432,162 research outputs found
Seismic analysis of Pine Flat concrete dam
No full textInvestigating the dynamic response of a concrete gravity dam (Pine Flat) is the objective
of this study. The acoustic-structure coupling interaction is applied to simulate the reservoir-dam system.
The effect of foundation size and the efficiency of the infinite element available in the ABAQUS code
to model boundaries are studied. From the comparison of displacement, dynamic pressure and
acceleration time history, the evaluation of the dam response to the rising water level is performed. The
concrete damaged plasticity model is adopted to evaluate the damage and cracking of the dam caused
by Taft earthquake
Differential expression of toll-like receptor mRNA in treatment non-responders and sustained virologic responders at baseline in patients with chronic hepatitis C
No full textBackground/Aims: The contribution of the host immune response to sustained virologic response is not clear in patients with chronic hepatitis C (CHC). The aim of this study was to explore the relationship of the toll-like receptor (TLR) expression with the outcome of antiviral therapy in hepatitis C viral infection. Methods: Peripheral blood mononuclear cells (PBMC) were obtained from 15 CHC patients before a 48-week treatment with pegylated interferon (PEG IFN) alpha-2a and ribavirin. A multiplex semi-quantitative reverse-trancriptase polymerase chain reaction (RT-PCR) was used to compare the relative abundance of TLR2-9 transcripts. Results: mRNA levels of TLR2, 3 and 6 were significantly higher in CHC subjects compared with normal controls (n=8). When patients were classified into non-responders (n=8) and sustained virological responders (n=7) according to the virological outcome of the treatment, there was a clear difference in baseline mRNA expression of TLRs and T-helper (Th) 1/2 cytokines. In addition, the mRNA expression of IFN-gamma and nuclear factor of activated T cells (NFAT), which is exclusively expressed in activated T cells, was inversely correlated with that of TLR4, 6 and 9 in non-responders. Conclusions: TLRs mRNA levels are differentially expressed in baseline PBMC of chronic HCV-infected subjects with or without responsiveness to antiviral therapy
q-Differential equations for q-classical polynomials and q-Jacobi-Stirling numbers
No full textWe introduce, characterise and provide a combinatorial interpretation for the so-called q-Jacobi–Stirling numbers.
This study is motivated by their key role in the (reciprocal) expansion of any power of a second order
q-differential operator having the q-classical polynomials as eigenfunctions in terms of other even order operators,
which we explicitly construct in this work. The results here obtained can be viewed as the q-version of
those given by Everitt et al. and by the first author, whilst the combinatorics of this new set of numbers is a
q-version of the Jacobi–Stirling numbers given by Gelineau and the second author
Ethanol affects NMDA receptor signaling at climbing fiber-Purkinje cell synapses in mice and impairs cerebellar LTD
No full textEthanol profoundly influences cerebellar circuit function and motor control. It has recently been demonstrated that functional N-methyl-D-aspartate (NMDA) receptors are postsynaptically expressed at climbing fiber (CF) to Purkinje cell synapses in the adult cerebellum. Using whole cell patch-clamp recordings from mouse cerebellar slices, we examined whether ethanol can affect NMDA receptor signaling in mature Purkinje cells. NMDA receptor-mediated currents were isolated by bath application of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor antagonist 2,3-dihydroxy-6-nitro-7-sulfamoylbenzol[f]quinoxaline (NBQX). The remaining D-2-amino-5-phosphonovaleric acid (D-APV)-sensitive current was reduced by ethanol at concentrations as low as 10 mM. At a concentration of 50 mM ethanol, the blockade of D-APV-sensitive CF-excitatory postsynaptic currents was significantly stronger. Ethanol also altered the waveform of CF-evoked complex spikes by reducing the afterdepolarization. This effect was not seen when NMDA receptors were blocked by D-APV before ethanol wash-in. In contrast to CF synaptic