511 research outputs found
Measurement of thermal cycles in the weld heat affected zone of mild steel
The thermal cycles in the mild steel parent plate adjacent to a bead
on plate weld have been measured for heat inputs of 108, 54 and 42 kJ/inch,
by means of embedded thermocouples connected to high response automatic
recorders. The results show that decreasing the heat input increases the
cooling rate and decreases the width of the heat affected zone.
For thermal cycles in which the peak temperatures reached 900°C or
above, two points of inflection have been noted in the temperature ranges
400° - 600°C and 950° - 1200°C. The inflection in the lower temperature
range, which has been observed by other workers, has been attributed to
latent heat from the exothermic transformation of austenite to ferrite.
The higher inflection point, not previously reported, has been tentatively
related to the solidification in the weld pool and the release of the
latent heat of fusion
Pre-movement changes in sensorimotor beta oscillations predict motor adaptation drive
International audienceBeta frequency oscillations in scalp electroencephalography (EEG) recordings over the primary motor cortex have been associated with the preparation and execution of voluntary movements. Here, we test whether changes in beta frequency are related to the preparation of adapted movements in human, and whether such effects generalise to other species (cat). Eleven healthy adult humans performed a joystick visuomotor adaptation task. Beta (15-25 Hz) scalp EEG signals recorded over the motor cortex during a pre-movement preparatory phase were, on average, significantly reduced in amplitude during early adaptation trials compared to baseline, late adaptation, or aftereffect trials. The changes in beta were not related to measurements of reaction time or reach duration. We also recorded local field potential (LFP) activity within the primary motor cortex of three cats during a prism visuomotor adaptation task. Analysis of these signals revealed similar reductions in motor cortical LFP beta frequencies during early adaptation. This effect was present when controlling for any influence of the reaction time and reach duration. Overall, the results are consistent with a reduction in pre-movement beta oscillations predicting an increase in adaptive drive in upcoming task performance when motor errors are largest in magnitude and the rate of adaptation is greatest
Non-invasive Stimulation of the Cerebellum in Health and Disease
The cerebellum is linked to motor, cognitive and affective functions. Anatomically, the cerebellum is part of an interconnected network including a wide range of other brain structures. This chapter reviews ways in which non-invasive stimulation has been used to activate or inhibit these circuits and how this has contributed to our understanding of cerebellar function in both motor and non-motor domains. The utility of non-invasive stimulation of the cerebellum in the treatment of neurological and psychiatric diseases (Parkinson’s disease, cerebellar ataxia, stroke, depression and schizophrenia) is discussed. The chapter concludes with consideration of the challenges that must be overcome if non-invasive cerebellar stimulation is to be adopted in a wider clinical setting
How do informal self-care strategies evolve among patients with chronic obstructive pulmonary disease managed in primary care? A qualitative study
Background: There is much description in the literature of how patients with chronic obstructive pulmonary disease (COPD) manage their breathlessness and engage in self-care activities; however, little of this is from the perspective of those with less severe disease, who are primarily managed in primary care. This study aimed to understand the self-care experiences of patients with COPD who are primarily managed in primary care, and to examine the challenges of engaging in such behaviors.
Methods: Semistructured interviews were carried out with 15 patients with COPD as part of a larger project evaluating a self-management intervention. Thematic analysis was supported by NVivo software (version 8, QSR International, Melbourne, Australia).
Results: Three main themes are described, ie, experiencing and understanding symptoms of COPD, current self-care activities, and the importance of family perceptions in managing COPD.
Conclusion: Self-care activities evolved spontaneously as participants experienced symptoms of COPD. However, there was a lack of awareness about whether these strategies would impact upon symptoms. Perceptions of COPD by family members posed a challenge to self-care for some participants. Health care professionals should elicit patients' prior disease experiences and utilize spontaneous attempts at disease management in future self-management. These findings have implications for promoting self-management and enhancing quality of life
Important, misunderstood, and challenging: a qualitative study of nurses' and allied health professionals' perceptions of implementing self-management for patients with COPD.
