Simultaneous size fractionation of plankton populations associated with NaH^14CO_3 and ^3H-glucose uptake was employed in eutrophic Lake Texoma (Texas and Oklahoma) and oligotrophic Flathead Lake (Montana). Autoradiography was utilized to determine the role of specific microorganisms in community metabolism. Ultraplankton (0.45-10 μm) dominated plankton numbers and metabolic activity in both aquatic systems. Many of the most abundant species were not the most productive, in terms of inorganic C fixation. Rates of heterotrophic uptake of ^3H-glucose were small in comparison to photolithotrophic uptake in both lakes, Photoheterotrophy was more extensive in Flathead Lake, Autoradiographs indicated that bacteria were responsible for observed photoheterotrophy. Oscillatoria sp. exhibited. mixotrophy in Lake Texoma,

Stability of the macrobenthic community in a regulated section of the Brazos River, Texas, was evaluated. Physicochemical data and information on spatial distribution of macrobenthos were collected. Populations of two invertebrate species, Isonychia sicca and Neoperla clymene, had been greatly reduced since 1970-71 and I. sicca had been practically eliminated from this section of the Brazos. Three other insect populations, Choroterpes mexicanus, Cheumatopsche campyla and Cheumatopsyche lasia, had more than doubled their numbers since the 1970-71 study. A physicochemical gradient existed in this regulated section of the Brazos but it appeared to have changed little in comparison of earlier chemical data. A gradation of the macrobenthic community was evident as distance from the dam increased,

The initial step in odor recognition by the nose is the binding of odorant molecules to receptor sites embedded in the dendritic membranes of olfactory receptor cells. Despite considerable interest and experimentation into the nature of these receptor sites, little is known of their specificity to different types of odorant molecules. This lack of knowledge partially stems from the fact that the nature of receptor proteins is most effectively studied when specific and irreversible inhibitors are available for use as chemical probes, yet no such agents have been discovered for use in the olfactory system. A series of alkylating agents and other chemically active odorants were tested to determine whether they might react with specific odorant receptors and modify olfactory responses. Electroolfactogram (EOG) recordings were obtained before, during, and after treatment of the olfactory mucosae of grass frogs (Rana pipiens) with a chemically active odorant.

Young, middle-aged and old rat adrenal gland steroidogenesis was measured in isolated, superfused glands and in their subcellular fractions before and after adrenocorticotropic hormone treatment. In the latter experiment, five corticosteroids were extracted from six different subcellular fractions. Superfused glands initially produced relatively high glucocorticoid levels; thereafter, production decayed asymptotically. Steroidogenesis by young and middle-aged glands was maintained at least 1.5 to 2.5 hours before it decayed; old glands were 50% less active than younger ones and production decayed within one hour. High cholesterol and progesterone levels in certain old gland fractions were associated with correspondingly reduced 11-deoxycorticosterone and corticosterone. It is suggested that synthesis of these glucocorticoids from their accumulating precursors weakens with age.

Responses of periphyton and phytoplankton productivity in the lower Sulphur River (Texas-Arkansas) to bleach-kraft mill effluent (BKME) were monitored using in situ ¹⁴C incubation. Carbon assimilation rates measured downstream of mill discharge were substantially reduced from upstream levels. Periphyton and phytoplankton chlorophyll a concentrations remained relatively unchanged by the presence of BKME. Periphyton ash-free dry weight increased near the mill outfall, but decreased further downstream. Calculated productivity efficiencies (productivity:biomass) varied with variations in ¹⁴C rates. A laboratory bioassay was designed to determine the effect of BKME light-attenuation on photosynthetic rates of upstream Sulphur River periphyton and Selenastrum capricornutum Prinz. Pooled results of bioassay runs indicated a 20 per cent BKME concentration effectively reduced control ¹⁴C-assimilation levels by 50 per cent. The downstream reduction observed for in situ productivity was 5 per cent lower than that predicted by the color bioassay.

The feeding ecologies of leaf pack-associated systellognathan stoneflies were examined from 6 June 1980 21 May 1981. Species composition, seasonal abundance, nymphal growth, feeding habits and mouthpart morphology were determined for the eight dominant stonefly species. Prey preferences and predator-prey size relationships were also examined for omnivorous and carnivorous species. Foregut analysis from 2860 individuals indicated opportunistic feeding on the most abundant prey insects, usually in proportion to prey frequency. Feeding preference studies generally indicated random feeding on major prey groups. Prey and predator sizes were usually highly correlated (p<0.01), with predators expanding their prey size thresholds with growth. The potential for competition between sympatric stoneflies for prey is discussed.

