Matching Items (115)
Description
Infectious diseases are a leading cause of death worldwide. With the development of drugs, vaccines and antibiotics, it was believed that for the first time in human history diseases would no longer be a major cause of mortality. Newly emerging diseases, re-emerging diseases and the emergence of microorganisms resistant to existing treatment have forced us to re-evaluate our optimistic perspective. In this study, a simple mathematical framework for super-infection is considered in order to explore the transmission dynamics of drug-resistance. Through its theoretical analysis, we identify the conditions necessary for the coexistence between sensitive strains and drug-resistant strains. Farther, in order to investigate the effectiveness of control measures, the model is extended so as to include vaccination and treatment. The impact that these preventive and control measures may have on its disease dynamics is evaluated. Theoretical results being confirmed via numerical simulations. Our theoretical results on two-strain drug-resistance models are applied in the context of Malaria, antimalarial drugs, and the administration of a possible partially effective vaccine. The objective is to develop a monitoring epidemiological framework that help evaluate the impact of antimalarial drugs and partially-effective vaccine in reducing the disease burden at the population level. Optimal control theory is applied in the context of this framework in order to assess the impact of time dependent cost-effective treatment efforts. It is shown that cost-effective combinations of treatment efforts depend on the population size, cost of implementing treatment controls, and the parameters of the model. We use these results to identify optimal control strategies for several scenarios.
ContributorsUrdapilleta, Alicia (Author) / Castillo-Chavez, Carlos (Thesis advisor) / Wang, Xiaohong (Thesis advisor) / Wirkus, Stephen (Committee member) / Camacho, Erika (Committee member) / Arizona State University (Publisher)
Created2011
Description
The concept of vaccination dates back further than Edward Jenner's first vaccine using cowpox pustules to confer immunity against smallpox in 1796. Nevertheless, it was Jenner's success that gave vaccines their name and made vaccinia virus (VACV) of particular interest. More than 200 years later there is still the need to understand vaccination from vaccine design to prediction of vaccine efficacy using mathematical models. Post-exposure vaccination with VACV has been suggested to be effective if administered within four days of smallpox exposure although this has not been definitively studied in humans. The first and second chapters analyze post-exposure prophylaxis of VACV in an animal model using v50ΔB13RMγ, a recombinant VACV expressing murine interferon gamma (IFN-γ) also known as type II IFN. While untreated animals infected with wild type VACV die by 10 days post-infection (dpi), animals treated with v50ΔB13RMγ 1 dpi had decreased morbidity and 100% survival. Despite these differences, the viral load was similar in both groups suggesting that v50ΔB13RMγ acts as an immunoregulator rather than as an antiviral. One of the main characteristics of VACV is its resistance to type I IFN, an effect primarily mediated by the E3L protein, which has a Z-DNA binding domain and a double-stranded RNA (dsRNA) binding domain. In the third chapter a VACV that independently expresses both domains of E3L was engineered and compared to wild type in cells in culture. The dual expression virus was unable to replicate in the JC murine cell line where both domains are needed together for replication. Moreover, phosphorylation of the dsRNA dependent protein kinase (PKR) was observed at late times post-infection which indicates that both domains need to be linked together in order to block the IFN response. Because smallpox has already been eradicated, the utility of mathematical modeling as a tool for predicting disease spread and vaccine efficacy was explored in the last chapter using dengue as a disease model. Current modeling approaches were reviewed and the 2000-2001 dengue outbreak in a Peruvian region was analyzed. This last section highlights the importance of interdisciplinary collaboration and how it benefits research on infectious diseases.
