Bench scale activated sludge reactors were acclimated to dextrose and then to low levels of pentachlorophenol. The metabolic activity of activated sludge was evaluated by its specific rate of dextrose uptake, Δs/Δt/X (measured by COD removal). Depression of the specific uptake rate, resulting from batch experiments in which the activated sludges were spiked with priority pollutants, indicated the relative inhibition caused by that toxin dosage. This study intended to determine if: (1) acclimation to low levels of PCP would provide any protection to the biomass against detrimental effects of higher shock loads of pentachlorophenol; (2) PCP-acclimation would decrease the inhibitory effect of related priority pollutants; (3) PCP would be consistently and efficiently degraded in the reactors. The practicality of this study was twofold. First, to determine the feasibility of introducing small concentrations of a toxin to the biological system of a treatment facility in order to gain protection against shock loads of that and related toxic chemicals. Secondly, to develop a rapid and easy method for evaluating the effects of a chemical load on activated sludge. The procedure was found to be applicable and it showed that acclimation of activated sludge to PCP provided protection against shock loads of pentachlorophenol as well as phenol, 4-nitrophenol, 2-chlorophenol, and 2,4,6-trichlorophenol. Gas chromatography analysis showed very little disappearance of PCP in the 1 mg PCP/L reactor; however, in the 15 mg PCP/L reactor, the penta concentration decreased to virtually zero for about a week and then it began to gradually increase. / Master of Science

Private physicians in the Bethesda, Md. area were surveyed via hand delivered questionnaire. Two hundred seven responses were received (response rate=61.4%). Data were analyzed according to specialty and year of graduation from medical school. A larger percentage of primary care providers than referral care providers routinely asked patients about food patterns. Approximately 84% of all physicians said they had patients in need of nutrition education (n.e.) and 76% had patients in need of consultation with a dietitian (R.D.); however only 54% of physicians provided for n.e. In their practice and only 21% made patient referrals to dietitians. Hospital/clinic R.D.'s were being utilized by twice as many physicians as R.D.'s in private practice; however, physicians indicated a slight preference for dietitians in private practice as the preferred mechanism for providing R.D. consultation for patients followed closely by hospital R.D.'s. Generally, providers of primary care gave more affirmative answers to the survey questions than physicians who provide care on a referral basis, indicating greater attention to nutritional aspects of patient assessment. / Master of Science

Maintenance of reduced protein sulfhydryl groups is an important function of lens metabolism. In an attempt to inter-relate how lens sulfhydryl metabolism, low molecular weight peptides and trace molecular weight Zn-containing protein population was studied. The concentration of rate lens Zn-containing protein population was studied. The concentration of rat lens Zn decreased 30% from day 10 to day 35 postpartum. After 6 weeks on a low-Zn diet, rats had 25% less lens Zn than control groups. Selenite-induced cataract did not affect lens Zn concentration. Of the total lens Zn, 25% was recovered in the ultrafiltration fraction of less than 20,000 molecular weight which contained 1% of the total soluble protein. Lens tissue has low molecular weight TCA-soluble components that can bind Hg. Isoelectric points of low molecular weight protein fractions were between pI 5.2-5.5. Polypeptide molecular weight was determined to be less than 5,000 daltons by gel filtration chromatography. Aggregation on SDS-polyacrylamide gel electrophoresis yielded apparent higher molecular weights of these proteins. Although the proteins isolated had metallothionein-like character in that they were of low molecular weight, contained Zn and had acidic pI values, the paucity of cysteine residues indicates that metallothionein is not a component of low molecular weight Zn-containing lens proteins. / Master of Science

Flight activity of adult European corn borer field populations was monitored in Bedford County (1980 - 1981), Painter (1958 - 1980), Blacksburg (1971 - 1973, 1975) and Warsaw, Virginia (1971 - 1972, 1981). Peak occurrence of flight activity was accurately estimated by measuring the accumulation of degree days above 10ºC. The appearance of cumulative percentages of adult European corn borer flight at predicted degree day accumulations is reported. The seasonal abundance, within - field and within - plant distribution of first generation European corn borer egg masses were observed in field corn in Bedford County, Virginia. Peak egg mass abundance occurred ca. 200 degree days after the first borer moths were taken in the light traps. The spatial pattern of first generation corn borer egg masses closely approximated the Poisson distribution. The within - plant distribution of egg masses was skewed towards the lower leaves of the plant throughout the oviposition period, and nearly all egg masses were deposited on the leaf undersurfaces. Optimum sample sizes for two levels of sampling precision were developed from the sampling data. The seasonal development of the European corn borer in the spring was studied in relation to the flowering phenology of several groups of trees and wildflowers. The potential indicator plants signalled the onset of overwintering generation adult emergence, peak overwintering generation peak flight activity - first generation egg mass abundance, and the end of overwintering generation adult European corn borer flight. / Master of Science

