Physical Sciences and Mathematics Commons^™

Electronic Behavior Of The Zn- And O-Polar Zno Surfaces Studied Using Conductive Atomic Force Microscopy, J. C. Moore, S. M. Kenny, C. S. Baird, H. Morkoç, A. A. Baski

Physics Publications

We have used conducting atomic force microscopy (CAFM) to study the morphology and electronic behavior of as-received and air-annealed (0001) Zn- and (0001¯) O-polar surfaces of bulk ZnO. Both polar surfaces exhibit relatively flat morphologies prior to annealing, which rearrange to form well-defined steps upon annealing in air at 1050 °C for 1 h. Long-term exposure to air results in surface layer pitting and the destruction of steps for both the as-received and air-annealed (0001¯)surfaces, indicating its enhanced reactivity relative to the (0001) surface. CAFM I-V spectra for polar surfaces are similar and indicate Ohmic to rectifying behavior that depends …

Magnetic Response Of Core-Shell Cobalt Ferrite Nanoparticles At Low Temperature, K. Maaz, M. Usman, S. Karim, A. Mumtaz, S. K. Hasanain, M. F. Bertino

Physics Publications

Cobaltferritenanoparticles (size: 26±4nm) have been synthesized by coprecipitation route. The coercivity of nanoparticles follows a simple model of thermal activation of particle moments over the anisotropy barrier in the temperature range of 30–300K in accordance with Kneller’s law; however, at low temperatures (

Photoelectron Imaging And Theoretical Investigation Of Bimetallic Bi1–2ga−0–2 And Pb−1–4 Cluster Anions, M. A. Sobhy, J. Ulises Reveles, Ujjwal Gupta, Shiv N. Khanna, A. W. Castleman Jr.

Physics Publications

We present the results of photoelectron velocity-map imaging experiments for the photodetachment of small negatively charged BimGan (m=1–2, n=0–2), and Pbn (n=1–4) clusters at 527 nm. The photoelectron images reveal new features along with their angular distributions in the photoelectron spectra of these clusters. We report the vertical detachment energies of the observed multiple electronic bands and their respective anisotropy parameters for the BimGan and Pbn clusters derived from the photoelectron images. Experiments on the BiGan clusters reveal that the electron affinity increases with the number of Ga atoms from n=0 to 2. The BiGa−2 cluster is found to be …

Doping Induced Anisotropic Growth In C60, Miao Miao Wu, Qiang Sun, Puru Jena, Yoshiyuki Kawazoe

Physics Publications

Using density functional theory with generalized gradient approximation for exchange and correlation energy, we show that substitution of a Si atom at one of the C sites in C60 not only allows C59Si to have a hydrophobic head with a hydrophilic tail but also the Si atom acts as a seed for anisotropic growth of the heterofullerene. This is demonstrated by interacting C59Si with N7Sc and B8Si. The resulting complex structures exhibit enhanced electric dipole moments and anisotropy. Thus, doping induced anisotropic growth of nanostructures provides a novel route for the synthesis of bifunctional particles with atomic-level control on selectivity …

The Three-Dimensional Dynamic Structure Of The Inner Orion Nebula, C. R. O'Dell, W. J. Henney, N. P. Abel, Gary J. Ferland, S. J. Arthur

Physics and Astronomy Faculty Publications

The three-dimensional structure of the brightest part of the Orion Nebula is assessed in the light of published and newly established data. We find that the widely accepted model of a concave blister of ionized material needs to be altered in the southwest direction from the Trapezium, where we find that the Orion-S feature is a separate cloud of very optically thick molecules within the body of ionized gas, which is probably the location of the multiple embedded sources that produce the optical and molecular outflows that define the Orion-S star formation region. Evidence for this cloud comes from the …

Addressing Distress And Pain In Animal Research: The Veterinary, Research, Societal, Regulatory And Ethical Contexts For Moving Forward, Kathleen Conlee, Martin Stephens, Andrew N. Rowan

