313 research outputs found
Human gene copy number spectra analysis in congenital heart malformations
The clinical significance of copy number variants (CNVs) in congenital heart disease (CHD) continues to be a challenge. Although CNVs including genes can confer disease risk, relationships between gene dosage and phenotype are still being defined. Our goal was to perform a quantitative analysis of CNVs involving 100 well-defined CHD risk genes identified through previously published human association studies in subjects with anatomically defined cardiac malformations. A novel analytical approach permitting CNV gene frequency âspectraâ to be computed over prespecified regions to determine phenotype-gene dosage relationships was employed. CNVs in subjects with CHD (n = 945), subphenotyped into 40 groups and verified in accordance with the European Paediatric Cardiac Code, were compared with two control groups, a disease-free cohort (n = 2,026) and a population with coronary artery disease (n = 880). Gains (â„200 kb) and losses (â„100 kb) were determined over 100 CHD risk genes and compared using a Barnard exact test. Six subphenotypes showed significant enrichment (P †0.05), including aortic stenosis (valvar), atrioventricular canal (partial), atrioventricular septal defect with tetralogy of Fallot, subaortic stenosis, tetralogy of Fallot, and truncus arteriosus. Furthermore, CNV gene frequency spectra were enriched (P †0.05) for losses at: FKBP6, ELN, GTF2IRD1, GATA4, CRKL, TBX1, ATRX, GPC3, BCOR, ZIC3, FLNA and MID1; and gains at: PRKAB2, FMO5, CHD1L, BCL9, ACP6, GJA5, HRAS, GATA6 and RUNX1. Of CHD subjects, 14% had causal chromosomal abnormalities, and 4.3% had likely causal (significantly enriched), large, rare CNVs. CNV frequency spectra combined with precision phenotyping may lead to increased molecular understanding of etiologic pathways
Direct optimization across computer generated reaction networks balances materials use and feasibility of synthesis plans for molecule libraries
The synthesis of thousands of candidate compounds in drug discovery and development offers opportunities for computer-aided synthesis planning to simplify the synthesis of molecule libraries by leveraging common starting materials and reaction conditions. We develop an optimization-based method to analyze large organic chemical reaction networks and design overlapping synthesis plans for entire molecule libraries so as to minimize the overall number of unique chemical compounds needed as either starting materials or reaction conditions. We consider multiple objectives, including the number of starting materials, the number of catalysts/solvents/reagents, and the likelihood of success of the overall syntheses plan, to select an optimal reaction network to access the target molecules. The library synthesis planning task was formulated as a network flow optimization problem, and we design an efficient decomposition scheme that reduces solution time by a factor of 5 and scales to instance with 48 target molecules and nearly 8000 intermediate reactions within hours. In four case studies of pharmaceutical compounds, the approach reduces the number of starting materials and catalysts/solvents/reagents needed by 32.2 and 66.0% on average and up to 63.2 and 80.0% in the best cases. The code implementation can be found at [https://github.com/Coughy1991/Molecule_library_synthesis](https://github.com/Coughy1991/Molecule_library_synthesis)
Supporting information: [https://pubs.acs.org/doi/10.1021/acs.jcim.0c01032?goto=supporting-info](https://pubs.acs.org/doi/10.1021/acs.jcim.0c01032?goto=supporting-info
Suzaku measurement of Abell 2204's intracluster gas temperature profile out to 1800 kpc
Context: Measurements of intracluster gas temperatures out to large radii are
important for the use of clusters for precision cosmology and for studies of
cluster physics. Previous attempts to measure robust temperatures at cluster
virial radii failed. Aims: The goal of this work is to measure the temperature
profile of the very relaxed galaxy cluster Abell 2204 out to large radii,
possibly reaching the virial radius. Methods: Taking advantage of its low
particle background due to its low-Earth orbit, Suzaku data are used to measure
the outer temperature profile of Abell 2204. These data are combined with
Chandra and XMM-Newton data of the same cluster in order to make the connection
to the inner regions, unresolved by Suzaku, and to determine the smearing due
to Suzaku's PSF. Results: The temperature profile of Abell 2204 is determined
from 10 kpc to 1800 kpc, close to an estimate of r200 (the approximation to the
virial radius). The temperature rises steeply from below 4 keV in the very
center up to more than 8 keV in the intermediate range and then decreases again
to about 4 keV at the largest radii. Varying the measured particle background
normalization artificially by +-10 percent does not change the results
significantly. Predictions for outer temperature profiles based on hydrodynamic
simulations show good agreement. In particular, we find the observed
temperature profile to be slightly steeper but consistent with a drop of a
factor of 0.6 from 0.3 r200 to r200, as predicted by simulations. Conclusions:
Temperature measurements up to the virial radius seem feasible with Suzaku,
when a careful analysis of the different background components and the effects
