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Background: Postpartum depression affects 13% of women after childbirth in the United States. Mothers who experience depression are less likely to breastfeed than those who do not experience depression. On the other hand, breastfeeding may have a positive effect on maternal mental health. Research aim: We aimed to analyze whether breastfeeding cessation is associated with postpartum depression symptoms among mothers of infants under six months old in Clark County, Nevada. Method: A cross-sectional study was conducted in 2021 using a purposive sample of 305 mother-infant dyads. Postpartum depression symptoms were assessed using the Patient Health Questionnaire-2 (PHQ-2), and the breastfeeding cessation was determined through a 24-hour dietary recall. Descriptive, bivariate, and multivariate logistic regression analyses were conducted. Results: Most participants were between 25 and 34 years old (n = 183, 60.0%), multiparous (n = 167, 55.1%), and had a vaginal delivery (n = 204, 70.6%). High frequency of postpartum depressive symptoms was found among mothers who were young (18–24 years) (24.2%), without a partner (25.0%), had unplanned pregnancies (12.7%), and were primiparous (13.2%). Breastfeeding cessation was independently associated with postpartum depressive symptoms (AOR = 3.30, 95% CI: 1.16–9.32) after controlling for sociodemographic, environmental, and obstetric characteristics. Conclusion: Breastfeeding cessation is strongly associated with postpartum depressive symptoms among mother-infant dyads in Nevada. Early identification of postpartum depressive symptoms and the promotion of breastfeeding can create a positive feedback loop to foster the well-being of mothers and infants. [ABSTRACT FROM AUTHOR]

Wildfires in the southwestern United States, particularly in northern California (nCA), have grown in size and severity in the past decade. As they have grown larger, they have been associated with large emissions of absorbing aerosols in to the troposphere. Utilizing satellite observations from MODIS, CERES, AIRS, and CALIPSO, the meteorological effects of aerosols associated with fires during the wildfire season (June–October) were discerned over the nCA-NV (northern California and Nevada) region in the 2003–2022 time frame. As higher temperatures and low relative humidity RH dominate during high surface pressure ps atmospheric conditions, the effects of the aerosols on high (90th percentile) fire days compared to low fire (10th percentile) days were stratified based on whether ps was anomalously high or anomalously low (10th percentile). An increase in tropospheric temperatures was found to be concurrent with more absorbing aerosol aloft, which is associated with significant reductions in tropospheric RH during both 90th and 10th percentile ps conditions. Furthermore, high fire days under low ps conditions are associated with reduced cloud fraction CF , which is consistent with the traditionally-defined aerosol- cloud semi-direct effect. The reduced CF , in turn, is associated with reduced T OA SW radiative flux, a warmer surface, and less precipitation. These changes could create a positive feedback that could intensify fire weather, and therefore extend fire lifetime and impacts. [ABSTRACT FROM AUTHOR]

This study describes an assemblage of Dzieduszyckia brachiopods preserved in sedimentary barite deposits from the Famennian, Upper Devonian of Nevada, USA. The brachiopods lived in a methane-seep environment like those described from Sonora, Mexico, and the Western Meseta, Morocco. Although the original carbonate fabrics are not preserved, pockets of limestone within the brachiopod barite are depleted in with δ13C values ranging from -31.1 to -27.3‰ VPDB. The fossils are preserved as internal and external molds only but record enough detail to demonstrate key internal features of Dzieduszyckia such as a pronounced dorsal septum, septalium, and vertical dental plates. The lack of common bifurcation or trifurcation of the costae as well as larger size of the shells recommends against inclusion within D. sonora as previously published. Based on the number of costae per width of shell, it is possible that there are two distinct species in Nevada, like other localities in Morocco, the Urals, and South China. These new data expand the body of knowledge of these earliest dimerelloids and it is hypothesized that this seep-dwelling macrofauna arose from depauperate-successful lineages between the Famennian biotic crises. As nearly all global Dzieduszyckia deposits are associated with active tectonic margins, it is also suggested that tectonically-driven methane expulsion in low nutrient waters spurred the evolution of dimerelloids. [ABSTRACT FROM AUTHOR]

Like many National Park Service sites, Tule Springs Fossil Beds National Monument in Nevada has associated off- site legacy paleontological collections in museum repositories across North America. These legacy paleontological collections, which were created during past expeditions, are at risk of becoming forgotten or inaccessible, yet they hold the potential to revisit old questions and old sites utilizing new techniques, methods, and ideas. The authors present a case study that outlines a suggested framework to reconcile problematic or underutilized legacy paleontological collections based on the 2020-2023 inventory of the Southwest Museum Expedition Tule Springs Collection curated at the Autry Museum of the American West. The authors also explore the effectiveness of an interdisciplinary approach to paleontological resource management. Digitization of associated historic archives and photographs can help assign updated geologic context to unprovenienced fossils, as well as locate historic paleontological sites for conservation and study. Legacy paleontological collections are also artifacts of the time of collection; the cultural context of fossil collections can be just as important as their geologic context. Although new data collection is beneficial for scientific inquiry and science-based natural resource management strategies, the importance of well-understood and accessible legacy paleontological collections for these efforts cannot be overstated. Revisiting these collections can facilitate scientific discovery by providing more accurate and comprehensive data to park staff and researchers. Paleontological and museum management programs and the scientific community will benefit from bridging the past and the present through an interdisciplinary approach. [ABSTRACT FROM AUTHOR]

