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Sample records for proving allelopathic chemical

  1. Chemical composition and allelopathic potential of essential oils obtained from Acacia cyanophylla Lindl. Cultivated in Tunisia.

    Science.gov (United States)

    El Ayeb-Zakhama, Asma; Sakka-Rouis, Lamia; Bergaoui, Afifa; Flamini, Guido; Ben Jannet, Hichem; Harzallah-Skhiri, Fethia

    2015-04-01

    Acacia cyanophylla Lindl. (Fabaceae), synonym Acacia saligna (Labill.) H. L.Wendl., native to West Australia and naturalized in North Africa and South Europe, was introduced in Tunisia for rangeland rehabilitation, particularly in the semiarid zones. In addition, this evergreen tree represents a potential forage resource, particularly during periods of drought. A. cyanophylla is abundant in Tunisia and some other Mediterranean countries. The chemical composition of the essential oils obtained by hydrodistillation from different plant parts, viz., roots, stems, phyllodes, flowers, and pods (fully mature fruits without seeds), was characterized for the first time here. According to GC-FID and GC/MS analyses, the principal compound in the phyllode and flower oils was dodecanoic acid (4), representing 22.8 and 66.5% of the total oil, respectively. Phenylethyl salicylate (8; 34.9%), heptyl valerate (3; 17.3%), and nonadecane (36%) were the main compounds in the root, stem, and pod oils, respectively. The phyllode and flower oils were very similar, containing almost the same compounds. Nevertheless, the phyllode oil differed from the flower oil for its higher contents of hexahydrofarnesyl acetone (6), linalool (1), pentadecanal, α-terpineol, and benzyl benzoate (5) and its lower content of 4. Principal component and hierarchical cluster analyses separated the five essential oils into four groups, each characterized by its main constituents. Furthermore, the allelopathic activity of each oil was evaluated using lettuce (Lactuca sativa L.) as a plant model. The phyllode, flower, and pod oils exhibited a strong allelopathic activity against lettuce. Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.

  2. Chemical Composition and Allelopathic Potential of Essential Oils from Tipuana tipu (Benth.) Kuntze Cultivated in Tunisia.

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    El Ayeb-Zakhama, Asma; Sakka-Rouis, Lamia; Bergaoui, Afifa; Flamini, Guido; Jannet, Hichem Ben; Harzallah-Skhiri, Fethia

    2016-03-01

    In Tunisia, Tipuana tipu (Benth.) Kuntze is an exotic tree, which was introduced many years ago and planted as ornamental street, garden, and park tree. The present work reported, for the first time, the chemical composition and evaluates the allelopathic effect of the hydrodistilled essential oils of the different parts of this tree, viz., roots, stems, leaves, flowers, and pods gathered in the area of Sousse, a coastal region, in the East of Tunisia. In total, 86 compounds representing 89.9 - 94.9% of the whole oil composition, were identified in these oils by GC-FID and GC/MS analyses. The root essential oil was clearly distinguished for its high content in sesquiterpene hydrocarbons (β-caryophyllene, 1 (44); 24.1% and germacrene D, 2 (53); 20.0%), while those obtained from pods, leaves, stems, and flowers were dominated by non-terpene hydrocarbons. The most important ones were n-tetradecane (41, 16.3%, pod oil), 1,7-dimethylnaphthalene (43, 15.6%, leaf oil), and n-octadecane (77, 13.1%, stem oil). The leaf oil was rich in the apocarotene (E)-β-ionone (4 (54); 33.8%), and the oil obtained from flowers was characterized by hexahydrofarnesylacetone (5 (81); 19.9%) and methyl hexadecanoate (83, 10.2%). Principal component and hierarchical cluster analyses separated the five essential oils into three groups and two subgroups, each characterized by the major oil constituents. Contact tests showed that the germination of lettuce seeds was totally inhibited by the root essential oil tested at 1 mg/ml. The inhibitory effect on the shoot and root elongation varied from -1.6% to -32.4%, and from -2.5% to -64.4%, respectively. © 2016 Verlag Helvetica Chimica Acta AG, Zürich.

  3. Chemical characterisation and allelopathic potential of essential oils from leaves and rhizomes of white ginger

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    Cíntia Alvarenga Santos Fraga Miranda

    Full Text Available ABSTRACTEssential oils have the potential to be used as bioherbicides, and possess the advantage of their biodegradability, high structural diversity and reduced natural resistance to weeds. The essential oils of the leaves and rhizomes of Hedychium coronarium, an exotic invasive plant adapted to different regions of Brazil, were extracted by hydrodistillation and characterised chemically by Gas-Liquid Chromatography and Gas-Liquid Chromatography/Mass Spectrometry. Allelopathic activity was determined using methodologies that evaluate the effects of volatility and direct contact on seed germination and seedling vigour in the lettuce. The major constituents of the essential oil from the leaves were β-pinene (46.9%, α-pinene (19.2% and β-caryophyllene (13.2% and from the rhizomes, β-pinene (41.5%, 1.8-cineole (23.6% and α-pinene (13.1%. When analysing the volatile effects of the essential oils, it was seen that their concentration did not affect seedling first germination count or total germination. The essential oil from the rhizomes was more effective than the essential oil from the leaves in reducing seedling response for SGI, dry weight, and length of the roots and shoots. When evaluating the effect of direct contact with the essential oils, it was seen that both oils reduced the response of all the variables under evaluation, and that in addition, the oil from the rhizomes caused greater reductions than that from the leaves, again for all variables. These results can be attributed to the higher levels of monoterpenes present in the essential oil from the rhizomes, mainly the presence of 1.8-cineole.

  4. Chemical composition of volatile oil from Artemisia ordosica and its allelopathic effects on desert soil microalgae, Palmellococcus miniatus.

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    Yang, Xiaolu; Deng, Songqiang; De Philippis, Roberto; Chen, Lanzhou; Hu, Chaozhen; Zhang, Weihao

    2012-02-01

    Plants have been used to restore vegetation in desert region in Shapotou, where naturally biological soil crusts (BSCs) have formed after planting for several years. However, few works have been done on the allelopathic effects between the plants and soil microalgae in BSCs currently. In this study, we investigated the chemical compositions of volatile oil of Artemisia ordosica and its allelopathic effects on photosynthetic system II (PSII) and antioxidant system of Palmellococcus miniatus, a green algae isolated from BSCs. 37 components, consisted of 17 terpenoids, 14 alcohols, 2 esters, 2 ketones and other 2 components were identified in the volatile oil from A. ordosica by GC-MS analysis. High concentration of volatile oil could significantly inhibit the growth and photosynthetic activity (Fv/Fm), and decreased the photosynthetic parameters by affecting photon absorption, electron transport and the reaction center of PSII of P. miniatus, and also cause the significant increase of superoxide dismutase (SOD; EC 1.15.1.) activity, peroxidase (POD; EC 1.11.1.7) activity, reactive oxygen evolution (ROS) and malondialdehyde (MDA) contents of P. miniatus through the combined effects of components in volatile oil. The results indicated that the emission of volatile oil of A. ordosica could inhibit the growth, photosynthesis of P. miniatus through the oxidative damage, and thus might negatively affect the development of BSCs. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  5. Allelopathic interactions between phytoplankton species : the roles of heterotrophic bacteria and mixing intensity

    NARCIS (Netherlands)

    Hulot, F.; Huisman, J.

    2004-01-01

    Toxin-producing phytoplankton species may compensate for competitive disadvantages by secreting chemicals that affect toxin-sensitive phytoplankton species. Heterotrophic bacteria, however, may, in turn, degrade the toxins produced by allelopathic phytoplankton, thus confounding allelopathic

  6. C15083. Chemical Composition and Allelopathic Potential of Essential Oils from Tipuana tipu (Benth.) Kuntze Cultivated in Tunisia.

    Science.gov (United States)

    El Ayeb-Zakhama, Asma; Sakka-Rouis, Lamia; Bergaoui, Afifa; Flamini, Guido; Jannet, Hichem Ben; Harzallah-Skhiri, Fethia

    2016-02-10

    In Tunisia, Tipuana tipu (Benth.) Kuntze is an exotic tree, which was introduced many years ago and planted as ornamental street, garden, and park tree. The present work reported, for the first time, the chemical composition and evaluates the allelopathic effect of the hydrodistilled essential oils of the different parts of this tree, viz., roots, stems, leaves, flowers and pods gathered in the area of Sousse, a coastal region, in the East of Tunisia. In total, 86 compounds representing 89.9-94.9% of the whole oil composition, were identified in these oils by GC-FID and GC/MS analyses. The root essential oil was clearly distinguished for its high content in sesquiterpene hydrocarbons (β-caryophyllene, 1 (44); 24.1% and germacrene D, 2 (53); 20.0%), while those obtained from pods, leaves, stems and flowers were dominated by non-terpene hydrocarbons. The most important ones were n-tetradecane (41, 16.3%, pod oil), 1.7-dimethylnaphthalene (43, 15.6%, leaf oil), and n-octadecane (77, 13.1%, stem oil). The leaf oil was rich in the apocarotene (E)-β-ionone (4 (54); 33.8%), and the oil obtained from flowers was characterized by hexahydrofarnesyl acetone (5 (81); 19.9%) and methyl hexadecanoate (83, 10.2%). Principal component and hierarchical cluster analyses separated the five essential oils into 3 groups and 2 subgroups, each characterized by the major oil constituents. Contact tests showed that the germination of lettuce seeds was totally inhibited by the root essential oil tested at 1 mg/ml. The inhibitory effect on the shoot and root elongation varied from -1.6 to -32.4%, and from -2.5 to -64.4%, respectively. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  7. Hydrogeologic and chemical data for the O-Field area, Aberdeen Proving Ground, Maryland

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    Nemoff, P.R.; Vroblesky, D.A.

    1989-01-01

    O-Field, located at the Edgewood area of Aberdeen Proving Ground , Maryland, was periodically used for disposal of munitions, waste chemicals, and chemical-warfare agents from World War II through the 1950' s. This report includes various physical, geologic, chemical, and hydrologic data obtained from well-core, groundwater, surface water, and bottom-sediment sampling sites at and near the O-Field disposal area. The data are presented in tables and hydrographs. Three site-location maps are also included. Well-core data include lithologic logs for 11 well- cluster sites, grain-size distributions, various chemical characteristics, and confining unit characteristics. Groundwater data include groundwater chemistry, method blanks for volatile organic carbon, available data on volatile and base/neutral organics, and compilation of corresponding method blanks, chemical-warfare agents, explosive-related products, radionuclides, herbicides, and groundwater levels. Surface-water data include field-measured characteristics; concentrations of various inorganic constituents including arsenic; selected organic constituents with method blanks; detection limits of organics; and a compilation of information on corresponding acids, volatiles, and semivolatiles. Bottom- sediment data include inorganic properties and constituents; organic chemistry; detection limits for organic chemicals; a compilation of information on acids, volatiles, and semivolatiles; and method blanks corresponding to acids, volatiles, and semivolatiles. A set of 15 water- level hydrographs for the period March 1986 through September 1987 also is included in the report. (USGS)

  8. Chemical Composition and Allelopathic, Antibacterial, Antifungal, and Antiacetylcholinesterase Activity of Fish-mint (Houttuynia cordataThunb.) from India.

    Science.gov (United States)

    Verma, Ram S; Joshi, Neeta; Padalia, Rajendra C; Singh, Ved R; Goswami, Prakash; Kumar, Ajay; Iqbal, Hina; Verma, Rajesh K; Chanda, Debabrata; Chauhan, Amit; Saikia, Dharmendra

    2017-10-01

    Fish-mint (Houttuynia cordataThunb.), belonging to family Saururaceae, has long been used as food and traditional herbal medicine. The present study was framed to assess the changes occurring in the essential-oil composition of H. cordata during annual growth and to evaluate allelopathic, antibacterial, antifungal, and antiacetylcholinesterase activities. The essential-oil content ranged from 0.06 - 0.14% and 0.08 - 0.16% in aerial parts and underground stem, respectively. The essential oils were analysed by GC-FID, GC/MS, and NMR (1 H and 13 C). Major constituents of aerial-parts oil was 2-undecanone (19.4 - 56.3%), myrcene (2.6 - 44.3%), ethyl decanoate (0.0 - 10.6%), ethyl dodecanoate (1.1 - 8.6%), 2-tridecanone (0.5 - 8.3%), and decanal (1.1 - 6.9%). However, major constituents of underground-stem oil were 2-undecanone (29.5 - 42.3%), myrcene (14.4 - 20.8%), sabinene (6.0 - 11.1%), 2-tridecanone (1.8 - 10.5%), β-pinene (5.3 - 10.0%), and ethyl dodecanoate (0.8 - 7.3%). Cluster analysis revealed that essential-oil composition varied substantially due to the plant parts and season of collection. The oils exhibited significant allelopathic (inhibition: 77.8 - 88.8%; LD50 : 2.45 - 3.05 μl/plate), antibacterial (MIC: 0.52 - 2.08 μl/ml; MBC: bacteriostatic) and antifungal (MIC: 2.08 - 33.33 μl/ml; MFC: 4.16 - 33.33 μl/ml) activities. The results indicate that the essential oil from H. cordata has a significant potential to allow future exploration and exploitation as a natural antimicrobial and allelopathic agent. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  9. Interference of allelopathic wheat with different weeds.

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    Zhang, Song-Zhu; Li, Yong-Hua; Kong, Chui-Hua; Xu, Xiao-Hua

    2016-01-01

    Interference of allelopathic wheat with weeds involves a broad spectrum of species either independently or synergistically with competitive factors. This study examined the interference of allelopathic wheat with 38 weeds in relation to the production of allelochemical 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) in wheat with and without root-root interactions. There were substantial differences in weed biomass and DIMBOA concentration in wheat-weed coexisting systems. Among 38 weeds, nine weeds were inhibited significantly by allelopathic wheat but the other 29 weeds were not. DIMBOA levels in wheat varied greatly with weed species. There was no significant relationship between DIMBOA levels and weed suppression effects. Root segregation led to great changes in weed inhibition and DIMBOA level. Compared with root contact, the inhibition of eight weeds was lowered significantly, while significantly increased inhibition occurred in 11 weeds with an increased DIMBOA concentration under root segregation. Furthermore, the production of DIMBOA in wheat was induced by the root exudates from weeds. Interference of allelopathic wheat with weeds not only is determined by the specificity of the weeds but also depends on root-root interactions. In particular, allelopathic wheat may detect certain weeds through the root exudates and respond by increasing the allelochemical, resulting in weed identity recognition. © 2015 Society of Chemical Industry.

  10. Chemical constituents of Cinnamomum septentrionale leaf litter and its allelopathic activity on the growth of maize (Zea mays).

    Science.gov (United States)

    Yang, Shanshan; Hu, Hongling; Hu, Tingxing; Wang, Qian; Ye, Mao; Luo, Jie; Peng, Yong; Zhang, Ruyi

    2017-06-01

    A pot experiment was conducted to study the effect of decomposing Cinnamomum septentrionale leaf litter on the growth of maize. In this study, the morphological traits of maize were significantly inhibited when the leaf litter amount reached or exceeded 40 g per pot; Furthermore, during the early growth stage or with a large amount of litter addition, the pigment contents were inhibited by C. septentrionale leaf litter. Gas chromatography-mass spectrometry was used to determine the volatile substances of leaf litter and 34 compounds were identified, several of which were reported to be phytotoxic. In conclusion, the leaf litter of C. septentrionale showed a strong allelopathic effect on the growth of maize. Thus, it is better to avoid the growing of maize under or near the C. septentrionale plantation unless the leaf litter could be eliminated in time or other effective leaf litter processing methods could be implemented.

  11. Are Radishes Really Allelopathic to Lettuce?

    Science.gov (United States)

    Santaniello, Catherine M.; Koning, Ross E.

    1996-01-01

    Presents an experiment that challenges the claim that sprouting radish seedlings release chemicals into the environment that inhibit germination of lettuce seeds. Reports that although no simple allelopathic demonstration was observed, the experiment provides fertile ground for further experimentation in inquiry-based laboratory experiences. (JRH)

  12. Allelopathic principles for sustainable agriculture

    Science.gov (United States)

    Allelopathic research of the past few decades has established the feasibility of weed and plant disease management by allelopathic crop plants, plant residues, cultural manipulation, and microorganisms as bioherbicides and rhizobacteria. Inconsistency in the effectiveness of plant-growth-promoting ...

  13. Chemical composition and evaluation of allelopathic potentials of Adiantum tetraphyllum Humb.and Bonpl. Ex. Willd (Pteridaceae); Constituintes quimicos e avaliacao do potencial alelopatico de Adiantum tetraphyllum Humb. and Bonpl. Ex. Willd (Pteridaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Melos, Jorge L.R. [Colegio Militar de Campo Grande, MS (Brazil). Secao de Ensino ' C' ; Silva, Luciana B.; Peres, Marize T. L. P.; Mapeli, Ana M.; Faccenda, Odival; Anjos, Hatino H.; Torres, Thais G.; Tiviroli, Soraia C.; Batista, Ana L.; Almeida, Felipe G. N.; Flauzino, Natasha S.; Tibana, Leticia A.; Hess, Sonia C. [Universidade Federal de Mato Grosso do Sul, Campo Grande, MS(Brazil). Dept. de Hidraulica e Transportes; Honda, Neli K. [Universidade Federal de Mato Grosso do Sul, Campo Grande, MS (Brazil). Dept. de Quimica]. E-mail: schess@nin.ufms.br

    2007-03-15

    Chemical studies of green leaves of A. tetraphyllum afforded {beta}-sitosterol, a mixture containing the ethyl esters of long chain carboxylic acids, 30-normethyl-lupan-20-one, hopan-22-ol, phytol, phyten-3(20)-1,2-diol, quercetin and quercetin-3-O-{beta}-D-glucoside. The structures of the compounds were elucidated by spectroscopic and GC analysis. The allelopathic potentials of the crude ethanolic extract and fractions were evaluated against Lactuca sativa (letuce) and Allium cepa (onion) seeds. (author)

  14. Chemical composition and antimicrobial and allelopathic activity of Tunisian Conyza sumatrensis (Retz.) E.WALKER essential oils.

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    Mabrouk, Samia; Salah, Karima Bel Hadj; Elaissi, Ameur; Jlaiel, Lobna; Jannet, Hichem Ben; Aouni, Mahjoub; Harzallah-Skhiri, Fethia

    2013-02-01

    Conyza sumatrensis (Retz.) E.WALKER (Asteraceae) is a spontaneous annual herb, fairly widespread throughout Tunisia, which has rarely been studied or valued in any sector. Essential oils were obtained by hydrodistillation of different parts (flower heads, leaves, stems, and roots) of C. sumatrensis plants, which were collected in autumn (November 2007) at the flowering stage in the area of Monastir, Tunisia. In total, 98 compounds, representing 88.1-99.3% of the oil composition, were identified by GC-FID and GC/MS analyses. The root essential oil was distinguished by its high content in acetylenes (matricaria ester, 4; 74.3%), while those from flower heads and leaves were dominated by oxygenated sesquiterpenes (61.1 and 50.3%, resp.). The oils of C. sumatrensis from Tunisia belonged to a matricaria ester/caryophyllene oxide chemotype. All the oils were evaluated for antibacterial, antifungal, and allelopathic activities. The results indicate that the leaf oil exhibited significant in vitro antibacterial activity against Enterococcus faecalis, Staphylococcus aureus, and Proteus mirabilis and that the C. sumatrensis oils isolated from the aerial parts presented high mycelia-growth inhibition of Candida albicans and the filamentous fungi tested. Moreover, the essential oils of the different plant parts inhibited the shoot and root growth of Raphanus sativus (radish) seedlings. Indeed, the inhibition of the hypocotyl growth varied from 28.6 to 90.1% and that of the radicle from 42.3 to 96.2%. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

  15. Use of allelopathic plant extract with herbicide

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    Ahmet Tansel SERİM

    2015-12-01

    Full Text Available Herbicides are one of the plant protection products that have been discussed due to their adversely effects caused by the usage of them although they have an important role on the sustainability of crop production. Researches on the plant protection practices, such as the development of new herbicide application techniques, the reduction of the application rate, the use of adjuvant, changing herbicide application time and the use of allelopathic plant extract, and the applications based on the results of these research have increased in recent years. The cost of weed control may exceed the economic benefits because a large amount of plant extract is needed to control weeds alone with allelopathic chemicals. Using the mixture of plant extracts with the reduced rate of herbicides is important both to reduce environmental and economic losses and to prevent some problem caused by use of herbicide. The extracts of plants which have got allelopathic character, such as sunflower, sorghum, brassica and rice, are commonly used for this aim. The aim of presented review is to emphasize the efficacy of allelopathic plant extract with herbicide to control weeds and its economical contribution.

  16. Hydrogeology and chemical quality of water and soil at Carroll Island, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Tenbus, F.J.; Phillips, S.W.

    1996-01-01

    Carroll Island was used for open-air testing of chemical warfare agents from the late 1940's until 1971. Testing and disposal activities weresuspected of causing environmental contamination at 16 sites on the island. The hydrogeology and chemical quality of ground water, surface water, and soil at these sites were investigated with borehole logs, environmental samples, water-level measurements, and hydrologic tests. A surficial aquifer, upper confining unit, and upper confined aquifer were defined. Ground water in the surficial aquifer generally flows from the east-central part of the island toward the surface-water bodies, butgradient reversals caused by evapotranspiration can occur during dry seasons. In the confined aquifer, hydraulic gradients are low, and hydraulic head is affected by tidal loading and by seasonal pumpage from the west. Inorganic chemistry in the aquifers is affected by brackish-water intrusion from gradient reversals and by dissolution ofcarboniferous shell material in the confining unit.The concentrations of most inorganic constituents probably resulted from natural processes, but some concentrations exceeded Federal water-quality regulations and criteria. Organic compounds were detected in water and soil samples at maximum concentrations of 138 micrograms per liter (thiodiglycol in surface water) and 12 micrograms per gram (octadecanoic acid in soil).Concentrations of organic compounds in ground water exceeded Federal drinking-water regulations at two sites. The organic compounds that weredetected in environmental samples were variously attributed to natural processes, laboratory or field- sampling contamination, fallout from industrial air pollution, and historical military activities.

  17. Isolation and identification of an allelopathic substance from Hibiscus sabdariffa.

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    Suwitchayanon, Prapaipit; Pukclai, Piyatida; Ohno, Osamu; Suenaga, Kiyotake; Kato-Noguchi, Hisashi

    2015-05-01

    In this study, an allelopathic substance was isolated from an aqueous methanol extract of Hibiscus sabdariffa L. by column chromatography and reverse phase HPLC. The chemical structure of the substance was determined by 1H NMR spectroscopy and mass spectrometry as trimethyl allo-hydroxycitrate. Trimethyl allo-hydroxycitrate inhibited the growth of cress hypocotyls and roots at concentrations greater than 10 mM. The concentrations required for 50% growth inhibition of the hypocotyls and roots of cress were 20.3 and 14.4 mM, respectively. The inhibitory activity of trimethyl allo-hydroxycitrate suggests that the substance may act as an allelopathic substance of H. sabdariffa.

  18. Allelopathic potential of switchgrass (Panicum virgatum L.) on perennial ryegrass (Lolium perenne L.) and alfalfa (Medicago sativa L.).

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    Shui, Junfeng; An, Yu; Ma, Yongqing; Ichizen, Nobumasa

    2010-10-01

    This study investigated allelopathy and its chemical basis in nine switchgrass (Panicum virgatum L.) accessions. Perennial ryegrass (Lolium perenne L.) and alfalfa (Medicago sativa L.) were used as test species. Undiluted aqueous extracts (5 g plant tissue in 50 ml water) from the shoots and roots of most of the switchgrass accessions inhibited the germination and growth of the test species. However, the allelopathic effect of switchgrass declined when extracts were diluted 5- or 50-fold. Seedling growth was more sensitive than seed germination as an indicator of allelopathic effect. Allelopathic effect was related to switchgrass ecotype but not related to ploidy level. Upland accessions displayed stronger allelopathic potential than lowland accessions. The aqueous extract from one switchgrass accession was separated into phenols, organic acids, neutral chemicals, and alkaloids, and then these fractions were bioassayed to test for allelopathic potential. Alkaloids had the strongest allelopathic effect among the four chemical fractions. In summary, the results indicated that switchgrass has allelopathic potential; however, there is not enough evidence to conclude that allelopathic advantage is the main factor that has contributed to the successful establishment of switchgrass on China's Loess Plateau.

  19. Allelopathic Potential of Switchgrass ( Panicum virgatum L.) on Perennial Ryegrass ( Lolium perenne L.) and Alfalfa ( Medicago sativa L.)

    Science.gov (United States)

    Shui, Junfeng; An, Yu; Ma, Yongqing; Ichizen, Nobumasa

    2010-10-01

    This study investigated allelopathy and its chemical basis in nine switchgrass ( Panicum virgatum L.) accessions. Perennial ryegrass ( Lolium perenne L.) and alfalfa ( Medicago sativa L.) were used as test species. Undiluted aqueous extracts (5 g plant tissue in 50 ml water) from the shoots and roots of most of the switchgrass accessions inhibited the germination and growth of the test species. However, the allelopathic effect of switchgrass declined when extracts were diluted 5- or 50-fold. Seedling growth was more sensitive than seed germination as an indicator of allelopathic effect. Allelopathic effect was related to switchgrass ecotype but not related to ploidy level. Upland accessions displayed stronger allelopathic potential than lowland accessions. The aqueous extract from one switchgrass accession was separated into phenols, organic acids, neutral chemicals, and alkaloids, and then these fractions were bioassayed to test for allelopathic potential. Alkaloids had the strongest allelopathic effect among the four chemical fractions. In summary, the results indicated that switchgrass has allelopathic potential; however, there is not enough evidence to conclude that allelopathic advantage is the main factor that has contributed to the successful establishment of switchgrass on China’s Loess Plateau.

  20. Sementes como fonte alternativa de substâncias químicas com atividade alelopática Seeds as alternative source of chemical substances with allelopathic activity

    Directory of Open Access Journals (Sweden)

    A.P.S Souza Filho

    2011-09-01

    Full Text Available Na literatura mundial, observa-se predominância das folhas como meio preferencial de estudos de compostos químicos promissores, embora informações sobre outras frações da planta também sejam encontradas. Essa tendência se deve ao fato de que a maioria dos estudos mostra as folhas com atividade potencialmente alelopática de intensidade superior à das demais frações. Nesta revisão, procurou-se compilar e analisar as informações disponíveis sobre a importância das sementes como fonte alternativa de compostos químicos com atividade alelopática. São discutidas as variações na produção e na alocação de aleloquímicos em função do estádio ontogenético das sementes presentes no banco de sementes. É discutido também o papel dos aleloquímicos produzidos por sementes na repelência de insetos, na inibição do desenvolvimento de patógenos nas sementes, na inibição do desenvolvimento inicial de plantas daninhas e como sinalizador positivo para a simbiose com microrganismos do solo. Apresenta-se ainda a atividade alelopática de diversas substâncias isoladas de sementes, destacando-se os alcaloides, flavonoides, benzoxazinoides e resinas glicosídicas. Os estudos de aleloquímicos produzidos por sementes podem contribuir expressivamente para o melhor entendimento do papel ecológico que essas substâncias desempenham na ecologia química dos agro e ecossistemas.In the literature, leaves predominate as preferred source of studies of promising allelopathic compounds, but information on other plant fractions are also found. This trend is due to the fact that most studies show that leaves have higher allelopathic potential than other plant fractions. In this review, we compiled and analyzed the information available on the importance of seeds as an alternative source of chemical compounds with allelopathic activity. We discussed the variations in production and allocation of allelochemicals at different ontogenetic stages of

  1. Allelobiosis in the interference of allelopathic wheat with weeds.

    Science.gov (United States)

    Li, Yong-Hua; Xia, Zhi-Chao; Kong, Chui-Hua

    2016-11-01

    Plants may chemically affect the performance of neighbouring plants through allelopathy, allelobiosis or both. In spite of increasing knowledge about allelobiosis, defined as the signalling interactions mediated by non-toxic chemicals involved in plant-plant interactions, the phenomenon has received relatively little attention in the scientific literature. This study examined the role of allelobiosis in the interference of allelopathic wheat with weeds. Allelopathic wheat inhibited the growth of five weed species tested, and the allelochemical (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one) production of wheat was elicited in the presence of these weeds, even with root segregation. The inhibition and allelochemical levels varied greatly with the mixed species density. Increased inhibition and allelochemical levels occurred at low and medium densities but declined at high densities. All the root exudates and their components of jasmonic acid and salicylic acid from five weeds stimulated allelochemical production. Furthermore, jasmonic acid and salicylic acid were found in plants, root exudates and rhizosphere soils, regardless of weed species, indicating their participation in the signalling interactions defined as allelobiosis. Through root-secreted chemical signals, allelopathic wheat can detect competing weeds and respond by increased allelochemical levels to inhibit them, providing an advantage for its own growth. Allelopathy and allelobiosis are two probably inseparable processes that occur together in wheat-weed chemical interactions. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  2. Análise comparativa dos efeitos alelopáticos das substâncias químicas titonina e titonina acetilada Comparative analysis of the allelopathic effects of the chemical compounds tithonine and acetylated tithonine

    Directory of Open Access Journals (Sweden)

    A.P.S. Souza Filho

    2006-06-01

    Full Text Available Este trabalho teve por objetivo estabelecer as variações na atividade alelopática da substância química titonina, em função da acetilação de sua molécula. Bioensaios de germinação (25 ºC de temperatura constante e fotoperíodo de 12 horas e de desenvolvimento da radícula e do hipocótilo (25 ºC de temperatura constante e fotoperíodo de 24 horas foram desenvolvidos. Como planta receptora, utilizou-se a planta daninha Mimosa pudica (malícia. Análise de espectros RMN ¹H e 13C e técnicas de RMN bidimensionais foram realizadas na molécula acetilada. O processo de acetilação produziu a molécula 3'-acetil-7,4'-dimetoxiflavona, que diferiu da molécula original, identificada como 3'-hidroxi-7,4'-dimetoxiflavona. A estrutura da titonina-Ac foi confirmada pelos espectros de RMN ¹H, 13C, DEPT, COSY e HETCOR. A titonina foi acetilada com anidrido acético em piridina. A análise comparativa da atividade alelopática das duas substâncias revelou que titonina-Ac apresentou maior potencial para inibir tanto a germinação das sementes como o desenvolvimento da radícula e do hipocótilo da planta daninha malícia. A intensidade dos efeitos alelopáticos das duas substâncias esteve positivamente associada à concentração. O conjunto das informações obtidas permite sugerir a possibilidade de se aumentar a atividade alelopática de uma substância química sem comprometer suas peculiaridades biológicas desejáveis à natureza e aos interesses da sociedade.The objective of this paper was to establish the variations in the allelopathic activity of the chemical substance tithonine, in function of the acetylation of its molecule. Germination bioassays, under 25 ºC of constant temperature and 12-hour photoperiod, and radicle and hypocotyl development bioassays under 25ºC of constant temperature and 24-hour photoperiod were developed. The receiving plant used was the weed Mimosa pudica. Spectral analysis RMN ¹H and 13C and

  3. Is Allelopathic Activity of Ipomoea murucoides Induced by Xylophage Damage?

    Science.gov (United States)

    Flores-Palacios, Alejandro; Corona-López, Angélica María; Rios, María Yolanda; Aguilar-Guadarrama, Berenice; Toledo-Hernández, Víctor Hugo; Rodríguez-López, Verónica; Valencia-Díaz, Susana

    2015-01-01

    Herbivory activates the synthesis of allelochemicals that can mediate plant-plant interactions. There is an inverse relationship between the activity of xylophages and the abundance of epiphytes on Ipomoea murucoides. Xylophagy may modify the branch chemical constitution, which also affects the liberation of allelochemicals with defense and allelopathic properties. We evaluated the bark chemical content and the effect of extracts from branches subjected to treatments of exclusion, mechanical damage and the presence/absence of epiphytes, on the seed germination of the epiphyte Tillandsia recurvata. Principal component analysis showed that branches without any treatment separate from branches subjected to treatments; damaged and excluded branches had similar chemical content but we found no evidence to relate intentional damage with allelopathy; however 1-hexadecanol, a defense volatile compound correlated positively with principal component (PC) 1. The chemical constitution of branches subject to exclusion plus damage or plus epiphytes was similar among them. PC2 indicated that palmitic acid (allelopathic compound) and squalene, a triterpene that attracts herbivore enemies, correlated positively with the inhibition of seed germination of T. recurvata. Inhibition of seed germination of T. recurvata was mainly correlated with the increment of palmitic acid and this compound reached higher concentrations in excluded branches treatments. Then, it is likely that the allelopathic response of I. murucoides would increase to the damage (shade, load) that may be caused by a high load of epiphytes than to damage caused by the xylophages.

  4. Allelopathic potential of selected rice varieties

    African Journals Online (AJOL)

    ajl10

    2012-11-01

    Nov 1, 2012 ... Azania AAPM, Azania CAMP, Alives LCA, Palaniraj R, Kadian HS, Sati. SC, Rawat LS, Dahiya DS, Narwal SS (2003). Allelopathic plants. 7. Barley (Hordeum vulgare L.). Allelopathy J. 11:1–20. Azmi M, Abdullah MZ, Fuji Y (2000). Exploratory study on allelopathic effect of selected Malaysian rice varieties ...

  5. Allelopathic interference of alfalfa (Medicago sativa L.) genotypes to annual ryegrass (Lolium rigidum).

    Science.gov (United States)

    Zubair, Hasan Muhammad; Pratley, James E; Sandral, G A; Humphries, A

    2017-07-01

    Alfalfa (Medicago sativa L.) genotypes at varying densities were investigated for allelopathic impact using annual ryegrass (Lolium rigidum) as the target species in a laboratory bioassay. Three densities (15, 30, and 50 seedlings/beaker) and 40 alfalfa genotypes were evaluated by the equal compartment agar method (ECAM). Alfalfa genotypes displayed a range of allelopathic interference in ryegrass seedlings, reducing root length from 5 to 65%. The growth of ryegrass decreased in response to increasing density of alfalfa seedlings. At the lowest density, Q75 and Titan9 were the least allelopathic genotypes. An overall inhibition index was calculated to rank each alfalfa genotype. Reduction in seed germination of annual ryegrass occurred in the presence of several alfalfa genotypes including Force 10, Haymaster7 and SARDI Five. A comprehensive metabolomic analysis using Quadruple Time of Flight (Q-TOF), was conducted to compare six alfalfa genotypes. Variation in chemical compounds was found between alfalfa root extracts and exudates and also between genotypes. Further individual compound assessments and quantitative study at greater chemical concentrations are needed to clarify the allelopathic activity. Considerable genetic variation exists among alfalfa genotypes for allelopathic activity creating the opportunity for its use in weed suppression through selection.

  6. Prospecção química de compostos produzidos por Senna alata com atividade alelopática Chemical prospecting of compounds produced by Senna alata with allelopathic activity

    Directory of Open Access Journals (Sweden)

    I.M.C. Rodrigues

    2010-01-01

    Full Text Available Senna alata é uma espécie daninha frequente em pastagens da região amazônica. Suas folhas apresentam propriedades medicinais capazes de influenciar a germinação e o desenvolvimento de outras plantas. Objetivou-se neste estudo a prospecção química e a avaliação da atividade alelopática dos compostos presentes nas folhas de S. alata. O material vegetal foi seco, triturado e submetido à extração exaustiva, com solução água:metanol (3:7. O extrato obtido foi então fracionado por coluna cromatográfica por via úmida. As frações mais puras foram submetidas à espectroscopia de Ressonância Magnética Nuclear, para determinação das fórmulas estruturais das moléculas. Na avaliação dos efeitos das substâncias químicas isoladas, utilizaram-se as concentrações de 50, 100, 150 e 200 ppm, tendo como eluente solução hidrometanólica (3:7 v/v. As frações foram adicionadas em placas de Petri e seus efeitos avaliados sobre a germinação de sementes e o alongamento da radícula e hipocótilo de três espécies daninhas de áreas de pastagens: Mimosa pudica, Senna obtusifolia e a própria S. alata. Os compostos com atividade alelopática encontrados em folhas de S. alata pertencem à classe dos flavonoides glicosilados, cujo núcleo aromático é um kaempferol, e causaram maior inibição sobre o crescimento da radícula e sobre a germinação de S. obtusifolia e M. pudica. Já os efeitos autotóxicos desse composto são pouco significativos para o desenvolvimento da plântula e nulos sobre a germinação.Senna alata is a weed species frequently found in pastures of the Amazonian region and whose leaves have medicinal properties. This study aimed to carry out a chemical prospecting and evaluation of the allelopathic activity of the compounds present in S. alata leaves. The plant material was dried, ground, and submitted to exhaustive extraction with water/methanol (3:7 solution. The crude extract obtained was fractioned by wet

  7. Allelopathic potential of Petiveria alliacea L.

    OpenAIRE

    Pérez-Leal, R.; García-Mateos, M.R.; Vásquez-Rojas, T.R.; M.T. Colinas-León,

    2005-01-01

    International audience; Petiveria alliacea (Phytolaccacea) is a herbaceous plant of great importance in traditional medicine. It has been reported to be effective as an insecticide and acaricide; however, its allelopathic activity is unknown. The objective of this study was to evaluate its allelopathic activity in seeds of Triticum aestivum, Oriza sativa, Lactuca sativa and Amaranthus hypochondriacus. Tests were performed with different concentrations of the aqueous, methanolic and dichlorome...

  8. Allelopathic activity of some grass species on Phleum pratense seed germination subject to their density

    Directory of Open Access Journals (Sweden)

    Halina Lipińska

    2012-12-01

    Full Text Available Efficient utilization of allelopathy in the agricultural practice requires searching for some species and developmental stages when the allelopathic substances are generated in bioactive concentrations. That also requires the knowledge of allelopathy mechanisms and primarily its separation from the other aspects of plant activity, mainly from competition for environmental resources. This task, however, has remained vital in the studies on plant interference, being extremely difficult to perform under field conditions. Therefore, the studies were conducted in the laboratory. To determine the activity of an allelopathic agent of the selected grass species, the density dependent phytotoxicity model was employed. The model is based on the fact that an increase of acceptor plants density evokes a decrease of their response to the allelopathic compounds, whereas the negative effects of the competition become more intense. A higher rate of acceptor plants growth accompanying their density increase in the given object does not agree with the competition rules and thus, it may imply an allelopathic background of the observed changes. In the presented studies, the allelopathic properties of grasses - donors were evaluated by studying the effect of two densities of the emerging seeds and two- and four weeks aged seedlings of F. arundinacea, L. multiflorum, L. perenne and P. pratensis. The tested species - acceptor Ph. pratensis was sown in the density of 10 and 20 seeds in a pan. The results revealed that the germination of acceptor seeds was differentiated depending on their density in the pan, and on the species, density and the age of the donor. Inhibition of Ph. pratense seed germination in objects with a lover density may prove allelopathic effects of the studied donor grasses.

  9. Allelopathic relations of selected cereal and vegetable species during seed germination and seedling growth

    Directory of Open Access Journals (Sweden)

    Bojović Biljana M.

    2015-01-01

    Full Text Available Allelopathy is the direct or indirect harmful effect which one plant produces on another through the production of chemical compounds that escape into the environment. In the presence paper allelopathic relationships were determined in three cereals - wheat (Triticum aestivum L., barley (Hordeum vulgare L., oat (Avena sativa L. and vegetable crops - spinach (Spinacia oleracea L., radish (Raphanus sativus L., pepper (Capsicum annum L.. In addition to the percentage of germination, allelopathic potential was tested measuring root and stem length of tested plant species germinated either alone or in combination with others. The obtained results showed that seed germination and plant growth of cereals and vegetables are depended on the presence of other plants in all tested combinations. In this study has proven largely inhibitory allelopathic effect on germination and plant growth.

  10. Soil microbial communities alter leaf chemistry and influence allelopathic potential among coexisting plant species.

    Science.gov (United States)

    Meiners, Scott J; Phipps, Kelsey K; Pendergast, Thomas H; Canam, Thomas; Carson, Walter P

    2017-04-01

    While both plant-soil feedbacks and allelochemical interactions are key drivers of plant community dynamics, the potential for these two drivers to interact with each other remains largely unexplored. If soil microbes influence allelochemical production, this would represent a novel dimension of heterogeneity in plant-soil feedbacks. To explore the linkage between soil microbial communities and plant chemistry, we experimentally generated soil microbial communities and evaluated their impact on leaf chemical composition and allelopathic potential. Four native perennial old-field species (two each of Aster and Solidago) were grown in pairwise combination with each species' soil microbial community as well as a sterilized inoculum. We demonstrated unequivocally that variation in soil microbial communities altered leaf chemical fingerprints for all focal plant species and also changed their allelopathic potential. Soil microbes reduced allelopathic potential in bioassays by increasing germination 25-54% relative to sterile control soils in all four species. Plants grown with their own microbial communities had the lowest allelopathic potential, suggesting that allelochemical production may be lessened when growing with microbes from conspecifics. The allelopathic potential of plants grown in congener and confamilial soils was indistinguishable from each other, indicating an equivalent response to all non-conspecific microbial communities within these closely related genera. Our results clearly demonstrated that soil microbial communities cause changes in leaf tissue chemistry that altered their allelopathic properties. These findings represent a new mechanism of plant-soil feedbacks that may structure perennial plant communities over very small spatial scales that must be explored in much more detail.

  11. Allelopathic impact of HoCP 96-540 field residue on seed germination

    Science.gov (United States)

    Research indicates that sugarcane field residue and sugarcane mill bagasse may be allelopathic. Allelopathy is the chemical interaction between plants, which may result in the inhibition of plant growth and development. Previous research in Louisiana indicated that sugarcane field residue may inhibi...

  12. Sugarcane field residue and bagasse allelopathic impact on vegetable seed germination

    Science.gov (United States)

    The chemical interaction between plants, which is referred to as allelopathy, may result in the inhibition of plant growth and development. The objective of this research was to determine the allelopathic impact of sugarcane (Saccharum officinarum) var. ‘HoCP 96-540’ field residue and sugarcane baga...

  13. Phytotoxic terpenes produced by phytopathogenic fungi and allelopathic plants.

    Science.gov (United States)

    Cimmino, Alessio; Andolfi, Anna; Evidente, Antonio

    2014-03-01

    This review is about the isolation as well as chemical and biological characterization of simple and complex mono-, sesqui-, di-, sester- and tri-terpenes produced by fungal pathogens of agrarian and forest plants and by some allelopathic plants. In several cases, the structure activity relationships are also discussed, as well as their potential application in agriculture as natural safe herbicides, fungicides and bactericides. Furthermore, the potential application of some fungal terpenes as anticancer compounds with a new mode of action is also discussed.

  14. Allelopathic Effects of Lantana (Lantana camara L.) Leaf Extracts on ...

    African Journals Online (AJOL)

    Bheema

    leaf litter (May and Ash, 1990). The report from Hussain et al. (2011), for example, showed strong allelopathic effects of aqueous extracts of all parts of lantana on the test species while the soil collected underneath lantana thickets had no allelopathic effects. 5. CONCLUSION. The results of the study showed allelopathic ...

  15. Evidence for an allelopathic interaction between rye and wild oats.

    Science.gov (United States)

    Macías, Francisco A; Oliveros-Bastidas, Alberto; Marín, David; Chinchilla, Nuria; Castellano, Diego; Molinillo, José M G

    2014-10-01

    Allelopathy is a biological phenomenon in which an organism produces one or more biochemicals that influence the growth, survival, and reproduction of other organisms. Allelopathy has been the subject of a great deal of research in chemical ecology since the 1930s. The characterization of the factors that influence this phenomenon has barely been explored, mainly due to the complexity of this area. The main aim of the research carried out to date has been to shed light on the importance of these interactions in agroecosystems, especially in relation to the interactions between crops and weeds. Herein we report the characterization of a complete allelochemical pathway involving benzoxazinones, which are known to participate in allelopathic plant defense interactions of several plants of high agronomic interest. The production of the defense chemicals by a donor plant (crop), the route and transformations of the chemicals released into the environment, and the uptake and phytotoxic effects on a target plant (weed) were all monitored. The results of this study, which is the first of its kind, allowed a complete dynamic characterization of the allelopathic phenomenon for benzoxazinones.

  16. A Case Study of Allelopathic Effect on Weeds in Wheat

    Directory of Open Access Journals (Sweden)

    Slaveya T. Petrova

    2015-06-01

    Full Text Available Most powerful and effective method of weed control is by chemical substances called herbicides. In recent years, they were published quite data on different side effects of herbicides on humans, animals, crops and the environment as a whole. Therefore, the increased interest for biological weed control lately is reasonable, since its improvement and expansion will contribute to limiting excessive use of herbicides, respectively their harmful effects and will support the successful implementation of complex weed control. The purpose of this study was to investigate the effect of selected plant species, containing allelopathic active substances, on germination, growth and biomass of some widespread weeds in wheat. Experiments were carried out at laboratory conditions using seeds of wheat (Triticum aestivum L., sort Sadovo 1 and most common weeds therein: Johnson grass (Sorghum halepense (L Pers, white pigweed (Chenopodium album L., twitch (Cynodon dactylon L. and curly dock (Rumex crispus L.. Allelopathic substances were extracted with distilled water from flowers of lavender (Lavandula angustifolia Mill., leaves of basil (Ocimum basilicum L., leaves of spearmint (Mentha longifolia (L Huds., and leaves of peppermint (Mentha piperita L.. Of the tested active allelopathic plants, the most negative impact on germination of all weeds seeds (including wheat, as well as on the development of plants exhibited the water extract of lavender. Lavender and basil had a stronger negative effect on white pigweed and twitch compared with both mint species. A significant inhibitory effect of spearmint even at low concentrations was recorded on the germination of all weed species tested while the wheat was slightly affected, which manifests this plant as a potential effective species in strategies for weed control management.

  17. Relationship Between Allelopathic Effects and Functional Traits of Different Allelopathic Potential Rice Accessions at Different Growth Stages

    Directory of Open Access Journals (Sweden)

    Xu Gaofeng

    2018-01-01

    Full Text Available In this study, effects of temperature, light and their interactions on allelopathic effects and the functional traits specific leaf area (SLA and stem mass fraction (SMF of different allelopathic potential rice accessions at different growth stages were analyzed. The main results were as follows: Allelopathic responses to temperature and light varied with different allelopathic potential rice accessions at different growth stages. With the rise of temperature and the extension of photoperiod, allelopathic effect increased firstly and then decreased at 2–3 leaf stage, but increased constantly at the 4–5 and 7–8 leaf stages in strong allelopathic rice accessions [O. longistaminata, F1 (O. longistaminata × RD23, F2 (RL159 and RL169]. Temperature had significant impact on allelopathic effect without considering light factors, but light showed little effect on rice allelopathy at the same temperature conditions. The greatest allelopathic effect was attained with moderate temperature and long photoperiod at 2–3 leaf stage in strong allelopathic rice accessions, but all the rice accessions showed weak allelopathic effects at the low temperature condition (15 °C/10 °C, and the influence of different factors on allelopathy followed a general trend as temperature > leaf stage > light, indicating that among the multiple factors impacting rice allelopathy, temperature was the main factor. Allelopathic characteristics of F1 and F2 to various temperature and light were similar to O. longistaminata, showing that allelopathic genes from wild rice can be expressed in its descendants. Temperature and light also had significant effects on SLA and SMF, and rice allelopathy was closely correlative to SLA in strong allelopathic rice accessions at the 4–5 and 7–8 leaf stages, but there was no correlation between rice allelopathy and SMF at different growth stages. These results suggested that rice adjust the relationship between allelopathy and SLA

  18. Unravelling the beneficial role of microbial contributors in reducing the allelopathic effects of weeds.

    Science.gov (United States)

    Mishra, Sandhya; Upadhyay, Ram Sanmukh; Nautiyal, Chandra Shekhar

    2013-07-01

    The field of allelopathy is one of the most fascinating but controversial processes in plant ecology that offers an exciting, interdisciplinary, complex, and challenging study. In spite of the established role of soil microbes in plant health, their role has also been consolidated in studies of allelopathy. Moreover, allelopathy can be better understood by incorporating soil microbial ecology that determines the relevance of allelopathy phenomenon. Therefore, while discussing the role of allelochemicals in plant-plant interactions, the dynamic nature of soil microbes should not be overlooked. The occurrence and toxicity of allelochemicals in soil depend on various factors, but the type of microflora in the surroundings plays a crucial role because it can interfere with its allelopathic nature. Such microbes could be of prime importance for biological control management of weeds reducing the cost and ill effects of chemical herbicides. Among microbes, our main focus is on bacteria--as they are dominant among other microbes and are being used for enhancing crop production for decades--and fungi. Hence, to refer to both bacteria and fungi, we have used the term microbes. This review discusses the beneficial role of microbes in reducing the allelopathic effects of weeds. The review is mainly focused on various functions of bacteria in (1) reducing allelopathic inhibition caused by weeds to reduce crop yield loss, (2) building inherent defense capacity in plants against allelopathic weed, and (3) deciphering beneficial rhizospheric process such as chemotaxis/biofilm, degradation of toxic allelochemicals, and induced gene expression.

  19. Allelopathic potential of extracts the from marine macroalga Plocamium brasiliense and their effects on pasture weed

    Directory of Open Access Journals (Sweden)

    Rainiomar Raimundo da Fonseca

    2012-08-01

    Full Text Available Four extracts from the marine red alga Plocamium brasiliense (Greville M.A.Howe & W.R.Taylor were prepared to identify and characterize their potential allelopathic effects on seed germination, radicle elongation and hypocotyl development of the weeds Mimosa pudica L. and Senna obtusifolia (L. Irwin & Barneby. The four extracts were prepared in a sequence of solvents of increasing polarity: n-hexane, dichloromethane, ethyl acetate and ethanol/water (7:3. The germination bioassay was carried out at 25 °C with a 12 h photoperiod and the radicle elongation and hypocotyl development at 25 °C with a 24 h photoperiod. The dichloromethane extract showed inhibitory effects on seed germination of both plants (35 and 14%, respectively, in M. pudica and S. obtusifolia, radical germination (52 and 41.7%, respectively and hypocotyl development (17.1 and 25.5%, respectively. Given the high sensitivity of this parameter to the potential allelopathic effects and the insufficient number of references found in the literature, these results are expected to stimulate new tests with other species of marine algae. Given the high sensitivity of the method for the detection of allelopathic potential, the species P. brasiliense emerges as a possible source of allelopathic substances against weed species. The results are attributed to the chemical composition, especially in relation to the presence of halogenated monoterpenes.

  20. Allelopathic potential of extracts the from marine macroalga Plocamium brasiliense and their effects on pasture weed

    Directory of Open Access Journals (Sweden)

    Rainiomar Raimundo da Fonseca

    2012-05-01

    Full Text Available Four extracts from the marine red alga Plocamium brasiliense (Greville M.A.Howe & W.R.Taylor were prepared to identify and characterize their potential allelopathic effects on seed germination, radicle elongation and hypocotyl development of the weeds Mimosa pudica L. and Senna obtusifolia (L. Irwin & Barneby. The four extracts were prepared in a sequence of solvents of increasing polarity: n-hexane, dichloromethane, ethyl acetate and ethanol/water (7:3. The germination bioassay was carried out at 25 °C with a 12 h photoperiod and the radicle elongation and hypocotyl development at 25 °C with a 24 h photoperiod. The dichloromethane extract showed inhibitory effects on seed germination of both plants (35 and 14%, respectively, in M. pudica and S. obtusifolia, radical germination (52 and 41.7%, respectively and hypocotyl development (17.1 and 25.5%, respectively. Given the high sensitivity of this parameter to the potential allelopathic effects and the insufficient number of references found in the literature, these results are expected to stimulate new tests with other species of marine algae. Given the high sensitivity of the method for the detection of allelopathic potential, the species P. brasiliense emerges as a possible source of allelopathic substances against weed species. The results are attributed to the chemical composition, especially in relation to the presence of halogenated monoterpenes.

  1. Background chemistry for chemical warfare agents and decontamination processes in support of delisting waste streams at the U.S. Army Dugway Proving Ground, Utah

    Energy Technology Data Exchange (ETDEWEB)

    Rosenblatt, D.H.; Small, M.J.; Kimmell, T.A.; Anderson, A.W.

    1996-04-01

    The State of Utah, Department of Environmental Quality (DEQ), Division of Solid and Hazardous Waste (DSHW), has declared residues resulting from the demilitarization, treatment, cleanup, and testing of military chemical agents to be hazardous wastes. These residues have been designated as corrosive, reactive, toxic, and acute hazardous (Hazardous Waste No. F999). The RCRA regulations (40 Code of Federal Regulations [CFR] 260-280), the Utah Administrative Code (R-315), and other state hazardous waste programs list specific wastes as hazardous but allow generators to petition the regulator to {open_quotes}delist,{close_quotes} if it can be demonstrated that such wastes are not hazardous. The U.S. Army Test and Evaluation Command (TECOM) believes that certain categories of F999 residues are not hazardous and has obtained assistance from Argonne National Laboratory (Argonne) to make the delisting demonstration. The objective of this project is to delist chemical agent decontaminated residues resulting from materials testing activities and to delist a remediation residue (e.g., contaminated soil). To delist these residues, it must be demonstrated that the residues (1) do not contain hazardous quantities of the listed agents; (2) do not contain hazardous quantities of constituents listed in 40 CFR Part 261, Appendix VIII; (3) do not exhibit other characteristics that could define the residues as hazardous; and (4) do not fail a series of acute toxicity tests. The first phase will focus on a subset of the F999 wastes generated at the U.S. Army Dugway Proving Ground (DPG), where the Army tests the effects of military chemical agents and agent-decontamination procedures on numerous military items. This effort is identified as Phase I of the Delisting Program. Subsequent phases will address other DPG chemical agent decontaminated residues and remediation wastes and similar residues at other installations.

  2. Isolation and identification of an allelopathic substance in Pisum sativum.

    Science.gov (United States)

    Kato-Noguchi, Hisashi

    2003-04-01

    The residue of peas (Pisum sativum L.) has allelopathic activity and the putative compound causing this inhibitory effect was isolated from a methanol extract of pea shoots. Chemical structure of this compound was determined by high-resolution MS, IR and 1H NMR spectral data as pisatin. Pisatin inhibited growth of cress (Lepidium sativum L.) and lettuce (Lactuca sativa L.) seedlings at concentrations greater than 10 and 30 microM, respectively. The doses required for 50% growth inhibition of roots and hypocotyls of cress were 61 and 91 microM, respectively, and those of lettuce were 78 and 115 microM, respectively. The concentration of pisatin in the pea shoots was 32.7 nmol x g(-1) fresh weight. The effectiveness of pisatin on growth inhibition in cress and lettuce, and its occurrence in pea shoots suggest that it may contribute to the growth inhibitory effect of pea residue, and may play an important role in pea allelopathy.

  3. Allelopathic assessment of selected common weeds in Malaysia

    Science.gov (United States)

    Nurul Ain, M. B.; Nornasuha, Y.; Ismail, B. S.

    2016-11-01

    A laboratory study was conducted to evaluate the allelopathic potential of eight common weed species in Malaysia, namely, Ageratum conyzoides, Tridax procumbens, Cyperus iria, Fimbristylis miliacea, Eleusine indica, Imperata cylindrica, Lygodium flexuosum and Nephrolepis biserrata of different morphological characteristics (broadleaves, sedges, grasses and ferns). The allelopathic study of these weeds was carried out by testing the leaf litter leachate through the Sandwich method and the volatile compounds of these weeds through the Dish pack method with three replicates for each donor species. The results obtained from both methods were statistically analyzed and the means had converted to percentage growth inhibition to determine the inhibition pattern on the radicle and hypocotyl growth of lettuce seedlings. Among the eight weed species tested, Ageratum conyzoides showed the strongest growth inhibition on lettuce radicle elongation (86%) in the sandwich bioassay compared to the control, followed by Tridax procumbens (71%), which both species being broadleaves weeds. In the dish pack bioassay Lygodium flexuosum (fern) demonstrated maximum inhibition on the growth the radicle and hypocotyl for each different distance from the source well. On the other hand, two weed species exhibited enhanced on the growth radicle and hypocotyl when compared to that of the control in dish pack bioassay. Nephrolepis biserrata and Fimbristylis miliacea were the species that showed the highest growth stimulatory effect. The results presented can be utilized as benchmark information for further research on the elucidation of leachates and volatile chemicals involved in allelopathy in nature. The information can also be helpful in the development of new bioactive chemicals from natural products in weed control strategies.

  4. Allelopathic studies on milk thistle (Silybum marianum

    Directory of Open Access Journals (Sweden)

    Shamima Sultana

    2012-06-01

    Full Text Available Declining crop yield due to weeds and their resistance to herbicides are major constraint for successful crop productions. Milk thistle (Silybum marianum is common weed species in Australian cropping rotation. Allelopathic potentiality of milk thistle on different crops has been documented sporadically, but there is no literature on about ryegrass and canola. Therefore, a laboratory based allelopathic extracts bioassay was conducted. The hot water extracts was prepared from milk thistle plant parts added into water with ration of 1: 10 (plant sample: distilled water where mixture was heated 10 minutes. After heat treatment samples was immediately sieved and centrifuged and the resulted solution was treated as 100% concentration. Separately, to get the fresh water extract plant sample was added into water (1:10 and kept 24 hours in room temperature. After 24 hours, the sample was sieved and centrifuged and collected samples result was treated 100% concentrations. To obtain 50% concentration, both hot and fresh samples were diluted with distilled water. Therefore the experiment was conducted with five different treatment concentrations (0, 50% hot water extracts, 50% fresh water extracts, 100% hot water extracts and 100% fresh water extracts. The experiment was comprised with RCBD design with three replications under control conditions. During experimental period the allelopathic effects of donor species on germination and seedling growth of ryegrass and canola was observed. Results shows, germination and seedling growth of both receiver species are inhibited by milk thistle extracts. Extracts from fresh water at 100% was more toxic to receiver species followed by 50% concentration of fresh and 100% from hot water extracts. This concentration reduced the root, shoot growth of ryegrass and canola 84.971%, 84.269% and 89.898%, 87.394%, respectively. The result also revealed that allelopathic pattern of hot water extracts was same however; it is less

  5. Proving allelopathy in crop-weed interactions

    Science.gov (United States)

    Allelopathy (plant/plant chemical warfare) is difficult to prove, especially when competition for resources is the dominant component of plant/plant interference (interference = allelopathy +competition). This paper describes experimental approaches for proving allelopathy and points out common pit...

  6. Evaluation of allelopathic effect of Eclipta alba (L.) Hassk on ...

    African Journals Online (AJOL)

    VAIO

    Weed infestation is one of the major causes of yield reduction in crops. The incidence of allelopathic effect of ..... heliotrope (Heliotropium europaeum L.) allelochemicals and increased activity of antioxidant enzymes. ... Allelopathic effects of phenolic acids on nucleic acid and protein levels in soybean seedlings. Can. J. Bot.

  7. Allelopathic potential of selected rice varieties | Karim | African ...

    African Journals Online (AJOL)

    Average percent inhibition (API) in lettuce due to allelopathic effect of different rice varieties/lines was estimated. Under greenhouse conditions, double-pot technique was followed using barnyard grass (Echinochloa crusgalli L.) as indicator plant. The changes in barnyard grass plant charcters due to allelopathic effect of ...

  8. Allelopathic Effects of Lantana ( Lantana camara L.) Leaf Extracts on ...

    African Journals Online (AJOL)

    Allelopathic potential of aqueous extracts of lantana (Lantana camara L.) leaf on germination and growth of three agricultural crops: Maize, Finger millet and Tef, commonly cultivated in Ethiopia were studied under laboratory condition. The aqueous extracts were assayed at 5, 10, 25, 50 and 75% and their allelopathic ...

  9. UV-irradiation enhances rice allelopathic potential in rhizosphere soil

    DEFF Research Database (Denmark)

    Mahmood, Khalid; Khan, Muhammad Bismillah; Song, Yuan Yuan

    2013-01-01

    Ultraviolet-B radiation is rising continuously due to stratospheric ozone depletion over temperate latitudes. This study investigated effects of UV exposure on rice allelopathic potentials. For this purpose, two rice (Oryza sativa L.) cultivars BR-41 (high allelopathic = able to inhibit neighbori...

  10. Allelopathic effect of Bromus spp. and Lolium spp. shoot extracts on some crops.

    Science.gov (United States)

    Lehoczky, E; Nelima, M Okumu; Szabó, R; Szalai, A; Nagy, P

    2011-01-01

    Allelopathy is an untapped resource for weed control in crops that could give good possibilities for environmentally sound, integrated crop production. Allelopathy is defined as the direct or indirect harmful or beneficial effects of one plant on another through the production of chemical compounds, called allelochemicals, which escape into the environment. Allelochemicals can be produced by weeds and affect crops, and the reverse is also true. Allelopathic interactions include weed-weed, weed-crop, and crop-crop. Allelopathy offers potential for selective biological weed control for instance weed-suppressing crops and the use of plant residues in cropping systems, allelopathic rotational crops, or companion plants with allelopathic potential. Bromus species occur in many habitats in temperate regions of the world, including America, Eurasia, Australia, and Africa. The genus Lolium is one of the most important forage grasses. The weed species usually grow in the same production zones as wheat and are considered weeds since they parasitize wheat fields. Some of the weed species in these two genus have been reported to have allelopathic effect. One of the methods that has been successful in studying allelopathic activity are bioassays. Laboratory experiments were conducted to determine allelopathic effect of watery shoot extracts of four weed species of the Poaceae family, namely Bromus rigidus, Bromus diandrus, Lolium multiflorum and Lolium temulentum on germination and growth of winter wheat (Triticum aestivum L.), spring barley (Hordeum vulgare L.), corn (Zea mays L), perennial ryegrass (Lolium perenne L.), bean (Phaseolus sp.) and sunflower (Helianthus annuus L.) and on each other. The experiment was carried out during the period March 2010 to October 2010. Twenty five seeds were put into one Petri-dish on filter paper, adding 15ml of extract to each in four repeats. The germination took place in a Binder-type thermostat in the dark. The timing of germination was

  11. Atividade alelopática de substâncias químicas isoladas do Capim-Marandu e suas variações em função do pH Allelopathic activity of chemical substances isolated from Brachiaria brizantha cv. Marandu and their variations in function of pH

    Directory of Open Access Journals (Sweden)

    L.S. Santos

    2008-01-01

    Full Text Available Este trabalho teve por objetivos isolar, identificar e caracterizar a atividade alelopática de substâncias químicas produzidas pela Brachiaria brizantha cv. Marandu e determinar as variações na atividade dessas substâncias em função da variação do pH da solução. A atividade alelopática foi realizada em bioensaios de germinação e desenvolvimento da radícula e do hipocótilo, utilizando as plantas daninhas malícia (Mimosa pudica e mata-pasto (Senna obtusifolia como receptoras. Os efeitos do pH foram analisados na faixa de 3,0 a 9,0. Os triterpenos pentacíclicos friedelina e epifriedelinol isolados da parte aérea de B. brizantha apresentaram baixa atividade inibitória na germinação de sementes e no desenvolvimento da radícula e do hipocótilo das duas plantas daninhas. As duas substâncias apresentaram comportamento diferenciado em relação à variação do pH da solução, com inibições mais marcantes em relação à planta daninha mata-pasto.This work aimed to isolate, identify and determine the allelopathic activity of the chemical substances produced by Brachiaria brizantha cv. Marandu and to verify the effects of the pH in the solution on the activity of these compounds. The allelopathic activity was evaluated based on germination bioassays and radicle and hypocotyl growth using the species 'malícia' (Mimosa pudica and 'mata-pasto' (Senna obtusifolia as receptors. The effect of pH was analyzed in a range from 3.0 to 9.0. The pentacyclic triterpenes friedelin and epifriefelinol isolated from the shoots of B. brizantha showed a low inhibitory activity against seed germination and radicle and hypocotyl growth of the two receptor plants evaluated. The pentacyclic triterpenes friedelin and epifrifelinol presented differentiated behaviors in relation to the pH variation in the solution, with stronger inhibition activity against the weed 'mata-pasto'.

  12. On Mathematical Proving

    Science.gov (United States)

    Stefaneas, Petros; Vandoulakis, Ioannis M.

    2015-12-01

    This paper outlines a logical representation of certain aspects of the process of mathematical proving that are important from the point of view of Artificial Intelligence. Our starting-point is the concept of proof-event or proving, introduced by Goguen, instead of the traditional concept of mathematical proof. The reason behind this choice is that in contrast to the traditional static concept of mathematical proof, proof-events are understood as processes, which enables their use in Artificial Intelligence in such contexts, in which problem-solving procedures and strategies are studied. We represent proof-events as problem-centered spatio-temporal processes by means of the language of the calculus of events, which captures adequately certain temporal aspects of proof-events (i.e. that they have history and form sequences of proof-events evolving in time). Further, we suggest a "loose" semantics for the proof-events, by means of Kolmogorov's calculus of problems. Finally, we expose the intented interpretations for our logical model from the fields of automated theorem-proving and Web-based collective proving.

  13. Allelopathic activity of saponins exctracted from Rhododendron luteum Sweet

    Directory of Open Access Journals (Sweden)

    Iryna M. Yezhel

    2013-04-01

    Full Text Available Article deals with allelopathic activity of saponins exctracted from Rhododendron luteumSweet leaves. Investigations show nonlinear correlation between saponins concetration and growth of the roots of test-cultures.

  14. Allelopathic activities of Jasminum officinale f. var. grandiflorum ...

    African Journals Online (AJOL)

    Allelopathic activities of Jasminum officinale f. var. grandiflorum (Linn.) Kob.: Inhibition effects on germination, seed imbibition, and α-amylase activity induction of Echinochloa crus-galli (L.) Beauv.

  15. Sugarcane crop residue and bagasse allelopathic impact on oat (Avena sative L.), morningglory (Ipomoea purpurea L.), and redroot pigweed (Amaranthus retroflexus L.) germination

    Science.gov (United States)

    Allelopathy, the chemical interaction between plants, may result in the inhibition of plant growth and development, and can include compounds released from a crop that adversely impact crop or weed species. The objective of this research was to determine the allelopathic impact of sugarcane (Sacchar...

  16. Allelopathic potential of a noxious weed on mung bean

    Directory of Open Access Journals (Sweden)

    Parthapratim Maiti

    2013-10-01

    Full Text Available Eupatorium odoratum have invaded the waste lands of South West Bengal, India. A field study indicated a gradual and also significant increase in Eupatorium odoratum accompanied with significant decrease in other coexisting species. Considering the above in mind, a study was undertaken to evaluate the existence of inhibitory effect of leaf extracts and leaf leachates noxious weed Eupatorium odoratum using fully viable seeds of mung bean (Vigna radiata as the bioassay material. The study showed the reduced the percentage germination and TTC stainability along with extended T50 values of mung bean seeds. The levels of protein, DNA and RNA, activities of dehydrogenase and catalase enzymes were significantly retarded in pretreated seed samples. Amino acid and sugar levels were increased in the leachates of seeds pretreated with leaf extracts and leaf leachates. Thus, from the overall results it can be concluded that various inhibitors present in E. odoratum can impart strong inhibitory effect on mung bean. The study suggests that the leaves of E. odoratum possess phytotoxic or allelopathic chemicals which potentially rendered the inhibitory action on mung bean seeds.

  17. Allelopathic potential of Chromolaena odorata and Mikania micrantha on Brassica chinensis var. parachinensis

    Science.gov (United States)

    Yusoff, Nornasuha; Ismail B., S.

    2015-09-01

    Laboratory and greenhouse experiments were conducted to study the allelopathic potential of the aqueous leaf extract and leaf debris (incorporated into the soil) of Chromolaena odorata and Mikania micrantha on the germination indices and growth as well as the allelopathic effect response index of Brassica chinensis. Three concentrations each of the aqueous leaf extract (12.5, 25.0 and 50.0 g/L) and leaf debris (2.5, 5.0 and 10.0 g/500 g soil) were used in the experiments. The treatments were arranged in a Completely Randomized Design (CRD) with three replications, and the experiment was conducted twice. The aqueous leaf extracts of both species significantly inhibited all growth parameters of B. chinensis at 50.0 g/L concentration by more than 50% (compared to that by the control). In contrast, the leaf debris of both species at most of the concentrations showed significant stimulatory effects on all growth parameters of B. chinensis. However, M. micrantha leaf debris showed no significant effect on the fresh weight of B. chinensis at all concentrations. The total germination percentage of B. chinensis was significantly decreased as concentration of the aqueous leaf extracts of both species increased. The aqueous leaf extract of both species at concentrations higher than 25.0 g/L, significantly reduced the initial speed of germination as well as the cumulative speed of germination of B. chinensis. The allelopathic effect response index was negative for both species, indicating that the extracts of both species have inhibitory effects on the germination and seedling growth of B. chinensis. Results from the study suggested that the leaves of C. odorata and M. micrantha have phytotoxic properties and have potential for use directly or indirectly on susceptible weeds, and thereby reducing the use of chemical pesticides.

