7 research outputs found
Parent Stars of Extrasolar Planets VII: New Abundance Analyses of 30 Systems
The results of new spectroscopic analyses of 30 stars with giant planet
and/or brown dwarf companions are presented. Values for Teff and [Fe/H] are
used in conjunction with Hipparcos data and Padova isochrones to derive masses,
ages, and theoretical surface gravities. These new data are combined with
spectroscopic and photometric metallicity estimates of other stars harboring
planets and published samples of F, G, and K dwarfs to compare several subsets
of planet bearing stars with similarly well-constrained control groups. The
distribution of [Fe/H] values continues the trend uncovered in previous studies
in that stars hosting planetary companions have a higher mean value than
otherwise similar nearby stars. We also investigate the relationship between
stellar mass and the presence of giant planets and find statistically marginal
but suggestive evidence of a decrease in the incidence of radial velocity
companions orbiting relatively less massive stars. If confirmed with larger
samples, this would represent a critical constraint to both planetary formation
models as well as to estimates of the distribution of planetary systems in our
galaxy.Comment: 27 pages, 13 figures. Accepted for publication in The Astronomical
Journa
miRâ29 contributes to normal endothelial function and can restore it in cardiometabolic disorders
Abstract We investigated the role of microRNAs (miRNA) in endothelial dysfunction in the setting of cardiometabolic disorders represented by type 2 diabetes mellitus (T2DM). miRâ29 was dysregulated in resistance arterioles obtained by biopsy in T2DM patients. Intraluminal delivery of miRâ29aâ3p or miRâ29bâ3p mimics restored normal endotheliumâdependent vasodilation (EDVD) in T2DM arterioles that otherwise exhibited impaired EDVD. Intraluminal delivery of antiâmiRâ29bâ3p in arterioles from nonâDM human subjects or rats or targeted mutation of Mir29bâ1/a gene in rats led to impaired EDVD and exacerbation of hypertension in the rats. miRâ29bâ3p mimic increased, while antiâmiRâ29bâ3p or Mir29bâ1/a gene mutation decreased, nitric oxide levels in arterioles. The mutation of Mir29bâ1/a gene led to preferential differential expression of genes related to nitric oxide including Lypla1. Lypla1 was a direct target of miRâ29 and could abrogate the effect of miRâ29 in promoting nitric oxide production. Treatment with Lypla1 siRNA improved EDVD in arterioles obtained from T2DM patients or Mir29bâ1/a mutant rats or treated with antiâmiRâ29bâ3p. These findings indicate miRâ29 is required for normal endothelial function in humans and animal models and has therapeutic potential for cardiometabolic disorders