637 research outputs found
Survey of respiratory sounds in infants
Background: Over the last decade there
has been an apparent increase in childhood
wheeze. We speculated that much of
the reported increase may be attributed to
the term wheeze being adopted by parents
to describe a variety of other forms of
noisy breathing.
Aims: To investigate terminology used by
parents to describe their children’s breath
sounds.
Methods: An interview was carried out
with the parents of 92 infants with noisy
breathing, beginning with an open question
and then directed towards a more
detailed description. Finally, the parents
were asked to choose from a wheeze,
ruttle, and stridor on imitation by the
investigator and video clips of children.
Results: Wheeze was the most commonly
chosen word on initial questioning (59%).
Only 36% were still using this term at the
end of the interview, representing a decrease
of one third, whereas the use of the
word ruttles doubled.
Conclusions: Our results reflect the degree
of inaccuracy involved in the use of
the term wheeze in clinical practice,
which may be leading to over diagnosis.
Imprecise use of this term has potentially
important implications for therapy and
clinical trials
Diversity and impact of rare variants in genes encoding the platelet G protein-coupled receptors
Platelet responses to activating agonists are influenced by common
population variants within or near G protein-coupled receptor (GPCR)
genes that affect receptor activity. However, the impact of rare GPCR
gene variants is unknown. We describe the rare single nucleotide variants
(SNVs) in the coding and splice regions of 18 GPCR genes in
7,595 exomes from the 1,000-genomes and Exome Sequencing
Project databases and in 31 cases with inherited platelet function disorders
(IPFDs). In the population databases, the GPCR gene target
regions contained 740 SNVs (318 synonymous, 410 missense, 7 stop
gain and 6 splice region) of which 70 % had global minor allele frequency
(MAF) < 0.05 %. Functional annotation using six computational
algorithms, experimental evidence and structural data identified
156/740 (21 %) SNVs as potentially damaging to GPCR function, most
commonly in regions encoding the transmembrane and C-terminal intracellular
receptor domains. In 31 index cases with IPFDs (Gi-pathway
defect n=15; secretion defect n=11; thromboxane pathway defect
n=3 and complex defect n=2) there were 256 SNVs in the target
regions of 15 stimulatory platelet GPCRs (34 unique; 12 with
MAF< 1 % and 22 with MAF≥ 1 %). These included rare variants predicting
R122H, P258T and V207A substitutions in the P2Y12 receptor
that were annotated as potentially damaging, but only partially explained
the platelet function defects in each case. Our data highlight
that potentially damaging variants in platelet GPCR genes have low
individual frequencies, but are collectively abundant in the population.
Potentially damaging variants are also present in pedigrees with IPFDs
and may contribute to complex laboratory phenotypes
Triple configuration coexistence in 44 S
The neutron-rich N=28 nucleus S44 was studied using the two-proton knockout reaction from Ar46 at intermediate beam energy. We report the observation of four new excited states, one of which is a strongly prolate deformed 4 + state, as indicated by a shell-model calculation. Its deformation originates in a neutron configuration which is fundamentally different from the "intruder" configuration responsible for the ground-state deformation. Consequently, we do not have three coexisting shapes in S44, but three coexisting configurations, corresponding to zero-, one-, and two-neutron particle-hole excitations. � 2011 American Physical Society
Non-linear instability of Kerr-type Cauchy horizons
Using the general solution to the Einstein equations on intersecting null
surfaces developed by Hayward, we investigate the non-linear instability of the
Cauchy horizon inside a realistic black hole. Making a minimal assumption about
the free gravitational data allows us to solve the field equations along a null
surface crossing the Cauchy Horizon. As in the spherical case, the results
indicate that a diverging influx of gravitational energy, in concert with an
outflux across the CH, is responsible for the singularity. The spacetime is
asymptotically Petrov type N, the same algebraic type as a gravitational shock
wave. Implications for the continuation of spacetime through the singularity
are briefly discussed.Comment: 11 pages RevTeX, two postscript figures included using epsf.st
Travel, tourism, climate change and behavioral change: travelers’ perspectives from a developing country, Nigeria
While studies have examined people's understanding of climate change and its relationship to tourism, these focus largely on developed country populations. Much future tourism growth will come from developing countries following economic development; often countries where climate change will be strongly felt. Do tourists from developing countries have the same knowledge gaps about travel, tourism, and climate change as in the developed world? Will behavioral change policies be successful in encouraging more environmentally friendly approaches to climate change and tourism in developing countries? This paper presents findings from 20 in-depth interviews with active Nigerian tourists, analyzing their understanding of climate change, the links known, or not, between their travel and climate change, and their willingness to change their tourism patterns. Understanding of climate change was limited and there was conceptual confusion. Participants did not view their own travel as a cause of climate change and many were embedded in air travel practice. Participants were unwilling to change their tourism patterns to reduce their contribution to climate change. Significant structural barriers limit low carbon tourism travel in Nigeria (and other developing countries), including reliability, availability safety, and speed. Behavioral change will be difficult to achieve
