UNT Theses and Dissertations - 18,578 Matching Results

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Effects of N⁶,O²'-Dibutyryl Cyclic Adenosine 3' ,5' Monophosphate on Transformation of Rat Kidney Cells and Chick Embryo Fibroblasts by Wild-Type and Temperature-Sensitive Rous Sarcoma Virus

Description: N^6,O^2' -Dibutyryl cyclic adenosine 3',5'-monophosphate (Bt_2cAMP) was investigated for its effects on various tissue culture cells infected with temperature-sensitive (ts) mutant, LA31 and Bratislava 77 (B77), a wild-type Rous sarcoma virus. Specifically, known parameters of transformation were investigated and a possible site of action has been tenably proposed. The drug Bt_2cAMP was found to have little effect on the transformation related properties of primary chick embryo fibroblasts (CEF) infected with either virus or normal rat kidney fibroblasts (NRK) infected with the wild-type B77-RSV. However, significant inhibition of the transforming properties in NRK infected with the ts mutant LA31 (LA31-NRK) were reported at the permissive temperature 33 degrees centigrade (33 C).
Date: December 1983
Creator: Marshall, David A. (David Allen)
Partner: UNT Libraries

Effects of Natural/anthropogenic Stressors and a Chemical Contaminant on Pre and Post Mycorrhizal Colonization in Wetland Plants

Description: Arbuscular mycorrhizal fungi, colonizing over 80% of all plants, were long thought absent in wetlands; however, recent studies have shown many wetland plants harbor arbuscular mycorrhizae (AM) and dark septate endophytes (DSE). Wetland services such as biodiversity, shoreline stabilization, water purification, flood control, etc. have been estimated to have a global value of $14.9 trillion. Recognition of these vital services is accompanied by growing concern for their vulnerability and continued loss, which has resulted in an increased need to understand wetland plant communities and mycorrhizal symbiosis. Factors regulating AM and DSE colonization need to be better understood to predict plant community response and ultimately wetland functioning when confronting natural and human induced stressors. This study focused on the effects of water quality, hydrology, sedimentation, and hurricanes on AM and DSE colonization in three wetland species (Taxodium distichum, Panicum hemitomon, and Typhal domingensis) and plant communities of coastal wetlands in Southeast Louisiana and effects of an antimicrobial biocide, triclosan (TCS), on AM (Glomus intraradices) spore germination, hyphal growth, hyphal branching, and colonization in fresh water wetland plants (Eclipta prostrata, Hibiscus laevis, and Sesbania herbacea) from bottom land hardwood forest in north central Texas. The former, mesocosm studies simulating coastal marsh vegetation ran for five years. In the latter studies, AM spores and wetland plants were exposed to 0 g/L, 0.4 g/L, and 4.0 g/L TCS concentrations in static renewal and flow through exposures for 21 and 30 days, respectively. AM and DSE colonization was significantly affected by individual and interactions of four independent variables in mesocosm experiments. Similarly, spore germination, hyphal growth, hyphal branching, and AM colonization in selected wetland plants were significantly lowered by exposure to the TCS at environmentally relevant concentrations. However, levels of effects were plant species and fungal propagules specific. My results showed that natural and human ...
Date: August 2013
Creator: Twanabasu, Bishnu Ram
Partner: UNT Libraries

The Effects of Naturalistic Language Interventions in Children with Autism

Description: Several evidence-based procedures based upon operant learning principles have been developed to teach language, and for young children with autism spectrum disorder (ASD), naturalistic interventions are commonly implemented as they are both effective and developmentally appropriate. The current investigation compared contingent responsive intervention and combined intervention on the effects of language use in four children diagnosed with ASD. Results suggest that a combined intervention procedure increases target language and requests in children with simplified language (e.g., one-word phrase) as well as complex language (e.g., simple sentences).
Date: August 2016
Creator: Degner, Brittany
Partner: UNT Libraries

The Effects of Neighboring, Social Networks, and Collective Efficacy on Crime Victimization: an Alternative to the Systemic Model

