150 research outputs found

    Detection of Remote Harmonics Using SVD

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    The paper examines the singular value decomposition (SVD) for detection of remote harmonics in signals, in the presence of high noise contaminating the measured waveform. When the number of harmonics is very large and at the same time certain harmonics are distant from the other, the conventional frequency detecting methods are not satisfactory. The methods developed for locating the frequencies as closely spaced sinusoidal signals are appropriate tools for the investigation of power system signals containing harmonics differing significantly in their multiplicity. The SVD methods are ideal tools for such cases. To investigate the methods several experiments have been performed. For comparison, similar experiments have been repeated using the FFT with the same number of samples and sampling period. The comparison has proved an absolute superiority of the SVD for signals burried in noise. However, the SVD computation is much more complex than the FFT, and requires more extensive mathematical manipulations

    Adaptive synthesis of a wavelet transform using fast neural network

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    This paper introduces a new method for an adaptive synthesis of a wavelet transform using a fast neural network with a topology based on the lattice structure. The lattice structure and the orthogonal lattice structure are presented and their properties are discussed. A novel method for unsupervised training of the neural network is introduced. The proposed approach is tested by synthesizing new wavelets with an expected energy distribution between low- and high-pass filters. Energy compaction of the proposed method and Daubechies wavelets is compared. Tests are performed using sound and image signals

    Comparison of Hepatic and Nephric Total Mercury Concentrations Between Feral and Ranch American Mink (Neovison vison) from Northwestern Poland

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    For many years the American mink (Neovison vison) has been used in North America (where it originates from) as a sensitive indirect bioindicator in assessing the degree of mercury (Hg) contamination in terrestrial ecosystems. The aim of this paper was the determination of total concentrations of Hg in the liver and kidneys of feral and ranch mink from the Warta Mouth National Park (WMNP) and from farms located in northwestern Poland, for comparison with similar data on American mink from North America. In road-killed feral mink from the WMNP, the mean concentrations were 11.8 and 14.1 mg/kg dry weight in the liver and kidney, respectively. Mean Hg concentrations in feral mink were from 240 to 90 times higher in these two respective tissues than in ranch mink. The feral mink from northwestern Poland had concentrations of hepatic and nephric Hg similar to the highest concentrations that have been recorded over the past several decades in wild American mink from certain areas of Canada and the USA

    Absence of diabetic retinopathy in a patient who has had diabetes mellitus for 69 years, and inadequate glycemic control: case presentation

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    The main risk factors for the development and progression of diabetic retinopathy (DR) are chronic hyperglycemia, disease duration and systemic blood pressure. So far chronic hyperglycemia is the strongest evidence concerning the risk of developing DR. However there are some patients with poor metabolic control who never develop this diabetic complication. We present a case of a 73-year-old woman with type 1 diabetes mellitus, diagnosed 69 years ago. The patient is 73 years old, with no evidence of DR, despite poor glycemic control and several risk factors for DR. This case suggests the presence of a possible protection factor, which could be genetic

    Gene Expression Signature of DMBA-Induced Hamster Buccal Pouch Carcinomas: Modulation by Chlorophyllin and Ellagic Acid

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    Chlorophyllin (CHL), a water-soluble, semi-synthetic derivative of chlorophyll and ellagic acid (EA), a naturally occurring polyphenolic compound in berries, grapes, and nuts have been reported to exert anticancer effects in various human cancer cell lines and in animal tumour models. The present study was undertaken to examine the mechanism underlying chemoprevention and changes in gene expression pattern induced by dietary supplementation of chlorophyllin and ellagic acid in the 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis model by whole genome profiling using pangenomic microarrays. In hamsters painted with DMBA, the expression of 1,700 genes was found to be altered significantly relative to control. Dietary supplementation of chlorophyllin and ellagic acid modulated the expression profiles of 104 and 37 genes respectively. Microarray analysis also revealed changes in the expression of TGFβ receptors, NF-κB, cyclin D1, and matrix metalloproteinases (MMPs) that may play a crucial role in the transformation of the normal buccal pouch to a malignant phenotype. This gene expression signature was altered on treatment with chlorophyllin and ellagic acid. Our study has also revealed patterns of gene expression signature specific for chlorophyllin and ellagic acid exposure. Thus dietary chlorophyllin and ellagic acid that can reverse gene expression signature associated with carcinogenesis are novel candidates for cancer prevention and therapy
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