Physical Sciences and Mathematics Commons^™

Suburban Life And The Boundaries Of Nature: Resilience And Rupture In Australian Backyard Gardens, Lesley M. Head, Pat Muir

Faculty of Science - Papers (Archive)

Despite an academic shift from dualistic to hybrid frameworks of culture/nature relations, separationist paradigms of environmental management have great resilience and vernacular appeal. The conditions under which they are reinforced, maintained or ruptured need more detailed attention because of the urgent environmental challenges of a humanly transformed earth. We draw on research in 265 Australian backyard gardens, focusing on two themes where conceptual and material bounding practices intertwine; spatial boundary-making and native plants. We trace the resilience of separationist approaches in the Australian context to the overlay of indigeneity/ non-indigeneity atop other dualisms, and their rupture to situations of close …

On Some Aspects Of The Differential Operator, Panakkal Jesu Mathew

Mathematics Theses

The Differential Operator D is a linear operator from C1[0,1] onto C[0,1]. Its domain C1[0,1] is thoroughly studied as a meager subspace of C[0,1]. This is analogous to the status of the set of all rational numbers Q in the set of the real numbers R. On the polynomial vector space Pn the Differential Operator D is a nilpotent operator. Using the invariant subspace and reducing subspace technique an appropriate basis for the underlying vector space can be found so that the nilpotent operator admits its Jordan Canonical form. The study of D on Pn is completely carried out. Finally, …

Interview With Peter Hayes, Hyla Woods, 2006 (Audio), Peter Hayes

All Sustainability History Project Oral Histories

Interview of Peter Hayes by Glen Esler on July 28th, 2006.

The interview index is available for download.

Uncertainty Principles On Nilpotent Lie Groups., Sanjay Parui Dr.

Doctoral Theses

No abstract provided.

Development Of Dynamically-Generated Pages On A Website, Jodi Wagner

Regis University Student Publications (comprehensive collection)

The purpose of this paper is to examine the project management techniques involved in developing dynamically-generated pages for an existing website. The dynamically-generated pages will allow the editors of a website to add and remove content from pages without directly editing the pages themselves. The project will benefit editors, who will be able to spend more time on creating content for the website, which will lead to benefits for site visitors as well, in the form of uniformly designed pages and more content for the site.

Estimating Relative Abundance Of Young Of Year American Eel, Anguilla Rostrata, In The Virginia Tributaries Of Chesapeake Bay (Spring 2005), Marcel M. Montane, Wendy A. Lowery, Hank Brooks, Aimee D. Halvorson

Reports

The Atlantic States Marine Fisheries Commission (ASMFC) adopted the Interstate Fishery Management Plan (hereafter referred to as FMP) for the American eel in November 1999. The FMP focuses on increasing coastal states’ efforts to collect American eel data through both fishery dependent and fishery independent studies. Consequently, member jurisdictions (including Virginia) agreed to implement an annual survey for YOY American eels. The survey is intended to “…characterize trends in annual recruitment of the YOY eels over time [to produce a] qualitative appraisal of the annual recruitment of American eel to the U.S. Atlantic Coast” (ASMFC, 2000). The development of these …

Photoreductive Dissolution Of Ferrihydrite By Methanesulfinic Acid: Evidence Of A Direct Link Between Dimethylsulfide And Iron-Bioavailability, Anne M. Johansen, Jennifer M. Key

All Faculty Scholarship for the College of the Sciences

Within open‐ocean regions where excess macronutrients are present, phytoplankton growth is limited by the bioavailability of iron supplied to these areas primarily within atmospheric aerosols of crustal origin. However, processes that control the abundance of biologically accessible iron in these aerosols are largely unknown. Here we show that dissolution of ferrihydrite, a surrogate iron(oxy)hydroxide phase found in atmospheric waters, is enhanced in the presence of methanesulfinic acid (MSIA, CH₃SO₂H, a dimethylsulfide (DMS) oxidation intermediate) in laboratory irradiation experiments with aqueous suspensions that simulate marine aerosol particles. The increased release of soluble Fe(II) is attributed to a …

Undulated Cylinders Of Charged Diblock Copolymers, Gregory M. Grason, Christian Santangelo

Christian Santangelo

We study the cylinder to sphere morphological transition of diblock copolymers in aqueous solution with a hydrophobic block and a charged block. We find a metastable undulated cylinder configuration for a range of charge and salt concentrations which, nevertheless, occurs above the threshold where spheres are thermodynamically favorable. By modeling the shape of the cylinder ends, we find that the free-energy barrier for the transition from cylinders to spheres is quite large and that this barrier falls significantly in the limit of high polymer charge and low solution salinity. This suggests that observed undulated cylinder phases are kinetically trapped structures.

