3,485 research outputs found

    Interaction of edge waves with swell on a beach

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    Excitation of edge waves on a beach by incoming swell is considered on the basis of shallow-water model. Subharmonic resonance mechanism of interaction is analyzed by multi-scaled expansion asymptotic techniques. The generation of edge waves between wave breakers is found to have a dynamic threshold. It is defined by intensity and frequency of incoming swell, geometry of a shore zone. Nonlinear no stationary wave solutions for the envelope of interacting edge waves are described by generalized Sine-Gordon model. An infinite set of exact solutions are received by the Lamb method for the phase synchronism regime of wave’s interaction

    Localizing Gravitational Wave Sources with Single-Baseline Atom Interferometers

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    Localizing sources on the sky is crucial for realizing the full potential of gravitational waves for astronomy, astrophysics, and cosmology. We show that the mid-frequency band, roughly 0.03 to 10 Hz, has significant potential for angular localization. The angular location is measured through the changing Doppler shift as the detector orbits the Sun. This band maximizes the effect since these are the highest frequencies in which sources live several months. Atom interferometer detectors can observe in the mid-frequency band, and even with just a single baseline can exploit this effect for sensitive angular localization. The single baseline orbits around the Earth and the Sun, causing it to reorient and change position significantly during the lifetime of the source, and making it similar to having multiple baselines/detectors. For example, atomic detectors could predict the location of upcoming black hole or neutron star merger events with sufficient accuracy to allow optical and other electromagnetic telescopes to observe these events simultaneously. Thus, mid-band atomic detectors are complementary to other gravitational wave detectors and will help complete the observation of a broad range of the gravitational spectrum.Comment: 16 pages, 3 figures, 2 table

    Magnolin targeting of ERK1/2 inhibits cell proliferation and colony growth by induction of cellular senescence in ovarian cancer cells

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    Ras/Raf/MEKs/ERKs and PI3 K/Akt/mTOR signaling pathways have key roles in cancer development and growth processes, as well as in cancer malignance and chemoresistance. In this study, we screened the therapeutic potential of magnolin using 15 human cancer cell lines and combined magnolin sensitivity with the CCLE mutaome analysis for relevant mutation information. The results showed that magnolin efficacy on cell proliferation inhibition were lower in TOV‐112D ovarian cancer cells than that in SKOV3 cells by G1 and G2/M cell cycle phase accumulation. Notably, magnolin suppressed colony growth of TOV‐112D cells in soft agar, whereas colony growth of SKOV3 cells in soft agar was not affected by magnolin treatment. Interestingly, phospho‐protein profiles in the MAPK and PI3 K signaling pathways indicated that SKOV3 cells showed marked increase of Akt phosphorylation at Thr308 and Ser473 and very weak ERK1/2 phosphorylation levels by EGF stimulation. The phospho‐protein profiles in TOV‐112D cells were the opposite of those of SKOV3 cells. Importantly, magnolin treatment suppressed phosphorylation of RSKs in TOV‐112D, but not in SKOV3 cells. Moreover, magnolin increased SA‐β‐galactosidase‐positive cells in a dose‐dependent manner in TOV‐112D cells, but not in SKOV3 cells. Notably, oral administration of Shin‐Yi fraction 1, which contained magnolin approximately 53%, suppressed TOV‐112D cell growth in athymic nude mice by induction of p16Ink4a and p27Kip1. Taken together, targeting of ERK1 and ERK2 is suitable for the treatment of ovarian cancer cells that do not harbor the constitutive active P13 K mutation and the loss‐of‐function mutations of the p16 and/or p53 tumor suppressor proteins

    A More Appropriate Cardiac Troponin T Level That Can Predict Outcomes in End-Stage Renal Disease Patients with Acute Coronary Syndrome

