Physical Sciences and Mathematics Commons^™

Review: On The Near Periodicity Of Eigenvalues Of Toeplitz Matrices, Stephan Ramon Garcia

Pomona Faculty Publications and Research

No abstract provided.

Nevada Interagency Volunteer Program: Helping Hands Across Public Lands – Phase Ii: Quarterly Progress Report, Period Covering October 1, 2011 To December 31, 2011, Margaret N. Rees

Get Outdoors Nevada

• The number of records in the volunteer database decreased by 20.7% over the last quarter. The database now contains 7,072 records.
• Results show an average of 1,080 visits per month, and with an average of 2,328 pages viewed per month.
• Get Outdoors Nevada supported 22 volunteer events in a variety of ways. These events utilized 867 volunteers whom contributed approximately 3,774.5 hours of service.
• Two community outreach events were attended, resulting in 476 direct contacts with 50 names added to the database.
• The 7th Annual Volunteer Recognition Banquet was held on 11/5/11 with 156 volunteers in attendance.

Take Pride In America In Southern Nevada: Annual Progress Report, Period Covering January 1, 2011 - December 31, 2011, Margaret N. Rees

Anti-littering Programs

• A meeting of stakeholders across Nevada was held to explore the potential for statewide collaboration on litter and dumping issues.
• Website activity for the first three quarters of the year averaged 1,122 hits per month, with an average of 1,927 pages viewed per month.
• The team attended 12 community outreach events resulting in 2,154 direct contacts and 324 new mailing list records.
• The Take Pride in America (TPIA) in Southern Nevada completed a total of 41 volunteer events contributing a total of 10,779 volunteer hours.
• The TPIA team filed a no-cost extension to SNPLMA and received an extension until December …

Limnological Assistance For Lake Mead National Recreation Area: Quarterly Report, Period Ending December 31, 2011, Margaret N. Rees

Limnological Studies

Project 1

• Technical assistance with the implementation of the Interagency Monitoring Action Plan (IMAP) for Quagga Mussels is ongoing; remaining analyses are underway with report delivery rescheduled for 05/2012.
• Data have been delivered for Veliger abundance and settlement at different depths of Lake Mead with report delivery re-scheduled for 05/2012.
• Growth of adult quagga mussels within Las Vegas Wash/Las Vegas Bay
• The Interagency Quagga Mussel Meeting was held on 11/17/2011; the next meeting is scheduled for 02/16/2011.

Project 2

• Appendix 7, an addition to the Long-term Limnological and Aquatic Resource Monitoring and Research Plan for Lakes Mead and Mohave, has …

Topographic Control Of Asynchronous Glacial Advances: A Case Study From Annapurna, Nepal, Beth Pratt-Sitaula, Douglas W. Burbank, Arjun M. Heimsath, Neil F. Humphrey, Michael Oskin, Jaakko Putkonen

All Faculty Scholarship for the College of the Sciences

Differences in the timing of glacial advances, which are commonly attributed to climatic changes, can be due to variations in valley topography. Cosmogenic 10Be dates from 24 glacial moraine boulders in 5 valleys define two age populations, late-glacial and early Holocene. Moraine ages correlate with paleoglacier valley hypsometries. Moraines in valleys with lower maximum altitudes date to the lateglacial, whereas those in valleys with higher maximum altitudes are early Holocene. Two valleys with similar equilibrium-line altitudes (ELAs), but contrasting ages, are < 5 km apart and share the same aspect, such that spatial differences in climate can be excluded. A glacial mass-balance cellular automata model of these two neighboring valleys predicts that change from a cooler-drier to warmer-wetter climate (as at the Holocene onset) would lead to the glacier in the higher altitude catchment advancing, while the lower one retreats or disappears, even though the ELA only shifted by ~120 m.

