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Johnson, D. W., S. E. Smith, and A. K. Dobrenz. "Breeding Strategies for Alfalfa Grown Under Saline Conditions." College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/200809.
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Hofmann, W. C., and P. T. Else. "Selecting for Cotton Seedlings Under Cool and Saline Conditions." College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/204473.
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A breeding program aimed at increasing the ability of long and short staple cotton strains to emerge in saline soils under cool springtime soil conditions has now completed the second cycle of selection. Cycle II emergence results show evidence of progress.
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Iqbal, Rana Muhammad. "Growth and physiology of spring wheat under saline conditions." Thesis, Bangor University, 1992. https://research.bangor.ac.uk/portal/en/theses/growth-and-physiology-of-spring-wheat-under-saline-conditions(fadba57d-0627-4506-807a-e6c80792f57c).html.
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A series of experiments were carried out in solution culture in growt~ ~ooms and a glasshouse, to study the effects of sallnlty on leaf extension rate ion concentrations, sap osmotic pressure, net photosynthesis and related parameters, stom~tal frequency, specific leaf weight and a number of agronomlc parameters of spring wheat. Rate of net photosynthesis, transpiration rate, stomatal conductance and sub-stomatal carbon dioxide concentration per unit area of leaf were determined using an Infra-red Gas Analyser. Experiments 1 and 3 were conducted in growth rooms set at a temperature cycle of 24°Cj16°C day and night and photoperiod of 16 hours. The seedlings received light from a bank of 125W fluorescent 'warm white' lights which provided between 200-300 ~mol m- 2 s-l photosynthetically active radiation at initial plant level. Experiments 2, 4 and 5 were carried out in a glasshouse with no control of light and temperature. In Experiment 1 the salinity treatments tested were control (0 mol m- 3 NaCI), 'constant' and 'variable' salinity. In the constant salinity treatment plants were grown at 100 mol m- 3 NaCI all the time after initial salt stress. In the variable salinity treatment a 12 day cycle was repeated with daily increments of 10 mol m- 3 NaCI after initial salt stress of 50 mol m- 3 NaCI till it reached to 150 mol m- 3 NaCI. During the final two days of the cycle salinity was stepped down from 150 to 100 to 50 mol m- 3 NaCl. In Experiment 2 the salinity levels tested were 0, 50, 100 and 150 mol m- 3 NaCI. CaCI was added in this and later experiments at 20:1 (mol Na~:mol ca2+) ratio. The results of the both Experiments 1 and 2 suggested that salinity had no effect on leaf appearance stage but tiller production was decreased. Salinity decreased leaf extension rate and final leaf length but leaf extension duration was not affected. Although leaf extension rate was the main factor influencing final leaf length, there were no consistent quantitative relationships between these parameters in different leaves and at different salinity levels. Plants in variable salinity performed better than those in constant salinity but these treatments were not significantly different and gave similar results. The results of Experiment 2 showed that a gradient of Na+ and Cl- concentrations was found in different leaves. Higher Na+ and Cl- concentrations were found in lower leaves than in expanding leaves. Calculated Na+ and CI- contents (ion concentrations x dry weight) suggested that these ions were mainly located in roots, stem and tillers irrespective of salinity levels. The effect of salinity was to increase concentrations of leaf Na+, Cl- and sap osmotic pressure in the youngest fully expanded leaves whereas K+ concentration was inconsistently affected. When gas exchange measurements were made in situ on leaves, light intensity showed wide i variation due to movement of clouds. Variations in light intensity and absence of any equilibration prior to measurements made it difficult to detect any effects of salinity on gas exchange. Therefore to determine the effects of salinity on gas exchange in expanding and senescing leaves, in Experiments 3, 4 and 5, a strong light source capable of providing photon flux densities at or near light saturation for gas exchange was used. In Experiments 3 and 4 light response curves were produced using neutral density filters. Using an exponential model, maximum net photosynthesis photosynthetic efficiency, photon flux compensation point and dark respiration for salinities and leaf insertions were calculated. In Exper~~ent 3 the .s~linity levels tested were 