UNT Theses and Dissertations - 18,439 Matching Results

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The Effects of Glyphosate Based Herbicides on Chick Embryo Development

Description: Glyphosate based herbicides are among the most widely used herbicides in the world. The purpose of this study was to determine developmental toxicity of glyphosate, the active ingredient in the common herbicide Roundup, on developing chicken embryos. Few studies have examined toxic effects of glyphosate alone versus the full compound formulations of Roundup, which include adjuvants and surfactants. Adjutants and surfactants are added to aid in solubility and absorption of glyphosate. In this study chicken embryos were exposed at the air cell on embryonic day 6 to 19.8 or 9.9 mg / Kg egg mass of glyphosate in Roundup or glyphosate only. Chickens treated with 19.8 and 9.9 mg / Kg glyphosate in Roundup showed significant reduction in survivability compared to glyphosate alone treatments and controls. On embryonic day 18, embryos were sacrificed for evaluation of developmental toxicity using wet embryo mass, dry embryo mass, and yolk mass as indicators. Morphology measurements were taken on liver mass, heart mass, tibiotarsus length and beak length. Embryos treated with 19.8 mg / Kg glyphosate and 9.9 mg / Kg glyphosate in Roundup showed significant reductions in wet and dry embryo mass and yolk mass. Tibiotarsus length in 9.9 mg / Kg glyphosate in Roundup treatments were significantly reduced compared to 9.9 mg / Kg glyphosate treatments. Beak length was significantly reduced in 9.9 mg /Kg glyphosate in Roundup treatments compared to all other groups.
Date: August 2013
Creator: Winnick, Blake Edward
Partner: UNT Libraries

The Effects of Goal Difficulty and Information Feedback on the Performance of an Endurance Task

Description: Few studies in the sporting realm have been conducted to verify the findings from industrial or organizational settings regarding the strong positive motivational effects of goal setting (Locke et al., 1981). Therefore, the purpose of the present investigation was to determine the effects of three levels of goal difficulty and two levels of feedback on the performance of males undertaking an endurance task. Performance results were analyzed using a 2 x 3 x 2 (feedback x goal difficulty x trials) ANOVA with repeated measures on the last factor. Results indicated a significant goal by trials interaction with both specific difficult goal groups improving from trial one to trial two. The "do best" group showed no significant improvements. It was also found that only the difficult, but not the extremely difficult goal group performed significantly better than the "do best" goal group. No significant differences were found between the two feedback groups. The results are discussed in terms of Locke's (1968) original theory of goal setting.
Date: December 1984
Creator: Hall, Howard (Howard Kingsley)
Partner: UNT Libraries

The Effects of Goal Difficulty and Monitoring Frequency on Effort and Risk Taking Decisions

Description: Management control systems perform a vital role in facilitating the accomplishment of organizational objectives. To effectively align the objectives of employees with those of the organization, firms balance multiple control mechanisms to encourage organizationally desired behaviors and discourage undesired behaviors. The purpose of my dissertation was two-fold. First, I assessed how changes in monitoring frequency influenced employee behaviors and the overall function of the management control system. Second, I investigated the effects of stretch goals on behavior to determine whether stretch goals can lead to harmful behaviors and whether continuous monitoring can mitigate these behaviors. Results suggest that individuals exert more effort when assigned a stretch or difficult goal compared to an easy goal. My study also finds that stretch goals can be harmful because of their effect on risk taking, goal commitment, and job insecurity. Finally, results indicate that accountability mediates the monitoring frequency-risk taking relationship such that continuous monitoring increases accountability and accountability decreases risk taking. However, the ability of monitoring frequency to decrease risk taking may depend on numerous factors. Results from this study allow practitioners to understand the potential benefits and drawbacks of implementing continuous monitoring systems and the combined effects of using these systems in conjunction with compensation systems. Consequently, this study highlights necessary considerations for practitioners during the implementation continuous monitoring systems. The study also informs practitioners of the potentially harmful effects of stretch goals, the conditions under which they occur, and the possible ways to mitigate these effects.
Date: May 2014
Creator: Shoemaker, Nikki L.
Partner: UNT Libraries

Effects of Goal Setting, E-mail Feedback and Graphic Feedback on the Productivity of Public School Attendance Clerks

Description: A package intervention, consisting of daily-adjusted goal setting, e-mail feedback, and graphic feedback, was used in a public school attendance office to increase the efficiency with which 3 attendance clerks documented student attendance. During the intervention phase, the attendance secretary set a daily goal for each attendance clerk. This goal was a percentage of student absences to be coded and entered in the school computer program. After establishing a daily goal, the attendance secretary provided daily feedback, in the form of a written e-mail response and graphed feedback to each clerk. If the subjects had attained their daily goal, the attendance secretary also delivered a praise statement along with the e-mail feedback. Results indicated that the intervention package was ineffective in producing change in the attendance clerks' absence coding behavior.
Date: August 2000
Creator: Rexroat, Robin D.
Partner: UNT Libraries

