Jae Chul Koo

Constitutive expression of a gene encoding tobacco mosaic virus (TMV) coat protein (CP) in transgenic plants confers resistance to infection by TMV and related tobamoviruses. Here, we examined resistance to TMV by temporal and quantitative control of TMV Cg CP (CgCP) gene expression using a simple, methoxyfenozide-inducible system in Arabidopsis plants. By soil drenching with a commercial ecdysone agonist (Intrepid-2F/methoxyfenozide), most transgenic lines were induced from undetectable levels

Pn-AMP1, Pharbitis nil antimicrobial peptide 1, is a small cysteine-rich peptide implicated in host-plant defense. We show here that Pn-AMP1 causes depolarization of the actin cytoskeleton in Saccharomyces cerevisiae and Candida albicans. Pn-AMP1 induces rapid depolarization of actin cables and patches within 15 min. Increased osmolarity or temperature induces transient actin depolarization and results in increased sensitivity to Pn-AMP1, while cells conditioned to these stresses show less sensi

Reactive oxygen species (ROS) are inevitable by-products of aerobic metabolic processes, causing non-specific oxidative damage and also acting as second messengers. Superoxide is a short-lived ROS that functions in various cellular responses, including aging and cell death. However, it is unclear as to how superoxide brings about age-dependent cell death and senescence. Here, we show that the accumulation and signaling of superoxide are mediated by three Arabidopsis proteins-RPK1, CaM4, and Rboh

For soft grippers to be applied in atypical industrial environments, they must conform to an object’s exterior shape and momentarily change their stiffness. However, many of the existing grippers have limitations with respect to these functions: they grasp an object with only a single curvature and a fixed stiffness. Consequently, those constraints limit the stability of grasping and the applications. This paper introduces a new multicurvature, variable-stiffness soft gripper. Inspired by the hu

Blood tests are one of the core processes in the clinical laboratory test field. In hospitals, an automated process called total laboratory automation (TLA), which relies on a set of sophisticated equipment, is normally adopted for the tests. Noting that the TLA system typically has a large footprint and requires a significant amount of power, slim, and easy-to-move blood test equipment is necessary for some specific demands such as emergency rooms or small-size local clinics. Although various p

The presence of a tactile sensor is essential to hold an object and manipulate it without damage. The tactile information helps determine whether an object is stably held. If a tactile sensor is installed at wherever the robot and the object touch, the robot could interact with more objects. In this paper, a skin type slip sensor that can be attached to the surface of a robot with various curvatures is presented. A simple mechanical sensor structure enables the cut and fit of the sensor accordin

Three-stage servo-valves are popularly used in hydraulic systems that require large flow rate and high pressure. For a proper control of flow direction and flow rate fed into a hydraulic actuator, securing a proper position control bandwidth is a critical task for the servo-valve. In this paper, a set of popular control methods are systematically studied and a control method is selected. It is proven that the feedforward model-inverse control is the most effective method in terms of the control