transmission, parallel fiber (PF) synaptic inputs were not affected by ethanol. Finally, ethanol (10 mM) impaired long-term depression (LTD) at PF to Purkinje cell synapses as induced under control conditions by paired PF and CF activity. However, LTD induced by pairing PF stimulation with depolarizing voltage steps (substituting for CF activation) was not blocked by ethanol. These observations suggest that the sensitivity of cerebellar circuit function and plasticity to low concentrations of ethanol may be caused by an ethanol-mediated impairment of NMDA receptor signaling at CF synapses onto cerebellar Purkinje cells. © 2013 the American Physiological Society
Periodic Q-learning
No full textThe use of target networks is a common practice in deep reinforcement learning for stabilizing the training; however, theoretical understanding of this technique is still limited. In this paper, we study the so-called periodic Q-learning algorithm (PQ-learning for short), which resembles the technique used in deep Q-learning for solving infinite-horizon discounted Markov decision processes (DMDP) in the tabular setting. PQ-learning maintains two separate Q-value estimates – the online estimate and target estimate. The online estimate follows the standard Q-learning update, while the target estimate is updated periodically. In contrast to the standard Q-learning, PQ-learning enjoys a simple finite time analysis and achieves better sample complexity for finding an epsilon-optimal policy. Our result provides a preliminary justification of the effectiveness of utilizing target estimates or networks in Q-learning algorithms
Synthesis of a novel Ce-Pr-Fe-O@C photocatalyst and its photocatalytic activity
No full textUsing Ce(NO3)3·6H2O, Pr(NO3)3·6H2O,and Fe(NO3)3·9H2O as metal sources, and Acid Red 14 (AR14) as carbon source, a Ce-Pr-Fe-O@C photocatalyst was synthesized via a codeposition method. An orthogonal matrix of experiments was used to investigate the effect of the main synthesis parameters on the photocatalytic activity of Ce-Pr-Fe-O@C for the degradation of AR14. The obtained materials were characterized by XRD, SEM, TEM, FT-IR, Raman, XPS techniques, and the results showed that a cubic fluorite structure was formed containing evenly distributed Fe, Pr and C in all samples. The AR14 degradation results showed that the photocatalytic activity of Ce-Pr-Fe-O@C doped with a small amount of Fe, Pr and C is more effective, due to the efficient visible light absorption and the effective separation of photoelectrons and holes resulting from the presence of oxygen vacancies and carbon bonds
Investigation of Lagrangian coherent structures in a wake-induced boundary layer transition
No full textThe evolution of coherent structures in a flat plate boundary layer transition induced by the cylinder wake is investigated using the particle image velocimetry (PIV) technique. The finite-time Lyapunov exponent (FTLE), which characterizes the amount of stretching about the flow trajectory, is used to extract the Lagrangian coherent structures. It is revealed that secondary vortex is induced by the cylinder wake vortices in the near wall region,which would evolve into hairpin vortex as it convects downstream. The subsequent evolvement of the hairpin vortex, characterized by the regeneration of offspring hairpin vortex upstream of it, leads to the appearance of the hairpin packet and the boundary layer finally reaches a turbulent state
Figure 3 from: He Q, Zhao R, He A, Zhu Z, Tong Y (2021) Taxonomic Identity of Carpinus dayongina Franchet (Betulaceae). PhytoKeys 177: 63-75. https://doi.org/10.3897/phytokeys.177.57725
No full textFigure 3 Nutlet trichomes of C. polyneuraA from isotype of C. dayongina (K. W. Liu 33359, PE01843387) B from paratype of C. dayongina (Y. T. Xiao 40700, CSFI017539) C from T. L. Dai 104469, PE00818275 D from W. P. Fang 7546, PE00818253. A, C, D photographed by Q. Q. He B photographed by X. Li
Differential Expression of Toll-Like Receptors mRNA in Baseline Peripheral Blood Mononuclear Cells (PBMC) of Chronic Hepatitis C Patients with Differential Responsiveness to Pegylated Interferon Plus Ribavirin Therapy
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