Digital Commons Network^™

Martian Magmatism From Plume Metasomatized Mantle, James M. D. Day, Kimberly T. Tait, Arya Udry, Frédéric Moynier, Yang Liu, Clive R. Neal

Geoscience Faculty Research

Direct analysis of the composition of Mars is possible through delivery of meteorites to Earth. Martian meteorites include ∼165 to 2400 Ma shergottites, originating from depleted to enriched mantle sources, and ∼1340 Ma nakhlites and chassignites, formed by low degree partial melting of a depleted mantle source. To date, no unified model has been proposed to explain the petrogenesis of these distinct rock types, despite their importance for understanding the formation and evolution of Mars. Here we report a coherent geochemical dataset for shergottites, nakhlites and chassignites revealing fundamental differences in sources. Shergottites have lower Nb/Y at a given Zr/Y …

Proteolysis Of Methylated Sox2 Protein Is Regulated By L3mbtl3 And Crl4Dcaf5 Ubiquitin Ligase, Chunxiao Zhang, Feng Leng, Lovely Saxena, Nam Hoang, Jiekai Yu, Salvador Alejo, Logan Lee, Dandan Qi, Fei Lu, Hong Sun, Hui Zhang

Chemistry and Biochemistry Faculty Research

SOX2 is a dose-dependent master stem cell protein that controls the self-renewal and pluripotency or multipotency of embryonic stem (ES) cells and many adult stem cells. We have previously found that SOX2 protein is monomethylated at lysine residues 42 and 117 by SET7 methyltransferase to promote SOX2 proteolysis, whereas LSD1 and PHF20L1 act on both methylated Lys-42 and Lys-117 to prevent SOX2 proteolysis. However, the mechanism by which the methylated SOX2 protein is degraded remains unclear. Here, we report that L3MBTL3, a protein with the malignant-brain-tumor (MBT) methylation–binding domain, is required for SOX2 proteolysis. Our studies showed that L3MBTL3 preferentially …

Trend Analysis Of Las Vegas Land Cover And Temperature Using Remote Sensing, Haroon Stephen

Civil and Environmental Engineering and Construction Faculty Research

The Las Vegas urban area expanded rapidly during the last two decades. In order to understand the impacts on the environment, it is imperative that the rate and type of urban expansion is determined. Remote sensing is an efficient and effective way to study spatial change in urban areas and Spectral Mixture Analysis (SMA) is a valuable technique to retrieve subpixel landcover information from remote sensing images. In this research, urban growth trends in Las Vegas are studied over the 1990 to 2010 period using images from Landsat 5 Thematic Mapper (TM) and National Agricultural Imagery Program (NAIP). The SMA …

Reflecting On 1 October: Using Research To Inform Public Policy And Heal Our Community, Brookings Mountain West

Brookings Scholar Lecture Series

On October 1, 2017, Las Vegas joined a growing list of cities in the United States home to a mass shooting, including Blacksburg, Virginia; Newtown, Connecticut; San Bernardino, California; Orlando, Florida; Columbine, Colorado; Fort Hood, Texas; Parkland and Jacksonville, Florida and other locations. In the weeks following the tragedy, the nation and the Las Vegas community, including UNLV, responded with tributes to the victims, short- and long-term memorials to those killed and wounded, and calls to investigate the circumstances that led to this tragic event and to find ways to prevent future atrocities. Following the one-year anniversary of the 1 …

Sensor-Based Safety Performance Assessment Of Individual Construction Workers, Jeewoong Park, Yong K. Cho, Ali Khodabandelu

Civil and Environmental Engineering and Construction Faculty Research

Over the last decade, researchers have explored various technologies and methodologies to enhance worker safety at construction sites. The use of advanced sensing technologies mainly has focused on detecting and warning about safety issues by directly relying on the detection capabilities of these technologies. Until now, very little research has explored methods to quantitatively assess individual workers’ safety performance. For this, this study uses a tracking system to collect and use individuals’ location data in the proposed safety framework. A computational and analytical procedure/model was developed to quantify the safety performance of individual workers beyond detection and warning. The framework …

Unlv Innovation: The Research Magazine Of The University Of Nevada, Las Vegas

UNLV Innovation

From health disparities to social injustices, UNLV researchers are tackling some of the toughest challenges our community faces.

