Theses and Dissertations from UMD
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New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM
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Item COMPARISON OF ACRYLAMIDE EXPOSURE BIOMARKERS IN CHILDREN AND ADOLESCENTS USING NATIONAL HEALTH AND NUTRITION EXAMINATION SURVEY (NHANES) 2003-04 AND 2015-16(2024) Vallejo, Jessica Vasquez; Turner, Paul C; Kadry, Abdel; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Acrylamide (AA) is an important industrial chemical of occupational concern due to its neurotoxicity and probable carcinogenicity; it is also a tobacco burning product and thus contributes to health concerns in smokers. More recently it was discovered to be thermally generated in the cooking of starch-rich foods, creating a potentially wider public health concern. Children and adolescents are a particularly vulnerable group because they consume more acrylamide-rich foods compared to adults. In addition, they are still going through important developmental stages. This study examines AA and its metabolite glycidamide (GA) using hemoglobin adduct biomarkers (HbAA and HbGA respectively) from the U.S. children (6-11) and adolescents’ (12-19) National Health and Nutrition Examination Survey’s 2003-04 (n=2814) and the 2015-16 (n=697). The study investigated changes in exposure over time and examined the contribution of potential modifiers including smoking status, race/ethnicity, poverty-to-income ratio, sex, and age. All HbAA and HbGA are reported as pmoL adduct per gram Hb (pmol/G Hb).Overall, HbAA biomarkers significantly (p<0.0001) declined from 2003-04, GMs (95% CI) (57.9 [55.7, 60.1] pmol/G Hb) versus (42.8 [41.4, 44.2] pmol/G Hb) in 2015-16 for all ages, with similar reductions observed in the individual children and the adolescent groups. Smokers had a higher burden of HbAA biomarkers than non-smokers, and with a significant reduction in numbers of smokers from 2003-04 to 2015-16, this likely contributes to the reduction in overall exposure. When non-smokers only were examined, a significant (p<0.0001) decrease in HbAA was still observed, from 2003-04 GMs (95% CI) (53.4 [52.0, 54.9] pmol/G Hb) versus (41.2 [40.2, 42.2] pmol/G Hb) in 2015-16, suggesting an additional contribution of changes in AA levels in food or frequency of high-risk food consumption. Similar statistically significant reductions were seen for both children and adolescent groups separately. HbGA is a marker of AA biotransformation to GA, which is a more mutagenic metabolite of AA. The ratio is of HbAA:HbGA is a phenotypic marker of mutagenic risk. In non-smokers, there was a significant (p=0.001) difference in the HbAA:HbGA ratio in children GMs (95% CI) (0.8 [0.8, 0.8] pmol/G Hb) at 2003-04 and (0.9 [0.9, 1.0] pmol/G Hb) at 2015-16 versus adolescents (1.0 [1.0, 1.1] pmol/G Hb) at 2003-04 and (1.1 [1.0, 1.2] pmol/G Hb) at 2015-16, respectively, suggesting children may be at greater risk to the mutational effects of AA exposure compared to adolescents. In multivariate regression analysis of non-smokers only, age and race significantly contributed to the HbAA biomarker levels, with higher HbAA in younger age groups and in non-Hispanic black participants, highlighting a disparity in exposure pattern. Overall, AA exposure seems to have reduced from 2003-04 to 2015-16; the reduction is driven by both changes in smoking but also diet. The young and non-Hispanic black participants remain at highest risk of exposure and potential health effects from exposure to AA.Item The Effects of Marijuana Legalization on Adolescent Alcohol Consumption(2019) Montano, Ashley Nicole; Dugan, Laura; Criminology and Criminal Justice; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Among researchers, there has been a long-standing debate on the issue of whether alcohol and marijuana are used as substitutes or complements of one another. In other words, does the increased usage of one decrease the usage of the other (substitution) or does usage of both substances simultaneously increase (complements)? The primary purpose of this study is to identify whether a suggested substitution or complementary effect exists among adolescent drinking patterns following the recent emergences of increased marijuana legalization. To explore these effects, data is used from 38 different states included in the Youth Risk Behavior Surveillance System between the years 1995 and 2017. The primary analysis finds limited support for a substitution effect and no evidence of a complementary effect among adolescents. This study also includes a supplementary analysis providing implications for the direction of future research on the apparent relationship between alcohol and marijuana usage patterns.Item Adolescents on the Lookout for Suicidal Friends on Social Networking Sites(2013) Berger, Jill; Gottfredson, Gary D.; Counseling and Personnel Services; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)There are opportunities to identify and intervene with suicidal adolescents through social media outlets. This study explored the effectiveness of using two types of persuasive messages to encourage adolescents to get help for Facebook friends who might be suicidal. Facebook-using adolescents (N = 299) were recruited to participate in an online survey within which a randomized experiment was embedded. More than one third of participants reported seeing Facebook friends post about suicide. Participants were randomly assigned in a 2x2x2 design to exposure or no exposure to suicide prevention information, a suicide intervention story, and a pre-test assessment. The effects of these conditions on participants' knowledge of what to do and their intentions to get adult help were examined. Participants exposed to information were more likely to report that they knew what to do for a suicidal friend; whereas those exposed to the story were more likely to express intentions to get adult help when presented with suicidal scenarios. Stories depicting social role models appear to be an effective way to encourage adolescents to take appropriate actions when friends post content suggestive of suicide on Facebook. Further research exploring how youth suicide prevention efforts can be integrated with social media is warranted.Item Using Argumentative Discussion to Enhance the Written Arguments of Middle School Students in Social Studies Classrooms(2012) Wissinger, Daniel