Acceleration of heavy ions in the solar wind

The preferential acceleration and heating of solar wind heavy ions by the resonant cyclotron interaction were studied. It is concluded that this interaction is incapable of producing the observed differential speeds for reasonable solar wind parameters

Sketchy rendering for information visualization

We present and evaluate a framework for constructing sketchy style information visualizations that mimic data graphics drawn by hand. We provide an alternative renderer for the Processing graphics environment that redefines core drawing primitives including line, polygon and ellipse rendering. These primitives allow higher-level graphical features such as bar charts, line charts, treemaps and node-link diagrams to be drawn in a sketchy style with a specified degree of sketchiness. The framework is designed to be easily integrated into existing visualization implementations with minimal programming modification or design effort. We show examples of use for statistical graphics, conveying spatial imprecision and for enhancing aesthetic and narrative qualities of visual- ization. We evaluate user perception of sketchiness of areal features through a series of stimulus-response tests in order to assess users’ ability to place sketchiness on a ratio scale, and to estimate area. Results suggest relative area judgment is compromised by sketchy rendering and that its influence is dependent on the shape being rendered. They show that degree of sketchiness may be judged on an ordinal scale but that its judgement varies strongly between individuals. We evaluate higher-level impacts of sketchiness through user testing of scenarios that encourage user engagement with data visualization and willingness to critique visualization de- sign. Results suggest that where a visualization is clearly sketchy, engagement may be increased and that attitudes to participating in visualization annotation are more positive. The results of our work have implications for effective information visualization design that go beyond the traditional role of sketching as a tool for prototyping or its use for an indication of general uncertainty

On the dynamics of generators of Cauchy horizons

We discuss various features of the dynamical system determined by the flow of null geodesic generators of Cauchy horizons. Several examples with non--trivial (``chaotic'', ``strange attractors'', etc.) global behaviour are constructed. Those examples are relevant to the ``chronology protection conjecture'', and they show that the occurrence of ``fountains'' is {\em not} a generic feature of Cauchy horizons.Comment: 16 pages, preprint MPA 773, December 93, Late

Yang-Mills Flow and Uniformization Theorems

We consider a parabolic-like systems of differential equations involving geometrical quantities to examine uniformization theorems for two- and three-dimensional closed orientable manifolds. We find that in the two-dimensional case there is a simple gauge theoretic flow for a connection built from a Riemannian structure, and that the convergence of the flow to the fixed points is consistent with the Poincare Uniformization Theorem. We construct a similar system for the three-dimensional case. Here the connection is built from a Riemannian geometry, an SO(3) connection and two other 1-form fields which take their values in the SO(3) algebra. The flat connections include the eight homogeneous geometries relevant to the three-dimensional uniformization theorem conjectured by W. Thurston. The fixed points of the flow include, besides the flat connections (and their local deformations), non-flat solutions of the Yang-Mills equations. These latter "instanton" configurations may be relevant to the fact that generic 3-manifolds do not admit one of the homogeneous geometries, but may be decomposed into "simple 3-manifolds" which do.Comment: 21 pages, Latex, 5 Postscript figures, uses epsf.st

Asymptotically Hyperbolic Non Constant Mean Curvature Solutions of the Einstein Constraint Equations

We describe how the iterative technique used by Isenberg and Moncrief to verify the existence of large sets of non constant mean curvature solutions of the Einstein constraints on closed manifolds can be adapted to verify the existence of large sets of asymptotically hyperbolic non constant mean curvature solutions of the Einstein constraints.Comment: 19 pages, TeX, no figure

On the preferential acceleration and heating of solar wind heavy ions

The feasibility of producing the observed velocities and temperatures of solar wind heavy ions by the resonant cyclotron interaction with left-polarized hydromagnetic waves was investigated. A "most favorable case" scenario in which the waves are parallel-propagating and dispersionless and the energy for the wave acceleration and heating is taken from saturated low-frequency Alfven waves via a cascade to higher frequencies, is incorporated into a numerical solar wind code and agreement with observation is tested. The resonant cyclotron interaction is shown to fail on at least three points, even in this most favorable case

Very Delayed Lupus Nephritis: a Report of Three Cases and Literature Review

Lupus nephritis (LN) affects up to 50% of patients with Systemic Lupus Erythematosus (SLE) and is associated with a worse prognosis. LN usually develops within the first 5 years of the onset of the disease. We report three patients with very delayed LN (DLN) diagnosed after 15 or more years after SLE diagnosis. The three patients were non-Caucasian women with adolescent or adult-onset SLE. Each had antinuclear, anti-dsDNA and anti-Ro antibodies. Hydroxychloroquine was prescribed for each. Their disease courses were characterised by sporadic non-renal flares controlled by steroids and, in two cases, by one cycle of rituximab. Unexpectedly, they developed proteinuria, haematuria and lowering of estimated glomerular filtration rate with clinical signs of renal disease. LN was confirmed by renal biopsy. Reviewing them, each showed serological signs of increasing disease activity (rising levels of anti-dsDNA antibodies and fall in C3) that predated clinical or laboratory signs of LN by 1-3 years. Reviewing the literature, we found a lack of knowledge about DLN starting more than 15 years after SLE diagnosis. With the increasing life expectancy of patients with SLE it is likely that more cases of very DLN will emerge.info:eu-repo/semantics/publishedVersio

Improving B-cell depletion in systemic lupus erythematosus and rheumatoid arthritis

INTRODUCTION: Rituximab-based B-cell depletion (BCD) therapy is effective in refractory rheumatoid arthritis (RA) and although used to treat patients with refractory systemic lupus erythematosus (SLE) in routine clinical practice, rituximab failed to meet the primary endpoints in two large randomised controlled trials (RCTs) of non-renal (EXPLORER) and renal (LUNAR) SLE. Areas covered: We review how BCD could be improved to achieve better clinical responses in RA and SLE. Insights into the variability in clinical response to BCD in RA and SLE may help develop new therapeutic strategies. To this end, a literature search was performed using the following terms: rheumatoid arthritis, systemic erythematosus lupus, rituximab and B-cell depletion. Expert commentary: Poor trial design may have, at least partly, contributed to the apparent lack of response to BCD in the two RCTs of patients with SLE. Enhanced B-cell depletion and/or sequential therapy with belimumab may improve clinical response at least in some patients with SLE

Gluing Initial Data Sets for General Relativity

We establish an optimal gluing construction for general relativistic initial data sets. The construction is optimal in two distinct ways. First, it applies to generic initial data sets and the required (generically satisfied) hypotheses are geometrically and physically natural. Secondly, the construction is completely local in the sense that the initial data is left unaltered on the complement of arbitrarily small neighborhoods of the points about which the gluing takes place. Using this construction we establish the existence of cosmological, maximal globally hyperbolic, vacuum space-times with no constant mean curvature spacelike Cauchy surfaces.Comment: Final published version - PRL, 4 page