737 resultados para Weeks, Harrison
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Considering the wide spectrum of situations that it may encounter, a robot navigating autonomously in outdoor environments needs to be endowed with several operating modes, for robustness and efficiency reasons. Indeed, the terrain it has to traverse may be composed of flat or rough areas, low cohesive soils such as sand dunes, concrete road etc. . .Traversing these various kinds of environment calls for different navigation and/or locomotion functionalities, especially if the robot is endowed with different locomotion abilities, such as the robots WorkPartner, Hylos [4], Nomad or the Marsokhod rovers. Numerous rover navigation techniques have been proposed, each of them being suited to a particular environment context (e.g. path following, obstacle avoidance in more or less cluttered environments, rough terrain traverses...). However, seldom contributions in the literature tackle the problem of selecting autonomously the most suited mode [3]. Most of the existing work is indeed devoted to the passive analysis of a single navigation mode, as in [2]. Fault detection is of course essential: one can imagine that a proper monitoring of the Mars Exploration Rover Opportunity could have avoided the rover to be stuck during several weeks in a dune, by detecting non-nominal behavior of some parameters. But the ability to recover the anticipated problem by switching to a better suited navigation mode would bring higher autonomy abilities, and therefore a better overall efficiency. We propose here a probabilistic framework to achieve this, which fuses environment related and robot related information in order to actively control the rover operations.
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Importance Approximately one-third of patients with peripheral artery disease experience intermittent claudication, with consequent loss of quality of life. Objective To determine the efficacy of ramipril for improving walking ability, patient-perceived walking performance, and quality of life in patients with claudication. Design, Setting, and Patients Randomized, double-blind, placebo-controlled trial conducted among 212 patients with peripheral artery disease (mean age, 65.5 [SD, 6.2] years), initiated in May 2008 and completed in August 2011 and conducted at 3 hospitals in Australia. Intervention Patients were randomized to receive 10 mg/d of ramipril (n = 106) or matching placebo (n = 106) for 24 weeks. Main Outcome Measures Maximum and pain-free walking times were recorded during a standard treadmill test. The Walking Impairment Questionnaire (WIQ) and Short-Form 36 Health Survey (SF-36) were used to assess walking ability and quality of life, respectively. Results At 6 months, relative to placebo, ramipril was associated with a 75-second (95% CI, 60-89 seconds) increase in mean pain-free walking time (P < .001) and a 255-second (95% CI, 215-295 seconds) increase in maximum walking time (P < .001). Relative to placebo, ramipril improved the WIQ median distance score by 13.8 (Hodges-Lehmann 95% CI, 12.2-15.5), speed score by 13.3 (95% CI, 11.9-15.2), and stair climbing score by 25.2 (95% CI, 25.1-29.4) (P < .001 for all). The overall SF-36 median Physical Component Summary score improved by 8.2 (Hodges-Lehmann 95% CI, 3.6-11.4; P = .02) in the ramipril group relative to placebo. Ramipril did not affect the overall SF-36 median Mental Component Summary score. Conclusions and Relevance Among patients with intermittent claudication, 24-week treatment with ramipril resulted in significant increases in pain-free and maximum treadmill walking times compared with placebo. This was associated with a significant increase in the physical functioning component of the SF-36 score. Trial Registration clinicaltrials.gov Identifier: NCT00681226
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In 2008, Weeks et al. published the results of a postal survey, which explored the views of the Society of Hospital Pharmacists of Australia’s (SHPA) members on collaborative prescribing, and the extent of de facto prescribing in their institution. Since then, significant work has been undertaken on non-medical prescribing, such as pilots of pharmacist prescribing across Australia and a National Health Workforce report on developing a nationally consistent approach to prescribing by nonmedical health professionals. The first stage of the Health Workforce Australia Health Practitioner Prescribing Pathway project is complete and the recommendations for implementation have been approved by the Standing Council in November 2013. New Zealand pharmacists obtained prescribing rights in 2013, and the first cohort of 14 prescribers have completed the postgraduate pharmacist prescribing course (jointly run by the Otago and Auckland Universities).
