Natural and Social Sciences

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    Locomotion, physical development, and brain myelination in rats treated with ionizing radiation in utero
    (1989-08) Zaman, Sarwar
    Effects of ionizing radiation on the emergence of locomotion skill and some physical development parameters were studied in laboratory rats (Fisher F-344 inbred strain). Rats were treated with 3 different doses of radiation (150 R, 15 R, and 6.8 R) delivered on the 20th day of the prenatal life. Results indicated that relatively moderate (15 R) to high (150 R) doses of radiation have effects on certain locomotion and physical development parameters. Exposure to 150 R affected pivoting, cliff-avoidance, upper jaw tooth eruption, body weight, and organs, such as brain, cerebral cortex, ovary, kidney, heart and spleen weights. Other parameters, such as negative geotaxis, eye opening, and lower jaw tooth eruption appeared to be affected in the 150 R treated animals. Exposure to 15 R affected pivoting and cliff-avoidance parameters. The cerebral cortex weight of the 15 R treated animals was found to be reduced at the age of day 30. Exposure to 6.8 R had no adverse effects on these parameters. Prenatal exposure to 150 R of radiation reduced the cerebral cortex weight by 22.07 percent at 30 days of age, and 20.15 percent at 52 days of age which caused a reduction in cerebral cortex myelin content by 20.16, and 22.89 percent at the ages of day 30 and day 52 respectively. Exposure to 150 R did not affect the myelin content of the cerebellum or the brain stem; or the myelin concentration (mg myelin/g brain tissue weight) of the cerebral cortex, cerebellum, and the brain stem. Exposure to 15 R, and 6.8 R did not affect either the myelin content or the myelin concentration of these brain areas.
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    The spatial distribution of transcripts of the segmentation gene Fushi tarazu during Coelopa embryonic development
    (1988-08) Osei-Frimpong, Joseph; Schwalm, Fritz; Knesek, John; Illegible; Illegible
    The expression of the Drosophila fushi tarazu (ftz) gene was investigated in the kelp fly, Coelopa frigida. The investigation included the detection of the gene in the genome of the kelp fly and the detection of the transcripts of the gene in unfertilized eggs and embryos. The spatial distribution of ftz$\sp+$ transcripts during normal Coelopa embryonic development was investigated by in situ hybridization. The results obtained in this study have led to the following conclusions: (1) The genome of the kelp fly, Coelopa frigida contains sequences homologous to the Drosophila ftz$\sp+$ gene. (2) The $ftz\sp+$ gene is probably not expressed maternally in the kelp fly. (3) In the Coelopa embryo the $ftz\sp+$ transcripts are generally distributed during early cleavage; at these stages the transcripts are of low intensity and there seem to be no regional differences. (4) $Ftz\sp+$ transcripts become localized around the periphery of the embryo around the 11$\sp{\rm th}$ nuclear division (syncytial blastoderm); transcripts after the 12$\sp{\rm th}$ nuclear division are generally restricted to a broad region between approximately 10 and 70% of the egg length. (5) After about the 13$\sp{\rm th}$ nuclear division when cell membranes begin to form and even before cells are formed, the parasegmental pattern of $ftz\sp+$ transcript distribution in the seven odd-numbered parasegments becomes more apparent. (6) It appears that by the time segmentation is first obvious and the germ band is fully extended (about 4.5 h of development) the $ftz\sp+$ gene is no longer expressed. (7) Similar results have been observed in Drosophila wild type embryos. Therefore the embryos used in these experiments were expressing the same dipteran gene at the corresponding morphological stages of development. Some general conclusions that can be drawn from this study are the following: (1) The data obtained on ftz expression graphically illustrate that spatially restricted gene expression can occur even at the syncytial blastoderm stage in the absence of cell membranes. (2) They confirm that a structural association between nuclei and their adjacent cytoplasm exists at this stage.(3) These observations provide direct molecular corroboration for the notion that differences in developmental potential already exist between nuclei prior to the cellular blastoderm completion.
