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Objectives: Patellar dislocations are associated with a high risk of patellofemoral osteoarthritis (OA). The risk is further elevated for adolescent patients and patients who experience multiple dislocations. Quantitative MRI using T1ρ relaxation time mapping characterizes cartilage properties based on concentration of proteoglycans. Elevated T1ρ values identify cartilage degradation that could develop into post-traumatic OA. The current study compares T1ρ relaxation times throughout the knee between adolescents being treated for a single dislocation, multiple dislocations, and healthy controls. The hypothesis of the study is that patellar dislocation will increase T1ρ relaxation times for patellofemoral cartilage, with higher T1ρ relaxation times for multiple dislocations than single dislocations. Methods: The IRB-approved study included 13 patients (16 ± 2 years; 5 females; BMI: 23 ± 3 kg/m², 47 ± 38 days since dislocation) being treated for an initial, unilateral traumatic lateral patellar dislocation, 10 being treated for multiple unilateral dislocations (17 ± 2 years, 2 females; 23 ± 4 kg/m², 55 ± 24 days since most recent dislocation), and 10 healthy controls (16 ± 2 years, 5 females; 22 ± 2 kg/m²). MRI scans included a 3D water excitation dual energy steady state (DESS) scan of the knee for segmentation of cartilage surfaces (slice thickness of 0.7 mm) and a T1ρ relaxation time scan (fat saturated scan, slice thickness = 4 mm, spin lock times = 0, 10, 40, and 80 ms, spin-lock frequency = 500 Hz). Automated algorithms based on machine learning were used to automatically segment cartilage into six compartments: patella, trochlear groove, lateral/medial femur, lateral/medial tibia. The cartilage on the patella and within the trochlear groove were further divided into medial, lateral and central regions. The central region was centered on the patellar ridge for the patella and the deepest points throughout the trochlear groove and extended one-third of the distance to the medial and lateral edges. Additional automated algorithms mapped T1ρ relaxation times to the reconstructed cartilage surfaces (Fig. 1). Mean T1ρ relaxation times were quantified within each region for each knee. The mean T1ρ relaxation times within the regions were compared between the three groups with ANOVA's and Student-Newman-Keuls post-hoc tests. Statistical significance was set at p < 0.05. Results: T1ρ relaxation times were significantly longer for injured knees (both single and multiple dislocations) than controls at the medial and central patella, central trochlear groove, and lateral tibia (Fig. 2). For regions on the patella, the significant differences represented a difference between injured and control knees of 20% or larger. For the other significant regions, the difference was approximately 10%. No significant differences were identified between single and multiple dislocations. Conclusions: For adolescent patients, a patellar dislocation is associated with elevated T1ρ relaxation times for cartilage throughout the knee. Elevated T1ρ values indicate loss of proteoglycan content that reduces cartilage integrity and could be an initiation point for progression to OA. Elevated relaxation times from quantitative MRI is consistent with previous studies focused on patellar dislocations. The current study uniquely focuses on an adolescent population and uniquely compares single to multiple dislocations in the acute phase following injury. The results set a baseline for characterization of progressive cartilage degradation to OA following patellar dislocation for adolescents. The elevated T1ρ relaxation times within the patellofemoral joint are consistent with high risk of long term patellofemoral OA for adolescents who experience patellar dislocations. The elevated T1ρ relaxation times at the lateral tibia indicate an additional risk of tibiofemoral OA. The similar T1ρ relaxation times for single and multiple dislocations was not expected due to the higher risk of patellofemoral OA following multiple dislocations. Traumatic impact of the medial patella against the lateral femoral condyle during a dislocation is a primary contributor to cartilage degradation in the acute phase following a patellar dislocation, as demonstrated by the largest difference between injured knees and controls occurring at the medial patella for first time dislocators. Additional dislocations did not further increase T1ρ relaxation times at the medial patella. Recurrent dislocations could be less traumatic due to previous injury to medial soft tissue restraints, decreasing the influence on cartilage properties. Inflammation and pathologic anatomy can also contribute to cartilage degradation in adolescents experiencing patellar dislocations. Traumatic injury induces an inflammatory response that can be detrimental to cartilage. Pathologic anatomy associated with patellar dislocations includes patella alta, trochlear dysplasia and a lateral position of the tibial tuberosity. Pathologic anatomy can create loading conditions during daily function that adversely influence cartilage. Inflammation and anatomy likely contribute to the significantly elevated T1ρ relaxation times away from the medial patella. Over the long term, inflammation and anatomy may play a greater role in the risk of OA for multiple dislocators than repeated impact injuries. To continue to characterize the continuum from patellar dislocation to OA, additional recruitment is warranted to determine if significant differences can be identified in additional regions. Additional characterization of the influence of inflammation and pathologic anatomy on cartilage degradation is also warranted to identify patients at highest risk of OA and develop treatment strategies to preserve cartilage following patellar dislocations. [ABSTRACT FROM AUTHOR]

In order to better serve our nation's youth, educational leadership preparation programs must be willing to transform current preparation practices. This paper emphasizes the need to develop high quality school leaders to successfully create and sustain necessary changes in schools. The dynamic transformation of a principal preparation program, which stemmed from a university-district collaborative, is discussed in detail. Key areas of the transformation and partnership are shared, such as the foundational needs, the stakeholders involved, the course sequence redesign, the course and syllabi revision process, the co-teaching model, the internship, culminating experience, and current funding sources. Finally, conclusions and recommendations for transforming principal preparation program partnerships to support all children.

