1,074 research outputs found
An Artificial Intelligence Technique to Characterizae Surface-Breaking Cracks
A neural network with an analog output is presented to determine the angle of inclination of a surface-breaking crack from ultrasonic backscattering data. A neural network which was trained by the use of synthetic data set to estimate the depth of a crack, assuming that the inclined crack angle is known, was presented earlier[1,2]. In this study, a neural network estimates the angle of inclination of the surface-breaking crack, assuming that the depth of the crack is 2.0mm, by utilizing the waveforms of backscattered signals from the crack. The plate with a surface-breaking crack is immersed in water and the crack is insonified from the opposite side of the plate. The angle of incidence with the normal to the insonified face of the plate is taken to be 18.9°. The neural network is a feed-forward three layered network. The training algorithm is an error back-propagation algorithm which has been discussed in Refs. [3,4]. The theoretical data obtained by the boundary element method are used for the training. The performance of the trained network is tested by synthetic and experimental data
Time to do more
AbstractAimsClinical inertia, the tendency to maintain current treatment strategies despite results demanding escalation, is thought to substantially contribute to the disconnect between clinical aspirations for patients with diabetes and targets achieved. We wished to explore potential causes of clinical inertia among physicians and people with diabetes.MethodsA 20-min online survey of 652 adults with diabetes and 337 treating physicians in six countries explored opinions relating to clinical inertia from both perspectives, in order to correlate perceptions and expectations relating to diagnosis, treatment, diabetes complications and therapeutic escalation.ResultsPhysicians had low expectations for their patients, despite the belief that the importance of good glycaemic control through lifestyle and pharmacological interventions had been adequately conveyed. Conversely, people with diabetes had, at best, a rudimentary understanding of the risks of complications and the importance of good control; indeed, only a small proportion believed lifestyle changes were important and the majority did not intend to comply.ConclusionsThe principal findings of this survey suggest that impairments in communication are at the heart of clinical inertia. This manuscript lays out four key principles that we believe are achievable in all environments and can improve the lives of people with diabetes
SXDF-UDS-CANDELS-ALMA 1.5 arcmin deep survey
We have conducted 1.1 mm ALMA observations of a contiguous or 1.5 arcmin window in the SXDF-UDS-CANDELS. We achieved a 5
sensitivity of 0.28 mJy, providing a flat sensus of dusty star-forming galaxies
with (for =40K) up to
thanks to the negative K-correction at this wavelength. We detected 5
brightest sources (S/N6) and 18 low-significance sources (5S/N4; these
may contain spurious detections, though). One of the 5 brightest ALMA sources
( mJy) is extremely faint in the WFC3 and
VLT/HAWK-I images, demonstrating that a contiguous ALMA imaging survey is able
to uncover a faint dust-obscured population that is invisible in deep
optical/near-infrared surveys. We found a possible [CII]-line emitter at
or a low- CO emitting galaxy within the field, which may allow us
to constrain the [CII] and/or the CO luminosity functions across the history of
the universe.Comment: 4 pages, 2 figures, 1 table, to appear in the proceedings of IAU
Symposium 319 "Galaxies at High Redshift and Their Evolution over Cosmic
Time", eds. S. Kaviraj & H. Ferguso
Very compact millimeter sizes for composite star-forming/AGN submillimeter galaxies
We report the study of far-IR sizes of submillimeter galaxies (SMGs) in
relation to their dust-obscured star formation rate (SFR) and active galactic
nuclei (AGN) presence, determined using mid-IR photometry. We determined the
millimeter-wave (m) sizes of 69 ALMA-identified
SMGs, selected with confidence on ALMA images (--7.4 mJy). We found that all the SMGs are located above an
avoidance region in the millimeter size-flux plane, as expected by the
Eddington limit for star formation. In order to understand what drives the
different millimeter-wave sizes in SMGs, we investigated the relation between
millimeter-wave size and AGN fraction for 25 of our SMGs at --3. We found
