Browsing by Subject "Behavior"
Now showing 1 - 20 of 29
Results Per Page
Sort Options
Item Acclimation of Holstein Calves to Transit Stress: The Integration of Endocrine, Immune, and Behavior Systems(2012-10-19) Adams, AmberLittle is known about the adaptation of livestock to repeated transport. This study determined how repeated transport affected calf feed intake, plasma cortisol (CORT), post-transport behavior, and the expression of immune-related genes. Thirty-six 4-month-old Holstein steer calves were housed in groups of six with each group randomly assigned to either transport (T) or control (C) treatments. The T calves were hauled for 6 h in a 7.3 m x 2.4 m goose-neck trailer, at an average density of 0.87 m2/calf, every 7 d for five consecutive weeks. Individual daily intake was determined using Calan gate feeders. Blood samples were obtained in the trailer or home pen via jugular venipuncture before loading, and after 2, 4, and 6 h of transport. Samples were analyzed for CORT, serotonin, tryptophan, and the gene expression of interleukin-4 (IL-4), interleukin-6 (IL-6), chemokine (C-X-C motif) receptor 2, interleukin-12, toll-like receptor-4, toll-like receptor-2, and 5-hydroxytryptamine receptor 2A in leukocytes. Behavior was recorded for transported calves at 5-min intervals for 1 h after return to their home pens. The C calves had a higher feed intake than T calves overall (P = 0.01), on the day of transport (P = 0.007), and the day after transport (P = 0.02). Pre-transport CORT concentrations did not differ by treatment (P = 0.77) or trial (P = 0.32). However, the T calves had higher response CORT concentrations than C calves during Transport 3 (P = 0.006), Transport 4 (P = 0.001) and Transport 5 (P = 0.02). The T calves had the highest response CORT concentrations after 2 h of transport and the lowest response CORT concentrations after 6 h of transport (P < 0.0001). Treatment did not affect gene expression in leukocytes, however, the expression of IL-4 (P = 0.01) and IL-6 (P = 0.05) was significantly lower after 2 h of transport than any other sampling times. These results suggest conflicting conclusions on whether the calves started to acclimate after being transported five times. However, CORT and gene expression differences occurred in response to the blood sampling regimen, which may provide insight to how calves acclimate during prolonged stress.Item Behavioral ecology of Western Burrowing Owls (Athene cunicularia hypugaea) in northwestern Texas(Texas Tech University, 2006-05) Chipman, Erica D.; McIntyre, Nancy E.; Schmidt, Kenneth A.; Wallace, Mark C.Western Burrowing Owls are a species of international conservation concern, yet their behavioral responses to urbanization and radio-telemetry are unknown. We monitored breeding male burrowing owls at urbanized and rural sites in 2 areas of northwestern Texas in 2004-05 in separate studies of behavioral responses to urbanization and radio-collars. For the urban behavioral study the activity budgets of urban and rural burrowing owls did not differ significantly for most behaviors, although urban burrowing owls (n = 17) displayed significantly greater vigilance and resting behaviors than did rural owls (n = 10). Other behaviors, including amount of time spent hunting or hunting success, did not show consistent trends by land-use type; instead, there was as much variation between owls as between land-use types. Further research on the behavioral effects of urbanization is needed with larger sample sizes, more locations, and longer duration. For the radio-collared study non-collared owls (n = 6) spent significantly more time being vigilant (P = 0.007) than did radio-collared owls (n = 3) in 2004, who spent significant amounts of time interacting with their collars. In 2005, radio-collared owl (n = 8) behaviors were significantly affected (P < 0.001) by the presence of radio-collars compared to control individuals (n = 4) but not consistently by treatment period (pre-collared vs. collared vs. post-collared periods). Behavioral activity budgets varied considerably among all individuals. Although the owls spent a significant amount of time interacting with their collars, they appeared to habituate to the presence of the collars within a relatively short period (<1 wk), and collars did not affect survivorship or fitness in the short-term.Item Boosting Lunch Is In The Bag(2011-12) Almansour, Fawaz; Briley, Margaret E.Lunch Is In The Bag (LIITB) was a multi-level behavioral intervention with the goal of increasing the amounts of fruits, vegetables, and whole grains that parents pack in their preschoolers' lunches. The purpose of this dissertation project was to: 1) to examine the temperatures of perishable food items packed in preschoolers' sack lunches; 2) to examine parents' psychosocial constructs that relate to packing fruits, vegetables, and whole grains at four periods during the booster study; 3) to assess the servings of fruits, vegetables, and whole grains with the related nutrient content at four periods during the booster study. The four assessment periods are before LIITB, after LIITB, before the one-week booster, and after the one-week