UNT Theses and Dissertations - 18,417 Matching Results

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The Effects of Jackpots on Responding and Choice in Two Domestic Dogs

Description: The current study investigated the impact of delivering a jackpot on response rate and response allocation in two domestic dogs. For the purpose of this research, a jackpot was defined as a one-time, within-session increase in the magnitude of reinforcement. Two experiments were conducted to investigate the effects of delivering a jackpot in both single-operant and concurrent schedule procedures. Experiment 1 investigated the impact of a one-time, within-session increase in the magnitude of reinforcement on response rate in a single-operant procedure. Results of Experiment 1 showed no clear change in response rate after the delivery of the jackpot. Experiment 2 investigated the impact of a one-time, within-session increase in the magnitude of reinforcement on response allocation in a concurrent schedule procedure. Results of Experiment 2 showed an increase in response allocation to the jackpotted contingency in both subjects. These results suggest that a jackpot, as defined here, has no effect in single-operant procedures while having an effect in concurrent schedule procedures. These effects are similar to those reported in the magnitude of reinforcement literature.
Date: May 2010
Creator: Muir, Kristy Lynn
Partner: UNT Libraries

The Effects of Labeling and Stigma on the Social Rejection of Striptease Performers

Description: This study uses survey data collected from a convenience sample of undergraduate students (N=89). A vignette survey design is employed to measure social rejection of striptease performers compared to a control group. Data is also collected on negative stereotypes held about striptease performers, which are correlated with social rejection. Link and Phelan's conceptualization of the stigma process provides the theoretical framework for this analysis. Findings suggest that striptease performers experience higher levels of social rejection and are perceived more negatively than the control group and that endorsement of negative stereotypes is associated with social rejection.
Date: December 2006
Creator: Ebeid, Omar Randi
Partner: UNT Libraries

The Effects of Lateralization of Task on the Use of the Dual Task Paradigm as a Measure of General Intelligence

Description: Stankov's work on attention and intelligence suggests that the dual task paradigm, requiring the division of attention, is a better measure of general intellectual ability than the single task paradigm which does not make this demand. Sixty right handed undergraduates remembered digit and visual-spatial sequences alone and in two dual task conditions involving lateralized key tapping as the primary task. R gher intercorrelations were found under dual task conditions in which the tasks competed for the same hemisphere's resources. Better memory performance resulted when both tasks were lateralized to the same hemisphere. Hierarchical models combining general attention resources with ,lateralized hemispheric resources best account for these resutsi
Date: December 1985
Creator: Urbanczyk, Sally Ann
Partner: UNT Libraries

Effects of Layer Double Hydroxide Nanoclays on the Toxicity of Copper to Daphnia Magna

Description: Nanoparticles may affect secondary pollutants such as copper. Layer Double Hydroxides (LDH) are synthetically produced nanoparticles that adsorb copper via cation exchange. Pretreatment of copper test solutions with LDH nanoparticles followed by filtration removal of LDH nanoparticles demonstrated the smallest LDH aggregates removed the most copper toxicity. This was due to increased surface area for cation exchange relative to larger particle aggregates. Co-exposure tests of copper chloride and clay were run to determine if smaller clay particles increased copper uptake by D. magna. Coexposure treatments had lower LC50 values compared to the filtration tests, likely as a result of additive toxicity. LDH nanoclays do reduce copper toxicity in Daphnia magna and may serve as a remediation tool.
Date: May 2012
Creator: Blake, Deanne Renee
Partner: UNT Libraries

The Effects of Lecture Discussion and Group Centered Counseling on Parents of Moderately Mentally Retarded Children

Description: The problem of this study was to determine if involvement in lecture-discussion classes of group centered counseling would significantly alter anxiety level, aspects of self-concept, or knowledge of mental retardation in parents of moderately mentally retarded children.
Date: May 1971
Creator: Siegel, Edward Morton
Partner: UNT Libraries

The Effects of Listening Skills Instruction on Students' Academic Performance

Description: Although it is widely assumed that listening is among the most important learning skills (Wolvin & Coakley, 1988), an examination of the literature indicates that it has been woefully neglected as subject matter in schools. Listening has also been neglected as an area of research. Surveys have been conducted to see if listening is being taught or can effectively be taught, but little evidence exists to suggest that effectively teaching listening improves students' academic performance. This study investigated the relationship between listening skills instruction and academic performance among university students. The purpose was to determine if teaching university students comprehensive listening skills improves their academic performance. It was assumed that listening can be effectively taught. The goal of the study was to compare 75 students who were enrolled in a listening course to a similar group of 75 students not enrolled in a listening course. The students were compared on the basis of grade point improvement the semester after the experimental group had completed the listening course. The t test was chosen because it can be used for testing the significance of the difference between the means of two independent samples. The grade point averages of the two groups were collected and the means and standard deviations of the two groups were determined. The t-value and the probability of rejection of the null hypothesis were also determined. The data showed little difference between the mean scores of the two groups or between the standard deviations of the two groups. The observed t-value did not support the hypothesis; therefore, there was insufficient evidence to reject the null, and the conclusion was that listening skills instruction has no impact on university students' academic performance.
Date: May 1993
Creator: Mangrum, C. W. (Clifton William)
Partner: UNT Libraries

