Tesi sul tema "Pollen – Effets de l'ozone"
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Hamzé, Mona. "Vers une meilleure connaissance de l'exposition aux grains de pollens allergisants et de leur altération par la pollution de l'air". Electronic Thesis or Diss., Université de Lille (2022-....), 2022. https://pepite-depot.univ-lille.fr/ToutIDP/EDSMRE/2022/2022ULILR009.pdf.
Although it is now accepted that allergenic pollen grains are altered by air pollution, the role of these alterations on allergy is not yet clearly known. The (bio)chemical mechanisms involved are not completely elucidated, especially with regard to the exacerbation of symptoms by air pollution. The main objective of this thesis is to improve the knowledge on the exposure to allergenic pollen grains by taking into account their degree of alteration: pollution and pollen grain rupture. A first laboratory study was carried out in order to explore the potential of several techniques for the characterization of the degree of alteration of the pollen grain. Pollen artificially polluted with ozone was analyzed by spectroscopic (Raman and infrared), microscopic and chromatographic techniques. Ozone uptake was also measured on a set of 22 pollen taxa with different bio-physical-chemical characteristics (grain size and mass, degree of allergenicity, lipid fraction...) to investigate possible determinants of ozone uptake. The potential of pollen analysis by gas chromatography-mass spectrometry (GC-MS) was exploited and a new method of counting pollen grains was developed. This method required a study on the variability of the lipid fraction on different batches of birch pollen from different geographical origins and depending on the year of harvest. In order to test this counting method in real conditions, a sampling campaign was carried out on sedimented birch pollen in indoor and outdoor environments. The determination of chemical tracers of pollen grains by GC-MS has a great potential for the rapid counting of pollen grains, the determination of their state (broken or intact) and their degree of pollution
Perié, Karine. "Interaction de l'ozone avec des complexes de type porphyrinique : Leur intérêt dans la catalyse des réactions d'ozonation". Dijon, 1996. http://www.theses.fr/1996DIJOS058.
Ramarotafika, Rivo. "Protection et dégradation des sucres et de leurs dérivés par l'ozone". Lyon 1, 1994. http://www.theses.fr/1994LYO10250.
Guyon, Frédérique. "Contribution à l'étude de la solidité à l'ozone de colorants anthraquinoniques acides". Mulhouse, 1998. http://www.theses.fr/1998MULH0521.
Leitao, Louis. "Impact de l'ozone sur la photosynthèse : effets sur les carboxylases (PEPc et Rubisco) des plantes en C3 et en C4". Pau, 2005. http://www.theses.fr/2005PAUU3016.
In order to study chronic and realistic ozone stress on C3 and C4 plant carboxylating enzymes, effects of increasing ozone concentrations on PEPc (phosphoenolpyruvate carboxylase) and Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase) enzymes have been determined and compared in bean (C3) and maize (C4) plants. We intended to seek possible correlations between carboxylases ' activity, quantity and quality, and connect them to pigment contents which can describe foliar senescence state. Using an open top chamber technology, it has been determined that, according to pollutant concentration and dynamic of exposure, ozone can modify bean and maize carboxylases' activity and quantity, as well as pigment contents. These modifications could be associated with foliar symptoms and/or plant biomass reductions. On bean, ozone could stimulate PEPc anaplerotic isoform activity whereas it could reduce Rubisco's one. Rubisco activity decrease had been associated with the formation of Rubisco small subunits carbonyls and with a decrease of native Rubisco's amount. In maize plants, moderate ozone concentrations have been shown to stimulate PEPc and Rubisco activities and contents whereas these same criteria were reduced by higher ozone concentrations. Real-time RT-PCR analyses revealed that only some of these variations can be explained at transcriptional level
Deborde, Marie. "Oxydation par le chlore et l'ozone de composés organiques à effets modulateurs endocriniens". Poitiers, 2006. http://www.theses.fr/2006POIT2254.
The objective of this work was to improve the present knowledge about fate of endocrine disruptors during water treatment process. Chlorination and ozonation (two disinfection steps frequently applied) of seven endocrine disruptors (17β-estradiol, estriol, estrone, 17α-ethinylestradiol, 4-n-nonylphenol et bisphenol A) were then studied. In a first time, a kinetic study was performed at 20 ± 2 °C and different pH levels. Under these conditions, all molecules with a phenolic group in their structure (17β-estradiol, estriol, estrone, 17α-ethinylestradiol, 4-n-nonylphenol et bisphenol A) were removed more or less rapidly as function of pH, irrespective of the studied oxidant. Elementary oxidation reactions and associated rate constants were then determined. Concerning progesterone (devoid of phenolic ring), no removal in presence of chlorine was shown. However, a possible oxidation by ozone was observed. In a second time, by-products ozonation of two studied endocrine disruptors (bisphenol A, progesterone) were studied. Numerous by-products were identified by chromatographic analyses (HPLC/UV, HPLC/MS, HPLC/MS/MS, GC/MS). Stability by-products in presence of ozone was then studied and reactional pathways were suggested
Bohler, Sacha. "Les effets de l'ozone sur les processus foliaires du peuplier : une approche protéomique". Thesis, Nancy 1, 2010. http://www.theses.fr/2010NAN10140/document.