A comparative study was made of environmental variables and the density, biomass, diversity, and species composition of macroinvertebrates in areas downstream from a dam with a hypolimnetic release (Hungry Horse Dam on the Flathead River) and a dam with a selective withdrawal system (Libby Dam on the Kootenai River). A major objective of this study was to examine the response of macroinvertebrate communities to defined environmental gradients in temperature, flow, substrate, and food-related variables (periphyton, particulate organic carbon in the seston). In addition, the effects of experimental manipulations in discharge on macroinvertebrate drift and stranding were assessed, and the effects of temperature on the growth rates and emergence of five species of insects were measured.

Twenty-two natural populations of the red shiner minnow, Notropis lutrensis were examined for morphological and genetic variation. This research was aimed at testing the hypothesis that morphological and genetic variation was primarily influenced by the degree of gene flow between populations. Ten linear measurements were taken from each of 1320 specimens. Morphological characters were adjusted for differential growth by least squares linear regression techniques. Genetic variability was estimated for each individual red shiner through the methods of starch gel electrophoresis. Twenty presumtive gene loci were resolved.

Adult stonefly emergence, nymphal growth, drift and microdistribution were examined in Battle Branch, a secondorder, spring-fed stream, from November, 1982 to May, 1984. Adults of 22 species emerged successionally, with specific adults present every month. Searching emergent objects and the stream margin was best for collection of winter and early spring emerging species. Sweeping the streamside and light trapping were most efficient for late spring and summer emerging species. Nymphal growth for nine abundant species generally fit double log or semilog models. Drift was low, but did show a post-sunset pulse. Generally, leaf material was found to be significantly related (p<O.001) to density, diversity and biomass of stoneflies in Battle Branch.

Etheostoma spectabile, E. punctulatum, and Cottus carolinae were sampled Mar., 1983, - Feb., 1984, in Flint Creek, Oklahoma. Immature E. spectabile ate primarily microcrustaceans, while mature fishes relied more on mayflies and amphipods. Juvenile E. punctulatum fed upon mayflies, amphipods, and Asellus. Mature E. punctulatum ate primarily mayflies, and other relatively larger prey. Cottus carolinae consumed chironomids almost exclusively in Jan. - Feb., 1984, while mayflies were predominant the remainder of the year. No significant habitat partitioning between the two darters, and seasonal habitat segregation between C. carolinae and the two darters was found. Dietary overlap between the darters was significantly correlated (p<0.0005) to differences in x prey sizes.

The role of Ca++ in olfactory responses was investigated with inorganic and organic calcium channel antagonists. Electrophysiological responses to odorants were recorded from frog olfactory mucosa before and after aerosol application of different agents. Electroolfactogram responses were blocked by certain inorganic ions with the order of effectiveness Zn++ >Ln+++>Cd++>Ca++>Co++>Sr++>Mg++. Ba++ potentiated olfactory responses, and is known to potentiate calcium channel-mediated responses in other tissues. Certain local anesthetics which are thought to act through calcium channel blockade were inhibitory to olfactory responses, with the order of effectiveness being dibucaine>tetracaine>procaine. These data support the idea that Ca++ is involved in olfaction, perhaps acting as a current carrier and/or a second messenger. Preliminary experiments on channel localization were performed using a silicon-labeled amine. Attempts to localize the silicon label were inconclusive, although silicon was detected in the olfactory tissue.

In recent years there has been a great deal of scientific interest in processes that affect the fate of organic chemicals in the environment. one main reason for this increased interest is due to greater environmental concern over accidental or purposeful release of these chemicals into the environment by man. A major environmental concern is the increased use of pesticides over the last few years. In the thirty years prior to 1978 the use of pesticides has increased by a factor of forty (Ridgeway et al., 1978). Recently the use of herbicides has been increasing, but that of insecticides has stabilized (Willis, 1983). Detectable amounts of organic pesticides can be found in many areas of the biosphere. For toxic organic chemicals to be used safely, researchers must have a clear understanding of the fate and persistence of these chemicals when they are released into the environment. This understanding will also allow the development of new products that, when properly used, will not produce adverse effects to man or the environment (Weber, 1972). According to the Toxic Substance Control Act (TSCA) any new or expanded-use chemical that might be released into the environment must be tested for environmental hazard.