  18. Total synthesis and allelopathic activity of cytosporones A-C

    Energy Technology Data Exchange (ETDEWEB)

    Zamberlam, Charles E.M.; Meza, Alisson; Lima, Denis P. de; Beatriz, Adilson [Centro de Ciencias Exatas e Tecnologia, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS (Brazil); Leite, Carla Braga; Marques, Maria Rita [Centro de Ciencias Biologicas e da Saude, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS (Brazil)

    2012-07-01

    The search for efficient, environmentally friendly herbicides has been the focus of numerous studies on the organic synthesis of compounds isolated from natural sources. Cytosporones, which are phenolic lipids isolated from fungi, exhibit noteworthy biological properties. This paper reports the preparation of cytosporones A-C from the same starting material through a short synthetic route, with good yields. All compounds were tested for allelopathic activity on lettuce (Lactuca sativa L) seeds. Cytosporone A and its methylated precursor showed remarkable allelopathic activity, inhibiting seed germination and plantule growth. (author)

  19. Allelopathic potential of Asarum europaeum toward Lycopersicon esculentum

    Directory of Open Access Journals (Sweden)

    Monica MARIAN

    2011-05-01

    Full Text Available Asarum europaeum L. contains water-soluble substances which manifest allelopathic potential. Aqueous extracts from leaves and stems of Asarum europaeum were assayed to determine their allelopathic effects on Lycopersicon esculentum and Zea mays seeds germination and early seedling growth. The germination of the investigated seeds was found to be inhibited with increasing of the Asarum europaeum L. extract concentration. Moreover, the active substances extracted from leaves were found to be more inhibitory on the seeds germination in comparison with those extracted from stems.

  20. Evaluation of the allelopathic potential of water-soluble compounds of barley (Hordeum vulgare L. subsp.vulgare and great brome (Bromus diandrus Roth. using a modified bioassay

    Directory of Open Access Journals (Sweden)

    Bouhaouel, I.

    2016-01-01

    Full Text Available Description of the subject. The present study focuses on the description of the allelopathic interactions between wild and crop species that may occur in a given ecosystem. Objectives. The objective is the evaluation of the allo- and autoinhibition activity of root exudates of barley (Hordeum vulgare L. subsp. vulgare and great brome (Bromus diandrus Roth. seedlings by water-soluble allelochemicals. Method. The allelopathic activities of five Tunisian barley genotypes (modern varieties and landraces, one Saudi Arabian barley landrace and great brome were assessed using a modified laboratory bioassay named "seedling-after-seedling agar method". Results. The barley or the great brome reduced, to a greater extent, the root growth compared to the shoot growth of receiver species. The response of the root system architecture of the great brome towards barley root exudates was studied in detail. All the measured root traits were highly sensitive to the presence of barley. In our conditions, the allelopathic activity of barley root exudates had no apparent relationship with the size of the root and a prominent action of genetic determinants in the allelopathic potential between genotypes is proposed. The alloinhibitory activity of barley or great brome root exudates deferred between the receiver species but was always higher than the autoinhibition potential. The autoinhibition in barley proved to depend on whether the genotypes used as donor and receiver are identical or different, suggesting a specific interaction of allelochemicals with the receiver plant. These molecules seem to be the main actors in the allelopathic barley potential as external factors such variations of pH have no evident relevance in the inhibition process. Conclusions. Barley and great brome exude molecules in their surroundings. This affects the growth of the receiver plants, suggesting that these compounds might contribute to the plant community dynamics.

  1. Interactive Theorem Proving and Verification

    Indian Academy of Sciences (India)

    Research in the area of automated reasoning is largely concentrated around two major themes – Automated Theorem Proving and Interactive Theorem Proving. The goal of Auto- mated Theorem Proving, as the name suggests, is to try to prove a wide range of mathematical theorems using a computer in an automatic ...

  2. Allelopathic interactions between the brown algal genus Lobophora (Dictyotales, Phaeophyceae) and scleractinian corals.

    Science.gov (United States)

    Vieira, Christophe; Thomas, Olivier P; Culioli, Gérald; Genta-Jouve, Grégory; Houlbreque, Fanny; Gaubert, Julie; De Clerck, Olivier; Payri, Claude E

    2016-01-05

    Allelopathy has been recently suggested as a mechanism by which macroalgae may outcompete corals in damaged reefs. Members of the brown algal genus Lobophora are commonly observed in close contact with scleractinian corals and have been considered responsible for negative effects of macroalgae to scleractinian corals. Recent field assays have suggested the potential role of chemical mediators in this interaction. We performed in situ bioassays testing the allelopathy of crude extracts and isolated compounds of several Lobophora species, naturally associated or not with corals, against four corals in New Caledonia. Our results showed that, regardless of their natural association with corals, organic extracts from species of the genus Lobophora are intrinsically capable of bleaching some coral species upon direct contact. Additionally, three new C21 polyunsaturated alcohols named lobophorenols A-C (1-3) were isolated and identified. Significant allelopathic effects against Acropora muricata were identified for these compounds. In situ observations in New Caledonia, however, indicated that while allelopathic interactions are likely to occur at the macroalgal-coral interface, Lobophora spp. rarely bleached their coral hosts. These findings are important toward our understanding of the importance of allelopathy versus other processes such as herbivory in the interaction between macroalgae and corals in reef ecosystems.

  3. Allelopathic interference of aqueous extracts of chinaberry on the germination and initial growth of tomato

    Directory of Open Access Journals (Sweden)

    Lindamir Hernandez Pastorini

    2012-09-01

    Full Text Available Allelopathy effects vegetative development and is caused by chemical substances produced and released by surrounding plants. The objective of this work was to investigate the allelopathic activity of aqueous extracts of fresh and dried leaves and fruits of chinaberry (Melia azedarach L. – Meliaceae on the germination and initial growth of tomato. The extracts were prepared at concentrations of 1, 2 and 4% and analyzed for their pH and osmotic potential. The experiment consisted of four replications of 25 tomato seeds that were distributed in Petri dishes containing two sheets of germitest paper. Each plate received 2mL of an extract. The seeds were evaluated for percentage of germination (PG, germination rate (VG and germination speed index (IVG. The initial growth was assessed based on the length of the radicle, hypocotyl and leaf, and fresh and dry weight. All concentrations of the extracts exhibited inhibitory activity on germination and radicle growth, and the inhibitory effect increased as the concentration of the extract increased. Extracts from dried leaves had the greatest effects. The osmotic potential and pH of the extracts did not vary significantly compared to the control, indicating that the allelopathic effect was due to the allelochemicals in the extracts.

  4. Interspecific competition and allelopathic interaction between Karenia mikimotoi and Dunaliella salina in laboratory culture

    Science.gov (United States)

    He, Dong; Liu, Jiao; Hao, Qiang; Ran, Lihua; Zhou, Bin; Tang, Xuexi

    2016-03-01

    Algal allelopathy is a manifold ecological/physiological phenomenon that is focused on chemical interactions and autotoxicity. We investigated the allelopathic interactions between Karenia mikimotoi and Dunaliella salina in laboratory cultures based on diff erent temperature (15°C, 20°C, and 25°C) and lighting (40, 80, and 160 μmol/(m2·s)) conditions. The growth of D. salina in bi-algae culture (1:1 size/density) was significantly restrained. The results of cell-free filtrate culture indicate that direct cell-tocell contact was not necessary in interspecific competition. Further experimental results demonstrated that allelochemicals released from K. mikimotoi were markedly influenced by both temperature ( P =0.013) and irradiance ( P =0.003), resulting in diff erent growth characteristics of D. salina in filtrate mediums. Compared with the plateau period, K. mikimotoi exudates in the exponential phase had a stronger short-term inhibition effect on D. salina in normal conditions. A clear concentration-dependent relationship was observed in the effect of allelochemicals released from K. mikimotoi with low-promoting and high-repressing effects on D. Salina in a short time-scale. In addition, allelopathic substances remain stable and effective under high temperature and pressure stress. Many flocculent sediments adhering with D. salina cells were observed in all filtrate mediums, while the quantity and color depended on the original culture conditions.

  5. Allelopathic interactions between the brown algal genus Lobophora (Dictyotales, Phaeophyceae) and scleractinian corals

    Science.gov (United States)

    Vieira, Christophe; Thomas, Olivier P.; Culioli, Gérald; Genta-Jouve, Grégory; Houlbreque, Fanny; Gaubert, Julie; de Clerck, Olivier; Payri, Claude E.

    2016-01-01

    Allelopathy has been recently suggested as a mechanism by which macroalgae may outcompete corals in damaged reefs. Members of the brown algal genus Lobophora are commonly observed in close contact with scleractinian corals and have been considered responsible for negative effects of macroalgae to scleractinian corals. Recent field assays have suggested the potential role of chemical mediators in this interaction. We performed in situ bioassays testing the allelopathy of crude extracts and isolated compounds of several Lobophora species, naturally associated or not with corals, against four corals in New Caledonia. Our results showed that, regardless of their natural association with corals, organic extracts from species of the genus Lobophora are intrinsically capable of bleaching some coral species upon direct contact. Additionally, three new C21 polyunsaturated alcohols named lobophorenols A-C (1-3) were isolated and identified. Significant allelopathic effects against Acropora muricata were identified for these compounds. In situ observations in New Caledonia, however, indicated that while allelopathic interactions are likely to occur at the macroalgal-coral interface, Lobophora spp. rarely bleached their coral hosts. These findings are important toward our understanding of the importance of allelopathy versus other processes such as herbivory in the interaction between macroalgae and corals in reef ecosystems.

  6. Differential sensitivity of green algae to allelopathic substances from Chara

    NARCIS (Netherlands)

    Mulderij, G.; Van Donk, E.; Roelofs, J.

    2003-01-01

    Three short-term laboratory experiments were conducted to investigate allelopathic effects of a mixture of Chara globularis var. globularis Thuillier and Chara contraria var. contraria A. Braun ex Kützing on three different green algae. Single phytoplankton species were exposed to filtered water

  7. Autotoxicity of chard and its allelopathic potentiality on germination ...

    African Journals Online (AJOL)

    SERVER

    2008-04-03

    Apr 3, 2008 ... Plants used were sampled in 2006, and then plant extracts were obtained after they were ... soluble extract of whole chard plant residue revealed the presence of eight phenolic aglycones that ... diaceae species produce allelopathic compounds; in .... seeds and wheat grains contain different food reserves,.

  8. Allelopathic appraisal effects of straw extract wheat varieties on the ...

    African Journals Online (AJOL)

    hope&shola

    2010-11-29

    Nov 29, 2010 ... or indirectly from live or dead parts and cause allelopathic and phytotoxic effects. In Kerman province of Iran, cultivating corn after winter wheat usually causes .... created by using excel software to show the difference between treatments graphically. The statistical analysis program used was. MSTAT-C.

  9. Allelopathic potential of some biocontrol agents for the control of ...

    African Journals Online (AJOL)

    The adverse effect of synthetic pesticides on human health and the natural ecosystem necessitate the need to explore natural mechanisms of disease control in plants. This study evaluated the allelopathic potential of five biocontrol agents: Trichoderma longibrachiatum, Trichoderma asperellum, Bacillus subtilis, Bacillus ...

  10. Evaluation of allelopathic effect of Eclipta alba (L.) Hassk on ...

    African Journals Online (AJOL)

    VAIO

    The reduction may be due to the allelochemicals present in E. alba leaves. Key words: Allelochemicals, aqueous leachate, organic fractions, chlorophyll content, carbohydrate content,. Eclipta alba. INTRODUCTION. Weed infestation is one of the major causes of yield reduction in crops. The incidence of allelopathic effect of.

  11. Allelopathic potential of some biocontrol agents for the control of ...

    African Journals Online (AJOL)

    user

    2015-02-11

    Feb 11, 2015 ... need to explore natural mechanisms of disease control in plants. This study evaluated the allelopathic potential of five biocontrol agents: Trichoderma longibrachiatum, Trichoderma asperellum, Bacillus subtilis, Bacillus cereus and Pseudomonas fluorescens in the control of six fungal pathogens associated ...

  12. Assessment of allelopathic potential of selected medicinal plants of ...

    African Journals Online (AJOL)

    Inula falconeri, Inula koelzii, Lactuca dissecta and Anthemis nobilis were collected from Himalaya and Hindukush ranges of Pakistan and their allelopathic effect was studied through Sandwich and Homogenated Sandwich methods. The study also aimed at analyzing whether method and concentration can affect the overall ...

  13. Potential allelopathic effects of sunflower ( Helianthus annuus L. ) on ...

    African Journals Online (AJOL)

    Potential allelopathic effects of sunflower (Helianthus annuus L.) cultivar Hysun 38 on Rhizobium, Azospirillum, and phosphate-solubilizing bacteria (PSB) were studied by applying oxidase, QTS tests and Gram staining. Microorganisms for the control group were isolated from soil sampled before sowing sunflower.

  14. Allelopathic potential of Jatropha curcas | Ma | African Journal of ...

    African Journals Online (AJOL)

    Aqueous extracts of Jatropha curcas leaves and roots inhibited the growth of corn (Zea mays L.) and tobacco (Nicotiana tabacum L.). Increased inhibition by increasing the concentration of extracts suggests that the extracts may have inhibitory substance which possesses allelopathic potential. Different extracts of leaves ...

  15. Allelopathic Effects of Chromolaena Odorata L. (R. M. King and ...

    African Journals Online (AJOL)

    Allelopathic effects of Chromolaena odorata L. (R. M. KING AND ROBINSON) aqueous leaf extract and residues incorporated in the soil on the growth and water status of Lycopersicon esculentum Mill were studied. Significant growth reductions in Lycopersicon esculentum were observed from additions of C. odorata ...

  16. Allelopathic effect of meskit ( Prosopis juliflora (Sw.) DC) aqueous ...

    African Journals Online (AJOL)

    Phytoinhibitory effect of Prosopis juliflora aqueous extracts on tropical crops were tested under laboratory conditions. Maize, Cotton, and forage grasses (Rodus and Panicum) were used as test plants. Litter fall and under canopy soils were tested for checking allelopathic effects under natural conditions. All the extracts ...

  17. Allelopathic potential, seed ecology and germination of the ...

    African Journals Online (AJOL)

    Seriphium plumosum encroachment in South Africa has converted extensive areas of grassland into less productive shrubland-grassland. In addition to its competitive ability, it is hypothesised that the encroachment of S. plumosum is linked to the allelopathic potential of the plant. Interference between S. plumosum and four ...

  18. Evaluation of allelopathic potential of some selected medicinal species

    African Journals Online (AJOL)

    GREGORY

    2010-09-13

    Sep 13, 2010 ... Laboratory trials were made to evaluate the allelopathic potential of selected medicinal species. The aqueous extracts bioassay on two test plants (wheat and pea) was carried out through filter paper method. Toxicity and non toxicity was assessed by recording their effects on germination and percentage ...

  19. The allelopathic effects of crude water extracts of Annona muricata ...

    African Journals Online (AJOL)

    Annona muricata (sour sop) belongs to the family Annonaceae. This plant inhibits the growth of other plants growing around it, a phenomenon called “allelopathic effect”. Allelopathy is the production of specific biomolecules by plant species mostly secondary metabolites that can induce suffering or give benefit to other plant ...

  20. Allelopathic potentials of residues of 6 brassica species on ...

    African Journals Online (AJOL)

    Johnsongrass ( Sorghum halepense (L.) Pers.) is a troublesome weed species of many crops in Turkey as well as worldwide. Allelopathic potential of residues of some brassica species, which are round white radish (Raphanus sativus L.), garden radish (R. sativus L.), black radish (R. sativus L. var. niger), little radish (R.

  1. Interspecific variation in the allelopathic potential of the family Myrtaceae

    Directory of Open Access Journals (Sweden)

    Maristela Imatomi

    2013-03-01

    Full Text Available Allelopathy is a type of biotic interference wherein a plant releases bioactive metabolites into an environment, thereby affecting the adjacent biota. Stressful environments stimulate the production of these metabolites. The present study tests the novel weapons hypothesis, which postulates that species belonging to the same genus and from the same environment have similar allelopathic effects. The aim of this study was to assess the allelopathic effects that the aqueous leaf extracts of 15 species belonging to five genera of the Myrtaceae family have on the seed germination and initial seedling growth of lettuce (Lactuca sativa L., tomato (Solanum lycopersicum L. and onion (Allium cepa L.. Germination rates, average germination times, informational entropy of germination and allelopathic effects, as quantified with a response index, were calculated. A taxonomic distance matrix based on Gower dissimilarity and a Euclidean distance matrix were constructed. The results revealed that all extracts from donor species significantly increased average germination time or reduced the germination rate of eudicotyledonous plant species. The only extracts that showed no effect on monocotyledonous seeds were those of Campomanesia pubescens O. Berg and Psidium cinereum Mart. We conclude that eudicotyledonous and monocotyledonous plants were both significantly affected by the presence of all extracts tested. Our results make it clear that each species behaves distinctly in relation to allelopathic activity, with no apparent grouping by genus or subtribe. Therefore, the hypothesis was rejected, because plants from the same environment and with taxonomic proximity do not necessarily display similar production of secondary metabolites.

  2. Physiological basis for allelopathic potential of different wheat ...

    African Journals Online (AJOL)

    The relationship between fluorescence kinetics and allelopathic expression of four winter-wheat ecotypes in heading period was discussed. With the breeding history from No. 1 Bima, No. 3 Fengchan, No. 1 Ningdong to No 22 Xiaoyan and agronomic properties of winter wheat like thousand seed weight and yield, etc ...

  3. Allelopathic potential of Anagalis arvensis L. | Ehsan | African ...

    African Journals Online (AJOL)

    Anagalis arvensis L. (Primulaceae) is a common cultivating weed, forming dense populations of undergrowth in warm and temperate regions of Pakistan. Allelopathic studies with aqueous extracts from whole plant including leaves, flowers, shoot and roots; litter and mulch in various experiments invariably reduced the ...

  4. Physiological basis for allelopathic potential of different wheat ...

    African Journals Online (AJOL)

    Jane

    2011-08-29

    Aug 29, 2011 ... furthermore, photosynthesis system PSII would be expressed superiorly under arid press. .... photochemical quenching of chlorophyll fluorescence as qN and ... Figure 2. Partial growth parameters of four wheat ecotypes in heading period. Figure 3. Allelopathic inhibition of four wheat ecotypes in heading ...

  5. Allelopathic Effect of Meskit (Prosopis juliflora (Sw.) DC) Aqueous ...

    African Journals Online (AJOL)

    Bheema

    plants. Litter fall and under canopy soils were tested for checking allelopathic effects under natural conditions. All the extracts ... and seedling growth of test crops. The effect of leaf extract was the highest, followed by litter ... IAS, but also a controversial resource and a serious threat to biodiversity. It has significant impacts on ...

  6. Allelopathic influence of aqueous extracts from the leaves of Morus alba L. on seed germination and seedling growth of Cucumis sativus L. and Sinapsis alba L.

    Directory of Open Access Journals (Sweden)

    Katarzyna Możdżeń

    2014-04-01

    Full Text Available The aim of the present study was to elucidate impact of the aqueous extracts from leaves of Morus alba L. on germination, growth and photosynthetic activity of Cucumis sativus L. and Sinapis alba L. Plants were grown for 21 days at the temperature 25°C (day and 18°C (night, within 12/12 hours photoperiod, light intensity 150 μmol·m-2·s-1 and relative humidity 60-70% (day/night. Our experiments proved that allelopathic compounds in aqueous extracts of the leaves M. alba at high concentrations, reduce power and energy of germination. Biometric analysis of seedlings and adult plants grown showed that allelopathic substances have stimulating or inhibiting function depending on the stage of treatment. Moreover, they cause changes in chlorophyll contents and activity of photosystem II (PS II.

  7. Allelopathic activity of medicinal plant essential oils on seed germination and vigor of lettuce achenes

    National Research Council Canada - National Science Library

    Cíntia Alvarenga Santos Fraga de Miranda; Maria das Graças Cardoso; Maria Laene Moreira de Carvalho; Samisia Maria Fernandes Machado; Marcos de Souza Gomes; Juliana de Andrade; Maria Luisa Teixeira

    2015-01-01

    In recent years, essential oils have gained commercial interest in the agricultural area, mainly for their allelopathic, insecticidal, antifungal, antimicrobial and antioxidant properties, and, also...

  8. Proceedings of the U.S. Army Chemical Research, Development and Engineering Center Scientific Conference on Chemical Defense Research Held in Aberdeen Proving Ground, Maryland on 14-17 November 1989

    Science.gov (United States)

    1990-08-01

    Scientific Conference on Chemical Defense Research, CRDEC-SP-013, Vol. 1, 407- 417 (1989). [4] C. D. Wagner, W. M. Riggs , L. E. Davis, J. F. Moulder, Handbook...requiring bioactivation to an ultimate carcinogenic form, some are thought to be direct acting genotoxic carcinogens while the sole apparent epigenetic

  9. Allelopathic potential of Hyptis suaveolens on physio-biochemical changes of mung bean seeds

    Directory of Open Access Journals (Sweden)

    Parthapratim Maiti

    2015-10-01

    Full Text Available Hyptis suaveolens is an exotic invasive weed in many areas of West Bengal, India. The allelopathic potential of leaf extracts and leachates of H. suaveolens was investigated on germination and metabolism of mung bean seeds (Vigna radiata cv. K851. The extracts and leachates reduced the germination and seed viability. The insoluble carbohydrates, proteins, and the activities of dehydrogenase and catalase enzymes were significantly reduced. Amino acid and soluble carbohydrate levels were increased in seeds pretreated with leaf extracts and leachates. The overall biochemical results indicate that various inhibitors present in H. suaveolens impart strong inhibitory effect on mung bean. The leaves of H. suaveolens possess phytotoxic chemicals, which potentially rendered the inhibitory action on mung bean seeds and provided key information for the proper management of H. suaveolens and other invasive weeds showing similar behavior.

  10. Isolation and identification of lepidimoide, a new allelopathic substance from mucilage of germinated cress seeds.

    Science.gov (United States)

    Hasegawa, K; Mizutani, J; Kosemura, S; Yamamura, S

    1992-10-01

    A new allelopathic substance that promoted the shoot growth of different plant species but inhibited the root growth was isolated as an amorphous powder from mucilage of germinated cress (Lepidium sativum L.) seeds. This substance was identified as sodium 2-O-rhamnopyranosyl-4-deoxy-threo-hex-4-enopyranosiduronate (designated lepidimoide) from the mass and the nuclear magnetic resonance and infrared spectra coupled with some chemical evidence. Lepidimoide promoted the hypocotyl growth of etiolated Amaranthus caudatus L. at concentrations higher than 3 mum and inhibited the root growth at concentrations higher than 100 mum. The growth-promoting activity in hypocotyls was 20 or 30 times as much as that of gibberellic acid.

  11. Antibacterial and allelopathic activity of extract from Castanea sativa leaves.

    Science.gov (United States)

    Basile, A; Sorbo, S; Giordano, S; Ricciardi, L; Ferrara, S; Montesano, D; Castaldo Cobianchi, R; Vuotto, M L; Ferrara, L

    2000-08-01

    Following the extraction of Castanea sativa with an aqueous solution of sulfuric acid (pH 3.0), the ethyl acetate soluble fraction was tested for its antibacterial and allelopathic activity. The extract was shown to have pronounced antibacterial effects against seven of the eight strains of Gram-positive and Gram-negative bacteria used (MIC in the range of 64-256 microg/ml and MBC in the range of 256-512 microg/ml). The active fraction was analyzed by TLC and HPLC showing the presence of rutin, hesperidin, quercetin, apigenin, morin, naringin, galangin and kaempferol. Standards of the identified flavonoids were tested against the same bacterial strains. The highest activity was shown by quercetin, rutin and apigenin. The allelopathic effect was tested against Raphanus sativus seed germination. The extract, quercetin, rutin and apigenin caused a decrease in the percentage of seed germination and root and epicotyl growth.

  12. [Allelopathic effects of companion weed Descurainia sophia on wheat].

    Science.gov (United States)

    Yang, Chao; Mu, Xiaoqian

    2006-12-01

    By using the techniques of laboratory bioassay, this paper studied the effects of Descurainia sophia extract on the germination rate, germination index, vigor index, root length, shoot height, fresh weight, and dry weight of wheat, and measured the contents of MDA, Chla/Chlb and carotene as well as the karyokinesis index of 5 more sensitive wheat strains. The results showed that D. sophia extract had allelopathic effects on all test wheat strains, though the responses of the strains were significantly different. The test 3 physiological indices of 5 more sensitive wheat strains suggested that the action spot of the allelopathic substances of D. sophia might be the cell membrane of wheat, and the measurement of karyokinesis index indicated that D. sophia extract had inhibitory effects on wheat karyokinesis.

  13. Allelopathic effects of orange (Citrus sinensis L.) peel essential oil

    OpenAIRE

    Ribeiro,Jose Pedro Nepomuceno; Lima,Maria Inês Salgueiro

    2012-01-01

    Crop weeds are the main problem in agriculture, causing a worldwide annual loss of about US$95 billion. The principal method for control is the use of synthetic herbicides. The continued use of these products increases crop costs, reduces crop quality, and leaves toxic residues in the environment, which are a threat to human and livestock health. Therefore, there is a demand for environmentally friendly methods of weed control. The use of allelopathic compounds from crop residues is an altern...

  14. Allelopathic potential of catechins of the Tachigali myrmecophyla (Leguminosae)

    OpenAIRE

    LÔBO, Lívia Trindade; CASTRO, Kelly Christina Ferreira; ARRUDA, Mara Silvia Pinheiro; SILVA, Milton Nascimento da; ARRUDA, Alberto Cardoso; MÜLLER, Adolfo Henrique; GUILHON, Giselle Maria Skelding Pinheiro; SANTOS, Alberdan Silva; SOUZA FILHO, Antonio Pedro da Silva

    2008-01-01

    Two compounds, (+)-catechin and epicatechin, were isolated from leaves of T. myrmecophyla, using chromatographic techniques. The structural identification was carried out on the basis of ¹H and 13C NMR spectral data and comparison with literature data. The compounds (+)-catechin and epicatechin were submitted to germination inhibition and radicle and hypocotyl growth assays. Results showed some significant activities confirming the initial hypothesis about allelopathic properties of that plant.

  15. Macroalgal terpenes function as allelopathic agents against reef corals.

    Science.gov (United States)

    Rasher, Douglas B; Stout, E Paige; Engel, Sebastian; Kubanek, Julia; Hay, Mark E

    2011-10-25

    During recent decades, many tropical reefs have transitioned from coral to macroalgal dominance. These community shifts increase the frequency of algal-coral interactions and may suppress coral recovery following both anthropogenic and natural disturbance. However, the extent to which macroalgae damage corals directly, the mechanisms involved, and the species specificity of algal-coral interactions remain uncertain. Here, we conducted field experiments demonstrating that numerous macroalgae directly damage corals by transfer of hydrophobic allelochemicals present on algal surfaces. These hydrophobic compounds caused bleaching, decreased photosynthesis, and occasionally death of corals in 79% of the 24 interactions assayed (three corals and eight algae). Coral damage generally was limited to sites of algal contact, but algae were unaffected by contact with corals. Artificial mimics for shading and abrasion produced no impact on corals, and effects of hydrophobic surface extracts from macroalgae paralleled effects of whole algae; both findings suggest that local effects are generated by allelochemical rather than physical mechanisms. Rankings of macroalgae from most to least allelopathic were similar across the three coral genera tested. However, corals varied markedly in susceptibility to allelopathic algae, with globally declining corals such as Acropora more strongly affected. Bioassay-guided fractionation of extracts from two allelopathic algae led to identification of two loliolide derivatives from the red alga Galaxaura filamentosa and two acetylated diterpenes from the green alga Chlorodesmis fastigiata as potent allelochemicals. Our results highlight a newly demonstrated but potentially widespread competitive mechanism to help explain the lack of coral recovery on many present-day reefs.

  16. Cytotoxic and molecular impacts of allelopathic effects of leaf residues of Eucalyptus globulus on soybean (Glycine max

    Directory of Open Access Journals (Sweden)

    Hala M. Abdelmigid

    2017-12-01

    Full Text Available Eucalyptus trees litter plays a crucial role in structuring plant populations and regulating crop quality. To help characterize the allelopathic impact of Eucalyptus plantations and understand the interactions between tree litter and understorey plant populations, we performed two different genomic approaches to determine soybean (Glycine max crop plant response to biotic stress induced by leaf residues of Eucalyptus globulus trees. For assessing cell death, a qualitative method of DNA fragmentation test (comet assay was employed to detect cleavage of the genomic DNA into oligonucleosomal fragments and help to characterize the apoptotic event among the experimental samples. In addition, quantitative method of genome analysis at the transcriptional level also was conducted to investigate the expression responses of soybean genome to allelochemicals. Expression of specific genes, which are responsible for the breakdown of proteins during programmed cell death PCD (cysteine proteases and their inhibitors, was examined using semi-quantitative RT-PCR (sqPCR. Results of both conducted analyses proved significant genetic effects of Eucalyptus leaf residues on soybean crop genome, revealed by steady increase in DNA damage as well as variation in the transcript levels of cysteine proteases and inhibitors. Further detailed studies using more sensitive methods are necessary for a comprehensive understanding of the allelopathic effects of Eucalyptus plantations on crops.

  17. Geometric inequalities methods of proving

    CERN Document Server

    Sedrakyan, Hayk

    2017-01-01

    This unique collection of new and classical problems provides full coverage of geometric inequalities. Many of the 1,000 exercises are presented with detailed author-prepared-solutions, developing creativity and an arsenal of new approaches for solving mathematical problems. This book can serve teachers, high-school students, and mathematical competitors. It may also be used as supplemental reading, providing readers with new and classical methods for proving geometric inequalities. .

  18. Isolation and Identification of Potential Allelochemicals from Aerial Parts of Avena fatua L. and Their Allelopathic Effect on Wheat.

    Science.gov (United States)

    Liu, Xingang; Tian, Fajun; Tian, Yingying; Wu, Yanbing; Dong, Fengshou; Xu, Jun; Zheng, Yongquan

    2016-05-11

    Five compounds (syringic acid, tricin, acacetin, syringoside, and diosmetin) were isolated from the aerial parts of wild oats (Avena fatua L.) using chromatography columns of silica gel and Sephadex LH-20. Their chemical structures were identified by means of electrospray ionization and high-resolution mass spectrometry as well as (1)H and (13)C nuclear magnetic resonance spectroscopic analyses. Bioassays showed that the five compounds had significant allelopathic effects on the germination and seedling growth of wheat (Triticum aestivum L.). The five compounds inhibited fresh wheat as well as the shoot and root growth of wheat by approximately 50% at a concentration of 100 mg/kg, except for tricin and syringoside for shoot growth. The results of activity testing indicated that the aerial parts of wild oats had strong allelopathic potential and could cause different degrees of influence on surrounding plants. Moreover, these compounds could be key allelochemicals in wild-oat-infested wheat fields and interfere with wheat growth via allelopathy.

  19. Allelopathic Effects of Shoot and Root Extracts From Three Alien and Native Chenopodiaceae Species on Lettuce Seed Germination

    Directory of Open Access Journals (Sweden)

    Yamina Bouchikh-Boucif

    2014-12-01

    Full Text Available One basic method of improving rangelands in the country is the use of native as well as exotic species of adaptable plants. Some species of Atriplex, like Atriplex canescens and Atriplex nummularia has been introduced in many thousands hectares of rangelands since more than 20 years, it feeds some debates on the algerian scientific community, so that’s why it is important to know the impact and necessary to consider its effects on native species. In the current study the effect of chemical competition of Atriplex canescens and Atriplex nummularia comparing to native Atriplex halimus by observing the effect of aqueous extracts of leaves, stems and roots of the three chenopod species assayed at 0.06, 0.63, 1.55, 3.12 and 6.25 g /l on the germination of lettuce seed test. Seed germination was significantly inhibited by shoot alien species extracts especially A.nummularia at concentrations ranging from 1.55 to 6.26 g/l with decrease rate of 20% in the lettuce seed tests indicating the presence of allelopathic substances, in 0,06 the germination increased to more than 10% comparing to the water irrigated seeds. An opposed effect than the expected had been found because Atriplex canescens had a less allelopathic effect than our native plant Atriplex halimus.

  20. Allelopathic Effects of Invasive Woody Plant Species in Hungary

    Directory of Open Access Journals (Sweden)

    CSISZÁR, Ágnes

    2009-01-01

    Full Text Available Allelopathy may play an important role in the invasion success of adventive plant species.The aim of this study was to determine the allelopathic potential of invasive woody plant species occurringin Hungary. Juglone index of fourteen invasive woody plant species in Hungary was determined by themethod of Szabó (1997, comparing the effects of juglone and substance extracted of plant species withunknown allelopathic potential on the germination rate, shoot length and rooth length of white mustard(Sinapis alba L. used as receiver species. Results have proven a more or less expressed allelopathicpotential in case of all species. The juglone index at higher concentration extracts (5 g dry plant materialextracted with 100 ml distilled water of almost every studied species approaches to 1 or is above 1, thismeans the effect of the extracts is similar to juglone or surpasses it. In terms of juglone index, theallelopathic potential of false indigo (Amorpha fruticosa L., tree-of-heaven (Ailanthus altissima (Mill.Swingle and hackberry (Celtis occidentalis L. were the highest. Besides these species the treatment withthe extracts of black walnut (Juglans nigra L., black cherry (Prunus serotina Ehrh. and green ash(Fraxinus pennsylvanica MARSH. var. subintegerrima (Vahl Fern. reduced extremely significantly thegermination rate, shoot and root length, compared to the control.

  1. Allelopathic Stress Produced by Bitter Gourd (Momordica charantia L.

    Directory of Open Access Journals (Sweden)

    N.B. Singh

    2014-05-01

    Full Text Available The present study deals with in vitro effects of allelochemicals present in leaf and fruit leachate of Momordica charantia in vitro on plant growth and metabolism of Lycopersicon esculentum. Momordica was selected as a donor plant and tomato as recipient. Seeds of tomato were shown in pots and after germination different concentrations viz. 25, 50, 75 and 100% of leaf and fruit leachates were applied as treatment. Twenty days old seedlings were harvested for biophysical and biochemical analyses. The root and shoot length, fresh and dry weight of the seedlings decreased in dose dependent manner. The reduction in pigment and protein contents and nitrate reductase activity was concentration dependent. Membrane leakage increased as the concentration of leachates increased. Activities of antioxidant enzymes viz. superoxide dismutase (SOD, catalase (CAT and peroxidase (POX activities significantly enhanced under allelopathic stress. Inhibition of various metabolic activities under allelopathic stress resulted in decreased plant growth and development. The fruit leachate of Momordica was more inhibitory than leaf leachate.

  2. Allelopathic and Bloom-Forming Picocyanobacteria in a Changing World

    Directory of Open Access Journals (Sweden)

    Sylwia Śliwińska-Wilczewska

    2018-01-01

    Full Text Available Picocyanobacteria are extremely important organisms in the world’s oceans and freshwater ecosystems. They play an essential role in primary production and their domination in phytoplankton biomass is common in both oligotrophic and eutrophic waters. Their role is expected to become even more relevant with the effect of climate change. However, this group of photoautotrophic organisms still remains insufficiently recognized. Only a few works have focused in detail on the occurrence of massive blooms of picocyanobacteria, their toxicity and allelopathic activity. Filling the gap in our knowledge about the mechanisms involved in the proliferation of these organisms could provide a better understanding of aquatic environments. In this review, we gathered and described recent information about allelopathic activity of picocyanobacteria and occurrence of their massive blooms in many aquatic ecosystems. We also examined the relationships between climate change and representative picocyanobacterial genera from freshwater, brackish and marine ecosystems. This work emphasizes the importance of studying the smallest picoplanktonic fractions of cyanobacteria.

  3. Allelopathic Effects of Cyanobacterial Filtrates on Baltic Diatom

    Science.gov (United States)

    Śliwińska, Sylwia; Latała, Adam

    2012-01-01

    Allelopathy may be one of the factors affecting the formation of massive and harmful algal blooms in aquatic environments. Recent studies indicate that blooms of cyanobacteria in the Baltic Sea has grown significantly in last decades, so it is important to determine the allelopathic interactions between the dominant species of cyanobacteria and microalgae. In this work we investigated the influence of allelopathic compounds on the growth of Skeletonema marinoi by addition of cell-free filtrate of the Baltic cyanobacterium Nodularia spumigena cultures grown under different temperature (15-25°C). Additionally the effects of filtrates of both an exponential and a stationary growing culture of N. spumigena were tested on diatom. These studies indicate that high temperature affected the donor species by increasing its production of allelochemicals. The highest drop of growth of analyzed diatom were observed after the addition of cell-free filtrate obtained from N. spumigena grown at 25°C and constituted 70% of their control. N. spumigena was only allelopathic in exponential growth phase, whereas the cyanobacteria filtrate from stationary phase have any effect on S. marinoi. These findings suggest that N. spumigena may reveal allelopathic activity and that the production of allelopathic substances is influenced by the temperature and growth phase of cyanobacteria. Allelopatia może być kluczowym czynnikiem wpływającym na tworzenie się masowych zakwitów sinic w wielu wodnych ekosystemach. Badania pokazują, że zakwity sinic w Morzu Bałtyckim w ostatnich dekadach znacznie się nasiliły, dlatego tak ważne jest określenie stopnia oddziaływania allelopatycznego dominujących w tym akwenie gatunków fitoplanktonu. W przeprowadzonych badaniach określono wpływ związków allelopatycznych produkowanych przez bałtycką sinicę Nodularia spumigena hodowaną w różnych temperaturach (15-25°C) na wzrost okrzemki Skeletonema marinoi. Dodatkowo w niniejszej pracy por

  4. Allelopathic effect of Ashwagandha against the germination and radicle growth of Cicer arietinum and Triticum aestivum.

    Science.gov (United States)

    Chandra, Sangita; Chatterjee, Priyanka; Dey, Protapaditya; Bhattacharya, Sanjib

    2012-07-01

    Ashwagandha (Withania somnifera) is an important medicinal plant in Indian traditional system of medicine and traditionally has been used for several medicinal purposes in the Indian subcontinent. The present study was aimed at the evaluation of allelopathic effect of hydroalcoholic extract of ashwagandha against germination and radicle growth of Cicer arietinum and Triticum aestivum seeds. The extract at different concentrations was incubated in controlled conditions with the surface sterilized seeds of C. arietinum and T. aestivum and observed periodically for seed germination and radicle growth to assess the allelopathic behavior. The extract mainly at higher concentrations demonstrated promising allelopathic potential by significantly affecting seed germination and radicle elongation of both C. arietinum and T. aestivum in a concentration dependent manner. T. aestivum was found to be more sensitive than C. arietinum. The present study demonstrated remarkable allelopathic potential of ashwagandha against the test seeds. The effect was plausibly due to the alkaloid and withanolide contents of ashwagandha.

  5. Creating of a plant compositions considering the Allelopathic activity of the Artemisia absinthium

    OpenAIRE

    N. Kornilova

    2014-01-01

    This paper deals with Allelopathic impact of Artemisia absinthium L. on the growth and development of other kinds of medicinal plants. The effect of water extract of Artemisia absinthium L. on ge-rmination of seeds of medicinal plants has been studied. It has been determined, that extracts from Artemisia absinthium L. are characterized by significant Allelopathic activity and this kind can be sown from seed Calendula officinalis L., Lophanthus anisatus Benht., Hyssopus officinalis L, Salvia s...

  6. Potential of Biochar to Mitigate Allelopathic Effects in Tropical Island Invasive Plants: Evidence From Seed Germination Trials

    National Research Council Canada - National Science Library

    Sujeeun, Leeladarshini; Thomas, Sean C

    2017-01-01

    ...; however, sorption of allelochemicals has received little attention. Strawberry guava (Psidium cattleianum) and lemongrass (Cymbopogon flexuosa) are important tropical island invasives thought to be allelopathic...

  7. Allelopathic activity of the Baltic cyanobacteria against microalgae

    Science.gov (United States)

    Żak, Adam; Musiewicz, Krzysztof; Kosakowska, Alicja

    2012-10-01

    The goal of this work was to investigate the influence of Baltic cyanobacteria Anabaena variabilis and Nodularia spumigena cells and cell-free filtrates on the growth of green algae Chlorella vulgaris. We have demonstrated that Anabaena variabilis and Nodularia spumigena caused allelopathic effects against microalgae. The cyanobacterial and microalgal cultures were provided on liquid medium, in 22 °C at continuous light. Cell-free filtrates were obtained by centrifugation and filtering aliquots of cyanobacterial cultures (including cultures in exponential and stationary phase of growth). Growth response of free cells (batch culture technique) and immobilized cultures (in alginate beads) of the unicellular green algae to cyanobacteria allelochemicals were tested and compared. In this experiment Anabaena variabilis supressed the growth of microalgae compared to control samples. Nodularia spumigena stimulated the growth of Chlorella vulgaris in most cases, however both positive and negative effects were observed.

  8. Transformation of toxic and allelopathic lantana into a benign organic fertilizer through vermicomposting

    Science.gov (United States)

    Hussain, Naseer; Abbasi, Tasneem; Abbasi, S. A.

    2016-06-01

    In a first study of its kind, the composition of vermicompost derived solely from the toxic and allelopathic weed lantana has been investigated using UV-visible and Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric (TG) and differential scanning calorimetry (DSC), gas chromatography-mass spectometry (GC-MS), and scanning electron microscopy (SEM). The studies reveal that a sharp reduction in humification index, substantial mineralization of organic matter and degradation of complex aromatics such as lignin and polyphenols into simpler carbohydrates and lipids occur in the course of vermicomposting. GC-MS analysis shows significant fragmentation, bio-oxidation and molecular rearrangements of chemical compounds in vermicompost in comparison to those in lantana. SEM micrographs of vermicompost reflect strong disaggregation of material compared to the much better formed lantana matrices. The phenols and sesquiterpene lactones which are specifically responsible for the toxicity and allelopathy of lantana are seen to get significantly degraded in the course of vermicomposting - turning it into a plant-friendly organic fertilizer. The study leads to the possibility that the millions of tons of phytomass that is generated annually by lantana can be gainfully utilized in producing organic fertilizer via vermicomposting.

  9. Atividade alelopática em folhas de Tachigali myrmecophyla (Leg. - Pap. Allelopathic activity in Tachigali myrmecophyla (Leg. - Pap. leaves

    Directory of Open Access Journals (Sweden)

    A.P.S. Souza Filho

    2005-12-01

    Full Text Available O uso de espécies florestais com atividade alelopática pode assegurar aos sistemas agroflorestais maior estabilidade, notadamente em relação à redução das espécies de plantas daninhas. Os objetivos deste trabalho foram isolar e identificar substâncias químicas produzidas pelo Tachigali myrmecophyla (tachi-preto e caracterizar a atividade alelopática sobre a germinação de sementes e o crescimento de plântulas de duas espécies de plantas daninhas. Os bioensaios foram realizados em condições controladas de 25 ºC e fotoperíodos de 12 horas para germinação e de 25 ºC e fotoperíodo de 24 horas para o desenvolvimento de radícula e hipocótilo. Os extratos brutos e as frações foram analisados em concentração de 1,0 e 0,5%, e a substância, em concentrações de 5, 10, 15 e 20 mg L-1. O processo de isolamento permitiu a identificação da substância química 4,5-diidroblumenol A. Essa substância evidenciou atividade alelopática, cujos efeitos variaram em função da concentração, da espécie de planta daninha e do parâmetro da planta analisado. A intensidade dos efeitos alelopáticos esteve positivamente associada à concentração, com os efeitos mais intensos observados na concentração de 20 mg L-1. Independentemente do parâmetro analisado, os efeitos foram de maior magnitude na planta malícia. Comparativamente, o desenvolvimento da radícula se mostrou mais sensível aos efeitos da substância que o desenvolvimento do hipocótilo e a germinação das sementes.The use of forest species with allelopathic activity can promote a higher stability to agroforestry systems, mainly relative to the reduction of weed species. The objective of this study was to isolate and identify chemical substances produced by Tachigali myrmecophyla and characterize its inhibitory allelopathic activity on the germination and seedling development of two weed species. Bioassays were carried out under controlled conditions of 25 ºC and 12

  10. Possible allelopathic effects of cyanotoxins, with reference to microcystin-LR, in aquatic ecosystems.

    Science.gov (United States)

    Pflugmacher, Stephan

    2002-01-01

    During recent years a shift from macrophyte-dominated to more phytoplankton-dominated lakes has been correlated to the process of eutrophication. The existence of numerous substances exhibiting allelopathic effects on the growth of algae has been shown in different aquatic macrophytes (e.g., Myriophyllum spicatum) and is thought to be an important mechanism in stabilizing the macrophyte-dominated clear-water state of a lake. A few recent studies have shown that algae themselves can produce special substances inhibiting growth or photosynthetic processes in other algae. A well-known cyanobacterial secondary metabolite, microcystin-LR, was tested for its allelopathic power on aquatic macrophytes such as Ceratophyllum demersum and Myriophyllum spicatum, resulting in growth inhibition, reduction in photosynthetic oxygen production, and changes in pigment pattern. This shows that microcystin-LR has a possible role as an allelopathic infochemical. Copyright 2002 Wiley Periodicals, Inc.

  11. [Studies on allelopathic effect of artemisinin on rhizobium].

    Science.gov (United States)

    Li, Qian; Wu, Yekuan; Huang, Jianguo

    2011-12-01

    Two strains of bean rhizobia, Rhizobium vigna 01 (slow-growing Rhizobium) and Rh. vigna 03 (fast-growing Rhizobium), were adopted to study allelopathic effect of artemisinin on the rhizobia. The results showed a significant inhibition of the reproduction and growth of rhizobium by artemisinin. After about 8 hours by adding 40 mg x L(-1) artemisinin into the culture medium, the number of rhizobia was less than half of those in normal culture. The utilization of sucrose and glucose by rhizobia decreased significantly as the concentration of artemisinin increased in the culture medium, which could be one of the main reasons for the inhibition of reproduction and growth of rhizobia by artemisinin. In addition, the activities of extracellular protease and acid phosphatase released from rhizobia decreased significantly as the concentrations of artemisinin increased. Artemisinin refluxed from Artemisia annua could thus inhibit the formation of root nodules and interfered with energy supply and reception between bacteroid and host cells. y = e(-ax) + b reflected the relationships between nitrogenase activities (y) and concentrations of artemisinin (x). In the culture medium with 48 mg x L(-1) of artemisinin, nitrogenase activities were about zero, resulting in the inactivation of nitrogenase in nodules formed. In general, artemisin in A. annua grown soils may inhibit the reproduction and growth of rhizobia, nodule formation and nitrogen biofixation, leading to less nitrogen supply, poor growth and development, and low yields of beans.

  12. Allelopathic potential ofnuphar lutea (L.) Sibth. & Sm. (Nymphaeaceae).

    Science.gov (United States)

    Elakovich, S D; Wooten, J W

    1991-04-01

    Aqueous extracts ofNuphar lutea (L.) Sibth. & Sm. leaves (blades plus petioles) and roots plus rhizomes were tested for allelopathic activity using lettuce seedling andLemna minor L. assay systems. The 12.5, 25, 125, and 250 parts per thousand (ppt) treatments of both extracts killed the lettuce seedlings. At 2.5 ppt of extract, radicle growth of lettuce was 29% of the control for leaves and 31% of the control for roots plus rhizomes.Lemna minor frond number was reduced to 34% of the control by the 25 ppt leaf extract and to 43% of the control by the 25 ppt roots plus rhizomes extract.L. minor was killed by concentrations of 125 ppt and above of both plant part extracts. As expected, the frond number and total chlorophyll content measured by theL. minor assay were highly correlated. Osmotic potentials below 143 mOsmol/kg had no influence onL. minor growth. Neither the osmotic potential nor the pH of the undiluted extracts ofN. lutea were in the range known to influence the growth of either lettuce seedlings orL. minor. Nuphar lutea extracts were many times more inhibitory than 16 other hydrophytes we previously examined.

  13. Allelopathic effects of Clinopodium menthifolium and Salvia sclarea aqueous extracts

    Directory of Open Access Journals (Sweden)

    Šućur Jovana T.

    2016-01-01

    Full Text Available Secondary plant biomolecules are the main agents in biochemical inter­actions between plants and the environment. It is possible to distinguish the role of secondary biomolecules in allelopathic (plant-plant activity, plant-insect, plant-microbe, plant-herbivore and others. These interactions can significantly affect the productivity of agricultural crops. Application of allelochemicals into agricultural practice may reduce the use of herbicides. Effect of Salvia sclarea L. and Clinopodium menthifolium (Host aqueous extracts on lipid peroxidation process, as well as the activity of antioxidant enzymes in leaves and roots of Jimson weed (Datura stramonium L. and soybean (Glycine max L. seedlings were examined 24 h, 72 h and 120 h after the treatment. The third aim was to evaluate effectiveness of aqueous extract as contact toxicant against Rhyzopertha dominica. Our results showed that S. sclarea aqueous extract induced lipid peroxidation in roots of Jimson weed seedlings 24 h after the treatment. Furthermore, both tested concentrations of C. menthifolium aqueous extract induced lipid peroxidation in Jimson weed roots 72 h and 120 h after the treatment. It was observed that S. sclarea aqueous extract showed toxic effect against R. dominica, with high mortality rate (above 95%.

  14. Lily Cultivars Have Allelopathic Potential in Controlling Orobanche aegyptiaca Persoon.

    Science.gov (United States)

    Chai, Min; Zhu, Xiaopei; Cui, Hongxia; Jiang, Chuangdao; Zhang, Jinzheng; Shi, Lei

    2015-01-01

    As a devastating holoparasitic weed, Orobanche aegyptiaca Persoon. (Egyptian broomrape) causes serious damage to agricultural production and threatens economic development, which has raised widespread concern. The present study was conducted to determine whether lilies have the potential to be used as 'trap crops' for controlling O. aegyptiaca Persoon. In the experiments, the ability of three popular lily cultivars (Lilium Oriental hybrids 'Sorbonne', Lilium LA (Longiflorum hybrids x Asiatic hybrids) hybrids 'Ceb Dazzle', and Lilium Longiflorum hybrids (L. formosanum x L. longiflorum) 'L. formolongo') to induce O. aegyptiaca Persoon. seed germination was assessed. Parts of the three lily cultivars, including the rhizosphere soil and underground and above-ground organs, all induced "suicidal germination" of parasitic O. aegyptiaca Persoon. seed at four growth stages. Specifically, Sorbonne and Ceb Dazzle behaved with similar allelopathy, and the bulb, scale leaf and aerial stem exhibited stronger allelopathic effects on O. aegyptiaca Pers. germination compared to other organs. Aqueous L. formolongo leaf extracts may contain more stable, effective stimulants given that they induced the highest germination rate at 76.7% even though the extracts were serially diluted. We speculate that these organs may be advantageous in further isolating and purifying economical active substances that can be substitutes for GR24. These results indicate that lilies have the potential to be used as a trap crops or can be processed into green herbicide formulations that can be applied in agriculture production to rapidly deplete the seed bank of O. aegyptiaca Persoon. parasitic weeds in soil.

  15. Lily Cultivars Have Allelopathic Potential in Controlling Orobanche aegyptiaca Persoon.

    Directory of Open Access Journals (Sweden)

    Min Chai

    Full Text Available As a devastating holoparasitic weed, Orobanche aegyptiaca Persoon. (Egyptian broomrape causes serious damage to agricultural production and threatens economic development, which has raised widespread concern. The present study was conducted to determine whether lilies have the potential to be used as 'trap crops' for controlling O. aegyptiaca Persoon. In the experiments, the ability of three popular lily cultivars (Lilium Oriental hybrids 'Sorbonne', Lilium LA (Longiflorum hybrids x Asiatic hybrids hybrids 'Ceb Dazzle', and Lilium Longiflorum hybrids (L. formosanum x L. longiflorum 'L. formolongo' to induce O. aegyptiaca Persoon. seed germination was assessed. Parts of the three lily cultivars, including the rhizosphere soil and underground and above-ground organs, all induced "suicidal germination" of parasitic O. aegyptiaca Persoon. seed at four growth stages. Specifically, Sorbonne and Ceb Dazzle behaved with similar allelopathy, and the bulb, scale leaf and aerial stem exhibited stronger allelopathic effects on O. aegyptiaca Pers. germination compared to other organs. Aqueous L. formolongo leaf extracts may contain more stable, effective stimulants given that they induced the highest germination rate at 76.7% even though the extracts were serially diluted. We speculate that these organs may be advantageous in further isolating and purifying economical active substances that can be substitutes for GR24. These results indicate that lilies have the potential to be used as a trap crops or can be processed into green herbicide formulations that can be applied in agriculture production to rapidly deplete the seed bank of O. aegyptiaca Persoon. parasitic weeds in soil.

  16. Allelopathic effects of ragweed (Ambrosia artemisiifolia L.) on cultivated plants.

    Science.gov (United States)

    Lehoczky, E; Gólya, G; Szabó, R; Szalai, A

    2011-01-01

    During the past years ragweed has been coming to the forefront of interest in Hungary and in other European countries as well because its serious health risk. Results of the 5th National Weed Survey has proven that ragweed is the most important weed species on Hungarian field lands, its coverage shows a rising tendency in cereals moreover it not only occurs in cultivated plants. Allelopathic effects of aqueous extracts derived from different parts of ragweed plants (air dried leafy stems, seeds) on the germination and growth of other cultivated plants [maize (Zea mays L.), winter wheat (Triticum aestivum L.), rye (Secale cereale L.), oat (Avena sativa L.)] were studied. The extracts made for the trials were prepared with distilled water. Petri dishes were used for the germination experiments and distilled water was used as a control treatment. The seven days long experiment was carried out within a Binder-type thermostat under dark conditions. The germination percentage was checked in every two days and the growth of sprouts was evaluated after a week counting the germinated seeds and measuring the length of the radicle and plumule. The measured data were statistically analysed and the effect of extracts on germinating and length of sprouts were assessed.

  17. Vermicomposting transforms allelopathic parthenium into a benign organic fertilizer.

    Science.gov (United States)

    Hussain, Naseer; Abbasi, Tasneem; Abbasi, S A

    2016-09-15

    Vermicompost, which had been derived solely by the action of the epigeic earthworm Eisenia fetida on parthenium (Parthenium hysterophorus), was tested for its impact on the germination and early growth of green gram (Vigna radiata), ladies finger (Abelmoschus esculentus) and cucumber (Cucumis sativus). Seedlings were germinated and grown in soil amended with 0 (control), 0.75, 1.5, 2, 4, 8, 20 and 40% (by weight) parthenium vermicompost. Even though parthenium is known to possess strong negative allelopathy, as also plant/animal toxicity in other forms, its vermicompost (VC) manifested none of these attributes. Rather the VC enhanced germination success, introduced plant-friendly physical features in the container media, increased biomass carbon, and was seen to promote early growth as reflected in several morphological and biochemical characteristics in plants which had received parthenium VC in comparison to those which had not. All these effects were statistically significant. Fourier Transform Infrared (FTIR) Spectrometry revealed that the phenols and the sesquiterpene lactones that are responsible for the negative allelopathic impact of parthenium were largely destroyed in the course of vermicomposting. FTIR spectra also indicated that lignin content of parthenium was reduced during its vermicomposting. The findings open up the possibility that several other invasives known for their negative allelopathy and toxicity may also produce vermicompost which may be plant-friendly and soil-friendly. It also makes it appear possible that the huge quantities of phytomass that is generated annually by parthenium can be gainfully utilized in producing organic fertilizer via vermicomposting, thereby providing a means of exercising some control over parthenium's rampant growth and invasion. Copyright © 2016. Published by Elsevier Ltd.

  18. Lily Cultivars Have Allelopathic Potential in Controlling Orobanche aegyptiaca Persoon

    Science.gov (United States)

    Cui, Hongxia; Jiang, Chuangdao; Zhang, Jinzheng; Shi, Lei

    2015-01-01

    As a devastating holoparasitic weed, Orobanche aegyptiaca Persoon. (Egyptian broomrape) causes serious damage to agricultural production and threatens economic development, which has raised widespread concern. The present study was conducted to determine whether lilies have the potential to be used as ‘trap crops’ for controlling O. aegyptiaca Persoon. In the experiments, the ability of three popular lily cultivars (Lilium Oriental hybrids ‘Sorbonne’, Lilium LA (Longiflorum hybrids x Asiatic hybrids) hybrids ‘Ceb Dazzle’, and Lilium Longiflorum hybrids (L. formosanum x L. longiflorum) ‘L. formolongo’) to induce O. aegyptiaca Persoon. seed germination was assessed. Parts of the three lily cultivars, including the rhizosphere soil and underground and above-ground organs, all induced “suicidal germination” of parasitic O. aegyptiaca Persoon. seed at four growth stages. Specifically, Sorbonne and Ceb Dazzle behaved with similar allelopathy, and the bulb, scale leaf and aerial stem exhibited stronger allelopathic effects on O. aegyptiaca Pers. germination compared to other organs. Aqueous L. formolongo leaf extracts may contain more stable, effective stimulants given that they induced the highest germination rate at 76.7% even though the extracts were serially diluted. We speculate that these organs may be advantageous in further isolating and purifying economical active substances that can be substitutes for GR24. These results indicate that lilies have the potential to be used as a trap crops or can be processed into green herbicide formulations that can be applied in agriculture production to rapidly deplete the seed bank of O. aegyptiaca Persoon. parasitic weeds in soil. PMID:26565398

  19. Symbolic logic and mechanical theorem proving

    CERN Document Server

    Chang, Chin-Liang

    1969-01-01

    This book contains an introduction to symbolic logic and a thorough discussion of mechanical theorem proving and its applications. The book consists of three major parts. Chapters 2 and 3 constitute an introduction to symbolic logic. Chapters 4-9 introduce several techniques in mechanical theorem proving, and Chapters 10 an 11 show how theorem proving can be applied to various areas such as question answering, problem solving, program analysis, and program synthesis.

  20. Allelopathic activity of medicinal plant essential oils on seed germination and vigor of lettuce achenes

    Directory of Open Access Journals (Sweden)

    Cíntia Alvarenga Santos Fraga de Miranda

    2015-07-01

    Full Text Available In recent years, essential oils have gained commercial interest in the agricultural area, mainly for their allelopathic, insecticidal, antifungal, antimicrobial and antioxidant properties, and, also for their natural compounds, which have generally displayed low toxicity, relatively low cost and rapid degradation in the environment. Medicinal plants have emerged as potential suppliers of essential oils because of their ethnopharmacological utility. The aim of this study was to evaluate the allelopathic potential of essential oils extracted from fresh leaves of lemon grass (Cymbopogon citratus, wild basil (Ocimum gratissimum L. and sweet basil (Ocimum basilicum L. with regard to their major constituents (citral, eugenol and cineol, respectively in different application forms (direct contact and the effect of volatile constituents on the germination and vigor of lettuce seeds (cultivar Regina SF 3500. The effects of the oils and their major components were evaluated with regard to the variables: first germination count, total germination, GVI (germination velocity index, seedling dry weight and average lengths of shoots and lettuce roots. The essential oils from lemon grass and basil displayed allelopathic potentials on seed germination and vigor of lettuce achenes that can be assigned to their respective major constituents citral and eugenol. On the other hand, the allelopathic effect of the essential oil from basil was a consequence of the combined effect of all the components, regardless the application method.

  1. Allelopathic potential of Arctotis arctotoides (L.f.) O. Hoffm aqueous ...

    African Journals Online (AJOL)

    Aqueous shoot and root extracts of Arctotis arctotoides were tested for their allelopathic properties on cabbage, carrot, tomato and spinach seed germination and seedling growth. The addition of the two extracts at 8 and 10 mg ml-1 resulted in the highest germination inhibitions. The shoot extract at 10 mg ml-1 inhibited ...

  2. Allelopathic effects of sunnhemp (Crotalaria juncea L.) on germination of vegetables and weeds

    Science.gov (United States)

    Sunnhemp (Crotalaria juncea L.) is a tropical legume that could be an important summer cover crop in the Southeastern U.S., but it has the potential for suppressing both crops and weeds. Allelopathic effects of sunnhemp on weeds, vegetable crops, and cover crops were evaluated in growth chamber an...

  3. Competitive and Allelopathic Effects of Wild Rice Accessions (Oryza longistaminata) at Different Growth Stages.

    Science.gov (United States)

    Shen, Shicai; Xu, Gaofeng; Clements, David Roy; Jin, Guimei; Zhang, Fudou; Tao, Dayun; Xu, Peng

    2016-01-01

    The competitive and allelopathic effects of wild rice (Oryza longistaminata) accessions on barnyard grass at different growth stages determined by days after sowing (0, 30, 60 and 90 days) were studied in greenhouse pot experiments. Wild rice accession RL159 exhibited the greatest height and tillering. The weed suppression rates of wild rice accessions OL and F1 on barnyard grass were significantly higher than for other rice accessions, with the lowest being O. sativa cultivar RD23. The highest suppression rates of OL and F1 were 80.23 and 73.96% at barnyard grass growth stages of 90 days and 60 days. At a 90 growth stage, wild rice accessions RL159 and RL169 caused 61.33 and 54.51% inhibition in barnyard grass growth, respectively. Under the same conditions, the competitive inhibition rates of OL, F1, RL159, RL169 and RL219 against barnyard grass were markedly lower than their weed suppressive effects, but were relatively similar for RD23. The allelopathic inhibition of OL and F1 on barnyard grass was significantly higher than other rice accessions. The highest allelopathic rates of OL and F1 were 60.61 and 56.87% at the 0 day growth stage. It is concluded that wild rice accessions OL and F1 exhibited the highest allelopathic activity along with moderate competitive ability against barnyard grass; wild rice accession RL159 had the highest competitive ability and moderate allelopathic activity on barnyard grass. Thus, the three wild rice accessions OL, F1 and RL159 could be used as ideal breeding materials for cultivated rice improvement.

  4. Allelopathic Effect of Leaf Water Extract of Hoary alyssum (Berteroa incana L. at Rosette Stage on Seed Germination

    Directory of Open Access Journals (Sweden)

    H. Madani

    2012-07-01

    Full Text Available The allelopathic effects of leaves at rosette stage of the hoary alyssum (Berteroa incana L. against some associated grasses like, prairie June grass (Koeleria macrantha, Idaho fescue (Festuca idahoensis, blue-bunch wheatgrass (Pseudoroegneria spicata and cheat grass (Bromus tectorum and its own were investigated. The experiment al materials used were the leaf extracts and its allelopathic effects on seed germination and seedling emergence of the abave mentioned grasses in Petri dishes. According to our study, leaves of hoary alyssum rosettes at stage have the potential to reduce germination rate, root and shoot growth of pasture grasses and hoary alyssum itself due to its allelopathic effect. The leaf leachate solution bioassays also showed that the germination of cheat grass was more susceptible to 4% solution of allelopathic extract of leaves. Hoary alyssum leaf extract also exhibited allelopathic self-inhibition, in both seedling root and shoot growth at 2 and 4% concentrations. Self- inhibitory allelopathic effects of hoary alyssum could also be important in preventing seed germination and seedling establishment of neighboring plant.

  5. APTE: An Algorithm for Proving Trace Equivalence

    OpenAIRE

    Cheval, Vincent

    2014-01-01

    This paper presents APTE, a new tool for automatically proving the security of cryptographic protocols. It focuses on proving trace equivalence between processes, which is crucial for specifying privacy type properties such as anonymity and unlinkability.\\ud \\ud The tool can handle protocols expressed in a calculus similar to the applied-pi calculus, which allows us to capture most existing protocols that rely on classical cryptographic primitives. In particular, APTE handles private channels...

  6. Unexploded ordnance issues at Aberdeen Proving Ground: Background information

    Energy Technology Data Exchange (ETDEWEB)

    Rosenblatt, D.H.

    1996-11-01

    This document summarizes currently available information about the presence and significance of unexploded ordnance (UXO) in the two main areas of Aberdeen Proving Ground: Aberdeen Area and Edgewood Area. Known UXO in the land ranges of the Aberdeen Area consists entirely of conventional munitions. The Edgewood Area contains, in addition to conventional munitions, a significant quantity of chemical-munition UXO, which is reflected in the presence of chemical agent decomposition products in Edgewood Area ground-water samples. It may be concluded from current information that the UXO at Aberdeen Proving Ground has not adversely affected the environment through release of toxic substances to the public domain, especially not by water pathways, and is not likely to do so in the near future. Nevertheless, modest but periodic monitoring of groundwater and nearby surface waters would be a prudent policy.

  7. Synthesis of a new allelopathic agent from the biotransformation of ent-15α-hydroxy-16-kauren-19-oic acid with Fusarium proliferatum.

    Science.gov (United States)

    Rocha, A D; Vieira, H da S; Takahashi, J A; Boaventura, M A D

    2017-11-01

    The use of kaurane diterpenes as substrates in fungal biotransformation to achieve bioactive compounds has been widely reported. In this work, the natural product kaurenoic acid, a diterpene widely distributed in the plant Kingdom, was chemically converted into ent-15α-hydroxy-kaur-16-en-19-oic acid (1). Substrate 1 was subjected to biotransformation by the fungus Fusarium proliferatum, furnishing a new derivative, ent-2α,15α-dihydroxy-kaur-16-en-19-oic acid (2). The structure of metabolite 2 was deduced on the basis of spectroscopy and MS data. Derivative 2 showed allelopathic activity on germination and growth of root and stem of lettuce (Lactuca sativa), inhibiting 100% of germination and growth of roots and stem, at higher concentration assayed (10(-4) mol/L).

  8. Allelopathic effects of two cover crops Commelina diffusa Burm. F. and Tradescantia zebrina Shunltz on Coffea arabica L.

    Directory of Open Access Journals (Sweden)

    Georgina Berroa Navarro

    2016-03-01

    Full Text Available Allelopathic effect of the cover crops Tradescantia zebrina Shunltz (cucaracha and Commelina diffusa Burm. F. (canutillo were evaluated on Coffea arabica Lin. seeds Caturra Rojo variety. Germination tests were carried out “in vitro” and it was evaluated the root longitude, percentage of total germination and period of germination, as well as the height of the plant and the emergency percentage for the incorporation tests to the soil. It was also carried out, to both over crops, the preliminary chemical qualitative characterization. The results showed that the extracts of T. zebrina and of C. diffusa stimulated the “in vitro” germination and growth of C. arabica at different concentration levels. The incorporation to the soil of the extracts of C. diffusa stimulated the development of the plants of C. arabica, in a significant way, that supposes a considerable advantage in that concerns to the employment of these cover crops, when not implying noxious effects beside all the benefits implied when using cover crops. These last ones go from the protection and improvement of the properties of the soil, to the control of the spontaneous flora in the coffee agroecosystems.

  9. Allelopathic interactions between the red-tide causative dinoflagellate Prorocentrum donghaiense and the diatom Phaeodactylum tricornutum

    Directory of Open Access Journals (Sweden)

    Zhuoping Cai

    2014-06-01

    Full Text Available The interactions between the red-tide causing dinoflagellate Prorocentrum donghaiense and the marine diatom Phaeodactylum tricornutum were investigated using a co-culture experiment and an enriched culture filtrate experiment. The results showed that when the two microalgae were cultured together with different initial cell densities, the growth of one species was basically suppressed by the other one. In addition, the enriched culture filtrates of one species had generally inhibitory effects on the other one. Our result inferred that P. donghaiense and P. tricornutum would interfere with each other mainly by releasing allelochemicals into the culture medium, and that the degree of allelopathic effects was dependent on the initial cell densities and growth phases. The allelopathic interactions between microalgal species may contribute to the formation and succession of red tides.

  10. The Impact of Microbial Biotransformation of Catechin in Enhancing the Allelopathic Effects of Rhododendron formosanum

    Science.gov (United States)

    Wang, Chao-Min; Li, Tsai-Chi; Jhan, Yun-Lian; Weng, Jen-Hsien; Chou, Chang-Hung

    2013-01-01

    Rhododendron formosanum is distributed widely in the central mountains in Taiwan and the major allelopathic compound in the leaves has been identified as (-)-catechin, which is also a major allelochemical of an invasive spotted knapweed in North America. Soil microorganisms play key roles in ecosystems and influence various important processes, including allelopathy. However, no microorganism has been identified as an allelochemical mediator. This study focused on the role of microorganisms in the allelopathic effects of R. formosanum. The microorganism population in the rhizosphere of R. formosanum was investigated and genetic analysis revealed that the predominant genera of microorganisms in the rhizosphere of R. formosanum were Pseudomonas, Herbaspirillum, and Burkholderia. The dominant genera Pseudomonas utilized (-)-catechin as the carbon source and catalyzed the conversion of (-)-catechin into protocatechuic acid in vitro. The concentrations of allelochemicals in the soil were quantified by liquid chromatography-electrospray ionization/tandem mass spectrometry. The concentration of (-)-catechin in the soil increased significantly during the extreme rainfall in the summer season and suppressed total bacterial populations. Protocatechuic acid accumulation was observed while total bacterial populations increased abundantly in both laboratory and field studies. Allelopathic interactions were tested by evaluating the effects of different allelochemicals on the seed germination, radicle growth, and photosynthesis system II of lettuce. Protocatechuic acid exhibited higher phytotoxicity than (-)-catechin did and the effect of (-)-catechin on the inhibition of seed germination was enhanced by combining it with protocatechuic acid at a low concentration. This study revealed the significance of the allelopathic interactions between R. formosanum and microorganisms in the rhizosphere. These findings demonstrate that knowledge regarding the precise biotransformation

  11. Allelopathic activity of medicinal plant essential oils on seed germination and vigor of lettuce achenes

    OpenAIRE

    Cíntia Alvarenga Santos Fraga de Miranda; Maria das Graças Cardoso; Maria Laene Moreira de Carvalho; Samisia Maria Fernandes Machado; Marcos de Souza Gomes; Juliana de Andrade; Maria Luisa Teixeira

    2015-01-01

    In recent years, essential oils have gained commercial interest in the agricultural area, mainly for their allelopathic, insecticidal, antifungal, antimicrobial and antioxidant properties, and, also for their natural compounds, which have generally displayed low toxicity, relatively low cost and rapid degradation in the environment. Medicinal plants have emerged as potential suppliers of essential oils because of their ethnopharmacological utility. The aim of this study was to evaluate the al...

