1,284 research outputs found
Duplication and diversification of the LEAFY HULL STERILE1 and Oryza sativa MADS5 SEPALLATA lineages in graminoid Poales
<p>Abstract</p> <p>Background</p> <p>Gene duplication and the subsequent divergence in function of the resulting paralogs via subfunctionalization and/or neofunctionalization is hypothesized to have played a major role in the evolution of plant form. The <it>LEAFY HULL STERILE1 (LHS1) SEPALLATA </it>(<it>SEP</it>) genes have been linked with the origin and diversification of the grass spikelet, but it is uncertain 1) when the duplication event that produced the <it>LHS1 </it>clade and its paralogous lineage <it>Oryza sativa MADS5 (OSM5) </it>occurred, and 2) how changes in gene structure and/or expression might have contributed to subfunctionalization and/or neofunctionalization in the two lineages.</p> <p>Methods</p> <p>Phylogenetic relationships among 84 <it>SEP </it>genes were estimated using Bayesian methods. RNA expression patterns were inferred using <it>in situ </it>hybridization. The patterns of protein sequence and RNA expression evolution were reconstructed using maximum parsimony (MP) and maximum likelihood (ML) methods, respectively.</p> <p>Results</p> <p>Phylogenetic analyses mapped the <it>LHS1/OSM5 </it>duplication event to the base of the grass family. MP character reconstructions estimated a change from cytosine to thymine in the first codon position of the first amino acid after the <it>Zea mays MADS3 </it>(<it>ZMM3</it>) domain converted a glutamine to a stop codon in the <it>OSM5 </it>ancestor following the <it>LHS1/OSM5 </it>duplication event. RNA expression analyses of <it>OSM5 </it>co-orthologs in <it>Avena sativa, Chasmanthium latifolium, Hordeum vulgare, Pennisetum glaucum</it>, and <it>Sorghum bicolor </it>followed by ML reconstructions of these data and previously published analyses estimated a complex pattern of gain and loss of <it>LHS1 </it>and <it>OSM5 </it>expression in different floral organs and different flowers within the spikelet or inflorescence.</p> <p>Conclusions</p> <p>Previous authors have reported that rice OSM5 and LHS1 proteins have different interaction partners indicating that the truncation of OSM5 following the <it>LHS1/OSM5 </it>duplication event has resulted in both partitioned and potentially novel gene functions. The complex pattern of <it>OSM5 </it>and <it>LHS1 </it>expression evolution is not consistent with a simple subfunctionalization model following the gene duplication event, but there is evidence of recent partitioning of <it>OSM5 </it>and <it>LHS1 </it>expression within different floral organs of <it>A. sativa, C. latifolium, P. glaucum </it>and <it>S. bicolor</it>, and between the upper and lower florets of the two-flowered maize spikelet.</p
Recommended from our members
Analysis of Regional Mechanics in Canine Lung Injury Using Forced Oscillations and 3D Image Registration
Acute lung injury is characterized by heterogeneity of regional mechanical properties, which is thought to be correlated with disease severity. The feasibility of using respiratory input impedance () and computed tomographic (CT) image registration for assessing parenchymal mechanical heterogeneity was evaluated. In six dogs, measurements of () before and after oleic acid injury at various distending pressures were obtained, followed by whole lung CT scans. Each () spectrum was fit with a model incorporating variable distributions of regional compliances. CT image pairs at different inflation pressures were matched using an image registration algorithm, from which distributions of regional compliances from the resulting anatomic deformation fields were computed. Under baseline conditions, average model compliance decreased with increasing inflation pressure, reflecting parenchymal stiffening. After lung injury, these average compliances decreased at each pressure, indicating derecruitment, alveolar flooding, or alterations in intrinsic tissue elastance. However, average compliance did not change as inflation pressure increased, consistent with simultaneous recruitment and strain stiffening. Image registration revealed peaked distributions of regional compliances, and that small portions of the lung might undergo relative compression during inflation. The authors conclude that assessments of lung function using () combined with the structural alterations inferred from image registration provide unique but complementary information on the mechanical derangements associated with lung injury
What asteroseismology can do for exoplanets
We describe three useful applications of asteroseismology in the context of
exoplanet science: (1) the detailed characterisation of exoplanet host stars;
(2) the measurement of stellar inclinations; and (3) the determination of
orbital eccentricity from transit duration making use of asteroseismic stellar
densities. We do so using the example system Kepler-410 (Van Eylen et al.
2014). This is one of the brightest (V = 9.4) Kepler exoplanet host stars,
containing a small (2.8 Rearth) transiting planet in a long orbit (17.8 days),
and one or more additional non-transiting planets as indicated by transit
timing variations. The validation of Kepler-410 (KOI-42) was complicated due to
the presence of a companion star, and the planetary nature of the system was
confirmed after analyzing a Spitzer transit observation as well as ground-based
follow-up observations.Comment: 4 pages, Proceedings of the CoRoT Symposium 3 / Kepler KASC-7 joint
meeting, Toulouse, 7-11 July 2014. To be published by EPJ Web of Conference
Third Order Effect of Rotation on Stellar Oscillations of a -Cephei Star
Here the effect of rotation up to third order in the angular velocity of a
star on the p, f and g modes is investigated. To do this, the third-order
perturbation formalism presented by Soufi et al. (1998) and revised by Karami
(2008), was used. I quantify by numerical calculations the effect of rotation
on the oscillation frequencies of a uniformly rotating -Cephei star with
12 . For an equatorial velocity of 90 , it is found
that the second- and third-order corrections for , for instance,
are of order of 0.07% of the frequency for radial order and reaches up
to 0.6% for .Comment: 13 pages, 2 figures, 10 table
The co-presence of clarity and ambiguity in strategic corporate communication:an exploratory study
HD 181068: A Red Giant in a Triply-Eclipsing Compact Hierarchical Triple System
Hierarchical triple systems comprise a close binary and a more distant
component. They are important for testing theories of star formation and of
stellar evolution in the presence of nearby companions. We obtained 218 days of
Kepler photometry of HD 181068 (magnitude of 7.1), supplemented by groundbased
spectroscopy and interferometry, which show it to be a hierarchical triple with
two types of mutual eclipses. The primary is a red giant that is in a 45-day
orbit with a pair of red dwarfs in a close 0.9-day orbit. The red giant shows
evidence for tidally-induced oscillations that are driven by the orbital motion
of the close pair. HD 181068 is an ideal target for studies of dynamical
evolution and testing tidal friction theories in hierarchical triple systems.Comment: 22 pages, including supporting on-line material. This is the author's
version of the work. It is posted here by permission of the AAAS for personal
use, not for redistribution. The definitive version was published in Science
Vol. 332 no. 6026 pp. 216-218 (8 April 2011), doi:10.1126/science.1201762.
