197 research outputs found
Atoms in Flight and the Remarkable Connections between Atomic and Hadronic Physics
Atomic physics and hadron physics are both based on Yang Mills gauge theory;
in fact, quantum electrodynamics can be regarded as the zero-color limit of
quantum chromodynamics. I review a number of areas where the techniques of
atomic physics provide important insight into the theory of hadrons in QCD. For
example, the Dirac-Coulomb equation, which predicts the spectroscopy and
structure of hydrogenic atoms, has an analog in hadron physics in the form of
light-front relativistic equations of motion which give a remarkable first
approximation to the spectroscopy, dynamics, and structure of light hadrons.
The renormalization scale for the running coupling, which is unambiguously set
in QED, leads to a method for setting the renormalization scale in QCD. The
production of atoms in flight provides a method for computing the formation of
hadrons at the amplitude level. Conversely, many techniques which have been
developed for hadron physics, such as scaling laws, evolution equations, and
light-front quantization have equal utility for atomic physics, especially in
the relativistic domain. I also present a new perspective for understanding the
contributions to the cosmological constant from QED and QCD.Comment: Presented at EXA2011, the International Conference on Exotic Atoms
and Related Topics, Vienna, September 5-9, 201
Autism as a disorder of neural information processing: directions for research and targets for therapy
The broad variation in phenotypes and severities within autism spectrum disorders suggests the involvement of multiple predisposing factors, interacting in complex ways with normal developmental courses and gradients. Identification of these factors, and the common developmental path into which theyfeed, is hampered bythe large degrees of convergence from causal factors to altered brain development, and divergence from abnormal brain development into altered cognition and behaviour. Genetic, neurochemical, neuroimaging and behavioural findings on autism, as well as studies of normal development and of genetic syndromes that share symptoms with autism, offer hypotheses as to the nature of causal factors and their possible effects on the structure and dynamics of neural systems. Such alterations in neural properties may in turn perturb activity-dependent development, giving rise to a complex behavioural syndrome many steps removed from the root causes. Animal models based on genetic, neurochemical, neurophysiological, and behavioural manipulations offer the possibility of exploring these developmental processes in detail, as do human studies addressing endophenotypes beyond the diagnosis itself
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Effect of rehabilitation worker input on visual function outcomes in individuals with low vision: study protocol for a randomised controlled trial
BACKGROUND: Visual Rehabilitation Officers help people with a visual impairment maintain their independence. This intervention adopts a flexible, goal-centred approach, which may include training in mobility, use of optical and non-optical aids, and performance of activities of daily living. Although Visual Rehabilitation Officers are an integral part of the low vision service in the United Kingdom, evidence that they are effective is lacking. The purpose of this exploratory trial is to estimate the impact of a Visual Rehabilitation Officer on self-reported visual function, psychosocial and quality-of-life outcomes in individuals with low vision.
METHODS/DESIGN: In this exploratory, assessor-masked, parallel group, randomised controlled trial, participants will be allocated either to receive home visits from a Visual Rehabilitation Officer (n = 30) or to a waiting list control group (n = 30) in a 1:1 ratio. Adult volunteers with a visual impairment, who have been identified as needing rehabilitation officer input by a social worker, will take part. Those with an urgent need for a Visual Rehabilitation Officer or who have a cognitive impairment will be excluded. The primary outcome measure will be self-reported visual function (48-item Veterans Affairs Low Vision Visual Functioning Questionnaire). Secondary outcome measures will include psychological and quality-of-life metrics: the Patient Health Questionnaire (PHQ-9), the Warwick-Edinburgh Mental Well-being Scale (WEMWBS), the Adjustment to Age-related Visual Loss Scale (AVL-12), the Standardised Health-related Quality of Life Questionnaire (EQ-5D) and the UCLA Loneliness Scale. The interviewer collecting the outcomes will be masked to the group allocations. The analysis will be undertaken on a complete case and intention-to-treat basis. Analysis of covariance (ANCOVA) will be applied to follow-up questionnaire scores, with the baseline score as a covariate.