The Effects of Goal Setting on Performance Enhancement in a Competitive Athletic Setting

Description: The purpose of the investigation was to determine if goal setting has an effect on physical performance in a realistic, natural, and competitive athletic environment. Results revealed no significant differences between the goal-setting group and the "do your best" group when performing lacrosse skills. However, results from the questionnaire indicated significant main effect difficulty of the tasks. These results imply that athletes in the goal-setting group felt that their goals were not realistic and that it was increasingly difficult to reach their goals as the season progressed. Because the athlete does not have control over some factors which influence game situations, he or she may be hindered in reaching his or her goals, whether specified or individually chosen. Therefore, a research methodology that manipulates and attempts to control types of goal setting may not be appropriate or realistic when applied to the natural field environment of a highly organized competitive sport.
Date: August 1989
Creator: Stitcher, Thomas P.
Partner: UNT Libraries

Effects of Gold Sodium Thiomalate on Murine Spleen Cells

Description: The effects of gold sodium thiomalate (GST) on murine spleen cells were investigated using in vitro mitogen blastogenesis techniques. Addition of GST to intact spleen cells resulted in a decreased blastogenic response to the T cell mitogen, concanavalin A (Con A). Thymidine uptake of spleen cells depleted of macrophages and cultured with Con A and GST demonstrated biphasic effects. At 2.5 pg Con A/ml, blastogenesis of macrophage depleted spleen cells was inhibited to a lesser degree than intact spleen cells; whereas, at 0.5 pg Con A/ml, the macrophage depleted spleen cells were inhibited to a greater degree than the intact spleen cells. Addition of GST at intervals ranging from 0 to 48 hours indicated that inhibition occurred within 36 hours following mitogen stimulation. These results suggest that GST inhibits early events of lymphocyte activation by direct interaction with lymphocytes.
Date: December 1986
Creator: Brownback, Paul (Paul Eldon)
Partner: UNT Libraries

The Effects of Graduated Exposure, Modeling, and Contingent Social Attention on Tolerance to Skin Care Products with Children Who Have Autism.

Description: The effects of graduated exposure, modeling and contingent social attention on tolerance to skincare products were evaluated with two boys with autism who displayed tactile defensiveness. Upon each presentation step of skincare products the number of positive and negative responses and successful step completion were measured. Procedures included modeling, presenting graduated opportunities, and providing social attention for step completion. Step advancement occurred if a child engaged in a step independently, without excessive refusals. A changing criterion design and a multiple baseline were employed to evaluate effects of this treatment package. Children demonstrated more positive and fewer negative responses as they completed the graduated steps. Effects maintained in follow-up observations.
Date: December 2001
Creator: South, Ellyn M.
Partner: UNT Libraries

Effects of Group Counseling and Group Discussion on Selected Personality Variables of First-Year Theology Students

Description: This study examined the use of group counseling and group discussion as a method of demonstrating changes on selected personality variables of first-year theology students. It was hypothesized that the subjects would become less dogmatic (more open-minded), motivated from a more internal locus of control, feel less anxious, and demonstrate greater creativity and self-concept following their participation in either group counseling or group discussion. Group counseling was hypothesized to be the best method for effecting changes. The subjects were first-year theology students at a southwestern theological seminary. These participants planned to work in some phase of ministry; several planning to be ordained as priests or to enter the deaconate. This study was based upon the premise that ministers often assume a counseling role and they therefore, need training in counseling skills and an opportunity to enhance their personal development. Group counseling and group discussion were explored as possible means to achieve these ends. Each of the five personality variables was measured on a pretest-posttest design. The subjects were tested prior to meeting in one of the two formats and tested again after fifteen hours of participation in one of the groups. A control group was also tested at these same times to allow for a comparison to be made as to which method was most effective. Chapter I presents a review of related literature on the five variables and the need for training of ministers in counseling skills and for providing an opportunity for self-growth. Chapter II states the procedures and includes definitions, the method of the study and a discussion of the instrumentation. Chapter III presents the results of the study and a discussion of the implications. Although the findings indicated some changes in the variables as predicted by the hypotheses, none of the changes was statistically significant. Therefore, ...
Date: August 1987
Creator: Qualia, Linda R. (Linda Raffel)
Partner: UNT Libraries

The Effects of Group Counseling upon Visual Perception and its Relationship to Other Forms of Perception

