implications for TOM users, measure refinement, and future research are discussed. [ABSTRACT FROM AUTHOR]

This paper reviews different approaches to the problem of finding the shape of the basement buried under sedimentary basins from gravity data and explores the applicability of a recently proposed method to a well-constrained real case, comparing the results obtained with the models computed using a variety of techniques. Many gravity inversion techniques to estimate the depth to basement based on rather different approaches have been proposed. As is well known, the interpretation of gravity data requires certain assumptions about the source, aimed at constraining the solution of an ambiguous problem. The different approaches imply different kinds of solutions, namely a density contrast distribution at depth, or a grid defining the depth to basement in the entire area of study or several single depth estimates. Each approach has its own advantages and weaknesses. In this context, special attention is given to the ITerative RESCaling method (ITRESC), which has been recently proposed. In this method, there is no need to assume a density function, which is estimated by a data-driven procedure and then used to generate a grid of the depth to basement. This technique is based on the depth–gravity relation plot, illustrating the link between the depth to basement, known at some control points (e.g., boreholes or interpretation of other geophysical data), and the values of the residual gravity anomaly. An important feature of the ITRESC method is that borehole control points are used globally rather than locally, providing constraints for all parts of the model. The main features of this innovative method are illustrated and evaluated by its application to the gravity anomalies of the Yucca Flat basin (Nevada). The results are compared with models obtained by previous gravity interpretations and by the processing of other geological and geophysical data. [ABSTRACT FROM AUTHOR]

Pollen identification is necessary for several subfields of geology, ecology, and evolutionary biology. However, the existing methods for pollen identification are laborious, time-consuming, and require highly skilled scientists. Therefore, there is a pressing need for an automated and accurate system for pollen identification, which can be beneficial for both basic research and applied issues such as identifying airborne allergens. In this study, we propose a deep learning (DL) approach to classify pollen grains in the Great Basin Desert, Nevada, USA. Our dataset consisted of 10,000 images of 40 pollen species. To mitigate the limitations imposed by the small volume of our training dataset, we conducted an in-depth comparative analysis of numerous pre-trained Convolutional Neural Network (CNN) architectures utilizing transfer learning methodologies. Simultaneously, we developed and incorporated an innovative CNN model, serving to augment our exploration and optimization of data modeling strategies. We applied different architectures of well-known pre-trained deep CNN models, including AlexNet, VGG-16, MobileNet-V2, ResNet (18, 34, and 50, 101), ResNeSt (50, 101), SE-ResNeXt, and Vision Transformer (ViT), to uncover the most promising modeling approach for the classification of pollen grains in the Great Basin. To evaluate the performance of the pre-trained deep CNN models, we measured accuracy, precision, F1-Score, and recall. Our results showed that the ResNeSt-110 model achieved the best performance, with an accuracy of 97.24%, precision of 97.89%, F1-Score of 96.86%, and recall of 97.13%. Our results also revealed that transfer learning models can deliver better and faster image classification results compared to traditional CNN models built from scratch. The proposed method can potentially benefit various fields that rely on efficient pollen identification. This study demonstrates that DL approaches can improve the accuracy and efficiency of pollen identification, and it provides a foundation for further research in the field. [ABSTRACT FROM AUTHOR]

Background: Regular school attendance is foundational to children's success but school absenteeism is a common, serious, and highly vexing problem. Researchers from various disciplines have produced a rich yet diverse literature for conceptualizing problematic absenteeism that has led to considerable confusion and lack of consensus about a pragmatic and coordinated assessment and intervention approach. Objective: To lay the foundation and suggested parameters for a Response to Intervention (RtI) model to promote school attendance and address school absenteeism. Methods: This is a theoretical paper guided by a systematic search of the empirical literature related to school attendance, chronic absenteeism, and the utilization of an RtI framework to address the needs of school-aged children and youth. Results: The RtI and absenteeism literature over the past 25 years have both emphasized the need for early identification and intervention, progress monitoring, functional behavioral assessment, empirically supported procedures and protocols, and a team-based approach. An RtI framework promotes regular attendance for all students at Tier 1, targeted interventions for at-risk students at Tier 2, and intense and individualized interventions for students with chronic absenteeism at Tier 3. Conclusions: An RtI framework such as the one presented here could serve as a blueprint for researchers as well as educational, mental health, and other professionals. To develop this model and further enhance its utility for all youth, researchers and practitioners should strive for consensus in defining key terms related to school attendance and absenteeism and focus more on prevention and early intervention efforts. [ABSTRACT FROM AUTHOR]

