UMD Theses and Dissertations
Permanent URI for this collectionhttp://hdl.handle.net/1903/3
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 given thesis/dissertation in DRUM.
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Item Proximate mechanisms and ultimate causes of female reproductive skew in cooperatively breeding golden lion tamarins, Leontopithecus rosalia(2011) Henry, MaLinda Dawn; Dietz, James M; Behavior, Ecology, Evolution and Systematics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Many cooperatively breeding species exhibit high reproductive skew. Delayed dispersal and cooperative breeding may have evolved as a consequence of the limits ecological constraints place on independent breeding. When simultaneous breeding by multiple females reduces the survival of the dominant's offspring, selection should favor dominants able to control subordinate reproduction. Monopolization of reproduction by dominant group members by means of suppression of subordinate reproduction has been documented in several taxa of cooperative breeders. In this dissertation I examine the proximate mechanisms and ultimate causes of reproductive skew in cooperatively breeding golden lion tamarins (Leontopithecus rosalia). In chapter one I combine data from phenological transects with hormonal evaluation of reproductive status to test whether caloric availability limits reproduction by female tamarins. Caloric availability was sufficient to support not only pregnancy polygyny in 83% of tamarin groups, but also the additional group members resulting from multiple litters. The super abundance of calories and the timing of births suggested that competition for allocare rather than for food resources may be the selective force limiting reproduction by subordinate females. In my second chapter I combine hormonal and demographic data to explain reproductive skew in terms of the costs and benefits to subordinate fitness under existing social circumstances. Subordinate females older than 18 months of age ovulated while residing within their natal group, but conceptions were delayed one to two years following reproductive maturity. The likelihood of successful reproduction by a subordinate female doubled with each year of age of the dominant female. Conceptions under incestuous mating conditions were rare (7 of 37 pregnancies). My results provide support for the hypothesis that subordinate adult females under three years old exercise reproductive self-restraint. I speculate that the threat of being evicted from the group and inbreeding avoidance are sufficient to delay attempts at reproduction by young subordinates without the need for costly fighting with the dominant female. In my third chapter I test whether reproduction by subordinate adult female tamarins is limited by dominant females who have incomplete control (incomplete control model, ICM) or complete control (optimal skew model, OSM) over subordinate reproduction. I combine hormonal data with group demography and caloric availability to determine variables useful in predicting a successful pregnancy to a subordinate female. Whereas subordinate females younger than 2.5 years of age ovulated but did not conceive, all females older than 3.9 years of age became pregnant. Reproduction in subordinate adult females was not limited by hormonal suppression of ovulation or conception, but by the failure of 7 of 11 pregnancies to produce live offspring. The likelihood of reproductive success increased 1.7 times with each additional group member. My results suggest that when caloric availability is sufficient to support reproduction by two breeding females and the group members necessary to provide allocare for two litters, subordinate females do not abide by a social contract that would limit their reproduction (OSM). Instead, older subordinates compete with dominant females for reproduction and succeed in producing live young if the dominant female is at least 10 years old, if subordinates conceive while the dominant is heavily pregnant, and if they reside within larger groups (ICM).Item The effects of social skills instruction on the social behaviors and academic engagement of elementary students with challenging behaviors(2011) Kieta, Sharon Ruth; Kohl, Frances L; Special Education; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Social skills are critical to the success of students in elementary school. Antisocial behaviors interfere with the development and maintenance of positive relationships and with the academic success of students. The purpose of this study was to examine the effects of social skills instruction on the social behaviors and academic engagement of elementary school students with challenging behaviors in classroom settings. A multiple probe across participants design was used. Three general education teachers conducted nine lessons from the SSIS Classwide Intervention Program during health class. Direct observations of positive social behaviors, antisocial behaviors, and academic engagement were conducted during baseline, intervention, and maintenance conditions on one target student with challenging behaviors in three general education teachers' classrooms during core instructional classes such as math, language arts. and science. The SSIS Classwide Intervention Program positively impacted