Copyright (c) 2013 Utah State University All rights reserved. http://digitalcommons.usu.edu/undergrad_research Recent documents in Browse All Undergraduate research en-us Sat, 04 May 2013 01:48:16 PDT 3600 http://digitalcommons.usu.edu/undergrad_research/27 http://digitalcommons.usu.edu/undergrad_research/27 Thu, 02 May 2013 09:00:06 PDT The EVE instrument of the NASA Solar Dynamics Observatory (SDO) provides for the first time EUV and XUV measurements of the solar irradiance that adequately define the major source of ionization of the atmosphere. In our study we modeled the E-region of the ionosphere and analyzed how it is affected by the solar irradiance data obtained by EVE and contrast this with the S2000 Solar Irradiance model, used previously. The ionosphere has two major layers, the E-layer at 100 km, and the F-layer at 300 km. The difference in solar irradiances are small except at some wavelength bands, it is these differences that lead to a better understanding of the physical/chemical processes of the E-region. Observations of the ionospheric layers is best achieved using incoherent scatter radars (ISR). We have compared our model with ISR data available from Arecibo Puerto Rico in an effort to understand how specific solar irradiance wavelength bands affect the E-region. This study focuses on two specific wavelength bands 0.1-15 nm and 91-103 nm. Both are responsible for E-region production, but in quite different manners.

]]> Joseph B. Jensen et al. http://digitalcommons.usu.edu/undergrad_research/26 http://digitalcommons.usu.edu/undergrad_research/26 Wed, 01 May 2013 09:40:55 PDT With LIGO coming back online soon, astronomers are attempting to solve the problems involved with coupling gravitational observations with electromagnetic telescope observations. To do this, my project aims to create all-sky surveys to characterize natural variability to reduce "false-alarm" rates in detections of gravitational emissions.

]]> Rachel K. Nydegger et al. Presentations http://digitalcommons.usu.edu/undergrad_research/23 http://digitalcommons.usu.edu/undergrad_research/23 Wed, 24 Apr 2013 14:01:37 PDT 日本の科学は第二次世界大戦から始まったと多くの人は思っている。もちろん、多くの発展は戦後に行われたのは事実。しかし、戦争以前にも「テクノロジージャパン」な考え方が非常に寿実していた。このスライドショーは日本科学発展の原因となることをいくつか見ています。

]]> Mario Harper http://digitalcommons.usu.edu/undergrad_research/20 http://digitalcommons.usu.edu/undergrad_research/20 Mon, 25 Feb 2013 08:05:58 PST Fire blight caused by the bacterium Erwinia amylovora results in millions of dollar in losses worldwide. It is the most important disease problem for apple and pear growers in Utah. Currently the only effective management strategy is application of the antibiotic streptomycin. In 2006, resistant isolates were detected in an apple orchard in Utah County. To determine the distribution of resistant isolates, samples collected in 2006, 2007, 2010 and 2011 from orchards across Utah were tested for resistance to streptomycin. Isolates were screened at 0, 100 and 1000ppm of streptomycin. Bacteria were spread on LB agar. A hole was punched from the agar and the streptomycin solution was pipetted into the well. After 24 hours a bacteria-free zone around the well was observed for sensitive isolates but not for resistant isolates. The majority of resistant isolates were found in Utah County where most orchards are located. The resistance in most Utah isolates is caused by a mutation in the rpsL gene but at least one isolate acquired a plasmid containing streptomycin resistance genes.

]]> Christine Dhiman http://digitalcommons.usu.edu/undergrad_research/19 http://digitalcommons.usu.edu/undergrad_research/19 Mon, 25 Feb 2013 08:05:52 PST In 2002, the Sounding of the Atmosphere us- ing Broadband Emission Radiometry (SABER) instru- ment aboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite went online and has since been providing radiometric data concern- ing the mesosphere and lower thermosphere/ionosphere (MLTI) region of the atmosphere. Researchers at the Utah State University NASA Space Grant Consortium have been tasked with validating measurements of the hydroxyl airglow volume emission rates (VER) taken by SABER. To this end, we compare SABER measurements of the altitude distribution of hydroxyl airglow to mea- surements taken by photometers aboard rockets launched between 1961 and 1986 that were catalogued in 1988 by Baker and Stair [1]. We select for comparison SABER scans taken near these launch sites at the same time of year, and at similar solar zenith angles. We then plot the selected SABER altitude profiles alongside renormalized rocket photometer profiles. Important considerations for comparison are the mean thickness of emission layers, the mean altitude of their centers, and relative numbers of bifurcated airglow emission layers, which manifest as altitude profiles with two or more peaks.