This paper develops a novel method, based on hidden Markov models, to forecast earthquakes and applies the method to mainshock seismic activity in southern California and western Nevada. The forecasts are of the probability of a mainshock within 1, 5, and 10 days in the entire study region or in specific subregions and are based on the observations available at the forecast time, namely the interevent times and locations of the previous mainshocks and the elapsed time since the most recent one. Hidden Markov models have been applied to many problems, including earthquake classification; this is the first application to earthquake forecasting. [ABSTRACT FROM AUTHOR]

In this paper we study an isolated high-mountain (Sierra Nevada, SE Iberian Peninsula) to identify the potential trends in the habitat-suitability of five key species (i.e. species that domain a given vegetation type and drive the conditions for appearance of many other species) corresponding to four vegetation types occupying different altitudinal belts, that might result from a sudden climatic shift. We used topographical variables and downscaled climate warming simulations to build a high-resolution spatial database (10 m) according to four different climate warming scenarios for the twenty-first century. The spatial changes in the suitable habitat were simulated using a species distribution model, in order to analyze altitudinal shifts and potential habitat loss of the key species. Thus, the advance and receding fronts of known occurrence locations were computed by introducing a new concept named differential suitability, and potential patterns of substitution among the key species were established. The average mean temperature trend show an increase of 4.8°C, which will induce the vertical shift of the suitable habitat for all the five key species considered at an average rate of 11.57 m/year. According to the simulations, the suitable habitat for the key species inhabiting the summit area, where most of the endemic and/or rare species are located, may disappear before the middle of the century. The other key species considered show moderate to drastic suitable habitat loss depending on the considered scenario. Climate warming should provoke a strong substitution dynamics between species, increasing spatial competition between both of them. In this study, we introduce the application of differential suitability concept into the analysis of potential impact of climate change, forest management and environmental monitoring, and discuss the limitations and uncertainties of these simulations. [ABSTRACT FROM AUTHOR]

This paper provides both a detailed history of environmental change in the Sierra Nevada over the past 1,800 years and evidence for climate teleconnections between the Sierra Nevada and Greenland during the late Holocene. A review of Greenland ice core data suggests that the magnitudes of abrupt changes in temperature and precipitation increased beginning c. 3,700 and 3,000 years ago, respectively. Precipitation increased abruptly 1,300 years ago. Comparing paleotemperature data from Cirque Peak, CA with paleoprecipitation data from Pyramid Lake, NV suggests that hot temperatures occurred at the beginnings of most severe droughts in the Sierra Nevada over the past 1,800 years. Severe fires and erosion also occurred at Coburn Lake, CA at the beginning of all severe droughts in the Sierra Nevada over the past 1,800 years. This suggests that abrupt climate change during the late Holocene caused vegetation and mountain slopes in some areas to be out of equilibrium with abruptly changed climates. Finally, the ending of drought conditions in Greenland coincided with the beginning of drought conditions in the Sierra Nevada over the past 1,800 years, perhaps as a result of the rapidly changed locations of the Earth's major precipitation belts during abrupt climate change events. [ABSTRACT FROM AUTHOR]

Maar volcanoes are generally understood to be the result of highly energetic, explosive interaction between magma and water (groundwater or surface water). Two end-member conceptual models have been proposed to explain the dimensions (diameter, depth) of maar craters: (1) an incremental growth model, where a crater grows due to subsidence and ejection of debris over the course of many explosions, and the final size is an integrated result of multiple explosive events; (2) a model in which the dimensions of a maar crater are the result of the largest single explosion during the lifetime of the maar (major-explosion dominated model). In the latter case, the maar size can be used to estimate the energy and depth of the largest explosion, which in turn allows estimation of the magma mass involved. This paper describes Lunar Crater maar (Nevada, USA) and tests the two models as explanations for the characteristics of the volcano, in particular the major-explosion dominated model. This model implies magma mass and supply rates that are unrealistic, and the tephra at the maar do not contain key features observed in the ejecta at large single-explosion craters. The incremental growth model seems most suitable based upon geological evidence. [ABSTRACT FROM AUTHOR]