0, 100 and 200 mol m NaCI. Sa11n1ty decreased green lamina area, maximum and net photosynthesis, stomatal conductance, transpiration rate, leaf productivity but increased dark respiration and photon flux compensation point. Photosynthetic efficiency and transpiration efficiency were inconsistently affected. In Experiment 3 at 200 mol m- 3 NaCI leaf 6 senesced rapidly. Therefore in Experiment 4 the salinity levels tested were 0, 75 and 150 mol m- 3 NaCI. In Experiment 4 the parameters studied were identical to those in Experiment 3 except that the measurements were performed on leaf 5 and the flag leaf. In Experiment 4 a similar trend for gas exchange parameters was noted at 0 and 150 mol m- 3 NaCl but at 75 mol m- 3 NaCI Pn was higher than in the control due to delayed senescence. In both Experiments 3 and 4 leaf sap Na+, CI- and osmotic pressure increased and Pn decreased during senescence but there were no consistent relationships between these parameters for different leaves and salinity treatments. Experiments 2, 3 and 4 suggested that salinity increased stomatal frequency per unit leaf area but stomatal frequency per leaf and specific leaf weight were inconsistently affected. Experiment 5 was conducted to examine the effects of salinity on changes in gas exchange in the flag leaf and two penultimate leaves simultaneously. The salinity levels tested were 0, 75 and 150 mol m- 3 NaCI. The leaf x salinity interaction showed that salinity had larger effects on the flag leaf than leaves 2 and 3. The leaf x salinity interaction was significant for leaf temperature, net photosynthesis, stomatal conductance, transpiration rate and transpiration efficiency but not for sUb-stomatal carbon dioxide concentration. Salinity significantly decreased all the yield components and grain yield. The results of these experiments suggest that salinity had large effects on photosynthesis, dry matter production and grain yield and that ion concentrations do not determine the observed changes in net photosynthesis with leaf age in salt stressed plants.
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Massey, Katherine. "The interactions between plants and invertebrate herbivores under saline conditions." Thesis, University of Sussex, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.441628.
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Ali, Rao Sajjad. "The potential for breeding Zea mays (L.) for saline conditions." Thesis, University of Liverpool, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387451.
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Ahmad, Manzoor. "Growth and gas exchange of wheat under saline and sodic conditions." Thesis, Bangor University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245308.
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Kenny, Lahcen. "Physiological studies on the propagation of Atriplex spp for saline conditions." Thesis, Bangor University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357358.
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Nasim, Muhammad. "Response of rice plants to plant growth regulators under saline conditions." Thesis, University of Aberdeen, 2003. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU164162.
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Responses of rice to plant growth regulators on germination and seedling growth under NaCl salinity were studied to identify possible means of increasing salinity tolerance. Gibberellic acid (GA) promoted germination processes and a-amylase activity and increased plumule but reduced radicle growth after emergence. GA partitioned more metabolites towards the plumule than the radicle. Chlormequat (CCC) showed no beneficial effects and abscisic acid (ABA) inhibited germination under saline conditions. Overall there was no large difference in the performance of three rice varieties, BR29, IR8 and Pokkali in germination. Artificially aged seeds showed increased sensitivity to salinity and GA produced similar effects on germination of artificially aged rice seeds as on unaged seeds. Seed pre-treatment with GA was as effective in promoting germination under saline conditions as applying GA in the germination media. GA with low Ca promoted germination and plumule growth as well as radicle growth. GA increased plant height and fresh weight of seedlings under saline conditions, however it did not show a large positive effect on rice seedlings. CCC had no beneficial effects on rice seedlings. ABA showed possible beneficial effects on rice seedlings as it reduced Na+ uptake and increased K+ and Ca2+ uptake. GA in combination with ABA appeared to adapt rice plants better to saline conditions. GA in combination with low Ca also promoted rice growth under saline conditions.