R.; De La Paz, Susan; Special Education; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The purpose of this study was to explore the effects of Walton, Reed, and Macagno's (2008) dialectical framework on middle school students' historical discussions and written arguments. To do this,151 middle school students from six classrooms were randomly assigned to one of two conditions and asked to participate in a three-week intervention that featured: (a) examining three controversial topics in history, (b) primary source documents, (b) argumentative discussions, and (c) constructing argumentative essays. Because students were taught in small groups, the average performance of 12 groups of students who were assigned to the experimental condition was compared to the average performance of 12 groups of students who were assigned to the comparison conditions. Students in the experimental condition learned argumentative schemes and asked critical questions during discussions. Students in the comparison condition participated in the same historical investigations, received the same materials for instruction, engaged in discussions, and learned about text structure for writing argumentative essays in ways comparable to the experimental group, but used a traditional set of questions during discussions. The findings indicated a significant relationship between teaching students to use argumentative schemes and to ask critical questions during discussions and performance on students' resulting content knowledge. Main effects were also evident regarding students' historical thinking, a writing outcome that reflected use of evidence, ability to write from an author's perspective, use of contextual information, and the inclusion of rebuttals in their essays. While significant differences were not present between conditions on three outcome measures (i.e., reading comprehension, length of essays, or overall writing quality) students' in both sets of groups averaged moderate-to-high scores for reading comprehension and constructed essays that were considered proficient or advanced on the PSSA writing rubric. Taken together, the results of the study were encouraging and align with many of those in the existing literature, which emphasize the positive effects of integrating discussion in classroom activities.Item Following the Leader: Examining peer influence on sexual behavior(2009) Bears, Megan Ann; McGloin, Jean M; Criminology and Criminal Justice; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)A number of previous studies have found that peers influence adolescent sexual behavior. Still, it remains unclear how the mechanisms of peer influence operate on the sexual behavior of adolescents. This is unfortunate because it limits theoretical clarity and inhibits the production of policy aimed at reducing adolescent sexual behavior. Using data from the National Longitudinal Study of Adolescent Health, this thesis extends upon current literature and determines the role of peer attitudes and behaviors on different forms of adolescent sexual behavior as measured by peer self-report data while addressing other limitations of previous research such as whether or not mechanisms of peer influence are conditioned by adolescent involvement with peers. The discussion of this work centers around the theoretical implications of the findings that peers do not influence all forms of sexual behavior and peer behaviors seem to be the only mechanism of peer influence that predict sexual onset.Item DEVELOPMENT OF STUDENT MOTIVATION IN THE VISUAL ARTS USING HIP HOP CULTURE, AN ART SHOW, AND GRAFFITI(2009) Jenkins, Stephanie Conley; Hendricks, Susan; Curriculum and Instruction; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This participatory action research study explored the development of student motivation in the visual arts using hip hop culture. Six adolescent middle school students from a Washington, DC, public charter school were studied. They participated in an after-school art club centered on the National Portrait Gallery's "Recognize: Hip Hop and Contemporary Portraiture" special exhibition. The subjects were interviewed before and after visiting the museum and creating their own graffiti self-portraits. The self-portraits were displayed in an art exhibit at the school along with their artist statements. The interviews, statements and field notes were analyzed using the coding method. The results showed that feelings of competence, adequate support, autonomy, authentic purpose and personal connections to hip hop culture and musical artists all increased student motivation to participate in the visual arts. Motivation decreased when students attempted to create `real' looking graffiti, consistent with existing research.Item A MULTILEVEL ANALYSIS OF CONTEXT EFFECTS ON ADOLESCENT CIVIC ENGAGEMENT: THE ROLE OF FAMILY, PEERS, SCHOOL, AND NEIGHBORHOOD(2009) Wilkenfeld, Britt Skeens; Torney-Purta, Judith; Human Development; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The relations between multiple contexts of influence and adolescents' civic engagement were examined in order to facilitate understanding of how adolescents are being prepared for citizenship. This study extends previous research by simultaneously examining the family, peer, school, and neighborhood contexts, including how contexts are interrelated in their influence, and by employing multilevel regression techniques. The purpose of the study was to understand how contexts interact to produce positive outcomes for adolescents, especially those deemed at risk for poor civic outcomes. Utilizing data from the 1999 Civic Education Study and the 2000 U.S. Census, I examined a nationally representative sample of 2,729 14-year-olds from 119 schools in the United States. Access to the zip-codes for each school that participated in the study enabled the connection between neighborhood characteristics and schools and students within schools. Given the multifaceted nature of civic engagement, the current study considered context effects on four different aspects of civic engagement: civic knowledge, support for the rights of ethnic minorities, anticipated voting behavior, and anticipated community participation. Predictors pertain to adolescents' demographic characteristics, political discourse with parents and peers, civic experiences in school, and the demographic composition of the