METEX21 was an atmospheric tracer release experiment executed at the Department of Energy's Nevada National Security Site (NNSS) in the southwestern U.S to study terrain-induced wind and thermodynamic conditions that influence local-scale (<5km) plume transport under varying atmospheric forcing conditions. Meteorological observations were collected using 10-m tall meteorological towers, 2-m tall tripods with 3-d sonic anemometers, a 3-m tall eddy covariance flux tower, Doppler profiling lidars, Doppler scanning lidars, weather-balloon launched radiosondes, and a tethered balloon equipped with wind, temperature, and aerosol sensors at heights up to 800 m. A smoke tracer was released along three transects in the horizontal and vertical directions and observed with video cameras, aerosol sensors and lidars (via aerosol backscatter). The observations showed evidence of large-scale/synoptic transience as well as local-scale upslope and downslope flows, along-axis valley flows, recirculation eddies on leeward slopes, and periods of strong shear and veer aloft. The release days were classified as either synoptically-driven or locally-driven, and a single case day is presented in detail for each. Synoptically-forced days show relatively narrow smoke plumes traveling down the valley from north to south (with the predominant wind direction), with little deviation in transport direction regardless of the elevation or ground locations of the smoke releases, except near the presence of leeside recirculation eddies. Locally-forced days exhibit a wider range of plume behavior due to the combination of thermally-induced valley and slope flows, which are often flowing in different cardinal directions, and wind shear found aloft at higher altitudes and elevations. We saw evidence of smoke lofting on top of the mesas due to strong upslope flows on these days. A major finding of this experiment was the effectiveness of scanning lidars to measure 2-dimensional plume transport out to a 2-3 km distance; much farther than could be visibly observed. METEX21 was the first of three planned tracer experiments at NNSS, and future experiments will incorporate multiple tracers to improve individual plume identification so that finer resolution flow details can be attained from these measurements, as well as deploy a larger suite of meteorological instrumentation, including more temperature profiling data. [ABSTRACT FROM AUTHOR]

Increasing pressure over water resources in the western U.S. is currently forcing alfalfa (Medicago sativa L.) producers to adopt water-saving irrigation techniques. Crop yield forecasting tools can be used to develop smart irrigation scheduling methods that can be used to estimate the future effects of a given irrigation amount applied during a current irrigation event on yield. In this work, a linear model and a random forest model were used to estimate the yield of irrigated alfalfa crops in northern Nevada. It was found that water (rain + irrigation), the occurrence of extreme temperatures, and wind have a greater effect on crop yield. Other variables that accounted for the photoperiod and the dormant period were also included in the model and are also important. The linear model had the best performance with an R2 of 0.854. On the other hand, the R2 value for the random forest was 0.793. The linear model showed a good response to water variability; therefore, it is a good model to consider for use as an irrigation decision support system. However, unlike the linear model, the random forest model can capture non-linear relationships occurring between the crop, water, and the atmosphere, and its results may be enhanced by including more data for its training. [ABSTRACT FROM AUTHOR]

The Miocene Columbia River Basalt Group (CRBG) of the Pacific Northwest of the United States is the world's youngest and smallest large igneous province. Its earliest formations are the Imnaha, Steens, and now the Picture Gorge Basalt (PGB), and they were sourced from three different dike swarms exposed from SE Washington to Nevada to northcentral Oregon. PGB is often viewed to be distinct from the other formations, as its magmas are sourced from a shallow, relatively depleted, and later subduction-induced metasomatized mantle, along with its young stratigraphic position. It has long been known that the lowermost American Bar flows (AB1&2) of the Imnaha Basalt are chemically similar to those of the PGB, yet the Imnaha Basalt is generally thought to carry the strongest plume source component. These opposing aspects motivated us to revisit the compositional relationships between AB1&2 and PGB. Our findings suggest that tapping a shallow, variably depleted, and metasomatized mantle reservoir to produce earliest CRBG lavas occurred across the province, now pinpointed to ~17 Ma. Moreover, compositional provinciality exists indicating regional differences in degree of depletion and subduction overprint that is preserved by regionally distributed lavas, which in turn implies relatively local lava emplacement at this stage. [ABSTRACT FROM AUTHOR]