The Effects of Locus of Control and Soluble Discrimination Problems on Intelligence Test Performance

Description: This study investigated the possible differential effects of a series of soluble discrimination problems on internal versus external locus of control subjects. It was hypothesized that externals exposed to a series of discrimination problems would perform better on a test task than external controls, while internals exposed to the same problems would not perform better on the test task relative to their controls. As anticipated, the internals were not affected by the discrimination problems. However, contrary to expectations, the externals were not facilitated by exposure to the soluble problems. Since many external subjects failed to solve all of the soluble problems, a facilitative effect may depend upon the problems being solved.
Date: December 1976
Creator: Smith, Alvin, active 1976-
Partner: UNT Libraries

Effects of Long-Term Moderate Ethanol Intake on the Stress Response in Rats

Description: The effect of ethanol on the stress response in rats was examined. Experimental animals were given 0.25 ml of 28 percent ethanol or 0.25 ml of water orally once a day, five days a week, for a period of twelve months and were then subjected to fifteen minute cold stress. Corticosterone levels in ethanol-treated males following stress were significantly lower (22 percent) than in the sham group. Adrenal weights in sham-treated females were significantly higher (15 percent) than in the ethanol group at the end of twelve months. Mortality in sham-treated males was significantly higher (60 percent) than in ethanol-treated males. The effects observed may be due to the sedative action of ethanol on cortical centers controlling the hypothalmus.
Date: December 1984
Creator: Williams, Judy L. (Judy Lee)
Partner: UNT Libraries

The effects of lower body negative pressure on the cardiovascular system: the relationships of gender and aerobic fitness

Description: Sixteen males and sixteen females were recruited for this study; eight of each gender were aerobically trained athletes; the remaining eight were untrained control subjects. Each subject performed a maximal exercise stress test for aerobic capacity (VO2max). On a separate day the blood volume and the cardiovascular responses to progressive (0 to -50 torr) lower body negative pressure (LBNP) were determined.
Date: 1986
Creator: Hudson, Donna Louise
Partner: UNT Libraries

Effects of lysolecithin on macrophages

Description: The effect of lysolecithin on the macrophage was studied using five macrophage function assays. The results of indicate that lyso lecithin is a macrophage activating agent which causes enhanced cell spreading, increased phagocytosis of sheep erythrocytes, heightened membrane activity in the presence of damaged autologous red blood cells, chemotaxis, and vigorous phagocytosis and intracellular killing of Staphylococcus albus.
Date: May 1988
Creator: Swee, Mei Hua
Partner: UNT Libraries

Effects of Macrophyte Functional Diversity on Taxonomic and Functional Diversity and Stability of Tropical Floodplain Fish Assemblages

Description: Multiple dimensions of biodiversity within and across producer and consumer guilds in the food web affect an ecosystem’s functionality and stability. Tropical and subtropical aquatic ecosystems, which are extremely diverse, have received much less attention than terrestrial ecosystems in regards to the effects of biodiversity on ecosystem functioning. We conducted a field experiment that tested for effects of macrophyte functional diversity on diversity and stability of associated fish assemblages in floodplain lakes of the Upper Paraná River floodplain, Brazil. Three levels of macrophyte functional diversity were maintained through time in five floodplain lakes and response variables included various components of fish taxonomic and functional diversity and stability. Components of functional diversity of fish assemblages were quantified using a suite of ecomorphological traits that relate to foraging and habitat use. Response variables primarily distinguished macrophyte treatments from the control. Macrophyte treatments had, on average, double the number of species and total abundance than the control treatment, but only limited effects on stability. The high diversity treatment was essentially nested within the low diversity for assemblage structure and had similar or even slightly lower levels of species richness and abundance in most cases. Gymnotiformes and young-of-year were diverse and relatively abundant in macrophyte treatments contributing to the large differences in diversity between macrophyte and control treatments. Higher fish diversity in structured habitats compared to more homogenous habitats is likely associated with increased ecomorphological diversity to exploit heterogeneous microhabitats and resources provided by the macrophytes.
Date: August 2015
Creator: Treviño, Jessica Marie
Partner: UNT Libraries

