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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Etude phytochimique de deux espèces de Platanaceae européennes Platanus acerifolia (France) et Platanus orientalis (Grèce) / Phytochemical study of two european species Platanaceae, Platanus acerifolia (France) and Platanus orientalis (Greece)

Thai, Quoc Dang 10 July 2014 (has links)
Le platane est un arbre de la famille des Platanaceae très commun en ville en particulier en Europe et dans toutes les zones tempérées. Les espèces du genre Platanus et plus particulièrement l’espèce Platanus orientalis, très répandue en Grèce, sont sévèrement attaquées par des agents phytopathogènes provoquant le chancre coloré du platane, l’anthracnose ou l’oïdium. En revanche, Platanus acerifolia, un hybride obtenu entre P. occidentalis and P. orientalis, très commun en France, se montre plus résistant vis-à-vis de ces pathogènes. L’étude par HPLC d’extraits de deux espèces de Platanaceae européennes P. acerifolia et P. orientalis a montré des différences selon le solvant d’extraction. L’extrait dichlorométhanique de P. acerifolia s’est montré plus riche en composés que l’espèce P. orientalis. Par contre, les chromatogrammes obtenus à partir des extraits méthanoliques sont très similaires et dominés par les deux composés majoritaires (tiliroside et platanoside). Des techniques préparatives comme la chromatographie de partage centrifuge (CPC), la moyenne pression (MPLC), la chromatographie sur colonne de Sephadex ou sur résine XAD-7 ont été utilisées afin d’isoler les différents constituants majoritaires et d’identifier les composés qui diffèrent d’une espèce à l’autre. L’élucidation structurale est réalisée grâce à des techniques telles que HR-EIS-MS et RMN 1D & 2D. L’étude de l’extrait dichlorométhanique nous a permis de compléter la connaissance phytochimique de ces deux plantes européennes et a conduit à l’isolement et à la détermination structurale de 38 molécules dont 7 composés nouveaux (1 coumarine, 3 flavonols prenylés, 2 dihydrochalcones, un terpénoïde. Par ailleurs, l’extrait méthanolique a conduit d’une part à l’isolement du tiliroside et du platanoside majoritaires et d’autre part à l’isolement de composés minoritaires, trente-trois autres molécules dont 5 nouveaux composés (1 flavonol glucosylé, 3 coumarines, 1 dihydrochalcone). Enfin, l’évaluation biologique des composés isolés in vitro ou in vivo a été réalisée sur différentes cibles : activités antifongiques, anti-âge, antioestrogéniques. Les activités cytotoxiques sur les cellules de cancer du sein MCF-7 et sur les cellules de cancer de l’endomètre (ISHIKAWA). / Platanus is a small genus of trees belonging to Platanaceae family, very common in Europe and temperate zones. Platanus species, and especially Platanus orientalis (Oriental plane), wide-spread in Greece are known to be severely attacked by phytopathogens such as Ceratocystis fimbriata f. sp. platani for canker stain, Apiognomonia veneta for anthracnose and Microsphaera platini for powdery mildew. However Platanus acerifolia (London plane), a hybrid between the P. occidentalis and P. orientalis, which is very common in France, have been found to be resistant to these pathogenic fungi. The HPLC profile of the dichloromethane extracts of the two species P. orientalis and P. acerifolia revealed a qualititative difference whereas, the methanol extracts were found to be similar with two predominant phenolic constituents (tiliroside and platanoside) present in both species. Further isolation and purification of their secondary metabolites were performed using various chromatographic techniques (CPC, MPLC, CC, XAD-7, Sephadex LH20, prep-TLC) and their identification was performed by HRMS and NMR (1 & 2D) spectroscopy. The studies of dichloromethane extract allowed us to deal with phytochemical knowledge of these two European plants in depth and led to isolation and structural elucidation of 38 compounds including 7 news constituents (1 coumarin, 3 flavonols, 2 dihydrochalcones and 1 terpenoid). Moreover, the methanol extract led to the isolation of their major constituents (tiliroside and platanoside) in one step. Furthermore, 33 minors compounds were isolated including 5 news compounds (one flavonol glycoside 3 coumarins and 1 dihydrochalcone). In addition, the isolated compounds have been subjected to in vitro or in vivo evaluation on different targets: antifungal, anti-ageing, anti-oestrogenic properties. Finally, the cytotoxic activity was studied on breast cancer cells (MCF-7) and endometrial cancer (Ishikawa).
