University of Nevada-Las Vegas is a public research university located in the Las Vegas suburb of Paradise, Nevada, USA. The 358-acre campus is located approximately 1.5-mile east of the Las Vegas Strip. The university includes the Shadow Lane Campus, located just east of the University Medical Center of Southern Nevada, which houses the School of Dental Medicine— the only dental school in the state of Nevada. In addition, UNLV's law school, the William Boyd School of Law, is also the only law school in the state.Noted for its strong emphasis on science and technology, business management, and the law programs, the university is classified a "research-intensive university" by the Carnegie Foundation for the Advancement of Teaching. The William Harrah College of Hotel Administration is annually ranked among the top hospitality programs in the United States due to the university's proximity to the Las Vegas Strip. Its famed Thomas & Mack Center hosted the 2007 NBA All-Star Game, concerts, as well as lectures by Bill Clinton and Mikhail Gorbachev as part of various UNLV-affiliated lecture series. Wikipedia.
Zhang B.,University of Nevada, Las Vegas
Astrophysical Journal Letters | Year: 2017
Recent observations of fast radio bursts (FRBs) indicate a perplexing, inconsistent picture. We propose a unified scenario to interpret diverse FRBs observed. A regular pulsar, otherwise unnoticeable at a cosmological distance, may produce a bright FRB if its magnetosphere is suddenly "combed" by a nearby, strong plasma stream toward the anti-stream direction. If the Earth is to the night side of the stream, the combed magnetic sheath would sweep across the direction of Earth and make a detectable FRB. The stream could be an AGN flare, a GRB or supernova blastwave, a tidal disruption event, or even a stellar flare. Since it is the energy flux received by the pulsar rather than the luminosity of the stream origin that defines the properties of the FRB, this model predicts a variety of counterparts of FRBs, including a possible connection between FRB 150418 and an AGN flare, a possible connection between FRB 131104 and a weak GRB, a steady radio nebula associated with the repeating FRB 121102, and probably no bright counterparts for some FRBs. © 2017. The American Astronomical Society. All rights reserved.
Lefevre C.T.,Aix - Marseille University |
Bazylinskib D.A.,University of Nevada, Las Vegas
Microbiology and Molecular Biology Reviews | Year: 2013
Magnetotactic bacteria (MTB) are widespread, motile, diverse prokaryotes that biomineralize a unique organelle called the magnetosome. Magnetosomes consist of a nano-sized crystal of a magnetic iron mineral that is enveloped by a lipid bilayer membrane. In cells of almost all MTB, magnetosomes are organized as a wellordered chain. The magnetosome chain causes the cell to behave like a motile, miniature compass needle where the cell aligns and swims parallel to magnetic field lines. MTB are found in almost all types of aquatic environments, where they can account for an important part of the bacterial biomass. The genes responsible for magnetosome biomineralization are organized as clusters in the genomes of MTB, in some as a magnetosome genomic island. The functions of a number of magnetosome genes and their associated proteins in magnetosome synthesis and construction of the mag- netosome chain have now been elucidated. The origin of magnetotaxis appears to be monophyletic; that is, it developed in a common ancestor to all MTB, although horizontal gene transfer of magnetosome genes also appears to play a role in their distribution. The purpose of this review, based on recent progress in this field, is focused on the diversity and the ecology of the MTB and also the evolution and transfer of the molecular determinants involved in magnetosome formation. Copyright © 2013, American Society for Microbiology. All Rights Reserved.
Zhang B.,University of Nevada, Las Vegas
Astrophysical Journal Letters | Year: 2014
The physical nature of fast radio bursts (FRBs), a new type of cosmological transient discovered recently, is not known. It has been suggested that FRBs can be produced when a spinning supra-massive neutron star loses centrifugal support and collapses to a black hole. Here, we suggest that such implosions can happen in supra-massive neutron stars shortly (hundreds to thousands of seconds) after their births, and an observational signature of such implosions may have been observed in the X-ray afterglows of some long and short gamma-ray bursts (GRBs). Within this picture, a small fraction of FRBs would be physically connected to GRBs. We discuss possible multi-wavelength electromagnetic signals and gravitational wave signals that might be associated with FRBs, and propose an observational campaign to unveil the physical nature of FRBs. In particular, we strongly encourage a rapid radio follow-up observation of GRBs starting from 100 s after a GRB trigger. © 2014. The American Astronomical Society. All rights reserved.
