205 research outputs found
Integrable models for shallow water with energy dependent spectral problems
We study the inverse problem for the so-called operators with energy
depending potentials. In particular, we study spectral operators with quadratic
dependance on the spectral parameter. The corresponding hierarchy of integrable
equations includes the Kaup-Bousinesq equation. We formulate the inverse
problem as a Riemann-Hilbert problem with a Z2 reduction group. The soliton
solutions are explicitly obtained.Comment: 17 pages, 3 figure
A dressing method for soliton solutions of the Camassa-Holm equation
The soliton solutions of the Camassa-Holm equation are derived by the
implementation of the dressing method. The form of the one and two soliton
solutions coincides with the form obtained by other methods.Comment: 18 pages, 2 figure
On the Peakon and Soliton Solutions of an Integrable PDE with Cubic Nonlinearities
The interest in the singular solutions (peakons) has been inspired by the Camassa-Holm (CH) equation and its peakons. An integrable peakon equation with cubic nonlinearities was first discovered by Qiao. Another integrable equation with cubic nonlinearities was introduced by V. Novikov . We investigate the peakon and soliton solutions of the Qiao equation
Camassa-Holm cuspons, solitons and their interactions via the dressing method
A dressing method is applied to a matrix Lax pair for the Camassa-Holm
equation, thereby allowing for the construction of several global solutions of
the system. In particular solutions of system of soliton and cuspon type are
constructed explicitly. The interactions between soliton and cuspon solutions
of the system are investigated. The geometric aspects of the Camassa-Holm
equation ar re-examined in terms of quantities which can be explicitly
constructed via the inverse scattering method.Comment: 35 pages, 10 figures. arXiv admin note: text overlap with
arXiv:1702.0112
A Dressing Method for Soliton Solutions of the Camass-Holm Equation
The soliton solutions of the Camassa-Holm equation are derived by the implementation of the dressing method. The form of the one and two soliton solutions coincides with the form obtained by other methods
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Regulation of nuclear factor-κ B and activator protein-1 activities after stimulation of T cells via glycosylphosphatidylinositol-anchored Ly-6A/E.
Cross-linking of glycosylphosphatidylinositol-anchored proteins, including mouse Ly-6A/E, leads to IL-2 secretion and T cell activation, whereas engagement of Ly-6A/E uniquely inhibits IL-2 production induced via TCR. However, little is known concerning the molecular mechanism by which glycosylphosphatidylinositol-anchored proteins regulate IL-2 expression. In this study, we have examined the ability of an anti-Ly-6A/E mAb to regulate transcription factors controlling IL-2 expression. Stimulation of EL4J(Ly-6E).A4 cells with anti-CD3 epsilon or anti-Ly6A/E mAbs induced nuclear factor (NF)-κ B p65-p50 (RelA/p50) and AP-1 (Fos/Jun) binding activities and increased nuclear factor of activated T cells (NF-AT) activity, whereas octamer-binding factor and NF-Y levels were stable. Cyclic AMP response element binding protein and T cell-specific factor-1 (α) activities were selectively enhanced by anti-CD3 epsilon, but not by anti-Ly6A/E, which suggests that signaling via the TCR and Ly-6 were not identical. Costimulation of these cells with both mAbs produced substantially reduced levels of AP-1, NF-AT, and, especially, NF-κ B p65-p50 whereas cyclic AMP response element binding protein and T cell-specific factor-1(α) were induced to a level seen after stimulation by anti-CD3 epsilon. The inducibility of the IL-2 enhancer in vivo and the contribution of individual transcription factors for this induction were assessed with use of reporter chloramphenicol acetyltransferase constructs containing the IL-2 enhancer or oligomerized binding sites for transcription factors. These experiments also demonstrated a key role for NF-κ B and AP-1 in the transcriptional regulation of the IL-2 gene by TCR- and Ly6A/E-mediated signaling. By using the 2B4.11 T cell hybridoma and a mutated variant, were revealed a crucial role for the zeta-chain in Ly6A/E-mediated activation of NF-κ B
System for assessment and forecast of air quality in populated areas
The paper provides an account of a system for collecting data, forecasting and assessing the quality of ambient air in a given locality. The developed system allows for extremely sustainable analysis of the results and due consideration of the utilization of artificial intelligence algorithms and methods for the development of accurate forecasts. The obtained results are expected to detect the problems related to the quality of air before their actual occurrence
