This thesis was concerned with investigating a visual-illusionary phenomenon that co-occurs with post-traumatic anxiety symptoms. More specifically, individuals who report recurring specific memories of a fearful event (RSM) also tend to report a persistent illusion of movement (PIM) upon prolonged visual fixation (Tym, Dyck & McGrath, 2000). The development of a visual test (i-Test) designed to reliably elicit PIM has enabled research to be conducted on the nature and correlates of this type of visual disturbance. The present research aimed: 1) To develop a standard protocol for assessment of PIM and RSM; 2) to test the reliability of the i-Test in eliciting PIM in a student sample 3) to test the predictive relationship between dissociation and anxiety symptoms with PIM and RSM 4) to formulate and test a hypothesis regarding a mechanism underlying PIM. The first study screened 142 participants for RSM and PIM using self-administered questionnaires designed by Tym (personal communication, 2001). There was an unexpectedly high rate (54.2%) of PIM and RSM (37.3%) in the sample, which appeared to be the product of questionnaire design limitations. Two semi-structured interviews were developed and subsequently tested on a new sample of 50 participants in Study 2. Study 2 documented intra-rater and inter-rater reliability co-efficient of sufficient strength to indicate good reliability for the semi-structured interviews. The results of Study 2 indicate that PIM is a relatively stable symptom over a 30-minute and one-week test-retest time frame. / The onset time for PIM was relatively consistent between participants, with a mean latency of approximately 7 seconds. The oscillation rate of PIM was relatively consistent between individuals, with a mean average oscillation of approximately 0.8Hz. The third study tested a sample of 148 participants using the revised assessment protocols. The base rate for PIM (16.2%) and RSM (18.9%), and the concordance rates (46% to 54%) were slightly stronger than the Tym et al. (2000) community based study (33%). In addition to this, 11 other illusionary phenomena were documented, however none of these visual symptoms significantly correlated with RSM. The average oscillation rate is comparable to the rate documented in Study 2, further establishing the consistency of the reported rate of PIM oscillations between individuals. In Study 3, each participant was assessed for levels of dissociation (Dissociative Experiences Scale), somatic arousal (Mood and Anxiety Symptoms Questionnaire – Anxious Arousal Scale) and anxiety sensitivity (Anxiety Sensitivity Index). The results indicate that gender and dissociation significantly predict RSM status, and self-reported levels of anxious-arousal significantly predict PIM status. A multiway frequency analysis between the sub-components of RSM and PIM revealed that the physiological arousal inducing properties of the recurring memory is the only significant predictor of PIM. / The observed relationship between RSM and PIM may reflect the broader relationship between anxiety and dissociation. A pulsatile hypothesis was proposed as a feasible mechanism underlying PIM, due to the rhythmical nature of the visual disturbance, the range of the documented oscillations, and its specificity to psychological disorders characterised by cardiovascular sensitivities. All participants were administered the i-Test prior to and following aerobic exercise aimed at increasing pulse rate to 80% of maximum load. An increase in physical exertion significantly increased the latency of PIM onset, but did not impact on the rate of PIM. PIM rate appeared relatively consistent between individuals at 0.6Hz to 0.8Hz at the pre-exercise condition. Several participants who reported PIM also displayed obvious nystagmoid-like movements during the i-Test perceptual task. The role of eye-movements in PIM requires further investigation by future ophthalmological research. The final aim of Study 3 was to investigate the relationship between RSM/PIM and flicker sensitivity. Through the use of a Critical Flicker Frequency/Fusion task (CFF), each participant’s sensitivity to flicker was determined. In addition to detecting sensitivity thresholds, CFF is also considered to be a reliable indicator of the level of cortical arousal. / The results of this study suggest that individuals with RSM have a higher sensitivity to flicker than other participants, however there was a non-significant relationship between CFF and PIM. The lack of relationship between PIM and CFF may be due to issues concerning statistical power and effect-size. Future research is required to investigate this link in more detail. The overall results of this thesis suggest that i-Test elicited PIM is a reliable phenomenon that is associated with higher rates of traumatic memories when compared with persons who do not report this visual symptom. The strength of the association between RSM and PIM, however, does not support the use of the i-Test as a marker for the presence of RSM outside a clinical sample. The reliability of PIM as a phenomenon and its association with anxiety symptoms may be of theoretical importance in enabling future research to investigate the relationship between visual symptoms and anxiety-related pathology.

