4,151 research outputs found
Mental time travel in dysphoria: Differences in the content and subjective experience of past and future episodes
Previous research has shown that depressed individuals demonstrate a number of biases in their ability to retrieve past events and simulate future events. The current study investigated the content and phenomenological experience of past and future events in dysphoric and non-dysphoric individuals. Results indicated that dysphoric, compared with non-dysphoric, individuals reported fewer positive events across both temporal directions. Furthermore, phenomenological characteristics ratings suggested that dysphoric individuals saw future, but not past, events as less vivid, coherent, sensorially detailed, bodily experienced, emotionally intense and important with respect to their life story and identity. These findings are discussed with reference to theories regarding the functions of ‘mental time travel’, in particular how the muted subjective experience of future episodes in depression may impair future planning, problem-solving and self regulation
Harnessing Opportunities in Non-Animal Asthma Research for a 21st-Century Science
The incidence of asthma is on the increase and calls for research are growing, yet asthma is a disease that scientists are still trying to come to grips with. Asthma research has relied heavily on animal use; however, in light of increasingly robust in vitro and computational models and the need to more fully incorporate the ‘Three Rs’ principles of Replacement, Reduction and Refinement, is it time to reassess the asthma research paradigm? Progress in non-animal research techniques is reaching a level where commitment and integration are necessary. Many scientists believe that progress in this field rests on linking disciplines to make research directly translatable from the bench to the clinic; a ‘21st-century’ scientific approach to address age-old questions
Relationships between exercise, energy balance, appetite and dietary restraint in overweight and obese women
Background: Exercise may acutely and chronically up-regulate appetite and energy intake in overweight and obese women preventing body mass reduction in the long term. Overweight and obese women may be most prone to compensatory responses to exercise but the possible mechanism for this is unclear. Appetite regulating hormones have been investigated as a possible mechanism but to date the evidence is somewhat mixed.
Identifying compensatory energy intake responses in overweight and obese women is complicated by the high prevalence of dietary under-reporting in this group. The laboratory-based buffet meal method has frequently been used in research studies that have assessed food intake in these women, but this method has only undergone preliminary validation.
Dietary restraint may also affect individual appetite responses to exercise; it has been theorised that restraint may be a behavioural adaptation to diminished energy requirements, and differences in physical activity levels could also contribute. Evidence thus far has produced mixed results, possibly because two distinct sub-groups of restrained eaters exist, those with flexible and rigid control of restraint. It is not known if there are differences in energy requirements between these two sub-groups.
Participants and Methods:
Participants in all studies were sedentary, healthy, pre-menopausal, overweight and obese, adult women.
Study 1: Fourteen women completed four trials; two exercise and two control, following the same protocol as study 1. Energy intake at three buffet meals and subjective appetite ratings were measured, and the reproducibility of these values under control and exercise conditions was tested using intraclass correlation coefficient (ri).
Study 2: Twenty-nine women completed two trials in a randomised, counterbalanced order; exercise and control. Each trial lasted 24 hours spanning 2 days; the afternoon of day 1 and morning of day 2. An exercise session to expend 1.65 MJ was completed on day 1 of exercise trials, and three buffet meals were served during each trial to measure energy intake. Appetite was assessed using a visual analogue scale and blood samples were taken to determine acylated ghrelin (n=15) and peptide YY (n=10) concentrations. A repeated measures ANOVA was used to investigate the effects of trial and time on appetite hormones, EI and appetite.
Study 3: Fifteen women participated in a sixteen week exercise intervention to expend 8360 kJ week-1. Participants exercised unsupervised in the University gym, and compliance was measured via heart rate monitoring. Sub-maximal fitness and body composition assessments were carried out at baseline, and after 8 and 16 weeks of exercise. Energy expenditure, energy intake, appetite, and acylated ghrelin (n=14) and peptide YY concentrations (n=11) were measured at baseline and after 8 weeks of exercise. Paired t tests were used to assess differences in time-averaged AUC for appetite, total and relative EI, metabolic rate, and exercise responses between trials. Repeated measures ANOVA was used to assess changes over time in body composition, appetite ratings, EI, acylated ghrelin, peptide YY, and cardiovascular fitness levels.
