7,281 research outputs found
The C242T polymorphism of the NAD(P)H oxidase p22(phox) subunit is associated with an enhanced risk for cerebrovascular disease at a young age
Background and Purpose: Oxidative stress has been proposed as a major contributing factor for vascular disease, that acts independently from its participation in predisposing disorders such as diabetes and arterial hypertension. A functionally relevant C242T polymorphism of the CYBA gene encoding the NAD(P)H oxidase p22(phox) subunit, is supposed to lead to an abnormal reduction in the generation of reactive oxygen species in vascular smooth-muscle and endothelial cells. Methods: We investigated the p22(phox) C242T single-nucleotide polymorphism by polymerase chain reaction in consecutive patients with ischemic stroke or transient ischemic attack under the age of 50 (n = 161) and in population-based control subjects (n = 136). Results: Homozygosity for the T variant was associated with an enhanced risk for cerebral ischemia (odds ratio 3.85, confidence interval 1.39-10.64) after adjusting for classical risk factors. Risk for cerebral ischemia was not increased in heterozygous subjects. Conclusion: The p22(phox) C242T single-nucleotide polymorphism is associated with stroke risk. This finding supports the hypothesis that oxidative stress may contribute to stroke pathogenesis. Copyright (C) 2008 S. Karger AG, Basel
Robust beamforming for interference rejection in mobile communications
The problem of robust beamformer design in the presence of moving sources is considered. A new technique based on a generalization of the constrained minimum variance beamformer is proposed. The method explicitly takes into account changes in the scenario due to the movement of the desired and interfering sources, requiring only estimation of the desired DOA. Computer simulations show that the resulting performance constitutes a compromise between interference and noise rejection, computational complexity, and sensitivity to source movement.Peer ReviewedPostprint (published version
Complex networks in brain electrical activity
We analyze the complex networks associated with brain electrical activity.
Multichannel EEG measurements are first processed to obtain 3D voxel
activations using the tomographic algorithm LORETA. Then, the correlation of
the current intensity activation between voxel pairs is computed to produce a
voxel cross-correlation coefficient matrix. Using several correlation
thresholds, the cross-correlation matrix is then transformed into a network
connectivity matrix and analyzed. To study a specific example, we selected data
from an earlier experiment focusing on the MMN brain wave. The resulting
analysis highlights significant differences between the spatial activations
associated with Standard and Deviant tones, with interesting physiological
implications. When compared to random data networks, physiological networks are
more connected, with longer links and shorter path lengths. Furthermore, as
compared to the Deviant case, Standard data networks are more connected, with
longer links and shorter path lengths--i.e., with a stronger ``small worlds''
character. The comparison between both networks shows that areas known to be
activated in the MMN wave are connected. In particular, the analysis supports
the idea that supra-temporal and inferior frontal data work together in the
processing of the differences between sounds by highlighting an increased
connectivity in the response to a novel sound.Comment: 22 pages, 5 figures. Starlab preprint. This version is an attempt to
include better figures (no content change
Photoproduction with a mini-jet model and Cosmic Ray showers
We present post-LHC updates of estimates of the total photo-production cross
section in a mini-jet model with infrared soft gluon resummation, and apply the
model to study Cosmic Ray shower development, comparing the results with those
obtained from other existing models.Comment: 7 pages, 5 figures, presented at Photon 2017, 22-26 May 2017 CER
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