Directional Limits On Persistent Gravitational Waves Using Ligo S5 Science Data, J. Abadie, B. P. Abbott, R. Abbott, M. Abernathy, T. Accadia, F. Acernese, C. Adams, R. Adhikari, P. Ajith, B. Allen, G. S. Allen, E. Amador Ceron, R. S. Amin, S. B. Anderson, W. G. Anderson, F. Antonucci, M. A. Arain, M. C. Araya, M. Aronsson, K. G. Arun, Y. Aso, S. M. Aston, P. Astone, D. Atkinson, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, G. Ballardin, S. Ballmer, Shaon Ghosh

Department of Physics and Astronomy Faculty Scholarship and Creative Works

The gravitational-wave (GW) sky may include nearby pointlike sources as well as stochastic backgrounds. We perform two directional searches for persistent GWs using data from the LIGO S5 science run: one optimized for pointlike sources and one for arbitrary extended sources. Finding no evidence to support the detection of GWs, we present 90% confidence level (C.L.) upper-limit maps of GW strain power with typical values between 2-20×10-50strain2Hz-1 and 5-35×10 -49strain2Hz-1sr-1 for pointlike and extended sources, respectively. The latter result is the first of its kind. We also set 90% C.L. limits on the narrow-band root-mean-square GW strain from interesting targets …

Correlation Of Inflation-Produced Magnetic Fields With Scalar Fluctuations, Robert R. Caldwell, Leonardo Motta, Marc Kamionkowski

Dartmouth Scholarship

If the conformal invariance of electromagnetism is broken during inflation, then primordial magnetic fields may be produced. If this symmetry breaking is generated by the coupling between electromagnetism and a scalar field—e.g. the inflaton, curvaton, or Ricci scalar—then these magnetic fields may be correlated with primordial density perturbations, opening a new window to the study of non-Gaussianity in cosmology. In order to illustrate, we couple electromagnetism to an auxiliary scalar field in a de Sitter background. We calculate the power spectra for scalar-field perturbations and magnetic fields, showing how a scale-free magnetic-field spectrum with rms amplitude of ∼nG at Mpc …

Directional Limits On Persistent Gravitational Waves Using Ligo S5 Science Data, J. Abadie, B. P. Abbott, R. Abbott, M. Abernathy, T. Accadia, F. Acernese, C. Adams, R. Adhikari, P. Ajith, B. Allen, G. S. Allen, E. Amador Ceron, R. S. Amin, S. B. Anderson, W. G. Anderson, F. Antonucci, M. A. Arain, M. C. Araya, M. Aronsson, K. G. Arun, Y. Aso, S. M. Aston, P. Astone, D. Atkinson, P. Aufmuth, C. Aulbert, S. Babak, P. Baker, G. Ballardin, S. Ballmer, D. Barker, Tiffany Z. Summerscales

Faculty Publications

The gravitational-wave (GW) sky may include nearby pointlike sources as well as stochastic backgrounds. We perform two directional searches for persistent GWs using data from the LIGO S5 science run: one optimized for pointlike sources and one for arbitrary extended sources. Finding no evidence to support the detection of GWs, we present 90% confidence level (C.L.) upper-limit maps of GW strain power with typical values between 2-20×10-50strain2Hz-1 and 5-35×10 -49strain2Hz-1sr-1 for pointlike and extended sources, respectively. The latter result is the first of its kind. We also set 90% C.L. limits on the narrow-band root-mean-square GW strain from interesting targets …

Superhalogen Properties Of Cumcln Clusters: Theory And Experiment, Y. J. Ko, H. Wang, K. Pradhan, P. Koirala, Anil K. Kandalam, K. H. Bowen, P. Jena

Physics & Engineering Faculty Publications

No abstract provided.

The Hubble Space Telescope * Cluster Supernova Survey. Ii. The Type Ia Supernova Rate In High-Redshift Galaxy Clusters, K Barbary, G Aldering, R Amanullah, M Brodwin, N Connolly, Ks Dawson, M Doi, P Eisenhardt, L Faccioli, V Fadeyev, Hk Fakhouri, As Fruchter, D G. Gilbank, Md Gladders, G Goldhaber, A Goobar, T Hattori, E Hsiao, Xiaosheng Huang, Y Ihara, K Kashikawa, B Koester, K Konishi, M Kowalski, C Lidman, L Lubin, J Meyers, T Morokuma, T Oda, N Panagia, S Perlmutter, M Postman, P Ripoche, P Rosati, D Rubin, Dj Schlegel, Al Spadafora, Sa Stanford, M Strovink, N Suzuki, N Takanashi, K Tokita, N Yasuda

