265 research outputs found
There's more to life than O: Simulating the detectability of a range of molecules for ground-based high-resolution spectroscopy of transiting terrestrial exoplanets
Within the next decade, atmospheric O 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 O
have not been thoroughly explored. Additional molecules may help indicate
planetary habitability, rule out abiotically generated O, 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 O buildup from CO and HO 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: O, O, CH,
CO, CO, HO, and CH. Our results suggest that CH and CO
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 O
NIR and HO 0.9 m 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
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
and up to 100 zodis. However, subtracting exozodiacal disk structures from
edge-on systems may be challenging, except for cases with densities 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
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
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Dialectic tensions in the financial markets: a longitudinal study of pre- and post-crisis regulatory technology
This article presents the findings from a longitudinal research study on regulatory technology in the UK financial services industry. The financial crisis with serious corporate and mutual fund scandals raised the profile of
compliance as governmental bodies, institutional and private investors introduced a ‘tsunami’ of financial regulations. Adopting a multi-level analysis, this study examines how regulatory technology was used by financial firms to meet their compliance obligations, pre- and post-crisis. Empirical data collected over 12 years examine the deployment of
an investment management system in eight financial firms. Interviews with public regulatory bodies, financial
institutions and technology providers reveal a culture of compliance with increased transparency, surveillance and
accountability. Findings show that dialectic tensions arise as the pursuit of transparency, surveillance and
accountability in compliance mandates is simultaneously rationalized, facilitated and obscured by regulatory
technology. Responding to these challenges, regulatory bodies continue to impose revised compliance mandates on
financial firms to force them to adapt their financial technologies in an ever-changing multi-jurisdictional regulatory landscape
Living for the weekend: youth identities in northeast England
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
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
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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