A 3-dimensional numerical hydrodynamic and water quality model of Lake Mead was used to improve understanding of the general limnology and aquatic ecology of Lake Mead and to assess the benefits and refine the designs of 2 large-scale capital improvement projects, with total project costs estimated to exceed $1.4 billion. The model, which was developed and validated as described in a companion paper (Preston et al. 2014), was utilized to illustrate the rapid advection of algae on the lake surface by wind, the variable insertion level and fate of inflows, the velocity fields within the lake, and the replenishment of dissolved oxygen in the hypolimnion through 2 different mechanisms. Water quality information from the model was critical in the selection of the final location for a new municipal drinking water intake, allowing designers to optimize the intake elevation and to identify the benefits of maintaining the existing intakes (such as enabling selective withdrawal). Alternative discharge scenarios were modeled and ultimately demonstrated that chlorophyllaconcentrations could be reduced to lower levels than the water quality standards by discharging treated wastewater effluent to the hypolimnion of Lake Mead via a proposed diffuser, rather than discharging to the surface via the Las Vegas Wash. Model results were used to facilitate port design and operation planning for the deep-water effluent diffuser to increase dilution and manage effluent concentrations at key locations. [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]

The thermal infrared (TIR) band of Thermal and Near-Infrared Sensor for carbon Observations Fourier Transform Spectrometer (TANSO-FTS) on the Greenhouse gases Observing SATellite (GOSAT) measures a wide range of scene temperatures using a single detector band with broad spectral coverage. This work describes the vicarious radiometric calibration over a large footprint (10.5 km) and high temperature surface using well-calibrated ground-based and airborne FTS sensors. The vicarious calibration campaign of GOSAT was conducted at Railroad Valley, NV in June 2011. During the campaign, the Scanning High-resolution Interferometer Sounder (S-HIS) mounted on the high-altitude NASA ER-2 aircraft observed upwelling radiation and the ground-based Surface-Atmospheric Emitted Radiance Interferometer (S-AERI) observed infrared thermal emission from the atmosphere and the surface at the same location and time as the GOSAT TANSO-FTS. We validated TANSO-FTS TIR radiance with S-HIS radiance using double difference method, which reduces the effect of differences in the observation geometry. In this paper, we estimated the TANSO-FTS Instantaneous Field of View average temperature and emissivity by the coincident S-AERI and S-HIS observed radiance. The double difference between TANSO-FTS and S-HIS result in a difference of 0.5 K at atmospheric window channels (800 ~ 900 cm-1) and CO2 warm brightness temperature channels (700 ~ 750 cm-1), 0.1 K at ozone channels (980 ~ 1080 cm-1), and more than 2 K at CO2 cool brightness temperature channels (650 ~ 700 cm-1). The main reason of remaining errors is attributed to a calibration error in the TANSO-FTS Level 1B product version under evaluation. [ABSTRACT FROM AUTHOR]

Nevada and eastern California are home to some of the driest and warmest climates, most mountainous regions, and fastest growing metropolitan areas of the United States. Throughout Nevada and eastern California, snow-dominated watersheds provide most of the water supply for both human and environmental demands. Increasing demands on finite water supplies have resulted in the need to better monitor drought and its associated hydrologic and agricultural impacts. Two multiscalar drought indices, the standardized precipitation index (SPI) and the standardized precipitation evapotranspiration index (SPEI), are evaluated over Nevada and eastern California regions of the Great Basin using standardized streamflow, lake, and reservoir water surface stages to quantify wet and dry periods. Results show that both metrics are significantly correlated to surface water availability, with SPEI showing slightly higher correlations over SPI, suggesting that the inclusion of a simple term for atmospheric demand in SPEI is useful for characterizing hydrologic drought in arid regions. These results also highlight the utility of multiscalar drought indices as a proxy for summer groundwater discharge and baseflow periods. [ABSTRACT FROM AUTHOR]

In December 2009, ramp meters along US 95 in Las Vegas between Rancho Drive and Craig Road were activated. A study was performed to quantify the benefits of ramp meters on the freeway mainline by using archived ITS data. Traditional performance measures such as average travel speed, speed standard deviation, interquartile speed range, travel time index (TTI), and buffer index (BI) were employed to conduct the evaluation. In addition, two new performance measures-delay volume (DV) and average vehicle delay (AVD)-developed by the Freeway and Arterial System of Transportation (FAST) Division of the Regional Transportation Commission (RTC) of Southern Nevada were used to enhance the evaluation. Specifically, DV quantifies the congestion with temporal, spatial, and congestion intensity values, and AVD measures the average delay per vehicle with traffic volume as a weighting factor. Comparing both the freeway and ramp performance with and without ramp meters clearly demonstrates that ramp meters are very effective in mitigating the recurring heavy congestion for southbound US 95 during weekday peak periods. The improvement is comparatively little on the more lightly congested northbound section of US 95. The evaluation results also demonstrate that the DV and AVD metrics are useful in evaluating operational strategies such as ramp metering. Finally, informative results are achieved regarding the influence of ramp meters on the bottleneck, and the comparative effects metering has on the general purpose and high occupancy vehicle (HOV) lanes. [ABSTRACT FROM AUTHOR]

