Dynamic event-triggered-based human-in-the-loop formation control for stochastic nonlinear MASs

The dynamic event-triggered (DET) formation control problem of a class of stochastic nonlinear multi-agent systems (MASs) with full state constraints is investigated in this article. Supposing that the human operator sends commands to the leader as control input signals, all followers keep formation through network topology communication. Under the command-filter-based backstepping technique, the radial basis function neural networks (RBF NNs) and the barrier Lyapunov function (BLF) are utilized to resolve the problems of unknown nonlinear terms and full state constraints, respectively. Furthermore, a DET control mechanism is proposed to reduce the occupation of communication bandwidth. The presented distributed formation control strategy guarantees that all signals of the MASs are semi-globally uniformly ultimately bounded (SGUUB) in probability. Finally, the feasibility of the theoretical research result is demonstrated by a simulation example

The non-gibberellic acid-responsive semi-dwarfing gene uzu affects Fusarium crown rot resistance in barley

BACKGROUND: Studies in Arabidopsis show that DELLA genes may differentially affect responses to biotrophic and necrophic pathogens. A recent report based on the study of DELLA-producing reduced height (Rht) genes in wheat and barley also hypothesized that DELLA genes likely increased susceptibility to necrotrophs but increased resistance to biotrophs. RESULTS: Effects of uzu, a non-GA (gibberellic acid)-responsive semi-dwarfing gene, on Fusarium crown rot (FCR) resistance in barley were investigated. Fifteen pairs of near isogenic lines for this gene were generated and assessed under two different temperature regimes. Similar to its impacts on plant height, the semi-dwarfing gene uzu also showed larger effects on FCR severity in the high temperature regime when compared with that in the low temperature regime. CONCLUSIONS: Results from this study add to the growing evidence showing that the effects of plant height on Fusarium resistances are unlikely related to DELLA genes but due to direct or indirect effects of height difference per se. The interaction between these two characteristics highlights the importance of understanding relationships between resistance and other traits of agronomic importance as the value of a resistance gene could be compromised if it dramatically affects plant development and morphology

Estimator-based event-triggered leader–following consensus of multiagent systems under denial-of-service attacks

International audienceThe leader–following consensus issue is investigated for multiagent systems under external disturbances and denial-of-service (DoS) attacks. DoS attacks are considered to be designed according to an unknown attack strategy and would block the communication network. First, a novel triggering mechanism is designed to save communication resources during normal communication periods by event-triggered strategy and to detect the end of attack periods by time-triggered strategy. Then, a set of estimators is constructed to predict the states of the agent itself and its neighbors when the attack occurs. The estimators do not contain the control signals, which only correct the prediction when the actual system states are received. As a result, a distributed switching controller is designed that includes event-triggered states during normal communication periods and predicted states during attack periods. Finally, the proposed secure control protocol is proven to ensure that the system states are eventually consensus and the Zeno behavior is not exhibited. Moreover, a simulation example is given to illustrate the effectiveness of the presented strategy

Molecular Characterization of Barley 3H Semi-Dwarf Genes

<div><p>The barley chromosome 3H accommodates many semi-dwarfing genes. To characterize these genes, the two-rowed semi-dwarf Chinese barley landrace ‘TX9425’ was crossed with the Australian barley variety ‘Franklin’ to generate a doubled haploid (DH) population, and major QTLs controlling plant height have been identified in our previous study. The major QTL derived from ‘TX9425’ was targeted to investigate the allelism of the semi-dwarf gene <i>uzu</i> in barley. Twelve sets of near-isogenic lines and a large NILF₂ fine mapping population segregating only for the dwarfing gene from ‘TX9425’ were developed. The semi-dwarfing gene in ‘TX9425’ was located within a 2.8 cM region close to the centromere on chromosome 3H by fine mapping. Molecular cloning and sequence analyses showed that the ‘TX9425’-derived allele contained a single nucleotide substitution from A to G at position 2612 of the <i>HvBRI1</i> gene. This was apparently the same mutation as that reported in six-rowed <i>uzu</i> barley. Markers co-segregating with the QTL were developed from the sequence of the <i>HvBRI1</i> gene and were validated in the ‘TX9425’/‘Franklin’ DH population. The other major dwarfing QTL derived from the Franklin variety was distally located on chromosome 3HL and co-segregated with the <i>sdw</i>1 diagnostic marker <i>hv20ox2</i>. A third dwarfing gene, expressed only in winter-sown trials, was identified and located on chromosome 3HS. The effects and interactions of these dwarfing genes under different growing conditions are discussed. These results improve our understanding of the genetic mechanisms controlling semi-dwarf stature in barley and provide diagnostic markers for the selection of semi-dwarfness in barley breeding programs.</p></div

Diagnostic markers developed from the <i>uzu</i> and <i>sdw1</i> sequences were mapped on barley chromosome 3H.

<p>The linkage maps were constructed using Joinmap4.0, QTLs were detected in a composite interval mapping using MapQTL5.0. The diagnostic markers co-segregated with QTLs representing the dwarfing genes in the ‘TX9425/Franklin’ doubled haploid population, with a third QTL identified and located on chromosome 3HS.</p

Phenotypes and height of the short-statured barley genotypes ‘TX9425’ and ‘Franklin’ grown under different temperature and day length conditions.

<p>(I) ‘TX9425’, grown in low temperatures and during short days; (II) ‘TX9425’, grown in warm temperatures and during long days; (III) ‘Franklin’, grown in low temperatures and during short days; and (IV) ‘Franklin’, grown in warm temperatures and during long days.</p

Distribution of plant height (cm) in the doubled haploid and NILF2 populations.

<p>Distribution of plant height (cm) in the doubled haploid and NILF2 populations.</p

Distribution of plant height in the DH and NILF2 populations.

<p>(a) Continuous normal distribution of plant height for the 92 DH lines used in the winter-sown trial; (b) continuous bi-modal distribution of plant height for the 92 DH lines used in the spring-sown trial; (c) height distribution of 903 NILF₂ plants showing two distinct groups.</p

Segregation of dwarf and tall progenies in the DH and NILF2 populations.

<p>Segregation of dwarf and tall progenies in the DH and NILF2 populations.</p

Primers used to clone <i>HvBRI1</i> in NIL lines segregating for the ‘TX9425’ dwarfing locus.

<p>Primers used to clone <i>HvBRI1</i> in NIL lines segregating for the ‘TX9425’ dwarfing locus.</p