Although a vast literature attests to the belief that psychosocial disturbance is an important component of functional gastrointestinal disorders (FGID), the relation of life stress, psychological distress and personality to the development of these disorders is poorly understood. The broad objective of this thesis is to provide data on relations between psychosocial factors and FGID, especially irritable bowel syndrome (IBS) and functional dyspepsia (FD), in representative outpatient samples. Issues not previously addressed are examined in a series of studies. The first two studies are concerned with relations between psychosocial factors, extraintestinal (somatic) symptoms and the number and type of FGID syndromes present at consultation and, in IBS patients, the prospective relation of psychosocial factors to changes in symptom intensity over 16 months. The last three studies relate psychosocial factors to gastrointestinal (GI) transit, motor, and sensory function in FGID, abnormalities in these parameters representing the putative origin of symptoms in FGID. In total, 350 patients participated, representing a 95% participation rate. Important features of the methodology include the use of a recently standardised symptom-based classification system for FGID, an objective and reliable interview-based life stress instrument (The Life Events and Difficulties Schedule), and sophisticated and sensitive technologies to assess GI transit, motor and sensory function. Novel measures, which conceptually take into account the chronic, fluctuating and recurrent course of IBS and FD syndromes, and the tendency of these syndromes to coexist, are also included. Thus, measures of symptom outcome assess the number of syndromes present, while the symptom intensity variable reflects the severity and frequency of both FD and IBS symptoms, if both are present. Similarly, with respect to altered transit, and motor and sensory function, physiological outcome variables reflect not only the presence of an abnormality but the number of regions affected, and the type and number of abnormalities present. Cross-sectional findings showed for the first time that psychosocial disturbance is associated with FGID symptomatology in a quantitative manner, that chronic life stress threat is central to this process and this stress-related process is a prominent feature of a particular group of syndromes (ie IBS/FD) defined primarily by the presence of pain and discomfort. A combination of psychological, social and biological factors combined to predict the number of FGID syndromes present at entry into the study. Prominent among them was an angry, reactive and anxious (neurotic) personality, chronic life stress threat, increased coping, poor emotional support and increased age. In addition to a greater number of FD/IBS syndromes, individuals with an anger-reactive response style had experienced more intense pain and discomfort, and displayed more complete sensorimotor disturbance. Longitudinal data demonstrated (also for the first time) the strength, consistency and unequivocal direction of the relation of chronic threat to symptom intensity over time. Almost all of the within subject variance in symptom intensity levels (assessed on 3 occasions over a 16 month period) was explained by the severity of chronic threat during the previous 6 months or more. For 76% of IBS patients, the presence vs the absence of one or more highly threatening chronic stressors predicted with considerable precision, the long-term clinical outcome. Thus, no patient exposed to even one such stressor improved clinically (ie by at least 50%) over the follow-up period, while in contrast, all patients who improved clinically did so in the absence of such a stressor. For 24% of patients, however, failure to improve clinically could not be explained by any psychological, social (including life stress) or demographic factor included in this study. Key risk indicators of a poor outcome at 16 months were identified - chronic life stress threat, the severity of baseline GI symptomatology, and female gender. Life stress is important because it alone determined the magnitude and direction of change in symptom intensity over time, while the severity of baseline GI symptomatology revealed the extent of improvement required to achieve a recovery, and female gender predicted the presence of a larger number of FD/IBS syndromes in women long-term. Widespread hypomotility, which was almost exclusive to women in this study, represents one factor that may inhibit improvement (or rate of improvement) for women over time. Finally, these findings have identified a psychophysiological subgroup, with underlying psychosocial, motor (and perhaps also sensory) dysfunctions that are more specific for women than men, and which does not seem to be distinctive of any particular FGID subgroup.