SUMMARY The depth of reflector layers in the Earth's crust is usually estimated using controlled sources or earthquake signals. Ambient seismic noise, however, can also be used for this purpose. We develop and apply a new method, based on continuous waveform analysis, to estimate the two-way P-wave reflection component of the Green's function beneath each station. The Green's functions are retrieved from continuous record autocorrelation stacks at broad-band sensor locations within the USArray EarthScope Transportable Array in the western Great Basin and the Sierra Nevada, in a region with complex crustal and upper-mantle structure. In this paper, we show evidence of a reflector at the crust-mantle boundary (Moho discontinuity) derived for the first time from ambient noise autocorrelations using short-period (∼1 s) data. Our results compare well with earthquake and controlled source investigations, and with tomography findings in the region. Moho depth is difficult to resolve seismically because of the lack of favourable spatial distribution of source and receiver geometries. In contrast, our method can be applied at any desired sensor spacing to estimate Earth reflector depth beneath surface-located sensors, providing unprecedented resolution. [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]

• Wavelength Mapper resolves overlapping reststrahlen features in airborne TIR images. • Creates overview map of spectrally dominating rock-forming minerals. • Small wavelength shifts can indicate rock composition changes in mineral mixtures. The Wavelength Mapper is an algorithm that searches for the deepest absorption feature in each pixel of a hyperspectral image. On a per pixel basis, it extracts the wavelength position, which serves as a proxy of the mineralogy and the feature depth as a proxy for the relative abundance. This algorithm has been used with near and shortwave infrared data, but has not yet been tested on hyperspectral thermal infrared images. It is unclear what results are expected when the Wavelength Mapper algorithm is applied to hyperspectral thermal infrared data since reststrahlen features characteristically overlap in emissivity spectra. In this paper, the Wavelength Mapper is tested on a multi-flightline airborne hyperspectral TIR dataset acquired over the Yerington Batholith, Nevada. Observations were made in the 8.05–11.65 μm wavelength range to include thermal spectral features of major rock-forming minerals, and a new color ramp is created to separate quartz-rich rocks from plagioclase-rich rocks. Our results indicate that the Wavelength Mapper creates coherent spatial patterns across flightlines. The results displayed represent different types of igneous and sedimentary rocks, as well as the products of hydrothermal alteration via different colors, mainly based on the relative abundance of quartz, feldspar and garnet, as well as mica and epidote. Comparison with published maps indicate that the Wavelength Mapper represents for each pixel a parameter value that can be linked to the spectrally dominate rock-forming mineral of that area, as mapped with traditional fieldwork methods. In conclusion, the Wavelength Mapper can be applied to airborne hyperspectral TIR data to achieve a simple, repeatable, per-pixel overview map of the dominating rock-forming mineral occurrences. [ABSTRACT FROM AUTHOR]

In this paper, we present aerosol retrieval results from the ACEPOL (Aerosol Characterization from Polarimeter and Lidar) campaign, which was a joint initiative between NASA and SRON - Netherlands Institute for Space Research. The campaign took place in October-November 2017 over the western part of the United States. During ACEPOL six different instruments were deployed on the NASA ER-2 high altitude aircraft, including four Multi-Angle Polarimeters (MAPs): SPEX airborne, the Airborne Hyper Angular Rainbow Polarimeter (AirHARP), the Airborne Multi-angle SpectroPolarimeter Imager (AirMSPI), and the Research Scanning Polarimeter (RSP). Also, two lidars participated: the High Spectral Resolution Lidar -2 (HSRL-2) and the Cloud Physics Lidar (CPL). Flights were conducted mainly for scenes with low aerosol load over land but also some cases with higher AOD were observed. We perform aerosol retrievals from SPEX airborne, RSP (410-865 nm range only), and AirMSPI using the SRON aerosol retrieval algorithm and compare the results against AERONET and HSRL-2 measurements (for SPEX airborne and RSP). All three MAPs compare well against AERONET for the Aerosol Optical Depth (AOD) (Mean Absolute Error (MAE) between 0.014-0.024 at 440 nm). For the fine mode effective radius the MAE ranges between 0.021-0.028 micron. For the comparison with HSRL-2 we focus on a day with low AOD (0.02-0.14 at 532 nm) over the California Central Valley, Arizona and Nevada (26 October) and a flight with high AOD (including measurements with AOD > 1.0 at 532 nm) over a prescribed forest fire in Arizona (9 November). For the day with low AOD the MAE in AOD (at 532 nm) with HSRL-2 are 0.014 and 0.022 for SPEX and RSP, respectively, showing the capability of MAPs to provide accurate AOD retrievals for the challenging case of low AOD over land. For the retrievals over the smoke plume also a reasonable agreement in AOD between the MAPs and HSRL-2 was found (MAE 0.088 and 0.079 for SPEX and RSP, respectively), despite the fact that the comparison is hampered by large spatial variability in AOD throughout the smoke plume. Also a good comparison is found between the MAPs and HSRL-2 for the aerosol depolarization ratio (a measure for particles sphericity) with MAE of 0.023 and 0.016 for SPEX and RSP, respectively. Finally, SPEX and RSP agree very well for the retrieved microphysical and optical properties of the smoke plume. [ABSTRACT FROM AUTHOR]

