Browsing by Subject "Exposure"

Now showing 1 - 4 of 4
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    Adolescents’ Exposure to Intimate Partner Violence, Delinquent Behaviors and the Role of Perceived Social Support
    (2022-05) Robinson, Renita
    An underestimated 10.7 million of the 52.7 million US children (ages 0-17) living with two parents live in homes where male-to-female intimate partner violence (IPV) between adults has occurred in the last year. Children’s exposure to IPV (EIPV) affects their behavior, development and educational outcomes. Adolescent’s exposure and behavioral responses to EIPV is understudied. This study uses a secondary analysis of data from the third National Survey of Children Exposed to Violence (the most comprehensive nationwide survey of the incidence and prevalence of children’s exposure to violence conducted to date) to explore the ways adolescents’ EIPV are associated with delinquent behaviors, and whether the perception of social support (SS) is a protective factor in the relationship between EIPV and delinquent behaviors. This analysis extends the understanding of the relationship between EIPV, delinquency, and SS: (a) It documented that SS was more protective for females than males. (b) While White non-Hispanic children experienced lower levels of EIPV and higher levels of SS, both “races” demonstrated a benefit from SS. 3) Measures of SS vary only minimally across the age ranges in this study. In contrast both measures of delinquency and EIPV got worse with age.
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    Exposures and the Impacts on the Epigenome that Persist from Youth to Adulthood and Intergenerationally
    (2022-01) Colwell, Mathia
    Environmental exposures have an impact on the epigenome that persists throughout a lifetime and can be transmitted intergenerationally. While a plethora of exposures exist, the mechanisms of epigenetic destruction are unique with each exposure. My research explores two exposures, arsenic and the chemotherapeutic drug 5-aza-2'-deoxycytidine (Decitabine), both of which disrupt different elements of the DNA methylation pathway resulting in persistent epigenetic changes. I first share my findings on the impacts of maternal arsenic exposure, which disrupts the 1-carbon metabolism pathway. I provide evidence that in utero arsenic exposure in mice disrupts epigenetic reprogramming in the developing embryo and primordial germ cells, causing dysregulated methylation and the onset of diseases into adulthood. This work is the first of its kind to show the intergenerational effects of in utero arsenic exposure on adulthood disease phenotypes and the inherited DNA methylation damage in offspring. In my second study I examine the epigenetic damage caused by decitabine exposure, which disrupts the maintenance of DNA methylation in replicating cells. I identify site specific and global methylation damage within the reproductive tracts of mice as a response to a curated chemotherapeutic exposure paradigm. This data highlights the persistent changes of the epigenome in healthy non-target tissues. My findings promote the cautionary application of decitabine as a hypomethylating agent, as it paradoxically alters DNA methylation where the long-term effects on non-target tissues remain unknown. Together my research contributes to the long-term goal of understanding how environmental exposures disrupt the methylation pathway and the lasting consequences of disrupted DNA methylation.
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    Potential Impacts of Per- and Polyfluoroalkyl Substance Contamination in Laboratory Materials and Model Organisms on Laboratory-based Studies
    (2021-12) Rushing, Julianna
    Per- and polyfluoroalkyl substances are persistent chemicals that present risks to human environmental health as a result of their ubiquitous nature. These compounds also impact laboratory based exposure and toxicology experiments through PFAS contamination in common materials used for aquatic laboratory exposure experiments. This thesis reviews literature surrounding PFAS bioaccumulation in aquatic organisms in laboratory exposure studies using several measures such as the bioaccumulation factor, bioconcentration factor, biomagnification factor, rate of uptake, and elimination rate. Lack of standardization in how the bioaccumulation factors were calculated creates challenges in statistical comparisons. This thesis also investigates potential PFAS contamination and impacts on aquatic laboratory based exposure experiments in habitat materials, fish feed, and aquaculture fish. Results suggest that PFAS contamination is present in common fish feed and can also be found in aquaculture fish. Unaccounted PFAS contamination in bioaccumulation and toxicity studies could confound results and ultimately influence environmental health recommendations.
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    Social diffusion of campaign effects: campaign-generated interpersonal communication as a polarizing mediator of anti-tobacco campaign effects.
    (2009-05) Hwang, Yoori
    Traditionally, campaign effects have been modeled as a result of individuals' direct exposure to campaign messages. A person's indirect exposure to messages through interpersonal conversation about a campaign, however, can be another way that campaign effects occur. Based on the notion of social diffusion of campaign effects, this dissertation research examined the role of campaign conversation in the generation and diffusion of campaign effects. More specifically, this dissertation research tested whether anti-smoking campaign-generated conversation affected individuals’ smoking-related perceptions using the TruthSM campaign data (Study 1) and experiment data (Study 2). Study 1 tested whether campaign conversation, along with individual exposure, can mediate the impact of the TruthSM campaign using secondary analyses of the Legacy Media Tracking Survey (LMTS) data. LMTS is a random digit dialing telephone survey of a nationally representative sample of youth (LMTS II: n =10,357; LMTS III: n = 10,079). Multilevel modeling results of LMTS II data show that both encoded exposure and campaign conversation mediated the relationship between TruthSM campaign availability and smoking beliefs, although the mediating roles of encoded exposure and campaign conversation were not found in LMTS III. The results of LMTS II data also show that campaign conversation widened the difference in smoking beliefs between non-smokers and hardcore smokers, indicating a possibility that campaign conversation can function as a polarizing mediator. Based on the concern of potential backlash effects of conversation among smokers, Study 2 tested whether a smoker’s campaign conversation with another smoker can produce elevated pro-smoking normative perceptions and behavioral intentions using a laboratory experiment (n =72). Results show that smokers’ conversation generated boomerang effects. Although campaign conversation did not affect participants’ injunctive norms, personal descriptive norms, or behavioral intention, it led to elevated pro-smoking societal descriptive norms (i.e., higher smoking prevalence estimates) among participants who had a low number of smoker friends. Altogether, this dissertation research provides general support for the social diffusion process of campaign effects and the important role of campaign conversation in this process. It shows that campaign-generated conversation can generate, amplify, and, sometimes, reduce campaign effects. Theoretical and practical implications for campaign planning and evaluation are discussed.