Fast Radio Burst Energetics And Detectability From High Redshifts, Bing Zhang

Physics & Astronomy Faculty Research

We estimate the upper limit redshifts of known fast radio bursts (FRBs) using the dispersion measure (DM)-redshift (z) relation and derive the upper limit peak luminosity L p and energy E of FRBs within the observational band. The average z upper limits range from 0.17 to 3.10, the average L p upper limits range from 1.24 × 1042 erg s−1 to 7.80 × 1044 erg s−1, and the average E upper limits range from 6.91 × 1039 erg to 1.94 × 1042 erg. FRB 160102 with DM = 2596.1 ± 0.3 pc cm−3 likely has a redshift greater than 3. …

Elevation And Azimuth-Aided Channel Estimation Scheme For Airborne Hyperspectral Data Transmission, Vahid Vahidi, Ebrahim Saberinia

Electrical & Computer Engineering Faculty Research

A channel-estimation (CE) scheme is proposed to estimate the complex amplitude, Doppler shift, angle-of-departure, and angle-of-arrival of the channel taps for sparse and doubly selective channels for hyperspectral image transmission from unmanned aircraft vehicles (UAVs) to ground stations. The proposed method is dubbed as compressed-sensing joint parameter estimation (CS-JPE) and finds the channel parameters matrix by employing a compressed-sensing (CS)-based method. Afterward, a modified version of the joint parameter estimation (JPE) is proposed as CS-JPE and is dubbed as M-CS-JPE, which employs the elevation-azimuth angles of the line-of-sight channel tap to estimate the channel parameters with higher accuracy and lower …

Oa Week Slideshow: Oa Journals From Around The World (Background)

Open Access Week 2018

A slideshow created by Scholarly Communication Initiatives staff highlighting several open access journals from around the world. This slideshow played in the background during the awards reception.

Oa Week Panel Opening Remarks, Andrea Wirth

Open Access Week 2018

These remarks were delivered as an introduction to the UNLV University Libraries 2018 Open Access Panel on The Intersection of Scholarly Publishing and Open Access with Diversity, Equity, and Inclusion.

Automated And Optimized Sensor Deployment Using Building Models And Electromagnetic Simulation, Chunhee Cho, Jeewoong Park, Kyungki Kim

Civil and Environmental Engineering and Construction Faculty Research

With the advent of wireless sensing technology and interest in tracking resources, researchers have developed advanced tracking algorithms by using one or more sensor systems for improved accuracy and reliability of tracking. The objective of this research lies in another aspect−deployment−of tracking that has received only little attention until now. The research explores a method for sensor deployment particularly designed for the building in which the sensors are used. To tailor our solution to a specific building, we integrate a building information model with an electromagnetic energy analysis. By using such a model, the system extracts the properties of building …

Linking Gait Dynamics To Mechanical Cost Of Legged Locomotion, David V. Lee, Sarah L. Harris

Life Sciences Faculty Research

For millenia, legged locomotion has been of central importance to humans for hunting, agriculture, transportation, sport, and warfare. Today, the same principal considerations of locomotor performance and economy apply to legged systems designed to serve, assist, or be worn by humans in urban and natural environments. Energy comes at a premium not only for animals, wherein suitably fast and economical gaits are selected through organic evolution, but also for legged robots that must carry sufficient energy in their batteries. Although a robot's energy is spent at many levels, from control systems to actuators, we suggest that the mechanical cost of …

Rotational Quenching Of Hd In Collisions With H2: Resolving Discrepancies For Low-Lying Rotational Transitions, Balakrishnan Naduvala, J. F.E. Croft, B. H. Yang, R. C. Forrey, P. C. Stancil