Small area population projections are useful in a range of business applications. This paper uses a case study to show how this type of task can be accomplished by using the Hamilton–Perry method, which is a variant of the cohort-component projection technique. We provide the documentation on the methods, data, and assumptions used to develop two sets of population projections for census tracts in Clark County, Nevada, and discuss specific factors needed to accomplish this task, including the need to bring expert judgment to bear on the task. Our experience suggests that the Hamilton–Perry Method is an important tool and we advise considering it for small forecasting needs in the private sector. [ABSTRACT FROM AUTHOR]

Hyperspectral imaging is a new emerging technology in remote sensing which generates hundreds of images, at different wavelength channels, for the same area on the surface of the Earth. Over the last years, many algorithms have been developed with the purpose of finding endmembers, assumed to be pure spectral signatures in remotely sensed hyperspectral data sets. One of the most popular techniques has been the pixel purity index (PPI). This algorithm is very time-consuming. The reconfigurability, compact size, and high computational power of Field programmable gate arrays (FPGAs) make them particularly attractive for exploitation in remote sensing applications with (near) real-time requirements. In this paper, we present an FPGA design for implementation of the PPI algorithm. Our systolic array design includes a DMA and implements a prefetching technique to reduce the penalties due to the I/O communications. We have also included a hardware module for random number generation. The proposed method has been tested using real hyperspectral data collected by NASA's Airborne Visible Infrared Imaging Spectrometer over the Cuprite mining district in Nevada. Experimental results reveal that the proposed hardware system is easily scalable and able to provide accurate results with compact size in (near) real-time, whichmake our reconfigurable system appealing for on-board hyperspectral data processing. [ABSTRACT FROM AUTHOR]

At the Nevada Terawatt Facility we investigated the generation of a sheared plasma flow using conical wire arrays with an additional wire located on the axis of the pinch. The additional center wire generates axial current carrying plasma that serves as a target for the plasma accelerated from the outer wires, generating a sheared plasma flow which leads to the growth of the Kelvin-Helmholtz instability. These experiments were conducted on Zebra, a 2 TW pulse power device capable of delivering a 1 MA current in 100 ns. This paper will focus on the implosion dynamics that lead to shear flow and the development of the Kelvin Helmholtz instability. [ABSTRACT FROM AUTHOR]

In many underground nuclear waste repository systems, such as Yucca Mountain project, water flow rate and amount of water seepage into the waste emplacement drifts are mainly determined by hydrological properties of fracture network in the surrounding rock mass. Natural fracture network system is not easy to describe, especially with respect to its connectivity which is critically important for simulating the water flow field. In this paper, we introduced a new method for fracture network description and prediction, termed multi-point-statistics (MPS). The process of Multi-point Statistical method is to record multiple-point statistics concerning the connectivity patterns of fracture network from a known fracture map, and to reproduce multiple-scale training fracture patterns in a stochastic manner, implicitly and directly. It is applied to fracture data to study flow field behavior at Yucca Mountain waste repository system. First, MPS method is used to create fracture network with original fracture training image from Yucca Mountain dataset. After we adopt a harmonic and arithmetic average method to upscale the permeability to a coarse grid, THM simulation is carried out to study near-field water flow in surrounding rock of waste emplacement drifts. Our study shows that connectivity or pattern of fracture network can be grasped and reconstructed by Multi-Point-Statistical method. In theory, it will lead to better prediction of fracture system characteristics and flow behavior. Meanwhile, we can obtain variance from flow field, which gives us a way to quantify uncertainty of models even in complicated coupled THM simulation. It indicates that Multi-Point Statistics is a potential method to characterize and reconstruct natural fracture network in a fractured rock mass with advantages of quantifying connectivity of fracture system and its simulation uncertainty simultaneously. [ABSTRACT FROM AUTHOR]

Until the recent introduction of real estate futures on the Chicago Mercantile Exchange (CME), there have been few opportunities to manage house price risk. This paper examines whether house price risk can be effectively hedged in Las Vegas, one of the CME contract cities. The analysis considers hedging from the viewpoint of real estate investment groups, mortgage portfolio investors, builder/developers and individual homeowners. For investment groups and mortgage holders holding a mix of new and existing home assets, CME futures would have reduced house price risk by more than 88% over the 1994–2006 period. Similarly, homeowners implicitly hedging price volatility of existing homes also would have fared well over the sample period. However, builder/developers worried about new home price appreciation would have been much less successful in managing their risk. One important caveat, minimum variance hedge ratios change over time and may cause hedge performance to suffer. [ABSTRACT FROM AUTHOR]