Description: The systemic model posits that informal social control directly reduces crime victimization and social networks indirectly reduce crime victimization through informal social control. While empirical testing of the systemic model advanced the theory, important analytical issues remain. First, social networks are inconsistently conceptualized and measured. Second, the conceptual relationship between social networks and informal social control remains unclear. This study addresses these issues by testing an alternative to the systemic model, including new constructs and hypotheses. The goal is to develop better indicators for the model and refine the theory, rethinking and deepening the existing theory about neighborhood effects on crime victimization. The data come from the 2002-2003 Seattle Neighborhoods and Crime Survey (N=2,200). Structural equation modeling (SEM), a multivariate statistical technique, was used to analyze these data. The SEM included five latent constructs (neighboring, neighborhood and non-neighborhood social networks, collective efficacy, and crime victimization) and six social structural variables (racially homogeneous neighborhood, resident tenure, household income, family disruption, male, and non-white ethnicity). One of my 9 hypotheses was supported; the remaining hypotheses were partly supported. The results support my argument that the systemic model is too simplistic, but the relationships among the variables are not exactly as I hypothesized. The results provide insight into the complexities of the systemic model and areas for future research.
Date: May 2015
Creator: Soto, Anthony Jaime
Partner: UNT Libraries

The Effects of Neonicotinoid Exposure on Embryonic Development and Organ Mass in Northern Bobwhite Quail

Description: Since their emergence in the early 1990s, neonicotinoid use has increased exponentially to make them the world's most prevalent insecticides. Although there is considerable research concerning the lethality of neonicotinoids, their sub-lethal and developmental effects are still being explored, especially with regards to non-mammalian species. The goal of this research was to investigate the effects of the neonicotinoid imidacloprid on the morphological and physiological development of northern bobwhite quail (Colinus virginianus). Bobwhite eggs (n = 650) were injected with imidacloprid concentrations of 0 (sham), 10, 50, 100 and 150 grams per kilogram of egg mass, which was administered at day 0 (pre-incubation), 3, 6, 9, or 12 of growth. Embryos were dissected on day 19 when they were weighed, staged, and examined for any overt structural deformities. Embryonic heart, liver, lungs and kidneys were also weighed and preserved for future use. Treated embryos exhibited increased frequency of severely deformed beaks and legs, as well as larger hearts and smaller lungs at the higher dosing concentrations. Some impacts are more pronounced in specific dosing periods, implying that there may be critical windows of development when embryos are highly susceptible to neonicotinoid exposure. This investigation suggests that imidacloprid could play a significant role in chick survival and declining quail populations in treated regions of the country.
Date: May 2016
Creator: Gobeli, Amanda
Partner: UNT Libraries

The Effects of News Commentary on the Image of Political Debaters: An Experimental Study

Description: The purpose of this study was to examine the effects of news commentary on the image of political candidates. Subjects were exposed to a political debate, which was followed by three experimental manipulations of a news commentary. One group saw a commentary biased toward one candidate and against the other. In a second group the bias was reversed. A third experimental group saw a neutral commentary and the control group viewed the debate but no commentary. The primary statistical analyses used were a multivariate analysis of variance, a multiple discriminant analysis and a factor analysis. The results indicated that the commentary did have some effects on the perception of the candidates' images. Furthermore, the commentaries affected the amount of the candidates' message which was recalled by the subjects, and cued the subjects to recall specific issues which were mentioned in the commentaries. Finally, the factor analysis indicated certain characteristics of the images of political candidates.
Date: December 1977
Creator: Hertzog, Robert L.
Partner: UNT Libraries

The Effects of Non-differential Reinforcement and Differential Reinforcement on Problem Behaviors and Accuracy of Responding of Autistic Children.

Description: The effects of non-differential reinforcement and differential reinforcement on problem behaviors and accuracy of responding of autistic children was examined. In experiment 1, one child with autism participated, and in experiment 2, two children with autism participated. In the non-differential reinforcement condition both prompted and unprompted responses were reinforced. In the differential reinforcement condition only unprompted responses were reinforced. Overall, problem behaviors were more frequent in the non-differential reinforcement condition. In experiment 1, accuracy was higher in the differential reinforcement condition, while experiment 2 showed inconclusive results with regards to accuracy. It is concluded that non-differential reinforcement can decrease problem behaviors in teaching situations, but may not be sufficient to ensure acquisition of target tasks.
Date: May 2002
Creator: Ingvarsson, Einar Thor
Partner: UNT Libraries

Effects of Non-homogeneous Population Distribution on Smoothed Maps Produced Using Kernel Density Estimation Methods