Spallation reactions. A successful interplay between modeling and applications
The spallation reactions are a type of nuclear reaction which occur in space
by interaction of the cosmic rays with interstellar bodies. The first
spallation reactions induced with an accelerator took place in 1947 at the
Berkeley cyclotron (University of California) with 200 MeV deuterons and 400
MeV alpha beams. They highlighted the multiple emission of neutrons and charged
particles and the production of a large number of residual nuclei far different
from the target nuclei. The same year R. Serber describes the reaction in two
steps: a first and fast one with high-energy particle emission leading to an
excited remnant nucleus, and a second one, much slower, the de-excitation of
the remnant. In 2010 IAEA organized a worskhop to present the results of the
most widely used spallation codes within a benchmark of spallation models. If
one of the goals was to understand the deficiencies, if any, in each code, one
remarkable outcome points out the overall high-quality level of some models and
so the great improvements achieved since Serber. Particle transport codes can
then rely on such spallation models to treat the reactions between a light
particle and an atomic nucleus with energies spanning from few tens of MeV up
to some GeV. An overview of the spallation reactions modeling is presented in
order to point out the incomparable contribution of models based on basic
physics to numerous applications where such reactions occur. Validations or
benchmarks, which are necessary steps in the improvement process, are also
addressed, as well as the potential future domains of development. Spallation
reactions modeling is a representative case of continuous studies aiming at
understanding a reaction mechanism and which end up in a powerful tool.Comment: 59 pages, 54 figures, Revie
The PHENIX Experiment at RHIC
The physics emphases of the PHENIX collaboration and the design and current
status of the PHENIX detector are discussed. The plan of the collaboration for
making the most effective use of the available luminosity in the first years of
RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program
available at http://www.rhic.bnl.gov/phenix
Gemini Observations of Galaxies in Rich Early Environments (GOGREEN) I: survey description
We describe a new Large Program in progress on the Gemini North and South telescopes: Gemini Observations of Galaxies in Rich Early Environments (GOGREEN). This is an imaging and deep spectroscopic survey of 21 galaxy systems at 1 10 in halo mass. The scientific objectives include measuring the role of environment in the evolution of low-mass galaxies, and measuring the dynamics and stellar contents of their host haloes. The targets are selected from the SpARCS, SPT, COSMOS, and SXDS surveys, to be the evolutionary counterparts of today's clusters and groups. The new red-sensitive Hamamatsu detectors on GMOS, coupled with the nod-and-shuffle sky subtraction, allow simultaneous wavelength coverage over λ ∼ 0.6–1.05 μm, and this enables a homogeneous and statistically complete redshift survey of galaxies of all types. The spectroscopic sample targets galaxies with AB magnitudes z΄ < 24.25 and [3.6] μm < 22.5, and is therefore statistically complete for stellar masses M* ≳ 1010.3 M⊙, for all galaxy types and over the entire redshift range. Deep, multiwavelength imaging has been acquired over larger fields for most systems, spanning u through K, in addition to deep IRAC imaging at 3.6 μm. The spectroscopy is ∼50 per cent complete as of semester 17A, and we anticipate a final sample of ∼500 new cluster members. Combined with existing spectroscopy on the brighter galaxies from GCLASS, SPT, and other sources, GOGREEN will be a large legacy cluster and field galaxy sample at this redshift that spectroscopically covers a wide range in stellar mass, halo mass, and clustercentric radius
Carbohydrate metabolism genes and pathways in insects: insights from the honey bee genome
Carbohydrate-metabolizing enzymes may have particularly interesting roles in the honey bee, Apis mellifera, because this social insect has an extremely carbohydrate-rich diet, and nutrition plays important roles in caste determination and socially mediated behavioural plasticity. We annotated a total of 174 genes encoding carbohydrate-metabolizing enzymes and 28 genes encoding lipid-metabolizing enzymes, based on orthology to their counterparts in the fly, Drosophila melanogaster, and the mosquito, Anopheles gambiae. We found that the number of genes for carbohydrate metabolism appears to be more evolutionarily labile than for lipid metabolism. In particular, we identified striking changes in gene number or genomic organization for genes encoding glycolytic enzymes, cellulase, glucose oxidase and glucose dehydrogenases, glucose-methanol-choline (GMC) oxidoreductases, fucosyltransferases, and lysozymes
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