An Automated Device (AGARS) for Studying Avoidance of Pollutant Gradients by Aquatic Organisms

Most apparatus designed to detect avoidance of pollutants by aquatic organisms require visual observations of test organisms in steep pollutant gradients. AGARS (Aquatic Gradient Avoidance Response System) was developed to eliminate these limitations. This system allows animals to choose between one uncontaminated zone and three increasingly toxic zones in a gradient trough that is monitored for extended time periods by infrared light sources, sensors, and a microprocessor. Data are accumulated hourly and processed by a paper tape reader/calculator/plotter system that records the time test animals remain in each zone and compares behavior before and during test exposures. Initial tests indicate that pinfish (Lagodon rhomboides) tested in the apparatus will avoid chlorine-produced oxidants at concentrations of 0.02–0.04 mg/L. Key words: avoidance responses, behavioral bioassays, automated monitoring systems, chlorine-produced oxidants

A Computer Compatible Multi-Purpose Event Recorder

We describe a multi-mode event recorder for registering behavioral events directly on a punched paper tape. The paper tape produced can be read by any computer equipped with a paper tape reader. For paper tape with an 8-bit code, 256 different events can be registered. The device itself can be operated in any one of four modes. In the first mode, pressing a key on the keyboard results in a unique code (hole combination) being punched on the paper tape. In the second mode of operation, a sequentially increasing number ("time") is punched automatically at preset intervals. In addition, other codes may be entered via the keyboard. A time punch may thus be used to signal that an observation should be entered from the keyboard. In the third mode, the machine punches, at regular intervals, the code of the key currently depressed. In mode 4, external events are counted for a given time interval and the sum punched onto the tape at the end of the interval. With each punch, the sum is reset to zero. The paper tapes produced are read directly and the data processed according to the program. This results in a great reduction in the time necessary to process data. The system is compared with other devices which use magnetic tape as an intermediate storage device. The main advantage of this system is the time saved in processing data.

Sacramento Peak Magnetograph

The Sac Peak magnetograph (DZA) has been modified from Evans' original scheme so that it measures the displacement of the right and left hand circularly polarized lines separately. The computer reduction calculates the Zeeman and radial velocity signals. A grating servo system has been added to correct for slow temperature drifts in the spectrograph. A paper-tape reader controls the raster scan and the formatting of data on to magnetic tape.