86 research outputs found

    The Future of U.S. Natural Gas Production, Use, and Trade

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    Abstract and PDF report are also available on the MIT Joint Program on the Science and Policy of Global Change website (http://globalchange.mit.edu/)Two computable general equilibrium models, one global and the other providing U.S. regional detail, are applied to analysis of the future of U.S. natural gas as an input to an MIT study of the topic. The focus is on uncertainties including the scale and cost of gas resources, the costs of competing technologies, the pattern of greenhouse gas mitigation, and the evolution of global natural gas markets. Results show that the outlook for gas over the next several decades is very favorable. In electric generation, given the unproven and relatively high cost of other low-carbon generation alternatives, gas likely is the preferred alternative to coal. A broad GHG pricing policy would increase gas use in generation but reduce use in other sectors, on a balance increasing its role from present levels. The shale gas resource is a major contributor to this optimistic view of the future of gas, but it is far from a panacea over the longer term. Gas can be an effective bridge to a lower emissions future, but investment in the development of still lower CO2 technologies remains an important priority. Also, international gas resources may well prove to be less costly than those in the U.S., except for the lowest-cost domestic shale resources, and the emergence of an integrated global gas market could result in significant U.S. gas imports.American Clean Skies Foundation, with additional support from the Hess Corporation, the Agencia Nacional de Hidrocarburos (Columbia), the Energy Futures Coalition, and the MIT Energy Initiative

    Can programme theory be used as a 'translational tool’ to optimise health service delivery in a national early years’ initiative in Scotland: a case study

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    Background Theory-based evaluation (TBE) approaches are heralded as supporting formative evaluation by facilitating increased use of evaluative findings to guide programme improvement. It is essential that learning from programme implementation is better used to improve delivery and to inform other initiatives, if interventions are to be as effective as they have the potential to be. Nonetheless, few studies describe formative feedback methods, or report direct instrumental use of findings resulting from TBE. This paper uses the case of Scotland’s, National Health Service, early years’, oral health improvement initiative (Childsmile) to describe the use of TBE as a framework for providing feedback on delivery to programme staff and to assess its impact on programmatic action.<p></p> Methods In-depth, semi-structured interviews and focus groups with key stakeholders explored perceived deviations between the Childsmile programme 'as delivered’ and its Programme Theory (PT). The data was thematically analysed using constant comparative methods. Findings were shared with key programme stakeholders and discussions around likely impact and necessary actions were facilitated by the authors. Documentary review and ongoing observations of programme meetings were undertaken to assess the extent to which learning was acted upon.<p></p> Results On the whole, the activities documented in Childsmile’s PT were implemented as intended. This paper purposefully focuses on those activities where variation in delivery was evident. Differences resulted from the stage of roll-out reached and the flexibility given to individual NHS boards to tailor local implementation. Some adaptations were thought to have diverged from the central features of Childsmile’s PT, to the extent that there was a risk to achieving outcomes. The methods employed prompted national service improvement action, and proposals for local action by individual NHS boards to address this.<p></p> Conclusions The TBE approach provided a platform, to direct attention to areas of risk within a national health initiative, and to agree which intervention components were 'core’ to its hypothesised success. The study demonstrates that PT can be used as a 'translational tool’ to facilitate instrumental use of evaluative findings to optimise implementation within a complex health improvement programme.<p></p&gt

    Strain-level metagenomic analysis of the fermented dairy beverage nunu highlights potential food safety risks

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    ACKNOWLEDGMENTS We thank the researchers at the Animal Research Institute (Accra, Ghana) for their help with sample collection, storage, and processing. This research was funded by Science Foundation Ireland in the form of a center grant (APC Microbiome Institute grant SFI/12/RC/2273). Research in the Cotter laboratory is also funded by Science Foundation Ireland through grant 11/PI/1137. O.O. is funded by Science Foundation Ireland through a Starting Investigator Research Grant (grant 13/SIRG/2160). K.D. is a PhD student funded by the Ghana Educational Trust Fund. The Rowett Institute receives funding from the Scottish Government (RESAS). The Rowett Institute receives funding from the Scottish Government strategic research portfolio (RAFE).Peer reviewedPostprin

    Validation of a self-efficacy instrument and its relationship to performance of crisis resource management skills