Characterization Of Polar Organic Components In Fine Aerosols In The Southeastern United States: Identity, Origin, And Evolution, Song Gao, Jason D. Surratt, Eladio M. Knipping, Eric S. Edgerton, Mona Shahgholi, John H. Seinfeld

Chemistry and Physics Faculty Articles

Filter samples of fine aerosols collected in the Southeastern United States in June 2004 were analyzed for the characterization of polar organic components. Four analytical techniques, liquid chromatography –mass spectrometry, ion trap mass spectrometry, laser desorption ionization mass spectrometry, and high-resolution mass spectrometry, were used for identification and quantification. Forty distinct species were detected, comprising on average 7.2% and 1.1% of the total particulate organic mass at three inland sites and a coastal site, respectively. The relative abundance of these species displays a rather consistent distribution pattern in the inland region, whereas a different pattern is found at the coastal …

Using A General Indexing Paradigm To Monitor Rodent Populations, Richard M. Engeman, Desley Whisson

United States Department of Agriculture Wildlife Services: Staff Publications

Population monitoring is a valuable component to managing invasive rodent populations. Indices can be efficient methods for monitoring rodent populations, as more labor-intensive density estimation procedures often are impractical or invalid to apply. Many monitoring objectives can be couched in an indexing framework. Indexing procedures obtain maximal utility if they exhibit key characteristics, including being practical to apply, being sensitive to population changes or differences in the target species, having an inherent variance formula to estimate precision of index values, and relying on as few assumptions as possible. Here, a general indexing paradigm that promotes the characteristics that make indices …

Thermal Imaging To Recover A Defect In Three Dimensional Objects, Breanne Baker

Mathematical Sciences Technical Reports (MSTR)

This paper focuses on the inverse problem of identifying an internal void in a bounded two- or three-dimensional region. Information, in form of a heat flux and temperature, is assumed to be obtainable only on the external boundary of the region. The reciprocity gap approach with a suitable test functions is used in both the two- and three-dimensional cases.

Improved Three-Step Phase Shifting Profilometry Using Digital Fringe Pattern Projection, Yingsong Hu, Jiangtao Xi, Joe F. Chicharo, Zongkai Yang

Faculty of Informatics - Papers (Archive)

In this paper, an improved method for three-step phase shifting profilometry (PSP) is presented to eliminate the errors introduced by the second order harmonic when digital projection are used to generate fringe patterns. Firstly, the error caused by the second order harmonic is theoretically analyzed. Then based on the error analysis and principle of PSP, we propose a novel approach, called improved threestep phase shifting profilometry (I3PSP), to eliminate the influence of the second order harmonic. Finally, simulations are performed to verify the effectiveness of the proposed I3PSP, which demonstrate that the reconstruction accuracy of using three-step PSP has been …

Low-Voltage Operation Of Metal-Ferroelectric-Insulator-Semiconductor Diodes Incorporating A Ferroelectric Polyvinylidene Fluoride Copolymer Langmuir-Blodgett Film, A. Gerber, Hermann Kohlstedt, M. Fitsilis, R. Waser, T.J. Reese, Stephen Ducharme, E. Rije

Stephen Ducharme Publications

We report the electrical characteristics of metal-ferroelectric-insulator-semiconductor structures, where the ferroelectric layer is a Langmuir-Blodgett film of a copolymer of 70% vinylidene fluoride and 30% trifluoroethylene. The 36-nm thick copolymer films were deposited on thermally oxidized (10 nm SiO₂) p-type silicon and covered with a gold gate electrode. Polarization-field hysteresis loops indicate polarization switching in the polymer film. The device capacitance shows hysteresis when cycling the applied voltage between ±3 V, exhibiting a zero-bias on/off capacitance ratio of over 3:1 and a symmetric memory window 1 V wide, with little evidence of bias that can arise from …

Structure-Activity Studies Of Glycosphingolipids As Antigens Of Natural Killer T Cells, Randal Donald Goff

Theses and Dissertations

Glycosphingolipids (GSLs), composed of a polar saccharide head and a lipophilic ceramide tail, are ubiquitous components of the plasma membrane of eukaryotic cells. They serve in many regulatory capacities and have antigenic properties towards natural killer T (NKT) cells of the innate immune system. Critical to the recognition of glycosylceramides by NKT cells are antigen presenting cells (APC), such as dendritic cells, which are responsible for binding, processing, and delivery of ligands to these lymphocytes. This event is mediated by CD1d, a major histocompatibility complex-like protein expressed on the surface of APCs, which binds GSL antigens by the ceramide moiety …

A Constructive Incremental Learning Algorithm For Binary Classification Tasks, Christophe G. Giraud-Carrier, Tony R. Martinez

Faculty Publications

This paper presents i-AA1*, a constructive, incremental learning algorithm for a special class of weightless, self-organizing networks. In i-AA1*, learning consists of adapting the nodes’ functions and the network’s overall topology as each new training pattern is presented. Provided the training data is consistent, computational complexity is low and prior factual knowledge may be used to “prime” the network and improve its predictive accuracy. Empirical generalization results on both toy problems and more realistic tasks demonstrate promise.