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Aims This paper is a report on the effectiveness of a self-management programme based on the self-efficacy construct, in older people with heart failure. Background Heart failure is a major health problem worldwide, with high mortality and morbidity, making it a leading cause of hospitalization. Heart failure is associated with a complex set of symptoms that arise from problems in fluid and sodium retention. Hence, managing salt and fluid intake is important and can be enhanced by improving patients' self-efficacy in changing their behaviour. Design Randomized controlled trial. Methods Heart failure patients attending cardiac clinics in northern Taiwan from October 2006–May 2007 were randomly assigned to two groups: control (n = 46) and intervention (n = 47). The intervention group received a 12-week self-management programme that emphasized self-monitoring of salt/fluid intake and heart failure-related symptoms. Data were collected at baseline as well as 4 and 12 weeks later. Data analysis to test the hypotheses used repeated-measures anova models. Results Participants who received the intervention programme had significantly better self-efficacy for salt and fluid control, self-management behaviour and their heart failure-related symptoms were significantly lower than participants in the control group. However, the two groups did not differ significantly in health service use. Conclusion The self-management programme improved self-efficacy for salt and fluid control, self-management behaviours, and decreased heart failure-related symptoms in older Taiwanese outpatients with heart failure. Nursing interventions to improve health-related outcomes for patients with heart failure should emphasize self-efficacy in the self-management of their disease.
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The majority of academic research has attempted to explain the effectiveness of sponsorship activities by focusing on individual outcomes (Cornwell, Weeks, & Roy, 2005). The current research builds upon the limited empirical studies that examine sponsorship outcomes using group behaviour theories (Cornwell & Coote, 2005; Gwinner & Swanson, 2003; Madrigal, 2000, 2001). Specifically, this study closely examines tenets of social identity theory (Brewer, 1991; Tajfel & Turner, 1979) within the context of sports sponsorship to test effects of team identification on attitudes toward associated sponsor brands. 1,840 unique surveys were collected from fans of the Queensland Maroons and New South Wales Blues rugby clubs over four timepoints during the 2012 State of Origin series. The results suggest that social identity effects were present regarding ingroup bias toward sponsor brands. Local sponsors were rated higher than non-local sponsors, suggesting that local brands may benefit more from sponsorship.
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Personal ultraviolet dosimeters have been used in epidemiological studies to understand the risks and benefits of individuals' exposure to solar ultraviolet radiation (UVR). We investigated the types and determinants of non-compliance associated with a protocol for use of polysulphone UVR dosimeters. In the AusD Study, 1,002 Australian adults (aged 18-75 years) were asked to wear a new dosimeter on their wrist each day for 10 consecutive days to quantify their daily exposure to solar UVR. Of the 10,020 dosimeters distributed, 296 (3%) were not returned or used (Type I non-compliance) and other usage errors were reported for 763 (8%) returned dosimeters (Type II non-compliance). Type I errors were more common in participants with predominantly outdoor occupations. Type II errors were reported more frequently on the first day of measurement; weekend days or rainy days; and among females; younger people; more educated participants or those with outdoor occupations. Half (50%) the participants reported a non-compliance error on at least one day during the 10-day period. However, 92% of participants had at least 7 days of usable data without any apparent non-compliance issues. The factors identified should be considered when designing future UVR dosimetry studies.
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The Quantitative Assessment of Solar UV [ultraviolet] Exposure for Vitamin D Synthesis in Australian Adults (AusD) Study aimed to better define the relationship between sun exposure and serum 25-hydroxyvitamin D (25(OH)D) concentration. Cross-sectional data were collected between May 2009 and December 2010 from 1,002 participants aged 18-75 years in 4 Australian sites spanning 24° of latitude. Participants completed the following: 1) questionnaires on sun exposure, dietary vitamin D intake, and vitamin D supplementation; 2) 10 days of personal ultraviolet radiation dosimetry; 3) a sun exposure and physical activity diary; and 4) clinical measurements and blood collection for 25(OH)D determination. Our multiple regression model described 40% of the variance in 25(OH)D concentration; modifiable behavioral factors contributed 52% of the explained variance, and environmental and demographic or constitutional variables contributed 38% and 10%, respectively. The amount of skin exposed was the single strongest contributor to the explained variance (27%), followed by location (20%), season (17%), personal ultraviolet radiation exposure (8%), vitamin D supplementation (7%), body mass index (weight (kg)/height (m)2) (4%), and physical activity (4%). Modifiable behavioral factors strongly influence serum 25(OH)D concentrations in Australian adults. In addition, latitude was a strong determinant of the relative contribution of different behavioral factors.