booster. Results showed that more than 97 percent of perishable food items in the sack lunches were stored at unacceptable temperatures (40-140°F). Servings of vegetables (-0.15, p=0.05) and whole grains (-0.53, p<0.0001) in preschool lunches decreased significantly before the booster in the intervention group. The booster increased the servings of vegetables (0.10, p=0.09) and whole grains (0.16, p =0.01) compared to booster baseline. The one-week booster increased thiamin, dietary fiber, and vitamin C content of foods in preschoolers' lunches. During the booster study, parents experienced improvement in psychosocial variables after LIITB and before the booster. Knowledge decreased before the booster. Parents' psychosocial variables were linked to packing more vegetables and significantly more whole grains due to the intervention. Education for parents and the public must focus on methods of packing safe, healthy lunches in order to prevent foodborne illness and chronic disease. The results of this study provide data for continued examination of an area of parental behavior related to packing lunches for their children. The booster study demonstrated that a booster was important for maintenance of program outcomes, and to increase the servings of vegetables and whole grains that parents packed in their preschool children's lunches.Item Coping with weight-related discrepancy and potential impacts on future self-regulation of weight loss behavior : development of the WEIGHT-COPE(2011-12) Faries, Mark Daniel; Bartholomew, John B.; Kohl, Harold W.; Loukas, Alexandra; Pasch, Keryn; Tyler, DianeThe purpose of this dissertation was to develop a reliable and valid measure to assess coping responses to weight-related discrepancy in women. The decision to create such a measure stemmed from the difficulties individuals have with initiation and consistent regulation of weight-related behavior. When salient, perceived discrepancies with one’s weight or body can be emotionally laden, producing negative affective responses and discontent, labeled here as dissatisfaction. The individual must then find ways to cope. However, not all coping responses are equal, and are theorized to have varied impacts on future regulation of weight loss efforts. The present research addressed these issues by developing a theoretically-based measure, labeled the WEIGHT-COPE. The WEIGHT-COPE originally sought to capture healthy and unhealthy problem-focused coping efforts to lose weight, as well as approach and avoidance coping efforts theorized as more distal influences on problem-focused efforts. The WEIGHT-COPE and other relevant measures were completed by 470 females ages 18-35 years. Results of an exploratory factor analysis revealed a 38-item measure consisting of eight coping factors: Exercise/Physical Activity, Healthy Eating, Cutting Calories/Appetite Suppression, Supplement Use, Monitor/Planning, Disengage/Denial, Camouflage, and Acceptance/Positive Reframing. All factors were internally consistent ( = 0.71 to 0.89), and converged with other pertinent measures of weight satisfaction, weight controllability/changeability, social physique anxiety, self-esteem, weight loss efficacy, physical activity level, dietary intake and objectified body consciousness. To test theoretical implications on future self-regulation of weight loss behavior, a structural regression model was run utilizing the WEIGHT-COPE factors. The factors were associated in a theoretically-driven pattern, illustrating that coping responses to weight-related discrepancy have varied impact on weight loss behavior choice. Thus, the present findings provide preliminary support for the WEIGHT-COPE and suggest that individuals cope with weight-related discrepancy in different ways, which may then have various impacts future self-regulation of weight loss behavior.Item Diazepam binding inhibitor and tolerance to ethanol in Drosophila melanogaster(2012-12) Robles, Roseanna Beth; Atkinson, Nigel (Nigel S.); Aldrich, Richard; Duvauchelle, Christine; Mihic, John; Zakon, HaroldTolerance to ethanol is an endophenotype of alcoholism, allowing the study of a complex psychiatric condition using animal models. To identify new genes involved in the acquisition of tolerance, I designed an automated and high-throughput tolerance assay and screened a collection of deficiency mutants for the inability to develop tolerance. The screen yielded several “regions of interest” where more than one overlapping deficiency failed to develop tolerance. One of these regions comprised nine genes, and testing the expression levels of each gene revealed that diazepam binding inhibitor (Dbi) showed grossly increased expression in the deficiency mutant compared to wild type. Another mutant stock, with a P-element transposon inserted downstream of the Dbi gene, both failed to develop tolerance and showed further increased expression of Dbi. There are two insulator binding sites flanking Dbi, and the P-element transposon also contains insulator binding sites. Based on these results, it was hypothesized that an insulator complex kept Dbi expression low in wild type flies and that disrupting the insulator complex