Search Results (70)

Ponderosa pine (Pinus ponderosa Lawson & C. Lawson) forests in the western United States have experienced reduced fire frequency since Euro-American settlement, usually because of successful fire suppression policies and even without such human impacts at remote sites in the Great Basin and Mojave Deserts. In an effort to improve our understanding of long-term environmental dynamics in sky-island ecosystems, we developed tree-ring chronologies from ponderosa pines located in the Sheep Mountain Range of southern Nevada, inside the Desert National Wildlife Refuge (DNWR). After comparing those dendrochronological records with other ones available for the south-central Great Basin, we analyzed their climatic response using station-recorded monthly precipitation and air temperature data from 1950 to 2024. The main climatic signal was December through May total precipitation, which was then reconstructed at annual resolution over the past five centuries, from 1490 to 2011 CE. The mean episode duration was 2.6 years, and the maximum drought duration was 11 years (1924–1934; the “Dust Bowl” period), while the longest episode, 19 years (1905–1923), is known throughout North America as the “early 1900s pluvial”. By quantifying multi-annual dry and wet episodes, the period since DNWR establishment was placed in a long-term dendroclimatic framework, allowing us to estimate the potential drought resilience of its unique, tree-dominated environments. Full article

In some regions, extreme heat can result in pavement temperatures that are high enough to cause severe burn injuries within seconds of skin contact. This risk is elevated for unhoused individuals who may lack adequate clothing and shelter and have susceptibility to other risk factors, including substance use and in turn loss of consciousness. While prior studies have shown worse outcomes for unhoused individuals due to delays in care and higher susceptibility, there is a lack of data on the impact of pavement burns specifically within this population. This single-institution retrospective cohort study aims to explore burn severity and hospital outcomes in housed vs. unhoused patients with pavement burns. The data were analyzed using independent samples t-tests and logistic regression when appropriate, with p < 0.05 considered statistically significant. A total of 305 individuals met the inclusion/exclusion criteria and comprised the final study cohort, 17.7% of which were unhoused. There was no significant difference in TBSA, survival to discharge, or hospital length of stay between housed and unhoused patients. While unhoused individuals may still be at heightened risk for pavement burns due to exposure to extreme heat and a lack of protective measures, these results may additionally suggest consistent emergency care for patients regardless of housing status. Furthermore, these results highlight the importance of developing targeted outreach and prevention programs and equitable emergency care protocols for vulnerable populations. Full article

The COVID-19 pandemic is a catastrophic event highlighting numerous health disparities. The social vulnerability index (SVI) has been widely utilized in COVID-19 research to assess vulnerable communities and to examine how social determinants influence various COVID-19 outcomes. This population-based study aims to determine whether COVID-19 testing and vaccination rates mediate the relationship between the SVI and COVID-19 prevalence. Mediation analysis was conducted using data from 535 census tracts in Clark County, Nevada. Findings indicate that COVID-19 testing rates were lower in areas with high SVI scores, potentially leading to more undetected cases. Moreover, COVID-19 testing, full vaccination, and follow-up vaccination rates significantly mediated the relationship between SVI and COVID-19 prevalence. These results suggest that greater location-based social vulnerability is associated with a sequential pathway of reduced testing and vaccination rates, contributing to underreported COVID-19 cases. Full article

Candida auris is an emerging fungal pathogen characterized by high levels of antifungal drug resistance and hospital outbreaks in a global distribution. Since introduction to the United States, it has been identified most frequently in New York, Illinois, California, Florida, and Nevada. Its surge poses significant risk as a nosocomial infection with multi-drug resistance, with clades bearing resistance to fluconazole, micafungin, and amphotericin B. Within the state of Nevada, and specifically the greater Las Vegas area in the southern part of the state, there are ongoing outbreaks from clade I and clade III, with 1728 confirmed clinical cases identified as of January 2025. In northern Nevada, three clinical cases have been identified to date, with two occurring at our facility. Both patients had been hospitalized at facilities in Las Vegas, Nevada. The C. auris strains isolated from these two cases have been identified as belonging to clade III and demonstrate resistance to fluconazole. Genome sequencing of the C. auris isolates indicates close genetic identity to strains from the Las Vegas outbreak. These data indicate that the spread of these clonal isolates is due to hospitalization and subsequent patient relocation to northern Nevada, revealing the ongoing importance of screening for geographic spread. Full article