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Chronic stress is an important risk factor for atherosclerosis, which is a chief process in the development of cardiovascular disease. Increased circulating levels of corticosterone have been documented in several animal models of chronic stress. However, it remains to be established whether corticosterone is sufficient to exacerbate atherosclerosis. To test this hypothesis, apolipoprotein E (ApoE)-deficient mice were fed a high-fat diet for 13 weeks with exposure to either corticosterone or vehicle in the drinking water (CORT and Con). Corticosterone treatment significantly increased atherosclerotic plaque area at the aortic root. Such exacerbation of atherosclerosis was accompanied by significantly lower levels of circulating white blood cells and serum interleukin-1β (IL-1β), and significantly elevated serum concentrations of total cholesterol, low-density lipoprotein (LDL), very-low-density lipoprotein (VLDL) and small dense low-density lipoprotein (sd-LDL) in CORT mice when compared to Con mice. These findings demonstrate that corticosterone is sufficient to exacerbate atherosclerosis in vivo despite its anti-inflammatory properties and that this marked pro-atherogenic phenotype is primarily associated with increased dyslipidaemia.
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Aging is associated with increased circulating pro-inflammatory and lower anti-inflammatory cytokines. Exercise training, in addition to improving muscle function, reduces these circulating pro-inflammatory cytokines. Yet, few studies have evaluated changes in the expression of cytokines within skeletal muscle after exercise training. The aim of the current study was to examine the expression of cytokines both at rest and following a bout of isokinetic exercise performed before and after 12 weeks of resistance exercise training in young (n = 8, 20.3 ± 0.8 yr) and elderly men (n = 8, 66.9 ± 1.6 yr). Protein expression of various cytokines was determined in muscle homogenates. The expression of MCP-1, IL-8 and IL-6 (which are traditionally classified as ‘pro-inflammatory’) increased substantially after acute exercise. By contrast, the expression of the anti-inflammatory cytokines IL-4, IL-10 and IL-13 increased only slightly (or not at all) after acute exercise. These responses were not significantly different between young and elderly men, either before or after 12 weeks of exercise training. However, compared with the young men, the expression of pro-inflammatory cytokines 2 h post exercise tended to be greater in the elderly men prior to training. Training attenuated this difference. These data suggest that the inflammatory response to unaccustomed exercise increases with age. Furthermore, regular exercise training may help to normalize this inflammatory response, which could have important implications for muscle regeneration and adaptation in the elderly.
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Visual localization in outdoor environments is often hampered by the natural variation in appearance caused by such things as weather phenomena, diurnal fluctuations in lighting, and seasonal changes. Such changes are global across an environment and, in the case of global light changes and seasonal variation, the change in appearance occurs in a regular, cyclic manner. Visual localization could be greatly improved if it were possible to predict the appearance of a particular location at a particular time, based on the appearance of the location in the past and knowledge of the nature of appearance change over time. In this paper, we investigate whether global appearance changes in an environment can be learned sufficiently to improve visual localization performance. We use time of day as a test case, and generate transformations between morning and afternoon using sample images from a training set. We demonstrate the learned transformation can be generalized from training data and show the resulting visual localization on a test set is improved relative to raw image comparison. The improvement in localization remains when the area is revisited several weeks later.
