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

Physical Sciences and Mathematics Commons™

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

Brigham Young University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1531 - 1560 of 3451

Full-Text Articles in Physical Sciences and Mathematics

Follicular Dendritic Cells As Reservoirs Of Diverse Human Immunodeficiency Virus: A Phylogenetic Analysis, Trever Bradley Burgon, Dr. Gregory F. Burton Nov 2013

Follicular Dendritic Cells As Reservoirs Of Diverse Human Immunodeficiency Virus: A Phylogenetic Analysis, Trever Bradley Burgon, Dr. Gregory F. Burton

Journal of Undergraduate Research

Human Immunodeficiency Virus (HIV), the retrovirus that causes Acquired Immunodeficiency Syndrome (AIDS), currently infects over 42 million people; more than three million of them are children under the age of 15. The Joint United Nations Program on HIV/AIDS calls the current AIDS epidemic: “the most devastating disease mankind has ever faced.”

Go to article

Collision Cross Section Measurements In A Fourier Transform Ion Cyclotron Resonance Mass Spectrometer, Daniel E. Austin, Dr. David Dearden Nov 2013

Collision Cross Section Measurements In A Fourier Transform Ion Cyclotron Resonance Mass Spectrometer, Daniel E. Austin, Dr. David Dearden

Journal of Undergraduate Research

I explored the possibility of using spectral linewidths in a Fourier transform ion cyclotron resonance mass spectrometer (FTICR-MS) to measure ion collision cross sections. A measurement of an ion’s collision cross section would provide important information about its conformation, or the spatial arrangement of the atoms and functional groups that make up the ion.

Go to article

The Surface Charging Behavior Of The Gibbsite (001) Surface: An Evaluation Of The Music Model, T. J. Campbell, Dr. Barry Bickmore Nov 2013

The Surface Charging Behavior Of The Gibbsite (001) Surface: An Evaluation Of The Music Model, T. J. Campbell, Dr. Barry Bickmore

Journal of Undergraduate Research

The struggle to find and maintain sources of clean water faces billions of people throughout the world. Increases in groundwater contamination have made this problem even more severe. It is therefore of great importance to understand how contaminants travel and interact in the subsurface. Chemical reactions with the surrounding rock often control the movement of these contaminants. Mineral surfaces can become charged, attracting oppositely charged contaminant particles and slowing their progress. This surface charging is dependent on the reactivity of the individual functional groups on mineral surfaces. Reliable predictions of the reactivity of these groups are necessary to improve the …

Go to article

Gender Differences In Byu Communications Students’ Career Attitudes, Alexis Allen, Dr. Shane Reese Nov 2013

Gender Differences In Byu Communications Students’ Career Attitudes, Alexis Allen, Dr. Shane Reese

Journal of Undergraduate Research

Women have made vast advancements in the workplace within the last thirty years, but gender career issues still exist today. The field of communications presents an interesting case study about discrepancies between male and female employees’ contrasting earnings and career roles. A phenomenon called the Glass Ceiling Effect exists in the public relations field, for example. Essentially, the Glass Ceiling Effect says that although there are more women practitioners in the field, male practitioners attain management positions more frequently and earn higher salaries than their female counterparts.

Go to article

A Comparison Of Computational Efficiency: Cholesky Decomposition And Spectral Methods For The Generation Of Fractional Brownian Motion, Micah S. Allred, Dr. David Clark Nov 2013

A Comparison Of Computational Efficiency: Cholesky Decomposition And Spectral Methods For The Generation Of Fractional Brownian Motion, Micah S. Allred, Dr. David Clark

Journal of Undergraduate Research

Since its popularization by Mandelbrot and Von Ness in the early 60’s, Fractional Brownian Motion (fBm), has found a great many applications in such fields as Option Pricing, Signal Processing, Internet Traffic, Hydrology, and Geology. This process is an extension of Brownian Motion which allows for a process with long memory, that is, the next increment is influenced by the evolution of increments in the past. Contrast this to Brownian Motion which is the continuous time analog to coin flipping. Here, each flip of the coin is completely independent and unaffected by past flips. As many processes exhibit dependent, rather …

