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The COVID‐19 pandemic highlighted the clear risk that zoonotic viruses pose to global health and economies. The scientific community responded by developing several efficacious vaccines which were expedited by the global need for vaccines. The emergence of SARS‐CoV‐2 breakthrough infections highlights the need for additional vaccine modalities to provide stronger, long‐lived protective immunity. Here we report the design and preclinical testing of small extracellular vesicles (sEVs) as a multi‐subunit vaccine. Cell lines were engineered to produce sEVs containing either the SARS‐CoV‐2 Spike receptor‐binding domain, or an antigenic region from SARS‐CoV‐2 Nucleocapsid, or both in combination, and we tested their ability to evoke immune responses in vitro and in vivo. B cells incubated with bioengineered sEVs were potent activators of antigen‐specific T cell clones. Mice immunised with sEVs containing both sRBD and Nucleocapsid antigens generated sRBD‐specific IgGs, nucleocapsid‐specific IgGs, which neutralised SARS‐CoV‐2 infection. sEV‐based vaccines allow multiple antigens to be delivered simultaneously resulting in potent, broad immunity, and provide a quick, cheap, and reliable method to test vaccine candidates. [ABSTRACT FROM AUTHOR]

The antiviral restriction factor, tetherin, blocks the release of several different families of enveloped viruses, including the Coronaviridae. Tetherin is an interferon‐induced protein that forms parallel homodimers between the host cell and viral particles, linking viruses to the surface of infected cells and inhibiting their release. We demonstrate that SARS‐CoV‐2 infection causes tetherin downregulation and that tetherin depletion from cells enhances SARS‐CoV‐2 viral titres. We investigate the potential viral proteins involved in abrogating tetherin function and find that SARS‐CoV‐2 ORF3a reduces tetherin localisation within biosynthetic organelles where Coronaviruses bud, and increases tetherin localisation to late endocytic organelles via reduced retrograde recycling. We also find that expression of Spike protein causes a reduction in cellular tetherin levels. Our results confirm that tetherin acts as a host restriction factor for SARS‐CoV‐2 and highlight the multiple distinct mechanisms by which SARS‐CoV‐2 subverts tetherin function. Synopsis: The anti‐viral restriction factor Tetherin blocks the egress of SARS‐CoV‐2. Expression of ORF3a and Spike protein antagonises tetherin to allow SARS‐CoV‐2 escape.Tetherin loss aids SARS‐CoV‐2 viral spread.SARS‐CoV‐2 ORF3a alters tetherin localization by impairing retrograde traffic and enhances virus release.SARS‐CoV‐2 Spike causes tetherin downregulation. [ABSTRACT FROM AUTHOR]

A dual-mode flyback inverter is proposed for photovoltaic power applications. The proposed dual-mode flyback inverter makes use of both discontinuous conduction mode (DCM) and continuous conduction mode (CCM) operations for more than 200 W power applications. However, it suffers from output current control problems such as low system gain during DCM and right-half-plain zero problem during CCM. To achieve accurate reference tracking, the authors propose to adopt the repetitive control scheme that increases the system gain at the fundamental and its harmonic frequencies of the grid. To reduce the burden from the conventional proportional-integral controller, the authors use the dual-mode nominal duty that helps the dual-mode flyback inverter generate the target output current while attenuating the effect of disturbances. To make the dualmode flyback inverter operate at the maximum power point (MPP), the authors use the incremental conductance method that offers smooth transition to the MPP. The experimental results show that the proposed flyback system implemented for 200 W dual-mode flyback inverter prototype achieves high MPP tracking efficiency, low total harmonic distortion, high power conversion efficiency, and high power capacity. [ABSTRACT FROM AUTHOR]

A dual‐mode flyback inverter is proposed for photovoltaic power applications. The proposed dual‐mode flyback inverter makes use of both discontinuous conduction mode (DCM) and continuous conduction mode (CCM) operations for more than 200 W power applications. However, it suffers from output current control problems such as low system gain during DCM and right‐half‐plain zero problem during CCM. To achieve accurate reference tracking, the authors propose to adopt the repetitive control scheme that increases the system gain at the fundamental and its harmonic frequencies of the grid. To reduce the burden from the conventional proportional‐integral controller, the authors use the dual‐mode nominal duty that helps the dual‐mode flyback inverter generate the target output current while attenuating the effect of disturbances. To make the dual‐mode flyback inverter operate at the maximum power point (MPP), the authors use the incremental conductance method that offers smooth transition to the MPP. The experimental results show that the proposed flyback system implemented for 200 W dual‐mode flyback inverter prototype achieves high MPP tracking efficiency, low total harmonic distortion, high power conversion efficiency, and high power capacity. [ABSTRACT FROM AUTHOR]