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Al-Rawahy, Salim Ali. "Nitrogen uptake, growth rate and yield of tomatoes under saline conditions." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184894.
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Results of two studies are reported here, a greenhouse study and a field study. In the greenhouse study, dry matter yield and nitrogen (total and 15N) uptake of leaves, stems and roots of tomato plants (Lycopersicum esculentum Mill., cv. Columbia) subjected to saline stress by NaCl were studied. The integrated effects of responses of these tissues to salinity on the whole plant basis and levels of Na⁺, Cl⁻ and K⁺ accumulation in these tissues were also studied. The treatments consisted of low (control, 0.3 bar), medium (4.3 bars), and high (8.3 bars) salinity. The saline treatments were prepared by adding NaCl to nutrient solution in sand culture. The plants were 80 days old at the start of the treatments and each was in a pot containing 1.8 kg of quartz sand. The ¹⁵N was provided to plants by adding K¹⁵NO₃ to the pots and the 15N treatment continued with the saline treatments up to 30 days. The plants were harvested at each 5-day interval during the treatment period. Dry matter production and nitrogen (total and ¹⁵N) uptake were significantly lower for saline treatments as compared with the control. Differences in dry matter production and ¹⁵N uptake on whole plant basis appeared in the latter part of the treatment period between the two saline treatments. For most of the parameters studied, the leaves were found to be affected most by salinity, the roots were intermediate in their response and the stems were the least affected by salinity. The effect of salinity on the studied parameters were attributed to osmotic effects and specific ion effects of Na⁺ and/or Cl⁻. A field study with two cultivars--Columbia and Pearson was conducted at the Safford Agricultural Center. Three N treatments were used: 0 kg N/ha, 84 kg N/ha and 168 kg N/ha and two treatments consisting of two water sources--river water with an EC of 1.15 dS/m and more saline well water of EC of 2.21 dS/m. Columbia had a significantly higher yield of tomatoes than Pearson for both water types. The N treatments had no effect on tomato yield apparently due to high residual N remaining in the field from the previous crop. Commercially acceptable fresh market yields were approached with both varieties and waters in spite of moderate salinity and sodium under heavy textural soil conditions, high temperatures and the presence of certain diseases in the area.
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Johnson, David Wayne. "Stress productivity in alfalfa: Selection under saline and nonsaline environmental conditions." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185176.
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Alfalfa (Medicago sativa L.) forage yield may be reduced by moderate levels of salinity. Increasing forage yield in saline environments through plant breeding could ameliorate this problem. Selection for increased salt tolerance in alfalfa in cell culture, at germination, or during seedling growth with high NaCl levels has not resulted in agronomically relevant levels of salt tolerance. Different selection schemes were examined to identify alfalfa plants with the ability to germinate, establish, and regrow at salinity levels common in agricultural areas. Data from 'Sonora' and its parental ecotype African grown in a greenhouse and irrigated with 0, 30, 60, or 80 mM NaCl were used to simulate selection for increased forage yield in each NaCl environment through five harvests. Predicted gains in forage yield were highest in non-saline conditions and gains decreased as the NaCl level increased in the selection environment. Selection based on plant yield from regrowth harvests was predicted to be more efficient than that based on seedling harvest. Genetic and phenotypic relationships between plant performance at seed germination, seedling development, and post-harvest regrowth at 0 or 80 mM NaCl were also determined. The effect of NaCl on forage yield of alfalfa regenerated from non-saline callus cultures was examined. This research showed that selection for increased forage yield can be made at moderate NaCl levels in germplasm with ample variation for yield when grown in saline environments. Selection for increased forage yield in non-saline conditions may eliminate potentially salt tolerant plants from a population. Selection for increased alfalfa forage yield in saline environments at early stages of development is not necessarily optimum. Selection methods that include each critical growth stage may be required to develop alfalfa cultivars with increased forage yield in saline environments. (Abstract shortened with permission of author.)