Go to article

A Practical Approach To Specific Heat-Phonon Spectrum Inversion, Thomas C. Butler, Dr. William E. Evenson Nov 2013

A Practical Approach To Specific Heat-Phonon Spectrum Inversion, Thomas C. Butler, Dr. William E. Evenson

Journal of Undergraduate Research

Inverse problems have long provided researchers in a variety of disciplines with fruitful and challenging problems with immense applicability. However, as early investigators discovered, most of these problems are ill-posed.1 This means that the existence of the solution is not guaranteed, and even if it does exist, the solution may not be unique. Additionally, the solution may be remarkably sensitive to small perturbations of the input data. This means that small inaccuracies in data can result in unphysical solutions when inversion is carried out. However, regularization methods can often be developed for a class of problems that allow a researcher …

Go to article

Towards Maximization Of Gain In A Capillary Discharge Plasma, Robert Bradford, Dr. Steven Turley Nov 2013

Towards Maximization Of Gain In A Capillary Discharge Plasma, Robert Bradford, Dr. Steven Turley

Journal of Undergraduate Research

Due to the high energy of soft x-ray radiation, coherent x-rays are rather difficult to produce. The most common source of x-rays is bremsstrahlung, or breaking radiation. Brehmsstahlung is produced by accelerating an electron across a potential, and then rapidly decelerating the particle, giving off an x-ray. Although the use of bremsstrahlung is widespread, it is not an adequate xray source for many potential applications because it is broadband in wavelength and incoherent. The shorter wavelength radiation of x-rays could be used to print smaller, more efficient electronic circuits through lithography, or could be used in medical imaging. Hence, the …

Go to article

Determining Ruthenium’S Optical Constants In The Spectral Range 11-14 Nm, Luke J. Bissell, Dr. David Allred Nov 2013

Determining Ruthenium’S Optical Constants In The Spectral Range 11-14 Nm, Luke J. Bissell, Dr. David Allred

Journal of Undergraduate Research

Computers are getting faster, and as they do, computer chips are getting smaller. Photolithography is a process used to design nanoscale patterns on a computer chip. In photolithography, the image of a circuit pattern is transferred from a mask to the semiconductor wafer. This is accomplished by exposing the mask to light and then reflecting the mask’s image through a series of image-reducing multilayer mirrors. These mirrors focus the reduced circuit pattern on to the semiconductor wafer. The wavelength of light incident on the mask determines the size of the resolvable features on the wafer. It has been predicted that …

Go to article

The Physiological Effects Of Music On Children In Health Clinics And Orphanages In Beira, Mozambique And Bapatla, India, Jordan Joseph Ash, Dr. Shane Reece Nov 2013

The Physiological Effects Of Music On Children In Health Clinics And Orphanages In Beira, Mozambique And Bapatla, India, Jordan Joseph Ash, Dr. Shane Reece

Journal of Undergraduate Research

Music therapy seeks to take advantage of specific sounds and rhythms that promote physical, mental, social, emotional, and spiritual well-being. While the physiological benefits of music have long been recognized, there have been few attempts to quantify the results and document their application. This paper seeks to provide numerical evidence of the effects of music on destitute children in third-world settings.

Go to article

Revised Estimates Of World Wide Anemia, Kentron R. Wride, Dr. Gilbert W. Fellingham Oct 2013

Revised Estimates Of World Wide Anemia, Kentron R. Wride, Dr. Gilbert W. Fellingham

Journal of Undergraduate Research

The stated mission of the World Health Organization (WHO) is to improve health around the world. One aspect of this mission involves preparing reliable models to describe patterns of health world wide. WHO has built a summary data file based on nearly 700 published and unpublished reports of anemia rates of women worldwide. Fellingham et. al (1996) prepared a preliminary report of the first model developed from this data as well as the resulting estimates of world wide anemia. The study was based on 448 records from 83 countries. The data included the mean hemoglobin concentration, sample size, a country …