The main objectives of this study were to explore the means of reducing or eliminating snow build-up on rear warning lights and snow cloud in the wake of snowplow trucks during high-speed snowplowing (HSSP). These snow build-up on rear surfaces and snow cloud in the wake zone cause serious safety and efficiency problems due to diminishing visibility for the following motorists and amount of time needed to clear snow off from rear surfaces of snowplows. Furthermore, research and studies were carried out to solve the visibility problems experienced by the State of Nevada Department of Transportation (NDOT) snowplow trucks. Fluent 6.3.26 and ANSYS Fluent 12.1 Computational Fluid Dynamics (CFD) were utilized, and field tests were conducted with the mechanical design methods which were feasible and compatible with the snowplow trucks. Previously designed and installed rear foil (airfoil) helped reducing snow accumulation on most of the rear surface of truck except the right taillight. However, its effect in reducing snow cloud in the wake of the truck was limited. In this study several new designs were developed computationally including modifications on the current airfoil design. Based on computational (CFD) results, two of these designs were constructed and tested on NDOT trucks during routine HSSP. Preliminary test results showed promising results. Design process and test results are discussed in this paper. • 3D Computational Fluid Dynamics (CFD) snowplow truck models were utilized to study flow around and rear section of snow plow trucks. • Aerodynamic add-on device prototypes were designed and simulated using 3D CFD models. • Two aerodynamics add-on devices were designed, manufactured, and tested on an actual (full-scale) snow plow trucks during High-Speed Snowplowing (HSSP). • Field tests validated with CFD results and showed promising results. [ABSTRACT FROM AUTHOR]

Motor vehicle crashes are one of the leading causes of death among teenagers. Many of these deaths are due to preventable causes, including impaired and distracted driving. You Drink, You Drive, You Lose (YDYDYL) is a prevention program to educate high school students about the consequences of impaired and distracted driving. YDYDYL was conducted at a public high school in Southern Nevada in March 2020. A secondary data analysis was conducted to compare knowledge and attitudes of previous participants with first-time participants. Independent-samples-t test and χ2 test/Fisher's exact test with post-contingency analysis were used to compare pre-event responses between students who had attended the program one year prior and students who had not. Significance was set at p < 0.05. A total of 349 students participated in the survey and were included for analysis; 177 had attended the program previously (50.7%) and 172 had not (49.3%). The mean age of previous participants and first-time participants was 16.2 (SD ± 1.06 years) and 14.9 (SD ± 0.92 years), respectively. Statistically significant differences in several self-reported baseline behaviors and attitudinal responses were found between the two groups; for example, 47.4% of previous participants compared to 29.4% of first-time participants disagreed that reading text messages only at a stop light was acceptable. Students were also asked how likely they were to intervene if a friend or family member was practicing unsafe driving behaviors; responses were similar between the two groups. The baseline behaviors and attitudes of participants regarding impaired and distracted driving were more protective among previous participants compared to first-time participants, suggesting the program results in long-term positive changes in behaviors and attitudes. The results of this secondary retrospective study may be useful for informing the implementation of future impaired and distracted driving prevention programs. [ABSTRACT FROM AUTHOR]

Due to high interferometric coherence in the Nevada region, Interferometric Synthetic Aperture Radar ( InSAR) phase stacking is capable of mapping coseismic signals from the 27 January 1999, Mw 4.8 Frenchman Flat earthquake. This is one of the smallest earthquakes yet studied using InSAR with line-of-sight displacements as small as - l. 5 cm. Modelling the event as dislocation in an elastic half space suggests that the fault centroid was located at ( l 15.96°W, 36.81°N) with a precision of 0.2- 0.3 km ( llT) at a depth of 3.4 ± 0.2 km. Despite the dense local seismic network in southern Nevada, differences as large as 2- 5 km were observed between our InSAR earthquake location and those estimated from seismic data. The InSAR-derived magnitude appeared to be greater than that from seismic data, which is consistent with other studies, and believed to be due to the relatively long time interval of InSAR data. [ABSTRACT FROM AUTHOR]

Beyrichitine ammonoids of NV Nevada reveal a high taxonomic diversity of Anisian (Middle Triassic). This diversity is, however, in contrast to their relatively low morphologic disparity. Depending on the exact definition, morphologic disparity of a data set is a direct consequence of the sum of all ontogenetic changes. In the past, however, the interplay of both morphological processes has only rarely been addressed. Using geometric morphometric methods, this study aims at a quantification of allometric processes and the morphologic disparity of beyrichitine ammonoids. The multivariate statistical analysis revealed that morphologic disparity, intraspecific variation respectively, within and between the studied species seems to be the result of deviations in the ontogenetic allometric growth pattern (i.e. heterochrony). During deposition of the studied stratigraphic sequence, a general progressive pedomorphism (juvenilization) was observed. The intraspecific variability pattern coincides with the total morphologic disparity of the analyzed species, which suggests that intraspecific variability facilitated morphologic disparity. The comparison of ontogenetic allometric patterns and changes in intraspecific variation and morphologic disparity are likely to refine our understanding of the intrinsic factors influencing the speciation of this group. [ABSTRACT FROM AUTHOR]

A middle Miocene, early Barstovian land mammal age vertebrate assemblage, the Eastgate local fauna (LF), is known in the basal-most part of the Monarch Mill Formation. This rich assemblage of fossil vertebrates occurs within the Middlegate Basin in Churchill County, Nevada, USA. The Eastgate LF includes the fossil remains of fish, amphibians, reptiles, birds, and over 25 families of mammals. Previous studies on the mammalian remains have revealed several endemic taxa of rodents and carnivores. Herein, we describe the ungulates, which include two taxa from two families of Artiodactyla (Ticholeptus sp., Merycoidodontidae and Barbouromeryx trigonocorneus, Palaeomerycidae) and three taxa from three families of Perissodactyla (Equidae gen. et sp. indet., Moropus merriami, Chalicotheriidae, and Teleoceras sp., Rhinocerotidae). Independent paleobotanical evidence nearly contemporaneous with the vertebrates indicates forest and shrubland paleovegetation, and suggests that the area had been uplifted to 2700-2800 m paleoaltitude. Therefore, this local fauna adds a rare glimpse of a medium-to high-altitude vertebrate community in the intermountain western interior of North America. Temporally-restricted taxa (especially the rodent Tardontia nevadans and chalicothere Moropus merriami) reinforce the early Barstovian age of the Eastgate LF and are consistent with tephrochronological dates and radiometric analyses. The presence of Barbouromeryx trigonocorneus at Eastgate is significant in that its occurrence potentially represents a temporal range extension into the early Barstovian (previously known from latest Arikareean to middle Hemingfordian), and extends the paleobiogeographic range from the Great Plains to the Great Basin. Unequivocally, the ungulates and other mammals of the Eastgate LF support the presence of a temperate forest ecosystem in the Great Basin just subsequent to the Miocene Climatic Optimum. [ABSTRACT FROM AUTHOR]

