261 research outputs found
Designing Fully Distributed Consensus Protocols for Linear Multi-agent Systems with Directed Graphs
This paper addresses the distributed consensus protocol design problem for
multi-agent systems with general linear dynamics and directed communication
graphs. Existing works usually design consensus protocols using the smallest
real part of the nonzero eigenvalues of the Laplacian matrix associated with
the communication graph, which however is global information. In this paper,
based on only the agent dynamics and the relative states of neighboring agents,
a distributed adaptive consensus protocol is designed to achieve
leader-follower consensus for any communication graph containing a directed
spanning tree with the leader as the root node. The proposed adaptive protocol
is independent of any global information of the communication graph and thereby
is fully distributed. Extensions to the case with multiple leaders are further
studied.Comment: 16 page, 3 figures. To appear in IEEE Transactions on Automatic
Contro
Integrated Fabry-Perot cavities as a mechanism for enhancing micro-ring resonator performance
We propose and experimentally demonstrate the enhancement in the filtering
quality (Q) factor of an integrated micro-ring resonator (MRR) by embedding it
in an integrated Fabry-Perot (FP) cavity formed by cascaded Sagnac loop
reflectors (SLRs). By utilizing coherent interference within the FP cavity to
reshape the transmission spectrum of the MRR, both the Q factor and the
extinction ratio (ER) can be significantly improved. The device is
theoretically analyzed, and practically fabricated on a silicon-on-insulator
(SOI) wafer. Experimental results show that up to 11-times improvement in Q
factor, together with an 8-dB increase in ER, can be achieved via our proposed
method. The impact of varying structural parameters on the device performance
is also investigated and verified by the measured spectra of the fabricated
devices with different structural parameters.Comment: 9 pages, 6 figures, 33 Reference
Inhibition of phosphodiesterase10A attenuates morphine-induced conditioned place preference
Background Phosphodiesterase (PDE) 10A is selectively expressed in medium spiny neurons of the striatum. Nucleus accumbens (NAc) is a key region that mediates drug reward and addiction-related behaviors. To investigate the potential role of PDE10A in the reinforcement properties of morphine, we tested the effect of MP-10, a selective inhibitor of PDE10A, on acquisition, expression, and extinction of morphine-induced conditioned place preference (CPP). Results The results show that 2.5 mg/kg MP-10, administered subcutaneously, significantly inhibited the acquisition of morphine-induced CPP. The same dose of MP-10 alone did not result in the CPP. Moreover, MP-10 did not alter the expression of morphine-induced CPP, but did accelerate the extinction of morphine-induced CPP. Additionally, chronic treatment with 2.5 mg/kg MP-10 decreased expression of phosphorylated CREB (pCREB), activated cAMP response element binding protein, in dorsomedial striatum, in shell of NAc, and in anterior cingulate cortex (ACC) as well as decreased expression of ΔFosB in the shell of NAc and ACC. Conclusion The results suggest that inhibition of PDE10A may have therapeutic potential in the treatment of opioid addiction
Spatio-temporal isolator in lithium niobate on insulator
In this contribution, we simulate, design, and experimentally demonstrate an
integrated optical isolator based on spatiotemporal modulation in the thin-film
lithium niobate on insulator waveguide platform. We used two cascaded
travelling wave phase modulators for spatiotemporal modulation and a ring
resonator as a wavelength filter to suppress the sidebands of the reverse
propagating light. This enabled us to achieve an isolation of 27 dB. The
demonstrated suppression of the reverse propagating light makes such isolators
suitable for the integration with III-V laser diodes and Erbium doped gain
sections in the thin-film lithium niobate on insulator waveguide platform.Comment: 9 pages, 3 figure
Deletion of FgHOG1 Is Suppressive to the mgv1 Mutant by Stimulating Gpmk1 Activation and Avoiding Intracellular Turgor Elevation in Fusarium graminearum
Fusarium head blight caused by Fusarium graminearum is an important disease of wheat and barley. Previous studies have showed that all three MAP kinase genes, MGV1, FgHOG1, and GPMK1, are involved in regulating hyphal growth, sexual reproduction, plant infection, and stress responses in this pathogen. To determine the relationship between the Mgv1 and FgHog1 pathways, in this study, we generated and characterized the mgv1 Fghog1 double mutant. Deletion of FgHOG1 partially rescued the defects of the mgv1 mutant in vegetative growth and cell wall integrity but had no effects on its defects in plant infection and DON production. The mgv1 Fghog1 mutant grew faster and was more tolerant to cell wall stressors than the mgv1 mutant. Swollen compartments and cell burst were observed frequently in the mgv1 mutant but rarely in the mgv1 Fghog1 mutant when treated with fungicide fludioxonil or cell wall stressor Congo red. Conversely, the deletion of MGV1 also alleviated the hyperosmotic sensitivity of the Fghog1 mutant in vegetative growth. TGY assays indicated increased phosphorylation of FgHog1 in the mgv1 mutant, and TEY assays further revealed elevated activation of Gpmk1 in the mgv1 Fghog1 double mutant, particularly under cell wall stress conditions. Overall, our data showed that deletion of FgHOG1 partially suppressed the defects of the mgv1 mutant, possibly by affecting genes related to cell wall integrity and osmoregulation via the over-activation of Gpmk1 MAP kinase and avoiding intracellular turgor elevation
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