DISCUSSION: This trial is expected to provide robust effect size estimates of the intervention effect. The data will be used to design a large-scale randomised controlled trial to evaluate fully the Visual Rehabilitation Officer intervention. A rigorous evaluation of Rehabilitation Officer input is vital to direct a future low vision rehabilitation strategy and to help direct government resources.
TRIAL REGISTRATION: The trial was registered with ( ISRCTN44807874 ) on 9 March 2015
Creating European guidelines for Chiropractic Incident Reporting and Learning Systems (CIRLS): relevance and structure
<p>Abstract</p> <p>Background</p> <p>In 2009, the heads of the Executive Council of the European Chiropractors' Union (ECU) and the European Academy of Chiropractic (EAC) involved in the European Committee for Standardization (CEN) process for the chiropractic profession, set out to establish European guidelines for the reporting of adverse reactions to chiropractic treatment. There were a number of reasons for this: first, to improve the overall quality of patient care by aiming to reduce the application of potentially harmful interventions and to facilitate the treatment of patients within the context of achieving maximum benefit with a minimum risk of harm; second, to inform the training objectives for the Graduate Education and Continuing Professional Development programmes of all 19 ECU member nations, regarding knowledge and skills to be acquired for maximising patient safety; and third, to develop a guideline on patient safety incident reporting as it is likely to be part of future CEN standards for ECU member nations.</p> <p>Objective</p> <p>To introduce patient safety incident reporting within the context of chiropractic practice in Europe and to help individual countries and their national professional associations to develop or improve reporting and learning systems.</p> <p>Discussion</p> <p>Providing health care of any kind, including the provision of chiropractic treatment, can be a complex and, at times, a risky activity. Safety in healthcare cannot be guaranteed, it can only be improved. One of the most important aspects of any learning and reporting system lies in the appropriate use of the data and information it gathers. Reporting should not just be seen as a vehicle for obtaining information on patient safety issues, but also be utilised as a tool to facilitate learning, advance quality improvement and to ultimately minimise the rate of the occurrence of errors linked to patient care.</p> <p>Conclusions</p> <p>Before a reporting and learning system can be established it has to be clear what the objectives of the system are, what resources will be required and whether the implementing organisation has the capacity to operate the system to its full advantage. Responding to adverse event reports requires the availability of experts to analyse the incidents and to provide feedback in a timely fashion. A comprehensive strategy for national implementation must be in place including, but not limited to, presentations at national meetings, the provision of written information to all practitioners and the running of workshops, so that all stakeholders fully understand the purposes of adverse event reporting. Unless this is achieved, any system runs the risk of failure, or at the very least, limited usefulness.</p
Guaranteed optimal reachability control of reaction-diffusion equations using one-sided Lipschitz constants and model reduction
We show that, for any spatially discretized system of reaction-diffusion, the
approximate solution given by the explicit Euler time-discretization scheme
converges to the exact time-continuous solution, provided that diffusion
coefficient be sufficiently large. By "sufficiently large", we mean that the
diffusion coefficient value makes the one-sided Lipschitz constant of the
reaction-diffusion system negative. We apply this result to solve a finite
horizon control problem for a 1D reaction-diffusion example. We also explain
how to perform model reduction in order to improve the efficiency of the
method
Prehospital emergency treatment of palliative care patients with cardiac arrest: a retrolective investigation
A BAX/BAK and Cyclophilin D-Independent Intrinsic Apoptosis Pathway