  12. The impact of microbial biotransformation of catechin in enhancing the allelopathic effects of Rhododendron formosanum.

    Directory of Open Access Journals (Sweden)

    Chao-Min Wang

    Full Text Available Rhododendron formosanum is distributed widely in the central mountains in Taiwan and the major allelopathic compound in the leaves has been identified as (--catechin, which is also a major allelochemical of an invasive spotted knapweed in North America. Soil microorganisms play key roles in ecosystems and influence various important processes, including allelopathy. However, no microorganism has been identified as an allelochemical mediator. This study focused on the role of microorganisms in the allelopathic effects of R. formosanum. The microorganism population in the rhizosphere of R. formosanum was investigated and genetic analysis revealed that the predominant genera of microorganisms in the rhizosphere of R. formosanum were Pseudomonas, Herbaspirillum, and Burkholderia. The dominant genera Pseudomonas utilized (--catechin as the carbon source and catalyzed the conversion of (--catechin into protocatechuic acid in vitro. The concentrations of allelochemicals in the soil were quantified by liquid chromatography-electrospray ionization/tandem mass spectrometry. The concentration of (--catechin in the soil increased significantly during the extreme rainfall in the summer season and suppressed total bacterial populations. Protocatechuic acid accumulation was observed while total bacterial populations increased abundantly in both laboratory and field studies. Allelopathic interactions were tested by evaluating the effects of different allelochemicals on the seed germination, radicle growth, and photosynthesis system II of lettuce. Protocatechuic acid exhibited higher phytotoxicity than (--catechin did and the effect of (--catechin on the inhibition of seed germination was enhanced by combining it with protocatechuic acid at a low concentration. This study revealed the significance of the allelopathic interactions between R. formosanum and microorganisms in the rhizosphere. These findings demonstrate that knowledge regarding the precise

  13. The impact of microbial biotransformation of catechin in enhancing the allelopathic effects of Rhododendron formosanum.

    Science.gov (United States)

    Wang, Chao-Min; Li, Tsai-Chi; Jhan, Yun-Lian; Weng, Jen-Hsien; Chou, Chang-Hung

    2013-01-01

    Rhododendron formosanum is distributed widely in the central mountains in Taiwan and the major allelopathic compound in the leaves has been identified as (-)-catechin, which is also a major allelochemical of an invasive spotted knapweed in North America. Soil microorganisms play key roles in ecosystems and influence various important processes, including allelopathy. However, no microorganism has been identified as an allelochemical mediator. This study focused on the role of microorganisms in the allelopathic effects of R. formosanum. The microorganism population in the rhizosphere of R. formosanum was investigated and genetic analysis revealed that the predominant genera of microorganisms in the rhizosphere of R. formosanum were Pseudomonas, Herbaspirillum, and Burkholderia. The dominant genera Pseudomonas utilized (-)-catechin as the carbon source and catalyzed the conversion of (-)-catechin into protocatechuic acid in vitro. The concentrations of allelochemicals in the soil were quantified by liquid chromatography-electrospray ionization/tandem mass spectrometry. The concentration of (-)-catechin in the soil increased significantly during the extreme rainfall in the summer season and suppressed total bacterial populations. Protocatechuic acid accumulation was observed while total bacterial populations increased abundantly in both laboratory and field studies. Allelopathic interactions were tested by evaluating the effects of different allelochemicals on the seed germination, radicle growth, and photosynthesis system II of lettuce. Protocatechuic acid exhibited higher phytotoxicity than (-)-catechin did and the effect of (-)-catechin on the inhibition of seed germination was enhanced by combining it with protocatechuic acid at a low concentration. This study revealed the significance of the allelopathic interactions between R. formosanum and microorganisms in the rhizosphere. These findings demonstrate that knowledge regarding the precise biotransformation

  14. Allelopathic effect of medicinal plant Cannabis sativa L. on Lactuca sativa L. seed germination

    OpenAIRE

    Homa MAHMOODZADEH; Mohsen GHASEMI; Hasan ZANGANEH

    2015-01-01

    In order to examine allelopathic effect of Cannabis sativa L. on germination capability and seedling growth of Lactuca sativa L., a study was performed in laboratory conditions. Treatments were set up in randomised block design in four replications for each of four concentration ranges of 25, 50, 75 and 100 % of aqueous extract made of shoot parts and 4 identical extract concentrations made of root of cannabis. Control variant was lettuce seed treated by distilled water. During the studies sh...

  15. Allelopathic potential of oil seed crops in production of crops: a review.

    Science.gov (United States)

    Shah, Adnan Noor; Iqbal, Javaid; Ullah, Abid; Yang, Guozheng; Yousaf, Muhammad; Fahad, Shah; Tanveer, Mohsin; Hassan, Waseem; Tung, Shahbaz Atta; Wang, Leishan; Khan, Aziz; Wu, Yingying

    2016-08-01

    Agricultural production enhancement has been realized by more consumption of fossil energy such as fertilizer and agrochemicals. However, the production provides the present human with sufficient and diversified commodities, but at the same time, deprives in some extent the resources from the future human as well. In the other hand, it is known that synthetic herbicides face worldwide threats to human's health and environment as well. Therefore, it is a great challenge for agricultural sustainable development. The current review has been focussed on various oilseed crop species which launch efficient allelopathic intervention, either with weeds or other crops. Crop allelopathic properties can make one species more persistent to a native species. Therefore, these crops are potentially harmful to both naturalized as well as agricultural settings. On the other side, allelopathic crops provide strong potential for the development of cultivars that are more highly weed suppressive in managed settings. It is possible to utilize companion plants that have no deleterious effect on neighbor crops and can be included in intercropping system, thus, a mean of contributing to agricultural sustainable development. In mixed culture, replacement method, wherein differing densities of a neighbor species are planted, has been used to study phytotoxic/competitive effects. So, to use alternative ways for weed suppression has become very crucial. Allelochemicals have the ability to create eco-friendly products for weed management, which is beneficial for agricultural sustainable development. Our present study assessed the potential of four oilseed crops for allelopathy on other crops and associated weeds.

  16. Proving program inclusion using Hoare's logic

    NARCIS (Netherlands)

    Bergstra, J.A.; Klop, J.W.

    1984-01-01

    We explore conservative refinements of specifications. These form a quite appropriate framework for a proof theory for program inclusion based on a proof theory for program correctness. We propose two formalized proof methods for program inclusion and prove these to be sound. Both methods are

  17. Affect, Behavioural Schemas and the Proving Process

    Science.gov (United States)

    Selden, Annie; McKee, Kerry; Selden, John

    2010-01-01

    In this largely theoretical article, we discuss the relation between a kind of affect, behavioural schemas and aspects of the proving process. We begin with affect as described in the mathematics education literature, but soon narrow our focus to a particular kind of affect--nonemotional cognitive feelings. We then mention the position of feelings…

  18. Proving a Result in Combinatorics using Equations

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 2. Proving a Result in Combinatorics using Equations. V Rajesh. Classroom Volume 9 Issue 2 February 2004 pp 85-87. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/009/02/0085-0087. Keywords.

  19. Bioensaios de atividade alelopática dos esteroides espinasterol, espinasterona e glicopiranosil espinasterol Bioassays of allelopathic activity of the steroids spinasterol, spinasterone, and spinasterol glicopyranosyl

    Directory of Open Access Journals (Sweden)

    H.S. Ripardo Filho

    2012-12-01

    spinasterol inhibited 10% of the seed germination of the species Mimosa pudica. These results showed that the difference of substitutes at the C-3 position of the steroids can influence allelopathic activity: the glicosyl group at the C-3 position enhanced the inhibition of hypocotyl growth of the species Mimosa pudica, compared to the hydroxilated and carbonylated steroid. This is the first chemical and allelopathic study with Moutabea guianensis.

  20. On proving syntactic properties of CPS programs

    DEFF Research Database (Denmark)

    Danvy, Olivier; Dzafic, Belmina; Pfenning, Frank

    1999-01-01

    Higher-order program transformations raise new challenges for proving properties of their output, since they resist traditional, first-order proof techniques. In this work, we consider (1) the “one-pass” continuation-passing style (CPS) transformation, which is second-order, and (2) the occurrences...... of parameters of continuations in its output. To this end, we specify the one-pass CPS transformation relationally and we use the proof technique of logical relations....

  1. Automated theorem proving theory and practice

    CERN Document Server

    Newborn, Monty

    2001-01-01

    As the 21st century begins, the power of our magical new tool and partner, the computer, is increasing at an astonishing rate. Computers that perform billions of operations per second are now commonplace. Multiprocessors with thousands of little computers - relatively little! -can now carry out parallel computations and solve problems in seconds that only a few years ago took days or months. Chess-playing programs are on an even footing with the world's best players. IBM's Deep Blue defeated world champion Garry Kasparov in a match several years ago. Increasingly computers are expected to be more intelligent, to reason, to be able to draw conclusions from given facts, or abstractly, to prove theorems-the subject of this book. Specifically, this book is about two theorem-proving programs, THEO and HERBY. The first four chapters contain introductory material about automated theorem proving and the two programs. This includes material on the language used to express theorems, predicate calculus, and the rules of...

  2. Theorem Proving In Higher Order Logics

    Science.gov (United States)

    Carreno, Victor A. (Editor); Munoz, Cesar A.; Tahar, Sofiene

    2002-01-01

    The TPHOLs International Conference serves as a venue for the presentation of work in theorem proving in higher-order logics and related areas in deduction, formal specification, software and hardware verification, and other applications. Fourteen papers were submitted to Track B (Work in Progress), which are included in this volume. Authors of Track B papers gave short introductory talks that were followed by an open poster session. The FCM 2002 Workshop aimed to bring together researchers working on the formalisation of continuous mathematics in theorem proving systems with those needing such libraries for their applications. Many of the major higher order theorem proving systems now have a formalisation of the real numbers and various levels of real analysis support. This work is of interest in a number of application areas, such as formal methods development for hardware and software application and computer supported mathematics. The FCM 2002 consisted of three papers, presented by their authors at the workshop venue, and one invited talk.

  3. Evaluation of allelopathic effects of eucalyptus (Eucalyptus globules Labill. on germination, morphological and biochemical criteria of barley (Hordeum vulgare L. and flixweed (Descurainia Sophia L.

    Directory of Open Access Journals (Sweden)

    R. Saraei

    2016-05-01

    Full Text Available In order to examine the allelochemic effects of seed and leaf aqueous extracts of eucalyptus (Eucalyptus globules Labill. on germination, growth, morphological and biochemical criteria of barley (Hordeum vulgare L. and flixweed (Descurainia Sophia L., a series of experiments with five levels of seed and leaf aqueous extract of eucalyptus, including concentrations of 30, 50, 70, 90 and 100 percents by weight–volume, separately for seed and leaf with control treatment (distilled water in a completely random design with three replications were conducted. All experiments conducted in laboratory of Biology, Faculty of Sciences, Ferdowsi University of Mashhad during 2010. The results showed that the seeds and leaves aqueous extracts of eucalyptus at all concentrations had inhibitory effects on final germination percentage and germination rate of both species. The inhibitory effects enhanced as the extract concentration increased. The shoot and root lengths and fresh and dry weights were greatly reduced in flixweed than in barley. Similarly, chlorophyll a and b and total chlorophyll contents were decreased in leaf of barley and flixweed In both species, accumulation of proline and soluble sugars amounts increased, it seems that this is an adjustment mechanism for ameliorate of stress tolerance. The results of this study also showed that the seeds aqueous extract of eucalyptus was more effective in morphological and biochemical characteristics of two species than to leaves; it was also observed that allelopathic impacts of eucalyptus seeds was more for dicotyledon species (flixweed than to monocot (barley. Finally, it seems that the allelopathic chemicals of seeds and leaves aqueous extracts of eucalyptus may have the potential as biological herbicide or new formulation of herbicide.

  4. Comparative characteristics of Lupinus albus L. and Lupinus luteus L. under allelopathic effect of Sorghum halepense L. (Pers.

    Directory of Open Access Journals (Sweden)

    Natalia Georgieva

    2015-01-01

    Full Text Available Allelopathic effects of aqueous extracts of Sorghum halepense L. (Pers. on seed germination and primary seedling growth and development of two lupine species was studied. Lupinus albus and Lupinus luteus showed different levels of susceptibility to the allelopathic effect of weed extracts. Increasing concentrations (1.25, 2.50, 5.00 and 10.00% of extracts from aboveground and belowground biomass suppressed seed germination of L. luteus from 53.2 to 74.7%. The germination of L. albus seeds was unaffected, except by the highest concentration of 10.00%. Fresh biomass accumulation in the initial germ of L. luteus was inhibited by 3.8-40.3% under the effect of concentrations of 2.50, 5.00 and 10.00%, which made the species susceptible to S. halepense extracts. L. albus was tolerant as it was not found to sustain a significant allelopathic effect of the extracts.

  5. Interval logic. Proof theory and theorem proving

    DEFF Research Database (Denmark)

    Rasmussen, Thomas Marthedal

    2002-01-01

    of a direction of an interval, and present a sound and complete Hilbert proof system for it. Because of its generality, SIL can conveniently act as a general formalism in which other interval logics can be encoded. We develop proof theory for SIL including both a sequent calculus system and a labelled natural...... deduction system. We conduct theoretical investigations of the systems with respect to subformula properties, proof search, etc. The generic theorem proving system Isabelle is used as a framework for encoding both proof theoretical systems. We consider a number of examples/small case-studies and discuss...

  6. Caracterização química e efeitos alelopáticos de exsudatos radiculares de plântulas de sorgo sobre alface Chemical characterization and allelopathic effects of radicular exudates of plants of sorghum over lettuce leaves

    Directory of Open Access Journals (Sweden)

    Tânia Maria L. Barbosa

    1998-12-01

    Full Text Available A análise química do exsudato radicular do sorgo resultou na identificação da quinona sorgoleona 1 e da diidroquinona 2, como seus principais constituintes. Em testes in vitro, uma solução a 20 mM do exsudato causou redução de 13,1% no crescimento radicular de Lactuca sativa L. Em um sistema de cultura hidropônico recirculante, o exsudato radicular produzido por quatro plantas de sorgo causou uma redução de 62,4% na área foliar da alface, 33 dias após o plantio.A chemical analysis of the Sorghum bicolor root exudate lead to the identification of the quinone sorgoleone 1 and the corresponding dihydroquinone 2 as the major components. An in vitro essay have shown that at the concentration of 20 mM this exudate caused a 13.1% reduction on the radicular growth of Lactuca sativa L. In a recirculating hydroponic culture system, the exudate produced by the roots of four plants of sorghum caused a 62.4% reduction on the lettuce leaf area after 33 days of planting.

  7. Resolution methods in proving the program correctness

    Directory of Open Access Journals (Sweden)

    Markoski Branko

    2007-01-01

    Full Text Available Program testing determines whether its behavior matches the specification, and also how it behaves in different exploitation conditions. Proving of program correctness is reduced to finding a proof for assertion that given sequence of formulas represents derivation within a formal theory of special predicted calculus. A well-known variant of this conception is described: correctness based on programming logic rules. It is shown that programming logic rules may be used in automatic resolution procedure. Illustrative examples are given, realized in prolog-like LP-language (with no restrictions to Horn's clauses and without the final failure. Basic information on LP-language are also given. It has been shown how a Pascal-program is being executed in LP-system proffer.

  8. Theorem Proving in Intel Hardware Design

    Science.gov (United States)

    O'Leary, John

    2009-01-01

    For the past decade, a framework combining model checking (symbolic trajectory evaluation) and higher-order logic theorem proving has been in production use at Intel. Our tools and methodology have been used to formally verify execution cluster functionality (including floating-point operations) for a number of Intel products, including the Pentium(Registered TradeMark)4 and Core(TradeMark)i7 processors. Hardware verification in 2009 is much more challenging than it was in 1999 - today s CPU chip designs contain many processor cores and significant firmware content. This talk will attempt to distill the lessons learned over the past ten years, discuss how they apply to today s problems, outline some future directions.

  9. allelopathic effects of eucalyptus tereticornis on phaseolus vulgaris ...

    African Journals Online (AJOL)

    user

    The water extracts of leaves (green, brown and decayed stages) and bark of Eucalyptus tereticornis were tested for seed ... percentage of Phaseolus vulgaris due to the treatments of water extracts of leaves and bark of Eucalyptus, also affected the ... chemicals from its leaves or litter which inhibits the germination or growth ...

  10. Allelopathic potential of sunflower (Helianthus annus L.) on soil ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-09-17

    Sep 17, 2008 ... consisting of 2 g diammonium phosphate, 1 g urea, and 1 g potash. When the plants reached the vegetative stage ... Physical and chemical properties of soil were determined by following the standard method (Nelson and ... magnesium, iron, and manganese. Nitrate-nitrogen was determined by following ...

  11. Kenaf’s allelopathic impact on seedling growth

    Science.gov (United States)

    Allelopathy is the chemical interaction between plants, which may result in the inhibition of plant growth and development. Research was conducted to determine the impact of kenaf (Hibiscus cannabinus L.) plant extracts on the post-germination growth of five plant species. Four concentrations (0, 16...

  12. Allelopathic effect of Jatropha curcas (Lin) leachate on germination ...

    African Journals Online (AJOL)

    Allelopathy refers to the chemical inhibition of one species by another. Decline in crop yields in cropping and agroforestry system in recent years has been attributed to allelopathy effects.Laboratory studies were conducted at Research Centre for Tissue Culture, Kazaure, Jigawa state (Longitude08¢ª 41 . N and Latitude12o ...

  13. Assessment of allelopathic potential of Cassia sophera L. on ...

    African Journals Online (AJOL)

    Allelopathy is described as both beneficial and deleterious biochemical interaction between plant and weeds, and/or plant and microorganisms through the production of chemical compounds that escape into the environment and subsequently influence the growth and development of neighbouring plants. The present ...

  14. Efeito alelopático de folhas de bamburral [Hyptis suaveolens (L. Poit.] sobre a germinação de sementes de sorgo (Sorghum vulgare Pers., rabanete (Raphanus sativus L. e alface (Lactuca sativa L. Allelopathic effects of leaves of "bamburral" [Hyptis suaveolens (L. Poit.] on the germination of seeds of sorghum (Sorghum vulgare Pers. , radish (Raphanus sativus L. and lettuce (Lactuca sativa L.

    Directory of Open Access Journals (Sweden)

    A.C. Rodrigues

    2012-01-01

    Full Text Available O objetivo do presente trabalho foi à verificação do efeito alelopático de Hyptis. suaveolens na germinação de sorgo, alface e rabanete, bem como, a comprovação da existência de compostos com potencial alelopático. Sementes de sorgo, alface e rabanete foram semeadas em substrato constituído de areia, terra e adubo orgânico contendo folhas de H. suaveolens. As análises da germinação foram feitas considerando a protrusão da radícula para o término do evento germinativo. Foi calculado o IVG (índice de velocidade de germinação e %G (porcentagem de germinação. Os resultados mostraram que sorgo e a alface foram mais susceptíveis ao potencial alelopático de H. suaveolens, sendo que para o rabanete foi observado um efeito benéfico. Entre os tratamentos, o substrato esterilizado e não esterilizado mostraram diferenças entre si. A análise cromatográfica do óleo essencial presente nas folhas de H. suaveolens revelou a presença de compostos com potencial alelopático. Portanto, H. suaveolens, pode apresentar efeito alelopático positivo no IVG de sementes de rabanete e a presença de microorganismos pode ser necessária para que esse efeito alelopático aconteça.The aim of this study was to verify the allelopathic effect of H. suaveolens on the germination of sorghum, lettuce and radish, as well as to prove the existence of compounds with allelopathic potential. Seeds of sorghum, lettuce and radish were sown in substrate consisting of sand, soil and organic fertilizer containing leaves of H. suaveolens. The germination tests were performed considering the protrusion of the radicle for the conclusion of the germinative event. GSI (germination speed index and G% (percentage of germination were calculated. The results showed that sorghum and lettuce were more susceptible to the allelopathic potential of H. suaveolens, while for radishes a beneficial effect was observed. Between treatments, the sterilized and unsterilized

  15. Potent endogenous allelopathic compounds in Lepidium sativum seed exudate: effects on epidermal cell growth in Amaranthus caudatus seedlings

    Science.gov (United States)

    Iqbal, Amjad; Fry, Stephen C.

    2012-01-01

    Many plants exude allelochemicals – compounds that affect the growth of neighbouring plants. This study reports further studies of the reported effect of cress (Lepidium sativum) seed(ling) exudates on seedling growth in Amaranthus caudatus and Lactuca sativa. In the presence of live cress seedlings, both species grew longer hypocotyls and shorter roots than cress-free controls. The effects of cress seedlings were allelopathic and not due to competition for resources. Amaranthus seedlings grown in the presence of cress allelochemical(s) had longer, thinner hypocotyls and shorter, thicker roots – effects previously attributed to lepidimoide. The active principle was more abundant in cress seed exudate than in seedling (root) exudates. It was present in non-imbibed seeds and releasable from heat-killed seeds. Release from live seeds was biphasic, starting rapidly but then continuing gradually for 24 h. The active principle was generated by aseptic cress tissue and was not a microbial digestion product or seed-treatment chemical. Crude seed exudate affected hypocotyl and root growth at ∼25 and ∼450 μg ml−1 respectively. The exudate slightly (28%) increased epidermal cell number along the length of the Amaranthus hypocotyl but increased total hypocotyl elongation by 129%; it resulted in a 26% smaller hypocotyl circumference but a 55% greater epidermal cell number counted round the circumference. Therefore, the effect of the allelochemical(s) on organ morphology was imposed primarily by regulation of cell expansion, not cell division. It is concluded that cress seeds exude endogenous substances, probably including lepidimoide, that principally regulate cell expansion in receiver plants. PMID:22268144

  16. Valutazione economica dello studio PROVE-IT

    Directory of Open Access Journals (Sweden)

    Lorenzo G. Mantovani

    2007-10-01

    Full Text Available Introduction: the PROVE-IT (“Intensive versus moderate lipid lowering with statins after acute coronary syndromes” was a comparison of pravastatin 40 mg/die versus atorvastatin 80 mg/die in patients with an acute coronary syndrome (ACS. Aim: our aim was to investigate the economic consequence of high dose of atorvastatin vs usual-dose of pravastatin in Italian patients with a history of acute coronary syndrome. Methods: the analysis is conducted on the basis of clinical outcomes of the PROVE-IT study. We conducted a cost-effectiveness analysis, comparing high dose of atorvastatin (80 mg/die versus usual-dose of pravastatin (40 mg/die in the perspective of the Italian National Health Service. We identified and quantified medical costs: drug costs according to the Italian National Therapeutic Formulary and hospitalizations were quantified based on the Italian National Health Service tariffs (2006. Effects were measured in terms of mortality and morbidity reduction (number of deaths, life years gained and frequency of hospitalizations. We considered an observation period of 24 months. The costs borne after the first 12 months were discounted using an annual rate of 3%. We conducted one and multi-way sensitivity analyses on unit cost and effectiveness. We also conducted a threshold analysis. Results: the cost of pravastatin or atorvastatin therapy over the 2 years period amounted to approximately 1.3 millions euro and 870,000 euro per 1,000 patients respectively. Atorvastatin was more efficacious compared to pravastatin and the overall cost of care per 1,000 patients over 24 months of follow-up was estimated at 3.2 millions euro in the pravastatin and 2.5 millions euro in the atorvastatin group, resulting into a cost saving of about 700,000 euro that is 27% of total costs occurred in the pravastatin group. Discussion: this study demonstrates that high does atorvastatin treatment leads to a reduction of direct costs for the National Health System

  17. a Test to Prove Cloud Whitening THEORY!

    Science.gov (United States)

    Buttram, J. W.

    2011-12-01

    Climate science researchers believe our planet can possibly tolerate twice the present carbon dioxide levels with no upwards temperature change, IF we could increase the amount of energy reflected back out into space by about 2.0%. (c)Cloudtec basically alters a blend of seawater and applies heat derived from magma to it at a temperature exceeding 2,000 degrees F. The interaction of seawater and magma displaces the oxygen, causing the volume of water to vaporize and expand over 4,000 times - transforming billions of tons of seawater into thousands of cubic miles of white, maritime, stratocumulus clouds to reflect the incident Sun's rays back out into space. A 6 month test to prove Cloud Whitening Theory will cost 6 million dollars. (No profit added.) This study will enable everyone on the planet with a computer the transparency to use satellite imagery and check out for themselves - if and when Cloud Whitening is occurring. If Cloud Whitening Theory is validated, (c)Cloudtec's innovation can strategically create the clouds we need to reflect the Sun's rays back out into space and help neutralize the projected 3.6 degrees F rise in temperature. Based on reasonable calculations of anthropogenic global warming: this one move alone would be comparable to slashing global carbon dioxide emissions by over 60% over the next 40 years.

  18. Simulated acid rain alters litter decomposition and enhances the allelopathic potential of the invasive plant Wedelia trilobata (Creeping Daisy)

    Science.gov (United States)

    Invasive species and acid rain cause global environmental problems. Limited information exists, however, concerning the effects of acid rain on the invasiveness of these plants. For example, creeping daisy, an invasive exotic allelopathic weed, has caused great damage in southern China where acid ra...

  19. Allelopathic influence of a wheat or rye cover crop on growth and yield of no-till cotton

    Science.gov (United States)

    TECHNICAL ABSTRACT No-till planting cotton into small grain cover crops has many benefits including reducing soil erosion and allelopathic suppression of weeds. It is suggested that the potentials of allelopathy on cotton plants. Nevertheless, little is known about the actual effects of alleloche...

  20. Allelopathic effect of essential oils of medicinal plants in Bidens pilosa L.

    Directory of Open Access Journals (Sweden)

    M.C.S. Alves

    2014-01-01

    Full Text Available We determined the inhibitory allelopathic effects of the volatile extracts of Cinnamomum zeylanicum Ness, Lippia sidoides Cham. and Cymbopogum nardus L. on seed germination and root growth of seedlings of Bidens pilosa. The experiment was conducted at the Seed Analysis Laboratory of the Department of Plant Science, Federal University of Ceará. For this end, we used oils at the concentrations of 0.01, 0.02, 0.04 and 0.08% (v/v. Five treatments were used for each of the oils arranged in a completely randomized design with four replications of 25 seeds. The seeds were sown in Petri dishes lined with filter paper moistened with distilled water and, aiming at the indirect contact with each oil, two sheets of filter paper were placed on top of the lid, in which three (3 mL of each oil solution were added. Then, the dishes were incubated in a germination chamber at 25°C. The pH did not contribute to alter the results; the volatile extracts of essential oils of C. zeylanicum, L. sidoides and C. nardus inhibited seed germination and root growth of seedlings of B. pilosa, which shows allelopathic potential; and the concentration of 0.08% of oils caused the overall deterioration of the roots and death of seedlings of B. pilosa.

  1. Allelopathic tolerance of pea cultivars to Sorghum halepense L. (Pers. extracts

    Directory of Open Access Journals (Sweden)

    Georgieva Natalia

    2016-01-01

    Full Text Available In order to evaluate the allelopathic effect of Sorghum halepense extracts on germination and initial growth of six pea (Pisum sativum subsp. sativum, Pisum sativum subsp. arvense cultivars and to identify tolerant cultivars, a laboratory experiment was conducted. The studied cultivars revealed different levels of susceptibility to allelopathic impact of root and aboveground biomass extracts of S. halepense. Root growth parameters (length and weight of the pea cultivars exhibited greater susceptibility to weed extracts than stem parameters. The inhibitory effects of the extracts on germ length of P. sativum ranged from 1.4% (cultivar Mir to 45.0% (Kamerton, on germ weight - from 3.5% (Pleven 4 to 42.9% (K-80, and on seed germination - from 11.8% (Mir to 31.3% (K-80. Total inhibitory effect, i.e. the impact of S. halepense extracts on all studied parameters of P.sativum, revealed that the cultivars Mir and Pleven 4 were the most tolerant. Growing such cultivars may reduce weed damage. Low tolerance was manifested by the cultivar K-80, while Modus, Glyans and Kamerton ranked intermediate. The cultivars with large-size seeds or lower grain protein content were more affected by the depressing effect of S. halepense extracts.

  2. Garlic exerts allelopathic effects on pepper physiology in a hydroponic co-culture system

    Directory of Open Access Journals (Sweden)

    Haiyan Ding

    2016-05-01

    Full Text Available A hydroponic co-culture system was adopted to determine the allelopathic potential of garlic on the growth of pepper plants. Different numbers of garlic plants (0, 2, 4, 8 and 12 were hydroponically co-cultured with two pepper plants to investigate allelopathic effects on the growth attributes and antioxidative defense system of the test pepper plants. The responses of the pepper plants depended on the number of garlic plants included in the co-culture system, indicating an association of pepper growth with the garlic root exudate concentration. When grown at a pepper/garlic ratio of 1:1 or 1:2, the pepper plant height, chlorophyll content, and peroxidase (POD, catalase (CAT and phenylalanine ammonia-lyase (PAL activities were significantly increased after 30 days of co-culture; in contrast, reduction in methane dicarboxylic aldehyde (MDA content was observed. However, when the pepper/garlic ratio was 1:4 or higher, these morphological indices and protective enzyme activities were significantly inhibited, whereas MDA levels in the pepper leaves were significantly increased due to severe membrane lipid peroxidation. The results indicate that although low concentrations of garlic root exudates appear to induce protective enzyme systems and promote pepper growth, high concentrations have deleterious effects. These findings suggest that further investigations should optimize the co-culture pepper/garlic ratio to reduce continuous cropping obstacles in pepper production.

  3. Combined effect of predatory zooplankton and allelopathic aquatic macrophytes on algal suppression.

    Science.gov (United States)

    Zuo, Shengpeng; Wan, Kun; Ma, Sumin

    2015-01-01

    The present study evaluated the combined effects of four typical predatory zooplankton and allelopathic aquatic macrophytes on algal control in a microcosm system. It would determine the effects of diverse species and biological restoration on the growth of harmful water-bloom microalgae in great lakes polluted by excess nutrients. It was found that the mixtures of each zooplankton and the floating plant Nymphoides peltatum had stronger inhibitory effects on harmful water-bloom microalgae than the individual species in clean or eutrophic water bodies. In addition, a community of four zooplankton types had a synergistic effect on algal inhibition. Algal suppression by the zooplankton community was enhanced significantly when the macrophyte was co-cultured in the microcosm. Furthermore, Chlorella pyrenoidosa was more susceptible than Microcystis aeruginosa when exposed to grazing by zooplankton and the allelopathic potential of the macrophyte. Algal inhibition was also weaker in eutrophic conditions compared with the control. These findings indicate that diverse species may enhance algal inhibition. Therefore, it is necessary to restore biological diversity and rebuild an ecologically balanced food chain or web to facilitate the control of harmful algal blooms in eutrophic lakes.

  4. Allelopathic interaction of Jatropha curcas L. with Helianthus annuus L. and Zea mays L.

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Siberti da Silva

    2012-09-01

    Full Text Available The goals of this work were to evaluate the effect of the allelopathic interaction of Jatropha curcas with Helianthus annuus and Zea mays from root exudates, as well as to evaluate how these exudates influenced the seeds of these species. Four replicates were made with seeds that were germinated in germiteste paper, which was previously autoclaved. Dormancy of the H. annuus seeds was broken by pre-cooling them in a freezer for seven days at 5°C. Jatropha curcas seeds were cultivated for eight days in a germination chamber under a controlled temperature and photoperiod. These seedlings were then discarded and the same substrate was used to germinate 50 H. annuus seeds; only distilled water was used as the control. The root exudates of H. annuus tested on J. curcas and the allelopathic interaction between J. curcas and Z. mays were carried out using the same methodology. Statistical analysis indicated that J. curcas has an inhibitory effect on the time and average speed of germination of H. annuus seedlings and Z. mays has an inhibitory effect on the germination of the seeds of J. curcas.

  5. New insights on the species-specific allelopathic interactions between macrophytes and marine HAB dinoflagellates.

    Science.gov (United States)

    Ben Gharbia, Hela; Kéfi-Daly Yahia, Ons; Cecchi, Philippe; Masseret, Estelle; Amzil, Zouher; Herve, Fabienne; Rovillon, Georges; Nouri, Habiba; M'Rabet, Charaf; Couet, Douglas; Zmerli Triki, Habiba; Laabir, Mohamed

    2017-01-01

    Macrophytes are known to release allelochemicals that have the ability to inhibit the proliferation of their competitors. Here, we investigated the effects of the fresh leaves of two magnoliophytes (Zostera noltei and Cymodocea nodosa) and thalli of the macroalgae Ulva rigida on three HAB-forming benthic dinoflagellates (Ostreopsis cf. ovata, Prorocentrum lima, and Coolia monotis). The effects of C. nodosa and U. rigida were also tested against the neurotoxic planktonic dinoflagellate Alexandrium pacificum Litaker sp. nov (former Alexandrium catenella). Co-culture experiments were conducted under controlled laboratory conditions and potential allelopathic effects of the macrophytes on the growth, photosynthesis and toxin production of the targeted dinoflagellates were evaluated. Results showed that U. rigida had the strongest algicidal effect and that the planktonic A. pacificum was the most vulnerable species. Benthic dinoflagellates seemed more tolerant to potential allelochemicals produced by macrophytes. Depending on the dinoflagellate/macrophyte pairs and the weight of leaves/thalli tested, the studied physiological processes were moderately to heavily altered. Our results suggest that the allelopathic activity of the macrophytes could influence the development of HAB species.

  6. New insights on the species-specific allelopathic interactions between macrophytes and marine HAB dinoflagellates.

    Directory of Open Access Journals (Sweden)

    Hela Ben Gharbia

    Full Text Available Macrophytes are known to release allelochemicals that have the ability to inhibit the proliferation of their competitors. Here, we investigated the effects of the fresh leaves of two magnoliophytes (Zostera noltei and Cymodocea nodosa and thalli of the macroalgae Ulva rigida on three HAB-forming benthic dinoflagellates (Ostreopsis cf. ovata, Prorocentrum lima, and Coolia monotis. The effects of C. nodosa and U. rigida were also tested against the neurotoxic planktonic dinoflagellate Alexandrium pacificum Litaker sp. nov (former Alexandrium catenella. Co-culture experiments were conducted under controlled laboratory conditions and potential allelopathic effects of the macrophytes on the growth, photosynthesis and toxin production of the targeted dinoflagellates were evaluated. Results showed that U. rigida had the strongest algicidal effect and that the planktonic A. pacificum was the most vulnerable species. Benthic dinoflagellates seemed more tolerant to potential allelochemicals produced by macrophytes. Depending on the dinoflagellate/macrophyte pairs and the weight of leaves/thalli tested, the studied physiological processes were moderately to heavily altered. Our results suggest that the allelopathic activity of the macrophytes could influence the development of HAB species.

  7. Chemical Composition and Allelopathic Potential of Essential Oils from Citharexylum spinosum L. Grown in Tunisia.

    Science.gov (United States)

    El Ayeb-Zakhama, Asma; Sakka-Rouis, Lamia; Flamini, Guido; Ben Jannet, Hichem; Harzallah-Skhiri, Fethia

    2017-04-01

    Citharexylum spinosum L. (Verbenaceae) also known as Citharexylum quadrangulare Jacq. or Citharexylum fruticosum L. is an exotic tree introduced many years ago in Tunisia, specially used as a street and park ornamental tree. Essential oils (EOs) were obtained by hydrodistillation of the different parts (roots, stems, leaves, flowers and fruits; drupes) collected from trees grown in the area of Monastir (Tunisia). In total, 84 compounds, representing 90.1 - 98.4% of the whole oil composition, were identified by GC-FID and GC/MS analyses. The root EO was distinguished by its high content in monoterpene hydrocarbons (α-phellandrene; 30.8%) whereas that obtained from stems was dominated by sesquiterpene hydrocarbons (cuparene; 16.4%). The leaf oil was rich in an apocarotenoid derivative (hexahydrofarnesylacetone; 26%) and an aliphatic hydrocarbon (nonadecane; 14.5%). Flowers oil was rich in esters (2-phenylethyl benzoate; 33.5%). Finally, drupes oil was rich in oxygenated sesquiterpenes (β-eudesmol; 33.1%). Flowers oil showed a significant phytotoxic effect against lettuce seeds germination, it induces a total inhibition when tested at 1 mg/ml. Root and shoot elongation seemed to be more affected than germination. The inhibition of the shoot length varied from 3.6% to 100% and that of the root from 16.1% to 100%. The highest inhibition of 100% was detected for flower oil tested at 1 mg/ml. Our in vitro studies suggest a possible and new alternative use of C. spinosum EOs in herbicidal formulations, further experiments involving field conditions are necessary to confirm its herbicidal potential. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  8. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  9. Evaluation of depleted uranium in the environment at Aberdeen Proving Grounds, Maryland and Yuma Proving Grounds, Arizona. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, P.L.; Clements, W.H.; Myers, O.B.; Bestgen, H.T.; Jenkins, D.G. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Fishery and Wildlife Biology

    1995-01-01

    This report represents an evaluation of depleted uranium (DU) introduced into the environment at the Aberdeen Proving Grounds (APG), Maryland and Yuma Proving Grounds (YPG) Arizona. This was a cooperative project between the Environmental Sciences and Statistical Analyses Groups at LANL and with the Department of Fishery and Wildlife Biology at Colorado State University. The project represents a unique approach to assessing the environmental impact of DU in two dissimilar ecosystems. Ecological exposure models were created for each ecosystem and sensitivity/uncertainty analyses were conducted to identify exposure pathways which were most influential in the fate and transport of DU in the environment. Research included field sampling, field exposure experiment, and laboratory experiments. The first section addresses DU at the APG site. Chapter topics include bioenergetics-based food web model; field exposure experiments; bioconcentration by phytoplankton and the toxicity of U to zooplankton; physical processes governing the desorption of uranium from sediment to water; transfer of uranium from sediment to benthic invertebrates; spead of adsorpion by benthic invertebrates; uptake of uranium by fish. The final section of the report addresses DU at the YPG site. Chapters include the following information: Du transport processes and pathway model; field studies of performance of exposure model; uptake and elimination rates for kangaroo rates; chemical toxicity in kangaroo rat kidneys.

  10. THE INITIAL GROWTH AND DEVELOPMENT OF POA PRATENSIS UNDER THE ALLELOPATHIC INFLUENCE OF TARAXACUM OFFICINALE

    Directory of Open Access Journals (Sweden)

    Kazimierz Jankowski

    2014-04-01

    Full Text Available This experiment was carried out in laboratory conditions. The aim of this work was estimating allelopathic potential of Taraxacum officinale on seeds germination and initial growth of Poa pratensis. In the experiment different concentration of soil’s and plant’s water solution obtained from common dandelion were employed. The inhibition of germination energy of Poa pratensis under the influence of plant extracts produced from roots and leaves of Taraxacum officinale was found. Germination availability was inhibited in a higher degree by extracts prepared from the leaves than the roots of Taraxacum officinale. Higher concentrations of all solutions of both the soil and the plant inhibited the length of seending of Poa pratensis.

  11. Composition of essential oil and allelopathic activity of aromatic water of Aster lanceolatus Willd: (Asteraceae

    Directory of Open Access Journals (Sweden)

    Josiane de Fátima Gaspari Dias

    2009-09-01

    Full Text Available The essential oil obtained from flowers of Aster lanceolatus was submitted the CG-MS and presented as result thirteen substances with largest concentration; among them, the caryophyllene oxide with the larger one. The aromatic water obtained during the extraction process of this essential oil was forwarded to allelopathic test, and demonstrated to be capable to inhibit the germination and growth of Lactuca sativa.O óleo essencial obtido das flores de Aster lanceolatus foi submetido a CG-EM e apresentou como resultado treze substâncias, entre elas o óxido de cariofileno com a maior concentração. A água aromática obtida durante o processo de extração do óleo essencial foi encaminhada para teste alelopático, a qual demonstrou ser capaz de inibir a germinação e crescimento de Lactuca sativa.

  12. [Allelopathic effects of Artemisia frigida on three Poaceae plants seed germination and seedling growth].

    Science.gov (United States)

    Li, Xue-feng; Wang, Jian; Xu, Wen-bo; Wang, Kun

    2010-07-01

    Aqueous extracts of Artemisia frigida leaf and stem and soils beneath A. frigida were used to test their allelopathic effects on the seed germination and seedling growth of three Poaceae plants (Leymus chinensis, Stipa krylovii, and Cleistogenes squarrosa) on Leymus chinensis grassland. The aqueous extracts of A. frigida leaf and stem decreased the seed germination index of test plants and prolonged their seed germination time, and inhibited the shoot growth of the three plants and the root growth of S. krylovii. The aqueous extracts at concentration > or = 0.075 g x ml(-1) presented a strong inhibition on the root growth of L. chinensis, while those at concentration L. chinense > C. squarrosa, with a higher sensitivity of root growth than shoot growth.

  13. Fate of allelopathic substances in space--allelopathy of velvet bean plant and gravity.

    Science.gov (United States)

    Tomita-Yokotani, Kaori; Hashimoto, Hirofumi; Fujii, Yoshiharu; Nakamura, Teruko; Yamashita, Masamichi

    2004-11-01

    Interactions between organisms and species have been long known. It has not been known that the interactive phenomena (allelopathy) may (or may not) differ in space from those on earth. We have studied the gravitational effects on allelopathy by exposing a plant-plant system to pseudo-microgravity, which was generated by a 3D-clinostat. We hypothesized that allelopathy would be modified under altered gravity. L-DOPA (L-3,4-dihydroxyphenylalanine) is known to be the major substance in the allelopathy of velvet bean, released from its root. It has been found that there have been some differences of the allelopathic action of velvet bean plant under pseudo-microgravity. Biosynthesis, release, transport and sensing mechanism associated with allelopathy might be affected by gravity.

  14. Allelopathic Effects of Myriophyllum aquaticum on Two Cyanobacteria of Anabaena flos-aquae and Microcystis aeruginosa.

    Science.gov (United States)

    Wang, Haiping; Liu, Feng; Luo, Pei; Li, Zihan; Zheng, Liguo; Wang, Hua; Zou, Dongsheng; Wu, Jinshui

    2017-04-01

    Allelopathy has been proposed as a sustainable means to control undesired algal growth and to reduce blooms threatening freshwater systems worldwide. In this study, the allelopathic effects of Myriophyllum aquaticum and its exudate on two typical bloom-forming cyanobacteria, Microcystis aeruginosa and Anabaena flos-aquae, were investigated under laboratory conditions. The growth of the cyanobacteria was strongly inhibited by live M. aquaticum while the primary addition of M. Aquaticum exudates had a significant inhibitory effect on the growth of M. aeruginosa but not A. flos-aquae. The results suggested that the persistent release of allelochemicals from live M. aquaticum was needed to effectively constrain the growth of A. flos-aquae. Analysis of cyanobacterial physiological indexes indicated that M. aquaticum produced an inhibitory effect on SOD enzyme activity of A. flos-aquae, while it affected membrane lipid peroxidation in M. aeruginosa. The results show the potential of M. aquaticum to mitigate cyanobacterial blooms in coexistence systems.

  15. Allelopathic effect of melissa, lemongrass, lavender and rosemary on germination and vigor of lettuce seeds

    Directory of Open Access Journals (Sweden)

    Daniela Aparecida Teixeira

    2014-09-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2014v27n4p37 The objective of this study was to evaluate the influence of four herbal plants on the germination and vigor of lettuce seeds, using aqueous preparations and teas of Melissa officinalis L. (melissa, Rosmarinus officinalis L. (rosemary, Lavandula angustifolia Mill. (lavender and Cymbopogon citratus (DC. Stapf. (lemongrass. A randomized complete block design was used with 9 treatments and 4 repetitions. The treatments were: melissa tea, melissa aqueous preparation, rosemary tea, rosemary aqueous preparation, lavender tea, lavender aqueous preparation, lemongrass tea, lemongrass aqueous preparation and control. The variables evaluated were: germination speed index, percentage of abnormal plants, percentage of germinated plants, fresh matter, dry matter, shoot length and radicle length. Lemongrass showed negative allelopathic effects on germination and vigor of L. sativa L. Melissa tea had a stimulatory effect.

  16. Examination of common ragweed's (Ambrosia artemisiifolia L.) allelopathic effect on some weed species.

    Science.gov (United States)

    Lehoczky, E; Szabó, R; Nelima, M Okumu; Nagy, P; Béres, I

    2010-01-01

    In the last decades the importance of some weed species increased in Hungary. The common ragweed (Ambrosia artemisiifolia L.) also belongs to this group. The allelopathic effect of watery extract made from different plant parts of common ragweed (air dried leafy shoots, seeds) were studied on the germination and growth of some weed species. The extracts were prepared with tap water, chopped dry plant materials were added to water and 24 hours later the material was filtered. The germination took place in a Binder KBW type thermostat in dark. 25 seeds were put into one Petri-dish, adding 15 ml plant extract to each in four repeats. The timing of germination was checked in every two days and the rate of growth was estimated after a week, by counting the numbers of germinated seeds and measuring the length of the radicle and plumula. The measured data were statistically analysed and the effect of extracts on germinating ratio and seedling length were evaluated.

  17. Allelopathic effect of new introduced biofuel crops on the soil biota: A comparative study

    Science.gov (United States)

    Heděnec, Petr; Frouz, Jan; Ustak, Sergej; Novotny, David

    2015-04-01

    Biofuel crops as an alternative to fossil fuels are a component of the energy mix in many countries. Many of them are introduced plants, so they pose a serious threat of biological invasions. Production of allelopathic compounds can increase invasion success by limiting co-occurring species in the invaded environment (novel weapons hypothesis). In this study, we focused on plant chemistry and production of allelopathic compounds by biofuel crops (hybrid sorrel Rumex tianschanicus x Rumex patientia and miscanthus Miscanthus sinensis) in comparison with invasive knotweed (Fallopia sachalinensis) and cultural meadow species. First, we tested the impact of leachates isolated from hybrid sorrel, miscanthus, knotweed and cultural meadow species compared to deionized water, used as a control, on seed germination of mustard (Sinapis arvensis) and wheat (Triticum aestivum) cultivated on sand and soil. Secondly, we studied the effect of leachates on the growth of soil fungal pathogens Fusarium culmorum, Rhizoctonia solani, Sclerotinia solani and Cochliobolus sativus. Finally, we tested the effect of litter of hybrid sorrel, miscanthus, knotweed and cultural meadow litter mixed with soil on population growth of Enchytraeus crypticus and Folsomia candida. Miscanthus and knotweed litter had a higher C:N ratio than the control meadow and hybrid sorrel litter. Miscanthus and hybrid sorrel litter had a higher content of phenols than knotweed and cultural meadow litter. Leachates from hybrid sorrel, miscanthus and knotweed biomass significantly decreased seed germination of wheat and mustard in both substrates. Soil fungal pathogens grew less vigorously on agar enriched by leachates from both biofuel crops than on agar enriched by knotweed and leachates. Litter from hybrid sorrel, miscanthus and knotweed significantly altered (both ways) the population growth of the soil mesofauna.

  18. Allelopathic effect of a native species on a major plant invader in Europe

    Science.gov (United States)

    Christina, Mathias; Rouifed, Soraya; Puijalon, Sara; Vallier, Félix; Meiffren, Guillaume; Bellvert, Floriant; Piola, Florence

    2015-04-01

    Biological invasions have become a major global issue in ecosystem conservation. As formalized in the "novel weapon hypothesis", the allelopathic abilities of species are actively involved in invasion success. Here, we assume that allelopathy can also increase the biotic resistance of native species against invasion. We tested this hypothesis by studying the impact of the native species Sambucus ebulus on the colonization of propagules of the invasive species Fallopia x bohemica and the subsequent development of plants from these. Achenes and rhizome fragments from two natural populations were grown in a greenhouse experiment for 50 days. We used an experimental design that involved "donor" and "target" pots in order to separate resource competition from allelopathy. An allelopathic treatment effect was observed for plant growth but not for propagule establishment. Treatment affected, in particular, the growth of Fallopia plants originating from achenes, but there was less influence on plants originating from rhizomes. By day 50, shoot height had decreased by 27 % for plants originating from rhizomes and by 38 % for plants originating from achenes. The number of leaves for plants originating from achenes had only decreased by 20 %. Leaf and above- and below-ground dry masses decreased with treatment by 40, 41 and 25 % for plants originating from rhizomes and 70, 61 and 55 % for plants originating from achenes, respectively. S. ebulus extracts were analysed using high-performance chromatography, and the choice of test molecules was narrowed down. Our results suggest native species use allelopathy as a biotic containment mechanism against the naturalization of invasive species.

  19. Potencial alelopático de catequinas de Tachigali myrmecophyla (leguminosae Allelopathic potential of catechins of the Tachigali myrmecophyla (Leguminosae

    Directory of Open Access Journals (Sweden)

    Lívia T. Lôbo

    2008-01-01

    Full Text Available Two compounds, (+-catechin and epicatechin, were isolated from leaves of T. myrmecophyla, using chromatographic techniques. The structural identification was carried out on the basis of ¹H and 13C NMR spectral data and comparison with literature data. The compounds (+-catechin and epicatechin were submitted to germination inhibition and radicle and hypocotyl growth assays. Results showed some significant activities confirming the initial hypothesis about allelopathic properties of that plant.

  20. Allelopathic potential of catechins of the Tachigali myrmecophyla (Leguminosae); Potencial alelopatico de catequinas de Tachigali myrmecophyla (leguminosae)

    Energy Technology Data Exchange (ETDEWEB)

    Lobo, Livia T.; Castro, Kelly Christina Ferreira; Arruda, Mara Silvia P.; Silva, Milton N. da; Arruda, Alberto C.; Mueller, Adolfo Henrique; Arruda, Giselle Maria Skelding P.; Santos, Alberdan Silva [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Centro de Ciencias Exatas e Naturais. Dept. de Quimica]. E-mail: livia_lobo@yahoo.com.br; Souza Filho, Antonio Pedro da Silva [EMBRAPA Amazonia Oriental, Belem, PA (Brazil). Lab. de Agroindustria

    2008-07-01

    Two compounds, (+)-catechin and epicatechin, were isolated from leaves of T. myrmecophyla, using chromatographic techniques. The structural identification was carried out on the basis of {sup 1}H and {sup 13}C NMR spectral data and comparison with literature data. The compounds (+)-catechin and epicatechin were submitted to germination inhibition and radicle and hypocotyl growth assays. Results showed some significant activities confirming the initial hypothesis about allelopathic properties of that plant. (author)

  1. A simple procedure for the purification of active fractions in aqueous extracts of plants with allelopathic properties

    OpenAIRE

    Fabian Borghetti; Elisa Coutinho de Lima; Lucas de Carvalho Ramos Silva

    2013-01-01

    Most studies conducted to test the allelopathic activity of plant parts have made use of water as solvent. However, the presence of polar, water-soluble substances, such as proteins and carbohydrates, tends to hamper the purifi cation of active compounds. In this study, we present a simple purifi cation procedure that separates the active fraction of the extract from the undesirable substances, thus facilitating the search for active molecules through standard chromatographic meth...

  2. Allelopathic Effects of Johnsongrass on Germination and Early Seedling Growth of Basil, Black Cumin, Cummin, Fennel, Isabgol and Psyllium

    Directory of Open Access Journals (Sweden)

    M Asgharipoor

    2012-12-01

    Full Text Available The allelopathic effect of weeds frequently inhibited the germination and seedling growth of crops. Johnsongrass (Sorghum halepens is known to contain water-soluble substances that are allelopathic. To identify the allelopathic effect of Johnsongrass, the effect of different aqueous extracts (0, 5, 10, 20, 30, 40 and 50 g L-1 obtained from roots and leaves of Johnsongrass on the seed germination and early seedling growth of some popular medicinal plants of Iran [basil (Ocimum basilicum, black cumin (Nigella sativa, cumin (Cuminum cyminum, fennel (Foeniculum vulgare, isabgol (Plantago ovate and psyllium (Plantago psyllium] were studied by bioassay. Both the root and leaf extracts of Johnsongrass in most cases inhibited the seed germination and early seedling growth of isabgol, psyllium, fennel and basil, while the seed germination and the early seedling growth of black cumin and cummin was simulated by both extracts at lower concentrations. However, this advantage was not found in higher concentrations, at which the extracts mostly had a negative effect on Nigella sativa and cumin. Leaf extracts was more effective to germination and early seedling growth than the root extract. The effectiveness of these extracts on the root growth was greater than that of the shoot growth of the test plants. The degree of sensitivity can be classified averaged across all extract concentrations in order of decreasing inhibition as follow: psyllium, isabgol, fennel, basil, black cumin and Cummin.

  3. Flavonoid profiling and nodulation of some legumes in response to the allelopathic stress of Sonchus oleraceus L.

    Directory of Open Access Journals (Sweden)

    Nasr Hassan Gomaa

    2015-12-01

    Full Text Available Annual sowthistle (Sonchus oleraceus has been reported to produce allelopathic effects. Two greenhouse experiments were conducted to estimate the allelopathic potential of both plant residue and root exudates of S. oleraceus on flavonoid composition and nodulation in a leguminous crop, Trifolium alexandrinum, and in two leguminous weeds, Melilotus indicus and T. resupinatum. The results of high performance liquid chromatography-mass spectrometry (HPLC-MS/MS showed that all three legumes contained six flavonoid aglycones: apigenin, daidzein, kaempferol, luteolin, myricetin and quercetin; and seven flavonoid glycosides: daidzin, genistin, hesperidin, hyperoside, kaempferol-7-O-glucoside, naringin and rutin. In general, both plant residue and root exudates had inhibitory effects on the flavonoid composition and nodulation of the target species. However, residue of S. oleraceus caused a significant increase in both individual and total detected flavonoids in T. alexandrinum. The results suggest that the phytotoxins released from S. oleraceus may restrain the biosynthesis of flavonoids in the target species, whereas the accumulated flavonoids in T. alexandrinum are allelopathic-induced metabolites and suggest a resistance mode in this crop.

  4. The allelopathic effects of invasive plant Solidago canadensis on seed germination and growth of Lactuca sativa enhanced by different types of acid deposition.

    Science.gov (United States)

    Wang, Congyan; Xiao, Hongguang; Zhao, Lulu; Liu, Jun; Wang, Lei; Zhang, Fei; Shi, Yanchun; Du, Daolin

    2016-04-01

    Invasive species can exhibit allelopathic effects on native species. Meanwhile, the types of acid deposition are gradually changing. Thus, the allelopathic effects of invasive species on seed germination and growth of native species may be altered or even enhanced under conditions with diversified acid deposition. This study aims to assess the allelopathic effects (using leaves extracts) of invasive plant Solidago canadensis on seed germination and growth of native species Lactuca sativa treated with five types of acid deposition with different SO4(2-) to NO3(-) ratios (1:0, sulfuric acid; 5:1, sulfuric-rich acid; 1:1, mixed acid; 1:5, nitric-rich acid; 0:1, nitric acid). Solidago canadensis leaf extracts exhibited significantly allelopathic effects on germination index, vigor index, and germination rate index of L. sativa. High concentration of S. canadensis leaf extracts also similarly exhibited significantly allelopathic effects on root length of L. sativa. This may be due to that S. canadensis could release allelochemicals and then trigger allelopathic effects on seed germination and growth of L. sativa. Acid deposition exhibited significantly negative effects on seedling biomass, root length, seedling height, germination index, vigor index, and germination rate index of L. sativa. This may be ascribed to the decreased soil pH values mediated by acid deposition which could produce toxic effects on seedling growth. Sulfuric acid deposition triggered more toxic effects on seedling biomass and vigor index of L. sativa than nitric acid deposition. This may be attributing to the difference in exchange capacity with hydroxyl groups (OH(-)) between SO4(2-) and NO3(-) as well as the fertilizing effects mediated by nitric deposition. All types of acid deposition significantly enhanced the allelopathic effects of S. canadensis on root length, germination index, vigor index, and germination rate index of L. sativa. This may be due to the negatively synergistic effects of

  5. [Potential allelopathic effects of Piper nigrum, Mangifera indica and Clausena lansium].

    Science.gov (United States)

    Yan, Guijun; Zhu, Chaohua; Luo, Yanping; Yang, Ye; Wei, Jinju

    2006-09-01

    With Piper nigrum, Mangifera indica and Clausena lansium as the donators, this paper studied their potential allelopathic effects on the germination and growth of Zea mays, Glycine max, Cucurbita moschata, Arachis hypogaea, Raphanus sativus, Echinochloa crusgalli, Digitaria sanguinalis and Stylosanthes guianensis. The results showed that the aqueous extracts of these donators could inhibit the germination and growth of Z. mays, G. max, C. moschata, E. crus-galli and D. sanguinalis at high concentration, but stimulate them at low concentration. In rhizosphere soil of P. nigrum and M. indica, the germination and growth of Z. mays L was stimulated, while A. hypogaea was inhibited. The aqueous extracts of the donators were extracted by ethyl acetate and n-butanol, respectively, and the inhibitory activity of both aqueous and n-butanol fractions from P. nigrum and M. indica on Z. mays, R. sativus and S. guianensis was stronger than that of ethyl acetate fraction, indicating that P. nigrum and M. indica contained the allelochemicals with high polarity.

  6. Growth, Toxin Production and Allelopathic Effects of Pseudo-nitzschia multiseries under Iron-Enriched Conditions.

    Science.gov (United States)

    Sobrinho, Bruna Fernanda; de Camargo, Luana Mocelin; Sandrini-Neto, Leonardo; Kleemann, Cristian Rafael; Machado, Eunice da Costa; Mafra, Luiz Laureno

    2017-10-24

    In order to assess the effects of Fe-enrichment on the growth and domoic acid (DA) production of the toxigenic diatom Pseudo-nitzschia multiseries, static cultures that received the addition of different iron (Fe) concentrations were maintained for 30 days. Intra- and extracellular DA concentrations were evaluated over time, and growth and chain-formation were compared to those of non-toxic diatoms, Bacillaria sp. Growth rates of P. multiseries (μ = 0.45-0.73 d-1) were similar among cultures containing different Fe concentrations. Likewise, the similar incidence and length of P. multiseries stepped cell chains (usually 2-4; up to 8-cell long) among the treatments reinforces that the cultures were not growth-inhibited under any condition tested, suggesting an efficient Fe acquisition mechanism. Moreover, DA concentrations were significantly higher under the highest Fe concentration, indicating that Fe is required for toxin synthesis. Bacillaria sp. reached comparable growth rates under the same Fe concentrations, except when the dissolved cell contents from a P. multiseries culture was added. The 50-70% reduction in cell density and 70-90% decrease in total chlorophyll-a content of Bacillaria sp. at early stationary growth phase indicates, for the first time, an allelopathic effect of undetermined compounds released by Pseudo-nitzschia to another diatom species.

  7. Allelopathic effect of medicinal plant Cannabis sativa L. on Lactuca sativa L. seed germination

    Directory of Open Access Journals (Sweden)

    Homa MAHMOODZADEH

    2015-11-01

    Full Text Available In order to examine allelopathic effect of Cannabis sativa L. on germination capability and seedling growth of Lactuca sativa L., a study was performed in laboratory conditions. Treatments were set up in randomised block design in four replications for each of four concentration ranges of 25, 50, 75 and 100 % of aqueous extract made of shoot parts and 4 identical extract concentrations made of root of cannabis. Control variant was lettuce seed treated by distilled water. During the studies shoot and seminal root length of lettuce seedlings were measured after treatments with different concentrations of extracts made of root and shoot parts of cannabis, and the obtained values were compared with the control. The obtained results suggest that the extract from the shoot parts of cannabis in high concentrations of 75 and 100 % had inhibiting effect to the germination indices while the extract from the root had no statistically significant effect on germination of lettuce seeds. Extract made of root part of cannabis showed also stimulatory effect to shoot and seminal root length of lettuce seedlings in extract concentrations of 50, 75 and 100 %.

  8. Allelopathic effects of barley straw on germination and seedling growth of corn, sugar beet and sunflower

    Directory of Open Access Journals (Sweden)

    mohamad taghi naseri poor yazdi

    2009-06-01

    Full Text Available Allelopathic effects of barley straw and root on germination and growth of maize, sugar beet, and sunflower were investigated under glasshouse and laboratory experiments in Faculty of Agriculture, Ferdowsi University of Mashhad in 2006. The glasshouse experiment was designed based on randomized complete block design with three replications, treatments included: 0, 200, 400, 600 g/m² of grounded barley straw and also 0 and 50 g/m2 barley root. A laboratory experiment was carried out in order to study the effect of different concentrations of barley water extracts on germination and seedling characteristics of corn, sugar beet and sunflower. Treatments in laboratory trial included 0, 33, 50 and 100 percent of barley extracts. Results showed that leaf area of corn was significantly affected by barley straw treatments. Shoot dry matter and seed weight per plant in corn , leaf and tuber weight in sugar beet and leaf , stem weights , plant per plant in corn , leaf and tuber weight in sugar beet and leaf, stem weights, plant height, head diameter, head weight and seed weight in sunflower were significantly higher in treatment of 50g/m² barley roots. Crop seed germination decreased with increasing the amount of barley straw. The best germination response to barley extract was observed in corn. Maize radicle weight was significantly decreased with increasing concentration of barley water extract.

  9. Alkaloid profile, antibacterial and allelopathic activities of Lupinus jaimehintoniana B.L. Turner (Fabaceae

    Directory of Open Access Journals (Sweden)

    Ruiz-González Nancy

    2012-01-01

    Full Text Available Herein we describe some aspects of the ethnobotanical use and the first alkaloid profile of Lupinus jaimehintoniana, the 5 to 8 m high arboreous lupine. Five quinolizidine alkaloids identified as sparteine, 5,6-dehydrolupanine, lupanine, nuttalline, and d-thermopsine, were characterized by the respective elution order according to their electronic impact spectra, lupanine being the most abundant in the four different tissues analyzed. Simultaneously, an antibacterial assessment of the four corresponding crude methanolic extracts, as well as the four semi-purified alkaloids was performed on specific Escherichia coli and Agrobacterium tumefaciens strains. These experiments resulted in MIC ranges of 37-61 µg mL-1 and 130-146 µg mL-1, respectively. for both bacterial species. Finally, the allelopathic activity of these extracts on the germination of Lactuca sativa seeds was demonstrated to be in the range of 50-300 µg mL-1 for both semi-purified alkaloid and methanolic extracts.

  10. Suppression of native Melaleuca ericifolia by the invasive Phragmites australis through allelopathic root exudates.

    Science.gov (United States)

    Uddin, Md Nazim; Robinson, Randall William; Caridi, Domenic; Al Harun, Md Abdullah Yousuf

    2014-03-01

    Invasive plants are a great threat to the conservation of natural ecosystems and biodiversity. Allelopathy as a mechanism for invasion of plants such as Phragmites australis, one of the most aggressive invaders, has the potential to suppress neighboring plant species. Allelopathic interference, through root exudates of P. australis on native Melaleuca ericifolia, was investigated to find out the underlying invasion mechanisms. Germination and growth effects of P. australis on M. ericifolia were studied in the greenhouse using potting mix both with and without activated carbon, and a combination of single and repeated cuttings of P. australis as the management tool. P. AUSTRALIS had significant negative effects on germination and growth of M. ericifolia by inhibiting germination percentage, maximum root length and plant height, biomass, stem diameter, and number of growth points with little effect on leaf physiology. Activated carbon (AC) in turn moderately counteracted these effects. The cutting of P. australis shoots significantly reduced the suppressive effects on M. ericifolia compared to the addition of AC to soil. Furthermore, significant changes in soil such as pH, electrical conductivity, osmotic potential, phenolics, and dehydrogenase activity were identified among cutting treatments with little variation between AC treatments. The results demonstrated that allelopathy through root exudates of P. australis had relatively low contribution in suppressing M. ericifolia in comparison to other competitive effects. Management tools combining repeated cutting of P. australis shoots with AC treatments may assist partly in the restoration of native ecosystems invaded by P. australis.

  11. Differential allelopathic effects of Japanese knotweed on willow and cottonwood cuttings used in riverbank restoration techniques.

    Science.gov (United States)

    Dommanget, Fanny; Evette, André; Spiegelberger, Thomas; Gallet, Christiane; Pacé, Marine; Imbert, Marika; Navas, Marie-Laure

    2014-01-01

    Using bioengineering techniques to restore areas invaded by Fallopia japonica shows promising results. Planting tree cuttings could allow both rapidly re-establishing a competitive native plant community and reducing F. japonica performance. However, F. japonica has been shown to affect native plant species through different mechanisms such as allelopathy. This article investigates the phytotoxic effect of F. japonica on the resprouting capacity and the growth of three Salicaceae species with potential value for restoration. An experimental design which physically separates donor pots containing either an individual from F. japonica or bare soil from target pots containing cuttings of Populus nigra, Salix atrocinerea or Salix viminali was used. Leachates from donor pots were used to water target pots. The effects of leachates were evaluated by measuring the final biomass of the cuttings. F. japonica leachates inhibited the growth of cuttings, and this effect is linked to the emission of polyphenol compounds by F. japonica. Leachates also induced changes in soil nitrogen composition. These results suggest the existence of allelopathic effects, direct and/or indirect, of F. japonica on the growth of Salicaceae species cuttings. However, the three species were not equally affected, suggesting that the choice of resistant species could be crucial for restoration success. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Allelopathic interactions between Prorocentrum micans and Skeletonema costatum or Karenia mikimotoi in laboratory cultures

    Science.gov (United States)

    Ji, Xiaoqing; Han, Xiaotian; Zheng, Li; Yang, Baijuan; Yu, Zhiming; Zou, Jingzhong

    2011-07-01

    Algal allelopathy is an ecological/physiological phenomenon that has focused attention on the interactions among algae and the production of algal toxins. We investigated the allelopathic interactions between the dinoflagellate genus Prorocentrum micans and diatom genus Skeletonema costatum and between P. micans and dinoflagellate genus Karenia mikimotoi using bi-algal cultures. Because the effects were species-specific and size-dependent, we evaluated the effect of different initial densities. At low densities of P. micans and high densities of S. costatum inoculated into the same medium, the growth of P. micans was weakly restrained, whereas the growth of S. costatum was significantly suppressed. S. costatum and K. mikimotoi were strongly inhibited by P. micans, in both the bi-algal cultures and enriched filtrates. Direct cell-to-cell contact was not necessary to gain a competitive advantage, thus, our results suggest that P. micans inhibited the growth of S. costatum and K. mikimotoi by the release of allelochemical(s). Last, a mathematical model was used to simulate growth and interactions between P. micans and S. costatum and between P. micans and K. mikimotoi in bi-algal cultures.

  13. Growth, Toxin Production and Allelopathic Effects of Pseudo-nitzschia multiseries under Iron-Enriched Conditions

    Directory of Open Access Journals (Sweden)

    Bruna Fernanda Sobrinho

    2017-10-01

    Full Text Available In order to assess the effects of Fe-enrichment on the growth and domoic acid (DA production of the toxigenic diatom Pseudo-nitzschia multiseries, static cultures that received the addition of different iron (Fe concentrations were maintained for 30 days. Intra- and extracellular DA concentrations were evaluated over time, and growth and chain-formation were compared to those of non-toxic diatoms, Bacillaria sp. Growth rates of P. multiseries (μ = 0.45–0.73 d−1 were similar among cultures containing different Fe concentrations. Likewise, the similar incidence and length of P. multiseries stepped cell chains (usually 2–4; up to 8-cell long among the treatments reinforces that the cultures were not growth-inhibited under any condition tested, suggesting an efficient Fe acquisition mechanism. Moreover, DA concentrations were significantly higher under the highest Fe concentration, indicating that Fe is required for toxin synthesis. Bacillaria sp. reached comparable growth rates under the same Fe concentrations, except when the dissolved cell contents from a P. multiseries culture was added. The 50–70% reduction in cell density and 70–90% decrease in total chlorophyll-a content of Bacillaria sp. at early stationary growth phase indicates, for the first time, an allelopathic effect of undetermined compounds released by Pseudo-nitzschia to another diatom species.

