Introduction The clinical features of sickle-cell disease have been recognized for many years, the disease being described by Herrick (1910), later Sydenstricker (1924) reported on a large series of cases. In 1931, Yater & Mollari described a case with fatal outcome; Kobak, Stein & Daro (1941) made a detailed study of pregnancy in association with sickle-cell disease. The demonstration by Pauli...

Several studies found that breathing abnormalities like OSA or Cheyne-Stokes ventilation are related to periodic changes in heart rate [1,2]. The influences of OSA on HRV analyzed by power spectral analysis have not been investigated until now. The purpose of this study was, therefore, to assess changes in the power spectrum of HRV during episodes of OSA as compared to a normal breathing patter...

Introduction: The origin of contrast in susceptibility weighted phase imaging (1) is not yet fully understood. Both grey and white matter show considerable heterogeneity on phase images (2) and white matter T2* was also found to be heterogeneous (3). Subjects and Method: Data from 2 healthy volunteers (1 female, 1 male, ages 29 and 31) were acquired on a Philips Achieva 3.0T system. SWI data we...

a windowing function that is based on the well-known Butterworth filters was proposed [1] with the claim that it can solve " the tradeoff problem between the frequency resolution and spectral leakage in the estimated power spectral density, unavoidable with the conventional windows. " That claim is a consequence of not considering the available time duration in the window design for which we pr...

UNLABELLED Abnormal glucose metabolic patterns in the brain have been reported for HIV-1 seropositive (HIV+) patients when compared with seronegative healthy individuals. The metabolic covariance pattern obtained from voxel- or volume-of-interest (VOI)-based multivariate data analysis techniques can be used to characterize disease and potentially to detect and monitor disease progression in the...

We present a straightforward and robust algorithm for periodicity detection, working in the lag (autocorrelation) domain. When it is tested for periodic signals and for signals with additive noise or jitter, it proves to be several orders of magnitude more accurate than the methods commonly used for speech analysis. This makes our method capable of measuring harmonics-to-noise ratios in the lag...

OBJECTIVES Both reconstruction algorithms, filtered backprojection (FBP) and ordered subsets expectation maximization (OSEM), are widely used in clinical positron emission tomography (PET) studies. Image reconstruction for most neurotransmission PET scan data is performed by FBP, while image reconstruction for whole-body [18F]FDG scan data is usually performed by OSEM. Although several investig...

Introduction: The recent introduction of pseudo-continuous inversion pulses (pCASL) has the potential to greatly facilitate the use of continuous Arterial Spin Labeling (ASL) (1). However, field inhomogeneities, can compromise the inversion efficiency of pCASL, which causes loss in SNR and severe quantification error (2). We propose a method to restore the loss in inversion efficiency by correc...

Registering video imagery in real-time is a demanding process. Multispectral imagery adds complexity due to the variances between different bands. This paper demonstrates a process that registers airborne multispectral imagery at a rate of thirty frames per second. It can create both mosaics and multispectral sets from a camera that captures a cycle of spectral bands with each spectral band in ...

This paper contains a proposal for a revision of the present Joint Nordic Method for assessing the audibility of tones in noise. The method is also a proposal for the revision of ISO 1996 (TC43/SC1/WG45). The procedure described here is based on a visual inspection of a narrow-band frequency spectrum. A more comprehensive description with documentation from listening tests, hints for the practi...