allowed aberrantly high expression of Dbi in the mutants. Furthermore, we assumed that induction of Dbi blocked tolerance by making the mutants resistant prior to the first sedation. A UAS-DBI transgene was constructed to over-express Dbi. Induction of the UAS-DBI with a heat shock gal4 driver induced resistance to ethanol sedation; a similar response was observed in the parental control, but the effect was smaller. Although driving UAS-DBI with the neural elav-gal4 driver did not block tolerance, the experimental stock was resistant to ethanol sedation compared to the parental controls, indicating that increased Dbi expression produced “pre-tolerance.” To confirm the theory that insulator disruption was responsible for the increase in Dbi and the resulting no-tolerance phenotype, the P-element in the second mutant was mobilized by introducing a transposase source. These offspring lines were analyzed using qualitative PCR to determine whether the transposon excised precisely, left a portion of the transposon behind, or removed some of the flanking region. A precise excision mutant was identified, but this mutation did not rescue tolerance as predicted. This result might indicate that genetic background was the cause of the no-tolerance phenotype, or it might indicate that the excision was not exactly precise and removed the native insulator binding site, causing the insulator complex to remain disrupted.Item The ecology of blue crab (Callinectes sapidus) megalopae in the Mission-Aransas Estuary, Texas : salinity, settlement, and transport(2013-12) Bittler, Kimberly Marie; Buskey, Edward Joseph, 1952-Blue crabs are a widely distributed estuarine species with broad economic and ecological importance. Several studies have linked blue crabs to freshwater inflows, but the precise nature of this link is still uncertain, as blue crabs have a complex life cycle that utilizes both marine and estuarine environments. One potential link between blue crabs and freshwater inflows is during recruitment, when megalopae developing offshore return to estuaries before molting into juvenile crabs. Megalopae swim during the flood tide to ensure delivery into and farther up estuaries. The behaviors regulating selective tidal stream transport (STST) on the flood tide were originally studied in North Carolina in an estuary with regular freshwater inflows and a strong salinity gradient. The model of STST was re-examined in the Mission-Aransas, an estuary with episodic freshwater inflows and salinity gradients ranging from normal estuarine conditions to hypersaline during droughts. The behavioral responses of megalopae to a range of rates of salinity increase were tested, and then modeled onto rates of salinity change observed in the field to determine the theoretical ecological consequences of STST for blue crab populations in the Mission-Aransas Estuary. To validate the ecological trends predicted by the behavioral model of STST, a simple, long-term data set reflecting changes in megalopae abundance is needed. Hog’s hair collectors are a simple and widely used method of quantifying abundance of brachyuran megalopae, including blue crabs. However, the efficiency of hog’s hair collectors in sampling for megalopae is unknown. Several studies have reported poor correlations between settlement on hog’s hair collectors, transport, and abundance of megalopae in the plankton due to disparate temporal scales and potentially turbulence-driven decoupling. Each of these issues were addressed in field and flume experiments, which were used to develop a model for interpreting settlement on hog’s hair collectors in terms of transport and planktonic abundance.Item Effect of duration of transport on indicators of stress in lambs(Texas A&M University, 2007-04-25) Krawczel, Peter DownsRecommendations for the transportation of lambs from a European Commission, which required rest stops of 6 or 24 h, every 8 h, were evaluated for efficacy of reducing stress indicators using Rambouillet x Suffolk lambs (17.6 ???? 0.5 kg). The lambs were randomly assigned to one of three groups: 1) transported for 22 h (Continuous; n = 15); 2) transported for 8 h, unloaded and rested for 6 h, transported for 8 h, unloaded and rested for 24 h, transported for 6 h (Rested, n = 15); and 3) Control, which remained in home pasture throughout the study (n = 16). The rest stops were off-trailer; a different pen was used for each; and, a limited amount of grain and ad lib hay and water were provided. Mean temperature in the trailer during the study was 28.4???? C with a range of 18.2???? C to 39.6???? C. Food deprivation in the Continuous lambs was reflected by a decrease in plasma glucose (P < 0.001) and an increase in blood urea nitrogen (P < 0.001), creatinine (P < 0.02) and total bilirubin (P < 0.001) relative to the Rested or the Control lambs. Electrolytes varied within and between all three treatments (P < 0.05), but no distinct pattern indicating dehydration was evident. Serum concentrations of cortisol were greater (P < 0.05) in Continuous lambs than in the Control lambs at 14 h and both the Continuous and Rested lambs had higher concentrations of cortisol (P < 0.05) compared