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    Effects of ultraviolet radiation on the survival and metabolic and products of bacteroides melaninogenicus
    (1987-12) Smith-Kappus, Sheryl
    Bacteroides melaninogenicus was determined to be an aerotolerant anaerobic bacterial species. It was shown that exposure to atmospheric air for up to 90 min does not affect the viability of these microorganisms. A growth curve constructed for the organism showed that after a 4 h lag growth phase, B. melaninogenicus reached stationary growth phase in just 3 h. B. melaninogenicus was found to be more sensitive to chloramphenicol, metronidazole, and streptomycin than to any other antibiotic tested. Chloramphenicol, metronidazole, fluoroacetate, and caffeine, used in irradiation co-insult studies in this dissertation, were considered to be bacteriocidal and yet all allowed some cell viability even at the high superinhibitory concentrations tested. In experiments investigating DNA repair, it was shown that B. melaninogenicus does not repair UV light induced damage via photoreactivation. Survival curves constructed for the organism after exposure to UV light at 254 nm and 365 nm under aerobic and anaerobic conditions while the organisms were in exponential or stationary growth phase, revealed that the cells were most sensitive to UV induced damage when exposed to radiation while in the exponential growth phase under aerobic conditions at either wavelength. B. melaninogenicus exposed to UV light under anaerobic conditions while the cells were in stationary growth phase were much more sensitive to UV induced damage at 254 nm than cells irradiated under the same conditions at 365 nm UV. Survival studies of B. melaninogenicus after co-insult with UV light and subinhibitory concentrations of chloramphenicol, metronidazole, caffeine, or fluoroacetate, at 254 nm UV or 365 nm UV, under aerobic and anaerobic atmospheric conditions illustrated a decreased shoulder region on the curves, particularly after 365 nm UV exposure, when compared to UV irradiation applied without subsequent chemical treatment. The end products of the fermentation of glucose by B. melaninogenicus were affected after co-insult by UV and metronidazole, and UV and fluoroacetate. As expected, fluoroacetate treated cells produced less acetic acid, and in one mutant strain, SKF2r, small amounts of ethanol and methanol were produced. From the VPI strain, nine strains were isolated which produced altered metabolic end products from glucose; these mutants were named SKM1s, SKM2r, SKM3s, SKF1s, SKF2r, SKF3r, SKF4s, SKF5s, and SKF6s.
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    Mutagenesis in cultured cells with altered poly (Adp-ribose) metabolism
    (1986-05) Nunbhakdi, Viyada
    Poly(ADP-ribose) is synthesized in response to DNA damage caused by either chemicals or radiation. The biological function of this polymer is not known. However, most of the evidence for role(s) of poly(ADP-ribose) is based on the inhibition of the enzyme poly(ADP-ribose) polymerase by different inhibitors. When the synthesis of poly(ADP-ribose) is inhibited following DNA damage, increases are observed in cytotoxicity, chromosomal aberrations, sister chromatid exchanges and malignant transformation. This investigation was conducted to study the effect of poly(ADP-ribose) metabolism on mutagenesis in C3H10T1/2 cells. Poly(ADP-ribose) metabolism was altered by the inhibitor, 3-methoxybenzamide (MBA) or by NAD-depletion. Ouabain-resistant mutations were induced by exposing cells to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the presence and absence of poly(ADP-ribose) synthesis. Mutations at the Na('+)/K('+)ATPase locus were selected by growth in ouabain containing medium. In dividing cells treated with MNNG, limiting poly(ADP-ribose) synthesis by MBA or NAD-depletion resulted in significant decreases in mutation. Since inhibiting poly(ADP-ribose) synthesis is known to enhance the cytotoxicity of MNNG and cause cell cycle blocks, it was not clear whether the observed decrease in mutation frequency was the result of a block in the expression of mutations or whether poly(ADP-ribose) synthesis normally effects an SOS type of response to DNA damage. Therefore, analogous studies were conducted in non-dividing cells which eliminated cell cycling during the period of DNA repair and inhibition of poly(ADP-ribose) synthesis doubled the mutation rates. These data suggest that poly(ADP-ribose) may function either directly or indirectly in limiting events which lead to mutations at the Oua('r) locus.