ContributorsHolechek, Susan A (Author) / Jacobs, Bertram L (Thesis advisor) / Castillo-Chavez, Carlos (Committee member) / Frasch, Wayne (Committee member) / Hogue, Brenda (Committee member) / Stout, Valerie (Committee member) / Arizona State University (Publisher)
Created2011
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
Externalizing behaviors are pervasive, widespread, and disruptive across a multitude of settings and developmental contexts. While the conventional diathesis-stress model typically measures the disordered end of the spectrum, studies that span the range of behavior, from externalizing to competence behaviors, are necessary to see the full picture. To that end, this study examined the additive and nonadditive relations of a dimension of parenting (ranging from warm to rejecting), and variants in dopamine, vasopressin, and neuropeptide-y receptor genes on externalizing/competence in a large sample of predominantly Caucasian twin children in toddlerhood, middle childhood, and early adolescence. Variants within each gene were hypothesized to increase biological susceptibility to both negative and positive environments. Consistent with prediction, warmth related to lower externalizing/higher competence at all ages. Earlier levels of externalizing/competence washed out the effect of parental warmth on future externalizing/competence with the exception of father warmth in toddlerhood marginally predicting change in externalizing/competence from toddlerhood to middle childhood. Warmth was a significant moderator of the heritability of behavior in middle childhood and early adolescence such that behavior was less heritable (mother report) and more heritable (father report) in low warmth environments. Interactions with warmth and the dopamine and vasopressin genes in middle childhood and early adolescence emphasize the moderational role gene variants play in relations between the rearing environment and child behavior. For dopamine, the long variant related to increased sensitivity to parent warmth such that the children displayed more externalizing behaviors when exposed to rejection but they also displayed more competence behaviors when exposed to high warmth. Vasopressin moderation was only present under conditions of parental warmth, not rejection. Interactions with neuropeptide-y and warmth were not significant. The picture that emerges is one of gene-environment interplay, wherein the influence of both parenting and child genotype each depend on the level of the other. As genetic research moves forward, gene variants previously implicated as conferring risk for disorder should be reexamined in conjunction with salient aspects of the environment on the full range of the behavioral outcome of interest.
ContributorsO'Brien, T. Caitlin (Author) / Lemery-Chalfant, Kathryn (Thesis advisor) / Eisenberg, Nancy (Committee member) / Enders, Craig (Committee member) / Nagoshi, Craig (Committee member) / Arizona State University (Publisher)
Created2011
Description
This study contributes to the ongoing discussion of Mathematical Knowledge for Teaching (MKT). It investigates the case of Rico, a high school mathematics teacher who had become known to his colleagues and his students as a superbly effective mathematics teacher. His students not only developed excellent mathematical skills, they also developed deep understanding of the mathematics they learned. Moreover, Rico redesigned his curricula and instruction completely so that they provided a means of support for his students to learn mathematics the way he intended. The purpose of this study was to understand the sources of Rico's effectiveness. The data for this study was generated in three phases. Phase I included videos of Rico's lessons during one semester of an Algebra II course, post-lesson reflections, and Rico's self-constructed instructional materials. An analysis of Phase I data led to Phase II, which consisted of eight extensive stimulated-reflection interviews with Rico. Phase III consisted of a conceptual analysis of the prior phases with the aim of creating models of Rico's mathematical conceptions, his conceptions of his students' mathematical understandings, and his images of instruction and instructional design. Findings revealed that Rico had developed profound personal understandings, grounded in quantitative reasoning, of the mathematics that he taught, and profound pedagogical understandings that supported these very same ways of thinking in his students. Rico's redesign was driven by three factors: (1) the particular way in which Rico himself understood the mathematics he taught, (2) his reflective awareness of those ways of thinking, and (3) his ability to envision what students might learn from different instructional approaches. Rico always considered what someone might already need to understand in order to understand "this" in the way he was thinking of it, and how understanding "this" might help students understand related ideas or methods. Rico's continual reflection on the mathematics he knew so as to make it more coherent, and his continual orientation to imagining how these meanings might work for students' learning, made Rico's mathematics become a mathematics of students--impacting how he assessed his practice and engaging him in a continual process of developing MKT.