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Emotions are inherently social, and are central to learning, online interaction and literacy practices (Shen, Wang, & Shen, 2009). Demonstrating the dynamic sociality of literacy practice, we used e-motion diaries or web logs to explore the emotional states of pre-service high school teachers’ experiences of online learning activities. This is because the methods of communication used by university educators in online learning and writing environments play an important role in fulfilling students’ need for social interaction and inclusion (McInnerney & Roberts, 2004). Feelings of isolation and frustration are common emotions experienced by students in many online learning environments, and are associated with the success or failure of online interactions and learning (Su, et al., 2005). The purpose of the study was to answer the research question: What are the trajectories of pre-service teachers’ emotional states during online learning experiences? This is important because emotions are central to learning, and the current trend toward Massive Open Online Courses (MOOCs) needs research about students’ emotional connections in online learning environments (Kop, 2011). The project was conducted with a graduate class of 64 high school science pre-service teachers in Science Education Curriculum Studies in a large Australian university, including males and females from a variety of cultural backgrounds, aged 22-55 years. Online activities involved the students watching a series of streamed live lectures for the first 5 weeks providing a varied set of learning experiences, such as viewing science demonstrations (e.g., modeling the use of discrepant events). Each week, students provided feedback on learning by writing and posting an e-motion diary or web log about their emotional response. Students answered the question: What emotions did you experience during this learning experience? The descriptive data set included 284 online posts, with students contributing multiple entries. Linguistic appraisal theory, following Martin and White (2005), was used to regroup the 22 different discrete emotions reported by students into the six main affect groups – three positive and three negative: unhappiness/happiness, insecurity/security, and dissatisfaction/satisfaction. The findings demonstrated that the pre-service teachers’ emotional responses to the streamed lectures tended towards happiness, security, and satisfaction within the typology of affect groups – un/happiness, in/security, and dis/satisfaction. Fewer students reported that the streamed lectures triggered negative feelings of frustration, powerlessness, and inadequacy, and when this occurred, it often pertained to expectations of themselves in the forthcoming field experience in classrooms. Exceptions to this pattern of responses occurred in relation to the fifth streamed lecture presented in a non-interactive slideshow format that compressed a large amount of content. Many students responded to the content of the lecture rather than providing their emotional responses to this lecture, and one student felt “completely disengaged”. The social practice of online writing as blogs enabled the students to articulate their emotions. The findings primarily contribute new understanding about students' wide range of differing emotional states, both positive and negative, experienced in response to streamed live lectures and other learning activities in higher education external coursework. The is important because the majority of previous studies have focused on particular negative emotions, such as anxiety in test taking. The research also highlights the potentials of appraisal theory for studying human emotions in online learning and writing.
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Background Sleep disturbances, including insomnia and sleep-disordered breathing, are a common complaint in people with heart failure and impair well-being. Exercise training (ET) improves quality of life in stable heart failure patients. ET also improves sleep quality in healthy older patients, but there are no previous intervention studies in heart failure patients. Aim The aim of this study was to examine the impact of ET on sleep quality in patients recently discharged from hospital with heart failure. Methods This was a sub-study of a multisite randomised controlled trial. Participants with a heart failure hospitalisation were randomised within six weeks of discharge to a 12-week disease management programme including exercise advice (n=52) or to the same programme with twice weekly structured ET (n=54). ET consisted of two one-hour supervised aerobic and resistance training sessions, prescribed and advanced by an exercise specialist. The primary outcome was change in Pittsburgh Sleep Quality Index (PSQI) between randomisation and week 12. Results At randomisation, 45% of participants reported poor sleep (PSQI≥5). PSQI global score improved significantly more in the ET group than the control group (–1.5±3.7 vs 0.4±3.8, p=0.03). Improved sleep quality correlated with improved exercise capacity and reduced depressive symptoms, but not with changes in body mass index or resting heart rate. Conclusion Twelve weeks of twice-weekly supervised ET improved sleep quality in patients recently discharged from hospital with heart failure.