]]> Jordan Rozum et al. http://digitalcommons.usu.edu/undergrad_research/22 http://digitalcommons.usu.edu/undergrad_research/22 Mon, 25 Feb 2013 08:04:03 PST A basic overview of the juggling notation known as "Siteswap". This is a way of describing juggling patterns using sequences of numbers.

]]> David Tate http://digitalcommons.usu.edu/undergrad_research/21 http://digitalcommons.usu.edu/undergrad_research/21 Mon, 25 Feb 2013 08:04:01 PST A set of nonzero entries of a (0,1)-matrix is an isolated set if no two entries belong to the same row, no two entries belong to the same column, and no two entries belong to a submatrix of the form [1 1; 1 1]. The isolation number of a matrix is the maximum size over all isolated sets. The isolation number of a matrix is a well-known and well-used lower bound for the matrix's Boolean rank. We will discuss the isolation number of the adjacency matrix of various graphs and develop some extremal results for n x n matrices with isolation number n.

]]> David Tate et al. http://digitalcommons.usu.edu/undergrad_research/18 http://digitalcommons.usu.edu/undergrad_research/18 Mon, 11 Feb 2013 12:55:07 PST Jordan Rozum et al. http://digitalcommons.usu.edu/undergrad_research/17 http://digitalcommons.usu.edu/undergrad_research/17 Mon, 11 Feb 2013 12:55:05 PST The distribution of spiral and bar galaxy inclination an- gles is expected to be uniform. However, analysis of sev- eral major galaxy catalogs shows this is not the case; galaxies oriented near edge-on are significantly more common in these catalogs. In an attempt to explain this discrepancy, we have developed a galaxy simulation code to compute the appearance of a spiral type galaxy as a function of its morphological parameters. We examine the dependence of observed brightness upon inclination angle by using smooth luminous mass density and in- terstellar medium (ISM) density distributions. The lu- minous mass component is integrated along a particular line of sight, thus producing a mass distribution, from which a surface luminosity profile is derived. The ISM component is integrated alongside the luminous mass component to account for light extinction. If the de- pendence of the total surface brightness on inclination strongly corresponds to the observed distribution of incli- nation angles, we can attribute much of the discrepancy to a geometrical selection effect.

]]> Jordan Rozum et al. http://digitalcommons.usu.edu/undergrad_research/16 http://digitalcommons.usu.edu/undergrad_research/16 Mon, 11 Feb 2013 10:59:37 PST Jordan Rozum et al. http://digitalcommons.usu.edu/undergrad_research/15 http://digitalcommons.usu.edu/undergrad_research/15 Tue, 22 Jan 2013 15:26:03 PST Multi-messenger astronomy employs both electromagnetic and gravitational wave detectors to paint a richer picture of celestial objects, providing more depth and in formation. Localizing sources with gravitational wave interferometers on the sky is difficult, with resolution of many square degrees. To have simultaneous electromagnetic observations (localized typically to less than one square degree) requires innovative techniques for the telescopes to find the origin of radiation. One idea is to tile the view of the interferometer, using multiple telescopes to simultaneously point at different areas of the field to observe the source. One problematic aspect of this observing paradigm is distinguishing random electromagnetic variable sources from a gravitational-wave counterpart. To better understand this problem, this project repeatedly observes a single field on the sky. Each observation is analyzed to count the number of sources that appear in the field as a function of brightness. Repeating this process over time will yield the frequency of random optical transients, as well as characterize the population and brightness distribution of variables in the field. Future work will extend this observation campaign to cover different galactic latitudes.

]]> Rachel Nydegger et al. http://digitalcommons.usu.edu/undergrad_research/14 http://digitalcommons.usu.edu/undergrad_research/14 Thu, 06 Dec 2012 13:46:45 PST Kristina Sorensen et al. http://digitalcommons.usu.edu/undergrad_research/13 http://digitalcommons.usu.edu/undergrad_research/13 Thu, 06 Dec 2012 13:46:42 PST Kristina Sorensen et al. http://digitalcommons.usu.edu/undergrad_research/12 http://digitalcommons.usu.edu/undergrad_research/12 Thu, 06 Dec 2012 13:46:29 PST Kristina Sorensen et al. http://digitalcommons.usu.edu/undergrad_research/11 http://digitalcommons.usu.edu/undergrad_research/11 Tue, 13 Sep 2011 14:32:50 PDT Utah State University’s Get Away Special (GAS) team will conduct research aboard NASA's microgravity research aircraft, the “vomit comet,” through the Reduced Gravity Student Flight Opportunities program. Team members come from mechanical and aerospace engineering, computer science, physics, science education, and business backgrounds. The team will spend ten days this summer at NASA’s Johnson Space Center and perform experiments on the aircraft to better understand nucleate boiling, a potential method of efficient heat transfer in space.

