653 research outputs found

    A New Method for Estimating Effects of Visual Field Loss in a Panoramic Driving Environment

    Get PDF
    Glaucoma is a key cause of peripheral visual field loss and increases risk of a vehicle crash. Patients may be unaware of their visual loss and of hazards in the driving panorama. Standard clinical automated perimetry, the ā€œgold standardā€ for monitoring glaucoma progression, lacks external validity to evaluate functional effect of visual field loss in driving environments. We developed and piloted a new technique to study the effects of glaucoma in a panoramic (290 forward FOV) simulated driving environment. Preliminary results in 11 drivers (7 with glaucoma and 4 with suspected glaucoma): (1) demonstrate the relationship between standard clinical perimetry and driving simulator visual fields, (2) replicate clinical evidence of glaucoma-related peripheral visual field loss, and (3) show added visual field loss due to visual occlusion by in-cab geometry

    Products of Nearly Holomorphic Eigenforms

    Full text link
    We prove that the product of two nearly holomorphic Hecke eigenforms is again a Hecke eigenform for only finitely many choices of factors.Comment: 8 page

    Ethical and methodological issues in engaging young people living in poverty with participatory research methods

    Get PDF
    This paper discusses the methodological and ethical issues arising from a project that focused on conducting a qualitative study using participatory techniques with children and young people living in disadvantage. The main aim of the study was to explore the impact of poverty on children and young people's access to public and private services. The paper is based on the author's perspective of the first stage of the fieldwork from the project. It discusses the ethical implications of involving children and young people in the research process, in particular issues relating to access and recruitment, the role of young people's advisory groups, use of visual data and collection of data in young people's homes. The paper also identifies some strategies for addressing the difficulties encountered in relation to each of these aspects and it considers the benefits of adopting participatory methods when conducting research with children and young people

    Aerosol meteorology of Maritime Continent for the 2012 7SEAS southwest monsoon intensive study - Part 2: Philippine receptor observations of fine-scale aerosol behavior

    Get PDF
    Abstract. The largest 7 Southeast Asian Studies (7SEAS) operations period within the Maritime Continent (MC) occurred in the Augustā€“SeptemberĀ 2012 biomass burning season. Data included were observations aboard the M/Y Vasco, dispatched to the Palawan Archipelago and Sulu Sea of the Philippines for SeptemberĀ 2012. At these locations, the Vasco observed MC smoke and pollution entering the southwest monsoon (SWM) monsoonal trough. Here we describe the research cruise findings and the finer-scale aerosol meteorology of this convectively active region. This 2012 cruise complemented a 2-week cruise in 2011 and was generally consistent with previous findings in terms of how smoke emission and transport related to monsoonal flows, tropical cyclones (TC), and the covariance between smoke transport events and the atmosphere's thermodynamic structure. Biomass burning plumes were usually mixed with significant amounts of anthropogenic pollution. Also key to aerosol behavior were squall lines and cold pools propagating across the South China Sea (SCS) and scavenging aerosol particles in their path. However, the 2012 cruise showed much higher modulation in aerosol frequency than its 2011 counterpart. Whereas in 2011 large synoptic-scale aerosol events transported high concentrations of smoke into the Philippines over days, in 2012 measured aerosol events exhibited a much shorter-term variation, sometimes only 3ā€“12ā€Æh. Strong monsoonal flow reversals were also experienced in 2012. Nucleation events in cleaner and polluted conditions, as well as in urban plumes, were observed. Perhaps most interestingly, several cases of squall lines preceding major aerosol events were observed, as opposed to 2011 observations where these lines largely scavenged aerosol particles from the marine boundary layer. Combined, these observations indicate pockets of high and low particle counts that are not uncommon in the region. These perturbations are difficult to observe by satellite and very difficult to model. Indeed, the Navy Aerosol Analysis and Prediction System (NAAPS) simulations captured longer period aerosol events quite well but largely failed to capture the timing of high-frequency phenomena. Ultimately, the research findings of these cruises demonstrate the real world challenges of satellite-based missions, significant aerosol life cycle questions such as those the future Aerosol/Clouds/Ecosystems (ACE) will investigate, and the importance of small-scale phenomena such as sea breezes, squall lines, and nucleation events embedded within SWM patterns in dominating aerosol life cycle and potential relationships to clouds