After the industrial revolution of the 1700s and 1800s, and the subsequent industrialization, many pollutants have accumulated in the atmosphere, mainly due to the use of coal and fossil fuels. Besides the primary pollutants such as nitrogen oxides and sulfur oxides, secondary oxides such as ozone started to accumulate. Nowadays, ozone is the third gas involved in global climate change, but is also a major health risk for humans, and induces considerable damage to vegetation. Starting in the 50s, ozone research was based on targeted studies. Nowadays, with the advent of global techniques such as transcriptomics and proteomics, new results can be produced in an unbiased way. In the thesis presented here, a proteomic study of the effects of ozone on poplar leaf processes was carried out. With the help of this technique, complemented with biochemical and physiological approaches and with morphological observations, it was possible to confirm previous results, but also to elaborate new hypotheses concerning the effects of ozone on poplar leaf metabolism. In parallel, studying the stress also allowed to clarify some of the changes that occur in metabolism during leaf development, under stress conditions and under control conditions. In this document, the procedures, results and conclusions obtained during this study are presented in detail
Cuny, Florence. "Processus d'induction d'embryons haploïdes par du pollen irradié chez le melon (cucumis melo l. ) : réponses du pollen à l'irradiation gamma". Avignon, 1992. http://www.theses.fr/1992AVIG0301.
Laval-Gilly, Philippe. "Analyse de la mobilité des macrophages pour le développement d'un biocapteur atmosphérique". Metz, 2000. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2000/Laval_Gilly.SMZ0052.pdf.
Roumeau, Stéphane. "Les réactions hétérogènes dans la troposphère tropicale : effets des aérosols carbonés et des cirrus sur l'ozone". La Réunion, 2001. http://elgebar.univ-reunion.fr/login?url=http://thesesenligne.univ.run/01_21_Roumeau.pdf.
Kanoun, Myriam. "Impact de l'ozone sur le végétal : modification du métabolisme phénolique et altération de la Rubisco chez Phaseolus vulgaris L". Pau, 2002. http://www.theses.fr/2002PAUU3008.
Laaidi, Mohamed. "Contribution à l'étude aéropollinique de la Haute-Bourgogne : introduction à une géographie des risques allergéniques". Dijon, 1999. http://www.theses.fr/1999DIJOMU08.
Half the allergic diseases are due to anemophilous pollen, wich represents a prevalence of 10% among the french population. So we wished to realise in this research a quite complete study of aeropalynology problems in Upper Burgundy. This induced us to set up three traps in Montbard, Dijon and Mâcon, and to use a fourth one already set up in Chalon-sur-Saône. Their results allowed us to list all the anemophilous pollens of the region, and to establish pollen calendars for each site. Then we compared pollinic counts and concomitant meteorological data, which showed the influence of rainfall, temperatures relative humidity, sunshine wind and atmospheric pressure on the release and scattering of the pollen in the air. But pollen collections vary substantially in space and time ; thi lead us to develop forecasting methods using meteorological parameters prevaling before flowering. These were applied to birch (Betula) and grasses (Poaceæ), which are the two most allergenic taxa in the region. Thus could be predicted the onset and duration of pollination, and there's no point in emphasizing how useful such data are for allergists and allergic people , so long as they are available beforehand enough
Eymard, Amandine. "Dynamique de la végétation et variations climatiques dans les Balkans au cours du dernier cycle climatique à partir des séquences polliniques des lacs Maliq et Ochrid (Albanie)". Besançon, 2008. http://www.theses.fr/2008BESA2068.
Over the past 150000 years, isotopic ice and ocean records have revealed a succession of rapid and high amplitude climate fluctuations. However, continental records showing sufficiently sensitive to determine the spatial extension of climate change are rare. This thesis therefore aims to analyze and compare the pollen records of Lakes Ohrid and Maliq in Albania, in order to obtain a climate reference record in the south-eastern Europe. The analysis of these pollen records allowed to: (1) Reconstitute, for the first time, the vegetation history at middle altitude in the southern Balkans during the last climatic cycle: the sequences of Lake Ohrid shows that the dynamics of vegetation during the last climatic cycle is very similar to that of other continental sequences of southern Europe, namely orders of succession of ecosystems very close; the differences involve the « timing » of the appearance of a species, its importance within the ecosystem and the duration of its presence in the same ecosystem, (2) Quantify climate changes associated with those in vegetation: the pollen sequence of Lake Maliq, which showed the complex history of mountain ecosystems, has helped to quantify changes in temperature, precipitation and seasonality during the last glacial-interglacial transition and the Holocene in the southern Balkans. The Saine method has been applied to the sequence of Lake Ohrid to obtain a quantitative reconstruction in the Balkansduring the last climatic cycle. To improve the quality of these environmental and climate reconstructions: (1) The modem relationships between pollen assemblages, vegetation and climate, which are the basis of past environmental and climate reconstructions, have been previously analyzed statistically, from moss samples collected in Albania, Greece and Republic of Macedonia. This study shows that it is possible to distinguish in modem pollen sedimentation the ecosystems and vegetation belts in a fragmented area, and therefore, that the corresponding surface samples can be used to transfer functions, (2) A new modem pollen database, including 2760 sites in Europe, Mediterranean area and Eurasia, has been developed with new samples of surface to improve the spatial coverage of the modem dataset that is used in the methods of quantitative paleoclimate reconstruction
Leclair, De Bellevue Jimmy. "Analyse et modélisation des échanges verticaux induits par les systèmes convectifs des latitudes tropicales : effets sur l'ozone troposphérique". Phd thesis, Université de la Réunion, 2006. http://tel.archives-ouvertes.fr/tel-00468500.
Leclair, de Bellevue Jimmy. "Analyse et modélisation des échanges verticaux induits par les systèmes convectifs des latitudes tropicales : effets sur l'ozone troposphérique". La Réunion, 2006. http://tel.archives-ouvertes.fr/tel-00468500/fr/.