positive social behaviors and academic engagement for all three target students and these improved behavioral outcomes persisted two to eight weeks after the intervention ended. Antisocial behaviors decreased for two of the three students and this improved behavioral outcome persisted four to eight weeks after the intervention ended. All three students had some difficulty using the skills learned when a substitute conducted their class. General education teacher participants reported satisfaction with program planning, implementation, and the effectiveness of the intervention for target students and their entire class. Two additional teachers providing intercultural education to the same three classes reported behavioral improvements for all three students but only improved behavior for one teacher's class as a whole. Student participant responses to the intervention were mixed. Overall, the SSIS Classwide Intervention Program was an effective and socially valid means of increasing positive social behavior and academic engagement and decreasing antisocial behavior among elementary students with challenging behaviors. The results of this study contributed to the research based on the efficacy of classwide social skills instruction. Furthermore, the results of this study provided evidence for teachers and administrators advocating for the financial resources and instructional time to implement social skills instruction in the general education program.Item UTILIZING SOCIAL NETWORKS ANALYSIS IN THE CHARACTERIZATION OF AFRICAN UNGULATE SOCIAL STRUCTURE(2010) Carpenter, Leah Danielle; Ottinger, Mary Ann; Thompson, Katerina V; Behavior, Ecology, Evolution and Systematics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Social networks analysis tools were used to investigate the social structures of two African ungulate species. Captive herds of addra gazelle (Gazella dama) and roan antelope (Hipptragus equinus) were observed. Social networks were constructed of each herd's affiliative (socially cohesive) interactions and nearest-neighbor (closest individual within 2 body lengths) associations during three time periods. I evaluated whether network measures could be explained by individual, dyadic or sub-group attributes at three levels of social network organization. Both roan and addra males were very central to their networks, and in some time periods so were juveniles. Roan and addra partner preferences differed, with addra tending to affiliate by age class while roan were more variable in their partner preferences. Matrilinealy-related sub-groups were also identified in addra. This networks analysis approach has broad applicability for characterizing animal social organizations as well monitoring captive populations.Item THE RELATIONSHIP BETWEEN INCOME, WEALTH, AND LIFE SATISFACTION(2010) Hitaj, Ermal; Murrell, Peter; Prucha, Ingmar; Economics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This dissertation inquires into the relationship between income, aspirations, and life satisfaction in post-transition Russia. It first explores the channels through which adaptation and social comparison contribute to higher income aspirations. The results show that social comparison is a strong agent in shaping aspirations, while the effect of adaptation is relatively weak. Subsequently, the dissertation tests for the effect of aspirations on two separate satisfaction indices, satisfaction with life and satisfaction with economic conditions. This dissertation uses a Chamberlain random-effects ordered probit estimation to control for time-invariant unobservable individual traits. In contrast to previous studies, the results suggest that increases in aspirations have a positive effect on life satisfaction. This dissertation argues that this is caused by the expectations contained in income aspirations. Higher aspirations reflect an increase in needs commensurate to changes in own and others' income, but they also reflect improved income expectations based on the information provided by the present income of relevant others. The improved outlook embedded in the higher income aspirations causes the latter to have a positive effect on life satisfaction. This suggests that, ten years into the transition process, the reaction patterns of life satisfaction in Russia differ substantially from those in developed countries. While the relationship between life satisfaction and income or institutions has recently received a lot attention, the relationship between life satisfaction and accumulated wealth remains unexplored. This dissertation makes use of the 2008 Gallup World Poll and a novel wealth database compiled by the World Bank to evaluate the effect of wealth, produced capital, and natural resources on life satisfaction. The dissertation finds that both produced capital and natural capital have a positive effect on life satisfaction. The effect of good institutions and informal safety nets is also positive. However, in results that parallel findings from the resource curse literature, this dissertation shows that the positive effect of natural capital is due to diffuse natural resources like cropland, pastureland and forestry. Subsoil asset wealth has no significant effect on life satisfaction. Blood feuds represent a significant challenge to law enforcement, institutional