Experimentation Collection

While most people recognize that biomedical scientists are searching for knowledge that will improve the health of humans and animals, the image of someone deliberately causing harm to an animal in order to produce data that may lead to some future benefit has always prompted an uncomfortable reaction outside the laboratory. However, proponents of animal research have usually justified the practice by reference to greater benefits (new knowledge and medical treatments) over lesser costs (in animal suffering and death). Given that one of the costs of animal research is the suffering experienced by the animals, the goal of eliminating distress …

The Role Of Clinical Veterinary Medicine In The Assessment And Treatment Of Laboratory Animal Distress, V. Hampshire

Veterinary Science and Medicine Collection

It is doubtful that the scientific community will ever arrive at a consensus definition for distress as it may be attempted for the purposes of improving animal welfare in and across the myriad of research, testing and teaching facilities in the United States and throughout the minuet of protocols that exist for animals. The stakeholders in this attempt can however address most causes of physiologic distress by instituting time-honored veterinary and agrarian approaches to animal surveillance. In this manner, the majority of individuals who participate in responsible and humane animal care might be assuaged in that a condition of maximum …

An Hsus Report: The Implications Of Farm Animal-Based Bioenergy Production, The Humane Society Of The United States

Impact of Animal Agriculture

As the current and potential impacts of climate change become more evident and increasingly urgent, entities such as governments, corporations, and non-governmental organizations (NGOs) are seeking out non-fossil fuelbased sources of energy to mitigate those effects. In addition, many governments are investigating ways to promote their own domestic energy sources as a result of rising oil prices. Bioenergy—made from recently living organic matter, such as plants, agricultural waste and crop residue, meat processing wastes, or farmed animals’ fats and manure—has quickly become one of the fastest growing, and controversial, alternative energy sources. Globally, production of biofuels, generally used for transport, …

Significant Limb-Brightening In The Inner Parsec Of Markarian 501, Glenn Piner

Physics

We present three 43 GHz images and a single 86 GHz image of Markarian 501 from VLBA observations in 2005. The 86 GHz image shows a partially resolved core with a flux density of about 200 mJy and a size of about 300 Schwarzschild radii, similar to recent results by Giroletti et al. Extreme limb-brightening is found in the inner parsec of the jet in the 43 GHz images, providing strong observational support for a “spine–layer” structure at this distance from the core. The jet is well-resolved transverse to its axis, allowing Gaussian model components to be fit to each …

The Two-Sum Of Ribbon Graphs And The Bolloba ́S-Riordan-Tutte Polynomial, Brittan Farmer

Honors Theses

No abstract provided.

Comments On Buzan Et Al. “Positive Relationships Between Freshwater Inflow And Oyster Abundance In Galveston Bay, Texas”, R. Eugene Turner

Faculty Publications

Buzan et al. critique Turner’s (Estuaries and Coasts 29:345–352, 2006) analysis of the relationship between freshwater inflow and oyster productivity in the Gulf of Mexico, using 16 years of fisheries-independent data for Galveston Bay. They conclude that the catch-per-unit effort (CPUE; number h−1) of marketable oysters increase 1 to 2 years after years with increased freshwater inflows, and they express concerns that water supply managers may mis-apply the results of Turner (Estuaries and Coasts 29:345–352, 2006) to justify a reduced freshwater inflow to Galveston Bay. I find no relationship between the CPUE of oyster spat or marketable oyster density and …

Effect Of Dlk1 And Rtl1 But Not Meg3 Or Meg8 On Muscle Gene Expression In Callipyge Lambs, Jolena N. Fleming-Waddell, Gayla R. Olbricht, Tasia M. Taxis, Jason D. White, Tony Vuocolo, Bruce A. Craig, Ross L. Tellam, Mike K. Neary, Noelle E. Cockett, Christopher A. Bidwell

