265 research outputs found

    There's more to life than O2_2: Simulating the detectability of a range of molecules for ground-based high-resolution spectroscopy of transiting terrestrial exoplanets

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    Within the next decade, atmospheric O2_2 on Earth-like M dwarf planets may be accessible with visible--near-infrared, high spectral resolution extremely large ground-based telescope (ELT) instruments. However, the prospects for using ELTs to detect environmental properties that provide context for O2_2 have not been thoroughly explored. Additional molecules may help indicate planetary habitability, rule out abiotically generated O2_2, or reveal alternative biosignatures. To understand the accessibility of environmental context using ELT spectra, we simulate high-resolution transit transmission spectra of previously-generated evolved terrestrial atmospheres. We consider inhabited pre-industrial and Archean Earth-like atmospheres, and lifeless worlds with abiotic O2_2 buildup from CO2_2 and H2_2O photolysis. All atmospheres are self-consistent with M2V--M8V dwarf host stars. Our simulations include explicit treatment of systematic and telluric effects to model high-resolution spectra for GMT, TMT, and E-ELT configurations for systems 5 and 12 pc from Earth. Using the cross-correlation technique, we determine the detectability of major species in these atmospheres: O2_2, O3_3, CH4_4, CO2_2, CO, H2_2O, and C2_2H6_6. Our results suggest that CH4_4 and CO2_2 are the most accessible molecules for terrestrial planets transiting a range of M dwarf hosts using an E-ELT, TMT, or GMT sized telescope, and that the O2_2 NIR and H2_2O 0.9 μ\mum bands may also be accessible with more observation time. Although this technique still faces considerable challenges, the ELTs will provide access to the atmospheres of terrestrial planets transiting earlier-type M-dwarf hosts that may not be possible using JWST.Comment: Accepted for publication in The Planetary Science Journa

    Mitigating Worst-Case Exozodiacal Dust Structure in High-contrast Images of Earth-like Exoplanets

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    Detecting Earth-like exoplanets in direct images of nearby Sun-like systems brings a unique set of challenges that must be addressed in the early phases of designing a space-based direct imaging mission. In particular, these systems may contain exozodiacal dust, which is expected to be the dominant source of astrophysical noise. Previous work has shown that it may be feasible to subtract smooth, symmetric dust from observations; however, we do not expect exozodiacal dust to be perfectly smooth. Exozodiacal dust can be trapped into mean motion resonances with planetary bodies, producing large-scale structures that orbit in lock with the planet. This dust can obscure the planet, complicate noise estimation, or be mistaken for a planetary body. Our ability to subtract these structures from high-contrast images of Earth-like exoplanets is not well understood. In this work, we investigate exozodi mitigation for Earth--Sun-like systems with significant mean motion resonant disk structures. We find that applying a simple high-pass filter allows us to remove structured exozodi to the Poisson noise limit for systems with inclinations <60< 60^\circ and up to 100 zodis. However, subtracting exozodiacal disk structures from edge-on systems may be challenging, except for cases with densities <5<5 zodis. For systems with three times the dust of the Solar System, which is the median of the best fit to survey data in the habitable zones of nearby Sun-like stars, this method shows promising results for mitigating exozodiacal dust in future HWO observations, even if the dust exhibits significant mean-motion resonance structure.Comment: Accepted to AJ. 18 pages, 10 figure

    Information practices of disaster preparedness professionals in multidisciplinary groups

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    OBJECTIVE: This article summarizes the results of a descriptive qualitative study addressing the question, what are the information practices of the various professionals involved in disaster preparedness? We present key results, but focus on issues of choice and adaptation of models and theories for the study. METHODS: Primary and secondary literature on theory and models of information behavior were consulted. Taylor's Information Use Environments (IUE) model, Institutional Theory, and Dervin's Sense-Making metatheory were used in the design of an open-ended interview schedule. Twelve individual face-to-face interviews were conducted with disaster professionals drawn from the Pennsylvania Preparedness Leadership Institute (PPLI) scholars. Taylor's Information Use Environments (IUE) model served as a preliminary coding framework for the transcribed interviews. RESULTS: Disaster professionals varied in their use of libraries, peer-reviewed literature, and information management techniques, but many practices were similar across professions, including heavy Internet and email use, satisficing, and preference for sources that are socially and physically accessible. CONCLUSIONS: The IUE model provided an excellent foundation for the coding scheme, but required modification to place the workplace in the larger social context of the current information society. It is not possible to confidently attribute all work-related information practices to professional culture. Differences in information practice observed may arise from professional training and organizational environment, while many similarities observed seem to arise from everyday information practices common to non-work settings