Abstract: This paper investigates influence of pavement macrotexture on paved road PM10 emissions. This study was conducted on different paved roadway types (local, collector and minor arterial) in the Las Vegas Valley, Nevada. Pavement macrotexture was measured using the ASTM E 965 sand patch method and the Digital Surface Roughness Meter™ (DSRM™). A controlled constant soil loading with known PM10 fraction was applied to cleaned road surfaces. The Desert Research Institute''s (DRI) Mini-PI-SWERL™ (Portable In-Situ Wind ERosion Lab) was used to estimate PM10 mass emissions and cumulative mass emitted from pavement surfaces. PM10 mass emissions using controlled applied soil loadings generally declined with increasing pavement macrotexture at all applied shear levels. The relationships were statistically significant, and indicate that pavement macrotexture may need to be included in future development of revised paved road PM10 emissions factors. A change in the slope of emitted PM10 mass and pavement macrotexture occurred between 0.8 and 0.9 mm mean texture depth (MTD). Anomalies in PM10 mass emissions were observed at MTDs exceeding 1.2 mm. Two-way frequency distributions of pavement surface features obtained from DSRM measurements were analyzed to explain the observed anomalies. Results showed that pavement surface feature size distributions may influence on PM10 emissions from paved roads at similar MTDs. PM10 mass emissions were found to linearly depend on adjusted mode size of the pavement surface aggregate. A sharp decrease in friction velocities, computed from wind erosion theory, at MTDs above 0.9 mm matched an observed sharp decrease in PM10 emissions rates at MTDs above 0.9 mm, indicating that classical wind erosion theory could be adapted for non-erodible pavement surfaces and linearly relate PM10 emissions rates to applied shear stress at an aerodynamic roughness height of 0.075 mm. [Copyright &y& Elsevier]

The need to accurately document the spatiotemporal distribution of earthquakegenerated strong ground motions is essential for evaluating the seismic vulnerability of sites of critical infrastructure. Understanding the threshold for maximum earthquakeinduced ground motions at such sites provides valuable information to seismologists, earthquake engineers, local agencies, and policymakers when determining ground motion hazards of seismically sensitive infrastructures. In this context, fragile geologic features such as precariously balanced rocks (PBRs) serve as negative evidence for earthquake-induced ground motions and provide important physical constraints on the upper limits of ground motions. The three-dimensional (3D) shape of a PBR is a critical factor in determining its static stability and thus susceptibility to toppling during strong ground shaking events. Furthermore, the geomorphic settings of PBRs provide important controls on PBR exhumation histories that are interpreted from surface exposure dating methods. In this paper, we present PBRslenderness, a MATLAB-based program that evaluates the two-dimensional (2D) static stabilities of PBRs from unconstrained digital photographs. The program's graphical user interface allows users to interactively digitize a PBR and calculates the 2D geometric parameters that define its static stability. A reproducibility study showed that our 2D calculations compare well against their counterparts that were computed in 3D (R2 = 0.77-0.98 for 22 samples). A sensitivity study for single-user and multiuser digitization routines further confirmed the reproducibility of PBRslenderness estimates (coefficients of variation cv = 4.3%-6.5% for 100 runs; R2 = 0.87-0.99 for 20 PBRs). We used PBRslenderness to analyze 261 PBRs in a low-seismicity setting to investigate the local geomorphic controls on PBR stability and preservation. PBRslenderness showed that a PBR's shape strongly controls its static stability and that there is no relationship between a PBR's stability and its geomorphic location in a drainage basin. However, the geomorphic settings of PBRs control their preservation potential by restricting their formation to hillslope gradients <40°and the upper reaches of drainage basins. Such examples of our program's utility have led to its use in archival efforts of PBRs in southern California and Nevada, USA. [ABSTRACT FROM AUTHOR]

The article discusses the highlights of the 8th annual IEEE Consumer Communications and Networking Conference held in Las Vegas, Nevada in 2011. The event attracted international consumer communications and networking experts. Topics tackled at the conference include industrial and academic research on technologies related to consumer communications and networking, vehicular communication systems and digital rights management, among others.

Information about the Annual Institute of Electrical and Electronics Engineers (IEEE) Inc. Consumer Communications and Networking Conference (CCNC) held in Las Vegas, Nevada in January 2010 is presented. The event included technical seminars, workshops, and demonstrations. Speakers addressed a wide spectrum of topics such as peer-to-peer networking, social television, video streaming, location-aware services and intelligent vehicle communications.

The article reports on topics which were discussed at the 2012 Association of Chiropractic Colleges Educational Conference and Research Agenda Conference, which was held in Las Vegas, Nevada on March 15-17. Topics included the role that the World Health Organization plays in association initiatives, workplace diversity and the impact changing demographics in the U.S. will have on the chiropractic profession. The event was attended by several health and chiropractic professionals.

Abstract: Between 1997 and 2002, 16 cases of acute childhood leukemia were diagnosed in children who either lived in Churchill County, Nevada at the time of diagnosis or had lived in the county before their diagnosis. The cases were characterized as a cluster of like illnesses and the probability of having such a cluster occur by chance was estimated to be very small (approximately one in 2.33×108). This suggested that the cluster could be linked to one or more physical, limnological, chemical, or biological agents. This review discusses the setting in which the cluster took place, the epidemiological investigations carried out by the Nevada Bureau of Health Protection Services, the National Center for Environmental Health Centers for Disease Control and Prevention and the Agency for Toxic Substances and Disease Registry, and subsequent investigations supported by a special allocation of federal funds through the US Environmental Protection Agency’s Region IX office in San Francisco, CA. This review is meant as background for the papers in this special issue that report results from multi- and interdisciplinary research into environmental and biological factors potentially related to the Churchill County leukemia cluster. [Copyright &y& Elsevier]

In February of 2009 and 2010, President Obama made what some in the media and gaming industries construed as negative public statements regarding trips to Las Vegas. Some claimed these statements could easily be interpreted as a suggestion that companies and individuals avoid casino areas, thus doing additional harm to their surrounding economies during already tough times. In this paper, we use event study methodology to examine stock market reactions ofU.S. casino-related businesses to the president's statements. We find that President Obama's statements were followed by significant negative abnormal returns in the segment of companies targeted more towards conventions, trade shows, and tourism, and by significant positive abnormal returns for companies with more of a local/regional focus. Our findings suggest that the president's statements did not adversely affect all casino-related businesses, but they also were not benign. [ABSTRACT FROM AUTHOR]

The article offers information on the description of a Miocene fossil crane fly Tipula nevadensis from a single male that is preserved in fine paper shale from Stewart Valley, Nevada. It states that Tipula nevadensis is a new species that is noted from other similar tertiary crane flies in western North America. It also mentions that the head of the species is rounded and narrowed behind compound eyes, and its total body length measures 15.8 millimeter (mm) with 18.3 mm wing length.

