990 research outputs found

    Poster Introductions III--Aging with Long-Term Physical Impairment: The Significance of Social Support

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    As the population ages more people are reaching old age having lived with a long-term physical impairment. This vulnerable group of people has specific needs that are often different from those of someone who reaches old age without a pre-existing physical impairment. This paper focuses on the significance of social support in ameliorating the aging experience when living with long-term physical impairment. It is based on a qualitative study of the aging experiences of eight men and women living in Ontario, Canada who were between the ages of 50 and 68 and had lived with their physical impairment for more than 10 years. Two participants had impairments on account of multiple sclerosis, two on account of rheumatoid arthritis, one had loss of limb, one had muscular dystrophy, one had hip deterioration from age 12, and one had polycystic kidney disease. Data were gathered through in-depth, semi-structured interviews. The findings suggest that coping with long-term physical impairment may be a lonely experience when the person lacks a strong network of family and/or friends to offer emotional support as they deal with the constant changes that can occur. Participants felt their experiences of aging with long-term physical impairment were improved when they shared their thoughts, feelings and problems with others. The paper also discusses the significance of gender and marital status with regard to access to social support. Rebecca Casey is a PhD candidate in Sociology at McMaster University. Her research interests include aging, disability, health and policies. Her MA thesis, at Lakehead University, focused on the experience of aging with long-term physical impairment. The poster presentation is based on this research. Rebecca’s PhD dissertation will use data collected through the Research Action Alliance on the Consequences of Work Injury (RAACWI), to focus on poverty and to relate it to aging concerns, such as loss of pensions through employment changes, reduced income following an injury and lack of employment opportunities due to reduced physical abilities. Sharon Dale Stone is Professor of Sociology at Lakehead University, where she is also affiliated with the Women’s Studies, Gerontology, and Masters of Public Health programs. Her research focuses on experiences of living with chronic impairments and issues that arise as a result. She recently published A Change of Plans: Women’s Stories of Hemorrhagic Stroke (2007) and is writing an analysis of the experiences of women who survived a hemorrhagic stroke at a young age. She is currently working with a team of academic researchers and community activists to investigate the experiences of injured workers with the worker’s compensation system

    Dobby: A Conversational Service Robot Driven by GPT-4

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    This work introduces a robotics platform which embeds a conversational AI agent in an embodied system for natural language understanding and intelligent decision-making for service tasks; integrating task planning and human-like conversation. The agent is derived from a large language model, which has learned from a vast corpus of general knowledge. In addition to generating dialogue, this agent can interface with the physical world by invoking commands on the robot; seamlessly merging communication and behavior. This system is demonstrated in a free-form tour-guide scenario, in an HRI study combining robots with and without conversational AI capabilities. Performance is measured along five dimensions: overall effectiveness, exploration abilities, scrutinization abilities, receptiveness to personification, and adaptability

    Towards Realistic Progenitors of Core-Collapse Supernovae

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    Two-dimensional (2D) hydrodynamical simulations of progenitor evolution of a 23 solar mass star, close to core collapse (about 1 hour, in 1D), with simultaneously active C, Ne, O, and Si burning shells, are presented and contrasted to existing 1D models (which are forced to be quasi-static). Pronounced asymmetries, and strong dynamical interactions between shells are seen in 2D. Although instigated by turbulence, the dynamic behavior proceeds to sufficiently large amplitudes that it couples to the nuclear burning. Dramatic growth of low order modes is seen, as well as large deviations from spherical symmetry in the burning shells. The vigorous dynamics is more violent than that seen in earlier burning stages in the 3D simulations of a single cell in the oxygen burning shell, or in 2D simulations not including an active Si shell. Linear perturbative analysis does not capture the chaotic behavior of turbulence (e.g., strange attractors such as that discovered by Lorenz), and therefore badly underestimates the vigor of the instability. The limitations of 1D and 2D models are discussed in detail. The 2D models, although flawed geometrically, represent a more realistic treatment of the relevant dynamics than existing 1D models, and present a dramatically different view of the stages of evolution prior to collapse. Implications for interpretation of SN1987A, abundances in young supernova remnants, pre-collapse outbursts, progenitor structure, neutron star kicks, and fallback are outlined. While 2D simulations provide new qualitative insight, fully 3D simulations are needed for a quantitative understanding of this stage of stellar evolution. The necessary properties of such simulations are delineated.Comment: 26 pages, 1 table, 4 figure

    Turbulent Convection in Stellar Interiors. II. The Velocity Field

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    We analyze stellar convection with the aid of 3D hydrodynamic simulations, introducing the turbulent cascade into our theoretical analysis. We devise closures of the Reynolds-decomposed mean field equations by simple physical modeling of the simulations (we relate temperature and density fluctuations via coefficients); the procedure (CABS, Convection Algorithms Based on Simulations) is terrestrially testable and is amenable to systematic improvement. We develop a turbulent kinetic energy equation which contains both nonlocal and time dependent terms, and is appropriate if the convective transit time is shorter than the evolutionary time scale. The interpretation of mixing-length theory (MLT) as generally used in astrophysics is incorrect; MLT forces the mixing length to be an imposed constant. Direct tests show that the damping associated with the flow is that suggested by Kolmogorov. The eddy size is approximately the depth of the convection zone, and this dissipation length corresponds to the "mixing length". New terms involving local heating by turbulent dissipation should appear in the stellar evolution equations. The enthalpy flux ("convective luminosity") is directly connected to the buoyant acceleration, and hence the velocity scale. MLT tends to systematically underestimate this velocity scale. Quantitative comparison with a variety of 3D simulations reveals a previously recognized consistency. Examples of application to stellar evolution will be presented in subsequent papers in this series.Comment: 47 pages, 7 figures, accepted by Ap

    Do partial glenohumeral degenerative changes in patients undergoing arthroscopic rotator cuff repair influence clinical outcomes?

