2,586 research outputs found
Non-additive response of the high-latitude Southern Hemisphere climate to aerosol forcing in a climate model with interactive chemistry
A suite of chemistryâclimate model simulations, forced by pairs of anthropogenic forcings [comprising greenhouse gases (GHGs), ozone depleting substances (ODSs), or aerosols], were employed to investigate whether the highâlatitude Southern Hemisphere (SH) circulation response to these forcings is linearly additive, a common assumption in attribution studies. We find that the geographical pattern of seaâlevel pressure (SLP) response to a combination of GHGs and ODSs is linearly additive. However, we find significant differences in the SLP response when combining GHGs and aerosols compared to the sum of the individual forcings, a nonâadditivity that is currently masked by the dominance of the ODSs forcing. This nonâlinearity also results in changes to the SH split jet. These results were obtained using a coupled chemistryâclimate model, indicating that the nonâlinear response is due to chemical interactions between the forcing agents. As such, future simulations investigating a postâozone hole Southern Hemisphere climate should consider this chemical interaction
The evolution of submillimetre galaxies: two populations and a redshift cut-off
We explore the epoch dependence of number density and star-formation rate for
submillimetre galaxies (SMGs) found at 850 um. The study uses a sample of 38
SMG in the GOODS-N field, for which cross-waveband identifications have been
obtained for 35/38 members together with redshift measurements or estimates. A
maximum-likelihood analysis is employed, along with the `single-source-survey'
technique. We find a diminution in both space density and star formation rate
at z > 3, closely mimicking the redshift cut-offs found for QSOs selected in
different wavebands. The diminution in redshift is particularly marked, at a
significance level too small to measure. The data further suggest, at a
significance level of about 0.001, that two separately-evolving populations may
be present, with distinct luminosity functions. These results parallel the
different evolutionary behaviours of LIRGs and ULIRGs, and represent another
manifestation of `cosmic down-sizing', suggesting that differential evolution
extends to the most extreme star-forming galaxies.Comment: 12 pages, 11 figures, MNRAS accepted. The new version, as accepted
for MNRAS, is substantially revised, with more detail on sample selection as
well as extended significance tests of the result
The Spectral Energy Distributions and Infrared Luminosities of z \approx 2 Dust Obscured Galaxies from Herschel and Spitzer
Dust-obscured galaxies (DOGs) are a subset of high-redshift (z \approx 2)
optically-faint ultra-luminous infrared galaxies (ULIRGs, e.g. L_{IR} > 10^{12}
Lsun). We present new far-infrared photometry, at 250, 350, and 500 um
(observed-frame), from the Herschel Space Telescope for a large sample of 113
DOGs with spectroscopically measured redshifts. Approximately 60% of the sample
are detected in the far-IR, confirming their high IR luminosities, which range
from 10^{11.6} Lsun < L_{IR} (8-1000 um) <10^{13.6} Lsun. 90% of the Herschel
detected DOGs in this sample are ULIRGs and 30% have L_{IR} > 10^{13} Lsun. The
rest-frame near-IR (1 - 3 um) SEDs of the Herschel detected DOGs are predictors
of their SEDs at longer wavelengths. DOGs with "power-law" SEDs in the
rest-frame near-IR show observed-frame 250/24 um flux density ratios similar to
the QSO-like local ULIRG, Mrk 231. DOGs with a stellar "bump" in their
rest-frame near-IR show observed-frame 250/24 um flux density ratios similar to
local star-bursting ULIRGs like NGC 6240. For the Herschel detected DOGs,
accurate estimates (within \approx 25%) of total IR luminosity can be predicted
from their rest-frame mid-IR data alone (e.g. from Spitzer observed-frame 24 um
luminosities). Herschel detected DOGs tend to have a high ratio of infrared
luminosity to rest-frame 8 um luminosity (the IR8= L_{IR}(8-1000 um)/v L_{v}(8
um) parameter of Elbaz et al. 2011). Instead of lying on the z=1-2 "infrared
main-sequence" of star forming galaxies (like typical LIRGs and ULIRGs at those
epochs) the DOGs, especially large fractions of the bump sources, tend to lie
in the starburst sequence. While, Herschel detected DOGs are similar to scaled
up versions of local ULIRGs in terms of 250/24 um flux density ratio, and IR8,
they tend to have cooler far-IR dust temperatures (20-40 K for DOGs vs. 40-50 K
for local ULIRGs). Abridged.Comment: 24 pages, 14 figures, 3 tables, accepted for publication in the
Astronomical Journa
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Implementation of influenza point-of-care-testing and patient-cohorting during a high-incidence season: a retrospective analysis of impact on infection prevention and control and clinical outcomes.
