The main purpose of this research was to investigate the phenomenon of tolerance to cocaine. Tolerance is operationally defined as a decreased drug effect due to prior history of drug administration. The animal model that was chosen to investigate tolerance to cocaine was the drug discrimination model, which is an animal analogue of human subjective drug effects. In the drug discrimination procedure, animals are trained to emit one behavior when injected with saline. In the present experiments, rats were trained to press one lever when injected with cocaine, 10 mg/kg, and a different lever when injected with saline for food reinforcement. Once rats are trained, they can accurately detect the cocaine stimulus greater than 95% of the time.

This investigation was concerned with determining the interaction of microwaves with germinating seeds. This study covers two different approaches. The preliminary efforts covered the response of germinating seeds to treatment by microwaves and heat. The second phase of the investigation used microwaves as a probe to determine some of the processes of early seed germination. The preliminary investigation measured the internal metabolic process by ATP production. Leakage of ions and organic material from germinating seeds indicated that membranes are a target of microwaves and heat. Electron photo-micrographs showed an increase in damage to membranes as heat and microwave treatments were increased. The second phase of this investigation was concerned with determining some of the biological activity at the initiation of germination of wheat seeds, Triticum aestivum L., using a resonating microwave cavity oscillating at 9.3 GHz as a probe. Direct current conductivity measurements were also made on the seeds as a means of confirming the observations made with the microwave cavity. There was no observable difference between treatment by UHF or heat in the ultrastructure of germinating seeds. A dielectric response far above that of free water was found as live seeds of wheat began to imbibe water. This effect …

Gray gulls Larus modestus are unique among birds of northern Chile as the only species nesting in the interior Atacama Desert, and the only seagull nesting far (30 - 100 km) from surface water. During breeding-nesting (August - February) gray gulls congregate on the coast of northern Chile where they feed and initiate courtship. As early as August, breeding pairs commute daily to the inner desert to establish nesting territories, round-trip distances of 60-200 Km. During incubation (30 days) and brooding (7 days) adults alternate daily foraging flights to the coast. Afterwards, both adults forage daily for their chick(s) until fledging (ca. 60 days). Foraging flights and thermoregulatory costs during the period of maximal solar radiation, when ground temperatures may reach 61 C in the day and drop to 2 C at night, have selected for adaptations which minimize those costs: tolerance of hypothermia and hyperthermia; dark plumage; low egg-shell water vapor conductance; low standard metabolic rate; elaborate repertory of thermoregulatory behavior which allow adults to take advantage of microclimatic variations in the desert and minimize costs relative to a sympatric congenor, Larus belcheri scheduling foraging flights to take advantage of optimal atmospheric conditions and presence of forage fish (anchovies) …

The objective of this investigation was to examine the changes in the nucleotide pools of Azotobacter vinelandii during the growth cycle. Endogenous ribonucleotides were extracted from A. vinelandii using trichloroacetic acid (TCA; 12% w/v). The 5' mono-, di- and triphosphates of adenine, guanine, uracil and cytosine were separated and quantified by anion-exchange high performance liquid chromatography. Results indicated that the adenylate energy charge of A. vinelandii paralleled the growth rate during exponential phase and that it declined rapidly as the stationary phase was reached. In addition, the amount of each nucleotide in A. vinelandii tended to increase in the logarithmic phase and decrease in the stationary phase in a similar manner to the energy charge.

In five separate experiments, weight-adjusted doses of TEM, EMS, and ENU were injected intraperitoneally into twelve week-old female mice six hours after mating. On day seventeen of gestation, the females were sacrificed and their uterine contents were examined. The effect of each agent was determined by its ability to cause malformations and death to the developing embryos. All treatment groups showed statistically significant elevated levels of malformations in comparison to their corresponding control groups. The reproductive damage induced in these experiments cannot be singularly attributed to teratogenesis or mutagenesis but a combination of the two.

High Performance Liquid Chromatography (HPLC) has been employed as an analytical tool for the purification and separation of nucleic acids. A Nucleogen DEAE 4000-10 weak anion exchange column, prepacked with modified silica gels, was used to purify and separate a number of Escherichia coli plasmids. Plasmid DNAs were extracted by the alkaline lysis method. The cleared lysate was injected directly onto the Nucleogen column, and the peaks were collected, desalted and analysed by gel electrophoresis. On the chromatogram, the pBR322 formed a distinctive peak at 27 minutes and partial separation was made for the E. coli V517 plasmids. Plasmid pBR322 showed a clear band without any detectable contamination on agarose gel. This purified plasmid DNA is biologically active for enzymatic reaction commonly used in genetic engineering techniques.