Hannah ML Young,1 Lindsay D Apps,1 Samantha L Harrison,1 Vicki L Johnson-Warrington,1 Nicky Hudson,2 Sally J Singh1,3 1National Institute of Health Research CLAHRC-LNR Pulmonary Rehabilitation Research Group, University Hospitals of Leicester NHS Trust, 2School of Applied Social Sciences, De Montfort University, Leicester, 3Applied Research Centre in Health and Lifestyle Interventions, Coventry University, Coventry, UK Background: In light of the growing burden of COPD, there is increasing focus on the role of self-management for this population. Currently, self-management varies widely. Little is known either about nurses’ and allied health professionals’ (AHPs’) understanding and provision of self-management in clinical practice. This study explores nurses’ and AHPs’ understanding and implementation of supported COPD self-management within routine clinical practice. Materials and methods: Nurses and AHPs participated in face-to-face semistructured interviews to explore their understanding and provision of COPD self-management, as well as their perceptions of the challenges to providing such care. Purposive sampling was used to select participants from a range of professions working within primary, community, and secondary care settings. Three researchers independently analyzed each transcript using a thematic approach. Results: A total of 14 participants were interviewed. Nurses and AHPs viewed self-management as an important aspect of COPD care, but often misunderstood what it involved, leading to variation in practice. A number of challenges to supporting self-management were identified, which related to lack of time, lack of insight regarding training needs, and assumptions regarding patients’ perceived self-management abilities. Conclusion: Nurses and AHPs delivering self-management require clear guidance, training in the use of effective self-management skills, and education that challenges their preconceptions regarding patients. The design of health care services also needs to consider the practical barriers to COPD self-management support for the implementation of such interventions to be successful. Keywords: self-management, COPD, qualitative, interviews, nurses, allied health professional
Development of a training program to support health care professionals to deliver the SPACE for COPD self-management program
Open access journalBackground: With the growing burden of COPD and associated morbidity and mortality, a need for self-management has been identified. The Self-management Programme of Activity, Coping and Education for Chronic Obstructive Pulmonary Disease (SPACE for COPD) manual was developed to support self-management in COPD patients. Currently, there is no literature available regarding health care professionals’ training needs when supporting patients with COPD on self-management.
Aim: This study sought to identify these needs to inform, design and develop a training program for health care professionals being trained to deliver a self-management program in COPD.
Methods: Fourteen health care professionals from both primary and secondary care COPD services participated in face-to-face semistructured interviews. Thematic analysis was used to produce a framework and identify training needs and views on delivery of the SPACE for COPD self-management program. Components of training were web-based knowledge training, with pre- and posttraining knowledge questionnaires, and a 1-day program to introduce the self-management manual. Feedback was given after training to guide the development of the training program.
Results: Health care professionals were able to identify areas where they required increased knowledge to support patients. This was overwhelming in aspects of COPD seen to be outside of their current clinical role. Skills in goal setting and behavioral change were not elicited as a training need, suggesting a lack of understanding of components of supporting self-management. An increase in knowledge of COPD was demonstrated following the training program.
Conclusion: Both knowledge and skill gaps existed in those who would deliver self-management. Analysis of this has enabled a training program to be designed to address these gaps and enable health care professionals to support patients in self-management.