The objective was to perform our knowledge on the mechanisms 'exchanges, close to the zone S of major convection, more particularly in periphery of the tropical cyclones by exploring the bonds between tropical convection and tropospheric ozone. A climatological approach showed that the influence of the occurrence attends these systems convectifs on tropospheric ozone is double. The analysis of a case of transfer intense subsident on April 6th, 1995 in Reunion, then on the West of the system Marlène, allowed to characterize this exchange stratosphere-troposphere. The examination of the model idealized by tropical cyclone Hurricane brought dynamic complements and generalized this study of mechanisms. In a additional way in the case Marlène, three different synoptic situations or a strong interaction between convection, jet-front system and Rossby waves induce stratosphere-troposphere exchanges have been documented
Malka, Pascale. "Étude en chambres à ciel ouvert, des effets de doses subnécrotiques d'ozone et de dyoxide de soufre sur la croissance et le fonctionnement stomatique de Picea abies". Paris 12, 1988. http://www.theses.fr/1988PA120053.
Servais, Stéphane. "Altérations mitochondriales et stress oxydant pulmonaire en réponse à l'ozone : Effets de l'âge et d'une supplémentation en oméga-3". Phd thesis, Université Claude Bernard - Lyon I, 2004. http://tel.archives-ouvertes.fr/tel-00012031.
Hmaidat, Mohammed. "Effets à court terme de l'ozone atmosphérique sur certaines enzymes impliquées dans les réactions de défense chez le blé". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ31735.pdf.
Saliba, Layal. "Etude de la transmission glutamatergique et des effets de l'ozone dans le noyau du tractus solitaire de rat adulte". Aix-Marseille 2, 2009. http://www.theses.fr/2009AIX20722.
This work joins within the framework of studies about the mechanisms of integration of the visceral information in response to environmental disturbances. In the first part of this work, our results suggest that neurons of the nucleus of tractus solitarii (NTS) could use different neurotransmission modes according to their projection pathway. In neurons involved in vital reflexes such as those regulating respiration, the lack of important iA current, as well as a synaptic transmission which depends mostly on AMPA receptors with less accessible NMDA receptors, would induce a very precise and highly reliable treatment of the information. On the contrary, in neurons implicated in the elaboration of visceral sensations such as respiratory distress, the presence of an important iA current, as well as a synaptic transmission involving perisynaptic NMDA receptors, would allow an easy modulation of the neurotransmission and a global activation of some brain areas. In the second part of this work, we show that ozone inhalation induces a neuronal activity in regions of adult rat NTS receiving pulmonary afferences, at doses causing a lung inflammation comparable to that provoked by atmospheric peaks of pollution to certain humans. Pulmonary inflammation and neuronal activity inferred by ozone inhalation increase from the first hours of exposure and remain high as long as stimuli is present. The continuation of this work aims to determine if ozone induces a neuronal inflammation, and to characterize its effects on the neurotransmission particularly in the NTS
Galaup, Serge. "Étude des effets combinés de l'ozone et de la contrainte hydrique sur la productivité et le fonctionnement stomatique du haricot (Phaseolus vulgaris) cultivé en chambres à ciel ouvert". Paris 12, 1992. http://www.theses.fr/1992PA120040.
Bagard, Matthieu. "Impact de l’ozone sur les processus photosynthétiques et photorespiratoires du peuplier (Populus x canescens [Aiton] Sm.) au cours du développement foliaire : Aspects écophysiologiques et cellulaires". Thesis, Nancy 1, 2008. http://www.theses.fr/2008NAN10017/document.
Ozone is considered the most important phytotoxic air pollutant and has well known effects on the metabolism of forest trees. However, the role of leaf development in ozone sensitivity remains unclear. In addition, the photorespiratory pathway has been scarcely investigated under ozone stress. To provide new insights into these issues, young poplar trees (Populus x canescens [Aiton] Sm.) were subjected to 120 ppb of ozone for 35 days in phytotronic chambers. Treated trees displayed foliar symptoms of injury (necrotic spots, chlorosis and precocious leaf senescence) and a reduced stem radial growth. In mature leaves, ozone reduced photosynthesis (A, ?PSII) by impairing CO2 fixation, mainly at the level of rubisco (Vcmax and in vitro activity). Photochemistry was also affected as shown by reduced chlorophyll content and Fv/Fm ratio. The rate of in vivo photorespiration and glycolate oxidase activity were reduced along with photosynthetic parameters, suggesting that photosynthesis and photorespiration were both inhibited by the ozone-induced impairment of rubisco. The amount of the H subunit of the glycine decarboxylase and total glutamine synthetase activity were respectively maintained and stimulated. As both enzymes are related to photorespiration, a potential shift in their metabolic involvement could have occurred under ozone stress. In addition, treated leaves showed a stimulation of mitochondrial respiration and phosphoenolpyruvate carboxylase activity which could be related to a higher demand for reducing power to sustain detoxification processes. As none of the parameters were modified by ozone in expanding leaves, ozone sensitivity may appear during leaf development, possibly when developing leaves undergo sink/source transition
Dziri, Leila. "Application de la spectroscopie photoacoustique et de fluorescence à l'étude des effets de l'ozone sur la photosynthèse de l'érable à sucre". Thèse, Université du Québec à Trois-Rivières, 1993. http://depot-e.uqtr.ca/5113/1/000603592.pdf.
Lemonnier--Le, Penhuizic Claire. "Effets d'oligosaccharides sur l'embryogenèse de microspores de brocoli : : mode d'action et transduction du signal". Rennes 1, 2001. http://www.theses.fr/2001REN10085.
Farah, Jinane. "Etude de la fraction lipidique de pollens allergisants et de ses modifications chimiques causées par les polluants atmosphériques". Thesis, Lille, 2018. http://www.theses.fr/2018LIL1R057.