Study 4: Forty-one sedentary women in a one week observational study. Participants were classed as restrained or unrestrained using the three factor eating questionnaire, and the former group were further classified as having flexible or rigid control of restraint. All participants completed a food frequency questionnaire, sub-maximal fitness test, body composition assessment and two fasted metabolic rate measurements. Average daily energy expenditure was calculated from a seven day physical activity diary combined with continuous heart rate data. Differences between restrained and unrestrained eaters, and restrained eaters with flexible and rigid control, were assessed using a paired t-test.
Results
Study 1: The ri for energy intake in control trials was significant but had large associated confidence intervals (ri 0.50 (95% CI 0.03, 0.80) p=0.0003). The ri was for energy intake in exercise trials was (ri 0.04 (95% CI -0.53, 0.55; p=0.45) and for the difference between control and exercise trials was (ri -0.05 (95% CI -0.54, 0.48; p=0.57) this was not significant. The ri values for satiety, fullness and desire to eat were significant in both control and exercise trials (p<0.05), but the associated confidence intervals were large.
Study 2: There was no effect of exercise on subjectively rated appetite, acylated ghrelin, or peptide YY concentrations (all p>0.05). Total energy intakes were not significantly different between trials (exercise: 10.9 ± 0.5 MJ, control: 10.8 ± 0.5 MJ; mean ± SEM).
Study 3: Total exercise energy expenditure during the intervention was 80.8 ± 7.7 MJ, which resulted in a significant reduction in total body mass (-1.9 ± 0.9 kg), fat mass (-1.7 ± 0.7 kg) and BMI (-0.7 ± 0.4 kg m-2). However individual changes in body and fat mass ranged from +2.8 to -9.9kg, and +1.78 to -6.55 kg respectively. There were no significant differences in appetite, energy intake, or expenditure after 8 weeks of exercise (p>0.05).
Study 4: There were no differences in metabolic rate, daily energy expenditure or physical activity patterns between restrained and unrestrained eaters (p>0.05), or between restrained eaters with flexible and rigid control of restraint (p>0.05).
Conclusions:
Study 1: The laboratory-based buffet meal method of measuring energy intake does not provide reliable, reproducible values in overweight and obese, pre-menopausal women either under control or exercise conditions.
Study 2: A walking-based exercise session which induces a moderate energy deficit of 1.65 MJ does not appear to affect subsequent twenty four hour energy intake, subjectively rated appetite, or plasma acylated ghrelin and peptide YY concentrations during the subsequent twenty four hours.
Study 3: This study concluded that 16 weeks aerobic exercise in overweight and obese women produces a small, but significant, reduction in body and fat mass (-1.9 ± 0.9 kg); however the extent of these changes varies greatly between individuals (+2.8 to -9.9kg). No evidence of compensatory changes in energy intake or expenditure, subjective appetite ratings, or circulating levels of acylated ghrelin and peptide YY was apparent after 8 weeks of exercise.
