800 research outputs found
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Making hurricane track data accessible
Our interactive tool allows the exploration, validation and presentation of hundreds of years of dynamically simulated storm tracks. The tracks were generated as part of a research project to improve the risk assessment of tropical storm damage by the insurance industry. The main impact of the tool is that exploratory interactive visualisation is now being used by the storm track modellers to (a) validate and improve model outputs, (b) discuss outputs with their peers (c) obtain a better understanding of the formation and development of tropical storms and (d) present examples of the behaviour of storms under different conditions to the insurance industry and others. Insights into tropical storm behaviour have been obtained and these insights are being articulated
Molecular basis of gap junctional communication in the CNS of the leech Hirudo medicinalis
Gap junctions are intercellular channels that allow the passage of ions and small molecules between cells. In the nervous system, gap junctions mediate electrical coupling between neurons. Despite sharing a common topology and similar physiology, two unrelated gap junction protein families exist in the animal kingdom. Vertebrate gap junctions are formed by members of the connexin family, whereas invertebrate gap junctions are composed of innexin proteins. Here we report the cloning of two innexins from the leech Hirudo medicinalis. These innexins show a differential expression in the leech CNS: Hm-inx1 is expressed by every neuron in the CNS but not in glia, whereas Hm-inx2 is expressed in glia but not neurons. Heterologous expression in the paired Xenopus oocyte system demonstrated that both innexins are able to form functional homotypic gap junctions. Hm-inx1 forms channels that are not strongly gated. In contrast, Hm-inx2 forms channels that are highly voltage-dependent; these channels demonstrate properties resembling those of a double rectifier. In addition, Hm-inx1 and Hm-inx2 are able to cooperate to form heterotypic gap junctions in Xenopus oocytes. The behavior of these channels is primarily that predicted from the properties of the constituent hemichannels but also demonstrates evidence of an interaction between the two. This work represents the first demonstration of a functional gap junction protein from a Lophotrochozoan animal and supports the hypothesis that connexin-based communication is restricted to the deuterostome clade
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Designing Interactive Graphics for Validating and Interpreting Storm Track Model Outputs
We report on some initial work in which we designed interactive graphics to help climate scientists identify and extract good examples of simulated storm-tracks from a large dataset to help disseminate information to various audiences. A side-effect of this work was that the exploratory potential offered by the interactive graphics helped our climate scientist coauthors validate and interpret their data in a way that was not previously possible for them. We are extending this work to provide support for a wider range of validation and interpretative tasks, with a focus on answering questions of relevance to the insurance industry. We describe our collaborative approach, that draws on ideas from âpatchwork prototypingâ [2, 5] in which a rapid iterative process of design, implementation and testing, is used to help provide the functionality to support a set of âuser storiesâ
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 usersâ 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
Crab cavities for linear colliders
Crab cavities have been proposed for a wide number of accelerators and
interest in crab cavities has recently increased after the successful operation
of a pair of crab cavities in KEK-B. In particular crab cavities are required
for both the ILC and CLIC linear colliders for bunch alignment. Consideration
of bunch structure and size constraints favour a 3.9 GHz superconducting,
multi-cell cavity as the solution for ILC, whilst bunch structure and
beam-loading considerations suggest an X-band copper travelling wave structure
for CLIC. These two cavity solutions are very different in design but share
complex design issues. Phase stabilisation, beam loading, wakefields and mode
damping are fundamental issues for these crab cavities. Requirements and
potential design solutions will be discussed for both colliders.Comment: 3 pages. To be published in proceedings of LINAC 2008, Victoria,
Canad
An extensible framework for provenance in human terrain visual analytics
We describe and demonstrate an extensible framework that supports data exploration and provenance in the context of Human Terrain Analysis (HTA). Working closely with defence analysts we extract requirements and a list of features that characterise data analysed at the end of the HTA chain. From these, we select an appropriate non-classified data source with analogous features, and model it as a set of facets. We develop ProveML, an XML-based extension of the Open Provenance Model, using these facets and augment it with the structures necessary to record the provenance of data, analytical process and interpretations. Through an iterative process, we develop and refine a prototype system for Human Terrain Visual Analytics (HTVA), and demonstrate means of storing, browsing and recalling analytical provenance and process through analytic bookmarks in ProveML. We show how these bookmarks can be combined to form narratives that link back to the live data. Throughout the process, we demonstrate that through structured workshops, rapid prototyping and structured communication with intelligence analysts we are able to establish requirements, and design schema, techniques and tools that meet the requirements of the intelligence community. We use the needs and reactions of defence analysts in defining and steering the methods to validate the framework
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