224 research outputs found
History on the Line: time as dimension
Boyd Davis’s work concerns representation, principally visual and spatial. This article discusses mapping historical time to a graphical surface, such as in timelines, focusing on the orientation of the time axis. Boyd Davis gained a £92K EPSRC grant to develop these inquiries into digital formats in 2012, and £70K from the Leverhulme Trust ending in 2010. It contrasts the paucity of intellectual debate on mapping time with the controversies over competing geographic projections, a dearth that Boyd Davis’s work is dedicated to correcting.
The article proposes a research agenda derived from a synthesis of the literatures of cognitive science and gesture studies, revealing that the metaphorical direction of time differs between verbal and gestural usage, and to a lesser extent between cultures. It features original archive research into the emergence of modern chronographics in the mid-18th century, a shift from typographic, tabular layouts to truly graphical time-maps based on a changing model of time spawned by Descartes and Newton. Research into the timelines of Nicole Oresme (1350s) and Jacques Barbeu-Dubourg and Joseph Priestley (1750s) reveals their difficulties in finding the ‘right’ direction for time.
Related work included a co-written paper for ‘Electronic Visualisation and the Arts’, London (2010), selected for the 2013 Springer book of best full papers (21 of c.160); a paper for the 26th ‘Computers and the History of Art’, London (2010); experimental work using virtual environments to represent historic time, a Leverhulme project co-led by Boyd Davis: two co-written articles for Computers & Education (2012); a chapter in Huang (ed.), Handbook of Human Centric Visualization (2013); a guest article for Joseph Priestley House Museum, PA, USA (2011); an invited talk on original research into French 18th-century contributions to chronographics, Centre de Recherches Texte/Image/Langage, Université de Bourgogne (2012); and a paper for ‘EVA2013’, London (2013)
On the Chiral Phase Transition in the Linear Sigma Model
The Cornwall-Jackiw-Tomboulis (CJT) effective action for composite operators
at finite temperature is used to investigate the chiral phase transition within
the framework of the linear sigma model as the low-energy effective model of
quantum chromodynamics (QCD). A new renormalization prescription for the CJT
effective action in the Hartree-Fock (HF) approximation is proposed. A
numerical study, which incorporates both thermal and quantum effect, shows that
in this approximation the phase transition is of first order. However, taking
into account the higher-loop diagrams contribution the order of phase
transition is unchanged.Comment: 12 pages, 4 figure
Accurate attribute mapping from volunteered geographic information: issues of volunteer quantity and quality
Crowdsourcing is a popular means of acquiring data, but the use of such data is limited by concerns with its quality. This is evident within cartography and geographical sciences more generally, with the quality of volunteered geographic information (VGI) recognized as a major challenge to address if the full potential of citizen sensing in mapping applications is to be realized. Here, a means to characterize the quality of volunteers, based only on the data they contribute, was used to explore issues connected with the quantity and quality of volunteers for attribute mapping. The focus was on data in the form of annotations or class labels provided by volunteers who visually interpreted an attribute, land cover, from a series of satellite sensor images. A latent class model was found to be able to provide accurate characterisations of the quality of volunteers in terms of the accuracy of their labelling, irrespective of the number of cases that they labelled. The accuracy with which a volunteer could be characterized tended to increase with the number of volunteers contributing but was typically good at all but small numbers of volunteers. Moreover, the ability to characterize volunteers in terms of the quality of their labelling could be used constructively. For example, volunteers could be ranked in terms of quality which could then be used to select a sub-set as input to a subsequent mapping task. This was particularly important as an identified subset of volunteers could undertake a task more accurately than when part of a larger group of volunteers. The results highlight that both the quantity and quality of volunteers need consideration and that the use of VGI may be enhanced through information on the quality of the volunteers derived entirely from the data provided without any additional information
Telling a Less Suspicious Story: Notes Toward a Non-Skeptical Approach to Legal/Cultural Analysis
Increasing the accuracy of crowdsourced information on land cover via a voting procedure weighted by information inferred from the contributed data
Simple consensus methods are often used in crowdsourcing studies to label cases when data are provided by multiple contributors. A basic majority vote rule is often used. This approach weights the contributions from each contributor equally but the contributors may vary in the accuracy with which they can label cases. Here, the potential to increase the accuracy of crowdsourced data on land cover identified from satellite remote sensor images through the use of weighted voting strategies is explored. Critically, the information used to weight contributions based on the accuracy with which a contributor labels cases of a class and the relative abundance of class are inferred entirely from the contributed data only via a latent class analysis. The results show that consensus approaches do yield a classification that is more accurate than that achieved by any individual contributor. Here, the most accurate individual could classify the data with an accuracy of 73.91% while a basic consensus label derived from the data provided by all seven volunteers contributing data was 76.58%. More importantly, the results show that weighting contributions can lead to a statistically significant increase in the overall accuracy to 80.60% by ignoring the contributions from the volunteer adjudged to be the least accurate in labelling
Vaccine Efficacy in Senescent Mice Challenged with Recombinant SARS-CoV Bearing Epidemic and Zoonotic Spike Variants
BACKGROUND: In 2003, severe acute respiratory syndrome coronavirus (SARS-CoV) was identified as the etiological agent of severe acute respiratory syndrome, a disease characterized by severe pneumonia that sometimes results in death. SARS-CoV is a zoonotic virus that crossed the species barrier, most likely originating from bats or from other species including civets, raccoon dogs, domestic cats, swine, and rodents. A SARS-CoV vaccine should confer long-term protection, especially in vulnerable senescent populations, against both the 2003 epidemic strains and zoonotic strains that may yet emerge from animal reservoirs. We report the comprehensive investigation of SARS vaccine efficacy in young and senescent mice following homologous and heterologous challenge. METHODS AND FINDINGS: Using Venezuelan equine encephalitis virus replicon particles (VRP) expressing the 2003 epidemic Urbani SARS-CoV strain spike (S) glycoprotein (VRP-S) or the nucleocapsid (N) protein from the same strain (VRP-N), we demonstrate that VRP-S, but not VRP-N vaccines provide complete short- and long-term protection against homologous strain challenge in young and senescent mice. To test VRP vaccine efficacy against a heterologous SARS-CoV, we used phylogenetic analyses, synthetic biology, and reverse genetics to construct a chimeric virus (icGDO3-S) encoding a synthetic S glycoprotein gene of the most genetically divergent human strain, GDO3, which clusters among the zoonotic SARS-CoV. icGD03-S replicated efficiently in human airway epithelial cells and in the lungs of young and senescent mice, and was highly resistant to neutralization with antisera directed against the Urbani strain. Although VRP-S vaccines provided complete short-term protection against heterologous icGD03-S challenge in young mice, only limited protection was seen in vaccinated senescent animals. VRP-N vaccines not only failed to protect from homologous or heterologous challenge, but resulted in enhanced immunopathology with eosinophilic infiltrates within the lungs of SARS-CoV–challenged mice. VRP-N–induced pathology presented at day 4, peaked around day 7, and persisted through day 14, and was likely mediated by cellular immune responses. CONCLUSIONS: This study identifies gaps and challenges in vaccine design for controlling future SARS-CoV zoonosis, especially in vulnerable elderly populations. The availability of a SARS-CoV virus bearing heterologous S glycoproteins provides a robust challenge inoculum for evaluating vaccine efficacy against zoonotic strains, the most likely source of future outbreaks
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