This study explores the archaeoacoustics of rock imagery at Site 26LN211, the northernmost petroglyph site in the White River Narrows (WRN) Archaeological District, Nevada, USA. The research examines the relationship between rock writing placement and acoustic properties, considering their potential significance to indigenous groups such as the Southern Paiute and Western Shoshone. Fieldwork conducted in 2024 employed impulse response recordings to analyze sound behavior in various spatial configurations, including near and distant measurements. The results indicate that, unlike other WRN sites with strong echoes and reverberation, Site 26LN211 exhibits clear sound transmission with limited acoustic reflections. This suggests its suitability for oral storytelling, song recitatives, and ritual practices rather than sound-enhanced ceremonial performances. Additionally, the presence of vision quest structures above the site implies spiritual significance, although the results do not show a significant acoustic relationship between them and the petroglyph zone. Comparative studies with other indigenous sites reinforce the role of acoustics in shaping cultural landscapes. These findings contribute to broader discussions on the interplay between rock writing, sound, and indigenous traditions, emphasizing the need for preservation. Full article

Delamar Valley is a unique landscape located in southern Nevada that contains places associated with ceremony and Southern Paiute Creation. This ceremonial landscape is composed of volcanic places, a large Pleistocene Lake, and an underground hydrological system that allows for the movement of spiritual beings known as water babies between Delamar Valley and neighboring Pahranagat Valley. Paiute shamans traveled to Delamar Valley to interact with the portals along a volcanic ridge that allowed them to travel to a mirrored ceremonial landscape in another dimension of the universe. While in this mirrored landscape, shamans engaged with elements of Creation. This essay examines the ways in which Paiute shamans interacted with various components of the physical and spiritual landscapes. Full article

The mountain pine beetle Dendroctonus ponderosae (Curculionidae: Scolytinae) (MPB) is one component of an intensively studied co-evolved insect–host system. We investigated the spatial genetic structure of the MPB within its historic and recent geographic range expansion as it relates to host use in western North America using 13 pre-selected microsatellite loci. Analysis of molecular variation (AMOVA) indicates that genetic structure is not correlated with the host tree species and therefore does not support the hypothesis of the formation of a host race within this species. STRUCTURE analysis delineates four main clusters in western North America: (1) northern: northern British Columbia/northern Alberta; (2) central: southern British Columbia/southern Alberta/Washington/Idaho/Montana; (3) southwestern: Oregon/California/Nevada; and (4) southeastern: Utah/Wyoming/Arizona/Colorado/South Dakota. Heterozygosity, allelic richness, and the number of private alleles are greatest in the Southwest cluster. This cluster correlates with one of the three refugia hypothesized from a recent analysis of neo-Y haplotypes and represents an important reservoir of MPBs’ genetic diversity. Full article

The COVID-19 pandemic has revealed significant disparities in health outcomes across various populations, with children being no exception. Objective: This study aimed to identify factors associated with hospital length of stay and intensive care unit (ICU) utilization among children hospitalized with COVID-19. Methods: The project evaluated inpatient COVID-19 hospitalization data of children aged 0 to 17 years between 2020 and 2021 with a positive PCR COVID-19 test 14 days prior to or during hospitalization. Using a multivariate linear regression model, hospital length of stay and ICU utilization were evaluated by sociodemographic factors, including age, gender, race/ethnicity, primary payer status, comorbidities, CDC Social Vulnerability Index (SVI), and clinical factors. Results: Among 376 hospitalized pediatric patients, 62.2% were non-White minorities, 4.3% had at least one comorbidity, and 58.5% were covered by public insurance. Additionally, 67.6% scored high on the SVI. The average hospital stay was 3.89 days (standard deviation (SD) = 4.8), and 25% of children utilized the ICU during their hospitalization (SD = 0.43). After adjusting for sociodemographic and clinical characteristics, minority patients were more likely to have a longer length of stay by 1.09 days compared to White patients. Minority patients were also 72% more likely to use the ICU than White patients. Conclusions: These findings demonstrate that non-White children experience more severe outcomes related to COVID-19, supporting the need for culturally specific mitigation and intervention strategies for children and families during a pandemic. Full article

Community vulnerability is influenced by various determinants beyond socioeconomic status and plays a crucial role in COVID-19 disparities. This study aimed to develop and evaluate a novel community vulnerability index (CVI) related to temporal variations in COVID-19 incidence to provide insights into spatial disparities and inform targeted public health interventions in Clark County, Nevada. Utilizing data from the American Community Survey and other sources, 23 community measures were identified at the census tract level. The CVI was constructed using a lagged weighted quantile sum (LWQS) regression linking these measures to the monthly COVID-19 incidence from March 2020 to November 2021. The Besag–York–Mollié model subsequently evaluated the spatial association between the CVI and COVID-19 incidence, controlling for temporal and spatial autocorrelations. This study identified minority status, housing inadequacy, and inactive commuting as primary contributors to the CVI that consistently influenced COVID-19 vulnerability over time. The CVI demonstrated significant spatial disparities, with higher values found in northern Clark County and the northeastern Las Vegas metropolitan area. Spatial analyses revealed varying associations between COVID-19 incidence and the CVI across census tracts, with significant associations clustered in the northern and eastern regions of the Las Vegas metropolitan area. These findings advance our understanding of the complex interplay between community conditions and COVID-19. The CVI framework may be applied to other COVID-19 outcomes such as testing, vaccination, and hospitalization, offering a valuable tool for assessing and addressing community vulnerability. Full article