neighborhood. Political discourse with parents was positively related to civic knowledge, attitudes, and anticipated behavior, indicating the consistency with which socialization occurs in the home. Across the contexts examined, student measures of civic experiences in school (or civic learning opportunities) had the most consistently positive relationships with students' civic outcomes. Civic experiences in school include student confidence in the effectiveness of school participation, perception of a classroom climate that is open for discussion, and learning about ideal civic practices. Interactions between the school and neighborhood contexts indicate that higher levels of civic learning opportunities particularly make a difference for students attending schools in impoverished neighborhoods, sometimes substantially improving their civic outcomes. Schools, although implicated in the existence of a civic engagement gap, have the potential to narrow the gaps. Civic experiences in schools contribute to the preparation of youth for active citizenship and full access to these experiences reduces civic engagement gaps between students of different demographic groups.Item The Relations Among Maternal Depression, Parenting Behaviors, and Adolescents' Perceptions of Family Functioning: The Moderating Effect of Mothers' Couple Relationship Status(2008-05-05) Drescher, Amanda; Epstein, Norman; Family Studies; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This study examined relations among maternal depression, parenting behaviors, and adolescents' perceptions of family functioning. It also investigated whether parenting behavior mediated the relation between maternal depression and adolescents' perceptions of family functioning, as well as whether mother's couple relationship status moderated the relation between depression and parenting behavior. Maternal depression was not associated with adolescents' perceptions of family functioning. Maternal depression was associated with authoritarian and permissive parenting but not with authoritative parenting. Authoritarian and permissive parenting was associated with adolescents' perceptions of less positive family functioning, whereas authoritative parenting was associated with perceptions of more positive family functioning. Parenting behavior did not mediate between maternal depression and adolescents' perceptions of family functioning. Overall, mother's couple relationship status did not moderate the relation between maternal depression and parenting behavior; but there was a trend for the relation between depression and permissive parenting to be stronger when mothers were unpartnered.Item Listening to Adolescent Heartsongs: Phenomenological Possibilities in Teaching Writing(2007-05-29) Hartshorn, Mary Ann M; Hultgren, Francine H; Education Policy, and Leadership; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)ABSTRACT Title of Dissertation: LISTENING TO ADOLESCENT HEARTSONGS: PHENOMENOLOGICAL POSSIBILITIES IN TEACHING WRITING Mary Ann McKenzie Hartshorn Doctor of Philosophy, 2007 Dissertation directed by: Professor Francine Hultgren Department of Education Policy and Leadership College of Education University of Maryland This hermeneutic phenomenological inquiry, is called by the question: What is the lived experience of high school students who share something they have written from the heart? The metaphor of the human heart opens my understanding of the experiences of thirty-two students who write and share their writings in sophomore English class. My understanding of this experience deepens during after-school conversations with twelve of those students. Text, offering words for hermeneutic pondering, was compiled from conversations, journals, student writings and sharing activities. All voices were taped and transcribed to provide a visual remembrance of these lived experiences. The methodology underpinning this human science inquiry, is identified by Max van Manen (2003) as one that "involves description, interpretation, and self-reflective or critical analysis" (p. 4). Through my students' heartfelt words, I see them write their way to self-discovery. The importance of "lived space" (van Manen, 2002, p. 102) is brought forward, and lets me understand that students need to feel at "home" in school if they are to be successful. As we create a sacred space together, my students and I experience safety and freedom. In this space we find our "i-dentities" and hear our heartsongs. When sharing those songs, students announce their fears of failure, death and the swift passage of time; their memories; their longing for communication and disappointment in not connecting. We dwell together in the unique, sacredness of each other, opening a listening space where relationality "allows us to transcend ourselves" (p. 105). It is here that we celebrate more similarities than differences. The valued end of any class should include a place where students feel comfortable with themselves and others. Curriculum should be relevant to each student, providing an opportunity for self discovery and acceptance. Writing of a personal nature must be included across the curriculum so students learn to value themselves, fellow human beings, and the universe.Item Adolescents and Antidepressants: Analyzing a Social Scientific Controversy(2007-02-19) Nelson, Amber Dawn; Mamo, Laura; Sociology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This thesis analyzes the scientific controversy over giving antidepressant medications to adolescents as it unfolded in a U.S. Federal Food and Drug Administration (FDA) hearing. Using the FDA hearing held on February 2, 2004, convened in response to a "crisis" evolving around the safety of antidepressant use among adolescents, this paper analyzes the unfolding response. This study utilizes social world's analysis, a qualitative methods approach designed to uncover the multiple stakes and claims of the problem as understood by each person at the hearing. I identified four distinct social worlds: 1) Adolescents, family and friends, 2) Independent professionals, 3) FDA, and 4) FDA-summoned professionals. Findings revealed that 103 actors came together around the crisis and each defined the problem of the controversy through one or more of the following four distinct frames; (1) side effects, (2) data, (3) practices and policies and/or (4) a lack of access to informed choice.