Physical Sciences and Mathematics Commons^™

Characterization Of Ips Pini Ipsdienol Dehydrogenase (Idol Dh), Heidi Pak, Claus Tittiger, William Welch

Festival of Communities: UG Symposium (Posters)

Ipsdienol is an important pheromone component for pine engraver beetle, Ips pini. Ipsdienol is a ten carbon monoterpenoid secondary alcohol and ipsdienone is the corresponding ketone. We are characterizing the activity of recombinant IDOL DH produced in Sf9 (insect) cells. The enzyme has a high stereospecificity: (-) ipsdienol was found to be a substrate while (+)-ipsdienol was neither a substrate nor inhibitor. Closely related monoterpenoids, such as nerol, geraniol, and citral, were neither substrates nor inhibitors. Smaller compounds, such as 2-propanol, also failed to act as an inhibitor or substrate. This indicates the binding site of this enzyme is highly …

Serpentinite Weathering And Implications For Mars, Valerie Tu, Julie Baumeister, Rodney Metcalf, A. Olsen, Elisabeth Hausrath

Festival of Communities: UG Symposium (Posters)

In the search for life on Mars near-surface soil environments may be important habitats for life accessible to future missions. Serpentinite rocks have been documented on Mars, as well as other clay minerals including smectite and kaolinites. Previous studies of soils formed on serpentinites on Earth have documented the formation of extensive clays. Serpentinites are additionally of interest as habitats for life such as methanogens. Here we examine weathering of serpentinites from bedrock to soil surface, as a potential route for the formation of clay minerals on Mars from abundant ultramafic minerals. We additionally test for the presence of Fe-oxidizing …

Event Program, Carl Reiber, Nicholle Booker

Festival of Communities: UG Symposium (Posters)

UNLV Undergraduates from all departments, programs and colleges participated in a campus-wide symposium on April 16, 2011. Undergraduate posters from all disciplines and also oral presentations of research activities, readings and other creative endeavors were exhibited throughout the festival.

Observation Of The Dalitz Decay Ds*+ → Ds*+ E+E-, Raymond Mountain, Marina Artuso, T. Skwarnicki, S. Stone

Physics - All Scholarship

Using 586 \textrm{pb}^{-1} of e^{+}e^{-} collision data acquired at \sqrt{s}=4.170 GeV with the CLEO-c detector at the Cornell Electron Storage Ring, we report the first observation of D_{s}^{*+} \to D_{s}^{+} e^{+} e^{-} with a significance of 5.3 \sigma. The ratio of branching fractions \calB(D_{s}^{*+} \to D_{s}^{+} e^{+} e^{-}) / \calB(D_{s}^{*+} \to D_{s}^{+} \gamma) is measured to be [ 0.72^{+0.15}_{-0.13} (\textrm{stat}) \pm 0.10 (\textrm{syst})]%, which is consistent with theoretical expectations.

Observation Of The Dalitz Decay D_{S}^{*+} \To D_{S}^{+} E^{+} E^{-}, Raymond Mountain, Marina Artuso, S. Blusk, T. Skwarnicki

Physics - All Scholarship

Using 586 \textrm{pb}^{-1} of e^{+}e^{-} collision data acquired at \sqrt{s}=4.170 GeV with the CLEO-c detector at the Cornell Electron Storage Ring, we report the first observation of D_{s}^{*+} \to D_{s}^{+} e^{+} e^{-} with a significance of 5.3 \sigma. The ratio of branching fractions \calB(D_{s}^{*+} \to D_{s}^{+} e^{+} e^{-}) / \calB(D_{s}^{*+} \to D_{s}^{+} \gamma) is measured to be [ 0.72^{+0.15}_{-0.13} (\textrm{stat}) \pm 0.10 (\textrm{syst})]%, which is consistent with theoretical expectations.

A New Perspective On Visual Word Processing Efficiency, Joseph W. Houpt, James T. Townsend

Joseph W. Houpt

No abstract provided.

A New Perspective On Visual Word Processing Efficiency, Joseph W. Houpt, James T. Townsend

Psychology Faculty Publications

No abstract provided.

