1,713 research outputs found
Do early-life exposures explain why more advantaged children get eczema? Findings from the U.K. Millennium Cohort Study
Background:
Atopic dermatitis (eczema) in childhood is socially patterned, with higher incidence in more advantaged populations. However, it is unclear what factors explain the social differences.
Objectives:
To identify early-life risk factors for eczema, and to explore how early-life risk factors explain any differences in eczema.
Methods:
We estimated odds ratios (ORs) for ever having had eczema by age 5 years in 14 499 children from the U.K. Millennium Cohort Study (MCS), with a focus on maternal, antenatal and early-life risk factors and socioeconomic circumstances (SECs). Risk factors were explored to assess whether they attenuated associations between SECs and eczema.
Results:
Overall 35·1% of children had ever had eczema by age 5 years. Children of mothers with degree-level qualifications vs. no educational qualifications were more likely to have eczema (OR 1·52, 95% confidence interval 1·31–1·76), and there was a gradient across the socioeconomic spectrum. Maternal atopy, breastfeeding (1–6 weeks and ≥ 6 months), introduction of solids under 4 months or cow's milk under 9 months, antibiotic exposure in the first year of life and grime exposure were associated with an increased odds of having eczema. Female sex, Pakistani and Bangladeshi ethnicity, smoking during pregnancy, exposure to environmental tobacco smoke and having more siblings were associated with reduced odds for eczema. Controlling for maternal, antenatal and early-life characteristics (particularly maternal smoking during pregnancy, breastfeeding and number of siblings) reduced the OR for eczema to 1·26 (95% confidence interval 1·03–1·50) in the group with the highest educational qualifications compared with the least.
Conclusions:
In a representative U.K. child cohort, eczema was more common in more advantaged children. This was explained partially by early-life factors including not smoking during pregnancy, breastfeeding and having fewer siblings
On Hawking's Local Rigidity Theorems for Charged Black Holes
We show the existence of a Hawking vector field in a full neighborhood of a
local, regular, bifurcate, non-expanding horizon embedded in a smooth
Einstein-Maxwell space-time without assuming the underlying space-time is
analytic. It extends one result of Friedrich, R\'{a}cz and Wald, which was
limited to the interior of the black hole region. Moreover, we also show, in
the presence of an additional Killing vector field which tangent to the
horizon and not vanishing on the bifurcate sphere, then space-time must be
locally axially symmetric without the analyticity assumption. This axial
symmetry plays a fundamental role in the classification theory of stationary
black holes.Comment: 20 page
Galois theory and Lubin-Tate cochains on classifying spaces
We consider brave new cochain extensions F(BG +,R) → F(EG +,R), where R is either a Lubin-Tate spectrum E n or the related 2-periodic Morava K-theory K n , and G is a finite group. When R is an Eilenberg-Mac Lane spectrum, in some good cases such an extension is a G-Galois extension in the sense of John Rognes, but not always faithful. We prove that for E n and K n these extensions are always faithful in the K n local category. However, for a cyclic p-group C p r, the cochain extension F(BC p r +,E n ) → F(EC p r +, E n ) is not a Galois extension because it ramifies. As a consequence, it follows that the E n -theory Eilenberg-Moore spectral sequence for G and BG does not always converge to its expected target
Use of cumulative mortality data in patients with acute myocardial infarction for early detection of variation in clinical practice: observational study
OBJECTIVES: Use of cumulative mortality adjusted for
case mix in patients with acute myocardial infarction
for early detection of variation in clinical practice.
DESIGN: Observational study.
SETTING: 20 hospitals across the former Yorkshire
region.
PARTICIPANTS: All 2153 consecutive patients with
confirmed acute myocardial infarction identified
during three months.
MAIN OUTCOME MEASURES: Variable lifeadjusted
displays showing cumulative differences between
observed and expected mortality of patients; expected
mortality calculated from risk model based on
admission characteristics of age, heart rate, and
systolic blood pressure.
