1,225 research outputs found
Gibson -Brydon , Thomas R. C. – The Moral Mapping of Victorian and Edwardian London. Charles Booth, Christian Charity, and the Poor-but-Respectable.
Multi-fluid cosmology: An illustration of fundamental principles
Our current understanding of the Universe depends on the interplay of several
distinct "matter" components, which interact mainly through gravity, and
electromagnetic radiation. The nature of the different components, and possible
interactions, tends to be based on the notion of coupled perfect fluids (or
scalar fields). This approach is somewhat naive, especially if one wants to be
able to consider issues involving heat flow, dissipative mechanisms, or
Bose-Einstein condensation of dark matter. We argue that a more natural
starting point would be the multi-purpose variational relativistic multi-fluid
system that has so far mainly been applied to neutron star astrophysics. As an
illustration of the fundamental principles involved, we develop the formalism
for determining the non-linear cosmological solutions to the Einstein equations
for a general relativistic two-fluid model for a coupled system of matter
(non-zero rest mass) and "radiation" (zero rest mass). The two fluids are
allowed to interpenetrate and exhibit a relative flow with respect to each
other, implying, in general, an anisotropic Universe. We use initial conditions
such that the massless fluid flux dominates early on so that the situation is
effectively that of a single fluid and one has the usual
Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime. We find that there is a
Bianchi I transition epoch out of which the matter flux dominates. The
situation is then effectively that of a single fluid and the spacetime evolves
towards the FLRW form. Such a transition opens up the possibility of imprinting
observable consequences at the specific scale corresponding to the transition
time.Comment: 12 pages, 6 figures, version taking account of referee remark
Forward-Backward Correlations and Event Shapes as probes of Minimum-Bias Event Properties
Measurements of inclusive observables, such as particle multiplicities and
momentum spectra, have already delivered important information on
soft-inclusive ("minimum-bias") physics at the Large Hadron Collider. In order
to gain a more complete understanding, however, it is necessary to include also
observables that probe the structure of the studied events. We argue that
forward-backward (FB) correlations and event-shape observables may be
particulary useful first steps in this respect. We study the sensitivity of
several different types of FB correlations and two event shape variables -
transverse thrust and transverse thrust minor - to various sources of
theoretical uncertainty: multiple parton interactions, parton showers, colour
(re)connections, and hadronization. The power of each observable to furnish
constraints on Monte Carlo models is illustrated by including comparisons
between several recent, and qualitatively different, PYTHIA 6 tunes, for pp
collisions at sqrt(s) = 900 GeV.Comment: 13 page
Long QT syndrome is associated with an increased burden of diabetes, psychiatric and neurological comorbidities:A nationwide cohort study
A Scheme to Numerically Evolve Data for the Conformal Einstein Equation
This is the second paper in a series describing a numerical implementation of
the conformal Einstein equation. This paper deals with the technical details of
the numerical code used to perform numerical time evolutions from a "minimal"
set of data.
We outline the numerical construction of a complete set of data for our
equations from a minimal set of data. The second and the fourth order
discretisations, which are used for the construction of the complete data set
and for the numerical integration of the time evolution equations, are
described and their efficiencies are compared. By using the fourth order scheme
we reduce our computer resource requirements --- with respect to memory as well
as computation time --- by at least two orders of magnitude as compared to the
second order scheme.Comment: 20 pages, 12 figure
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Influence of volcanic eruptions on midlatitude upper tropospheric aerosol and consequences for cirrus clouds
The influence of downwelling stratospheric sulfurous aerosol on the UT (upper troposphere) aerosol concentrations and on cirrus clouds is investigated using CARIBIC (Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrument Container observations) (between 1999–2002 and 2005–2013) and the cirrus reflectance product from Moderate Resolution Imaging Spectroradiometer (MODIS). The initial period, 1999–2002, was volcanically quiescent after which the sulfurous aerosol in the LMS (lowermost stratosphere) (SLMS) became enhanced by several volcanic eruptions starting 2005. From 2005 to 2008 and in 2013, volcanic aerosol from several tropical eruptions increased SLMS. Due to consequent subsidence, the sulfur loading of the upper troposphere (SUT) was increased by a factor of 2.5 compared to background levels. Comparison of SLMS and SUT during the seasons March–July and August–November shows a close coupling of the UT and LMS. Finally, the relationship between SLMS and the cirrus cloud reflectance (CR) retrieved from MODIS spectrometer (on board the satellites Terra and Aqua) is studied. SLMS and CR show a strong anticorrelation, with a factor of 3.5 increase in SLMS and decrease of CR by 8 ± 2% over the period 2001–2011. We propose that the increase of SLMS due to volcanism has caused the coinciding cirrus CR decrease, which would be associated with a negative radiative forcing in the Northern Hemisphere midlatitudes
