261 research outputs found
Bounds On Anomalous Magnetic And Electric Moments Of Tau Lepton From LEP And Lepton Flavor Violation
The most stringent bounds on the anomalous magnetic and electric dipole
moments of the tau lepton was derived by Escribano and Mass\'{o}[6] from the Z
width at LEP in an effective lagrangian approach to the new physics. In this
paper we point out that the higher dimensional operators introduced by
Escribano and Mass\'{o} not only modify the neutral currents of the tau lepton
to Z gauge boson and the photon, but also induce lepton flavor violation (LFV).
The size of the LFV effect depends crucially on the dynamics of the lepton mass
generation. Assuming the lepton mass matrices in the form of an Fritzsch
ansatz, we point out that the experimental limit on will
push the anomalous magnetic and electric dipole moments of the tau lepton down
to and respectively.Comment: 6 pages, latex, no figure
Harnessing LSTM for Nonlinear Ship Deck Motion Prediction in UAV Autonomous Landing amidst High Sea States
Autonomous landing of UAVs in high sea states requires the UAV to land
exclusively during the ship deck's "rest period," coinciding with minimal
movement. Given this scenario, determining the ship's "rest period" based on
its movement patterns becomes a fundamental prerequisite for addressing this
challenge. This study employs the Long Short-Term Memory (LSTM) neural network
to predict the ship's motion across three dimensions: longi-tudinal,
transverse, and vertical waves. In the absence of actual ship data under high
sea states, this paper employs a composite sine wave model to simulate ship
deck motion. Through this approach, a highly accurate model is established,
exhibiting promising outcomes within various stochastic sine wave combination
models.Comment: 11 pages, 7 figures, accept by ICANDVC202
The PWM strategies of grid-connected distributed generation active NPC inverters
The Neutral Point Clamped topology due to high
efficiency, low leakage current and EMI, its integration is widely
used in the distributed generation (DG) systems. However the
main disadvantage of the NPC inverter is given by an unequal
distribution of the losses in the semiconductor devices, which
leads to an unequal distribution of temperature. By using the
Active NPC topology, the power losses distribution problem is
alleviated. The modulation strategy is a key issue for losses
distribution in this topology. In this paper two known strategies
are discussed and a new proposed PWM strategy, namely the
Adjustable Losses Distribution (ALD) PWM strategy is
proposed for better losses distribution in the Active NPC
(ANPC) topology. Simulations using Simulink and the PLECS
toolbox have been done for evaluating efficiency of different
NPC topologies and some experimental results are presented in
this paper to validate the operation of the different strategies.Peer ReviewedPostprint (published version
Adiabatic Gravitational Perturbation During Reheating
We study the possibilities of parametric amplification of the gravitational
perturbation during reheating in single-field inflation models. Our result
shows that there is no additional growth of the super-horizon modes beyond the
usual predictions.Comment: Refs added; New version to appear in PR
Aqueous Extract of Black Maca (Lepidium meyenii) on Memory Impairment Induced by Ovariectomy in Mice
The present study aims to test two different doses of aqueous extract of black maca on learning and memory in ovariectomized (OVX) mice and their relation with malonalehyde (MDA), acetylcholinesterase (Ache) and monoamine oxidase (MAO) brain levels. Female mice were divided into five groups: (i) naive (control), (ii) sham, (iii) OVX mice and OVX mice treated with (iv) 0.50 g kg−1 and (v) 2.00 g kg−1 black maca. Mice were orally treated with distilled water or black maca during 35 days starting 7 days after surgery. Memory and learning were assessed using the water Morris maze (from day 23–27) and the step-down avoidance test (days 34 and 35). At the end of each treatment, mice were sacrificed by decapitation and brains were dissected out for MDA, Ache and MAO determinations. Black maca (0.5 and 2.0 g/kg) increased step-down latency when compared to OVX control mice. Black maca decreased MDA and Ache levels in OVX mice; whereas, no differences were observed in MAO levels. Finally, black maca improved experimental memory impairment induced by ovariectomy, due in part, by its antioxidant and Ache inhibitory activities
Stat3 regulates microtubules by antagonizing the depolymerization activity of stathmin
Stat3 is a member of the signal transducer and activator of transcription family, which is important in cytokine signaling. Gene ablation studies have revealed a requirement for Stat3 in diverse biological processes (Akira, S. 2000. Oncogene. 19: 2607–2611; Levy, D.E., and C.K. Lee. 2002. J. Clin. Invest. 109:1143–1148). Previously, the function of Stat3 had been attributed exclusively to its transcriptional activity in the nucleus. In this study, we reveal an interaction between Stat3 and the microtubule (MT)-destabilizing protein stathmin. Stathmin did not overtly affect ligand-stimulated Stat3 activation. In contrast, the expression of Stat3 is required for the stabilization of MTs and cell migration. We further demonstrate that Stat3-containing cells are resistant to the MT-destabilizing effect of stathmin overexpression. In addition, down-regulation of stathmin protein levels in Stat3-deficient cells partially reversed the MT and migration deficiencies. Recombinant Stat3 was also capable of reversing stathmin inhibition of tubulin polymerization in vitro. Our results indicate that Stat3 modulates the MT network by binding to the COOH-terminal tubulin-interacting domain of stathmin and antagonizing its MT destabilization activity
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