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    Purpose: Cardiac troponin T (cTnT), a useful marker for diagnosing acute myocardial infarction (AMI) in the general population, is significantly higher than the usual cut-off value in many end-stage renal disease (ESRD) patients without clinically apparent evidence of AMI. The aim of this study was to evaluate the clinical usefulness of cTnT in ESRD patients with acute coronary syndrome (ACS). Materials and methods: Two hundred eighty-four ESRD patients with ACS were enrolled between March 2002 and February 2008. These patients were followed until death or June 2009. Medical records were reviewed retrospectively. The cut-off value of cTnT for AMI was evaluated using a receiver operating characteristic (ROC) curve. We calculated Kaplan-Meier survival curves, and potential outcome predictors were determined by Cox proportional hazard analysis. Results: AMIs were diagnosed in 40 patients (14.1%). The area under the curve was 0.98 in the ROC curve (p<0.001; 95% CI, 0.95-1.00). The summation of sensitivity and specificity was highest at the initial cTnT value of 0.35 ng/mL (sensitivity, 0.95; specificity, 0.97). Survival analysis showed a statistically significant difference in all-cause and cardiovascular mortalities for the group with an initial cTnT ≥0.35 ng/mL compared to the other groups. Initial serum cTnT concentration was an independent predictor for mortality. Conclusion: Because ESRD patients with an initial cTnT concentration ≥0.35 ng/mL have a poor prognosis, it is suggested that urgent diagnosis and treatment be indicated in dialysis patients with ACS when the initial cTnT levels are ≥0.35 ng/mL.ope

    RSK2-Mediated ELK3 Activation Enhances Cell Transformation and Breast Cancer Cell Growth by Regulation of c-fos Promoter Activity

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    Ribosomal S6 kinase 2 (RSK2), regulated by Ras/Raf/MEKs/ERKs, transmits upstream activation signals to downstream substrates including kinases and transcription and epigenetic factors. We observed that ELK members, including ELK1, 3, and 4, highly interacted with RSK2. We further observed that the RSK2-ELK3 interaction was mediated by N-terminal kinase and linker domains of RSK2, and the D and C domains of ELK3, resulting in the phosphorylation of ELK3. Importantly, RSK2-mediated ELK3 enhanced c-fos promoter activity. Notably, chemical inhibition of RSK2 signaling using kaempferol (a RSK2 inhibitor) or U0126 (a selective MEK inhibitor) suppressed EGF-induced c-fos promoter activity. Moreover, functional deletion of RSK2 by knockdown or knockout showed that RSK2 deficiency suppressed EGF-induced c-fos promoter activity, resulting in inhibition of AP-1 transactivation activity and Ras-mediated foci formation in NIH3T3 cells. Immunocytofluorescence assay demonstrated that RSK2 deficiency reduced ELK3 localization in the nucleus. In MDA-MB-231 breast cancer cells, knockdown of RSK2 or ELK3 suppressed cell proliferation with accumulation at the G1 cell cycle phase, resulting in inhibition of foci formation and anchorage-independent cancer colony growth in soft agar. Taken together, these results indicate that a novel RSK2/ELK3 signaling axis, by enhancing c-Fos-mediated AP-1 transactivation activity, has an essential role in cancer cell proliferation and colony growth

    NDE Detection and Characterization of Damage in Honeycomb Sandwich Composites

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    This study deals with a non-destructive evaluation technique for detecting defects in composite panels. In this non-destructive evaluation technique, various low-frequency techniques are applied such as a tapping technology. Another terahertz wave application will be utilized. In particular, the tapping technique is utilized in order to evaluate the characteristics of the honeycomb member based on the hysteresis effect analysis. Here, the area surrounded by the hysteresis loop in the force-displacement curve is related to the increased internal friction loss that is the cause of the energy absorption absorbed by the composite member after the load is applied. The loop area where the composite member was damaged was well agreed with the damage level. Artificial defects were manufactured on the surface of honeycomb sandwich composite panels. An NDE technique was proposed in order to detect defects by using terahertz waves and was discussed for tuning the practical use

    Transgenic Expression of Decoy Receptor 3 Protects Islets from Spontaneous and Chemical-induced Autoimmune Destruction in Nonobese Diabetic Mice

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    Decoy receptor 3 (DCR3) halts both Fas ligand– and LIGHT-induced cell deaths, which are required for pancreatic β cell damage in autoimmune diabetes. To directly investigate the therapeutic potential of DCR3 in preventing this disease, we generated transgenic nonobese diabetic mice, which overexpressed DCR3 in β cells. Transgenic DCR3 protected mice from autoimmune and cyclophosphamide-induced diabetes in a dose-dependent manner and significantly reduced the severity of insulitis. Local expression of the transgene did not alter the diabetogenic properties of systemic lymphocytes or the development of T helper 1 or T regulatory cells. The transgenic islets had a higher transplantation success rate and survived for longer than wild-type islets. We have demonstrated for the first time that the immune-evasion function of DCR3 inhibits autoimmunity and that genetic manipulation of grafts may improve the success and survival of islet transplants
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