Desert springs, often the sole sources of water for wildlife and cattle, support wetland and wetland/upland transition ecosystems including rare and endemic species. In the basin and range province in Nevada, USA, springs in the Great Basin and Mojave deserts are sustained by interconnected deep carbonate and shallow basin-fill aquifers which are threatened by proposed groundwater withdrawal to sustain rapidly expanding urban areas, a common problem in arid regions worldwide. This paper draws on historic groundwater data, groundwater modeling, and studies of environmental controls of spring ecosystems to speculate on the potential effects of groundwater withdrawal and water table decline on spring-supported vegetation. The focus is on springs in the Great Basin and Mojave deserts representative of those that may be affected by future, planned groundwater withdrawal. Groundwater withdrawal is expected to reduce spring discharge directly through reduced flows from the shallow basin-fill aquifer or through reduction of the hydraulic head of the deep carbonate aquifer. This flow reduction will truncate the outflow stream, reducing the areal cover of wetland and wetland/upland transition vegetation. Lowering the local water table may also reduce the amount of upland phreatophytic vegetation by causing water levels to drop below plant rooting depths. Percolation of salts to surface soils may be reduced, eventually altering desert shrub cover from halophytes to nonhalophytes. The extent of these effects will vary among springs, based on their distance from extraction sites and location relative to regional groundwater flow paths. On-site monitoring of biotic variables (including cover of selected hygrophytes and phreatophytes) should be a necessary complement to the planned monitoring of local hydrologic conditions. [ABSTRACT FROM AUTHOR]

For more than two decades, an extensive scientific effort has been underway to determine whether Yucca Mountain, Nevada, is a suitable site for a deep underground repository for spent nuclear fuel and high-level radioactive waste. Even though the geologic site is stable, additional engineered barriers are planned, including waste packages, drip shields, and tunnel inverts that will be within the emplacement tunnels. Research is under way into the best materials for corrosion prevention in those engineered barriers to ensure their long-term mechanical integrity. [ABSTRACT FROM AUTHOR]

Samples of rock, soil and seepage were collected from Yucca Mountain, USA, and analyzed for 36Cl/Cl ratios by accelerator mass spectrometry (AMS). Rock excavated from the Drill Hole Wash fault at repository horizon depths produced a ratio suggesting that small amounts of water with “bomb-pulse” 36Cl had percolated to that site over the past 50 years. Rock from four other sites within the exploratory studies facility did not yield bomb-pulse ratios. Ratios in the soil varied depending on depth and location, with some samples producing bomb-pulse signatures. Ratios for seep water were slightly elevated above the present cosmogenic background value. This paper also discusses results from a column study mimicking the passage of 36Cl through volcanic rock and from an experiment using bromide instead of chloride as a carrier in sample preparation for AMS. [ABSTRACT FROM AUTHOR]

This paper presents a probabilistic formulation of unsaturated flow through rough multi-segmented fractures, with emphasis on Dripping Initiation Time (DIT), and attempts to explain the fast flow paths detected at the Yucca Mountain (YM) Exploratory Studies Facility (ESF). Three scenarios of parameters were used to test the validity of the model with these fast flow paths. The scenarios differed in the DITs and the corresponding parameter configurations were also tested for three different stratigraphic horizon depths. Each depth represented a different location where fast flow has been detected at YM. The first depth corresponds to the Bow Ridge Fault; the second represents a network of steep fractures and cooling joints with large variability in dip; and the third location, probably connected to the Diabolous Ridge Fault, has a flow path that is low dipping. Monte Carlo simulations for each configuration and depth produced probabilistic results from nine scenarios for DITs, which are quite consistent with field observations. [ABSTRACT FROM AUTHOR]

This paper explores how property-right assignment affects social efficiency when a public program has both “public good” and “public bad” components. We show that when willingness to accept a public bad exceeds the willingness to pay, the net benefit is unambiguously lower when the property right supports the status quo institutional structure. Thus, Kaldor–Hicks efficiency tests tend to favor public programs and mitigation over the status quo even when mitigation negatively affects another group. To illustrate the result, we develop social-cost estimates for moving nuclear waste from current temporary-storage facilities to a permanent central repository at Yucca Mountain, NV, USA. For a representative city with a population of 226,195, the present value of the external cost of shipping waste is $1.42 billion when those living near temporary nuclear-waste storage facilities are assigned the property right to “health and safety.” That number swells to $5.95 billion when those living near the transport route are assigned the property right. Thus, property-right assignment affects the efficient level of nuclear-waste, and thus nuclear energy, produced. [ABSTRACT FROM AUTHOR]