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    Influence of niacin metabolism in malignant transformation in vitro
    (1985-12) Smith, Debra
    The potential role of niacin metabolism in the prevention of carcinogen-induced malignant transformation was investigated. The conversion of niacin to NAD, and its subsequent conversion to poly(ADP-ribose) was blocked by using an inhibitor of poly(ADP-ribose) or by nutritional depletion of the cellular NAD pool. Transformation frequency in exponentially dividing cells treated with the carcinogen, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), was elevated 12-fold in the presence of 3-methoxybenzamide (MBA), a poly(ADP-ribose) polymerase inhibitor. A two-fold increase in transformation frequency was observed in exponentially dividing, NAD-depleted cells treated with MNNG. In contrast, the transformation frequency of confluent cultures treated with MNNG was not affected by either method of perturbing niacin metabolism. However, a significant increase in spontaneous, noninduced transformations occurred in confluent cultures when niacin metabolism was perturbed by poly(ADP-ribose) polymerase inhibitors or by niacin deprivation. These data suggest that poly(ADP-ribose) plays a critical role in recovery from DNA damage in exponentially dividing cells. Moreover, niacin metabolism may be involved in the prevention of spontaneous transformation in nondividing cells.
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    Morphological and histochemical observations of hepatic peroxisomes and lysosomes of rats after treatment with methylmercuric chloride, hydrogen peroxide and gamma radiation
    (1985-08) Chowdhury, Anisuzzaman
    The ultrastructure of cytochemically identified hepatic peroxisomes and lysosomes was studied at days 2, 7 and 21 following treatment with hydrogen peroxide (HP), methylmercuric chloride (MMC) and gamma radiation (I). The HP group received five daily intraperitoneal (IP) injections of 1.8 ml of 1.5% HP; the MMC group received a single IP injection of 6 mg MMC per kg body weight; the I group received 750 R whole body irradiation. Morphometric parameters were quantitated by stereological methods. The volume, surface and numerical densities on unbiased representative micrographs were estimated by point counting. The mean volume densities of hepatic peroxisomes of HP, MMC and I rats fell in the range of 0.94 (+OR-) 0.13 to 1.31 (+OR-) 0.14% of hepatocyte cytoplasm; surface densities ranged from 0.104 (+OR-) 0.013 to 0.127 (+OR-) 0.016 (mu)m('2)/(mu)m('3); numerical densities were in the range of 0.106 (+OR-) 0.013 to 0.128 (+OR-) 0.003 (mu)m('-3). The estimated mean volume densities of hepatic lysosomes of HP, MMC and I rats ranged from 0.45 (+OR-) 0.03 to 0.74 (+OR-) 0.04% of hepatocyte cytoplasm; mean surface densities ranged from 0.052 (+OR-) 0.002 to 0.077 (+OR-) 0.004 (mu)m('2)/(mu)m('3); mean numerical densities were in the range of 0.052 (+OR-) 0.004 to 0.070 (+OR-) 0.033 (mu)m('-3). None of the parameters showed any significant difference (P (LESSTHEQ) 0.05) between treated and control animals. Morphological observations revealed severe cytoplasmic degradation at day 2 after HP treatment which persisted to a moderate extent at day 7; no signs of toxic effect were observed at day 21. Livers of MMC treated rats demonstrated disruption of peroxisomal, lysosomal and mitochondrial membranes and formation of different shapes and sizes of peroxisomes at day 2. Damage appeared to be mild at day 7 and no apparent damage persisted until day 21. Following the whole body irradiation of 750 R, granularity in hepatic peroxisomes, accumulation of rough endoplasmic reticulum, loss of mitochondrial cristae and presence of polyribosomes and/or glycogen were observed at day 2. Seepage of hydrolytic enzymes from disrupted lysosomal membrane and persistence of polyribosomes or glycogen and dissolution of mitochondrial cristae were observed at day 7. Diffusion of reaction products from peroxisomes and apparent dissolution and peripheral movement of crystalline cores was observed at day 21 after irradiation.
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    Effects of Escherichia coli B/r ornl membranes on he growth and characterization of Peptostreptococcus anerobius and the induction of mutants by means of cesium-137 ionizing radiation
    (1987-05) Gathings, Shellye; Fuerst, Robert; Erdman, Howard; Cockerline, Alan; Sterling, Smith; Stewart, G.
