This paper extends the diagonalization method on the basis of the modal space disturbance observer (MDOB) for application to a multidegree-of-freedom (DOF) system. The aim of this method is to ...suppress the interference between the position and force control systems and realize a bilateral control system. The utility of the proposed method is experimentally verified by using a multi-DOF manipulator. It is confirmed that the MDOB-based decoupling method has better performance than oblique coordinate control. Conventional oblique coordinate control causes oscillation in cases where the modeling error is large and the cutoff frequency of an observer is not high enough to change the system dynamics. On the other hand, the MDOB-based decoupling method becomes unstable when the difference in mass is large.
This paper presents the effectiveness of a time-delay compensation method based on the concept of network disturbance and communication disturbance observer for bilateral teleoperation systems under ...time-varying delay. The most efficient feature of the compensation method is that it works without time-delay models (model-based time-delay compensation approaches like Smith predictor usually need time-delay models). Therefore, the method is expected to be widely applied to network-based control systems, in which time delay is usually unknown and time varying. In this paper, the validity of the time-delay compensation method in the cases of both constant delay and time-varying delay is verified by experimental results compared with Smith predictor.
Phospholipid signaling plays an important role in plant immune responses. Here, we isolated two phospholipase C4 (PLC4) orthologs in the Nicotiana benthamiana genome, designated as N. benthamiana ...PLC4-1 and PLC4-2 (NbPLC4-1 and NbPLC4-2). We created NbPLC4-1- and NbPLC4-2- silenced plants. Induction of the hypersensitive response (HR), including HR cell death and bacterial population reduction, was accelerated in both NbPLC4-1- and NbPLC4-2-silenced plants challenged with N. benthamiana-incompatible Ralstonia solanacearum 8107. The NbPLC4-1- and NbPLC4-2-silenced plants also showed enhanced expression of Nbhin1, a HR marker gene. Expressions of genes for salicylic acid (SA) and jasmonic acid (JA) signaling were drastically increased in NbPLC4-1- and NbPLC4-2-silenced plants by R. solanacearum inoculation. In addition, NbPLC4-1 and NbPLC4-2 silencing triggered reactive oxygen species (ROS) hyper-production. These results suggest that NbPLC4s are closely associated with JA, SA, and ROS signaling and act as negative regulators of the HR in N. benthamiana.
Target of rapamycin (TOR) regulates essential processes associated with plant growth, development, and cell death by modulating metabolic activities and translation in response to environmental ...signals. The ATP-competitive TOR inhibitor AZD8055 suppressed the hypersensitive response (HR) cell death in Nicotiana benthamiana infected with the incompatible Ralstonia solanacearum. The induced expression of the HR marker gene hin1 was also inhibited by the AZD8055 treatment. To further clarify the mechanisms underlying TOR-regulated HR cell death, we focused on TOR-related ErbB3-binding protein 1 (EBP1) in N. benthamiana (NbEBP1). We found four EBP1 orthologs in the N. benthamiana genome. The expression levels of all four EBP1 orthologs in N. benthamiana were up-regulated by the R. solanacearum infection. The silencing of the four NbEBP1 orthologs suppressed the induction of HR cell death, hin1 expression, and the production of reactive oxygen species. These results suggest that the TOR signaling pathway helps regulate HR cell death along with reactive oxygen species-related signaling in N. benthamiana.
Ralstonia solanacearum, a plant pathogenic bacterium causing “bacterial wilt” on crops, uses a quorum sensing (QS) system consisting of phc regulatory elements to control its virulence. Methyl ...3‐hydroxypalmitate (3‐OH PAME) was previously identified as the QS signal in strain AW1. However, 3‐OH PAME has not been reportedly detected from any other strains, and this suggests that they produce another unknown QS signal. Here we identify (R)‐methyl 3‐hydroxymyristate (R)‐3‐OH MAME as a new QS signal that regulates the production of virulence factors and secondary metabolites. (R)‐3‐OH MAME was synthesized by the methyltransferase PhcB and sensed by the histidine kinase PhcS. The phylogenetic trees of these proteins from R. solanacearum strains were divided into two groups, according to their QS signal types—(R)‐3‐OH MAME or (R)‐3‐OH PAME. These results demonstrate that (R)‐3‐OH MAME is another crucial QS signal and highlight the unique evolution of QS systems in R. solanacearum.