Obesity is a serious health concern in Canada. Thirty-seven percent of the population are overweight and approximately 25% are obese. Increased energy intake from eating outside the home has contributed to the rise in obesity. Approximately one quarter of all Canadians consume food in a quick-service restaurant on a given day. Although not all food consumed outside the home is of poor nutritional quality, restaurants generally offer foods that have larger portions, and are higher in calories and fat. Menu labelling has the potential to promote healthier eating by informing consumers about the calorie content of meals. Currently, there is little or no research on possible unintended effects of displaying calorie information at restaurants and quick-service establishments. In particular, it is unclear how such information would affect individuals with clinical eating disorders, or those with eating disturbances. In the current study, 325 female undergraduate students over the age of 16 took part in a 10-minute paper-based survey after meal consumption in a cafeteria on the University of Waterloo campus. The study employed a pre-post design, with data collection occurring in paired and unpaired samples one month before calorie information was added to menu boards, and one week after. In the 299 participants with usable data the prevalence of eating disturbances (EAT-26 > 20) was 10.4%. Calorie consumption decreased from baseline (mean=678.2 kcal) to follow-up (mean=602.3 kcal; p=0.049). There were no statistically significant changes in any of the other outcomes from baseline to follow-up, including body image satisfaction, anxiety, mood, and frequency of engaging in unhealthy behaviours. Additionally, there were no interactions between eating disturbance level and time, which suggests that calorie labels did not differentially affect those in this high-risk population. Overall, no adverse outcomes related to eating disturbances were associated with the implementation of calorie labels in this at-risk population. The results have potential implications for menu labelling regulations.

Tropical rainforests are among the most complex and diverse ecosystems, composed of a mosaic of shady understory under the closed canopy and tree-fall gaps of varying sizes and age. The light reaching the forest floor favors the recruitment of fast growing plant species and provide food resources for other animal species including butterflies. The Nymphalidae are the most species rich butterfly family in the tropics, and are ideal bioindicators. We investigated the effect of the tree-fall gaps on the assemblages of fruit feeding Nymphalidae. We used fruit-bait traps in 15 tree-fall gaps from 100 to 1000 m2 and 15 in undisturbed understory, from July until November, in a lowland tropical rainforest in southeastern Peru. We found distinct differences in butterfly assemblages between tree-fall gaps and understory, with a higher number of species in gaps, associated with a higher level light. We identified several species mostly found in one of the habitats, and generalist species. The heterogeneity was large within the same site both in gaps and in the understory. The difference between butterfly assemblages increased with gap size. Butterfly species were mainly associated with the absence of vines in the gaps, and found in large and light gaps. We distinguished several species according to their preferences for the vegetation structure, light level and size of gaps. We concluded that one example that maintains the biodiversity in the tropical rainforest is the formation of tree fall gaps of different sizes resulting in different species assemblages.

No description available.

Obesity is a serious health concern in Canada. Thirty-seven percent of the population are overweight and approximately 25% are obese. Increased energy intake from eating outside the home has contributed to the rise in obesity. Approximately one quarter of all Canadians consume food in a quick-service restaurant on a given day. Although not all food consumed outside the home is of poor nutritional quality, restaurants generally offer foods that have larger portions, and are higher in calories and fat. Menu labelling has the potential to promote healthier eating by informing consumers about the calorie content of meals. Currently, there is little or no research on possible unintended effects of displaying calorie information at restaurants and quick-service establishments. In particular, it is unclear how such information would affect individuals with clinical eating disorders, or those with eating disturbances. In the current study, 325 female undergraduate students over the age of 16 took part in a 10-minute paper-based survey after meal consumption in a cafeteria on the University of Waterloo campus. The study employed a pre-post design, with data collection occurring in paired and unpaired samples one month before calorie information was added to menu boards, and one week after. In the 299 participants with usable data the prevalence of eating disturbances (EAT-26 > 20) was 10.4%. Calorie consumption decreased from baseline (mean=678.2 kcal) to follow-up (mean=602.3 kcal; p=0.049). There were no statistically significant changes in any of the other outcomes from baseline to follow-up, including body image satisfaction, anxiety, mood, and frequency of engaging in unhealthy behaviours. Additionally, there were no interactions between eating disturbance level and time, which suggests that calorie labels did not differentially affect those in this high-risk population. Overall, no adverse outcomes related to eating disturbances were associated with the implementation of calorie labels in this at-risk population. The results have potential implications for menu labelling regulations.