Physics and Astronomy

We report a measurement of the Type Ia supernova (SN Ia) rate in galaxy clusters at 0.9 < z < 1.46 from the Hubble Space Telescope Cluster Supernova Survey. This is the first cluster SN Ia rate measurement with detected z > 0.9 SNe. Finding 8 ± 1 cluster SNe Ia, we determine an SN Ia rate of 0.50+0.23 –0.19 (stat) +0.10 –0.09 (sys) h 2 70 SNuB (SNuB ≡ 10–12 SNe L –1 ☉, B yr–1). In units of stellar mass, this translates to 0.36+0.16 –0.13 (stat) +0.07 –0.06 (sys) h 2 70 SNuM (SNuM ≡ 10–12 SNe M –1 ☉ yr–1). This represents a …

Gravity Wave Heating And Cooling Of The Thermosphere: Sensible Heat Flux And Viscous Flux Of Kinetic Energy, Michael P. Hickey Ph.D., R. L. Walterscheid, G. Schubert

Publications

Total wave heating is the sum of the convergence of the sensible heat flux and the divergence of the viscous flux of wave kinetic energy. Numerical simulations, using a full-wave model of the viscous damping of atmospheric gravity waves propagating in a nonisothermal atmosphere, are carried out to explore the relative contributions of these sources of wave heating as a function of wave properties and altitude. It is shown that the sensible heat flux always dominates in the lower thermosphere, giving a lower region of heating and an upper stronger region of cooling. The heating due to the divergence of …

Entangled-Photon Compressive Ghost Imaging, Petros Zerom, Kam Wai Clifford Chan, John C. Howell, Robert W. Boyd

Mathematics, Physics, and Computer Science Faculty Articles and Research

We have experimentally demonstrated high-resolution compressive ghost imaging at the single-photon level using entangled photons produced by a spontaneous parametric down-conversion source and using single-pixel detectors. For a given mean-squared error, the number of photons needed to reconstruct a two-dimensional image is found to be much smaller than that in quantum ghost imaging experiments employing a raster scan. This procedure not only shortens the data acquisition time, but also suggests a more economical use of photons for low-light-level and quantum image formation.

Science With A Skew: The Nuclear Power Industry After Chernobyl And Fukushima, Gayle Greene

Scripps Faculty Publications and Research

It is one of the marvels of our time that the nuclear industry managed to resurrect itself from its ruins at the end of the last century, when it crumbled under its costs, inefficiencies, and mega-accidents. Chernobyl released hundreds of times the radioactivity of the Hiroshima and Nagasaki bombs combined, contaminating more than 40% of Europe and the entire Northern Hemisphere. But along came the nuclear lobby to breathe new life into the industry, passing off as “clean” this energy source that polluted half the globe. The “fresh look at nuclear”—in the words of a New York Times makeover piece …

A Cultured Greigite-Producing Magnetotactic Bacterium In A Novel Group Of Sulfate-Reducing Bacteria, Christopher T. Lefèvre, Nicholas Menguy, Fernanda Abreu, Ulysses Lins, Mihály Pósfai, Tanya Prozorov, David Pignol, Richard B. Frankel, Dennis A. Bazylinski

Physics

Magnetotactic bacteria contain magnetosomes—intracellular, membrane-bounded, magnetic nanocrystals of magnetite (Fe₃O₄) or greigite (Fe₃S₄)—that cause the bacteria to swim along geomagnetic field lines. We isolated a greigite-producing magnetotactic bacterium from a brackish spring in Death Valley National Park, California, USA, strain BW-1, that is able to biomineralize greigite and magnetite depending on culture conditions. A phylogenetic comparison of BW-1 and similar uncultured greigite- and/or magnetite-producing magnetotactic bacteria from freshwater to hypersaline habitats shows that these organisms represent a previously unknown group of sulfate-reducing bacteria in the Deltaproteobacteria. Genomic analysis of BW-1 reveals …

Learning The Structure Of Gene Regulatory Networks From Time Series Gene Expression Data, Haoni Li, Nan Wang, Ping Gong, Edward J. Perkins, Chaoyang Zhang

Faculty Publications

Background: Dynamic Bayesian Network (DBN) is an approach widely used for reconstruction of gene regulatory networks from time-series microarray data. Its performance in network reconstruction depends on a structure learning algorithm. REVEAL (REVerse Engineering ALgorithm) is one of the algorithms implemented for learning DBN structure and used to reconstruct gene regulatory networks (GRN). However, the two-stage temporal Bayes network (2TBN) structure of DBN that specifies correlation between time slices cannot be obtained by score metrics used in REVEAL.

