722 research outputs found

    Spurious detection of phase synchronization in coupled nonlinear oscillators

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    Coupled nonlinear systems under certain conditions exhibit phase synchronization, which may change for different frequency bands or with presence of additive system noise. In both cases, Fourier filtering is traditionally used to preprocess data. We investigate to what extent the phase synchronization of two coupled R\"{o}ssler oscillators depends on (1) the broadness of their power spectrum, (2) the width of the band-pass filter, and (3) the level of added noise. We find that for identical coupling strengths, oscillators with broader power spectra exhibit weaker synchronization. Further, we find that within a broad band width range, band-pass filtering reduces the effect of noise but can lead to a spurious increase in the degree of synchronization with narrowing band width, even when the coupling between the two oscillators remains the same.Comment: 4 pages,6 figure

    Nonparametric assessment of safety levels in ecological risk assessment (ERA)

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    In ecological risk assessment (ERA), it is important to know whether the exposure that animal species receive from a chemical concentration exceeds the desired safety level. This study examined several statistical methods currently being used in ecological risk assessment and reviewed several statistical procedures related to this subject in the literature. Two large sample nonparametric tests were developed for this study. Monte Carlo study showed that these tests performed well even when the sample size was moderately large. A real data set was used to show that the new methodologies provide a good method for assessing the potential risks of pesticides residues at an investigated site

    Method of identifying and treating invasive carcinomas (CIP)

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    Prostasin protein has been found to be a useful marker for determination of the invasiveness of and as a means to treat human carcinomas. Using RT-PCR and western blot analyses, prostasin protein and mRNA expression were found in normal human prostate epithelial cells and the human prostate cancer cell line LNCaP, but not in the highly invasive human prostate cancer cell lines DU-145 and PC-3. Imunohistochemistry studies of human prostate cancer specimens revealed a down-regulation of prostasin in high-grade tumors. Using RT-PCR and western blot analyses, prostasin protein and mRNA expression were found in a non-invasive human breast cancer cell line, MCF-7, while invasive human breast cancer cell lines MDA-MB-231 and MDA-MB-435s were found not to express either the prostasin protein or the mRNA. A non-invasive human breast cancer cell line, MDA-MB-453, was shown to express prostasin mRNA but not prostasin protein. Transfection of DU-145 and PC-3 cells with a full-length human prostas

    Method of identifying and treating invasive carcinomas

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    Prostasin protein has been found to be a useful marker for determination of the invasiveness of and as a means to treat human carcinomas. Using RT-PCR and western blot analyses, prostasin protein and mRNA expression were found in normal human prostate epithelial cells and the human prostate cancer cell line LNCaP, but not in the highly invasive human prostate cancer cell lines DU-145 and PC-3. Imunohistochemistry studies of human prostate cancer specimens revealed a down-regulation of prostasin in high-grade tumors. Using RT-PCR and western blot analyses, prostasin protein and mRNA expression were found in a non-invasive human breast cancer cell line, MCF-7, while invasive human breast cancer cell lines MDA-MB-231 and MDA-MB-435s were found not to express either the prostasin protein or the mRNA. A non-invasive human breast cancer cell line, MDA-MB-453, was shown to express prostasin mRNA but not prostasin protein. Transfection of DU-145 and PC-3 cells with a full-length human prostas

    Effectiveness of hydropathic compress of dandelion in ameliorating complications of arteriovenous fistula

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    Purpose: To investigate the effect of dandelion hydropathic compress on the complications of autologous arteriovenous fistula (AVF).Methods: From January to June 2019, a total of 162 patients treated with arteriovenous fistula for hemodialysis in the blood purification department of Affiliated Hospital of Jining Medical University were enrolled. They were randomly assigned at a ratio of 1:1 to receive either conventional infrared irradiation (control group) or conventional irradiation plus dandelion hydropathic compress (study group). The clinical endpoint was the amelioration of the complications of arteriovenous fistula after 6 months of treatment.Results: Dandelion hydropathic compress combined with conventional infrared irradiation was associated with a significantly higher clinical efficacy (96.30 %) than conventional infrared irradiation alone (77.78 %). The application of dandelion hydropathic compress plus infrared irradiation resulted in significantly reduced pain, a better quality of life, and a lower incidence of complications (p < 0.05).Conclusion: Dandelion hydropathic compress plus routine nursing and infrared irradiation lower the incidence of complications, improve blood flow, relieve pain, and enhance the quality of life of patients. Further clinical trials are needed to confirm the usefulness of this therapeutic strategy

    Self-absorption in the solar transition region

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    Transient brightenings in the transition region of the Sun have been studied for decades and are usually related to magnetic reconnection. Recently, absorption features due to chromospheric lines have been identified in transition region emission lines raising the question of the thermal stratification during such reconnection events. We analyse data from the Interface Region Imaging Spectrograph (IRIS) in an emerging active region. Here the spectral profiles show clear self-absorption features in the transition region lines of Si\,{\sc{iv}}. While some indications existed that opacity effects might play some role in strong transition region lines, self-absorption has not been observed before. We show why previous instruments could not observe such self-absorption features, and discuss some implications of this observation for the corresponding structure of reconnection events in the atmosphere. Based on this we speculate that a range of phenomena, such as explosive events, blinkers or Ellerman bombs, are just different aspects of the same reconnection event occurring at different heights in the atmosphere.Comment: Accepted for publication in Ap

    X-ray absorption of liquid water by advanced ab initio methods

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    Oxygen K-edge X-ray absorption spectra of liquid water are computed based on the configurations from advanced ab initio molecular dynamics simulations, as well as an electron excitation theory from the GW method. One one hand, the molecular structures of liquid water are accurately predicted by including both van der Waals interactions and hybrid functional (PBE0). On the other hand, the dynamic screening effects on electron excitation are approximately described by the recently developed enhanced static Coulomb hole and screened exchange approximation by Kang and Hybertsen [Phys. Rev. B 82, 195108 (2010)]. The resulting spectra of liquid water are in better quantitative agreement with the experimental spectra due to the softened hydrogen bonds and the slightly broadened spectra originating from the better screening model.Comment: 10 pages, 5 figures, accepted by Phys. Rev.
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