that the SMGs for which the mid-IR emission is dominated by star formation or
AGN have extended millimeter-sizes, with respective median and 1.5 kpc. Instead, the SMGs for which
the mid-IR emission corresponds to star-forming/AGN composites have more
compact millimeter-wave sizes, with median
kpc. The relation between millimeter-wave size and AGN fraction suggests that
this size may be related to the evolutionary stage of the SMG. The very compact
sizes for composite star-forming/AGN systems could be explained by supermassive
black holes growing rapidly during the SMG coalescing, star-formation phase.Comment: 9 pages, 4 figures, 1 table. Accepted for publication in ApJ Lette
Vulnerability of primitive human placental trophoblast to Zika virus
Infection of pregnant women by Asian lineage strains of Zika virus (ZIKV) has been linked to brain abnormalities in their infants, yet it is uncertain when during pregnancy the human conceptus is most vulnerable to the virus. We have examined two models to study susceptibility of human placental trophoblast to ZIKV: cytotrophoblast and syncytiotrophoblast derived from placental villi at term and colonies of trophoblast differentiated from embryonic stem cells (ESC). The latter appear to be analogous to the primitive placenta formed during implantation. The cells from term placentas, which resist infection, do not express genes encoding most attachment factors implicated in ZIKV entry but do express many genes associated with antiviral defense. By contrast, the ESC-derived trophoblasts possess a wide range of attachment factors for ZIKV entry and lack components of a robust antiviral response system. These cells, particularly areas of syncytiotrophoblast within the colonies, quickly become infected, produce infectious virus and undergo lysis within 48 h after exposure to low titers (multiplicity of infection > 0.07) of an African lineage strain (MR766 Uganda: ZIKVU) considered to be benign with regards to effects on fetal development. Unexpectedly, lytic effects required significantly higher titers of the presumed more virulent FSS13025 Cambodia (ZIKVC). Our data suggest that the developing fetus might be most vulnerable to ZIKV early in the first trimester before a protective zone of mature villous trophoblast has been established. Additionally, MR766 is highly trophic toward primitive trophoblast, which may put the early conceptus of an infected mother at high risk for destruction
GALEX selected Lyman Break Galaxies at z~2: Comparison with other Populations
We present results of a search for bright Lyman break galaxies at 1.5<=z<=2.5
in the GOODS-S field using a NUV-dropout technique in combination with
color-selection. We derived a sample of 73 LBG candidates. We compare our
selection efficiencies to BM/BX- and BzK methods (techniques solely based on
ground-based data sets), and find the NUV data to provide greater efficiency
for selecting star-forming galaxies. We estimate LBG candidate ages, masses,
star formation rates, and extinction from fitting PEGASE synthesis evolution
models. We find about 20% of our LBG candidates are comparable to infrared
luminous LBGs or sub-millimeter galaxies which are thought to be precursors of
massive elliptical galaxies today. Overall, we can show that although BM/BX and
BzK methods do identify star-forming galaxies at z~2, the sample they provide
biases against those star-forming galaxies which are more massive and contain
sizeable red stellar populations. A true Lyman break criterion at z~2 is
therefore more directly comparable to the populations found at z~3, which does
contain a red fraction.Comment: 14 pages, 11 figures, accepted for publication in Ap
The Subaru-XMM-Newton Deep Survey (SXDS) VIII.: Multi-wavelength Identification, Optical/NIR Spectroscopic Properties, and Photometric Redshifts of X-ray Sources
We report the multi-wavelength identification of the X-ray sources found in
the Subaru-XMM-Newton Deep Survey (SXDS) using deep imaging data covering the
wavelength range between the far-UV to the mid-IR. We select a primary
counterpart of each X-ray source by applying the likelihood ratio method to
R-band, 3.6micron, near-UV, and 24micron source catalogs as well as matching
catalogs of AGN candidates selected in 1.4GHz radio and i'-band variability
surveys. Once candidates of Galactic stars, ultra-luminous X-ray sources in a
nearby galaxy, and clusters of galaxies are removed there are 896 AGN