  14. 25 CFR 11.702 - Proving and admitting will.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Proving and admitting will. 11.702 Section 11.702 Indians... ORDER CODE Probate Proceedings § 11.702 Proving and admitting will. (a) Upon initiating the probate of an estate, the will of the decedent shall be filed with the court. Such will may be proven and...

  15. Reasoning and Proving Opportunities in Textbooks: A Comparative Analysis

    Science.gov (United States)

    Hong, Dae S.; Choi, Kyong Mi

    2018-01-01

    In this study, we analyzed and compared reasoning and proving opportunities in geometry lessons from American standard-based textbooks and Korean textbooks to understand how these textbooks provide student opportunities to engage in reasoning and proving activities. Overall, around 40% of exercise problems in Core Plus Mathematics Project (CPMP)…

  16. The Earth is Flat, and I Can Prove It!

    Science.gov (United States)

    Klinger, Art

    1998-01-01

    Describes an educational program that asks students to attempt to prove that the earth is spherical and that it rotates. Presents tips to pique student interest and charts related to sensing the spin, nonrotation notions, flat earth fallacies, evidence that the earth is spherical and rotates, and the role of watersheds in proving that the earth…

  17. 20 CFR 219.23 - Evidence to prove death.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Evidence to prove death. 219.23 Section 219... EVIDENCE REQUIRED FOR PAYMENT Evidence of Age and Death § 219.23 Evidence to prove death. (a) Preferred evidence of death. The best evidence of a person's death is— (1) A certified copy of or extract from the...

  18. Allelopathic interactions between the macrophyte Egeria densa and plankton (alga, Scenedesmus acutus and cladocerans, Simocephalus spp.: a laboratory study

    Directory of Open Access Journals (Sweden)

    Cristian A. Espinosa-Rodríguez

    2016-03-01

    Full Text Available Allelopathic interactions between macrophytes and zooplankton are important to understand the plankton dynamics in shallow waterbodies. Egeria densa is a native, perennial, submerged macrophyte in the tropical and subtropical zones of South America. It has been introduced to Central and North America and is now common in many Mexican lakes. This macrophyte produces chemical substances that negatively affect some phytoplankton species. However, it is not clear how zooplankton species adapt different life history strategies in the chemical presence of this macrophyte. Here, we tested the direct and indirect effects of allelochemicals released by E. densa on the population growth of Scenedesmus acutus and on the demographic variables of three species of Simocephalus, S. exspinosus, S. serrulatus and S. mixtus (via alga exposed to the macrophyte allelochemicals. To quantify the effect of E. densa on S. acutus we set up four treatments: control, artificial Egeria, natural Egeria and allelochemicals from Egeria. To test the allelochemical effects on Simocephalus species, we compared four treatments: Control, indirect effect (using S. acutus grown on Egeria-allelochemicals, direct effect (using Egeria-conditioned medium and together with both these kinds of direct and indirect effects. Scenedesmus had the highest cell density in the presence of allelochemicals from Egeria, followed by controls. The specific algal growth rate (µ between control and allelochemicals treatment was not significant (P<0.05. However, the µ of alga in the presence of artificial or natural Egeria was significantly lower than controls or in treatment involving allelochemicals. The age-specific survivorship of the three cladoceran species was longer in treatments containing Egeria-conditioned medium. Cladocerans receiving Egeria conditioned-medium and algae cultured on macrophyte-allelochemicals also had a longer survivorship. Daily fecundity of S. serrulatus increased after

  19. Allelopathic cover crop prior to seeding is more important than subsequent grazing/mowing in grassland establishment

    Science.gov (United States)

    Milchunas, Daniel G.; Vandever, Mark W.; Ball, Leonard O.; Hyberg, Skip

    2011-01-01

    The effects of grazing, mowing, and type of cover crop were evaluated in a previous winter wheat–fallow cropland seeded to grassland under the Conservation Reserve Program in eastern Colorado. Prior to seeding, the fallow strips were planted to forage sorghum or wheat in alternating strips (cover crops), with no grazing, moderate to heavy grazing, and mowing (grazing treatments) superimposed 4 yr after planting and studied for 3 yr. Plots previously in wheat had more annual and exotic species than sorghum plots. Concomitantly, there were much greater abundances of perennial native grass and all native species in sorghum than wheat cropped areas. The competitive advantage gained by seeded species in sorghum plots resulted in large increases in rhizomatous western wheatgrass. Sorghum is known to be allelopathic and is used in crop agriculture rotations to suppress weeds and increase crop yields, consistent with the responses of weed and desired native species in this study. Grazing treatment had relatively minor effects on basal and canopy cover composition of annual or exotic species versus perennial native grass or native species. Although grazing treatment never was a significant main effect, it occasionally modified cover crop or year effects. Opportunistic grazing reduced exotic cheatgrass by year 3 but also decreased the native palatable western wheatgrass. Mowing was a less effective weed control practice than grazing. Vegetative basal cover and aboveground primary production varied primarily with year. Common management practices for revegetation/restoration currently use herbicides and mowing as weed control practices and restrict grazing in all stages of development. Results suggest that allelopathic cover crop selection and opportunistic grazing can be effective alternative grass establishment and weed control practices. Susceptibility, resistance, and interactions of weed and seeded species to allelopathic cover species/cultivars may be a fruitful area

  20. Study on the mechanism of allelopathic influence on cyanobacteria and chlorophytes by submerged macrophyte (Myriophyllum spicatum) and its secretion.

    Science.gov (United States)

    Zhu, Junying; Liu, Biyun; Wang, Jing; Gao, Yunni; Wu, Zhenbin

    2010-06-10

    For revealing the mechanism of allelopathic influence on phytoplankton by aquatic macrophytes, the growth and photosynthetic activities of cyanobacteria Microcystis aeruginosa and the chlorophyte Selenastrum capricornutum were investigated when they coexisted with submerged macrophyte Myriophyllum spicatum and were exposed to allelopathic polyphenols: pyrogallic acid (PA), gallic acid (GA), ellagic acid (EA) and (+)-catechin (CA). According to the results of coexistence assays, the non-photochemical quenching (NPQ) and effective quantum efficiency (YII) of M. aeruginosa were affected earlier and more rapidly than the cell density. However, the influence of M. spicatum on S. capricornutum was not found. When the Toxicity Index (TI) was applied to evaluate the combined effects of binary and multiple mixtures of polyphenols, it was found that the four tested polyphenols with the proportion identified in the M. spicatum-cultured solution were observed to present synergistic effect (0.36-0.49) according to the cell density, NPQ and YII of M. aeruginosa. With the combined effects of polyphenols on S. capricornutum, only additive action (0.52-1.62) was found. On the other hand, PA (2.97mgL(-1)), GA (2.65mgL(-1)) caused significant reductions of photosystem II (PSII) and whole electron transport chain activities of M. aeruginosa by 71.43 and 18.37%, 70.95 and 40.77% (Pelectron transport activities of the tested organisms. These results indicate that the reduction in photosynthetic activity of M. aeruginosa and the synergistic effect of allelochemicals may be two important causes for the inhibition of undesired phytoplankton by submersed macrophytes in natural aquatic ecosystems, and PSII in cyanobacteria is considered to be one of the target sites attacked by allelopathic polyphenols.

  1. Root distribution and interactions between allelopathic rice and c4 grass weed species as determined by 13c isotope discrimination analysis

    Science.gov (United States)

    Cultivars which carry allelopathic traits (traits that enable them to suppress weeds) could improve the economical management and sustainability of rice production. Interactions between roots of rice and weeds are thought to be modulated by the weed-suppressive activity of some rice cultivars, but ...

  2. Importance of nutrient competition and allelopathic effects in suppression of the green alga Scenedesmus obliquus by the macrophytes Chara, Elodea and Myriophyllum

    NARCIS (Netherlands)

    Lürling, M.; Van Geest, G.J.; Scheffer, M.

    2006-01-01

    Possible allelopathic effects of substances released from the macrophytes Chara globularis, Elodea canadensis, Myriophyllum spicatum on the common green alga Scenedesmus obliquus were tested in the laboratory with plastic plants and untreated medium as controls. A two-phase approach was used in

  3. Allelopathic Effects of Aqueous Extract of Leaf Stem and Root of Sorghum bicolor on Seed Germination and Seedling Growth of Vigna radiata L.

    Directory of Open Access Journals (Sweden)

    Amir MOOSAVI

    2011-05-01

    Full Text Available Seed germination under field conditions is highly influenced by the presence of other plants. Allelopathy is an important mechanism of plant competition, by producing phytotoxins to the plant environment in order to decline other plants� growth. Soil sickness problem in farm lands is also known as an allelopathic effect or even autotoxicity. The toxicity of released allelochemicals by a plant in the environment is attributed to its function of concentration, age and metabolic stage. In this study we investigate the effect (5, 20, 35 and 50 g l-1 of leaf, stem and root water extract of sorghum on seed germination and seedling growth of mung bean. The results of the experiment showed that allelopathic effect of different concentrations was not significant for germination percentage, but germination rate and mean germination time decreased significantly by increasing the concentration of allelopathic extracts; also, there was a clear allelopathic effect of sorghum extract on seedling growth of mung bean. 50 g l-1 sorghum stem extract exhibited the highest inhibitory effect on root and shoot growth of mung bean. Among all parts of sorghum, stem extracts showed the highest allelopatic effect on seedling growth. Root extract showed higher inhibitory effect than leaf extracts.

  4. Allelopathic Effects of Aqueous Extract of Leaf Stem and Root of Sorghum bicolor on Seed Germination and Seedling Growth of Vigna radiata L.

    Directory of Open Access Journals (Sweden)

    Amir MOOSAVI

    2011-05-01

    Full Text Available Seed germination under field conditions is highly influenced by the presence of other plants. Allelopathy is an important mechanism of plant competition, by producing phytotoxins to the plant environment in order to decline other plants growth. Soil sickness problem in farm lands is also known as an allelopathic effect or even autotoxicity. The toxicity of released allelochemicals by a plant in the environment is attributed to its function of concentration, age and metabolic stage. In this study we investigate the effect (5, 20, 35 and 50 g l-1 of leaf, stem and root water extract of sorghum on seed germination and seedling growth of mung bean. The results of the experiment showed that allelopathic effect of different concentrations was not significant for germination percentage, but germination rate and mean germination time decreased significantly by increasing the concentration of allelopathic extracts; also, there was a clear allelopathic effect of sorghum extract on seedling growth of mung bean. 50 g l-1 sorghum stem extract exhibited the highest inhibitory effect on root and shoot growth of mung bean. Among all parts of sorghum, stem extracts showed the highest allelopatic effect on seedling growth. Root extract showed higher inhibitory effect than leaf extracts.

  5. Allelopathic effects of jungle rice (Echinochloa colona (L.Link extract on seed germination and seedling growth of rice

    Directory of Open Access Journals (Sweden)

    Pimjai Sitthinoi

    2017-04-01

    Full Text Available The allelopathic effects of jungle rice were investigated on the seed germination and seedling growth of the two rice cultivars, Khao Dawk Mali 105 and RD41. Jungle rice extract with varying concentrations (0 mg/mL, 1 mg/mL, 5 mg/mL and 10 mg/mL was prepared using three solvents (hexane, dichloromethane and methanol from shoots and roots separately. The jungle rice extracts from the shoot part showed a higher inhibitory effect on the root length and seedling dry weight of rice compared to the extracts from the root part. Different extraction solvents caused differences in the inhibitory effect on the germination and seedling growth of rice and had an interaction with the extract concentration in all parameters measured. Methanol extraction solvent severely inhibited the seed germination of both cultivars regardless of the extract concentrations, whereas the jungle rice extracts using dichloromethane and hexane showed moderate inhibitory effects depending on the concentrations of 1–10 mg/mL, respectively. It can be concluded that jungle rice extracts contain allelopathic compounds and can inhibit the seed germination and seedling growth of rice. Methanol should be used as an extraction solvent if the inhibitory effect of the jungle rice extract is required.

  6. Allelopathic effects of the aqueous extract of the leaf and seed of Leucaena leucocephala on three selected weed species

    Science.gov (United States)

    Ishak, Muhamad Safwan; Sahid, Ismail

    2014-09-01

    A laboratory experiment was conducted to study the allelopathic effects of the aqueous extract of the leaf and seed of Leucaena leucocephala. The aqueous extracts were individually tested on three selected weed species, namely goatweed (Ageratum conyzoides), coat buttons (Tridax procumbens) and lilac tasselflower (Emilia sonchifolia). The allelopathic effects of the leaf and seed extracts on germination, shoot length, root length and fresh weight of each of the selected weed species were determined. Germination of goatweed, coat buttons and lilac tasselflower were inhibited by the aqueous extracts of both the leaf and seed of L. leucocephala and was concentration dependent. Different concentrations of the aqueous extracts showed various germination patterns on the selected weeds species. Seedling length and fresh weight of goatweed, coat buttons and lilac tasselflower were reduced in response to respective increasing concentrations of the seed extracts. Maximum inhibition by the aqueous seed extract was observed more on the root rather than the shoot growth. The aqueous seed extract at T3 concentration reduced root length of goatweed, coat buttons and lilac tasselflower by 95%, 86% and 91% (of the control) respectively. The aqueous seed extract showed greater inhibitory effects than that of the aqueous leaf extract.

  7. Allelopathic effect boosts Chrysosporum ovalisporum dominance in summer at the expense of Microcystis panniformis in a shallow coastal water body.

    Science.gov (United States)

    Zhang, Wei; Jeppesen, Erik; Wang, Mengmeng; Xu, Xiaoying; Wang, Liqing

    2017-02-01

    The increased occurrence of harmful cyanobacterial species and, with this, higher frequency of cyanobacteria blooms, closely associated with eutrophication and climate change, have attracted increasing attention worldwide. However, competition mechanisms between the different bloom-forming cyanobacteria species remain to be elucidated. In this paper, for the first time, the allelopathic effect of the cyanobacterium Chrysosporum ovalisporum on the cyanobacterium Microcystis panniformis is reported. The results of our study conducted in a Chinese shallow coastal water body demonstrated that the biomass of M. panniformis was relatively low during the C. ovalisporum blooming period. Co-cultivation of a C. ovalisporum strain with a M. panniformis strain showed strong inhibition of the growth of M. panniformis but stimulation of C. ovalisporum. Thus, filtrate of C. ovalisporum culture had a strong inhibitory effect on the performance of M. panniformis by decreasing the maximum optical quantum yield (F v/F m), the electron transport rate (ETR) of PS II and the onset of light saturation (I k) and by increasing the alkaline phosphatase (ALP) activity and superoxide dismutase (SOD) activity of M. panniformis. Our results suggest that the inter-specific allelopathic effect plays an important role in the competition between different cyanobacteria species. We foresee the importance of C. ovalisporum to intensify in a future warmer world, not least in small- to medium-sized, warm and high conductivity coastal water bodies.

  8. Study of allelopathic effects of Eucalyptus erythrocorys L. crude extracts against germination and seedling growth of weeds and wheat.

    Science.gov (United States)

    Ben Ghnaya, Asma; Hamrouni, Lamia; Amri, Ismail; Ahoues, Haifa; Hanana, Mohsen; Romane, Abderrahmane

    2016-09-01

    Allelopathic materials inside a tree can produce positive or negative change in the survival, growth, reproduction and behaviour of other organisms if they escape into the environment. To assess these effects, this work was carried out to evaluate the allelopathic impact of Eucalyptus erythrocorys L. on seed germination and seedling growth of two weeds: Sinapis arvensis L. and Phalaris canariensis L.; on one cultivated crop: Triticum durum L. Aqueous; and on ethanolic leaf extracts of E. erythrocorys L. The study was effected using four concentrations (10, 20, 25 and 30 μL/mL) while distilled water was used as a control. The results showed that the E. erythrocorys L. crude extracts had an inhibitory effect on seed germination and seedling growth of both studied weeds and wheat. The inhibition rate was increased by the increase in extract concentration. Only ethanolic extracts of E. erythrocorys L. induced a significant inhibition of seed germination of durum wheat. The effect of E. erythrocorys L. crude extracts was more severe on weeds than on durum wheat. These results indicate that the seedling growth, especially radicle elongation, was the more sensitive indicator to evaluate the effects of extracts than was the seed germination.

  9. Allelopathic effects of leaf extracts of three agroforestry trees on germination and early seedling growth of wheat (Triticum aestivum L.

    Directory of Open Access Journals (Sweden)

    Abdul Majeed

    2017-06-01

    Full Text Available Understanding of the growth promotory or inhibitory allelopathic effects of agroforestry trees on other plants is necessary for selection of suitable crops to be cultivated in their vicinity. In this experiment, aqueous leaf extracts of three agroforestry trees (Populus deltoides, Melia azedarach and Morus alba were evaluated on germination and seedling growth of wheat applied at concentration 1, 1.5, 2.0 and 2.5 g L-1 while distilled water was used as control treatment. Lower concentration of extracts (1 and 1.5 g L-1 of P. deltoides stimulated percent germination, root and stem height and dry biomass while higher concentration (2 and 2.5 g L-1 had no effect on these parameters. Mean germination time (MGT was not affected by the extract and its concentration. Aqueous extracts of M. azedarach and M. alba at concentration > 1 g L-1 significantly lowered the studied parameters except MGT which was significantly prolonged. Negative allelopathy was more evident at the highest aqueous extract concentration (2.5 g L-1 of the two trees. Extracts of M. alba were found more growth inhibitory than those of M. azedarach. The study suggests that lower concentration of leaf extracts of P. deltoides imparts stimulatory while M. azedarch and M. alba have negative allelopathic effects on wheat germination.

  10. Lodox Statscan proves to be invaluable in forensic medicine ...

    African Journals Online (AJOL)

    Lodox Statscan proves to be invaluable in forensic medicine: forensic files. GJ Knobel, G Flash, GF Bowie. Abstract. No Abstract. South African Medical Journal Vol. 96(7) 2006: 593-594. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals ...

  11. Conditional and preferential logics proof methods and theorem proving

    CERN Document Server

    Pozzato, GL

    2010-01-01

    Contains a version of the author's PhD dissertation and focuses on proof methods and theorem proving for conditional and preferential logics. This book introduces proof methods (sequent and tableau calculi) for conditional and preferential logics, as well as theorem provers obtained by implementing the proposed calculi.

  12. Proving the correctness of client/server software

    Indian Academy of Sciences (India)

    , formal specification and verification of RPC mechanisms is a prerequisite for the verification of any such software. In this paper, we present a mathematical specification of an RPC mechanism and we outline how to prove the correctness of an ...

  13. Overcoming the Obstacle of Poor Knowledge in Proving Geometry Tasks

    Directory of Open Access Journals (Sweden)

    Zlatan Magajna

    2013-12-01

    Full Text Available Proving in school geometry is not just about validating the truth of a claim. In the school setting, the main function of the proof is to convince someone that a claim is true by providing an explanation. Students consider proving to be difficult; in fact, they find the very concept of proof demanding. Proving a claim in planar geometry involves several processes, the most salient being visual observation and deductive argumentation. These two processes are interwoven, but often poor observation hinders deductive argumentation. In the present article, we consider the possibility of overcoming the obstacle of a student’s poor observation by making use of computer-aided observation with appropriate software. We present the results of two small-scale research projects, both of which indicate that students are able to work out considerably more deductions if computer-aided observation is used. Not all students use computer-aided observation effectively in proving tasks: some find an exhaustive computer-provided list of properties confusing and are not able to choose the properties that are relevant to the task.

  14. Engaging Students in Proving: A Double Bind on the Teacher.

    Science.gov (United States)

    Herbst, Patricio G.

    2002-01-01

    Explores what is involved in the teacher's work of engaging students in producing a proof. Analyzes what teachers do to create a task in which students can produce a proof and what teachers do to get students to prove a proposition. Indicates that traditional, formal, two-column proofs place contradictory demands on teachers regarding how ideas…

  15. Proof phenomenon as a function of the phenomenology of proving.

    Science.gov (United States)

    Hipólito, Inês

    2015-12-01

    Kurt Gödel wrote (1964, p. 272), after he had read Husserl, that the notion of objectivity raises a question: "the question of the objective existence of the objects of mathematical intuition (which, incidentally, is an exact replica of the question of the objective existence of the outer world)". This "exact replica" brings to mind the close analogy Husserl saw between our intuition of essences in Wesensschau and of physical objects in perception. What is it like to experience a mathematical proving process? What is the ontological status of a mathematical proof? Can computer assisted provers output a proof? Taking a naturalized world account, I will assess the relationship between mathematics, the physical world and consciousness by introducing a significant conceptual distinction between proving and proof. I will propose that proving is a phenomenological conscious experience. This experience involves a combination of what Kurt Gödel called intuition, and what Husserl called intentionality. In contrast, proof is a function of that process - the mathematical phenomenon - that objectively self-presents a property in the world, and that results from a spatiotemporal unity being subject to the exact laws of nature. In this essay, I apply phenomenology to mathematical proving as a performance of consciousness, that is, a lived experience expressed and formalized in language, in which there is the possibility of formulating intersubjectively shareable meanings. Copyright © 2015. Published by Elsevier Ltd.

  16. Feedback theory extended for proving generation of contraction semigroups

    NARCIS (Netherlands)

    Kurula, Mikael; Zwart, Hans

    2016-01-01

    Recently, the following novel method for proving the existence of solutions for certain linear time-invariant PDEs was introduced: The operator associated with a given PDE is represented by a (larger) operator with an internal loop. If the larger operator (without the internal loop) generates a

  17. Prove It! Putting Together the Evidence-Based Practice Puzzle

    Science.gov (United States)

    Little, Hannah Byrd

    2015-01-01

    Why is it important to prove that school libraries add value to the school program? The National Center for Education Statistics reports that 20 percent of U.S. public schools lack a full or part-time certified librarian (NCES 2013). In California the ratio of certified school librarians to students is 1:7,374 (California Department of Education…

  18. Pengembangan Perangkat Pembelajaran Geometri Ruang dengan Model Proving Theorem

    Directory of Open Access Journals (Sweden)

    Bambang Eko Susilo

    2016-03-01

    Full Text Available Kemampuan berpikir kritis dan kreatif mahasiswa masih lemah. Hal ini ditemukan pada mahasiswa yang mengambil mata kuliah Geometri Ruang yaitu dalam membuktikan soal-soal pembuktian (problem to proof. Mahasiswa masih menyelesaikan secara algoritmik atau prosedural sehingga diperlukan pengembangan perangkat pembelajaran Geometri Ruang berbasis kompetensi dan konservasi dengan model Proving Theorem. Dalam penelitian ini perangkat perkuliahan yang dikembangkan yaitu Silabus, Satuan Acara Perkuliahan (SAP, Kontrak Perkuliahan, Media Pembelajaran, Bahan Ajar, Tes UTS dan UAS serta Angket Karakter Konservasi telah dilaksanakan dengan baik dengan kriteria (1 validasi perangkat pembelajaran mata kuliah Geometri ruang berbasis kompetensi dan konservasi dengan model proving theorem berkategori baik dan layak digunakan dan (2 keterlaksanaan RPP pada pembelajaran yang dikembangkan secara keseluruhan berkategori baik.Critical and creative thinking abilities of students still weak. It is found in students who take Space Geometry subjects that is in solving problems to to prove. Students still finish in algorithmic or procedural so that the required the development of Space Geometry learning tools based on competency and conservation with Proving Theorem models. This is a research development which refers to the 4-D models that have been modified for the Space Geometry learning tools, second semester academic year 2014/2015. Instruments used include validation sheet, learning tools and character assessment questionnaire. In this research, the learning tools are developed, namely Syllabus, Lesson Plan, Lecture Contract, Learning Media, Teaching Material, Tests, and Character Conservation Questionnaire had been properly implemented with the criteria (1 validation of Space Geometry learning tools based on competency and conservation with Proving Theorem models categorized good and feasible to use, and (2 the implementation of Lesson Plan on learning categorized

  19. Allelopathic cover crop of rye for integrated weed control in sustainable agroecosystems

    Directory of Open Access Journals (Sweden)

    Vincenzo Tabaglio

    2013-02-01

    Full Text Available The allelopathic potential of rye (Secale cereale L. is mainly due to phytotoxic benzoxazinones, compounds that are produced and accumulated in young tissues to different degrees depending on cultivar and environmental influences. Living rye plants exude low levels of benzoxazinones, while cover crop residues can release from 12 to 20 kg ha–1. This paper summarizes the results obtained from several experiments performed in both controlled and field environments, in which rye was used as a cover crop to control summer weeds in a following maize crop. Significant differences in benzoxazinoid content were detected between rye cultivars. In controlled environments, rye mulches significantly reduced germination of some broadleaf weeds. Germination and seedling growth of Amaranthus retroflexus and Portulaca oleracea were particularly affected by the application of rye mulches, while Chenopodium album was hardly influenced and Abutilon theophrasti was advantaged by the presence of the mulch. With reference to the influence of agronomic factors on the production of benzoxazinoids, nitrogen fertilization increased the content of allelochemicals, although proportionally less than dry matter. The field trial established on no-till maize confirmed the significant weed suppressiveness of rye mulch, both for grass and broadleaf weeds. A significant positive interaction between nitrogen (N fertilization and notillage resulting in the suppression of broadleaf weeds was observed. The different behavior of the weeds in the presence of allelochemicals was explained in terms of differential uptake and translocation capabilities. The four summer weeds tested were able to grow in the presence of low amounts of benzoxazolin-2(3H-one (BOA, between 0.3 and 20 mmol g–1 fresh weight. Although there were considerable differences in their sensitivity to higher BOA concentrations, P. oleracea, A. retroflexus, and Ch. album represented a group of species with a consistent

  20. Antimicrobial and allelopathic potential of the amides isolated from the roots of Ottonia martiana miq., piperaceae; Potencial antimicrobiano e alelopatico das amidas isoladas do extrato das raizes de Ottonia martiana Miq

    Energy Technology Data Exchange (ETDEWEB)

    Cunico, Miriam Machado; Dias, Josiane G.; Miguel, Marilis D.; Miguel, Obdulio Gomes [Parana Univ., Curitiba, PR (Brazil). Dept. de Farmacia]. E-mail: obdulio@ufpr.br; Auer, Celso Garcia [Empresa Brasileira de Pesquisa Agropecuaria, EMBRAPA-Floresta, Colombo, PR (Brazil). Dept. de Fitopatologia; Cocco, Lilian C.; Lopes, Andre R.; Yamamoto, Carlos I. [Parana Univ., Curitiba, PR (Brazil). Dept. de Engenharia Quimica; Monache, Franco Delle [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Microbiologia e Parasitologia

    2006-07-15

    Two amides, piperovatine and isopiperlonguminine, were isolated from the roots of Ottonia martiana Miq., a herbaceous shrub commonly used in folk medicine in the treatment of toothache. The crude extract (CE) and isolated compounds were submitted to bioautography and allelopathic assay. The bioautograms allowed the detection of compounds with antibacterial activity and the identification of the bioactive substance piperovatine. The CE and amides exhibited an allelopathic effect on Lactuca sativa (lettuce) seedling growth but did not affect the seeds' germinability. (author)

  1. Unicorns do exist: a tutorial on "proving" the null hypothesis.

    Science.gov (United States)

    Streiner, David L

    2003-12-01

    Introductory statistics classes teach us that we can never prove the null hypothesis; all we can do is reject or fail to reject it. However, there are times when it is necessary to try to prove the nonexistence of a difference between groups. This most often happens within the context of comparing a new treatment against an established one and showing that the new intervention is not inferior to the standard. This article first outlines the logic of "noninferiority" testing by differentiating between the null hypothesis (that which we are trying to nullify) and the "nill" hypothesis (there is no difference), reversing the role of the null and alternate hypotheses, and defining an interval within which groups are said to be equivalent. We then work through an example and show how to calculate sample sizes for noninferiority studies.

  2. Renewable Energy Opportunties at Dugway Proving Ground, Utah

    Energy Technology Data Exchange (ETDEWEB)

    Orrell, Alice C.; Kora, Angela R.; Russo, Bryan J.; Horner, Jacob A.; Williamson, Jennifer L.; Weimar, Mark R.; Gorrissen, Willy J.; Nesse, Ronald J.; Dixon, Douglas R.

    2010-05-31

    This document provides an overview of renewable resource potential at Dugway Proving Ground, based primarily upon analysis of secondary data sources supplemented with limited on-site evaluations. This effort focuses on grid-connected generation of electricity from renewable energy sources and ground source heat pumps (GSHPs). The effort was funded by the U.S. Army Installation Management Command (IMCOM) as follow-on to the 2005 Department of Defense (DoD) Renewables Assessment.

  3. Programming and Proving Correctness of the Scanning Algorithm with Backtrack,

    Science.gov (United States)

    1980-09-19

    components A, . A2,...An of the Cartesian product and that all eie- ments of the set A are generated sequentially from them. It is simplest to program how n...the gradual refine- ment of the program and proving its correctness and we do not work towards a meaningful program which will solve a given problem and...Privara, I..- " Teoria a aplikacia formalnej semantiky programovacich jazykov" LThe Theory and Application of ?ormal Semantics in Program- .m~ng

  4. Logic for computer science foundations of automatic theorem proving

    CERN Document Server

    Gallier, Jean H

    2015-01-01

    This advanced text for undergraduate and graduate students introduces mathematical logic with an emphasis on proof theory and procedures for algorithmic construction of formal proofs. The self-contained treatment is also useful for computer scientists and mathematically inclined readers interested in the formalization of proofs and basics of automatic theorem proving. Topics include propositional logic and its resolution, first-order logic, Gentzen's cut elimination theorem and applications, and Gentzen's sharpened Hauptsatz and Herbrand's theorem. Additional subjects include resolution in fir

  5. Allelopathic effect of phenolic acids from humic solutions on two spruce mycorrhizal fungi:Cenococcum graniforme andLaccaria laccata.

    Science.gov (United States)

    Pellissier, F

    1993-10-01

    The aim of this investigation was to determine the impact ofp-hydroxyacetophenone,p-hydroxybenzoic acid, catechol, and protocatechuic acid on respiration of two spruce mycorrhizal fungi:Laccaria laccata andCenococcum graniforme. These phenols are produced byVaccinium myrtillus,Athyrium filixfemina, andPicea abies, predominant species of spruce forests in the Alps, and they are also present in humic solutions at 10(-10) M or 10(-5) M. Respiration of the two fungi was inhibited by the four phenolic acids, even at concentrations ranging from 10(-5) M to 10(-7) M. These data show phenolic acids from humic solutions have biological activity at extremely low concentrations, suggesting a contribution ofV. myrtillus, A. filixfemina, andP. abies to allelopathic inhibition of mycorrhizal fungi.

  6. Preparing for Mars: The Evolvable Mars Campaign 'Proving Ground' Approach

    Science.gov (United States)

    Bobskill, Marianne R.; Lupisella, Mark L.; Mueller, Rob P.; Sibille, Laurent; Vangen, Scott; Williams-Byrd, Julie

    2015-01-01

    As the National Aeronautics and Space Administration (NASA) prepares to extend human presence beyond Low Earth Orbit, we are in the early stages of planning missions within the framework of an Evolvable Mars Campaign. Initial missions would be conducted in near-Earth cis-lunar space and would eventually culminate in extended duration crewed missions on the surface of Mars. To enable such exploration missions, critical technologies and capabilities must be identified, developed, and tested. NASA has followed a principled approach to identify critical capabilities and a "Proving Ground" approach is emerging to address testing needs. The Proving Ground is a period subsequent to current International Space Station activities wherein exploration-enabling capabilities and technologies are developed and the foundation is laid for sustained human presence in space. The Proving Ground domain essentially includes missions beyond Low Earth Orbit that will provide increasing mission capability while reducing technical risks. Proving Ground missions also provide valuable experience with deep space operations and support the transition from "Earth-dependence" to "Earth-independence" required for sustainable space exploration. A Technology Development Assessment Team identified a suite of critical technologies needed to support the cadence of exploration missions. Discussions among mission planners, vehicle developers, subject-matter-experts, and technologists were used to identify a minimum but sufficient set of required technologies and capabilities. Within System Maturation Teams, known challenges were identified and expressed as specific performance gaps in critical capabilities, which were then refined and activities required to close these critical gaps were identified. Analysis was performed to identify test and demonstration opportunities for critical technical capabilities across the Proving Ground spectrum of missions. This suite of critical capabilities is expected to

  7. Atividade alelopática de chalcona sintética, de seus precursores e de cetonas e aldeídos relacionados Allelopathic activity of synthetic chalcone, its precursors and of related cetones and aldehydes

    Directory of Open Access Journals (Sweden)

    H.R. Bitencourt

    2007-12-01

    objective of this work was to evaluate the allelopathic activity of synthetic chalcone, 2,4'-dimethoxychalcone, its precursors, 4-methoxyacetophenone (A and ortho-anisaldehyde (B, and some of their chemical alterations. The bioassays were developed under 25 ºC and photoperiod of 12 hours. The allelopathic effects of the compounds were tested on seed germination of Mimosa pudica and Senna obtusifolia weeds, under a concentration of 100, 200 and 300 mg L-1 of the compounds. The results indicated that precursor A (4-methoxyacetophenone plays an important role in allelopathic activity of the chalcones. These results show that synthesis is a possible pathway, helping to overcome problems such as characterization and isolation of natural products with herbicidal activity against weed species.

  8. Potencial alelopático de espécies nativas na germinação e crescimento inicial de Lactuca sativa L. (Asteraceae Allelopathic potential of native species in Lactuca sativa L. (Asteraceae germination and initial growth

    Directory of Open Access Journals (Sweden)

    Fabiana Maraschin-Silva

    2006-03-01

    Full Text Available A alelopatia caracteriza-se pelos efeitos danosos ou benéficos sobre o desenvolvimento da vegetação, causados por substâncias químicas produzidas e liberadas para o ambiente por uma planta. Com o objetivo de avaliar o potencial alelopático de espécies brasileiras, foram testados extratos foliares de Cecropia pachystachya Trec. (Urticaceae, Peltophorum dubium (Spreng. Taub. (Fabaceae, Psychotria leiocarpa Cham. & Schltdl (Rubiaceae, Sapium glandulatum (Vell. Pax (Euphorbiaceae e Sorocea bonplandii (Baill. Burg., Lanj. & Boer (Moraceae, utilizando-se bioensaios de germinação e crescimento e alface (Lactuca sativa L. como planta alvo. Nesses bioensaios, foram usados extratos foliares aquosos nas concentrações de 2 e 4%, preparados por maceração estática com água fria e quente. Os extratos das cinco espécies causaram atraso na germinação dos aquênios da alface, bem como efeitos tóxicos no crescimento das plântulas, com redução e enfraquecimento das raízes. Os resultados obtidos mostraram a presença de substâncias químicas inibidoras nos extratos, revelando potencial alelopático para as cinco espécies avaliadas.Allelopathy is characterized by harmful or beneficial effects on vegetation development, caused by chemical substances produced and released into the environment by the plant. Aiming to assess the allelopathic potential of Brazilian species, aqueous leaf extracts of Cecropia pachystachya Trec. (Urticaceae, Peltophorum dubium (Spreng. Taub. (Fabaceae, Psychotria leiocarpa Cham. & Schltdl (Rubiaceae, Sapium glandulatum (Vell. Pax (Euphorbiaceae, and Sorocea bonplandii (Baill. Burger, Lanj. & Boer (Moraceae were tested on lettuce using germination and growth bioassays. In these bioassays, aqueous leaf extracts were used at concentrations of 2 and 4%, prepared by static maceration with cold and hot water. The five species extracts delayed lettuce germination and produced toxic effects on seedling growth, with root

  9. Proving Causation With Epidemiological Evidence in Tobacco Lawsuits

    Directory of Open Access Journals (Sweden)

    Sun Goo Lee

    2016-03-01

    Full Text Available Recently, a series of lawsuits were filed in Korea claiming tort liability against tobacco companies. The Supreme Court has already issued decisions in some cases, while others are still pending. The primary issue in these cases is whether the epidemiological evidence submitted by the plaintiffs clearly proves the causal relationship between smoking and disease as required by civil law. Proving causation is difficult in tobacco lawsuits because factors other than smoking are involved in the development of a disease, and also because of the lapse of time between smoking and the manifestation of the disease. The Supreme Court (Supreme Court Decision, 2011Da22092, April 10, 2014 has imposed some limitations on using epidemiological evidence to prove causation in tobacco lawsuits filed by smokers and their family members, but these limitations should be reconsidered. First, the Court stated that a disease can be categorized as specific or non-specific, and for each disease type, causation can be proven by different types of evidence. However, the concept of specific diseases is not compatible with multifactor theory, which is generally accepted in the field of public health. Second, when the epidemiological association between the disease and the risk factor is proven to be significant, imposing additional burdens of proof on the plaintiff may considerably limit the plaintiff’s right to recovery, but the Court required the plaintiffs to provide additional information such as health condition and lifestyle. Third, the Supreme Court is not giving greater weight to the evidential value of epidemiological study results because the Court focuses on the fact that these studies were group-level, not individual-level. However, group-level studies could still offer valuable information about individual members of the group, e.g., probability of causation.

  10. On proving confluence modulo equivalence for Constraint Handling Rules

    DEFF Research Database (Denmark)

    Christiansen, Henning; Kirkeby, Maja Hanne

    2017-01-01

    Previous results on proving confluence for Constraint Handling Rules are extended in two ways in order to allow a larger and more realistic class of CHR programs to be considered confluent. Firstly, we introduce the relaxed notion of confluence modulo equivalence into the context of CHR: while...... with meta-level restrictions that reflect the non-logical and incomplete predicates. This language represents subproofs as diagrams, which facilitates a systematic enumeration of proof cases, pointing forward to a mechanical support for such proofs. The Project is supported by The Danish...

  11. Allelopathic Activity of Extracts from Different Brazilian Peanut (Arachis hypogaeaL.) Cultivars on Lettuce(Lactuca sativa)and Weed Plants.

    Science.gov (United States)

    Casimiro, G S; Mansur, E; Pacheco, G; Garcia, R; Leal, I C R; Simas, N K

    2017-01-01

    Peanut ( Arachis hypogaea L.) is the fourth most consumed oleaginous plant in the world, producing seeds with high contents of lipids, proteins, vitamins, and carbohydrates. Biological activities of different extracts of this species have already been evaluated by many researchers, including antioxidant, antitumoral, and antibacterial. In this work, the allelopathic activity of extracts from different Brazilian peanut cultivars against lettuce (Lactuca sativa) and two weed plants ( Commelina benghalensis and Ipomoea nil ) was studied. Aerial parts, roots, seeds, and seed coats were used for the preparation of crude extracts. Seed extract partitioning was performed with n -hexane, dichloromethane, ethyl acetate, n -butanol, and aqueous residue. Germination and growth of hypocotyls and rootlets were evaluated after one and five days of incubation with plant extracts, respectively. Crude seed extract and its dichloromethanic partition displayed highest allelopathic activity. These results contribute for the study of new potential natural herbicides.

  12. Allelopathic effects of water extracts of Sorghum halepense (L. Pers., Convolvulus arvensis L. and Cirsium arvense Scop. on early seedling growth of some leguminous crops

    Directory of Open Access Journals (Sweden)

    Irena Golubinova

    2014-03-01

    Full Text Available In order to study the allelopathic effect of aboveground dry biomass of Sorghum halepense, Convolvulus arvensis and Cirsium arvense on seed germination and early seedling growth of Pisum sativum (L., varieties Mir (winter form and Kerpo (spring form; Vicia sativa (L., variety Tempo, and Medicago sativa (L., variety Dara, a laboratory experiment was conducted at the Institute of Forage Crops - Pleven. Four concentrations: 1.25, 2.5, 5.0 and 10.0% were applied to each weed biotype used to study allelopathic effects. The results showed that weed extracts significantly decreased germination percentage, shoot and root length (cm, shoot and root weight (g, and seed vigor index (SVI1 and SVI2 of the tested species. In general, the variable effects are related to the weed species and extract concentrations.

  13. Allelopathic effects of the invasive Prosopis juliflora (Sw.) DC. on selected native plant species in Middle Awash, Southern Afar Rift of Ethiopia

    OpenAIRE

    Samuel Getachew; Sebsebe Demissew; Tadesse Woldemariam

    2012-01-01

    The allelopathic effects of the invasive Prosopis juliflora (Sw.) DC. was studied on seed germination and seedling growth of Acacia nilotica(L.) Willd. ex Del., Acacia tortilis (Forssk.) Hayne, Cenchrus ciliaris L. and Enteropogon rupestris (J.A. Schmidt) A. Chev. Vegetation sampling in different habitat types in the area was made to identify the target plant species. Comparison of canopy characteristics among P. juliflora, A. nilotica and A. tortilis was also made to observe differences if a...

  14. Model Checking Failed Conjectures in Theorem Proving: A Case Study

    Science.gov (United States)

    Pike, Lee; Miner, Paul; Torres-Pomales, Wilfredo

    2004-01-01

    Interactive mechanical theorem proving can provide high assurance of correct design, but it can also be a slow iterative process. Much time is spent determining why a proof of a conjecture is not forthcoming. In some cases, the conjecture is false and in others, the attempted proof is insufficient. In this case study, we use the SAL family of model checkers to generate a concrete counterexample to an unproven conjecture specified in the mechanical theorem prover, PVS. The focus of our case study is the ROBUS Interactive Consistency Protocol. We combine the use of a mechanical theorem prover and a model checker to expose a subtle flaw in the protocol that occurs under a particular scenario of faults and processor states. Uncovering the flaw allows us to mend the protocol and complete its general verification in PVS.

  15. Formal Analysis of Soft Errors using Theorem Proving

    Directory of Open Access Journals (Sweden)

    Sofiène Tahar

    2013-07-01

    Full Text Available Modeling and analysis of soft errors in electronic circuits has traditionally been done using computer simulations. Computer simulations cannot guarantee correctness of analysis because they utilize approximate real number representations and pseudo random numbers in the analysis and thus are not well suited for analyzing safety-critical applications. In this paper, we present a higher-order logic theorem proving based method for modeling and analysis of soft errors in electronic circuits. Our developed infrastructure includes formalized continuous random variable pairs, their Cumulative Distribution Function (CDF properties and independent standard uniform and Gaussian random variables. We illustrate the usefulness of our approach by modeling and analyzing soft errors in commonly used dynamic random access memory sense amplifier circuits.

  16. A Hybrid Approach to Proving Memory Reference Monotonicity

    KAUST Repository

    Oancea, Cosmin E.

    2013-01-01

    Array references indexed by non-linear expressions or subscript arrays represent a major obstacle to compiler analysis and to automatic parallelization. Most previous proposed solutions either enhance the static analysis repertoire to recognize more patterns, to infer array-value properties, and to refine the mathematical support, or apply expensive run time analysis of memory reference traces to disambiguate these accesses. This paper presents an automated solution based on static construction of access summaries, in which the reference non-linearity problem can be solved for a large number of reference patterns by extracting arbitrarily-shaped predicates that can (in)validate the reference monotonicity property and thus (dis)prove loop independence. Experiments on six benchmarks show that our general technique for dynamic validation of the monotonicity property can cover a large class of codes, incurs minimal run-time overhead and obtains good speedups. © 2013 Springer-Verlag.

  17. NASA SPoRT GOES-R Proving Ground Activities

    Science.gov (United States)

    Stano, Geoffrey T.; Fuell, Kevin K.; Jedloec, Gary J.

    2010-01-01

    The NASA Short-term Prediction Research and Transition (SPoRT) program is a partner with the GOES-R Proving Ground (PG) helping prepare forecasters understand the unique products to come from the GOES-R instrument suite. SPoRT is working collaboratively with other members of the GOES-R PG team and Algorithm Working Group (AWG) scientists to develop and disseminate a suite of proxy products that address specific forecast problems for the WFOs, Regional and National Support Centers, and other NOAA users. These products draw on SPoRT s expertise with the transition and evaluation of products into operations from the MODIS instrument and the North Alabama Lightning Mapping Array (NALMA). The MODIS instrument serves as an excellent proxy for the Advanced Baseline Imager (ABI) that will be aboard GOES-R. SPoRT has transitioned and evaluated several multi-channel MODIS products. The true and false color products are being used in natural hazard detection by several SPoRT partners to provide better observation of land features, such as fires, smoke plumes, and snow cover. Additionally, many of SPoRT s partners are coastal offices and already benefit from the MODIS sea surface temperature composite. This, along with other surface feature observations will be developed into ABI proxy products for diagnostic use in the forecast process as well as assimilation into forecast models. In addition to the MODIS instrument, the NALMA has proven very valuable to WFOs with access to these total lightning data. These data provide situational awareness and enhanced warning decision making to improve lead times for severe thunderstorm and tornado warnings. One effort by SPoRT scientists includes a lightning threat product to create short-term model forecasts of lightning activity. Additionally, SPoRT is working with the AWG to create GLM proxy data from several of the ground based total lightning networks, such as the NALMA. The evaluation will focus on the vastly improved spatial

  18. The GOES-R Proving Ground: 2012 Update

    Science.gov (United States)

    Gurka, J.; Goodman, S. J.; Schmit, T.; Demaria, M.; Mostek, A.; Siewert, C.; Reed, B.

    2011-12-01

    The Geostationary Operational Environmental Satellite (GOES)-R will provide a great leap forward in observing capabilities, but will also offer a significant challenge to ensure that users are ready to exploit the vast improvements in spatial, spectral, and temporal resolutions. To ensure user readiness, forecasters and other users must have access to prototype advanced products well before launch, and have the opportunity to provide feedback to product developers and computing and communications managers. The operational assessment is critical to ensure that the end products and NOAA's computing and communications systems truly meet their needs in a rapidly evolving environment. The GOES-R Proving Ground (PG) engages the National Weather Service (NWS) forecast, watch and warning community and other agency users in pre-operational demonstrations of select products with GOES-R attributes (enhanced spectral, spatial, and temporal resolution). In the PG, developers and forecasters test and apply algorithms for new GOES-R satellite data and products using proxy and simulated data sets, including observations from current and future satellite instruments (MODIS, AIRS, IASI, SEVIRI, NAST-I, NPP/VIIRS/CrIS, LIS), lightning networks, and computer simulated products. The complete list of products to be evaluated in 2012 will be determined after evaluating results from experiments in 2011 at the NWS' Storm Prediction Center, National Hurricane Center, Aviation Weather Center, Ocean Prediction Center, Hydrometeorological Prediction Center, and from the six NWS regions. In 2012 and beyond, the PG will test and validate data processing and distribution systems and the applications of these products in operational settings. Additionally developers and forecasters will test and apply display techniques and decision aid tools in operational environments. The PG is both a recipient and a source of training. Training materials are developed using various distance training tools in

  19. Pacific Proving Grounds radioisotope imprint in the Philippine Sea sediments.

    Science.gov (United States)

    Pittauer, Daniela; Roos, Per; Qiao, Jixin; Geibert, Walter; Elvert, Marcus; Fischer, Helmut W

    2018-06-01

    Radionuclide concentrations were studied in sediment cores taken at the continental slope of the Philippine Sea off Mindanao Island in the equatorial Western Pacific. High resolution deposition records of anthropogenic radionuclides were collected at this site. Excess 210 Pb together with excess 228 Th and anthropogenic radionuclides provided information about accumulation rates. Concentrations of Am and Pu isotopes were detected by gamma spectrometry, alpha spectrometry and ICP-MS. The Pu ratios indicate a high portion (minimum of 60%) of Pu from the Pacific Proving Grounds (PPG). This implies that the transport of PPG derived plutonium with the Mindanao Current southward is similarly effective as the previously known transport towards the north with the Kuroshio Current. The record is compared to other studies from northwest Pacific marginal seas and Lombok basin in the Indonesian Archipelago. The sediment core top was found to contain a 6 cm thick layer dominated by terrestrial organic matter, which was interpreted as a result of the 2012 Typhoon Pablo-related fast deposition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Environmental geophysics, offshore Bush River Peninsula, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S.F.; Kuecher, G.J.; Davies, B.E. [and others

    1995-11-01

    Geophysical studies in shallow waters adjacent to the Bush River Peninsula, Edgewood Area of Aberdeen Proving Ground, Maryland, have delineated the extent of waste disposal sites and established a hydrogeologic framework, which may control contaminant transport offshore. These studies indicate that during the Pleistocene Epoch, alternating stands of high and low sea levels resulted in a complex pattern of shallow channel-fill deposits around the Bush River Peninsula. Ground-penetrating radar studies reveal paleochannels greater than 50 ft deep. Some of the paleochannels are also imaged with marine seismic reflection. Conductivity highs measured with the EM-31 are also indicative of paleochannels. This paleochannel depositional system is environmentally significant because it may control the shallow groundwater flow regime beneath the peninsula. Magnetic, conductivity, and side-scan sonar anomalies outline anthropogenic anomalies in the study area. On the basis of geophysical data, underwater anthropogenic materials do exist in some isolated areas, but large-scale offshore dumping has not occurred in the area studied.

  1. Why prove it again? alternative proofs in mathematical practice

    CERN Document Server

    Dawson, Jr , John W

    2015-01-01

    This monograph considers several well-known mathematical theorems and asks the question, “Why prove it again?” while examining alternative proofs.   It  explores the different rationales mathematicians may have for pursuing and presenting new proofs of previously established results, as well as how they judge whether two proofs of a given result are different.  While a number of books have examined alternative proofs of individual theorems, this is the first that presents comparative case studies of other methods for a variety of different theorems. The author begins by laying out the criteria for distinguishing among proofs and enumerates reasons why new proofs have, for so long, played a prominent role in mathematical practice.  He then outlines various purposes that alternative proofs may serve.  Each chapter that follows provides a detailed case study of alternative proofs for particular theorems, including the Pythagorean Theorem, the Fundamental Theorem of Arithmetic, Desargues’ Theorem, the...

  2. Long-term allelopathic control of phytoplankton by the submerged macrophyte Elodea nuttallii

    NARCIS (Netherlands)

    Vanderstukken, M.; Declerck, S.A.J.; Decaestecker, E.; Muylaert, K.

    2014-01-01

    Keywords: allelochemicals; chemical ecology; competition; nutrient limitation; shallow lakes Summary 1.It is well known that submerged macrophytes can suppress phytoplankton blooms in lakes and thus promote water quality and biodiversity. One of the possible mechanisms through which submerged

  3. Use of Allelopathic Traits of Several Medicinal Plants on Some Germination Characteristics and Early Growth of Wheat and Wild Oat

    Directory of Open Access Journals (Sweden)

    H Piraste Anoshe

    2012-02-01

    Full Text Available Ecosystem pollution and weed resistance to herbicides have led researchers to pay more attention to natural herbicides. To examine allelopathic effects of liquorice, rosemary, chamomile and eucalypt on germination characteristics and early growth of wheat (Triticum aestivum L. and wild oat (Avena fatua L., a factorial experiment based on completely randomized design with 20 treatments and four replicates was conducted at Cereal Laboratory of College of Agricultural, Shiraz University, Iran in 2010. The results showed that rosemary essential oil had most negative effect on germination percentage (G%, seedling length (SL, radicle length (RL, shoot to root length ratio (S/R, relative water content (RWC and total water content (TWC. The lowest negative effect on G%, SL, RL and TWC was obtained from eucalypt essential oil and the least effect on RWC was observed from liquorice essential oil treatments. Most reduction on S/R was obtained from chamomile essential oil. The effect of stem essential oil on all measured traits, except G%, was more than leaf essential oil. Also wild oat was found to be more responsive than wheat to rosemary and chamomile essential oils. Considering these results, it appeared that control of wild oat by using such essential oil as rosemary and chamomile might be possible under some conditions with appropriate cautions.

  4. ALLELOPATHIC EFFECT OF PARSLEY (Petroselinum crispum Mill. COGERMINATION, WATER EXTRACTS AND RESIDUES ON HOARY CRESS (Lepidium draba (L. Desv.

    Directory of Open Access Journals (Sweden)

    Marija Ravlić

    2014-06-01

    Full Text Available The aim of the study was to examine allelopathic effect of parsley (Petroselinum crispum Mill. on germination and growth parameters of weed species hoary cress (Lepidium draba (L. Desv.. Cogermination of hoary cress with parsley seeds, water extracts from fresh and dry parsley biomass in concentrations of 5 and 10% (50 and 100 g per litre of distilled water were evaluated in Petri dishes. Effect of water extracts from fresh parsley biomass in aforementioned concentrations as well as effects of fresh and dry parsley residues in two rates (10 and 20 g/kg of soil were examined in pots with soil. Cogermination of seeds stimulated root length, but decreased shoot length and fresh weight of hoary cress seedlings. In the Petri dish assay, extracts from fresh and dry parsley biomass reduced germination of hoary cress, but had both stimulatory as well as inhibitory effect on other parameters. The highest concentration of dry biomass extract completely reduced germination rate of hoary cress (by 100%. In the pot experiment, extracts from fresh parsley biomass had stimulatory effect on weed growth parameters except for root length which was inhibited with higher concentration by 4.2%. Fresh parsley residues reduced germination, root and shoot length of hoary cress, while dry parsley residues promoted measured parameters, with the exception of root length.

  5. Antibacterial, allelopathic and antioxidant activities of essential oil of Salvia officinalis L. growing wild in the Atlas Mountains of Morocco.

    Science.gov (United States)

    Bouajaj, S; Benyamna, A; Bouamama, H; Romane, A; Falconieri, D; Piras, A; Marongiu, B

    2013-01-01

    Salvia officinalis (Common sage, Culinary sage) is an aromatic plant that is frequently used as a spice in Mediterranean cookery and in the food industry and as a traditional medicine for the treatment of several infectious diseases. The essential oils were obtained by two different methods [hydrodistillation (HD) and microwave (Mw)] from the aerial part of S. officinalis L. growing wild in Ourika-Marrakech in Morocco. Ourika is a large zone of the Atlas Mountains which is considered as a large reserve of Flora, especially medicinal and aromatic plants. The obtained oils were analysed by gas chromatography and gas chromatography-mass spectrometry and compared with that of Tunisia. Thirty-six compounds were identified from the Mw-extracted oil which accounted for 97.32% of the total oil composition. However, 33 compounds obtained by HD representing 98.67%. The major components were trans-thujone (14.10% and 29.84%), 1,8-cineole (5.10% and 16.82%), camphor (4.99% and 9.14%), viridiflorol (16.42% and 9.92%), β-caryophyllene (19.83% and 5.20%) and α-humulene (13.54% and 4.02%). Antibacterial, allelopathic (% germination in lettuce seeds and inhibited root growth obtained after treatment with S. officinalis oils) and antioxidant (IC₅₀ values 22 mg/mL) activities were studied.

  6. Depleted uranium human health risk assessment, Jefferson Proving Ground, Indiana

    Energy Technology Data Exchange (ETDEWEB)

    Ebinger, M.H.; Hansen, W.R.

    1994-04-29

    The risk to human health from fragments of depleted uranium (DU) at Jefferson Proving Ground (JPG) was estimated using two types of ecosystem pathway models. A steady-state, model of the JPG area was developed to examine the effects of DU in soils, water, and vegetation on deer that were hunted and consumed by humans. The RESRAD code was also used to estimate the effects of farming the impact area and consuming the products derived from the farm. The steady-state model showed that minimal doses to humans are expected from consumption of deer that inhabit the impact area. Median values for doses to humans range from about 1 mrem ({plus_minus}2.4) to 0.04 mrem ({plus_minus}0.13) and translate to less than 1 {times} 10{sup {minus}6} detriments (excess cancers) in the population. Monte Carlo simulation of the steady-state model was used to derive the probability distributions from which the median values were drawn. Sensitivity analyses of the steady-state model showed that the amount of DU in airborne dust and, therefore, the amount of DU on the vegetation surface, controlled the amount of DU ingested by deer and by humans. Human doses from the RESRAD estimates ranged from less than 1 mrem/y to about 6.5 mrem/y in a hunting scenario and subsistence fanning scenario, respectively. The human doses exceeded the 100 mrem/y dose limit when drinking water for the farming scenario was obtained from the on-site aquifer that was presumably contaminated with DU. The two farming scenarios were unrealistic land uses because the additional risk to humans due to unexploded ordnance in the impact area was not figured into the risk estimate. The doses estimated with RESRAD translated to less than 1 {times} 10{sup {minus}6} detriments to about 1 {times} 10{sup {minus}3} detriments. The higher risks were associated only with the farming scenario in which drinking water was obtained on-site.

  7. NASA'S Space Launch System: Progress Toward the Proving Ground

    Science.gov (United States)

    Jackman, Angie; Johnson, Les

    2017-01-01

    With significant and substantial progress being accomplished toward readying the Space Launch System (SLS) rocket for its first test flight, work is already also underway on preparations for the second flight – using an upgraded version of the vehicle – and beyond. Designed to support human missions into deep space, Space Launch System (SLS), is the most powerful human-rated launch vehicle the United States has ever undertaken, and together with the Orion spacecraft will support human exploration missions into the proving ground of cislunar space and ultimately to Mars. For its first flight, SLS will deliver a near-term heavy-lift capability for the nation with its 70-metric-ton Block 1 configuration. Each element of the vehicle now has flight hardware in production in support of the initial flight of the SLS, which will propel Orion around the moon and back. For its second flight, SLS will be upgraded to the more-capable Block 1B configuration. While the Block 1 configuration is capable of delivering more than 70 metric tons to low Earth orbit, the Block 1B vehicle will increase that capability to 105 metric tons. For that flight, the new configuration introduces two major new elements to the vehicle – an Exploration Upper Stage (EUS) that will be used for both ascent and in-space propulsion, and a Universal Stage Adapter (USA) that serves as a “payload bay” for the rocket, allowing the launch of large exploration systems along with the Orion spacecraft. Already, flight hardware is being prepared for the Block 1B vehicle. Beyond the second flight, additional upgrades will be made to the vehicle. The Block 1B vehicle will also be able to launch 8.4-meter-diameter payload fairings, larger than any previously flown, and the Spacecraft Payload Integration and Evolution (SPIE) Element will oversee development and production of those fairings. Ultimately, SLS will be evolved to a Block 2 configuration, which will replace the solid rocket boosters on the Block

  8. Bronchoscopic diagnostic procedures and microbiological examinations in proving endobronchial tuberculosis.

    Science.gov (United States)

    Şimşek, Abdullah; Yapıcı, İlhami; Babalık, Mesiha; Şimşek, Zekiye; Kolsuz, Mustafa

    2016-01-01

    To determine the proportional distribution of endobronchial tuberculosis (EBTB) subtypes and to evaluate the types of bronchoscopic diagnostic procedures that can prove granulomatous inflammation. This was a retrospective study of 18 HIV-negative patients with biopsy-proven EBTB treated between 2010 and 2014. The most common EBTB subtypes, as classified by the bronchoscopic features, were tumorous and granular (in 22.2% for both). Sputum smear microscopy was performed in 11 patients and was positive for AFB in 4 (36.3%). Sputum culture was also performed in 11 patients and was positive for Mycobacterium tuberculosis in 10 (90.9%). Smear microscopy of BAL fluid (BALF) was performed in 16 patients and was positive for AFB in 10 (62.5%). Culture of BALF was also performed in 16 patients and was positive for M. tuberculosis in 15 (93.7%). Culture of BALF was positive for M. tuberculosis in 93.7% of the 16 patients tested. Among the 18 patients with EBTB, granulomatous inflammation was proven by the following bronchoscopic diagnostic procedures: bronchial mucosal biopsy, in 8 (44.4%); bronchial brushing, in 7 (38.8%); fine-needle aspiration biopsy, in 2 (11.1%); and BAL, in 2 (11.1%). Bronchial anthracofibrosis was observed in 5 (27.7%) of the 18 cases evaluated. In our sample of EBTB patients, the most common subtypes were the tumorous and granular subtypes. We recommend that sputum samples and BALF samples be evaluated by smear microscopy for AFB and by culture for M. tuberculosis, which could increase the rates of early diagnosis of EBTB. We also recommend that bronchial brushing be employed together with other bronchoscopic diagnostic procedures in patients suspected of having EBTB. Determinar a distribuição proporcional dos subtipos de tuberculose endobrônquica (TBEB) e avaliar os tipos de procedimentos diagnósticos broncoscópicos que podem revelar inflamação granulomatosa. Este foi um estudo retrospectivo com 18 pacientes HIV negativos com TBEB comprovada

  9. The allelopathic effect of the black nut leaves (Juglans nigra L. over the species of moon – raddish (Raphanus sativus L. and white mustard (Sinapis alba L.

    Directory of Open Access Journals (Sweden)

    Sorina CORBU

    2006-05-01

    Full Text Available The present experiment is a research on the effect of the allelopathic substances in the leaves of the black nut (Juglans nigra L. over the species of white mustard (Sinapis alba L. and the moon – raddish (Raphanus sativus L.. We have prepared a watery extract of a concentration of 5, 15, 25, 50, 75 and 100% from the leaves in different seasons (spring, autumn and winter. The watery extract presents an inhibitory effect over the germination and growth of the plants subdued to experiments, especialy over the leaves collected in spring.

  10. Potential of Root Exudates from Wetland Plants and Their Potential Role for Denitrification and Allelopathic Interactions

    DEFF Research Database (Denmark)

    Zhai, Xu

    chemicals to suppress the growth of native species. Phragmites australis is recognized as the most invasive species in wetland ecosystems in North America, and allelopathy has been reported to be involved in the invasion success of the introduced exotic P. australis. The composition of the root exudates may...

  11. Hydrogeologic, soil, and water-quality data for j-field, Aberdeen Proving Ground, Maryland, 1989-94

    Science.gov (United States)

    Phelan, D.J.

    1996-01-01

    Disposal of chemical-warfare agents, munitions, and industrial chemicals in J-Field, Aberdeen Proving Ground, Maryland, has resulted in ground-water, surface-water, and soil contamination. This report presents data collected by the U.S. Geological Survey from Novembr 1989 through September 1994 as part of a remedial investigation of J-Field in response to the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). Hydrogeologic data, soil-gas and soil-quality data, and water-qualtiy data are included.

  12. ALLELOPATHIC EFFECTS OF NATIVE AND INVASIVE FRESHWATER MACROPHYTES ON PHYTOPLANKTON AND AQUATIC INVERTEBRATES

    OpenAIRE

    FARIBA MOSLIH PAKDEL

    2017-01-01

    Invasive freshwater plants impose extensive negative impacts on different biota. They usually form mono-specific stands that provide a less suitable habitat than mix stands, or may produce novel chemicals that can have deleterious and deterrent effects for native aquatic species. I tested the bioactivity of three invasive aquatic plants on different biota. My study demonstrated that several interrelated mechanisms used by invasive plants are responsible for the success of these species. For i...

  13. Allelopathic Effect of Powdered Russian Knapweed (Acroptilon repens L. on the Growth Parameters of Redroot Amaranth (Amaranthus retroflexus L.

    Directory of Open Access Journals (Sweden)

    Alireza PIRZAD

    2013-08-01

    Full Text Available To evaluate probable allelopathic effect of different parts of Russian knapweed (Acroptilon repens L. on the growth of redroot amaranth (Amaranthus retroflexus L. seedling, a factorial experiment was conducted based on randomized complete block design with three replications at the Faculty of Agriculture, Urmia University in 2012 (Iran. In this experiment, treatments were different parts of Russian knapweed (aerial part, flower and root in different amounts (1, 2, 3 and 4 g/pot. Pots included 300 g of soil. Results showed the significant effect of Russian knapweed plant parts on the seedling emergence percent, root length, ratio of root/shoot length, seedling length, seedling fresh weight, and the significant effect of plant material amounts on the seedling emergence percent, seedling fresh weight and seedling dry weight. Interaction effect between plant material type and amount on the shoot length, root length, ratio of root/shoot length, seedling length was significant, too. The longest shoot (3.51 cm, root (1.75 cm, the highest ratio of root/shoot length (0.49 and seedling length (5.26 cm belonged to control treatment. The highest seedling emergence percent of Amaranthus retroflexus (34.73% and seedling fresh weight (0.176 g were occurred at pots treated by Russian knapweed aerial part. The lowest seedling emergence percent (21.94 % and seedling fresh weight (0.111 g were obtained from application of Acroptilon repens powdered root. The maximum seedling dry (0.0126 g and fresh (0.177 g weight of Amaranthus retroflexus were obtained from control treatment.

  14. A simple procedure for the purification of active fractions in aqueous extracts of plants with allelopathic properties

    Directory of Open Access Journals (Sweden)

    Fabian Borghetti

    2013-03-01

    Full Text Available Most studies conducted to test the allelopathic activity of plant parts have made use of water as solvent. However, the presence of polar, water-soluble substances, such as proteins and carbohydrates, tends to hamper the purification of active compounds. In this study, we present a simple purification procedure that separates the active fraction of the extract from the undesirable substances, thus facilitating the search for active molecules through standard chromatographic methods. Aqueous leaf extracts of three Cerrado species (Caryocar brasiliense, Qualea parviflora and Eugenia dysenterica were prepared at 5% concentration (w/v and stored at 4ºC (crude extracts. After 24 h, these solutions were filtered and freeze-dried. The powder obtained was dissolved in methanol, filtered again, evaporated and dissolved in water for bioassays (purified extracts. For the bioassays, seedlings of Sesamum indicum were grown for five days in aqueous solutions prepared from crude and purified extracts at concentrations ranging from 0.1% to 1.0% (w/v. Seedling growth in distilled water was set as a control. In comparison with the control, we found that test solutions prepared from both crude and purified extracts significantly inhibited sesame seedling growth. However, solutions prepared from purified extracts were two to ten times more inhibitory to seedling growth than were those prepared from crude extracts. The inhibition of root growth ranged from 35% to 77%, depending on the plant species, at a concentration as low as 0.1%. Roots were more affected than were shoots. The effects of purified extracts on seedling morphology were similar to those observed when crude extracts were employed, indicating that the procedure of purification of crude extracts did not interfere with the mode of action of the active substances

  15. Allelopathic potential of leaf and seed of Mucuna bracteata DC. ex Kurz on Eleusine indica (L.) gaertn

    Science.gov (United States)

    Halimshah, Syamimi; Ismail B., S.; Ahmad, Wan Juliana Wan

    2015-09-01

    A study was conducted to determine the allelopathic potential of leaf and seed of Mucuna bracteata on the growth of E. indica through aqueous extract and debris (incorporated into the soil) experiment. Three concentrations of leaf and seed aqueous extract (16.7, 33.3 and 66.7 g/L) and debris (2.5, 5.0 and 10.0 g/500 g soil) of M. bracteata were used in the experiment. Complete randomized design (CRD) with three replications was applied in this experiment which was conducted twice. Results demonstrated that the leaf and seed extracts of M. bracteata exhibited higher suppression effect on the growth and germination of E. indica as the concentration increased. The leaf and seed extracts significantly reduced all measured parameters at all concentrations except for the shoot length and germination of E. indica by seed extract at 16.7 g/L which recorded insignificant reduction by 40.5% and 4% respectively. The leaf and seed debris significantly reduced the root length of E. indica at all treatments. Seed debris also showed significant reduction on the germination at all treatments and other seedling growth parameters (shoot length, fresh weight and dry weight) at 2.5 and 10.0 g/500 g soil. Meanwhile, the leaf debris demonstrated stimulation effect on the seedling growth parameters. As a whole, the leaf showed higher suppression effect in aqueous extract experiment while the seed recorded higher suppression effect in the debris experiment. Further studies need to be conducted to investigate the type of inhibition mechanism involved in both experiments.

  16. Hydrogeology and soil gas at J-Field, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Hughes, W.B.

    1993-01-01

    Disposal of chemical warfare agents, munitions, and industrial chemicals in J-Field, Aberdeen Proving Ground, Maryland, has contaminated soil, groundwater and surface water. Seven exploratory borings and 38 observation wells were drilled to define the hydrogeologic framework at J-Field and to determine the type, extent, and movement of contaminants. The geologic units beneath J-Field consist of Coastal Plain sediments of the Cretaceous Patapsco Formation and Pleistocene Talbot Formation. The Patapsco Formation contains several laterally discontinuous aquifers and confining units. The Pleistocene deposits were divided into 3 hydrogeologic units--a surficial aquifer, a confining unit, and a confined aquifer. Water in the surficial aquifer flows laterally from topographically high areas to discharge areas in marshes and streams, and vertically to the underlying confined aquifer. In offshore areas, water flows from the deeper confined aquifers upward toward discharge areas in the Gunpowder River and Chesapeake Bay. Analyses of soil-gas samples showed high relative-flux values of chlorinated solvents, phthalates, and hydrocarbons at the toxic-materials disposal area, white-phosphorus disposal area, and riot-control-agent disposal area. The highest flux values were located downgradient of the toxic materials and white phosphorus disposal areas, indicating that groundwater contaminants are moving from source areas beneath the disposal pits toward discharge points in the marshes and estuaries. Elevated relative-flux values were measured upgradient and downgradient of the riot-control agent disposal area, and possibly result from soil and (or) groundwater contamination.

  17. Contamination source review for Building E2370, Edgewood Area, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    O`Reilly, D.P.; Glennon, M.A.; Draugelis, A.K.; Rueda, J.; Zimmerman, R.E.