Methods: In this paper, we study a more sophisticated score function for DBN first proposed by Nir Friedman for stationary …

Are Three Flavors Special?, Joseph Schechter, Amir H. Fariborz, Renata Jora, M. Naeem Shahid

Physics - All Scholarship

It has become clearer recently that the regular pattern of three flavor nonets describing the low spin meson multiplets seems to require some modification for the case of the spin 0 scalar mesons. One picture which has had some success, treats the scalars in a chiral Lagrangian framework and considers them to populate two nonets. These are, in turn, taken to result from the mixing of two "bare" nonets, one of which is of quark- antiquark type and the other of two quark- two antiquark type. Here we show that such a mixing is, before chiral symmetry breaking terms are …

U.S. Extended Continental Shelf Cruise To Map Sections Of The Mariana Trench And The Eastern And Southern Insular Margins Of Guam And The Northern Mariana Islands, Andy Armstrong

Center for Coastal and Ocean Mapping

U.S. Extended Continental Shelf Cruise to Map Sections of the Mariana Trench and the Eastern and Southern Insular Margins of Guam and the Northern Mariana Islands

CCOM-JHC CRUISE SU10-02

Leg 2: September 24 to October 21, 2010

Apra Harbor, Guam to Apra Harbor, Guam

Ensemble Forecast Spread Induced By Soil Moisture Changes Over Mid-South And Neighbouring Midwestern Region Of The Usa, Arturo I. Quintanar, Rezaul Mahmood

School of Natural Resources: Faculty Publications

This study investigated the potential impact of soil moisture perturbations on the statistical spread of an ensemble forecast for three different synoptic events during the summer of 2006. Soil moisture was perturbed from a control simulation to generate a 12 member ensemble with six drier and six moister soils. The impacts on the near-surface atmospheric conditions and on precipitation were analysed. It was found, as previous studies have confirmed, that soil moisture can change the spatial and temporal distribution of precipitation and of the overlying circulation. It was found that regardless of the conditions in synoptic forcing, temperature, relative humidity …

Ubvri Photometric Analysis Of The Solar-Type Eclipsing Binary Tyc 3034-299-1, Ronald G. Samec, Adam Jaso, Jesse White, Danny R. Faulkner, Nicholas Blum, Walter Van Hamme

Department of Physics

TYC 3034-0299-1 (CV_n) is a magnetically active, contact binary, ROTSE variable. UBVR_cI_c light curves are presented along with a period study and a simultaneous UBVRI light curve solution. Our light curves show eclipse amplitudes of 0.72 and 0.62 mags (V) in the primary and secondary eclipses. Modeled results include a dark spot region, found at longitude 51°, a 24% Roche lobe fill-out, and a mass ratio of 0.48. A total eclipse is found to occur in the secondary eclipse making TYC 3034-0299-1 a W-type (less massive star is hotter) W UMa variable.

Formation Of Organized Nanostructures From Unstable Bilayers Of Thin Metallic Liquids, Mikhail Khenner, Sagar Yadavali, Ramki Kalyanaraman

Mathematics Faculty Publications

Dewetting of pulsed-laser irradiated, thin (< 20 nm), optically reflective metallic bilayers on an optically transparent substrate with a reflective support layer is studied within the lubrication equations model. A steady-state bilayer film thickness (h) dependent temperature profile is derived based on the mean substrate temperature estimated from the elaborate thermal model of transient heating and melting/freezing. Large thermocapillary forces are observed along the plane of the liquid-liquid and liquid-gas interfaces due to this h-dependent temperature, which, in turn, is strongly influenced by the h-dependent laser light reflection and absorption. Consequently the dewetting is a result of the competition between thermocapillary and intermolecular forces. A linear analysis of the dewetting length scales established that the non-isothermal calculations better predict the experimental results as compared to the isothermal case within the bounding Hamaker coefficients. Subsequently, a computational non-linear dynamics study of the dewetting pathway was performed for Ag/Co and Co/Ag bilayer systems to predict the morphology evolution. We found that the systems evolve towards formation of different morphologies, including core-shell, embedded, or stacked nanostructure morphologies.