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Khan, Mohammad Jamal. "Water and nutrient management for wheat and barley grown under saline conditions." Diss., The University of Arizona, 1994. http://hdl.handle.net/10150/187026.
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Two separate investigations, on wheat and barley were conducted under control environments. In the first experiment, two wheat varieties, selection line (SL) and Yecoro Rojo (YR) were grown in 100 mM NaCl salinized sand culture with the additional 2 levels (4 and 8 meq/L) of Ca, Mg and NH₄ application. Control treatments (0 salt plus 4 meq/L of Ca, Mg and NH₄) were also included. The fresh and dry matter yield after 4 weeks in salinized Hoagland solution and supplemental nutrient addition reveals that salinity significantly reduced the yield and the addition of 8 meq/L NH₄ increase the yield among the salt treatment pots followed by 8 meq/L supplemental Ca. Likewise, number of tillers and grain yield was also increased by the addition of 8 meq/L NH₄ to salinized Hoagland solution. SL produced significantly higher yields than YR. Water and osmotic potential were significantly increased with salinity but turgor potential was not effected significantly. Concentrations of Na and Cl were significantly higher in both varieties in the salt added plants, and the uptake was reduced by the high level of supplemental NH₄. Generally, YR (a salt sensitive variety) absorbed higher amount of Na, Mg, Cl and PO₄, which might be the possible cause of nutritional disturbance and hence reduced yield. In the second experiment, two selected barley varieties (California Mariout and Gustoe) were grown in lysimeter, irrigated with two NaCl salinity water (150 and 250 mM) and a control with two LF (0.2 and 0.4). As the salt concentrations of irrigation water increased, vegetative growth and grain yield reduced significantly. LF 0.4 had significant effect at moderate salinity on yield but was similar as LF, 0.2 when the salinity increased to 250 mM. Both varieties achieved the highest WUE for the above ground dry matter and grain yield at moderate salinity. Mariout was salt tolerant and high yielding both in and out of salinity. Soil salinity (ECₑ) and Na content increased as the salinity of irrigation water increased. Na concentration of leaf tissue was significantly increased, while Ca and K concentration decreased with increase in salinity. The possible reason for reduced yield at high salinity was the Ca deficiency.
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Pennington, Karrie Sellers 1949. "Alfalfa water-production functions under conditions of deficit irrigation with saline water." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/191117.
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This experiment was designed to determine the shape of the yield response function relating crop yield to total amount of saline irrigation water applied. Such a function contains a built-in leaching fraction that is the inevitable consequence of the inability of the plant to extract 100 % of the water from a saline soil. In order to define the production function and to determine the leaching fractions, alfalfa (Medicago sativa L. cv. 'Mesa Sirsa') was planted in soil columns in a greenhouse. Two experiments were run sequentially. These were irrigated with water of differing salinities. The first with an EC of 4 dS/m (1.4 bars) and the second with an EC of 8 dS/m (2.9 bars). Both solutions were prepared by adding equivalent amounts of sodium chloride and calcium chloride to distilled water. The treatment variables were amounts of irrigation water applied. The amounts in both experiments were 110%, 100%, 75%, 50% and 25% of the measured evapotranspiration (ET). Four crop harvests were made in each experiment. At the end of experiment 1, (approximately 120 days), one column from each treatment was destructively sampled for soil salinity and water content measurements. The remaining columns were similarly sampled at the end of experiment 2 (approximately 120 days). The crop-saline water production functions for both experiments were linear. Leaching fractions in experiment 1 were 9, 9, 6, 5 and 5% for treatments 1-5 respectively. Experiment 2 leaching fractions for treatments 1-5 respectively were 23, 25, 18, 15 and 17%. The lowest rootzone soil water osmotic potentials achieved by the end of experiment 1 for treatments 1-5 were -19, -20, -18, -26 and -24 bars. Corresponding treatment values achieved by the end of experiment 2 were -18, -22, -28, -31 and -45 bars.