Abstract The Gold Flat Tuff is the youngest (9.15 Ma) ash-flow sheet erupted from the Black Mountain Volcanic Centre, southwest Nevada, USA. This paper explores some aspects of the very complex nature of the tuff's magmatic plumbing system. The main body of the deposit is a mixed magma product, comprising pantelleritic and comenditic melts derived from independently evolving reservoirs, and antecrysts and enclaves derived from a range of basic to intermediate sources. Metre-scale cognate xenoliths point to the presence of alkali feldspar accumulation zones. The pantellerite contains phenocrysts of fluorite and chevkinite-(Ce). The inferred intermediate magma component contains perrierite-(Ce) phenocrysts. The pantellerite has unusually high contents of F (≤2.2 wt%), F + Cl (≤2.9 wt%) and ZrO 2 (≤1.04 wt%). The high halogen contents may have influenced the evolution of the strongly peralkaline magma. The crystallization conditions are poorly constrained but those for the pantelleritic magma may have been close to water-saturation (>4 wt% melt water) at temperatures ~740 °C and f O 2 around FMQ. Highlights • Syn-eruptive of two peralkaline silicic magmas • Simultaneous tapping of two independent reservoirs • Complex suite of enclaves and antecrysts from mafic and intermediate magmas • Occurrence of chevkinite-(Ce) and fluorite phenocrysts in a pantelleritic magma [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]

Recent studies indicate that strong cold fronts develop frequently downstream of the Sierra Nevada over the Intermountain West. To help ascertain why, this paper examines the influence of the Sierra Nevada on the rapidly developing Intermountain cold front of 25 March 2006. Comparison of a Weather Research and Forecasting (WRF) model control simulation with a simulation in which the height of the Sierra Nevada is restricted to 1500 m (roughly the elevation of the valleys and basins of the Intermountain West) shows that the interaction of southwesterly prefrontal flow with the formidable southern High Sierra produces a leeward orographic warm anomaly that enhances the cross-front temperature contrast. Several processes generate this orographic warm anomaly, including flow modification by the Sierra Nevada (i.e., windward blocking of low-level Pacific air, leeward subsidence, and increased southerly flow from the Mojave Desert and lower Colorado River basin into the Intermountain West), diabatic heating and water vapor loss associated with orographic precipitation, and increased sensible heating and reduced subcloud diabatic cooling in the downstream cloud and precipitation shadow. In contrast, the postfrontal air mass experiences comparatively little orographic modification as it moves across the relatively low northern Sierra Nevada. These results show that the Sierra Nevada can enhance frontal development, which may contribute to the high frequency of strong cold-frontal passages over the Intermountain West. [ABSTRACT FROM AUTHOR]

In this paper we report chemically resolved measurements of organic aerosol (OA) and related tracers during the Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX) at the Blodgett Forest Research Station, California from 15 August-10 October 2007. OA contributed the majority of the mass to the fine atmospheric particles and was predominately oxygenated (OOA). The highest concentrations of OA were during sporadic wild- fire influence when aged plumes were impacting the site. In situ measurements of particle phase molecular markers were dominated by secondary compounds and along with gas phase compounds could be categorized into six factors or sources: (1) aged biomass burning emissions and oxidized urban emissions, (2) oxidized urban emissions (3) oxidation products of monoterpene emissions, (4) monoterpene emissions, (5) anthropogenic emissions and (6) local methyl chavicol emissions and oxidation products. There were multiple biogenic components that contributed to OA at this site whose contributions varied diurnally, seasonally and in response to changing meteorological conditions, e.g. temperature and precipitation events. Concentrations of isoprene oxidation products were larger when temperatures were higher during the first half of the campaign (15 August-12 September) due to more substantial emissions of isoprene and enhanced photochemistry. The oxidation of methyl chavicol, an oxygenated terpene emitted by ponderosa pine trees, contributed similarly to OA throughout the campaign. In contrast, the abundances of monoterpene oxidation products in the particle phase were greater during the cooler conditions in the latter half of the campaign (13 September-10 October), even though emissions of the precursors were lower, although the mechanism is not known. OA was correlated with the anthropogenic tracers 2-propyl nitrate and carbon monoxide (CO), consistent with previous observations, while being comprised of mostly non-fossil carbon (>75 %). The correlation between OA and an anthropogenic tracer does not necessarily identify the source of the carbon as being anthropogenic but instead suggests a coupling between the anthropogenic and biogenic components in the air mass that might be related to the source of the oxidant and/or the aerosol sulfate. Observations of organosulfates of isoprene and α-pinene provided evidence for the likely importance of aerosol sulfate in spite of neutralized aerosol although acidic plumes might have played a role upwind of the site. This is in contrast to laboratory studies where strongly acidic seed aerosols were needed in order to form these compounds. These compounds together represented only a minor fraction (<1 %) of the total OA mass, which may be the result of the neutralized aerosol at the site or because only a small number of organosulfates were quantified. The low contribution of organosulfates to total OA suggests that other mechanisms, e.g. NOx enhancement of oxidant levels, are likely responsible for the majority of the anthropogenic enhancement of biogenic secondary organic aerosol observed at this site. [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]

