17,523 research outputs found
Influence of the first wave of COVID-19 on asthma inhaler prescriptions
In the beginning of the COVID-19 pandemic there were major concerns regarding the huge demand for asthma inhalers. Using primary care medical records for 614,700 asthma patients between January and June 2020, we found that there was a substantial increase in inhalers solely in March 2020. Patients significantly associated with receiving higher inhaled corticosteroid prescriptions were younger, of higher socioeconomic status and had milder asthma
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The Influence of Nonmarital Childbearing on the Formation of First Marriages
We examine the association between nonmarital childbearing and the subsequent likelihood of first marriage and document a negative association between these variables controlling for a variety of potentially confounding influences in several large survey data sets for the United States. We then subject possible explanations of this finding to empirical test. The analyses performed support the following conclusions: Nonmarital childbearing does not appear to be driven by low expectations of future marriage. Rather, the direction of causation is just the reverse: Nonmarital childbearing tends to be an unexpected and unwanted event that has multiple effects, which on balance are negative, on a woman's subsequent likelihood of first marriage. Further, the upward trend in the proportion of childbearing that occurs outside of marriage may account for one-fourth of the increase in the proportion of women never marrying in the United States over cohorts separated by almost two decades. We do, however, find that nonmarital childbearers are more likely to enter informal cohabitational unions than are their single counterparts who do not bear a child. We find evidence that the negative association between out-of-wedlock childbearing and subsequent marriage is particularly strong among welfare recipients as well as evidence that out-of-wedlock childbearing increases the likelihood that a woman marries her child's biological father. On the other hand, we find no evidence that (a) stigma associated with nonmarital childbearing plays an important role in this process or (b) the demands of children reduce the time that unmarried mothers have to devote to marriage market activities
Hints of the existence of Axion-Like-Particles from the gamma-ray spectra of cosmological sources
Axion Like Particles (ALPs) are predicted to couple with photons in the
presence of magnetic fields. This effect may lead to a significant change in
the observed spectra of gamma-ray sources such as AGNs. Here we carry out a
detailed study that for the first time simultaneously considers in the same
framework both the photon/axion mixing that takes place in the gamma-ray source
and that one expected to occur in the intergalactic magnetic fields. An
efficient photon/axion mixing in the source always means an attenuation in the
photon flux, whereas the mixing in the intergalactic medium may result in a
decrement and/or enhancement of the photon flux, depending on the distance of
the source and the energy considered. Interestingly, we find that decreasing
the value of the intergalactic magnetic field strength, which decreases the
probability for photon/axion mixing, could result in an increase of the
expected photon flux at Earth if the source is far enough. We also find a 30%
attenuation in the intensity spectrum of distant sources, which occurs at an
energy that only depends on the properties of the ALPs and the intensity of the
intergalactic magnetic field, and thus independent of the AGN source being
observed. Moreover, we show that this mechanism can easily explain recent
puzzles in the spectra of distant gamma-ray sources... [ABRIDGED] The
consequences that come from this work are testable with the current generation
of gamma-ray instruments, namely Fermi (formerly known as GLAST) and imaging
atmospheric Cherenkov telescopes like CANGAROO, HESS, MAGIC and VERITAS.Comment: 16 pages, 7 figures. Replaced to match the published version in Phys.
Rev. D. Minor changes with respect to v
Microsomal incubation test of potentially hemolytic drugs for glucose‐6‐phosphate dehydrogenase deficiency
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109761/1/cptclpt198354.pd
On CSP and the Algebraic Theory of Effects
We consider CSP from the point of view of the algebraic theory of effects,
which classifies operations as effect constructors or effect deconstructors; it
also provides a link with functional programming, being a refinement of Moggi's
seminal monadic point of view. There is a natural algebraic theory of the
constructors whose free algebra functor is Moggi's monad; we illustrate this by
characterising free and initial algebras in terms of two versions of the stable
failures model of CSP, one more general than the other. Deconstructors are
dealt with as homomorphisms to (possibly non-free) algebras.
