Implementation of two high through-put techniques in a novel application: detecting point mutations in large EMS mutated plant populations

Background  

The establishment of mutant populations together with the strategies for targeted mutation detection has been applied successfully to a large number of organisms including many species in the plant kingdom. Considerable efforts have been invested into research on tomato as a model for berry-fruit plants. With the progress of the tomato sequencing project, reverse genetics becomes an obvious and achievable goal.     

Insect control by genetic manipulation of natural populations

The possible use of chromosome rearrangements is considered as a means for introducing genes into insect populations for their own control. The release of laboratory-constructed strains differing from the field population for a number of chromosome interchanges should create an unstable situation leading to the rapid replacement of the field population. This replacement should allow introduction of genes for insecticide susceptibility, cold sensitivity, or the like. The process would produce sterile hybrids while the genetic displacement occurs which itself will contribute to a reduction in pest numbers.     

Phencyclidine-induced immunodepression

Phencyclidine ("PCP" or "angel dust") and some of its derivatives are psychotomimetic drugs that have been used in general anesthesia for some time. This drug blocks potassium ion channels in brain tissue, and there is a specific PCP binding to lymphocytes. In a study of the effects of this drug on immunocyte function, it was found that humoral and cellular immune responses in vitro were depressed when immunocytes were treated with PCP before biological assay. This finding has implications for PCP abuse and also for the use of its derivative in general anesthesia, where it may contribute to postoperative infection.     

Thermal Structure and Energy Influx to the Day-and Nightside Venus Ionosphere

Pioneer Venus in situ measurements made with the retarding potential analyzer reveal strong variations in the nightside ionospheric plasma density from location to location in some orbits and from orbit to orbit. The ionopause is evident at night as a relatively abrupt decrease in the thermal plasma concentration from a few hundred to ten or fewer ions per cubic centimeter. The nightside ion and electron temperatures above an altitude of 250 kilometers, within the ionosphere and away from the terminator, are comparable in magnitude and have a value at the ionopause of approximately 8000 K. The electron temperature increases from a few tens of thousands of degrees Kelvin just outside the ionopause to several hundreds of thoussands of degrees Kelvin further into the shocked solar wind. The coldest ion temperatures measured at an altitude of about 145 kilometers are 140 to 150 K and are still evidently above the neutral temperature. Preliminary day-and nightside model ion and electron temperature height profiles are compared with measured profiles. To raise the model ion temperature to the measured ion temperature on both day-and nightsides, it was necessary to include an ion energy source of the order of 4 x 10(-3) erg per square centimeter per second, presumably Joule heating. The heat flux through the electron gas from the solar wind into the neutral atmosphere averaged over day and night may be as large as 0.05 erg per square centimeter per second. Integrated over the planet surface, this heat flux represents one-tenth of the solar wind energy expended in drag on the sunward ionopause hemisphere.     

Chemical Scent Constituents in the Urine of the Red Fox (Vulpes vulpes L.) During the Winter Season

Four volatile chemical compounds have been identified as apparently unique constituents in urines of red foxes (both sexes) during the winter season when mating occurs. Quinaldine was found only in male fox urine. Several other compounds identified are found in other species also. Some or all of these compounds may function in olfactory communication in the red fox.