Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2007

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 1801 - 1830 of 6758

Full-Text Articles in Physical Sciences and Mathematics

Hunter-Gatherer Use Of Small Animal Food Resources: Coprolite Evidence, Karl J. Reinhard, J. R. Ambler, C. R. Szuter Jul 2007

Hunter-Gatherer Use Of Small Animal Food Resources: Coprolite Evidence, Karl J. Reinhard, J. R. Ambler, C. R. Szuter

School of Natural Resources: Faculty Publications

Faunal remains are commonly found in coprolites and provide direct evidence of animal consumption. An evaluation of hunter-gatherer coprolites from the Southwest United States shows that animal bone in coprolites can be used to assess patterns of hunting, food preparation, and general importance of small animals in diet. This is demonstrated by a comparison of faunal assemblages between two hunter-gatherer sites with respect to small animal hunting strategies. The sites are Dust Devil Cave on the Colorado Plateau, an Archaic winter habitation, and Hinds Cave, a warm season Archaic habitation in the lower Pecos of Texas. The results indicate that …


49th Rocky Mountain Conference On Analytical Chemistry Jul 2007

49th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 49th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-endorsed by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Breckenridge, Colorado, July 22-26, 2007.


Array-Based Sensing Of Proteins Using Conjugated Polymers, Or Miranda, Cc You, R Phillips, Ib Kim, Ps Ghosh, Uhf Bunz, Vm Rotello Jul 2007

Array-Based Sensing Of Proteins Using Conjugated Polymers, Or Miranda, Cc You, R Phillips, Ib Kim, Ps Ghosh, Uhf Bunz, Vm Rotello

Vincent Rotello

A sensor array comprising six functionalized poly(p-phenyleneethynylene) polymers was constructed and used to detect and identify protein analytes. The presence of proteins alters the fluorescence properties of the polymers, generating a distinct fluorescence response pattern for a given protein. Linear discriminant analyses accurately differentiate the patterns of 17 proteins at nano- to micromolar concentrations. An identification accuracy of 97% was obtained on the basis of the tests with 68 unknown protein samples from the training set.


Revisiting He-Like X-Ray Emission-Line Plasma Diagnostics, R. L. Porter, Gary J. Ferland Jul 2007

Revisiting He-Like X-Ray Emission-Line Plasma Diagnostics, R. L. Porter, Gary J. Ferland

Physics and Astronomy Faculty Publications

A complete model of helium-like line and continuum emission has been incorporated into the plasma simulation code Cloudy. All elements between He and Zn are treated, any number of levels can be considered, and radiative and collisional processes are included. This includes photoionization from all levels, line transfer, including continuum pumping and destruction by background opacities, scattering, and collisional processes. The model is calculated self-consistently along with the ionization and thermal structure of the surrounding nebula. The result is a complete line and continuum spectrum of the plasma. Here we focus on the ions of the He I sequence and …


Methyl Esterification Of Fatty Acids And Eicosanoids With A Novel Reagent Trimethylsilyldiazomethane For Analysis By Gas Chromatography-Mass Spectrometry, Aditi Munmun Sengupta Jul 2007

Methyl Esterification Of Fatty Acids And Eicosanoids With A Novel Reagent Trimethylsilyldiazomethane For Analysis By Gas Chromatography-Mass Spectrometry, Aditi Munmun Sengupta

Master's Theses and Doctoral Dissertations

Fatty acids are compounds with limited water solubility that belong to the lipid class of bio-organic compounds and can be utilized as a source of energy by the body or as precursors to oxidized compounds that have roles in inflammation and in the regulation of vascular tone. The prostaglandins are naturally occurring 20-carbon cyclopentano fatty acid derivatives produced in mammalian tissue from polyunsaturated fatty acids (PUFAs) and are generated from endoperoxide precursors of arachidonic acid and related polyunsaturated fatty acids by the enzyme cyclo-oxygenase (COX). The lipoxygenase (LOX) enzymes convert arachidonic acid into hydroperoxy derivatives of PUFAs termed leukotrienes, which …