BACKGROUND: During high-incidence influenza seasons, a robust infection prevention and control policy is imperative to reduce nosocomial transmission of influenza. AIM: To assess the impact of Emergency Department (ED) influenza point-of-care-testing (POCT) and influenza-ward patient-cohorting on infection prevention and control and clinical outcomes. METHODS: Influenza POCT was operational in our adult ED from 21st January 2018 and an influenza-ward from 25th January 2018. A retrospective 'before-after' analysis was performed with pre-intervention defined as 1st November 2017-20th January 2018 and post-intervention 21st January-30th April 2018. Primary outcome was rate of hospital-acquired influenza (HAI). Secondary outcomes included antiviral prescription and length of stay. The length of time inpatients remain influenza RNA detected by polymerase chain reaction (PCR) was also analysed
Strengthening impact assessment: a call for integration and focus
We suggest that the impact assessment community has lost its way based on our observation that impact assessment is under attack because of a perceived lack of efficiency. Specifically, we contend that the proliferation of different impact assessment types creates separate silos of expertise and feeds arguments for not only a lack of efficiency but also a lack of effectiveness of the process through excessive specialisation and a lack of interdisciplinary practice. We propose that the solution is a return to the basics of impact assessment with a call for increased integration around the goal of sustainable development and focus through better scoping. We rehearse and rebut counter arguments covering silo-based expertise, advocacy, democracy, sustainability understanding and communication. We call on the impact assessment community to rise to the challenge of increasing integration and focus, and to engage in the debate about the means of strengthening impact assessment
Particulate matter air pollution and national and county life expectancy loss in the USA: a spatiotemporal analysis
Background Exposure to fine particulate matter pollution (PM2.5) is hazardous to health. Our aim was to directly estimate the health and longevity impacts of current PM2.5 concentrations, and the benefits of reductions from 1999 to 2015, nationally and at county level, for the entire contemporary population of the contiguous United States. Methods and findings We used vital registration and population data with information on sex, age, cause of death and county of residence. We used four Bayesian spatio-temporal models, with different adjustments for other determinants of mortality, to directly estimate mortality and life expectancy loss due to current PM2.5 pollution, and the benefits of reductions since 1999, nationally and by county. The covariates included in the adjusted models were per capita income; percentage of population whose family income is below the poverty threshold, who are of Black or African American race, who have graduated from high-school, who live in urban areas, and who are unemployed; cumulative smoking; and mean temperature and relative humidity. In the main model, which adjusted for these covariates and for unobserved county characteristics through the use of county random intercepts, PM2.5 pollution in excess of the lowest observed concentration (2.8 ”g/m3) was responsible for an estimated 15,612 deaths (95% credible interval 13,248-17,945) in females and in 14,757 deaths (12,617-16,919) for males. These deaths would lower national life expectancy by an estimated 0.15 years (0.13-0.17) for women and 0.13 years (0.11-0.15) for men. The life expectancy loss due to PM2.5 was largest around Los Angeles and in some southern states, such as Arkansas, Oklahoma or Alabama. At any PM2.5 concentration, life expectancy loss was, on average, larger in counties with lower income than in wealthier counties. Reductions in PM2.5 since 1999 have lowered mortality in all but 14 counties where PM2.5 increased slightly. The main limitation of our study, similar to other observational studies, is that it is not guaranteed for the observed associations to be causal. We did not have annual county-level data on other important determinants of mortality, such as healthcare access and quality and diet, but these factors were adjusted for with use of county random intercepts. Conclusions According to our estimates, recent reductions in particulate matter pollution in the USA have resulted in public health benefits. Nonetheless, we estimate that current concentrations are associated with mortality impacts and loss of life expectancy, with larger impacts in counties with lower income and higher poverty rate