Description: The study of perception of visual images and the influence of counseling upon them has received little if any attention. This study was designed to investigate this uncharted area and to demonstrate the effects of counseling upon visual perception. The primary function of this investigation was to seek answers to the following questions. Is it possible for group counseling to have an effect on one's perception of visual stimuli? Will a counseling experience which produces a change in a person' behavior also cause that person to perceive visual images in a different way than he perceived them before counseling? In other words, does a concomitant relationship exist between visual perception and other forms of perception?
Date: May 1969
Creator: Berryman, Berle Wayne
Partner: UNT Libraries

The Effects of Group Membership upon Birth Order Differences in Anxiety and Affiliation

Description: The present study has a twofold purpose. First, it will attempt to ascertain whether ordinal position remains an effective discriminator of affiliative need and level of anxiety within the selective confines of a strong social organization, a college sorority; or whether the selective criterion of membership in the strong social organization tends to suppress the differences in affiliative need and level of anxiety between the ordinal positions. Secondly, it will attempt to further explore the relationship between affiliation and dependency.
Date: June 1963
Creator: Kennelly, Kevin Joseph
Partner: UNT Libraries

The Effects of Hearsee/Say and Hearsee/Write on Acquisition, Generalization and Retention.

Description: This study examines the effects of training in two yoked learning channels (hearsee/say and hearsee/write) on the acquisition, generalization and retention of learning. Four fifth-grade participants were taught the lower-case letters of the Greek alphabet. Twelve letters were taught in the hearsee/say channel and twelve letters taught in the hearsee/write channel for equal amounts of time. The see/say channel reached higher frequencies at the end of training and showed higher acquisition celerations than the see/write channel. However, the see/write channel showed higher accuracy and retention than the see/say channel. The see/write channel also showed greater generalization across learning channels including the see/say, think/say, think/write and see-name/draw-symbol.
Date: May 2001
Creator: Zanatta, Laraine Theresa
Partner: UNT Libraries

Effects of Heart Rate Variability Biofeedback-assisted Stress Management Training on Pregnant Women and Fetal Heart Rate Measures.

Description: This study examined effectiveness of heart rate variability (HRV) biofeedback-assisted stress management training in reducing anxiety and stress in pregnant women and the effect of maternal stress management skills practice on fetal heart rate measures in real time. Participants were seven working pregnant women who volunteered in response to recruitment announcements and invitations from cooperating midwives. Reported state and trait anxiety and pregnancy specific stress were measured during five 45- to 50-minute training sessions. Training included bibliotherapy, instruction in the use of emotion-focused stress management techniques, and HRV biofeedback. Subjects used portable biofeedback units for home practice and were encouraged to practice the skills for 20 minutes a day and for short periods of time during stressful life events. At the end of training, fetal heart rate was monitored and concurrent maternal HRV measures were recorded. Repeated measures ANOVA and paired samples t-test analysis of study data revealed no statistically significant reductions in state or trait anxiety measures or in pregnancy specific stress measures. Partial eta squared (n²) and Cohen's d calculations found small to medium effect sizes on the various test scales. Friedman's analysis of variance of biofeedback measures showed a statistically significant decrease in low HRV coherence scores (X2 = 10.53, p = .03) and medium HRV coherence scores (X2 = 11.58, p = .02) and a statistically significant increase in high HRV coherence scores (X2 = 18.16, p = .001). This change is an indication of improved autonomic function. Results of concurrent maternal and fetal HRV recordings were generally inconclusive. A qualitative discussion of individual subject results is included. During follow-up interviews five subjects reported that they felt they were better able to cope with stress at the end of the study than at the beginning, that they used the stress management skills during labor, and that ...
Date: August 2008
Creator: Keeney, Janice E.
Partner: UNT Libraries

Effects of Heart-Rate Variability Biofeedback Training and Emotional Regulation on Music Performance Anxiety in University Students

Description: Student musicians were recruited to participate in an experimental repeated measures research design study to identify effects of heart rate variability (HRV) biofeedback training and emotional self-regulation techniques, as recommended by HeartMath® Institute, on music performance anxiety (MPA) and music performance. Fourteen students were randomly assigned to a treatment or control group following a 5 minute unaccompanied baseline performance. Treatment group participants received 4-5 HRV training sessions of 30-50 minutes each. Training included bibliotherapy, using the computerized Freeze-Framer® 2.0 interactive training software, instruction in the Freeze-Frame® and Quick Coherence® techniques of emotional regulation, and also use of an emWave® portable heart rate variability training device for home training. Measures included the State-Trait Anxiety Inventory (STAI), Performance Anxiety Inventory (PAI), Flow State Scale (FSS), average heart rate (HR), and heart rate variability (HRV). Quade's rank transformed ANCOVA was used to evaluate treatment and no-treatment group comparisons. Combined MPA scores showed statistical significance at p=.05 level with large effect size of eta2=.320. Individual measurements of trait anxiety showed a small effect size of eta2=.001. State anxiety measurement showed statistical significance at the p=.10 level with a large effect size eta2=.291. FSS showed no statistical or effect size difference. PAI showed no statistical significance and a large effect size eta2=.149. HR showed no statistical significance and a large effect size eta2=.143. HRV showed statistical significance at p=.000 level and a large effect size eta2=.698. This study demonstrated practical/clinical significance of a relatively quick and inexpensive biofeedback training that had large effect at decreasing mental, emotional, and physiological symptoms of MPA for university students.
Date: December 2006
Creator: Thurber, Myron Ross
Partner: UNT Libraries