Late Pleistocene Climate And Proboscidean Paleoecology In North America: Insights From Stable Isotope Compositions Of Skeletal Remains, Jessica Z. Metcalfe

Electronic Thesis and Dissertation Repository

This thesis uses the carbon, nitrogen, and oxygen isotope compositions of mammoth (Mammuthus) and mastodon (Mammut) skeletal remains to reconstruct paleoclimate and paleoecology in Late Pleistocene North America. Analytical methods, sampling strategies, environmental adaptations and seasonal behaviors of proboscideans were investigated.

Reliable and reproducible results are crucial for a study of this nature. A persistent methodological problem in the isotope analysis of structural carbonate in bioapatite was solved by reacting bioapatite under “sealed vessel” conditions.

Growth rate determinations are critical for designing sampling strategies and interpreting results. Histological and isotopic measurements demonstrated variations in enamel growth …

Basic Queuing: Discrete Model Of Jmu’S Dining Halls, D. Macdonald, Caroline Lubert

Caroline P Lubert

No abstract provided.

Lecture 10: Human Activities And Future Coast, Carl T. Friedrichs

Presentations

No abstract provided.

Lecture 7: Deltas And Estuaries, Carl T. Friedrichs

Presentations

No abstract provided.

Beating The Spin-Down Limit On Gravitational Wave Emission From The Vela Pulsar, Duncan Brown, J. Abadie, Collin Capano, J. A. Garofoli, A. P. Lundgren

Physics - All Scholarship

We present direct upper limits on continuous gravitational wave emission from the Vela pulsar using data from the Virgo detector's second science run. These upper limits have been obtained using three independent methods that assume the gravitational wave emission follows the radio timing. Two of the methods produce frequentist upper limits for an assumed known orientation of the star's spin axis and value of the wave polarization angle of, respectively, $1.9\ee{-24}$ and $2.2\ee{-24}$, with 95% confidence. The third method, under the same hypothesis, produces a Bayesian upper limit of $2.1\ee{-24}$, with 95% degree of belief. These limits are below the …

Search For Gravitational Wave Bursts From Six Magnetars, Duncan Brown, J. Abadie

Physics - All Scholarship

Soft gamma repeaters (SGRs) and anomalous X-ray pulsars (AXPs) are thought to be magnetars: neutron stars powered by extreme magnetic fields. These rare objects are characterized by repeated and sometimes spectacular gamma-ray bursts. The burst mechanism might involve crustal fractures and excitation of non-radial modes which would emit gravitational waves (GWs). We present the results of a search for GW bursts from six galactic magnetars that is sensitive to neutron star f-modes, thought to be the most efficient GW emitting oscillatory modes in compact stars. One of them, SGR 0501+4516, is likely ~1 kpc from Earth, an order of magnitude …

Optimization Of The Nanolens Consisting Of Coupled Metal Nanoparticles: An Analytical Approach, Greg Sun, Jacob B. Khurgin

Physics Faculty Publications

Using a simple and intuitive analytical approach, we perform optimization of a nanolens composed of coupled metal nanoparticles capable of subwavelength focusing of light inside the narrow gap separating the particles. Specifically, we optimize the structure of two nanospheres of different sizes to achieve maximum field enhancement at an off-center position in the gap. We demonstrate that the nanolens of two or more spheres acts simultaneously as an efficient antenna with large dipole and an efficient cavity with small effective volume.

A General Implementation Of Tmle For Longitudinal Data Applied To Causal Inference In Survival Analysis, Ori M. Stitelman, Victor De Gruttola, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

In many randomized controlled trials the outcome of interest is a time to event, and one measures on each subject baseline covariates and time-dependent covariates until the subject either drops-out, the time to event is observed, or the end of study is reached. The goal of such a study is to assess the causal effect of the treatment on the survival curve. Standard methods (e.g., Kaplan-Meier estimator, Cox-proportional hazards) ignore the available baseline and time-dependent covariates, and are therefore biased if the drop-out is affected by these covariates, and are always inefficient. We present a targeted maximum likelihood estimator of …

Multiple Solutions For An Elliptic Problem Related To Vortex Pairs, Yi Li, Shuangjie Peng

Yi Li

Let Ω be a bounded domain in RN (N⩾2), φ a harmonic function in Ω¯. In this paper we study the existence of solutions to the following problem arising in the study of vortex pairs(Pλ){−Δu=λ(u−φ)+p−1,x∈Ω,u=0,x∈∂Ω. The set Ωp={x∈Ω,u(x)>φ} is called “vortex core”. Existence of solutions whose “vortex core” consists of one component and asymptotic behavior of “vortex core” were studied by many authors for large λ recently. Under the condition that φ has k strictly local minimum points on the boundary ∂Ω, we obtain in this paper that for λ large enough, (Pλ) has a solution with “vortex core” …