    Living for the weekend: youth identities in northeast England

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    Consumption and consumerism are now accepted as key contexts for the construction of youth identities in de-industrialized Britain. This article uses empirical evidence from interviews with young people to suggest that claims of `new community' are overstated, traditional forms of friendship are receding, and increasingly atomized and instrumental youth identities are now being culturally constituted and reproduced by the pressures and anxieties created by enforced adaptation to consumer capitalism. Analysis of the data opens up the possibility of a critical rather than a celebratory exploration of the wider theoretical implications of this process

    Clinical leadership in service redesign using Clinical Commissioning Groups: a mixed-methods study

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    Background: A core component of the Health and Social Care Act 2012 (Great Britain. Health and Social Care Act 2012. London: HMSO; 2012) was the idea of devolving to general practitioners (GPs) a health service leadership role for service redesign. For this purpose, new Clinical Commissioning Groups (CCGs) were formed in the English NHS.Objectives: This research examined the extent to which, and the methods by which, clinicians stepped forward to take up a leadership role in service redesign using CCGs as a platform.Design: The project proceeded in five phases: (1) a scoping study across 15 CCGs, (2) the design and administration of a national survey of all members of CCG governing bodies in 2014, (3) six main in-depth case studies, (4) a second national survey of governing body members in 2016, which allowed longitudinal comparisons, and (5) international comparisons.Participants: In addition to GPs serving in clinical lead roles for CCGs, the research included insights from accountable officers and other managers and perspectives from secondary care and other provider organisations (local authority councillors and staff, patients and the public, and other relevant bodies).Results: Instances of the exercise of clinical leadership utilising the mechanism of the CCGs were strikingly varied. Some CCG teams had made little of the opportunity. However, we found other examples of clinicians stepping forward to bring about meaningful improvements in services. The most notable cases involved the design of integrated care for frail elderly patients and others with long-term conditions. The leadership of these service redesigns required cross-boundary working with primary care, secondary care, community care and social work. The processes enabling such breakthroughs required interlocking processes of leadership across three arenas: (1) strategy-level work at CCG board level, (2) mid-range operational planning and negotiation at programme board level and (3) the arena of practical implementation leadership at the point of delivery. The arena of the CCG board provided the legitimacy for strategic change; the programme boards worked through the competing logics of markets, hierarchy and networks; and the practice arena allowed the exercise of clinical leadership in practical problemsolving, detailed learning and routinisation of new ways of working at a common-sense everyday level.Limitations: Although the research was conducted over a 3-year period, it could be argued that a much longer period is required for CCGs to mature and realise their potential.Conclusions: Despite the variation in practice, we found significant examples of clinical leaders forging new modes of service design and delivery. A great deal of the service redesign effort was directed at compensating for the fragmented nature of the NHS – part of which had been created by the 2012 reforms. This is the first study to reveal details of such work in a systematic way

    The impact of housing payment problems on health status during economic recession: A comparative analysis of longitudinal EU SILC data of 27 European states, 2008–2010

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    Although the recent Great Recession had its origins in the housing sector, the short-term health impact of the housing crisis is not well understood. We used longitudinal data to evaluate the impact of housing payment problems on health status among home-owners and renters in 27 European states. Multi-level and fixed-effects models were applied to a retrospective cohort drawn from the EU Statistics on Income and Living Conditions survey of employed persons, comprising those without housing arrears in the base year 2008 and followed through to 2010 (n=45,457 persons, 136,371 person-years). Multi-variate models tested the impact of transitioning into housing payment arrears on self-reported health (0-worst to 4-best), adjusting for confounders including age, sex, baseline health, and individual fixed effects. Transitioning into housing arrears was associated with a significant deterioration in the health of renters (−0.09 units, 95% CI −0.05 to −0.13), but not owners (0.00, 95% CI −0.05 to 0.06), after adjusting for individual fixed effects. This effect was independent of and greater than the impact of job loss for the full sample (−0.05, 95% CI −0.002 to −0.09). The magnitude of this association varied across countries; the largest adverse associations were observed for renters in Belgium, Austria, and Italy. There was no observed protective association of differing categories of social protection or of the housing regulatory structure for renters. Women aged 30 and over who rented appeared to have worse self-reported health when transitioning into arrears than other groups. Renters also fared worse in those countries where house prices were escalating. We therefore find that housing payment problems are a significant risk factor for worse-self reported health in persons who are renting their homes. Future research is needed to understand potential sources of health resilience among renters, especially at a time when housing prices are rising in many European states
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