Cost/Effectiveness Analysis Of Obtaining Operational Estimates Of Reference Evapotranspiration, Peninsular Florida, Usa, Michael G. Kittridge Jul 2007

Cost/Effectiveness Analysis Of Obtaining Operational Estimates Of Reference Evapotranspiration, Peninsular Florida, Usa, Michael G. Kittridge

USF Tampa Graduate Theses and Dissertations

The objective of this study is to conduct a cost/effectiveness analysis of the computation of reference evapotranspiration (ETo) in the peninsular of Florida. A meteorological station on the Fort Meade Mine in Polk County, Florida was used to provide data for the calculation of ETo. Five ETo equations were tested to determine the accuracy and cost/effectiveness to the fully measured ASCE Penman-Monteith (Full ASCE-PM) equation on daily, monthly, and annually time steps. The ETo equations ranged in amounts of parameters from the Full ASCE-PM to the Hargreaves. The energy terms accounted for approximately 90% of the total ETo flux. Solar …


On The Age And Metallicity Estimation Of Spiral Galaxies Using Optical And Near-Infrared Photometry, Hyun Chul Lee, Guy Worthey, Scott C. Trager, S. M. Faber Jul 2007

On The Age And Metallicity Estimation Of Spiral Galaxies Using Optical And Near-Infrared Photometry, Hyun Chul Lee, Guy Worthey, Scott C. Trager, S. M. Faber

Physics and Astronomy Faculty Publications and Presentations

In integrated light, some color-color diagrams that use optical and near-infrared photometry show surprisingly orthogonal grids as age and metallicity are varied, and they are coming into common usage for estimating the average age and metallicity of spiral galaxies. In this paper we reconstruct these composite grids using simple stellar population models from several different groups convolved with some plausible functional forms of star formation histories at fixed metallicity. We find that the youngest populations present (t < 2 Gyr) dominate the light, and because of their presence the age-metallicity degeneracy can be partially broken with broadband colors, unlike older populations. The scatter among simple stellar population models by different authors is, however, large at ages t < 2 Gyr. The dominant uncertainties in stellar population models arise from convective core overshoot assumptions and the treatment of the thermally pulsing asymptotic giant branch phase and helium abundance may play a significant role at higher metallicities. Real spiral galaxies are unlikely to have smooth, exponential star formation histories, and burstiness will cause a partial reversion to the single-burst case, which has even larger model-to-model scatter. Finally, it is emphasized that the current composite stellar population models need some implementation of chemical enrichment histories for the proper analysis of the observational data. © 2007. The American Astronomical Society. All rights reserved.


Physical And Oxidative Removal Of Organics During Fenton Treatment Of Mature Municipal Landfill Leachate, Yang Deng Jul 2007

Physical And Oxidative Removal Of Organics During Fenton Treatment Of Mature Municipal Landfill Leachate, Yang Deng

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Municipal landfill leachate, especially mature leachate, may disrupt the performance of moderately-sized municipal activated sludge wastewater treatment plants, and likewise tend to be recalcitrant to biological pretreatment. Recently, Fenton methods have been investigated for chemical treatment or pre-treatment of mature leachate. In this paper, the results of laboratory tests to determine the roles of oxidation and coagulation in reducing the organic content of mature leachate during Fenton treatment are presented. The efficiencies of chemical oxygen demand (COD) oxidation and coagulation were tested, and the ratio of COD removal by oxidation to that by coagulation was assessed, under various operating conditions. …


On Stability And Evolution Of Solutions In General Relativity, Stephen M. Taylor Jul 2007

On Stability And Evolution Of Solutions In General Relativity, Stephen M. Taylor

Theses and Dissertations

This thesis is concerned with several problems in general relativity and low energy string theory that are pertinent to the time evolution of the gravitational field. We present a formulation of the Einstein field equations in terms of variational techniques borrowed from geometric analysis. These equations yield the evolution equations for the Cauchy problems of both general relativity and low energy string theory. We then proceed to investigate the evolutionary linear stability of Schwarzschild-like solutions in higher dimensional relativity called black strings. These objects are determined to be linearly unstable. This motivates a further stability analysis of the charged p-brane …


