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Individual variation and fitness are the cornerstones of evolution by natural selection. The trophic niche represents an important source of phenotypic variation on which natural selection can act. Although individual variation is fundamental to species-level ecological and evolutionary change, individual variation is often ignored in population-level approaches to wildlife ecology, conservation and management. Failing to link individual resource use to fitness or to biological outcomes related to fitness limits us to managing for the average resource needs of a population, which may be insufficient for protecting the diversity of resource use within populations and the underlying eco-evolutionary processes that generate that diversity. My goals were to provide insights into the mechanisms that generate and constrain intrapopulation trophic niche variation, evaluate whether linkages exist between individual biological outcomes and variation in food habits across the range of resources consumed within generalist consumer populations and examine how that variation manifests in population-level responses. I investigated the causes and physiological consequences of intrapopulation trophic niche variation in two generalist consumers, the American black bear (Ursus americanus) and brown bear (U. arctos) across three sites in British Columbia, CAN and at one site in Alaska, USA. My primary tools included stable isotope analysis to estimate diet, enzyme-linked immunoassay of hair to quantify the hormone cortisol for indexing physiological stress, and genetic analyses to identify individuals, species, and sex and to estimate ancestry. I found that individual differences in resource use can result in similar biological outcomes and that similar resource use can result in different biological outcomes. Intra- and interspecific competition, sex-based differences in nutritional and social constraints and annual variation in food availability all influenced trophic niche variation and the resultant biological outcomes. I also found evidence of a link between intrapopulation trophic niche variation and population genetic structure. My results highlight the diverse ecological drivers and diverse consequences of trophic niche variation, which further illuminates why the trophic niche is a nexus for eco-evolutionary dynamics.

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Indiana University-Purdue University Indianapolis (IUPUI) / Atherosclerosis preferentially develops in vascular regions of low or disturbed flow and high spatial gradients. Endothelial cells that line the vessel walls actively participate in translating mechanical stimuli, shear stress due to fluid flow, into intracellular signals to regulate cellular activities. Atherosclerosis is a chronic disease. During its development, a cascade of inflammatory signals alters the arterial endothelial homeostatic functions. Death-associated protein (DAP) kinase and its correlated pathway have been associated with cell apoptosis, turnover, and cytoskeleton remodeling in cellular networks, ultimately leading to changes in cell motility and vascular wall permeability. DAP-kinase is also highly regulated by inflammatory triggers such as TNF-α. This thesis investigates DAP-kinase modulation due to shear stress, and the role of DAP-kinase activity in endothelial responses toward applied shear stress. Using bovine aortic endothelial cells (BAEC), DAP-kinase expression is demonstrated in both sheared (10 dynes/cm2) and static conditions. Overall DAPK expression increased with extended shearing, while the presence of phosphorylated DAPK decreased with applied shear stress, as demonstrated in Western blot analysis. In correlation, DAPK RNA expression profiles were explored to understand pre-translational behavior and to understand just how shear stress influences DAPK expression over time. There is a temporal increase in DAPK mRNA, occurring at earlier time points when compared to DAPK protein expression, displaying the precedence of mRNA expression leading to increased translation into protein. From our apoptosis assay results, shear stress reduces apoptotic and late stage/necrotic cell fractions. The exposure of shear stress potentially plays a role in inhibiting apoptosis activation and TNF-α induced death cascade. Overall, the apoptosis activity influenced by shear further exhibits a possible connection between shear stress and apoptosis inhibition. The shear stress ultimately decreases overall apoptosis, while DAPK expression is increased. Therefore, DAPK may have a function in other possible mechano-transduction cascades, when endothelial cells are exposed to constant shear. Our data suggests shear stress modulation of DAP-kinase expression and activity, and the potential crosstalk of mechano-transduction and DAPK/apoptosis pathway, may lead to further understanding the responsibility of DAPK in endothelial cell function.

The main purpose of the present study was to determine empirically whether differences in perceived role conflict, role ambiguity, and Type A proclivities are associated with differences in perceived psychosomatic dysfunction. Moreover, an ancillary purpose of the present study was to determine whether differences in perceived job performance were associated with Type A-B tendencies and perceived role conflict and ambiguity. Data for 72 workers from all levels of two types of organizations (i.e., citizen protection and health) were obtained. All workers completed a role conflict and ambiguity measure, a 15-item self-report index of psychosomatic dysfunction, a 7-poimt measure of job performance, and the Jenkins Activity Survey (Form C) which was designed to tap the Type A behavior pattern. On the basis of their health reports, workers were classified into one of the following two groups: (a) psychosomatic, and (2) "no" psychosomatic. In order to identify whether differences in vectors, comprised of measures or role conflict, role ambiguity, and Type A-B behavior, existed among the two health groups, a discriminant function analysis was used. The only function extracted resulted in a Wilks' lambda of .8625 (p< .01). Moreover, Type A-B behavior and role conflict were found to contribute .798 and .201 to unit variance, respectively. In order to determine whether differences in perceived job performance were associated with Type A-B tendencies and perceived role conflict and ambiguity, two 3 x 2 fixed effects ANOVAs were performed. Significant main effects were found for role conflict (p< .005) and Type A-B behavior (p< .05). Neither interaction term proved significant. In sum, the results indicate that differences in perceived stress, as defined by role conflict, and Type A proclivities are associated with differences in perceived psychosomatic dysfunction. Moreover, Type B persons' perceptions concerning their own job performance are more favorable than Type A persons' perceptions concerning their own job performance, and this holds regardless of the perceived intensity of the stressor. Finally, persons under perceived "moderate" levels of stressor intensity were found to have significantly more favorable perceptions concerning their own job performance, than those who were under either perceived "low" or "high" levels of stressor intensity. This relationship help regardless of Type A or Type B proclivities.