to the Control lambs at 22 h. Plasma IgG antibody response to ovalbumin was suppressed (P < 0.05) in the Continuous and Rested lambs compared to the Control lambs. Lambs in both transported treatments ate grain immediately upon release into the rest pens and drinking occurred following the food consumption. The Continuous lambs lost a greater (P < 0.05) amount of initial BW at the conclusion of transport compared to the Rested lambs and had a lower BW (P < 0.05) than the Rested and Control lambs 8 d after the start of transport. Rest stops improved welfare by reducing physical stress of food deprivation and eliminating BW loss during transport. However, rest stops failed to completely alleviate immunosuppression and 52 h were required to complete the otherwise 22 h long trip. The additional costs of providing the benefits of the rest stops should be examined before these regulations are widely implemented.Item An evaluation of resurgence of appropriate communicative responses in children with developmental disabilities(2011-08) Hoffman, Katherine J.; Falcomata, Terry S.; Ringdahl, JoelThe purpose of the current study was to evaluate the conditions under which resurgence of appropriate communicative responses (mands) would occur with children with developmental disabilities. The experimental preparation consisted of a sequence of conditions that included (a) the reinforcement of one mand (i.e., microswitch activation or card exchange) on a FR 1 schedule, (b) an extinction condition in which the mand was no longer reinforced, (c) the reinforcement of a second mand (i.e., microswitch activation or card exchange) on a FR 1 schedule, and (d) a test for resurgence of the first mand which consisted of placing the second mand on extinction. The results demonstrated resurgence of mands during 2 out of 3 tests for resurgence for one participant. Resurgence of mands was demonstrated during all three tests for resurgence with the second participant.Item Fatigue behavior of post-installed shear connectors used to strengthen continuous non-composite steel bridge girders(2016-08) Ghiami Azad, Amir Reza; Engelhardt, Michael D.; Williamson, Eric B., 1968-; Helwig, Todd A; Jirsa, James O; Taleff, Eric MMany older bridges in Texas are constructed with floor systems consisting of a concrete slab over steel girders. A potentially economical means of strengthening these floor systems is to connect the existing concrete slab and steel girders using post-installed shear connectors to change the behavior of the beam from non-composite to partially-composite. Since fatigue is one of the main concerns in designing bridges, investigating the fatigue properties of these post-installed shear connectors becomes crucial. Results from direct-shear testing show that post-installed shear connectors have a better fatigue life compared to conventional welded shear studs. However, based on currently available data from direct-shear tests, fatigue life of post-installed shear connectors is still inadequate for economical retrofit in some cases. Furthermore, it is unclear if direct-shear tests provide an appropriate means of evaluating fatigue performance. The objective of this dissertation is to develop new and more accurate approaches for evaluating the fatigue characteristics of post-installed shear connectors. This objective is addressed through large-scale beam fatigue tests and computational studies. The focus of the work is on evaluating fatigue life of shear connectors based on both slip and stress demands.Item The impact of a reading intervention on reading and behavioral outcomes for fourth and fifth grade students with reading difficulties(2016-05) Roberts, Garrett James; Vaughn, Sharon, 1952-; Roberts, Greg; Barnes, Marcia; Powell, Sarah; Toste, JessicaEvidence supports a positive relationship between problem behaviors and reading difficulties across Grades K-12 yet there is a lack of research investigating the role of problem behavior in the context of reading interventions. In this study, data was analyzed from a site-specific subset of students from a multi-site randomized controlled trial (RCT) implementing a multi-component reading intervention for struggling readers in Grades 4 – 5. Data were analyzed to answer the following research questions: (1) What is the impact of multi-component reading intervention for 4th and 5th grade students who are struggling readers on both reading and problem behavior outcomes? and (2) Does problem behavior moderate the effect of a multi-component reading intervention for 4th and 5th grade students who are struggling readers? Students (n = 108) were randomly assigned to a one-year multi-component comprehension reading intervention or a school determined business as usual (BAU) comparison condition after meeting the criterion for identification as a struggling reader by scoring at or below a 90 standard score on the Test of Silent Reading Efficiency and Comprehension (Wagner, Torgesen, Rashotte, & Pearson, 2010) screener assessment. To answer the research questions, data (reading and behavior outcomes) were analyzed using an analysis of covariance to: 1) test the impact of the reading intervention