An exact collisionless equilibrium for the force-free Harris sheet with low plasma beta

We present a first discussion and analysis of the physical properties of a new exact collisionless equilibrium for a one-dimensional nonlinear force-free magnetic field, namely, the force-free Harris sheet. The solution allows any value of the plasma beta, and crucially below unity, which previous nonlinear force-free collisionless equilibria could not. The distribution function involves infinite series of Hermite polynomials in the canonical momenta, of which the important mathematical properties of convergence and non-negativity have recently been proven. Plots of the distribution function are presented for the plasma beta modestly below unity, and we compare the shape of the distribution function in two of the velocity directions to a Maxwellian distribution

Evidence-based decision support for pediatric rheumatology reduces diagnostic errors.

BACKGROUND: The number of trained specialists world-wide is insufficient to serve all children with pediatric rheumatologic disorders, even in the countries with robust medical resources. We evaluated the potential of diagnostic decision support software (DDSS) to alleviate this shortage by assessing the ability of such software to improve the diagnostic accuracy of non-specialists. METHODS: Using vignettes of actual clinical cases, clinician testers generated a differential diagnosis before and after using diagnostic decision support software. The evaluation used the SimulConsult® DDSS tool, based on Bayesian pattern matching with temporal onset of each finding in each disease. The tool covered 5405 diseases (averaging 22 findings per disease). Rheumatology content in the database was developed using both primary references and textbooks. The frequency, timing, age of onset and age of disappearance of findings, as well as their incidence, treatability, and heritability were taken into account in order to guide diagnostic decision making. These capabilities allowed key information such as pertinent negatives and evolution over time to be used in the computations. Efficacy was measured by comparing whether the correct condition was included in the differential diagnosis generated by clinicians before using the software ( unaided ), versus after use of the DDSS ( aided ). RESULTS: The 26 clinicians demonstrated a significant reduction in diagnostic errors following introduction of the software, from 28% errors while unaided to 15% using decision support (p \u3c 0.0001). Improvement was greatest for emergency medicine physicians (p = 0.013) and clinicians in practice for less than 10 years (p = 0.012). This error reduction occurred despite the fact that testers employed an open book approach to generate their initial lists of potential diagnoses, spending an average of 8.6 min using printed and electronic sources of medical information before using the diagnostic software. CONCLUSIONS: These findings suggest that decision support can reduce diagnostic errors and improve use of relevant information by generalists. Such assistance could potentially help relieve the shortage of experts in pediatric rheumatology and similarly underserved specialties by improving generalists\u27 ability to evaluate and diagnose patients presenting with musculoskeletal complaints. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT02205086

Patient preferences for topical treatment of actinic keratoses:a discrete-choice experiment

Funding: This study was funded by the National Institute for Health Research (NIHR) Research for Patient Benefit programme (PB-PG-0110-21244), Department of Health, UK. The funder was not involved in the study design. Acknowledgments: The authors gratefully acknowledge support from the Cancer Research UK Clinical Trials Unit, the UK Dermatology Clinical Trials Network, the NIHR Clinical Studies Group, and support for investigators from the British Skin Foundation and Cancer Research UK. We would also like to thank Martin Jones, Daniel Rigby and Ariel Bergmann for constructive comments on the design of the DCE.Peer reviewedPostprin

Multi-basin depositional framework for moisture-balance reconstruction during the last 1300 years at Lake Bogoria, central Kenya Rift Valley