An algorithm that can compute the rotation angle between two images is proposed, independently of the translation angle by using only two‐point correspondence pairs. A parameterised solution vector can be calculated from the null‐space of a matrix constructed of two‐point correspondence pairs, and then the rotation angle is evaluated from this vector by using the relation between the elements of the essential matrix. Once the rotation angle is determined, the translation angle can be computed by using the Ackermann steering constraint, and then the translation distance can be determined. In the experiments, the proposed algorithm estimated the rotation angle and the translation distance better than did previous algorithms. [ABSTRACT FROM AUTHOR]

Mitogen-activated protein kinase (MAPK) signalling networks are important regulators of environmental responses and developmental processes in plants. To understand the role of MAPK signalling modules in the regulation of plant microtubule functions, we searched for MAPKs that interact with the dual-specificity MAPK phosphatase, PROPYZAMIDE HYPERSENSITIVE 1 ( PHS1), whose mutation has previously been reported to confer hypersensitivity to microtubule-disrupting drugs in Arabidopsis. Yeast two-hybrid assays demonstrated that PHS1 specifically interacts with two MAPKs, MPK12 and MPK18. Bimolecular fluorescence complementation (BiFC) studies confirmed that the PHS1 and MPK18 proteins are physically coupled, and that this interaction occurs in the cytoplasm. At the biochemical level, in vitro dephosphorylation assays indicated that phospho-MPK18 can be dephosphorylated by recombinant PHS1. Mutant mpk18 seedlings show defects in microtubule-related functions, and have moderately stabilized microtubules. Absence of MPK18 in the phs1-1 background partially complements the phs1-1 root growth phenotypes, providing genetic evidence for involvement of MPK18 signalling in microtubule-related functions. We propose a model whereby the PHS1–MPK18 signalling module is involved in a phosphorylation/dephosphorylation switch that regulates cortical microtubule functions. [ABSTRACT FROM AUTHOR]

This paper develops a kinematic path-tracking algorithm for a nonholonomic mobile robot using an iterative learning control (ILC) technique. The proposed algorithm produces a robot velocity command, which is to be executed by the proper dynamic controller of the robot. The difference between the velocity command and the actual velocity acts as state disturbances in the kinematic model of the mobile robot. Given the kinematic model with state disturbances, we present an ILC-based path-tracking algorithm. An iterative learning rule with both predictive and current learning terms is used to overcome uncertainties and the disturbances in the system. It shows that the system states, outputs, and control inputs are guaranteed to converge to the desired trajectories with or without state disturbances, output disturbances, or initial state errors. Simulations and experiments using an actual mobile robot verify the feasibility and validity of the proposed learning algorithm. © 2005 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

In this paper, an adaptive controller is designed for rigid-link flexible-joint robot manipulators based on link and actuator position measurements only. It is based on the adaptive integrator backstepping method and the link and actuator velocity filters are used to estimate the unknown velocity terms. Moreover, the proposed controller exploits the estimate of the joint stiffness matrix inverse to overcome the overparametrization problem, which has been a significant drawback in adaptive partial state feedback controllers. It achieves asymptotic tracking of link positions while keeping all states and signals bounded. The tracking capability of the presented method is shown through simulation results of one- and two-link flexible joint manipulators. © 2004 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

This paper presents a P-type iterative learning control (ILC) scheme for uncertain robotic systems that perform the same tasks repetitively. The proposed ILC scheme comprises a linear feedback controller consisting of position error and exponentially weighted velocity error with respect to the number of iterations, and a feedforward learning controller updated by the exponentially weighted velocity error from previous trial. As the learning iteration proceeds, the position and velocity errors converge uniformly to zero within error bounds that decay exponentially through the sequence of iterations with arbitrarily selected convergence rate. Consequently, the proposed ILC scheme enables analysis and tuning of the exponential convergence rate in the iteration domain in contrast to other existing P-type ILC schemes. © 2003 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

An algorithm that can compute the rotation angle between two images is proposed, independently of the translation angle by using only two-point correspondence pairs. A parameterised solution vector can be calculated from the null-space of a matrix constructed of twopoint correspondence pairs, and then the rotation angle is evaluated from this vector by using the relation between the elements of the essential matrix. Once the rotation angle is determined, the translation angle can be computed by using the Ackermann steering constraint, and then the translation distance can be determined. In the experiments, the proposed algorithm estimated the rotation angle and the translation distance better than did previous algorithms. [ABSTRACT FROM AUTHOR]