The objectives of this research were to identify the form of Azotobacter as it exists in situ in the soil; to compare its resistance to that of laboratory grown cysts typical of those described in the literature; and to compare its resistance to that of cells grown on dialyzed soil agar. In addition, the morphology of the cells grown on dialyzed soil agar was examined by light and electron microscopy and then compared to the cysts grown on n-butanol Burk's medium. Dipicolinic acid and oxygen uptake rate were measured in cysts and on cells grown on dialyzed soil agar in order to determine whether the cells grown on dialyzed soil agar were endospores or other dormant form and also to measure the respiratory quotient in these cells.

During the purification of the enzyme glycogen synthase from the muscle of the nematode Ascaris suum, approximately 70% of the glycogen synthase activity can be separated from the bulk of cellular glycogen by centrifugation for 60 min at 105,000 x . The glycogen synthase in the supernatant fraction has an Mr of 1.2 x 106 as determined by Sepharose 4B gel filtration chromatography. The glycogen synthase in this high molecular weight complex (glycogen primer complex) can be further purified by ConA-Sepharose affinity chromatography; the enzyme activity was eluted with 100 .mM a-methylmannoside. The glycogen synthase in glycogen'primer complex is predominately in the glucose 6-phosphatedependent form. The glycogen primer complex can catalyze the transfer of glucosyl units from UDP-glucose to an endogenous acceptor in the absence of exogenous glycogen. Analysis by SDS-PAGE showed three proteins (Mr 140,000, 78,000 and 34,000) and a carbohydrate polymer. The carbohydrate polymer can be partially digested with a-amylase. The glycogen primer complex was further digested by acid hydrolysis, and upon descending paper chromatography analysis, eight different carbohydrates were isolated, two of which were tentatively identified as glucose and sialic acid. The [14 C]-autoradiograph showed that in vitro synthesis of a glycogen-like polysaccharide occurred on this carbohydrate …

The objectives of this project were to develop a high performance liquid chromatographic method for separating the pigment esters mixture, to determine the locations of the pigment moiety in the isolated esters using pholosiphases, and to characterize the pigment-protein complex and determine its distribution in other bacteria. Saponification of the two pigment esters 1 and 2 with aqueous KOH yielded two free pigments on TLC plates developed by two solvent systems. The fasters moving of these two free pigments co-chromatographed with the one free pigment produced from each pigment ester by phospholipase A2 treatment. This suggests that the pigment molecule is a methoxy derivative of xanthomonadin and is esterified to the 2-position of the glycerol moiety of each pigment ester. No free pigment was released from phospholipases C and D treatment of the two pigment esters, indicating that pigment is not esterified to the sorbitol or phosphate moiety of pigment esters 1 or 2.

The effect of boron deficiency was studied in tomato plants grown hydroponically. Morphological studies showed that boron deficiency in the root system caused a cessation of root elongation, browning and thickening of root tips, the formation of branch roots close to the apex and decrease in the overall size of the root. The pyrimidine biosynthetic pathway remained intact and functional under boron limitation. The sugar nucleotide, uridine diphosphate glucose, was diminished in boron deficient medium and its level was restored to that of born sufficiency when uracil, cytosine, uridine, cytidine or orotic acid was provided.

This study determined effects of addition of secondarily treated municipal wastewater effluent on an urban reservoir receiving system. Monthly water quality monitoring of the receiving reservoir and the wastewater, chemical analysis, and monthly laboratory algal assays, were conducted from September 1984 to September 1985. The nutrient status and algal growth potential of the receiving water and the wastewater confirmed the biostimulatory properties of the wastewater. Field validation studies were conducted using limnocorrals. Tertiary treatment of the wastewater using chemical coagulation precipitation with alum and ferric chloride reduced phosphorus concentrations in the wastewater to levels which supported significantly less algal biomass than untreated wastewater. These studies indicate ferric chloride to be a more effective coagulant for phosphorous removal alum.

Lethal toxicity values (96 h LC50; mg Cd/L) for the test species were similar: Lepomis cyanellus, 11.52; Notropis lutrensis, 6.62; Pimephales promelus, 3.58. However the effects of cadmium concentration and exposure time on temperature tolerance varied between species. Neither cadmium concentration nor exposure time had a significant effect on the CTM of green sunfish. Both cadmium concentration and exposure time had a significant effect on the CTMs of red shiners and fathead minnows. By day 10 mean CTMs were 2.3 t- 4.5 C (red shiners) and 4.2 to 5.7 C (fathead minnows) lower than control CTM. These results suggest a potential problem in cadmium contaminated systems for high environmental temperatures to stress or kill fish.