Stephen L. Redman

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The following article is intended to illustrate the place of scintigraphy and computed tomography pulmonary angiography (CTPA) in the investigation of acute PE in current practice, and to guide non-radionuclide radiologists and other medical professionals to the best test for patients. We share our early experiences with ventilation-perfusion (V/Q)(More)
Ultrasound is a routine investigation for the assessment of scrotal masses. Many of the detected lesions involve the paratesticular structures. The most common paratesticular masses in clinical practice are epididymal cysts and spermatoceles, but there are a large number of other pathologies that can be encountered and may result in diagnostic uncertainty.(More)
We describe and characterize a 25 GHz laser frequency comb based on a cavity-filtered erbium fiber mode-locked laser. The comb provides a uniform array of optical frequencies spanning 1450 nm to 1700 nm, and is stabilized by use of a global positioning system referenced atomic clock. This comb was deployed at the 9.2 m Hobby-Eberly telescope at the McDonald(More)
We have designed and tested an in-plane echelle spectrograph configured to investigate precision radial velocities from ground-based near-infrared observations. The spectrograph operates across the spectral range of 0.9–1.7 μm at a spectral resolution of R 1⁄4 50; 000, and uses a liquid nitrogen-cooled HAWAII 1 K detector. Repeated measurements of the(More)
We have designed and tested an in-plane échelle spectrograph configured to investigate precision radial velocities from ground-based near-infrared observations. The spectrograph operates across the spectral range of 0.9-1.7 μm at a spectral resolution of R = 50, 000, and uses a liquid nitrogen-cooled hawaii 1K detector. Repeated measurements of the Earth’s(More)
We investigate a new scheme for astronomical spectrograph calibration using the laser frequency comb at the Solar VacuumTower Telescope onTenerife. Our concept is based upon a single-mode fiber channel, that simultaneously feeds the spectrographwith comb light and sunlight. This yields nearly perfect spatialmodematching between the two sources. In(More)
Analyses of multiple pulse sequences of B2303+30 reveal that this pulsar has two distinct emission modes. One mode (B) follows a steady even-odd pattern and is more intense. The second mode (Q) is characteristically weak, but has intermittent driftbands with a periodicity of approximately 3P1/cycles, and nulls much more frequently than the B mode. Both(More)
Analyses of multiple pulse sequences of B2303+30 reveal that this pulsar has two distinct emission modes. One mode (B) follows a steady even-odd pattern and is more intense. The second mode (Q) is characteristically weak, but has intermittent driftbands with a periodicity of approximately 3P1/cycles, and nulls much more frequently than the B mode. Both(More)
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