on both reading and behavior outcomes; and 2) test for a significant interaction between measures of problem behavior and condition (i.e., treatment or comparison) on reading outcomes (e.g., Gates MacGinitie Reading Test; MacGainitie, 2000). Models controlled for student-level differences (e.g., reading pretest scores). Type I error associated with multiple comparisons was controlled for using the Benjamani-Hochberg correction to adjust for false discovery rates. Results suggested that the impact of treatment resulted in significant posttest group differences on word reading fluency (p < .05). Additionally, externalizing behavior moderated the reading outcomes on the Gates MacGinitie Reading Test for students with higher levels of externalizing behavior. Overall this research added to the research field by suggesting that problem behavior impacts reading outcomes. Future research is warranted to improve reading interventions that target students with problem behaviors.Item The impact of teaching self-determination skills on the on-task and off-task behaviors of students with emotional and behavioral disorders(2010-08) Kelly, John R., 1950-; Shogren, Karrie Ann, 1980-; Rieth, Herbert J.; Wilkinson, Cheryl Y.; Whittaker, Tiffany A.; Patton, Jim; Flower, AndreaHistorically, youth with emotional and behavioral disorders (EBD) have experienced higher rates of absenteeism, lower grade point averages, and higher course failure than their non-disabled peers; as a result, students with EBD are at significant risk of school failure, dropping out of school, and experiencing poor life outcomes. Emerging literature suggests that teaching self-determination to students with EBD may be an effective strategy to address the in-school and post-school challenges faced by youth with EBD. The purpose of this study was to examine the impact of teaching self-determination on adolescents with EBD's on- and off-task behavior, grades, progress towards self-selected goals, and global self-determination. The Self-Determined Learning Model of Instruction (SDLMI) was implemented with four high school students with EBD between the ages of 14 and 16 years who were having difficulty meeting classroom behavioral expectations in two general education classrooms. The SDLMI teaches key components of self-determination, is suitable for diverse students, and is compatible with major academic content areas. Twelve lessons were taught as a separate curriculum individually to each participant. The entire study took 25-weeks, between October and April, to complete. A multiple baseline across participants design was used to examine the functional relation between SDLMI intervention and the on- and off-task behaviors of high school students with EBD. The results showed that all four students significantly increased on-task behaviors and decreased off-task behaviors and all four participants maintained the increase of on-task behaviors and the decrease of off-task behaviors after the intervention was withdrawn. Moreover, all four students made progress towards their goal of implementing on-task behavior in the classroom and generalized on-task behavior to a second general education classroom. However, data regarding the impact on students' grades and self-determination were inconclusive. The study provides evidence of effective self-determination instruction that supports students to improve their behavior in a general education classroom. It also provides direction for future research exploring the relationship between behavior and academic skills. Contributions to the field, limitations, and implications for practice and future research are provided.Item Investigating the female mate preference brain : identifying molecular mechanisms underlying variation in mate preference in specific regions of a swordtail (Xiphophorus nigrensis) brain(2011-05) Wong, Ryan Ying; Hofmann, Hans A.; Cummings, Molly E.; Ryan, Michael J.; Crews, David; Zakon, Harold H.Choosing with whom to mate is one of the most important decisions a female makes in her lifetime and inter-individual variation of these preferences can have important evolutionary consequences. In order to get a complete understanding of why and how females choose a mate, we must identify factors that can contribute to variation of female mate choice. Many decades of research sought to understand ultimate mechanisms of female mate choice with proximate mechanisms receiving a lot more attention in recent years. For my thesis, I identify intrinsic and extrinsic factors that correlate with individual variation of female Xiphophorus nigrensis mate preference. I provide evidence that a female’s size (e.g. age and sexual experience) as well as male behavioral displays can predict female mate preference. Using genes associated with female mate preference (neuroserpin, neurologin-3), I identify four brain regions (Dl, Dm, HV, POA) that show significant differences in gene expression between females exhibiting high preference for males relative to females displaying little mate preference. Neuroserpin and neuroligin-3 gene expression within these brain regions are also positively correlated with female mate