RESULTS: The performance of two individual hospitals
over three months was examined as an example. One,
the smallest district hospital in the region, had a series
of 30 consecutive patients but had five more deaths
than predicted. The variable lifeadjusted display
showed minimal variation from that predicted for the
first 15 patients followed by a run of unexpectedly
high mortality. The second example was the main
tertiary referral centre for the region, which admitted
188 consecutive patients. The display showed a period
of apparently poor performance followed by
substantial improvement, where the plot rose steadily
from a cumulative net lives saved of - 4 to 7. These
variations in patient outcome are unlikely to have
been revealed during conventional audit practice.
CONCLUSIONS: Variable lifeadjusted display has been
integrated into surgical care as a graphical display of
riskadjusted survival for individual surgeons or centres.
In combination with a simple risk model, it may have a
role in monitoring performance and outcome in
patients with acute myocardial infarction
The quadratic spinor Lagrangian is equivalent to the teleparallel theory
The quadratic spinor Lagrangian is shown to be equivalent to the teleparallel
/ tetrad representation of Einstein's theory. An important consequence is that
the energy-momentum density obtained from this quadratic spinor Lagrangian is
essentially the same as the ``tensor'' proposed by Moller in 1961.Comment: 10 pages, RevTe
Degenerative mitral valve disease: Survival of dogs attending primary-care practice in england
Asymptotic channels and gauge transformations of the time-dependent Dirac equation for extremely relativistic heavy-ion collisions
We discuss the two-center, time-dependent Dirac equation describing the
dynamics of an electron during a peripheral, relativistic heavy-ion collision
at extreme energies. We derive a factored form, which is exact in the
high-energy limit, for the asymptotic channel solutions of the Dirac equation,
and elucidate their close connection with gauge transformations which transform
the dynamics into a representation in which the interaction between the
electron and a distant ion is of short range. We describe the implications of
this relationship for solving the time-dependent Dirac equation for extremely
relativistic collisions.Comment: 12 pages, RevTeX, 2 figures, submitted to PR
Effect of oleic acid supplementation on prostaglandin production in maternal endometrial and fetal allantochorion cells isolated from late gestation ewes
Elevated circulating non-esterified fatty acids including oleic acid (OA) are associated with many pregnancy related complications. Prostaglandins (PGs) play crucial roles during parturition. We investigated the effect of OA supplementation on PG production using an in vitro model of ovine placenta
A black ring with a rotating 2-sphere
We present a solution of the vacuum Einstein's equations in five dimensions
corresponding to a black ring with horizon topology S^1 x S^2 and rotation in
the azimuthal direction of the S^2. This solution has a regular horizon up to a
conical singularity, which can be placed either inside the ring or at infinity.
This singularity arises due to the fact that this black ring is not balanced.
In the infinite radius limit we correctly reproduce the Kerr black string, and
taking another limit we recover the Myers-Perry black hole with a single
angular momentum.Comment: 10 page
Towards a formalism for mapping the spacetimes of massive compact objects: Bumpy black holes and their orbits
Observations have established that extremely compact, massive objects are
common in the universe. It is generally accepted that these objects are black
holes. As observations improve, it becomes possible to test this hypothesis in
ever greater detail. In particular, it is or will be possible to measure the
properties of orbits deep in the strong field of a black hole candidate (using
x-ray timing or with gravitational-waves) and to test whether they have the
characteristics of black hole orbits in general relativity. Such measurements
can be used to map the spacetime of a massive compact object, testing whether
the object's multipoles satisfy the strict constraints of the black hole
hypothesis. Such a test requires that we compare against objects with the
``wrong'' multipole structure. In this paper, we present tools for constructing
bumpy black holes: objects that are almost black holes, but that have some
multipoles with the wrong value. The spacetimes which we present are good deep
into the strong field of the object -- we do not use a large r expansion,
except to make contact with weak field intuition. Also, our spacetimes reduce
to the black hole spacetimes of general relativity when the ``bumpiness'' is
set to zero. We propose bumpy black holes as the foundation for a null
experiment: if black hole candidates are the black holes of general relativity,
their bumpiness should be zero. By comparing orbits in a bumpy spacetime with
those of an astrophysical source, observations should be able to test this
hypothesis, stringently testing whether they are the black holes of general
relativity. (Abridged)Comment: 16 pages + 2 appendices + 3 figures. Submitted to PR
- …
