4,092 research outputs found
Linkage analysis of systolic blood pressure: a score statistic and computer implementation
A genome-wide linkage analysis was conducted on systolic blood pressure using a score statistic. The randomly selected Replicate 34 of the simulated data was used. The score statistic was applied to the sibships derived from the general pedigrees. An add-on R program to GENEHUNTER was developed for this analysis and is freely available
Outflow and hot dust emission in broad absorption line quasars
We have investigated a sample of 2099 broad absorption line (BAL) quasars
with z=1.7-2.2 built from the Sloan Digital Sky Survey Data Release Seven and
the Wide-field Infrared Survey. This sample is collected from two BAL quasar
samples in the literature, and refined by our new algorithm. Correlations of
outflow velocity and strength with hot dust indicator (beta_NIR) and other
quasar physical parameters, such as Eddington ratio, luminosity and UV
continuum slope, are explored in order to figure out which parameters drive
outflows. Here beta_NIR is the near-infrared continuum slope, a good indicator
of the amount of hot dust emission relative to accretion disk emission. We
confirm previous findings that outflow properties moderately or weakly depends
on Eddington ratio, UV slope and luminosity. For the first time, we report
moderate and significant correlations of outflow strength and velocity with
beta_NIR in BAL quasars. It is consistent with the behavior of blueshifted
broad emission lines in non-BAL quasars. The statistical analysis and composite
spectra study both reveal that outflow strength and velocity are more strongly
correlated with beta_NIR than Eddington ratio, luminosity and UV slope. In
particular, the composites show that the entire C IV absorption profile shifts
blueward and broadens as beta_NIR increases, while Eddington ratio and UV slope
only affect the high and low velocity part of outflows, respectively. We
discuss several potential processes and suggest that dusty outflow scenario,
i.e. dust is intrinsic to outflows and may contribute to the outflow
acceleration, is most likely. The BAL quasar catalog is available from the
authors upon request.Comment: 16 pages, 10 figures, 2 tables; Accepted for publication in The
Astrophysical Journa
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A key variant in the cis-regulatory element of flowering gene Ghd8 associated with cold tolerance in rice.
Variations in the gene promoter play critical roles in the evolution of important adaptive traits in crops, but direct links of the regulatory mutation to the adaptive change are not well understood. Here, we examine the nucleotide variations in the promoter region of a transcription factor (Ghd8) that control grain number, plant height and heading date in rice. We find that a dominant promoter type of subspecies japonica displayed a high activity for Ghd8 expression in comparison with the one in indica. Transgenic analyses revealed that higher expression levels of Ghd8 delayed heading date and enhanced cold tolerance in rice. Furthermore, a single-nucleotide polymorphism (T1279G) at the position -1279 bp that locates on the potential GA-responsive motif in the Ghd8 promoter affected the expression of this gene. The 1279 T variant has elevated expression of Ghd8, thus conferring increased cold tolerance of rice seedlings. Nucleotide diversity analysis revealed that the approximately 25-kb genomic region surrounding Ghd8 in the subspecies japonica was under significant selection pressure. Our findings demonstrate that the join effects of the regulatory and coding variants largely contribute to the divergence of japonica and indica and increase the adaptability of japonica to the cold environment
Dissect two-halo galactic conformity effect for central galaxies: The dependence of star formation activities on the large-scale environment
We investigate the two-halo galactic conformity effect for central galaxies,
which is the spatial correlation of the star formation activities for central
galaxies to several Mpcs, by studying the dependence of the star formation
activities of central galaxies on their large-scale structure in our local
Universe using the SDSS data. Here we adopt a novel environment metric using
only central galaxies quantified by the distance to the -th nearest central
galaxy. This metric measures the environment within an aperture from 1
Mpc to 10 Mpc, with a median value of 4 Mpc. We found that two
kinds of conformity effects in our local Universe. The first one is that
low-mass central galaxies are more quenched in high-density regions, and we
found that this effect mainly comes from low-mass centrals that are close to a
more massive halo. A similar trend is also found in the IllustrisTNG
simulation, which can be entirely explained by backsplash galaxies. The second
conformity effect is that massive central galaxies in low-density regions are
more star-forming. This population of galaxies also possesses a higher fraction
of spiral morphology and lower central stellar velocity dispersion, suggesting
that their low quiescent fraction is due to less-frequent major merger events
experienced in the low-density regions, and as a consequence, less-massive
bulges and central black holes.Comment: 13 pages, 9 figures, accepted by MNRA
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