Influence of volcanic eruptions on midlatitude upper tropospheric aerosol and consequences for cirrus clouds – Volc Affects S Aerosol in UT and Cirrus
The influence of downwelling stratospheric sulfurous aerosol on the UT (upper troposphere) aerosol concentrations and on cirrus clouds is investigated using CARIBIC (Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrument Container observations) (between 1999–2002 and 2005–2013) and the cirrus reflectance product from Moderate Resolution Imaging Spectroradiometer (MODIS). The initial period, 1999–2002, was volcanically quiescent after which the sulfurous aerosol in the LMS (lowermost stratosphere) (S) became enhanced by several volcanic eruptions starting 2005. From 2005 to 2008 and in 2013, volcanic aerosol from several tropical eruptions increased S. Due to consequent subsidence, the sulfur loading of the upper troposphere (S) was increased by a factor of 2.5 compared to background levels. Comparison of SLMS and S during the seasons March–July and August–November shows a close coupling of the UT and LMS. Finally, the relationship between S and the cirrus cloud reflectance (CR) retrieved from MODIS spectrometer (on board the satellites Terra and Aqua) is studied. S and CR show a strong anticorrelation, with a factor of 3.5 increase in SLMS and decrease of CR by 8 ± 2% over the period 2001–2011. We propose that the increase of S due to volcanism has caused the coinciding cirrus CR decrease, which would be associated with a negative radiative forcing in the Northern Hemisphere midlatitudes
Open Charm Production in an Equilibrating Parton Plasma
Open charm production during the equilibration of a gluon dominated parton
plasma is calculated, with both the time-dependent temperature and parton
densities given by a set of rate equations. Including pre-thermal production,
the total enhancement of open charm production over the initial gluon fusion
depends sensitively on the initial parton density and the effective
temperature. The dependence of the pre-thermal charm production on the
space-momentum correlation in the initial parton phase-space distribution is
also discussed.Comment: 23 pages REVTEX, 7 uuencoded postscript figures include
Effects of oral glucose-lowering drugs on long term outcomes in patients with diabetes mellitus following myocardial infarction not treated with emergent percutaneous coronary intervention - a retrospective nationwide cohort study
<p>Abstract</p> <p>Background</p> <p>The optimum oral pharmacological treatment of diabetes mellitus to reduce cardiovascular disease and mortality following myocardial infarction has not been established. We therefore set out to investigate the association between individual oral glucose-lowering drugs and cardiovascular outcomes following myocardial infarction in patients with diabetes mellitus not treated with emergent percutaneous coronary intervention.</p> <p>Materials and methods</p> <p>All patients aged 30 years or older receiving glucose-lowering drugs (GLDs) and admitted with myocardial infarction (MI) not treated with emergent percutaneous coronary intervention in Denmark during 1997-2006 were identified by individual-level linkage of nationwide registries of hospitalizations and drug dispensing from pharmacies. Multivariable Cox regression models adjusted for age, sex, calendar year, comorbidity, and concomitant pharmacotherapy were used to assess differences in the composite endpoint of non-fatal MI and cardiovascular mortality between individual GLDs, using metformin monotherapy as reference.</p> <p>Results</p> <p>The study comprised 9876 users of GLDs admitted with MI. The mean age was 72.3 years and 56.5% of patients were men. A total of 3649 received sulfonylureas and 711 received metformin at admission. The average length of follow-up was 2.2 (SD 2.6) years. A total of 6,171 patients experienced the composite study endpoint. The sulfonylureas glibenclamide, glimepiride, glipizide, and tolbutamide were associated with increased risk of cardiovascular mortality and/or nonfatal MI with hazard ratios [HRs] of 1.31 (95% confidence interval [CI] 1.17-1.46), 1.19 (1.06-1.32), 1.25 (1.11-1.42), and 1.18 (1.03-1.34), respectively, compared with metformin. Gliclazide was the only sulfonylurea not associated with increased risk compared with metformin (HR 1.03 [0.88-1.22]).</p> <p>Conclusions</p> <p>In patients with diabetes mellitus admitted with MI not treated with emergent percutaneous coronary intervention, monotherapy treatment with the sulfonylureas glibenclamide, glimepiride, glipizide, and tolbutamide was associated with increased cardiovascular risk compared with metformin monotherapy.</p
Temporal trends in the initiation of glucose-lowering medications after a first-time myocardial infarction - a nationwide study between 1997 and 2006
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