Abstract: Significant advances in regional groundwater flow modeling have been driven by the demand to predict regional impacts of human inferences on groundwater systems and associated environment. The wide availability of powerful computers, user friendly modeling systems and GIS stimulates an exponential growth of regional groundwater modeling. Large scale transient groundwater models have been built to analyze regional flow systems, to simulate water budget components changes, and to optimize groundwater development scenarios. This paper reviews the historical development of regional groundwater modeling. Examples of Death Valley and Great Artesian Basin transient groundwater models are introduced to show the application of large scale regional groundwater flow models. Specific methodologies for regional groundwater flow modeling are descried and special issues in regional groundwater flow modeling are discussed. [Copyright &y& Elsevier]

The Nevada Test Site (NTS) covers 3,561 km2 and extends over portions of both the Mojave and Great Basin Deserts. The resulting diverse and complex flora and fauna exhibit elements of both deserts. There are 20 vegetation associations, composed primarily of shrubs, nested within 10 vegetation alliances. Of the more than 1,200 invertebrate and 339 vertebrate species found in these shrubland habitats, 267 are considered sensitive or protected/regulated by federal or state laws. Wildlife and wildlife habitat monitoring ensures NTS activities comply with all federal and state laws enacted for the protection of these valuable biological resources and provides ecological information that can be used to predict and evaluate the potential impacts of proposed projects and current activities on these resources. This paper describes the monitoring approach used at this large site. Monitoring strategies include conducting preactivity surveys, proactively monitoring sensitive species, monitoring long-term population trends, and collaborating with other agencies and biologists. Ways to make monitoring more efficient and examples of successful monitoring and collaborations are discussed. [ABSTRACT FROM AUTHOR]

Pueblo Grande de Nevada, more popularly known as "Lost City" refers to a loosely defined series of archaeological sites in the Moapa Valley of southern Nevada. Excavated between the years of 1924 and 1941, these sites were to have a major impact on early-twentieth-century Southwestern archaeology. Despite the excitement that surrounded these finds at the time of their discovery their legacy has largely been forgotten today. We argue one reason for this oversight is that the data obtained by the original researchers are inadequate for addressing the questions being asked of the region today. In particular, because plant and animal remains were not systematically recovered by the original researchers, the early fieldwork has provided only a broad sketch of the subsistence activities practiced in the region. To remedy these shortcomings, in 2006 archaeologists from the University of Nevada Las Vegas conducted additional excavations at House 20, a roomblock located within one of the so-called Lost City sites. In this paper, the history of the Lost City fieldwork is reviewed and results from our 2006 excavations are presented. The newly obtained data suggest that the inhabitants of House 20 were heavily invested in agriculture and utilized wild resources that could be obtained in the immediate vicinity. [ABSTRACT FROM AUTHOR]

This study analyzed the websites of major Las Vegas Strip hotels, examined their corporate financial reports, and conducted two in-depth telephone interviews with hotel managers, all with regard to their "green" (pro-environmental) policies. The study found a distinct lack of evidence to support assertions that these properties had truly "gone green" in their daily operations. Thus, although the hotels might actually have been engaged in green procedures, they did not express environmental policy in their corporate websites or financial reports. Several possible reasons for this apparent duality are suggested. [ABSTRACT FROM AUTHOR]

Abstract: Field experiments were conducted in Nellis Dunes Recreational Area (Clark County, Nevada, USA) to investigate emission of dust produced by off-road driving. Experiments were carried out with three types of vehicles: 4-wheelers (quads), dirt bikes (motorcycles) and dune buggies, on 17 soil types characteristic for a desert environment. Tests were done at various driving speeds, and emissions were measured for a large number of grain size fractions. This paper reports the results for two size fractions of emissions: PM10 (particles <10 μm) and PM60 (particles <60 μm). The latter was considered in this study to be sufficiently representative of the total suspendable fraction (TSP). Off-road driving was found to be a significant source of dust. However, the amounts varied greatly with the type of soil and the characteristics of the top layer. Models predicting emission of dust by off-road driving should thus consider a number of soil parameters and not just one key parameter. Vehicle type and driving speed are additional parameters that affect emission. In general, 4-wheelers produce more dust than dune buggies, and dune buggies, more than dirt bikes. Higher speeds also result in higher emissions. Dust emitted by off-road driving is less coarse than the parent sediment on the road surface. Off-road driving thus results in a progressive coarsening of the top layer. Exceptions to this are silty surfaces with no, or almost no, vegetation. For such surfaces no substantial differences were observed between the grain size distribution of road dust and emitted dust. Typical emission values for off-road driving on dry desert soils are: for sandy areas, 30–40 g km−1 (PM10) and 150–250 g km−1 (TSP); for silty areas, 100–200 g km−1 (PM10) and 600–2000 g km−1 (TSP); for drainages, 30–40 g km−1 (PM10) and 100–400 g km−1 (TSP); and for mixed terrain, 60–100 g km−1 (PM10) and 300–800 g km−1 (TSP). These values are for the types of vehicles tested in this study and do not refer to cars or trucks, which produce significantly more dust. [Copyright &y& Elsevier]

Framing prostitution as an economic exchange, this paper evaluates some of the consequences of conceiving of sex as a commodity rather than as an aspect of an intimate interpersonal relationship among the customers of prostitutes. Subjects were 700 men arrested while trying to hire street prostitutes. Questionnaires were administered prior to intervention programs designed to discourage re-offense in San Francisco, California (N=588); Portland, Oregon (N=82); and Las Vegas, Nevada (N=30). Significant predictors of conceiving of sex as a commodity included being unmarried, having served in the military, and more frequent visits to prostitutes. Conceiving of sex as a commodity significantly predicted rape myth acceptance, attraction to violent sexuality, less frequent use of condoms while with prostitutes, support for prostitution, and the attitude that prostitution is positive for women. We argue that that conceiving of sex as a commodity has a number of negative implications for the men involved, their sexual partners, and for gender relations in general. [ABSTRACT FROM AUTHOR]