preference behavior. Two of these brain regions (Dm and Dl) integrate multisensory information and are found in the putative teleost mesolimbic reward circuitry; the other two regions (HV and POA) are involved in sexual behaviors. With the implication of the reward circuitry, I assess whether there are changes in dopamine synthesis (via tyrosine hydroxylase, TH) in dopaminergic brain regions associated with the degree of mate preference. I do not find evidence of rapid changes (within 30 minutes) of TH expression (i.e. dopamine synthesis) in dopaminergic brain regions related to variation in female mate preference. Collectively my results suggest that mate preference behavior in the brain may be coordinated not just through regions associated with sexual response but also through forebrain areas that may integrate primary sensory information, with no associated changes of a proxy for dopamine synthesis in dopaminergic brain regions.Item Joseph Butler's view of conscience : the voice of moral behavior(1988) Goldman, Barry Richard; Not availableItem Knockdown of HCN1 channels in the dorsal hippocampal CA1 region(2011-12) Kim, Chung Sub; Johnston, Daniel, 1947-; Aldrich, Richard; Mauk, Michael; Raab-Graham, Kimberly; Seidemann, EyalThe hippocampus is an integral brain region for affective disorders. HCN1 protein shows age-dependent increase in expression resulting in an increase in I[subscript h] in the dorsal hippocampal CA1 region. TRIP8b knockout mice lacking functional HCN channels as well as both HCN1 and HCN2 knockout mice have been shown to display antidepressant-like behaviors. The mechanisms or brain regions involved in these alterations in behavior, however, are not clear. We developed a lentiviral shRNA system to examine whether knockdown of HCN1 protein, and therefore h-channels, in the dorsal hippocampal CA1 region is sufficient to produce antidepressant-like effects. We found that silencing of HCN1 gene resulted in physiological changes consistent with a reduction of I[subscript h] and increased cellular excitability of CA1 pyramidal neurons. Rats infused with lentiviral-shRNA-HCN1 in the dorsal hippocampal CA1 region displayed antidepressant- and anxiolytic-like behaviors. Using voltage-sensitive dye imaging, we found that knockdown of HCN1 in the dorsal hippocampal CA1 region led to enhancement of hippocampal activity in large regions of the dorsal hippocampus. Our results demonstrate that changed hippocampal network activity by local manipulation of HCN1 channels in dorsal hippocampus led to anxiolytic- and antidepressant-like behaviors and suggest that HCN1 channels could be a potential target for treatment of anxiety and depression.Item Leisure time exercise behavior and motives of university administrators in China(2012-08) Shangguan, Rulan; Keating, Xiaofen; Lambdin, DorothyBackground: University administrator physical activity (PA) attitudes and actions may play an important role in student fitness promotion on campus but have been given little attention. Guided by the Theory of Planned Behavior (TPB), this study explored the relationships of factors that influence Chinese university administrator PA behaviors. Methods: A survey was designed to collect information regarding participants’ PA behaviors, intentions, perceived health, body mass index (BMI) and common demographic factors. A total of 474 Chinese university administrators participated in this study with 443 completed surveys. Path analysis was used to test the predictive and mediational role of the aforementioned variables on total PA. Results: Results revealed a good model fit. Attitudes mediated the effects of BMI and perceived health on total PA; subjective norms and self-efficacy had significant direct effects and mediated the effects of satisfaction and attitudes on total PA. The effects of intentions on total PA were not significant. Conclusions: Chinese university administrator PA behaviors were significantly influenced by attitudes, subjective norms, self-efficacy, BMI, perceived health and satisfaction with exercise facilities. The non-significant effects of intention on PA participation were not expected. More studies on university administrator’s PA are needed in the future.Item Living in a plant : brain and behavioral traits of acacia ants(2014-12) Amador Vargas, Sabrina; Mueller, Ulrich G.Acacia ants evolved obligate protective mutualisms with acacia trees, which they defend against herbivores, food parasites and encroaching vegetation. In this mutualism, the fitness of one partner entirely depends on the other. Other ant species are parasitic on acacia trees; they nest on the tree, harvest food rewards, do not defend their own tree, and occasionally try to steal food from other trees, usually inhabited by mutualistic ants. To understand the behavioral and anatomical effects of the interaction between ants and host trees, I integrated brain anatomy, morphology and field experiments to study parasitic and mutualistic species of Pseudomyrmex ants associated with acacia trees. In Chapter 1, I describe a previously unknown behavior of stealing food from other ant-defended acacia trees in the parasitic acacia ant P. nigropilosus, and