On The Radio And Optical Luminosity Evolution Of Quasars, Jack Singal, V. Petrosian, A. Lawrence, L. Stawarz

Physics Faculty Publications

We calculate simultaneously the radio and optical luminosity evolutions of quasars, and the distribution in radio loudness R defined as the ratio of radio and optical luminosities, using a flux-limited data set containing 636 quasars with radio and optical fluxes from White et al. We first note that when dealing with multi-variate data it is imperative to first determine the true correlations among the variables, not those introduced by the observational selection effects, before obtaining the individual distributions of the variables. We use the methods developed by Efron and Petrosian which are designed to obtain unbiased correlations, distributions, and evolution …

Optical Polarization And Spectral Variability In The M87 Jet, Eric S. Perlman, Mihai Cara, Matthew Bourque, Raymond C. Simons

Aerospace, Physics, and Space Science Faculty Publications

During the last decade, M87's jet has been the site of an extraordinary variability event, with one knot (HST-1) increasing by over a factor 100 in brightness. Variability has also been seen on timescales of months in the nuclear flux. Here we discuss the optical-UV polarization and spectral variability of these components, which show vastly different behavior. HST-1 shows a highly significant correlation between flux and polarization, with P increasing from 20% at minimum to >40% at maximum, while the orientation of its electric vector stayed constant. HST-1's optical-UV spectrum is very hard (αUV-O 0.5, F ν ∞ ν-α), and …

Hyperspectral Data Processing In A High Performance Computing Environment: A Parallel Best Band Selection Algorithm, Stefan Robila, Gerald Busardo

Department of Computer Science Faculty Scholarship and Creative Works

Hyperspectral data are characterized by a richness of information unique among various visual representations of a scene by representing the information in a collection of grayscale images with each image corresponding to a narrow interval in the electromagnetic spectrum. Such detail allows for precise identification of materials in the scene and promises to support advances in imaging beyond the visible range. However, hyperspectral data are considerably large and cumbersome to process and efficient computing solutions based on high performance computing are needed. In this paper we first provide an overview of hyperspectral data and the current state of the art …

A Search For The Transit Of Hd 168443b: Improved Orbital Parameters And Photometry, G. Pilyavsky, S. Mahadevan, S. R. Kane, A. W. Howard, D. R. Ciardi, C. De Pree, D. Dragomir, D. A. Fischer, G. W. Henry, Eric L.N. Jensen, G. Laughlin, H. Marlowe, M. Rabus, K. Von Braun, J. T. Wright, X. X. Wang

Physics & Astronomy Faculty Works

The discovery of transiting planets around bright stars holds the potential to greatly enhance our understanding of planetary atmospheres. In this work we present the search for transits of HD 168443b, a massive planet orbiting the bright star HD 168443 (V = 6.92) with a period of 58.11 days. The high eccentricity of the planetary orbit (e = 0.53) significantly enhances the a priori transit probability beyond that expected for a circular orbit, making HD168443 a candidate for our ongoing Transit Ephemeris Refinement and Monitoring Survey. Using additional radial velocities from Keck High Resolution Echelle Spectrometer, we refined the orbital …

Ordered Phases In Ruthenium Binary Alloys From High-Throughput First-Principles Calculations, Gus L. W. Hart, Lance J. Nelson, Michal Jahnátek, Ohad Levy, Roman V. Chepulskii, J. Xue, Stephano Curtarolo

Faculty Publications

Despite the increasing importance of ruthenium in numerous technological applications, e.g., catalysis and electronic devices, experimental and computational data on its binary alloys are sparse. In particular, data are scant on those binary systems believed to be phase-separating. We performed a comprehensive study of ruthenium binary systems with the 28 transition metals, using high-throughput first-principles calculations. These computations predict novel unsuspected compounds in 7 of the 16 binary systems previously believed to be phase-separating and in two of the three systems reported with only a high-temperature σ phase. They also predict a few unreported compounds in five additional systems and …