Camp J.P.,University of Nevada, Las Vegas
Journal of consulting and clinical psychology | Year: 2013
The psychopathy checklist-revised (PCL-R; Hare, 1991, 2003) is often used to assess risk of violence, perhaps based on the assumption that it captures emotionally detached individuals who are driven to prey upon others. This study is designed to assess the relation between (a) core interpersonal and affective traits of psychopathy and impulsive antisociality on the one hand and (b) the risk of future violence and patterns of motivation for past violence on the other. A research team reliably assessed a sample of 158 male offenders for psychopathy, using both the interview-based PCL-R and the self-report psychopathic personality inventory (PPI: Lilienfeld & Andrews, 1996). Then, a second independent research team assessed offenders' lifetime patterns of violence and their motivation. After these baseline assessments, offenders were followed in prison or the community for up to 1 year to assess their involvement in 3 different forms of violence. Baseline and follow-up assessments included both interviews and reviews of official records. First, the PPI manifested incremental validity in predicting future violence over the PCL-R (but not vice versa)-and most of its predictive power derived solely from impulsive antisociality. Second, impulsive antisociality-not interpersonal and affective traits specific to psychopathy-were uniquely associated with instrumental lifetime patterns of past violence. The latter psychopathic traits are narrowly associated with deficits in motivation for violence (e.g., lack of fear or lack of provocation). These findings and their consistency with some past research led us to advise against making broad generalizations about the relation between psychopathy and violence.
Kumar P.,University of Texas at Austin |
Zhang B.,University of Nevada, Las Vegas
Physics Reports | Year: 2015
We provide a comprehensive review of major developments in our understanding of gamma-ray bursts, with particular focus on the discoveries made within the last fifteen years when their true nature was uncovered. We describe the observational properties of photons from the radio to 100s GeV bands, both in the prompt emission and the afterglow phases. Mechanisms for the generation of these photons in GRBs are discussed and confronted with observations to shed light on the physical properties of these explosions, their progenitor stars and the surrounding medium. After presenting observational evidence that a powerful, collimated, jet moving at close to the speed of light is produced in these explosions, we describe our current understanding regarding the generation, acceleration, and dissipation of the jet. We discuss mounting observational evidence that long duration GRBs are produced when massive stars die, and that at least some short duration bursts are associated with old, roughly solar mass, compact stars. The question of whether a black-hole or a strongly magnetized, rapidly rotating neutron star is produced in these explosions is also discussed. We provide a brief summary of what we have learned about relativistic collisionless shocks and particle acceleration from GRB afterglow studies, and discuss the current understanding of radiation mechanism during the prompt emission phase. We discuss theoretical predictions of possible high-energy neutrino emission from GRBs and the current observational constraints. Finally, we discuss how these explosions may be used to study cosmology, e.g. star formation, metal enrichment, reionization history, as well as the formation of first stars and galaxies in the universe. © 2014 Elsevier B.V.
Agency: NSF | Branch: Continuing grant | Program: | Phase: GoLife | Award Amount: 632.71K | Year: 2016
Over half of the major groups of microorganisms on Earth have never been cultivated in the laboratory, and most have never been explicitly targeted for scientific investigation and remain poorly understood. One such group of microbes is Aigarchaeota, a diverse, globally distributed group that inhabits terrestrial, geothermal hot springs and marine hydrothermal vents. The overall goal of this project is to dramatically expand our knowledge of the species diversity, distribution, ecological function, and organismal biology of Aigarchaeota and to establish a taxonomic classification for the entire group. More generally, this project aims to set a precedent for the investigation of poorly studied microbial biodiversity and integration of biodiversity research on microbes into a meaningful taxonomy. This project will support a variety of researchers at Minority-Serving Institutions and Hispanic-Serving Institutions, and will provide research opportunities for students who are underrepresented in science. In addition, this project will contribute to an educational outreach program that provides content knowledge to K-12 students and teachers throughout from Clark County School District, and provide high-school teachers the opportunity to participate in a workshop and field excursion to collect samples for microbial analysis.