Chemistry and Biochemistry Faculty Research

The deuterated hydrogen molecule HD has been observed in a variety of cool molecular astrophysical environments. By virtue of its small dipole moment the HD molecule is believed to have played an important role in the cooling of the primordial gas in the formation of the first stars and galaxies. HD has also recently been proposed as a tracer of molecular hydrogen in protoplanetary disk evolution, providing a diagnostic for the total disk mass. Here we report benchmark computations of rotational quenching rate coefficients for HD in collisions with H2based on quantum coupled channel methods within the rigid rotor model, …

Streaming Instability Of Multiple Particle Species In Protoplanetary Disks, Noemi Schaffer, Chao-Chin Yang, Anders Johansen

Physics & Astronomy Faculty Research

The radial drift and diffusion of dust particles in protoplanetary disks affect both the opacity and temperature of such disks, as well as the location and timing of planetesimal formation. In this paper, we present results of numerical simulations of particle-gas dynamics in protoplanetary disks that include dust grains with various size distributions. We have considered three scenarios in terms of particle size ranges, one where the Stokes number τs = 10−1−100, one where τs = 10−4−10−1, and finally one where τs= 10−3−100. Moreover, we considered both discrete and continuous distributions in particle size. In accordance with previous works we …

A Bayesian Framework For Exoplanet Direct Detection And Non-Detection, Jean-Baptiste Ruffio, Dimitri Mawet, Ian Czekala, Bruce Macintosh, Robert J. De Rosa, Garreth Ruane, Michael Bottom, Laurent Pueyo, Jason J. Wang, Lea Hirsch, Zhaohuan Zhu, Eric L. Nielsen

Physics & Astronomy Faculty Research

Rigorously quantifying the information in high-contrast imaging data is important for informing follow-up strategies to confirm the substellar nature of a point source, constraining theoretical models of planet–disk interactions, and deriving planet occurrence rates. However, within the exoplanet direct imaging community, non-detections have almost exclusively been defined using a frequentist detection threshold (i.e., contrast curve) and associated completeness. This can lead to conceptual inconsistencies when included in a Bayesian framework. A Bayesian upper limit is such that the true value of a parameter lies below this limit with a certain probability. The associated probability is the integral of the posterior …

Reaction Optimization Of Pyrazinoquinoxaline Based Organic Semiconductor With Cruciform Shape, Marco Valverde Paredes, Dong-Chan Lee

LSAMP Poster Presentations

In this work, an optimum reaction condition was established to synthesize a pyrazinoquinoxaline based organic semiconductor with cruciform shape.

Multicolor Blackbody Emission In Grb 081221, Shu-Jin Hou, Bin-Bin Zhang, Yan-Zhi Meng, Xue-Feng Wu, En-Wei Liang, Hou-Jun Lü, Tong Liu, Yun-Feng Liang, Lin Lin, Rui-Jing Lu, Jin-Shu Huang, Bing Zhang

Physics & Astronomy Faculty Research

The radiation mechanism of the prompt emission of gamma-ray bursts (GRBs) remains an open question. Although their spectra are usually well fitted with the empirical Band function, which is widely believed to be fully nonthermal and interpreted as an optically thin synchrotron emission, accumulating evidence shows that a thermal component actually exists. In this paper, a multicolor blackbody (mBB) model is proposed for the time-integrated spectrum of GRB 081221 by assuming a power-law distribution of the thermal luminosities with temperature, which manifests photospheric emissions from a different radius and/or angle. The effects of the minimum temperature kT min, the maximum …

Estimates Of Female Breast Cancer Mortality-To-Incidence Ratio (Mir) Of The Counties And The Senatorial Districts Grouped To County Boundaries (Sdgcs) In Missouri 2008 - 2012, Awatef A. Ben Ramadan, Jeannette Jackson-Thompson, Chester L. Schmaltz

Journal of Health Disparities Research and Practice

Purpose: To measure Mortality-to-Incidence Ratios (MIRs) on Senatorial Districts Grouped to County Boundaries (SDGCs) to explore the female breast cancer (FBC) racial and age disparities in Missouri.

