Matching Items (182)
Description
Diseases have been part of human life for generations and evolve within the population, sometimes dying out while other times becoming endemic or the cause of recurrent outbreaks. The long term influence of a disease stems from different dynamics within or between pathogen-host, that have been analyzed and studied by many researchers using mathematical models. Co-infection with different pathogens is common, yet little is known about how infection with one pathogen affects the host's immunological response to another. Moreover, no work has been found in the literature that considers the variability of the host immune health or that examines a disease at the population level and its corresponding interconnectedness with the host immune system. Knowing that the spread of the disease in the population starts at the individual level, this thesis explores how variability in immune system response within an endemic environment affects an individual's vulnerability, and how prone it is to co-infections. Immunology-based models of Malaria and Tuberculosis (TB) are constructed by extending and modifying existing mathematical models in the literature. The two are then combined to give a single nine-variable model of co-infection with Malaria and TB. Because these models are difficult to gain any insight analytically due to the large number of parameters, a phenomenological model of co-infection is proposed with subsystems corresponding to the individual immunology-based model of a single infection. Within this phenomenological model, the variability of the host immune health is also incorporated through three different pathogen response curves using nonlinear bounded Michaelis-Menten functions that describe the level or state of immune system (healthy, moderate and severely compromised). The immunology-based models of Malaria and TB give numerical results that agree with the biological observations. The Malaria--TB co-infection model gives reasonable results and these suggest that the order in which the two diseases are introduced have an impact on the behavior of both. The subsystems of the phenomenological models that correspond to a single infection (either of Malaria or TB) mimic much of the observed behavior of the immunology-based counterpart and can demonstrate different behavior depending on the chosen pathogen response curve. In addition, varying some of the parameters and initial conditions in the phenomenological model yields a range of topologically different mathematical behaviors, which suggests that this behavior may be able to be observed in the immunology-based models as well. The phenomenological models clearly replicate the qualitative behavior of primary and secondary infection as well as co-infection. The mathematical solutions of the models correspond to the fundamental states described by immunologists: virgin state, immune state and tolerance state. The phenomenological model of co-infection also demonstrates a range of parameter values and initial conditions in which the introduction of a second disease causes both diseases to grow without bound even though those same parameters and initial conditions did not yield unbounded growth in the corresponding subsystems. This results applies to all three states of the host immune system. In terms of the immunology-based system, this would suggest the following: there may be parameter values and initial conditions in which a person can clear Malaria or TB (separately) from their system but in which the presence of both can result in the person dying of one of the diseases. Finally, this thesis studies links between epidemiology (population level) and immunology in an effort to assess the impact of pathogen's spread within the population on the immune response of individuals. Models of Malaria and TB are proposed that incorporate the immune system of the host into a mathematical model of an epidemic at the population level.
ContributorsSoho, Edmé L (Author) / Wirkus, Stephen (Thesis advisor) / Castillo-Chavez, Carlos (Thesis advisor) / Chowell-Puente, Gerardo (Committee member) / Arizona State University (Publisher)
Created2011
Description
The purpose of our study was to examine the effectiveness of a cycling intervention on body composition in adolescents with Down syndrome (DS). Participants completed one of three interventions over eight consecutive weeks. The interventions were: 1) Voluntary Cycling (VC), in which participants cycled at their self-selected pedaling rate 2) Assisted Cycling (AC), in which the participants' voluntary pedaling rates were assisted with a motor to ensure the maintenance of 80 rpms. 3) No cycling (NC), in which the participants acted as controls. Participants in the AC intervention did not decrease body fat or increase lean body mass however they did maintain these measures during the intervention as compared to the VC and NO participants who increased body fat and decreased lean body mass. These statistics were not exactly as expected nor were they statistically significant. Future research will try to replicate this data with statistically significant values for more cycling adolescents with DS using more randomized intervention groups.