Extraction and quantitation of myosin light chain two coupled with myograph recordings from Ascaris muscle perfused with calmodulin inhibitors and neurotransmitters in conjunction with their respective agonists and antagonists have been used to establish the regulation of contraction in this muscle. Densitometric tracings of isolectric focusing gels separating the regulatory light chain were used to quantitate phosphorylation in resting, contracted and flaccid muscle. These studies indicated that inhibitory neurostimulation is mediated by a true GABA receptor. Myosin-mediated contraction is responsible for maintaining the level of tension observed in resting actin-mediated muscle. Actin-mediated contraction is responsible for the rapid rise in tension following excitatory stimuli. Both systems function simultaneously and are independant.

The relationship among eosinophils, lysophospholipase activity and the immune response in animals infected with Trichinella spiralis was studied using in vivo and in vitro techniques. In an in vivo experiment, anti-thymocyte serum (ATS) was administered to mice infected with T. spiralis and its effects on intestinal lysophospholipase (EC 3.1.1.5.) activity, peripheral blood, bone marrow and intestinal eosinophilia were measured in the same experimental animal. The ATS caused a significant temporally related suppression of both the tissue lysophospholipase response and eosinophilia, in all three compartments. These findings support the hypothesis that parasite-induced eosinophilia is the cause of the increased lysophospholipase activity of parasitized tissue and that the responses are thymus cell-dependent. In vitro experiments demonstrated that the eosinophil was the primary inflammatory cell source of lysophospholipase among eosinophils, neutrophils macrophages and lymphocytes. The role of other cells and antigen in the production of the enzyme by the eosinophil was also investigated in vitro• Results demonstrated that eosinophils cultured with both T. spiralis antigen and other leukocytes yielded enzyme activities significantly greater than eosinophils cultured alone or with only antigen. More specific experiments showed that T-lymphocytes were the cells responsible for influencing the eosinophils' lysophospholipase activity in the presence of antigen, and …

Corynebacterium poinsettiae mutant strains blocked in carotenoid biosynthesis were obtained by treatment with the mutagen N-methyl-N1-nitro-N-nitrosoguanidine. Additional carotenoid (Crt) mutant strains were obtained from a previous study conducted in our laboratory. Fifty-nine Crt mutants affected in carotenoid biosynthesis were examined by a normal phase high performance liquid chromatography (HPLC) system. Pigment extracts of Crt mutants and C. poinsettiae wild type strains were resolved by an isocratic system with hexane:acetone:dicholoromethane, 11.35:1.73:1.00 (by vol.) as the eluting solvent. In addition to the five major peaks, twelve minor peaks were observed in the wild type C. poinsettiae strain used in this study. Crt mutant and wild type strain peak heights were measured from the individual chromatograms and the peak height data set created was analyzed using the Statistical Analysis System program to perform a cluster analysis. The cluster analysis revealed five carotenoid mutant groups. Carotenoid pigments which accumulated or were absent in each of the cluster groups are reported. Cluster group 1 mutants (CrtA) are blocked in the dehydrogenase(s) which is(are) responsible for the dehydrogenations between phytoene and lycopene. Cluster group 2 mutants (CrtB) appear to be blocked at a second dehydrogenase specific for the dehydrogenation from C.p. 470 to C.p. 496. Cluster …

High performance liquid chromatography was used to measure ribonucleoside triphosphates in microbial samples. Anion exchange columns in a radial compression module were used to separate and quantify purine and pyrimidine ribonucleotides. Endogenous ribonucleoside triphosphates were extracted from Escherichia coli and pseudomonas aeruginosa using three different solvents, namely trifluorocetic acid (TFA; 0.5M), trichloroacetic acid (TCA; 6 per cent w/v) and formic acid (1.0M) Extracts were assayed for uridine 5'-triphosphate (ATP), and guanosine 5'-triphosphate (GTP) by using anion exchange radial compression high performance (pressure) liquid chromatography. The three extraction produres were compared for yield of triphosphates. E. coli, the TFA extraction procedure was more sensitive and reliable than TCA and formic acid extraction procedures, but , in P. aeruginosa, the best yields of ATP and GTP were obrained following extraction with TFA. Yields of UTP and CTP increased when extraction was performed in TCA. These data illustrate that different extraction produres produce different measures for different triphosphates, a point often overlooked.