    Current methodologies used in the production, screening and characterization of bacterial mutants poses inherent problems when these methods are applied to strict anaerobes. Inclusion of sterile stable Escherichia• coli B/r ORNL membranes in the cell suspension fluid during irradiation resulted in the scave~ging of oxygen radicals and peroxides produced during exposure. This decreases bacterial death caused by these factors and increases the possibility that the radiation will produce cha:nges in the chromosome. The P 2 membranes eliminate the need for cysteine-HCl which acts as a radioprotective agent and allow aerobic culturing techniques to be applied to strict anaerobes in mutation studies. P. anaerobius VPI# 4330 was exposed to Cesium-137 gamma radiation. Cell survival, biochemical ·activities and changes in antibiotic resistance as effected by the inclusion of the P2 membranes were determined on the prototype and the isolated variants. Resistance parameters were established, with and without the presence of the P2 iv membranes, using the Kirby-Bauer disk diffusion method, the Minimal Inhibitory Concentration (MIC) determination and Gas Liquid Chromatography (GLC). The P2 membranes were also used to investigate changes in tyrosine degradation and cell sensitivity to sodium polyanethol sulfonate, both of which are used in P. anaerobius identification.
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    Neuronal viability or death after dendrite amputation within 200 μm of the perikaryon: Correlation with electrophysiologic and morphological changes and the presence or absence of extracellular calcium
    (1986-05) Lucas, Jen; Gross, Guenter; Schwalm, Fritz; Jacobson, Elaine
    The responses of cultured mammalian spinal neurons to physical trauma were observed following UV laser amputation of primary dendrites within 400 (mu)m of perikarya. The following observations were made. First, neuronal survival is a function of lesion distance from the perikaryon and of process diameter at the lesion site. For an average lesion diameter of 3.2 (mu)m, dendrite transections at 50 (mu)m, 100 (mu)m, and 150 (mu)m were associated with survival probabilities of 31%, 54% and 70% respectively. Second, the fate of the injured cells was definitely established 24 hours after injury and very likely was determined as early as two hours. Third, phase microscopic observation revealed that the early stages of deterioration leading to cell death were associated with increased cytoplasmic phase brightness; this optical effect correlated ultrastructurally with the appearance of numerous, small, electron-lucent vacuoles and swollen mitochondria. Fourth, the magnitude and time course of injury potentials recorded at the somata were a function of the lesion distance and did not return to prelesion levels within 30 minutes after transection. Fifth, at 24 hours after surgery, the average membrane potential of lesioned neurons was 8% below that of control neurons. Sixth, at a lesion distance of approximately 300 (mu)m both anticipated injury potentials and the probability of cell death approach zero. The influence of lesion physical parameters upon neuronal survival after dendrite amputation suggests that neuronal deterioration and death after dendrite amputation trauma depend upon the magnitude of the injury currents reaching the soma. Removal of the calcium from the culture medium, however, does not protect lesioned neurons and actually decreases the probability of survival. It is, therefore, hypothesized that the influx of external sodium after physical trauma may mediate the death of injured neurons both indirectly by triggering the release of endogenous mitochondrial calcium stores, and directly by causing osmotic swelling and irreversible damage to mitochondria.