ContributorsLage Ramírez, Ana Elisa (Author) / Thompson, Patrick W. (Thesis advisor) / Carlson, Marilyn P. (Committee member) / Castillo-Chavez, Carlos (Committee member) / Saldanha, Luis (Committee member) / Middleton, James A. (Committee member) / Arizona State University (Publisher)
Created2011
Description
The purpose of this study was to examine the longitudinal relations of maternal behaviors, children`s temperamental negative emotionality, and children`s emotion perception processes, including emotion perception accuracy (EPA) and emotion perception bias (EPB), to children`s conduct disorder symptoms in a normative sample. Separate structural equation models were conducted to assess whether parenting or children`s proneness to negative emotions at 24-30 (T2), 36-42 (T3) and 48-54 (T4) months predicted children`s EPA and EPB over time, and whether T3 and T4 children`s emotion perception processes were predictive of children`s conduct disorder at 72 months of age (T5). None of the hypothesized longitudinal relations was supported; however, other noteworthy results were observed. T3 children`s proneness to negative emotions was positively related to children`s concurrent bias toward anger. The latent constructs of negative parenting, children`s proneness to negative emotions, and the observed measure of children`s emotion perception accuracy showed stability over time, whereas the observed measures of children`s bias toward understanding distinct negative emotions were unrelated across time. In addition, children`s expressive language was predicted by children`s earlier emotion perception accuracy, which emphasized the importance of improving children`s emotion understanding skills during early years. Furthermore, the previously established negative relation between EPA and EPB variables was only partially supported. Findings regarding the relations between parenting, children`s negative emotionality and emotion perception processes are discussed from a developmental perspective.
ContributorsSeyed Nozadi, Sara (Author) / Spinrad, Tracy L. (Thesis advisor) / Eisenberg, Nancy (Committee member) / Bradley, Robert (Committee member) / Eggum, Natalie (Committee member) / Arizona State University (Publisher)
Created2011
Description
This dissertation examines Japanese preschool teachers' cultural practices and beliefs about the pedagogy of social-emotional development. The study is an interview-based, ethnographic study, which is based on the video-cued mutivocal ethnographic method. This study focuses on the emic terms that Japanese preschool teachers use to explain their practices, such as amae (dependency), omoiyari (empathy), sabishii (loneliness), mimamoru (watching and waiting) and garari (peripheral participation). My analysis suggests that sabishii, amae, and omoiyari form a triad of emotional exchange that has a particular cultural patterning and salience in Japan and in the Japanese approach to the socialization of emotions in early childhood. Japanese teachers think about the development of the class as a community, which is different from individual-centric Western pedagogical perspective that gives more attention to each child's development. Mimamoru is a pedagogical philosophy and practice in Japanese early childhood education. A key component of Japanese teachers' cultural practices and beliefs about the pedagogy of social-emotional development is that the process requires the development not only of children as individuals, but also of children in a preschool class as a community. In addition, the study suggests that at a deeper level these emic concepts reflect more general Japanese cultural notions of time, space, sight, and body. This dissertation concludes with the argument that teachers' implicit cultural practices and beliefs is "A cultural art of teaching." Teachers' implicit cultural practices and beliefs are harmonized in the teachers' mind and body, making connections between them, and used depending on the nuances of a situation, as informed by teachers' conscious and unconscious thoughts. The study has also shown evidence of similar practices and logic vertically distributed within Japanese early childhood education, from the way teachers act with children, to the way directors act with teachers, to the way government ministries act with directors, to the way deaf and hearing educators act with their deaf and hearing students. Because these practices are forms of bodily habitus and implicit Japanese culture, it makes sense that they are found across fields of action.