Go to article

Generation And Formal Analysis Of Algorithmic Fractals In Hyperspaces, Minglei Xu, Dr. Robert P. Burton Oct 2013

Generation And Formal Analysis Of Algorithmic Fractals In Hyperspaces, Minglei Xu, Dr. Robert P. Burton

Journal of Undergraduate Research

n-D fractals, where n> 4, have long been under scrutiny for their mathematical properties and artistic values. Multi-dimensional space filling curves, for instance, are a focus for contemporary topologists. Notable works in this area include the uses of quaternions, commutative hyper-complex calculus, and, most recently, doubling processes. However, all these discoveries have been limited to algebraic fractals such as the Mandelbrot set and the Julia sets. Algorithmic fractals are equally interesting since they serve as bridges connecting chaos theory to well studied formal language theory.1 2-D and 3-D algorithmic fractals are conventionally generated and analyzed using L-systems and iterated function …

Go to article

Updating Thompson On Real Property, Thomas Edition, Justin Wright, Dr. David Thomas Oct 2013

Updating Thompson On Real Property, Thomas Edition, Justin Wright, Dr. David Thomas

Journal of Undergraduate Research

Thompson on Real Property, Thomas Edition is a comprehensive commentary on real property law. Each year, Dr. Thomas, Editor-In-Chief, produces a supplement to each volume of the treatise; the supplement updates both text and footnotes to the original volume and to the prior year supplement. During my brief training period, Dr. Thomas demonstrated several legal-research techniques and showed me several software research tools he uses to update the yearly supplement, including Lexis-Nexis, WESTLAW, and InfoTrac. Dr. Thomas assigned me to update chapters 12 and 97.

Go to article

Development Of A New Sugar Receptor, William D. Thomas, Dr. Paul B. Savage Oct 2013

Development Of A New Sugar Receptor, William D. Thomas, Dr. Paul B. Savage

Journal of Undergraduate Research

Oligosaccharides are enormously rich in structural information. They are often branched and can be bonded together by a variety of different linkages, unlike polypeptides which contain identical peptide bonds.1 For this reason, polysaccharides play a crucial role in cell recognition.2 Although carbohydrate recognition is known to take place, the event is not well understood.3 In order to better understand the hydrophobic interactions that enhance binding between sugar based receptors and various small hydrophobic molecules in aqueous solvents, the synthesis of a glucose based cavity was attempted (see Fig. 3). The cavity was carefully designed to maximize hydrophobic interactions with small …

Go to article

A Topics Analysis Model For Health Insurance Claims, Jared Anthony Webb Oct 2013

A Topics Analysis Model For Health Insurance Claims, Jared Anthony Webb

Theses and Dissertations

Mathematical probability has a rich theory and powerful applications. Of particular note is the Markov chain Monte Carlo (MCMC) method for sampling from high dimensional distributions that may not admit a naive analysis. We develop the theory of the MCMC method from first principles and prove its relevance. We also define a Bayesian hierarchical model for generating data. By understanding how data are generated we may infer hidden structure about these models. We use a specific MCMC method called a Gibbs' sampler to discover topic distributions in a hierarchical Bayesian model called Topics Over Time. We propose an innovative use …

Go to article

The Growth Of Single-Walled Carbon Nanotubes On Atomic Force Microscope Tips, Michael Clemens, Dr. Robert Davis Oct 2013

The Growth Of Single-Walled Carbon Nanotubes On Atomic Force Microscope Tips, Michael Clemens, Dr. Robert Davis

Journal of Undergraduate Research

The Atomic Force Microscope (AFM) is a powerful instrument that has many applications in various fields of scientific research. It has the ability to image surfaces without requiring a high vacuum and has the ability to image samples that are in a fluid. It also is able to image surfaces without damaging them, and doesn’t require as much time in sample preparation. It has the resolution capability on the order of tens of nanometers (nm), which is one millionth of a meter. These qualities make the AFM very useful in doing scientific research.