    1995-09-01

    The US Army Aberdeen Proving Ground (APG) commissioned Argonne National Laboratory (ANL) to conduct a contamination source review to identify and define areas of toxic or hazardous contaminants and to assess the physical condition and accessibility of APG buildings. The information obtained from this review may be used to assist the US Army in planning for the future use or disposition of the buildings. The contamination source review consisted of the following tasks: historical records search, physical inspection, photographic documentation, and geophysical investigation. This report provides the results of the contamination source review for Building E2370. Many of the APG facilities constructed between 1917 and the 1960s are no longer used because of obsolescence and their poor state of repair. Because many of these buildings were used for research, development, testing, and/or pilot-scale production of chemical warfare agents and other military substances, the potential exists for portions of the buildings to be contaminated with these substances, their degradation products, and other laboratory or industrial chemicals. These buildings and associated structures or appurtenances may contribute to environmental concerns at APG.

  18. Contamination source review for Building E6891, Edgewood Area, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Zellmer, S.D.; Draugelis, A.K.; Rueda, J.; Zimmerman, R.E.

    1995-09-01

    The US Army Aberdeen Proving Ground (APG) commissioned Argonne National Laboratory (ANL) to conduct a contamination source review to identify and define areas of toxic or hazardous contaminants and to assess the physical condition and accessibility of various APG buildings. This report provides the results of the contamination source review for Building E6891. The information obtained from this review may be used to assist the US Army in planning for the future use or disposition of the buildings. The contamination source review consisted of the following tasks: historical records search, physical inspection, photographic documentation, geophysical investigation, and collection of air samples. This building is part of the Lauderick Creek Concrete Slab Test Site, located in the Lauderick Creek Area in the Edgewood Area. Many of the APG facilities constructed between 1917 and the 1960s are no longer used because of obsolescence and their poor state of repair. Because many of these buildings were used for research, development, testing, and/or pilot-scale production of chemical warfare agents and other military substances the potential exists` for portions of the buildings to be contaminated with these substances, their degradation products, and other laboratory or industrial chemicals. These buildings and associated structures or appurtenances may contribute to environmental concerns at APG.

  19. Allelopathic Effect of Echinochloa colona L. and Cyperus iria L. Weed Extracts on the Seed Germination and Seedling Growth of Rice and Soyabean

    Directory of Open Access Journals (Sweden)

    Neha Chopra

    2017-01-01

    Full Text Available The present study was undertaken to assess the allelopathic effect of Echinochloa colona L. and Cyperus iria L. in relation to the germination and primary growth of Oryza sativa L. (rice and Glycine max L. (soyabean. Effects of dichloromethane (DCM and double distilled water soluble (DDW fractions of E. colona L. and C. iria L. root and aerial part extracts reduced germination and suppressed early seedling growth of rice and soyabean. With increase in extract concentration from 1 to 100 mg/mL, a gradual decrease in seed germination and seedling length occurred. The highest growth of G. max seedling was recorded in DDW fraction of E. colona aerial part extract at 1 mg/mL concentration with 94% germination and the lowest length was found in DCM fraction of C. iria root extract at 100 mg/mL concentration with 65% germination. In O. sativa, the highest length was noted at 1 mg/mL concentration in DDW fraction of E. colona aerial part extract with 82% germination and the lowest length was found in DCM fraction of C. iria and E. colona root extracts with germination 57% and 62%, respectively, at 100 mg/mL concentration. The results suggested that these weeds had good allelopathic potential which reduces germination and plant growth.

  20. Effect of vermicast generated from an allelopathic weed lantana (Lantana camara) on seed germination, plant growth, and yield of cluster bean (Cyamopsis tetragonoloba).

    Science.gov (United States)

    Karthikeyan, M; Hussain, N; Gajalakshmi, S; Abbasi, S A

    2014-11-01

    In perhaps the first-ever study of its kind, the effect of vermicompost, derived solely from an allelopathic weed, on the germination, growth, and yield of a botanical species, has been carried out. In test plots, the soil was treated with the vermicompost of lantana (Lantana camara) at the rates of 5, 7.5, and 10 t ha(-1), and cluster bean (Cyamopsis tetragonoloba) was grown on it. The performance of these systems was compared with the systems in which the soil was fortified with inorganic fertilizers (IFs) in concentrations equivalent to those present in the respective vermicompost (VC) treatments. Additionally, a set of control was studied in which the soil was used without fortification by either VC or IF. It was seen that up to 51.5 % greater germination success occurred in the VC treatments compared to controls. VC also supported better plant growth in terms of stem diameter, shoot length, shoot mass, number of leaves, and leaf pigments. The positive impact extended up to fruit yield. In addition, vermicast application enhanced root nodule formation, reduced disease incidence, and allowed for a smaller number of stunted plants. The results indicate that allelopathic ingredients of lantana seem to have been totally eliminated during the course of its vermicomposting and that lantana vermicompost has the potential to support germination, growth, and fruit yield better than equivalent quantities of IFs.

  1. 78 FR 60238 - Proposed Modification and Establishment of Restricted Areas; Aberdeen Proving Ground, MD

    Science.gov (United States)

    2013-10-01

    ...; Aberdeen Proving Ground, MD AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed..., within the existing restricted areas R-4001A and R- 4001B, at the U.S. Army's Aberdeen Proving Ground in... nonparticipating aircraft from a hazard to navigation in the Aberdeen Proving Ground airspace. DATES: Comments must...

  2. Allelopathic effects of microcystin-LR on the germination, growth and metabolism of five charophyte species and a submerged angiosperm.

    Science.gov (United States)

    Rojo, Carmen; Segura, Matilde; Cortés, Francisco; Rodrigo, María A

    2013-11-15

    Microcystins (MCs) are produced by cyanobacteria in aquatic environments and adversely affect macrophytes at very high concentrations. However, the effects of MC on macrophytes at concentrations of environmental relevance are largely unknown. The main objective of this study was to analyze the allelopathic effects of MC-LR at natural concentrations (1, 8 and 16 μg MC-LR/L) on five charophyte species (Chara aspera, C. baltica, C. hispida, C. vulgaris and Nitella hyalina) and the angiosperm Myriophyllum spicatum. Macrophyte specimens were obtained from a restored area located in Albufera de València Natural Park, a protected coastal Mediterranean wetland. Two different experiments were conducted involving (i) the addition of MC-LR to natural sediment to evaluate its effects on seed germination and (ii) the addition of MC-LR to water cultures of macrophytes to evaluate its effects on growth and metabolic functions. In water, the MC-LR concentration decreased by 84% in two weeks; the loss was not significant in sediment. The first seedlings (all C. hispida) emerged from the wetland sediment following a delay of a few days in the presence of MC-LR. The germination rates in 8 and 16 μg MC-LR/L treatments were 44% and 11% of that occurring in the absence of MC, but these differences disappeared over time. The final density was 6-7 germlings/dm(3). Final germling length was unaffected by MC-LR. Rotifers (Lecane spp.) emerging from the natural sediment during the experiment were favored by MC-LR; the opposite pattern was observed in the cladoceran Daphnia magna. The growth rates of C. vulgaris, C. baltica and N. hyalina were unaffected by MC exposure, whereas those of C. hispida and C. aspera were reduced in the MC treatments relative to the control treatment. The concentration of chlorophyll-a and the in vivo net photosynthetic rate were lower in the presence of MC-LR, even at the lowest concentration, for all of the characeans tested. M. spicatum was sensitive to the

  3. Bioassay standardization for the detection of allelopathic compounds and environmental toxicants using lettuce

    Directory of Open Access Journals (Sweden)

    Mateus Salomão Simões

    2013-09-01

    Full Text Available The purpose of this study was to assess different experimental conditions to determine a protocol for bioassays based on seed germination and early seedling growth using lettuce (Lactuca sativa L. cv. Grand Rapids as indicator species. This protocol aims to provide support for the standardization of assays of various chemicals such as allelochemicals and environmental toxicants. The following tests were performed: time of germination, temperature, light, solution volume and Petri dish size. For each test (except for time of germination, the influence of the conditions investigated was determined by the endpoints germination percentage, germination speed index, root length, seedling fresh weight and total dry weight. The results showed that variations in the methods altered the results. It is recommended that bioassays using L. sativa L. cv. Grand Rapids be carried out for a minimum period of four days for assessments of both germination and initial growth and that the experimental conditions include a temperature of 20°C, 90-mm Petri dishes or larger, 0.1 mL cypsela solution, and continuous light or 12-hour photoperiod.

  4. Work plan for conducting an ecological risk assessment at J-Field, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Hlohowskyj, I.; Hayse, J.; Kuperman, R. [Argonne National Lab., IL (United States). Environmental Assessment Div.] [and others

    1995-03-01

    The Environmental Management Division of Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation and feasibility study (RI/FS) of the J-Field area at APG pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. J-Field is within the Edgewood Area of APG in Harford County, Maryland, and activities at the Edgewood Area since World War II have included the development, manufacture, testing, and destruction of chemical agents and munitions. The J-Field site was used to destroy chemical agents and munitions by open burning and open detonation. This work plan presents the approach proposed to conduct an ecological risk assessment (ERA) as part of the RI/FS program at J-Field. This work plan identifies the locations and types of field studies proposed for each area of concern (AOC), the laboratory studies proposed to evaluate toxicity of media, and the methodology to be used in estimating doses to ecological receptors and discusses the approach that will be used to estimate and evaluate ecological risks at J-Field. Eight AOCs have been identified at J-Field, and the proposed ERA is designed to evaluate the potential for adverse impacts to ecological receptors from contaminated media at each AOC, as well as over the entire J-Field site. The proposed ERA approach consists of three major phases, incorporating field and laboratory studies as well as modeling. Phase 1 includes biotic surveys of the aquatic and terrestrial habitats, biological tissue sampling and analysis, and media toxicity testing at each AOC and appropriate reference locations. Phase 2 includes definitive toxicity testing of media from areas of known or suspected contamination or of media for which the Phase 1 results indicate toxicity or adverse ecological effects. In Phase 3, the uptake models initially developed in Phase 2 will be finalized, and contaminant dose to each receptor from all complete pathways will be estimated.

  5. Air monitoring for volatile organic compounds at the Pilot Plant Complex, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, J.F.; O`Neill, H.J.; Raphaelian, L.A.; Tomczyk, N.A.; Sytsma, L.F.; Cohut, V.J.; Cobo, H.A.; O`Reilly, D.P.; Zimmerman, R.E.

    1995-03-01

    The US Army`s Aberdeen Proving Ground has been a test site for a variety of munitions, including chemical warfare agents (CWA). The Pilot Plant Complex (PPC) at Aberdeen was the site of development, manufacture, storage, and disposal of CWA. Deterioration of the buildings and violations of environmental laws led to closure of the complex in 1986. Since that time, all equipment, piping, and conduit in the buildings have been removed. The buildings have been declared free of surface CWA contamination as a result of air sampling using the military system. However, no air sampling has been done to determine if other hazardous volatile organic compounds are present in the PPC, although a wide range of toxic and/or hazardous materials other than CWA was used in the PPC. The assumption has been that the air in the PPC is not hazardous. The purpose of this air-monitoring study was to screen the indoor air in the PPC to confirm the assumption that the air does not contain volatile organic contaminants at levels that would endanger persons in the buildings. A secondary purpose was to identify any potential sources of volatile organic contaminants that need to be monitored in subsequent sampling efforts.

  6. Contamination source review for Building E3162, Edgewood Area, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Miller, G.A.; Draugelis, A.K.; Rueda, J.; Zimmerman, R.E.

    1995-09-01

    This report was prepared by Argonne National Laboratory (ANL) to document the results of a contamination source review for Building E3162 at the Aberdeen Proving Ground (APG) in Maryland. The report may be used to assist the US Army in planning for the future use or disposition of this building. The review included a historical records search, physical inspection, photographic documentation, geophysical investigation, and collection of air samples. The field investigations were performed by ANL during 1994 and 1995. Building E3162 (APG designation) is part of the Medical Research Laboratories Building E3160 Complex. This research laboratory complex is located west of Kings Creek, east of the airfield and Ricketts Point Road, and south of Kings Creek Road in the Edgewood Area of APG. The original structures in the E3160 Complex were constructed during World War 2. The complex was originally used as a medical research laboratory. Much of the research involved wound assessment involving chemical warfare agents. Building E3162 was used as a holding and study area for animals involved in non-agent burns. The building was constructed in 1952, placed on inactive status in 1983, and remains unoccupied. Analytical results from these air samples revealed no distinguishable difference in hydrocarbon and chlorinated solvent levels between the two background samples and the sample taken inside Building E3162.

  7. Remedial investigation report for J-Field, Aberdeen Proving Ground, Maryland. Volume 1: Remedial investigation results

    Energy Technology Data Exchange (ETDEWEB)

    Yuen, C. R.; Martino, L. E.; Biang, R. P.; Chang, Y. S.; Dolak, D.; Van Lonkhuyzen, R. A.; Patton, T. L.; Prasad, S.; Quinn, J.; Rosenblatt, D. H.; Vercellone, J.; Wang, Y. Y.

    2000-03-14

    This report presents the results of the remedial investigation (RI) conducted at J-Field in the Edgewood Area of Aberdeen Proving Ground (APG), a U.S. Army installation located in Harford County, Maryland. Since 1917, activities in the Edgewood Area have included the development, manufacture, and testing of chemical agents and munitions and the subsequent destruction of these materials at J-Field by open burning and open detonation. These activities have raised concerns about environmental contamination at J-Field. This RI was conducted by the Environmental Conservation and Restoration Division, Directorate of Safety, Health and Environmental Division of APG, pursuant to requirements outlined under the Comprehensive Environmental Response, Compensation, and Liability Act, as amended (CERCLA). The RI was accomplished according to the procedures developed by the U.S. Environmental Protection Agency (EPA 1988). The RI provides a comprehensive evaluation of the site conditions, nature of contaminants present, extent of contamination, potential release mechanisms and migration pathways, affected populations, and risks to human health and the environment. This information will be used as the basis for the design and implementation of remedial actions to be performed during the remedial action phase, which will follow the feasibility study (FS) for J-Field.

  8. The allelopathic effect of Taraxacum officinale F.G. Wigg on the seeds germination and initial growth of Lolium westerwoldicum R.Br.

    Directory of Open Access Journals (Sweden)

    Jolanta Jankowska

    2012-12-01

    Full Text Available The common dandelion (Taraxacum officinale F.H. Wigg is a perennial plant often found in large concentrations in the sward of natural meadows. This species expands quickly, displacing other species. In literature there is a lack of data relating to the effect of common dandelion on plants growing in its vicinity. It is also not known why this species creates large clusters. Perhaps it competes with different plants through the allelopathic effect. Hence, the aim of this study was to determine the influence of water extracts from leaves and roots of common dandelion (Taraxacum officinale as well as soil extracts from the root layer of this species on seed germination and the initial growth of Lolium westerwoldicum R.Br. The investigated material comprised leaves and roots of Taraxacum officinale. The germination biotest most often used in experiments was applied. The seeds germination energy of westerwolds ryegrass was most inhibited by plant extracts prepared from roots and leaves of Taraxacum officinale. The germination ability of seeds of Lolium westerwoldicum was the highest in the treatments in which soil extracts were applied; however, the value of this feature was limited to a larger extent by the plant extracts from leaves of Taraxacum officinale than from roots. Higher concentrations of both soil and plant solutions had an inhibitory effect both on root growth and the growth of the leaf sheath and leaves of westerwolds ryegrass. The results of the tested parameters can confirm the allelopathic effect of Taraxacum officinale on germination and initial growth of Lolium westerwoldicum, and especially that of extracts prepared from leaves.

  9. Metabolomics and proteomics reveal impacts of chemically mediated competition on marine plankton

    Science.gov (United States)

    Poulson-Ellestad, Kelsey L.; Jones, Christina M.; Roy, Jessie; Viant, Mark R.; Fernández, Facundo M.; Kubanek, Julia; Nunn, Brook L.

    2014-01-01

    Competition is a major force structuring marine planktonic communities. The release of compounds that inhibit competitors, a process known as allelopathy, may play a role in the maintenance of large blooms of the red-tide dinoflagellate Karenia brevis, which produces potent neurotoxins that negatively impact coastal marine ecosystems. K. brevis is variably allelopathic to multiple competitors, typically causing sublethal suppression of growth. We used metabolomic and proteomic analyses to investigate the role of chemically mediated ecological interactions between K. brevis and two diatom competitors, Asterionellopsis glacialis and Thalassiosira pseudonana. The impact of K. brevis allelopathy on competitor physiology was reflected in the metabolomes and expressed proteomes of both diatoms, although the diatom that co-occurs with K. brevis blooms (A. glacialis) exhibited more robust metabolism in response to K. brevis. The observed partial resistance of A. glacialis to allelopathy may be a result of its frequent exposure to K. brevis blooms in the Gulf of Mexico. For the more sensitive diatom, T. pseudonana, which may not have had opportunity to evolve resistance to K. brevis, allelopathy disrupted energy metabolism and impeded cellular protection mechanisms including altered cell membrane components, inhibited osmoregulation, and increased oxidative stress. Allelopathic compounds appear to target multiple physiological pathways in sensitive competitors, demonstrating that chemical cues in the plankton have the potential to alter large-scale ecosystem processes including primary production and nutrient cycling. PMID:24889616

  10. Efeitos potencialmente alelopáticos dos óleos essenciais de Piper hispidinervium C. DC. e Pogostemon heyneanus Benth sobre plantas daninhas Potentially allelopathic effects of the essential oils of Piper hispidinervium C. DC. and Pogostemon heyneanus (Benth on weeds

    Directory of Open Access Journals (Sweden)

    Antônio Pedro da Silva Souza Filho

    2009-01-01

    pudica and mata-pasto (Senna obtusifolia. Depending on their concentrations, oils of the two species showed intensities of allelopathic activity on the donor species, on the receptor plant and on the examined plant factor. The germination of seeds was the factor most strongly inhibited by the oils. The intensities of inhibitions were positively related to the concentration, with the maximum inhibitions verified at 1%. Mimosa pudica was the receptor species most sensitive to the effects of oil. In comparison, the essential oil of Piper hispidinervium showed a higher potential for inhibiting the germination and development of the two receptor plants, notably in relation to the germination of seeds, when the differences were more striking. The results were attributed to the chemical composition of oils, especially in relation to the presence of monoterpenes, oxygenated monoterpenes and sesquiterpenes.

  11. Toxicity of sediments surrounding the Gunpowder Neck Superfund Site at Aberdeen Proving Ground, Maryland. Final report, August 1992-December 1993

    Energy Technology Data Exchange (ETDEWEB)

    Haley, M.V.; Anthony, J.S.; Chester, N.A.; Kurnas, C.W.

    1995-07-01

    From the late 1940s through the 1960s, the standard practice for disposing of toxic chemicals at Aberdeen Proving Ground, MD, was open burning. This disposal site has since been placed on the National Priority List (NPt) by U.S. Environmental Protection Agency. In the spring 1992, sediment samples were taken from waterways that surround that disposal area. Chemical analysis and sediment toxicity assays (Ampelisca abdita) were conducted. Toxicity comparison, with sediment leachate from an Adapted Toxicity Characteristic teaching Procedure (ATCLP), were made using Daphnia magna and a fluorescent bacterium Photobacterium phosphoreum in MICROTOX assays. Amphipods showed a wide range of mortality in mud as well as coarser sediments indicating substrate preference is not critical to the outcome of the assay. Toxicity results from the leachates showed the sediments were not toxic to daphnia and MICROTOX assays.

  12. Potential health impacts from range fires at Aberdeen Proving Ground, Maryland.

    Energy Technology Data Exchange (ETDEWEB)

    Willians, G.P.; Hermes, A.M.; Policastro, A.J.; Hartmann, H.M.; Tomasko, D.

    1998-03-01

    This study uses atmospheric dispersion computer models to evaluate the potential for human health impacts from exposure to contaminants that could be dispersed by fires on the testing ranges at Aberdeen Proving Ground, Maryland. It was designed as a screening study and does not estimate actual human health risks. Considered are five contaminants possibly present in the soil and vegetation from past human activities at APG--lead, arsenic, trichloroethylene (TCE), depleted uranium (DU), and dichlorodiphenyltrichloroethane (DDT); and two chemical warfare agents that could be released from unexploded ordnance rounds heated in a range fire--mustard and phosgene. For comparison, dispersion of two naturally occurring compounds that could be released by burning of uncontaminated vegetation--vinyl acetate and 2-furaldehyde--is also examined. Data from previous studies on soil contamination at APG are used in conjunction with conservative estimates about plant uptake of contaminants, atmospheric conditions, and size and frequency of range fires at APG to estimate dispersion and possible human exposure. The results are compared with US Environmental Protection Agency action levels. The comparisons indicate that for all of the anthropogenic contaminants except arsenic and mustard, exposure levels would be at least an order of magnitude lower than the corresponding action levels. Because of the compoundingly conservative nature of the assumptions made, they conclude that the potential for significant human health risks from range fires is low. The authors recommend that future efforts be directed at fire management and control, rather than at conducting additional studies to more accurately estimate actual human health risk from range fires.

  13. Page 1 238 S Kesavan 5. Conclusion It has been proved that non ...

    Indian Academy of Sciences (India)

    which has been used only to prove the existence of a solution via a priori estimates. Indeed this condition can be removed and replaced by any other which guarantees the existence of a non-singular solution of the homogenized problem alone. Then the method of this paper can be used to prove (without new hypotheses) ...

  14. Electrothermal-Chemical Modeling Workshop, Held in Aberdeen Proving Ground, Maryland on 12-13 May 1993. Volume 1

    Science.gov (United States)

    1994-05-01

    141 PC 00 PCu PCU 6PC CPC PCU ~OWN 4E142 ZI POU) CICc S.•,p I I ’P I II P 04 3 143 "CBP EQUATIONS Ve-M ; - Vb =, .- -•)(1) z = 1 2pt 2 ZP 2 Z, - y (3...Phone: 813-578- 8239 Ft. Washington. PA 19034-3211 FAX: 813-578-8119 Phone: 215-542-1200 Mr. Michael Nusca Dr. C. -C Hsiao U.S. Army Research Laboratory

  15. Classificació de proves no paramètriques. Com aplicar-les en SPSS

    Directory of Open Access Journals (Sweden)

    Vanesa Berlanga-Silvente

    2012-07-01

    Full Text Available Les proves no paramètriques engloben una sèrie de proves estadístiques, que tenen com a denominador comú l'absència de assumpcions sobre la llei de probabilitat que segueix la població de la qual ha estat extreta la mostra. Per aquesta raó és comú referir-s'hi com a proves de distribució lliure. A l'article es descriuen i treballen les proves no paramètriques ressaltant el seu fonament i les indicacions per al seu ús quan es tracta d'una sola mostra (Chi-quadrat, de dues mostres amb dades independents (U de Mann-Whitney, de dues mostres amb dades relacionades (T de Wilcoxon, de diverses mostres amb dades independents (H de Kruskal-Wallis i de diverses mostres amb dades relacionades (Friedman.

  16. PROVE GOES-8 Images of Jornada Experimental Range, New Mexico, 1997

    Data.gov (United States)

    National Aeronautics and Space Administration — As part of the Prototype Validation Experiment (PROVE) at the Jornada Experimental Range, GOES-8 images were collected every 30 minutes for 15 days overlapping the...

  17. 33 CFR 334.140 - Chesapeake Bay; U.S. Army Proving Ground Reservation, Aberdeen, Md.

    Science.gov (United States)

    2010-07-01

    ... Island to Locust Point; thence along straight line from Locust Point to Turkey Point for a distance of... right to land nor to cut or procure pound net poles or stakes on the Aberdeen Proving Ground Reservation...

  18. PROVE Land Cover and Leaf Area of Jornada Experimental Range, New Mexico, 1997

    Data.gov (United States)

    National Aeronautics and Space Administration — Field measurement of shrubland ecological properties is important for both site monitoring and validation of remote-sensing information. During the PROVE exercise on...

  19. The Development of the Proving Process Within a Dynamic Geometry Environment

    Directory of Open Access Journals (Sweden)

    Danh Nam Nguyen

    2012-10-01

    Full Text Available In this paper we classify student’s proving level and design an interactive help system (IHS corresponding with these levels in order to investigate the development of the proving process within a dynamic geometry environment. This help system was also used to provide tertiary students with a strategy for proving and to improve their proving levels. The open-ended questions and explorative tasks in the IHS make a contribution to support students’ learning of proving, especially during the processes of realizing invariants, formulating conjectures, producing arguments, and writing proofs. This research wants to react on the well-known students’ difficulties in writing a formal proof. The hypothesis of this work is that these difficulties are based on the lack of students’ understanding the relationship between argumentation and proof. Therefore, we used Toulmin model to analyze student’s argumentation structure and examine the role of abduction in writing a deductive proof. Furthermore, this paper also provides mathematics teachers with three basic conditions for understanding the development of the proving process and teaching strategies for assisting their students in constructing formal proofs.

  20. Allelopathic effects of orange (Citrus sinensis L. peel essential oil Efeitos alelopáticos do óleo essencial da casca da laranja (Citrus sinensis L.

    Directory of Open Access Journals (Sweden)

    Jose Pedro Nepomuceno Ribeiro

    2012-03-01

    Full Text Available Crop weeds are the main problem in agriculture, causing a worldwide annual loss of about US$95 billion. The principal method for control is the use of synthetic herbicides. The continued use of these products increases crop costs, reduces crop quality, and leaves toxic residues in the environment, which are a threat to human and livestock health. Therefore, there is a demand for environmentally friendly methods of weed control. The use of allelopathic compounds from crop residues is an alternative. Orange is one of the biggest crops in the world, and its cultivation generates large amounts of residues. There is strong evidence of bioactivity in orange peel essential oil. Therefore, the objective in this work was to verify the allelopathic proprieties of this oil. We extracted the oil from the peels of recently discarded oranges using water vapor flow with a Clevenger extractor, and tested it against the growth of Euphorbia heterophylla L. and Ipomoea grandifolia (Dammer O'Donell seedlings when placed in contact with the oil vapor. The results were both quantitative and qualitative in the inhibition of the seedlings.Plantas daninhas são o principal problema da agricultura no mundo, causando anualmente um prejuízo de U$95 bilhões. A principal forma de combate às plantas daninhas são os herbicidas sintéticos. Entretanto, o uso continuado desses produtos encarece a produção, reduz a qualidade dos alimentos, deixa resíduos tóxicos no ambiente e ameaça a saúde humana e animal. Existe assim, uma demanda por técnicas menos agressivas de controle. O uso de compostos alelopáticos de descartes de culturas para esse fim é uma alternativa. A laranja é uma das maiores culturas do mundo, e gera grandes quantidades de resíduos. Existem evidências da bioatividade no óleo essencial da casca da laranja. Nesse trabalho, nosso objetivo foi verificar a existência de propriedades alelopáticas desse óleo. Para isto, extraímos o óleo por arraste

  1. Potencial alelopático de Cyperus rotundus L. sobre espécies cultivadas Allelopathic potential of Cyperus rotundus L. upon cultivated species

    Directory of Open Access Journals (Sweden)

    Heloísa Monteiro de Andrade

    2009-01-01

    Full Text Available Metabótitos secundários produzidos em algumas plantas podem provocar alterações no desenvolvimento de outras plantas ou até mesmo de outros organismos. Neste trabalho, objetivou-se identificar possíveis efeitos alelopáticos de extratos aquosos de folhas de Cyperus rotundus na germinação e no crescimento de plântulas de Brassica campestris, Brassica oleracea var. botrytis, Brassica oleracea var. capitata, Brassica oleracea var. italica, Brassica rapa, Lactuca sativa cv. Grand rapids, Lycopersicum esculentum e Raphanus sativus. Foram utilizadas sete concentrações do extrato aquoso (0, 10, 30, 50, 70, 90 e 100%. Os tratamentos foram arranjados em delineamento inteiramente casualizado, com cinco repetições de dez sementes das espécies cultivadas, constituindo a unidade amostral. Os extratos aquosos de C. rotundus evidenciaram potencialidades alelopáticas na germinação das sementes e no crescimento das duas partes vegetais (raiz e parte aérea, de todas as espécies testadas, exceto na germinação de sementes de tomate e de alface, sendo que a redução aumentou com o aumento das concentrações dos extratos aquosos utilizados. A estrutura vegetal mais afetada em presença dos extratos aquosos foi o sistema radicular das plântulas.Secondary metabolites produced in some plant species may promote changes in the development of other plants or even in other organisms. The aim of this work was to identify the possible allelopathic effects of aqueous extracts of Cyperus rotundus leaves on germination and growth of Brassica campestris, Brassica oleracea var. botrytis, Brassica oleracea var. capitata, Brassica oleracea var. italica, Brassica rapa, Lactuca sativa cv. Grand rapids, Lycopersicum esculentum and Raphanus sativus seedlings. Seven aqueous extract concentrations were used (0, 10, 30, 50, 70, 90, and 100%. The treatments were arranged in a completely randomized desing, with five replications of ten seeds of each cultivated species

  2. Phenolic profile, antioxidant capacity of five Ziziphus spina-christi (L.) Willd provenances and their allelopathic effects on Trigonella foenum-graecum L. and Lens culinaris L. seeds.

    Science.gov (United States)

    Elaloui, M; Ghazghazi, H; Ennajah, A; Manaa, S; Guezmir, W; Karray, N B; Laamouri, A

    2017-05-01

    The aim of this work was to evaluate some secondary metabolites, antioxidant activity of methanolic leaf extracts of five Ziziphus spina-christi provenances (INRGREF, Tozeur, Degueche, Nafta and Kebelli) and their allelopathic effects on Trigonella foenum-graecum and Lens culinaris. Leaves were collected during 2013 and 2014. Total phenols, flavonoids, tannins and antioxidant activity were evaluated using the Folin ciocalteux, Aluminum trichloride, vanillin and scavenging activity on 22-diphenyl-1-picrylhydrazyl (DPPH) radical methods, respectively. Total phenols, tannins and flavonoids were present, at levels of 57.41 mg GAE/g DW, 31.98 mg RE/g DW and 14.68 μg CE/g DW, respectively. The high antioxidant activity (0.086 μg/mL) was noted in kebelli provenance (2013). The highest germination, plumule and radicle lengths of tested species were observed in INRGREF provenance. Z. spina-christi leaf extracts may be suggested in foods and pharmaceutical industries. Leaf extracts could also provide a natural herbicide with a positive impact on the environment.

  3. Anti-Fungal Activity and Allelopathic Influence of Vitex agnus-castus L. (Verbenaceae Essential Oils on Actinidia deliciosa in vitro Culture

    Directory of Open Access Journals (Sweden)

    N. Ya. Levchyk

    2016-12-01

    Full Text Available The results of research of Vitex agnus-castus L. plants from the collection of M. M. Gryshko National Botanical Garden, NAS of Ukraine are given. The species belongs to a group of prospective essential oil plants which are characterized by valuable medicinal, food, aromatic, honey, technical and decorative properties, and can be used in many industries, including pharmaceutical, cosmetic and food. The quantitative content and qualitative composition of the vegetating plant’s essential oil are determined, its antifungal influence on the cultures of Aspergillus niger, Alternaria alternatа andFusarium culmorum is assessed. Antifungal properties of V. agnus-castus essential oil were used to sterilize Actinidia deliciosa (A. Chev C.F. Liang & A.R. Fergusonexplants introduced in vitro. V. agnus-castusessential oil is shown to have allelopathic effect on A. deliciosa plants. The possibility of using the oil in vitro to cultivate A. deliciosa callus as a source of bioactive substances and to enhance the effectiveness of biotechnological methods of plant propagation is discussed.

  4. Allelopathic inhibition of photosynthesis in the red tide-causing marine alga, Scrippsiella trochoidea (Pyrrophyta), by the dried macroalga, Gracilaria lemaneiformis (Rhodophyta)

    Science.gov (United States)

    Ye, Changpeng; Liao, Heping; Yang, Yufeng

    2014-07-01

    The red tide-causing microalga, Scrippsiella trochoidea was co-cultured with different quantities of dried macroalga Gracilaria lemaneiformis under laboratory conditions, to characterize the allelopathic inhibition effect of the seaweed on photosynthesis of the microalga. Photosynthetic oxygen evolution was measured, and chlorophyll a (Chl a) fluorescence transient O-J-I-P (O, J, I and P point in primary photochemistry reaction curve in photosystem II) curves associated with its specific parameters were determined. A concentration-dependent inhibition of S. trochoidea was observed when the dried seaweed was added. The rate of light-saturated maximum photosynthetic oxygen evolution (Pmax) was markedly decreased, and the O-J-I-P curve coupled with its specific parameters was reduced. The inhibitory effects of the macroalga on the microalga, according to the JIP-test (the relative fluorescence analysis based on O-J-I-P curve) and the activity of oxygen evolution, include a decrease in the number of active reaction centers, the blocking-up of the electron transport chain, and the damage to the oxygen-evolving complex. This study suggests that dried G. lemaneiformis is effective in inhibiting photosynthesis of S. trochoidea, and could thus be a potential candidate for mitigating S. trochoidea blooms.

  5. Allelopathic potential of Jimsonweed (Datura stramonium L. on the early growth of maize (Zea mays L. and sunflower (Helianthus annuus L.

    Directory of Open Access Journals (Sweden)

    Zvonko Pacanoski

    2014-09-01

    Full Text Available Laboratory and glasshouse experiments were carried out to investigate the allelopathic potential of different plant parts of D. stramonium on maize and sunflower on early growth stages. The aqueous leachates of D. stramonium roots and shoot did not produc a significant effect on germination and shoot length of maize, but root length of maize was significantly reduced at the highest (1/1 D. stramonium roots leachate compared to control. From the other side, germination of sunflower was significantly reduced at the highest (1/1 D. stramonium shoot leachate concentration, but lower (1/5 and 1/2 D. stramonium roots leachate concentrations significantly increased root and shoot length of sunflower compared to control. In glasshouse experiment, no one treatment with different D. stramonium plant residues significantly affected density, height and fresh weight of maize plants compared to control. Contrary, D. stramonium mixtures with 1/1 root and shoot residues significantly reduced plants density and fresh weight of sunflower plants compared to control. Lower (1/2 and 1/5 mixtures of D. stramonium roots residues and mixture with 1/5 D. stramonium shoot residues significantly increased the height of the sunflower plants.

  6. Formalizing and proving a typing result for security protocols in Isabelle/HOL

    DEFF Research Database (Denmark)

    Hess, Andreas Viktor; Modersheim, Sebastian

    2017-01-01

    or the positive output of a verification tool. However several of these works have used a typed model, where the intruder is restricted to "well-typed" attacks. There also have been several works that show that this is actually not a restriction for a large class of protocols, but all these results so far...... are again pen-and-paper proofs. In this work we present a formalization of such a typing result in Isabelle/HOL. We formalize a constraint-based approach that is used in the proof argument of such typing results, and prove its soundness, completeness and termination. We then formalize and prove the typing...... result itself in Isabelle. Finally, to illustrate the real-world feasibility, we prove that the standard Transport Layer Security (TLS) handshake satisfies the main condition of the typing result....

  7. Artocarpus altilis proving its worth in toxic metal removal from the ...

    African Journals Online (AJOL)

    Artocarpus altilis proving its worth in toxic metal removal from the environment. PO Okolo, EEI Irabor, TP Abugu. Abstract. Nuts of breadfruit tree (Artocarpus altilis) obtained from Ugbowo Campus of University of Benin, Benin City, were dehusked and the husk thoroughly washed with distilled water, air-dried, pulverized and ...

  8. Using eternity variables to specify and prove a serializable database interface

    NARCIS (Netherlands)

    Hesselink, Wim H.

    Eternity variables are introduced to specify and verify serializability of transactions of a distributed database. Eternity variables are a new kind of auxiliary variables. They do not occur in the implementation but are used in specification and verification. Elsewhere it has been proved that

  9. The Secret Prover : Proving Possession of Arbitrary Files While not Giving Them Away

    NARCIS (Netherlands)

    Teepe, Wouter

    2005-01-01

    The Secret Prover is a Java application which allows a user (A) to prove to another user (B), that A possesses a file. If B also possesses this file B will get convinced, and if B does not possess this file B will gain no information on (the contents of) this file. This is the first implementation

  10. Mathematical Understanding and Proving Abilities: Experiment with Undergraduate Student by Using Modified Moore Learning Approach

    Science.gov (United States)

    Maya, Rippi; Sumarmo, Utari

    2011-01-01

    This paper reports findings of a post test experimental control group design conducted to investigate the role of modified Moore learning approach on improving students' mathematical understanding and proving abilities. Subjects of study were 56 undergraduate students of one state university in Bandung, who took advanced abstract algebra course.…

  11. Wind tunnel experiments to prove a hydraulic passive torque control concept for variable speed wind turbines

    NARCIS (Netherlands)

    Diepeveen, N.F.B.; Jarquin-Laguna, A.

    2014-01-01

    In this paper the results are presented of experiments to prove an innovative concept for passive torque control of variable speed wind turbines using fluid power technology. It is demonstrated that by correctly configuring the hydraulic drive train, the wind turbine rotor operates at or near

  12. Genetic and toxinological characterization of North Atlantic strains of the dinoflagellate Ostreopsis and allelopathic interactions with toxic and non-toxic species from the genera Prorocentrum, Coolia and Gambierdiscus.

    Science.gov (United States)

    García-Portela, María; Riobó, Pilar; Franco, José Mariano; Bañuelos, Rosa Mª; Rodríguez, Francisco

    2016-12-01

    The genus Ostreopsis includes several toxic species that can develop blooms in benthic ecosystems, with potential harmful consequences for human health and marine invertebrates. Despite of this, little is known about the allelopathic interactions between these organisms and other co-occurring microalgae that exploit similar spatial and nutrient resources in benthic ecosystems. The aim of this study was to follow these interactions in cultures of two Ostreopsis ribotypes with different toxin profiles (O. cf. ovata contained ovatoxins-a, b, c and e, while only ovatoxin-d was found in O .sp. "Lanzarote-type"), mixed with species of three benthic dinoflagellate genera (Coolia, Prorocentrum and Gambierdiscus), isolated from the same area (North East Atlantic, Canary Islands). In a first experiment, the potential allelopathic effects on growth rates were followed, in mixed cultures of Coolia monotis (a non toxic species) exposed to the clarified medium and to cells of O. sp."Lanzarote-type" and O. cf. ovata. Growth delayed in C. monotis was observed specially in clarified medium, while the O. sp. "Lanzarote-type" strain attained much lower densities in mixed cultures. In a second experiment, we examined the potential effects of clarified media from O. sp."Lanzarote-type" and O. cf. ovata on the adherence capacity in two toxic species (Prorocentrum hoffmannianum and Gambierdiscus excentricus). Contrasting effects were found: a significant increase of adherence capacity in P. hoffmannianum vs attachment decline in G. excentricus, that experienced also severe deleterious effects (cell lysis). Our results suggest the existence of weak to moderate allelopathic interactions between the studied organisms, although the outcome is dependent on the species involved. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Searching for fixed point combinators by using automated theorem proving: A preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Wos, L.; McCune, W.

    1988-09-01

    In this report, we establish that the use of an automated theorem- proving program to study deep questions from mathematics and logic is indeed an excellent move. Among such problems, we focus mainly on that concerning the construction of fixed point combinators---a problem considered by logicians to be significant and difficult to solve, and often computationally intensive and arduous. To be a fixed point combinator, THETA must satisfy the equation THETAx = x(THETAx) for all combinators x. The specific questions on which we focus most heavily ask, for each chosen set of combinators, whether a fixed point combinator can be constructed from the members of that set. For answering questions of this type, we present a new, sound, and efficient method, called the kernel method, which can be applied quite easily by hand and very easily by an automated theorem-proving program. For the application of the kernel method by a theorem-proving program, we illustrate the vital role that is played by both paramodulation and demodulation---two of the powerful features frequently offered by an automated theorem-proving program for treating equality as if it is ''understood.'' We also state a conjecture that, if proved, establishes the completeness of the kernel method. From what we can ascertain, this method---which relies on the introduced concepts of kernel and superkernel---offers the first systematic approach for searching for fixed point combinators. We successfully apply the new kernel method to various sets of combinators and, for the set consisting of the combinators B and W, construct an infinite set of fixed point combinators such that no two of the combinators are equal even in the presence of extensionality---a law that asserts that two combinators are equal if they behave the same. 18 refs.

  14. Searching for allelopathic effects of submerged macrophytes on phytoplankton-state of the art and open questions

    NARCIS (Netherlands)

    Gross, E.M.; Hilt (nee Körner), S.; Lombardo, P.; Mulderij, G.

    2007-01-01

    Allelopathy, here defined as biochemical interactions between aquatic primary producers, has always been intriguing as a process explaining the dominance of certain plant or algal species over others. Negative chemical interference has been invoked as one of the steering mechanisms behind mutual

  15. Mathematical Understanding and Proving Abilities: Experiment With Undergraduate Student By Using Modified Moore Learning Approach

    Directory of Open Access Journals (Sweden)

    Rippi Maya

    2011-07-01

    Full Text Available This paper reports findings of  a  post test experimental control group design conducted to investigate the role of modified Moore learning approach  on improving students’ mathematical understanding and proving abilities. Subject of study were 56 undergradute students of one state university in Bandung, who took advanced abstract algebra course. Instrument of study were a set test of mathematical understanding ability, a set test of mathematical proving ability, and a set of students’ opinion scale on modified Moore learning approach. Data were analyzed by using two path ANOVA. The study found that proof construction process was more difficult than mathematical understanding  task  for all students, and students still posed some difficulties on constructing mathematical proof task.  The study also found there were not differences  between students’  abilities on mathematical understanding and on proving abilities of  the both classes, and both abilities were classified as mediocre. However, in modified Moore learning approach class there were more students who got above average grades on mathematical understanding than those of conventional class. Moreover, students performed positive  opinion toward  modified Moore learning approach. They  were  active in questioning and solving problems, and in explaining their works in front of class as well, while students of conventional teaching prefered to listen to lecturer’s explanation. The study also found that there was no interaction between learning approach and students’ prior mathematics ability on mathematical understanding and proving abilities,  but  there were  quite strong  association between students’ mathematical understanding and proving abilities.Keywords:  modified Moore learning approach, mathematical understanding ability, mathematical proving ability. DOI: http://dx.doi.org/10.22342/jme.2.2.751.231-250

  16. The Case Against (-)-Catechin Involvement in Allelopathy in Centaurea stoebe (spotted knapweed)

    Science.gov (United States)

    Proving allelopathic chemical interference is a daunting endeavor, in that production and movement of a phytotoxin from a donor plant to a receiving plant must be demonstrated in the substrate in which the plants grow, which is usually a complex soil matrix. The soil levels or soil flux levels of th...

  17. Remedial investigation report for J-Field, Aberdeen Proving Ground, Maryland. Volume 3: Ecological risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hlohowskyj, I.; Hayse, J.; Kuperman, R.; Van Lonkhuyzen, R.

    2000-02-25

    The Environmental Management Division of the U.S. Army Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation (RI) and feasibility study (FS) of the J-Field area at APG, pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. As part of that activity, Argonne National Laboratory (ANL) conducted an ecological risk assessment (ERA) of the J-Field site. This report presents the results of that assessment.

  18. Proving and Improving Wave Models in the Arctic Ocean and its MIZ

    Science.gov (United States)

    2015-09-30

    scale, the Greenland Sea Odden which is important for deep convection. The increased open water area present in the autumn Arctic Ocean , particularly...263(5144), 218–221, doi:10.1126/science.263.5144.218. Hunkins, K. (1966), Ekman drift currents in the Arctic Ocean , Deep Sea Res., 13(4), 607–620...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Proving and Improving Wave Models in the Arctic Ocean

  19. Concept of Operations for a Prospective "Proving Ground" in the Lunar Vicinity

    Science.gov (United States)

    Love, Stanley G.; Hill, James J.

    2016-01-01

    NASA is studying a "Proving Ground" near the Moon to conduct human space exploration missions in preparation for future flights to Mars. This paper describes a concept of operations ("conops") for activities in the Proving Ground, focusing on the construction and use of a mobile Cislunar Transit Habitat capable of months-long excursions within and beyond the Earth-Moon system. Key elements in the conops include the Orion spacecraft (with mission kits for docking and other specialized operations) and the Space Launch System heavy-lift rocket. Potential additions include commercial launch vehicles and logistics carriers, solar electric propulsion stages to move elements between different orbits and eventually take them on excursions to deep space, a node module with multiple docking ports, habitation and life support blocks, and international robotic and piloted lunar landers. The landers might include reusable ascent modules which could remain docked to in-space elements between lunar sorties. The architecture will include infrastructure for launch preparation, communication, mission control, and range safety. The conops describes "case studies" of notional missions chosen to guide the design of the architecture and its elements. One such mission is the delivery of a 10-ton pressurized element, co-manifested with an Orion on a Block 1B Space Launch System rocket, to the Proving Ground. With a large solar electric propulsion stage, the architecture could enable a year-long mission to land humans on a near-Earth asteroid. In the last case, after returning to near-lunar space, two of the asteroid explorers could join two crewmembers freshly arrived from Earth for a Moon landing, helping to safely quantify the risk of landing deconditioned crews on Mars. The conops also discusses aborts and contingency operations. Early return to Earth may be difficult, especially during later Proving Ground missions. While adding risk, limited-abort conditions provide needed practice

  20. Allelopathic effects of the invasive Prosopis juliflora (Sw. DC. on selected native plant species in Middle Awash, Southern Afar Rift of Ethiopia

    Directory of Open Access Journals (Sweden)

    Samuel Getachew

    2012-12-01

    Full Text Available The allelopathic effects of the invasive Prosopis juliflora (Sw. DC. was studied on seed germination and seedling growth of Acacia nilotica(L. Willd. ex Del., Acacia tortilis (Forssk. Hayne, Cenchrus ciliaris L. and Enteropogon rupestris (J.A. Schmidt A. Chev. Vegetation sampling in different habitat types in the area was made to identify the target plant species. Comparison of canopy characteristics among P. juliflora, A. nilotica and A. tortilis was also made to observe differences if any in canopy closure. P. juliflora was recorded in all habitat types in highest density and observed affecting the plant diversity there in. Its growth characteristics and dense thicket formation restrict light to the ground flora and hence diminishes plant diversity. Leaf, bark and root aqueous extract of P. juliflora at 0, 0.5, 0.8, 1, 2 and 6% wereprepared and their effect studied on germination percentage and seedling growth of the study plant species. Germination of A. nilotica and A. tortilis was not affected by all aqueous extracts of different organ parts of P. juliflora while leaf and root extracts at higher concentrations inhibited germination of C. ciliaris and E. rupestris. Shoot and root growth of the study species were inhibited by leaf and root at higher concentrations. Seed germination of all species except A. nilotica was inhibited by soil amended with decaying plant parts and under canopy soil. The effect is species specific and annuals (grasses and herbs were affected more than perennials. Leaf seems to contain greater number/amount of inhibitors than does root and bark. Bark seems to contain the least. Heavy accumulation of toxic substances at under canopy soil of P. juliflora may be one of the reasons for its invasiveness and low plant diversity.

  1. Models analyses for allelopathic effects of chicory at equivalent coupling of nitrogen supply and pH level on F. arundinacea, T. repens and M. sativa.

    Directory of Open Access Journals (Sweden)

    Quanzhen Wang

    Full Text Available Alllelopathic potential of chicory was investigated by evaluating its effect on seed germination, soluble sugar, malondialdehyde (MDA and the chlorophyll content of three target plants species (Festuca arundinacea, Trifolium repens and Medicago sativa. The secretion of allelochemicals was regulated by keeping the donor plant (chicory separate from the three target plant species and using different pH and nitrogen levels. Leachates from donor pots with different pH levels and nitrogen concentrations continuously irrigated the target pots containing the seedlings. The allelopathic effects of the chicory at equivalent coupling of nitrogen supply and pH level on the three target plants species were explored via models analyses. The results suggested a positive effect of nitrogen supply and pH level on allelochemical secretion from chicory plants. The nitrogen supply and pH level were located at a rectangular area defined by 149 to 168 mg/l nitrogen supply combining 4.95 to 7.0 pH value and point located at nitrogen supply 177 mg/l, pH 6.33 when they were in equivalent coupling effects; whereas the inhibitory effects of equivalent coupling nitrogen supply and pH level were located at rectangular area defined by 125 to 131 mg/l nitrogen supply combining 6.71 to 6.88 pH value and two points respectively located at nitrogen supply 180 mg/l with pH 6.38 and nitrogen supply 166 mg/l with pH 7.59. Aqueous extracts of chicory fleshy roots and leaves accompanied by treatment at different sand pH values and nitrogen concentrations influenced germination, seedling growth, soluble sugar, MDA and chlorophyll of F. arundinacea, T. repens and M. sativa. Additionally, we determined the phenolics contents of root and leaf aqueous extracts, which were 0.104% and 0.044% on average, respectively.

  2. [Allelopathic effects of the humus soils from Betula platyphylla and Quercus liaotungensis pure plantations on 9 kinds of common shrubs and herbs].

    Science.gov (United States)

    Huang, Liang-Jia; Liu, Zeng-wen; Zhu, Bo-Chao; Bing, Yuan-Hao; Zhang, Xiao-Xi; Lü, Chen

    2014-06-01

    The humus soils were collected from Betula platyphylla and Quercus liaotungensis pure plantations and woodless land separately where the site conditions were basically the same, and taken as medium for potting culture test of 9 kinds of shrubs or herbs in plastic greenhouse to assess the allelopathic effects of humus soils of pure plantations on shrubs or herbs. Humus soils from B. platyphylla plantation significantly inhibited the seed germinations of Medicago sativa and Melilotus officinalis, decreased the catalase (CAT) activity of M. officinalis, Coronilla varia, M. sativa and Lespedeza davurica, and improved malondialdehyde (MDA) contents in seedlings of Caragana kor-shinskii, C. varia and Astragalus adsurgens. The biomass growths of C. varia, Amorpha fruticosa, M. sativa, M. officinalis and A. adsurgens in humus soils from B. platyphylla plantation were significantly decreased by 48.2%, 45.1%, 44.3%, 37.3% and 36.0%, respectively. In addition, humus soil of Q. liaotungensis plantation significantly decreased the germination rates of M. sativa and A. adsurgens, the chlorophyll contents of Vicia villosa, A. fruticosa and M. sativa, and improved malondialdehyde (MDA) contents in seedlings of Lespedeza davurica, Caragana korshinskii, M. officinalis and A. adsurgens. The biomass growths of A. adsurgens, M. sativa, M. officinalis and A. fruticosa were significantly decreased by 52.6% , 43.8%, 35.5% and 34.6%, respective- ly. B. platyphylla plantation humus soil had obvious inhibition effects on M. sativa, M. officinalis and A. fruticosa, while Q. liaotungensis plantation humus soil had obvious inhibition effects on M. sativa, A. adsurgens and A. fruticosa.

  3. SPoRT's Participation in the GOES-R Proving Ground Activity

    Science.gov (United States)

    Jedlovec, Gary; Fuell, Kevin; Smith, Matthew; Stano, Geoffrey; Molthan, Andrew

    2011-01-01

    The next generation geostationary satellite, GOES-R, will carry two new instruments with unique atmospheric and surface observing capabilities, the Advanced Baseline Imager (ABI) and the Geostationary Lightning Mapper (GLM), to study short-term weather processes. The ABI will bring enhanced multispectral observing capabilities with frequent refresh rates for regional and full disk coverage to geostationary orbit to address many existing and new forecast challenges. The GLM will, for the first time, provide the continuous monitoring of total lightning flashes over a hemispherical region from space. NOAA established the GOES-R Proving Ground activity several years ago to demonstrate the new capabilities of these instruments and to prepare forecasters for their day one use. Proving Ground partners work closely with algorithm developers and the end user community to develop and transition proxy data sets representing GOES-R observing capabilities. This close collaboration helps to maximize refine algorithms leading to the delivery of a product that effectively address a forecast challenge. The NASA Short-term Prediction Research and Transition (SPoRT) program has been a participant in the NOAA GOES-R Proving Ground activity by developing and disseminating selected GOES-R proxy products to collaborating WFOs and National Centers. Established in 2002 to demonstrate the weather and forecasting application of real-time EOS measurements, the SPoRT program has grown to be an end-to-end research to operations activity focused on the use of advanced NASA modeling and data assimilation approaches, nowcasting techniques, and unique high-resolution multispectral data from EOS satellites to improve short-term weather forecasts on a regional and local scale. Participation in the Proving Ground activities extends SPoRT s activities and taps its experience and expertise in diagnostic weather analysis, short-term weather forecasting, and the transition of research and experimental

  4. SPoRT's Participation in the GOES-R Proving Ground Activity

    Science.gov (United States)

    Jedlovec, G.; Fuell, K.; Smith, M. R.; Stano, G. T.; Molthan, A.

    2011-12-01

    The next generation geostationary satellite, GOES-R, will carry two new instruments with unique atmospheric and surface observing capabilities, the Advanced Baseline Imager (ABI) and the Geostationary Lightning Mapper (GLM), to study short-term weather processes. The ABI will bring enhanced multispectral observing capabilities with frequent refresh rates for regional and full disk coverage to geostationary orbit to address many existing and new forecast challenges. The GLM will, for the first time, provide the continuous monitoring of total lightning flashes over a hemispherical region from space. NOAA established the GOES-R Proving Ground activity several years ago to demonstrate the new capabilities of these instruments and to prepare forecasters for their day one use. Proving Ground partners work closely with algorithm developers and the end user community to develop and transition proxy data sets representing GOES-R observing capabilities. This close collaboration helps to maximize refine algorithms leading to the delivery of a product that effectively address a forecast challenge. The NASA Short-term Prediction Research and Transition (SPoRT) program has been a participant in the NOAA GOES-R Proving Ground activity by developing and disseminating selected GOES-R proxy products to collaborating WFOs and National Centers. Established in 2002 to demonstrate the weather and forecasting application of real-time EOS measurements, the SPoRT program has grown to be an end-to-end research to operations activity focused on the use of advanced NASA modeling and data assimilation approaches, nowcasting techniques, and unique high-resolution multispectral data from EOS satellites to improve short-term weather forecasts on a regional and local scale. Participation in the Proving Ground activities extends SPoRT's activities and taps its experience and expertise in diagnostic weather analysis, short-term weather forecasting, and the transition of research and experimental

  5. Chemical Emergencies

    Science.gov (United States)

    When a hazardous chemical has been released, it may harm people's health. Chemical releases can be unintentional, as in the case of an ... the case of a terrorist attack with a chemical weapon. Some hazardous chemicals have been developed by ...

  6. Allelopathic effects of leaf and corm water extract of saffron (Crocus sativus L. on germination and seedling growth of flixweed (Descurainia sophia L. and downy brome (Bromus tectorum L.

    Directory of Open Access Journals (Sweden)

    Zeinab Alipoor

    2015-04-01

    Full Text Available This study was conducted in two factorial experiment based on completely randomized design with three replications at research laboratory of faculty of agriculture in University of Birjand in 2013. Factors included saffron organs at 2 levels (leaves and corms and water extract concentrations at 5 levels (0, 0.5, 1, 1.5 and 2 percent.The allelopathic effects of saffron leaves and corms on seed germination and seedling growth characteristics of flixweed (Descurainia sophia L. and downy brome (Bromus tectorum L. were studied in two separate experiments. Results indicated lowest seed germination percentage of downy brome and flixweed were observed at concentration of 2% of corm extract (by 65% and 66% reduce compared to control, respectively. The rate of germination of downy brome decreased (by 71% compared to control with concentration of 2% of leaf extract but the rate of germination on flixweed was not significantly affected by extract concentrations. Different concentrations of leaf and corm extracts significantly decreased length and weight of plumule and radicals of two weeds. A logistic model provided a successful estimation of relationship between leaf water extract and germination percentage of two weeds. Based on orthogonal comparison tests, the allelopathic inhibition effects of saffron leaves and corms were more on downy brome and flixweed, respectively.

  7. Ground-water flow and the possible effects of remedial actions at J-Field, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Hughes, W.B.

    1995-01-01

    J-Field, located in the Edgewood Area of Aberdeen Proving Ground, Md, has been used since World War II to test and dispose of explosives, chemical warfare agents, and industrial chemicals resulting in ground-water, surface-water, and soil contami- nation. The U.S. Geological Survey finite-difference model was used to better understand ground-water flow at the site and to simulate the effects of remedial actions. A surficial aquifer and a confined aquifer were simulated with the model. A confining unit separates these units and is represented by leakance between the layers. The area modeled is 3.65 mi2; the model was constructed with a variably spaced 40 X 38 grid. The horizontal and lower boundaries of the model are all no-flow boundaries. Steady-state conditions were used. Ground water at the areas under investigation flows from disposal pit areas toward discharge areas in adjacent estuaries or wetlands. Simulations indicate that capping disposal areas with an impermeable cover effectively slows advective ground water flow by 0.7 to 0.5 times. Barriers to lateral ground-water flow were simulated and effectively prevented the movement of ground water toward discharge areas. Extraction wells were simulated as a way to contain ground-water contamination and to extract ground water for treatment. Two wells pumping 5 gallons per minute each at the toxic-materials disposal area and a single well pumping 2.5 gallons per minute at the riot-control-agent disposal area effectively contained contamination at these sites. A combi- nation of barriers to horizontal flow east and south of the toxic-materials disposal area, and a single extraction well pumping at 5 gallons per minute can extract contaminated ground water and prevent pumpage of marsh water.

  8. Avaliação do potencial alelopático de genótipos de aveia no final do ciclo Evaluation of allelopathic potential of oat genotypes at the end of life cycle

    Directory of Open Access Journals (Sweden)

    Ubiratã S. Jacobi

    1998-12-01

    Full Text Available Em sistemas de cultivo em semeadura direta, a aveia é uma das culturas de inverno mais importantes entre as que são utilizadas para formação de cobertura morta. Nos tecidos da aveia existem aleloquímicos, o que torna importante o entendimento deste fenômeno nesta cultura. Através da análise da palha de resíduos de genótipos de aveia, bem como dos seus aleloquímicos, poder-se-á obter uma avaliação ampla do seu potencial alelopático. Nesta análise, pode-se verificar que os genótipos de aveia mantém o potencial alelopático no final do ciclo de vida, revelando-se com maior efeito alelopático UFRGS 6, UFRGS 9, UFRGS 10 e UPF 13. Ao mesmo tempo, os genótipos que exibem menor efeito alelopático são UFRGS 12, UFRGS 17, UFRGS 884077 e UPF 12. Os efeitos produzidos por compostos aleloquímicos (ácidos fenólicos são similares aos provocados pelos extratos dos genótipos de aveia, mostrando uma relação entre o efeito alelopático dessas substâncias e os genótipos testados. Os aleloquímicos apresentam maior fitotoxicidade para as infestantes do que para as culturas, assim como ocorre com os resíduos de genótipos de aveia.In no-till cropping systems, oat represents one of the winter most important crops among those that are used to form cover crops. The presence of allelochemicals in its tissues point to the importance of understanding this phenomenon in the crop. By analyzing the straw of oat genotypes and its allelochemicals, it is possible to obtain a evaluation of its allelopathic potential. Results of this study show that oat genotypes maintain their allelopathic potential during the final period of the life cycle. Genotypes that present greater allelopathic effects during that period are UFRGS 6, UFRGS 9, UFRGS 10, and UPF 13. Genotypes that exhibit least allelopathic effects during the same period are UFRGS 12, UFRGS 17, UFRGS 884077, and UPF 12. The effects produced by allelochemical compounds (phenolic acids are

  9. Research Objectives for Human Missions in the Proving Ground of Cis-Lunar Space

    Science.gov (United States)

    Spann, James; Niles, Paul; Eppler, Dean; Kennedy, Kriss; Lewis, Ruthan; Sullivan, Thomas

    2016-07-01

    Introduction: This talk will introduce the preliminary findings in support of NASA's Future Capabilities Team. In support of the ongoing studies conducted by NASA's Future Capabilities Team, we are tasked with collecting re-search objectives for the Proving Ground activities. The objectives could include but are certainly not limited to: demonstrating crew well being and performance over long duration missions, characterizing lunar volatiles, Earth monitoring, near Earth object search and identification, support of a far-side radio telescope, and measuring impact of deep space environment on biological systems. Beginning in as early as 2023, crewed missions beyond low Earth orbit will be enabled by the new capabilities of the SLS and Orion vehicles. This will initiate the "Proving Ground" phase of human exploration with Mars as an ultimate destination. The primary goal of the Proving Ground is to demonstrate the capability of suitably long dura-tion spaceflight without need of continuous support from Earth, i.e. become Earth Independent. A major component of the Proving Ground phase is to conduct research activities aimed at accomplishing major objectives selected from a wide variety of disciplines including but not limited to: Astronomy, Heliophysics, Fun-damental Physics, Planetary Science, Earth Science, Human Systems, Fundamental Space Biology, Microgravity, and In Situ Resource Utilization. Mapping and prioritizing the most important objectives from these disciplines will provide a strong foundation for establishing the architecture to be utilized in the Proving Ground. Possible Architectures: Activities and objectives will be accomplished during the Proving Ground phase using a deep space habitat. This habitat will potentially be accompanied by a power/propulsion bus capable of moving the habitat to accomplish different objectives within cis-lunar space. This architecture can also potentially support stag-ing of robotic and tele-robotic assets as well as

  10. Satellite Proving Ground for the GOES-R Geostationary Lightning Mapper (GLM)

    Science.gov (United States)

    Goodman, Steven J.; Gurka, James; Bruning, E. C.; Blakeslee, J. R.; Rabin, Robert; Buechler, D.

    2009-01-01

    The key mission of the Satellite Proving Ground is to demonstrate new satellite observing data, products and capabilities in the operational environment to be ready on Day 1 to use the GOES-R suite of measurements. Algorithms, tools, and techniques must be tested, validated, and assessed by end users for their utility before they are finalized and incorporated into forecast operations. The GOES-R Proving Ground for the Geostationary Lightning Mapper (GLM) focuses on evaluating how the infusion of the new technology, algorithms, decision aids, or tailored products integrate with other available tools (weather radar and ground strike networks; nowcasting systems, mesoscale analysis, and numerical weather prediction models) in the hands of the forecaster responsible for issuing forecasts and warning products. Additionally, the testing concept fosters operation and development staff interactions which will improve training materials and support documentation development. Real-time proxy total lightning data from regional VHF lightning mapping arrays (LMA) in Northern Alabama, Central Oklahoma, Cape Canaveral Florida, and the Washington, DC Greater Metropolitan Area are the cornerstone for the GLM Proving Ground. The proxy data will simulate the 8 km Event, Group and Flash data that will be generated by GLM. Tailored products such as total flash density at 1-2 minute intervals will be provided for display in AWIPS-2 to select NWS forecast offices and national centers such as the Storm Prediction Center. Additional temporal / spatial combinations are being investigated in coordination with operational needs and case-study proxy data and prototype visualizations may also be generated from the NASA heritage Lightning Imaging Sensor and Optical Transient Detector data. End users will provide feedback on the utility of products in their operational environment, identify use cases and spatial/temporal scales of interest, and provide feedback to the developers for adjusted or

  11. How cytogenetical methods help victims prove radiation exposure and claim right for social support: NCERM experience

    Energy Technology Data Exchange (ETDEWEB)

    Aleksanin, S., E-mail: Aleksanin@arcerm.spb.ru [Nikiforov Russian Center of Emergency and Radiation Medicine EMERCOM of Russia, (NRCERM) ul. Akademika Lebedeva 4/2, 194044 St. Petersburg (Russian Federation); Slozina, N., E-mail: NataliaSlozina@peterlink.ru [Nikiforov Russian Center of Emergency and Radiation Medicine EMERCOM of Russia, (NRCERM) ul. Akademika Lebedeva 4/2, 194044 St. Petersburg (Russian Federation); Neronova, E.; Smoliakov, E. [Nikiforov Russian Center of Emergency and Radiation Medicine EMERCOM of Russia, (NRCERM) ul. Akademika Lebedeva 4/2, 194044 St. Petersburg (Russian Federation)

    2011-09-15

    Russian citizens who were irradiated because of radiation disasters, nuclear weapons testing and some other sources have a right to some social support and financial compensation. In order to get this compensation people have to prove that they were irradiated. As it is, not all victims for a variety of reasons have formal documents. Thus they apply for cytogenetic investigation to prove irradiation months, years and even decades after irradiation. Since 1992 the cytogenetic investigations related to radiation exposure were performed in NRCERM for more than 700 people. At the beginning of this investigation FISH method was not certified as a biodosimenty test in Russia. Only dicentric analysis was approved as a proof of irradiation. It is known that the rate of dicentrics decrease in time, but the residual level of cytogenetical markers could be revealed a long time after a radiation accident. Thus the dicentric analysis was performed for the people who applied for biological indication of radiation exposure at that time. Rates of dicentrics exceeding control levels were revealed in half the people who applied for radiation conformation. Now FISH method is certified in Russia and both cytogenetic tests of biodosimetry (dicentrics and FISH) are available for all comers. Increased levels of translocations were found in 8 cases (the dose rate from 0.16 to 0.64 Gy). On the basis of the results of cytogenetic tests official documents were supplied to these people and they were entitled to apply for radiation exposure compensation. Thus cytogenetic tests are very effective and in some cases the only possible way for the victims to prove irradiation exposure and to apply for radiation exposure compensation a long time after an accident.

  12. Proving Unlawful Discrimination in Capital Cases: In Quest of an Adequate Standard of Proof

    Directory of Open Access Journals (Sweden)

    Gregor Maučec

    2017-08-01

    Full Text Available In spite of some early judicial, political and scholarly discussions, as well as more recent scientific explorations of the topic, problems and concerns with proving discrimination in individual capital cases continue to be among the most debatable issues in human rights and criminal justice. In general, domestic courts (in particular US courts seem to remain relatively perfunctory and hostile to individual discrimination challenges in capital trials. They normally require capital defendants alleging discrimination to prove something which is virtually impossible to prove. On the other hand, numerous capital defence attorneys, legal commentators and even some of the trial judges themselves lay strictures on the existing judicial approach which almost routinely rejects discrimination claims in capital cases. They contend that appropriate modifications in current legislative arrangements and mechanical adjudication policy and practice are urgent and indispensable for more equitable resolutions and for a truly even-handed criminal justice system. In particular, there are concerns regarding the adequate distribution of the burden of proof between the litigants. Moreover, no clear or uniform approach to this conundrum can be identified in the international jurisprudence. This article seeks to provide some definite answers to open and conceptual questions posed in an attempt to legally define ‘the minimum core content’ of the evidentiary standard – as implicitly contained in the relevant international human rights treaties’ provisions – to be applied in capital sentencing discrimination cases. Additionally, part of this same standard of proof can also qualify as a general principle of international law, particularly in relation to impartial, unbiased and non-discriminatory approaches and decision-making by the judges and jurors involved in complex capital cases.

  13. Ground-water flow and the potential effects of remediation at Graces Quarters, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Tenbus, F.J.; Fleck, W.B.

    1996-01-01

    Ground water in the east-central part of Graces Quarters, a former open-air chemical-agent test facility at Aberdeen Proving Ground, Maryland, is contaminated with chlorinated volatile organic compounds. The U.S. Geological Survey's finite- difference model was used to help understand ground-water flow and simulate the effects of alternative remedial actions to clean up the ground water. Scenarios to simulate unstressed conditions and three extraction well con- figurations were used to compare alternative remedial actions on the contaminant plume. The scenarios indicate that contaminants could migrate from their present location to wetland areas within 10 years under unstressed conditions. Pumping 7 gal/min (gallons per minute) from one well upgradient of the plume will not result in containment or removal of the highest contaminant concentrations. Pumping 7 gal/min from three wells along the central axis of the plume should result in containment and removal of dissolved contami- nants, as should pumping 7 gal/min from three wells at the leading edge of the plume while injecting 7 gal/min back into an upgradient well.

  14. A Simple Application of Lightweight Fusion to Proving the Equivalence of Abstract Machines

    DEFF Research Database (Denmark)

    Danvy, Olivier; Millikin, Kevin

    2007-01-01

    We show how Ohori and Sasano's recent lightweight fusion by fixed-point promotion provides a simple way to prove the equivalence of the two standard styles of specification of abstract machines: (1) as a transition function together with a `driver loop' implementing the iteration of this transition...... function; and (2) as a function directly iterating upon a configuration until reaching a final state, if ever. The equivalence hinges on the fact that the latter style of specification is a fused version of the former one. The need for such a simple proof is motivated by our recent work on syntactic...... correspondences between reduction semantics and abstract machines, using refocusing...