This study is sponsored by the Regional Transportation Commission of Washoe County to assess the impact of lime treatment on the moisture damage of hot-mixture asphalt (HMA) mixtures near Reno, Nevada. This paper presents the laboratory evaluation of lime application in HMA mixtures, mechanistic analyses of those results and an evaluation of plant-produced HMA mixtures to evaluate the variability of moisture susceptibility. The laboratory evaluation based upon resilient modulus testing detected moisture sensitivity benefits with the use of lime over multiple freeze-thaw cycles, but could not distinguish between the marinated and non-marinated laboratory mixtures. The mechanistic analysis based upon laboratory mixtures indicated similar results in terms of the presence of lime and showed slight signs of improvement with the marination process. The field variability based on tensile strength ratios (TSR) indicated that the marination process does reduce the variability of the benefits of lime treatment on moisture sensitivity. [ABSTRACT FROM AUTHOR]

The purpose of the study was to examine training professionals' insights and beliefs about the challenges they face in training and the corresponding coping mechanisms by analyzing the opinions of training experts. A qualitative implicit method, the Zaltman Metaphor Elicitation Technique, which performs interviews using pictures, was conducted with ten training professionals. Metaphors were widely used, and links between concepts were identified. The training challenges that resulted from the current study included measurement, deadlines, frustration, and keeping current. The study took place in Las Vegas, Nevada, and the interviewees were employed by large hotel-casino corporations. Future studies need to research different sized hospitality institutions and different tourist destinations. Current and future training professionals can use the outcome of the study as a guide to better understanding training challenges and to acquiring the corresponding competencies to be more effective in training. Moreover, the outcome of the paper can be beneficial to industry employees and educators, since training and teaching are in many ways similar. [ABSTRACT FROM AUTHOR]

This paper asks whether speculative house-price pressure in an economic center can spill into related housing markets. In other words, are bubbles contagious? I develop a theoretical model that allows for speculative price appreciation to spread from one market to another. I estimate an error-correction model using quarterly housing data for Las Vegas and Los Angeles and fundamental market variables from 1978 Quarter 2 through 2008 Quarter 1. Las Vegas prices show significant persistence and adjust slowly to disequilibrium. Contagious price and income growth from the Los Angeles market sustained by naive expectations contributed to the bubble that formed in Las Vegas [ABSTRACT FROM AUTHOR]

Background: Online learning in K-12 education has grown rapidly in the past decade. Cyber charter schools (CCSs) have been a particularly controversial form of online school, but there is very little scholarly examination of these new organizations. As CCSs expand, policymakers and stakeholders have a critical need to understand how to evolve the charter school policies that govern these new school forms. Focus of Study: Through a three-site case study, this paper (1) explores what current charter policies govern CCSs and (2) outlines the practices in these schools that might illuminate future policy needs. Specifically, the findings highlight how cyber charters problematize existing charter school policies in the areas of authorizers and governance, teacher policy, and student achievement. Research Design: The study presents an exploratory, comparative case study. The exploratory analyses illuminate implications for how policymakers understand governance, teacher policy, and the evaluation of student achievement in cyber charters. The comparative case design also highlights how different state policy contexts might influence the practices of CCSs. Conclusions: Cyber charter schools introduce new ways of delivering public schooling. The study shows how state leadership is vital to coordinate student enrollment across geographic boundaries, funding mechanisms, and conflicts between CCSs and established stakeholders. This paper also illuminates how teaching and learning practices differ in an online environment and introduces questions of teacher preparation and professional practices. Finally, CCSs in this study serve unique, niche student populations that opt out of the traditional school system. These considerations are vital for evaluating student achievement in cyber charters. [ABSTRACT FROM AUTHOR]

This study examined the dynamic behavior of two-column bents used to support box-girder bridges. Three 0.3-scale specimens were subjected to earthquake records from the 1994 Northridge Earthquake using a large shake table (4.3 x 4.4 m [14 ft × 14 ft 6 in.] in plan) at the University of Nevada, Reno. Details in the bents were based on the 1999 California Department of Transportation design standards. The specimens were identical except for the column aspect ratios, which were 2.5, 4.5, and 6.64. Experimental data were collected at the critical sections in each specimen. The three specimens successfully resisted high levels of seismic loadings and achieved sufficient ductilities. The observed and measured results of the three specimens were helpful in understanding dynamic behavior and are documented in this paper. [ABSTRACT FROM AUTHOR]

This paper provides a detailed description and evaluation of a three-year professional development project in a large urban setting in the southwestern United States. The impetus for the project was curriculum development focused on integrated scientific inquiry. Project goals included the development of a professional learning community, reformed teacher practice, and improved content knowledge for teachers and their students. Annually, a two-week summer institute was provided for approximately 50 high school science teachers with graduate-level coursework during the academic year. The results document improvements in teacher content knowledge and key changes in the classroom characteristics of teacher participants. Further, students enrolled in a target course with teachers who participated fully in the professional development were more than twice as likely to pass the state science examination. The results from this project add to what is known about delivering successful, contextually relevant professional development. [ABSTRACT FROM AUTHOR]