Housing insecurity is a critical issue within Southern Nevada. However, little is known about the housing-insecurity-related needs of LGBTQIA+ Southern Nevadans. The aim of this study was to identify strategies to address housing insecurity among this vulnerable community. Utilizing community-based participatory research and concept mapping, the most salient solutions were identified and prioritized at a Community Housing Forum. This Forum brought together stakeholders with expertise in housing or who work with the LGBTQIA+ community. The most important identified solutions consistently emphasized the criticality of culturally competent mental health services; the need for affordable housing options; and various social and environmental factors. There is a continued need for research and collaboration among organizations and providers to better serve LGBTQIA+ individuals experiencing housing insecurity. Additional research is needed to determine the efficacy of the identified solutions and to inform the development of context-specific and broadly applicable strategies to address housing insecurity within this community. Full article

To people living with Alzheimer’s Disease-Related Disorders (ADRD), timely and coordinated communication is essential between their informal caregivers and healthcare providers. In provider shortage areas, for example, the state of Nevada, telehealth can be an effective primary care delivery alternative to in-person visits. To evaluate the cost-effectiveness of telehealth visits for people living with ADRD in the state of Nevada, a decision-analytic Markov model was developed from healthcare system perspectives with a 10-year horizon/1-year cycle. To estimate the effects of demographic and geographic parameters on the Markov model, race parameters were divided into non-Hispanic White individuals vs. others and location parameters were divided into urban vs. rural. A 12-item short-version Zarit Burden Interview (ZBI-12) was applied to measure the informal caregiver burdens of non-institutionalized people living with ADRD. The values of mortality rate and healthcare utilization were obtained from healthcare systems’ publicly available payor administrative data and Nevada State Inpatient/Emergency Department datasets. Among urban-residing non-Hispanic White individuals, the Incremental Cost-Effectiveness Ratio (ICER) per modified ZBI-12 indicated a cost saving of USD 9.44 with telehealth visits; among urban-residing racial minorities, the ICER per modified ZBI-12 indicated a cost saving of USD 29.26 with in-person visits; and among rural residents, the ICER per modified ZBI-12 indicated a cost-saving of USD 320.93 with telehealth visits. Distributional differences in the cost-saving effects of telehealth primary care were noted in line with racial and geographic parameters. Workforce and caregiver training is necessary for reducing distributional differences, especially among urban-residing racial monitories living with ADRD in the provider shortage area of the state of Nevada. Full article

The goal of this study was to assess health of male Common Carp (carp, Cyprinus carpio) at four sites with a wide range in environmental organic contaminant (EOC) concentrations and water temperatures in Lake Mead National Recreation Area NV/AZ, US, and the potential influence of regional drought. Histological and reproductive biomarkers were measured in 17–30 carp at four sites and 130 EOCs in water per site were analyzed using passive samplers in 2010. Wide ranges among sites were noted in total EOC concentrations (>10Xs) and water temperature/degree days (10Xs). In 2007/08, total polychlorinated biphenyls (tPCBs) in fish whole bodies from Willow Beach (WB) in the free-flowing Colorado River below Hoover Dam were clearly higher than at the other sites. This was most likely due to longer exposures in colder water (12–14 °C) and fish there having the longest lifespan (up to 54 years) for carp reported in the Colorado River Basin. Calculated estrogenicity in water exceeded long-term, environmentally safe criteria of 0.1–0.4 ng/L by one to three orders of magnitude at all sites except the reference site. Low ecological screening values for four contaminants of emerging concern (CEC) in water were exceeded for one CEC in the reference site, two in WB and Las Vegas Bay and three in the most contaminated site LVW. Fish health biomarkers in WB carp had 25% lower liver glycogen, 10Xs higher testicular pigmented cell aggregates and higher sperm abnormalities than the reference site. Sperm from LVW fish also had significantly higher fragmentation of DNA, lower motility and testis had lower percent of spermatozoa, all of which can impair reproduction. Projections from a 3D water quality model performed for WB showed that EOC concentrations due to prolonged regional drought and reduced water levels could increase as high as 135%. Water temperatures by late 21st century are predicted to rise between 0.7 and 2.1 °C that could increase eutrophication, algal blooms, spread disease and decrease dissolved oxygen over 5%. Full article