Mathematics and Statistics Faculty Research & Creative Works

Callipyge sheep exhibit extreme postnatal muscle hypertrophy in the loin and hindquarters as a result of a single nucleotide polymorphism (SNP) in the imprinted DLK1-DIO3 domain on ovine chromosome 18. The callipyge SNP up-regulates the expression of surrounding transcripts when inherited in cis without altering their allele-specific imprinting status. The callipyge phenotype exhibits polar overdominant inheritance since only paternal heterozygous animals have muscle hypertrophy. Two studies were conducted profiling gene expression in lamb muscles to determine the down-stream effects of over-expression of paternal allele-specific DLK1 and RTL1 as well as maternal allele-specific MEG3, RTL1AS and MEG8, using Affymetrix bovine expression …

A Finite Element Splitting Extrapolation For Second Order Hyperbolic Equations, Xiaoming He, Tao Lü

Mathematics and Statistics Faculty Research & Creative Works

Splitting extrapolation is an efficient technique for solving large scale scientific and engineering problems in parallel. This article discusses a finite element splitting extrapolation for second order hyperbolic equations with time-dependent coefficients. This method possesses a higher degree of parallelism, less computational complexity, and more flexibility than Richardson extrapolation while achieving the same accuracy. By means of domain decomposition and isoparametric mapping, some grid parameters are chosen according to the problem. The multiparameter asymptotic expansion of the d-quadratic finite element error is also established. The splitting extrapolation formulas are developed from this expansion. An approximation with higher accuracy on a …

Characterization Of Partial Derivatives With Respect To Boundary Conditions For Solutions Of Nonlocal Boundary Value Problems For Nth Order Differential Equations, Jeffrey W. Lyons, Johnny Henderson

Mathematics Faculty Articles

Under certain conditions, solutions of the nonlocal boundary value problem, y⁽ⁿ⁾ = f(x, y, y', ... , y^{(n- 1)}), y(x_i) = Y_i for 1 £ i £ n- 1, and y(x_n) - Σ^m_k=1 Υ_iy (n_i) = y _n, are differentiated with respect to boundary conditions, where a < X₁ < X₂ < · · · < X_n-1 < n₁ < · · · < n_m < X_n < b, r₁, ... , r_m, Y1, ... , Y_n ∈ R .

Winter 2009, Nsu Oceanographic Center

Currents

No abstract provided.

Spectroscopy Of Prebiotic Molecules Formed From O(1D) Insertion Reactions, Thomas A. Anderson, Jay A. Kroll, Susanna L. Widicus Weaver

Thomas A. Anderson

Many important molecules in astrochemistry are unstable or reactive species, and therefore difficult to study in the lab. Three such molecules are methoxymethanol (CH₃OCH₂OH), methanediol (HOCH₂OH), and aminomethanol (NH₂CH₂OH). These molecules are predicted to form on grain surfaces in the initial steps of interstellar prebiotic molecular evolution. These molecules are thought to be precursors to complex molecules such as sugars and amino acids. To test these prebiotic interstellar chemical pathways, a pure rotational spectrum is required for comparison to interstellar line surveys. Given the reactivity and instability of these molecules …

Parallel Synthesis Of A Library Of Symmetrically- And Dissymmetrically-Disubstituted Imidazole-4, 5- Dicarboxamides Bearing Amino Acid Esters, John C. Dicesare, Rosanna Solinas, Paul W. Baures

John C. DiCesare

The imidazole-4,5-dicarboxylic acid scaffold is readily derivatized with amino acid esters to afford symmetrically- and dissymmetrically-disubstituted imidazole-4,5-dicarboxamides with intramolecularly hydrogen bonded conformations that predispose the presentation of amino acid pharmacophores. In this work, a total of 45 imidazole-4,5-dicarboxamides bearing amino acid esters were prepared by parallel synthesis. The library members were purified by column chromatography on silica gel and the purified compounds characterized by LC-MS with LC detection at 214 nm. A selection of the final compounds was also analyzed by (1)H-NMR spectroscopy. The analytically pure final products have been submitted to the Molecular Library Small Molecule Repository (MLSMR) for …

A Submillimeter Spectral Line Survey Of Orion, Mary L. Radhuber, Jay A. Kroll, Jacob C. Laas, Thomas A. Anderson, Matthew C. Sumner, Frank Rice, Jonas Zmuidzinas, Geoffrey A. Blake, Susanna L. Widicus Weaver

Thomas A. Anderson

No abstract provided.

