1,065 research outputs found
On General Axial Gauges for QCD
General Axial Gauges within a perturbative approach to QCD are plagued by
'spurious' propagator singularities. Their regularisation has to face major
conceptual and technical problems. We show that this obstacle is naturally
absent within a Wilsonian or 'Exact' Renormalisation Group approach and explain
why this is so. The axial gauge turns out to be a fixed point under the flow,
and the universal 1-loop running of the gauge coupling is computed.Comment: 4 pages, latex, talk presented by DFL at QCD'98, Montpellier, July
2-8, 1998; to be published in Nucl. Phys. B (Proc. Suppl.
Un algorithme evolutionniste pour l'auto-apprentissage de groupes de robots mobiles autonomes
Variation at the capsule locus, cps, of mistyped and non-typable Streptococcus pneumoniae isolates
The capsule polysaccharide locus (cps) is the site of the capsule biosynthesis gene cluster in encapsulated Streptococcus pneumoniae. A set of pneumococcal samples and non-pneumococcal streptococci from Denmark, the Gambia, the Netherlands, Thailand, the UK and the USA were sequenced at the cps locus to elucidate serologically mistyped or non-typable isolates. We identified a novel serotype 33B/33C mosaic capsule cluster and previously unseen serotype 22F capsule genes, disrupted and deleted cps clusters, the presence of aliB and nspA genes that are unrelated to capsule production, and similar genes in the non-pneumococcal samples. These data provide greater understanding of diversity at a locus which is crucial to the antigenic diversity of the pathogen and current vaccine strategies
Advances, limitations and future perspectives in the diagnosis and management of dry eye in Sjogren's syndrome
Primary Sjogren's syndrome is a complex systemic autoimmune disorder that primarily affects exocrine glands such as the lacrimal glands. Dry eye disease is one of the most prevalent complications of Sjogren's syndrome, affecting most patients. It significantly impairs quality of life and management is often difficult and unsatisfactory, in part due to weak correlation between symptoms and signs and poor recognition of the three main subtypes aqueous-deficient, evaporative and neuropathic dry eye. This review provides an overview of key aspects of dry eye disease, such as its multifactorial aetiology and recent insights into pathophysiology. The uses and pitfalls of commonly-used diagnostic tests for dry eye are reviewed, as well as the increasing number of new imaging technologies and biomarkers to refine diagnosis. There are many current and emerging treatment options for dry eye in Sjogren's syndrome, but high-level evidence of efficacy is mostly lacking, as are evidence-based treatment algorithms. All these aspects make the management of dry eye in Sjogren's syndrome challenging
Advances, limitations and future perspectives in the diagnosis and management of dry eye in Sjogren's syndrome
Primary Sjogren's syndrome is a complex systemic autoimmune disorder that primarily affects exocrine glands such as the lacrimal glands. Dry eye disease is one of the most prevalent complications of Sjogren's syndrome, affecting most patients. It significantly impairs quality of life and management is often difficult and unsatisfactory, in part due to weak correlation between symptoms and signs and poor recognition of the three main subtypes aqueous-deficient, evaporative and neuropathic dry eye. This review provides an overview of key aspects of dry eye disease, such as its multifactorial aetiology and recent insights into pathophysiology. The uses and pitfalls of commonly-used diagnostic tests for dry eye are reviewed, as well as the increasing number of new imaging technologies and biomarkers to refine diagnosis. There are many current and emerging treatment options for dry eye in Sjogren's syndrome, but high-level evidence of efficacy is mostly lacking, as are evidence-based treatment algorithms. All these aspects make the management of dry eye in Sjogren's syndrome challenging
Advances, limitations and future perspectives in the diagnosis and management of dry eye in Sjogren's syndrome
Development and performance of the Clinical Trials ESSDAI (ClinTrialsESSDAI), consisting of frequently active clinical domains, in two randomised controlled trials in primary Sjogren's syndrome
Objective. To develop and evaluate the Clinical Trials EULAR Sjogren's Syndrome Disease Activity Index (ClinTrialsESSDAI), consisting of frequently active clinical domains of the ESSDAI, using two randomised controlled trials in primary Sjogren's syndrome (pSS). Methods. The ASAP-III trial in abatacept (80 pSS patients) and TRACTISS trial in rituximab (133 pSS patients) were analysed. The most frequently active clinical domains were selected, and ClinTrialsESSDAI total score was calculated using existing weightings of the ClinESSDAI (which also excludes the biological domain). Performance of the ClinTrialsESSDAI was compared to ClinESSDAI and ESSDAI. Responsiveness was assessed using standardised response mean (SRM), and discrimination was assessed using adjusted mean difference. Results. Besides the biological domain, the most frequently active domains were glandular, articular, haematological, constitutional, lymphadenopathy and cutaneous. These domains were selected for the ClinTrialsESSDAI. At primary endpoint visits, SRM values of ClinTrialsESSDAI, ClinESSDAI and ESSDAI were respectively -0.65/-0.59, -0.63/-0.59 and - 0.64/-0.61 for abatacept/placebo and -0.33/-0.13, -0.34/0.12 and -0.41/-0.16 for rituximab/placebo. Adjusted mean differences between active treatment and placebo groups were respectively -1.7, -1.4 and -1.1 for ASAP-III and -1.1, -1.1 and -1.2 for TRACTISS. Conclusion. The ClinTrialsESSDAI, consisting of six frequently active clinical domains of the ESSDAI, shows closely similar responsiveness and discrimination between treatment groups compared to the ClinESSDAI and ESSDAI. Therefore, this ClinTrialsESSDAI is not preferable to ClinESSDAI and ESSDAI for use as primary endpoint. A composite endpoint combining response at multiple clinically relevant items seems more suitable as primary study endpoint in pSS
Development and performance of the Clinical Trials ESSDAI (ClinTrialsESSDAI), consisting of frequently active clinical domains, in two randomised controlled trials in primary Sjogren's syndrome
Failure to Engage Neural Plasticity through Practice of a High-difficulty Task is Accompanied by Reduced Motor Skill Retention in Older Adults
White the difficulty of a motor task can act as a stimulus for learning in younger adults, it is unknown how task difficulty interacts with age-related reductions in motor performance and altered brain activation. We examined the effects of task difficulty on motor performance and used electroencephalography (EEG) to probe task-related brain activation after acquisition and 24-h retention of a mirror star-tracing skill in healthy older adults (N = 36, 65-86 years). The results showed that the difficulty of the motor skill affected both the magnitude of motor skill learning and the underlying neural mechanisms. Behavioral data revealed that practicing a motor task at a high difficulty level hindered motor skill consolidation. The EEG data indicated that task difficulty modulated changes in brain activation after practice. Specifically, a decrease in task-related alpha power in frontal and parietal electrodes was only present after practice of the skill at the low and medium, but not the high difficulty level. Taken together, our findings show that a failure to engage neural plasticity through practice of a highdifficulty task is accompanied by reduced motor skill retention in older adults. The data help us better understand how older adults learn new motor skills and might have implications for prescribing motor skill practice according to its difficulty in rehabilitation settings. (c) 2020 The Author(s). Published by Elsevier Ltd on behalf of IBRO. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
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