ContributorsBennett, Kristen Leigh (Author) / Ringenbach, Shannon (Thesis director) / Brown, Steven (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2015-05
Description
This research study examined the effects of assisted cycling using a stationary recumbent bicycle that had an internal motor to help participants pedal at a desired cadence. The participants were either placed in an Assisted Cycling (AC), Voluntary Cycling (VC), or No Cycling (NC) intervention group. Those placed in the AC of VC groups then came to a laboratory setting 3 days a week for 8 weeks to cycle for 30 minutes. This research specifically analyzes the Vineland Adaptive Behavior Scale II to analyze the changes in daily living skills and maladaptive behaviors pre and post the exercise intervention. After analyzing the VABS II scores it was found that those in the VC intervention had statistically significant improvements in maladaptive behaviors. An interpretation of this finding is that the VC intervention had an increased heart rate over the span of the intervention and had a larger power output than those in the AC group. A limitation of this research is that it was a self-reported questionnaire that was given to the caregivers of the participant. The caregivers were not always controlled for, so in some cases two different caregivers were given the questionnaire for a single participant. A suggestion for future research would be to use the participant's mental age versus their chronological age when using the VABS-II and to use the Adaptive Behaviors Assessment System III (ABAS-III).
ContributorsJenkins, Cayla Marie (Author) / Ringenbach, Shannon (Thesis director) / Kulinna, Pamela (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2015-05
Description
Solution methods for certain linear and nonlinear evolution equations are presented in this dissertation. Emphasis is placed mainly on the analytical treatment of nonautonomous differential equations, which are challenging to solve despite the existent numerical and symbolic computational software programs available. Ideas from the transformation theory are adopted allowing one to solve the problems under consideration from a non-traditional perspective. First, the Cauchy initial value problem is considered for a class of nonautonomous and inhomogeneous linear diffusion-type equation on the entire real line. Explicit transformations are used to reduce the equations under study to their corresponding standard forms emphasizing on natural relations with certain Riccati(and/or Ermakov)-type systems. These relations give solvability results for the Cauchy problem of the parabolic equation considered. The superposition principle allows to solve formally this problem from an unconventional point of view. An eigenfunction expansion approach is also considered for this general evolution equation. Examples considered to corroborate the efficacy of the proposed solution methods include the Fokker-Planck equation, the Black-Scholes model and the one-factor Gaussian Hull-White model. The results obtained in the first part are used to solve the Cauchy initial value problem for certain inhomogeneous Burgers-type equation. The connection between linear (the Diffusion-type) and nonlinear (Burgers-type) parabolic equations is stress in order to establish a strong commutative relation. Traveling wave solutions of a nonautonomous Burgers equation are also investigated. Finally, it is constructed explicitly the minimum-uncertainty squeezed states for quantum harmonic oscillators. They are derived by the action of corresponding maximal kinematical invariance group on the standard ground state solution. It is shown that the product of the variances attains the required minimum value only at the instances that one variance is a minimum and the other is a maximum, when the squeezing of one of the variances occurs. Such explicit construction is possible due to the relation between the diffusion-type equation studied in the first part and the time-dependent Schrodinger equation. A modication of the radiation field operators for squeezed photons in a perfect cavity is also suggested with the help of a nonstandard solution of Heisenberg's equation of motion.
ContributorsVega-Guzmán, José Manuel, 1982- (Author) / Sulov, Sergei K (Thesis advisor) / Castillo-Chavez, Carlos (Thesis advisor) / Platte, Rodrigo (Committee member) / Chowell-Puente, Gerardo (Committee member) / Arizona State University (Publisher)
Created2013
Description
This study examines the effectiveness of two modes of exercise on inhibitory control in adults with Down Syndrome (DS). Thirteen participants attended four sessions: a baseline assessment, an Assisted Cycling Therapy (ACT) session, a Resistance Training (RT) session, and a session of No Training (NT). In the baseline assessment, 1-repetition max (1RM) measurements and voluntary pedal rate measurements were taken. In the resistance training session, the leg press, chest press, seated row, leg curl, shoulder press, and latissimus pulldown were performed. In the cycling intervention, the participant completed 30 minutes of cycling. The Erikson Flanker task was administered prior to each session (i.e., pretest) and after the intervention (i.e., post-test). The results were somewhat consistent with the hypothesis that inhibition time improved more following RT and ACT than NT. there was also a significant difference between ACT and NT. Additionally, it was hypothesized that all measures would improve following each acute exercise intervention, but the most significant improvements were seen following ACT. In conclusion, an acute session of ACT demonstrated a significant trend towards improvements in inhibitory control in adults with DS which we interpreted using a model of neural changes.