http://www.sciencemag.org/content/332/6026/216.ful
MUSE Analysis of Gas around Galaxies (MAGG) - I: Survey design and the environment of a near pristine gas cloud at z ≈ 3.5
We present the design, methods, and first results of the MUSE Analysis of Gas around Galaxies (MAGG) survey, a large programme on the Multi Unit Spectroscopic Explorer (MUSE) instrument at the Very Large Telescope (VLT) which targets 28 z > 3.2 quasars to investigate the connection between optically-thick gas and galaxies at z ∼ 3 − 4. MAGG maps the environment of 52 strong absorption line systems at z ≳ 3, providing the first statistical sample of galaxies associated with gas-rich structures in the early Universe. In this paper, we study the galaxy population around a very metal poor gas cloud at z ≈ 3.53 towards the quasar J124957.23−015928.8. We detect three Lyα emitters within ≲200 km s−1 of the cloud redshift, at projected separations ≲185 kpc (physical). The presence of star-forming galaxies near a very metal-poor cloud indicates that metal enrichment is still spatially inhomogeneous at this redshift. Based on its very low metallicity and the presence of nearby galaxies, we propose that the most likely scenario for this LLS is that it lies within a filament which may be accreting onto a nearby galaxy. Taken together with the small number of other LLSs studied with MUSE, the observations to date show a range of different environments near strong absorption systems. The full MAGG survey will significantly expand this sample and enable a statistical analysis of the link between gas and galaxies to pin down the origin of these diverse environments at z ≈ 3 − 4
Taurolidine-citrate lock solution (TauroLock) significantly reduces CVAD-associated grampositive infections in pediatric cancer patients
<p>Abstract</p> <p>Background</p> <p>Taurolidin/Citrate (TauroLock™), a lock solution with broad spectrum antimicrobial activity, may prevent bloodstream infection (BSI) due to coagulase-negative staphylococci (CoNS or 'MRSE' in case of methicillin-resistant isolates) in pediatric cancer patients with a long term central venous access device (CVAD, Port- or/Broviac-/Hickman-catheter type).</p> <p>Methods</p> <p>In a single center prospective 48-months cohort study we compared all patients receiving anticancer chemotherapy from April 2003 to March 2005 (group 1, heparin lock with 200 IU/ml sterile normal saline 0.9%; Canusal<sup>® </sup>Wockhardt UK Ltd, Wrexham, Wales) and all patients from April 2005 to March 2007 (group 2; taurolidine 1.35%/Sodium Citrate 4%; TauroLock™, Tauropharm, Waldbüttelbrunn, Germany).</p> <p>Results</p> <p>In group 1 (heparin), 90 patients had 98 CVAD in use during the surveillance period. 14 of 30 (47%) BSI were 'primary Gram positive BSI due to CoNS (n = 4) or MRSE (n = 10)' [incidence density (ID); 2.30 per 1000 inpatient CVAD-utilization days].</p> <p>In group 2 (TauroLock™), 89 patients had 95 CVAD in use during the surveillance period. 3 of 25 (12%) BSI were caused by CoNS. (ID, 0.45). The difference in the ID between the two groups was statistically significant (P = 0.004).</p> <p>Conclusion</p> <p>The use of Taurolidin/Citrate (TauroLock™) significantly reduced the number and incidence density of primary catheter-associated BSI due to CoNS and MRSE in pediatric cancer patients.</p
Human RTEL1 associates with Poldip3 to facilitate responses to replication stress and R-loop resolution
International audienc
Evaluating the use of the Child and Adolescent Intellectual Disability Screening Questionnaire (CAIDS-Q) to estimate IQ in children with low intellectual ability
In situations where completing a full intellectual assessment is not possible or desirable the clinician or researcher may require an alternative means of accurately estimating intellectual functioning. There has been limited research in the use of proxy IQ measures in children with an intellectual disability or low IQ. The present study aimed to provide a means of converting total scores from a screening tool (the Child and Adolescent Intellectual Disability Screening Questionnaire: CAIDS-Q) to an estimated IQ. A series of linear regression analyses were conducted on data from 428 children and young people referred to clinical services, where FSIQ was predicted from CAIDS-Q total scores. Analyses were conducted for three age groups between ages 6 and 18 years. The study presents a conversion table for converting CAIDS-Q total scores to estimates of FSIQ, with corresponding 95% prediction intervals to allow the clinician or researcher to estimate FSIQ scores from CAIDS-Q total scores. It is emphasised that, while this conversion may offer a quick means of estimating intellectual functioning in children with a below average IQ, it should be used with caution, especially in children aged between 6 and 8 years old
- …