2

Parasitologia, toxicidade e evermifugação com formol e histopatologia de juvenis da tainha Mugil Platanus

Pahor Filho, Eduardo January 2010 (has links)
Dissertação(mestrado)-Universidade Federal do Rio Grande, Programa de Pós-Graduação em Aqüicultura, Instituto de Oceanografia, 2010. / Submitted by Cristiane Silva (cristiane_gomides@hotmail.com) on 2012-07-27T17:53:57Z No. of bitstreams: 1 dissertao de eduardo em pdf.pdf: 149902 bytes, checksum: 3c4a46e26293690177aa2d20d50a32ae (MD5) / Approved for entry into archive by Bruna Vieira(bruninha_vieira@ibest.com.br) on 2012-07-27T18:31:32Z (GMT) No. of bitstreams: 1 dissertao de eduardo em pdf.pdf: 149902 bytes, checksum: 3c4a46e26293690177aa2d20d50a32ae (MD5) / Made available in DSpace on 2012-07-27T18:31:32Z (GMT). No. of bitstreams: 1 dissertao de eduardo em pdf.pdf: 149902 bytes, checksum: 3c4a46e26293690177aa2d20d50a32ae (MD5) Previous issue date: 2010 / Considerando a importância da tainha Mugil platanus Günther, 1880 como fonte de alimento e alternativa de emprego para comunidades locais, este estudo objetiva estabelecer a fauna parasitária e a forma de utilização de M. platanus pelos parasitos, definir a toxicidade do formol e a concentração eficaz para erradicar ou mesmo minimizar a parasitose e, por último, verificar quais as lesões causadas pelo formol e/ou pelos parasitos em juvenis da tainha M. platanus. Quarenta juvenis de tainha M. platanus com peso 1 ± 0,26g e comprimento 4,1 ± 0,4cm foram coletados em arroio na Praia do Cassino, no município de Rio Grande - RS - Brasil. Os hospedeiros foram necropsiados e os ectoparasitos foram fixados em formol 5 %, corados, clarificados e posteriormente montados em lâminas permanentes com bálsamo do Canadá para identificação. Outros foram montados em meio de Grey-Wess para verificação de estruturas esclerotizadas. Os endoparasitos foram fixados em AFA e corados em carmim de Semichon, clarificados e posteriormente montados em lâminas permanentes com bálsamo do Canadá para identificação. Foram identificados Ligophorus cf. uruguayense (Monogenoidea: Ancyrocephalidae) e Solostamenides cf. platyorchis (Monogenoidea: Microcotylidae) nas brânquias. Foram reportados Digenea e Nematoda nos intestinos. A prevalência (P %) de L. cf. uruguayense foi 100 %, a intensidade de infestação (II) variou entre 2 e 110, a intensidade média de infestação (IMI) foi 23,4 e a abundância média (AX) foi 23,4. A prevalência (P %) de S. cf. platyorchis foi 10 %, a intensidade de infestação (II) variou entre 1 e 3, a intensidade média de infestação (IMI) foi 1,5 e a abundância média (AX) foi 0,15. A prevalência (P %) de Digenea foi 92,5 %, a intensidade de infecção (II) variou entre 1 e 40, a intensidade média de infecção (IMI) foi 2,67 e a abundância média (AX) foi 2,47. A prevalência (P %) de Nematoda foi 6,7 %, a intensidade de infecção (II) foi 1, a intensidade média de infecção (IMI) foi 1 e a abundância média (AX) foi 0,07. Os elevados índices de infestação por Monogenoidea e de infecção por Digenea apontam o potencial dano que estes parasitos podem representar nos cultivos. Para analisar a toxicidade do formol para M. platanus e a eficácia deste quimioterápico no controle de parasitos, foram realizados quatro experimentos. Os juvenis foram mantidos em béqueres de 1 L, densidade 8 peixes/ béquer, temperatura da água 21 °C, fotoperíodo 12 h, salinidade da água 5, aeração suave e constante e mantidos em jejum e em observação para análise da sobrevivência. Para determinar a toxicidade do formol aos juvenis foi realizado um