Multi-proxy analysis of sediment cores from five key locations in hypersaline, alkaline Lake Bogoria (central Kenya Rift Valley) has allowed reconstruction of its history of depositional and hydrological change during the past 1300years. Analyses including organic matter and carbonate content, granulometry, mineralogical composition, charcoal counting and high-resolution scanning of magnetic susceptibility and elemental geochemistry resulted in a detailed sedimentological and compositional characterization of lacustrine deposits in the three lake basins and on the two sills separating them. Thesepalaeolimnological data were supplemented with information on present-day sedimentation conditions based on seasonal sampling of settling particles and on measurement of physicochemical profiles through the water column. A new age model based on Pb-210, Cs-137 and C-14 dating captures the sediment chronology of this hydrochemically complex and geothermally fed lake. An extensive set of chronological tie points between the equivalent high-resolution proxy time series of the five sediment sequences allowed transfer of radiometric dates between the basins, enabling interbasin comparison of sedimentation dynamics through time. The resulting reconstruction demonstrates considerable moisture-balance variability through time, reflecting regional hydroclimate dynamics over the past 1300years. Between ca 690 and 950AD, the central and southern basins of Lake Bogoria were reduced to shallow and separated brine pools. In the former, occasional near-complete desiccation triggered massive trona precipitation. Between ca 950 and 1100AD, slightly higher water levels allowed the build-up of high pCO(2) leading to precipitation of nahcolite still under strongly evaporative conditions. Lake Bogoria experienced a pronounced highstand between ca 1100 and 1350AD, only to recede again afterwards. For a substantial part of the time between ca 1350 and 1800AD, the northern basin was probably disconnected from the united central and southern basins. Throughout the last two centuries, lake level has been relatively high compared to the rest of the past millennium. Evidence for increased terrestrial sediment supply in recent decades, due to anthropogenic soil erosion in the wider Bogoria catchment, is a reason for concern about possible adverse impacts on the unique ecosystem of Lake Bogoria

Photographic protocol for image acquisition in craniofacial microsomia

Craniofacial microsomia (CFM) is a congenital condition associated with orbital, mandibular, ear, nerve, and soft tissue anomalies. We present a standardized, two-dimensional, digital photographic protocol designed to capture the common craniofacial features associated with CFM

Linking Human Diseases to Animal Models Using Ontology-Based Phenotype Annotation

A novel method for quantifying the similarity between phenotypes by the use of ontologies can be used to search for candidate genes, pathway members, and human disease models on the basis of phenotypes alone

The CDKL5 disorder is an independent clinical entity associated with early-onset encephalopathy

The clinical understanding of the CDKL5 disorder remains limited, with most information being derived from small patient groups seen at individual centres. This study uses a large international data collection to describe the clinical profile of the CDKL5 disorder and compare with Rett syndrome (RTT). Information on individuals with cyclin-dependent kinase-like 5 (CDKL5) mutations (n=86) and females with MECP2 mutations (n=920) was sourced from the InterRett database. Available photographs of CDKL5 patients were examined for dysmorphic features. The proportion of CDKL5 patients meeting the recent Neul criteria for atypical RTT was determined. Logistic regression and time-to-event analyses were used to compare the occurrence of Rett-like features in those with MECP2 and CDKL5 mutations. Most individuals with CDKL5 mutations had severe developmental delay from birth, seizure onset before the age of 3 months and similar non-dysmorphic features. Less than one-quarter met the criteria for early-onset seizure variant RTT. Seizures and sleep disturbances were more common than in those with MECP2 mutations whereas features of regression and spinal curvature were less common. The CDKL5 disorder presents with a distinct clinical profile and a subtle facial, limb and hand phenotype that may assist in differentiation from other early-onset encephalopathies. Although mutations in the CDKL5 gene have been described in association with the early-onset variant of RTT, in our study the majority did not meet these criteria. Therefore, the CDKL5 disorder should be considered separate to RTT, rather than another variant

The phenotype of Floating-Harbor syndrome: Clinical characterization of 52 individuals with mutations in exon 34 of SRCAP

Background: Floating-Harbor syndrome (FHS) is a rare condition characterized by short stature, delays in expressive language, and a distinctive facial appearance. Recently, heterozygous truncating mutations in SRCAP were determined to be disease-causing. With the availability of a DNA based confirmatory test, we set forth to define the clinical features of this syndrome. Methods and results. Clinical information on fifty-two individuals with SRCAP mutations was collected using standardized questionnaires. Twenty-four males and twenty-eight females were studied with ages ranging from

Uncharted waters: rare and unclassified cardiomyopathies characterized on cardiac magnetic resonance imaging

Cardiac magnetic resonance imaging (CMR) has undergone considerable technology advances in recent years, so that it is now entering into mainstream cardiac imaging practice. In particular, CMR is proving to be a valuable imaging tool in the detection, morphological assessment and functional assessment of cardiomyopathies. Although our understanding of this broad group of heart disorders continues to expand, it is an evolving group of entities, with the rarer cardiomyopathies remaining poorly understood or even unclassified. In this review, we describe the clinical and pathophysiological aspects of several of the rare/unclassified cardiomyopathies and their appearance on CMR