Demographics Of Black Vultures In North Carolina, Bradley F. Blackwell, Michael L. Avery, Bryan D. Watts, Martin S. Lowney Jul 2007

Demographics Of Black Vultures In North Carolina, Bradley F. Blackwell, Michael L. Avery, Bryan D. Watts, Martin S. Lowney

United States Department of Agriculture Wildlife Services: Staff Publications

Understanding the contributions of vital rates to species population growth is critical to developing new management protocols. We constructed a model population for black vultures (Coragyps atratus) in North Carolina, USA, based on demographic data from a 14-year study. The model population was similar in stage structure to the reference population, and adult survival was the primary contributor to the annual rate of increase (10.6%). We suggest that the North Carolina black vulture population is experiencing high rates of survival and fertility, potentially breeding at an age younger than previously assumed, and growing rapidly.


Development Of Informative Priors In Microarray Studies, Kassandra M. Fronczyk Jul 2007

Development Of Informative Priors In Microarray Studies, Kassandra M. Fronczyk

Theses and Dissertations

Microarrays measure the abundance of DNA transcripts for thousands of gene sequences, simultaneously facilitating genomic comparisons across tissue types or disease status. These experiments are used to understand fundamental aspects of growth and development and to explore the underlying genetic causes of many diseases. The data from most microarray studies are found in open-access online databases. Bayesian models are ideal for the analysis of microarray data because of their ability to integrate prior information; however, most current Bayesian analyses use empirical or flat priors. We present a Perl script to build an informative prior by mining online databases for similar …


Biosedimentology Of Thermal Features In The Uzon Caldera, Kamchatka, Russia : Implications For Biosignature Formation, Jessica Christine Goin Jul 2007

Biosedimentology Of Thermal Features In The Uzon Caldera, Kamchatka, Russia : Implications For Biosignature Formation, Jessica Christine Goin

Dissertations and Theses

Modern hot springs serve as a habitat for microorganisms similar in metabolism, morphology, and cellular structure to the microbes that existed relatively early in Earth history. To maximize our ability to interpret evidence for these microorganisms and their communities in the rock record, we need to understand how their biosignatures form and become preserved.

This biosedimentological study of four thermal features in the Uzon Caldera (K4 Well, Ochki Pool, Thermophile Spring, and Zavarzin Pool) focused on identifying how chemical, physical and biological inputs contribute to the characteristics of sinter biofabrics. The biofabrics of K4 Well outflow channel were studied in …


The Future Of Unl Energy Sciences Jul 2007

The Future Of Unl Energy Sciences

Nebraska Center for Energy Sciences Research: White Papers and Presentations

UNL has a large number of faculty conducting research on energy-related topics. However, strategic coordination needs improvement, and there are significant opportunities to leverage synergies across departments and colleges, centers, and institutes. In addition, there are critical gaps in expertise that need filling to achieve critical mass and national prominence in key areas.

This white paper seeks to identify a set of thematic areas that would help focus UNL faculty resources on emerging opportunities in the energy-related sciences and serve as a framework to achieve the following goals:

♦ Develop innovative research programs that enhance renewable energy resources and energy …


Quantum Analysis Of A Linear Dc Squid Mechanical Displacement Detector, M. P. Blencowe, E. Buks Jul 2007

Quantum Analysis Of A Linear Dc Squid Mechanical Displacement Detector, M. P. Blencowe, E. Buks

Dartmouth Scholarship

We provide a quantum analysis of a dc SQUID mechanical displacement detector within the subcritical Josephson current regime. A segment of the SQUID loop forms the mechanical resonator and motion of the latter is transduced inductively through changes in the flux threading the loop. Expressions are derived for the detector signal response and noise, which are used to evaluate the position and force detection sensitivity. We also investigate cooling of the mechanical resonator due to detector back reaction.


