Matching Items (293)
Description
It is well known that deficiencies in key chemical elements (such as phosphorus, P) can reduce animal growth; however, recent empirical data have shown that high levels of dietary nutrients can also reduce animal growth. In ecological stoichiometry, this phenomenon is known as the "stoichiometric knife edge," but its underlying mechanisms are not well-known. Previous work has suggested that the crustacean zooplankter Daphnia reduces its feeding rates on phosphorus-rich food, causing low growth due to insufficient C (energy) intake. To test for this mechanism, feeding rates of Daphnia magna on algae (Scenedesmus acutus) differing in C:P ratio (P content) were determined. Overall, there was a significant difference among all treatments for feeding rate (p < 0.05) with generally higher feeding rates on P-rich algae. These data indicate that both high and low food C:P ratio do affect Daphnia feeding rate but are in contradiction with previous work that showed that P-rich food led to strong reductions in feeding rate. Additional experiments are needed to gain further insights.
ContributorsSchimpp, Sarah Ann (Author) / Elser, James (Thesis director) / Neuer, Susanne (Committee member) / Peace, Angela (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of Sustainability (Contributor)
Created2014-05
Description
This thesis addresses the conception and eventual execution of Walt Disney's model of the city of the future, one in which individuals would work, live and play. EPCOT, representing an Experimental Prototype Community of Tomorrow, was envisioned as a utopian and idealized society in a bubble. Aimed at eliminating the ills that plagued American society of the 1960s by returning individuals to community roots, complete with emerging technologies and innovations to improve lifestyles, EPCOT would take inspiration from unique urban planners and innovators. But EPCOT failed to materialize in its original form once Disney passed away on December 15, 1966. The massive city planning venture eventually evolved into a World's Fair-like theme park called Epcot Center, where the correlations between culture and technology would become blurred in this entertainment venue. The park's success stems from its ability to carry components of its community vision, but to appeal to visitors' interests in experiencing application of new technologies through exposure of other cultures and ideas. Technology and culture, while often interrelated, but sometimes at odds with one another, substantially account for Epcot's development over the past 50 years. This thesis not only reflects on Walt Disney's EPCOT the community, but also details how the Walt Disney World theme park has contended with addressing the dualistic relationship between technology and culture.
ContributorsNachman, Brett Ranon (Author) / Stewart, Pamela (Thesis director) / Dombrowski, Rosemarie (Committee member) / Kurtti, Jeff (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor) / Walter Cronkite School of Journalism and Mass Communication (Contributor)
Created2014-12
Description
Background
The transmission dynamics of Tuberculosis (TB) involve complex epidemiological and socio-economical interactions between individuals living in highly distinct regional conditions. The level of exogenous reinfection and first time infection rates within high-incidence settings may influence the impact of control programs on TB prevalence. The impact that effective population size and the distribution of individuals’ residence times in different patches have on TB transmission and control are studied using selected scenarios where risk is defined by the estimated or perceive first time infection and/or exogenous re-infection rates.
Methods
This study aims at enhancing the understanding of TB dynamics, within simplified, two patch, risk-defined environments, in the presence of short term mobility and variations in reinfection and infection rates via a mathematical model. The modeling framework captures the role of individuals’ ‘daily’ dynamics within and between places of residency, work or business via the average proportion of time spent in residence and as visitors to TB-risk environments (patches). As a result, the effective population size of Patch i (home of i-residents) at time t must account for visitors and residents of Patch i, at time t.
Results
The study identifies critical social behaviors mechanisms that can facilitate or eliminate TB infection in vulnerable populations. The results suggest that short-term mobility between heterogeneous patches contributes to significant overall increases in TB prevalence when risk is considered only in terms of direct new infection transmission, compared to the effect of exogenous reinfection. Although, the role of exogenous reinfection increases the risk that come from large movement of individuals, due to catastrophes or conflict, to TB-free areas.
Conclusions
The study highlights that allowing infected individuals to move from high to low TB prevalence areas (for example via the sharing of treatment and isolation facilities) may lead to a reduction in the total TB prevalence in the overall population. The higher the population size heterogeneity between distinct risk patches, the larger the benefit (low overall prevalence) under the same “traveling” patterns. Policies need to account for population specific factors (such as risks that are inherent with high levels of migration, local and regional mobility patterns, and first time infection rates) in order to be long lasting, effective and results in low number of drug resistant cases.