This project focuses on two major study sites, Great Boiling Spring in northwest Nevada, and springs in Tengchong County, Yunnan Province, China, but also includes investigations of terrestrial and marine geothermal systems worldwide. The specific aims are: 1) To discover new Aigarchaeota taxa and erect a candidate taxonomic structure, 16S rRNA gene sequences amplified from natural samples and mined from databases will be combined with single-cell genomic and metagenomic datasets; phylogenetics, phylogenomics, comparative genomics, and ecological niche modeling will be integrated to erect a candidate taxonomic structure; 2) To assess the function of Aigarchaeota, stable isotope labeling experiments, quantitative reverse-transcriptase PCR, and metaproteomics will test explicit hypotheses about Aigarchaeota metabolism, providing a window into how Aigarchaeota organisms function in nature; and 3) To cultivate, isolate, and describe Aigarchaeota pure cultures, enrichment cultures will be established in the laboratory and used to try to isolate and describe axenic cultures by using both traditional and innovative approaches. The combination of large-scale data mining, phylogenetics, taxonomy, ecological niche modeling, and field and wet lab work described here spans all components of the Systematics and Biodiversity Sciences Cluster and aims to transform our knowledge of a major lineage of Archaea and provide insight into species- to domain-level evolution.
Agency: NSF | Branch: Standard Grant | Program: | Phase: LAW AND SOCIAL SCIENCES | Award Amount: 276.04K | Year: 2016
Unprecedented video coverage of negative police-citizen encounters has fueled civil unrest and questions about the public trust in police and the criminal justice system. When the police are viewed positively (e.g., fair, impartial, trustworthy), previous research reveals strong public support for them. Over the last decade, however, the convergence of major social changes in the U.S. (e.g., the wider availability of video technology to capture images of police violence and abuse of power, the growing racial divide, and declining confidence in social institutions) challenge this notion that fairness and trust are enough to produce positive police-citizen relations. The proposed study will conduct a large national survey and citywide interviews to test these ideas about the impact of public perceptions of officer conduct, institutional anomie, procedural justice, and police legitimacy on police-citizen relations and support for video policing activities through the use of body-worn cameras and aerial drones. In this post-Ferguson period of racial animus and strained police-citizen relations, the obtained survey results will provide direct evidence of the best practices for improving public support for various police practices and developing a more nuanced approach to community policing that is more effective in crime control and fosters better police-citizen relations, especially in minority neighborhoods where basic trust in police may be most problematic.
By exploring the impact of public perceptions about procedural justice and police legitimacy on their support for video policing activities in contemporary American society, the proposed study departs from extant research by its (1) focus on public support for police use of evolving video technology (e.g., body-worn cameras, aerial drones), (2) empirical evaluation of whether the influence of perceptions of police fairness and legitimacy are highly contextual, mediated or moderated by ones race, direct experiences with police and negative video images of them, the type of police activity (e.g., proactive versus reactive policing) and feelings of institutional anomie, and (3) analytic methods (i.e., the use conjunctive analysis to study this causal complexity). The results of this study will provide direct social benefits by identifying particular conditions under which police can use mobile video technology (i.e., body cameras and aerial drones) to increase community safety and support with lower public resistance. It will also identify conditions under which video technology is viewed as invasive, ineffective and/or selectively (mis)used, thereby eroding this public safety and support.
