Modulation of the Gibberellin Content in Transgenic Turf-Type Bahiagrass for Improved Turf Characteristics and Reduced Mowing Requirements

Bahiagrass is extensively used for utility turf along highways and for residential lawns in the southern USA and in the subtropical regions around the world. The objective of this experiment was to enhance turf quality of bahiagrass and reduce the mowing frequency by over-expression of a gibberellin catabolizing enzyme, Gibberellin 2-oxidase

Evaporation of bacteria-laden surrogate respiratory fluid droplets: On a hydrophilic substrate versus contact-free environment confers differential bacterial infectivity

The transmission of viruses/ bacteria cause infection predominantly via aerosols. The transmission mechanism of respiratory diseases is complex, including direct or indirect contact, large droplet, and airborne routes apart from close contact transmission. With this pretext, we have investigated two modes of droplet evaporation to understand its significance in airborne disease transmission; a droplet in a contact-free environment, which evaporates and forms droplet nuclei, and a droplet on a hydrophilic substrate (fomite). The study examines mass transport, the deposition pattern of bacteria in the precipitates, and their survival and virulence. The osmotic pressure increases with the salt concentration, inactivating the bacteria embedded in the precipitates with accelerated evaporation. Further, the bacteria's degree of survival and enhanced pathogenicity are compared for both evaporation modes. The striking differences in pathogenicity are attributed to the evaporation rate, oxygen availability, and reactive oxygen species (ROS) generation

Graphene-Based Nanocomposites for Energy Storage

Since the first report of using micromechanical cleavage method to produce graphene sheets in 2004, graphene/graphene-based nanocomposites have attracted wide attention both for fundamental aspects as well as applications in advanced energy storage and conversion systems. In comparison to other materials, graphene-based nanostructured materials have unique 2D structure, high electronic mobility, exceptional electronic and thermal conductivities, excellent optical transmittance, good mechanical strength, and ultrahigh surface area. Therefore, they are considered as attractive materials for hydrogen (H2) storage and high-performance electrochemical energy storage devices, such as supercapacitors, rechargeable lithium (Li)-ion batteries, Li–sulfur batteries, Li–air batteries, sodium (Na)-ion batteries, Na–air batteries, zinc (Zn)–air batteries, and vanadium redox flow batteries (VRFB), etc., as they can improve the efficiency, capacity, gravimetric energy/power densities, and cycle life of these energy storage devices. In this article, recent progress reported on the synthesis and fabrication of graphene nanocomposite materials for applications in these aforementioned various energy storage systems is reviewed. Importantly, the prospects and future challenges in both scalable manufacturing and more energy storage-related applications are discussed

Path Planning Algorithms for Robotic Agents

The focus of this work is path planning algorithms for autonomous agents. Specifically, we study problems in three areas where path planning to direct the motion of autonomous agents is critical for their performance. The first problem is a vehicle routing problem in which mobile demands appear in an environment and the task of the autonomous agent is to stop the demands from escaping the environment boundary. We first propose two fundamental performance bounds for the proposed problem. We then propose routing algorithms for this problem with performance guarantees. We examine the gap between these guarantees and the fundamental performance bounds. The second problem is a surveillance problem in a networked environment. The tasks of the autonomous surveillance agent in this problem are to (1) detect unknown intruder locations and (2) detect anomalies based on noisy measurements. We propose Markov chain based routing algorithms for the surveillance agent to achieve these goals. We parameterize these routing algorithms using a property of Markov chains called the mean first passage time. We also frame optimization problems to obtain optimal algorithms for the two surveillance tasks. The third problem studied in this work is a boundary guarding problem in which the task of a set of patrolling agents constrained to move on a ring is to achieve synchronization using only local communication. We propose a coordination algorithm to solve this problem and identify initial agent configurations under which synchronization is guaranteed