Quorum sensing is a form of cell-to-cell communication by which bacteria communicate by secreting signaling molecules called autoinducers that help regulate gene expression. Quorum sensing was first detected in Photobacterium fischeri [1]. A specific acylated homoserine lactone was found to regulate transcription of the luciferase operon resulting in light emission [2]. A related organism, Vibr...

Photosynthetic prokaryotes have highly developed abilities to detect and react to environmental signals. Light sensing is one of the most important capabilities of organisms that use light for photosynthesis and photomorphogenesis. This review addresses photoreception in cyanobacteria from the perception of light through the physiological responses observed in response to light-dependent signal...

The purpose of vision-based sensing devices in the welding industry is to electronically replicate the role of a skilled welder and emulate the human eye with a light-sensing device such as camera and the human brain with a computer algorithm that interprets the images. Just as an optical feedback from human eye guides the human welder, optical feedback in this electronic system would be used t...

This article presents a method for online learning of robot navigation a↵ordances from spatiotemporally correlated haptic and depth cues. The method allows the robot to incrementally learn which objects present in the environment are actually traversable. This is a critical requirement for any wheeled robot performing in natural environments, in which the inability to discern vegetation from no...

A novel inexpensive optical-sensing technique has been developed for colorimetric flow analysis. This sensing system employs two LEDs whereby one is used as the light source and the other as a light detector. The LED used as light detector is reverse biased with a 5-V supply so that the photocurrent generated by the incident light discharges the capacitance. Direct digital output is provided by...

In nature, plants integrate a wide range of light signals from solar radiation to adapt to the surrounding light environment, and these light signals also regulate a variety of important agronomic traits. Blue light-sensing cryptochrome (cry) and red/far-red light-sensing phytochrome (phy) play critical roles in regulating light-mediated physiological responses via the regulated transcriptional...

The intertidal brown alga Silvetia compressa releases gametes from receptacles (the reproductive tissue) rapidly upon a dark transfer (following a photosynthesisdependent period in the light, termed potentiation). In this study, the wavelength-dependence of this process was investigated. During the potentiation period in white light (WL), gametes are not released. However, gametes were released...

A distributed sensing system for apolar hydrocarbons is presented which is built from a chemically sensitive polymer-clad silica fiber adapted to an optical time domain reflectometer (OTDR) setup. OTDR measurements allow locating and detecting chemicals by measuring the time delay between short light pulses entering the fiber and discrete changes in the backscatter signals that are caused by lo...