Agency: NSF | Branch: Standard Grant | Program: | Phase: | Award Amount: 295.67K | Year: 2016
The propensity for fault zones to become long-lived zones of weakness that can be reactivated during geologic history plays a significant role in the migration of fluids in Earth?s crust and formation of hydrocarbon, economic mineral and ground water resources, seismic hazards, and the evolution of mountain belts. From 160 to 50 million years ago, the western U.S. was tectonically similar to modern day western South America, which is characterized by high elevation mountains (the Andes) that formed in the continental crust above an actively subducting oceanic plate. When subduction ceased along western North America, a new regime of widespread crustal extension began, resulting in localized exposures at the surface of deep levels of the ancient mountain belt. This project will examine the Funeral Mountains in Death Valley National Park, which the principal investigators hypothesize records the cycle of mountain building followed by extension. In particular, they hypothesize that the same fault (a thrust fault) initially responsible for substantial burial and thickening of the crust was reactivated twice during the exhumation of the rocks to the surface. They further argue that the reactivation of thrust faults may be a common phenomenon in the western U.S., explaining many similar occurrences in other mountain ranges. Rocks in the Funeral Mountains are ideal for testing this hypothesis due to excellent exposures and abundant rocks suitable for study. This project will accomplish many benefits to society as identified by NSF: (1) helping the U.S. maintain competitiveness and leadership in the global Science Technology Engineering and Mathematics (STEM) workforce; students who participate in the project (three graduate students and five undergraduates) will develop high-level expertise and teamwork experience in a STEM discipline; (2) increased public scientific literacy by dissemination of findings to the academic community through presentations at professional conferences and publications, and to the general public and Death Valley enthusiasts by presenting at meetings of the Death Valley Natural History Association, the Las Vegas Natural History Museum, and the Nevada Geological Society; (3) development of research partnerships between two universities as part of collaborative research efforts, and the development of research infrastructure at each institution; and; (4) the investigators seek to engage the full participation of women and underrepresented students in STEM education through targeted recruiting efforts.
Reactivation and tectonic inheritance are long-recognized phenomena, important to our understanding of how the continental lithosphere deforms. The thesis of this proposal is that many Tertiary detachment faults and shear zones in the western US reactivate faults or sub-planar zones of earlier deformation. The Funeral Mountains metamorphic core complex of the Death Valley region represents an ideal locality in the Sevier-Laramide hinterland to evaluate the role of tectonic reactivation in the development of metamorphic core complexes, as well as to resolve important details regarding the tectonic history that predates Tertiary extension. We hypothesize that the Boundary Canyon detachment fault, which underwent greater than 40 kilometers of top-the northwest slip in the Miocene, formed as the last reactivation of a major Jurassic thrust of opposite slip that was responsible for deep burial and regional metamorphism of the footwall. We propose a multi-faceted approach to evaluate the hypothesis of protracted tectonic reactivation through detailed studies along the metamorphic and strain gradient that includes: (1) field mapping and structural analysis, (2) petrographic, microstructural, and kinematic analyses aided by Electron Backscatter Diffraction analysis of quartz-rich rocks, (3) applying petrochronology (Laser Ablation Split Stream Inductively Coupled Plasma Mass Spectrometry) to date accessory minerals (metamorphic titanite, monazite, xenotime, and zircon overgrowths) and Lutetium-Hafnium dating of garnet in garnet amphibolites, and (4) determining the metamorphic conditions and prograde pressure-temperature paths to evaluate the prograde burial history, possible grade discordances across major shear zones, and the regional thrust-induced paleodip. Recognition of tectonic reactivation has important implications for understanding the older Jurassic and Cretaceous history of the Sevier-Laramide orogen, the magnitude and distribution of contraction and extension that occurred during orogenesis, and the episodic nature of post-orogenic extension.
Agency: NSF | Branch: Continuing grant | Program: | Phase: DISCOVERY RESEARCH K-12 | Award Amount: 72.82K | Year: 2017
Students with disabilities often have fewer opportunities for experiential learning, an important component of quality STEM education. With continued shifts toward the use of digital media to supplement instruction in STEM classrooms, much of the content remains inaccessible, particular for students with visual impairments. The promise of technology and use of tactile graphics is an effective, emerging innovation for providing more complete access to important information and materials. Tactile graphics are images that use raised surfaces to convey non-textual information such as maps, paintings, graphs and diagrams. Touchscreen-based smart devices allow visual information to be digitally and dynamically represented via tactile, auditory, visual, and kinesthetic feedback. Tactile graphic technology embedded in touchscreen devices can be leveraged to make STEM content more accessible to blind and visually impaired students.