I evaluate four strategies that may allow parasitic ants to overcome the usually effective defenses of the robbed mutualistic ants protecting a host tree. In Chapter 2, I study how colony size correlates with the degree of division of labor and brain anatomy of workers, focusing on a species of acacia ant lacking morphological castes among workers, P. spinicola. In Chapter 3, I study acacia-ant behavior of killing vegetation encroaching on a host tree. I document the interspecific differences among acacia ants in the size of the area around the host tree that workers clear from encroaching vegetation. I further test for interspecific variation in pruning behavior, and whether mandibular force correlate with worker pruning decisions. In Chapter 4, I test whether ant species that routinely leave the host tree to forage or to prune encroaching vegetation are better at orienting themselves when returning to their host tree, compared to ant species that rarely leave their host tree. This dissertation documents how the obligate protective mutualism of an ant with a tree has consequences for division of labor, navigational skills, behavioral specializations, head shape and brain anatomy of ant workers.Item Maintenance effects of strategy instruction for algebra skills with students with challenging behavior(2011-12) Roundhill, Marie Colleen; Flower, Andrea; Garcia, Shernaz; Pazey, BarbaraThis thesis consists of a single subject multiple baseline study of a math intervention for students with behavioral challenges. Students with behavioral challenges were given instruction using a concrete, representational, abstract (CRA) sequence in Algebra problems requiring transformations on both sides of the equation. This study examined maintenance of those skills. Results indicate that while accuracy decreased from the post-intervention to maintenance phases, scores remained well-above baseline levels indicating that the students retained understanding of the concepts taught. In a social validity survey, participants indicated that they liked the intervention, found it beneficial, and sometimes use it in their classes.Item Mate choice and hybridization within swordtail fishes (Xiphophorus spp.) and wood warblers (family Parulidae)(2011-05) Willis, Pamela Margaret; Ryan, Michael J. (Michael Joseph), 1953-; Bolnick, Daniel I.; Mueller, Ulrich G.; Rosenthal, Gil G.; Singer, Michael C.Behavioral isolation is an important barrier to gene flow, contributing to the formation and maintenance of animal species. Nevertheless, hybridization occurs more commonly than is generally recognized, occurring in over ten percent of animal species in the wild. Although the genetic consequences of hybridization are of considerable interest given their evolutionary implications, the reasons that animals choose to mate with other species are less clear. I apply mate choice theory to the question of hybridization, using wood warblers (family Parulidae) and swordtail fishes (genus Xiphophorus) as study systems. Over half of the 45 species of North American wood warbler have produced hybrids. Using comparative methods, I address the questions: Do ecological and demographic factors predict hybridization in this family? Similarly, how do phylogeny, song similarity, and sympatry with congeners correlate with hybridization? As with North American wood warblers, behavioral isolation is also considered of primary importance in isolating sympatric species of swordtail fishes. Two species, X. birchmanni and X. malinche, hybridize in several locations in the wild. Through experimentation with these and other Xiphophorus species, I investigate some of the factors that cause female mate choice to vary, possibly contributing to hybridization. Specifically, I address the following questions: Do females become less choosy when predation risk is high, or encounter rates with conspecifics are low? Are female preferences for conspecifics innate, or can they be modified by experience? And, do female preferences for conspecifics vary among species, populations, or experiments? These studies illustrate the utility of treating hybridization as just another possible outcome of variation in mate choice. I find that warbler hybridization correlates with ecological and other variables, that female swordtails become more responsive to heterospecifics when mate choice is costly, and that female preferences for conspecifics are species- and context-dependent. As animal hybridization can have important evolutionary consequences, studying the factors that contribute to this variation can enhance our understanding of the evolutionary process.Item Money attitudes, economic locus of control, and financial strain among college students(Texas Tech University, 2006-08) Hayes, John V.; Bagwell, Dorothy C.; Olivarez, Arturo; Gustafson, Bill; Joo, So-Hyun; Shumway, Sterling T.The relationship between attitudes and behavior has been studied extensively, yet research on money attitudes, perceptions of economic locus of control, and financial strain among college students is less abundant. Toward a better understanding of college student�s attitudes and perceptions about money, an