Hypertrophic cardiomyopathy (HCM) is characterized by excessive growth of myocardial tissue, most commonly due to genetic mutations in sarcomere proteins. This can lead to complications such as heart failure, mitral regurgitation, syncope, arrhythmias, sudden cardiac death, and myocardial ischemia. While we have come a long way in our understanding of the pathophysiology, genetics, and epidemiology of HCM, the past 10 years have seen significant advancements in diagnosis and treatment. As the body of evidence on hypertrophic cardiomyopathy continues to grow, a comprehensive review of the current literature is an invaluable resource in organizing this knowledge. By doing so, the vast progress that has been made thus far will be widely available to all experts in the field. This review provides a comprehensive analysis of the scientific literature, exploring both well-established and cutting-edge diagnostic and therapeutic options. It also presents a unique perspective by incorporating topics such as exercise testing, genetic testing, radiofrequency ablation, risk stratification, and symptomatic management in non-obstructive HCM. Lastly, this review highlights areas where current and future research is at the forefront of innovation in hypertrophic cardiomyopathy. Full article

To address the recent increase in wildfire severity and incidence, as well as the subsequent financial and physical costs, forest managers and wildland firefighting agencies rely on remotely sensed products for better decision-making and mitigation efforts. To address the remote sensing needs of these agencies, which include high spatial resolution, immunity to atmospheric and solar illumination effects, and day/night capabilities, the use of synthetic aperture radar (SAR) is under investigation for application in current and upcoming systems for all phases of a wildfire. Focusing on the active phase, a method for monitoring wildfire activity is presented based on changes in the radar vegetation index (RVI). L-band backscatter measurements from NASA/JPL’s UAVSAR instrument are used to obtain RVI images on multiple dates during the 2020 Bobcat (located in Southern CA, USA) and Hennessey (located in Northern CA, USA) fires and the 2021 Caldor (located in the Sierra Nevada region of CA, USA) fire. Changes in the RVI between measurement dates of a single fire are then compared to indicators of fire activity such as ancillary GIS-based burn extent perimeters and the Landsat 8-based difference normalized burn ratio (dNBR). An RVI-based wildfire “burn” detector/index is then developed by thresholding the RVI change. A combination of the receiver operating characteristic (ROC) curves and F1 scores for this detector are used to derive change detection thresholds at varying spatial resolutions. Six repeat-track UAVSAR lines over the 2020 fires are used to determine appropriate threshold values, and the performance is subsequently investigated for the 2021 Caldor fire. The results show good performance for the Bobcat and Hennessey fires at 100 m resolution, with optimum probability of detections of 67.89% and 71.98%, F1 scores of 0.6865 and 0.7309, and Matthews correlation coefficients of 0.5863 and 0.6207, respectively, with an overall increase in performance for all metrics as spatial resolution becomes coarser. The results for pixels identified as “burned” compare well with other fire indicators such as soil burn severity, known progression maps, and post-fire agency publications. Good performance is also observed for the Caldor fire where the percentage of pixels identified as burned within the known fire perimeters ranges from 37.87% at ~5 m resolution to 88.02% at 500 m resolution, with a general increase in performance as spatial resolution increases. All detections for Caldor show dense collections of burned pixels within the known perimeters, while pixels identified as burned that lie outside of the know perimeters have a sparse spatial distribution similar to noise that decreases as spatial resolution is degraded. The Caldor results also align well with other fire indicators such as soil burn severity and vegetation disturbance. Full article

Understanding the socioecological contexts of gay men living with HIV is critical to addressing the environmental conditions that influence their lifetime experiences of housing insecurity and homelessness. In line with the strategies of the US Center for Disease Control and Prevention to end the HIV epidemic, it is of utmost importance to recognize how the allocation of available resources impacts health inequities affecting gay men living with HIV who experience housing insecurity and homelessness. Drawing from the World Health Organization’s social determinants of health (SDoH) framework, we used an exploratory, community-based research (CBR) approach to examine the lifetime experiences and important sources of support of gay men living with HIV at midlife who have experienced housing insecurity in Southern Nevada. Thematic analysis of our semi-structured interviews with 12 gay men living with HIV at midlife revealed three overarching themes: (1) challenges to obtaining housing and related support, (2) informal support from friends, and (3) formal support from community-based sources employing diverse support strategies. In this article, we discuss the different sub-themes we identified under these overarching themes and the implications of our findings from an SDoH perspective. We conclude with a discussion on the dire need to (1) highlight the considerable value of both informal and formal sources of support for the housing insecure, and (2) generate recommendations for interventions to address housing insecurity and homelessness with greater consideration for the impacts of SDoH in the work dedicated to helping gay men living with HIV at midlife overcome housing insecurity as they age. Full article