One can view CSP's action and choice operators as constructors and the rest,
such as concealment and concurrency, as deconstructors. Carrying this programme
out results in taking deterministic external choice as constructor rather than
general external choice. However, binary deconstructors, such as the CSP
concurrency operator, provide unresolved difficulties. We conclude by
presenting a combination of CSP with Moggi's computational {\lambda}-calculus,
in which the operators, including concurrency, are polymorphic. While the paper
mainly concerns CSP, it ought to be possible to carry over similar ideas to
other process calculi
Local Duality Predictions for x ~ 1 Structure Functions
Recent data on the proton F_2 structure function in the resonance region
suggest that local quark-hadron duality works remarkably well for each of the
low-lying resonances, including the elastic, to rather low values of Q^2. We
derive model-independent relations between structure functions at x ~ 1 and
elastic electromagnetic form factors, and predict the x -> 1 behavior of
nucleon polarization asymmetries and the neutron to proton structure function
ratios from available data on nucleon electric and magnetic form factors.Comment: 10 pages, 2 figures, typos in Eq. (2) correcte
On Shape Transformations and Shape Fluctuations of Cellular Compartments and Vesicles
We discuss the shape formation and shape transitions of simple bilayer vesicles in context with their role in biology. In the first part several classes of shape changes of vesicles of one lipid component are described and it is shown that these can be explained in terms of the bending energy concept in particular augmented by the bilayer coupling hypothesis. In the second
part shape changes and vesicle fission of vesicles composed of membranes of lipid mixtures are reported. These are explained in terms of coupling between local curvature and phase separation
GRB 050408: An Atypical Gamma-Ray Burst as a Probe of an Atypical Galactic Environment
The bright GRB 050408 was localized by HETE-II near local midnight, enabling
an impressive ground-based followup effort as well as space-based followup from
Swift. The Swift data from the X-Ray Telescope (XRT) and our own optical
photometry and spectrum of the afterglow provide the cornerstone for our
analysis. Under the traditional assumption that the visible waveband was above
the peak synchrotron frequency and below the cooling frequency, the optical
photometry from 0.03 to 5.03 days show an afterglow decay corresponding to an
electron energy index of p_lc = 2.05 +/- 0.04, without a jet break as suggested
by others. A break is seen in the X-ray data at early times (at ~12600 sec
after the GRB). The spectral slope of the optical spectrum is consistent with
p_lc assuming a host-galaxy extinction of A_V = 1.18 mag. The optical-NIR
broadband spectrum is also consistent with p = 2.05, but prefers A_V = 0.57
mag. The X-ray afterglow shows a break at 1.26 x 10^4 sec, which may be the
result of a refreshed shock. This burst stands out in that the optical and
X-ray data suggest a large H I column density of N_HI ~ 10^22 cm^-2; it is very
likely a damped Lyman alpha system and so the faintness of the host galaxy (M_V
> -18 mag) is noteworthy. Moreover, we detect extraordinarily strong Ti II
absorption lines with a column density through the GRB host that exceeds the
largest values observed for the Milky Way by an order of magnitude.
Furthermore, the Ti II equivalent width is in the top 1% of Mg II
absorption-selected QSOs. This suggests that the large-scale environment of GRB
050408 has significantly lower Ti depletion than the Milky Way and a large
velocity width (delta v > 200 km/s).Comment: ApJ submitte
The Supernova Gamma-Ray Burst Connection
The chief distinction between ordinary supernovae and long-soft gamma-ray
bursts (GRBs) is the degree of differential rotation in the inner several solar
masses when a massive star dies, and GRBs are rare mainly because of the
difficulty achieving the necessary high rotation rate. Models that do provide
the necessary angular momentum are discussed, with emphasis on a new single
star model whose rapid rotation leads to complete mixing on the main sequence
and avoids red giant formation. This channel of progenitor evolution also gives
a broader range of masses than previous models, and allows the copious
production of bursts outside of binaries and at high redshifts. However, even
the production of a bare helium core rotating nearly at break up is not, by
itself, a sufficient condition to make a gamma-ray burst. Wolf-Rayet mass loss
must be low, and will be low in regions of low metallicity. This suggests that
bursts at high redshift (low metallicity) will, on the average, be more
energetic, have more time structure, and last longer than bursts nearby. Every
burst consists of three components: a polar jet (~0.1 radian), high energy,
subrelativistic mass ejection (~1 radian), and low velocity equatorial mass
that can fall back after the initial explosion. The relative proportions of
these three components can give a diverse assortment of supernovae and high
energy transients whose properties may vary with redshift.Comment: 10 pages, to appear in AIP Conf. Proc. "Gamma Ray Bursts in the Swift
Era", Eds. S. S. Holt, N. Gehrels, J. Nouse
Selective excision of the centromere chromatin complex from Saccharomyces cerevisiae.
We have taken advantage of the known structural parameters associated with centromere DNA in vivo to construct a CEN fragment that can be selectively excised from the chromatin DNA with restriction endonucleases. CEN3 DNA is organized in chromatin such that a 220-250- bp region encompassing the elements of centromere homology is resistant to nuclease digestion. Restriction enzyme linkers encoding the Bam HI- recognition site were ligated to a 289 base pair DNA segment that spans the 220-250-bp protected core (Bloom et al., 1984). Replacement of this CEN3-Bam HI linker cassette into a chromosome or plasmid results in formation of a complete structural and functional centromeric unit. A centromere core complex that retains its protected chromatin conformation can be selectively excised from intact nuclei by restriction with the enzyme Bam HI. The centromeric protein-DNA complex is therefore not dependent upon the intact torsional constrains on linear chromosomes for its structural integrity. Isolation of this complex provides a novel approach to characterizing authentic centromeric proteins bound to DNA in their native state
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