This project will develop a learner-centered, perceptually-motivated framework addressing the requirements for students with blindness and visual impairments to access graphical content in STEM. Using TouchSense technology, the investigators will create instructional materials using tactile graphics and test them in a pilot classroom of both sighted and BVI students. The investigators will work with approximately 150 students with visual impairments to understand the kind of feedback that is most appropriate for specific content in algebra (coordinate plane), cell biology, and geography. Qualitative research methods will be used to analyze the video-based data set.
This project is supported by NSFs EHR Core Research (ECR) program and the Discovery Research PreK-12 Program. The ECR program emphasizes fundamental STEM education research that generates foundational knowledge in the field. Investments are made in critical areas that are essential, broad and enduring: STEM learning and STEM learning environments, broadening participation in STEM, and STEM workforce development. The program supports the accumulation of robust evidence to inform efforts to understand, build theory to explain, and suggest intervention and innovations to address persistent challenges in STEM interest, education, learning and participation. The Discovery Research PreK-12 program (DRK-12) seeks to significantly enhance the learning and teaching of science, technology, engineering and mathematics (STEM) by preK-12 students and teachers, through research and development of innovative resources, models and tools (RMTs). Projects in the DRK-12 program build on fundamental research in STEM education and prior research and development efforts that provide theoretical and empirical justification for proposed projects.
Agency: NSF | Branch: Standard Grant | Program: | Phase: Dimensions of Biodiversity | Award Amount: 366.64K | Year: 2017
Mosses are the second most diverse group of land plants and they play important ecological roles in terrestrial ecosystems. Since an early divergence from other land plants some 450 million years ago, mosses took a different path than vascular plants to solving the challenges to survival and reproduction posed by terrestrial environments. One important trait that is well developed in mosses is the capability of drying without dying, known as desiccation tolerance (DT). This critical trait allows many mosses to survive and reproduce even in drylands, and may be the key to their survival in the face of current, rapid climate change. Syntrichia is a large and diverse genus of mosses occurring worldwide and generally in dryland habitats. Despite their dominance in certain communities such as biological soil crusts, surprisingly little is known about the drivers of biodiversity in this clade. This interdisciplinary project integrates research from genomic, organismal, population, and community levels of organization in order to build a robust understanding of past and present dimensions of biodiversity in Syntrichia. The overall goals are to understand the evolutionary and ecological mechanisms that have produced and maintained functional diversity at these different levels of organization, and promote training, teaching, and learning via: (1) formal education through field and laboratory research; (2) informal education involving a classroom module, short-film series featuring mosses and biocrusts transitioning from desiccation dormancy, a citizen science program Citizens of the Crust, and a series of free public workshops.
The research will examine tradeoffs between asexual and sexual reproduction, and between phenotypic plasticity and canalization into specialized genotypes, by examining the mechanisms underlying traits (including phenotypic plasticity) that drive diversification, reproduction, habitat selection, and physiological trait evolution in environments with varying degrees of water stress. Specific methods to be employed include: (1) sequencing the full genomes of S. caninervis and S. ruralis; (2) using next generation sequencing (NGS) to develop genotypic markers for population-level genetic variation studies, signature transcriptome tools for phenotypic analyses (related to ecophysiological and ecosystem investigations), and multiple single-copy genes for phylogenetic analysis; (3) transcriptomics experiments comparing different development stages and sexes of both species in response to desiccation stress and reproductive state; (3) ecophysiological experiments on multiple populations of S. caninervis and S. ruralis, and all 15 species of N. American Syntrichia, to assess phenotypic plasticity in the key trait of DT; (5) population genetic studies of S. caninervis and S. ruralis in different environments; (6) building a robust phylogeny for Syntrichia and using it to understand evolutionary trends and correlations among the traits under study, as well as to produce a refined classification; (7) examining the role of genetic, functional, and phylogenetic diversity in the resilience to climate change of biocrust communities that are dominated by Syntrichia (with co-occurring mosses, lichens, and cyanobacteria) in field and greenhouse experiments.