Description: Understanding spatial perspectives on the spread and incidence of a disease is invaluable for public health planning and intervention. Choropleth maps are commonly used to provide an abstraction of disease risk across geographic space. These maps are derived from aggregated population counts that are known to be affected by the small numbers problem. Kernel density estimation methods account for this problem by producing risk estimates that are based on aggregations of approximately equal population sizes. However, the process of aggregation often combines data from areas with non-uniform spatial and population characteristics. This thesis presents a new method to aggregate space in ways that are sensitive to their underlying risk factors. Such maps will enable better public health practice and intervention by enhancing our ability to understand the spatial processes that result in disparate health outcomes.
Date: December 2014
Creator: Jones, Jesse Jack
Partner: UNT Libraries

Effects of Note-Taking and Trust Level on Self-Disclosure of Prisoners

Description: This study investigated the effects of trust level and note-taking upon the level of self-disclosure among prisoners. Sixty inmates at a federal prison were administered the Rotter Interpersonal Trust Scale. Next, using a median split, participants were divided into two groups of high and low mistrust. Subjects within each of these groups were then randomly assigned to a high, low, or no note-taking condition. Each prisoner then discussed an intimate topic for thirty minutes. Level of self-disclosure was measured by an abbreviated version of the Rotter Incomplete Sentences Blank. No significant differences were found as a function of trust level or note-taking condition. Some implications for further research are suggested.
Date: August 1989
Creator: Gontz, Barbara J. (Barbara Jeanne)
Partner: UNT Libraries

Effects of Note-Taking on Self-Disclosure Among Prisoners

Description: The effects of note-taking on self-disclosure during a clinical interview among prisoners were investigated. Participants consisted of 60 male and female inmates incarcerated in a minimum security prison. Subjects within each gender were randomly assigned to either high note-taking, low note-taking or no note-taking conditions. Subjects were asked to discuss intimate information during an interview while varying levels of notes were taken. Self-disclosure was assessed using items from the Rotter Incomplete Sentences Blank. A 3 x 2 ANOVA was conducted. No significant main effects were found. However, a significant interaction was found. Further analysis revealed that females in the high note-taking condition disclosed less than females in the no note-taking condition. Some theoretical and clinical implications are suggested.
Date: December 1989
Creator: Lowrey, Kimberly D. (Kimberly Dawn)
Partner: UNT Libraries

The Effects of Oat Fiber and Corn Bran on Blood Serum Cholesterol and Triglyceride Levels

Description: Forty Sprague Dawley rats were randomly placed in five groups with eight rats per group. Each group varied in dietary composition for fiber type and carbohydrate source. Groups one and two received oat fiber and either sucrose or corn starch as the carbohydrate source. Groups three and four received corn bran as the fiber source and either sucrose or corn starch as the carbohydrate source. Group five (considered the control group), received Purina standard rat chow. Analysis of variance showed only significant differences for food intake, and the control group had a significantly higher food intake. Weight gain, serum cholesterol and triglyceride levels showed no significant differences.
Date: August 1985
Creator: Broeder, Craig E. (Craig Elliot)
Partner: UNT Libraries

The Effects of Organic Surface Amendments on Soil Nutrients and Initial Tree Establishment

Description: This study examined the effects of replicating woodland soil surface horizonation on the nutrient status of underlying soils and the initial establishment and growth of trees. A total of 283 container grown trees were planted in a bufferzone around a future landfill site. Control amendments consisted of an 8 cm layer (0.5 m3) of wood chips applied in a circular area of 4.6 m2 around the trees' planting pit. For the treatment, a 2.5 cm layer of composted biosolids (0.15 m3 or 80 Mg/ha) was applied in a circular area of 4.6 m2 around the trees' planting pit followed by an 8 cm layer (0.5 m3) of wood chips. The results indicate that the replication of woodland soil surface attributes using composted biosolids can significantly improve the nutrient status of underlying soil. Some significant effects were seen under control conditions, too. However, the effects on tree establishment and growth parameters were, for the most part, not statistically significant.
Date: May 1999
Creator: Thuesen, Kevin (Kevin Andrew)
Partner: UNT Libraries

The effects of organizational climate and leadership behavior on teacher job satisfaction in selected schools

Description: The study proposed to determine the relationship of the teachers' perception of the organizational climate of the school as measured by the Organizational Climate Description Questionnaire (Halpin) and leader behavior as measures by the Leader Behavior Description Questionnaire (Halpin) with teacher job satisfaction as measured by the Minnesota Satisfaction Questionnaire.
Date: December 1979
Creator: Craig, Larry V.
Partner: UNT Libraries

The Effects of Parent Training on the Amount and Variety of Food Consumed By a Child with Autism.