Polyethylene And Polypropylene Nanocomposites Based On Polymerically - Modified Clay Containing Alkylstyrene Units, Jinguo Zhang, Charles A. Wilkie

Chemistry Faculty Research and Publications

Sodium montmorillonite was modified with a new polymeric surfactant. The high molecular weight of the surfactant appears to have led to incomplete cation exchange of the clays, but did promote nanocomposite formation with polyethylene and polypropylene. X-ray diffraction combined with transmission electron microscopy revealed a mixed nanocomposite morphology. The thermal stability of the nanocomposites was evaluated by thermogravimetric analysis, while flammability of the nanocomposites was evaluated by cone calorimetry. A significant 40% reduction in peak heat release rate was observed at 10% organo-clay (3% inorganic clay) loading with an even higher 50% reduction at a loading level of 16% modified …

Two Energy Efficient Algorithms For Tracking Objects In A Sensor Network, Arvind Rapaka, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

We propose two energy efficient algorithms for locating a target object moving in an area covered by a wireless ad hoc network. The first algorithm developed conserve energy by efficiently identifying sensor nodes, as Home Nodes, and use only local messages between neighboring nodes to follow the trail of the object. Since we avoid the long-range transmission and maximize the localization, the algorithms reduce the communication cost. The dynamic nature of the second algorithm exploits the predefined parameters such as the object velocity. Our algorithm represents query shipping against the conventional data shipping as a means to reduce the amount …

Characterization Of The Domain Chaos Convection State By The Largest Lyapunov Exponent, Janet Scheel, A. Jayaraman, H. Greenside, P. Fischer

Janet D. Scheel

Using numerical integrations of the Boussinesq equations in rotating cylindrical domains with realistic boundary conditions, we have computed the value of the largest Lyapunov exponent λ1 for a variety of aspect ratios and driving strengths. We study in particular the domain chaos state, which bifurcates supercritically from the conducting fluid state and involves extended propagating fronts as well as point defects. We compare our results with those from Egolf et al., [Nature 404, 733 (2000)], who suggested that the value of λ1 for the spiral defect chaos state of a convecting fluid was determined primarily by bursts of instability arising …

Spectral Methods Based On Prolate Spheroidal Wave Functions For Hyperbolic Pdes, Qian-Yong Chen, D. Gottlieb, J. S. Hesthaven

Qian-Yong Chen

We examine the merits of using prolate spheroidal wave functions (PSWFs) as basis functions when solving hyperbolic PDEs using pseudospectral methods. The relevant approximation theory is reviewed and some new approximation results in Sobolev spaces are established. An optimal choice of the band-limit parameter for PSWFs is derived for single-mode functions. Our conclusion is that one might gain from using the PSWFs over the traditional Chebyshev or Legendre methods in terms of accuracy and efficiency for marginally resolved broadband solutions.

The Provenance Of Eocene Tuff Beds In The Fossil Butte Member Of The Green River Formation Of Wyoming: Relation To The Absaroka And Challis Volcanic Fields, Matthew R. Chandler

Theses and Dissertations

The Green River Formation was deposited between 53.5 and 48.5 Ma. The Angelo, Fossil Butte, and Lower members of the Green River Formation at Fossil Basin, preserve ash fall tuffs deposited in ancient Fossil Lake. 40Ar/39Ar dating of sanidine yielded eruptive ages of 51.29 ± 1.29 Ma and 52.20 ± 3.08 Ma for two of the tuff beds within Fossil Basin. Immobile element and mineral compositions of Fossil Basin tuffs indicate that most tuffs erupted from a subduction zone originally as rhyolites and dacites. X-ray diffraction analyses reveal that the tuffs' glassy matrices have been altered to illite, calcite, clinoptilolite, …

Transients Of The Electromagnetically-Induced-Transparency-Enhanced Refractive Kerr Nonlinearity: Theory, M. V. Pack, R. M. Camacho, John C. Howell

Mathematics, Physics, and Computer Science Faculty Articles and Research

We present a theory describing the transients and rise times of the refractive Kerr nonlinearity which is enhanced using electromagnetically induced transparency (EIT). We restrict our analysis to the case of a pulsed signal field with continuous-wave EIT fields, and all fields are well below saturation. These restrictions enable the reduction of an EIT Kerr, four-level, density-matrix equation to a two-level Bloch-vector equation which has a simple and physically intuitive algebraic solution. The physically intuitive picture of a two-level Bloch vector provides insights that are easily generalized to more complex and experimentally realistic models. We consider generalization to the cases …

An Informative Bayesian Structural Equation Model To Assess Source-Specific Health Effects Of Air Pollution, Margaret C. Nikolov, Brent A. Coull, Paul J. Catalano, John J. Godleski

Harvard University Biostatistics Working Paper Series

No abstract provided.

