137 research outputs found

    Sulfur Dioxide From the Atmospheric Chemistry Experiment Satellite

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    The version 4.0 dataset from the Atmospheric Chemistry Experiment – Fourier Transform Spectrometer (ACE-FTS) on SCISAT, released in March of 2019, has sulfur dioxide (SO2) volume mixing ratio (VMR) profiles as a routine data product. From this dataset, global SO2 distributions between the altitudes of 10.5 km and 23.5 km are analyzed. The global distribution of all SO2 VMR data by altitude is broken down into 30° and 5° latitude zones. Seasonality of the global SO2 distribution is explored. Volcanic SO2 plumes are isolated in the dataset and compared with extinction data from the ACE-FTS Imager.https://digitalcommons.odu.edu/gradposters2020_sciences/1005/thumbnail.jp

    Bootstrap-Based Improvements for Inference with Clustered Errors

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    Microeconometrics researchers have increasingly realized the essential need to account for any within-group dependence in estimating standard errors of regression parameter estimates. The typical preferred solution is to calculate cluster-robust or sandwich standard errors that permit quite general heteroskedasticity and within-cluster error correlation, but presume that the number of clusters is large. In applications with few (5-30) clusters, standard asymptotic tests can over-reject considerably. We investigate more accurate inference using cluster bootstrap-t procedures that provide asymptotic refinement. These procedures are evaluated using Monte Carlos, including the much-cited differences-in-differences example of Bertrand, Mullainathan and Duflo (2004). In situations where standard methods lead to rejection rates in excess of ten percent (or more) for tests of nominal size 0.05, our methods can reduce this to five percent. In principle a pairs cluster bootstrap should work well, but in practice a Wild cluster bootstrap performs better.clustered errors; random effects; cluster robust; sandwich; bootstrap; bootstrap-t; clustered bootstrap; pairs bootstrap; wild bootstrap.

    Uncovering phantom shocks in cardiac patients with an implantable cardioverter defibrillator

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    Background: Implantable cardioverter defibrillator recipients sometimes report “phantom shocks” (PSs), defined as a reported shock lacking objective evidence. The aim of this study was to describe the subjective experience of PSs and their psychosocial correlates using a mixed methods approach. Methods: PS participants were matched on sex and age with individuals who received objective shocks only (OSO). Participants were interviewed and completed measures of posttraumatic stress disorder (PTSD Checklist—Civilian Version), depression and anxiety (Hospital Anxiety and Depression Scale), disease-specific distress (Cardiac Anxiety Questionnaire—CAQ), and social desirability (Socially Desirable Response Set—SDRS). Interviews were analyzed using interpretative phenomenological analysis (IPA). Results: Seventeen male patients participated (PS: n = 9; OSO: n = 8). Three themes emerged from IPA: (1) PS as a somatic experience, (2) the emotional impact of PSs, and (3) searching for meaning. Quantitative analyses showed that both groups exhibited elevated trauma and anxiety levels. Effect size differences (ESD) suggested a medium ESD on depression (P = 0.176, ηp 2 = 0.118) and PTSD (avoidance: P = 0.383, ηp 2 = 0.055, numbing: P = 0.311, ηp 2 = 0.068), and a large ESD on SDRS (P = 0.081, ηp 2 = 0.189), where PS participants, comparatively, exhibited elevated levels. A medium ESD was detected on CAQ-fear (P = 0.237, ηp 2 = 0.092) where OSO participants exhibited greater heart-focused worry. Conclusion: The qualitative and quantitative findings of this mixed method study show convergence in terms of the emotional factors associated with the experience of PSs. PSs are often reported to be indistinguishable from objective shocks, evoking alarm, frustration, and confusion, forcing the individual to face the uncertainties of what to them is a novel and confusing experience. (PACE 2013; 36:673–683)This study has not been funded by any source. AB was supported by an Ontario Graduate Scholarship. Dr. Kovacs has received speaking engagement honoraria from Medtronic Inc. Dr. Katz is supported by the Canadian Institutes of Health Research Canada Research Chair in Health Psychology. This paper is derived, in part, from the first author’s Master’s thesis

    The ALLEGRO trial : a placebo controlled randomised trial of intravenous lidocaine in accelerating gastrointestinal recovery after colorectal surgery