Abstract: We analyzed a data set of thermally induced changes in fractured rock permeability during a 4-year heating (up to 200°C) and subsequent 4-year cooling of a large volume, partially saturated and highly fractured volcanic tuff at the Yucca Mountain Drift Scale Test, Nevada, USA. Permeability estimates were derived from about 700 pneumatic (air-injection) tests, taken periodically at 44 packed-off borehole intervals during the heating and cooling cycle from November 1997 through November 2005. We analyzed air-permeability data by numerical modeling of thermally induced stress and moisture movements and their impact on air permeability within the highly fractured rock. Our analysis shows that changes in air permeability during the initial 4-year heating period, which were limited to about one order of magnitude, were caused by the combined effects of thermal-mechanically induced stress on fracture aperture and thermal-hydrologically induced changes in fracture moisture content. At the end of the subsequent 4-year cooling period, air-permeability decreases (to as low as 0.2 of initial) and increases (to as high as 1.8 of initial) were observed. By comparison to the calculated thermo-hydro-elastic model results, we identified these remaining increases or decreases in air permeability as irreversible changes in intrinsic fracture permeability, consistent with either inelastic fracture shear dilation (where permeability increased) or inelastic fracture surface-asperity shortening (where permeability decreased). In this paper, we discuss the possibility that such fracture asperity shortening and associated decrease in fracture permeability might be enhanced by dissolution of highly stressed surface asperities over years of elevated stress and temperature. [Copyright &y& Elsevier]

Objectives: To determine the percentage of gamblers who smoke while gambling at three of Nevada's major gambling destinations, Las Vegas, Reno/Sparks and Lake Tahoe. Methods: Teams of two people counted the number of smokers and total number of gamblers at various Nevada casinos. The total number of gamblers observed smoking was then multiplied by three to determine the total number of smokers. This methodology for determining the number of smokers in a room was established by Repace and Lowry in 1980. Results: We observed a total of 14 052 gamblers at the three sites, of which a total of 947 were smoking. We estimated the percentage of smokers at three gaming tourist centres in Nevada (Las Vegas, Reno/Sparks and Lake Tahoe). The percentage of smokers at Las Vegas (20.3% (95% CI 0.9)) and Reno/ Sparks (21.5% (95% CI 1.2%)) did not significantly differ from the US population percentage of smokers (20.9% (95% CI 0.6%)) (p>0.05). However, at Lake Tahoe the percentage of smokers (16.4% (95% CI 1.8%)) was significantly lower than the published US population smoker percentage (p<0.0001). Mean percentage of smokers by location did not significantly differ (p = 0.43) Conclusions: The results of this study suggest that the percentage of gamblers who smoke was less than or not different from the overall US percentage of a population who smoke. These findings provide additional evidence to refute the exemption to smoking bans for casinos based upon the supposition that a greater percentage of casino customers are smokers than the general population and therefore a smoking ban for casinos may result in an economic hardship. [ABSTRACT FROM AUTHOR]

A new freshwater ostracode, Cyclocypris vinyardi n. sp., belonging to the family Cyclocyprididae is described from a slow flowing rheocrene spring in Nevada, U.S.A. The new species is distinguished from the other 12 extant species of the genus in the United States based on the double rows of pore openings on the anterior end of the carapace, differences in the shape of the hemipenis, and asymmetry in the clasping organs. [ABSTRACT FROM AUTHOR]

Sediment flux on transport-limited hillslopes is well known to vary nonlinearly with slope, diverging as the angle of stability is approached. To date, however, no study has validated the precise form of the nonlinear slope-dependent transport model over geologic time scales in a non-steady-state landform. In this paper, we show how cinder cones can be used to validate the nonlinear transport model using Lathrop Wells cinder cone in Nye County, Nevada, as a type example. Cinder cones are well suited for this purpose because they can be radiometrically dated and their angles of stability can be constrained by measurement of subsurface contacts between primary fallout and overlying colluvial deposits reworked from upslope. Forward model results with a generalized, nonlinear transport model characterized by diffusivity, κ, and nonlinear exponent, n, show that the evolution of the cone rim and base are most sensitive to κ, while the cone midpoint is most sensitive to n. Analyses of the full cone shape, therefore, permit the two model parameters to be independently inferred if the cone age and angle of stability are independently known. Results for Lathrop Wells imply that n = 2 in the generalized, nonlinear transport model, which is consistent with Roering et al.'s (1999) widely used form of that model. [ABSTRACT FROM AUTHOR]

This paper describes total gaseous mercury (TGM) concentrations measured in Reno, Nevada from 2002 to 2005. The 3-year mean and median air Hg concentrations were 2.3 and 2.1ngm−3, respectively. Mercury concentrations exhibited seasonality, with the highest concentrations in winter, and the lowest in summer and fall. A well-defined diel pattern in TGM concentration was observed, with maximum daily concentrations observed in the morning and minimum in the afternoon. A gradual increase of TGM concentration was observed in the evening and over night. The early morning increase in TGM was likely due to activation of local surface emission sources by rising solar irradiance and air temperature. The subsequent decline and afternoon minimum in TGM were likely related to increased vertical mixing and the buildup of atmospheric oxidants during the day resulting in increased conversion to oxidized species that are quickly deposited, coupled with weakening of the surface emissions processes. The described diel pattern was seasonally modulated with the greatest amplitude in variation of TGM concentrations occurring in the summer. It is suggested based on the comparison of diel TGM pattern with other gaseous pollutants that natural source surface emissions are a dominant source of TGM in the study area. [Copyright &y& Elsevier]

The authors discuss their views and experiences from conducting ATMS 748: Measurement in the Atmosphere, a course on the principles and practice of atmospheric measurements that was required for Ph.D. students in the atmospheric science program of University of Nevada in Reno. In this course, professors tackle lessons related to instrumentation and its role in atmospheric science curriculum. It aims to train those whose career is to follow instrument design, use and deployment as well as those who analyze climatological or synoptic records. The authors hope that other university departments will introduce similar instrumentation courses and that national facilities will be made available for such courses.

