1,555 research outputs found
The Origin of \lya Absorption Systems at ---Implications from the Hubble Deep Field
The Hubble Deep Field images have provided us with a unique chance to relate
statistical properties of high-redshift galaxies to statistical properties of
\lya absorption systems. Combining an {\em empirical} measure of the galaxy
surface density versus redshift with an {\em empirical} measure of the gaseous
extent of galaxies, we predict the number density of \lya absorption systems
that originate in extended gaseous envelopes of galaxies versus redshift. We
show that at least 50% and as much as 100% of observed \lya absorption systems
of W\apg0.32 \AA can be explained by extended gaseous envelops of galaxies.
Therefore, we conclude that known galaxies of known gaseous extent must produce
a significant fraction and perhaps all of \lya absorption systems over a large
redshift range.Comment: 12 pages, 3 figures, accepted for publication in the Astrophysical
Journal, April 10, 2000 issu
A uni-lateral soft exosuit for the paretic ankle can reduce gait compensations in patients post-stroke
Unilateral ankle assisting soft robotic exosuit can improve post-stroke gait during overground walking
Soft wearable robots can reduce the energy cost of poststroke walking: a proof-of-concept study
QSO Absorbing Galaxies at z<~1: Deep Imaging and Spectroscopy in the Field of 3C 336
We present very deep WFPC2 images and FOS spectroscopy from the Hubble Space
Telescope (HST) together with numerous supporting ground-based observations of
the field of the quasar 3C 336 (). The observations are designed
to investigate the nature of galaxies producing metal line absorption systems
in the spectrum of the QSO. Along a single line of sight, we find at least 6
metal line absorption systems (of which 3 are newly discovered) ranging in
redshift from 0.317 to 0.892. Through an extensive program of optical and IR
imaging, QSO spectroscopy, and faint galaxy spectroscopy, we have identified 5
of the 6 metal line absorption systems with luminous (L_K > 0.1 L*_K) galaxies.
These have morphologies ranging from very late-type spiral to S0, and exhibit a
wide range of inclination and position angles with respect to the QSO
sightline. The only unidentified absorber, despite our intensive search, is a
damped Lyman system at . Analysis of the absorption
spectrum suggests that the metal abundances ([Fe/H]) in this system are
similar to those in damped systems at , and to the two other damped
systems for which abundances have been determined at . We have found no
examples of intrinsically faint galaxies () at small impact
parameters that might have been missed as absorber candidates in our previous
ground-based imaging and spectroscopic programs on MgII absorbing galaxies.
There are no bright galaxies (L > 0.1 L_K) within 50h^{-1} kpc which do not
produce detectable metal lines (of Mg II 2796, 2803 and/or C IV 1548, 1550) in
the QSO spectrum. All of these results generally support the inferences which
we have previously reached from a larger survey for absorption-selected
galaxies at z\simlt 1.Comment: 32 pages latex (AAS v4.0 style). 8 Postscript figures (including HST
plate) available at ftp://astro.caltech.edu/users/ccs/3c336_figs.ps.gz .
Submitted to Ap
Narrow Technihadron Production at the First Muon Collider
In modern technicolor models, there exist very narrow spin-zero and spin-one
neutral technihadrons---, and ---with masses of a
few 100 GeV. The large coupling of to , the direct
coupling of and to the photon and , and the superb
energy resolution of the First Muon Collider may make it possible to resolve
these technihadrons and produce them at extraordinarily large rates.Comment: 11 pages, latex, including 2 postscript figure
Kidney after nonrenal transplantation-the impact of alemtuzumab induction
BACKGROUND.: Calcineurin inhibitor nephrotoxicity in nonrenal allograft recipients can lead to end-stage renal disease and the need for kidney transplantation. We sought to evaluate the role of alemtuzumab induction in this population. PATIENTS AND METHODS.: We evaluated 144 patients undergoing kidney transplantation after nonrenal transplantation between May 18, 1998, and October 8, 2007. Seventy-two patients transplanted between January 15, 2003, and October 8, 2007, received alemtuzumab induction and continued their pretransplant immunosuppression. Seventy-two patients transplanted between May 18, 1998, and July 21, 2007, did not receive alemtuzumab induction, but received additional steroids and maintenance immunosuppression. Donor and recipient demographics were comparable. RESULTS.: Overall, 1-and 3-year patient survival and renal function were comparable between the two groups. One-and 3-year graft survival was 93.0% and 75.3% in the alemtuzumab group and 83.3% and 68.7% in the no alemtuzumab group, respectively (P=0.051). The incidence of acute rejection was lower in the alemtuzumab group, 15.3%, than in the no alemtuzumab group, 41.7% (P=0.0001). The incidence of delayed graft function was lower in the alemtuzumab group, 9.7%, than in the no alemtuzumab group, 25.0% (P=0.003). The incidence of viral complications was comparable. CONCLUSION.: Alemtuzumab induction with simple resumption of baseline immunosuppression in patients undergoing kidney transplantation after nonrenal transplantation represents a reasonable immunosuppressive strategy. Copyright © 2009 by Lippincott Williams & Wilkins
Beyond the androgen receptor II: New approaches to understanding and treating metastatic prostate cancer; Report from the 2017 CoffeyâHolden Prostate Cancer Academy Meeting
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138883/1/pros23424.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138883/2/pros23424_am.pd
GNOSIS: the first instrument to use fibre Bragg gratings for OH suppression
GNOSIS is a prototype astrophotonic instrument that utilizes OH suppression
fibres consisting of fibre Bragg gratings and photonic lanterns to suppress the
103 brightest atmospheric emission doublets between 1.47-1.7 microns. GNOSIS
was commissioned at the 3.9-meter Anglo-Australian Telescope with the IRIS2
spectrograph to demonstrate the potential of OH suppression fibres, but may be
potentially used with any telescope and spectrograph combination. Unlike
previous atmospheric suppression techniques GNOSIS suppresses the lines before
dispersion and in a manner that depends purely on wavelength. We present the
instrument design and report the results of laboratory and on-sky tests from
commissioning. While these tests demonstrated high throughput and excellent
suppression of the skylines by the OH suppression fibres, surprisingly GNOSIS
produced no significant reduction in the interline background and the
sensitivity of GNOSIS and IRIS2 is about the same as IRIS2. It is unclear
whether the lack of reduction in the interline background is due to physical
sources or systematic errors as the observations are detector noise-dominated.
OH suppression fibres could potentially impact ground-based astronomy at the
level of adaptive optics or greater. However, until a clear reduction in the
interline background and the corresponding increasing in sensitivity is
demonstrated optimized OH suppression fibres paired with a fibre-fed
spectrograph will at least provide a real benefits at low resolving powers.Comment: 15 pages, 13 figures, accepted to A
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