investigation of student money attitudes and perceptions of economic locus of control is advanced. Research favors the validity of Furnham�s assertion that money attitudes are clearly not one-dimensional, and encompass a multitude of dimensions. Assessing these attitudes yields clearly defined constructs that may be influenced through additional stimuli. Numerous studies support the contention that money attitudes are learned dispositions, initially developed through parental teachings and observation of family money practices, later refined through socialization and experience. Thus it might be considered that money behavior change may be best accomplished through money attitude change, the latter accomplished by additional focused stimuli. Results of this study indicate significant differences in attitudes and perceptions of control over money matters between female and male college students, differences in the perceptions of influence over money matters between students from the Mexican American, Latino / Latina cultures and students from the Anglo American cultures, and differences in attitudes and practices between freshman students and upper class students. This analysis suggests female students tended to feel less personal control over positive outcomes compared to male students, yet perceived uncontrollable chance as less influential on their financial circumstances. Female students indicated less difficulty in meeting current obligations than did male students, while placing less importance on planning for future financial circumstances. Female students feel higher levels of anxiety over financial issues, have lower scores in financial literacy, and use money to impress or influence others less than male students. This analysis found that freshman students from the Mexican American and Latino / Latina cultures felt a significantly higher influence over their financial situation from Powerful Others; this influence increasing as the student advanced through class levels. The analysis also indicates junior and senior level students spend significantly higher amounts of time working (including work study), and have a much higher probability of reducing class load or withdrawing from class due to financial constraints. Implications of the study and recommendations for further research are discussed.Item Money attitudes, economic locus of control, and financial strain among college students(2006-08) Hayes, John V.; Bagwell, Dorothy C.; Olivarez, Arturo; Joo, So-Hyun; Gustafson, Bill; Shumway, Sterling T.The relationship between attitudes and behavior has been studied extensively, yet research on money attitudes, perceptions of economic locus of control, and financial strain among college students is less abundant. Toward a better understanding of college student’s attitudes and perceptions about money, an investigation of student money attitudes and perceptions of economic locus of control is advanced. Research favors the validity of Furnham’s assertion that money attitudes are clearly not one-dimensional, and encompass a multitude of dimensions. Assessing these attitudes yields clearly defined constructs that may be influenced through additional stimuli. Numerous studies support the contention that money attitudes are learned dispositions, initially developed through parental teachings and observation of family money practices, later refined through socialization and experience. Thus it might be considered that money behavior change may be best accomplished through money attitude change, the latter accomplished by additional focused stimuli. Results of this study indicate significant differences in attitudes and perceptions of control over money matters between female and male college students, differences in the perceptions of influence over money matters between students from the Mexican American, Latino / Latina cultures and students from the Anglo American cultures, and differences in attitudes and practices between freshman students and upper class students. This analysis suggests female students tended to feel less personal control over positive outcomes compared to male students, yet perceived uncontrollable chance as less influential on their financial circumstances. Female students indicated less difficulty in meeting current obligations than did male students, while placing less importance on planning for future financial circumstances. Female students feel higher levels of anxiety over financial issues, have lower scores in financial literacy, and use money to impress or influence others less than male students. This analysis found that freshman students from the Mexican American and Latino / Latina cultures felt a significantly higher influence over their financial situation from Powerful Others; this influence increasing as the student advanced through class levels. The analysis also indicates junior and senior level students spend significantly higher amounts of time working (including work study), and have a much higher probability of reducing class load or withdrawing from class due to financial constraints. Implications of the study and recommendations for further research are discussed.