Entobia, a sponge boring commonly consisting of interconnected chambers and galleries (i.e., it is camerate), is a dominant agent of bioerosion in Mesozoic and Cenozoic marine carbonates. A similar camerate boring, Topsentopsis devonica, is widely recognized from the Devonian, and its classification is reappraised here. This paper synonymizes Topsentopsis with the senior synonym Entobia, making E. devonica n. comb. the oldest representative of the ichnogenus. New specimens of E. devonica borings in stromatoporoids and megalodont bivalves are described from the Frasnian Guilmette Formation of Nevada, which includes breccias of the Alamo Bolide Impact. The borings occur in skeletal substrates both within and above the impact event breccias, demonstrating their existence prior to the impact and their survival of the catastrophic event. The Nevada discovery extends the geographic distribution of the oldest Entobia to include the western and midcontinental United States, western Canada, and eastern Europe. E. devonica was an important bioerosive agent during the Givetian-Frasnian, but it is unknown following the Frasnian-Famennian mass extinction. [ABSTRACT FROM AUTHOR]

Abstract: Increasing tension in the Nevada ranch community may have had a negative impact on social capital. Social capital is important because it facilitates cooperation in resolving social dilemmas related to public range management. In this paper, we use a survey of public grazing permit holders in Nevada to investigate factors that affect ranchers'' relationships with the U.S. Forest Service and Bureau of Land Management. Results indicate that, contrary to expectations, economic factors such as income and ranch size have little or no effect on relationships in the Nevada ranch community — on ranchers'' disagreements with public land managers and the deterioration in rancher-land agency relations. Rather, these relationships appear to be affected to a greater extent by our measures of social capital, personal characteristics and experience with wildfire. Indeed, disagreements with the public agencies were mainly affected by gender (males tended to have more disagreements), lack of trust, and disputes concerning responses to wildfire (which increased the chance of disagreement). Not surprisingly, disagreement resulted in a deterioration of relationships that could be offset by higher levels of social capital, particularly trust and positive attitudes towards the future of ranching and the community (as measured by responses to a variety of attitudinal questions). We conclude that, while there remain opportunities to build on existing social capital in the community (horizontal relations), ranchers and the public agencies need to work on building vertical relations, thereby increasing trust. This could potentially help in the resolution of social dilemmas related to range management. [Copyright &y& Elsevier]

Abstract: This paper presents results of five creep tests conducted in uniaxial compression at room temperature. The test specimens were from the welded Topopah Spring tuff formation at Yucca Mountain, Nevada. The specimens exhibited brittle failure. Multiple stress levels were applied in steps to each specimen. Each stress level was maintained for 3 days or longer. The transient creep for all the stress levels can be well described by power functions. The transient creep is caused by an elastic aftereffect. The tuff does not show real steady-state creep. The so-called steady-state creep rate decreases with time. In general it is very low, typically in the range of 10−7 h−1. For the first 50h, the so-called steady-state creep rate may be described as a power function of stress. The specimen failed shortly after it entered into the accelerating creep phase. [Copyright &y& Elsevier]

Abstract: This paper presents thermo-hydro-mechanical (THM) analyses simulating the Drift Scale Test (DST) performed at Yucca Mountain. A double structure approach based on two superimposed domains is adopted. Intrinsic permeability changes with deformations imply full THM coupling. Temperatures and gas permeabilities were measured during 4 years and are used to validate the model. Measured gas permeability variations show patterns that are successfully explained by the model calculations. These gas permeability variations may be attributed to thermo-hydraulic effects, and also to mechanical effects. Different cases of intrinsic permeability variations have been considered in the model and their influence on the calculated temperatures, degree of saturations and gas permeabilities are presented. Volumetric deformation, in contraction or dilatancy, implies changes in the aperture of rock fractures that in turn lead to changes in intrinsic permeability. Dilatancy, caused by shear stresses, increases intrinsic permeability. Consideration of this factor contributes significantly to improve the agreement of calculated gas permeability with the measured values obtained during the DST experiment. [Copyright &y& Elsevier]

Abstract: Xu et al. (2003) [Xu, T., Sonnenthal, E., Bodvarsson, G., 2003. A reaction-transport model for calcite precipitation and evaluation of infiltration–percolation fluxes in unsaturated fractured rock. J. Contam. Hydrol., 64, 113–127.] presented results of a reaction-transport model for calcite deposition in the unsaturated zone at Yucca Mountain, and compared the model results to measured abundances in core from a surface-based borehole. Marshall et al. (2003) [Marshall, B.D., Neymark, L.A., Peterman, Z.E., 2003. Estimation of past seepage volumes from calcite distribution in the Topopah Spring Tuff, Yucca Mountain, Nevada. J. Contam. Hydrol., 62–63, 237–247.] used the calcite distribution in the Topopah Spring Tuff to estimate past seepage into lithophysal cavities as an analog for seepage into the potential repository waste emplacement drifts at Yucca Mountain in southern Nevada (USA). Dublyansky and Smirnov (2005) [Dublyansky, Y.V., Smirnov, S.Z., 2005. Commentary: assessment of past infiltration fluxes through Yucca mountain on the basis of the secondary mineral record—is it a viable methodology? J. Contam. Hydrol. (this issue).] wrote a commentary paper to Marshall et al. (2003) [Marshall, B.D., Neymark, L.A., Peterman, Z.E., 2003. Estimation of past seepage volumes from calcite distribution in the Topopah Spring Tuff, Yucca Mountain, Nevada. J. Contam. Hydrol., 62–63, 237–247.] and Xu et al. (2003) [Xu, T., Sonnenthal, E., Bodvarsson, G., 2003. A reaction-transport model for calcite precipitation and evaluation of infiltration–percolation fluxes in unsaturated fractured rock. J. Contam. Hydrol., 64, 113–127.], containing two points: (1) questionable phenomenological model for the secondary mineral deposits and (2) inappropriate thermal boundary conditions. In this reply we address primarily the modeling approach by showing results of a sensitivity simulation regarding the effect of an elevated temperature history that approximates the temperature history inferred from fluid inclusions by Wilson et al. (2003) [Wilson, N.S.F., Cline, J.S., Amelin, Y.V., 2003. Origin, timing, and temperature of secondary calcite–silica mineral formation at Yucca Mountain, Nevada. Geochimica et Cosmochimica Acta, 67 (6), 1145–1184.]. Modeled calcite abundances using the time-varying temperature history are similar to the results for the steady-state ambient temperature profile (Xu, T., Sonnenthal, E., Bodvarsson, G., 2003. A reaction-transport model for calcite precipitation and evaluation of infiltration–percolation fluxes in unsaturated fractured rock. J. Contam. Hydrol., 64, 113–127), and are still consistent with the measured abundances at the proposed repository horizon. [Copyright &y& Elsevier]

