593 research outputs found
Gestational Age at Birth and Risk of Developmental Delay: The Upstate KIDS Study
Objective—To model the association between gestational age at birth and early child development through 3 years of age.
Study Design—Development of 5868 children in Upstate KIDS (New York State; 2008–2014) was assessed at 7 time-points using the Ages and Stages Questionnaire (ASQ). The ASQ was implemented using gestational age corrected dates of birth at 4, 8, 12, 18, 24, 30, and 36 months. Whether children were eligible for developmental services from the Early Intervention Program (EIP) was determined through linkage. Gestational age was based on vital records. Statistical models adjusted for covariates including sociodemographic factors, maternal smoking and plurality.
Results——Compared to gestational age of 39 weeks, adjusted odds ratios (aOR) and 95% confidence intervals of failing the ASQ for children delivered at \u3c 32, 32–34, 35–36, 37, 38, and 40 weeks gestational age were: 5.32 (3.42, 8.28), 2.43 (1.60, 3.69), 1.38 (1.00, 1.90), 1.37 (0.98, 1.90), 1.29 (0.99, 1.67), 0.73 (0.55, 0.96), and 0.51 (0.32, 0.82). Similar risks of being eligible for EIP services were observed (aOR: 4.19, 2.10, 1.29, 1.20, 1.01, 1.00 (ref), 0.92, 0.78, respectively for \u3c 32, 32–34, 37, 38, 39 (ref), 40, 41 weeks).
Conclusion—Gestational age was inversely associated with developmental delays for all gestational ages. Evidence from our study is potentially informative for low-risk deliveries at 39 weeks but it is notable that deliveries at 40 weeks exhibited further lower risk
Staggered Schemes for Fluctuating Hydrodynamics
We develop numerical schemes for solving the isothermal compressible and
incompressible equations of fluctuating hydrodynamics on a grid with staggered
momenta. We develop a second-order accurate spatial discretization of the
diffusive, advective and stochastic fluxes that satisfies a discrete
fluctuation-dissipation balance, and construct temporal discretizations that
are at least second-order accurate in time deterministically and in a weak
sense. Specifically, the methods reproduce the correct equilibrium covariances
of the fluctuating fields to third (compressible) and second (incompressible)
order in the time step, as we verify numerically. We apply our techniques to
model recent experimental measurements of giant fluctuations in diffusively
mixing fluids in a micro-gravity environment [A. Vailati et. al., Nature
Communications 2:290, 2011]. Numerical results for the static spectrum of
non-equilibrium concentration fluctuations are in excellent agreement between
the compressible and incompressible simulations, and in good agreement with
experimental results for all measured wavenumbers.Comment: Submitted. See also arXiv:0906.242
The star formation history of mass-selected galaxies in the COSMOS field
We explore the evolution of the specific star formation rate (SSFR) for
3.6um-selected galaxies of different M_* in the COSMOS field. The average SFR
for sub-sets of these galaxies is estimated with stacked 1.4GHz radio continuum
emission. We separately consider the total sample and a subset of galaxies (SF)
that shows evidence for substantive recent star formation in the rest-frame
optical SED. At 0.2<z<3 both populations show a strong and M_*-independent
decrease in their SSFR towards z=0.2, best described by a power- law (1+z)^n,
where n~4.3 for all galaxies and n~3.5 for SF sources. The decrease appears to
have started at z>2, at least above 4x10^10M_Sun where our conclusions are most
robust. We find a tight correlation with power-law dependence, SSFR (M_*)^beta,
between SSFR and M_* at all z. It tends to flatten below ~10^10M_Sun if
quiescent galaxies are included; if they are excluded a shallow index beta_SFG
-0.4 fits the correlation. On average, higher M_* objects always have lower
SSFRs, also among SF galaxies. At z>1.5 there is tentative evidence for an
upper SSFR-limit that an average galaxy cannot exceed. It is suggested by a
flattening of the SSFR-M_* relation (also for SF sources), but affects massive
(>10^10M_Sun) galaxies only at the highest z. Below z=1.5 there thus is no
direct evidence that galaxies of higher M_* experience a more rapid waning of
their SSFR than lower M_* SF systems. In this sense, the data rule out any
strong 'downsizing'. We combine our results with recent measurements of the
galaxy (stellar) mass function in order to determine the characteristic mass of
a SF galaxy (M_*=10^(10.6\pm0.4)M_Sun). In this sense, too, there is no
'downsizing'. Our analysis constitutes the most extensive SFR density
determination with a single technique to z=3. Recent Herschel results are