Go to article

Understanding The Absorption Edge Energy Shift Of Thorium Dioxide, Uranium Oxide, And Uranium Nitride In The Euv *Or* Optical Applications Of Uranium Thin-Film Compounds For The Extreme Ultraviolet And Soft X-Ray Region, Richard L. Sandberg, Dr. David D. Allred Oct 2013

Understanding The Absorption Edge Energy Shift Of Thorium Dioxide, Uranium Oxide, And Uranium Nitride In The Euv *Or* Optical Applications Of Uranium Thin-Film Compounds For The Extreme Ultraviolet And Soft X-Ray Region, Richard L. Sandberg, Dr. David D. Allred

Journal of Undergraduate Research

Recently, the extreme ultraviolet (EUV) and soft x-ray region of the electromagnetic spectrum (between about 1 and 100 nm in wavelength or 20 eV to 5 keV photon energy) has become increasingly important in technological applications. The next generation of optical technologies will include EUV astronomy, high resolution soft x-ray microscopy for medical/materials science imaging, and EUV computer lithography. These technologies all require optical devices: mirrors, lenses, and other imaging equipment. The Brigham Young University’s EUV Optics research team has been studying the properties of uranium as an EUV optical material for several years. Here I review the research I …

Go to article

Charactering Titanium Dioxide By Use Of Transmission Electron Microscope, Jason Neff, Dr. Richard Vanfleet Oct 2013

Charactering Titanium Dioxide By Use Of Transmission Electron Microscope, Jason Neff, Dr. Richard Vanfleet

Journal of Undergraduate Research

The original title submitted for my research was “Stacking Faults in GaN”. This study was aimed at employing the use of the Transmission Electron Microscope (TEM) to understand and image defects in the crystal lattice of Gallium Nitride (GaN) that lead to stacking faults. Because of difficulties in the preparation of the material we decided to use the resources and time granted us to work on a project in conjunction with some individuals in the chemistry department. This new project is consistent with the prior investigation, in that the same procedures would be followed, with the same equipment, but with …

Go to article

A Real-Time 3d Engine For Students, Joshua Gustafson, Dr. Robert P. Burton Oct 2013

A Real-Time 3d Engine For Students, Joshua Gustafson, Dr. Robert P. Burton

Journal of Undergraduate Research

A real-time 3D engine is a software system which allows a computer to generate and display three-dimensional graphics at interactive speeds. Faster, more capable, and less expensive video hardware has encouraged improvement in real-time engines and a diversification of their applications. They have been used traditionally in applications such as games and simulators, but increasingly are appearing in other applications such as home modeling, ticket purchasing, and other uses. Real-time 3D engines are therefore an area of understandable interest and considerable value to students of Computer Science.

Go to article

The Role Of Rgs16 In Germinal Center T Cells, Aaron Lewis, Dr. Gregory Burton Oct 2013

The Role Of Rgs16 In Germinal Center T Cells, Aaron Lewis, Dr. Gregory Burton

Journal of Undergraduate Research

RGS16 is an inhibitor of the chemokine receptor, CXCR4, and HIV uses CXCR4 to infect CD4+ T cells. CXCR4 is upregulated in germinal center (GC) T cells even though RGS16 is present in GC T cells

Go to article

Preliminary Paleostress And Deformation Analysis Of The Backlimb Of The Miners Mountain Uplift, Capitol Reef National Park, Utah, Samuel Sorber Oct 2013

Preliminary Paleostress And Deformation Analysis Of The Backlimb Of The Miners Mountain Uplift, Capitol Reef National Park, Utah, Samuel Sorber

Journal of Undergraduate Research

Measurement of fracture sets and small-scale folds along the backlimb of the Miners Mountain uplift in the northern portion of Capitol Reef National Park reveal a paleostress direction of approximately 20° azimuth, nearly 45° counterclockwise from the principle stress observed by Bump and Davis (2003). Slickenlines along the plane of a major fault across the hinge of the Miners Mountain uplift reveal right-lateral oblique-normal movement along the fault. This information has potential significance in modeling basement involvement as well as the kinematic development of this uplift.

