130 research outputs found

    Turn It This Way: Remote Gesturing in Video-Mediated Communication

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    Collaborative physical tasks are working tasks characterised by workers 'in-the-field' who manipulate task artefacts under the guidance of a remote expert. Examples of such interactions include paramedics requiring field-surgery consults from hospital surgeons, soldiers requiring support from distant bomb-disposal experts, technicians inspecting and repairing machinery under the guidance of a chief engineer or scientists examining artefacts with distributed colleagues. This thesis considers the design of technology to support such forms of distributed working. Early research in video-mediated communication (VMC) which sought to support such interactions presumed video links between remote spaces would improve collaboration. The results of these studies however, demonstrated that in such tasks audio-video links alone were unlikely to improve performance beyond that achievable by simpler audio-only links. In explanation of these observations a reading of studies of situated collaborative working practices suggests that to support distributed object-focussed interactions it is beneficial to not only provide visual access to remote spaces but also to present within the task-space the gestural actions of remote collaborators. Remote Gestural Simulacra are advanced video-mediated communication tools that enable remote collaborators to both see and observably point at and gesture around and towards shared task artefacts located at another site. Technologies developed to support such activities have been critiqued; their design often fractures the interaction between the collaborating parties, restricting access to aspects of communication which are commonly used in co-present situations to coordinate interaction and ground understanding. This thesis specifically explores the design of remote gesture tools, seeking to understand how remote representations of gesture can be used during collaborative physical tasks. In a series of lab-based studies, the utility of remote gesturing is investigated, both qualitatively, examining its collaborative function and quantitatively exploring its impact on both facets of task performance and collaborative language. The thesis also discusses how the configuration of remote gesture tools impacts on their usability, empirically comparing various gesture tool designs. The thesis constructs and examines an argument that remote gesture tools should be designed from a 'mixed ecologies' perspective (theoretically alleviating the problems engendered by 'fractured ecologies' in which collaborating partners are given access to the most salient and relevant features of communicative action that are utilised in face-to-face interaction, namely mutual and reciprocal awareness of commonly understood object-focussed actions (hand-based gestures) and mutual and reciprocal awareness of task-space perspectives. The thesis demonstrates experimental support for this position and concludes by presenting discussion of how the findings generated from the thesis research can be used to guide the design of future iterations of remote gesture tools, and presents directions for areas of further research

    Turn It This Way: Remote Gesturing in Video-Mediated Communication

    Get PDF
    Collaborative physical tasks are working tasks characterised by workers 'in-the-field' who manipulate task artefacts under the guidance of a remote expert. Examples of such interactions include paramedics requiring field-surgery consults from hospital surgeons, soldiers requiring support from distant bomb-disposal experts, technicians inspecting and repairing machinery under the guidance of a chief engineer or scientists examining artefacts with distributed colleagues. This thesis considers the design of technology to support such forms of distributed working. Early research in video-mediated communication (VMC) which sought to support such interactions presumed video links between remote spaces would improve collaboration. The results of these studies however, demonstrated that in such tasks audio-video links alone were unlikely to improve performance beyond that achievable by simpler audio-only links. In explanation of these observations a reading of studies of situated collaborative working practices suggests that to support distributed object-focussed interactions it is beneficial to not only provide visual access to remote spaces but also to present within the task-space the gestural actions of remote collaborators. Remote Gestural Simulacra are advanced video-mediated communication tools that enable remote collaborators to both see and observably point at and gesture around and towards shared task artefacts located at another site. Technologies developed to support such activities have been critiqued; their design often fractures the interaction between the collaborating parties, restricting access to aspects of communication which are commonly used in co-present situations to coordinate interaction and ground understanding. This thesis specifically explores the design of remote gesture tools, seeking to understand how remote representations of gesture can be used during collaborative physical tasks. In a series of lab-based studies, the utility of remote gesturing is investigated, both qualitatively, examining its collaborative function and quantitatively exploring its impact on both facets of task performance and collaborative language. The thesis also discusses how the configuration of remote gesture tools impacts on their usability, empirically comparing various gesture tool designs. The thesis constructs and examines an argument that remote gesture tools should be designed from a 'mixed ecologies' perspective (theoretically alleviating the problems engendered by 'fractured ecologies' in which collaborating partners are given access to the most salient and relevant features of communicative action that are utilised in face-to-face interaction, namely mutual and reciprocal awareness of commonly understood object-focussed actions (hand-based gestures) and mutual and reciprocal awareness of task-space perspectives. The thesis demonstrates experimental support for this position and concludes by presenting discussion of how the findings generated from the thesis research can be used to guide the design of future iterations of remote gesture tools, and presents directions for areas of further research