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    Acknowledgements The authors wish to acknowledge the following persons who have helped deliver the ALLEGRO trial: the programming team based in the Centre for Healthcare Randomised Trials, for their work in developing the study web portal; Sharon Wren and Zoe Batham for their administrative support; ACCORD in Edinburgh; the Perioperative Medicine Clinical Trials Network (POMCTN) for adopting the trial for promotion; and the local recruiting teams and participants. We are also indebted to the late Professor Kenneth Fearon, University of Edinburgh, for protocol development and study design. The views and opinions expressed herein are those of the authors and do not necessarily reflect those of the Health Technology Assessment Programme, National Institute for Health Research (NIHR), NHS or the Department of Health. Funding The trial is funded by the NIHR Health and Technology Assessment programme, project number 15/130/95. The funding body had no role in the design of the study, collection of data or the writing of this paper, nor will the funding body have a role in analysis, interpretation of data or in writing future manuscripts. The co-sponsors are University of Edinburgh & Lothian Health Board (AC- CORD), The Queen’s Medical Research Institute, 47 Little France Crescent, Ed- inburgh EH16 4TJ.Peer reviewedPublisher PD

    Haloes gone MAD: The Halo-Finder Comparison Project

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    [abridged] We present a detailed comparison of fundamental dark matter halo properties retrieved by a substantial number of different halo finders. These codes span a wide range of techniques including friends-of-friends (FOF), spherical-overdensity (SO) and phase-space based algorithms. We further introduce a robust (and publicly available) suite of test scenarios that allows halo finder developers to compare the performance of their codes against those presented here. This set includes mock haloes containing various levels and distributions of substructure at a range of resolutions as well as a cosmological simulation of the large-scale structure of the universe. All the halo finding codes tested could successfully recover the spatial location of our mock haloes. They further returned lists of particles (potentially) belonging to the object that led to coinciding values for the maximum of the circular velocity profile and the radius where it is reached. All the finders based in configuration space struggled to recover substructure that was located close to the centre of the host halo and the radial dependence of the mass recovered varies from finder to finder. Those finders based in phase space could resolve central substructure although they found difficulties in accurately recovering its properties. Via a resolution study we found that most of the finders could not reliably recover substructure containing fewer than 30-40 particles. However, also here the phase space finders excelled by resolving substructure down to 10-20 particles. By comparing the halo finders using a high resolution cosmological volume we found that they agree remarkably well on fundamental properties of astrophysical significance (e.g. mass, position, velocity, and peak of the rotation curve).Comment: 27 interesting pages, 20 beautiful figures, and 4 informative tables accepted for publication in MNRAS. The high-resolution version of the paper as well as all the test cases and analysis can be found at the web site http://popia.ft.uam.es/HaloesGoingMA

    Crop Updates 2011 - Farming Systems

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    This session covers twelve papers from different authors: 1. Fallowing 50% of the farm each year – does it pay? Janette Drew and Rob Grima Department of Agriculture and Food 2. How crop sequences affect the productivity and resilience of cropping systems in two Western Australian environments, Bob French, Raj Malik, Mark Seymour, Department of Agriculture and Food 3. When is continuous wheat or barley sustainable? Christine Zaicou-Kunesch and Rob Grima Department of Agriculture and Food 4. Identifying constraints to bridging the yield gap, Glenn McDonald, Department of Agriculture and Food 5. Land constraints limiting wheat yields in the Bridging the Yield Gap project area, Brendan Nicholas and Dennis van Gool, Department of Agriculture and Food 6. Can livestock have a long-term role in no-till cropping systems? James Fisher1, Peter Tozer2, and Doug Abrecht3, 1DĂ©sirĂ©e Futures, York, WA, 2PRT Consulting, West Wyalong, NSW and 3Department of Agriculture and Food 7. Pros and cons of dry seeding to counter variable seasonal breaks, Michael Robertson1, Cameron Weeks2, Michael O’Connor1, Doug Abrecht3, Rob Grima3, Peter Newman3, 1CSIRO, 2PlanFarm, 3Department of Agriculture and Food 8. Defining economic optimum plant densities of open pollinated and hybrid canola in WA, Mark Seymour, Department of Agriculture and Food 9. Alternative uses for unproductive soils examined in the North Eastern Agricultural Region (NEAR), Mike Clarke and Andrew Blake, Department of Agriculture and Food MARKETS 10. What the world wants from Australian wheat, Gordon MacAulay, Principal Economist, BRI Australia, Emeritus Professor of Agricultural Economics, University of Sydney 11. Effect of lupin flour incorporation on the physical and sensory quality of pasta, Vijay Jayasena1,2 and Syed M. Nasar-Abbas1,2, 1Food Science and Technology, School of Public Health, Curtin Health Innovation Research Institute, Curtin University, 2Centre for Food and Genomic Medicine 12. Wheat quality requirements for Saudi Arabia: baking quality and blending potential of some Australian exporting grades, Larisa Cato1, Robert Loughman1 and Ken Quail2, 1Department of Agriculture and Food, 2BRI Australi

    First Sample of Hα\alpha+[O III] λ\lambda5007 Line Emitters at z>6z > 6 through JWST/NIRCam Slitless Spectroscopy: Physical Properties and Line Luminosity Functions