Keywords: self-management, COPD, health care professionals, trainin
The development and pilot testing of the Self-management Programme of Activity, Coping and Education for Chronic Obstructive Pulmonary Disease (SPACE for COPD)
Purpose: There is no independent standardized self-management approach available for chronic obstructive pulmonary disease (COPD). The aim of this project was to develop and test a novel self-management manual for individuals with COPD. Patients: Participants with a confirmed diagnosis of COPD were recruited from primary care. Methods: A novel self-management manual was developed with health care professionals and patients. Five focus groups were conducted with individuals with COPD (N = 24) during development to confirm and enhance the content of the prototype manual. The Self-management Programme of Activity, Coping and Education for Chronic Obstructive Pulmonary Disease (SPACE for COPD) manual was developed as the focus of a comprehensive self-management approach facilitated by health care professionals. Preference for delivery was initial face-to-face consultation with telephone follow-up. The SPACE for COPD manual was piloted with 37 participants in primary care. Outcome measures included the Self-Report Chronic Respiratory Questionnaire, Incremental Shuttle Walk Test, and Endurance Shuttle Walking Test (ESWT); measurements were taken at baseline and 6 weeks. Results: The pilot study observed statistically significant improvements for the dyspnea domain of the Self-Report Chronic Respiratory Questionnaire and ESWT. Dyspnea showed a mean change of 0.67 (95% confidence interval 0.23–1.11, P = 0.005). ESWT score increased by 302.25 seconds (95% confidence interval 161.47–443.03, P < 0.001). Conclusion: This article describes the development and delivery of a novel self-management approach for COPD. The program, incorporating the SPACE for COPD manual, appears to provoke important changes in exercise capacity and breathlessness for individuals with COPD managed in primary care
Whightman function and scalar Casimir densities for a wedge with a cylindrical boundary
Whightman function, vacuum expectation values of the field square, and the
energy-momentum tensor are investigated for a scalar field inside a wedge with
and without a coaxial cylindrical boundary. Dirichlet boundary conditions are
assumed on the bounding surfaces. The vacuum energy-momentum tensor is
evaluated in the general case of the curvature coupling parameter. Making use
of a variant of the generalized Abel-Plana formula, expectation values are
presented as the sum of two terms. The first one corresponds to the geometry
without a cylindrical boundary and the second one is induced by the presence of
this boundary. The asymptotic behaviour of the field square, vacuum energy
density and stresses near the boundaries are investigated. The additional
vacuum forces acting on the wedge sides due the presence of the cylindrical
boundary are evaluated and it is shown that these forces are attractive. As a
limiting case, the geometry of two parallel plates perpendicularly intersected
by a third one is analyzed.Comment: 19 pages, 6 figures, new section is added on the VEVs for the region
outside the cylidrical shell, discussion and references added, accepted for
publication in J. Phys.
Slower rates of prism adaptation but intact aftereffects in patients with early to mid-stage Parkinson's disease
There is currently mixed evidence on the effect of Parkinson's disease on motor adaptation. Some studies report that patients display adaptation comparable to age-matched controls, while others report a complete inability to adapt to novel sensory perturbations. Here, early to mid-stage Parkinson's patients were recruited to perform a prism adaptation task. When compared to controls, patients showed slower rates of initial adaptation but intact aftereffects. These results support the suggestion that patients with early to mid-stage Parkinson's disease display intact adaptation driven by sensory prediction errors, as shown by the intact aftereffect. But impaired facilitation of performance through cognitive strategies informed by task error, as shown by the impaired initial adaptation. These results support recent studies that suggest that patients with Parkinson's disease retain the ability to perform visuomotor adaptation, but display altered use of cognitive strategies to aid performance and generalises these previous findings to the classical prism adaptation task
Structural and regulatory diversity shape HLA-C protein expression levels
Expression of HLA-C varies widely across individuals in an allele-specific manner. This variation in expression can influence efficacy of the immune response, as shown for infectious and autoimmune diseases. MicroRNA binding partially influences differential HLA-C expression, but the additional contributing factors have remained undetermined. Here we use functional and structural analyses to demonstrate that HLA-C expression is modulated not just at the RNA level, but also at the protein level. Specifically, we show that variation in exons 2 and 3, which encode the α1/α2 domains, drives differential expression of HLA-C allomorphs at the cell surface by influencing the structure of the peptide-binding cleft and the diversity of peptides bound by the HLA-C molecules. Together with a phylogenetic analysis, these results highlight the diversity and long-term balancing selection of regulatory factors that modulate HLA-C expression
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