7,036 research outputs found
Modulation of the cytosolic androgen receptor in striated muscle by sex steroids
The influence of orchiectomy (GDX) and steroid administration on the level of the cytosolic androgen receptor in the rat levator ani muscle and in rat skeletal muscles (tibialis anterior and extensor digitorum longus) was studied. Androgen receptor binding to muscle cytosol was measured using H-3 methyltrienolone (R1881) as ligand, 100 fold molar excess unlabeled R1881 to assess nonspecific binding, and 500 fold molar excess of triamcinolone acetonide to prevent binding to glucocorticoid and progestin receptors. Results demonstrate that modification of the levels of sex steroids can alter the content of androgen receptors of rat striated muscle. Data suggest that: (1) cytosolic androgen receptor levels increase after orchiectomy in both levator ani muscle and skeletal muscle; (2) the acute increase in receptor levels is blocked by an inhibitor of protein synthesis; and (3) administration of estradiol-17 beta to castrated animals increases receptor binding in levator ani muscle but not in skeletal muscle
Transcriptome analysis of the synganglion from the honey bee mite, Varroa destructor and RNAi knockdown of neural peptide targets
Acknowledgements This work was funded by BBSRC-LINK grant # BB/J01009X/1 and Vita Europe Ltd. We are grateful to the Scottish Beekeepers Association, especially Mr Phil McAnespie in supporting this work at its inception. We acknowledge partial funding from a Genesis Faraday SPARK Award, part of a Scottish Government SEEKIT project for the early part of this work. We are grateful to Prof David Evans for his advice on Varroa destructor viruses.Peer reviewedPostprin
Rapid communication: Physical and genetic mapping of the Peroxisome Proliferator Activated Receptor Ī³ (PPARĪ³) gene to porcine chromosome 13
Genus and Species. Sus scrofa. Locus Name. Peroxisome Proliferator Activated Receptor gamma (PPARĪ³). Source and Description of Primers. Primers were designed in exon 5 from a published porcine cDNA sequence (GenBank accession no. AJ006756). Forward primer: 5ā² GAC ATG AAT TCC TTA ATG 3ā²; reverse primer: 5ā² ACT TCA CAG CGA ACT CGA ACT T 3ā²
Spatially Resolved Stellar Populations of Eight GOODS-South Active Galactic Nuclei at z ~ 1
We present a pilot study of the stellar populations of eight active galactic nucleus (AGN) hosts at z ~ 1 and compare with (1) lower redshift samples and (2) a sample of nonactive galaxies of similar redshift. We utilize K' images in the Great Observatories Origins Deep Survey South field obtained with the laser guide star adaptive optics system at Keck Observatory. We combine these K' data with B, V, i, and z imaging from the Advanced Camera for Surveys on Hubble Space Telescope to give multicolor photometry at a matched spatial resolution better than 100 mas in all bands. The hosts harbor AGNs as inferred from their high X-ray luminosities (LX > 10^42 erg s^ā1) or mid-IR colors. We find a correlation between the presence of younger stellar populations and the strength of the AGN, as measured with [O III] line luminosity or X-ray (2-10 keV) luminosity. This finding is consistent with similar studies at lower redshift. Of the three Type II galaxies, two are disk galaxies and one is of irregular type, while in the Type I sample there are only one disk-like source and four sources with smooth, elliptical/spheroidal morphologies. In addition, the mid-IR spectral energy distributions of the strong Type II AGNs indicate that they are excited to Luminous InfraRed Galaxy (LIRG) status via galactic starbursting, while the strong Type I AGNs are excited to LIRG status via hot dust surrounding the central AGN. This supports the notion that the obscured nature of Type II AGNs at z ~ 1 is connected with global starbursting and that they may be extincted by kpc-scale dusty features that are by-products of this starbursting
The First Galaxies: Clues from Element Abundances
It has recently become possible to measure directly the abundances of several
chemical elements in a variety of environments at redshifts up to z = 5. In
this review I summarise the latest observations of Lyman break galaxies, damped
Lyman alpha systems and the Lyman alpha forest with a view to uncovering any
clues which these data may offer to the first episodes of star formation. The
picture which is emerging is one where the universe at z = 3 already included
many of the components of today's galaxies--even at these early times we see
evidence for Populations I and II stars, while the `smoking gun' for Population
III objects may be hidden in the chemical composition of the lowest density