Mortality and sexuality after diagnosis of penile cancer: A participative study
Objectives: Survival for penile cancer is high but treatment can have a long-term detrimental effect on urological function and quality of life. Due to its rarity, it is difficult to include men with penile cancer in research about their condition. The aim of this study was to identify aspects of their diagnosis and treatment that they would want explored in penile cancer research. Â Â Design: The study employed a participative, mixed-qualitative-methods design; it utilised focus groups and patient-conducted interviews, combined into a one-day âpilot workshopâ. The data were analysed using framework analysis. Â Results: âEarly signs and seeking helpâ, âdisclosure of a âpersonalâ cancerâ and âurological (dys)functionâ emerged as three key themes. Â Conclusions: Men with penile cancer want research about their condition to explore early signs and helping seeking, disclosure of a âpersonalâ cancer and urological (dys)function. Research could use methodologies that include consideration of the chronological narrative of the experiences of men with penile cancer, which could be applied in clinical practice by integrating opportunities to explore specific aspects of their experiences at appropriate times along the care pathway
A Two Zone Synchrotron Model for the Knots in the M87 Jet
The flux and the spectral index in X-ray energy band from the knots of M87
jet as observed by {\it{Chandra}} indicate a possible synchrotron origin but
cannot be explained by simple one zone models with continuous injection of
non-thermal electrons. In this letter we propose a two-zone model to explain
the observed spectra of the knots of M87 jet. We consider the synchrotron
emission from a region with tangled magnetic field where relativistic
non-thermal electrons are continuously injected in from an associated
acceleration region. The acceleration region is assumed to be compact zone
possibly around a shock front. A power-law distribution of electron is injected
into the acceleration region and are accelerated to a maximum energy determined
by the acceleration time scale and the loss processes. With the present model
we are able to explain the overall broadband features of the knots of M87 jet.
Also the present model predicts a change in spectral index at ultraviolet
energies and future observations at these energies can be used to constrain the
parameters involved in the model.Comment: 5 pages, 1 figure, typos correcte
Unprecedented springtime retreat of Antarctic sea ice in 2016
During austral spring 2016 Antarctic sea ice extent (SIE) decreased at a record rate of 75 x 10(3) km(2) d(-1), which was 46% faster than the mean rate and 18% faster than in any previous spring season during the satellite era. The decrease of sea ice area was also exceptional and 28% greater than the mean. Anomalous negative retreat occurred in all sectors of the Antarctic but was greatest in the Weddell and Ross Seas. Record negative SIE anomalies for the day of year were recorded from 3 November 2016 to 9 April 2017. Rapid ice retreat in the Weddell Sea took place in strong northerly flow after an early maximum ice extent in late August. Rapid ice retreat occurred in November in the Ross Sea when surface pressure was at a record high level, with the Southern Annular Mode at its most negative for that month since 1968
Jackson County Community Health Improvement Plan
This CHIP is a product of the Schneck Medical Center Community Health Needs Assessment, a Community Conversation event, and many workgroup and taskforce meetings. As a result of the latter, the significant needs in Jackson County were identified as: Access to Care, Tobacco and Substance Use, Nutrition, Physical Activity and Weight, and Mental Health. The CHIPâs goals and strategies address these needs by building partnerships with organizations and leaders established in the community who influence the environment of health in Jackson County
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