Analytic Derivative Couplings Between Configuration-Interaction-Singles States With Built-In Electron-Translation Factors For Translational Invariance, Shervin Fatehi, Ethan Alguire, Yihan Shao, Joseph Subotnik

Chemistry Faculty Publications and Presentations

We present a method for analytically calculating the derivative couplings between a pair of configuration-interaction-singles (CIS) excited states obtained in an atom-centered basis. Our theory is exact and has been derived using two completely independent approaches: one inspired by the Hellmann-Feynman theorem and the other following from direct differentiation. (The former is new, while the latter is in the spirit of existing approaches in the literature.) Our expression for the derivative couplings incorporates all Pulay effects associated with the use of an atom-centered basis, and the computational cost is minimal, roughly comparable to that of a single CIS energy gradient. …

Satellite Evidence For A Large Source Of Formic Acid From Boreal And Tropical Forests, T Stavrakou, J F. Muller, J Peeters, A Razavi, L Clarisse, C Clerbaux, P Coheur, D Hurtmans, M De Maziere, C Vigouroux, Nicholas Deutscher, David Griffith, Nicholas Jones, Clare Paton-Walsh

Faculty of Science - Papers (Archive)

Formic acid contributes significantly to acid rain in remote environments1, 2. Direct sources of formic acid include human activities, biomass burning and plant leaves. Aside from these direct sources, sunlight-induced oxidation of non-methane hydrocarbons (largely of biogenic origin) is probably the largest source3, 4. However, model simulations substantially underpredict atmospheric formic acid levels5, 6, 7, indicating that not all sources have been included in the models. Here, we use satellite measurements of formic acid concentrations to constrain model simulations of the global formic acid budget. According to our simulations, 100–120 Tg of formic acid is produced annually, which is two …

Quantitative Field Testing Rotylenchulus Reniformis Dna From Metagenomic Samples Isolated Directly From Soil., Kurt Showmaker, Gary W. Lawrence, Shien Lu, Clarissa Balbalian, Vincent P. Klink

College of Agriculture & Life Sciences Publications and Scholarship

A quantitative PCR procedure targeting the ?-tubulin gene determined the number of Rotylenchulus reniformis Linford & Oliveira 1940 in metagenomic DNA samples isolated from soil. Of note, this outcome was in the presence of other soil-dwelling plant parasitic nematodes including its sister genus Helicotylenchus Steiner, 1945. The methodology provides a framework for molecular diagnostics of nematodes from metagenomic DNA isolated directly from soil.

Reactions With Platinum (Ll) Complexes And Selenium-Containing Amino Acids, Stephanie Robey

Mahurin Honors College Capstone Experience/Thesis Projects

We have reacted [Pt(Me₄en)(D₂O)₂]²⁺ [Me₄En=N,N,N’N’-tetramethylethylenediamine] with Selenomethionine (SeMet), Methionine (Met), and Methylselenocysteine (MeSeCys). When MeSeCys was reacted with [Pt(Me₄en)(D₂O)₂]²⁺, we observed both stereoisomers of Se,N chelates, as well as [Pt(Me₄en)(MeSeCys)Cl]⁺ from ­¹­H NMR Spectroscopy; the latter formed due to the presence of Cl^- in the solution. Both isomers of the chelate seemed to form proportionally to one another, not favoring a specific stereoisomer. Eventually the [Pt(Me₄en)(MeSeCys)Cl]⁺ products became Se,N chelates. We incubated SeMet with …

3-D Transient Hydraulic Tomography In Unconfined Aquifers With Fast Drainage Response, Michael Cardiff, Warren Barrash

CGISS Publications and Presentations

We investigate, through numerical experiments, the viability of three-dimensional transient hydraulic tomography (3DTHT) for identifying the spatial distribution of groundwater flow parameters (primarily, hydraulic conductivity K) in permeable, unconfined aquifers. To invert the large amount of transient data collected from 3DTHT surveys, we utilize an iterative geostatistical inversion strategy in which outer iterations progressively increase the number of data points fitted and inner iterations solve the quasi-linear geostatistical formulas of Kitanidis. In order to base our numerical experiments around realistic scenarios, we utilize pumping rates, geometries, and test lengths similar to those attainable during 3DTHT field campaigns performed at …