The pollen lipidic fraction has an adjuvant effect on the allergic reaction and it is involved in germination processes. The alteration of pollen lipids by atmospheric pollutants is poorly documented in the literature although negative health effects are suspected. Our work was carried out on two highly allergenic pollens: timothy grass (phleum pratense) and birch tree (betula pendula). The lipid fraction of intact pollen was identified and quantified by gas chromatography equipped with a flame ionization detector or coupled to mass spectrometry. The main chemical families identified are: alkanes, alcohols, alkenes, saturated and unsaturated fatty acids, aldehydes and sterols. In vitro exposure of pollen to ozone has exhibited the reactivity of alkenes and the production of saturated fatty acids and aldehydes. Nitrogen dioxide has shown a protective role toward the reactivity of ozone. Furthermore, the bioavailability of lipids from intact pollen appears to be low as shown by pollen extractions with aqueous solvent without agitation. Moreover, our results give a new role to the rupture of pollen in the atmosphere. In fact, we observed a facilitated extraction of lipids for crushed pollen and in particular the release of immunostimulatory species such as linoleic and α-linolenic acids. The adjuvancy effects of the lipids extracted from broken or polluted pollen grains to the allergic reaction should be unraveled in a future work
Choisnard, Luc. "Réduction de l'aptitude au feutrage des fibres de laine par traitements oxydatifs et protéolytique de surface". Lille 1, 2000. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2000/50376-2000-244.pdf.
L'optimisation d'un deuxieme traitement oxydatif par l'ozone et hydrolyse enzymatique a ete realisee par un plan factoriel complet 2 4 complete par un plan composite centre. A l'issue de cette etude, nous avons demontre que ce procede permet d'eliminer toute forme de feutrage, ameliore les caracteristiques colorimetriques et diminue favorablement le diametre moyen des fibres sans en alterer la tenacite. Une chute importante du taux de 18-methyleicosanoate present au niveau de la cuticule a egalement ete mesuree finalement, un test norme de lavage en machine conclut cette etude en confirmant le caractere irretrecissable des fibres oxydees par l'ozone et attaquees par les subtilisines
Bhugwant, Chatrapatty. "Étude physico-chimique des aérosols de combustion et de l'ozone troposphérique à la Réunion". La Réunion, 2001. http://elgebar.univ-reunion.fr/login?url=http://thesesenligne.univ.run/01_16_Bhugwant.pdf.
Lebamba, Judicael. "Relation pollen-végétation-climat actuels en Afrique centrale : une approche numérique appliquée à la séquence quaternaire du lac Barombi Mbo, Cameroun". Montpellier 2, 2009. http://www.theses.fr/2009MON20203.
This work presents the analysis of 80 new modern pollen samples from central Africa, mainly in forest environment. Complemented by pollen assemblages previously obtained in this region, i. E. A total of 199 assemblages, statistical analysis and the application of the biomisation method have allowed to test the reliability of the pollen content of this dataset compared to local botanical data, showing that potential biomes (tropical rain forest, tropical seasonal forest, savanna) and forest successional stages (savanna, secondary forest, mature forest) were reconstructed with more than 95% of confidence level. Based on a more extended pollen database toward drier vegetations from West Africa and using the biomisation method, the best analogues and the artificial neural networks techniques, we proposed new quantitative and more precise reconstructions of the vegetation and climate at Lake Barombi Mbo, in Cameroon, during the last 33,000 cal yrs BP
Rakotomanga-Rasolonjatovo, Vololonirina. "Incidences des traitements pesticides sur les grains de pollen de Tradescantia et de l'orge : Aspects cellulaires et moléculaires". Toulouse, INPT, 1995. http://www.theses.fr/1995INPT019A.
Farah, Jinane. "Etude de la fraction lipidique de pollens allergisants et de ses modifications chimiques causées par les polluants atmosphériques". Electronic Thesis or Diss., Université de Lille (2018-2021), 2018. http://www.theses.fr/2018LILUR057.
The pollen lipidic fraction has an adjuvant effect on the allergic reaction and it is involved in germination processes. The alteration of pollen lipids by atmospheric pollutants is poorly documented in the literature although negative health effects are suspected. Our work was carried out on two highly allergenic pollens: timothy grass (phleum pratense) and birch tree (betula pendula). The lipid fraction of intact pollen was identified and quantified by gas chromatography equipped with a flame ionization detector or coupled to mass spectrometry. The main chemical families identified are: alkanes, alcohols, alkenes, saturated and unsaturated fatty acids, aldehydes and sterols. In vitro exposure of pollen to ozone has exhibited the reactivity of alkenes and the production of saturated fatty acids and aldehydes. Nitrogen dioxide has shown a protective role toward the reactivity of ozone. Furthermore, the bioavailability of lipids from intact pollen appears to be low as shown by pollen extractions with aqueous solvent without agitation. Moreover, our results give a new role to the rupture of pollen in the atmosphere. In fact, we observed a facilitated extraction of lipids for crushed pollen and in particular the release of immunostimulatory species such as linoleic and α-linolenic acids. The adjuvancy effects of the lipids extracted from broken or polluted pollen grains to the allergic reaction should be unraveled in a future work
Azouaou, Zahia. "Contribution à l'étude des effets de la nutrition en cuivre sur le rendement du blé : incidence des carences sur la formation du pollen". Toulouse, INPT, 1992. http://www.theses.fr/1992INPT007A.
Pages, Marielle. "Effets et mécanismes d'action de l'ozone utilisé comme moyen de lutte contre des champignons pathogènes du pommier : études in vitro et in vivo". Thesis, Toulouse, INPT, 2015. http://www.theses.fr/2015INPT0102.