    Squeezing in the audio gravitational wave detection band

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    We demonstrate the generation of broad-band continuous-wave optical squeezing down to 200Hz using a below threshold optical parametric oscillator (OPO). The squeezed state phase was controlled using a noise locking technique. We show that low frequency noise sources, such as seed noise, pump noise and detuning fluctuations, present in optical parametric amplifiers have negligible effect on squeezing produced by a below threshold OPO. This low frequency squeezing is ideal for improving the sensitivity of audio frequency measuring devices such as gravitational wave detectors.Comment: 5 pages, 6 figure

    Angiotensin-Converting Enzyme Inhibitor Therapy Affects Left Ventricular Mass in Patients With Ejection Fraction >40% After Acute Myocardial Infarction

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    AbstractObjectives. We tested the hypothesis that angiotensin-converting enzyme (ACE) inhibitor therapy decreases left ventricular (LV) mass in patients with a left ventricular ejection fraction (LVEF) >40% and no evidence of heart failure after their first acute Q wave myocardial infarction (MI).Background. Recently, ACE inhibitor therapy has been shown to have an early mortality benefit in unselected patients with acute MI, including patients without heart failure and a LVEF >35%. However, the effects on LV mass and volume in this patient population have not been studied.Methods. Thirty-five patients with a LVEF >40% after their first acute Q wave MI were randomized to titrated oral ramipril (n = 20) or conventional therapy (control, n = 15). Magnetic resonance imaging (MRI) performed an average of 7 days and 3 months after MI provided LV volumes and mass from summated serial short-axis slices.Results. Left ventricular end-diastolic volume index did not change in ramipril-treated patients (62 ± 16 [SD] to 66 ± 17 ml/m2) or in control patients (62 ± 16 to 68 ± 17 ml/m2), and stroke volume index increased significantly in both groups. However, LV mass index decreased in ramipril-treated patients (82 ± 18 to 73 ± 19 g/m2, p = 0.0002) but not in the control patients (77 ± 15 to 79 ± 23 g/m2). Systolic arterial pressure did not change in either group at 3-month follow-up.Conclusions. In patients with a LVEF >40% after acute MI, ramipril decreased LV mass, and blood pressure and LV function were unchanged after 3 months of therapy. Whether the decrease in mass represents a sustained effect that is associated with a decrease in morbid events requires further investigation.(J Am Coll Cardiol 1997;29:49–54)

    The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

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    The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

    Combined mutation screening of NKX2-5, GATA4, and TBX5 in congenital heart disease: multiple heterozygosity and novel mutations

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    Background: Variants of several genes encoding transcription modulators, signal transduction, and structural proteins are known to cause Mendelian congenital heart disease (CHD). NKX2-5 and GATA4 were the first CHD-causing genes identified by linkage analysis in large affected families. Mutations of TBX5 cause Holt–Oram syndrome, which includes CHD as a clinical feature. All three genes have a well-established role in cardiac development. Design: In order to investigate the possible role of multiple mutations in CHD, a combined mutation screening was performed in NKX2-5, GATA4, and TBX5 in the same patient cohort. Samples from a cohort of 331 CHD patients were analyzed by polymerase chain reaction, double high-performance liquid chromatography and sequencing in order to identify changes in the NKX2-5, GATA4, and TBX5 genes. Results: Two cases of multiple heterozygosity of putative disease-causing mutations were identified. One patient was found with a novel L122P NKX2-5 mutation in combination with the private A1443D mutation of MYH6. A patient heterozygote for a D425N GATA4 mutation carries also a private mutation of the MYH6 gene (V700M). Conclusions: In addition to reporting two novel mutations of NKX2-5 in CHD, we describe families where multiple individual mutations seem to have an additive effect over the pathogenesis of CHD. Our findings highlight the usefulness of multiple gene mutational analysis of large CHD cohorts

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors

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    Background Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors. Results Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged. Conclusions Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.Peer reviewe
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