  15. Operation UPSHOT-KNOTHOLE. Operational Summary, Nevada Proving Grounds, 1 March - 9 June 1953

    Science.gov (United States)

    1982-08-01

    projaing stabi±izing agents were tested including sand-cementt sodium silicateg and lignin , The sand-cemnt test panels showed no damage to the effects of... Lignin proved its valua ana mohan.tc1a stabilizing agent in regions where the peak overpressure was less than 20 psi. Evaluation of these materials from a...selected officer volunp towns trained in culoulating the offscts of atomic wespona,, wase pomi~ tionod in trenches at 2W0 and AM0 Ids fr pom sex (a

  16. Respirometry applied to kinetic characterization of activated sludge; Caratterizzazione cinetica di fanghi attivi mediante prove respirometriche

    Energy Technology Data Exchange (ETDEWEB)

    Ricco, G. [Consiglio Nazionale delle Ricerche, Bari (Italy). Istituto Nazionale di Ricerca sulle Acque; Tomei, M.C. [Consiglio Nazionale delle Ricerche, Rome (Italy). Istituto Nazionale di Ricerca sulle Acque

    1999-10-01

    In this paper an experimental procedure to evaluate the biomass characterization parameters by utilizing respirometric tests is presented. Beside, a procedure for data analysis based on the kinetic, stoichiometric and mass balance equations describing the system in the various operating conditions required for the evaluation of the different parameters is proposed. Finally, the results of a first example of application to the sludge characterization of a civil waste water treatment plant are reported. [Italian] Viene presentato un primo esempio applicativo relativo alla caratterizzazione di un fango attivo proveniente da un impianto di trattamento di reflui civili utilizzando il modello cinetico di Monod con l'impiego di prove respirometriche.

  17. Proving the correctness of unfold/fold program transformations using bisimulation

    DEFF Research Database (Denmark)

    Hamilton, Geoff W.; Jones, Neil

    2011-01-01

    proofs show the original and transformed programs are contextually equivalent, i.e., have the same termination behaviour in all closed contexts. Contextual equivalence can, however, be difficult to establish directly. Gordon and Howe use an alternative approach: to represent a program's behaviour...... to describe contextually, due to use of non-local information. We show that weak bisimulation on labelled transition systems gives an elegant framework to prove contextual equivalence of original and transformed programs. One reason is that folds can be seen in the context of corresponding unfolds....

  18. Hydrogeologic data for the Canal Creek area, Aberdeen Proving Ground, Maryland, April 1986-March 1988

    Science.gov (United States)

    Oliveros, J.P.; Gernhardt, Patrice

    1989-01-01

    This report is a compilation of hydrologic and geologic data collected for the period April 1986 through March 1988 for the Canal Creek area of Aberdeen Proving Ground, Maryland. Geologic data include lithologic logs for 73 sites and geophysical logs for 71 sites. Hydrologic data consist of hydrographs and synoptic water level measurements. The hydrographs were taken from eight wells that were equipped with continuous water level recorders, and the synoptic water-level measurements were made four times during the study. Well-construction data also are included for 149 observation wells. (USGS)

  19. Initial building investigations at Aberdeen Proving Ground, Maryland: Objectives and methodology

    Energy Technology Data Exchange (ETDEWEB)

    Brubaker, K.L.; Dougherty, J.M.; McGinnis, L.D.

    1994-12-01

    As part of an environmental-contamination source-definition program at Aberdeen Proving Ground, detailed internal and external inspections of 23 potentially contaminated buildings are being conducted to describe and characterize the state of each building as it currently exists and to identify areas potentially contaminated with toxic or other hazardous substances. In addition, a detailed geophysical investigation is being conducted in the vicinity of each target building to locate and identify subsurface structures, associated with former building operations, that are potential sources of contamination. This report describes the objectives of the initial building inspections, including the geophysical investigations, and discusses the methodology that has been developed to achieve these objectives.

  20. How to prove the validity of a complex ballot encryption to the voter and the public

    OpenAIRE

    Joaquim, Rui

    2014-01-01

    One crucial aspect of any verifiable electronic voting system that uses encryption is the proof that the vote encryption is well-formed, i.e. the proof that the vote encryption encrypts a valid vote accordingly to the race specification. It makes no sense accepting an encrypted vote if, at the end of the election, the vote cannot be included in the tally because it is badly formed. Proving the validity of a complex vote encryption, without revealing the vote, is a hard problem. This paper...

  1. Seismic proving test of ultimate piping strength (current status of preliminary tests)

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K.; Namita, Y.; Abe, H.; Ichihashi, I. [Seismic Engineering Center, NUPEC, Tokyo (Japan); Suzuki, K. [Tokyo Metropolitan Universtity, Hachioji (Japan); Ishiwata, M. [Hitachi, Ltd., Hitachi (Japan); Fujiwaka, T. [Ishikawajima-Harima Heavy Industries Co., Ltd., Yokohama (Japan); Yokota, H. [Mitsubishi Heavy Industries Ltd., Kobe (Japan)

    2001-07-01

    In 1998 Fiscal Year, the 6 year program of piping tests was initiated with the following objectives: i) to clarify the elasto-plastic response and ultimate strength of nuclear piping, ii) to ascertain the seismic safety margin of the current seismic design code for piping, and iii) to assess new allowable stress rules. In order to resolve extensive technical issues before proceeding on to the seismic proving test of a large-scale piping system, a series of preliminary tests of materials, piping components and simplified piping systems is intended. In this paper, the current status of the material tests and the piping component tests is reported. (author)

  2. Ecological survey of M-Field, Edgewood Area Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Downs, J.L.; Eberhardt, L.E.; Fitzner, R.E.; Rogers, L.E.

    1991-12-01

    An ecological survey was conducted on M-Field, at the Edgewood Area, Aberdeen Proving Ground, Maryland. M-Field is used routinely to test army smokes and obscurants, including brass flakes, carbon fibers, and fog oils. The field has been used for testing purposes for the past 40 years, but little documented history is available. Under current environmental regulations, the test field must be assessed periodically to document the presence or potential use of the area by threatened and endangered species. The M-Field area is approximately 370 acres and is part of the US Army`s Edgewood Area at Aberdeen Proving Ground in Harford County, Maryland. The grass-covered field is primarily lowlands with elevations from about 1.0 to 8 m above sea level, and several buildings and structures are present on the field. The ecological assessment of M-Field was conducted in three stages, beginning with a preliminary site visit in May to assess sampling requirements. Two field site visits were made June 3--7, and August 12--15, 1991, to identify the biota existing on the site. Data were gathered on vegetation, small mammals, invertebrates, birds, large mammals, amphibians, and reptiles.

  3. Ecological survey of M-Field, Edgewood Area Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Downs, J.L.; Eberhardt, L.E.; Fitzner, R.E.; Rogers, L.E.

    1991-12-01

    An ecological survey was conducted on M-Field, at the Edgewood Area, Aberdeen Proving Ground, Maryland. M-Field is used routinely to test army smokes and obscurants, including brass flakes, carbon fibers, and fog oils. The field has been used for testing purposes for the past 40 years, but little documented history is available. Under current environmental regulations, the test field must be assessed periodically to document the presence or potential use of the area by threatened and endangered species. The M-Field area is approximately 370 acres and is part of the US Army's Edgewood Area at Aberdeen Proving Ground in Harford County, Maryland. The grass-covered field is primarily lowlands with elevations from about 1.0 to 8 m above sea level, and several buildings and structures are present on the field. The ecological assessment of M-Field was conducted in three stages, beginning with a preliminary site visit in May to assess sampling requirements. Two field site visits were made June 3--7, and August 12--15, 1991, to identify the biota existing on the site. Data were gathered on vegetation, small mammals, invertebrates, birds, large mammals, amphibians, and reptiles.

  4. Proving the infringement of digital intellectual property rights: Overview of the Anglo-saxon legal system

    Directory of Open Access Journals (Sweden)

    Spasić Vidoje

    2015-01-01

    Full Text Available The multifaceted process of identifying and proving the infringement of intellectual property rights is further complicated and aggravated in the so-called analogue environment. The development of Information Technologies has given rise to a new set of problems. The digital technology has facilitated the infringement of intellectual property rights and additionally aggravated the process of proving these infringements. Hence, it is the duty of digital forensics to identify relevant (valid evidence and present it in the court of law, which is not an easy task. In that course, the problems are twofold: legal and technical. First of all, the legislation in many countries is not adjusted to resolving the issues constantly emerging in the digital environment and there are apparent differences in the manner of regulating these issues. On the other hand, there is no standardized and unified technology which would provide for a uniform qualification and comprehensive treatment of these issues. Moreover, the place of commission of these criminal offences as a rule does not coincide with the place of occurring legal consequences. Yet, in spite of all these difficulties, there are technological methods and tools which facilitate the detection of cybercrime and provide evidence for securing relevant punishment. In the time to come, the developments in this area are expected to be aimed at strengthening the protection of legitimate interests of holders of intellectual property rights.

  5. Ehrlichia chaffeensis (Rickettsiales: Ehrlichieae) infection in Amblyomma americanum (Acari: Ixodidae) at Aberdeen Proving Ground, Maryland.

    Science.gov (United States)

    Stromdahl, E Y; Randolph, M P; O'Brien, J J; Gutierrez, A G

    2000-05-01

    Human monocytic ehrlichiosis (HME) is a sometimes fatal, emerging tick-borne disease caused by the bacterium Ehrlichia chaffeensis. It is frequently misdiagnosed because its symptoms mimic those of the flu. Current evidence indicates that Amblyomma americanum (L.), the lone star tick, is the major vector of HME. To determine if E. chaffeensis is present in ticks at Aberdeen Proving Ground, MD, questing A. americanum ticks were collected from 33 sites. Nucleic acid was extracted from 34 adult and 81 nymphal pools. Sequences diagnostic for E. chaffeensis from three different loci (16S rRNA, 120-kDa protein, and a variable-length polymerase chain reaction [PCR] target, or VLPT) were targeted for amplification by the PCR. Fifty-two percent of the collection sites yielded pools infected with E. chaffeensis, confirming the presence and widespread distribution of E. chaffeensis at Aberdeen Proving Ground. Analysis with the both the 120-kDa protein primers and the VLPT primers showed that genetic variance exists. A novel combination of variance for the two loci was detected in two tick pools. The pathogenic implications of genetic variation in E. chaffeensis are as yet unknown.

  6. artocarpus altilis proving its worth in toxic metal removal from the ...

    African Journals Online (AJOL)

    DR. AMINU

    2012-12-02

    Dec 2, 2012 ... Toxic metals are taken up by man and other organisms through the food chain, and the ones dissolved in water have the greatest potential of causing the most deleterious effects (Lagrana et al,. 2011; Garbarino et al., 1995; Manahan, 1994). Treatment of wastewater to remove toxic metals include chemical ...

  7. A theorem proving framework for the formal verification of Web Services Composition

    Directory of Open Access Journals (Sweden)

    Petros Papapanagiotou

    2011-08-01

    Full Text Available We present a rigorous framework for the composition of Web Services within a higher order logic theorem prover. Our approach is based on the proofs-as-processes paradigm that enables inference rules of Classical Linear Logic (CLL to be translated into pi-calculus processes. In this setting, composition is achieved by representing available web services as CLL sentences, proving the requested composite service as a conjecture, and then extracting the constructed pi-calculus term from the proof. Our framework, implemented in HOL Light, not only uses an expressive logic that allows us to incorporate multiple Web Services properties in the composition process, but also provides guarantees of soundness and correctness for the composition.

  8. Myoid hamartoma of the breast that proved difficult to diagnose: a case report

    Directory of Open Access Journals (Sweden)

    Mizuta Naruhiko

    2012-01-01

    Full Text Available Abstract Myoid hamartomas of the breast are extremely rare breast lesions, with a poorly understood pathogenesis. We describe the case of a 38-year-old premenopausal woman who presenting with a mass in the left breast. Mammography revealed an oval mass that was partly indistinct, and ultrasonography showed a hypoechoic mass with a slightly irregular margin. Bilateral breast dynamic magnetic resonance imaging was performed for a more detailed evaluation. The images showed rapid initial enhancement and a microlobulated margin. Because the suspicion of malignancy was strong at that time, core needle biopsy was performed. Histologically, the tumor was identified as fibroadenoma. A case of myoid hamartoma of the breast that proved difficult to diagnose is reported, and discussed with reference to the literature.

  9. An Overview of NASA SPoRT GOES-R JPSS Proving Ground Testbed Activities

    Science.gov (United States)

    Berndt, Emily; Stano, Geoffrey; Fuell, Kevin; Leroy, Anita; Mcgrath, Kevin; Molthan, Andrew; Schultz, Lori; Smith, Matthew; White, Kris; Schultz, Christopher; hide

    2017-01-01

    The Short-term Prediction Research and Transition (SPoRT) Center is funded by NASA's Earth Science Division and NOAA's JPSS and GOES-R Proving Grounds to transition satellite products and capabilities to the NWS to improve short term (0-48 hr) forecasts on a regional and local scale. SPoRT currently collaborates with 30+ NWS WFOs (at least one in each NWS region) and 5 National Centers/Testbeds. SPoRT matches user-identified forecast challenges to specific products, providing access to these data in AWIPS through new plug-in development, and generating applications-based training to use the products for their needs (R20). Upon transition, SPoRT collaborates with the user to assess the product impact in a real-world environment for feedback to product developers (O2R) and to benefit their peers.

  10. Calculus using proximities: a mathematical approach in which students can actually prove theorems

    Directory of Open Access Journals (Sweden)

    O’Donovan Richard

    2017-02-01

    Full Text Available Teaching and learning calculus are notoriously difficult and the didactic solutions may involve resorting to intuitive but vague definitions or informal gestures offered as proofs. The teaching literature is rife with examples of metaphors, adverb manipulations and descriptions of what happens “just before” the limit. It is then difficult to leave the domain of the mental image, thus losing the training in rigour. The author (with Karel Hrbacek and Olivier Lessmann has endeavoured a radically different approach with the objective of training students to prove theorems while preserving both intuition and mathematical rigour. Hence we change the mathematical setting rather than the didactic setting. The result (which is a by-product of nonstandard analysis has been used in several high schools in Geneva – Switzerland – for over ten years.

  11. NOAA's Joint Polar Satellite System's Proving Ground and Risk Reduction Program - Bringing New Capabilities to Operations!

    Science.gov (United States)

    Sjoberg, B.

    2015-12-01

    This presentation will focus on the NOAA Joint Polar Satellite System (JPSS) Program's Proving Ground and Risk Reduction (PGRR) initiative and how it has prepared NOAA users to effectively utilize new polar-orbiting capabilities. The PGRR Program was established in 2012, following the launch of the Suomi National Polar Partnership (SNPP) satellite. Two sets of PGRR Projects have been established grouped together in thirteen different initiatives. Details about how these projects have been continually tailored through the years to meet user requirements, will be highlighted. The presenter will focus on how the success of the first set of PGRR projects have been used to evaluate a follow-on set of projects and focus on exactly what the JPSS user community needs to meet their mission requirements. Details on the Dec 2014 PGRR Call-for-Proposals and the projects selected for funding will be discussed.

  12. An Abstract Model for Proving Safety of Multi-lane Traffic Manoeuvres

    DEFF Research Database (Denmark)

    Hilscher, Martin; Linker, Sven; Olderog, Ernst-Rüdiger

    2011-01-01

    We present an approach to prove safety (collision freedom) of multi-lane motorway traffic with lane-change manoeuvres. This is ultimately a hybrid verification problem due to the continuous dynamics of the cars. We abstract from the dynamics by introducing a new spatial interval logic based...... on the view of each car. To guarantee safety, we present two variants of a lane-change controller, one with perfect knowledge of the safety envelopes of neighbouring cars and one which takes only the size of the neighbouring cars into account. Based on these controllers we provide a local safety proof...... for unboundedly many cars by showing that at any moment the reserved space of each car is disjoint from the reserved space of any other car....

  13. Fractal geometry as a new approach for proving nanosimilarity: a reflection note.

    Science.gov (United States)

    Demetzos, Costas; Pippa, Natassa

    2015-04-10

    Nanosimilars are considered as new medicinal outcomes combining the generic drugs and the nanocarrier as an innovative excipient, in order to evaluate them as final products. They belong to the grey area - concerning the evaluation process - between generic drugs and biosimilar medicinal products. Generic drugs are well documented and a huge number of them are in market, replacing effectively the off-patent drugs. The scientific approach for releasing them to the market is based on bioequivalence studies, which are well documented and accepted by the regulatory agencies. On the other hand, the structural complexity of biological/biotechnology-derived products demands a new approach for the approval process taking into consideration that bioequivalence studies are not considered as sufficient as in generic drugs, and new clinical trials are needed to support their approval process of the product to the market. In proportion, due to technological complexity of nanomedicines, the approaches for proving the statistical identity or the similarity for generic and biosimilar products, respectively, with those of prototypes, are not considered as effective for nanosimilar products. The aim of this note is to propose a complementary approach which can provide realistic evidences concerning the nanosimilarity, based on fractal analysis. This approach is well fit with the structural complexity of nanomedicines and smooths the difficulties for proving the similarity between off-patent and nanosimilar products. Fractal analysis could be considered as the approach that completely characterizes the physicochemical/morphological characteristics of nanosimilar products and could be proposed as a start point for a deep discussion on nanosimilarity. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Fake News: A Technological Approach to Proving the Origins of Content, Using Blockchains.

    Science.gov (United States)

    Huckle, Steve; White, Martin

    2017-12-01

    In this article, we introduce a prototype of an innovative technology for proving the origins of captured digital media. In an era of fake news, when someone shows us a video or picture of some event, how can we trust its authenticity? It seems that the public no longer believe that traditional media is a reliable reference of fact, perhaps due, in part, to the onset of many diverse sources of conflicting information, via social media. Indeed, the issue of "fake" reached a crescendo during the 2016 U.S. Presidential Election, when the winner, Donald Trump, claimed that The New York Times was trying to discredit him by pushing disinformation. Current research into overcoming the problem of fake news does not focus on establishing the ownership of media resources used in such stories-the blockchain-based application introduced in this article is technology that is capable of indicating the authenticity of digital media. Put simply, using the trust mechanisms of blockchain technology, the tool can show, beyond doubt, the provenance of any source of digital media, including images used out of context in attempts to mislead. Although the application is an early prototype and its capability to find fake resources is somewhat limited, we outline future improvements that would overcome such limitations. Furthermore, we believe that our application (and its use of blockchain technology and standardized metadata) introduces a novel approach to overcoming falsities in news reporting and the provenance of media resources used therein. However, while our application has the potential to be able to verify the originality of media resources, we believe that technology is only capable of providing a partial solution to fake news. That is because it is incapable of proving the authenticity of a news story as a whole. We believe that takes human skills.

  15. Hydrogeologic setting, hydraulic properties, and ground-water flow at the O-Field area of Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Banks, W.S.; Smith, B.S.; Donnelly, C.A.

    1996-01-01

    The U.S. Army disposed chemical agents, laboratory materials, and unexploded ordnance at O-Field in the Edgewood area of Aberdeen Proving Ground, Maryland, from before World War II until at least the 1950's. Soil, ground water, surface water,and wetland sediments in the O-Field area were contaminated from the disposal activity. A ground-water-flow model of the O-Field area was constructed by the U.S. Geological Survey (USGS) in 1989 to simulate flow in the central and southern part of the Gunpowder Neck. The USGS began an additional study of the contamination in the O-Field area in cooperation with the U.S. Army in 1990 to (1) further define the hydrogeologic framework of the O-Field area, (2) characterize the hydraulic properties of the aquifers and confining units, and (3) define ground-water flow paths at O-Field based on the current data and simulations of ground-water flow. A water-table aquifer, an upper confining unit, and an upper confined aquifer comprise the shallow ground-water aquifer system of the O-Field area. A lower confining unit, through which ground-water movement is negligible, is considered a lower boundary to the shallow aquifer system. These units are all part of the Pleistocene Talbot Formation. The model developed in the previous study was redesigned using the data collected during this study and emphasized New O-Field. The current steady-state model was calibrated to water levels of June 1993. The rate of ground-water flow calculated by the model was approximately 0.48 feet per day (ft/d) and the rate determined from chlorofluorocarbon dates was approximately 0.39 ft/d.

  16. Inorganic and organic ground-water chemistry in the Canal Creek area of Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Lorah, M.M.; Vroblesky, D.A.

    1989-01-01

    Groundwater chemical data were collected from November 1986 through April 1987 in the first phase of a 5-year study to assess the possibility of groundwater contamination in the Canal Creek area of Aberdeen Proving Ground, Maryland. Water samples were collected from 87 observation wells screened in Coastal Plain sediments; 59 samples were collected from the Canal Creek aquifer, 18 from the overlying surficial aquifer, and 10 from the lower confined aquifer. Dissolved solids, chloride, iron, manganese, fluoride, mercury, and chromium are present in concentrations that exceed the Federal maximum contaminant levels for drinking water. Elevated chloride and dissolved-solids concentrations appear to be related from contaminant plumes but also could result from brackish-water intrusion. Excessive concentrations of iron and manganese were the most extensive water quality problems found among the inorganic constituents and are derived from natural dissolution of minerals and oxide coatings in the aquifer sediments. Volatile organic compounds are present in the Canal Creek and surficial aquifers, but samples from the lower confined aquifer do not show any evidence of contamination by inorganic or organic chemicals. The volatile organic contaminants detected in the groundwater and their maximum concentrations (in micrograms/L) include 1,1,2,2- tetrachloroethane (9,000); carbon tetrachloride (480); chloroform (460); 1,1,2-trichloroethane (80); 1,2-dichloroethane (990); 1,1-dichloroethane (3.1); tetrachloroethylene (100); trichloroethylene (1,800); 1,2-trans- dichloroethylene (1,200); 1,1-dichloroethylene (4.4); vinyl chloride (140); benzene (70); and chlorobenzene (39). On the basis of information on past activities in the study area, some sources of the volatile organic compounds include: (1) decontaminants and degreasers; (2) clothing-impregnating operations; (3) the manufacture of impregnite material; (4) the manufacture of tear gas; and (5) fuels used in garages and at

  17. 76 FR 50771 - Submission for Review: RI 25-37, Evidence To Prove Dependency of a Child, 3206-0206

    Science.gov (United States)

    2011-08-16

    ... MANAGEMENT Submission for Review: RI 25-37, Evidence To Prove Dependency of a Child, 3206-0206 AGENCY: U.S... Dependency of a Child. As required by the Paperwork Reduction Act of 1995 (Pub. L. 104-13, 44 U.S.C. chapter.... SUPPLEMENTARY INFORMATION: Evidence to Prove Dependency of a Child is designed to collect sufficient information...

  18. Outperforming whom? A multilevel study of performance-prove goal orientation, performance, and the moderating role of shared team identification.

    Science.gov (United States)

    Dietz, Bart; van Knippenberg, Daan; Hirst, Giles; Restubog, Simon Lloyd D

    2015-11-01

    Performance-prove goal orientation affects performance because it drives people to try to outperform others. A proper understanding of the performance-motivating potential of performance-prove goal orientation requires, however, that we consider the question of whom people desire to outperform. In a multilevel analysis of this issue, we propose that the shared team identification of a team plays an important moderating role here, directing the performance-motivating influence of performance-prove goal orientation to either the team level or the individual level of performance. A multilevel study of salespeople nested in teams supports this proposition, showing that performance-prove goal orientation motivates team performance more with higher shared team identification, whereas performance-prove goal orientation motivates individual performance more with lower shared team identification. Establishing the robustness of these findings, a second study replicates them with individual and team performance in an educational context. (c) 2015 APA, all rights reserved).

  19. A Tool Use Task Proves Enriching for a Captive Sea Otter (Enhydra lutris

    Directory of Open Access Journals (Sweden)

    Pepper R. Hanna

    2016-05-01

    Full Text Available Environmental enrichment is used to improve an animal’s physical and psychological well-being while housed in a captive environment. Alligood and Leighty (2015 suggested that enrichment that emulates the natural and preferred behaviors of the species may be optimal for improving welfare. Cognitive tasks that mirror challenges in an animal’s natural environment may prove especially beneficial (Washburn, 2015. The present study was designed to determine whether two sea otters (Enhydra lutis, Emma and Buck, were capable of learning to use a novel tool in a novel context. The otters’ time spent engaged with the apparatus was also examined to determine if such a task would be enriching to these animals. Although the sea otters were not successful in solving the tool use task, interaction with the apparatus appeared enriching to Emma. She spent on average 55.4% of each trial at the apparatus, whereas Buck spent only 6.2%. Only Emma’s interaction with the apparatus suggests that this device was very interesting and consequently enriching for her. Cognitive challenges, then, may be enriching even when animals fail to solve the intended problem.

  20. A Mechanically Proved and an Incremental Development of the Session Initiation Protocol INVITE Transaction

    Directory of Open Access Journals (Sweden)

    Rajaa Filali

    2014-01-01

    Full Text Available The Session Initiation Protocol (SIP is an application layer signaling protocol used to create, manage, and terminate sessions in an IP based network. SIP is considered as a transactional protocol. There are two main SIP transactions, the INVITE transaction and the non-INVITE transaction. The SIP INVITE transaction specification is described in an informal way in Request for Comments (RFC 3261 and modified in RFC 6026. In this paper we focus on the INVITE transaction of SIP, over reliable and unreliable transport mediums, which is used to initiate a session. In order to ensure the correctness of SIP, the INVITE transaction is modeled and verified using event-B method and its Rodin platform. The Event-B refinement concept allows an incremental development by defining the studied system at different levels of abstraction, and Rodin discharges almost all proof obligations at each level. This interaction between modeling and proving reduces the complexity and helps in assuring that the INVITE transaction SIP specification is correct, unambiguous, and easy to understand.

  1. An Evaluation of Activated Bismuth Isotopes in Environmental Samples From the Former Western Pacific Proving Grounds

    Energy Technology Data Exchange (ETDEWEB)

    Robison, W.L.; Brunk, J.A.; Jokela, T.A.

    2000-03-21

    {sup 207}Bi (t{sub 1/2}=32.2 y) was generated by activation of weapons material during a few ''clean'' nuclear tests at the U.S. Western Pacific Proving Grounds of Enewetak and Bikini Atolls. The radionuclides first appeared in the Enewetak environment during 1958 and in the environment of Bikini during 1956. Crater sediments from Bikini with high levels of {sup 207}Bi were analyzed by gamma spectrometry in an attempt to determine the relative concentrations of {sup 208}Bi (t{sup 1/2} = 3.68 x 10{sup 5} y). The bismuth isotopes were probably generated during the ''clean'', 9.3 Mt Poplar test held on 7/12/58. The atom ratio of {sup 208}Bi to {sup 207}Bi (R value) ranges from {approx}12 to over 200 in sections of core sediments from the largest nuclear crater at Bikini atoll. The presence of bismuth in the device is suggested to account for R values in excess of 10.

  2. Natural attenuation of chlorinated volatile organic compounds in a freshwater tidal wetland, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Lorah, Michelle M.; Olsen, Lisa D.; Smith, Barrett L.; Johnson, Mark A.; Fleck, William B.

    1997-01-01

    Ground-water contaminant plumes that are flowing toward or currently discharging to wetland areas present unique remediation problems because of the hydrologic connections between ground water and surface water and the sensitive habitats in wetlands. Because wetlands typically have a large diversity of microorganisms and redox conditions that could enhance biodegradation, they are ideal environments for natural attenuation of organic contaminants, which is a treatment method that would leave the ecosystem largely undisturbed and be cost effective. During 1992-97, the U.S. Geological Survey investigated the natural attenuation of chlorinated volatile organic compounds (VOC's) in a contaminant plume that discharges from a sand aquifer to a freshwater tidal wetland along the West Branch Canal Creek at Aberdeen Proving Ground, Maryland. Characterization of the hydrogeology and geochemistry along flowpaths in the wetland area and determination of the occurrence and rates of biodegradation and sorption show that natural attenuation could be a feasible remediation method for the contaminant plume that extends along the West Branch Canal Creek.

  3. Atrial overdriving is beneficial in patients with atrial arrhythmias: first results of the PROVE Study.

    Science.gov (United States)

    Funck, R C; Adamec, R; Lurje, L; Capucci, A; Ritter, P; Shekan, D; Slegers, L C; Tavernier, R; Ishikawa, T

    2000-11-01

    The AF Prevention by Overdriving (PROVE) trial is an ongoing prospective study of the effectiveness of atrial overdrive pacing combined with an Automatic Rest Rate function in the prevention of atrial arrhythmias. All patients who have received a Talent DR 213 pacemaker are eligible for enrollment into the study. After a 1-month monitoring period, the patients are divided into two groups. Group I includes patients with > or = 2 appropriate mode-switch (MS) episodes, or 1 MS episode of > or = 10 minutes, and/or > 300 atrial runs of > 5 beats/month. Group II includes all other patients. The number and duration of atrial arrhythmias are measured the pacemaker's Automatic Interpretation and Data Analysis software (AIDA). Patients' quality-of-life is measured by a validated functional status questionnaire. After having been grouped, the patients are randomly assigned, in a crossover design, to standard DDDR or overdrive pacing + Rest Rate, each programmed for a 3-month period. Preliminary results in 78 patients show a 34% reduction in the mean number of MS, and a mean 48% shortening of the overall duration of the episodes by overdrive pacing + Rest Rate, achieved by a mean 84% prevalence of atrial pacing. Overdrive pacing + Rest Rate was well tolerated and associated with a slight improvement in quality-of-life.

  4. The written mathematical communication profile of prospective math teacher in mathematical proving

    Science.gov (United States)

    Pantaleon, K. V.; Juniati, D.; Lukito, A.; Mandur, K.

    2018-01-01

    Written mathematical communication is the process of expressing mathematical ideas and understanding in writing. It is one of the important aspects that must be mastered by the prospective math teacher as tool of knowledge transfer. This research was a qualitative research that aimed to describe the mathematical communication profile of the prospective mathematics teacher in mathematical proving. This research involved 48 students of Mathematics Education Study Program; one of them with moderate math skills was chosen as the main subject. Data were collected through tests, assignments, and task-based interviews. The results of this study point out that in the proof of geometry, the subject explains what is understood, presents the idea in the form of drawing and symbols, and explains the content/meaning of a representation accurately and clearly, but the subject can not convey the argument systematically and logically. Whereas in the proof of algebra, the subject describes what is understood, explains the method used, and describes the content/meaning of a symbolic representation accurately, systematically, logically, but the argument presented is not clear because it is insufficient detailed and complete.

  5. Search for diagnostic proteins to prove authenticity of organic wheat grains (Triticum aestivum L.).

    Science.gov (United States)

    Zörb, Christian; Betsche, Thomas; Langenkämper, Georg

    2009-04-08

    Research comparing the biochemical composition of wheat grains from organic or conventional agriculture has used the targeted analytical approach. To obtain a more comprehensive record of the food's composition, we employed protein profiling techniques. Levels of 1049 proteins were recorded in wheat grains (Triticum aestivum L., cv. Titlis) of two growing seasons from a rigorously controlled field trial in Switzerland, containing organic and conventional plots. Levels of 25 proteins were different between organic and conventional wheat in both years. Storage proteins, enzymes of carbohydrate metabolism, a peroxidase, and proteins of unknown function were affected by the agricultural regime. Total protein content was lower in organic wheat. We consider these differences negligible with regard to nutrition in an average diet and propose that food quality of conventional and organic wheat grown in the field trial was equal. Applying various filters and calculations, one of which takes seasonal influences into account, 16 of the 25 proteins with different levels in organic and conventional wheat were retained. These 16 "diagnostic" proteins have the potential to afford a signature to prove authenticity of organic wheat.

  6. Ultrasonic Assessment of Females with Carpal Tunnel Syndrome Proved by Nerve Conduction Study

    Directory of Open Access Journals (Sweden)

    Ihsan M. Ajeena

    2013-01-01

    Full Text Available Introduction. Carpal tunnel syndrome (CTS is the most commonly diagnosed entrapment neuropathy of the upper extremity. The objective of this study was to diagnose CTS and to assess its severity using high resolution ultrasound (HRUS depending on the results of nerve conduction study (NCS. Methods. A prospective cross-sectional study, in which HRUS was performed at 63 wrists of 35 female patients with different severity of CTS (as proved by NCS. Furthermore, 40 healthy volunteers (80 wrists underwent the same tests as the patients and have been chosen to match the patients in gender, age, and body mass index (BMI. The cross section area (CSA of the median nerve (MN was obtained using HRUS at the carpal tunnel inlet by direct tracing method. Results. There was a significant difference in the CSA of the MN at the tunnel inlet in CTS patients when compared with the control group. In fact, the CSA of the control group showed a significant difference from each of patients subgroups. Furthermore, a significant difference in the CSA was seen in between these subgroups. In conclusion, the US examination of the MN seems to be a promising method in diagnosing and grading of carpal tunnel syndrome.

  7. Contamination source review for Building E1489, Edgewood Area, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Billmark, K.A.; Hayes, D.C.; Draugelis, A.K. [and others

    1995-09-01

    This report was prepared by Argonne National Laboratory (ANL) to document the results of a contamination source review of Building E1489 at the Aberdeen Proving Ground (APG) in Maryland. This report may be used to assist the U.S. Army-in planning for the future use or disposition of this building. The review included a historical records search, physical inspection, photographic documentation, and geophysical investigation. The field investigations were performed in 1994-1995. Building E1489 located in J-Field on the Gunpowder Peninsula in APG`s Edgewood Area housed a power generator that supplied electricity to a nearby observation tower. Building E1489 and the generator were abandoned in 1974, demolished by APG personnel and removed from real estate records. A physical inspection and photographic documentation of Building E1489 were completed by ANL staff during November 1994. In 1994, ANL staff conducted geophysical surveys in the immediate vicinity of Building E1489 by using several nonintrusive methods. Survey results suggest the presence of some underground objects near Building E1489, but they do not provide conclusive evidence of the source of geophysical anomalies observed during the survey. No air monitoring was conducted at the site, and no information on underground storage tanks associated with Building E1489 was available.

  8. Contamination source review for Building E3180, Edgewood Area, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Zellmer, S.D.; Smits, M.P.; Rueda, J.; Zimmerman, R.E.

    1995-09-01

    This report was prepared by Argonne National Laboratory (ANL) to document the results of a contamination source review of Building E3180 at the Aberdeen Proving Ground (APG) in Maryland. The report may be used to assist the US Army in planning for the future use or disposition of this building. The review included a historical records search, physical inspection, photographic documentation, geophysical investigation, collection of air samples, and review of available records regarding underground storage tanks associated with Building E3180. The field investigations were performed by ANL during 1994. Building,E3180 (current APG designation) is located near the eastern end of Kings Creek Road, north of Kings Creek, and about 0.5 miles east of the airstrip within APG`s Edgewood Area. The building was constructed in 1944 as a facsimile of a Japanese pillbox and used for the development of flame weapons systems until 1957 (EAI Corporation 1989). The building was not used from 1957 until 1965, when it was converted and used as a flame and incendiary laboratory. During the 1970s, the building was converted to a machine (metal) shop and used for that purpose until 1988.

  9. Review of analytical results from the proposed agent disposal facility site, Aberdeen Proving Ground

    Energy Technology Data Exchange (ETDEWEB)

    Brubaker, K.L.; Reed, L.L.; Myers, S.W.; Shepard, L.T.; Sydelko, T.G.

    1997-09-01

    Argonne National Laboratory reviewed the analytical results from 57 composite soil samples collected in the Bush River area of Aberdeen Proving Ground, Maryland. A suite of 16 analytical tests involving 11 different SW-846 methods was used to detect a wide range of organic and inorganic contaminants. One method (BTEX) was considered redundant, and two {open_quotes}single-number{close_quotes} methods (TPH and TOX) were found to lack the required specificity to yield unambiguous results, especially in a preliminary investigation. Volatile analytes detected at the site include 1, 1,2,2-tetrachloroethane, trichloroethylene, and tetrachloroethylene, all of which probably represent residual site contamination from past activities. Other volatile analytes detected include toluene, tridecane, methylene chloride, and trichlorofluoromethane. These compounds are probably not associated with site contamination but likely represent cross-contamination or, in the case of tridecane, a naturally occurring material. Semivolatile analytes detected include three different phthalates and low part-per-billion amounts of the pesticide DDT and its degradation product DDE. The pesticide could represent residual site contamination from past activities, and the phthalates are likely due, in part, to cross-contamination during sample handling. A number of high-molecular-weight hydrocarbons and hydrocarbon derivatives were detected and were probably naturally occurring compounds. 4 refs., 1 fig., 8 tabs.

  10. Prefixation Ability Index and Verbal Grammar Correlation Index prove the reality of Buyeo group

    Directory of Open Access Journals (Sweden)

    Alexander AKULOV

    2016-06-01

    Full Text Available All suggestions about reality of Buyeo group were based on the representation of a language as a heap of lexemes: such method allows different scholars to make different conclusions and doesn't suppose verification. Language is first of all structure/grammar, but not a heap of lexemes, so methods of comparative linguistics should be based on comparison of grammars. Prefixation Ability Index (PAI and Verbal Grammar Correlation Index (VGCI are typology based tools of comparative linguistics. PAI allows us to see whether languages are potentially related: if values of PAI differ more than fourfold, it's a sign of unrelatedness, if PAI values differ less than fourfold, there is a possibility for some further search to find proves of relatedness. VGCI completely answers questions about relatedness/unrelatedness: if VGCI value is 0.4 and more then languages are related, if VGCI is 0.3 and less then  languages are unrelated. PAI of Japanese is 0.13, PAI of Korean is 0.13; it means they can be related. VGCI of Japanese and Korean is 0.57, it's almost the same as VGCI of English and Afrikaans that is 0.56, so it means that Japanese and Korean belong to the same group, but not just to the same family.

  11. Potencial alelopático de macrófitas aquáticas de um estuário cego Allelopathic potential of aquatic macrophytes from a blind estuary

    Directory of Open Access Journals (Sweden)

    Leandro Kenji Takao

    2011-06-01

    Full Text Available Macrófitas aquáticas representam uma das comunidades mais produtivas e através de sua atividade metabólica são capazes de produzir grandes interferências no ambiente. As interações alelopáticas são aparentemente aumentadas sob condições de estresse biótico e abiótico e podem existir em estuários devido à competição, variações de salinidade e outros fatores. O objetivo desse trabalho foi avaliar as propriedades alelopáticas de extratos aquosos foliares de 25 espécies de macrófitas aquáticas de um estuário cego. Testamos os efeitos dos extratos foliares em quatro concentrações sobre a germinação de alface. Ordenamos e comparamos as espécies doadoras de acordo com a dose reposta sobre a variedade de tratamentos a partir de valores únicos de índices alelopáticos. Onze das 25 espécies diminuíram a porcentagem de germinação, todas diminuíram a velocidade de germinação e aumentaram a entropia informacional de germinação das sementes da espécie alvo em pelo menos uma das concentrações testadas. Crinum americanum L., Sagittaria montevidensis Cham. & Schl. e Ipomoea cairica (L Sweet apresentaram os maiores valores de índice alelopático. Em geral, as menores porcentagens de germinação coincidiram com as menores velocidades e maiores entropias informacionais de germinação das sementes de alface, mostrando um conjunto de alterações ocorrendo simultaneamente com o aumento da concentração dos extratos.Aquatic macrophytes represent one of the most productive communities and through metabolic activity are capable of producing great interference in the environment. Allelopathic interactions are apparently increased under biotic and abiotic stress and may exist in estuaries due to competition, salinity variation and other factors. The aim of this study was to evaluate the allelopathic properties of leaf extracts of 25 aquatic macrophyte species from a blind estuary. We tested leaf extract effects in four

  12. Concurrently inhibitory and allelopathic effects of allelochemicals secreted by Myriophyllum spicatum on growth of blue-green algae; Hozakinofusamo ga hoshutsushita areropashi busshitsu no aisorui ni taisuru fukugo sayo oyobi areropashi koka no hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Nakai, S.; Inoue, Y.; Hosomi, M.; Murakami, A. [Tokyo Univ. of Agriculture and Technology, Tokyo (Japan)

    1998-10-10

    This paper describes effects of allelochemicals secreted by Myriophyllum spicatum on growth of blue-green algae. In order to propose an effective growth inhibitory method of blue-green algae with less impact on the ecosystem, biological interaction (allelopathy) between large aquatic plants and algae was investigated. Pyrogallic acid, gallic acid, catechin and ellagic acid secreted by M. spicatum provided growth inhibitory effects of blue-green algae (Microcyctis aeruginosa), individually. Complex interaction and allelopathic contribution of these four polyphenols were evaluated. By comparing the actual effects with the expected values, synergetic growth inhibitory effects were recognized by adding four polyphenols at the same time. Furthermore, growth inhibitory effects were evaluated for actual culture solution of M. spicatum and simulated culture solution made by four polyphenols. As a result, it was found that these four polyphenols relate to allelopathy of M. spicatum. 25 refs., 6 figs., 4 tabs.

  13. Research of Pre-Service Elementary Mathematics Teachers’ Beliefs in Proof, Proving Processes and Proof Evaluation Processes

    Directory of Open Access Journals (Sweden)

    Candaş Uygan

    2014-08-01

    Full Text Available The purpose of this study is to research pre-service elementary mathematics teachers’ beliefs on meaning and features of mathematical proof, their proving processes and their reasoning process while evaluating validities of proof examples. This study is a qualitative research. Participants of the study are three pre-service elementary mathematics teachers who continue to study in a state university from Central Anatolia Region. Participants’ beliefs on proof were researched with semi-structured interview whilst proving processes and evaluation processes of proof examples were researched with clinical interviews. Interviews were recorded with video camera and data were analyzed according to qualitative methods. When beliefs on proof were analyzed, it was indicated that participants see mathematical proofs as problem solving process and exploration of source of mathematical knowledge, and believe that proofs have to be deductive, apprehensible and have to include generalizable results. Also according to opinions of all three participants, they believe that their proving abilities are insufficient. Analyze results related to proving processes indicated that pre-service teachers considered conclusions of theorems as if they are conditions of theorems and also used proving strategies uncomprehendingly in proving process. Finally, analyze results related to proof evaluation process indicated that participants assessed computer based experimental verifications as valid mathematical proofs and had mistakes when they evaluated warrants used in verifications that break axiomatical structure of proofs.Key Words:    Beliefs in the context of proof, proving, proof evaluation, teacher education

  14. A Prochlorococcus proving ground for constraint-based metabolic modeling and multi-`omics data integration

    Science.gov (United States)

    Casey, J.; Ji, B.; Shaoie, S.; Mardinoglu, A.; Sarathi Sen, P.; Jahn, O.; Reda, K.; Leigh, J.; Follows, M. J.; Nielsen, J.; Karl, D. M.

    2016-02-01

    Representatives of the oligotrophic marine cyanobacterium Prochlorococcus marinus are the smallest free-living photosynthetic organisms, both in terms of physical size and genome size, yet are the most abundant photoautotrophic microbes in the oceans and profoundly influence global biogeochemical cycles. Physiological and regulatory control of nutrient and light stress has been observed in MED4 in culture and in its closely related `ecotype' eMED4 in the field, however its metabolism has not been investigated in detail. We present a genome-scale metabolic network reconstruction of the high-light adapted axenic strain MED4ax ("iJCMED4") for the quantitative analysis of a range of its metabolic phenotypes. The resulting structure is a proving ground for the incorporation of enzyme kinetics, biochemical and elemental compositional data, transcriptomic, proteomic, metabolomic, and fluxomic datasets which can be implemented within a constraint-based metabolic modeling environment. The iJCMED4 stoichiometric model consists of 523 metabolic genes encoding 787 reactions with 673 unique metabolites distributed in 5 sub-cellular compartments and is mass, charge, and thermodynamically balanced. Several variants of flux balance analysis were used to simulate growth and metabolic fluxes over the diel cycle, under various stress conditions (e.g., nitrogen, phosphorus, light), and within the framework of a global biogeochemical model (DARWIN). Model simulations accurately predicted growth rates in culture under a variety of defined medium compositions and there was close agreement of photosynthetic performance, biomass and energy yields and efficiencies, and transporter fluxes for iJCMED4 and culture experiments. In addition to a nearly optimal photosynthetic quotient and central carbon metabolism efficiency, MED4 has made dramatic alterations to redox and phosphorus metabolism across biosynthetic and intermediate pathways. We propose that reductions in phosphate reaction

  15. Benefit of Intensive Statin Therapy in Women: Results from PROVE IT-TIMI 22

    Science.gov (United States)

    Truong, Quynh A.; Murphy, Sabina A; McCabe, Carolyn H.; Armani, Annemarie; Cannon, Christopher P.

    2011-01-01

    Background Despite the known benefit of intensive statin therapy for reducing future cardiovascular events, its effectiveness in women has been questioned by some. Methods and Results In the Pravastatin or Atorvastatin Evaluation and Infection Therapy–Thrombolysis in Myocardial Infarction 22 (PROVE IT-TIMI 22) trial, 911 (21.9%) women and 3251 (78.1%) men were randomized to intensive statin (atorvastatin 80 mg) versus standard therapy (pravastatin 40 mg) for a median duration of 2.1 years. The primary endpoint was death, myocardial infarction (MI), unstable angina (UA), revascularization (occurring after 30 days) or stroke. Safety endpoints included elevations in liver function tests, creatine kinase and myalgias/myositis. Women had a reduction in LDL of 42.8% from baseline at 30 days (to a median of 60 mg/dL) in the intensive therapy arm with 88.8% reaching LDL goal of <100 mg/dL and 65.0% with <70 mg/dL as compared with a 16.8% reduction in LDL (to a median of 88 mg/dL) in the standard therapy. Women on intensive statin therapy had a significant 25% relative reduction over standard-dose (hazard ratio [HR] 0.75; 95% confidence interval [CI] 0.57-0.99; p=0.04) for primary composite endpoint, compared with a 14% reduction for men (HR 0.86; 95% CI 0.75-0.99; p=0.04), p-interaction=0.38. No differences were observed between genders for safety (all p-interaction ≥0.11). Conclusions This trial provides evidence that both women and men derived benefit from intensive statin therapy following ACS and thus gender should not be a factor in determining who should be treated with intensive statin therapy. PMID:21487089

  16. A theorem proving approach for automatically synthesizing visualizations of flow cytometry data.

    Science.gov (United States)

    Raj, Sunny; Hussain, Faraz; Husein, Zubir; Torosdagli, Neslisah; Turgut, Damla; Deo, Narsingh; Pattanaik, Sumanta; Chang, Chung-Che Jeff; Jha, Sumit Kumar

    2017-06-07

    Polychromatic flow cytometry is a popular technique that has wide usage in the medical sciences, especially for studying phenotypic properties of cells. The high-dimensionality of data generated by flow cytometry usually makes it difficult to visualize. The naive solution of simply plotting two-dimensional graphs for every combination of observables becomes impractical as the number of dimensions increases. A natural solution is to project the data from the original high dimensional space to a lower dimensional space while approximately preserving the overall relationship between the data points. The expert can then easily visualize and analyze this low-dimensional embedding of the original dataset. This paper describes a new method, SANJAY, for visualizing high-dimensional flow cytometry datasets. This technique uses a decision procedure to automatically synthesize two-dimensional and three-dimensional projections of the original high-dimensional data while trying to minimize distortion. We compare SANJAY to the popular multidimensional scaling (MDS) approach for visualization of small data sets drawn from a representative set of benchmarks, and our experiments show that SANJAY produces distortions that are 1.44 to 4.15 times smaller than those caused due to MDS. Our experimental results show that SANJAY also outperforms the Random Projections technique in terms of the distortions in the projections. We describe a new algorithmic technique that uses a symbolic decision procedure to automatically synthesize low-dimensional projections of flow cytometry data that typically have a high number of dimensions. Our algorithm is the first application, to our knowledge, of using automated theorem proving for automatically generating highly-accurate, low-dimensional visualizations of high-dimensional data.

  17. Allelopathic effect of Raphanus sativus on Urochloa decumbens and Lactuca sativa = Efeito alelopático de Raphanus sativus em Urochloa decumbens e Lactuca sativa

    Directory of Open Access Journals (Sweden)

    Rafael Navas

    2016-10-01

    Full Text Available The aim of this study was to evaluate the allelopathic potential of an extract from the leaves and roots of Raphanus sativus, on the species Urochloa decumbens and Lactuca sativa L. To obtain the extract, the leaves and roots of R. sativus were used separately, crushed at a proportion of 200 g of leaves to 1 L of water to give a crude aqueous extract (100%. Dilutions of 60%, 40% and 20%, and the control were produced from this extract. Seeds of U. decumbens and L. sativa were evenly distributed over two sheets of germitest paper, with four replications of 40 seeds each. Germination was evaluated at 7 and 14 days after sowing, together with the germination speed index (GSI, length of the shoots and roots, and dry weight. The design was completely randomised, and the values submitted to analysis of variance by F-test and regression analysis. The leaf extract gave a reduction in the germination of L. sativa at all tested doses. With application of the root extract, an increase was seen in germination, in the GSI and length of the radicle in U. decumbens at doses of from 40%. Moreover, with application of the leaf extract, the length of the shoot and radicle were also greater, irrespective of the dose applied. There was no effect from the treatments on the dry mass of the species. = Objetivou-se com este trabalho avaliar o potencial alelopático de extrato de folhas e raízes de Raphanus sativus, nas espécies Urochloa decumbens e Lactuca sativa L. Para obtenção do extrato, foram utilizadas separadamente folhas e raízes de R. sativus, trituradas na proporção de 200 g de folhas para 1 L de água, resultando no extrato aquoso bruto (100%. A partir desse extrato, foram realizadas as diluições de 60%, 40% e 20% e testemunha. Sementes de U. decumbens e L. sativa foram distribuídas uniformemente sobre duas folhas de papel germitest, com quatro repetições, com 40 sementes cada. As avaliações de germinação foram realizadas aos 7 e aos 14 dias

  18. Atividade alelopática de extratos de diferentes partes de juazeiro (Ziziphus joazeiro Mart. - Rhamnaceae Allelopathic activity of different parts of juazeiro (Ziziphus joazeiro Mart. - Rhamnaceae

    Directory of Open Access Journals (Sweden)

    Andreya Kalyana de Oliveira

    2012-09-01

    Full Text Available O objetivo neste trabalho foi avaliar o potencial alelopático do extrato de cascas e de folhas juazeiro (Ziziphus joazeiro Mart. sobre as sementes de alface (Lactuca sativa L.. Foram conduzidos dois experimentos, em ambos foi usado o delineamento inteiramente casualizado. No primeiro foram realizadas quatro repetições e cinco tratamentos (EF - extrato de folhas a 100 ºC, EF - extrato de folhas a 25 ºC, EC - extrato de cascas a 100 ºC, EC - extrato de cascas a 25 ºC, e água destilada. No segundo foram realizados cinco tratamentos (0%, 25%, 50%, 75% e 100% de concentração do extrato bruto e quatro repetições com 20 sementes de alface. O extrato bruto foi obtido após a agitação das cascas e das folhas com água em liquidificador utilizando-se 50 g de material para 500 ml de água. Os resultados mostraram efeito do extrato dependendo da concentração. Os extratos brutos e diluídos de Z. joazeiro não afetaram a germinação, mas nas maiores concentrações causaram elevada porcentagem de plântulas anormais e o extrato de folhas e de cascas extraído a 100 ºC reduziram o crescimento da raiz e parte aérea. Extratos aquosos de cascas e de folhas de Z. juazeiro apresentam efeito fitotóxico na germinação de sementes de L. sativa.This study aimed to identify the allelopathic activity of extracts from Ziziphus joazeiro bark and leaves on the seeds of lettuce (Lactuca sativa. Two experiments were conducted, which both used a randomized design. The first four replicates were the following treatments (EF-extract of leaves at 100ºC, EF-extract of leaves at 25ºC, EC-extract of bark at 100ºC, EC-extract of bark at 25ºC, and distilled water. The next five treatments used 0%, 25%, 50%, 75% and 100% concentrations of the crude extract and four replicates of 20 seeds. The crude extract was obtained after the bark and leaves were blended with water (50 g of material for 500 ml of water. The results showed that the effect of the extract

  19. Prospective Retinal and Optic Nerve Vitrectomy Evaluation (PROVE study: findings at 3 months

    Directory of Open Access Journals (Sweden)

    Reddy RK

    2013-09-01

    Full Text Available Rahul K Reddy,1 Maziar Lalezary,1 Stephen J Kim,1 Jeffrey A Kammer,1 Rachel W Kuchtey,1 Edward F Cherney,1 Franco M Recchia,2 Karen M Joos,1 Anita Agarwal,1 Janice C Law11Department of Ophthalmology, Vanderbilt University School of Medicine, Nashville, TN, USA; 2Tennessee Retina, PC, Nashville, TN, USABackground: The purpose of this paper is to report the 3-month findings of the Prospective Retinal and Optic Nerve Vitrectomy Evaluation (PROVE study.Methods: Eighty eyes of 40 participants undergoing vitrectomy were enrolled. Participants underwent baseline evaluation of the study (surgical and fellow (control eye that included: intraocular pressure, central corneal thickness, gonioscopy, cup-to-disc ratio measurement, color fundus and optic disc photography, automated perimetry, and optical coherence tomography of the macula and optic nerve. Evaluation was repeated at 3 months. Main outcome measures were changes in macula and retinal nerve fiber layer (RNFL thickness and intraocular pressure.Results: All participants completed follow-up. Mean cup-to-disc ratio of study and fellow eyes at baseline was 0.43 ± 0.2 and 0.46 ± 0.2, respectively, and 13% of participants had undiagnosed narrow angles. There was no significant change in intraocular pressure, cup-to-disc ratio, or pattern standard deviation in study eyes compared with baseline or fellow eyes at 3 months. Vision improved in all study eyes at 3 months compared with baseline (P = 0.013, but remained significantly worse than fellow eyes (P < 0.001. Central subfield and temporal peripapillary RNFL thickness were significantly greater in eyes with epiretinal membrane (P < 0.05, and resolution after surgery correlated with visual improvement (P < 0.05.Conclusion: The 3-month results do not indicate any increased risk for open-angle glaucoma but suggest that a relatively high percentage of eyes may be at risk of angle closure glaucoma. Temporal RNFL thickness and central subfield were increased

  20. An Analysis of the Extratropical Transition of Hurricane Arthur (2014) from a JPSS Proving Ground Perspective

    Science.gov (United States)

    Folmer, M. J.; Berndt, E.; Halverson, J. B.; Dunion, J. P.; Goldberg, M.

    2015-12-01

    As part of the GOES-R and JPSS Satellite Proving Grounds, multiple proxy and operational products were available to analyze and forecast the complex evolution of Hurricane Arthur (2014). The National Hurricane Center, Ocean Prediction Center, Weather Prediction Center, and NESDIS Satellite Analysis Branch were able to monitor the tropical and extratropical transition of Arthur using various convective and red, green, blue (RGB) products that have been introduced in recent years. During the extratropical transition, the Air Mass RGB (AM RGB) product and AIRS/CrIS ozone products were available as a compliment to water vapor imagery to identify the upper-level low with associated stratospheric drying that absorbed much of Arthur's energy. The AM RGB product provides forecasters with an enhanced view of various air masses that are combined into a single image and can help differentiate between possible stratospheric/tropospheric interactions, moist tropical air masses, and cool, continental/maritime air masses. Even though this product provides a wealth of qualitative information about the horizontal distribution of synoptic features, forecasters are also interested in more quantitative information such as the vertical distribution of temperature, moisture, and ozone which impact the coloring of the resulting AM RGB. Currently, NOAA Unique CrIS/ATMS Processing System (NUCAPS) temperature and moisture soundings are available in AWIPS-II as a point-based display. Traditionally, soundings are used to anticipate and forecast severe convection, however unique and valuable information can be gained from soundings for other forecasting applications, such as extratropical transition, especially in data sparse regions. Additional research has been conducted to look at how NUCAPS soundings might help forecasters identify the pre-extratropical transition environment, leading to earlier diagnosis and better public advisories. NUCAPS soundings, AIRS soundings, NOAA G-IV GPS

  1. GOES-R Proving Ground Activities at the NASA Short-Term Prediction Research and Transition (SPoRT) Center

    Science.gov (United States)

    Molthan, Andrew

    2011-01-01

    SPoRT is actively involved in GOES-R Proving Ground activities in a number of ways: (1) Applying the paradigm of product development, user training, and interaction to foster interaction with end users at NOAA forecast offices national centers. (2) Providing unique capabilities in collaboration with other GOES-R Proving Ground partners (a) Hybrid GOES-MODIS imagery (b) Pseudo-GLM via regional lightning mapping arrays (c) Developing new RGB imagery from EUMETSAT guidelines

  2. Optimization of ground-water withdrawal at the old O-Field area, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Banks, William S.L.; Dillow, Jonathan J.A.

    2001-01-01

    The U.S. Army disposed of chemical agents, laboratory materials, and unexploded ordnance at the Old O-Field landfill at Aberdeen Proving Ground, Maryland, beginning prior to World War II and continuing until at least the 1950?s. Soil, ground water, surface water, and wetland sediments in the Old O-Field area were contaminated by the disposal of these materials. The site is in the Atlantic Coastal Plain, and is characterized by a complex series of Pleistocene and Holocene sediments formed in various fluvial, estuarine, and marine-marginal hydrogeologic environments. A previously constructed transient finite-difference ground-water-flow model was used to simulate ground-water flow and the effects of a pump-and-treat remediation system designed to prevent contaminated ground water from flowing into Watson Creek (a tidal estuary and a tributary to the Gunpowder River). The remediation system consists of 14 extraction wells located between the Old O-Field landfill and Watson Creek.Linear programming techniques were applied to the results of the flow-model simulations to identify optimal pumping strategies for the remediation system. The optimal management objective is to minimize total withdrawal from the water-table aquifer, while adhering to the following constraints: (1) ground-water flow from the landfill should be prevented from reaching Watson Creek, (2) no extraction pump should be operated at a rate that exceeds its capacity, and (3) no extraction pump should be operated at a rate below its minimum capacity, the minimum rate at which an Old O-Field pump can function. Water withdrawal is minimized by varying the rate and frequency of pumping at each of the 14 extraction wells over time. This minimizes the costs of both pumping and water treatment, thus providing the least-cost remediation alternative while simultaneously meeting all operating constraints.The optimal strategy identified using this objective and constraint set involved operating 13 of the 14

  3. Simulation of ground-water flow and transport of chlorinated hydrocarbons at Graces Quarters, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Tenbus, Frederick J.; Fleck, William B.

    2001-01-01

    Military activity at Graces Quarters, a former open-air chemical-agent facility at Aberdeen Proving Ground, Maryland, has resulted in ground-water contamination by chlorinated hydrocarbons. As part of a ground-water remediation feasibility study, a three-dimensional model was constructed to simulate transport of four chlorinated hydrocarbons (1,1,2,2-tetrachloroethane, trichloroethene, carbon tetrachloride, and chloroform) that are components of a contaminant plume in the surficial and middle aquifers underlying the east-central part of Graces Quarters. The model was calibrated to steady-state hydraulic head at 58 observation wells and to the concentration of 1,1,2,2-tetrachloroethane in 58 observation wells and 101direct-push probe samples from the mid-1990s. Simulations using the same basic model with minor adjustments were then run for each of the other plume constituents. The error statistics between the simulated and measured concentrations of each of the constituents compared favorably to the error statisticst,1,2,2-tetrachloroethane calibration. Model simulations were used in conjunction with contaminant concentration data to examine the sources and degradation of the plume constituents. It was determined from this that mixed contaminant sources with no ambient degradation was the best approach for simulating multi-species solute transport at the site. Forward simulations were run to show potential solute transport 30 years and 100 years into the future with and without source removal. Although forward simulations are subject to uncertainty, they can be useful for illustrating various aspects of the conceptual model and its implementation. The forward simulation with no source removal indicates that contaminants would spread throughout various parts of the surficial and middle aquifers, with the100-year simulation showing potential discharge areas in either the marshes at the end of the Graces Quarters peninsula or just offshore in the estuaries. The

  4. Chemical use

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a summary of research and activities related to chemical use on Neal Smith National Wildlife Refuge between 1992 and 2009. The chemicals used on the Refuge...

  5. The U.S. Army Occupational and Environmental Medicine Residency at Aberdeen Proving Ground, Maryland: 1960-1996.

    Science.gov (United States)

    Gaydos, Joel C; Mallon, Timothy M; Rice, William A

    2016-11-01

    Reorganization of the Army and critical assessment of Army Graduate Medical Education programs prompted the Occupational and Environmental Medicine (OEM) Consultant to the Army Surgeon General to initiate a review of current Army OEM residency training. Available information indicated the Army OEM residency at Aberdeen Proving Ground, MD, was the first and longest operating Army OEM residency. Describing this residency was identified as the first step in the review, with the objectives of determining why the residency was started and sustained and its relevance to the needs of the Army. Records possibly related to the residency were reviewed, starting with 1954 since certification of physicians as Occupation Medicine specialists began in 1955. Interviews were conducted with selected physicians who had strong affiliations with the Army residency and the practice of Army OEM. The Army OEM residency began in 1960 and closed in 1996 with the transfer of Army OEM residency training to the Uniformed Services University of the Health Sciences, Bethesda, MD. Over 36 years, 47 uniformed residency graduates were identified; 44 were from the Army. Forty graduated between 1982 and 1996. The OEM residency was part of a dynamic cycle. Uniformed OEM leaders identified the knowledge and skills required of military OEM physicians and where these people should be stationed in the global Army. Rotations at military sites to acquire the needed knowledge and skills were integrated into the residency. Residency graduates were assigned to positions where they were needed. Having uniformed residents and preceptors facilitated the development of trust with military leaders and access to areas where OEM physician skills and knowledge could have a positive impact. Early reports indicated the residency was important in recruiting and retaining OEM physicians, with emphasis placed on supporting the Army industrial base. The late 1970s into the 1990s was a more dynamic period. There was

  6. Focused feasibility study for surface soil at the main pits and pushout area, J-field toxic burning pits area, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Patton, T.; Benioff, P.; Biang, C.; Butler, J. [and others

    1996-06-01

    The Environmental Management Division of Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation and feasibility study of the J-Field area at APG pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act, as amended (CERCLA). J-Field is located within the Edgewood Area of APG in Harford County, Maryland. Since World War II, activities in the Edgewood Area have included the development, manufacture, testing, and destruction of chemical agents and munitions. These materials were destroyed at J-Field by open burning/open detonation. Portions of J-Field continue to be used for the detonation and disposal of unexploded ordnance (UXO) by open burning/open detonation under authority of the Resource Conservation and Recovery Act.

  7. Hydrogeology and water quality in the Graces Quarters area of Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Tenbus, Frederick J.; Blomquist, Joel D.

    1995-01-01

    Graces Quarters was used for open-air testing of chemical-warfare agents from the late 1940's until 1971. Testing and disposal activities have resulted in the contamination of ground water and surface water. The hydrogeology and water quality were examined at three test areas, four disposal sites, a bunker, and a service area on Graces Quarters. Methods of investigation included surface and borehole geophysics, water-quality sampling, water- level measurement, and hydrologic testing. The hydrogeologic framework is complex and consists of a discontinuous surficial aquifer, one or more upper confining units, and a confined aquifer system. Directions of ground-water flow vary spatially and temporally, and results of site investigations show that ground-water flow is controlled by the geology of the area. The ground water and surface water at Graces Quarters generally are unmineralized; the ground water is mildly acidic (median pH is 5.38) and poorly buffered. Inorganic constituents in excess of certain Federal drinking-water regulations and ambient water-quality criteria were detected at some sites, but they probably were present naturally. Volatile and semivolatile organic com- pounds were detected in the ground water and surface water at seven of the nine sites that were investi- gated. Concentrations of organic compounds at two of the nine sites exceeded Federal drinking-water regulations. Volatile compounds in concentrations as high as 6,000 m/L (micrograms per liter) were detected in the ground water at the site known as the primary test area. Concentrations of volatile compounds detected in the other areas ranged from 0.57 to 17 m/L.

  8. Users manual on database of the Piping Reliability Proving Tests at the Japan Atomic Energy Research Institute

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    Japan Atomic Energy Research Institute(JAERI) conducted Piping Reliability Proving Tests from 1975 to 1992 based upon the contracts between JAERI and Science and Technology Agency of Japan under the auspices of the special account law for electric power development promotion. The purposes of those tests are to prove the structural reliability of the primary cooling piping constituting a part of the pressure boundary in the water reactor power plants. The tests with large experimental facilities had ended already in 1990. After that piping reliability analysis by the probabilistic method followed until 1992. This report describes the users manual on databases about the test results using the large experimental facilities. Objectives of the piping reliability proving tests are to prove that the primary piping of the water reactor (1) be reliable throughout the service period, (2) have no possibility of rupture, (3) bring no detrimental influence on the surrounding instrumentations or equipments near the break location. The research activities using large scale piping test facilities are described. The present report does the database about the test results pairing the former report. With these two reports, all the feature of Piping Reliability Proving Tests is made clear. Briefings of the tests are described also written in Japanese or English. (author)

  9. Epigenetics and environmental chemicals.

    Science.gov (United States)

    Baccarelli, Andrea; Bollati, Valentina

    2009-04-01

    Epigenetics investigates heritable changes in gene expression occurring without changes in DNA sequence. Several epigenetic mechanisms, including DNA methylation, histone modifications, and microRNA expression, can change genome function under exogenous influence. Here, we review current evidence indicating that epigenetic alterations mediate toxicity from environmental chemicals. In-vitro, animal, and human investigations have identified several classes of environmental chemicals that modify epigenetic marks, including metals (cadmium, arsenic, nickel, chromium, and methylmercury), peroxisome proliferators (trichloroethylene, dichloroacetic acid, and TCA), air pollutants (particulate matter, black carbon, and benzene), and endocrine-disrupting/reproductive toxicants (diethylstilbestrol, bisphenol A, persistent organic pollutants, and dioxin). Most studies conducted so far have been centered on DNA methylation, whereas only a few investigations have studied environmental chemicals in relation to histone modifications and microRNA. For several exposures, it has been proved that chemicals can alter epigenetic marks, and that the same or similar epigenetic alterations can be found in patients with the disease of concern or in diseased tissues. Future prospective investigations are needed to determine whether exposed individuals develop epigenetic alterations over time and, in turn, which such alterations increase the risk of disease. Also, further research is needed to determine whether environmental epigenetic changes are transmitted transgenerationally.

  10. [Chemical weapons and chemical terrorism].

    Science.gov (United States)

    Nakamura, Katsumi

    2005-10-01

    Chemical Weapons are kind of Weapons of Mass Destruction (WMD). They were used large quantities in WWI. Historically, large quantities usage like WWI was not recorded, but small usage has appeared now and then. Chemical weapons are so called "Nuclear weapon for poor countrys" because it's very easy to produce/possession being possible. They are categorized (1) Nerve Agents, (2) Blister Agents, (3) Cyanide (blood) Agents, (4) Pulmonary Agents, (5) Incapacitating Agents (6) Tear Agents from the viewpoint of human body interaction. In 1997 the Chemical Weapons Convention has taken effect. It prohibits chemical weapons development/production, and Organization for the Prohibition of Chemical Weapons (OPCW) verification regime contributes to the chemical weapons disposal. But possibility of possession/use of weapons of mass destruction by terrorist group represented in one by Matsumoto and Tokyo Subway Sarin Attack, So new chemical terrorism countermeasures are necessary.

  11. E-squared nine do-it-yourself energy experiments that prove your thoughts create your reality

    CERN Document Server

    Grout, Pam

    2013-01-01

    E-Squared is a lab manual with simple experiments to prove once and for all that there really is a good, loving, totally hip force in the universe. Rather than take it on faith, you are invited to conduct ten 48-hour experiments to prove each of the principles in this book. Yes, you read that right. It says prove. The experiments, each of which can be conducted with absolutely no money and very little time expenditure, demonstrate that spiritual principles are as dependable as gravity, as consistent as Newton's 2nd law of motion. For years, you've been hoping and praying that spiritual principles are true. Now, you can know.

  12. Chemical and biological studies of Microgramma vacciniifolia (Langsd. and Fisch.) Copel (Polypodiaceae); Estudos quimicos e biologicos de Microgramma vacciniifolia (Langsd. and Fisch.) Copel (Polypodiaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Peres, Marize T.L.P.; Simionatto, Euclesio; Hess, Sonia C.; Bonani, Vanderlea F.L.; Candido, Ana C.S.; Castelli, Caroline [Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Dept. de Hidraulica e Transportes; Poppi, Nilva R.; Honda, Neli K. [Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Dept. de Quimica; Cardoso, Claudia A.L.; Faccenda, Odival [Universidade Estadual de Mato Grosso do Sul (UFMS), Dourados, MS (Brazil). Dept. de Quimica e de Computacao

    2009-07-01

    Chemical studies with aerial parts of Microgramma vacciniifolia (Langsd. and Fisch.) Copel. afforded {beta}-sitosterol, hopan-22-ol, 6-metoxiapinenin-7-O-{beta}-D-allopyranoside and a mixture containing ethyl esters of carboxylic acids. The structures of the compounds were elucidated by spectroscopy and GC-MS analysis. The total phenolics contents of the crude extract and fractions were determined by Folin-Ciocalteau method. The antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH). The AcOEt fraction showed better activity in DPPH assay (9.9 {+-} 0.03 {mu}g/mL), and presented also higher contents of the total phenolic (93.60 {+-} 1.11 {mu}g/mg). Antimicrobial and allelopathic effects of the crude ethanolic extract and fractions also were evaluated. In addition, the combination of biological activities was discussed. (author)

  13. Chemical Composition

    Science.gov (United States)

    May, Willie; Cavanagh, Richard; Turk, Gregory; Winchester, Michael; Travis, John; Smith, Melody; Derose, Paul; Choquette, Steven; Kramer, Gary; Sieber, John; Greenberg, Robert; Lindstrom, Richard; Lamaze, George; Zeisler, Rolf; Schantz, Michele; Sander, Lane; Phinney, Karen; Welch, Michael; Vetter, Thomas; Pratt, Kenneth; Scott, John; Small, John; Wight, Scott; Stranick, Stephan

    Measurements of the chemical compositions of materials and the levels of certain substances in them are vital when assessing and improving public health, safety and the environment, are necessary to ensure trade equity, and are required when monitoring and improving industrial products and services. Chemical measurements play a crucial role in most areas of the economy, including healthcare, food and nutrition, agriculture, environmental technologies, chemicals and materials, instrumentation, electronics, forensics, energy, and transportation.