Abstract: Two papers recently published in the Journal of Contaminant Hydrology by Marshall et al. [Marshall, B.D., Neymark, L.A., Peterman, Z.E., 2003. Estimation of past seepage volumes from calcite distribution in the Topopah Spring Tuff, Yucca Mountain, Nevada. J. Contam. Hydrol. 62–63, 237–247] and Xu et al. [Xu, T., Sonnenthal, E., Bodvarsson, G., 2003. A reaction–transport model for calcite precipitation and evaluation of infiltration fluxes in unsaturated fractured rock. J. Contam. Hydrol. 64, 113–127] attempt to assess past volumes of seepage and infiltration fluxes through the vadose zone of Yucca Mountain, Nevada, on the basis of the modeling of the spatial distribution of secondary calcite. In this commentary, we argue that the employed methodology is not viable. In addition, the thermal boundary conditions used in simulations do not correspond to the temperatures of the mineral forming fluids established on the basis of the fluid inclusion studies. [Copyright &y& Elsevier]

Abstract: The use of cosmogenic nuclide dating methods place in doubt the long-term future of weathering rinds (WRs) as a chronometric tool. Why estimate ages when radiometric control is possible? This paper presents evidence that WRs can provide invaluable clues about what particular sample would provide the most accurate cosmogenic age by avoiding “inheritance” of cosmogenic nuclides and by avoiding boulders undergoing spalling. The key to this new use requires testing the occurrence and nature of WR erosion. Back-scattered electron microscopy reveals that ignimbrite, andesite, basalt, and granitic clasts experience WR erosion in all subsurface and surface contexts thus far studied in Arizona, California, Hawaii, Oregon, and Washington. To understand the magnitude of WR erosion, we measured WR thicknesses, all while controlling the cosmogenic and surface stability ages of clasts by chlorine-36 and rock varnish microlamination dating methods. Our data reveal that traditional methodologies of sampling cobbles remove two-thirds of the true thickness of weathering rinds, calling into question many beliefs including the notion that clay minerals are not produced during weathering-rind formation. Comparisons of optical and electron microscope measurements support concerns that measurement of WRs by color changes, while useful as a pedagogical tool, creates serious biases in underestimating the true dynamics of WRs. In the end, we found that concordance of WR and rock coating “age trends” indicates the ideal boulder for cosmogenic nuclide dating. Offsets reveal either ongoing boulder erosion, invalidating “zero erosion” model ages, or a potential problem with “inheritance” of cosmogenic nuclides. [Copyright &y& Elsevier]

Local gamblers are an important market segment for casino marketers providing a reliable source of revenue during slow periods. This paper presents selected gaming behavior of local residents in the Las Vegas area, linking socio-demographic characteristics with gaming behavior. In addition, this article examines the relationships of Las Vegas area locals and their visiting friends and family members in two aspects. First, we identified the influence local residents have on visiting friends and family in terms of recommendations made regarding gambling in general and specific gaming locations. Second, this article describes how visiting friends and family influence local residents in terms of gaming behavior and additional spending. [ABSTRACT FROM AUTHOR]

Lockdown measures implemented in response to the COVID-19 pandemic produced sudden behavioral changes. We implement counterfactual time series analysis based on seasonal autoregressive integrated moving average models (SARIMA), to examine the extent of air pollution reduction attained following state-level emergency declarations. We also investigate whether these reductions occurred everywhere in the US, and the local factors (geography, population density, and sources of emission) that drove them. Following state-level emergency declarations, we found evidence of a statistically significant decrease in nitrogen dioxide (NO2) levels in 34 of the 36 states and in fine particulate matter (PM2.5) levels in 16 of the 48 states that were investigated. The lockdown produced a decrease of up to 3.4 µg/m3 in PM2.5 (observed in California) with range (− 2.3, 3.4) and up to 11.6 ppb in NO2 (observed in Nevada) with range (− 0.6, 11.6). The state of emergency was declared at different dates for different states, therefore the period "before" the state of emergency in our analysis ranged from 8 to 10 weeks and the corresponding "after" period ranged from 8 to 6 weeks. These changes in PM2.5 and NO2 represent a substantial fraction of the annual mean National Ambient Air Quality Standards (NAAQS) of 12 µg/m3 and 53 ppb, respectively. As expected, we also found evidence that states with a higher percentage of mobile source emissions (obtained from 2014) experienced a greater decline in NO2 levels after the lockdown. Although the socioeconomic restrictions are not sustainable, our results provide a benchmark to estimate the extent of achievable air pollution reductions. Identification of factors contributing to pollutant reduction can help guide state-level policies to sustainably reduce air pollution. [ABSTRACT FROM AUTHOR]

Copyright of Arab Journal of Plant Protection is the property of Arab Society for Plant Protection 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.)

We present a data‐driven approach to clustering or grouping Global Navigation Satellite System (GNSS) stations according to observed velocities, displacements or other selected characteristics. Clustering GNSS stations provides useful scientific information, and is a necessary initial step in other analysis, such as detecting aseismic transient signals (Granat et al., 2013, https://doi.org/10.1785/0220130039). Desired features of the data can be selected for clustering, including some subset of displacement or velocity components, uncertainty estimates, station location, and other relevant information. Based on those selections, the clustering procedure autonomously groups the GNSS stations according to a selected clustering method. We have implemented this approach as a Python application, allowing us to draw upon the full range of open source clustering methods available in Python's scikit‐learn package (Pedregosa et al., 2011, https://doi.org/10.5555/1953048.2078195). The application returns the stations labeled by group as a table and color coded KML file and is designed to work with the GNSS information available from GeoGateway (Donnellan et al., 2021, https://doi.org/10.1007/s12145-020-00561-7; Heflin et al., 2020, https://doi.org/10.1029/2019ea000644) but is easily extensible. We demonstrate the methodology on California and western Nevada. The results show partitions that follow faults or geologic boundaries, including for recent large earthquakes and post‐seismic motion. The San Andreas fault system is most prominent, reflecting Pacific‐North American plate boundary motion. Deformation reflected as class boundaries is distributed north and south of the central California creeping section. For most models a cluster boundary connects the southernmost San Andreas fault with the Eastern California Shear Zone (ECSZ) rather than continuing through the San Gorgonio Pass. Key Points: Unsupervised clustering methods provide a data‐driven way of analyzing and partitioning Global Navigation Satellite System observations of crustal deformationDeformation is distributed across the San Andreas fault system but is localized at the creeping section in central CaliforniaThe Southern San Andreas fault connects with the Eastern California Shear Zone rather than the rest of the San Andreas fault system [ABSTRACT FROM AUTHOR]

Copyright of Ornithological Applications is the property of Oxford University Press / USA 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.)