This thesis analyses the political development and the growth of popular political awareness in Glasgow and the west of Scotland from the Union with England of 1707 to the burgh reform movement in the mid-1780s, examining political disputes among the urban elite as well as the activities, arguments, and ideology of ordinary people. Through the rapid growth of Atlantic trade and manufacturing industries, Glasgow and the west of Scotland in this period experienced social and economic changes which had significant implications for the ways that political control was contested and political opinions were expressed. The region also possessed a distinctive tradition of orthodox presbyterianism and loyal support for the Revolution Settlement and the Hanoverian Succession, both of which underpinned the growth of popular political awareness in the mid- and later eighteenth century. By taking these social and economic changes as well as traditional religious and political characteristics of the region into account, this thesis establishes a dynamic picture of eighteenth-century Scottish politics which has in the past been overshadowed by an image of its stability. Chapter One outlines the conditions, structure, and operation of urban and popular politics in eighteenth-century Glasgow. Chapters Two and Three demonstrate the existence of challenges to the political management by the great landowners and point out the popular dimension of these struggles. Chapter Four analyses how and why popular political consciousness developed in the age of the American Revolution, which led to the emergence of the burgh reform movement. Chapter Five examines popular disturbances, revealing the agency and vibrancy of the politics of the people. Chapter Six explores popular political ideology, focusing on the widespread appreciation of the British constitution and a distinctive Scottishness in the concept of liberty. This thesis concludes by asserting the importance of understanding politics in its broadest sense and also of incorporating the popular element as an integral part of any understanding of eighteenth-century Scottish politics.

Coral reef environments have been degrading steadily over the last few decades. It is generally accepted now that coral reefs are one of the first marine ecosystems to show measurable perturbations driven by global warming. Some of theses perturbations are consequence of extreme stochastic disturbances like hurricanes or extreme thermal anomalies and therefore, can be easily identified using broad indicators like coral cover. These indicators are easy to measure and provide a general description of the system in question. The detection and interpretation of more subtle perturbation in coral communities is more complicated, both logistically and conceptually. However, detecting chronic perturbations at an early stage can increase significantly the success of early mitigating management strategies. This thesis focuses on the development and application of highly sensitive indicators that can detect subtle perturbations in coral communities. It also studies the ecological interpretation of mild perturbations and their effect on the future structure of coral reef environments. The mild thermal disturbance experienced by the Heron Island reef in the south of the Great Barrier Reef during the 2005-2006 summer, and an environmental gradient along the central coast of Venezuela (south Caribbean Sea), were used as models to test the sensitivity of coral reefs to mild disturbances at different organisation levels (organism, population, and community). At the organismal level my results showed that the intensity of bleaching that a colony shows during a mild thermal disturbance is affected by the morphology of the colony as well as the substrates surrounding the colony. Colonies surrounded by sand bleached more than colonies surrounded by dead coral or rubble. I propose that reef specific information on the relative cover of sand, rubble, and dead coral can improve the fine scale accuracy of bleaching predicting models. Studying the same mild thermal disturbance at Heron Island, I showed how demographic parameters of some populations are more sensitive to mild thermal disturbances than coral cover (the most widely used response variable in coral monitoring programs around the world). Furthermore, my results suggest that the response of coral populations to mild thermal disturbance is different in nature and intensity to the respond observed during extreme thermal disturbances. Some taxa like Stylophora pistillata, are highly sensitive to extreme thermal disturbances, and tend to be the first to die under these conditions. In contrast, this taxon was extremely tolerant to the mild thermal disturbance of early 2006 in comparison to other taxa identified previously as more tolerant than S. pistillata. This difference in the response of coral environments to milder more common disturbances can have great influence in the trajectory that coral reefs follow in a rapidly changing world. Finally at a community level, I demonstrated how the power to detect the effect of environmental conditions on coral environments is drastically increased when the coral host-endosymbiotic algae relationship is interpreted holistically. The percentage of the variability of the community structure that can be explained by environmental variables in the central coast of Venezuela is doubled when the unit of selection considered is the holobiont instead of the coral host or the endosymbiont independently. This approach can be crucial for the detection of subtle changes in coral communities as the frequency and intensity of disturbances increase rapidly. The increase in detection power provided by the different approaches developed in this project can both improve our understanding of the structuring role of mild disturbances in coral communities as well as help identify the effect of disturbances in an early stage before the perturbation reaches catastrophic proportions. This early identification of perturbations can be used for the development of adaptive management strategies that can increase the resistance and resilience of coral reefs in the future.