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    Background The prognostic factors for patients with full-thickness rotator cuff tears (RCTs) include tear size, muscle atrophy and fatty infiltration. However, the influence of early coexisting degenerative changes on RCT outcomes is unappreciated. The purpose of this study was to calculate the impact that pre-existing partial glenohumeral cartilaginous changes have on patients undergoing arthroscopic RCT repair. Methods A study of 54 patients undergoing arthroscopic RCT repair was undertaken. The presence of co-existing patches of glenohumeral degenerative cartilaginous changes and RCT size was recorded at surgery. Pre- and postoperative outcomes were assessed using traditional (Oxford Shoulder Score [OSS], 5-level EuroQol-5D [EQ-5D-5L] questionnaire and EuroQol visual analog scale [EQ-VAS]) and patient-centric re-formatted prisms. Outcomes were assessed as an entire dataset, and sub-group analysis was performed according to the grade of co-existing arthritis and tear size. Results Significant improvements (p<0.05) in clinical outcomes were recognized when assessed using either the traditional or reformatted prisms (average % improvements in OSS, EQ-5D-5L and EQ-VAS were 47%, 33% and 43%, respectively; average improvements in pain, function, and psychological well-being were 48%, 33% and, 29%, respectively). Positive gain was noted in all sub-groups of arthritic grading and tear size. Conclusions Good clinical outcomes can be achieved following RCT repair even in the presence of local partial degenerative cartilage changes and advancing tear size. These benefits are patient-centered but require RCT repairability

    Limited granulomatosis with polyangiitis in an adolescent with Crohn's disease on infliximab therapy: cause or coincidence?

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    Pulmonary involvement in Crohn's disease (CD) may precede the development of intestinal inflammation, but in most cases occurs during the course of treatment, either as an extra‐intestinal manifestation, because of secondary infections, or as a side effect of the therapy itself. This case highlights the differential diagnosis and work up for multiple pulmonary nodules that developed in a patient with CD who had been in remission on infliximab therapy. Even though infectious causes, such as Mycobacteria and Fungi, account for majority of these cases, the possibility of non‐infectious conditions such as autoimmune disorders should also be considered.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/115908/1/crj12168.pd

    Trait urgency and gambling problems in young people by age: The mediating role of decision-making processes

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    Although the personality trait of urgency has been linked to problem gambling, less is known about psychological mechanisms that mediate the relationship between urgency and problem gambling. One individual variable of potential relevance to impulsivity and addictive disorders is age. The aims of this study were to examine: (i) a theoretical model associating urgency and gambling problems, (ii) the mediating effects of decision-making processes (operationalized as preference for small/immediate rewards and lower levels of deliberative decision-making); and (iii) age differences in these relationships. Participants comprised 986 students (64% male; mean age=19.51 years; SD=2.30) divided into three groups: 16-17 years, 18-21 years, and 22-25 years. All participants completed measures of urgency, problem gambling, and a delay-discounting questionnaire involving choices between a smaller amount of money received immediately and a larger amount of money received later. Participants were also asked to reflect on their decision-making process. Compared to those aged 16-17 years and 22-25 years, participants aged 18-21 years had a higher level of gambling problems and decreased scores on lower levels of deliberative decision-making. Higher levels of urgency were associated with higher levels of gambling problems. The association was mediated by a lower level of deliberative decision-making and preference for an immediate/small reward. A distinct pathway was observed for lower levels of deliberative decision-making. Young people who tend to act rashly in response to extreme moods, had lower levels of deliberative decision-making, that in turn were positively related to gambling problems. This study highlights unique decision-making pathways through which urgency trait may operate, suggesting that those developing prevention and/or treatment strategies may want to consider the model’s variables, including urgency, delay discounting, and deliberative decision-making

    Floral temperature and optimal foraging: is heat a feasible floral reward for pollinators?

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    As well as nutritional rewards, some plants also reward ectothermic pollinators with warmth. Bumble bees have some control over their temperature, but have been shown to forage at warmer flowers when given a choice, suggesting that there is some advantage to them of foraging at warm flowers (such as reducing the energy required to raise their body to flight temperature before leaving the flower). We describe a model that considers how a heat reward affects the foraging behaviour in a thermogenic central-place forager (such as a bumble bee). We show that although the pollinator should spend a longer time on individual flowers if they are warm, the increase in total visit time is likely to be small. The pollinator's net rate of energy gain will be increased by landing on warmer flowers. Therefore, if a plant provides a heat reward, it could reduce the amount of nectar it produces, whilst still providing its pollinator with the same net rate of gain. We suggest how heat rewards may link with plant life history strategies
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