Seismic And Well Log Attribute Analysis Of The Jurassic Entrada/Curtis Interval Within The North Hill Creek 3d Seismic Survey, Uinta Basin, Utah, A Case History, Ryan J. Oneal Jul 2007

Seismic And Well Log Attribute Analysis Of The Jurassic Entrada/Curtis Interval Within The North Hill Creek 3d Seismic Survey, Uinta Basin, Utah, A Case History, Ryan J. Oneal

Theses and Dissertations

3D seismic attribute analysis of the Jurassic Entrada/Curtis interval within the North Hill Creek (NHC) survey has been useful in delineating reservoir quality eolian-influenced dune complexes. Amplitude, average reflection strength and spectral decomposition appear to be most useful in locating reservoir quality dune complexes, outlining their geometry and possibly displaying lateral changes in thickness. Cross sectional views displaying toplap features likely indicate an unconformity between Entrada clinoforms below and Curtis planar beds above. This relationship may aid the explorationist in discovering this important seismic interval. Seismic and well log attribute values were cross plotted and have revealed associations between these …


Development Of Chemomechanical Functionalization And Nanografting On Silicon Surfaces, Michael Vernon Lee Jul 2007

Development Of Chemomechanical Functionalization And Nanografting On Silicon Surfaces, Michael Vernon Lee

Theses and Dissertations

Progress in chemomechanical functionalization was made by investigating the binding of molecules and surface coverage on the silicon surface, demonstrating functionalization of silicon with gases by chemomechanical means, analyzing atomic force microscopy probe tip wear in atomic force microscopy (AFM) chemomechanical nanografting, combining chemomechanical functionalization and nanografting to pattern silicon with an atomic force microscope, and extending chemomechanical nanografting to silicon dioxide. Molecular mechanics of alkenes and alkynes bound to Si(001)-2x1 as a model of chemomechanically functionalized surfaces indicated that complete coverage is energetically favorable and becomes more favorable for longer chain species. Scribing a silicon surface in the presence …


Topoisomerase Ii-Drug Interaction Domains: Identification Of Substituents On Etoposide That Interact With The Enzyme, Amy M. Wilstermann, Ryan P. Bender, Murrell Godfrey, Sungjo Choi, Clemens Anklin, David B. Berkowitz, Neil Osheroff, David E. Graves Jul 2007

Topoisomerase Ii-Drug Interaction Domains: Identification Of Substituents On Etoposide That Interact With The Enzyme, Amy M. Wilstermann, Ryan P. Bender, Murrell Godfrey, Sungjo Choi, Clemens Anklin, David B. Berkowitz, Neil Osheroff, David E. Graves

David Berkowitz Publications

Etoposide is one of the most successful chemotherapeutic agents used for the treatment of human cancers. The drug kills cells by inhibiting the ability of topoisomerase II to ligate nucleic acids that it cleaves during the double-stranded DNA passage reaction. Etoposide is composed of a polycyclic ring system (rings A–D), a glycosidic moiety at the C4 position, and a pendant ring (E–ring) at the C1 position. Although drug-enzyme contacts, as opposed to drug-DNA interactions, mediate the entry of etoposide into the topoisomerase II-drug-DNA complex, the substituents on etoposide that interact with the enzyme have not been identified. Therefore, saturation transfer …


Transmission Dynamics Of Avian Influenza Among Poultry With And Without Vaccination, Qiao Liang Jul 2007

Transmission Dynamics Of Avian Influenza Among Poultry With And Without Vaccination, Qiao Liang

Mathematics & Statistics ETDs

The continuing avian influenza (AI) out break that began in late 2003 and early 2004 has been disastrous for the poultry industry worldwide. It has resulted in severe socio-economic damage, and it has raised serious concerns for general public health. In this research, we use mathematics to analyze transmission dynamics of AI among poultry. We use a status-based approach to construct systems of differential equations to describe virus transmission dynamics. We develop theoretical means to eradicate the spread of the disease, and we calculate the size of healthy and infected populations during an AI outbreak, and the final population size …


Assessment Of Sample Size And Power For The Analysis Of Clustered Matched-Pair Data, William F. Mccarthy Jul 2007

Assessment Of Sample Size And Power For The Analysis Of Clustered Matched-Pair Data, William F. Mccarthy

COBRA Preprint Series

This paper outlines how one can determined the sample size or power of a study design that is based on clustered matched-pair data. Detailed examples are provided.