Methods: The MIRs and their 95% CI by age and race were calculated for the 20 SDGCs for the period from 2008-2012.

Results: For the 65+ years old FBC cases, the MIRs for whole Missouri and the 20 SDGCs were typically twice the MIR for thewhites.

Conclusions: FBC MIRs can be used as a measure of cancer inequalities in Missouri. These measures might be informative for policy makers to assess the existing policies …

Pressure Effect On The Antiferromagnetic Compound Ce2ni3ge5, Jun Gouchi, Yuki Nakamura, Miho Nakashima, Tasushi Amako, Ravhi Kumar, Yoshiya Uwatoko

Physics & Astronomy Faculty Research

In this study, the electrical resistivity and magnetization of a single crystal of Ce2Ni3Ge5 heavy fermion compound were performed under pressure. The resistivity and magnetization showed two antiferromagnetic transitions at ambient pressure. On applying pressure, the transitions merged at 1 GPa. At higher pressures, the antiferromagnetic transition temperature decreases, and disappears. It is suggesting that the critical pressure of Ce2Ni3Ge5 was 4.1 GPa.

A Comprehensive Analysis Of Fermi Gamma-Ray Burst Data. Iv. Spectral Lag And Its Relation To E P Evolution, Rui-Jing Lu, Yun-Feng Liang, Da-Bin Lin, Jing Lü, Xiang-Gao Wang, Hou-Jun Lü, Hong-Bang Liu, En-Wei Liang, Bing Zhang

Physics & Astronomy Faculty Research

The spectral evolution and spectral lag behavior of 92 bright pulses from 84 gamma-ray bursts observed by the Fermi Gamma-ray Burst Monitor (GBM) telescope are studied. These pulses can be classified into hard-to-soft pulses (H2S; 64/92), H2S-dominated-tracking pulses (21/92), and other tracking pulses (7/92). We focus on the relationship between spectral evolution and spectral lags of H2S and H2S-dominated-tracking pulses. The main trend of spectral evolution (lag behavior) is estimated with ( ), where E p is the peak photon energy in the radiation spectrum, t + t 0 is the observer time relative to the beginning of pulse −t …

Speciation Of Technetium In Carbonate Media Under Helium Ions And Γ Radiation, Mohammad Ghalei, Johan Vandenborre, Frederic Poineau, Guillaume Blain, Pier-Lorenzo Solari, Jerome Rôques, Ferid Haddad, Massoud Fattahi

Chemistry and Biochemistry Faculty Research

Technetium carbonates complexes produced by chemical, electrochemical and radiolytic methods have been studied by UV-Visible, X-ray Absorption Fine Structure (XAFS) and Density Functional Theory methods. The (NH4)2TcCl6 salt was dissolved in 2 M KHCO3. The resulting purple solution was analyzed by XAFS and UV-Visible spectroscopy. The UV-Visible spectra exhibits a band centered at 515 nm. The XAFS results were consistent with the presence of polymeric species containing the [Tc2(μ−O)2]4+ core coordinated to carbonate ligand. Concerning the electrochemical methods, the pertechnetate anion was electrochemically reduced in concentrated carbonate solution [(CO32−)=5 M and (HCO3−)=0.5 M]. For the radiolytic reduction, the speciation of …

Giving Matters: Donors Making A Difference, Unlv Foundation

Giving Matters

No abstract provided.

The Optical/Nir Afterglow Of Grb 111209a: Complex Yet Not Unprecedented, D. A. Kann, P. Schady, E. F. Olivares, S. Klose, A. Rossi, D. A. Perley, Bing Zhang, T. Krühler, J. Greiner, A. Nicuesa Guelbenzu, J. Elliott, F. Knust, Z. Cano, R. Filgas, E. Pian, P. Mazzali, J. P. U. Fynbo, G. Leloudas, P. M. J. Afonso, C. Delvaux, J. F. Graham, A. Rau, S. Schmidl, S. Schulze, M. Tanga, A. C. Updike, K. Varela

