Spelling suggestions: "subject:"fuscus"" "subject:"fuscata""
1 |
Contamination atmosphérique en éléments traces au sein de tourbières ombrotrophes situées à proximité d’une fonderie de cuivreKessler-Nadeau, Max Émile 08 1900 (has links)
La région de Rouyn-Noranda est fortement touchée par la contamination en éléments traces (ET), tels que l’arsenic (As), le cadmium (Cd), le cuivre (Cu) et le plomb (Pb), provenant des dépositions atmosphériques générées par les émissions de la fonderie Horne. Bien que des études aient démontré l’influence biogéochimique de la fonderie sur l’environnement, aucune recherche ne s’est penchée spécifiquement sur la distribution spatiale des ET dans les écosystèmes terrestres situés en périphérie de la fonderie. Ce mémoire vise donc à cartographier l’étendue spatiale des ET dans la région de Rouyn-Noranda et d’évaluer leurs distributions, spatialement au sein du territoire, mais également entre les composantes écosystémiques de tourbières exposées à des niveaux contrastants de déposition. À partir des concentrations analysées au sein du bryophyte Sphagnum fuscum, échantillonné dans 54 bogs jusqu’à 50 km à l’est de la fonderie, la modélisation de la distribution spatiale des ET a été réalisée par l’entremise d’interpolation spatiale par krigeage. La contamination en ET est plus importante près de la fonderie et diminue significativement dès que la distance augmente de cette dernière. De même, les niveaux d’ET dans la tourbe, l’eau interstitielle et les composantes (racine, tige et feuille) de quatre espèces végétales caractéristiques des tourbières, sont systématiquement plus importants dans les sites situés à 10 km de la fonderie que dans ceux à 25 km. Au sein des végétaux, la remobilisation verticale des ET est limitée et ces éléments s’accumulent en majorité dans les racines, qui sont exposées aux concentrations élevées d’ET dans la tourbe et l’eau interstitielle. Mes travaux ont démontré que l’étendue de la contamination environnementale en ET à Rouyn-Noranda est fonction de la distance à la fonderie Horne et que la mobilité des ET dans les tourbières se concentre à l’interface sol-eau-racine. / The Rouyn-Noranda region is strongly affected by trace element (TE) contamination, such as arsenic (As), cadmium (Cd), copper (Cu) and lead (Pb), from atmospheric deposition of the Horne copper smelter emissions. Although studies have demonstrated the biogeochemical influence of the Horne smelter on the environment, no research has particularly investigated the spatial distribution of TEs in the vicinity of the smelter. This thesis aims to map the spatial extent of TEs in the Rouyn-Noranda region and to evaluate their distribution between the ecosystem components of peat bogs exposed to contrasting levels of TE depositions. Based on the TE concentrations analyzed in the bryophyte Sphagnum fuscum, sampled in 54 bogs up to 50 km east from the smelter, we modelled the spatial extent of TE through spatial kriging interpolation. Trace element contamination is higher near the smelter and decreases with increasing distance from the latter. Consequently, TE levels in the peat, pore water, and components (roots, shoots, and leaves) of four plant species within bogs are consistently higher at sites 10 km from the smelter than at sites 25 km away. Within plants, the vertical translocation of TE is limited, and these elements accumulate specifically in the roots, which are exposed to considerable concentrations of TE in the peat and in the pore water. My work has shown that the extent of the environmental contamination of TEs in Rouyn-Noranda is a function of the distance from the Horne smelter and their mobility in peatlands is localized at the root-soil-water interface.
|
2 |
Sekundarni biomolekuli u vrstama Allium sect. Codonoprasum Rchb. – biološke aktivnosti, fitohemijski i hemotaksonomski aspekti / Secondary metabolites from selected species of genus Allium sect. Codonoprasum Rchb. – biological activities, phytochemical and chemotaxonomic aspectsSimin Nataša 30 January 2015 (has links)
<p>U ovoj doktorskoj disertaciji ispitan je hemijski sastav i biološke aktivnosti<br />ekstrakata deset samoniklih taksona roda <em>Allium</em> sect. <em> Codonoprasum: A. carinatum</em> subsp. <em>pulchellum, A. carinatum </em> subsp. <em>carinatum, A. fuscum </em> var. <em>gracile, A. fuscum </em> var. <em>fuscum, A. flavum</em> subsp. <em>flavum, A. melanantherum, A. paniculatum </em> subsp. <em> marginatum, A. pallens</em> subsp. <em>tenuiflorum, A. oleraceum </em>i <em> A. rhodopeum</em>, sakupljenih na 27 lokaliteta u Srbiji. Cilj rada bio je da se dobiju podaci o sadržaju biološki aktivnih jedinjenja u ovim, do sada veoma malo ispitanim vrstama roda <em>Allium</em>, i utvrdi njihova potencijalna lekovita vrednost.