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    Self-efficacy is thought to be important for resuscitation proficiency in that it influences the development of and access to the associated medical knowledge, procedural skills and crisis resource management (CRM) skills. Since performance assessment of CRM skills is challenging, self-efficacy is often used as a measure of competence in this area. While self-efficacy may influence performance, the true relationship between self-efficacy and performance in this setting has not been delineated. We developed an instrument to measure pediatric residents’ self-efficacy in CRM skills and assessed its content validity, internal structure, and relationship to other variables. After administering the instrument to 125 pediatric residents, critical care fellows and faculty, we performed an exploratory factor analysis within a confirmatory factor analysis as well as a known group comparison. The analyses specified four factors that we defined as: situation awareness, team management, environment management, and decision making. Pediatric residents reported lower self-efficacy than fellows and faculty in each factor. We also examined the correlation between self-efficacy and performance scores for a subset of 30 residents who led video recorded simulated resuscitations and had their performances rated by three observers. We found a significant, positive correlation between residents’ self-efficacy in situation awareness and environment management and their overall performance of CRM skills. Our findings suggest that in a specific context, self-efficacy as a form of self-assessment may be informative with regards to performance

    Living at home after emergency hospital admission:prospective cohort study in older adults with and without cognitive spectrum disorder

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    Background: Cognitive spectrum disorders (CSDs) are common in hospitalised older adults and associated with adverse outcomes. Their association with the maintenance of independent living has not been established. The aim was to establish the role of CSDs on the likelihood of living at home 30 days after discharge or being newly admitted to a care home. Methods: A prospective cohort study with routine data linkage was conducted based on admissions data from the acute medical unit of a district general hospital in Scotland. 5570 people aged ≥ 65 years admitted from a private residence who survived to discharge and received the Older Persons Routine Acute Assessment (OPRAA) during an incident emergency medical admission were included. The outcome measures were living at home, defined as a private residential address, 30 days after discharge and new care home admission at hospital discharge. Outcomes were ascertained through linkage to routine data sources. Results: Of the 5570 individuals admitted from a private residence who survived to discharge, those without a CSD were more likely to be living at home at 30 days than those with a CSD (93.4% versus 81.7%; difference 11.7%, 95%CI 9.7–13.8%). New discharge to a care home affected 236 (4.2%) of the cohort, 181 (76.7%) of whom had a CSD. Logistic regression modelling identified that all four CSD categories were associated with a reduced likelihood of living at home and an increased likelihood of discharge to a care home. Those with delirium superimposed on dementia were the least likely to be living at home (OR 0.25), followed by those with dementia (OR 0.43), then unspecified cognitive impairment (OR 0.55) and finally delirium (OR 0.57). Conclusions: Individuals with a CSD are at significantly increased risk of not returning home after hospitalisation, and those with CSDs account for the majority of new admissions to care homes on discharge. Individuals with delirium superimposed on dementia are the most affected. We need to understand how to configure and deliver healthcare services to enable older people to remain as independent as possible for as long as possible and to ensure transitions of care are managed supportively

    A model for uranium, rhenium, and molybdenum diagenesis in marine sediments based on results from coastal locations