Adjustment To The Mcnemar’S Test For The Analysis Of Clustered Matched-Pair Data, William F. Mccarthy Jul 2007

Adjustment To The Mcnemar’S Test For The Analysis Of Clustered Matched-Pair Data, William F. Mccarthy

COBRA Preprint Series

This paper presents how one can adjust the McNemar’s test for the analysis of clustered matched-pair data. A McNemar’s-like table for K clusters of matched-pair data is used.


Flicker Propagation In Interconnected Power Systems, S. Tennakoon, S. Perera, Danny Sutanto Jul 2007

Flicker Propagation In Interconnected Power Systems, S. Tennakoon, S. Perera, Danny Sutanto

Faculty of Informatics - Papers (Archive)

Voltage fluctuations leading to lamp flicker can propagate from the point of origin to various parts of the power system with some attenuation depending on the system impedances and load composition. Field measurements and theoretical studies suggest that the industrial loads containing large proportions of induction motors assist in attenuating flicker compared to residential loads consisting ofpassive devices. This paper describes a frequency domain approach which can be used to determine the propagation ofvoltagefluctuations when there are induction motor loads in the vicinity of the disturbing load. The method involves linearization of the network in d-q domain to evaluate various …


Aspects And Exception Handling: The Case Of Explicit Join Points, Kevin Hoffman, Patrick Eugster Jul 2007

Aspects And Exception Handling: The Case Of Explicit Join Points, Kevin Hoffman, Patrick Eugster

Department of Computer Science Technical Reports

No abstract provided.


Scalable Data Collection In Dense Wireless Sensor Networks, Asad Awan, Suresh Jagannathan, Ananth Y. Grama Jul 2007

Scalable Data Collection In Dense Wireless Sensor Networks, Asad Awan, Suresh Jagannathan, Ananth Y. Grama

Department of Computer Science Technical Reports

No abstract provided.


Memoizing Communication, Lukasz Ziarek, Jeremy Orlow, Suresh Jagannathan Jul 2007

Memoizing Communication, Lukasz Ziarek, Jeremy Orlow, Suresh Jagannathan

Department of Computer Science Technical Reports

No abstract provided.


Analysis Of Network Asymmetry Of Interconnected 66kv Sub-Transmission Systems In Relation To Voltage Unbalance, Prabodha Paranavithana, S. Perera, Danny Sutanto Jul 2007

Analysis Of Network Asymmetry Of Interconnected 66kv Sub-Transmission Systems In Relation To Voltage Unbalance, Prabodha Paranavithana, S. Perera, Danny Sutanto

Faculty of Informatics - Papers (Archive)

The levels of voltage unbalance that exist in some interconnected sub-transmission networks in Australia has been observed to be above the code requirements (e.g. 1% in Victoria). There is a perception that these high levels arise as a result of asymmetrical loads. However, it is identified that the network asymmetry in relation to transmission lines also play a significant role in the lead up to this situation, employing an interconnected 66kV sub-transmission system as the study case. The individual transmission lines of the study network are analysed in order to observe their possible influence arising as a result of line …


The Existence Of Maximum Likelihood Estimates For The Binary Response Logistic Regression Model, William F. Mccarthy Jul 2007

The Existence Of Maximum Likelihood Estimates For The Binary Response Logistic Regression Model, William F. Mccarthy

COBRA Preprint Series

The existence of maximum likelihood estimates for the binary response logistic regression model depends on the configuration of the data points in your data set. There are three mutually exclusive and exhaustive categories for the configuration of data points in a data set: Complete Separation, Quasi-Complete Separation, and Overlap. For this paper, a binary response logistic regression model is considered. A 2 x 2 tabular presentation of the data set to be modeled is provided for each of the three categories mentioned above. In addition, the paper will present an example of a data set whose data points have a …