Systems Views Of The Economics Of Sustainable Development, Joshua Hughes

Systems Science Friday Noon Seminar Series

The mainstream economics of the 20th century (and now 21st century) has often failed to predict what will happen--or explain what has happened--in the real world, even with (or because of?) an ever-increasing reliance on quantitative and computational methods. Since the mid-20th century a number of people part of, or closely associated with, the systems community--economists among them--have provided insights about what is wrong with "traditional" economics. Systems science offers a number of alternative methods for understanding economic systems that take heed of these criticisms, especially in the context of sustainable development. Yet, while promising, few of these alternatives …

Graph Games: A Human Computing Game Framework, Ryan Alfuth, Matt Jara, Jeff Largent, Dan Simpson

10th Annual Celebration of Undergraduate Research and Creative Performance (2011)

Graph Games is a suite of online casual games that make use of human computation to help solve several NP-complete graph problems. These problems are very difficult for computers to solve efficiently because they rapidly become computationally infeasible as their size increases. However, humans possess intelligent decision-making abilities that computers do not, so they can solve these problems more resourcefully than computers.

Graph Games seeks to harness these abilities to increase the body of knowledge about solving NP-complete problem by presenting problems in the form of puzzle-like games. Graph Games currently consists of three families of games, each being comprised …

A Rank-Based Estimate For Cell Lineage Data, Tamer M. Elbayoumi, Jeffrey Terpstra

Research and Creative Activities Poster Day

The presence of aberrant observations (i.e. outliers) in cell lineage data is quite common. As such, it is desirable to have an outlier-resistant estimation procedure as an alternative to least squares estimation (maximum likelihood estimation under normality). In this work, we consider rankbased estimates of the parameters of a first order bifurcating autoregressive [BAR(1)] model. The BAR(1) model was proposed by Cowan and Staudte (1986) for cell lineage data. In it, each line of descendents follows a first order autoregressive [AR(1)] model and allows sister cells from the same mother to be correlated. Real examples and a simulation study are …

K-X-Ray Emission In Fast O5+ On Ar Collisions, Tamer Elkafrawy

Research and Creative Activities Poster Day

The goal of the present work is to observe x-rays from oxygen for the purpose of investigating resonant-transfer and excitation (RTE) [1], and projectile and target x-ray emission resulting from inner-shell capture. Projectile energies in the range 5-25 MeV will be examined to investigate RTE for heavy targets [2,3].

Multiple Solutions For An Elliptic Problem Related To Vortex Pairs, Yi Li, Shuangjie Peng

Mathematics and Statistics Faculty Publications

Let Ω be a bounded domain in RN (N⩾2), φ a harmonic function in Ω¯. In this paper we study the existence of solutions to the following problem arising in the study of vortex pairs(Pλ){−Δu=λ(u−φ)+p−1,x∈Ω,u=0,x∈∂Ω. The set Ωp={x∈Ω,u(x)>φ} is called “vortex core”. Existence of solutions whose “vortex core” consists of one component and asymptotic behavior of “vortex core” were studied by many authors for large λ recently. Under the condition that φ has k strictly local minimum points on the boundary ∂Ω, we obtain in this paper that for λ large enough, (Pλ) has a solution with “vortex core” …

Evaluation Of Drought Indices Based On Thermal Remote Sensing Of Evapotranspiration Over The Continental United States, Martha C. Anderson, Christopher R. Hain, Brian Wardlow, Agustin Pimstein, John R. Mecikalski, William P. Kustas

Drought Mitigation Center: Faculty Publications

The reliability of standard meteorological drought indices based on measurements of precipitation is limited by the spatial distribution and quality of currently available rainfall data. Furthermore, they reflect only one component of the surface hydrologic cycle, and they cannot readily capture nonprecipitation-based moisture inputs to the land surface system (e.g., irrigation) that may temper drought impacts or variable rates of water consumption across a landscape. This study assesses the value of a new drought index based on remote sensing of evapotranspiration (ET). The evaporative stress index (ESI) quantifies anomalies in the ratio of actual to potential ET (PET), mapped using …

Lecture 9: Morphodynamics Of Coastal Systems, Carl T. Friedrichs

Presentations

No abstract provided.