  14. A case of chemical assault in Hong Kong (case report

    Directory of Open Access Journals (Sweden)

    B.C. Leung

    2015-01-01

    Conclusion: The benefits of urgent reduction in chemical load is intuitively obvious, and by shaving tangentially to bleeding, vital tissue is preserved. Trying to prove benefit in terms of an RCT is however ethically challenging.

  15. Chemical oceanography

    National Research Council Canada - National Science Library

    Millero, F.J

    1996-01-01

    Chemical Oceanography presents a comprehensive examination of the chemistry of oceans through discussions of such topics as descriptive physical oceanography, the composition of seawater and the major...

  16. New and improved methods for monitoring air quality and the terrestrial environment: Applications at Aberdeen Proving Ground-Edgewood area. Annual report, 1 April--14 November 1997

    Energy Technology Data Exchange (ETDEWEB)

    Bromenshenk, J.J.; Smith, G.C.

    1998-03-01

    Honey bees (Apis mellifera L.) have been shown to be multi-media monitors of chemical exposures and resultant effects. This five-year project has developed an automated system to assess in real-time colony behavioral responses to stressors, both anthropogenic and natural, including inclement weather. Field trials at the Aberdeen Proving Ground-Edgewood included the Old O Field and J field landfills, the Canal Creek and Bush River areas, and a Churchville, MD reference site. Preliminary results show varying concentrations of bioavailable inorganic elements and chlorinated hydrocarbons in bee colonies from all Maryland sites. Industrial solvents in the air inside beehives exhibited the greatest between site differences, with the highest levels occurring in hives near landfills at Old O Field, J Field, and at some sites in the Bush River and Canal Creek areas. Compared to 1996, the 1997 levels of solvents in Old O Field hives decreased by an order of magnitude, and colony performance significantly improved, probably as a consequence of capping the landfill. Recent chemical monitoring accomplishments include development of a new apparatus to quantitatively calibrate TD/GC/MS analysis, a QA/QC assessment of factors that limit the precision of these analyses, and confirmation of transport of aqueous contaminants into the hive. Real-time effects monitoring advances include development of an extensive array of software tools for automated data display, inspection, and numerical analysis and the ability to deliver data from remote locations in real time through Internet or Intranet connections.

  17. Proceedings of the Annual Chemical Defense Bioscience Review (4th) Held at Aberdeen Proving Ground, Maryland on 30 May-1 June 1984

    Science.gov (United States)

    1984-06-01

    depression was accompanied by a persistent d oolarization of the endplate region. Recovery from depresion was observed after a 10 sec quiescent period...molecular forms (10) of human brain AChE have been reported in several neurological or genetic disorders, such as Alzheimer disease (11) or Down’s...Drosophila - . metanogaoteT. The genetics of the nervous system in Drosophila is well-characterized, and various mutants are available in which the

  18. Implementing an energetic life cycle analysis to prove the benefits of lignocellulosic feedstocks with protein separation for the chemical industry from the existing bioethanol industry

    NARCIS (Netherlands)

    Brehmer, B.; Sanders, J.P.M.

    2009-01-01

    The biofuel ethanol is currently being produced in large quantities from corn in the US and from wheat in the EU and further capacity expansion is expected. Relying on the so-called 1st generation technology, only the starch contained in the edible portion of the crops (ears/grains) is subjected to

  19. Chemical intolerance

    DEFF Research Database (Denmark)

    Dantoft, Thomas Meinertz; Andersson, Linus; Nordin, Steven

    2015-01-01

    Chemical intolerance (CI) is a term used to describe a condition in which the sufferer experiences a complex array of recurrent unspecific symptoms attributed to low-level chemical exposure that most people regard as unproblematic. Severe CI constitutes the distinguishing feature of multiple...

  20. Chemical modification

    Science.gov (United States)

    R. M. Rowell

    2004-01-01

    Wood is a hygroscopic resource that was designed to perform, in nature, in a wet environment. Nature is programmed to recycle wood in a timely way through biological, thermal, aqueous, photochemical, chemical, and mechanical degradations. In simple terms, nature builds wood from carbon dioxide and water and has all the tools to recycle it back to the starting chemicals...

  1. Allelopathic effect of sunflower water extract on the germination of soybean and hairy beggartick / Efeito alelopático do extrato aquoso de folhas de girassol sobre a germinação de soja e picão-preto

    Directory of Open Access Journals (Sweden)

    Raquel Leszczynski

    2010-07-01

    Full Text Available The aim of this work was to evaluate the allelopathic effect of water extract from sunflower fresh leaves on the germination and initial development of conventional and transgenic soybean cultivars, and of the invasive hairy beggartick (Bidens pilosa L.. Experiments were carried out at Laboratory of Plant Physiology, Universidade Estadual do Oeste do Paraná, in 2007. Fresh leaves from sunflower were ground in a blender at the proportion 200g/1L distilled water, resulting in crude extract (100%, in which pH was measured. Dilutions of 80%, 60%, 40% and 20% were done from the crude extract, and only distilled water was used as control. Statistical analysis (Tukey 5% probability indicated that only the highest extract concentrations (60%, 80% and 100% influenced the analyzed parameters for conventional and transgenic soybean. Beggartick seeds, however, had germination percentage completely inhibited when 40% water extract was applied, which indicates that sunflower straw could be used as a natural herbicide. Nevertheless, field studies must be carried out to prove such effect.O objetivo deste trabalho foi avaliar o efeito alelopático do extrato aquoso de folhas frescas de girassol sobre a germinação das sementes e desenvolvimento inicial das plântulas das cultivares de soja (Glycine max (L. Merrill convencional (CD232, transgênica (CD213RR e uma de suas invasoras, o picão preto (Bidens pilosa L.. Os experimentos foram realizados no Laboratório de Fisiologia Vegetal da Universidade Estadual do Oeste do Paraná no ano de 2007. As folhas de girassol colhidas na época da floração foram trituradas com o auxílio de um liquidificador na proporção de 200g/1L de água destilada resultando no extrato bruto (100%. A partir do extrato bruto foram feitas as diluições de 80%, 60%, 40% e 20%, sendo utilizado como testemunha apenas água destilada. Após análise estatística (Tukey 5% de probabilidade, pode-se verificar que o extrato aquoso das

  2. Efeito de cascas de café e de arroz dispostas nas camadas do solo sobre a germinação e o crescimento inicial do caruru-de-mancha Allelopathic effect of coffee and rice husks arranged in soil layers on the germination and initial growth of Amaranthus viridis

    Directory of Open Access Journals (Sweden)

    J.C.F. Santos

    2001-08-01

    Full Text Available Estudos dos efeitos dos resíduos de plantas pela utilização de coberturas mortas no controle das plantas daninhas têm apresentado dificuldade de determinar a diferenciação entre alelopatia e competição. Atualmente, muitas pesquisas têm se referido a critérios que propõem evidência à alelopatia. Este trabalho em casa de vegetação visou determinar os efeitos alelopáticos proporcionados pelas cascas de café e de arroz sobre o caruru-de-mancha, por meio das disposições desses resíduos nas camadas do solo. O delineamento experimental foi o de blocos casualizados, com os tratamentos em quatro repetições e organizados num esquema fatorial (3x3, sendo cascas de café e de arroz e vermiculita expandida como um fator e suas disposições, com resíduos depositados no topo, incorporados na superfície e incorporados no fundo, como segundo fator. Como testemunha foi usado um tratamento adicional sem cobertura. De modo geral, resíduos de cascas proporcionaram inibição da germinação e estímulo ao crescimento do caruru-de-mancha. A casca de arroz proporcionou menor índice de velocidade de emergência e germinação de sementes do que a casca de café. A casca de café depositada no topo proporcionou maior crescimento e maior peso da matéria seca do caruru-de-mancha, seguido pela mesma casca incorporada na superfície do solo.Studies of plant residue effects involving mulches to control weeds in perennial crops are difficult to carry out due to the need to differentiate between allelopathy and competition. Many researches, nowadays, refer to criteria proving allelopathy. This work was established under greenhouse conditions to determine the allelopathic effects of coffee and rice husks on Amaranthus viridis through their arrangements in soil layers. The experimental design was a randomized block with four replications, arranged in a 3 x 3 factorial scheme, with coffee and rice husks and expanded vermiculite being one factor and

  3. Chemical explosive stimulation

    Energy Technology Data Exchange (ETDEWEB)

    LaRocca, S.J.; McLamore, R.T.; Spencer, A.M. Jr.

    1974-02-01

    A safe, reliable chemical explosive fracturing process has been demonstrated and prototype equipment for its use has been successfully field tested.Called the Astro-Flow II process, it utilizes a highly energetic, hydrazine-based family of liquid explosives known as Astrolite. A unique property of these explosives is that they can be divided into 2 nonexplosive pumpable components that can be handled safely. The 2 components are pumped independently and simultaneously into the well and blended together downhole to form the explosive which is circulated in place or displaced into formation fractures. Explosive hazards to surface equipment and personnel are eliminated. Extensive testing of the physical and chemical stability of the mixed explosive indicates that the material can be reliable and safely used at elevated temperatures, pressures, and in the adverse chemical environment often found in deep oil and gas wells. These tests of prototype equipment proved that the 2 components could be independently pumped with precision and blended together to form the desired explosive formulation. How the process works is described.

  4. Effects on the Liver of Chemicals Encountered in the Workplace

    OpenAIRE

    Pond, Susan M.

    1982-01-01

    The liver plays a central role in toxicology. It is the primary organ of detoxification and elimination by metabolism of many chemicals. Many workplace chemicals can affect the liver in animals; fewer have been proved to do so in humans. The diverse hepatic effects observed in humans from occupational exposure to chemicals range from fatty infiltration, acute hepatitis and cholestasis to cirrhosis and angiosarcoma. Three important workplace chemicals, prototypes for the toxicities of many oth...

  5. Hazardous Chemicals

    Centers for Disease Control (CDC) Podcasts

    2007-04-10

    Chemicals are a part of our daily lives, providing many products and modern conveniences. With more than three decades of experience, The Centers for Disease Control and Prevention (CDC) has been in the forefront of efforts to protect and assess people's exposure to environmental and hazardous chemicals. This report provides information about hazardous chemicals and useful tips on how to protect you and your family from harmful exposure.  Created: 4/10/2007 by CDC National Center for Environmental Health.   Date Released: 4/13/2007.

  6. An inverse relationship between allelopathic activity and salt tolerance in suspension cultures of three mangrove species, Sonneratia alba, S. caseolaris and S. ovata: development of a bioassay method for allelopathy, the protoplast co-culture method.

    Science.gov (United States)

    Hasegawa, Ai; Oyanagi, Tomoya; Minagawa, Reiko; Fujii, Yoshiharu; Sasamoto, Hamako

    2014-11-01

    A bioassay method for allelopathy, the 'protoplast co-culture method' was developed to study the relationship between salt tolerance and allelopathy of three mangrove species, Sonneratia alba, S. caseolaris, and S. ovata. Plants of S. alba grow in the seaward-side high salinity region and plants of the latter two species grow in upstream-side regions of a mangrove forest, respectively. Effects of five sea salts (NaCl, KCl, MgCl2, MgSO4 and CaCl2) on the growth of the suspension cells of the latter two species were first investigated by a small-scale method using 24-well culture plates. S. ovata cells showed higher tolerance than S. caseolaris cells to NaCl and other salts, but were not as halophilic as S. alba cells. Protoplasts isolated from suspension cells were co-cultured with lettuce protoplasts in Murashige and Skoog's (MS) basal medium containing 1 μM 2,4-dichlorophenoxyacetic acid, 0.1 μM benzyladenine, 3% sucrose and 0.6-0.8 M osmoticum. S. caseolaris protoplasts had a higher inhibitory effect on lettuce protoplast cell divisions than S. alba protoplasts at any lettuce protoplast density, and the effect of S. ovata was intermediate between the two. These results were similar to those obtained from a different in vitro bioassay method for allelopathy, the 'sandwich method' with dried leaves. The inverse relationship between allelopathic activity and salt tolerance in suspension cells of Sonneratia mangroves is discussed.

  7. Preliminary assessment of microbial communities and biodegradation of chlorinated volatile organic compounds in wetlands at Cluster 13, Lauderick Creek area, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Lorah, Michelle M.; Voytek, Mary A.; Spencer, Tracey A.

    2003-01-01

    A preliminary assessment of the microbial communities and biodegradation processes for chlorinated volatile organic compounds was con-ducted by the U.S. Geological Survey in wetlands at the Cluster 13, Lauderick Creek area at Aberdeen Proving Ground, Maryland. The U.S. Geological Survey collected wetland sediment samples from 11 sites in the Lauderick Creek area for microbial analyses, and used existing data to evaluate biodegradation processes and rates. The bacterial and methanogen communities in the Lauderick Creek wetland sediments were similar to those observed in a previous U.S. Geological Survey study at the West Branch Canal Creek wet-land area, Aberdeen Proving Ground. Evaluation of the degradation rate of 1,1,2,2-tetrachloroethane and the daughter compounds produced also showed similar results for the two wetlands. How-ever, a vertical profile of contaminant concentra-tions in the wetlands was available at only one site in the Lauderick Creek area, and flow velocities in the wetland sediment are unknown. To better evaluate natural attenuation processes and rates in the wetland sediments at Lauderick Creek, chemi-cal and hydrologic measurements are needed along ground-water flowpaths in the wetland at additional sites and during different seasons. Nat-ural attenuation in the wetlands, enhanced biore-mediation, and constructed wetlands could be feasible remediation methods for the chlorinated volatile organic compounds discharging in the Lauderick Creek area. The similarities in the microbial communities and biodegradation pro-cesses at the Lauderick Creek and West Branch Canal Creek areas indicate that enhanced bioreme-diation techniques currently being developed for the West Branch Canal Creek wetland area would be transferable to this area.

  8. The Relevance of Marine Chemical Ecology to Plankton and Ecosystem Function: An Emerging Field

    Science.gov (United States)

    Ianora, Adrianna; Bentley, Matthew G.; Caldwell, Gary S.; Casotti, Raffaella; Cembella, Allan D.; Engström-Öst, Jonna; Halsband, Claudia; Sonnenschein, Eva; Legrand, Catherine; Llewellyn, Carole A.; Paldavičienë, Aistë; Pilkaityte, Renata; Pohnert, Georg; Razinkovas, Arturas; Romano, Giovanna; Tillmann, Urban; Vaiciute, Diana

    2011-01-01

    Marine chemical ecology comprises the study of the production and interaction of bioactive molecules affecting organism behavior and function. Here we focus on bioactive compounds and interactions associated with phytoplankton, particularly bloom-forming diatoms, prymnesiophytes and dinoflagellates. Planktonic bioactive metabolites are structurally and functionally diverse and some may have multiple simultaneous functions including roles in chemical defense (antipredator, allelopathic and antibacterial compounds), and/or cell-to-cell signaling (e.g., polyunsaturated aldehydes (PUAs) of diatoms). Among inducible chemical defenses in response to grazing, there is high species-specific variability in the effects on grazers, ranging from severe physical incapacitation and/or death to no apparent physiological response, depending on predator susceptibility and detoxification capability. Most bioactive compounds are present in very low concentrations, in both the producing organism and the surrounding aqueous medium. Furthermore, bioactivity may be subject to synergistic interactions with other natural and anthropogenic environmental toxicants. Most, if not all phycotoxins are classic secondary metabolites, but many other bioactive metabolites are simple molecules derived from primary metabolism (e.g., PUAs in diatoms, dimethylsulfoniopropionate (DMSP) in prymnesiophytes). Producing cells do not seem to suffer physiological impact due to their synthesis. Functional genome sequence data and gene expression analysis will provide insights into regulatory and metabolic pathways in producer organisms, as well as identification of mechanisms of action in target organisms. Understanding chemical ecological responses to environmental triggers and chemically-mediated species interactions will help define crucial chemical and molecular processes that help maintain biodiversity and ecosystem functionality. PMID:22131962

  9. The Relevance of Marine Chemical Ecology to Plankton and Ecosystem Function: An Emerging Field

    Directory of Open Access Journals (Sweden)

    Urban Tillmann

    2011-09-01

    Full Text Available Marine chemical ecology comprises the study of the production and interaction of bioactive molecules affecting organism behavior and function. Here we focus on bioactive compounds and interactions associated with phytoplankton, particularly bloom-forming diatoms, prymnesiophytes and dinoflagellates. Planktonic bioactive metabolites are structurally and functionally diverse and some may have multiple simultaneous functions including roles in chemical defense (antipredator, allelopathic and antibacterial compounds, and/or cell-to-cell signaling (e.g., polyunsaturated aldehydes (PUAs of diatoms. Among inducible chemical defenses in response to grazing, there is high species-specific variability in the effects on grazers, ranging from severe physical incapacitation and/or death to no apparent physiological response, depending on predator susceptibility and detoxification capability. Most bioactive compounds are present in very low concentrations, in both the producing organism and the surrounding aqueous medium. Furthermore, bioactivity may be subject to synergistic interactions with other natural and anthropogenic environmental toxicants. Most, if not all phycotoxins are classic secondary metabolites, but many other bioactive metabolites are simple molecules derived from primary metabolism (e.g., PUAs in diatoms, dimethylsulfoniopropionate (DMSP in prymnesiophytes. Producing cells do not seem to suffer physiological impact due to their synthesis. Functional genome sequence data and gene expression analysis will provide insights into regulatory and metabolic pathways in producer organisms, as well as identification of mechanisms of action in target organisms. Understanding chemical ecological responses to environmental triggers and chemically-mediated species interactions will help define crucial chemical and molecular processes that help maintain biodiversity and ecosystem functionality.

  10. Chemical ecology of marine angiosperms: opportunities at the interface of marine and terrestrial systems.

    Science.gov (United States)

    Sieg, R Drew; Kubanek, Julia

    2013-06-01

    This review examines the state of the field for chemically mediated interactions involving marine angiosperms (seagrasses, mangroves, and salt marsh angiosperms). Small-scale interactions among these plants and their herbivores, pathogens, fouling organisms, and competitors are explored, as are community-level effects of plant secondary metabolites. At larger spatial scales, secondary metabolites from marine angiosperms function as reliable cues for larval settlement, molting, or habitat selection by fish and invertebrates, and can influence community structure and ecosystem function. Several recent studies illustrate the importance of chemical defenses from these plants that deter feeding by herbivores and infection by pathogens, but the extent to which allelopathic compounds kill or inhibit the growth of competitors is less clear. While some phenolic compounds such as ferulic acid and caffeic acid act as critical defenses against herbivores and pathogens, we find that a high total concentration of phenolic compounds within bulk plant tissues is not a strong predictor of defense. Residual chemical defenses prevent shredding or degradation of plant detritus by detritivores and microbes, delaying the time before plant matter can enter the microbial loop. Mangroves, marsh plants, and seagrasses remain plentiful sources of new natural products, but ecological functions are known for only a small proportion of these compounds. As new analytical techniques are incorporated into ecological studies, opportunities are emerging for chemical ecologists to test how subtle environmental cues affect the production and release of marine angiosperm chemical defenses or signaling molecules. Throughout this review, we point to areas for future study, highlighting opportunities for new directions in chemical ecology that will advance our understanding of ecological interactions in these valuable ecosystems.

  11. Chemical Peel

    Science.gov (United States)

    ... complications in chemical peeling. Journal of Cutaneous and Aesthetic Surgery. 2010;3:186. Langsdon PR, et al. ... Discovery's Edge Magazine Search Publications Training Grant Positions Education Mayo Clinic College of Medicine and Science Mayo ...

  12. Chemical carcinogens

    National Research Council Canada - National Science Library

    Searle, Charles E

    1976-01-01

    Cancer causing agents are now known to exist throughout the environment-in polluted air and tobacco smoke, in various plants and foods, and in many chemicals that are used in industry and laboratories...

  13. Chemical Carcinogenesis

    OpenAIRE

    Oliveira, Paula A.; Aura Colaço; Raquel Chaves; Henrique Guedes-Pinto; Luis F. De-La-Cruz P.; Carlos Lopes

    1980-01-01

    The use of chemical compounds benefits society in a number of ways. Pesticides, for instance, enable foodstuffs to be produced in sufficient quantities to satisfy the needs of millions of people, a condition that has led to an increase in levels of life expectancy. Yet, at times, these benefits are offset by certain disadvantages, notably the toxic side effects of the chemical compounds used. Exposure to these compounds can have varying effects, ranging from instant death to a gradual process...

  14. Proving Refinement Using Transduction

    DEFF Research Database (Denmark)

    Jonsson, Bengt; Pnueli, Amir; Rump, Camilla Østerberg

    1999-01-01

    We present a verification method, in which refinement between two systems is proven by constructing a transducer that inputs a computation of a concrete system and outputs a matching computation of the abstract system.......We present a verification method, in which refinement between two systems is proven by constructing a transducer that inputs a computation of a concrete system and outputs a matching computation of the abstract system....

  15. 'God' particle proves elusive

    CERN Document Server

    Radford, T

    2001-01-01

    For more than a decade, scientists at CERN have been hoping that a key theoretical particle called the Higgs boson, would turn up in a subatomic collision. Some of them are now though beginning to wonder if it has ever existed.

  16. A new lower bound for the total domination number in graphs proving a Graffiti.pc Conjecture

    DEFF Research Database (Denmark)

    Henning, Michael A.; Yeo, Anders

    2014-01-01

    the maximum distance in G of a vertex outside B to a vertex of B. The following conjecture is known as Graffiti.pc Conjecture #233 (http://cms.dt.uh.edu/ faculty/delavinae/research/wowII): if G is a connected graph of order at least two, then γt(G)≥2(ecc(B)+1)/3. We prove this conjecture. In fact...

  17. Seismic test facilities at the ENEA Casaccia Research Center; Prove sismiche con le tavole vibranti al centro ricerche Enea Casaccia

    Energy Technology Data Exchange (ETDEWEB)

    De Canio, G. [ENEA, Divisione Servizi Tecnologici, Centro Ricerche Casaccia, Rome (Italy)

    2000-07-01

    The main experimental facilities for seismic tests at the ENEA C.R. Casaccia laboratories consist of two high performance shake table for three axial seismic tests of structures up to 10 ton mass and 3g acceleration applied at the Center of Gravity at 1m from the base table. The activities are principally devoted to the dynamic characterization and vibration tests for mechanical and aero spatial structures, and the experimental analysis of innovative systems for the seismic isolation and retrofitting of civil, industrial, and historical buildings; together with the seismic tests of sub-structures and scaled mock-ups, in order to evaluate the isolation/dissipation performance of the anti-seismic devices, and the failure modes of the structural parts of the building. [Italian] Le principali attrezzature per le prove sismiche presso i laboratori del C.R. Casaccia consistono di due tavole vibranti triassali per prove su strutture fino a 10t di peso con una accelerazione di 3g applicata al centro di gravita' posto ad 1 m di altezza dal piano della tavola. Le principali attivita' riguardano: (a) test di caratterizzazione dinamica e prove di vibrazioni per strutture meccaniche ed aerospaziali; (b) l'analisi sperimentale di sistemi innovativi per l'isolamento sismico ed il consolidamento di strutture civili, industriali e storico monumentali, e le prove sismiche di elementi strutturali e di modelli in scala per la valutazione della capacita' di dissipazione dei dispositivi antisismici e le modalita' di formazione delle fratture.

  18. Legal frame for proving the safety of rail energy supply; Rechtlicher Rahmen fuer den Sicherheitsnachweis bei der Bahnenergieversorgung

    Energy Technology Data Exchange (ETDEWEB)

    Leitzke, C. [Deutsche Bahn AG, Berlin (Germany)

    2008-07-01

    The legal frame for proving the safety of rail energy supply is, as usual in technical and scientific matters, characterized by comparatively abstract expressions in the law and besides by reference to technical standards. Often only a view in the technical standards makes it possible to understand, what must be done to comply with the law and which behaviour must be judged as negligent under the law. For that reason ruling committees for technical standards bear a high responsibility. (orig.)

  19. Finding and proving the exact ground state of a generalized Ising model by convex optimization and MAX-SAT

    Science.gov (United States)

    Huang, Wenxuan; Kitchaev, Daniil A.; Dacek, Stephen T.; Rong, Ziqin; Urban, Alexander; Cao, Shan; Luo, Chuan; Ceder, Gerbrand

    2016-10-01

    Lattice models, also known as generalized Ising models or cluster expansions, are widely used in many areas of science and are routinely applied to the study of alloy thermodynamics, solid-solid phase transitions, magnetic and thermal properties of solids, fluid mechanics, and others. However, the problem of finding and proving the global ground state of a lattice model, which is essential for all of the aforementioned applications, has remained unresolved for relatively complex practical systems, with only a limited number of results for highly simplified systems known. In this paper, we present a practical and general algorithm that provides a provable periodically constrained ground state of a complex lattice model up to a given unit cell size and in many cases is able to prove global optimality over all other choices of unit cell. We transform the infinite-discrete-optimization problem into a pair of combinatorial optimization (MAX-SAT) and nonsmooth convex optimization (MAX-MIN) problems, which provide upper and lower bounds on the ground state energy, respectively. By systematically converging these bounds to each other, we may find and prove the exact ground state of realistic Hamiltonians whose exact solutions are difficult, if not impossible, to obtain via traditional methods. Considering that currently such practical Hamiltonians are solved using simulated annealing and genetic algorithms that are often unable to find the true global energy minimum and inherently cannot prove the optimality of their result, our paper opens the door to resolving longstanding uncertainties in lattice models of physical phenomena. An implementation of the algorithm is available at https://github.com/dkitch/maxsat-ising.

  20. Chemical carcinogenesis.

    Science.gov (United States)

    Oliveira, Paula A; Colaço, Aura; Chaves, Raquel; Guedes-Pinto, Henrique; De-La-Cruz P, Luis F; Lopes, Carlos

    2007-12-01

    The use of chemical compounds benefits society in a number of ways. Pesticides, for instance, enable foodstuffs to be produced in sufficient quantities to satisfy the needs of millions of people, a condition that has led to an increase in levels of life expectancy. Yet, at times, these benefits are offset by certain disadvantages, notably the toxic side effects of the chemical compounds used. Exposure to these compounds can have varying effects, ranging from instant death to a gradual process of chemical carcinogenesis. There are three stages involved in chemical carcinogenesis. These are defined as initiation, promotion and progression. Each of these stages is characterised by morphological and biochemical modifications and result from genetic and/or epigenetic alterations. These genetic modifications include: mutations in genes that control cell proliferation, cell death and DNA repair--i.e. mutations in proto-oncogenes and tumour suppressing genes. The epigenetic factors, also considered as being non-genetic in character, can also contribute to carcinogenesis via epigenetic mechanisms which silence gene expression. The control of responses to carcinogenesis through the application of several chemical, biochemical and biological techniques facilitates the identification of those basic mechanisms involved in neoplasic development. Experimental assays with laboratory animals, epidemiological studies and quick tests enable the identification of carcinogenic compounds, the dissection of many aspects of carcinogenesis, and the establishment of effective strategies to prevent the cancer which results from exposure to chemicals.

  1. Learn, see, practice, prove, do, maintain: an evidence-based pedagogical framework for procedural skill training in medicine.

    Science.gov (United States)

    Sawyer, Taylor; White, Marjorie; Zaveri, Pavan; Chang, Todd; Ades, Anne; French, Heather; Anderson, JoDee; Auerbach, Marc; Johnston, Lindsay; Kessler, David

    2015-08-01

    Acquisition of competency in procedural skills is a fundamental goal of medical training. In this Perspective, the authors propose an evidence-based pedagogical framework for procedural skill training. The framework was developed based on a review of the literature using a critical synthesis approach and builds on earlier models of procedural skill training in medicine. The authors begin by describing the fundamentals of procedural skill development. Then, a six-step pedagogical framework for procedural skills training is presented: Learn, See, Practice, Prove, Do, and Maintain. In this framework, procedural skill training begins with the learner acquiring requisite cognitive knowledge through didactic education (Learn) and observation of the procedure (See). The learner then progresses to the stage of psychomotor skill acquisition and is allowed to deliberately practice the procedure on a simulator (Practice). Simulation-based mastery learning is employed to allow the trainee to prove competency prior to performing the procedure on a patient (Prove). Once competency is demonstrated on a simulator, the trainee is allowed to perform the procedure on patients with direct supervision, until he or she can be entrusted to perform the procedure independently (Do). Maintenance of the skill is ensured through continued clinical practice, supplemented by simulation-based training as needed (Maintain). Evidence in support of each component of the framework is presented. Implementation of the proposed framework presents a paradigm shift in procedural skill training. However, the authors believe that adoption of the framework will improve procedural skill training and patient safety.

  2. Chemical genetics of Plasmodium falciparum

    Science.gov (United States)

    Guiguemde, W. Armand; Shelat, Anang A.; Bouck, David; Duffy, Sandra; Crowther, Gregory J.; Davis, Paul H.; Smithson, David C.; Connelly, Michele; Clark, Julie; Zhu, Fangyi; Jiménez-Díaz, María B; Martinez, María S; Wilson, Emily B.; Tripathi, Abhai K.; Gut, Jiri; Sharlow, Elizabeth R.; Bathurst, Ian; El Mazouni, Farah; Fowble, Joseph W; Forquer, Isaac; McGinley, Paula L; Castro, Steve; Angulo-Barturen, Iñigo; Ferrer, Santiago; Rosenthal, Philip J.; DeRisi, Joseph L; Sullivan, David J.; Lazo, John S.; Roos, David S.; Riscoe, Michael K.; Phillips, Margaret A.; Rathod, Pradipsinh K.; Van Voorhis, Wesley C.; Avery, Vicky M; Guy, R. Kiplin

    2010-01-01

    Malaria caused by Plasmodium falciparum is a catastrophic disease worldwide (880,000 deaths yearly). Vaccine development has proved difficult and resistance has emerged for most antimalarials. In order to discover new antimalarial chemotypes, we have employed a phenotypic forward chemical genetic approach to assay 309,474 chemicals. Here we disclose structures and biological activity of the entire library, many of which exhibited potent in vitro activity against drug resistant strains, and detailed profiling of 172 representative candidates. A reverse chemical genetic study identified 19 new inhibitors of 4 validated drug targets and 15 novel binders among 61 malarial proteins. Phylochemogenetic profiling in multiple organisms revealed similarities between Toxoplasma gondii and mammalian cell lines and dissimilarities between P. falciparum and related protozoans. One exemplar compound displayed efficacy in a murine model. Overall, our findings provide the scientific community with new starting points for malaria drug discovery. PMID:20485428

  3. The effect of herbal formula PROVE 1 and Stevia levels in diets on diet utilization of growing pigs

    Directory of Open Access Journals (Sweden)

    Kooprasert, S.

    2007-05-01

    Full Text Available The objective of this experiment was to study the effect of 0.2% antibiotic (ascomix-s®, one kilogram of which contains lincomycin hydrochloride 44 g and sulfamethazine 110 g or 0.25% herbal formulaPROVE 1, combined with five levels of Stevia supplementation in the diets on digestibility of pigs. Two factors; 1 type of drug (0.2% antibiotic and 0.25% herbal formula PROVE 1 and 2 five Stevia levels (0,0.2, 0.4, 0.6 and 0.8% were investigated and 10 dietary treatments were used in this study. Ten related growing crossbred (Large White x Landrace barrow pigs (30±1.5 kg body weight were raised in individualmetabolism cages for three collecting periods (30, 40 and 50 kg body weight, each pig was fed one experimental diet throughout the collecting period.The results showed that pigs fed diet with either 0.2% antibiotic or 0.25% herbal formula PROVE 1 had similar digestibility of diet, crude protein (CP, fiber, ash and nitrogen free extract (NFE (89.01 vs 87.83,94.96 vs 94.23, 60.73 vs 59.03, 61.22 vs 60.44 and 93.28 vs 92.03%, respectively. Negligible differences were observed between 0 and 0.4% Stevia supplementation in diet, but levels showed better digestibility than the other levels of Stevia supplementation, and the diet with 0.4% Stevia supplementation had the highestdigestibility of diet, CP, fiber, ash and NFE (91.04, 96.43, 69.48, 70.47 and 94.07%, respectively. The diet with antibiotic combined with 0.4% Stevia had digestibility of diet, CP, fat and fiber better than the otherlevels of Stevia supplementation, especially digestibility of ash, which was significantly higher than that of diet with 0.2% Stevia, but not significantly different from the other levels of Stevia supplementation. A partof herbal formula PROVE1 combined with 0% Stevia had the highest digestibility of ash (72.90%, significantly higher than the other levels of Stevia supplementation, except the diet with herbal formula PROVE 1combined with 0.4% Stevia supplementation

  4. Ryecyanatines A and B and ryecarbonitrilines A and B, substituted cyanatophenol, cyanatobenzo[1,3]dioxole, and benzo[1,3]dioxolecarbonitriles from rye (Secale cereale L.) root exudates: Novel metabolites with allelopathic activity on Orobanche seed germination and radicle growth.

    Science.gov (United States)

    Cimmino, Alessio; Fernández-Aparicio, Mónica; Avolio, Fabiana; Yoneyama, Koichi; Rubiales, Diego; Evidente, Antonio

    2015-01-01

    Orobanche and Phelipanche species (the broomrapes) are root parasitic plants, some of which represent serious weed problems causing heavy yield losses on important crops. Current control relies on the use of certain agronomic practices, resistant crop varieties, and herbicides, albeit success has been marginal. Agronomic practices such as the use of allelopathic species in intercropping or cover crops, or the use of direct seedling over residues of allelopathic species incorporate the principle of allelopathy exerted by molecules exuded from roots or released by crop residues to control broomrapes. In addition, the isolation of natural substances from root exudates of plants with potential to inhibit broomrape development opens the door to the design of new herbicides based on natural and benign sources. Ryecyanatines A and B and ryecarbonitrilines A and B, the first new substituted cyanatophenol, substituted cyanatobenzo[1,3]dioxole, and the latter two new substituted benzo[1,3]dioxolecarbonitriles were isolated from rye (Secale cereale L.) root exudates. They were characterized as 4-cyanato-2-methoxyphenol, 2-cyanato-benzo[1,3]dioxole, 2-methoxybenzo[1,3]dioxole-5-carbonitrile and benzo[1,3]dioxole-2-carbonitrile by spectroscopic (essentially NMR and HRESI MS spectra) methods. These compounds were investigated for allelopathic activity on Orobanche germination and development. Ryecarbonitriline A induced germination of Orobanche cumana seeds, and this germination can be considered as suicidal because O. cumana does not parasite rye roots and cannot survive without host resources beyond germination stage. In addition, ryecyanatine A promotes a rapid cessation of O. cumana, Orobanche crenata and Orobanche minor radicle growth with the promotion of a layer of papillae at the radicle tip in O. cumana and O. crenata hampering the contact of the parasite to the host. Ryecarbonitriline B also displayed the same activity although being less active than ryecyanatine A and

  5. Allelopathic potential of aqueous extracts of cover crops on the germination and development of Bidens pilosaPotencial alelopático de extratos aquosos de culturas de cobertura de solo na germinação e desenvolvimento inicial de Bidens pilosa

    Directory of Open Access Journals (Sweden)

    Claudia Oliveira

    2012-08-01

    Full Text Available The objective of the study was to evaluate the influence of cover crops extracts on growth and development of Bidens pilosa. The experimental design was completely randomized in factorial scheme 4 x 3 x 5 with four replications. The factor A was composed by cover crops (Brassica napus; Raphanus sativus; Trifolium vesiculosum; Lolium multiflorum, B was parts plants (whole plant, shoot and root system and C extracts concentrations (0; 1, 2.5, 5 and 10% weight / volume. Variables evaluated were: speed of germination; germination percentage; length and dry matter of shoot and root. Extracts of Brassica napus followed by extracts of Trifolium vesiculosum, in general, had more allelopathic potential. The shoots of the cover crops, presented in general larger allelopathic activity. Allelopathic activity on germination and development of Bidens pilosa increases with the increment of extracts concentration, of differents plants parts. The speed germination is the best indicator of allelopathic activity of cover crops on Bidens pilosa. Objetivou-se com o trabalho avaliar a influência de extratos de culturas de cobertura de estação estival de inverno sobre o crescimento e desenvolvimento de Bidens pilosa (picão-preto. O delineamento experimental foi inteiramente casualizado, arranjado em esquema fatorial 4 x 3 x 5, com quatro repetições. O fator A foi constituído pelas culturas de cobertura (canola, nabo-forrageiro, trevovesiculoso e azevém, o B pelas partes da planta (planta inteira, parte aérea ou sistema radicular e o C pelas concentrações dos extratos vegetais (0; 1; 2,5; 5 e 10% peso/volume. Foram avaliados o índice de velocidade de germinação, a percentagem de germinação e comprimento e massa seca da parte aérea e radicular. Os extratos de canola seguidos dos de trevo-vesiculoso, apresentaram maior potencial alelopático. A parte aérea das culturas de cobertura foi a que apresentou a maior atividade alelopática. A atividade alelop

  6. Changes in microstructure of two ammonium-based protic ionic liquids proved by in situ variable-temperature 1 H NMR spectroscopy: influence of anion.

    Science.gov (United States)

    Tang, Xiaochen; Xu, Yingjie; Zhu, Xiao; Lu, Yueqing

    2017-04-22

    In this work, changes in microstructure of two protic ionic liquids (PILs), namely n-butylammonium acetate (N4Ac) and n-butylammonium nitrate (N4NO3 ), are proved by in situ variable-temperature 1 H NMR spectroscopy at the temperature range from 25 to 115 °C, and the influence of the nature of anion is discussed accordingly. The results demonstrate that 1 H NMR chemical shifts of alkyl protons of both N4Ac and N4NO3 are almost not changed with the increasing of temperature, due to the absence of hydrogen bond interaction between alkyl protons with anions. Whereas those of + N-H of cation decrease linearly with the temperature increasing, indicating that the hydrogen bond interaction between + N-H and anion weakens gradually. In addition, the strength of hydrogen bond interaction between + N-H and NO3- is stronger than that between + N-H and Ac- , suggesting that anions have a significant influence on microstructure due to the acidity of a Brønsted acid. Consequently, the proton transfer from cation to anion is much easier in N4Ac compared to N4NO3 . Further analyses of 1 H NMR chemical shifts of + N-H in N4Ac at the temperature range from 100 to 115 °C suggest that the splitting of + N-H peak may be attributed to obvious evidence of the existence of the proton transfer from + N-H to Ac- , which leads to dissociate the contact ion-pair in N4Ac to form the neutral ion-pair 'molecule'. The results will help us to extensively understand the behavior of proton transfer and offer us some valuable information for the design of PILs. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  7. Some chemical characteristics of selected geological materials in ...

    African Journals Online (AJOL)

    This study was carried out in order to characterize some selected local geological materials so as to prove their potential use for crop production. For this purpose, two types of volcanic breccias, volcanic ash and marl from West Cameroon region were selected for chemical characterization. These chemical analyses were ...

  8. Chemical Debridement of Burns

    Science.gov (United States)

    Levenson, Stanley M.; Kan, Dorinne; Gruber, Charles; Crowley, Leo V.; Lent, Richard; Watford, Alvin; Seifter, Eli

    1974-01-01

    The development of effective, non-toxic (local and systemic) methods for the rapid chemical (enzymatic and non-enzymatic) debridement of third degree burns would dramatically reduce the morbidity and mortality of severely burned patients. Sepsis is still the major cause of death of patients with extensive deep burns. The removal of the devitalized tissue, without damage to unburned skin or skin only partially injured by burning, and in ways which would permit immediate (or very prompt) skin grafting, would lessen substantially the problems of sepsis, speed convalescence and the return of these individuals to society as effective human beings, and would decrease deaths. The usefulness and limitations of surgical excision for patients with extensive third degree burns are discussed. Chemical debridement lends itself to complementary use with surgical excision and has the potential advantage over surgical excision in not requiring anesthesia or a formal surgical operation. The authors' work with the chemical debridement of burns, in particular the use of Bromelain, indicates that this approach will likely achieve clinical usefulness. The experimental studies indicate that rapid controlled debridement, with minimal local and systemic toxicity, is possible, and that effective chemotherapeutic agents may be combined with the Bromelain without either interfering with the actions of the other. The authors believe that rapid (hours) debridement accomplished by the combined use of chemical debriding and chemotherapeutic agents will obviate the possibility of any increase in infection, caused by the use of chemical agents for debridement, as reported for Paraenzyme21 and Travase.39,48 It is possible that the short term use of systemic antibiotics begun just before and continued during, and for a short time after, the rapid chemical debridement may prove useful for the prevention of infection, as appears to be the case for abdominal operations of the clean-contaminated and

  9. Contamination of ground water, surface water, and soil, and evaluation of selected ground-water pumping alternatives in the Canal Creek area of Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Lorah, Michelle M.; Clark, Jeffrey S.

    1996-01-01

    Chemical manufacturing, munitions filling, and other military-support activities have resulted in the contamination of ground water, surface water, and soil in the Canal Creek area of Aberdeen Proving Ground, Maryland. Chlorinated volatile organic compounds, including 1,1,2,2-tetrachloroethane and trichloroethylene, are widespread ground-water contaminants in two aquifers that are composed of unconsolidated sand and gravel. Distribution and fate of chlorinated organic compounds in the ground water has been affected by the movement and dissolution of solvents in their dense immiscible phase and by microbial degradation under anaerobic conditions. Detection of volatile organic contaminants in adjacent surface water indicates that shallow contaminated ground water discharges to surface water. Semivolatile organic compounds, especially polycyclic aromatic hydrocarbons, are the most prevalent organic contaminants in soils. Various trace elements, such as arsenic, cadmium, lead, and zinc, were found in elevated concentrations in ground water, surface water, and soil. Simulations with a ground-water-flow model and particle tracker postprocessor show that, without remedial pumpage, the contaminants will eventually migrate to Canal Creek and Gunpowder River. Simulations indicate that remedial pumpage of 2.0 million gallons per day from existing wells is needed to capture all particles originating in the contaminant plumes. Simulated pumpage from offsite wells screened in a lower confined aquifer does not affect the flow of contaminated ground water in the Canal Creek area.

  10. Investigation of soil contamination at the Riot Control Burning Pit area in J-Field, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ying-Ya; Yuen, C.R.; Martino, L.

    1996-05-01

    A remedial investigation was conducted to identify soil contamination in the Riot Control Burning Pit area in J-field, Aberdeen Proving Ground, Maryland. The investigation included geophysical surveys to delineate the filled section of the pit, soil-gas surveys to locate the organic contamination area, field X-ray fluorescence measurements along the burning pit to identify the major metal contamination, and surface and subsurface soil analyses to investigate the nature and extent of contamination. This paper presents the results of this investigation

  11. Feasibility of using damage to body armour as evidence to prove the degree of intent of wounding

    OpenAIRE

    Watson, Celia H.; Parker, Fiona; Horsfall, Ian; Fenne, Paul

    2008-01-01

    It has become standard practice for Police Authorities to issue stab resistant body armour to all officers who are placed at risk of knife assault. Subsequently if the officer is subjected to a knife attack it has been difficult to prove the degree of intent of wounding by a suspect. Arguments that no real harm could be intended, as the officer was protected by armour, are presented in court to mitigate any sentence of intent to wound. Several Police Forces have requested that damaged armour ...

  12. Mean of the top ten percent of NDVI values in the Yuma Proving Ground during monsoon season, 1986-2011

    Science.gov (United States)

    Birtwistle, Amy N; Laituri, Melinda J.; Bledsoe, Brian P.; Friedman, Jonathan M.

    2016-01-01

    This study uses growth in vegetation during the monsoon season measured from LANDSAT imagery as a proxy for measured rainfall. NDVI values from 26 years of pre- and post-monsoon season Landsat imagery were derived across Yuma Proving Ground (YPG) in southwestern Arizona, USA. The LANDSAT imagery (1986-2011) was downloaded from USGS’s GlobeVis website (http://glovis.usgs.gov/). Change in NDVI was calculated within a set of 2,843 Riparian Area Polygons (RAPs) up to 1 km in length defined in ESRI ArcMap 10.2.

  13. Allelopathic interactions between the red-tide causative dinoflagellate Prorocentrum donghaiense and the diatom Phaeodactylum tricornutum* This study was supported by the Natural Science Foundation of China-Guangdong Province Joint Key Project (U1133003 Science Technology Planning Project of Guangdong Province (2012B020307009 Open Fund from Key Laboratory of Aquatic Eutrophication Control of Harmful Algal Blooms of Guangdong Higher Education Institutes Open Fund from Key Laboratory of Microbial Resources Collection Preservation Ministry of Agriculture.

    Directory of Open Access Journals (Sweden)

    Zhuoping Cai

    2014-06-01

    Full Text Available The interactions between the red-tide causing dinoflagellate Prorocentrum donghaiense and the marine diatom Phaeodactylum tricornutum were investigated using a co-culture experiment and an enriched culture filtrate experiment. The results showed that when the two microalgae were cultured together with different initial cell densities, the growth of one species was basically suppressed by the other one. In addition, the enriched culture filtrates of one species had generally inhibitory effects on the other one. Our result inferred that P. donghaiense and P. tricornutum would interfere with each other mainly by releasing allelochemicals into the culture medium, and that the degree of allelopathic effects was dependent on the initial cell densities and growth phases. The allelopathic interactions between microalgal species may contribute to the formation and succession of red tides.

  14. Delicious Chemicals.

    Science.gov (United States)

    Barry, Dana M.

    This paper presents an approach to chemistry and nutrition that focuses on food items that people consider delicious. Information is organized according to three categories of food chemicals that provide energy to the human body: (1) fats and oils; (2) carbohydrates; and (3) proteins. Minerals, vitamins, and additives are also discussed along with…

  15. Chemical dispersants

    NARCIS (Netherlands)

    Rahsepar, Shokouhalsadat; Smit, Martijn P.J.; Murk, Albertinka J.; Rijnaarts, Huub H.M.; Langenhoff, Alette A.M.

    2016-01-01

    Chemical dispersants were used in response to the Deepwater Horizon oil spill in the Gulf of Mexico, both at the sea surface and the wellhead. Their effect on oil biodegradation is unclear, as studies showed both inhibition and enhancement. This study addresses the effect of Corexit on oil

  16. Chemical Oscillations

    Indian Academy of Sciences (India)

    processes at the cellular level like the glycolytic pathway, peroxi- dase-catalysed reaction or the biosynthesis of certain proteins. A systematic study of oscillating chemical reactions is of consider- able interest, since these oscillating reactions can be used as prototype examples of the behaviours possible in reactions gov-.

  17. Allelopathic Effects of Sunflower Residue on Growth of Rice and Subsequent Wheat Crop Efectos Alelopáticos de Residuos de Girasol sobre el Crecimiento de Arroz y Cultivo de Trigo Subsecuente

    Directory of Open Access Journals (Sweden)

    Uzma Bashir

    2012-09-01

    Full Text Available Sunflower (Helianthus annuus L. is a well known allelopathic plant species. However, Pakistani farmers generally incorporate the sunflower residue in the soil with the aim to enhance soil fertility and organic matter. Field experiments were, therefore, carried out to evaluate the effect of sunflower residue incorporation on growth and yield of rice (Oryza sativa L. and subsequent wheat (Triticum aestivum L. crop. For rice crop, there were four treatments viz. control, sunflower residue incorporation (RI, NPK fertilizers, and NPK+RI. Two rice varieties (Basmati Pak and Basmati Super were cultivated. Incorporation of sunflower residue markedly reduced plant growth and yield in 'Basmati Pak'. There was 34% reduction in yield of this variety due to RI. 'Basmati Super' was tolerant to sunflower allelopathy, where the effect of RI was generally insignificant on plant growth and grain yield. Two commonly cultivated varieties of wheat (Inqalab 91 and Punjab 96 were sown in the same plots after harvesting the rice, without any addition of either RI or NPK. In 'Punjab 96', the effect of RI or RI+NPK was insignificant on grain yield. In contrast, in 'Inqalab 91', RI in combination with NPK fertilizers significantly reduced the grain yield by 41% as compared to NPK alone. The present study concluded that rice 'Basmati Super' and wheat 'Punjab 96' are suitable for cultivation under sunflower allelopathic stress.El girasol (Helianthus annuus L. es una planta alelopática bien conocida. Sin embargo, los agricultores de Paquistán generalmente incorporan el residuo de girasol en el suelo con el objetivo de mejorar la fertilidad y la materia orgánica del suelo. Los experimentos de campo se realizaron para evaluar el efecto de la incorporation de residuos de girasol en el crecimiento y production de arroz (Oryza sativa L. y trigo (Triticum aestivum L. subsecuente. Para el cultivo de arroz hubo cuatro tratamientos viz. Control, incorporation de residuo de girasol

  18. Ground-water, surface-water, and bottom-sediment contamination in the O-field area, Aberdeen Proving Ground, Maryland, and the possible effects of selected remedial actions on ground water

    Science.gov (United States)

    Vroblesky, Don A.; Lorah, Michelle M.; Oliveros, James P.

    1995-01-01

    Disposal of munitions and chemical-warfare substances has introduced inorganic and organic contaminants to the ground water, surface water, and bottom sediment at O-Field, in the Edgewood area of Aberdeen Proving Ground, Maryland. Contaminants include chloride, arsenic, transition metals, chlorinated aliphatic hydrocarbons, aromatic compounds, and organosulfur and organophosphorus compounds. The hydrologic effects of several remedial actions were estimated by use of a ground-water-flow model. The remedial actions examined were an impermeable covering, encapsulation, subsurface barriers, a ground-water drain, pumping of wells to manage water levels or to remove contaminated ground water for treatment, and no action.

  19. Allelopathic potential of Gleichenella pectinata (Willd. Ching on weed plant species Potencial alelopático de Gleichenella pectinata (Willd. Ching (Gleicheniaceae sobre espécies infestantes de culturas

    Directory of Open Access Journals (Sweden)

    Valquiria Marin Voltarelli

    2012-12-01

    Full Text Available The goal of this paper was to determine the allelopathic potential of Gleichenella pectinata on three weed species (Echinochloa crus-galli (L. Beauv (Poaceae, Ipomoea grandifolia (Dammer O'Donell (Convolvulaceae and Euphorbia heterophylla L. (Euphorbiaceae. The experimental design was entirely randomized, with six replicates. The target plant responses were analyzed individually (percentage and average time of germination of the seeds and initial growth of seedlings or combined, using the Global Effect Index. The extracts had a low effect on the percentage and average time of seed germination, but inhibited the seedling growth. The combined analysis revealed that almost all treatments caused inhibition. This analysis also showed the differences between the two phenological stages.Com o objetivo de determinar o potencial alelopático de Gleichenella pectinata sobre três espécies de plantas infestantes de culturas (Echinochloa crus-galli (L. Beauv (Poaceae, Ipomoea grandifolia (Dammer O'Donell (Convolvulaceae e Euphorbia heterophylla L. (Euphorbiaceae foram realizados experimentos em laboratório. O delineamento experimental foi totalmente casualizado, com seis tratamentos e cinco réplicas. As respostas das plantas alvo foram analisadas individualmente (porcentagem e tempo de germinação das sementes e crescimento inicial das plântulas ou combinadas, através do Índice do efeito Global. Os extratos tiveram pouco efeito sobre a porcentagem e tempo de germinação das sementes, mas inibiram significativamente o tamanho das plântulas. A análise combinada dos parâmetros revelou uma inibição provocada por quase todos os tratamentos. Essa análise evidenciou também efeitos distintos entre os extratos de frondes férteis e frondes estéreis.

  20. Prospecção química de compostos produzidos por Senna alata com atividade alelopática Chemical prospecting of compounds produced by Senna alata with allelopathic activity

    OpenAIRE

    I.M.C. Rodrigues; A.P.S. Souza Filho; F.A. Ferreira; A.J. Demuner

    2010-01-01

    Senna alata é uma espécie daninha frequente em pastagens da região amazônica. Suas folhas apresentam propriedades medicinais capazes de influenciar a germinação e o desenvolvimento de outras plantas. Objetivou-se neste estudo a prospecção química e a avaliação da atividade alelopática dos compostos presentes nas folhas de S. alata. O material vegetal foi seco, triturado e submetido à extração exaustiva, com solução água:metanol (3:7). O extrato obtido foi então fracionado por coluna cromatogr...

  1. Chemical composition and biological activities of Salvia officinalis essential oil from Tunisia.

    Science.gov (United States)

    Khedher, Med Raâfet Ben; Khedher, Saoussen Ben; Chaieb, Ikbal; Tounsi, Slim; Hammami, Mohamed

    2017-01-01

    The aim of this study is to evaluate the chemical composition, antioxidant, antimicrobial, insecticidal and allelopathic activities of Tunisia Salvia officinalis essential oil (SoEO). The SoEO was characterized by the presence of 49 components with camphor (25.14 %), α-thujone (18.83 %), 1,8-cineole (14.14 %), viridiflorol (7.98 %), β-thujone (4.46 %) and β-caryophyllene (3.30 %) as the major components, determined by gas chromatography-mass spectrometry. The level of antioxidant activity, determined by complementary tests, namely 2,2-diphenyl-1-picrylhydrazyl radical-scavenging (IC50= 6.7 mg/mL), linoleic acid peroxidation (IC50= 9.6 mg/mL) and ferric reducing assays (IC50= 28.4 mg/mL), was relatively moderate. The SoEO was also screened for its antimicrobial activity. Good to moderate inhibitions were recorded for most of tested microorganisms. It also exhibited important insecticidal activity against Spodoptera littoralis larvae and Tribolium castaneum adults with LC50 values of 55.99 and 97.43 µl/L air, respectively. The effect of the SoEO on seeds germination and growth showed different activities against radical and hypocotyl elongation of the tested species. These results suggest the potential use of the SoEO as natural antimicrobial preservative in cosmetic, pharmaceutical industry and in pest management.

  2. Finding and proving the exact ground state of a generalized Ising model by convex optimization and MAX-SAT

    CERN Document Server

    Huang, Wenxuan; Dacek, Stephen; Rong, Ziqin; Urban, Alexander; Cao, Shan; Luo, Chuan; Ceder, Gerbrand

    2016-01-01

    Lattice models, also known as generalized Ising models or cluster expansions, are widely used in many areas of science and are routinely applied to alloy thermodynamics, solid-solid phase transitions, magnetic and thermal properties of solids, and fluid mechanics, among others. However, the problem of finding the true global ground state of a lattice model, which is essential for all of the aforementioned applications, has remained unresolved, with only a limited number of results for highly simplified systems known. In this article, we present the first general algorithm to find the exact ground states of complex lattice models and to prove their global optimality, resolving this fundamental problem in condensed matter and materials theory. We transform the infinite-discrete-optimization problem into a pair of combinatorial optimization (MAX-SAT) and non-smooth convex optimization (MAX-MIN) problems, which provide upper and lower bounds on the ground state energy respectively. By systematically converging th...

  3. Historical wildlife dynamics on Dugway Proving Ground: population and disease trends in jack rabbits over two decades. [Lepus californicus

    Energy Technology Data Exchange (ETDEWEB)

    Eberhardt, L.E.; Van Voris, P.

    1986-08-01

    In an effort to determine whether US Army activities on the Dugway Proving Ground (DPG) have had an impact on resident wildlife, intensive studies have been conducted on the biology and ecology of the black-tailed jack rabbit (Lepus californicus) since 1965. in addition, the incidence of endemic diseases in several species of resident wildlife on the DPG have been studied from the late 1950s through the mid-1970s. The objectives of this report are to: (1) compile and summarize the jack rabbit data and some of the disease information that is presently contained only in annual reports; (2) compare the DPG jack rabbit data to data available on other jack rabbit populations; and (3) analyze the data for unusual or unexplained fluctuations in population densities or in incidence of disease.

  4. THE OLKHON GEODYNAMIC PROVING GROUND (LAKE BAIKAL: HIGH RESOLUTION SATELLITE DATA AND GEOLOGICAL MAPS OF NEW GENERATION

    Directory of Open Access Journals (Sweden)

    Valentin S. Fedorovsky

    2015-09-01

    Full Text Available The Olkhon region of the Western Pribaikalie is highly attractive for geologists due to the presence of diverse metamorphic complexes and highly complicated combinations of folded structures in this region. The Olkhon region is located within the area of the Pribaikalsky National Park of Russia. At abundant outcrops in the subject area, various geological aspects resulting from the Early Palaeozoic collision system can be studied in detail. By its parameters, the subject area can be considered a «geodynamic proving ground». In recent years, abundant aerospace materials on the area have been accumulated, and long-term field studies resulted in many discoveries and findings which encourage critical revision of the initial conceptions. The material available allows compilation of a new package of geological maps in hard and electronic versions.

  5. Effects of different autotoxins on antioxidant enzymes and chemical ...

    African Journals Online (AJOL)

    Jane

    2011-07-25

    Jul 25, 2011 ... allelopathic agents and the mechanism of action of autotoxins in tea seedlings is still unknown. To investigate the mechanism between autotoxins and membrane lipid peroxidation, the objective of this study was to determine the effects of root exudates autotoxins on antioxidant enzymes activity and index ...

  6. JPSS Proving Ground Activities with NASA's Short-term Prediction Research and Transition (SPoRT) Center

    Science.gov (United States)

    Schultz, L. A.; Smith, M. R.; Fuell, K.; Stano, G. T.; LeRoy, A.; Berndt, E.

    2015-12-01

    Instruments aboard the Joint Polar Satellite System (JPSS) series of satellites will provide imagery and other data sets relevant to operational weather forecasts. To prepare current and future weather forecasters in application of these data sets, Proving Ground activities have been established that demonstrate future JPSS capabilities through use of similar sensors aboard NASA's Terra and Aqua satellites, and the S-NPP mission. As part of these efforts, NASA's Short-term Prediction Research and Transition (SPoRT) Center in Huntsville, Alabama partners with near real-time providers of S-NPP products (e.g., NASA, UW/CIMSS, UAF/GINA, etc.) to demonstrate future capabilities of JPSS. This includes training materials and product distribution of multi-spectral false color composites of the visible, near-infrared, and infrared bands of MODIS and VIIRS. These are designed to highlight phenomena of interest to help forecasters digest the multispectral data provided by the VIIRS sensor. In addition, forecasters have been trained on the use of the VIIRS day-night band, which provides imagery of moonlit clouds, surface, and lights emitted by human activities. Hyperspectral information from the S-NPP/CrIS instrument provides thermodynamic profiles that aid in the detection of extremely cold air aloft, helping to map specific aviation hazards at high latitudes. Hyperspectral data also support the estimation of ozone concentration, which can highlight the presence of much drier stratospheric air, and map its interaction with mid-latitude or tropical cyclones to improve predictions of their strengthening or decay. Proving Ground activities are reviewed, including training materials and methods that have been provided to forecasters, and forecaster feedback on these products that has been acquired through formal, detailed assessment of their applicability to a given forecast threat or task. Future opportunities for collaborations around the delivery of training are proposed

  7. Demonstration of the Military Ecological Risk Assessment Framework (MERAF): Apache Longbow - Hell Missile Test at Yuma Proving Ground

    Energy Technology Data Exchange (ETDEWEB)

    Efroymson, R.A.

    2002-05-09

    This ecological risk assessment for a testing program at Yuma Proving Ground, Arizona, is a demonstration of the Military Ecological Risk Assessment Framework (MERAF; Suter et al. 2001). The demonstration is intended to illustrate how risk assessment guidance concerning-generic military training and testing activities and guidance concerning a specific type of activity (e.g., low-altitude aircraft overflights) may be implemented at a military installation. MERAF was developed with funding from the Strategic Research and Development Program (SERDP) of the Department of Defense. Novel aspects of MERAF include: (1) the assessment of risks from physical stressors using an ecological risk assessment framework, (2) the consideration of contingent or indirect effects of stressors (e.g., population-level effects that are derived from habitat or hydrological changes), (3) the integration of risks associated with different component activities or stressors, (4) the emphasis on quantitative risk estimates and estimates of uncertainty, and (5) the modularity of design, permitting components of the framework to be used in various military risk assessments that include similar activities. The particular subject of this report is the assessment of ecological risks associated with a testing program at Cibola Range of Yuma Proving Ground, Arizona. The program involves an Apache Longbow helicopter firing Hellfire missiles at moving targets, i.e., M60-A1 tanks. Thus, the three component activities of the Apache-Hellfire test were: (1) helicopter overflight, (2) missile firing, and (3) tracked vehicle movement. The demonstration was limited, to two ecological endpoint entities (i.e., potentially susceptible and valued populations or communities): woody desert wash communities and mule deer populations. The core assessment area is composed of about 126 km{sup 2} between the Chocolate and Middle Mountains. The core time of the program is a three-week period, including fourteen days of

  8. Long-term fate of depleted uranium at Aberdeen and Yuma Proving Grounds: Human health and ecological risk assessments

    Energy Technology Data Exchange (ETDEWEB)

    Ebinger, M.H.; Beckman, R.J.; Myers, O.B. [Los Alamos National Lab., NM (United States); Kennedy, P.L.; Clements, W.; Bestgen, H.T. [Colorado State Univ., Ft. Collins, CO (United States). Dept. of Fishery and Wildlife Biology

    1996-09-01

    The purpose of this study was to evaluate the immediate and long-term consequences of depleted uranium (DU) in the environment at Aberdeen Proving Ground (APG) and Yuma Proving Ground (YPG) for the Test and Evaluation Command (TECOM) of the US Army. Specifically, we examined the potential for adverse radiological and toxicological effects to humans and ecosystems caused by exposure to DU at both installations. We developed contaminant transport models of aquatic and terrestrial ecosystems at APG and terrestrial ecosystems at YPG to assess potential adverse effects from DU exposure. Sensitivity and uncertainty analyses of the initial models showed the portions of the models that most influenced predicted DU concentrations, and the results of the sensitivity analyses were fundamental tools in designing field sampling campaigns at both installations. Results of uranium (U) isotope analyses of field samples provided data to evaluate the source of U in the environment and the toxicological and radiological doses to different ecosystem components and to humans. Probabilistic doses were estimated from the field data, and DU was identified in several components of the food chain at APG and YPG. Dose estimates from APG data indicated that U or DU uptake was insufficient to cause adverse toxicological or radiological effects. Dose estimates from YPG data indicated that U or DU uptake is insufficient to cause radiological effects in ecosystem components or in humans, but toxicological effects in small mammals (e.g., kangaroo rats and pocket mice) may occur from U or DU ingestion. The results of this study were used to modify environmental radiation monitoring plans at APG and YPG to ensure collection of adequate data for ongoing ecological and human health risk assessments.

  9. Characterization of Preferential Ground-Water Seepage From a Chlorinated Hydrocarbon-Contaminated Aquifer to West Branch Canal Creek, Aberdeen Proving Ground, Maryland, 2002-04

    Science.gov (United States)

    Majcher, Emily H.; Phelan, Daniel J.; Lorah, Michelle M.; McGinty, Angela L.

    2007-01-01

    Wetlands act as natural transition zones between ground water and surface water, characterized by the complex interdependency of hydrology, chemical and physical properties, and biotic effects. Although field and laboratory demonstrations have shown efficient natural attenuation processes in the non-seep wetland areas and stream bottom sediments of West Branch Canal Creek, chlorinated volatile organic compounds are present in a freshwater tidal creek at Aberdeen Proving Ground, Maryland. Volatile organic compound concentrations in surface water indicate that in some areas of the wetland, preferential flow paths or seeps allow transport of organic compounds from the contaminated sand aquifer to the overlying surface water without undergoing natural attenuation. From 2002 through 2004, the U.S. Geological Survey, in cooperation with the Environmental Conservation and Restoration Division of the U.S. Army Garrison, Aberdeen Proving Ground, characterized preferential ground-water seepage as part of an ongoing investigation of contaminant distribution and natural attenuation processes in wetlands at this site. Seep areas were discrete and spatially consistent during thermal infrared surveys in 2002, 2003, and 2004 throughout West Branch Canal Creek wetlands. In these seep areas, temperature measurements in shallow pore water and sediment more closely resembled those in ground water than those in nearby surface water. Generally, pore water in seep areas contaminated with chlorinated volatile organic compounds had lower methane and greater volatile organic compound concentrations than pore water in non-seep wetland sediments. The volatile organic compounds detected in shallow pore water in seeps were spatially similar to the dominant volatile organic compounds in the underlying Canal Creek aquifer, with both parent and anaerobic daughter compounds detected. Seep locations characterized as focused seeps contained the highest concentrations of chlorinated parent compounds

  10. Chemical carcinogenesis

    Directory of Open Access Journals (Sweden)

    Paula A. Oliveira

    2007-12-01

    Full Text Available The use of chemical compounds benefits society in a number of ways. Pesticides, for instance, enable foodstuffs to be produced in sufficient quantities to satisfy the needs of millions of people, a condition that has led to an increase in levels of life expectancy. Yet, at times, these benefits are offset by certain disadvantages, notably the toxic side effects of the chemical compounds used. Exposure to these compounds can have varying effects, ranging from instant death to a gradual process of chemical carcinogenesis. There are three stages involved in chemical carcinogenesis. These are defined as initiation, promotion and progression. Each of these stages is characterised by morphological and biochemical modifications and result from genetic and/or epigenetic alterations. These genetic modifications include: mutations in genes that control cell proliferation, cell death and DNA repair - i.e. mutations in proto-oncogenes and tumour suppressing genes. The epigenetic factors, also considered as being non-genetic in character, can also contribute to carcinogenesis via epigenetic mechanisms which silence gene expression. The control of responses to carcinogenesis through the application of several chemical, biochemical and biological techniques facilitates the identification of those basic mechanisms involved in neoplasic development. Experimental assays with laboratory animals, epidemiological studies and quick tests enable the identification of carcinogenic compounds, the dissection of many aspects of carcinogenesis, and the establishment of effective strategies to prevent the cancer which results from exposure to chemicals.A sociedade obtém numerosos benefícios da utilização de compostos químicos. A aplicação dos pesticidas, por exemplo, permitiu obter alimento em quantidade suficiente para satisfazer as necessidades alimentares de milhões de pessoas, condição relacionada com o aumento da esperança de vida. Os benefícios estão, por

  11. Chemical cosmology

    CERN Document Server

    Boeyens, Jan CA

    2010-01-01

    The composition of the most remote objects brought into view by the Hubble telescope can no longer be reconciled with the nucleogenesis of standard cosmology and the alternative explanation, in terms of the LAMBDA-Cold-Dark-Matter model, has no recognizable chemical basis. A more rational scheme, based on the chemistry and periodicity of atomic matter, opens up an exciting new interpretation of the cosmos in terms of projective geometry and general relativity. The response of atomic structure to environmental pressure predicts non-Doppler cosmical redshifts and equilibrium nucleogenesis by alp

  12. Changes in ground-water quality in the Canal Creek Aquifer between 1995 and 2000-2001, West Branch Canal Creek area, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Phelan, Daniel J.; Fleck, William B.; Lorah, Michelle M.; Olsen, Lisa D.

    2002-01-01

    Since 1917, Aberdeen Proving Ground, Maryland has been the primary chemical-warfare research and development center for the U.S. Army. Ground-water contamination has been documented in the Canal Creek aquifer because of past disposal of chemical and ordnance manufacturing waste. Comprehensive sampling for volatile organic compounds in ground water by the U.S. Geological Survey in the West Branch Canal Creek area was done in June?October 1995 and June?August 2000. The purpose of this report is (1) to compare volatile organic compound concentrations and determine changes in the ground-water contaminant plumes along two cross sections between 1995 and 2000, and (2) to incorporate data from new piezometers sampled in spring 2001 into the plume descriptions. Along the southern cross section, total concentrations of volatile organic compounds in 1995 were determined to be highest in the landfill area east of the wetland (5,200 micrograms per liter), and concentrations were next highest deep in the aquifer near the center of the wetland (3,300 micrograms per liter at 35 feet below land surface). When new piezometers were sampled in 2001, higher carbon tetrachloride and chloroform concentrations (2,000 and 2,900 micrograms per liter) were detected deep in the aquifer 38 feet below land surface, west of the 1995 sampling. A deep area in the aquifer close to the eastern edge of the wetland and a shallow area just east of the creek channel showed declines in total volatile organic compound concentrations of more than 25 percent, whereas between those two areas, con-centrations generally showed an increase of greater than 25 percent between 1995 and 2000. Along the northern cross section, total concentrations of volatile organic compounds in ground water in both 1995 and 2000 were determined to be highest (greater than 2,000 micrograms per liter) in piezometers located on the east side of the section, farthest from the creek channel, and concentrations were progressively lower

  13. 33 CFR 334.730 - Waters of Santa Rosa Sound and Gulf of Mexico adjacent to Santa Rosa Island, Air Force Proving...