</p><p>Analiza hemijskog sastava obuhvatila je: analizu volatilnih komponenti svežih <br />lukovica primenom headspace GC-MS tehnike, kvalitativnu analizu metanolnih <br />ekstrakata primenom tečnohromatografskih metoda (LC-DAD-MS i LC-MS-MS), <br />kvantitativnu analizu odabranih fenolnih jedinjenja LC-MS-MS tehnikom, određivanje sadržaja ukupnih monomernih antocijana i određivanje aktivnosti aliinaze. Ispitivanja bioloških aktivnosti ekstrakata obuhvatila su: određivanje antioksidantne, antiinflamatorne, antimikrobne, antimutagene i genotoksične aktivnosti, kao i ispitivanje uticaja na rast zdravih i tumorskih ćelija i sposobnosti indukcije ćelijske smrti. </p><p>Sumiranjem dobijenih rezultata može se zaključiti da ispitivani predstavnici roda <br /><em>Allium </em> sect. <em>Codonoprasum </em> predstavljaju bogate izvore biološki aktivnih jedinjenja sa širokim spektrom bioloških aktivnosti. Sa hemotaksonomskog aspekta značajno je da se dimetil-disulfid izdvaja kao najdominantnija i često jedina isparljiva komponenta, da ekstrakti većine vrsta sadrže veliku količinu flavonoida (prvenstveno derivata kvercetina), da se vrste <em> A. pallens </em> i <em>A. oleraceum</em> izdvajaju od ostalih po tome što ne sadrže rutin a sadrže hiperozid, da je vrsta <em> A. rhodopeum</em> siromašna fenolnim jedinjenjima i da su sve vrste, osim vrste <em>A. flavum</em>, bogate antocijanima. Aktivnost aliinaze je visoka u svim ispitivanim vrstama. Većina ispitivanih ekstrakata, izuzev ekstrakata vrsta <em>A. carinatum </em>i <em>A. melanantherum</em>, pokazala je izraženu antioksidantnu aktivnost, dok su ekstrakti vrsta <em>A. flavum</em>, <em>A. rhodopeum</em>, <em>A. oleraceum </em>i <em>A. paniculatum </em>snažni antiinflamatorni agensi. Ekstrakti ispitivanih predstavnika sect. <em> Codonoprasum </em>nisu pokazali antimikrobnu i antimutagenu aktivnost. Takođe, ovi ekstrakti nisu ispoljili genotoksični efekat na ćelije zdravog tkiva (izuzev slabog genotoksičnog efekta ekstrakta nadzemnih delova <em> A. flavum</em>), što ukazuje na bezbednost upotrebe vrsta sect. <em>Codonoprasum </em> kao hrane ili u obliku lekova. Ekstrakti celih biljaka <em>A. paniculatum</em> i <em>A. rhodopeum</em>, kao i ekstrakt nadzemnih delova <em>A. melanantherum</em> pokazali su snažnu antiproliferativnu aktivnost sa povoljnim ne-tumor/tumor koeficijentima i indukovali apoptozu u tumorskim ćelijama, iz čega se može zaključiti da imaju visok potencijal primene u antitumorskoj terapiji. </p> / <p>In the present doctoral thesis the chemical composition and biological activities of <br />10 wild growing taxa of genus <em>Allium</em> sect. <em>Codonoprasum</em> (<em>A. carinatum </em> subsp. <br /><em>pulchellum, A. carinatum </em> subsp. <em>carinatum, A. fuscum </em> var. <em>gracile, A. fuscum</em> var. <br /><em>fuscum, A. flavum </em> subsp. <em>flavum, A. melanantherum, A. oleraceum, A. paniculatum</em><br />subsp. <em>marginatum, A. pallens</em> subsp. <em>tenuiflorum</em> and <em>A. rhodopeum</em>) were investigated. The samples were collected from 27 locations in Serbia. The aim of the study was to obtain data on the content of biologically active compounds in extracts of these unexplored species of the genus Allium and to determine their potential medicinal value.</p><p>Phytochemical caracterisation included: headspace GC-MS analysis of fresh bulb <br />volatiles, LC-DAD-MS and LC-MS-MS qualitative analysis of methanol extracts, LC-MS-MS quantitative analysis of 44 selected phenolic compounds in methanol extracts, determination of total monomeric anthocyanins content and alliinase activity. In order to assess the biological potential of methanol extracts, the antioxidant, anti-inflammatory, antimicrobial, antimutagenic, genotoxic and antiproliferative activities of the extracts were studied.</p><p>Summing up all the results obtained, it can be concluded that species of genus <em>Allium </em> sect. <em>Codonoprasum </em> are rich sources of biologically active compounds with a broad spectrum of biological activities. Dimethyl disulfide is the most dominant and often the only volatile component of most species, which is significant from chemotaxonomic point of view. The methanol extracts of investigated species contain high levels of flavonoids (primarily quercetin derivatives). Specificity of <em>A. pallens</em> and <em>A. oleraceum</em> extracts is that they do not contain rutin, but contain hyperoside, while small quantity of phenolic compounds is characteristic for <em>A. rhodopeum</em> extract. All investigated species, except of <em>A. flavum</em>, are rich in anthocyanins. Alliinase activity was high in all examined species. Most of the extracts, except <em>A. carinatum</em> and <em>A. melanantherum</em> extracts, express considerable antioxidant activity, while extracts of <em> A. flavum</em>, <em>A. rhodopeum</em>, <em>A. paniculatum</em> and <em>A. oleraceum </em> are potent anti-inflammatory agents. The investigated <em>Allium</em> extracts did not show antimicrobial and antimutagenic activity. Also, the extracts did not express genotoxic effect on healthy tissue cells (except the weak genotoxic effects of aerial parts extract of <em>A. flavum</em>), indicating that the use of these species as a food or as a drug is safe. Whole plant extracts of <em>A. paniculatum</em> and <em> A. rhodopeum</em>, as well as aerial parts extract of <em> A. melanantherum</em> showed strong antiproliferative activity (with a favorable non-tumor/tumor ratios) and induced apoptosis in tumor cells, suggesting that these plants have a high potential for application in antitumor therapy.</p>
|
Page generated in 0.0311 seconds