Mudbed: Multi-Disciplinary Benthic Exchange Dynamics, Carl T. Friedrichs

Presentations

No abstract provided.

Lecture 8: Muddy Coasts, Carl T. Friedrichs

Presentations

No abstract provided.

The Model Seed Plug-In For Viewing And Editing Metabolic Models, Benjamin Bockstege, Nicholas Hazekamp

10th Annual Celebration of Undergraduate Research and Creative Performance (2011)

The goal of our research is to develop a plug-in for Cytoscape that will be used in tandem with the Model SEED Viewer to help biologists better understand and visualize the metabolic pathways of bacteria. The Model SEED is an online resource at www.theseed.org/models that provides biologists with a static but very detailed view of metabolic models. It uses KEGG (www.genome.jp) metabolic pathway maps which cannot be edited by users. This ability to edit metabolic pathways is one of our primary focuses in creating the plug-in – in particular, adding, removing, and moving reaction and compound nodes. Additionally, we want …

A Bis-Urea Naphthalene Macrocycle Displaying Two Crystal Structures With Parallel Ureas, Michael F. Geer, Mark D. Smith, Linda S. Shimizu

Faculty Publications

Herein we synthesized a bis-urea macrocycle from 2,7-dimethylnaphthalene that displays an unusual parallel urea conformation. The naphthalenes also adopt a bowl shape over the anticipated parallel planar orientation. Crystallization of the macrocycle from different solvent systems affords two solvated forms. 1·DMSO·(H₂O)₂ has an extended columnar structure where parallel macrocycles are linked by intervening hydrogen bonded water molecules. In 1·(MeOH)₂direct hydrogen-bonds link the macrocycles into chains, which hydrogen-bond with methanolmolecules to form a layered structure.

Effects Of Rodent Species, Seed Species, And Predator Cues On Seed Fate, Kelly J. Sivy, Steven M. Ostoja, Eugene W. Schupp, Susan Durham

United States Geological Survey: Staff Publications

Seed selection, removal and subsequent management by granivorous animals is thought to be a complex interaction of factors including qualities of the seeds themselves (e.g., seed size, nutritional quality) and features of the local habitat (e.g. perceived predator risk). At the same time, differential seed selection and dispersal is thought to have profound effects on seed fate and potentially vegetation dynamics. In a feeding arena, we tested whether rodent species, seed species, and indirect and direct predation cues influence seed selection and handling behaviors (e.g., scatter hoarding versus larder hoarding) of two heteromyid rodents, Ord’s kangaroo rat (Dipodomys ordii) and …

Monitoring Relative Abundance Of American Shad In Virginia Rivers 2010 Annual Report, Eric J. Hilton, Rob Latour, Brian Watkins, Ashleigh Magee

Reports

Concern about the decline in landings of American shad (Alosa sapidissima) along the Atlantic coast prompted the development of an interstate fisheries management plan (FMP) under the auspices of the Atlantic States Marine Fisheries Management Program (ASMFC 1999). Legislation enables imposition of federal sanctions on fishing in those states that fail to comply with the FMP. To be in compliance, coastal states are required to implement and maintain fishery-dependent and fishery-independent monitoring programs as specified by the FMP. For Virginia, these requirements include spawning stock assessments, the collection of biological data on the spawning run (e.g., age-structure, sex ratio, and …

Dicarbonyldichloridobis(Trimethylphosphane)Iron(Ii)–Carbonyldichloridotris(Trimethylphosphane)Iron(Ii)–Tetrahydrofuran (1/1/2), Nigam Rath, Meghan Stouffer, Matthew Janssen, John Bleeke

Chemistry & Biochemistry Faculty Works

The asymmetric unit of the title crystal, [FeCl2(C3H9P)3(CO)]·[FeCl2(C3H9P)2(CO)2]·2C4H8O, contains half mol­ecules of the two closely related FeII complexes lying on mirror planes and a tetra­hydro­furan solvent mol­ecule, one C atom of which is disordered over two sets of sites with site occupancy factors 0.633 (9) and 0.367 (9). In both FeII complex mol­ecules, a distorted octa­hedral coordination geometry has been observed around the Fe atoms. Weak intermolecular C-H...O inter­actions are observed in the crystal structure.