Background: The Substance Abuse and Mental Health Administration awarded State Targeted Response grants to support states' efforts to address the opioid epidemic. In Nevada, one component of this grant was mobile recovery outreach teams (MROTs) that utilized peer recovery support specialists to provide care for qualifying patients in emergency departments (EDs). The Mobile Emergency Recovery Intervention Trial (MERIT) is a mixed methods study to assess the feasibility/acceptability and effectiveness of the MROT intervention. This protocol mainly describes the R33 research activities and outcomes. The full protocol can be found protocols.io. Methods: Data will be derived from state-level data sets containing de-identified emergency department visits, substance use disorder treatment records, and mortality files; in-person mixed methods interviews; participant observation; and self-report process evaluation forms. Primary outcomes include Medication Assisted Treatment (MAT) initiation and non-fatal overdose; secondary outcomes include MAT retention and fatal overdose. Quantitative hypotheses will be tested using generalized linear mixed effects models, Bayesian hierarchical models, and marginal Cox models. Qualitative interview data will be analyzed using an inductive thematic analysis procedure. Discussion: It is impossible to conduct a randomized controlled trial of the effectiveness of the MROTs, given the ethical and logistical considerations of this intervention. This study's innovative design employs a mixed methods formative phase to examine feasibility and acceptability, and a quasi-experimental outcomes evaluation phase employing advanced statistical methods to mitigate bias and suggest causal inference regarding the effectiveness of the MROTs. Innovative interventions have been deployed in many states; evidence regarding their effectiveness is lacking, but critical to informing an effective public health response to the opioid epidemic. [ABSTRACT FROM AUTHOR]

Traditional approaches to evaluating and predicting safety issues in traffic systems are via crash records. However, considering the characteristics of scarcity, inconsistency, inaccuracy, and incompleteness of crash records, conclusions and recommendations drawn purely based on crashes have limitations. Tire skid marks are considered an indication of some safety hazards, and it could have good potential to be used as surrogates for crashes. By collecting and analyzing the data based on selected arterial and freeway segments in the Reno-Sparks area in northern Nevada, a methodology was developed to categorize different tire skid marks. Sliding window and linear regression techniques were applied to determine any correlation between tire skid marks and crashes. The analyses indicated that there was a relatively strong linear correlation between skid marks and crashes on freeway segments. [ABSTRACT FROM AUTHOR]

Copyright of Western North American Naturalist is the property of Monte L. Bean Life Science Museum 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.)

A weakly sorbing cation, lithium, will be used as a reactive tracer in upcoming field tracer tests in the saturated alluvium south of Yucca Mountain, Nevada. One objective of the field tests is to determine how well field-scale reactive transport can be predicted using transport parameters derived from laboratory experiments. This paper describes several laboratory lithium batch sorption and column transport experiments that were conducted using ground water and alluvium obtained from the site of the planned field tests. In the batch experiments, isotherms were determined over 2.5 orders of magnitude of lithium concentrations, corresponding to the range expected in the field tests. In addition to measuring equilibrium lithium concentrations, concentrations of other cations, namely Na+, K+, and Ca2+, were measured in the batch tests to determine Li+-exchangeable equilibria. This information was used in conjunction with alluvium cation exchange capacity measurements to parameterize a three-component cation-exchange model (EQUIL) that describes lithium sorption in the alluvium system. This model was then applied to interpret the transport behavior of lithium ion in saturated alluvium column tests conducted at three different lithium bromide injection concentrations. The concentrations were selected such that lithium ion either dominated, accounted for a little over half, or accounted for only a small fraction of the total cation equivalents in the injection solution. Although tracer breakthrough curves differed significantly under each of these conditions, with highly asymmetric responses occurring at the highest injection concentrations, the three-component cation-exchange model reproduced the observed transport behavior of lithium and the other cations in each case with a similar set of model parameters. In contrast, a linear Kd-type sorption model could only match the lithium responses at the lowest injection concentration. The three-component model will be used to interpret the field tests, with the expectation that it will help refine estimates of effective flow porosity, particularly if the lithium response curves are asymmetric. [Copyright &y& Elsevier]

This paper presents several different conceptual models of the Large Hydraulic Gradient (LHG) region north of Yucca Mountain and describes the impact of those models on groundwater flow near the potential high-level repository site. The results are based on a numerical model of site-scale saturated zone beneath Yucca Mountain. This model is used for performance assessment predictions of radionuclide transport and to guide future data collection and modeling activities. The numerical model is calibrated by matching available water level measurements using parameter estimation techniques, along with more informal comparisons of the model to hydrologic and geochemical information. The model software (hydrologic simulation code FEHM and parameter estimation software PEST) and model setup allows for efficient calibration of multiple conceptual models. Until now, the Large Hydraulic Gradient has been simulated using a low-permeability, east–west oriented feature, even though direct evidence for this feature is lacking. In addition to this model, we investigate and calibrate three additional conceptual models of the Large Hydraulic Gradient, all of which are based on a presumed zone of hydrothermal chemical alteration north of Yucca Mountain. After examining the heads and permeabilities obtained from the calibrated models, we present particle pathways from the potential repository that record differences in the predicted groundwater flow regime. The results show that Large Hydraulic Gradient can be represented with the alternate conceptual models that include the hydrothermally altered zone. The predicted pathways are mildly sensitive to the choice of the conceptual model and more sensitive to the quality of calibration in the vicinity on the repository. These differences are most likely due to different degrees of fit of model to data, and do not represent important differences in hydrologic conditions for the different conceptual models. [Copyright &y& Elsevier]

This paper presents a numerical study on the response of the unsaturated zone (UZ) system of Yucca Mountain to heat generated from decaying radioactive wastes emplaced at the proposed repository. The modeling study is based on the current thermal–hydrological (TH) mountain-scale model, which uses a locally refined 2D north–south cross-section and dual-permeability numerical approach. The model provides a prediction of the mountain-scale TH response under the thermal-load scenario of 1.45 kW/m, while accounting for future climatic changes and the effects of drift ventilation. The TH simulation results show that ventilation of the repository drifts has a large impact on thermal–hydrologic regimes and moisture-flow conditions at the repository. In both cases, with and without ventilation, the TH model predicts dry or reduced liquid saturation near the drifts for over 1000 years, during which liquid flux through the drifts is reduced to either zero or less than the ambient flux. Without ventilation, the model predicts higher temperatures at the repository, but no major moisture redistribution in the UZ except in the areas very near the heated drifts. [Copyright &y& Elsevier]