Most intrinsic death signals converge into the activation of pro-apoptotic BCL-2 family members BAX and BAK at the mitochondria, resulting in the release of cytochrome c and apoptosome activation. Chronic endoplasmic reticulum (ER) stress leads to apoptosis through the upregulation of a subset of pro-apoptotic BH3-only proteins, activating BAX and BAK at the mitochondria. Here we provide evidence indicating that the full resistance of BAX and BAK double deficient (DKO) cells to ER stress is reverted by stimulation in combination with mild serum withdrawal. Cell death under these conditions was characterized by the appearance of classical apoptosis markers, caspase-9 activation, release of cytochrome c, and was inhibited by knocking down caspase-9, but insensitive to BCL-XL overexpression. Similarly, the resistance of BIM and PUMA double deficient cells to ER stress was reverted by mild serum withdrawal. Surprisingly, BAX/BAK-independent cell death did not require Cyclophilin D (CypD) expression, an important regulator of the mitochondrial permeability transition pore. Our results suggest the existence of an alternative intrinsic apoptosis pathway emerging from a cross talk between the ER and the mitochondria
The involvement of interleukin-1 and interleukin-4 in the response of human annulus fibrosus cells to cyclic tensile strain: an altered mechanotransduction pathway with degeneration
Indigenous well-being in four countries: An application of the UNDP'S Human Development Index to Indigenous Peoples in Australia, Canada, New Zealand, and the United States
<p>Abstract</p> <p>Background</p> <p>Canada, the United States, Australia, and New Zealand consistently place near the top of the United Nations Development Programme's <it>Human Development Index (HDI) </it>rankings, yet all have minority Indigenous populations with much poorer health and social conditions than non-Indigenous peoples. It is unclear just how the socioeconomic and health status of Indigenous peoples in these countries has changed in recent decades, and it remains generally unknown whether the overall conditions of Indigenous peoples are improving and whether the gaps between Indigenous peoples and other citizens have indeed narrowed. There is unsettling evidence that they may not have. It was the purpose of this study to determine how these gaps have narrowed or widened during the decade 1990 to 2000.</p> <p>Methods</p> <p>Census data and life expectancy estimates from government sources were used to adapt the Human Development Index (HDI) to examine how the broad social, economic, and health status of Indigenous populations in these countries have changed since 1990. Three indices – life expectancy, educational attainment, and income – were combined into a single HDI measure.</p> <p>Results</p> <p>Between 1990 and 2000, the HDI scores of Indigenous peoples in North America and New Zealand improved at a faster rate than the general populations, closing the gap in human development. In Australia, the HDI scores of Indigenous peoples decreased while the general populations improved, widening the gap in human development. While these countries are considered to have high human development according to the UNDP, the Indigenous populations that reside within them have only medium levels of human development.</p> <p>Conclusion</p> <p>The inconsistent progress in the health and well-being of Indigenous populations over time, and relative to non-Indigenous populations, points to the need for further efforts to improve the social, economic, and physical health of Indigenous peoples.</p
Stiffness in total knee arthroplasty
Stiffness is a relatively uncommon complication after total knee arthroplasty. It has been defined as a painful limitation in the range of movement (ROM). Its pathogenesis is still unclear even if some risk factors have been identified. Patient-related conditions may be difficult to treat. Preoperative ROM is the most important risk factor, but an association with diabetes, reflex sympathetic dystrophy, and general pathologies such as juvenile rheumatoid arthritis and ankylosing spondylitis has been demonstrated. Moreover, previous surgery may be an additional cause of an ROM limitation. Postoperative factors include infections, arthrofibrosis, heterotrophic ossifications, and incorrect rehabilitation protocol. Infections represent a challenging problem for the orthopaedic surgeon, and treatment may require long periods of antibiotics administration. However, it is widely accepted that an aggressive rehabilitation protocol is mandatory for a proper ROM recovery and to avoid the onset of arthrofibrosis and heterotrophic ossifications. Finally, surgery-related factors represent the most common cause of stiffness; they include errors in soft-tissue balancing, component malpositioning, and incorrect component sizing. Although closed manipulation, arthroscopic and open arthrolysis have been proposed, they may lead to unpredictable results and incomplete ROM recovery. Revision surgery must be proposed in the case of well-documented surgical errors. These operations are technically demanding and may be associated with high risk of complications; therefore they should be accurately planned and properly performed
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