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Inhibition of ATM kinase upregulates levels of cell death induced by cannabidiol and γ-irradiation in human glioblastoma cells
Despite advances in glioblastoma (GBM) therapy, prognosis of the disease remains poor with a low survival rate. Cannabidiol (CBD) can induce cell death and enhance radiosensitivity of GBM but not normal astrocytes. Inhibition of ATM kinase is an alternative mechanism for radiosensitization of cancer cells. In this study, we increased the cytotoxic effects of the combination of CBD and gamma-irradiation in GBM cells through additional inhibition of ATM kinase with KU60019, a small molecule inhibitor of ATM kinase. We observed in GBM cells treated by CBD, gamma-irradiation and KU60019 high levels of apoptosis together with strong upregulation of the percentage of G2/M-arrested cells, blockade of cell proliferation and a massive production of pro-inflammatory cytokines. Overall, these changes caused both apoptotic and non-apoptotic inflammation-linked cell death. Furthermore, via JNK-AP1 activation in concert with active NF-(kappa)B, CBD upregulated gene and protein expression of DR5/TRAIL-R2 and sensitize GBM cells to TRAIL-induced apoptosis. In contrast, CBD notably decreased in GBM surface levels of PD-L1, a critical immune checkpoint agent for T-lymphocytes. We also used in the present study TS543 human proneural glioma cells that were grown as spheroid culture. TS543 neurospheres exhibited dramatic sensitivity to CBD-mediated killing that was additionally increased in combination with gamma-irradiation and KU60019. In conclusion, treatment of human GBM by the triple combination (CBD, gamma-irradiation and KU60019) could significantly increase cell death levels in vitro and potentially improve the therapeutic ratio of GBM
Thermal performance of diamond field-effect transistors
In this report, the thermal performance of a hydrogen (H)-terminated diamond field-effect transistor (FET) is investigated using Raman spectroscopy and electrothermal device modeling. First, the thermal conductivity (κdiamond) of the active diamond channel was determined by measuring the temperature rise of transmission line measurement structures under various heat flux conditions using nanoparticle-assisted Raman thermometry. Using this approach, κdiamond was estimated to be 1860 W/m K with a 95% confidence interval ranging from 1610 to 2120 W/m K. In conjunction with measured electrical output characteristics, this κ was used as an input parameter for an electrothermal device model of an H-terminated diamond FET. The simulated thermal response showed good agreement with surface temperature measurements acquired using nanoparticle-assisted Raman thermometry. These diamond-based structures were highly efficient at dissipating heat from the active device channel with measured device thermal resistances as low as ∼1 mm K/W. Using the calibrated electrothermal device model, the diamond FET was able to operate at a very high power density of 40 W/mm with a simulated temperature rise of ∼33 K. Finally, the thermal resistance of these lateral diamond FETs was compared to lateral transistor structures based on other ultrawide bandgap materials (Al0.70Ga0.30N, β-Ga2O3) and wide bandgap GaN for benchmarking. These results indicate that the thermal resistance of diamond-based lateral transistors can be up to ∼10× lower than GaN-based devices and ∼50× lower than other UWBG devices
A stochastic model for heart rate fluctuations
Normal human heart rate shows complex fluctuations in time, which is natural,
since heart rate is controlled by a large number of different feedback control
loops. These unpredictable fluctuations have been shown to display fractal
dynamics, long-term correlations, and 1/f noise. These characterizations are
statistical and they have been widely studied and used, but much less is known
about the detailed time evolution (dynamics) of the heart rate control
mechanism. Here we show that a simple one-dimensional Langevin-type stochastic
difference equation can accurately model the heart rate fluctuations in a time
scale from minutes to hours. The model consists of a deterministic nonlinear
part and a stochastic part typical to Gaussian noise, and both parts can be
directly determined from the measured heart rate data. Studies of 27 healthy
subjects reveal that in most cases the deterministic part has a form typically
seen in bistable systems: there are two stable fixed points and one unstable
one.Comment: 8 pages in PDF, Revtex style. Added more dat
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