Wildfire events are becoming more frequent and severe on a global scale. Rising temperatures, prolonged drought, and the presence of pyrophytic invasive grasses are contributing to the degradation of native vegetation communities. Within the Great Basin region of the western U.S., increasing wildfire frequency is transforming the ecosystem toward a higher degree of homogeneity, one dominated by invasive annual grasses and declining landscape productivity. Greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) are a species of conservation concern that rely on large tracts of structurally and functionally diverse sagebrush (Artemisia spp.) communities. Using a 12-year (2008–2019) telemetry dataset, we documented immediate impacts of wildfire on demographic rates of a population of sage-grouse that were exposed to two large wildfire events (Virginia Mountains Fire Complex—2016; Long Valley Fire—2017) near the border of California and Nevada. Spatiotemporal heterogeneity in demographic rates were accounted for using a Before-After Control-Impact Paired Series (BACIPS) study design. Results revealed a 40% reduction in adult survival and a 79% reduction in nest survival within areas impacted by wildfires. Our results indicate that wildfire has strong and immediate impacts to two key life stages of a sagebrush indicator species and underscores the importance of fire suppression and immediate restoration following wildfire events. [ABSTRACT FROM AUTHOR]

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Here, we report on new data (75 analyses) of plutonium (Pu) isotopes to elucidate activity concentrations, inventories, sources, and their transport from the ocean surface to the seafloor from a collection of six deep-sea sediment cores (depths ranging from 257 to 3739 m) in the southern Gulf of Mexico. Sediment cores collected from the continental shelf and upper slope region of the Gulf of Mexico showed 240Pu/239Pu ratios of 0.15 to 0.26, and 239+240Pu-inventories ranging from 14.7 to 33.0 Bq m−2. Inventories and ratios are consistent with global fallout Pu for this tropical region. In contrast, sediment cores collected from the lower slope region and abyssal plain showed low 240Pu/239Pu ratios of 0.07 to 0.13 and much lower 239+240Pu inventories below 6.8 Bq m−2. This implies that only a small fraction of the expected global fallout Pu has reached the deep-sea sediments. The low 240Pu/239Pu isotope ratios indicate that fallout from the Nevada testing site was an important source of Pu in deep-sea sediments, and that this Pu was likely more efficiently scavenged from the water column than Pu from global fallout. We estimated that up to 44% of the total inventory of 239+240Pu in deep-sea sediments is due to the Nevada source. Low values and a progressive decrease of 240Pu/239Pu ratios and 239+240Pu inventories with increasing water depth have been previously reported for the Gulf of Mexico. Analysis of Pu isotopes in two sediment traps from the upper slope regions shows 240Pu/239Pu ratios comparable to those observed in global fallout. These results indicate that global fallout Pu is currently the main source of Pu in sinking particles in the water column. Therefore, a significant fraction of global fallout Pu must still be present, either in a dissolved phase, or as biologically recycled material in the water column, or scavenged on the shelf and shelf break. Our results bring to light important questions on the application of Pu isotopes to establish sediment chronologies in deep-sea sediments, since global fallout features such as the 1963 maximum are not available. [ABSTRACT FROM AUTHOR]

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Porphyry-type deposits are a vital source of green technology metals such as copper and molybdenum. They typically form in subduction-related settings from large, long-lived magmatic systems. The most widely accepted model for their formation requires that mantle-derived magmas undergo an increase in volatiles and ore-forming constituents in mid- to lower crustal reservoirs over millions of years, however, this is mostly based on observations from shallow, sporadically exposed parts of porphyry systems. To examine this paradigm, we have evaluated the timeframe and geochemical signatures of magmatism in a ~ 8 km palaeodepth cross-section through plutonic and volcanic rocks of the classic Yerington magmatic system, Nevada. We show that the magmas in the upper parts of the system (< 8 km) underwent a major and rapid change in chemistry over a period of < 200 kyrs that is coincident with the initiation of ore formation. We attribute this change to a shift from extraction of quartz monzodiorite and quartz monzonite magmas evolving in mid-crustal reservoirs, and that had relatively poor ore-forming potential, to extraction of volatile-rich granitic magmas from greater (~ 30 km) depths. As the granites crystallised, late stage melts were intruded through the carapace as aplite dykes which contain traceable expressions of the porphyry deposit-forming fluids. The rapid nature of the shift in ore-forming potential narrows the temporal-geochemical footprint of magmas associated with porphyry mineralisation and provides new constraints for exploration models. [ABSTRACT FROM AUTHOR]