    Gravitational collapse with tachyon field and barotropic fluid

    Full text link
    A particular class of space-time, with a tachyon field, \phi, and a barotropic fluid constituting the matter content, is considered herein as a model for gravitational collapse. For simplicity, the tachyon potential is assumed to be of inverse square form i.e., V(\phi) \sim \phi^{-2}. Our purpose, by making use of the specific kinematical features of the tachyon, which are rather different from a standard scalar field, is to establish the several types of asymptotic behavior that our matter content induces. Employing a dynamical system analysis, complemented by a thorough numerical study, we find classical solutions corresponding to a naked singularity or a black hole formation. In particular, there is a subset where the fluid and tachyon participate in an interesting tracking behaviour, depending sensitively on the initial conditions for the energy densities of the tachyon field and barotropic fluid. Two other classes of solutions are present, corresponding respectively, to either a tachyon or a barotropic fluid regime. Which of these emerges as dominant, will depend on the choice of the barotropic parameter, \gamma. Furthermore, these collapsing scenarios both have as final state the formation of a black hole.Comment: 18 pages, 7 figures. v3: minor changes. Final version to appear in GR

    Naked Singularity Formation In f(R) Gravity

    Full text link
    We study the gravitational collapse of a star with barotropic equation of state p=wĻp=w\rho in the context of f(R)f({\mathcal R}) theories of gravity. Utilizing the metric formalism, we rewrite the field equations as those of Brans-Dicke theory with vanishing coupling parameter. By choosing the functionality of Ricci scalar as f(R)=Ī±Rmf({\mathcal R})=\alpha{\mathcal R}^{m}, we show that for an appropriate initial value of the energy density, if Ī±\alpha and mm satisfy certain conditions, the resulting singularity would be naked, violating the cosmic censorship conjecture. These conditions are the ratio of the mass function to the area radius of the collapsing ball, negativity of the effective pressure, and the time behavior of the Kretschmann scalar. Also, as long as parameter Ī±\alpha obeys certain conditions, the satisfaction of the weak energy condition is guaranteed by the collapsing configuration.Comment: 15 pages, 4 figures, to appear in GR

    An impact and feasibility evaluation of a 6 week (9 hour) active play intervention on fathers' engagement with their preschool children: A feasibility study

    Get PDF
    Research has demonstrated the benefits of father involvement with their children and a link between uninvolved fatherhood and societal problems. Childrenā€™s Centres (n=15) received 6 x 90 minute active play sessions designed to foster six aspects of parental engagement. Fathersā€™ engagement and attitudes to child PA were measured pre- and post-intervention via questionnaire. Acceptability of the intervention was explored through participant and staff focus groups. Results showed no effect on overall time fathers spent with their child during the week (t (36) = 0.178, p = 0.860) and the weekend (t (36) =1.166, p = 0.252). Qualitative results demonstrated the sessions provided opportunities for fathers to spend quality time with their children. Parenting self-efficacy increased across the subscale control, t (36) = -2.97, p = 0.04. Fathers increased awareness of their role in motivating their child to play (z = -2.46, p = 0.01). Further longitudinal research is recommended. Key Words: fathersā€™ engagement; childcare settings; parenting programmes; active play; parenting self-efficac

    Genital ulcer severity score and genital health quality of life in BehƧet's disease

    Get PDF
    Background: BehƧet's Disease (BD) is a chronic auto-inflammatory, multisystem relapsing/remitting disorder of unknown aetiology. Oro-genital ulceration is a key feature of the disease and has a major impact on the patients' quality of life. Other clinical manifestations include ocular inflammation, rheumatologic and skin involvement, while CNS and vascular complications can lead to considerable morbidity. The availability of a valid monitoring tool for BD activity is crucial in evaluating the impact of the disease on daily life activity. The aims of this study were to validate a novel tool for monitoring genital ulceration severity in BD and to assess the impact of genital ulcers on the Genital Health Quality of Life (GHQoL). Methods: Genital Ulcer Severity Score (GUSS) was developed using six genital ulcer characteristics: number, size, duration, ulcer-free period, pain and site. A total of 207 BD patients were examined, (137 females: mean ageāˆˆĀ±āˆˆSD: 39.83āˆˆĀ±āˆˆ13.42 and 70 males: mean ageāˆˆĀ±āˆˆSD: 39.98āˆˆĀ±āˆˆ11.95) from the multidisciplinary BehƧet's Centre of Excellence at Barts Health NHS Trust. GUSS was used in conjunction with BehƧet's Disease Current Activity Form (BDCAF). Results: The over-all score of GUSS showed a strong correlation with all genital ulcer characteristics, and the strongest correlation was with the pain domain (rāˆˆ=āˆˆ0.936; Pāˆˆ2: 0.600; Pāˆˆ<āˆˆ0.0001). Conclusions: This study established the practicality of GUSS as a severity monitoring tool for BD genital ulcers and validated its use in 207 patients. Genital ulcers of BD have a considerable impact on the patients GHQoL
    • ā€¦
    corecore