The Effects of Mainstreaming on the Self-Concept of Physically Handicapped Children

Description: The Piers-Harris Self-Concept Scale for Children, the Florida Key: A Scale to Inter Learner Self-Concept, and the Walker Problem Behavior Identification Checklist were used to assess the self-concepts of 18 ambulatory physically handicapped children between the ages of 6 and 12 years. Data were analysed via one-sample t-tests. The hypothesis that mainstreamed handicapped children would exhibit somewhat lower self-concept than their nonhandicapped peers was not supported. In fact, some mainstreamed physically handicapped children may indeed exhibit higher frequencies of relating to peers and teachers, less acting-out behavior (among males), and better overall self-concept than the nonhandicapped populations from which the normative data were obtained (p < .05). These results were discussed in terms of the children's experiences within the hospital environment from which they were selected.
Date: August 1983
Creator: Walters, Terry L. (Terry Lynne)
Partner: UNT Libraries

Effects of Managerial Experience on Assertiveness, Anxiety, and Locus of Control

Description: The purpose of this study was to examine the effects of managerial experience on the relationships between assertiveness, trait anxiety, and internality, and on each of these constructs individually. Hypotheses were as follows: a) managers would be more assertive, internal, and less trait anxious than business students; b) males would be more assertive than females when students, not managers; and c) assertiveness and internality would relate positively to each other and negatively to trait anxiety. Subjects consisted of 30 managers and 53 business students. The first and third hypotheses were confirmed, although the assertiveness differences were not significant. Reasons for the observed outcome are discussed as well as implications for these constructs' ability to predict management potential.
Date: December 1983
Creator: Dick, William E.
Partner: UNT Libraries

Effects of Manifest Anxiety Upon a Measure of Memory Span

Description: This study will attempt to verify the Hullian drive theory, E = f(HxD), as others have done before, but with one exception. The H, or habit strength, will be held to be neutral so that the E, or excitatory potentials, will be a function of drive alone. Without any habit to reinforce, any increase in excitatory potential can be related directly to increase in drive. Four hypotheses were investigated: The first hypothesis was that the HA, or high-anxiety groups, will also be the high-drive groups, and this will follow for the NA and LA groups, to be determined by the performance on the digit-span test. The second hypothesis was that the high-drive groups will perform better on the digit-span tests than the low-drive groups. The third hypothesis stressed that in accordance with Hullian theory, with increased stress being introduced with a single habit tendency, the low-drive groups will be outperformed by the high-drive groups. The fourth hypothesis presumed that verification of the first three hypotheses will show the "Taylor Manifest Anxiety Scale" to be capable of differentiating between high and low manifest anxiety groups and will verify the Taylor-Spence hypothesis based on Hullian theory that the HA's will outperform the LA's in a stress situation.
Date: January 1963
Creator: Winston, Robert M. L.
Partner: UNT Libraries

The Effects of Mastery, Competitive and Cooperative Goals on Performance in Simple and Complex Sport Skills

Description: The present study investigated the effects of different goal and feedback conditions on performance of a basketball field goal shooting task and a more complex one-on-one offensive basketball task. Subjects (N = 100) were matched, based on pre-test performance, into one of five conditions: competitive goal, cooperative goal, mastery goal, "do your best" with feedback, and "do your best" without feedback. Results indicated the competitive group was significantly better than the "do your best" without feedback group in one-on-one performance. No other between group differences were significant, although some consistent group trends were present. Subjects' goal orientations were not related to performance in specific goal conditions, with the exception of mastery oriented subjects in the mastery goal condition.
Date: December 1986
Creator: Giannini, John
Partner: UNT Libraries

Effects of Maternal Aerobic Exercise on Selected Pregnancy Outcomes in Nulliparas

Description: This study evaluated the effects of participation in aerobic exercise on pregnancy outcomes. Pregnancy outcomes included type of delivery, length of labor, gestational age, neonatal birth weight, and maternal weight gain. The 137 nulliparas were categorized as active (N=44) or sedentary (N=93) based on self-reported aerobic exercise. Findings from this study suggest that pregnant women who were active during pregnancy were more likely to have vaginal deliveries than sedentary women. No significant differences between active and sedentary women were found in neonatal birth weight, maternal weight gain, length of labor, or gestational age.
Date: August 1997
Creator: Melgar, Dian L. (Dian Louise)
Partner: UNT Libraries