1,769 research outputs found
Improved electrodes for skin contacts
Design is described of thick, flexible electrodes with appropriate metal surfaces which prevent unnecessary skin motion. Electrodes provide sufficient radial pressure directed toward body surface to depress skin a noticeable portion of its normal resilient thickness
On the possible role of massive neutrinos in cosmological structure formation
In addition to the problem of galaxy formation, one of the greatest open
questions of cosmology is represented by the existence of an asymmetry between
matter and antimatter in the baryonic component of the Universe. We believe
that a net lepton number for the three neutrino species can be used to
understand this asymmetry. This also implies an asymmetry in the
matter-antimatter component of the leptons. The existence of a nonnull lepton
number for the neutrinos can easily explain a cosmological abundance of
neutrinos consistent with the one needed to explain both the rotation curves of
galaxies and the flatness of the Universe. Some propedeutic results are
presented in order to attack this problem.Comment: RevTeX4, 25 pages, 5 figures, to appear in the "Proceedings of the
Xth Brazilian School of Cosmology and Gravitation", M. Novello, editor, AIP,
in pres
Evidence for orbital motion of CW Leonis from ground-based astrometry
© 2017 The Authors.Recent Atacama Large Millimeter/submillimeter Array (ALMA) observations indicate that CW Leo, the closest carbon-rich asymptotic giant branch star to Sun, might have a low-mass stellar companion. We present archival ground-based astrometric measurements of CW Leo obtained within the context of the Torino Parallax Program and with > 6 yr (1995-2001) of time baseline. The residuals to a single-star solution show significant curvature, and they are strongly correlatedwith thewell-known I-band photometric variations due to stellar pulsations. We describe successfully the astrometry of CW Leo with a variability-induced motion (VIM) + acceleration model. We obtain proper motion and parallax of the centre-of-mass of the binary, the former in fair agreement with recent estimates, the latter at the near end of the range of inferred distances based on indirect methods. The VIM + acceleration model results allow us to derive a companion mass in agreement with that inferred by ALMA, they point towards a somewhat longer period than implied by ALMA, but are not compatible with much longer period estimates. These data will constitute a fundamental contribution towards the full understanding of the orbital architecture of the system when combined with Gaia astrometry, providing an ~25 yr time baseline.Peer reviewe
Testing Planet Formation Models with Gaia as Astrometry
In this paper, we first summarize the results of a large-scale double-blind
tests campaign carried out for the realistic estimation of the Gaia potential
in detecting and measuring planetary systems. Then, we put the identified
capabilities in context by highlighting the unique contribution that the Gaia
exoplanet discoveries will be able to bring to the science of extrasolar
planets during the next decade.Comment: 4 pages, 1 figure. To appear in the proceedings of "IAU Symposium 248
- A Giant Step: from Milli- to Micro-arcsecond Astrometry", held in Shanghai,
China, 15-19 Oct. 200
Gaia: The Astrometry Revolution
The power of micro-arcsecond (as) astrometry is about to be unleashed.
ESA's Gaia mission, now headed towards the end of the first year of routine
science operations, will soon fulfil its promise for revolutionary science in
countless aspects of Galactic astronomy and astrophysics. The potential of Gaia
position measurements for important contributions to the astrophysics of
planetary systems is huge. We focus here on the expectations for detection and
improved characterization of 'young' planetary systems in the neighborhood of
the Sun using a combination of Gaia as astrometry and direct imaging
techniques.Comment: 6 pages, 3 figures, to appear in the Proceedings of IAU Symposium 314
'Young Stars & Planets Near the Sun', held on May 11-15 2015 in Atlanta (GA),
USA (J. H. Kastner, B. Stelzer, & S. A. Metchev, eds.
Arginine 125 is an essential residue for the function of MRAP2
MRAP2 is a small simple transmembrane protein arranged in a double antiparallel topology
on the plasma membrane. It is expressed in the paraventricular nucleus of the hypothalamus, where
it interacts with various G protein-coupled receptors, such as the prokineticin receptors, and regulates
energy expenditure and appetite. The aim of this work was to analyze the functional role of the specific
arginine residue at position 125 of MRAP2, which affects protein conformation, dimer formation,
and PKR2 binding. Results obtained with the MRAP2 mutants R125H and R125C, which are found
in human patients with extreme obesity, and mouse MRAP2, in which arginine 125 is normally
replaced by histidine, were compared with those obtained with human MRAP2. Understanding
the mechanism by which MRAP2 regulates G protein-coupled receptors helps in elucidating the
metabolic pathways involved in metabolic dysfunction and in developing new drugs as specific
targets of the MRAP2-PKR2 complex
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