teste de toxicidade aguda 96 h, em que os tratamentos foram um controle (sem adição de formol na água) mais 5 concentrações: T1 (5), T2 (8), T3 (15), T4 (30) e T5 (50) mg/L de formol em triplicata. Para verificar a eficácia no controle parasitário foi administrado um banho profilático de 1 h de formol, em que os tratamentos foram um controle (sem adição de formol na água) mais 5 concentrações: T1 (25), T2 (50), T3 (100), T4 (150) e T5 (200) mg/L de formol na água em triplicata. No teste letal de toxicidade aguda, não houve diferença significativa (P > 0,05) entre as réplicas e a temperatura (°C), salinidade, pH, O2 dissolvido na água (mg/L), amônia total (mg/L) e a concentração letal mediana a 50 % (CL50) em 96 h foi estimada em 20,77 mg/L de formol. No banho profilático com formalina durante 1 h, todos os tratamentos foram eficientes eliminando 100 % dos parasitos, exceto no tratamento com 25 mg/L, em que foram identificados L. cf. uruguayense em 13,33 % dos peixes. Houve 100 % de sobrevivência dos hospedeiros em todos os tratamentos, exceto na concentração 200 mg/L em que a sobrevivência foi 87,5 %. Banhos com 25 mg/L de formol durante 1 h são indicados para o controle de S. cf. platyorchis e 50 mg/L para o controle de L. cf. uruguayense, por possuir menor concentração de formol e alta sobrevivência dos peixes. Porém, nenhuma das concentrações testadas é eficiente no controle de endoparasitos. Por último, para determinar as lesões causadas nas brânquias de formol e/ou pelos Monogenoidea, três peixes de cada tratamento, provindos do banho profilático com formol para o controle de parasitoses foram encaminhados para análise histológica. Foi observado que o aumento da concentração de formol causou lesões mais graves nas brânquias. Foi observada hiperplasia leve nos animais mantidos como controle, desprendimento do epitélio respiratório no T2, hiperplasia moderada no T3, aumento da atividade opercular no T4 e necrose, natação errática e mortalidade no T5. Os resultados histopatológicos deste estudo mostram que banhos de 50 mg/L de formol durante 1 hora podem ser aplicados em juvenis de M. platanus para o controle de Monogenoidea, pois nesta concentração, as lesões histológicas causadas nos hospedeiros são leves e a sobrevivência dos juvenis é alta. / Considering the importance of mullet Mugil platanus Günther, 1880 as a food source and alternative employment for local communities, this study aims to establish the parasitic fauna and how M. platanus use by the parasites to define the toxicity of formaldehyde and the effective concentration to minimize or even eradicate the parasites and, lastly, to evaluate the damages caused by formaldehyde and/or parasites in the juvenile mullet M. platanus. Forty juvenile mullet M. platanus weighing 1 ± 0.26 g and length 4.1 ± 0.4 cm were collected in the stream at Cassino Beach, in Rio Grande - RS - Brazil. The hosts were necropsied and the parasites were fixed in 5 % formaldehyde, stained, clarified and subsequently mounted on permanent slides with Canada balsam for identification. Others parasites specimens were mounted in the middle of Gray-Wess to check sclerotic structures. The endoparasites were fixed in AFA and stained with carmine Semichon, clarified and subsequently mounted on permanent slides with Canada balsam for identification. It was identified Ligophorus cf. uruguayense (Ancyrocephalidae) and Solostamenides cf. platyorchis (Microcotylidae) in the gills. It was reported Digenea and Nematoda in the intestines. The prevalence (P %) of L. cf. uruguayense