]]> Stephanie Peterson et al. http://digitalcommons.usu.edu/undergrad_research/10 http://digitalcommons.usu.edu/undergrad_research/10 Fri, 09 Jul 2010 09:15:12 PDT Influenza viruses are classified based on their surface glycoproteins: hemagglutinin and neuraminidase. Hemagglutinin (HA) is responsible for binding to the host cell, while neuraminidase (NA) facilitates escape of newly formed virus particles. These studies determined the NA activity of three subtypes of influenza A virus that differ in their ability to cause disease in mice: influenza A/NWS/33 (H1N1), influenza A/Victoria/3/75 (H3N2), and influenza A/Duck/MN/1525/81 (H5N1). Chemiluminescent quantitation of NA activity in equal amounts of each virus was determined in three replicate experiments. Results indicate that N1 virus subtypes have higher NA activity than do N2 subtypes. In addition, the NA activity of each virus was tested in the presence of the NA inhibitor oseltamivir. Effective antiviral concentrations of oseltamivir for each virus were EC50 = 0.51, 0.19, and 0.70 nM for NWS, Victoria, and Duck viruses, respectively. These results do not support the hypothesis that NA activity alone determines the ability of the virus to cause disease. However, these data do suggest a correlation between NA activity and virus resistance to oseltamivir.

]]> Benjamin Hanks Brown et al. http://digitalcommons.usu.edu/undergrad_research/9 http://digitalcommons.usu.edu/undergrad_research/9 Mon, 10 May 2010 15:02:39 PDT Biofuels from algae are a promising source of alternative energy. One algae species, Neochloris oleoabundans, shows potential for successful biodiesel production, where biodiesel is produced from the neutral lipid content of the algae. Algal neutral lipid content may be influenced and increased by changes in the surrounding environment. One possible way to influence lipid synthesis is through the growth medium. Two published growth mediums were compared using photobioreactors. Two experimental runs were performed with each medium: 1) continuous light and 2) 12 hour on, 12 hour off light cycle. In addition to medium composition, the effect of light cycle on kinetics and energy content was investigated.

]]> Candace Clark http://digitalcommons.usu.edu/undergrad_research/8 http://digitalcommons.usu.edu/undergrad_research/8 Mon, 10 May 2010 14:36:34 PDT Studies have shown that maternal book reading strategies in the toddler years impacts language and emergent literacy in the preschool years (Roberts, Jurgens, Burchinal, 2005). Certain forms of linguistic input, including the use of complex syntax and vocabulary, have been shown to be associated with better language and literacy outcomes for children. There is some research that suggests that parents from low income (SES), low education homes use fewer words and less complex vocabulary and syntax during book reading than parents from high SES, mid-high education homes (Horton-Ikard & Ellis Weisner, 2007) although results are mixed. More research is necessary to disentangle the effects of SES and education from the kinds of linguistic input parents use with their children.

]]> Jessica Shaw et al. http://digitalcommons.usu.edu/undergrad_research/7 http://digitalcommons.usu.edu/undergrad_research/7 Mon, 10 May 2010 14:13:12 PDT Laval Morris was the founder of the Landscape Architecture and Environmental Planning department at USU. He is an important figure in the history of our university, state, and intermountain region. One of the last remaining landscapes that he designed for the university is USU's Passive Recreation Garden. Over time the garden has become degraded, overrun by invasive plants and by last year, had become almost completely destroyed. It is important to preserve and restore this garden because of its importance to Laval and to LAEP's history.

]]> Jeremy Nelson http://digitalcommons.usu.edu/undergrad_research/6 http://digitalcommons.usu.edu/undergrad_research/6 Thu, 29 Apr 2010 09:02:40 PDT The purpose of the current study was to examine the extent to which select maternal variables were related to and best predicted the home literacy environment of toddlers with language delays. A number of maternal variables were considered including maternal education, maternal vocabulary, household income, and maternal depression. There is a growing body of research that suggests that mothers who are depressed demonstrate lower language abilities, and are less responsive and more directive than mothers who have never experienced depression (Newhoff & West, 1993). Maternal depression has been associated with poorer language outcomes for preschoolers particularly when experienced during the first 3 years of a child's life. Mother's who are depressed may also be less likely to engage in book reading interactions with children. There is also evidence that parents from low income, low education homes use fewer words and less complex vocabulary and syntax during book reading than parents from mid to high income, mid-high education homes (Horton-Ikard & Ellis Weismer, 2007) although results are mixed. A firm understanding of the influences of these factors on child language and literacy development will lead to the development of better interventions and ultimately, better child outcomes. Children in the current study were between 20 and 30 months of age. Information on mother's vocabulary, income, education, levels of depression and reading frequency were obtained. Relationships among variables are discussed.

]]> Jessica Cox et al.