Lachenbruch’S Method For Determining The Sample Size Required For Testing Interactions: How It Compares To Nquery Advisor And O’Brien’S Sas Unifypow., William F. Mccarthy Jul 2007

Lachenbruch’S Method For Determining The Sample Size Required For Testing Interactions: How It Compares To Nquery Advisor And O’Brien’S Sas Unifypow., William F. Mccarthy

COBRA Preprint Series

Lachenbruch (1988) proposed a simple method based on the use of orthogonal contrasts to determine the sample size or power for testing main effects and interactions, and uses the normal distribution instead of the non-central F distribution. This method can be used for factorial designs of various size. The example illustrated in this paper considers a 2 x 2 factorial design. This paper will determine both sample size and power of a particular study design with anticipated (assumed) means for each cell of the 2 x 2 factorial design. Lachenbruch’s method will be compared to nQuery Advisor 6.0 (2005) and …


The Minimum Rank Problem Over Finite Fields, Jason Nicholas Grout Jul 2007

The Minimum Rank Problem Over Finite Fields, Jason Nicholas Grout

Theses and Dissertations

We have two main results. Our first main result is a sharp bound for the number of vertices in a minimal forbidden subgraph for the graphs having minimum rank at most 3 over the finite field of order 2. We also list all 62 such minimal forbidden subgraphs and show that many of these are minimal forbidden subgraphs for any field. Our second main result is a structural characterization of all graphs having minimum rank at most k for any k over any finite field. This characterization leads to a very strong connection to projective geometry and we apply projective …


Microfacies Analysis, Sedimentary Petrology, And Reservoir Characterization Of The Sinbad Limestone Based Upon Surface Exposures In The San Rafael Swell, Utah, Caleb R. Osborn Jul 2007

Microfacies Analysis, Sedimentary Petrology, And Reservoir Characterization Of The Sinbad Limestone Based Upon Surface Exposures In The San Rafael Swell, Utah, Caleb R. Osborn

Theses and Dissertations

The Lower Triassic Sinbad Limestone Member of the Moenkopi Formation has produced minor amounts of oil in the Grassy Trail Creek field near Green River, Utah and is present below much of central Utah including the recently discovered Covenant field. Superb outcrops of this thin (15 m), mixed carbonate-silicilastic unit in the San Rafael Swell permit detailed analysis of its vertical and lateral reservoir heterogeneity. Vertically, the Sinbad Limestone comprises three facies associations: (A) a basal storm-dominated, well-circulated skeletal-oolitic-peloidal limestone association, (B) a storm-dominated, poorly-circulated hummocky cross-stratified siliciclastic/peloidal association, and (C) a capping peritidal cross-bedded oolitic dolograinstone association. Eleven microfacies …


Synthesis Of Resveratrol And Its Analogs, Phase-Transfer Catalyzed Asymmetric Glycolate Aldol Reaction, And Total Synthesis Of 8,9-Methylamido-Geldanamycin, Jing Liu Jul 2007

Synthesis Of Resveratrol And Its Analogs, Phase-Transfer Catalyzed Asymmetric Glycolate Aldol Reaction, And Total Synthesis Of 8,9-Methylamido-Geldanamycin, Jing Liu

Theses and Dissertations

The phytoalexin resveratrol and its acetyl analogs have been made using a decarbonylative Heck reaction. The acid chloride derived from 3,5-dihydroxybenzoic acid was coupled with suitable protected 4-hydroxystyrene in the presence of palladium acetate and N,N-bis-(2,6-diisopropylphenyl)-4,5-dihydro imidazolium chloride to give the substituted stilbene in good yield as the key step. Human HL-60 cell assays showed the 4'-acetyl resveratrol variant improved activity (ED50 17 μM) relative to resveratrol (24 μM). Cinchona phase-transfer catalysts (PTC) were developed for glycolate aldol reactions to give differentially protected 1,2-diol products. Silyl enol ether of diphenylmethoxy-2,5-dimethoxyacetophenone reacted to generate benzhydryl-protected products. O-Allyl trifluorobenzyl cinchonium hydrodifluoride (20 …