Chemical signaling in Ralstonia: We report that (R)‐methyl 3‐hydroxymyristate (R)‐3‐OH MAME is a quorum sensing (QS) signal that regulates the production of virulence factors in Ralstonia solanacearum strain OE1‐1. (R)‐3‐OH MAME was also produced by many other strains. Thus, the compound is another Ralstonia QS signal that has been overlooked for nearly two decades.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The twenty-one papers in this special section focus on bringing the ideas of the worldwide research community working on various disturbance/uncertainty estimation and rejection methods in different ...engineering sectors into common platform and to present the latest advances and developments in design methods for disturbance/uncertainty estimation, design methods for disturbance/uncertainty attenuation, stability and performance analysis, practical implementation, and various case studies of the applications of these techniques.
Hand recovery process is a major issue in the rehabilitation field as hands are vital to perform most daily activities. This paper presents the design and evaluation of a one actuated ...degree-of-freedom exoskeleton finger using flexible actuator to assist patients in rehabilitation process and more specifically in tendon recovery protocols. The control strategy based on the motion-copying system is used to be able to take advantages of the sensation of the patient. The wearability and adaptability of the device are improved, compared to other specific devices, mainly by the use of remote actuation and light-weight materials. Evaluation of the device in terms of wearability, adaptability, repeatability and accuracy of the position estimation are conducted. All these criteria are confirmed. The next step is to test the device in actual recovery protocols to evaluate its efficiency.
The Tn7-based genomic integration system enables direct insertion of foreign gene elements into chromosome downstream of glms in many bacteria species. The glms gene is greatly conserved in Ralstonia ...solanacearum species complex (RSSC), while its downstream regions are mostly different in the RSSC. Here, we provided genetic evidence to validate that this Tn7-integration is dependent on a conserved 30-bp motif in the glms, called attTn7 box, and artificial attTn7 boxes elsewhere are competent for the Tn7-integration, which is further confirmed to be simultaneous at downstream of both original and artificial attTn7 boxes using the PCR. With the whole genome re-sequencing on 500 Tn7-colonies, the Tn7-integration was confirmed to be site- specific at 25-bp downstream of glms with monocopy as chromosome of the RSSC. Characteristic of the monocopy in chromosome enables the Tn7-based complementation to fully restore phenotypes of mutants to those of parent strains that is advantageous than those based on plasmids with low-copy numbers. The Tn7-based genomic integration system provides a generally applicable and versatile genetic tool for studies of complementation, pathogenesis, overexpression, and in-vivo promoter activity assays with monocopy in the RSSC.
It is a well-known fact that minimally invasive surgery (MIS) has many benefits, e.g., unnecessary trauma and blood loss can be minimized by opening tiny surgery scars, recovery process of patients ...can be lessened, and the possibilities of complications can be decreased. Although robots are widely used in MIS due to their fundamental superiorities such as high precision, current surgery robots mainly suffer from absence/limitation of haptic feedback during operation. This paper proposes a novel electrohydraulic haptic transmission system to improve the haptic feedback of a surgery robot. This new device replaces the highly nonlinear mechanical friction of thrust wire by viscous friction and avoids the backlash due to the incompressibility of fluid. Moreover, since the fluid is constantly occupying the entire volume of the hydraulic tube, the system behavior during bending of the tube can be modeled much easier than the thrust wire, for which position, shape, and bending angles of the inner wire inside the outer tube are hardly predictable. The validity of the proposal and its superiorities over conventional transmission mechanisms, such as thrust wire, are experimentally verified.
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