consistent with our results, but rely on far smaller samples.Comment: 37 pages, 14 figures, 7 tables; accepted for publication in the
Astrophysical Journal; High resolution versions of all figures available at
www.mpia-hd.mpg.de/homes/karim/research.htm
A catalogue of galaxies behind the southern Milky Way. - II. The Crux and Great Attractor regions (l = 289deg - 338deg)
In this second paper of the catalogue series of galaxies behind the southern
Milky Way, we report on the deep optical galaxy search in the Crux region
(289deg <= l <= 318deg and -10deg <= b <= 10deg) and the Great Attractor region
(316deg <= l <= 338deg and -10deg <= b <= 10deg). The galaxy catalogues are
presented, a brief description of the galaxy search given, as well as a
discussion on the distribution and characteristics of the uncovered galaxies. A
total of 8182 galaxies with major diameters D >= 0.2 arcmin were identified in
this ~850 square degree area: 3759 galaxies in the Crux region and 4423
galaxies in the Great Attractor region. Of the 8182 galaxies, 229 (2.8%) were
catalogued before in the optical (3 in radio) and 251 galaxies have a reliable
(159), or likely (92) cross-identification in the IRAS Point Source Catalogue
(3.1%). A number of prominent overdensities and filaments of galaxies are
identified. They are not correlated with the Galactic foreground extinction and
hence indicative of extragalactic large-scale structures. Redshifts obtained at
the South African Astronomical Observatory (SAAO) for 518 of the newly
catalogued galaxies in the Crux and Great Attractor regions (Fairall et al.
1998; Woudt et al. 1999) confirm distinct voids and clusters in the area here
surveyed. With this optical galaxy search, we have reduced the width of the
optical `Zone of Avoidance' for galaxies with extinction-corrected diameters
larger than 1.3 arcmin from extinction levels A_B >= 1.0 mag to A_B >= 3.0 mag:
the remaining optical Zone of Avoidance is now limited by |b| <= 3deg (see Fig.
16).Comment: 19 pages, 16 figures, accepted for publication in A&A. Tables will
shortly be available in electronic version at the CDS. Full resolution
(colour) copies of Figures 1, 2, 3 and 16 are available at
http://mensa.ast.uct.ac.za/~pwoud
The Effects of an AGN on Host Galaxy Colour and Morphology Measurements
We assess the effects of simulated active galactic nuclei (AGNs) on the
colour and morphology measurements of their host galaxies. To test the
morphology measurements, we select a sample of galaxies not known to host AGNs
and add a series of point sources scaled to represent specified fractions of
the observed V band light detected from the resulting systems; we then compare
morphology measurements of the simulated systems to measurements of the
original galaxies. AGN contributions >20 per cent bias most of the morphology
measurements tested, though the extent of the apparent bias depends on the
morphological characteristics of the original galaxies. We test colour
measurements by adding to non-AGN galaxy spectra a quasar spectrum scaled to
contribute specified fractions of the rest-frame B band light detected from the
resulting systems. A quasar fraction of 5 per cent can move the NUV-r colour of
an elliptical galaxy from the UV-optical red sequence to the green valley, and
20 per cent can move it into the blue cloud. Combining the colour and
morphology results, we find that a galaxy/AGN system with an AGN contribution
>20 per cent may appear bluer and more bulge-dominated than the underlying
galaxy. We conclude that (1) bulge-dominated, E/S0/Sa, and early-type
morphology classifications are accurate for red AGN host galaxies and may be
accurate for blue host galaxies, unless the AGN manifests itself as a
well-defined point source; and (2) although highly unobscured AGNs, such as the
quasar used for our experiments, can significantly bias the measured colours of
AGN host galaxies, it is possible to identify such systems by examining optical
images of the hosts for the presence of a point source and/or measuring the
level of nuclear obscuration.Comment: 18 pages, 19 figures, 1 table. Accepted for publication in MNRA
An Intercomparison of Ground-Based Solar FTIR Measurements of Atmospheric Gases at Eureka, Canada
Deficiency in origin licensing proteins impairs cilia formation: implications for the aetiology of meier-gorlin syndrome