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    We present a sample of four emission-line galaxies at z=6.11−6.35z=6.11-6.35 that were serendipitously discovered using the commissioning data for the JWST/NIRCam wide-field slitless spectroscopy (WFSS) mode. One of them (at z=6.11z=6.11) has been reported previously while the others are new discoveries. These sources are selected by the secure detections of both [O III] λ\lambda5007 and Hα\alpha lines with other fainter lines tentatively detected in some cases (e.g., [O II] λ\lambda3727, [O III] λ\lambda4959 and [N II] λ\lambda6583). In the [O III]/HÎČ\beta - [N II]/Hα\alpha Baldwin-Phillips-Terlevich diagram, these galaxies occupy the same parameter space as that of z∌2z\sim2 star-forming galaxies, indicating that they have been enriched rapidly to sub-solar metallicities (∌\sim0.6 Z⊙Z_{\odot}), similar to galaxies with comparable stellar masses at much lower redshifts. The detection of strong Hα\alpha lines suggests a higher ionizing photon production efficiency within galaxies in the early Universe. We find brightening of the [O III] λ\lambda5007 line luminosity function (LF) from z=3z=3 to 6, and no or weak redshift evolution of the Hα\alpha line LF from z=2z=2 to 6. Both LFs are under-predicted at z∌6z\sim6 by a factor of ∌\sim10 in certain cosmological simulations. This further indicates a global Lyα\alpha photon escape fraction of 5-7% at z∌6z\sim6, much lower than previous estimates through the comparison of the UV-derived star-formation rate density and Lyα\alpha luminosity density. Our sample recovers 88−57+16488^{+164}_{-57}% of z=6.0−6.6z=6.0-6.6 galaxies in the survey volume with stellar masses greater than 5×1085\times10^8 M⊙M_{\odot}, suggesting the ubiquity of strong Hα\alpha and [O III] line emitters in the Epoch of Reionization, which will be further uncovered in the era of JWST.Comment: 25 pages, 11 figures, submitted to Ap

    Multiple and Multidimensional life transitions in the context of life-limiting health conditions:Longitudinal study focussing on perspectives of Young Adults, Families and Professionals

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    Background: There is a dearth of literature that investigates life transitions of young adults (YAs) with life-limiting conditions, families and professionals. The scant literature that is available has methodological limitations, including not listening to the voice of YAs, collecting data retrospectively, at one time point, from one group’s perspective and single case studies. The aim of this study was to address the gaps found in our literature review and provide a clearer understanding of the multiple and multi-dimensional life transitions experienced by YAs and significant others, over a period of time. Methods: This qualitative study used a longitudinal design and data were collected using semi-structured interviews over a 6-month period at 3 time points. Participants included 12 YAs with life-limiting conditions and their nominated significant others (10 family members and 11 professionals). Data were analysed using a thematic analysis approach. Results: Life transitions of YA and significant others are complex; they experience multiple and multi-dimensional transitions across several domains. The findings challenge the notion that all life transitions are triggered by health transitions of YAs, and has highlighted environmental factors (attitudinal and systemic) that can be changed to facilitate smoother transitions in various aspects of their lives. Conclusions: This study makes a unique and significant contribution to literature. It provides evidence and rich narratives for policy makers and service providers to change policies and practices that are in line with the needs of YAs with life-limiting conditions as they transition to adulthood. Families and professionals have specific training needs that have not yet been met fully

    Haloes gone MAD: The Halo-Finder Comparison Project

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    We present a detailed comparison of fundamental dark matter halo properties retrieved by a substantial number of different halo finders. These codes span a wide range of techniques including friends-of-friends, spherical-overdensity and phase-space-based algorithms. We further introduce a robust (and publicly available) suite of test scenarios that allow halo finder developers to compare the performance of their codes against those presented here. This set includes mock haloes containing various levels and distributions of substructure at a range of resolutions as well as a cosmological simulation of the large-scale structure of the universe. All the halo-finding codes tested could successfully recover the spatial location of our mock haloes. They further returned lists of particles (potentially) belonging to the object that led to coinciding values for the maximum of the circular velocity profile and the radius where it is reached. All the finders based in configuration space struggled to recover substructure that was located close to the centre of the host halo, and the radial dependence of the mass recovered varies from finder to finder. Those finders based in phase space could resolve central substructure although they found difficulties in accurately recovering its properties. Through a resolution study we found that most of the finders could not reliably recover substructure containing fewer than 30-40 particles. However, also here the phase-space finders excelled by resolving substructure down to 10-20 particles. By comparing the halo finders using a high-resolution cosmological volume, we found that they agree remarkably well on fundamental properties of astrophysical significance (e.g. mass, position, velocity and peak of the rotation curve). We further suggest to utilize the peak of the rotation curve, vmax, as a proxy for mass, given the arbitrariness in defining a proper halo edg
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