Effects of Hedonic and Utilitarian Shopping Satisfaction on Mall Consumption

Description: The modern consumer expects a consumption experience with both hedonic and utilitarian rewards during a single visit to the mall. The orchestrating of both hedonic and utilitarian benefits in one visit challenges mall management and retailers to deliver the maximum shopping experience. This study seeks to reveal relationships among six variables: demographic characteristics, mall shopping orientation, mall perception, hedonic satisfaction, utilitarian satisfaction, and mall consumption. The intercept survey was conducted at a major entertainment-themed mall in north Texas. Multiple regression analyses (N = 202) indicate that demographic characteristics and mall shopping orientation were significant predictors of mall perception. Also, two mall perception factors (Sensation and Physical Environment) were predictors of hedonic and utilitarian mall shopping satisfaction. However, hedonic and utilitarian mall shopping satisfaction were found not to predict mall consumption in terms of cross-shopping, money spent, and time spent.
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Date: August 2002
Creator: Buhrman, Tiffany
Partner: UNT Libraries

The Effects of Heparin on the Development of Resistance to Antibiotics by Staphylococcus Aureus

Description: Since heparin combines with some antibiotics to decrease the toxicity of the antibiotic to the patient, the purpose of this investigation is to determine whether it has any effect upon the development of resistance to antibiotics by Staphylococcus aureus.
Date: August 1959
Creator: Blanton, William George
Partner: UNT Libraries

The Effects of Hexadecanol on the Microbiota of Lake Hefner

Description: It seemed desirable to investigate more fully the effect of hexadecanol on the microbial population of a reservoir. It was the purpose of this investigation to determine the effect of hexadecanol on the micro-biota of Lake Hefner, to ascertain which organisms were stimulated by hexadecanol both in the laboratory and the reservoir, and to investigate the degradation of hexadecanol by microorganisms selected from Lake Hefner.
Date: May 1968
Creator: Dickson, Kenneth L.
Partner: UNT Libraries

Effects of High Altitude Exposure on Capillary Permeability

Description: Observations of decreases in plasma volume, shifts in plasma and lymph protein concentrations, and increases in capillary permeability at high altitude have been reported in the literature by several investigators. This investigation was begun in an attempt to elucidate the possible significance of these phenomena in future space exploration, and because of the lack of knowledge concerning the underlying mechanisms. The purpose of this investigation was to determine the effects of exposure to hypobaric pressures on the capillary permeability to the normal plasma and lymph proteins.
Date: December 1971
Creator: Reaves, Troy Albert
Partner: UNT Libraries

The Effects of Homework Sessions on Undergraduate Students' Homework Performance

Description: Experimenters evaluated the effects of a homework session on undergraduate students' homework performance through an adapted alternating treatments design in two introduction to behavior analysis courses. Several participants attended homework sessions; however, homework submission and homework mastery did not vary as a function of homework session attendance or availability. Homework submission remained high throughout the experiment regardless of attendance at or availability of a homework session. Many participants responded that they were not interested in or did not need homework sessions. Participants who attended homework sessions rated them as neutral or helpful overall, with longer time and different time as the most common suggestions for improvement.
Date: May 2013
Creator: Hamilton, Elissa R.
Partner: UNT Libraries

The Effects of Hypothermia on the Release of Cardiac Enzymes

Description: The myocardium is known to release CPK, LDH1 , and GOT in response to ischemia as a result of myocardial infarction. This study was designed to induce the release of cardiac enzymes without adversely effecting the myocardium by perfusion hypothermia, thereby suggesting that these enzymes are not as specific in the diagnosis of myocardial infarction as once thought. Hypothermia was by in vivo perfusion of the left anterior descending coronary artery. Enzyme activity was measured from sera samples spectrophotometrically and electrophoretically. Significant CPK and LDH1 increases were observed in animals perfused between 25 and 19 C. These results indicate that, while heart function remained unchanged, an alteration occurred in the membrane integrity of the myocardial cells.
Date: August 1977
Creator: Strawn, William B.
Partner: UNT Libraries