Hall's (this issue) comment to my paper published in American Antiquity five years ago (Hockett 2005) makes the following statements: (1) I calculated "depositional rates" for a series of Great Basin faunal assemblages; (2) my analysis did not account for atmospheric radiocarbon fluctuations; and (3) my paper argued "against an increase in hunting artiodactyls from the Middle to Late Holocene." He further argues that recalculation of the data I presented demonstrates that both large- and small-game hunting increased from the Middle to the Late Holocene. Hall is wrong on all accounts. I agree, however, that calibrated dates should now be used instead of the raw radiocarbon dates I used in my original paper. Using calibrated dates, however, does nothing to change the initial patterns I outlined five years ago. Three more recent papers (Hockett 2007, 2009; Hockett and Murphy 2009) on large game hunting in the Great Basin also corroborate my 2005 interpretations. [ABSTRACT FROM AUTHOR]

This paper reports the results of a consensus conference of the Council of Emergency Medicine Residency Directors (CORD) to discuss the experiential training component of residency education in the emergency department (ED) and to make recommendations on structuring clinical training. Self-selected emergency medicine (EM) educators discussed experiential training focusing on three topic areas: 1) methods to optimize training in the clinical setting, 2) identification of goals and objectives by training year, and 3) determination of measurable behaviors demonstrating achievement of goals and objectives by residents. Topic areas were organized into the following questions: 1) what is the optimal number and evolution of ED shifts for EM residents during their residency training, 2) what clinical skills are expected of a resident at each level of training, and 3) what objective measures should be used to provide evidence of resident competency? Participants attended a lecture on the goals of the conference, the questions to be answered, and the role and implementation of deliberate practice into experiential training. Attendees were divided into three groups, each discussing one question. Each group had two discussion leaders. All discussions were digitally recorded for accuracy. After discussion all groups reconvened and reported summaries of discussions and recommendations to ensure group agreement. There were 59 participants representing 42 training programs. Educators agree that essential features of designing the ED clinical experience include the need to: 1) structure and tailor the clinical experience to optimize learning, 2) establish expectations for clinical performance based on year of training, and 3) provide feedback that is explicit to year-specific performance expectations. ACADEMIC EMERGENCY MEDICINE 2010; 17:S78-S86 © 2010 by the Society for Academic Emergency Medicine [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a study of solute transport through ground water in the saturated zone and the resulting breakthrough curves (BTCs), using a field-scale numerical model that incorporates the processes of advection, dispersion, matrix diffusion in fractured volcanic formations, sorption, and colloid-facilitated transport. Such BTCs at compliance boundaries are often used as performance measures for a site. The example considered here is that of the saturated zone study prepared for the Yucca Mountain license application. The saturated zone at this site occurs partly in volcanic, fractured rock formations and partly in alluvial formations. This paper presents a description of the site and the ground water flow model, the development of the conceptual model of transport, model uncertainties, model validation, and the influence of uncertainty in input parameters on the downstream BTCs at the Yucca Mountain site. [ABSTRACT FROM AUTHOR]

This study explores the spaces of globalization by the globalized businesses of gambling, entertainment, and resort operations. In particular, it re-examines how the real estate development, finance, and entertainment industries have allied in the early twenty-first century in two unusual spatial settings: a newly returned territory to the People's Republic of China (PRC), or the Macau Special Administrative Region (SAR), and Clark County, Nevada in the United States of America (USA) with the city of Las Vegas at its core. Neither of these sites is known for its cosmopolitan sophistication, but socio-economic networks of the global gaming, resort, shopping, and entertainment industries are using the theme park motifs rooted in huge new casino properties to generate a simulated cosmopolitan allure, which could be characterized as 'casinopolitanism'. This paper analyzes how the fantasy destination spaces built by gaming corporations unfold as packaged globalist cultural revolutions and casinopolitan modes of life in the otherwise (un)(under)valorized spaces of Macau and Nevada. Este estudio explora los espacios de la globalizacion, mediante los negocios globalizados del juego, entretenimiento y operaciones de centros vacacionales. En particular, reexamina como el desarrollo de los bienes raices, las finanzas y las industrias de entretenimiento se han aliado a principios del siglo veintiuno en dos entornos espaciales: un nuevo territorio recientemente devuelto a la Republica Popular de la China (RPC), o la Region Administrativa Especial de Macao (SAR) y el Condado de Clark, Nevada en los Estados Unidos de America (E.E.U.U.) con la ciudad de Las Vegas en su centro. Ninguno de estos sitios se conoce por su sofisticacion cosmopolita, mas por sus redes socio-economicas del juego global, centros vacacionales, comercio e industrias de entretenimiento, que estan usando los motivos de los parques tematicos arraigados en nuevas propiedades inmensas de casinos, para generar una atraccion cosmopolita simulada, que podria caracterizarse como 'casinopolitanismo'. Este articulo analiza como los espacios del destino de la fantasia construidos por las corporaciones del juego, se presentan como revoluciones culturales globalistas empaquetadas y modos de vida casinopolitas en otros espacios (des)(sub) valorizados de Macao y Nevada. [image omitted] [ABSTRACT FROM AUTHOR]