    Science.gov (United States)

    2010-07-01

    ... Gulf of Mexico adjacent to Santa Rosa Island, Air Force Proving Ground Command, Eglin Air Force Base... Sound and Gulf of Mexico adjacent to Santa Rosa Island, Air Force Proving Ground Command, Eglin Air... regulations. (1) Experimental test operations will be conducted by the U.S. Air Force within the prohibited...

  14. Seeing a Colleague Encourage a Student to Make an Assumption while Proving: What Teachers Put in Play when Casting an Episode of Instruction

    Science.gov (United States)

    Nachlieli, Talli; Herbst, Patricio

    2009-01-01

    This article reports on an investigation of how teachers of geometry perceived an episode of instruction presented to them as a case of engaging students in proving. Confirming what was hypothesized, participants found it remarkable that a teacher would allow a student to make an assumption while proving. But they perceived this episode in various…

  15. 20 CFR 1002.33 - Does the employee have to prove that the employer discriminated against him or her in order to be...

    Science.gov (United States)

    2010-04-01

    ... employer discriminated against him or her in order to be eligible for reemployment? 1002.33 Section 1002.33... have to prove that the employer discriminated against him or her in order to be eligible for reemployment? No. The employee is not required to prove that the employer discriminated against him or her...

  16. Combining Theorem Proving and Model Checking in the Safety-Critical Software Development through Translating Event-B to SMV

    Directory of Open Access Journals (Sweden)

    Sen Liang

    2017-01-01

    Full Text Available Model checking and theorem proving are two key vertification techniques in the formal method, but each has its advantages and disadvantages. In this paper, we first try to present the general model transformation rules from Event-B to SMV in order to realize complementary advantages, and then design the model converter of Event-B to SMV according to the rules. ProB is the only tool to implement Event-B model checking, but it lacks the real-time property verification, while nuXmv is able to verify temporal logic formulas with the real-time property for SMV models. After completing the model transformation, we use ProB and nuXmv to make the verification of LTL and CTL formulas for two equivalent models respectively. Compared to the experimental results, in solving the same problem, nuXmv has more advantages over memory consumption, time efficiency and so on than ProB, especially when the formula to be verified is very complex. Therefore, if complex verifications of system models need to be performed, it is necessary to implement the model transformation between Event-B and SMV by using our translation rules, which is of great significance for the development, design and verification of safety-critical system softwares.

  17. The “incredible” difficulty of proving “incredibility” – Example of fire-induced multiple spurious operations

    Energy Technology Data Exchange (ETDEWEB)

    Gallucci, Raymond H.V., E-mail: Ray.Gallucci@nrc.gov

    2016-11-15

    “Risk-informed” regulation is often an alternative to “deterministically-based” regulation that offers relaxation in criteria for acceptability while possibly requiring greater analytical effort. “Risk-informed determinism” is an attempt to meld the best of both worlds by using risk information to set deterministic acceptance criteria a priori. A recent joint effort by the US Nuclear Regulatory Commission’s Office of Nuclear Regulatory Research (RES) and Electric Power Research Institute (EPRI) originally endeavored to do this for several examples involving fire-induced multiple spurious operations (MSOs) in electrical circuits at nuclear power plants. While a noble effort, this did not consider the actual distributions involved in the events, originally limiting the analysis to mean values and, in some cases, qualitative considerations. A much more comprehensive and defensible approach is performed here where the probabilistic distributions for all the factors are considered via simulation to meet quantitative acceptance criteria related to the concept of “incredibility” that is often the figure of merit that must be met in a deterministic world. The effort demonstrates that it can be “incredibly” difficult to prove “incredibility” in this context.

  18. Temporal and vertical variation of hydraulic head in aquifers in the Edgewood area, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Donnelly, Colleen A.; Tenbus, Fredrick J.

    1998-01-01

    Water-level data and interpretations from previous hydrogeological studies conducted by the U.S. Geological Survey in the Edgewood Area of Aberdeen Proving Ground (APG), Maryland, were compared to determine similarities and differences among the aquifers. Because the sediments that comprise the shallow aquifers are discontinuous, the shallow ground-water-flow systems are local rather than extensive across the Edgewood Area. Hydrogeologic cross sections, hydrographs of water levels, and vertical gradients calculated from previous studies in the Canal Creek area, Graces Quarters, the O-Field area, Carroll Island, and the J-Field area, over periods of record ranging from 1 to 10 years during 1986-97, were used to determine recharge and discharge areas, connections between aquifers, and hydrologic responses of aquifers to natural and anthropogenic stress. Each of the aquifers in the study areas exhibited variation of hydraulic head that was attributed to seasonal changes in recharge. Upward hydraulic gradients and seasonal reversals of vertical hydraulic gradients between aquifers indicate the potential for local ground-water discharge from most of the aquifers that were studied in the Edgewood Area. Hydraulic head in individual aquifers in Graces Quarters and Carroll Island responded to offsite pumping during part of the period of record. Hydraulic head in most of the confined aquifers responded to tidal loading effects from nearby estuaries.

  19. Nonwoven-based gelatin/polycaprolactone membrane proves suitability in a preclinical assessment for treatment of soft tissue defects.

    Science.gov (United States)

    Schulz, Simon; Angarano, Marco; Fabritius, Martin; Mülhaupt, Rolf; Dard, Michel; Obrecht, Marcel; Tomakidi, Pascal; Steinberg, Thorsten

    2014-07-01

    Standard preclinical assessments in vitro often have limitations regarding their transferability to human beings, mainly evoked by their nonhuman and tissue-different/nontissue-specific source. Here, we aimed at employing tissue-authentic simple and complex interactive fibroblast-epithelial cell systems and their in vivo-relevant biomarkers for preclinical in vitro assessment of nonwoven-based gelatin/polycaprolactone membranes (NBMs) for treatment of soft tissue defects. NBMs were composed of electrospun gelatin and polycaprolactone nanofiber nonwovens. Scanning electron microscopy in conjunction with actin/focal contact integrin fluorescence revealed successful adhesion and proper morphogenesis of keratinocytes and fibroblasts, along with cells' derived extracellular matrix deposits. The "feel-good factor" of cells under study on the NBM was substantiated by forming a confluent connective tissue entity, which was concomitant with a stratified epithelial equivalent. Immunohistochemistry proved tissue authenticity over time by abundance of the biomarker vimentin in the connective tissue entity, and chronological increase of keratins KRT1/10 and involucrin expression in epithelial equivalents. Suitability of the novel NBM as wound dressing was evidenced by an almost completion of epithelial wound closure in a pilot mini-pig study, after a surgical intervention-caused gingival dehiscence. In summary, preclinical assessment by tissue-authentic cell systems and the animal pilot study revealed the NBM as an encouraging therapeutic medical device for prospective clinical applications.

  20. Environmental geophysics of the Pilot Plant on the west branch of Canal Creek, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    McGinnis, L.D.; Miller, S.F.; Daudt, C.R.; Thompson, M.D.; Borden, H.; Benson, M. [Argonne National Lab., IL (United States). Reclamation Engineering and Geosciences Section; Wrobel, J. [Directorate of Safety, Health, and Environment, Aberdeen Proving Ground, MD (United States)

    1994-05-01

    Plans to demolish and remediate the Pilot Plant complex in the Edgewood Area of Aberdeen Proving Ground have served to initiate a series of nonintrusive, environmental-geophysical studies. The studies are assisting in the location and identification of pipes, tanks, trenches, and liquid waste in the subsurface. Multiple databases have been integrated to provide support for detection of underground utilities and to determine the stratigraphy and lithology of the subsurface. The studies were conducted within the double security fence and exterior to the double fence, down gradient toward the west branch of Canal Creek. To determine if contaminants found in the creek were associated with the Pilot Plant, both the east and west banks were included in the study area. Magnetic, conductivity, inductive emf, and ground-penetrating-radar anomalies outline buried pipes, trenches, and various pieces of hardware associated with building activities. Ground-penetrating-radar imagery also defines a paleovalley cut 30 ft into Potomac Group sediments of Cretaceous age. The paleovalley crosses the site between Building E5654 and the Pilot Plant fence. The valley is environmentally significant because it may control the pathways of contaminants. The Pilot Plant complex was used to manufacture CC2 Impregnite and incapacitating agents; it also served as a production facility for nerve agents.

  1. Nonwoven-Based Gelatin/Polycaprolactone Membrane Proves Suitability in a Preclinical Assessment for Treatment of Soft Tissue Defects

    Science.gov (United States)

    Schulz, Simon; Angarano, Marco; Fabritius, Martin; Mülhaupt, Rolf; Dard, Michel; Obrecht, Marcel; Tomakidi, Pascal

    2014-01-01

    Standard preclinical assessments in vitro often have limitations regarding their transferability to human beings, mainly evoked by their nonhuman and tissue-different/nontissue-specific source. Here, we aimed at employing tissue-authentic simple and complex interactive fibroblast-epithelial cell systems and their in vivo-relevant biomarkers for preclinical in vitro assessment of nonwoven-based gelatin/polycaprolactone membranes (NBMs) for treatment of soft tissue defects. NBMs were composed of electrospun gelatin and polycaprolactone nanofiber nonwovens. Scanning electron microscopy in conjunction with actin/focal contact integrin fluorescence revealed successful adhesion and proper morphogenesis of keratinocytes and fibroblasts, along with cells' derived extracellular matrix deposits. The “feel-good factor” of cells under study on the NBM was substantiated by forming a confluent connective tissue entity, which was concomitant with a stratified epithelial equivalent. Immunohistochemistry proved tissue authenticity over time by abundance of the biomarker vimentin in the connective tissue entity, and chronological increase of keratins KRT1/10 and involucrin expression in epithelial equivalents. Suitability of the novel NBM as wound dressing was evidenced by an almost completion of epithelial wound closure in a pilot mini-pig study, after a surgical intervention-caused gingival dehiscence. In summary, preclinical assessment by tissue-authentic cell systems and the animal pilot study revealed the NBM as an encouraging therapeutic medical device for prospective clinical applications. PMID:24494668

  2. Alelopatia de acículas de Pinus taeda na germinação e no desenvolvimento de plântulas de Avena strigosa Allelopathic of Pinus taeda needles on the germination and development of Avena strigosa seedlings

    Directory of Open Access Journals (Sweden)

    Laércio Ricardo Sartor

    2009-09-01

    Full Text Available O trabalho teve por objetivo caracterizar o efeito alelopático do extrato aquoso de acículas de Pinus taeda na germinação e no desenvolvimento inicial de plântulas de aveia preta comum (Avena strigosa. O experimento foi conduzido no Laboratório de Bioquímica e Fisiologia Vegetal da Universidade Tecnológica Federal do Paraná (UTFPR, Campus de Pato Branco, utilizando o delineamento inteiramente casualizado, com tratamento fatorial (bifatorial com parcela subdividida no tempo, com três repetições, sob condições de temperatura, umidade e luminosidade controladas. Os tratamentos foram compostos por cinco concentrações (0, 25, 50, 75 e 100% de extrato bruto de acículas de pínus em estágio vegetativo (acícula verde, moderadamente decomposto (acícula seca e em decomposição avançada (acícula decomposta. As avaliações foram realizadas a cada 24 horas. Foram avaliados os parâmetros porcentagem de germinação, velocidade média de germinação e comprimento de radículas e epicótilos das plântulas de Avena strigosa. O estágio de acícula verde afetou significativamente as variáveis avaliadas e esse problema aumentou com a concentração do extrato.The purpose of this study was to verify the allelopathic effect of aqueous extract from the Pinus taeda needles on the germination and development of black oat (Avena strigosa seedlings. The work was carried out at the Plant Physiology and Biochemistry Laboratory at the Federal Technological University of Paraná (UTFPR, Campus Pato Branco, using a completely randomized design with factorial distribution in three replicates, under temperature, humidity and light controlled conditions. The extract from the pine needles was composed of five percentages (0, 25, 50, 75 and 100% from the crude extract (EB dilution, composed of distilled water + pine needles in vegetative stage (green needles, moderately decomposed (dry needles and in advanced decomposition (decomposed needles. The

  3. Efeito alelopático e toxicidade frente à Artemia salina Leach dos extatos do fruto de Euterpe edulis Martius Allelopathic effects and toxicity against Artemia salina Leach of extracts of the fruit of Euterpe edulis Martius

    Directory of Open Access Journals (Sweden)

    Cristina Peitz de Lima

    2011-06-01

    Full Text Available Alelopatia é um processo envolvendo metabólitos secundários produzidos por plantas que infl uenciam o crescimento e desenvolvimento de sistemas agrícolas. Devido à toxicidade dos herbicidas sintéticos para o meio ambiente e para a saúde humana tem-se aumentado o interesse na exploração da alelopatia como uma alternativa para o controle de plantas daninhas. O presente trabalho avaliou efeito dos extratos dos frutos de Euterpe edulis Martius sobre o desenvolvimento de cipselas e plântulas de Lactuca sativa Linné, foram determinados o índice de velocidade de germinação, o crescimento da radícula e do hipocótilo. Para a avaliação da toxicidade dos extratos foi realizado o ensaio de toxicidade frente ao microcrustáceo Artemia salina Leach determinando-se a CL50 e percentual de mortalidade. A fração remanescente demonstrou efeito alelopático, pois todas as concentrações alteraram os valores do índice de velocidade de germinação e as concentrações de 0,2 e 0,4 mg inibiram tanto o crescimento da radícula quanto o crescimento do hipocótilo. No ensaio de toxicidade todos os extratos apresentaram CL50 superior a 1000 ppm e 0% de mortalidade das artemias, indicando a não toxicidade dos extratos.Allelopathy is a process involving secondary metabolites produced by plants that influence growth and development of agricultural systems. Because of the toxicity of synthetic herbicides to the environment and human health, there has been increased interest in exploiting allelopathy as an alternative for weed control. This study evaluated the eff ect of extracts of Euterpe edulis Martius fruits on the development of cypselae and seedlings of Lactuca sativa Linné; the germination speed index, radicle and hypocotyl growth were determined. To evaluate the toxicity of the extracts the toxicity test against Artemia salina Leach was used, where the LC50 and mortality rate were determined. Th e remaining fraction showed allelopathic effect

  4. Allelopathic potential of Sapindus saponaria L. leaves in the control of weeds=Potencial alelopático de folhas de Sapindus saponaria L. no controle de plantas daninhas

    Directory of Open Access Journals (Sweden)

    Denise Garcia Santana

    2012-01-01

    Full Text Available The objective of this work was to evaluate the allelopathic potential of aqueous extracts of young and mature leaves from Sapindus saponaria on diaspore germination and seedling growth of barnyardgrass (Echinochloa crus-galli and morningglory (Ipomoea grandifolia. The aqueous extract was prepared in a proportion of 100 g of dried, ground leaves dissolved in 1000 mL of distilled water, resulting in a 10% extract concentrate. Dilutions of this concentrate were made with distilled water to 7.5, 5.0 and 2.5%. In seedling growth tests, we compared the effect of these extracts with the herbicide nicosulfuron. Both extracts of mature and young leaves caused delays and reductions in diaspore germination and seedling length of barnyardgrass and morningglory, with the most intense effects observed at a concentration of 10%. The effects of the young leaf extract were more similar to those observed with the herbicide, demonstrating that leaf maturation stage of S. saponaria affects its inhibitory effects on the growth of other plants and that this species is effective in controlling weeds.O objetivo deste trabalho foi avaliar o potencial alelopático do extrato aquoso de folhas jovens e maduras de Sapindus saponaria (sabão-de-soldado na germinação de diásporos e no crescimento de plântulas de capim-arroz (Echinochloa crus-galli e corda-de-viola (Ipomoea grandifolia. O extrato aquoso foi preparado na proporção de 100 g de folhas secas e trituradas dissolvidas em 1000 mL de água destilada, produzindo-se o extrato considerado concentrado (10%. A partir deste, foram feitas diluições em água destilada para 7,5; 5,0 e 2,5%. No teste de crescimento de plântulas comparou-se o efeito desses extratos com o herbicida nicosulfuron. Os extratos de folhas maduras e jovens causaram atraso e redução na germinação dos diásporos e no comprimento das plântulas de capim-arroz e corda-de-viola, com efeitos mais intensos na concentração de 10%. No entanto, os

  5. Allelopathic effects of aqueous extracts of leaves of tree marigold (Tithonia diversifolia (Hemsl. A. Gray on seed germination and seedling growth of lettuce (Lactuca sativa L.

    Directory of Open Access Journals (Sweden)

    José Alberto Laynez Garsaball

    2013-09-01

    Full Text Available Some chemical compounds released by plants can to control the presence of other plants in their environment both of their own species and different ones, allelopathy is an important factor in regulating the structure of plant communities, a better understanding of these relationships is critical for appropriate agricultural development. The objective was to determine the effects of aqueous extracts of leaves of tree marigold (Tithonia diversifolia on seed germination and seedling growth of lettuce (Lactuca sativa L. cultivar Parris Island. A 15% w/v extract was prepared with leaves of tree marigold gold, it was allowed to stand for 48 h. After, diluting extracts at 0.5, 1.0, 1.5 and 2.0% w/v were obtained and pH and electrical conductivity (S.cm-1 were determined. Sowing was carried out in trays covered with a double layer of absorbent paper on which were placed 25 seeds/tray. Irrigation was applied twice per day using leaf extracts. The control treatment received tap water. A randomized complete block design was used with four replications. Seedlings were harvested at 14 days after sowing. pH decreased and electrical conductivity increased with increases in the concentration of leaf extracts. The germination was negatively affected by extracts. A lowering effect was observed on the overall growth of lettuce seedlings.

  6. Analytical and chemical profile of pidotimod.

    Science.gov (United States)

    Crimella, T; Orlandi, R; Bocchiola, G; Anders, U; Stradi, R

    1994-12-01

    Pidotimod ((R)-3-[(S)-(5-oxo-2-pyrrolidinyl)carbonyl]-thiazolidine- 4-carboxylic acid, PGT/1A, CAS 121808-62-6) is a new synthetic immunostimulant, which has proved to possess a high activity. This paper describes its physico-chemical properties, structural identification including polymorphism, detection of impurities, determination of related compounds, separation, quantification and purity assay using high-performance liquid chromatography (HPLC).

  7. Properties and applications of chemically functionalized graphene.

    Science.gov (United States)

    Craciun, M F; Khrapach, I; Barnes, M D; Russo, S

    2013-10-23

    The vast and yet largely unexplored family of graphene materials has great potential for future electronic devices with novel functionalities. The ability to engineer the electrical and optical properties in graphene by chemically functionalizing it with a molecule or adatom is widening considerably the potential applications targeted by graphene. Indeed, functionalized graphene has been found to be the best known transparent conductor or a wide gap semiconductor. At the same time, understanding the mechanisms driving the functionalization of graphene with hydrogen is proving to be of fundamental interest for energy storage devices. Here we discuss recent advances on the properties and applications of chemically functionalized graphene.

  8. Caratterizzazione microstrutturale e prove di resilienza su giunti Friction Stir Welding e Linear Friction Welding di compositi a matrice metallica

    Directory of Open Access Journals (Sweden)

    M. Merlin

    2010-04-01

    Full Text Available In questo studio sono stati caratterizzati giunti Friction Stir Welding e Linear Friction Welding su compositi a matrice in lega di alluminio e rinforzo particellare ceramico. Il processo FSW è stato applicato a due compositi ottenuti con processo fusorio, quindi estrusi e trattati termicamente T6: AA6061/20%vol.Al2O3p e AA7005/10%vol.Al2O3p. I giunti LFW sono stati invece realizzati su un composito con matrice in lega di alluminio e rinforzo particellare in carburo di silicio, ottenuto mediante metallurgia delle polveri, quindi forgiato e trattato termicamente T4: AA2124/25%vol.SiCp. Sono stati esaminati gli effetti della saldatura sullecaratteristiche microstrutturali dei giunti, avvalendosi di tecniche di microscopia ottica con analisi di immagine e di microscopia elettronica in scansione (SEM con microsonda a dispersione di energia (EDS. Sono state quindi condotte prove di resilienza con pendolo strumentato Charpy. Lo studio dei meccanismi di danneggiamento è stato effettuato mediante analisi al SEM delle superfici di frattura. Entrambi i processi di saldatura hanno portato a giunti sostanzialmente esenti da difetti. La microstruttura dei cordoni è risultata dipendente sia dalle caratteristiche microstrutturali iniziali dei compositi considerati, sia dalla tipologia di processo di saldatura. Nel caso dei compositi AA6061/20%Al2O3p e AA7005/10%Al2O3p saldati FSW si è osservato un sostanziale incremento di resilienza, rispetto al materiale base, in conseguenza dell’affinamento dei grani della matrice, della riduzione della dimensione media delle particelle di rinforzo e della loro spigolosità, indotte dal processo di saldatura. Il composito AA2124/25%SiCp saldato LFW ha presentato valori di resilienza confrontabili con quelli del materiale base, in conseguenza, soprattutto, dei limitati effetti della saldatura su dimensione e distribuzione delle particelle di rinforzo.

  9. Assessment of volatile organic compounds in surface water at West Branch Canal Creek, Aberdeen Proving Ground, Maryland, 1999

    Science.gov (United States)

    Olsen, Lisa D.; Spencer, Tracey A.

    2000-01-01

    The U.S. Geological Survey (USGS) collected 13 surface-water samples and 3 replicates from 5 sites in the West Branch Canal Creek area at Aberdeen Proving Ground from February through August 1999, as a part of an investigation of ground-water contamination and natural attenuation processes. The samples were analyzed for volatile organic compounds, including trichloroethylene, 1,1,2,2-tetrachloroethane, carbon tetrachloride, and chloroform, which are the four major contaminants that were detected in ground water in the Canal Creek area in earlier USGS studies. Field blanks were collected during the sampling period to assess sample bias. Field replicates were used to assess sample variability, which was expressed as relative percent difference. The mean variability of the surface-water replicate analyses was larger (35.4 percent) than the mean variability of ground-water replicate analyses (14.6 percent) determined for West Branch Canal Creek from 1995 through 1996. The higher variability in surface-water analyses is probably due to heterogeneities in the composition of the surface water rather than differences in sampling or analytical procedures. The most frequently detected volatile organic compound was 1,1,2,2- tetrachloroethane, which was detected in every sample and in two of the replicates. The surface-water contamination is likely the result of cross-media transfer of contaminants from the ground water and sediments along the West Branch Canal Creek. The full extent of surface-water contamination in West Branch Canal Creek and the locations of probable contaminant sources cannot be determined from this limited set of data. Tidal mixing, creek flow patterns, and potential effects of a drought that occurred during the sampling period also complicate the evaluation of surface-water contamination.

  10. Ex Vivo and In Vivo Mice Models to Study Blastocystis spp. Adhesion, Colonization and Pathology: Closer to Proving Koch's Postulates.

    Directory of Open Access Journals (Sweden)

    Sitara S R Ajjampur

    Full Text Available Blastocystis spp. are widely prevalent extra cellular, non-motile anerobic protists that inhabit the gastrointestinal tract. Although Blastocystis spp. have been associated with gastrointestinal symptoms, irritable bowel syndrome and urticaria, their clinical significance has remained controversial. We established an ex vivo mouse explant model to characterize adhesion in the context of tissue architecture and presence of the mucin layer. Using confocal microscopy with tissue whole mounts and two axenic isolates of Blastocystis spp., subtype 7 with notable differences in adhesion to intestinal epithelial cells (IEC, isolate B (ST7-B and isolate H (more adhesive, ST7-H, we showed that adhesion is both isolate dependent and tissue trophic. The more adhesive isolate, ST7-H was found to bind preferentially to the colon tissue than caecum and terminal ileum. Both isolates were also found to have mucinolytic effects. We then adapted a DSS colitis mouse model as a susceptible model to study colonization and acute infection by intra-caecal inoculation of trophic Blastocystis spp.cells. We found that the more adhesive isolate ST7-H was also a better colonizer with more mice shedding parasites and for a longer duration than ST7-B. Adhesion and colonization was also associated with increased virulence as ST7-H infected mice showed greater tissue damage than ST7-B. Both the ex vivo and in vivo models used in this study showed that Blastocystis spp. remain luminal and predominantly associated with mucin. This was further confirmed using colonic loop experiments. We were also successfully able to re-infect a second batch of mice with ST7-H isolates obtained from fecal cultures and demonstrated similar histopathological findings and tissue damage thereby coming closer to proving Koch's postulates for this parasite.

  11. Ex Vivo and In Vivo Mice Models to Study Blastocystis spp. Adhesion, Colonization and Pathology: Closer to Proving Koch's Postulates.

    Science.gov (United States)

    Ajjampur, Sitara S R; Png, Chin Wen; Chia, Wan Ni; Zhang, Yongliang; Tan, Kevin S W

    2016-01-01

    Blastocystis spp. are widely prevalent extra cellular, non-motile anerobic protists that inhabit the gastrointestinal tract. Although Blastocystis spp. have been associated with gastrointestinal symptoms, irritable bowel syndrome and urticaria, their clinical significance has remained controversial. We established an ex vivo mouse explant model to characterize adhesion in the context of tissue architecture and presence of the mucin layer. Using confocal microscopy with tissue whole mounts and two axenic isolates of Blastocystis spp., subtype 7 with notable differences in adhesion to intestinal epithelial cells (IEC), isolate B (ST7-B) and isolate H (more adhesive, ST7-H), we showed that adhesion is both isolate dependent and tissue trophic. The more adhesive isolate, ST7-H was found to bind preferentially to the colon tissue than caecum and terminal ileum. Both isolates were also found to have mucinolytic effects. We then adapted a DSS colitis mouse model as a susceptible model to study colonization and acute infection by intra-caecal inoculation of trophic Blastocystis spp.cells. We found that the more adhesive isolate ST7-H was also a better colonizer with more mice shedding parasites and for a longer duration than ST7-B. Adhesion and colonization was also associated with increased virulence as ST7-H infected mice showed greater tissue damage than ST7-B. Both the ex vivo and in vivo models used in this study showed that Blastocystis spp. remain luminal and predominantly associated with mucin. This was further confirmed using colonic loop experiments. We were also successfully able to re-infect a second batch of mice with ST7-H isolates obtained from fecal cultures and demonstrated similar histopathological findings and tissue damage thereby coming closer to proving Koch's postulates for this parasite.

  12. Constrained Parameterization of the Multichannel Analysis of Surface Waves Approach with Application at Yuma Proving Ground, Arizona

    Science.gov (United States)

    Schwenk, Jacob Tyler

    Field data from Yuma Proving Ground, Arizona was used to test the feasibility of merging common multichannel analysis of surface waves (MASW) processing routines with mode-consistent shear-wave refraction traveltime tomography and synthetic modeling to optimize and constrain inversion results. Shear-wave first-arrival refraction tomography was used to enhance layer-model resolution and refine the MASW layer model with independent body-wave information. Shear-wave tomograms suggested a high-velocity layer, not found in initial 'smooth' MASW velocity sections that were used as initial models for tomographic inversion. Increasing the stratification of the MASW layer model, to generally match tomogram structure, resulted in a higher-resolution MASW model constrained through joint analysis. This mutual analysis of shear-wave velocity (Vs) provided multiplicity to the structural interpretation of the site. Constrained-parameterization MASW results, compressional-wave tomography (Vp:Vs ratio), and density well logs populated a 2D model for numerical modeling, which was manually updated over several iterations to converge upon the site's first-arrival and dispersion characteristics. Further evaluation of the synthetic seismograms gave insight into the relationship between acquisition geometry (offset selection) and the associated dispersion-image character. Furthermore, modeling gave a secondary measurement on depth to half-space, velocity structure, and relative Vp:Vs ratios, which formulated a final MASW profile. The gradual change of the earth model, given an evolving hierarchy of constraint, is seen as the main finding of this thesis. The calculated movement towards a higher-resolution inversion based on joint geophysical measurements, analysis, and interpretation, engenders a constrained-parameterization solution with highest confidence.

  13. CAMEO Chemicals Software

    Science.gov (United States)

    CAMEO Chemicals is an extensive chemical database, available for download, with critical response information for thousands of chemicals, and a tool that tells you what reactions might occur if chemicals were mixed together.

  14. Ground-water and surface-water quality data for the West Branch Canal Creek area, Aberdeen Proving Ground, Maryland

    Science.gov (United States)

    Spencer, Tracey A.; Phelan, Daniel J.; Olsen, Lisa D.; Lorah, Michelle M.

    2001-01-01

    This report presents ground-water and surface-water quality data from samples collected by the U.S. Geological Survey from November 1999 through May 2001 at West Branch Canal Creek, Aberdeen Proving Ground, Maryland. The report also provides a description of the sampling and analytical methods that were used to collect and analyze the samples, and includes an evaluation of the quality-assurance data. The ground-water sampling network included two 4-inch wells, two 2-inch wells, sixteen 1-inch piezometers, one hundred thirteen 0.75-inch piezometers, two 0.25-inch flexible-tubing piezo-meters, twenty-seven 0.25-inch piezometers, and forty-two multi-level monitoring system depths at six sites. Ground-water profiler samples were collected from nine sites at 34 depths. In addition, passive-diffusion-bag samplers were deployed at four sites, and porous-membrane sampling devices were installed in the upper sediment at five sites. Surface-water samples were collected from 20 sites. Samples were collected from wells and 0.75-inch piezometers for measurement of field parameters and reduction-oxidation constituents, and analysis of inorganic and organic constituents, during three sampling events in March?April and June?August 2000, and May 2001. Surface-water samples were collected from November 1999 through September 2000 during five sampling events for analysis of organic constituents. Ground-water profiler samples were collected in April?May 2000, and analyzed for field measure-ments, reduction-oxidation constituents, and inorganic constituents and organic constituents. Passive-diffusion-bag samplers were installed in September 2000, and samples were analyzed for organic constituents. Multi-level monitoring system samples were collected and analyzed for field measurements and reduction-oxidation con-stituents, inorganic constituents, and organic con-stituents in March?April and June?August 2000. Field measurements and organic constituents were collected from 0.25-inch

  15. Assessment of volatile organic compounds in surface water at Canal Creek, Aberdeen Proving Ground, Maryland, November 1999-September 2000

    Science.gov (United States)

    Phelan, Daniel J.; Olsen, Lisa D.; Senus, Michael P.; Spencer, Tracey A.

    2001-01-01

    The purpose of this report is to describe the occurrence and distribution of volatile organic compounds in surface-water samples collected by the U.S. Geological Survey in the Canal Creek area of Aberdeen Proving Ground, Maryland, from November 1999 through September 2000. The report describes the differences between years with below normal and normal precipitation, the effects of seasons, tide stages, and location on volatile organic compound concentrations in surface water, and provides estimates of volatile organic concentration loads to the tidal Gunpowder River. Eighty-four environmental samples from 20 surface-water sites were analyzed. As many as 13 different volatile organic compounds were detected in the samples. Concentrations of volatile organic compounds in surface-water samples ranged from below the reporting limit of 0.5 micrograms per liter to a maximum of 50.2 micrograms per liter for chloroform. Chloroform was detected most frequently, and was found in 55 percent of the environmental samples that were analyzed for volatile organic compounds (46 of 84 samples). Carbon tetrachloride was detected in 56 percent of the surface-water samples in the tidal part of the creek (34 of 61 samples), but was only detected in 3 of 23 samples in the nontidal part of the creek. 1,1,2,2-Tetrachloroethane was detected in 43 percent of the tidal samples (26 of 61 samples), but was detected at only two nontidal sites and only during November 1999. Three samples were collected from the tidal Gunpowder River about 300 feet from the mouth of Canal Creek in May 2000, and none of the samples contained volatile organic compound concentrations above detection levels. Volatile organic compound concentrations in surface water were highest in the reaches of the creek adjacent to the areas with the highest known levels of ground-water contamination. The load of total volatile organic compounds from Canal Creek to the Gunpowder River is approximately 1.85 pounds per day (0

  16. The Importance of “Corpus Delicti” in Proving “Causation” in Homicide Cases in Nigeria

    Directory of Open Access Journals (Sweden)

    Ngozi Alili

    2017-08-01

    Full Text Available In homicide cases, it may be difficult to prove the cause of death if the body of the victim of an alleged murderous attack is not made available for medical examination. It is therefore obvious that there are instances and circumstances where persons accused of committing the offence of culpable homicide punishable with death take steps to destroy the body of their victims in order to avoid prosecution or conviction and punishment if prosecuted. It would seem that the legal perception and meaning of the body of the deceased in homicide cases otherwise called “corpus delicti” is largely misconstrued by lawyers and laymen alike. This paper examined this identified problem and attempted to correct same and also considered the importance of “corpus delicti” in criminal trials generally and in homicide cases in particular. It also considered the importance and relevance of the legal presumption of death which is of evidential value in both civil and criminal proceedings in bridging the gap that may be created by the absence of corpus delicti. The views of the courts in some decided cases to the effect that it is not in all homicide cases that the prosecution case may fail simply because the body of the deceased was not produced or medically examined, was challenged and it was argued that conviction in homicide cases in the absence of the corpus delicti can only be sustained where evidence of its destruction by the accused is established and this may also require the production of some parts or pieces of what was destroyed. It was observed that corpus delicti and causation are twin legal concepts in criminal law constituting the physical element (octus reus of result offences, such as culpable homicide punishable with death, with the result that one cannot exist in isolation from the other without a resultant miscarriage of justice. The courts were urged to sparingly and cautiously convict persons alleged to have committed culpable homicide

  17. CTP-based tissue outcome. Promising tool to prove the beneficial effect of mechanical recanalization in acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Drewer-Gutland, F.; Niederstadt, T.U.; Heindel, W. [University Hospital Muenster (Germany). Inst. for Clinical Radiology; Kemmling, A. [University Hospital Schleswig-Holstein, Luebeck (Germany). Dept. of Neuroradiology; Ligges, S. [Muenster Univ. (Germany). Inst. of Biostatistics and Clinical Research; Ritter, M.; Dziewas, R.; Ringelstein, E.B. [University Hospital Muenster (Germany). Dept. of Neurology; Hesselmann, V. [Asklepios-Clinic North, Hamburg (Germany). Radiology/Neuroradiology

    2015-06-15

    To prove the tissue-protecting effect of mechanical recanalization, we assessed the CT perfusion-based tissue outcome (''TO'') and correlated this imaging parameter with the 3-month clinical outcome (''CO''). 159 patients with large intracranial artery occlusions revealing mechanical recanalization were investigated by CCT, CT angiography (CTA) and CT perfusion (CTP) upon admission. For the final infarct volume, native CCT was repeated after 24h. The ''TO'' (''percentage mismatch loss'' = %ML) was defined as the difference between initial penumbral tissue on CTP and final infarct volume on follow-up CCT. We monitored the three-month modified Rankin Scale (mRS), age, bleeding occurrence, time to recanalization, TICI score and collateralization grade, infarct growth and final infarct volume. Spearman's correlation and nominal regression analysis were used to evaluate the impact of these parameters on mRS Significant correlations were found for %ML and mRS (c=0.48, p<0.001), for final infarct volume and mRS (c=0.52, p<0.001), for TICI score and mRS (c=-0.35, p<0.001), for initial infarct core and mRS (c=0.14, p=0.039) as well as for age and mRS (c=0.37, p<0.001). According to the regression analysis, %ML predicted the classification of mRS correctly in 38.5% of cases. The subclasses mRS 1 and 6 could be predicted by %ML with 86.4% and 60.9% reliability, respectively. No correlations were found for time to recanalization and mRS, for collateralization grade and mRS, and for post-interventional bleeding and mRS. Better than the TICI score, CT-based TO predicts the clinical success of mechanical recanalization, showing that not recanalization, but reperfusion should be regarded as a surrogate parameter for stroke therapy.

  18. Military Base Realignments and Closures: Army is Developing Plans to Transfer Functions from Fort Monmouth, New Jersey, to Aberdeen Proving Ground, Maryland, but Challenges Remain

    National Research Council Canada - National Science Library

    2008-01-01

    ...) close Fort Monmouth, New Jersey, and realign most of its technical functions to Aberdeen Proving Ground, Maryland, as one of 182 recommendations in the 2005 base realignment and closure (BRAC) round...

  19. Remedial investigation sampling and analysis plan for J-Field, Aberdeen Proving Ground, Maryland: Volume 2, Quality Assurance Project Plan

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, S.; Martino, L.; Patton, T.

    1995-03-01

    J-Field encompasses about 460 acres at the southern end of the Gunpowder Neck Peninsula in the Edgewood Area of APG (Figure 2.1). Since World War II, the Edgewood Area of APG has been used to develop, manufacture, test, and destroy chemical agents and munitions. These materials were destroyed at J-Field by open burning and open detonation (OB/OD). For the purposes of this project, J-Field has been divided into eight geographic areas or facilities that are designated as areas of concern (AOCs): the Toxic Burning Pits (TBP), the White Phosphorus Burning Pits (WPP), the Riot Control Burning Pit (RCP), the Robins Point Demolition Ground (RPDG), the Robins Point Tower Site (RPTS), the South Beach Demolition Ground (SBDG), the South Beach Trench (SBT), and the Prototype Building (PB). The scope of this project is to conduct a remedial investigation/feasibility study (RI/FS) and ecological risk assessment to evaluate the impacts of past disposal activities at the J-Field site. Sampling for the RI will be carried out in three stages (I, II, and III) as detailed in the FSP. A phased approach will be used for the J-Field ecological risk assessment (ERA).

  20. Chemical changes in concentrated acidic metal-bearing wastewaters when treated with lime

    Energy Technology Data Exchange (ETDEWEB)

    Jenke, D.R.

    1983-04-01

    Lime neutralization of acidic wastewaters can prove to be an effective treatment process provided sufficient lime is added. The chemical changes that occur in the system are extensive and varied. Precipitation is predominant with complexation, oxidation and adsorption playing major roles. Total chemical analyses have identified the chemical changes, and controlled laboratory simulations have identified the relative importance of the physical-chemical processes. Exchange of oxygen and carbon dioxide are discussed, and optimum lime addition rates are predicted by thermodynamic computer simulation.

  1. Biodiesel production by chemical or enzymatic esterification of sunflower oil

    Energy Technology Data Exchange (ETDEWEB)

    Passarinho, Paula C.; Rosa, M. Fernanda; Oliveira, A.C.; Pingarilho, M.S.; Beirao, S.G.; Vieira, Ana Maria Soares

    1998-07-01

    In this work, two processes of sunflower oil transesterification, with methanol or ethanol, were studied for biodiesel production: chemical (catalyst- NaOH) and enzymatic (catalyst - rhizomucor miehei lipase). The chemical catalysis proved to be more efficient, having been obtained higher conversion yields and a better quality biodiesel, mainly in the case where methanol was used. The transesterification product had, in all cases, to be purified in order to be used as a diesel substitute.

  2. Chemical Function Predictions for Tox21 Chemicals

    Data.gov (United States)

    U.S. Environmental Protection Agency — Random forest chemical function predictions for Tox21 chemicals in personal care products uses and "other" uses. This dataset is associated with the following...

  3. Chemical Profile of the Volatile Oil from the Leaves of Erythroxylum deciduum A. St.-Hil. (Erythroxylaceae, Collected in Goiânia, Goiás

    Directory of Open Access Journals (Sweden)

    Giuliana Muniz Vila Verde

    2016-06-01

    Full Text Available The Erythroxylum (Erythroxylaceae genus has about 130 species, which can be found in forest environments and cerrado. Studies with Erythroxylum species led to the isolation of secondary metabolites such as flavonóides, alkaloids, tannins, terpenes and phenylpropanoids that exhibit anti-oxidant activity, anti-carcinogenic, anti-inflammatory activity among others to be operated with pharmaceutical purposes. In order to contribute to the chemical elucidation of Erythroxylum genus, this research aimed to evaluate the composition of the essential oil from the leaves of E. deciduum A. St.-Hil. The botanical material was collected in the peri-urban area of the city of Goiânia, Goiás, Brazil, it was identified and had a voucher specimen deposited in the Herbarium of the State University of Goiás. The essential oil extraction was performed by hydrodistillation adapted by Clevenger. The essential oil chemical composition was determined by gas chromatography-mass spectrometry (GC/ MS. The species studied showed as major components: himachalol (3.49%, sandaracopimarinal (4.87%, ethyl 8cedren-13-ol (5.65% and ternina (6.37% whose description on the literature, points to the antimicrobial and allelopathic activity. Thus, These volatile components may be viable in obtaining bioproducts or as prototypes in the synthesis of compounds of pharmacotherapeutic, food and agricultural interest.

  4. Modern Chemical Technology, Guidebook for Chemical Technicians.

    Science.gov (United States)

    Pecsok, Robert L.; Chapman, Kenneth

    This volume is a part of the ACS "Modern Chemical Technology" (ChemTeC) curriculum that is developed for chemical technicians. It is intended as a handbook that will be used throughout the instruction. Safety is stressed in eight of the ten chapters under the headings: safety in the chemical laboratory, personal protective equipment, fire safety…

  5. Chemical analysis of the Assale (Ethiopia) rock salt deposit | Binega ...

    African Journals Online (AJOL)

    contaminants) elements found in the Assale (Ethiopia) rock salt. The results showed that the rock salt is found to be the best natural common salt. This was proved by comparison with the chemical requirement and trace elements in common ...

  6. Efeito alelopático de capim-braquiária (Brachiaria decumbens sobre o crescimento inicial de sete espécies de plantas cultivadas Allelopathic effects of Brachiaria decumbens on the initial development of seven crops

    Directory of Open Access Journals (Sweden)

    L.S. Souza

    2006-12-01

    Full Text Available O presente trabalho constou de sete experimentos, que foram conduzidos na Faculdade de Ciências Agronômicas, campus de Botucatu, UNESP, São Paulo, Brasil, com o objetivo de avaliar os efeitos alelopáticos de Brachiaria decumbens, colhida em diferentes épocas, sobre o crescimento inicial de milho, arroz, trigo, soja, feijão, algodão e capim-braquiária (B. decumbens, bem como a dinâmica do nitrogênio no solo. A parte aérea de B. decumbens foi coletada durante as estações seca (outono-inverno e chuvosa (primavera-verão, em área de pastagem localizada no município de Botucatu-SP. A matéria seca triturada de B. decumbens foi incorporada ao solo dos vasos na proporção de 3% p/p. O delineamento experimental foi inteiramente casualizado, com cinco repetições. Contando-se a partir do transplante, o experimento foi conduzido por 21 dias para milho e feijão, 24 dias para soja e trigo, 28 dias para arroz e 30 dias para algodão e capim-braquiária. O crescimento dessas plantas foi reduzido com a adição de capim-braquiária para as duas épocas, sendo o próprio capim-braquiária o mais afetado. Os efeitos inibitórios foram mais intensos para capim-braquiária coletado na estação chuvosa. A incorporação da matéria seca da parte aérea de B. decumbens reduziu, significativamente, os teores de nitrato no solo, em todos os estudos realizados.This work consisted of seven experiments carried out at UNESP Botucatu-SP Brazil to evaluate the allelopathic effects of Brachiaria decumbens collected in different seasons on the initial growth of corn, rice, wheat, soybean, bean, cotton and B. decumbens and to evaluate nitrogen dynamics in the soil. The upper part of B. decumbens was collected during the dry and wet seasons in a pasture area located in the district of Botucatu-SP. The dry matter was ground and incorporated into the soil in 3% w/w. The experimental design was arranged in completely randomized plots with 5 replications

  7. Microfluidic chemical reaction circuits

    Science.gov (United States)

    Lee, Chung-cheng [Irvine, CA; Sui, Guodong [Los Angeles, CA; Elizarov, Arkadij [Valley Village, CA; Kolb, Hartmuth C [Playa del Rey, CA; Huang, Jiang [San Jose, CA; Heath, James R [South Pasadena, CA; Phelps, Michael E [Los Angeles, CA; Quake, Stephen R [Stanford, CA; Tseng, Hsian-rong [Los Angeles, CA; Wyatt, Paul [Tipperary, IE; Daridon, Antoine [Mont-Sur-Rolle, CH

    2012-06-26

    New microfluidic devices, useful for carrying out chemical reactions, are provided. The devices are adapted for on-chip solvent exchange, chemical processes requiring multiple chemical reactions, and rapid concentration of reagents.

  8. Safer Chemicals Research

    Science.gov (United States)

    EPA's Chemical Safety research protects human health and the environment by evaluating chemicals for potential risk and providing tools and guidance for improved chemical production that supports a sustainable environment.

  9. LCA of Chemicals and Chemical Products

    DEFF Research Database (Denmark)

    Fantke, Peter; Ernstoff, Alexi

    2017-01-01

    This chapter focuses on the application of Life Cycle Assessment (LCA) to evaluate the environmental performance of chemicals as well as of products and processes where chemicals play a key role. The life cycle stages of chemical products, such as pharmaceuticals drugs or plant protection products......, are discussed and differentiated into extraction of abiotic and biotic raw materials, chemical synthesis and processing, material processing, product manufacturing, professional or consumer product use, and finally end-of-life . LCA is discussed in relation to other chemicals management frameworks and concepts...... of potential environmental impacts occurs during the early product life cycle stages, potential impacts related to chemicals that are found as ingredients or residues directly in products can be dominated by the product use stage. Finally, methodological challenges in LCA studies in relation to chemicals...

  10. Chemical Security Analysis Center

    Data.gov (United States)

    Federal Laboratory Consortium — In 2006, by Presidential Directive, DHS established the Chemical Security Analysis Center (CSAC) to identify and assess chemical threats and vulnerabilities in the...

  11. Efeito alelopático de folhas de Solanum lycocarpum A. St.-Hil. (Solanaceae na germinação e crescimento de Sesamum indicum L. (Pedaliaceae sob diferentes temperaturas Allelopathic effect of Solanum lycocarpum A. St.-Hil. leaves on the germination and growth of Sesamum indicum L.(Pedaliaceae under different temperatures

    Directory of Open Access Journals (Sweden)

    Sarah C. Caldas Oliveira

    2004-09-01

    through production of chemical compounds released into the environment. Several Solanum species have shown some allelopathic property. S. lycocarpum islargely distributed on disturbed areas of the Brazilian Cerrado. In the present study the effects of aqueous extracts of S. lycocarpum leaves on the germination and growth of Sesanum indicum L. (sesame were investigated. Aqueous leaf extracts at concentrations of 1%, 2%, 3%, 4%, and 5% (w/v were prepared. The osmolarity of the extracts were measured and solutions of polyethylene glycol (PEG 6000 of similar osmolarity were prepared to evaluate osmotic effects of the extracts on sesame germination and growth. The experiments were carried out on petri dishes lined by two layers of filter paper plus the solutions to be tested. For the germination experiments the number of germinated seeds was checked every 8h. For the growth experiments sesame seeds were previously germinated in water and disposed to grow in the extracts. After five days of incubation the root and shoot length of the seedlings was measured. All the experiments were performed at 22 ºC, 30 ºC and 38 ºC. The extracts did not affect the germinability but increased the average germination time in a dose-dependent manner at the three temperatures. The root growth was more affected by the extracts, showing tip-necrosis, absence of root hairs, and formation of secondary roots. These effects were more evident at 38 ºC. Using PEG 6000 it was shown that the observed effects were not due to osmotic properties of the leaf extracts.

  12. Environmental Chemistry and Chemical Ecology of "Green Tide" Seaweed Blooms.

    Science.gov (United States)

    Van Alstyne, Kathryn L; Nelson, Timothy A; Ridgway, Richard L

    2015-09-01

    Green tides are large growths or accumulations of green seaweeds that have been increasing in magnitude and frequency around the world. Because green tides consist of vast biomasses of algae in a limited area and are often seasonal or episodic, they go through periods of rapid growth in which they take up large amounts of nutrients and dissolved gases and generate bioactive natural products that may be stored in the plants, released into the environment, or broken down during decomposition. As a result of the use and production of inorganic and organic compounds, the algae in these blooms can have detrimental impacts on other organisms. Here, we review some of the effects that green tides have on the chemistry of seawater and the effects of the natural products that they produce. As blooms are developing and expanding, algae in green tides take up inorganic nutrients, such as nitrate and ortho-phosphate, which can limit their availability to other photosynthetic organisms. Their uptake of dissolved inorganic carbon for use in photosynthesis can cause localized spikes in the pH of seawater during the day with concomitant drops in the pH at night when the algae are respiring. Many of the algae that form green-tide blooms produce allelopathic compounds, which are metabolites that affect other species. The best documented allelopathic compounds include dimethylsulfoniopropionate (DMSP), dopamine, and reactive oxygen species (ROS) and their breakdown products. DMSP and dopamine are involved in defenses against herbivores. Dopamine and ROS are released into seawater where they can be allelopathic or toxic to other organisms. Thus, these macroalgal blooms can have harmful effects on nearby organisms by altering concentrations of nutrients and dissolved gas in seawater and by producing and releasing allelopathic or toxic compounds. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved

  13. Allelopathic inhibition of seedling emergence in dicotyledonous ...

    African Journals Online (AJOL)

    This study was initiated to determine suitability of crude extracts of ground C. myriocarpus fruits as a pre-emergent bionematicide on 10 cultivars of different dicotyledonous crops. In each trial, ten levels of crude extracts of C. myriocarpus fruits viz. 0, 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, 1.75, 2.00 and 2.25 g, were arranged in a ...

  14. Allelopathic effects of invasive Eucalyptus camaldulensis on ...

    African Journals Online (AJOL)

    Eucalyptus camaldulensis Dehnh. (red river gum; Myrtaceae) is an invasive tree in riparian habitats of the Western Cape, South Africa, where it replaces indigenous vegetation and affects ecosystem functioning. These invasions lead to changes in river geomorphology and reduction in stream flow. The mechanisms that ...

  15. Allelopathic effects of water hyacinth [Eichhornia crassipes].

    Directory of Open Access Journals (Sweden)

    Sanaa M M Shanab

    Full Text Available Eichhornia crassipes (Mart Solms is an invasive weed known to out-compete native plants and negatively affect microbes including phytoplankton. The spread and population density of E. crassipes will be favored by global warming. The aim here was to identify compounds that underlie the effects on microbes. The entire plant of E. crassipes was collected from El Zomor canal, River Nile (Egypt, washed clean, then air dried. Plant tissue was extracted three times with methanol and fractionated by thin layer chromatography (TLC. The crude methanolic extract and five fractions from TLC (A-E were tested for antimicrobial (bacteria and fungal and anti-algal activities (green microalgae and cyanobacteria using paper disc diffusion bioassay. The crude extract as well as all five TLC fractions exhibited antibacterial activities against both the gram positive bacteria; Bacillus subtilis and Streptococcus faecalis; and the gram negative bacteria; Escherichia coli and Staphylococcus aureus. Growth of Aspergillus flavus and Aspergillus niger were not inhibited by either E. crassipes crude extract nor its five fractions. In contrast, Candida albicans (yeast was inhibited by all. Some antialgal activity of the crude extract and its fractions was manifest against the green microalgae; Chlorella vulgaris and Dictyochloropsis splendida as well as the cyanobacteria; Spirulina platensis and Nostoc piscinale. High antialgal activity was only recorded against Chlorella vulgaris. Identifications of the active antimicrobial and antialgal compounds of the crude extract as well as the five TLC fractions were carried out using gas chromatography combined with mass spectroscopy. The analyses showed the presence of an alkaloid (fraction A and four phthalate derivatives (Fractions B-E that exhibited the antimicrobial and antialgal activities.

  16. Allelopathic effects of water hyacinth [Eichhornia crassipes].

    Science.gov (United States)

    Shanab, Sanaa M M; Shalaby, Emad A; Lightfoot, David A; El-Shemy, Hany A

    2010-10-08

    Eichhornia crassipes (Mart) Solms is an invasive weed known to out-compete native plants and negatively affect microbes including phytoplankton. The spread and population density of E. crassipes will be favored by global warming. The aim here was to identify compounds that underlie the effects on microbes. The entire plant of E. crassipes was collected from El Zomor canal, River Nile (Egypt), washed clean, then air dried. Plant tissue was extracted three times with methanol and fractionated by thin layer chromatography (TLC). The crude methanolic extract and five fractions from TLC (A-E) were tested for antimicrobial (bacteria and fungal) and anti-algal activities (green microalgae and cyanobacteria) using paper disc diffusion bioassay. The crude extract as well as all five TLC fractions exhibited antibacterial activities against both the gram positive bacteria; Bacillus subtilis and Streptococcus faecalis; and the gram negative bacteria; Escherichia coli and Staphylococcus aureus. Growth of Aspergillus flavus and Aspergillus niger were not inhibited by either E. crassipes crude extract nor its five fractions. In contrast, Candida albicans (yeast) was inhibited by all. Some antialgal activity of the crude extract and its fractions was manifest against the green microalgae; Chlorella vulgaris and Dictyochloropsis splendida as well as the cyanobacteria; Spirulina platensis and Nostoc piscinale. High antialgal activity was only recorded against Chlorella vulgaris. Identifications of the active antimicrobial and antialgal compounds of the crude extract as well as the five TLC fractions were carried out using gas chromatography combined with mass spectroscopy. The analyses showed the presence of an alkaloid (fraction A) and four phthalate derivatives (Fractions B-E) that exhibited the antimicrobial and antialgal activities.

  17. Allelopathic Effects of Eucalyptus Tereticornis on Phaseolus ...

    African Journals Online (AJOL)

    The water extracts of leaves (green, brown and decayed stages) and bark of Eucalyptus tereticornis were tested for seed germination and primary root and shoot development of Phaseolus vulgaris seedlings. There was no significant difference in the germination percentage of Phaseolus vulgaris due to the treatments of ...

  18. Allelopathic inhibition of seedling emergence in dicotyledonous ...

    African Journals Online (AJOL)

    hope&shola

    2010-12-06

    Dec 6, 2010 ... cides, namely aldicarb and fenamiphos (Mashela et al.,. 2008). Generally, the damage caused by nematodes on plants is directly proportional to the initial population density of nematodes (Pi) at planting (Seinhorst, 1965). Thus, it is preferable that Pi be at its lowest at planting. Most synthetic nematicides ...

  19. 20 CFR 30.231 - How does a claimant prove employment-related exposure to a toxic substance at a DOE facility or a...

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false How does a claimant prove employment-related exposure to a toxic substance at a DOE facility or a RECA section 5 facility? 30.231 Section 30.231 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR ENERGY EMPLOYEES OCCUPATIONAL ILLNESS COMPENSATION PROGRAM ACT OF...

  20. The chemical life(1).

    Science.gov (United States)

    Hodges, Nathan

    2015-01-01

    You write this narrative autoethnography to open up a conversation about our chemical lives. You go through your day with chemical mindfulness, questioning taken-for-granted ideas about natural and artificial, healthy and unhealthy, dependency and addiction, trying to understand the chemical messages we consume through the experiences of everyday life. You reflect on how messages about chemicals influence and structure our lives and why some chemicals are celebrated and some are condemned. Using a second-person narrative voice, you show how the personal is relational and the chemical is cultural. You write because you seek a connection, a chemical bond.

  1. Existing chemicals: international activities.

    Science.gov (United States)

    Purchase, J F

    1989-01-01

    The standards of care used in the protection of the health and safety of people exposed to chemicals has increased dramatically in the last decade. Standards imposed by regulation and those adopted by industry have required a greater level of knowledge about the hazards of chemicals. In the E.E.C., the 6th amendment of the dangerous substances directive imposed the requirement that al new chemicals should be tested according to prescribed programme before introduction on to the market. The development of a European inventory of existing chemicals was an integral part of the 6th amendment. It has now become clear that increased standards of care referred to above must be applied to the chemicals on the inventory list. There is, however, a considerable amount of activity already under way in various international agencies. The OECD Chemicals Programme has been involved in considering the problem of existing chemicals for some time, and is producing a priority list and action programme. The International Programme on Chemical Safety produces international chemical safety cards, health and safety guides and environmental health criteria documents. The international register of potentially toxic compounds (part of UNEP) has prepared chemical data profiles on 990 compounds. The International Agency for Research on Cancer prepared monographs on the carcinogenic risk of chemicals to man. So far 42 volumes have been prepared covering about 900 substances. IARC and IPCS also prepare periodic reports on ongoing research on carcinogenicity or toxicity (respectively) of chemicals. The chemical industry through ECETOC (the European Chemical Industry Ecology and Toxicology Centre) has mounted a major initiative on existing chemicals. Comprehensive reviews of the toxicity of selected chemicals are published (Joint Assessment of Commodity Chemicals). In its technical report no. 30 ECETOC lists reviews and evaluations by major national and international organisations, which provides

  2. Advances in chemical physics

    CERN Document Server

    Rice, Stuart A

    2012-01-01

    The Advances in Chemical Physics series-the cutting edge of research in chemical physics The Advances in Chemical Physics series provides the chemical physics field with a forum for critical, authoritative evaluations of advances in every area of the discipline. Filled with cutting-edge research reported in a cohesive manner not found elsewhere in the literature, each volume of the Advances in Chemical Physics series serves as the perfect supplement to any advanced graduate class devoted to the study of chemical physics. This volume explores: Quantum Dynamical Resonances in Ch

  3. Proving the Ocean Nourishment Concept

    Science.gov (United States)

    Jones, I. S.

    2007-12-01

    Vast regions of the sea are barren because of a lack of essential nutrients. Ocean Nourishment is the concept of injecting nutrients into the photic zone of the ocean to store carbon and increase the base of the marine food web. It is elaborated in Jones & Young (1997). The first step in demonstrating this concept is to see if the limiting nutrients can be recognised and provided to the oligotrophic ocean. To this end water samples from three sites were collected in ultraclean polycarbonate culture bottles and enriched with various mixtures of nutrients. They were then placed in a water bath and subjected to natural sunlight for a number of days. Fluorescence levels were measured daily. Previously Thomas (1969) carried out enrichment experiments in and out of high nutrient water in the North Pacific and again Thomas (1970) cultured on the deck of his ship nutrient poor waters in the Pacific. He found nitrogen was the most important limiting nutrient in the poor waters but that micronutrients produced growth in the nutrient rich waters. Ryther and Dunstan (1971) in the Atlantic cultured coastal water with only nitrogen and phosphorus separately. The addition of nitrogen without phosphate produced growth in all cases. To increase the geographic coverage of enrichment experiments, samples were collected off Morocco twice, in the Tasman Sea and in the Sulu Sea. The samples enriched with different concentrations of urea (typically 10 microM) and phosphorous. An increase concentration of chlorophyll is the result of growth of phytoplankton exceeding death and grazing by zooplankton. At five sites an increase of chlorophyll was observed in the macronutrient enriched bottles over that in the control. At the sixth site the control grew at much the same rate as the enriched sample possibly due to contamination by the fluorometer. The maximum chlorophyll level was observed after 4 or 5 days. Replicate samples showed different levels of chlorophyll growths. It was concluded that there were sufficient micronutrients present to support some additional photosynthesis at the sites investigated. These results suggest that it will be practical to nourish broad regions of the ocean to increase primary production. References Jones, I. S. F. and H. E. Young (1997) Engineering a large sustainable world fishery.Environmental Conservation, 24, 99-104. Ryther, J.H. and W. M.Dunstan (1971) Nitrogen, Phosphorus and Eutrophication in the coastal marine environment, Science, 171, 1008-1013. Thomas, W H (1970) Effect of Ammonium and Nitrate Concentration on Chlorophyll increase in Natural Tropical Pacific Phytoplankton Populations, Limnology and Oceanography, 15, 386-394. Thomas, W.H., (1969). Phytoplankton nutrient enrichment experiments off Baja California and in the eastern equatorial Pacific Ocean. J. Fish Res. Bd. Can., 26: 1133-1145. Acknowledgement A Eddington made a number of the obsevations. The Ocean Nourishment Corporation Pty Ltd funded some of the reearch.

  4. Combining norms to prove termination

    DEFF Research Database (Denmark)

    Genaim, S.; Codish, M.; Gallagher, John Patrick

    2002-01-01

    Automatic termination analysers typically measure the size of terms applying norms which are mappings from terms to the natural numbers. This paper illustrates howt o enable the use of size functions defined as tuples of these simpler norm functions. This approach enables us to simplify the problem...

  5. A Local Feud Proves Toxic

    Science.gov (United States)

    Jacobson, Linda

    2008-01-01

    A school leadership crisis that has dragged on since last fall is threatening Clayton County public school system to lose its accreditation. Loss of this accreditation could mean future Clayton County graduates would have trouble being accepted to college or would miss out on merit scholarships. Clayton County's members have feuded with each…

  6. Project management skills prove invaluable.

    Science.gov (United States)

    Corfield, Louise

    2008-09-01

    IHEEM business development manager Louise Corfield examines the role of project management in the skill set of today's healthcare estates and facilities manager, and explains how the Institute has joined forces with a number of organisations to offer members access to training in this increasingly vital area.

  7. Efeito alelopático do fruto de Sapindus saponaria na germinação e na morfologia de plântulas daninhas e de hortaliças Allelopathic effect of Sapindus saponaria fruit on germination and seedlings morphology of weed and vegetables

    Directory of Open Access Journals (Sweden)

    P.U. Grisi

    2011-06-01

    Full Text Available O objetivo deste estudo foi avaliar o potencial alelopático do extrato aquoso de frutos de Sapindus saponaria (sabão-de-soldado na germinação de diásporos e na morfologia de plântulas de Lactuca sativa (alface, Allium cepa (cebola, Echinochloa crus-galli (capim-arroz e Ipomoea grandifolia (corda-de-viola. O extrato aquoso dos frutos foi preparado na proporção de 100 g de material vegetal fresco para 1.000 mL de água destilada, produzindo-se a concentração de 10%. A partir dele, foram feitas diluições em água destilada para 7,5, 5,0 e 2,5%. O extrato do fruto Sapindus saponaria evidenciou potencialidades alelopáticas tanto sobre as espécies de hortaliças quanto sobre as de plantas daninhas. O efeito inibitório sobre o processo de germinação dos diásporos e morfologia das plântulas de alface, cebola, capim-arroz e corda-de-viola foi dependente da concentração. Os resultados mostram o potencial do extrato proveniente dos frutos de Sapindus saponaria como um herbicida a ser utilizado em práticas de agricultura sustentável.The aim of this study was to evaluate the allelopathic potential of the aqueous extract of Sapindus saponaria (soapberry fruit on seed germination and seedling morphology of Lactuca sativa (lettuce, Allium cepa (onion, Echinochloa crus-galli (barnyard grass, and Ipomoea grandifolia (morningglory. The aqueous extract of the fruit was prepared using 100 g of fresh plant material dissolved in 1,000 mL of distilled water, resulting in 10% concentration. The dilutions were made with distilled water to 7.5, 5.0, and 2.5%. The Sapindus saponaria fruit extract showed allelopathic potential on the vegetable and weed species. The inhibitory effect on the seed germination process and seedling morphology of lettuce, onion, barnyard grass, and morningglory was concentration dependent. The results showed the potential use of the Sapindus saponaria fruit extract as herbicide in sustainable agricultural practices.

  8. On the theory of time dilation in chemical kinetics

    Science.gov (United States)

    Baig, Mirza Wasif

    2017-10-01

    The rates of chemical reactions are not absolute but their magnitude depends upon the relative speeds of the moving observers. This has been proved by unifying basic theories of chemical kinetics, which are transition state theory, collision theory, RRKM and Marcus theory, with the special theory of relativity. Boltzmann constant and energy spacing between permitted quantum levels of molecules are quantum mechanically proved to be Lorentz variant. The relativistic statistical thermodynamics has been developed to explain quasi-equilibrium existing between reactants and activated complex. The newly formulated Lorentz transformation of the rate constant from Arrhenius equation, of the collision frequency and of the Eyring and Marcus equations renders the rate of reaction to be Lorentz variant. For a moving observer moving at fractions of the speed of light along the reaction coordinate, the transition state possess less kinetic energy to sweep translation over it. This results in the slower transformation of reactants into products and in a stretched time frame for the chemical reaction to complete. Lorentz transformation of the half-life equation explains time dilation of the half-life period of chemical reactions and proves special theory of relativity and presents theory in accord with each other. To demonstrate the effectiveness of the present theory, the enzymatic reaction of methylamine dehydrogenase and radioactive disintegration of Astatine into Bismuth are considered as numerical examples.

  9. Sensitive chemical compass assisted by quantum criticality

    Science.gov (United States)

    Cai, C. Y.; Ai, Qing; Quan, H. T.; Sun, C. P.

    2012-02-01

    A radical-pair-based chemical reaction might be used by birds for navigation via the geomagnetic direction. The inherent physical mechanism is that the quantum coherent transition from a singlet state to triplet states of the radical pair could respond to a weak magnetic field and be sensitive to the direction of such a field; this then results in different photopigments to be sensed by the avian eyes. Here, we propose a quantum bionic setup, inspired by the avian compass, as an ultrasensitive probe of a weak magnetic field based on the quantum phase transition of the environments of the two electrons in the radical pair. We prove that the yield of the chemical products via recombination from the singlet state is determined by the Loschmidt echo of the environments with interacting nuclear spins. Thus quantum criticality of environments could enhance the sensitivity of detection of weak magnetic fields.

  10. Chemicals Industry Vision

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1996-12-01

    Chemical industry leaders articulated a long-term vision for the industry, its markets, and its technology in the groundbreaking 1996 document Technology Vision 2020 - The U.S. Chemical Industry. (PDF 310 KB).

  11. Chemical Industry Bandwidth Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2006-12-01

    The Chemical Bandwidth Study provides a snapshot of potentially recoverable energy losses during chemical manufacturing. The advantage of this study is the use of "exergy" analysis as a tool for pinpointing inefficiencies.

  12. Chemical Search Web Utility

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Chemical Search Web Utility is an intuitive web application that allows the public to easily find the chemical that they are interested in using, and which...

  13. Capacitive chemical sensor

    Science.gov (United States)

    Manginell, Ronald P; Moorman, Matthew W; Wheeler, David R

    2014-05-27

    A microfabricated capacitive chemical sensor can be used as an autonomous chemical sensor or as an analyte-sensitive chemical preconcentrator in a larger microanalytical system. The capacitive chemical sensor detects changes in sensing film dielectric properties, such as the dielectric constant, conductivity, or dimensionality. These changes result from the interaction of a target analyte with the sensing film. This capability provides a low-power, self-heating chemical sensor suitable for remote and unattended sensing applications. The capacitive chemical sensor also enables a smart, analyte-sensitive chemical preconcentrator. After sorption of the sample by the sensing film, the film can be rapidly heated to release the sample for further analysis. Therefore, the capacitive chemical sensor can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.

  14. Chemical Data Reporting

    Science.gov (United States)

    The Chemical Data Reporting (CDR) site provides information on reporting requirements under TSCA's Chemical Data Reporting Rule. The site provides instruction to data submitters on how to report and enable users to download the reported information.

  15. Personal Chemical Exposure informatics

    Science.gov (United States)

    Chemical Exposure science is the study of human contact with chemicals (from manufacturing facilities, everyday products, waste) occurring in their environments and advances knowledge of the mechanisms and dynamics of events that cause or prevent adverse health outcomes. (adapted...

  16. Chemical burn or reaction

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000059.htm Chemical burn or reaction To use the sharing features on ... the burned area from pressure and friction. Minor chemical burns will generally heal without further treatment. However, if ...

  17. Advances in chemical physics

    CERN Document Server

    Prigogine, Ilya

    2009-01-01

    The Advances in Chemical Physics series provides the chemical physics and physical chemistry fields with a forum for critical, authoritative evaluations of advances in every area of the discipline. Filled with cutting-edge research reported in a cohesive manner not found elsewhere in the literature, each volume of the Advances in Chemical Physics series serves as the perfect supplement to any advanced graduate class devoted to the study of chemical physics.

  18. Chemical Spill Response Manual

    NARCIS (Netherlands)

    Marieke Zeinstra; Wierd Koops

    2014-01-01

    A two year programme has been carried out by the NHL University of Applied Sciences together with private companies in the field of oil and chemical spill response to finalize these manuals on oil and chemical spill response. These manuals give a good overview of all aspects of oil and chemical

  19. Endocrine Disrupting Chemicals (EDCs)

    Science.gov (United States)

    ... Pacientes y Cuidadores Hormones and Health The Endocrine System Hormones Endocrine Disrupting Chemicals (EDCs) Steroid and Hormone Abuse Peer ... and Health › Endocrine Disrupting Chemicals (EDCs) The Endocrine System Hormones Endocrine Disrupting Chemicals (EDCs) EDCs Myth vs. Fact Steroid ...

  20. Chemical Recycle of Plastics

    OpenAIRE

    Sara Fatima

    2014-01-01

    Various chemical processes currently prevalent in the chemical industry for plastics recycling have been discussed. Possible future scenarios in chemical recycling have also been discussed. Also analyzed are the effects on the environment, the risks, costs and benefits of PVC recycling. Also listed are the various types of plastics and which plastics are safe to use and which not after rcycle