Apple trees are the target of a lot of pests and fungal diseases, responsible for many economic losses. Farmers treat these micro-organisms mainly with pesticides. Plant-protection products are today very controversial. French and European authorities control their use by means of numerous regulations. Therefore, an alternative solution with a low remanence must be found in order to limit fungal diseases. The aim of this thesis is to evaluate the innovative process efficiency based on the use of ozonated water against four fungal species: Venturia inaequalis, Botrytis cinerea, Neofabraea alba and Phytophthora syringae. Firstly, this work of thesis verified the ozone antifungal action on spores suspensions of the four fungal species and on different stages of development of V.inaequalis spores. According to the species and stages of development considered, a difference of sensibility was detected. Moreover, alteration of the membrane, due to ozone action, was observed thanks to several experimentations: quantification of phospholipids peroxidation, spore observations with Scanning Electron Microscopy and with Optical Microscopy after staining. Secondly, the ozonated water effects on seedlings previously contaminated by V.inaequalis spores were evaluated. This study confirmed the anti-fungal action of water containing ozone. It was also observed the importance of the water and of ozone quantities supplied. These quantities must be controlled to optimize the antifungal action of the treatment. These results validated the ozone application as a fungicide alternative of use of pesticides. Additional researches will be made concerning the treatment modalities: the aim is to transfer the technology from the laboratory to the orchard
Podor, Myriam. "Effets de la sécheresse et de l'ozone sur le statut hydrique et la gestion du carbone chez le pin d'Alep (Pinus halepensis Mill. )". Vandoeuvre-les-Nancy, INPL, 1997. http://www.theses.fr/1997INPL040N.
Saüt, Carine. "Transport et évolution de l'ozone et de ses précurseurs au-dessus de l'Océan Pacifique : impact de la convection nuageuse organisée". Toulouse 3, 2003. http://www.theses.fr/2003TOU30141.
Leroux, Benoît. "Approches cytologique et pharmacologique de la levée des effets inhibiteurs exercés par l'éthylène sur l'embryogenèse de microspores isolées de colza et de chou-fleur". Rennes 1, 2007. http://www.theses.fr/2007REN1S074.
To obtain embryos from isolated microspores of cauliflower it is necessary to apply them a heat shock. However, in some instances this treatment is not found to be effective. We have hypothesized that embryogenesis could be inhibited by production in excess of the stress-hormone ethylene. Cytological and pharmacological studies have been developed to assess the involvement of ethylene in the control of development in microspores from the rape variety Topas. We demonstrated that weak reactivity of microspores was related with high ability to produce ethylene. This could be reversed through addition in culture media of ethylene biosynthesis inhibitors. The transposition of this approach to non-responsive microspores of cauliflower supported the inference that restricted embryogenesis is partly due to over-production of ethylene which can be counteracted. This indicated that the use of ethylene inhibitors could lead to relevant applications in production of doubled haploids of cauliflower
Have, Marien. "Effets de l'ozone troposphérique sur le blé tendre (Triticum aestivum L.) : caractérisation de l'endoprotéolyse vacuolaire et du niveau d'oxydation des protéines dans la feuille drapeau". Thesis, Paris Est, 2013. http://www.theses.fr/2013PEST1112.
The present study was undertaken to investigate whether vacuolar endoproteolysis and/or protein carbonylation (measured here with a newly developed method) were functionally linked and if either of these processes or both could differentiate between ozone sensitive and tolerant wheat cultivars (cvs). Two winter wheat (Triticum aestivum L.) cvs released in 1986 (Soissons) and 2006 (Premio) were grown in the field and exposed to ambient and semi-controlled chronic ozone concentrations, from pre-anthesis to harvest, using a new linear ozone fumigation device that generates gradients of the pollutant. Grain yield and quality were more affected by the ozone treatments in the older cv Soissons that appeared to be the most sensitive. Because stomatal conductance did not differ significantly between the two cvs, differential ozone sensitivity was rather ascribed to differences in the biochemical and molecular responses between the two cvs. Ozone detrimental effects were mainly characterized by premature induction of leaf senescence, causing the shortening of the assimilation and grain-filling periods. Even though Soissons exhibited higher constitutive levels of carbonyl content in total soluble proteins, the increases in protein carbonylation, in response to the ozone treatments, were equivalent in both cvs. Thus basal levels of protein carbonyl seems a more relevant parameters to distinguish between ozone sensitive and tolerant wheat cvs than actual change in this parameter in response to ozone treatments. However, ozone induced more carbonyl groups on Rubisco large subunit (LSU) and small subunit (SSU) in Soissons and this was associated with a more pronounced decline in LSU and SSU contents and a lower Rubisco activity. Increased protein carbonyl levels and losses in total chlorophyll contents were concurrent, suggesting a link between the extent of oxidative stress and senescence development. Moreover, ozone treatments induced a stimulation of endoproteolytic activities that resulted mostly from increases in cysteine protease activities, for both cvs. Surprisingly, total proteolytic and cysteine protease activities were more enhanced in the tolerant cv, whereas elevated proteolysis is usually associated with high sensitivity to environemental stresses, like drought. Expression analysis for three genes encoding papain-like cysteine proteases showed poor correlation with total cysteine protease activities, which suggested that post-transcriptional regulation mechanisms were prevalent over transcriptional ones. Increased endoproteolytic activities were associated with increased protein carbonylation and with a decline in total soluble protein contents. Oxidized proteins could be more susceptible to proteolysis. Therefore, we suggest that ozone-induced ROS caused protein oxidation on one hand and acted as a signal that triggered senescence processes, such as enhanced proteolysis, on the other hand
Bourgin, Marc. "Étude de la décomposition de produits phytosanitaires par l'ozone : Application au traitement des semences déclassées". Phd thesis, Toulouse, INPT, 2011. http://oatao.univ-toulouse.fr/16230/1/bourgin.pdf.