Mutations in ORC1, ORC4, ORC6, CDT1, and CDC6, which encode proteins required for DNA replication origin licensing, cause Meier-Gorlin syndrome (MGS), a disorder conferring microcephaly, primordial dwarfism, underdeveloped ears, and skeletal abnormalities. Mutations in ATR, which also functions during replication, can cause Seckel syndrome, a clinically related disorder. These findings suggest that impaired DNA replication could underlie the developmental defects characteristic of these disorders. Here, we show that although origin licensing capacity is impaired in all patient cells with mutations in origin licensing component proteins, this does not correlate with the rate of progression through S phase. Thus, the replicative capacity in MGS patient cells does not correlate with clinical manifestation. However, ORC1-deficient cells from MGS patients and siRNA-mediated depletion of origin licensing proteins also have impaired centrosome and centriole copy number. As a novel and unexpected finding, we show that they also display a striking defect in the rate of formation of primary cilia. We demonstrate that this impacts sonic hedgehog signalling in ORC1-deficient primary fibroblasts. Additionally, reduced growth factor-dependent signaling via primary cilia affects the kinetics of cell cycle progression following cell cycle exit and re-entry, highlighting an unexpected mechanism whereby origin licensing components can influence cell cycle progression. Finally, using a cell-based model, we show that defects in cilia function impair chondroinduction. Our findings raise the possibility that a reduced efficiency in forming cilia could contribute to the clinical features of MGS, particularly the bone development abnormalities, and could provide a new dimension for considering developmental impacts of licensing deficiency
Extreme Emission Line Galaxies in CANDELS: Broad-Band Selected, Star-Bursting Dwarf Galaxies at z>1
We identify an abundant population of extreme emission line galaxies (EELGs)
at redshift z~1.7 in the Cosmic Assembly Near-IR Deep Extragalactic Legacy
Survey (CANDELS) imaging from Hubble Space Telescope/Wide Field Camera 3
(HST/WFC3). 69 EELG candidates are selected by the large contribution of
exceptionally bright emission lines to their near-infrared broad-band
magnitudes. Supported by spectroscopic confirmation of strong [OIII] emission
lines -- with rest-frame equivalent widths ~1000\AA -- in the four candidates
that have HST/WFC3 grism observations, we conclude that these objects are
galaxies with 10^8 Msol in stellar mass, undergoing an enormous starburst phase
with M_*/(dM_*/dt) of only ~15 Myr. These bursts may cause outflows that are
strong enough to produce cored dark matter profiles in low-mass galaxies. The
individual star formation rates and the co-moving number density (3.7x10^-4
Mpc^-3) can produce in ~4 Gyr much of the stellar mass density that is
presently contained in 10^8-10^9 Msol dwarf galaxies. Therefore, our
observations provide a strong indication that many or even most of the stars in
present-day dwarf galaxies formed in strong, short-lived bursts, mostly at z>1.Comment: accepted for publication in ApJ; 10 pages; 6 figures; 1 tabl
Climate change: what competencies and which medical education and training approaches?
<p>Abstract</p> <p>Background</p> <p>Much research has been devoted to identifying healthcare needs in a climate-changing world. However, while there are now global and national policy statements about the importance of health workforce development for climate change, little has been published about what competencies might be demanded of practitioners in a climate-changing world. In such a context, this debate and discussion paper aims to explore the nature of key competencies and related opportunities for teaching climate change in medical education and training. Particular emphasis is made on preparation for practice in rural and remote regions likely to be greatly affected by climate change.</p> <p>Discussion</p> <p>The paper describes what kinds of competencies for climate change might be included in medical education and training. It explores which curricula, teaching, learning and assessment approaches might be involved. Rather than arguing for major changes to medical education and training, this paper explores well established precedents to offer practical suggestions for where a particular kind of literacy--eco-medical literacy--and related competencies could be naturally integrated into existing elements of medical education and training.</p> <p>Summary</p> <p>The health effects of climate change have, generally, not yet been integrated into medical education and training systems. However, the necessary competencies could be taught by building on existing models, best practice and innovative traditions in medicine. Even in crowded curricula, climate change offers an opportunity to reinforce and extend understandings of how interactions between people and place affect health.</p
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