Effect Of Chirality Of Small Molecule Organofluorine Inhibitors Of Amyloid Self-Assembly On Inhibitor Potency, Abha Sood, Abid Shaikh, Samson Hailemichael, Michelle Foster, Béla Török, Marianna Török

Abid Shaikh

The effect of enantiomeric trifluoromethyl-indolyl-acetic acid ethyl esters on the fibrillogenesis of Alzheimer’s amyloid β (Aβ) peptide is described. These compounds have been previously identified as effective inhibitors of the Aβ self-assembly in their racemic form. Thioflavin-T Fluorescence Spectroscopy and Atomic Force Microscopy were applied to assess the potency of the chiral target compounds. Both enantiomers showed significant inhibition in the in vitro assays. The potency of the enantiomeric inhibitors appeared to be very similar to each other suggesting the lack of the stereospecific binding interactions between these small molecule inhibitors and the Aβ peptide.

Carbon Nanotube Membranes For Use In The Transdermal Treatment Of Nicotine Addiction And Opioid Withdrawal Symptoms, Ji Wu, Caroline L. Strasinger, Nicole N. Scheff, Audra L. Stinchcomb, Bruce J. Hinds

Ji Wu

Transdermal systems are attractive methods of drug administration specifically when treating patients for drug addiction. Current systems however are deficient in therapies that allow variable flux values of drug, such as nicotine for smoking cessation or complex dosing regimens using clonidine when treating opioid withdrawal symptoms. Through the use of functionalized carbon nanotube (CNT) membranes, drug delivery to the skin can be controlled by applying a small electrical bias to create a programmable drug delivery system. Clearly, a transdermal patch system that can be tailored to an individual’s needs will increase patient compliance as well as provide much more efficient …

The Pecos River Hypogene Speleogenetic Province: A Basin-Scale Karst Paradigm For Eastern New Mexico And West Texas, Usa, Kevin W. Stafford, Alexander Klimchouk, Lewis Land, Marcus O. Gary

Faculty Publications

Since the mid-Tertiary, lateral migration and entrenchment of the Pecos River Valley in eastern New Mexico and west Texas, USA, has significantly influenced regional groundwater flow paths, providing a focus for ascending flow in multi-storey artesian systems and a powerful potentiometric driving force for hypogene speleogenesis. Individual occurrences of hypogene karst phenomena associated with the central Pecos River Valley are widespread throughout the greater Delaware Basin region, including development in a wide range of Permian carbonate and evaporate fades. Hypogene occurrences are well-documented as far north as Santa Rosa, New Mexico and as far south as Lake Amistad, Texas. Throughout …

Eogenetic Karst Of The Carbonate Islands Of The Northern Marianas [Abstract], Kevin W. Stafford, John W. Jenson, John E. Mylroie

Faculty Presentations

No abstract provided.

Ascending Water Of The Delaware Basin, Southeastern New Mexico, And Far West Texas [Abstract], Kevin W. Stafford, Raymond Nance

Faculty Presentations

No abstract provided.

Habitat Selection By Anolis Carolinensis (Green Anole) In Open Pine Forests In Eastern Texas, Richard R. Schaefer, Robert R. Fleet, D. Craig Rudolph, Nancy E. Koerth

Faculty Publications

We initiated a mark-recapture study to determine the effects of shrub density on Anolis carolinensis (Green Anole) populations. Green Anole perch site, shrub species, and shrub volume preferences were also examined. We established two study plots of different shrub densities in open pine forests on the Angelina National Forest in eastern Texas. In late spring, the Green Anole population at the higher shrub-density plot was estimated to be 16 times greater than the population at the lower shrub-density plot. Green Anoles most commonly perched on live shrubs, but exhibited very little preference or avoidance of any particular species of live …

Sfa Weather Station-January 2009, Arthur Temple College Of Forestry And Agriculture, Stephen F. Austin State University

Weather Station Data

No abstract provided.