consolidation and economic development due to the violence they generate and the other forms of crime they contribute to. This paper seeks to model and explain the decision making dynamics behind blood feuds. Rather than a simple retaliatory act, the violence associated with blood feuds is very much an integral aspect of an institutional framework that reflects a different set of ecological conditions and preferences. This paper incorporates different cultural and ecological aspects of various societies into a theoretical model that explains how blood feuds are sustained in a society. In addition, the model developed in this paper helps explain the longevity of blood feuds and reconcile different views from the anthropology literature.Item The Challenge of Teen Nutrition: An Ecological View of Sociocognitive Influences on Urban, African-American Adolescent Diet Quality(2010) Wrobleski, Margaret Mary; Atkinson, Nancy L.; Public and Community Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The routine food choices that adolescents make impact their nutritional status, health, and their risk of developing chronic illnesses such as heart disease, cancer, and osteoporosis in the future. Nutrient requirements during adolescence are comparable to those in early infancy, emphasizing the importance of a high quality diet for healthy growth and development. A myriad of personal, social, and environmental factors influence adolescents in shaping their dietary intake and quality of diet. Low-income, African-American adolescents in Baltimore were identified as having sub-optimal nutritional intake compared to national dietary recommendations. This study explored the dynamic and relative contributions that factors within three environmental levels (personal, social, and community) made as predictors of diet quality in a sample of low-income, urban African-American adolescents using an integrated Social Cognitive Theory (SCT) / ecological theoretical framework. It was hypothesized that 1) the personal, social, and community environmental levels of dietary influences would all significantly contribute to diet quality, with community environment making the largest relative contribution; 2) self-efficacy for healthy eating moderated the relationship between parental beliefs about nutrition and diet quality; and 3) self-efficacy for healthy eating moderated the relationship between peer eating behaviors and diet quality. There have been very few studies using an integrated SCT/ecological model to explore the dietary influences on adolescent nutrition, especially on this demographic. The significant influence the SCT construct of observational learning has on adolescents was evidenced in this study by the positive relationship found between diet quality, parental beliefs about nutrition, and peer eating behavior. Younger participants in early adolescence and females were predominately guided by their parents' beliefs about nutrition, while males in this study appeared to identify more with their peers' nutrition-related behaviors. This study revealed that parents and peers play important roles in African-American adolescents' food choices and subsequent diet quality. Nutrition interventions should focus on parent-teen interactions and on improving the dietary habits of parents so they may be more effective role models for youth. Nutrition promotion research targeting young African-American men may consider using group interactive behavioral interventions with peers that build and reinforce peer modeling of positive nutrition behaviors.Item The Role of Provider-Role Ideology and Consistency in Couple Communication(2010) Brenneman, Jessica Lynn; Leslie, Leigh A; Family Studies; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This study investigated how problem solving and conflict in couples' communication is affected by their beliefs about provider role ideology, and the consistency between their beliefs and their actions. It was predicted that couples who have the same provider-role ideology and couples who are consistent in their behavior and beliefs will use more problem solving and less hostile conflict behaviors than couples who are unmatched in their beliefs or inconsistent in beliefs and behavior. Contrary to predictions, no relationship between ideology, consistency, and communication was found. However, the results did show a significant relationship between women earning a large portion of the household income and greater amounts of hostile conflict in the couple communication. The implications for future research and clinical applications are discussed.Item Infant Preferences for Two Properties of Infant-Directed Speech(2010) Segal, Judith Lee; Newman, Rochelle S; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This study examined preferences for prosodic and structural properties of infant-directed speech (IDS) in 20 infants, 11 girls and 9 boys, ages 0;11;3 to 0;13;0 (mean age 0;11;28). It was hypothesized that year-old infants would demonstrate a preference for infant-directed structure (IS) over adult-directed structure (AS) regardless of prosody, and that infants would demonstrate no preference for either infant-directed prosody (IP) or adult-directed prosody (AP) regardless of structure. Listening times to passages were compared across infants