candidates in the sample. We conduct spectroscopic observations of the primary
counterparts with multi-object spectrographs in the optical and NIR; 65\% of
the X-ray AGN candidates are spectroscopically-identified. For the remaining
X-ray AGN candidates, we evaluate their photometric redshift with photometric
data in 15 bands. Utilising the multi-wavelength photometric data of the large
sample of X-ray selected AGNs, we evaluate the stellar masses, M*, of the host
galaxies of the narrow-line AGNs. The distribution of the stellar mass is
remarkably constant from z=0.1 to 4.0. The relation between M* and 2--10 keV
luminosity can be explained with strong cosmological evolution of the
relationship between the black hole mass and M*. We also evaluate the scatter
of the UV-MIR spectral energy distribution (SED) of the X-ray AGNs as a
function of X-ray luminosity and absorption to the nucleus. The scatter is
compared with galaxies which have redshift and stellar mass distribution
matched with the X-ray AGN. The UV-NIR SEDs of obscured X-ray AGNs are similar
to those of the galaxies in the matched sample. In the NIR-MIR range, the
median SEDs of X-ray AGNs are redder, but the scatter of the SEDs of the X-ray
AGN broadly overlaps that of the galaxies in the matched sample.Comment: Accepted for publication in PASJ Subaru special issue. 42 pages, 22
figures. Entire contents of Tables 3, 8, 9, 10, and 11, and ASCII format
tables are available from
http://www.astr.tohoku.ac.jp/~akiyama/SXDS/index.htm
On the physical properties of z~6-8 galaxies
We analyse the spectral energy distributions (SEDs) of the most distant
galaxies discovered with the Hubble Space telescope and from the COSMOS survey
and determine their physical properties, such as stellar age and mass, dust
attenuation, and star-formation rate. We use our SED fitting tool including the
effects of nebular emission to analyse three samples of z ~6-8 galaxies with
observed magnitudes J_AB~23 to 29. Our models cover a wide parameter space. We
find that the physical parameters of most galaxies cover a wide range of
acceptable values. Stellar ages, in particular, are not strongly constrained,
even for objects detected longward of the Balmer break. As already pointed out
earlier, the effects of nebular lines significantly affect the age
determinations of star-forming galaxies at z ~6-8. We find no need for stellar
populations with extreme metallicities or other non-standard assumptions (IMF,
escape fraction) to explain the observed properties of faint z-dropout
galaxies. Albeit with large uncertainties, our fit results show indications of
dust attenuation in some of the z ~6-8 galaxies, which have best-fit values of
A_V up to ~1. Furthermore, we find a possible trend of increasing dust
attenuation with galaxy mass, and a relatively large scatter in specific
star-formation rates, SFR/M*. The physical parameters of very high-z galaxies
may be more uncertain than indicated by previous studies. Dust attenuation
seems also to be present in some z ~6-8 galaxies, and may be correlated with
galaxy mass, as is also the case for SFR.Comment: Accepted for publication in Astronomy and Astrophysics. 28 Figures.
Final, language edited version, with Figs. 6 and 12 corrected
Initial Results from the Nobeyama Molecular Gas Observations of Distant Bright Galaxies
We present initial results from the CO survey toward high redshift galaxies
using the Nobeyama 45m telescope. Using the new wide bandwidth spectrometer
equipped with a two-beam SIS receiver, we have robust new detections of three
high redshift (z=1.6-3.4) submillimeter galaxies (SXDF 1100.001, SDP9, and
SDP17), one tentative detection (SDSS J160705+533558), and one non-detection
(COSMOS-AzTEC1). The galaxies observed during the commissioning phase are
sources with known spectroscopic redshifts from previous optical or from
wide-band submm spectroscopy. The derived molecular gas mass and line widths
from Gaussian fits are ~10^11 Msun and 430-530 km/s, which are consistent with
previous CO observations of distant submm galaxies and quasars. The
spectrometer that allows a maximum of 32 GHz instantaneous bandwidth will
provide new science capabilities at the Nobeyama 45m telescope, allowing us to
determine redshifts of bright submm selected galaxies without any prior
redshift information.Comment: 4 pages, 1 figure, PASJ Letter Accepte
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