The transmission dynamics of Tuberculosis (TB) involve complex epidemiological and socio-economical interactions between individuals living in highly distinct regional conditions. The level of exogenous reinfection and first time infection rates within high-incidence settings may influence the impact of control programs on TB prevalence. The impact that effective population size and the distribution of individuals’ residence times in different patches have on TB transmission and control are studied using selected scenarios where risk is defined by the estimated or perceive first time infection and/or exogenous re-infection rates.
Methods
This study aims at enhancing the understanding of TB dynamics, within simplified, two patch, risk-defined environments, in the presence of short term mobility and variations in reinfection and infection rates via a mathematical model. The modeling framework captures the role of individuals’ ‘daily’ dynamics within and between places of residency, work or business via the average proportion of time spent in residence and as visitors to TB-risk environments (patches). As a result, the effective population size of Patch i (home of i-residents) at time t must account for visitors and residents of Patch i, at time t.
Results
The study identifies critical social behaviors mechanisms that can facilitate or eliminate TB infection in vulnerable populations. The results suggest that short-term mobility between heterogeneous patches contributes to significant overall increases in TB prevalence when risk is considered only in terms of direct new infection transmission, compared to the effect of exogenous reinfection. Although, the role of exogenous reinfection increases the risk that come from large movement of individuals, due to catastrophes or conflict, to TB-free areas.
Conclusions
The study highlights that allowing infected individuals to move from high to low TB prevalence areas (for example via the sharing of treatment and isolation facilities) may lead to a reduction in the total TB prevalence in the overall population. The higher the population size heterogeneity between distinct risk patches, the larger the benefit (low overall prevalence) under the same “traveling” patterns. Policies need to account for population specific factors (such as risks that are inherent with high levels of migration, local and regional mobility patterns, and first time infection rates) in order to be long lasting, effective and results in low number of drug resistant cases.
ContributorsMoreno Martinez, Victor (Author) / Espinoza Cortes, Baltazar (Author) / Barley, Kamal (Author) / Paredes Gutierrez, Marlio (Author) / Bichara, Derdei (Author) / Mubayi, Anuj (Author) / Castillo-Chavez, Carlos (Author) / Simon M. Levin Mathematical, Computational and Modeling Sciences Center (Contributor) / College of Liberal Arts and Sciences (Contributor) / School of Human Evolution and Social Change (Contributor)
Created2017-01-11
Description
Large quantities of sodic and alkaline bauxite residue are produced globally as a by-product from alumina refineries. Ecological stoichiometry of key elements [nitrogen (N) and phosphorus (P)] plays a critical role in establishing vegetation cover in bauxite residue sand (BRS). Here we examined how changes in soil chemical properties over time in rehabilitated sodic and alkaline BRS affected leaf N to P stoichiometry of native species used for rehabilitation. Both Ca and soil pH influenced the shifts in leaf N:P ratios of the study species as supported by consistently significant positive relationships (P < 0.001) between these soil indices and leaf N:P ratios. Shifts from N to P limitation were evident for N-fixing species, while N limitation was consistently experienced by non-N-fixing plant species. In older rehabilitated BRS embankments, soil and plant indices (Ca, Na, pH, EC, ESP and leaf N:P ratios) tended to align with those of the natural ecosystem, suggesting improved rehabilitation performance. These findings highlight that leaf N:P stoichiometry can effectively provide a meaningful assessment on understanding nutrient limitation and productivity of native species used for vegetating highly sodic and alkaline BRS, and is a crucial indicator for assessing ecological rehabilitation performance.