of the PSF is performed. The result obtained here indicates that numerical
simulations capture the intracluster gas physics well in cluster outskirts.Comment: 7 pages; Astronomy and Astrophysics, accepted; additional systematic
effects have been quantified, results unchanged; also available at
http://www.reiprich.ne
The architecture of Abell 1386 and its relationship to the Sloan Great Wall
We present new radial velocities from AAOmega on the Anglo-Australian
Telescope for 307 galaxies (b_J < 19.5) in the region of the rich cluster Abell
1386. Consistent with other studies of galaxy clusters that constitute
sub-units of superstructures, we find that the velocity distribution of A1386
is very broad (21,000--42,000 kms^-1, or z=0.08--0.14) and complex. The mean
redshift of the cluster that Abell designated as number 1386 is found to be
~0.104. However, we find that it consists of various superpositions of
line-of-sight components. We investigate the reality of each component by
testing for substructure and searching for giant elliptical galaxies in each
and show that A1386 is made up of at least four significant clusters or groups
along the line of sight whose global parameters we detail. Peculiar velocities
of brightest galaxies for each of the groups are computed and found to be
different from previous works, largely due to the complexity of the sky area
and the depth of analysis performed in the present work. We also analyse A1386
in the context of its parent superclusters: Leo A, and especially the Sloan
Great Wall. Although the new clusters may be moving toward mass concentrations
in the Sloan Great Wall or beyond, many are most likely not yet physically
bound to it.Comment: 21 pages, 9 figures, includes the full appendix table. Accepted for
publication in MNRA
Deep high-resolution X-ray spectra from cool-core clusters
We examine deep XMM-Newton Reflection Grating Spectrometer (RGS) spectra from
the cores of three X-ray bright cool core galaxy clusters, Abell 262, Abell
3581 and HCG 62. Each of the RGS spectra show Fe XVII emission lines indicating
the presence of gas around 0.5 keV. There is no evidence for O VII emission
which would imply gas at still cooler temperatures. The range in detected gas
temperature in these objects is a factor of 3.7, 5.6 and 2 for Abell 262, Abell
3581 and HCG 62, respectively. The coolest detected gas only has a volume
filling fraction of 6 and 3 per cent for Abell 262 and Abell 3581, but is
likely to be volume filling in HCG 62. Chandra spatially resolved spectroscopy
confirms the low volume filling fractions of the cool gas in Abell 262 and
Abell 3581, indicating this cool gas exists as cold blobs. Any volume heating
mechanism aiming to prevent cooling would overheat the surroundings of the cool
gas by a factor of 4. If the gas is radiatively cooling below 0.5 keV, it is
cooling at a rate at least an order of magnitude below that at higher
temperatures in Abell 262 and Abell 3581 and two-orders of magnitude lower in
HCG 62. The gas may be cooling non-radiatively through mixing in these cool
blobs, where the energy released by cooling is emitted in the infrared. We find
very good agreement between smooth particle inference modelling of the cluster
and conventional spectral fitting. Comparing the temperature distribution from
this analysis with that expected in a cooling flow, there appears to be a even
larger break below 0.5 keV as compared with previous empirical descriptions of
the deviations of cooling flow models.Comment: 19 pages, 22 figures, accepted by MNRA
Cosmological parameters from the clustering of AGN
We attempt to put constraints on different cosmological and biasing models by
combining the recent clustering results of X-ray sources in the local () and distant universe ().Comment: 9 pages, 3 figures, to be published in the proceedings of the ''2nd
Hellenic Cosmology Workshop'', Athens 2001, eds, Manolis Plionis & Spiros
Kotsaki
Mark correlations: relating physical properties to spatial distributions
Mark correlations provide a systematic approach to look at objects both
distributed in space and bearing intrinsic information, for instance on
physical properties. The interplay of the objects' properties (marks) with the
spatial clustering is of vivid interest for many applications; are, e.g.,
galaxies with high luminosities more strongly clustered than dim ones? Do
neighbored pores in a sandstone have similar sizes? How does the shape of
impact craters on a planet depend on the geological surface properties? In this
article, we give an introduction into the appropriate mathematical framework to
deal with such questions, i.e. the theory of marked point processes. After
having clarified the notion of segregation effects, we define universal test
quantities applicable to realizations of a marked point processes. We show
their power using concrete data sets in analyzing the luminosity-dependence of
the galaxy clustering, the alignment of dark matter halos in gravitational
-body simulations, the morphology- and diameter-dependence of the Martian
crater distribution and the size correlations of pores in sandstone. In order
to understand our data in more detail, we discuss the Boolean depletion model,
the random field model and the Cox random field model. The first model
describes depletion effects in the distribution of Martian craters and pores in