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    The role of poly (adp-ribose) metabolism in cell survival following various forms of stress
    (1985-08) Smith, Janice; Jacobson, Elaine; Robert, P.; Kendrick, Michael
    The role of poly(ADP-ribose) metabolism in cell survival following DNA damage and/or hyperthermia was examined. The effects of inhibitors of poly(ADP-ribose) polymerase on the recovery of cell division in C3H10T 1/2 cells following N-methyl-N'-nitro-N-nitroso-guanidine (MNNG) were examined. 3-methoxybenzamide (MBA), 3-aminobenzamide, and benzamide blocked recovery of cell division more effectively than did theophylline or caffeine. Three noninhibitory compounds, 3-methoxybenzoic acid, 3-aminobenzoic acid, and benzoic acid had no effect on the recovery of cell division. MBA synergistically enhanced the cytotoxicity of MNNG. In the presence of MBA, cells progressively lost the ability to resume cell division during the first 24 to 36 h following DNA damage. In the presence of MBA, the rates of RNA and protein synthesis following MNNG treatment were slightly higher than those in cells treated with MNNG alone while a dramatic decrease in the rate of DNA synthesis occurred approximately 16 h after MNNG treatment. These results suggested that poly(ADP-ribose) is required for subsequent rather than ongoing rounds of DNA synthesis following DNA damage. The effect of MBA on the survival of quiescent cells following MNNG treatment was examined. Quiescent cells effected repair of potentially lethal damage (PLD) over a 48 h period following 68 (mu)M MNNG treatment. In contrast to observations made with dividing cells, MBA had no effect on PLD repair. These results suggest that poly(ADP-ribosylation) is required to coordinate DNA repair with cell cycle progression following DNA damage in dividing cells. The effect of MBA following acute hyperthermia (45(DEGREES)C) was also examined. MBA synergistically potentiated the cytotoxicity of a 40 min, but not a 10 min, heat treatment. The time course of the development of thermotolerance was altered by the presence of MBA. When treatment with 34 (mu)M MNNG for 20 min was preceeded by a 10 min 45(DEGREES)C treatment, the cytotoxicity of MNNG was synergistically enhanced. The presence of MBA for 48 h following the combined heat and MNNG treatment further enhanced the observed cytotoxicity.
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    Modification of fecundity and fertility during oogenesis by gamma radiation and/or ozone with a cytological analysis in the ectoparasitic wasp, Habrobracon juglandis (Ashmead)
    (1984-05) Ofuoku, Edith; Erdman, Howard; Hupp, Eugene; Aboul-Ela, Mohamed; Fuerst, Robert; Schwalm, Fritz
    In Experiment I, adult female wasps were exposed to 44.1 ppm ozone for 0, 2, 4, 6, 8, 10, 12, 16, 24, and 27 h. The results indicated that the 27 h of ozone exposure produced 100% lethality on the first day. Exposures below 27 h progressively decreased life span with increasing length of exposure. In Experiment II A, adult virgin Habrobracon females were exposed to 44.1 ppm ozone for 0, 2, 4, 6, 8, 10, 12, 16, and 24 h to determine the effects of ozone on fecundity (egg laying ability) and fertility (egg hatching ability). The results showed that ozone significantly decreased fecundity and fertility in all meiotic stages except metaphase I. In Experiment II B, adult virgin Habrobracon females were exposed to 0, 25, 35, 45, and 65 Gy of Co-60 gamma radiation. All treated wasps showed significant progressive decreases in fecundity and fertility with increases in radiation dose; females given 45 and 65 Gy experienced temporary infecundity and permanent sterility, respectively. The results indicated the differential sensitivity of the various meiotic stages. In Experiment II C, adult virgin Habrobracon females were exposed to 0, 22.5, or 45 Gy of Co-60 gamma radiation; to 0, 8, or 16 h of 44.1 ppm ozone; or to combinations thereof to determine the effects of these insults on fecundity and fertility. Together or singly ozone and radiation reduced fecundity and fertility. The co-insult treatments resulted in additive or synergistic effects. In Experiment III, adult virgin Habrobracon females were exposed to the conditions of Experiment II C to correlate by cytological examination of the ovarioles the effects of ionizing radiation and/or ozone on the germ cells at specific meiotic stages. The ovarioles from females exposed to 8 and 16 h ozone had gaps in the series of developing reproductive units and these abnormalities increased with time. Radiation doses above 22.5 Gy caused destruction of germ cells and degeneration or atrophy of the ovarioles; while, the co-insult treatments resulted in more adverse effects on the ovarioles than the single insults. Results obtained from the cytological study explain the fecundity and fertility observations.