ContributorsHayes, Claire (Author) / Ringenbach, Shannon (Thesis director) / Arnold, Nate (Committee member) / Rand, Miya (Committee member) / Edson College of Nursing and Health Innovation (Contributor) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
The purpose of this study is to first investigate the role of political socialization on young men and women and what motivates them to become politically active and make the ultimate decision to run for elected office. These effects include parental attitudes, exposure to political shows and news sources, participation in voluntary organizations, and overall community involvement. After understanding these direct and indirect effects of political socialization, I can attempt to explain the causes for the gender gap in political ambition \u2014 meaning that significantly more men are running for elected office compared to women.
ContributorsOsgood, Shannon Marie (Author) / Woodall, Gina (Thesis director) / Herrera, Richard (Committee member) / Barrett, The Honors College (Contributor) / College of Public Service and Community Solutions (Contributor) / School of Public Affairs (Contributor) / School of Politics and Global Studies (Contributor)
Created2015-05
Description
This study examines cognitive planning in adolescents with Down syndrome (DS) following an 8-week assisted cycling therapy intervention. Forty-three participants were randomly assigned to assisted cycling (AC) (i.e., at least 30% faster than self-selected cadence accomplished by a motor), voluntary cycling (VC) (self-selected cadence), and no cycling (NC) control group. Both AC and VC rode a stationary bicycle three times/week, 30 minutes/session, for eight weeks in duration. Participants completed cognitive testing that assessed cognitive planning at the beginning (i.e., pretest) and end (i.e., posttest) of the 8-week intervention. Consistent with our hypothesis, the results showed that cognitive planning improved following eight weeks of cycling for the AC group. The same results were not seen for individuals in the VC or NC groups. Our results suggest that assisted cycling therapy may induce permanent changes in the prefrontal cortex in adolescents with DS.
ContributorsMillar, Kelsey Leann (Author) / Ringenbach, Shannon (Thesis director) / Amazeen, Eric (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2015-05
Description
This study examines the effectiveness of two modes of exercise on depression in adolescents with Down syndrome (DS). Thirty nine participants were randomly divided into a voluntary cycling group (VC) (i.e., self-selected cadence), an assisted cycling group (AC) (i.e., at least 30% faster than self-selected cadence accomplished by a motor), or a no exercise group (NC). In each cycling intervention the participant completed 30 minute cycling sessions, three times per week for a total of eight weeks. The Children's Depression Inventory II was administered prior to cycling (i.e., pretest) and after the eight week intervention (i.e., posttest). Although the data did not reach conventional levels of statistical significance, the results of the study demonstrated partial support for our hypothesis that adolescents with DS showed improvements in depression as measured by the Children's Depression Inventory II following assisted cycling, but not following eight weeks of voluntary cycling. In other words, eight weeks of moderate AC exercise demonstrated a trend for improved depression in adolescents with DS.
ContributorsMcgownd, Shana Leah (Author) / Ringenbach, Shannon (Thesis director) / Youngstedt, Shawn (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2015-05
Description
Mortality of 1918 influenza virus was high, partly due to bacteria coinfections. We characterize pandemic mortality in Arizona, which had high prevalence of tuberculosis. We applied regressions to over 35,000 data points to estimate the basic reproduction number and excess mortality. Age-specific mortality curves show elevated mortality for all age groups, especially the young, and senior sparing effects. The low value for reproduction number indicates that transmissibility was moderately low.
ContributorsJenner, Melinda Eva (Author) / Chowell-Puente, Gerardo (Thesis director) / Kostelich, Eric (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
The Undoing Project is an ongoing educational feminist YouTube channel that serves as an introduction to feminism and feminist theory. The objective for this project is to present feminist theory and feminist ideology in an accessible and entertaining way. Through this project I sought to accomplish three goals: to challenge the negative image of feminism, bridge the gap between the language of academia and the public, and to acknowledge and unlearn ingrained prejudices. The videos focus on theory, history, legislation, current events, and pop culture. The initial project consists of ten videos addressing the feminist wave models, a brief history of the feminist movement, and discussions of concepts like hegemony, intersectionality, masculinity, femininity, and race.
ContributorsBuchholtz, Kaylee Marie (Author) / Brian, Jennifer (Thesis director) / Grzanka, Patrick (Committee member) / Brouwer, Dan (Committee member) / Barrett, The Honors College (Contributor) / College of Public Service and Community Solutions (Contributor) / School of Social Transformation (Contributor) / Department of English (Contributor)
Created2015-05