Mixed Multiplicative Factor Analysis Model For Air Pollution Exposure Assessment, Margaret C. Nikolov, Brent A. Coull, Paul J. Catalano, John J. Godleski

Harvard University Biostatistics Working Paper Series

No abstract provided.

Survival Analysis Of Longitudinal Microarrays, Natasa Rajicic, Dianne M. Finkelstein, David A. Schoenfeld

COBRA Preprint Series

Motivation: The development of methods for linking gene expressions to various clinical and phenotypic characteristics is an active area of genomic research. Scientists hope that such analysis may, for example, describe relationships between gene function and clinical events such as death or recovery. Methods are available for relating gene expression to measurements that are categorized or continuous, but there is less work in relating expressions to an observed event time such as time to death, response, or relapse. When gene expressions are measured over time, there are methods for differentiating temporal patterns. However, no methods have yet been proposed for …

Vectorization Of Raster Images Using B-Spline Surfaces, Curtis A. Armstrong

Theses and Dissertations

A system has been developed for converting raster images into vector images. Raster images are made of pixels, while vector images are made of smoother shapes. The image is first segmented, and the segments are layered. The boundary of each segment is approximated with a periodic B-Spline curve. This curve is then used to create a B-Spline surface to approximate the interior of the segment. The algorithm fits each B-Spline to the colors of the image using least-squares approximation. The color and shape of each B-Spline surface are extrapolated into regions behind other segments. The result is a vector image …

Results From A Decade Of Black-Tailed Prairie Dog Monitoring, David Peitz, J. Tyler Cribbs

United States National Park Service: Publications

The black-tailed prairie dog (Cynomys ludovicianus), a keystone prairie species, historically occupied over 404,700 ha (100 million ac) of short- and mixed-grass prairie. Today, they occupy less than 2% of their original range. Scotts Bluff National Monument, Nebraska is one of eight National Park Service units with one or more black-tailed prairie dog colonies. Since 1995, a total of 202 observations were made on the population of the main colony at Scotts Bluff National Monument, to estimate annual densities and abundances. Estimated annual densities ranged between 9.2 and 53.0 individuals/ha (2.5 ac). Average density of prairies dogs was …

Quality Control Of Protein Folding In Extracellular Space, J. J. Yerbury, E. M. Stewart, A. R. Wyatt, M. R. Wilson

Faculty of Science - Papers (Archive)

The pathologies of many serious human diseases are thought to develop from the effects of intra- or extracellular aggregates of non-native proteins. Inside cells, chaperone and protease systems regulate protein folding; however, little is known about any corresponding mechanisms that operate extracellularly. The identification of these mechanisms is important for the development of new disease therapies. This review briefly discusses the consequences of protein misfolding, the intracellular mechanisms that control folding and the potential corresponding extracellular control processes. Finally, a new speculative model is described, which proposes that newly discovered extracellular chaperones bind to exposed regions of hydrophobicity on non-native, …

48th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 48th 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 23-27, 2006.

Large Wind Shift On The Great Plains During The Medieval Warm Period, Venkataramana Sridhar, David B. Loope, James B. Swinehart, Joseph A. Mason, Robert J. Oglesby, Clinton M. Rowe

Department of Earth and Atmospheric Sciences: Faculty Publications

Spring-summer winds from the south move moist air from the Gulf of Mexico to the Great Plains. Rainfall in the growing season sustains prairie grasses that keep large dunes in the Nebraska Sand Hills immobile. Longitudinal dunes built during the Medieval Warm Period (800 to 1000 years before the present) record the last major period of sand mobility. These dunes are oriented NW-SE and are composed of cross-strata with bipolar dip directions. The trend and structure of the dunes record a drought that was initiated and sustained by a historically unprecedented shift of spring-summer atmospheric circulation over the Plains: Moist …

Comparison Of Protein Active Site Structures For Functional Annotation Of Proteins And Drug Design, Robert Powers, Jennifer C. Copeland, Katherine Germer, Kelly A. Mercier, Viswanathan Ramanathan, Peter Revesz

Robert Powers Publications

Rapid and accurate functional assignment of novel proteins is increasing in importance, given the completion of numerous genome sequencing projects and the vastly expanding list of unannotated proteins. Traditionally, global primary-sequence and structure comparisons have been used to determine putative function. These approaches, however, do not emphasize similarities in active site configurations that are fundamental to a protein’s activity and highly conserved relative to the global and more variable structural features. The Comparison of Protein Active Site Structures (CPASS) database and software enable the comparison of experimentally identified ligand-binding sites to infer biological function and aid in drug discovery. The …