ContributorsGoloran, Johnvie B. (Author) / Chen, Chengrong (Author) / Phillips, Ian R. (Author) / Elser, James (Author) / College of Liberal Arts and Sciences (Contributor) / School of Life Sciences (Contributor)
Created2015-10-07
Description
Peoria, a city of about 171,000 residents in the northwest Valley, is recognized as one of Arizona's fastest growing cities. Peoria does not have a news source that engages millennials, despite the fact that adults ages 18 to 34 make up about 20% of Peoria's population. Thus, I created a digital news outlet with a complementary social media presence to target a millennial audience. Peoria Next covers news about Peoria that is either not currently covered by other news outlets or is covered in a different way. The goal of the website is to inform millennials of news and events in Peoria with a focus on topics millennials are interested in. The website receives 40 to 50 unique visitors and around 90 views every month, and Facebook insights show that 32% of the people reached by Peoria Next are in the target age range of 18 to 34. This paper discusses the process involved in creating a news outlet for millennials in Peoria with social media platforms as the main avenue for audience development. The first section discusses the role of local news in a community, using social media to engage the audience and how millennials receive and engage with news. The second section discusses how I developed the website and the overall results.
ContributorsRogers, Anya Bryn (Author) / Leonard, Christina (Thesis director) / Pucci, Jessica (Committee member) / WPC Graduate Programs (Contributor) / Economics Program in CLAS (Contributor) / Walter Cronkite School of Journalism and Mass Communication (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Examining whether or not a bias exists on individual shows on CNN, FOX News, and MSNBC by using content analysis. Each individual show following the third presidential debate was coded using content analysis, then that information was used to determine whether a bias existed on any of the shows and then whether or not a bias existed across the network as a whole.
ContributorsNelson, Roy Emil (Author) / Kenney, Patrick (Thesis director) / Woodall, Gina (Committee member) / Wells, David (Committee member) / Barrett, The Honors College (Contributor) / Walter Cronkite School of Journalism and Mass Communication (Contributor) / School of Politics and Global Studies (Contributor)
Created2013-05
Description
This project aims to aggregate recent information on broadcast journalism curriculum and propose a website design to help educate broadcast students about the most-needed web skills in newsrooms. Television reporters must go beyond re-hashing their broadcast package and script on the station's website, and this includes knowledge of the best site design practices to house more in-depth content. The Grady Undergraduate Survey, as well as the opinions and experience of professionals today, show that web design and web writing skills are two of the most important skills a broadcast student can possess as they prepare to graduate and seek jobs.
ContributorsPorter, Caroline (Author) / Lodato, Mark (Thesis director) / Carpenter, Serena (Committee member) / Barrett, The Honors College (Contributor) / Walter Cronkite School of Journalism and Mass Communication (Contributor)
Created2012-12
ContributorsHeath, Chelsey (Author) / Goodman, Rebekka (Thesis director) / Gillmor, Dan (Committee member) / McGuire, Tim (Committee member) / Barrett, The Honors College (Contributor) / Walter Cronkite School of Journalism and Mass Communication (Contributor)
Created2012-12
Description
Empathy is a characteristic fully developed and manifested in one creature: the human being. In February 2011, we saw the supercomputer, Watson, challenge highly intelligent human beings on Jeopardy. The human beings put up a brutal battle of wits but ultimately, the computer was declared victor. Scientists have made remarkable leaps when it comes to creating artificial intelligence. We have "smart" phones that sit in the palm of our hand and can do far more than what we expected of bulky desktops in the 90s.
ContributorsFidura, E. L. Monica (Author) / Knopf, Richard (Thesis director) / Sylvester, Edward (Committee member) / Rodriguez, Ariel (Committee member) / Barrett, The Honors College (Contributor) / Walter Cronkite School of Journalism and Mass Communication (Contributor)
Created2012-12
Description
Organizations use news releases to promote coverage of its operations and enhance the image and issues pertinent to the organization. In most cases, the primary focus of press releases and news media coverage differs. This thesis analyzes the resonance between coverage by news organizations and the materials released by the organization. Analysis of coverage by the news media and the NBA illustrates the resonance and connections in coverage by all three organizations. It also shows how information regarding the NBA lockout released by the NBA and news outlets can be differentiated into unique issue arenas. These issue arenas can have influence on each other, while also allowing organizations to provide their own unique perspectives.
ContributorsEckert, Marshall (Author) / Gilpin, Dawn (Thesis director) / Matera, Fran (Committee member) / Barrett, The Honors College (Contributor) / College of Liberal Arts and Sciences (Contributor) / Walter Cronkite School of Journalism and Mass Communication (Contributor)
Created2012-12