Go to article

Synthesis And Characterization Of Novel Amino-Retinoid A4-Spermine, Jeffrey Swallow, Dr. Heidi Vollmer-Snarr Oct 2013

Synthesis And Characterization Of Novel Amino-Retinoid A4-Spermine, Jeffrey Swallow, Dr. Heidi Vollmer-Snarr

Journal of Undergraduate Research

Age Related Macular Degeneration (AMD) is the leading cause of vision loss in developed countries. The accumulation of lipofuscin in the eye causes death of the retinal pigment epithelium (RPE) leading to blindness (1,2). The lipofuscin chemical A2E has been shown to have cytotoxic effect in RPE, yet much of lipofuscin has remained uncharacterized (3). We have shown that other compounds exist in lipofuscin through preliminary mass spectroscopy (MS) and high-pressure liquid chromatography (HPLC) data collected from lipofuscin samples. Our lab is working to first characterize these lipofuscin compounds and then we will also study their oxidative products in order …

Go to article

Production Of A Novel Anti-Tumor Chemotherapy Agent, Jeffrey Stephens, Dr. Merrit Andrus Oct 2013

Production Of A Novel Anti-Tumor Chemotherapy Agent, Jeffrey Stephens, Dr. Merrit Andrus

Journal of Undergraduate Research

Cancer is a condition unlike any other known to man. It is one of the leading causes of death in the United States. In 2000, over 500,000 deaths resulted from various cancers.1 This has led to an extensive search for improved ways to treat cancer, and has left a daunting challenge to develop new ways to treat this condition. The natural product Geldanamycin (GA), the most potent of the benzoquinone absamycin antibiotics, has shown to have great promise as an anti-tumor agent. The analog of Geldanamycin, 17-Allylanino-GA, is currently in clinical trials2, and the first total synthesis of GA was …

Go to article

Retinal-Bio-Amine Synthesis Related To Age-Related Macular Degeneration, Matthew Sparks, Dr. Heidi Vollmer-Snarr Oct 2013

Retinal-Bio-Amine Synthesis Related To Age-Related Macular Degeneration, Matthew Sparks, Dr. Heidi Vollmer-Snarr

Journal of Undergraduate Research

Age-related Macular Degeneration (AMD) is the leading cause for blindness among the world’s elderly population1. As the central region of the retina, known as the macula, is damaged and begins to deteriorate, central vision becomes clouded. This vision loss progresses until the affected person becomes completely and permanently blind. To date, AMD is an incurable disease.

Go to article

Investigate And Study Of The Properties Of 2,2-Dipicolyamine And It Interactions With Anions, Martin Conda Sheridan, Dr. John Lamb Oct 2013

Investigate And Study Of The Properties Of 2,2-Dipicolyamine And It Interactions With Anions, Martin Conda Sheridan, Dr. John Lamb

Journal of Undergraduate Research

Compared to cation ligand interactions, anion ligand studies are less well known. We studied the interactions of protonated cavitands, Fig 1, with anions because of their many applications, including: environmental waste remediation, anion separation, binding constant determination, and molecular structure recognition.

Go to article

Stereo-Selective Photochemical [2+2] Cycloaddition: Π-Π Interactions Or Radical Stabilization, Alexander Parent, Dr. Steven Fleming Oct 2013

Stereo-Selective Photochemical [2+2] Cycloaddition: Π-Π Interactions Or Radical Stabilization, Alexander Parent, Dr. Steven Fleming