Context: The challenge of providing meaningful health care services to veterans living in rural communities is a major public health concern that involves redefining the traditional facility-based model of care delivery employed in urban areas. Purpose: This paper describes the steps of a demonstration project, the Elko Telehealth Outreach Clinic. The clinic, located in Elko, Nevada, was created to meet the health care needs of veterans who expressed a desire for greater access to VA services. Methods: The Elko Telehealth Outreach Clinic is a specific example of the real-life implementation of the community-as-partner model as an operational framework for coordinating local, regional, and VA resources. The Elko Clinic provides a limited set of health care services including medication management, health education, prescription refills, routine lab tests, and specialty services through telehealth. Findings: From December 2006 to December 2007, a total of 84 unique veterans received health care services through the Elko Clinic. Conclusions: Our findings support the usefulness of an expanded community-as-partner model to guide a process for addressing the health care needs of veterans in Elko, Nevada, and they have implications for the development and maintenance of outreach clinics in other rural settings. [ABSTRACT FROM AUTHOR]

A series of experiments to study the behavior of thick wires (0.5–2 mm in diameter) driven by currents of about 1 MA has recently been conducted on the Zebra facility at the University of Nevada, Reno. The objective of these experiments was to study plasma formation on the surface of conductors under the influence of megagauss magnetic fields. Laser shadowgraphy, filtered optical and extreme ultraviolet photodiodes, and extreme ultraviolet spectroscopy used in the experiments provided data on radial expansion of wires and on plasma radiation. This paper focuses on numerical simulations of these experiments. Simulations with wires having diameters up to 1.6 mm demonstrated plasma formation with temperatures above 3 eV, which is in preliminary agreement with the experiment. For 2-mm-diameter wires, although plasma can be observed in the simulations, it has substantially smaller optical thickness than in the simulations of the smaller diameter wires, and the radiation fluxes prove to be much lower. This can shed light on the experimental results where the radiation of the 2-mm wires was very weak. The simulated time dependences of the wire radii agree rather well with the experimental results obtained using laser diagnostics and visible-light imaging. The experimental data of the photodiodes also agree well with the simulated time dependence of the detected radiation. [ABSTRACT FROM PUBLISHER]

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]

This paper examines the use of scientific models of organising and displaying data in Venturi's, Scott Brown's and Izenour's seminal work Learning from Las Vegas. The paper will demonstrate the affiliations between the project of measuring and documenting the architectural signification of Las Vegas and broader cultural, social and political shifts that reoriented intellectual culture in the period. Drawing from the emerging multi-disciplinary practices of critical theory, the paper will demonstrate the scientific aspirations of Learning from Las Vegas as well as the limitations inherent in its pseudo-scientific method. The paper focuses in particular on the relationship between "figure" and "ground" and its broader influence on systems of urban analysis. [ABSTRACT FROM AUTHOR]

High-level radioactive waste (HLW) disposal policy in the USA since 1987 has focused on a site in volcanic tuffs 305 meters beneath Yucca Mountain, Nevada, with current plans calling for the repository to be opened in 2017 subject to approval by the Obama Administration. Yet the offsite radiation release standards of the US Environmental Protection Agency are still being finalized, and there is significant doubt over whether a repository at Yucca Mountain can be successfully licensed by the Nuclear Regulatory Commission. Moreover, the proposed repository has a capacity cap insufficient to accept the total HLW stream from the civilian and military sectors, and focus on a single site is unnecessarily risky. Thus, the HLW problem in the USA remains far from being solved. After providing an overview of the nuclear waste regime of the USA, this paper reviews the technical, legal, and political status of the Yucca Mountain project. A large range of current issues and social values are discussed in this context, including the recently proposed Global Nuclear Energy Partnership that would revive spent fuel reprocessing and has important implications for national security and nuclear non-proliferation. [ABSTRACT FROM AUTHOR]

Globally, normal-fault displacement bends and warps rift flanks upwards, as adjoining basins drop downwards. Perhaps the most evident manifestations are the flanks of the East African Rift, which cuts across the otherwise minimally deformed continent. Flank uplift was explained by Vening Meinesz (1950, Institut Royal Colonial Belge, Bulletin des Seances, v. 21, p. 539-552), who recognized that isostasy should cause uplift of a normal-faulted footwall and subsidence of its hanging wall. Uplift occurs because slip on a dipping normal fault creates a broader root of less-dense material beneath the footwall, and a narrowed one beneath the hanging wall. In this paper, we investigate the potential influence of this process on the latest stages of Sierra Nevada uplift. Through theoretical calculations and 3D finite element modelling, we find that cumulative slip of about 4 km on range-front faults would have produced about 1.3 km peak isostatic uplift at the ridge crest. Numerical models suggest that the zone of uplift is narrow, with the width controlled by bending resistance of the seismogenic crust. We conclude that footwall unloading cannot account for the entire elevation of the Sierran crest above sea level, but if range-front faulting initiated in an already elevated plateau like the adjacent Basin and Range Province, then a hybrid model of pre-existing regional uplift and localized footwall unloading can account for the older and newer uplift phases suggested by the geologic record. [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]