was 100 %, the intensity of infestation (II) ranged between 2 and 110, the average intensity of infestation (IMI) was 23.4 and average abundance (AX) was 23.4. The prevalence (P %) of S. cf. platyorchis was 10 %, the intensity of infestation (II) ranged between 1 and 3, the average intensity of infestation (IMI) was 1.5 and mean abundance (AX) was 0.15. The prevalence (P %) of Digenea was 92.5 %, the intensity of infection (II) ranged between 1 and 40, the average intensity of infection (IMI) was 2.67 and the average abundance (AX) was 2.47. The prevalence (P %) of Nematoda was 6.7 %, the intensity of infection (II) was 1, the mean intensity of infection (IMI) was 1 and mean abundance (AX) was 0.07. High levels of infestation Monogenoidea and infection Digenea point to the potential damage that these bodies may represent the cultures. To analyze the toxicity of formalin to M. platanus and efficacy of chemotherapy in the control of parasites, four experiments were conducted. Juveniles were kept in beakers of 1 liter, density 8 fish/beaker, water temperature 21 °C, 12 h photoperiod, water salinity 5, smooth and constant aeration and maintained at fasting and under observation for survival analysis. To determine the toxicity of formaldehyde was carried out acute toxicity test, in which the treatments were a control (no added formaldehyde in water) and 5 more concentrations: T1 (5), T2 (8), T3 (15), T4 (30) and T5 (50) mg/L of formaldehyde in triplicate. To verify the effectiveness of formaldehyde on parasite control was given a bath of 1 h of the substance in which the treatments were a control (no added formaldehyde in water) and 5 more concentrations of formaldehyde: T1 (25), T2 (50) , T3 (100), T4 (150) and T5 (200) mg/L of formaldehyde in water in triplicate. In the test lethal acute toxicity, no significant difference (P > 0.05) between treatment and temperature (°C), salinity, pH, dissolved O2 in water (mg/L), total ammonia (mg/L) and lethal concentration to 50 % of the sample (LC50) at 96 h was estimated to be 20.77 mg/L of formaldehyde. In the final bath of formaldehyde for 1 h, all treatments were efficient by eliminating 100 % of parasites, except for treatment with 25 mg/L, which were identified L. cf. uruguayense in 13.33 % of the fish. There was 100 % survival of the hosts in all treatments, except at the concentration 200 mg/L in which survival was 87.5 %. Baths with 25 mg/L formaldehyde for 1 h are indicated for the control of S. cf. platyorchis and 50 mg/L for the control of L. cf. uruguayense, because it has lower concentration of formaldehyde and high survival of fish. However, none of the concentrations tested is effective against endoparasites. Finally, to determine the damage caused by formaldehyde in the gills and/or the Monogenoidea, three fish per treatment, coming the final bath of formaldehyde to control parasitosis were sent for histological analysis. It was observed that increasing the concentration of formaldehyde caused more severe lesions in the gills. Mild hyperplasia was observed in animals kept as control, detachment of the respiratory epithelium in T2, moderate hyperplasia in T3, increased opercular activity in T4 and necrosis, erratic swimming and mortality in T5. Histopathological results of this study show that bath of formaldehyde at a concentration of 50 mg/L for 1 hour can be applied to juveniles of M. platanus to control Monogenoidea, because in this concentration, histological lesions caused in the host are lightweight and survival of juveniles is high.