Chiron, Hélène. "Effets de l'ozone et/ou d'un champignon pathogène dans les aiguilles et le phloème de pins sylvestre (Pinus sylvestris L. ) : étude moléculaire du métabolisme des stilbènes". Nancy 1, 2000. http://www.theses.fr/2000NAN10047.
The present study describes first the molecular cloning and the functional expression of the pinosylvin O-methyltransferase (PMT) gene, and then the dose-dependent ozone induction of stilbene synthase (STS) and PMT genes responsible of stilbene biosynthesis in needles and sapwood of 7-year-old Scots pine trees prior to sterile and fungal inoculations (Leptographium wingfieldii)
Charlebois, Denis. "Potentiel et limitations de la spectroscopie photoacoustique pour l'étude des effets de l'ozone, du bioxyde de soufre et de l'ion sulfite sur l'activité photosynthétique des plantes". Thèse, Université du Québec à Trois-Rivières, 1994. http://depot-e.uqtr.ca/6695/1/000611356.pdf.
Desprat, Stéphanie. "Réponses climatiques marines et continentales du Sud-Ouest de l'Europe lors des dernières interglaciaires et des entrées en glaciations". Bordeaux 1, 2005. http://www.theses.fr/2005BOR12963.
The main purpose of this work is to characterise the climatic variability of the last five isotopic interglacials which have occurred during the last 450, 000 years, in particular that of marine isotope stage 11, 9 and 7. For that, a multiproxy study (pollen, assemblages of planktic foraminifera, and planktic and benthic delta^18O) was performed from NW Iberian margin deep-sea cores. All isotopic interglacials show a similar climate dynamic related to astronomical forcing cyclicity, on which abrupt climatic oscillations are superimposed. However, they differ from each other by the amplitude of the climatic phases and the forest vegetation succession during warm periods. The marine and continental realms synchronously respond to climate changes. However, a time-lag is detected between temperature variations and ice volume changes. The direct land-sea-ice correlation highlights interactions between insolation, ice volume and vegetation during glacial inception
Gaüzère, Julie. "Effets de la dispersion du pollen à longue distance sur les capacités d'adaptation de populations de Hêtre commun le long d'un gradient altitudinal". Thesis, Montpellier, SupAgro, 2014. http://www.theses.fr/2014NSAM0028/document.
The rapidity of the climate change observed and predicted raises the issue of how fast species can adapt to future. In face of environmental change, populations can adapt without migrating thanks to their plastic response in a first time, and to their response to selection in the long term (genetic adaptation). In conditions of environment variable both in space and time, gene flow can enhance the spread of beneficial alleles between populations. The objective of this thesis is to experimentally measure the adaptive differentiation and the long-distance pollen dispersal along an elevational gradient of beech populations (Fagus sylvatica). In this study we investigated three beech populations located on the northern side of the Mont-Ventoux (from 900m to 1400m of elevation). Twelve potential adaptive functional traits (phenological, physiological and morphological) have been measured on 60 maternal families collected from these populations (20 mothers/population, 100 offspring/mother) and planted in nursery. The results of this thesis show that that (i) the strong pollen immigrant rate received by the populations (m = 56 %) did not their prevent adaptive differentiation, (ii) the action of natural selection erodes the genetic variance of the traits, (iii) despite significant genetic variance for all the traits, the genetic covariance between traits should affect the rate and direction of evolution in the future, and (iv) gene flow contribute to increase the total genetic variance within the populations. Finally, populations at medium and high elevations may have the potential to adapt to future climate
O'Heix, Bruno-Charles. "Etude écologique du changement climatique et des effets de l'ozone sur les chênes ainsi que sur l'écosystème d'une forêt dépérissante en Europe Centrale : vers une intégration dans les prises de décisions politiques pour un aménagement forestier durable". Nancy 1, 1999. http://www.theses.fr/1999NAN10290.
The condition of Hungarian forest ecosystems was analysed and compared to the European and world ecosystems, taking into account the global climatic changes. The Hungarian site of Síkfökút, continuously studied during the last twenty-five years has been considered in the light of new concepts. Two oak species Quercus petraea and Quercus cerris are growing in this stand, showing contrasting declining symptoms, Q. Cerris being considered as more resistant. Different analyses were made on the site, including dendrochronology and litter decomposition. In parallel, a fumigation experiment with ozone was carried out in a phytotronic chamber including two more oak species Q. Robur and Q. Rubra. The four oak species showed differential responses to ozone and they can be ranged from the more ozone tolerant to the more sensitive as follows: Q. Cerris > Q. Rubra > Q. Petraea > Q. Robur. These results led to suggestions for recommendations of species selection in reforestation and afforestation
Chassard, Guillaume. "Interaction de l’ozone avec des particules carbonées : cinétiques de capture, dégradation des HAP et impact sur la réponse inflammatoire épithéliale". Electronic Thesis or Diss., Lille 1, 2014. http://www.theses.fr/2014LIL10140.