ContributorsHayashi, Akiko (Author) / Tobin, Joseph (Thesis advisor) / Eisenberg, Nancy (Committee member) / Nakagawa, Kathryn (Committee member) / Fischman, Gustavo (Committee member) / Swadener, Elizabeth (Committee member) / Arizona State University (Publisher)
Created2011
Description
Using data from an eight-year longitudinal study of 214 children's social and emotional development, I conducted three studies to (1) examine patterns of agreement for internalizing (INT) and externalizing (EXT) symptomatology among different informants (mothers, fathers, teachers, and adolescents) using a recently developed structural equation modeling approach for multi-trait, multi-method data; (2) examine the developmental trajectories for INT and EXT and predict individual differences in symptom development using temperament and parenting variables; and (3) describe patterns of INT and EXT co-occurrence and predict these patterns from temperament and parenting. In Study 1, longitudinal invariance was established for mothers', fathers' and teachers' reports over a six-year period. Sex, age, and SES did not substantially moderate agreement among informants, although both sex and age were differentially related to symptomatology depending on the informant. Agreement among teachers and mothers, but not among mothers and fathers, differed by domain of symptomatology, and was greater for EXT than for INT. In Study 2, latent profile analysis, a person-centered analytic approach, did not provide easily interpretable patterns of symptom development, a failure that is likely the result of the relatively modest sample size. Latent growth curve models, an alternative analytic approach, did provide good fit to the data. Temperament and parenting variables were examined as predictors of the latent growth parameters in these models. Although there was little prediction of the slope, effortful control was negatively related to overall levels of EXT, whereas impulsivity and anger were positively related. Mutually responsive orientation, a measure of the parent-child relationship, was a more consistent predictor of EXT than was parental warmth. Furthermore, the relation between mutually responsive orientation and EXT was partially mediated by inhibitory control. Across informants, there were few consistent predictors of INT. In Study 3, latent profile analysis was used to classify individuals into different patterns of INT and EXT co-occurrence. In these models, a similar class structure was identified for mothers and for teachers. When temperament and parenting were examined as predictors of co-occurring symptomatology, few significant interactions were found and results largely replicated prior findings from this data set using arbitrary symptom groups.
ContributorsSulik, Michael John (Author) / Eisenberg, Nancy (Thesis advisor) / Spinrad, Tracy L (Thesis advisor) / Lemery-Chalfant, Kathryn (Committee member) / Wolchik, Sharlene A (Committee member) / Arizona State University (Publisher)
Created2013
Description
Black Laurel is a book-length manuscript which has at its center poems that reveal and explore issues related to Michele Poulos's identity as a Greek-American writer, discovering the connections that link the past and present of both Greece and America. These poems often work as a quest to recover identity. They explore the idea that it is her own privileged perspective as an educated Greek-American woman that both allows and in some ways prevents her seeing herself in the Greeks who today are struggling economically, emotionally, and psychologically. Many of the poems work to achieve a complex understanding of both an individual as well as a broader cultural history. These poems sometimes take on the personas of striking figures from other times and other landscapes, while others draw on materials which are somewhat more autobiographical. In one poem titled "Before My Mother Set Herself on Fire," the speaker is an imagined daughter in a modern-day Greek family. The poem, inspired by a news story about an elderly man who shot himself in the head in front of Syntagma Square in Athens to protest the austerity measures imposed on the Greek population, explores the various ways in which a national crisis may affect an individual family. Alternatively, Poulos delves into her personal family history in "When the Wind Falls," a poem about the Nazi invasions of northern Greece. At the same time, this focus on past and present Greece is only one strand in a wide-ranging manuscript woven of materials which also include a variety of subjects related to science, history, eroticism, mysticism, and much more.
ContributorsPoulos, Michele (Author) / Dubie, Norman (Thesis advisor) / Hogue, Cynthia (Committee member) / Hummer, Terry (Committee member) / Arizona State University (Publisher)
Created2013
Description
Chris Miller's Souvenirs of Sleep is as serious as it is whimsical, if this is a possibility. The "Museum of the Zoo-real" may be an equally appropriate title as animals are often in performance. In this visual and spiritual investigation, childhood, dream, and the loss of a mother to suicide are the currents. Miller's work is informed by the cinema of Werner Herzog, Andrei Tarkovsky, Robert Bresson and beyond. Miller believes in the power of implication. The poems begin with intense focus, but are often in the business of expansion. Souvenirs of Sleep is a journey toward sense-making, a search for language that might allow it.
ContributorsMiller, Christopher (Author) / Dubie, Norman (Thesis advisor) / Hogue, Cynthia (Committee member) / Ball, Sally (Committee member) / Arizona State University (Publisher)
Created2013