Journal of Undergraduate Research

Organic chemistry centers around the stereo- and regioselective formation of C–C bonds. Although [4+2] and [2+2] cycloadditions present the opportunity for single-step creation of multiple stereocenters and two C–C bonds, the products resulting from intermolecular cycloadditions can be hard to predict and yields of any single isomer can be low. These obstacles can be overcome by the use of a removable tether, which induces regio- and stereo-control through the forced intramolecular reaction. The silyl acetal-tethered [2+2] photocycloaddition has been shown to produce high yields of a single product when both of the reacting alkenes contain extended p-systems. This phenomenon is …

Go to article

Cadmium Specific Ion Sensor, David Michaelis, Dr. Paul Savage Oct 2013

Cadmium Specific Ion Sensor, David Michaelis, Dr. Paul Savage

Journal of Undergraduate Research

In recent years it has become critical to detect and monitor concentrations of heavy metal ions in the environment. Cadmium and other heavy metals have detrimental effects to human health. The main difficulty of sensing these ions is selectively detecting the ions in the presence of other naturally present metal ions such as calcium, zinc, and copper. Fluorescent molecular sensors provide an ideal solution to the problem. These organic sensors can be constructed to selectively bind with target metal ions. While many such sensors exist today, little work has been done to incorporate such sensors into portable sensing devices.

Go to article

Isolation, Structure Identification And Cytotoxic Studies Of Biologically Active Compounds In Carica Papaya Of Ghana, Kurtis S. Staples, Dr. Steven G. Wood Oct 2013

Isolation, Structure Identification And Cytotoxic Studies Of Biologically Active Compounds In Carica Papaya Of Ghana, Kurtis S. Staples, Dr. Steven G. Wood

Journal of Undergraduate Research

Carica papaya, commonly known as the papaya plant, is found in large abundance throughout the tropical regions of the planet. The fruit of the plant has been extensively studied with papain, a protease, being the center of research. Preliminary studies showed that compounds found in the leaves of the plant possessed anti-cancer properties. As alternatives for cancer treatment are constantly being sought, plant extracts have risen to the forefront in this hunt.1 An understanding of the structure and mode of activity of the compounds in this plant will further knowledge of how to develop chemotherapeutic agents.

Go to article

Synthesis Of Hiv Integrase Inhibitors, Carl Jones, Dr. Matt A. Peterson Oct 2013

Synthesis Of Hiv Integrase Inhibitors, Carl Jones, Dr. Matt A. Peterson

Journal of Undergraduate Research

We have made significant progress toward the synthesis of one branch of the library of compounds that we plan to synthesize. The scheme we have followed is shown below. Once synthesized, we plan to have the compounds tested by expert collaborators to see how well they bind HTLV integrase. In addition, they will be tested against many viruses and cancers, as well as HIV. Because they are nucleoside based, it is impossible to predict exactly what type of biological activity these compounds will have. They could possibly treat a variety of diseases.

Go to article

Thermodynamics Of Titanium Oxide Nanoparticles, Marcus Donaldson, Dr. Juliana Boerio-Goates Oct 2013

Thermodynamics Of Titanium Oxide Nanoparticles, Marcus Donaldson, Dr. Juliana Boerio-Goates

Journal of Undergraduate Research

I studied the thermodynamics of titanium oxide nanoparticles using adiabatic and semi-adiabatic calorimetry.

Go to article

Preferential Infection Of Germinal Center T Cells By X4 Tropic Hiv, Christopher M. Cherry, Dr. Gregory F. Burton Oct 2013

Preferential Infection Of Germinal Center T Cells By X4 Tropic Hiv, Christopher M. Cherry, Dr. Gregory F. Burton

Journal of Undergraduate Research

HIV infects CD4 T cells through binding to CD4 and an appropriate co-receptor. Two co-receptors of concern in HIV biology are CXCR4 and CCR5 because of their affect on disease progression. The majority of transmittable HIV strains use CCR5 as a co-receptor. However, during the latter stages of disease the virus may shift from using CCR5 to using CXCR4 as its co-receptor. This change is referred to as a shift in tropism, and it is of major concern because it leads to rapid disease progression (3). The site and mechanism by which this shift occurs still elude scientists. Recent findings …

Go to article

First Prev Next Last