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    Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 73 (2009): 2938-2960, doi:10.1016/j.gca.2009.02.029.The purpose of this research is to characterize the mobilization and immobilization processes that control the authigenic accumulation of uranium (U), rhenium (Re) and molybdenum (Mo) in marine sediments. We analyzed these redox– sensitive metals (RSM) in benthic chamber, pore water and solid phase samples at a site in Buzzards Bay, Massachusetts, U.S.A., which has high bottom water oxygen concentrations (230–300 mol/L) and high organic matter oxidation rates (390 mol C/cm2/y). The oxygen penetration depth varies from 2–9 mm below the sediment–water interface, but pore water sulfide is below detection (< 2M). The RSM pore water profiles are modeled with a steady–state diagenetic model that includes irrigation, which extends 10–20 cm below the sediment–water interface. To present a consistent description of trace metal diagenesis in marine sediments, RSM results from sediments in Buzzards Bay are compared with previous research from sulfidic sediments (Morford et al., GCA 71). Release of RSM to pore waters during the remineralization of solid phases occurs near the sediment–water interface at depths above the zone of authigenic RSM formation. This release occurs consistently for Mo at both sites, but only in the winter for Re in Buzzards Bay and intermittently for U. At the Buzzards Bay site, Re removal to the solid phase extends to the bottom of the profile, while the zone of removal is restricted to ~2–9 cm for U and Mo. Authigenic Re formation is independent of the anoxic remineralization rate, which is consistent with an abiotic removal mechanism. The rate of authigenic U formation and its modeled removal rate constant increase with increasing anoxic remineralization rates, and is consistent with U reduction being microbially mediated. Authigenic Mo formation is related to the formation of sulfidic microenvironments. The depth and extent of Mo removal from pore water is closely associated with the balance between iron and sulfate reduction and the consumption of pore water sulfide via iron sulfide formation. Pore water RSM reach constant asymptotic concentrations in sulfidic sediments, but only pore water Re is constant at depth in Buzzards Bay. The increases in pore water U at the Buzzards Bay site are consistent with addition via irrigation and subsequent upward diffusion to the removal zone. Deep pore water Mo concentrations exceed its bottom water concentration due to irrigation–induced oxidation and remobilization from the solid phase. In sulfidic sediments, there is no evidence for higher pore water U or Mo concentrations at depth due to the absence of irrigation and/or the presence of more stable authigenic RSM phases. There are good correlations between benthic fluxes and authigenic accumulation rates for U and Mo in sulfidic sediments. However, results from Buzzards Bay suggest irrigation ultimately results in the partial loss of U and Mo from the solid phase, with accumulation rates that are 20–30% of the modeled flux. Irrigation can augment (Re, possibly U) or compromise (U, Mo) authigenic accumulation in sediments, and is important when determining burial rates in continental margin sediments.The authors also acknowledge financial support from the National Science Foundation (JLM, WRM: OCE–0220892), Research Corporation (JLM, CMC), Franklin & Marshall College, and the Hackman Summer Research Program at F&M

    The Rapid ASKAP Continuum Survey III: Spectra and Polarisation In Cutouts of Extragalactic Sources (SPICE-RACS) first data release

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    The Australian SKA Pathfinder (ASKAP) radio telescope has carried out a survey of the entire Southern Sky at 887.5 MHz. The wide area, high angular resolution, and broad bandwidth provided by the low-band Rapid ASKAP Continuum Survey (RACS-low) allow the production of a next-generation rotation measure (RM) grid across the entire Southern Sky. Here we introduce this project as Spectral and Polarisation in Cutouts of Extragalactic sources from RACS (SPICE-RACS). In our first data release, we image 30 RACS-low fields in Stokes I, Q, U at 25" angular resolution, across 744-1032 MHz with 1 MHz spectral resolution. Using a bespoke, highly parallelised, software pipeline we are able to rapidly process wide-area spectro-polarimetric ASKAP observations. Notably, we use `postage stamp' cutouts to assess the polarisation properties of 105912 radio components detected in total intensity. We find that our Stokes Q and U images have an rms noise of ∼ 80 μJy PSF-1, and our correction for instrumental polarisation leakage allows us to characterise components with ≳ 1% polarisation fraction over most of the field of view. We produce a broadband polarised radio component catalogue that contains 5818 RM measurements over an area of ∼ 1300 deg2 with an average error in RM of 1.6+1.1-1.0 rad m-2, and an average linear polarisation fraction 3.4+3.0-1.6%. We determine this subset of components using the conditions that the polarised signal-to-noise ratio is > 8, the polarisation fraction is above our estimated polarised leakage, and the Stokes I spectrum has a reliable model. Our catalogue provides an areal density of 4±2 RMs deg-2; an increase of ∼ 4 times over the previous state-of-the-art (Taylor, Stil, Sunstrum 2009, ApJ, 702, 1230). Meaning that, having used just 3% of the RACS-low sky area, we have produced the 3rd largest RM catalogue to date. This catalogue has broad applications for studying astrophysical magnetic fields; notably revealing remarkable structure in the Galactic RM sky. We will explore this Galactic structure in a follow-up paper. We will also apply the techniques described here to produce an all-Southern-sky RM catalogue from RACS observations. Finally, we make our catalogue, spectra, images, and processing pipeline publicly available
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