Soot particles, ubiquitous in the urban atmosphere, exhibit extreme chemical and morphological complexity. Adsorbed on their surface, polycyclic aromatic hydrocarbons (PAHs) have a proven pulmonary toxicity. During atmospheric transport, they may, through oxidation and photolysis process, form oxygenated and nitrated products about which health impacts are not well known. We propose to characterize the atmospheric aging of soot particles and to study the impact of aging on the lungs. This work deals with the generation of soot models particles; laboratory simulation of aging by exposures to ozone; and the study of the inflammatory effects of aged or not particles on lung cells. In a first step a carbonaceous aerosol has been exposed to ozone in a flow reactor. The influences of contact time, initial ozone concentration, relative humidity, UV radiations and particle size were studied. The role of the atomic oxygen in the reaction mechanism was also evaluated. Then the heterogeneous reactivity between PAHs adsorbed on carbonaceous particles and ozone has been investigated. Degradation kinetics of particulate PAHs were thus performed. Finally, we studied the inflammatory response of PAHs alone or in particulate phase on lung cells by assay of pro-inflammatory interleukins. The effect of aging models particles and the role of pulmonary surfactant were evaluated
Vella, Roxane. "Une exposition à l'ozone induit une insulino-résistance via un stress oxydant systémique et un stress du réticulum endoplasmique musculaire : pollution à l'ozone et diabète de type 2 : peut-on imaginer une origine environnementale aux maladies métaboliques ?" Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10176.
A growing body of evidence suggests that exposure to traffic-related air pollution is a risk factor for type 2 diabetes. Ozone, a major photochemical pollutant in urban areas, is negatively associated with fasting glucose and insulin concentrations but most aspects of this association remain to be elucidated. Using an environmentally realistic concentration (0.8 ppm), we demonstrated that exposition of rats to ozone induced whole body insulin resistance and oxidative stress, with associated endoplasmic reticulum (ER) stress, JNK activation and disruption of insulin signaling in skeletal muscle. Bronchoalveolar lavage fluids from ozone-treated rats reproduced this effect in C2C12 myotubes, suggesting that toxic lung mediators were responsible for the phenotype. Pre-treatments with the chemical chaperone 4-phenyl butyric acid, the JNK inhibitor SP600125 or the antioxidant N-acetylcysteine alleviated insulin resistance, demonstrating that ozone sequentially triggered oxidative stress, ER stress and JNK activation to impair insulin signaling in muscle. This study is the first to report that ozone plays a causative role in the development of insulin resistance, suggesting that it could boost the development of diabetes. We therefore provide a potential mechanism linking pollutant exposure and the increased incidence of metabolic diseases
Guion, Antoine. "Droughts and heatwaves in the Western Mediterranean, impact on ozone pollution". Electronic Thesis or Diss., Sorbonne université, 2022. http://www.theses.fr/2022SORUS056.
Droughts and heatwaves are extreme events able to affect both vegetation and atmospheric chemistry, notably through surface-troposphere interactions. The objective of this thesis is to assess their effects on biomass, fire activity and ozone pollution in the western Mediterranean. This study is mainly based on regional numerical models of the land surface (hydrology and vegetation) and the atmosphere (meteorology and atmospheric chemistry). In addition, several datasets of in situ and satellite observations are used.Identifying droughts and heatwaves over the period 1979-2016 (WRF-ORCHIDEE), I highlighted their spatial and temporal distribution. Based on observations (MODIS), I demonstrated that the decline in vegetation activity (decrease in biomass) is mainly attributable to droughts, while the increase in fire intensity results from a synergy between droughts and heatwaves. Finally, these events both lead to an increase in surface ozone concentration including simulated (CHIMERE) and observed (AQ e-Reporting) pollution peaks. This is explained by an increase in precursor emissions, a decrease in dry deposition in the canopy and favourable meteorological conditions for photochemistry
Alami, Sophia. "Action de stress physiques (froid, obscurité) sur le développement et la viabilité du pollen de plusieurs variétés de sorgho-grain : incidence sur le métabolisme des acides nucléiques dans les méiocytes et le tapis". Toulouse, INPT, 1988. http://www.theses.fr/1988INPT004A.
Gaucher, Catherine. "Effets physiologiques de fortes teneurs d'ozone et de CO2 seul et en combinaison, chez des semis d'érable à sucre (Acer saccharum Marsh. )". Nancy 1, 2001. http://www.theses.fr/2001NAN10182.
Experiments in OTC and phytotronic chambers were conducted during one growing season to study the effects of high CO2 and O3 on regeneration of sugar maple seedlings. Assimilation rate and growth of seedlings were decreased after an exposure at constant O3 (100 to 300 nL. L-1). Stimulation of GR, G6PDH, PEPC and NR activities allowed an increased availability of reducing power, carbon skeletons and nitrogen necessary for the detoxification and repair mechanisms. Under 650 [mu]L. L-1 CO2, increase of growth (10 to 100%) depends of nutrient and light availability of the experiment. Under high CO2 + O3, growth and stimulation of G6PDH, PEPC and NR were intermediary to these of the seedlings exposed under high O3 and those exposed under high CO2. Under high CO2, assimilation rate was stimulated. This allowed an increased synthesis of NADPH and carbons skeletons, which may be allocated to detoxification and repair mechanisms and, thus, contributed to reduce the propagation of oxidative damages
Ahmad, Rafiq. "Effet de l'ozone troposphérique sur la physiologie des feuilles de maïs (Zea mays L.) : étude de gènes impliqués dans le catabolisme cellulaire". Thesis, Paris Est, 2012. http://www.theses.fr/2012PEST1018.