The purpose of this study was to obtain data on the impact of machine-paced industrial inspection tasks upon workers. Psychological and physiological stress reaction measures were gathered from subjects under simulated work conditions. Typical stress indicators such as heart rate, electromyograph readings, temperature, and psychological stress scales comprised the raw data. After being subjected to statistical analysis, results and conclusions will be discussed in order to gain knowledge and insight as to the stress reactions of the machine-paced inspection worker, and to provide implications for further research.

Previous research suggests that sex differences in cardiovascular reactivity (CVR) are a function of differences in cognitive appraisal of stressors as masculine-relevant or feminine-relevant tasks. Two studies were conducted to examine the role of the appraised gender relevance of stressors as a mediator of sex differences in CVR. In the first study the CVR of male and female college students (<u>N</u> = 95) to the cold-pressor test (CPT) was compared under masculine-relevant and gender-neutral stressor instructions during an anticipation phase, a stressor phase, and a recovery phase. Men were expected to show greater CVR than women to the masculine-relevant CPT, but not to the gender-neutral CPT. Results supported this prediction for systolic blood pressure (SBP) and heart rate (HR) reactivity, but not diastolic blood pressure (DBP) reactivity. In the second study the CVR of male and female college students (<u>N</u> = 121) to the CPT was compared under masculine-relevant and female-relevant stressor instructions during an anticipation phase, a stressor phase, and a recovery phase. Men were predicted to show greater CVR than women to the masculine-relevant CPT while women were expected to show greater CVR to the feminine-relevant CPT. Results supported these predictions for SBP, but not HR reactivity. The results for DBP were mixed. Men did not show greater DBP reactivity than women to the masculinerelevant CPT, but women showed greater DBP reactivity than men to the feminine-relevant CPT. The potential influence of sex differences in cognitive appraisal of situations on CVR and coronary heart disease is discussed. / Ph. D.

This study investigated the differences in the cardiovascular reactivity (CVR: HR, SBP, DBP) of trained and untrained individuals who performed the cold pressor test (CPT) after exercising for 30 minutes at 70% VO₂ max and participating in an attention control. Eighteen untrained and eleven trained males were randomly assigned to a treatment sequence. The subjects performed either 30 minutes of cycling at 70% VO₂ max Or an attention control. Following 48 hours, the other activity was performed. The CPT followed 1 hour after each treatment session. Rest, peak, and recovery measurements were acquired. Examination of trained and untrained group means, regardless of condition, indicated that trained subjects had lower HR measurements at rest (F_1,25 = 6.86, p < .05) and peak (F_1,25 = 6.33, p < .05). Closer examination of the different effects due to the acute exercise and control conditions regardless of training state did not reveal any beneficial effects due to the exercise bout. In addition, this study did not support differences in CVR to the CPT due to an interaction of acute exercise with the trained and untrained states of individuals. Resting measures did reveal reduced DBP (F_1,25 = 4.06, p < .05) and HR (F_1,25 = 3.19, p = .09) in trained subjects compared with the untrained following the exercise session indicating a beneficial reduction in the anticipatory response to the stressor. This study did not statistically support the effectiveness of 30 minutes of exercise at 70% VO₂ max or advantages of a physically trained state in reducing CVR to the CPT. In addition, this study did not support the effectiveness of the interaction of exercise at 70% VO₂ max with the trained or untrained state in reducing CVR to the CPT. / Master of Science

Twenty-eight endurance trained male volunteers, 18-41 years or age, were studied to determine whether the heart rate-oxygen consumption relationships observed during Bruce protocol stress tests were similar to those observed during steady-state exercise. In addition, maximal oxygen consumption and maximal heart rate values obtained during the stress tests were compared to predicted values. The heart rate-oxygen consumption relationship observed during the stress tests was dissimilar from the relationship observed during the steady-state exercise tests. Heart rate was round to be significantly higher during the stress tests. No significant difference was round in predicted maximal oxygen consumption and maximal heart rate and actual values obtained during the stress tests. / M.S.

Behavioral and physiological reactivity, and its relationship to cardiovascular disease has been studied in men for a number of years, and the expression of anger has been identified as a possible contributing factor. Few studies, however, have focused specifically on the reactivity of women, and those which have suggest that women are less reactive to laboratory tasks than men. For the present study, 45 undergraduate women, ages 19-21 were selected from a larger sample of 135 women to represent three discrete groups: (1) low anger/low denial, (2) high anger/low denial, and (3) low anger/high denial, based on their scores on the State-Trait Anger Expression Inventory, P and the Marlowe-Crowne Social Desirability Scale. It was hypothesized that the three groups would show reliable differences in heart rate and blood pressure during presentation of a stressful laboratory stimulus, the Stroop Color and Word Test. Each subject received three counterbalanced conditions: (1) no feedback, (2) error feedback without observer present, (3) error feedback with observer present. As hypothesized, women who reported a high level of denial and a low level of anger exhibited reliably greater systolic blood pressure to the no-feedback condition than subjects who reported low levels of denial and anger. The hypothesis that all groups would display greater A reactivity in a condition which provided error feedback with observation was not supported. / Master of Science