We present radio, optical, ultraviolet, and X-ray observations of the isolated, thermally-emitting neutron star RX J0720.4−3125 using the Parkes radio telescope, the Very Large Array, the Hubble Space Telescope, and the Chandra X-ray Observatory. From these data we show that the optical/UV spectrum of RX J0720.4−3125 is not well fit by a Rayleigh-Jeans tail as previously thought, but is instead...

Hypertension is the most common, costly, and preventable cardiovascular disease risk factor. Numerous professional organizations and committees recommend exercise as initial lifestyle therapy to prevent, treat, and control hypertension. Yet, these recommendations differ in the components of the Frequency, Intensity, Time, and Type (FITT) principle of exercise prescription (Ex Rx); the evidence ...

The remarkable astrometric capabilities of the Chandra Observatory offer the possibility to measure proper motions of X-ray sources with an unprecedented accuracy in this wavelength range. We recently completed a proper motion survey of three of the seven thermally emitting radio-quiet isolated neutron stars (INSs) discovered in the ROSAT all-sky survey. These INSs (RX J0420.0−5022, RX J0806.4−...

The transmit-receive (Tx/Rx) birdcage head coil is often used for excitation instead of the body coil because of the presumably lower risk of heating in and around conductive implants. However, this common practice has not been systematically tested. To investigate whether the Tx/Rx birdcage head coil produces less heating than the body coil when scanning individuals with implants, we used a 3T...

BACKGROUND The RAMQ prescription claims database (RAMQ-Rx) is increasingly being used in perinatal pharmacoepidemiologic studies; but, there are reasons to believe that results generated with the RAMQ-Rx might not be generalizable to all patient populations. OBJECTIVES Compare characteristics between pregnant women insured by the RAMQ-Rx and those insured by a private drug insurance plan. M...

We report the discovery of a transient jet in the supersoft X-ray source RX J0925.7-4758. The jet was observed in the Hα line during a single night in June 1997 and had disappeared one day later. RX J0925.7-4758 is the third supersoft source to exhibit collimated outflows. The peak jet velocity of 5,200 km s−1, strongly argues in favour of a white dwarf in RX J0925.7-4758. Simple modelling of t...

We report the discovery of a new isolated neutron star candidate, RX J0420.0–5022, showing evidence (4σ) for 22.7 s X-ray pulsations in ROSAT data. NTT observations of the field around the soft X-ray source do not reveal any likely optical counterpart brighter than B = 25.25 implying an X-ray to optical flux ratio of > 103.3 and ruling out other possible kinds of X-ray emitters. The X-ray spect...

Current methods for imaging joint motion are limited to either two-dimensional (2D) video fluoroscopy, or to animated motions from a series of static three-dimensional (3D) images. 3D movement patterns can be detected from biplane fluoroscopy images matched with computed tomography images. This involves several x-ray modalities and sophisticated 2D to 3D matching for the complex wrist joint. We...

The performance of OFDM based systems is seriously affected by imperfections in system implementation. To gain a beter understanding of the influence of these impairments on the performance of multiple antenna OFDM systems, this paper studies a zero-forcing based MIMO OFDM system with imperfections modeled as additive error sources in both transmitter (TX) and receiver (RX). Based on this model...

Inequalities for convex functions on the lattice of partitions of a set partially ordered by refinement lead to multivariate generalizations of inequalities of Cauchy and Rogers-Hölder and to eigenvalue inequalities needed in the theory of population dynamics in Markovian environments: If A is an n× n nonnegative matrix, n > 1, D is an n× n diagonal matrix with positive diagonal elements, r(·) ...