Physics & Astronomy Faculty Research

Context. Afterglows of gamma-ray bursts (GRBs) are simple in the most basic model, but can show many complex features. The ultra-long duration GRB 111209A, one of the longest GRBs ever detected, also has the best-monitored afterglow in this rare class of GRBs. Aims. We want to address the question whether GRB 111209A was a special event beyond its extreme duration alone, and whether it is a classical GRB or another kind of high-energy transient. The afterglow may yield significant clues. Methods. We present afterglow photometry obtained in seven bands with the GROND imager as well as in further seven bands …

Time-Dependent Radiation-Driven Winds, Sergei Dyda, Daniel Proga

Physics & Astronomy Faculty Research

We study temporal variability of radiation-driven winds using one-dimensional, time-dependent simulations and an extension of the classic theory of line-driven winds developed by Castor Abbott & Klein. We drive the wind with a sinusoidally varying radiation field and find that after a relaxation time, determined by the propagation time for waves to move out of the acceleration zone of the wind, the solution settles into a periodic state. Winds driven at frequencies much higher than the dynamical frequency behave like stationary winds with time averaged radiation flux, whereas winds driven at much lower frequencies oscillate between the high and low …

Unlv Magazine, Marta Meana, Tiffany Pereira, Juliet V. Casey, Jason Scavone, Keyonna Summers

UNLV Magazine

No abstract provided.

Women's Research Institute Of Nevada Newsletter, Women's Research Institute Of Nevada

Newsletters

No abstract provided.

Review Of: Families At Play: Connecting And Learning Through Video Games, Matthew Murray

Library Faculty Research

No abstract provided.

Finite-Time Sliding Mode And Super-Twisting Control Of Fighter Aircraft, Kaushik Raj, Venkatesan Muthukumar, Sahjendra N. Singh, Keum W. Lee

Electrical & Computer Engineering Faculty Research

The development of two nonlinear robust higher-order flight control systems for roll-coupled maneuvers of fighter aircraft with uncertain parameters is discussed in this article. The objective is to independently control the output variables (roll angle, pitch angle and sideslip angle) using aileron, elevator and rudder control surfaces. For a nominal model of aircraft, first a finite time stabilizing (FTS) control law, based on the notion of geometric homogeneity, is designed. Then for robust control in the presence of parameter uncertainties, (i) a discontinuous sliding mode (DSM) control law and (ii) a super-twisting (STW) continuous control law is designed. It is …

A Cognitive Framework To Secure Smart Cities, Shahab Tayeb, Neha Raste, Matin Pirouz, Shahram Latifi

Electrical & Computer Engineering Faculty Research

The advancement in technology has transformed Cyber Physical Systems and their interface with IoT into a more sophisticated and challenging paradigm. As a result, vulnerabilities and potential attacks manifest themselves considerably more than before, forcing researchers to rethink the conventional strategies that are currently in place to secure such physical systems. This manuscript studies the complex interweaving of sensor networks and physical systems and suggests a foundational innovation in the field. In sharp contrast with the existing IDS and IPS solutions, in this paper, a preventive and proactive method is employed to stay ahead of attacks by constantly monitoring network …

Simulation Of The Oxygen Reduction Reaction (Orr) Inside The Cathode Catalyst Layer (Ccl) Of Proton Exchange Membrane Fuel Cells Using The Kinetic Monte Carlo Method, Baosheng Bai, Yi-Tung Chen

Mechanical Engineering Faculty Research

In this paper, a numerical model of the kinetic Monte Carlo (KMC) method has been developed to study the oxygen reduction reaction (ORR) that occurs inside the cathode catalyst layer (CCL). Firstly, a 3-D model of the CCL that consists of Pt and carbon spheres is built using the sphere packing method; secondly, an efficient procedure of the proton-oxygen reaction process is developed and simulated. In the proton-oxygen reaction process, all of the continuous movements of protons and oxygen are considered. The maximum reaction distance is determined to be 8 Å. The input pressures of protons and oxygen are represented …