3

The Effects of Mechanical Site Preparation Treatment and Species Selection on Survival and Carbon Pools in 12-Year-Old American Sycamore (<i>Platanus occidentalis</i>) and Willow Oak (<i>Quercus phellos</i>) Riparian Plantations in the Southeastern U.S. Piedmont

Lynn, Drake Havelock 16 July 2024 (has links)
Riparian wetlands may provide numerous ecosystem services, including water quality protection, food and fiber supply, wildlife habitat, and carbon sequestration. In recent years, riparian forests have received increased attention and funding for riparian forest restoration projects. Unfortunately, failures of riparian restoration efforts are likely due to mortality of planted trees. Tree mortality is commonly attributable to several factors, including selection of species that are not well suited to the wetland sites, inadequate planting densities, soil compaction associated with former agricultural activities, lack of microtopographic relief that allow small seedling to survive on wet sites, competition by herbaceous plants, and browse. Selection of well-suited species, dense planting and use of mechanical soil site preparations are all potential remedies to partially address success of wetland restoration plantings. Riparian restoration projects have historically been undertaken with goals of improving water quality and/or wildlife habitat, but in recent years there has been increased valuation of carbon sequestration. Carbon valuation appears to be increasing, but more research is needed to determine rates and pools of carbon accumulation in riparian areas. Our research quantifies forest establishment effects on multiple carbon pools in a densely planted, 12-year-old old-field riparian restoration. Our research evaluated the effects of four soil mechanical site preparations (bed, disk, pit, and mound and rip) and species selection (American sycamore (Platanus occidentalis) and willow oak, (Quercus phellos) on forest establishment and carbon storage across multiple pools, namely in planted trees, herbaceous vegetation, fine roots, organic soil horizons, and the mineral soil. At 12 years, we found that species selection was more important to carbon storage than site preparation. American sycamore was well suited to the site and had better survival than willow oak (64% vs 42% survival). American sycamore also stored more carbon across all site preparations than willow oak. Measured carbon storage averaged 74.8 Mg ha-1 for American sycamore treatments and 63.1 Mg ha-1 for willow oak treatments. The plots were densely planted (1.2 m (4ft) by 1.8 m (6ft) spacing), and forests were established even in higher mortality willow oak plots. These results indicate that high planting density is potentially a viable practice for establishing riparian forest cover, especially if desired species are marginally site suited or other survival inhibiting factors exist. / Master of Science / Riparian forests located within the floodplain of streams are known to protect stream water quality, provide wildlife habitat, and store carbon. Due to these benefits, trees may be replanted on riparian areas that were formerly used for agriculture. Unfortunately, trees planted on these restoration sites have often died. The tree mortality may be due to planting incorrect tree species that may struggle on wet floodplains, soil compaction from agricultural practices, not enough trees being planted, and restored floodplains lacking small, elevated areas common across natural wetlands known to favor tree rooting and survival. Reasonably, selecting species that are well suited to a specific site, planting trees more densely, and using plowing methods designed to break up compaction and create some relief in elevation would amend these issues. Traditionally, floodplain restorations have focused on improving water quality and providing habitat for wildlife, but the benefits of storing carbon have become increasingly valuable in recent years. While we know that wetlands store carbon, research is needed to examine how quickly and where carbon is stored. Our research quantifies forest establishment and carbon storage of very densely planted, 12-year-old American sycamore (Platanus occidentalis) and willow oak (Quercus phellos) plantations. This research examines the effects four soil tillage methods and tree species selection had on tree survival and carbon storage. Carbon storage was measured in vegetation, soil, and small roots. Twelve years after planting, species selection had a greater impact on carbon storage than soil tillage methods. No tillage method altered survival or total carbon after 12 years, but American sycamore was found to have better survival and more carbon than willow oak in all soil tillage treatments. Both species were successful in establishing planted forests on the floodplain, but the success was aided by the very high initial numbers of planted trees that ensured enough trees would survive on the site even after trees were lost to mortality. Creation of willow oak forests benefitted more from dense planting, as it was less suited to the site and more planted willow oaks died. We recommend tillage for compacted soil, selecting the most suitable tree species, and planting adequate numbers of trees.