Binary solubility data of hydrocarbon solids in supercritical fluids were correlated using the compressed gas model. Data included in the analysis were for solubilities of binary mixtures of napthalene, 2,3- and 2,6-dimethylnapthalene, benzoic acid, phenanthrene, anthracene and pyrene in both ethylene and carbon dioxide, and of napthalene, phenanthrene and anthracene in ethane. Two equations of state--the Peng-Robinson equation and the Lee-Kesler equation with Plocker, Knapp and Prausnitz mixing rules--were tested in conjunction with the compressed gas model, permitting a direct comparison of the two equations of state. The sensitivity of the model to changes in the parameters was analyzed for each equation of state. Prediction of the solubility data of five binary mixtures was attempted. The mixtures were hexamethyl benzene and fluorene in both ethylene and carbon dioxide, and diphenylamine in carbon dioxide. The binary attraction parameter (or"unlike pair energy parameter") of the Peng-Robinson equation was correlated with the heat of vaporization of the solid. The binary interaction parameter of Plocker, Knapp and Prausnitz (1978) mixing rules was correlated as they suggested for high-pressure vapor-liquid-equilibria. The most accurate predictions were obtained using the Lee-Kesler equation with Plocker, Knapp and Prausnitz mixing rules. Predictions of the solubilities of hexamethyl benzene and fluorene in carbon dioxide were accurate to within 30 percent error; results for hexamethyl benzene in ethylene were accurate to within 50 percent error; and results for fluorene in ethylene and diphenylamine in carbon dioxide were inaccurate. / Master of Science

Putrescine is a polyamine with multiple roles in cellular metabolism. It is also a minor precursor of the inhibitory neurotransmitter, gamma-aminobutyric acid (GABA). Conversion of systemically administered putrescine to GABA in rat neural tissues has been reported. In this thesis, three experiments were conducted to characterize changes in rat behavior after putrescine administration, and determine if any effects resembled known GABAergic behaviors. Experiments l and 2 investigated the behavioral consequences of oral and intraperitoneal putrescine treatment. Male adult rats were given either saline or putrescine doses and tested with seven procedures which evaluated motor behavior, sensory reactivity, body temperature, and other behaviors. Results showed that putrescine-treated subjects exhibited significant changes in behavior compared to saline controls, and that certain effects resembled behaviors related to the function of GABA and/or other neurochemicals. Experiment 3 investigated the modifying effects of putrescine treatment on behavior induced by a dopamine agonist, apomorphine, and were compared to effects produced by a GABA agonist, muscimol. Male adult rats were given either saline, putrescine, or muscimol, and later treated with saline or apomorphine. Locomotor and specific activities were time sampled for 45 minutes. Results indicated that putrescine and muscimol had similar interactions with apomorphine in modifying sniffing stereotypies. From the behavioral evidence obtained in this thesis, it was suggested that systemic putrescine administration may indirectly influence behavior in the rat via GABAergic mechanisms. The results were interpreted as preliminary support for a significant neuropharamacological role of putrescine in the mammalian central nervous system. / Master of Science