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Because cartilage and bone tissues have different lineage-specific biological properties, it is challenging to fabricate a single type of scaffold that can biologically fulfill the requirements for regeneration of these two lineages simultaneously within osteochondral defects. To overcome this challenge, a lithium-containing mesoporous bioglass (Li-MBG) scaffold is developed. The efficacy and mechanism of Li-MBG for regeneration of osteochondral defects are systematically investigated. Histological and micro-CT results show that Li-MBG scaffolds significantly enhance the regeneration of subchondral bone and hyaline cartilage-like tissues as compared to pure MBG scaffolds, upon implantation in rabbit osteochondral defects for 8 and 16 weeks. Further investigation demonstrates that the released Li+ ions from the Li-MBG scaffolds may play a key role in stimulating the regeneration of osteochondral defects. The corresponding mechanistic pathways involve Li+ ions enhancing the proliferation and osteogenic differentiation of bone mesenchymal stem cells (BMSCs) through activation of the Wnt signalling pathway, as well as Li+ ions protecting chondrocytes and cartilage tissues from the inflammatory osteoarthritis (OA) environment through activation of autophagy. These findings suggest that the incorporation of Li+ ions into bioactive MBG scaffolds is a viable strategy for fabricating bi-lineage conducive scaffolds that enhance regeneration of osteochondral defects.
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Background and Purpose The β1-adrenoceptor has at least two binding sites, high and low affinity sites (β1H and β1L, respectively), which mediate cardiostimulation. While β1H-adrenoceptor can be blocked by all clinically used β-blockers, β1L-adrenoceptor is relatively resistant to blockade. Thus, chronic β1L-adrenoceptor activation may mediate persistent cardiostimulation, despite the concurrent blockade of β1H-adrenoceptors. Hence, it is important to determine the potential significance of β1L-adrenoceptors in vivo, particularly in pathological situations. Experimental Approach C57Bl/6 male mice were used. Chronic (4 or 8 weeks) β1L-adrenoceptor activation was achieved by treatment, via osmotic mini pumps, with (-)-CGP12177 (10 mg·kg−1·day−1). Cardiac function was assessed by echocardiography and micromanometry. Key Results (-)-CGP12177 treatment of healthy mice increased heart rate and left ventricular (LV) contractility. (-)-CGP12177 treatment of mice subjected to transverse aorta constriction (TAC), during weeks 4–8 or 4–12 after TAC, led to a positive inotropic effect and exacerbated fibrogenic signalling while cardiac hypertrophy tended to be more severe. (-)-CGP12177 treatment of mice with TAC also exacerbated the myocardial expression of hypertrophic, fibrogenic and inflammatory genes compared to untreated TAC mice. Washout of (-)-CGP12177 revealed a more pronounced cardiac dysfunction after 12 weeks of TAC. Conclusions and Implications β1L-adrenoceptor activation provides functional support to the heart, in both normal and pathological (pressure overload) situations. Sustained β1L-adrenoceptor activation in the diseased heart exacerbates LV remodelling and therefore may promote disease progression from compensatory hypertrophy to heart failure.
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Olfactory ensheathing cells (OECs) are specialized glial cells in the mammalian olfactory system supporting growth of axons from the olfactory epithelium into the olfactory bulb. OECs in the olfactory bulb can be subdivided into OECs of the outer nerve layer and the inner nerve layer according to the expression of marker proteins and their location in the nerve layer. In the present study, we have used confocal calcium imaging of OECs in acute mouse brain slices and olfactory bulbs in toto to investigate physiological differences between OEC subpopulations. OECs in the outer nerve layer, but not the inner nerve layer, responded to glutamate, ATP, serotonin, dopamine, carbachol, and phenylephrine with increases in the cytosolic calcium concentration. The calcium responses consisted of a transient and a tonic component, the latter being mediated by store-operated calcium entry. Calcium measurements in OECs during the first three postnatal weeks revealed a downregulation of mGluR(1) and P2Y(1) receptor-mediated calcium signaling within the first 2 weeks, suggesting that the expression of these receptors is developmentally controlled. In addition, electrical stimulation of sensory axons evoked calcium signaling via mGluR(1) and P2Y(1) only in outer nerve layer OECs. Downregulation of the receptor-mediated calcium responses in postnatal animals is reflected by a decrease in amplitude of stimulation-evoked calcium transients in OECs from postnatal days 3 to 21. In summary, the results presented reveal striking differences in receptor responses during development and in axon-OEC communication between the two subpopulations of OECs in the olfactory bulb.