Description: The current study assessed the effectiveness of a training package, delivered in the form of a manual, to teach a parent to increase the variety and amount of food consumed by her son. The participant was a 5-year-old boy with Pervasive Developmental Disorder and limited food consumption. A changing criterion design across two variables, variety of food and quantity of food, was used. Results were that the parent who used the manual, with limited assistance from the experimenter, did succeed in increasing food variety and quantity of target foods.
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Date: May 2004
Creator: VanKirk, Tessa Schreiber
Partner: UNT Libraries

The Effects of Parental Divorce and Conflict on Adolescent Separation-Individuation

Description: The influence of parental marital status and parental conflict on the separation-individuation process of college students was investigated in the present study. Past studies have suggested that parental divorce and parental conflict accelerate separation. However, no studies have measured more than one dimension of separation-individuation. In this study the process of separation-individuation was operationalized as involving three dimensions: psychological separation from parents (Psychological Separation Inventory); emotional attachments to parents and peers (Inventory of Parent and Peer Attachment); and the development of an identity (Extended Objective Measure of Ego Identity Status). The sample consisted of 120 male and 120 female undergraduates between the ages of 18 and 22, one-half with parents who were married and one-half with parents who had divorced in the last five years. Subjects completed self-report measures of parental conflict, psychological separation, attachment to parents and to peers, and identity status. Predictions that parental conflict would affect students in intact families differently than their peers with divorced parents were not supported. Instead, parental divorce and conflict were found to have different effects on the components of the separation-individuation process. Subjects reporting higher parental conflict levels described more independent functioning, more negative feelings toward parents, less attachment to parents and to peers, and greater exploration of identity-related issues in comparison to those reporting low levels of conflict. Subjects with parents who had recently divorced reported lower attachment to parents, and greater identity exploration and reluctance to commit to an identity than subjects from intact families. Males reported greater independence from and less attachment to parents, and had committed to an identity without exploration less often than females. Results suggest that parental divorce and conflict may influence adolescent development in different ways. Exploratory analyses suggested that measures of conflict style are more highly related to indices of separation-individuation than measures ...
Date: August 1993
Creator: Marsh, Greg (Gregory Gene)
Partner: UNT Libraries

The Effects of Parental Divorce and Family Conflict on Young Adults Females' Perceptions of Social Support and Adjustment

Description: The purpose of this study was to explore the effects of parental divorce and family conflict during adolescence on young adult females' social support and psychological adjustment. The three areas explored were perceptions of relationship satisfaction and closeness, sources and amount of social support and adjustment. One hundred and forty-one female undergraduates, 53% from families in which their parents are still married and 47% from families in which a parental divorce occurred during adolescence, completed the following measures: the Dyadic Adjustment Scale (Spanier, 1976), the Social Provisions Scale-Source Specific (Cutrona, 1989), the Inventory of Common Problems (Hoffman & Weiss, 1986), the Family Environment Scale (Moos & Moos, 1981), and the Sibling Relationship Questionnaire (Furman & Buhrmester, 1985).
Date: May 1998
Creator: Quinn, M. Theresa
Partner: UNT Libraries

The Effects of Parental Marital Status, Just World Beliefs, and Parental Conflict on Trust in Intimate Heterosexual Relationships

Description: The effects of divorce on trust in intimate heterosexual relationships were investigated using a sample of 478 college students (156 males, 322 females). Subjects were asked to respond to scenarios and questionnaires assessing parental marital status, just world beliefs, parental conflict, and trust. Attitudes toward divorce and common problems were also assessed.
Date: December 1993
Creator: Taylor, Bryce E. (Bryce Ernest)
Partner: UNT Libraries

The Effects of Parental Substance Abuse on the Behavior of School Children

Description: The purpose of the present archival study was to investigate the relationship between parental substance abuse and the risk for maladjustment and psychopathology in children in a clinic sample. Children of alcoholic parents and children of drug-dependent parents were compared to children of non-substance abusing parents. The subjects were 83 boys age 6 to 12. Children of substance abuse parents had lower levels of adaptive functioning and higher levels of school behavioral problems. Although previous studies have reported a strong association between an adverse family environment and the risk of child maladjustment, the present study did not find that the addition of an adverse family environment increased the risk for maladjustment or school behavioral problems in children of substance abusers.
Date: May 1993
Creator: Prelow, Hazel (Hazel M.)
Partner: UNT Libraries