Respiratory and metabolic patterns in response to variations in exercise workload (WL) and pedal frequency (RPM) were examined in 10 healthy males. Each subject performed WLs of low (L), moderate (M) and high (H) intensity, equivalent to 25%, 50% and 75% V02 m a x at 7 pedal frequencies (40, 50, 60, 70, 80, 90 and 100 RPM). ANOVA ( 3 X 7 design) indicated that WL and RPM had independent and significant effects on all respiratory and metabolic measures; i.e., the greater the WL and RPM, the higher the HR, V02, VC02, Ve, Fb, Vt, Vt/Ti, Vt/Te and Ti/TtQt and the lower the Ti and Te. However, analysis of the interaction effect revealed different response patterns for Fb, Vt, Ti, Vt/Ti, Vt/Te and Ve among the WLs. During L-WL, increases in RPM produced increases in Ve which were due to progressive increases in both Fb and Vt. However, during M-WL and H-WL, increases in RPM produced increases in Ve which were accomplished by a constant Vt and a progressive increase in Fb. My findings suggest that during low WLs, the signal for Vt is dependent on rate of contraction, while during M-WL and H-WL, the signal for Vt appears …

The roles of Ca2 + and cAMP in olfactory transduction were explored using agents which affect calcium channels and second messenger systems. These agents were applied at certain calculated final concentrations onto olfactory epithelia of urethane-anesthetized frogs (Sana PiPlens) by two-sec aerosol spray. During extracellular recording, saturated vapors of isoamyl acetate were delivered every 100 sec in 0.3 sec pulses to produce an electroolfactogram (EOG). Inorganic cations that block inward calcium currents inhibit EOG responses with the following rank order: (La3+) > (Zn2+, Cd2+) > (Al3+, Ca2+, Sr2+) > (Co2+). Application of 7.5 mM La3+ eradicates £0G's, while Ba2+ (which can carry more current that Ca2+) initially produces significant enhancement (F=43.04, p<0.001, df=19). Magnesium ion has no effect on EOG's at 7.5 mM, while 1.5 X 10"4M Ca2+ is significantly inhibitory (F=5.74; p=0.0355; df=12). Control aerosol sprays of distilled water depress EOG's by an average of 5%. The organic calcium channel antagonists diltiazem and verapamil inhibit EOG's by 17% and 36X, respectively, at a concentration of 1.5 X 10~*M. Verapamil produces significant inhibition (F=17.17; p=0.002; df=ll) at 1.5 X 10" 5 M, while the 1,4-dihydropyridine calcium channel antagonists, nicardipine and nifedipine, do not inhibit beyond 1% DMSO controls. Several calmodulin …

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.

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 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 …

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 …

Following a study of normal reproductive behavior of fathead minnows, Pimephales promelas, experiments were conducted to determine the stability/variability of behavior by sexually mature, territorial males under a variety of manipulated conditions. Collectively, these experiments indicate that although the individual behaviors of fathead minnows appear to be quite variable, the overall process, reproductive behavior, is stable.

Excessive nutrient loading of natural and artificial lakes has led, in some systems, to plethoric algal and aquatic macrophyte growth which can result in aesthetic degradation and undesirable tastes and odors. It would be advantageous to have some indication of the potential trophic status of a reservoir before it is filled. An objective of this study was to assess the water quality and nutrient loading potential of the tributaries entering Ray Roberts Lake, a large reservoir located in north central Texas. Samples from a maximum of thirteen sites were collected on the Elm Fork, Trinity River, Isle duBois Creek, and five additional tributaries. Data were also collected during six storms, from atmospheric deposition collectors, and from soil-water microcosms. The relationship between watershed landuse and mean water nutrient concentrations was evaluated. Significant differences will exist between the two major arms of Ray Roberts Lake: Elm Fork, Trinity River and Isle duBois Creek. While the majority of the annual phosphorus and nitrogen load entering both tributaries is coming from overland flow, the proportion is higher in Isle duBois Creek. Point sources in the Elm Fork contribute a larger percentage of the bioavailable phosphorus, which is significantly greater than in Isle duBois Creek. …