2,983 research outputs found

    Automatic Detection of Seizures with Applications

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    There are an estimated two million people with epilepsy in the United States. Many of these people do not respond to anti-epileptic drug therapy. Two devices can be developed to assist in the treatment of epilepsy. The first is a microcomputer-based system designed to process massive amounts of electroencephalogram (EEG) data collected during long-term monitoring of patients for the purpose of diagnosing seizures, assessing the effectiveness of medical therapy, or selecting patients for epilepsy surgery. Such a device would select and display important EEG events. Currently many such events are missed. A second device could be implanted and would detect seizures and initiate therapy. Both of these devices require a reliable seizure detection algorithm. A new algorithm is described. It is believed to represent an improvement over existing seizure detection algorithms because better signal features were selected and better standardization methods were used

    The ATLAS tile calorimeter digitizer

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    The ATLAS Tile Calorimeter digitizer system samples photomultiplier signals from the scintillating tiles of the hadronic calorimeter. For each channel a pair of 10-bit ADCs digitize high and low gain signals at 40.08 MHz to provide the necessary 16-bit dynamic range. The sampled data is temporarily stored in digital pipelines for up to 6.375 \mu­s, awaiting a level-1 accept. For each accept received, the corresponding sampled pulse is transferred to a derandomizer buffer for subsequent readout to the data acquisition system (DAQ). The main functionality of the digitizer is implemented in radiation tolerant ASICs, using a fault tolerant architecture to minimize the consequences of radiation induced faults

    An extended view of the Pisces Overdensity from the SCUSS survey

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    SCUSS is a u-band photometric survey covering about 4000 square degree of the South Galactic Cap, reaching depths of up to 23 mag. By extending around 1.5 mag deeper than SDSS single-epoch u data, SCUSS is able to probe much a larger volume of the outer halo, i.e. with SCUSS data blue horizontal branch (BHB) stars can trace the outer halo of the Milky Way as far as 100-150 kpc. Utilizing this advantage we combine SCUSS u band with SDSS DR9 gri photometric bands to identify BHB stars and explore halo substructures. We confirm the existence of the Pisces overdensity, which is a structure in the outer halo (at around 80 kpc) that was discovered using RR Lyrae stars. For the first time we are able to determine its spatial extent, finding that it appears to be part of a stream with a clear distance gradient. The stream, which is ~5 degrees wide and stretches along ~25 degrees, consists of 20-30 BHBs with a total significance of around 6sigma over the background. Assuming we have detected the entire stream and that the progenitor has fully disrupted, then the number of BHBs suggests the original system was similar to smaller classical or a larger ultra-faint dwarf galaxy. On the other hand, if the progenitor still exists, it can be hunted for by reconstructing its orbit from the distance gradient of the stream. This new picture of the Pisces overdensity sheds new light on the origin of this intriguing system.Comment: 8 pages, 4 figures, accepted by Ap

    Glycosylated hemoglobin, but not advanced glycation end products, predicts severity of coronary artery disease in patients with or without diabetes.

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    Background:The association between coronary artery disease (CAD) and diabetes mellitus (DM) is strong but the physiologic mechanisms responsible for this association remain unclear. Patients with DM exhibit high circulating levels of glycated proteins and lipoproteins called advanced glycation end products (AGEs) which have been implicated in the development of oxidative damage to vascular endothelium. We examined the relationships between the presence and extent of CAD and AGEs in patients undergoing elective coronary artery catheterization in an urban teaching hospital. Methods:Patients with possible CAD (n = 364) were recruited prior to elective cardiac catheterization (52% male, 48% diabetic). Regression and correlation analyses were used to examine the relationship between serum AGE concentrations, soluble AGE receptor (sRAGE) concentration, HbA1c, LDL and the presence of obstructive CAD along with the burden of CAD measured by SYNTAX and SYNTAX II scores. Results:AGE and sRAGE levels did not significantly correlate with any of the studied coronary artery disease parameters. HbA1c showed positive correlation with both SYNTAX and SYNTAX II scores in patients with and without diabetes. Conclusion:In this cross-sectional study of patients with possible CAD, serum AGEs and sRAGE concentrations did not correlate with SYNTAX or SYNTAX II scores regardless of diabetic status. HbA1C correlated positively with the SYNTAX and SYNTAX II scores in both diabetic and non-diabetic populations

    The SDSS-IV extended Baryon Oscillation Spectroscopic Survey: selecting emission line galaxies using the Fisher discriminant

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    We present a new selection technique of producing spectroscopic target catalogues for massive spectroscopic surveys for cosmology. This work was conducted in the context of the extended Baryon Oscillation Spectroscopic Survey (eBOSS), which will use ~200 000 emission line galaxies (ELGs) at 0.6<zspec<1.0 to obtain a precise baryon acoustic oscillation measurement. Our proposed selection technique is based on optical and near-infrared broad-band filter photometry. We used a training sample to define a quantity, the Fisher discriminant (linear combination of colours), which correlates best with the desired properties of the target: redshift and [OII] flux. The proposed selections are simply done by applying a cut on magnitudes and this Fisher discriminant. We used public data and dedicated SDSS spectroscopy to quantify the redshift distribution and [OII] flux of our ELG target selections. We demonstrate that two of our selections fulfil the initial eBOSS/ELG redshift requirements: for a target density of 180 deg^2, ~70% of the selected objects have 0.6<zspec<1.0 and only ~1% of those galaxies in the range 0.6<zspec<1.0 are expected to have a catastrophic zspec estimate. Additionally, the stacked spectra and stacked deep images for those two selections show characteristic features of star-forming galaxies. The proposed approach using the Fisher discriminant could, however, be used to efficiently select other galaxy populations, based on multi-band photometry, providing that spectroscopic information is available. This technique could thus be useful for other future massive spectroscopic surveys such as PFS, DESI, and 4MOST.Comment: Version published in A&
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