Singlet Oxygen Delivery Through The Porous Cap Of A Hollow-Core Fiber Optic Device, Matibur Zamadar, David Aebisher, Alexander Greer

Faculty Publications

The development of the first photosensitizer/fiber optic device is reported. An oxygen-flowing, fiber-capped configuration is used for the application of heterogeneous, spatially confined singlet oxygen delivery in aqueous media. This is a unique device, unlike other heterogeneous photosensitizers, in which local concentrations of singlet oxygen can be delivered via introduction and withdrawal of the fiber tip.

Joint Computing And Network Resource Scheduling In A Lambda Grid Network, Vaidhehi Lakshmiraman, Byrav Ramamurthy

CSE Conference and Workshop Papers

Data-intensive Grid applications require huge data transfers between grid computing nodes. These computing nodes, where computing jobs are executed, are usually geographically separated. A grid network that employs optical wavelength division multiplexing (WDM) technology and optical switches to interconnect computing resources with dynamically provisioned multi-gigabit rate bandwidth lightpath is called a Lambda Grid network. A computing task may be executed on any one of several computing nodes which possesses the necessary resources. In order to reflect the reality in job scheduling, allocation of network resources for data transfer should be taken into consideration. However, few scheduling methods consider the communication …

Optimal Segment Size For Fixed-Sized Segment Protection In Wavelength-Routed Optical Networks, Raghunath Tewari, Byrav Ramamurthy

CSE Conference and Workshop Papers

Protecting a network against link failures is a major challenge faced by network operators. The protection scheme has to address two important objectives - fast recovery and minimizing the amount of backup resources needed. Every protection algorithm is a tradeoff between these two objectives.

In this paper, we study the problem of segment protection. In particular, we investigate what is the optimal segment size that obtains the best tradeoff between the time taken for recovery and minimizing the bandwidth used by the backup segments. We focus on the uniform fixed-length segment protection method, where each primary path is divided into …

Using Hadoop As A Grid Storage Element, Brian Bockelman

CSE Conference and Workshop Papers

Hadoop is an open-source data processing framework that includes a scalable, fault- tolerant distributed file system, HDFS. Although HDFS was designed to work in conjunction with Hadoop's job scheduler, we have re-purposed it to serve as a grid storage element by adding GridFTP and SRM servers. We have tested the system thoroughly in order to understand its scalability and fault tolerance. The turn-on of the Large Hadron Collider (LHC) in 2009 poses a significant data management and storage challenge; we have been working to introduce HDFS as a solution for data storage for one LHC experiment, the Compact Muon Solenoid …

The Communicator, Volume [5], Issue [1], January 2009

The Communicator: News from the Nebraska Cooperative Fish and Wildlife Research Unit

Faces – New and Old (Cassie Manhart; Peter Spirk; Nate Gosch; Beth Forbus)

Changes (Dustin Martin; Chris Lewis; Thad Miller; Justin Williams)

New Federal Staff (Dr. Joseph (TJ) Fontaine)

Publications

New Research

Angler Behavior in Response to Management

Actions on Nebraska Reservoirs

Missouri River Mitigation: Implementation of

Amphibian Monitoring and Adaptive

Management for Wetland Restoration Evaluation

Current Research

Assessing the Relationship between Stable

Isotopes and Grassland Bird Productivity on

Great Plains National Park Service Properties

Cross-Scale Structure in Ecosystems

Diversity and Ecological Functions

Conferences/Meetings/Workshops

Teaching

Awards & Recognitions

UCARE Project

Graduate Student News (Aaron Alai; Aaron Lotz; Ryan Lueckenhoff; Annabel …