for four conditions: IS/IP; IS/AP; AS/IP; AS/AP. Results indicate a non-significant but noticeable trend toward a preference for infant-directed structure. In addition, weak correlations were found between vocabulary size and strength of preference for adult-directed prosody, and between age and strength of preference for adult-directed prosody. A non-significant but noticeable interaction was found between prosody and structure and vocabulary. Overall, infants appear to prefer listening to infant-directed structure to adult-directed structure; more advanced language learners show a stronger preference for adult-directed prosody than do their less advanced age-mates; older infants show a stronger preference for adult-directed prosody than do younger infants; and preference for infant-directed structure (but not infant-directed prosody) depends on vocabulary level.Item Voice Onset Time in Infant-directed Speech at Two Ages(2010) Synnestvedt, Anna; Bernstein Ratner, Nan; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Studies have reported differences between infant-directed speech (IDS) and adult-directed speech (ADS), suggesting that mothers adjust speech to their infants in ways that may help children process the incoming acoustical signal. One aspect of IDS that has been examined is clarification of voice onset time (VOT). Results have been inconsistent and many studies only report differences in VOT values rather than differences in amount of overlap between voiced and voiceless items. The present study examines 15 mothers' VOT in IDS at 7.5 months old and again at 11 months as compared to their VOT values in ADS. Words with initial stop consonants that occurred in IDS and ADS conditions were analyzed using PRAAT. Contrary to hypotheses, results show that VOT in IDS was less differentiated than VOT in ADS. Additionally, voiced items had significantly longer VOT in IDS than ADS, with no difference for voiceless items. Possible explanations are discussed.Item Racial Differences in the Effectiveness of After School Programs(2010) Son, Daniel; Gottfredson, Denise; Criminology and Criminal Justice; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)After school programs (ASPs) are intended to support children by providing supervised academic and recreational activities during after school hours. Recently ASPs have been gaining popularity and public support which has led to increased funding for such programs. Before we increase federal funds further, it is important to know whether these programs are effective. The research on the effectiveness of ASPs is mixed and inconclusive. Therefore more research is needed. The focus of this study is to see if ASPs are differentially effective for students in different racial groups. The ASP was implemented in five low-performing middle schools in Baltimore County. Students were randomly assigned into treatment and control groups. No significant interactions of race by ASP were observed. A marginally significant interaction (p<.10) was observed for math scores and victimization. The marginally significant interactions were explained by pre-treatment variables. Race does not play a major role in the program effects of ASPs.Item Spirituals And Gospel Music Performance Practice: A Dual Curriculum That Bridges The Cultural Divide(2010) Jefferson, Robert Lee; Mabbs, Linda; Music; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This study explores methods in which the teaching of Gospel Music and Spirituals can be used as a conduit to bridge ethnic, cultural, and racial divides that are often found in American society. After working with various cultural and racial groups within religious and secular circles, the researcher has observed that individual cultures can have very distinct and opposite approaches to learning music, even in the United States, which some consider to be a cultural "melting pot." More specifically, there are cultures that embrace the written or visual learning tradition, while others lean more heavily toward the aural or oral learning tradition. As a result, the perceived differences deriving from these two opposite learning traditions can often create both unconscious and conscious divisions among various cultural and ethnic groups. However, using teaching techniques and performance practices related to both Gospel Music and Spirituals (which use different although related learning approaches), one can create an opportunity to bridge the gap between the aural and visual learning traditions and can create an environment ripe for intra-cultural and cross-cultural communication. This dissertation studied two separate groups of individuals; one group from the visual cultural learning tradition and one group from the aural cultural learning tradition. Both groups were taught music through the process of either an aural or visual process (or in some cases, by a combination of both), and their behavioral responses were observed during rehearsals. The results of these observations are used to create an outline for curricular approaches to teaching groups from opposing learning traditions, utilizing the opportunity that this presents not only to bridge the divide which often exists between individuals from different learning traditions, but also to offer a way to address ethnic and cultural divides.