regions of the IGM, yet to be deciphered.Comment: 15 pages, LaTex, 8 Postscript Figures. To appear in the Philosophical
Transactions of The Royal Society, Series
Rapid communication: Physical and linkage mapping of the porcine calcitonin (CALC) gene
Genus and Species. Sus scrofa. Locus. Porcine calcitonin (CALC) gene. Source and Description of Primers. Primers, CCA1F and CCA1R, were designed from canine calcitonin sequence (GenBank Accession no. AJ271090) to amplify genomic porcine DNA. Using sequence obtained from the amplified PCR product, additional pig-specific primers (CIPBF, CIPBR, CIPCF, CIPCR) were designed
Mapping and Investigation of Novel Candidate Genes for Fatness, Growth, and Feed Intake in the Pig
Five new candidate genes for fatness, growth, and feed intake traits were studied. The genes were chosen based on their presumed biological action for a given trait of interest. A molecular genetics polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) approach was used to identify genetic differences (polymorphisms) in the porcine melanocortin-4 receptor (MC4R), melanocortin-5 receptor (MC5R), cocaine and amphetamine-regulated transcript (CART), peroxisome proliferator activated receptor _ (PPAR_), and prepro-orexin genes. These genes were genetically mapped using several markers on porcine chromosomes (SSC) 1, 6, 12, 13, and 16, respectively. All five genes also were physically mapped with a pig/rodent somatic cell hybrid panel. The physical locations of all five genes are as follows: MC4R (SSC1q22-27), MC5R (SSC6q24-(1/2)q31), prepro-orexin (SSC12p13- p11), PPAR_ (SSC13q23-q41), and CART (SSC16q21). The localization of these genes is reasonably consistent with previous chromosome painting results, indicating conserved (similar) regions between human and pig chromosomes. We also looked at the effect of these genes on traits of interest. The effect of a MC4R polymorphism was investigated in a large population of pigs from several commercial lines. MC4R genotypes were significantly associated with fatness, growth rate, and feed intake traits. Further studies on the effect of these candidate genes are underway
A new 1.6-micron map of Titanās surface
We present a new map of Titan's surface obtained in the spectral 'window' at ā¼1.6 Ī¼m between strong methane absorption. This pre-Cassini view of Titan's surface was created from images obtained using adaptive optics on the W.M. Keck II telescope and is the highest resolution map yet made of Titan's surface. Numerous surface features down to the limits of the spatial resolution (ā¼200ā300 km) are apparent. No features are easily identifiable in terms of their geologic origin, although several are likely craters
Integrated Laboratory Demonstrations of Multi-Object Adaptive Optics on a Simulated 10-Meter Telescope at Visible Wavelengths
One important frontier for astronomical adaptive optics (AO) involves methods
such as Multi-Object AO and Multi-Conjugate AO that have the potential to give
a significantly larger field of view than conventional AO techniques. A second
key emphasis over the next decade will be to push astronomical AO to visible
wavelengths. We have conducted the first laboratory simulations of wide-field,
laser guide star adaptive optics at visible wavelengths on a 10-meter-class
telescope. These experiments, utilizing the UCO/Lick Observatory's Multi-Object
/ Laser Tomography Adaptive Optics (MOAO/LTAO) testbed, demonstrate new
techniques in wavefront sensing and control that are crucial to future on-sky
MOAO systems. We (1) test and confirm the feasibility of highly accurate
atmospheric tomography with laser guide stars, (2) demonstrate key innovations
allowing open-loop operation of Shack-Hartmann wavefront sensors (with errors
of ~30 nm) as will be needed for MOAO, and (3) build a complete error budget
model describing system performance. The AO system maintains a performance of
32.4% Strehl on-axis, with 24.5% and 22.6% at 10" and 15", respectively, at a
science wavelength of 710 nm (R-band) over the equivalent of 0.8 seconds of
simulation. The MOAO-corrected field of view is ~25 times larger in area than
that limited by anisoplanatism at R-band. Our error budget is composed of terms
verified through independent, empirical experiments. Error terms arising from
calibration inaccuracies and optical drift are comparable in magnitude to
traditional terms like fitting error and tomographic error. This makes a strong
case for implementing additional calibration facilities in future AO systems,
including accelerometers on powered optics, 3D turbulators, telescope and LGS
simulators, and external calibration ports for deformable mirrors.Comment: 29 pages, 11 figures, submitted to PAS
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