Study 4: This study concluded that there is no evidence of a difference in body composition or energy requirements between overweight and obese female restrained and unrestrained eaters, or between sub-groups of restrained eaters. Dietary restraint does not appear to be an adaptation to diminished energy requirements
Impact of Forest Management on Ozark Big-Eared Bat (Corynorhinus townsendii ingens) Prey and Foraging Ecology
Ozark big-eared bats (Corynorhinus townsendii ingens) are an endangered species of bat found only in Oklahoma and Arkansas. I conducted a study on the impact of forest management treatments, such as prescribed fire and mechanical thinning, in White Rock Mountain Wildlife Management Area, which is home to a maternity colony of Ozark big-eared bats. My goal was to understand how prescribed fire and mechanical thinning influence Ozark big-eared bat prey and foraging, and therefore be able to provide management recommendations for the habitat of this endangered species. My results indicated that bat prey availability was influenced by forest structure, and was higher in areas that had higher percentages of woody and herbaceous groundcover and more open canopies. Prioritizing these areas through a combination of burning and thinning could be beneficial for bat prey and influence foraging ecology of Ozark big-eared bats. I found that bats were using burned areas less than expected and areas that had not been managed more than expected, but were using thinned areas in proportion to their availability. These results indicate that forest management in this area is not having detrimental effects to bat foraging. I conducted a Hot Spot Analysis to determine potential insect prey availability hot spots, but found that these hot spots were not influencing where bats were foraging. This study provided insight to how the forest has responded to disturbance in this area and information to use in further studies relating to foraging ecology and management for this bat colony
Boundaries of governance: Social responsibility in mining in Western Australia
This research investigated the boundaries of governance of social responsibility in three multinational mining organisations based in Perth, Western Australia. The mining industry has economic, environmental and social impacts, both positive and negative. While most of the attention of the media and supporters in government seems to focus on the positive impacts, a growing concern regarding the social implications of mining is clearly evident in public discourse and the academic literature. In response to public concern, the mining industry has adopted terms such as ‘sustainability’, ‘sustainable development’, ‘social licence to operate’ and ‘social responsibility’. Such phrases are widely used in annual reports and public statements. It seems reasonable then to expect that organisations in the industry would be managing the social impacts of mining with the same diligence that is applied to economic and environmental impacts. However the governance of social impacts and the social responsibilities of mining organisations have historically been managed reactively, rather than proactively, or have not been addressed at all. This study used phenomenological research methods to examine the perceptions of the people who are at the forefront of decision making for social responsibility in the mining industry: the managers in mining companies. The findings detail different conceptions of social responsibility, and how these affected governance and boundaries. The term ‘boundaries’ is used here to express what participants perceived as the limits of their organisation’s social responsibility. The thesis explores whether boundary setting was formal or informal, how boundaries were defined and under what conditions they changed. The research confirmed that terms such as ‘sustainable development’ were used widely; however the meanings attributed to these often obscured the narrow conception of the terms. This interpretation aligned with an organisationally strategic approach to social responsibility that primarily aimed to benefit the organisation, while the provision of benefits to other parties was a secondary consideration. The research found that the perceived level of risk to the organisation was most influential in defining boundaries, and risk itself was in a constant state of flux based on changing economic and social circumstances and changing perceptions. The findings showed that the organisations governed social responsibility to reduce risk to the organisation, and construed their social responsibilities through narrow interpretations of sustainability and sustainable development that foregrounded the organisation, rather than as a way to effectively and systematically reduce the negative impacts of mining on society or to contribute to sustainability in a broader sense
To what extent do psychological distance and knowledge mediate the impact of algae blooms on cultural ecosystem services in the Lake Champlain Basin?
This research examines the relationships between psychological distance and knowledge of blue green algae on cultural ecosystem services with the hope of understanding how to better incorporate these values into managing the issue of harmful blue-green algae blooms within Lake Champlain. A questionnaire was developed and conducted to characterize the relationships between the three concepts. I hypothesized there would be a significant relationship between both people’s knowledge of algae blooms, their psychological distance from algae blooms, and the corresponding impact on cultural ecosystem services from Lake Champlain. In order to test this hypothesis, a mediation model was created and run to determine the relationship between the three variables. Although there was a significant relationship between psychological distance and CES, knowledge of blue-green algae blooms failed to significantly mediate the primary relationship, with the exceptions of the Bequest and Heritage variables. By understanding these relationships, one can better frame the tradeoff between valuable ecosystem services and environmental degradation in decision-making. Additionally, applying the concept of psychological distance to cultural ecosystem services can motivate individuals to take action against the collective problem of phosphorus management within the Lake Champlain Basin
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