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Historical mine and mineral deposit datasets are routinely used to inform quantitative mineral assessment models, but they also can contain a wealth of supplementary qualitative information that is generally underutilized. We present a workflow that uses correspondence analysis, an exploratory tool commonly applied to multivariate abundance data, to better utilize qualitative data in these historical datasets. The workflow involves extraction of qualitative information on ore mineralogy from a mineral deposit database, attaches those data to a target geological feature, and analyzes the underlying data structure with correspondence analysis and hierarchical clustering. The output of correspondence analysis is inversely weighted to the relative frequency of ore minerals, and therefore rare mineral species (i.e., those with unusually low frequencies) can disproportionately contribute to the total variance of the dataset. We present a novel technique for aggregating frequencies of rare mineral species that minimizes this effect. We apply this workflow to evaluate how ore mineral assemblages in former and active mines vary in spatial relation to silicic calderas in the southwestern United States. The most common ore mineral associations observed spatially and genetically associated to calderas include those related to polymetallic, base metal-rich systems and epithermal Au–Ag systems. Three other groups of mineralized calderas were identified, including: (1) Hg–Sb mineralized calderas in the northern Great Basin and western Nevada volcanic field; (2) calderas associated with elevated abundances of Mn oxides/hydroxides, fluorite, and Be-minerals, mostly in eastern Utah and New Mexico; and (3) calderas with numerous U ± F deposits, which are located in central Colorado, the eastern Great Basin and in northern Nevada. The latter three groups are associated with economically significant critical mineral resources, including the Li resources of the McDermitt complex and Be associated with the Spor Mountain on the margin of the Thomas caldera complex. We conclude that correspondence analysis is a promising technique that can enhance data exploration of the qualitative information held within mineral deposit datasets. Consequently, it could have numerous applications for mineral potential mapping, resource assessment projects, and characterization of mineral systems. [ABSTRACT FROM AUTHOR]

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Spatial patterns of tungsten and cobalt are described for surface dust of Fallon, Nevada, where a cluster of childhood leukemia has been ongoing since 1997. In earlier research, airborne tungsten and cobalt was shown to be elevated in total suspended particulates in Fallon. To fine-tune the spatial patterns of tungsten and cobalt deposition in Fallon, surface dust was collected in a grid pattern within as well as outside of Fallon to establish background concentrations of metals. In surface dust, tungsten and cobalt show sharp peaks (934 ppm and 98 ppm, respectively) within Fallon just north of highway 50 and west of highway 95. These two peaks overlap spatially, and given the grid pattern used for collecting surface dust, the source area of these two airborne metals can be pinpointed to the vicinity of hard-metal industry located north of highway 50 and west of highway 95. Fallon is distinctive in west central Nevada because of high airborne tungsten and cobalt particulates, and given its cluster of childhood leukemia, it stands to reason that additional biomedical research is in order to test directly the leukogenicity of combined airborne tungsten and cobalt particulates. [ABSTRACT FROM AUTHOR]

The article presents abstracts of papers related to endoscopic surgery to be presented at the 2007 Scientific Session of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) in Las Vegas, Nevada, from April 18-22, 2007. They include "Laparoscopic Sleeve Gastrectomy for Weight Loss in Morbid Obesity," "Laparoscopic Management of Adjustable Gastric Band Slippage," and "Laparoscopic Duodenojejunostomy for Benign Duodenal Obstruction."

The article presents abstracts of papers related to endoscopic surgery to be presented at the 2007 Scientific Session of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) in Las Vegas, Nevada, from April 18-22, 2007. They include "The Use of Epidural Analgesia in Laparoscopic Colorectal Surgery," "Effect of Carbon Dioxide Pneumoperitoneum on Hepatic Tissue Perfusion," and "Laparoscopic Sigmoid Colectomy For Diverticulitis After Percutaneous Drainage."