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    An In Vitro mammalian model for investigating locomotor pattern generation
    (1989-08) Hernandez, Patricia; Droge, Michael; Hines, John; Uphouse, Linda
    The goal of our research was to establish an in vitro mammalian spinal preparation suitable for investigating the mechanisms underlying motor pattern generation. The objective of the study was to compare the step cycle timing of intact, freely moving neonatal and adult Balb/C mice with the pattern generating capability of spinal cord-hindlimb explants taken from animals aged from birth to 4 days. The analysis was based on EMG recordings from the gastrocnemius (G) and tibialis anterior (TA) muscles, an antagonist set of muscles used in stepping. In intact animals, electrodes were placed in the G and TA muscles to ascertain the step cycle pattern and timing. Adult mice displayed reciprocal activation of the G and TA muscles and a faster cycle periods than the neonates. The neonates also exhibited reciprocal activation of the muscles, as well as asymmetrical activation and synchronous bursting. For the in vitro preparation, neonatal mice were anesthetized, electrodes were positioned into the G and TA muscles, and the spinal cord with the hindlimbs attached were surgically removed and perfused with ACSF. The spinal cord-hindlimb explant was investigated under 3 types of conditions: (1) nonhemisected spinal cord with Mg$\sp{++}$ present in the ACSF; (2) nonhemisected spinal cord without Mg$\sp{++}$ present in the ACSF; (3) hemisected spinal cord without Mg$\sp{++}$ in the ACSF. The pattern generating capability was first investigated spontaneously, and afterwards upon pharmacological stimulation with NMDA (an excitatory amino acid which is inhibited by Mg$\sp{++}$). Spontaneous bursting activity rarely occurred. In contrast, NMDA increased the occurrence of rhythmicity, especially in the absence of Mg$\sp{++}$. When rhythmic activity occurred spontaneously or was evoked by NMDA, rhythm was usually present in one muscle and faster step cycles were exhibited than in the intact neonate. There was a higher incidence of rhythmicity in the day 2 nonhemisected Mg$\sp{++}$ free explant. This preparation, with pharmacological stimulation, is useful for further investigation of motor pattern generation.
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    A spectrophotometric procedure for phytate determination
    (1980-12) Erwin, Kathy Jean; Wendel, Carlton; Barton, Janice; Stewart, George
    No abstract available
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    The status of the sociology of aging as evidenced in a content anlysis of the Journal of Gerontology and the Gerontologist
    (1978-12) Stern, Ruth Byers; Johansen, Elinor; Albert, Rodney; Davis, Ethelyn; Martin, Cora; McGeehon, Carol
    No abstract available
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    The Federal Equal Rights Amendment as an issue in the Texas Legislature 1971-1975
    (1979-12) Ross, Charlotte Guinn; Yarborough, Kemp; Gilbert, Norma
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    Factors influencing the pattern of female lawlessness and contributing to the emergence of the violent female offender
    (1978-12) Jaber, Melinda Ann; Albert, Charles Rodney; Davis, Ethelyn; Gilbert, Norma
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    Marital satisfaction: A comparative study of black and white college students' attitudes toward marriage
    (1978-12) An, Judy Yi-Bii Li; Albert, Charles Rodney; Davis, Ethelyn; Johansen, Elinor; McGeehon, Carl; Malhotra, Valerie
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    World War II and Camp Howze: The impact upon Gainesville and Cooke County, Texas
    (1984-08) Burns, Barbara K.; Collins, Michael; Swain, Martha; Belfiglio, Valentine
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    "Fletcher Warren reporting for duty, sir. I have left all in order for my successor."
    (1986-08) Phillips, Mary Ann; DeMoss, Dorothy; Landry, Harral; Alexander, Jim
    The life story of Ambassador Fletcher Warren chronicles the evolution of an ordinary Texas farm boy of pioneer stock, who was among the first of his kind admitted to the Foreign Service, in his rise through the ranks to become privy to the nation's best-kept secrets. On two occasions Warren was a hero of no small dimension on the international scene, and also played an extraordinary role in national security. Warren's knowledge of Nicaraguan intrigue during the Thirties, together with his opinion of Anastasio Somoza and Augusto c. Sandino, provide a timely observation by which to appraise current events in Nicaragua.
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    Atomic fluorination of selected organic compounds
    (1978-12) Shariff, Syeda Ruqia; Sams, Lewis C.; Hamilton, Walter; Hurdis, Everett; Johnson, James; Mecay, William
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    Police officer: The person and the role an exploratory study of the extent to which the role affects the person
    (1979-12) Adams, E. R. (Rae) Banks; Albert, Rodney; Johansen, Elinor; McGeehon, Carl; Jolly, Virginia; Davis, Ethelyn