The purpose of this study was twofold: first, to present a methodology that is systematic, yet flexible, for the descriptive assessment of landscapes, and second, to develop a minimal set of basic dimensions or scales that are invariant across observers and places described. The Landscape Adjective Check List (LACL), first developed by Kenneth Craik (1971), and modeled after the Gough Adjective Check List (1960) used for personality assessment, was administered to a group of 150 college students. Each was instructed to rate a series of natural scenes by marking off those adjectives they felt were descriptive of the particular scene they were viewing. The major results of a principal components factor analysis suggested that, within the range of scenes used, there are approximately twenty dimensions which people use in their descriptive assessments of natural scenery. The first factor, termed General Positive Evaluation, appeared consistently throughout the literature on both environmental and landscape perception and assessment. Other dimensions appearing both in the factor analysis and the literature included Ruggedness, Potency, Spaciousness, Barrenness, and Cultivation/Vegetation. A comparison was made between the factor analytic scales and a set of scales which had initially been hypothesized to be relevant to variations among landscapes. These dimensions consisted of two sets of scales which had been generated in different ways. First, a set of dimensions was proposed based upon a content analysis of the Landscape Adjective Check List. A second set of dimensions was developed based upon an analysis of the research literature. In general, the findings indicated a moderate to high degree of convergence between the factor analytic scales and the two sets of hypothesized scales. Before generalizing any further, however, it will be necessary to obtain comparable results from other persons (besides college students) and a wider range of scenery, as stimuli. / M.S.

The purpose of this study was to examine the development of children's understanding of animal death as compared with human death, clarify the order and interrelationships of the concepts of causality, state of death, irreversibility and universality of death, as well as to examine the influence of experience with death and parental explanations on children's understanding of death. Twenty children at each of three age groups (4, 6, and 9 years) were read two animal and two human stories dealing with the topic of death and asked a series of questions designed to assess their understanding of the four concepts. Experience with death and parental explanations were assessed through the use of parental questionnaires. Results indicated children's understanding of the concepts of death increased with age. The most rapid development of the understanding of causality, state of death and irreversibility was indicated between 4- and 6-years-of-age, with universality continuing through 9-years-of-age. Correlations between the UDI subscales for both animal and human death indicated the concepts were unrelated until after six years of age. A developmental progression in the interrelationships of animal with human concepts of death was found. Correlations were significant for causality at 4-years, state of death and universality at 6-years and state of death, irreversibility and universality at 9-years-of age. Experience with human death influenced the human scores for the concepts of causality, state of death and irreversibility. No significant correlations for universality or animals was found. / Master of Science

This study was undertaken to research and modify the Georgia Project hockey/golf Physical Education Experimental Teaching Unit (PEETU). The PEETU is a short instructional unit involving a pre-test, instructional period, and posttest. The object of the PEETU instructional skill is to hit a tennis ball into a hoop in the least amount of strokes (hits). The modification of the PEETU consisted of simply lengthening the distance between the starting line and the hoop from thirty yards to forty-five yards. It was hypothesized that the reverse chaining method of teaching would not cause greater significant learning than the lecture/demonstration method, and that Academic Learning Time-Physical Education(M) (Motor ALT) would not be a better student process indicator for achievement independently of instructional method or length of the PEETU. The results indicated there were no significant differences between teaching methods or instructional periods within the PEETU. The results also indicated that Motor ALT is an important student process indicator when the student received between two and seven minutes of Motor ALT during the instructional period of the PEETU. / Master of Science

This research investigated homeowner rationale for, and feelings about, living in passive solar homes. Satisfaction, use, and extent of involvement with the home and solar features were determined. Twenty-eight owners of passive solar homes from the state of Virginia participated in this study. Data were collected by a hand-delivered questionnaire which was self-administered. Frequency and percentage distributions were calculated to describe the sample and characterize the findings from the study. Findings that were of a significant nature indicated that a vast majority of respondents felt that saving money on fuel bills was a major factor in their decision to live in passive solar homes. Over three-fourths of the homeowners sought information about solar energy utilization in order to make an educated choice. Over half were responsible for the building or modification of the homes and were directly involved with the functioning of their solar systems. All of these solar features were rated OK-to-high as functional units. Slightly more than half of the homeowners described unanticipated benefits as well as complaints related to their homes. Savings on fuel bills resulted in feelings of independence from utility companies for many of the respondents. Several were also pleased with their new awareness of nature and the weather. Areas of dissatisfaction were most often related to construction techniques. Others noted that cooling in the summer and heating in the winter posed problems. Almost half of the respondents reported changes in room use in their current residence as compared to previous non-solar homes. There appears to be a trend toward a more functional design, and multipurpose use of rooms incorporated into passive solar homes. Over half had a thermal mass in the floor and were satisfied with the hard floor surface. A majority had not purchased specific furnishings that they felt would perform well in their solar home and have had no problem with fading. Overall, homeowners were satisfied with the general interior, exterior, and overall features of their passive solar homes. / Master of Science