sandstone, whereas the last one accounts at least qualitatively for the
observed luminosity-dependence of the galaxy clustering.Comment: 35 pages, 12 figures. to be published in Lecture Notes of Physics,
second Wuppertal conference "Spatial statistics and statistical physics
The XMMâNEWTON ⊠Project: I. The X-ray luminosity â temperature relation at z>0.4
We describe XMM-Newton Guaranteed Time observations of a sample of eight high redshift (0.45 < z < rvirial) bolometric luminosities, performed ÎČ-model fits to the radial surface profiles and made spectral fits to a single temperature isothermal model. We describe data analysis techniques that pay particular attention to background mitigation. We have also estimated temperatures and luminosities for two known clusters (Abell 2246 and RXJ1325.0-3814), and one new high redshift cluste r candidate (XMMU J084701.8 +345117), that were detected o ff-axis. Characterizing the L x â Tx relation as L x = L 6 ( T 6keV ) α , we find L 6 = 15 . 9 + 7 . 6 â 5 . 2 Ă 1044erg s â 1 and α =2.7 ±0.4 for an ⊠Π= 0 . 0 , ⊠M = 1 .0, H0 = 50 km s â 1 Mpc â 1 cosmology at a typical redshift z ⌠0 .55. Comparing with the low redshift study by Markevitch, 1998, we find α to be in agreement, and assuming L x â Tx to evolve as (1 + z ) A , we find A =0.68 ±0.26 for the same cosmology and A = 1 .52 + 0 .26 â 0 .27 for an ⊠Π= 0 . 7 , ⊠M = 0 . 3 cosmology. Our A values are very similar to those found previously by Vikhlinin et al., 2002 using a compilation of Chandra observations of 0 .39 < z < 1 .26 clusters. We conclude that there is now evidence from both XMM-Newton and Chandra for an evolutionary trend in the L x â Tx relation. This evolution is significantly below the level expected from the predictions of the self-similar model for an ⊠Π= 0 . 0 , ⊠M = 1 .0, cosmology, but consistent with self-similar model in an ⊠Π= 0 . 7 , ⊠M = 0 . 3 cosmology. Our observations lend support to the robustness and completeness of the SHARC and 160SD surveys
Evidence for Companion-Induced Secular Changes in the Turbulent Disk of a Be Star in the LMC MACHO Database
The light curve of a blue variable in the MACHO LMC database (FTS ID
78.5979.72) appeared nearly unvarying for ~4 years (quasi-flat segment) but
then rapidly changed to become periodic with noisy minima for the remaining 4
years (periodic segment); there are no antecedent indications of a gradual
approach to this change. Lomb Periodogram analyses indicate the presence of two
distinct periods of ~61 days and 8 days in both the quasi-flat and the periodic
segments. Minima of the periodic segment cover at least 50% of the orbital
period and contain spikes of light with the 8-day period; maxima do not show
this short period. The system typically shows maxima to be redder than minima.
The most recent OGLE-III light curve shows only a 30-day periodicity. The
variable's V and R magnitudes and color are those of a Be star, and recent sets
of near infrared spectra four days apart, secured during the time of the
OGLE-III data, show H-alpha emission near and at a maximum, confirming its Be
star characteristics. The model that best fits the photometric behavior
consists of a thin ring-like circumstellar disk of low mass with four obscuring
sectors orbiting the central B star in unison at the 61-day period. The central
star peers through the three equi- spaced separations between the four sectors
producing the 8-day period. The remainder of the disk contains hydrogen in
emission making maxima appear redder. A companion star of lower mass in an
inclined and highly eccentric orbit produces an impulsive perturbation near its
periastron to change the disk's orientation, changing eclipses from partial to
complete within ~ 10 days.Comment: 42 pages, 14 figures, and 2 tables Submitted to AJ v3: Title changed,
figures added, model modifie
Radial kinematics of brightest cluster galaxies
This is the first of a series of papers devoted to the investigation of a large sample of brightest cluster galaxies (BCGs), their kinematic and stellar population properties, and the relationships between those and the properties of the cluster. We have obtained high signal-to-noise ratio, long-slit spectra of these galaxies with Gemini and William Herschel Telescope with the primary purpose of investigating their stellar population properties. This paper describes the selection methods and criteria used to compile a new sample of galaxies, concentrating on BCGs previously classified as containing a halo (cD galaxies), together with the observations and data reduction. Here, we present the full sample of galaxies, and the measurement and interpretation of the radial velocity and velocity dispersion profiles of 41 BCGs. We find clear rotation curves for a number of these giant galaxies. In particular, we find rapid rotation (>100 km sâ1) for two BCGs, NGC 6034 and 7768, indicating that it is unlikely that they formed through dissipationless mergers. Velocity substructure in the form of kinematically decoupled cores is detected in 12 galaxies, and we find five galaxies with velocity dispersion increasing with radius. The amount of rotation, the velocity substructure and the position of BCGs on the anisotropyâluminosity diagram are very similar to those of âordinaryâ giant ellipticals in high-density environments
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