Although a vast literature attests to the belief that psychosocial disturbance is an important component of functional gastrointestinal disorders (FGID), the relation of life stress, psychological distress and personality to the development of these disorders is poorly understood. The broad objective of this thesis is to provide data on relations between psychosocial factors and FGID, especially irritable bowel syndrome (IBS) and functional dyspepsia (FD), in representative outpatient samples. Issues not previously addressed are examined in a series of studies. The first two studies are concerned with relations between psychosocial factors, extraintestinal (somatic) symptoms and the number and type of FGID syndromes present at consultation and, in IBS patients, the prospective relation of psychosocial factors to changes in symptom intensity over 16 months. The last three studies relate psychosocial factors to gastrointestinal (GI) transit, motor, and sensory function in FGID, abnormalities in these parameters representing the putative origin of symptoms in FGID. In total, 350 patients participated, representing a 95% participation rate. Important features of the methodology include the use of a recently standardised symptom-based classification system for FGID, an objective and reliable interview-based life stress instrument (The Life Events and Difficulties Schedule), and sophisticated and sensitive technologies to assess GI transit, motor and sensory function. Novel measures, which conceptually take into account the chronic, fluctuating and recurrent course of IBS and FD syndromes, and the tendency of these syndromes to coexist, are also included. Thus, measures of symptom outcome assess the number of syndromes present, while the symptom intensity variable reflects the severity and frequency of both FD and IBS symptoms, if both are present. Similarly, with respect to altered transit, and motor and sensory function, physiological outcome variables reflect not only the presence of an abnormality but the number of regions affected, and the type and number of abnormalities present. Cross-sectional findings showed for the first time that psychosocial disturbance is associated with FGID symptomatology in a quantitative manner, that chronic life stress threat is central to this process and this stress-related process is a prominent feature of a particular group of syndromes (ie IBS/FD) defined primarily by the presence of pain and discomfort. A combination of psychological, social and biological factors combined to predict the number of FGID syndromes present at entry into the study. Prominent among them was an angry, reactive and anxious (neurotic) personality, chronic life stress threat, increased coping, poor emotional support and increased age. In addition to a greater number of FD/IBS syndromes, individuals with an anger-reactive response style had experienced more intense pain and discomfort, and displayed more complete sensorimotor disturbance. Longitudinal data demonstrated (also for the first time) the strength, consistency and unequivocal direction of the relation of chronic threat to symptom intensity over time. Almost all of the within subject variance in symptom intensity levels (assessed on 3 occasions over a 16 month period) was explained by the severity of chronic threat during the previous 6 months or more. For 76% of IBS patients, the presence vs the absence of one or more highly threatening chronic stressors predicted with considerable precision, the long-term clinical outcome. Thus, no patient exposed to even one such stressor improved clinically (ie by at least 50%) over the follow-up period, while in contrast, all patients who improved clinically did so in the absence of such a stressor. For 24% of patients, however, failure to improve clinically could not be explained by any psychological, social (including life stress) or demographic factor included in this study. Key risk indicators of a poor outcome at 16 months were identified - chronic life stress threat, the severity of baseline GI symptomatology, and female gender. Life stress is important because it alone determined the magnitude and direction of change in symptom intensity over time, while the severity of baseline GI symptomatology revealed the extent of improvement required to achieve a recovery, and female gender predicted the presence of a larger number of FD/IBS syndromes in women long-term. Widespread hypomotility, which was almost exclusive to women in this study, represents one factor that may inhibit improvement (or rate of improvement) for women over time. Finally, these findings have identified a psychophysiological subgroup, with underlying psychosocial, motor (and perhaps also sensory) dysfunctions that are more specific for women than men, and which does not seem to be distinctive of any particular FGID subgroup.

Thesis (Ph. D.)--University of Nevada, Reno, 2007. / "December 2007." Includes bibliographical references. Online version available on the World Wide Web.