4

Water Fluxes in Soil-Pavement Systems: Integrating Trees, Soils and Infrastructure

de la Mota Daniel, Francisco Javier 31 January 2019 (has links)
In urban areas, trees are often planted in bare soil sidewalk openings (tree pits) which recently are being covered with permeable pavements. Pavements are known to alter soil moisture and temperature, and may have implications for tree growth, root development and depth, drought resilience, and sidewalk lifting. Furthermore, tree pits are often the only unsealed soil surface and are important for water exchange between soil and atmosphere. Therefore, covering tree pits with pavement, even permeable, may have implications for the urban water balance and stormwater management. A better understanding of permeable pavement on tree pavement soil system functioning can inform improved tree pit and street design for greater sustainability of urban environments. We conducted experiments at two sites in Virginia, USA (Mountains and Coastal Plain) with different climate and soil. At each location, we constructed 24 tree pits in a completely randomized experiment with two factors: paved with resin-bound porous-permeable pavement versus unpaved, and planted with Platanus x acerifolia 'Bloodgood' versus unplanted (n = 6). We measured tree stem diameter, root growth and depth, and soil water content and temperature over two growing seasons. We also monitored tree sap flow one week in June 2017 at the Mountains. In addition, we calibrated and validated a soil water flow model, HYDRUS-1D, to predict soil water distribution for different rooting depths, soil textures and pavement thicknesses. Trees in paved tree pits grew larger, with stem diameters 29% (Mountains) and 51% (Coastal Plain) greater. Roots developed faster under pavement, possibly due to the increased soil water content and the extended root growing season (14 more days). Tree transpiration was 33% of unpaved and planted pit water outputs, while it was 64% for paved and planted pits. In June 2016, planted pits had decreased root-zone water storage, while unplanted pits showed increased storage. A water balance of the entire experimental site showed overall decreased soil water storage due to tree water extraction becoming the dominant factor. HYDRUS-1D provided overall best results for model validation at 10 cm depth from soil surface (NSE = 0.447 for planted and paved tree pits), compared to 30- and 60 cm depths. HYDRUS-1D simulations with greater pavement thickness resulted in changes in predicted soil water content at the Coastal Plain, with higher values at 10- and 30-cm depths, but lower values at 60-cm depth. At the Mountains, virtually no difference was observed, possibly due to different soil texture (sandy vs clayey). Tree pits with permeable pavement accelerated tree establishment, but promoted shallower roots, possibly increasing root-pavement conflicts and tree drought susceptibility. Paved tree pits resulted in larger trees, increasing tree transpiration, but reduced soil evaporation compared to unpaved pits. Larger bare soil pits surrounded by permeable pavement might yield the best results to improve urban stormwater retention. Also, HYDRUS 1D was successful at simulating soil water content at 10-cm depth and may be valuable to inform streetscape design and planning. / PHD / Trees in cities are often planted in pavement cutouts (tree pits) that are usually the only available area for water exchange between soil and atmosphere. Tree pits are typically covered with a variety of materials, including permeable pavement. Pavements are known to modify soil water distribution and temperature, affecting tree growth, rooting depth, drought resilience, and sidewalk lifting. A better understanding of this system can inform tree pit and street design for greater sustainability. We constructed 24 tree pits at each of two regions in Virginia, USA (Mountains and Coastal Plain). These tree pits were paved with permeable pavement or unpaved, and planted with London Plane or unplanted. We measured stem diameter, root growth, and soil water content and temperature over two years and tree sap flow for one week in summer (Mountains only). We also used a soil water flow model, HYDRUS-1D, to predict water distribution for different rooting depths, soil textures and pavement thicknesses. After the first growing season trees in pavement were larger, with stem diameters 29% (Mountains) and 51% (Coastal Plain) greater. Roots developed faster under pavement, possibly due to increased soil water content and a 14-day increase in root growing season. Also, in June 2017, tree transpiration was 33% of unpaved-and-planted pit water outputs, and 64% of paved-and-planted pits. In June 2016, root-zone water storage decreased in planted pits but increased in unplanted pits. When considering the entire experimental site, soil water storage decreased, with tree water extraction being the dominant factor. HYDRUS-1D performed better at 10-cm soil depth than at 30- and 60-cm depths. At the Coastal Plain, HYDRUS-1D predicted higher soil water content at 10- and 30-cm depths with increased pavement thickness, but lower values at 60-cm depth. At the Mountains, there was no effect, possibly due to higher clay content. Permeable pavement accelerated tree establishment, but promoted shallower roots, increasing drought susceptibility and risk for root-pavement conflicts. Pavement resulted in larger trees and greater transpiration, but reduced soil evaporation. Larger bare-soil pits surrounded by permeable pavement might optimize stormwater retention.

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