Maize is a major crop cultivated all over the world. Its yield and growth is affected by numerous environmental stresses. In the present work, the impact of the gaseous phytotoxic pollutant, ozone, on maize leaves was studied, using a molecular and biochemical approach. Concentrations of ozone in the troposphere have increased dramatically in the recent past and it now negatively affects crops growth and yield. In this work, a recently developed fumigation system was used to expose maize plants in the field. Seventy-one days after sowing, the plants were submitted to ozone fumigation at an average concentration of 98 ppb.h-1. The 10th and 12th leaves were harvested after 20, 35 and 50 days of treatment. Expression of three genes coding caspase-like cysteine proteases “metacaspases” (denoted as ZmMCII-1, ZmMCII-2 and ZmMCII-3) and their global activity was studied in senescent and ozone-exposed maize leaves. For the first time, we observed that mRNA accumulation of the three caspase-like cysteine proteases increased significantly in response to ozone exposure. Moreover, the global activity of metacaspases also increased significantly in both senescencing and ozone-exposed plants. The metacaspases activity and mRNA up-regulation could represent control points for leaf tissues to determine the degree and timing of protein catabolism during senescence and ozone treatment. Protein catabolism was indeed stimulated in response to ozone since increases in the expression of a gene coding an ozone-induced papain-like cysteine protease (Mor-CP) and in global papain-like cysteine proteases activities in leaf tissues were observed. In addition, we identified new cysteine protease inhibitor CC11 “cystatin” in maize leaves. After the recombinant CC11 protein was purified from a bacterial heterologous system (E. coli strain BL21 (DE3) plyS with a pET 30 (EK/LIC) vector), it was shown to be active in vitro against commercial papain (100% inhibition) and against total maize leaf cysteine protease extract (57-80% inhibition). Therefore its involvement in the regulation of cysteine protease activity in response to ozone exposure could be supposed. Production of the recombinant proteins corresponding to the active regions of ZmMCII-2 and Mor-CP was achieved. The corresponding polyclonal antibodies were obtained to study post-transcriptional events in maize leaves, in the future. In conclusion, we have identified the new enzymes, metacaspases and cysteine proteases involved in proteolysis which could be used as novel parameters for screening different maize varieties for improved tolerance to ozone pollution
Palluau, Fabienne. "Mise au point et optimisation des techniques de prélèvement et d'analyse des composés organiques volatils (COV) dans l'atmosphère : Etude de l'influence de facteurs climatiques et de l'ozone sur les teneurs mesurées en COV". Université Louis Pasteur (Strasbourg) (1971-2008), 2003. http://www.theses.fr/2003STR13162.
Pelloux, Jérôme. "Contribution à l'étude des effets de l'ozone, de la sécheresse et du stress salin sur le métabolisme carboné du pin d'Alep (Pinus halepensis Mill. ). Régulation de la rubisco et de la rubisco activase". Nancy 1, 2000. http://www.theses.fr/2000NAN10086.
The decline of aleppo pine forests (Pinus halepensis M. ) observed in natural conditions have prompted research concerning the effects of abiotic stresses on this species. For this purpose, the effects of ozone, water stress and salt stress on aleppo pine's carbon metabolism were carried out in this study. Ozone did induce chlorotic mottles, linked to a decrease in chlorophyll content. A decline in total rubiseo activity, and an increase in the activities of several enzymes associated to the catabolic pathway such as pyruvate kinase (PK), phosphoenolpyruvate carboxylase (PEPc) and malic enzymes (EM-NAD and EM-NADP) were shown in needles of pines submitted to ozone. These results tend to show that an increase in compounds potentially used in detoxifying repair processes is occuring under ozone stress. Water and salt stresses would limit the deleterious effects of ozone on plant metabolism, presumably by inducing stomatal closure which would limit the pollutant input into the leaves. Studies on the regulation of rubisco and rubisco aetivase, were undertaken at a molecular level in needles of pines submitted to ozone and/or drought. For this purpose, the cloning of cDNA fragments coding for rubisco large subunit (LSU) and for rubisco activase (RCA) was realized, allowing a phylogenetic analysis of both proteins. A decrease of LSU and RCA protein quantities, associated to a transcriptional regulation, was shown in response to ozone,> suggesting a potential coregulation of both proteins in those particular conditions. Even though the effects of drought on the large subunit of rubisco and on rubisco activase were similar, no correlation between the effects of this stress on the two proteins could be drawn. When ozone was combined to drought, a difference in the regulation of rubisco large subunit and of rubisco activase was shown. Under those conditions, rubisco large subunit was under a transcriptional control whereas rubisco activase was under a post transcriptionnal regulation. For the very first time in this study, a conifer' s rubisco activase is partially cloned and its regulation studied in reponse to abiotic constraints
Dumont, Jennifer. "Rôle de la régulation stomatique et de la capacité de détoxication foliaire dans l'estimation d'un seuil de risque à l'ozone pour la végétation". Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0022/document.
Tropospheric ozone is a major air pollutant that acts as a phytotoxin. It enters the leaf through the stomata before being dissolved in the apoplast by generating reactive oxygen species (ROS) causing oxidative stress. Two defenses exist to restrict the effects of ozone: (i) the stomata which can limit ozone uptake by regulating stomatal conductance and (ii) the detoxification processes of ROS generated by ozone.We studied the effects of ozone (120 ppb) on these two mechanisms of defense in three euramerican poplar genotypes (Populus deltoides x Populus nigra) under controlled conditions in phytotronic chambers. A direct effect of ozone on photosynthesis and stomatal movements in response to changes in environmental factors (by slowing the stomatal opening and closure) has been highlighted. Models of stomatal conductance, on which indicators of critical level of ozone for vegetation are based, must take them into account. In addition, these studies have highlighted the role of constitutive concentrations of antioxidants in tolerance to ozone as well as the complexity of these detoxification mechanisms. The notion of effective ozone flux must consider these two aspects to better characterize the intra-and inter-specific differences in sensitivity to ozone