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Yen, Tzu Chuan. "The Role of Calcineurin B-Like 10 in Flowers During Growth in Saline Conditions." Thesis, The University of Arizona, 2014. http://hdl.handle.net/10150/322094.
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Boh, Michael Yongha [Verfasser], and Joachim [Akademischer Betreuer] Sauerborn. "Human urine as a crop fertilizer under saline conditions / Michael Yongha Boh. Betreuer: Joachim Sauerborn." Hohenheim : Kommunikations-, Informations- und Medienzentrum der Universität Hohenheim, 2014. http://d-nb.info/1047472813/34.
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Monihan, Shea M., Courtney A. Magness, Ramin Yadegari, Steven E. Smith, and Karen S. Schumaker. "Arabidopsis CALCINEURIN B-LIKE10 Functions Independently of the SOS Pathway during Reproductive Development in Saline Conditions." AMER SOC PLANT BIOLOGISTS, 2016. http://hdl.handle.net/10150/615779.
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The accumulation of sodium in soil (saline conditions) negatively affects plant growth and development. The Salt Overly Sensitive (SOS) pathway in Arabidopsis (Arabidopsis thaliana) functions to remove sodium from the cytosol during vegetative development preventing its accumulation to toxic levels. In this pathway, the SOS3 and CALCINEURIN B-LIKE10 (CBL10) calcium sensors interact with the SOS2 protein kinase to activate sodium/proton exchange at the plasma membrane (SOS1) or vacuolar membrane. To determine if the same pathway functions during reproductive development in response to salt, fertility was analyzed in wild type and the SOS pathway mutants grown in saline conditions. In response to salt, CBL10 functions early in reproductive development before fertilization, while SOS1 functions mostly after fertilization when seed development begins. Neither SOS2 nor SOS3 function in reproductive development in response to salt. Loss of CBL10 function resulted in reduced anther dehiscence, shortened stamen filaments, and aborted pollen development. In addition, cbl10 mutant pistils could not sustain the growth of wild-type pollen tubes. These results suggest that CBL10 is critical for reproductive development in the presence of salt and that it functions in different pathways during vegetative and reproductive development.
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Morelová, Nikoleta [Verfasser], and H. [Akademischer Betreuer] Geckeis. "Steel corrosion and actinide sorption by iron corrosion products under saline conditions / Nikoleta Morelová ; Betreuer: H. Geckeis." Karlsruhe : KIT-Bibliothek, 2020. http://d-nb.info/121957791X/34.
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Maaroufi, Dguimi Houda. "Régulation de l’assimilation de l’azote minéral chez Arabidopsis en conditions de stress salin." Thesis, Paris 11, 2012. http://www.theses.fr/2012PA112029.
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L’activité de croissance des plantes se trouve souvent limitée par les conditions contraignantes de l’environnement. La salinité du sol est l’une des majeures contraintes abiotiques qui ne cesse d’envahir les surfaces cultivés chaque année. Elle entraine chez les espèces glycophytes des perturbations d’ordre osmotique, nutritionnel et métaboliques. La nutrition et le métabolisme de l’azote minéral constituent des étapes primordiales dans la synthèse des acides aminés et des composés azotés indispensables chez les plantes. Par conséquent, l’étude de l’expression des enzymes impliquées dans l’assimilation d’azote telle que l’asparagine synthétase (AS, EC 6.3.5.4) chez l’arabette des dames (Arabidopsis thaliana) permet d’avancer nos connaissances sur la régulation transcriptionnelle du métabolisme azoté sous stress salin. Au cours des travaux de recherche entamés dans le cadre de cette thèse, un intérêt particulier est accordé au gène ASN2 chez Arabidopsis. Les résultats obtenus ont montré que la mutation ASN2 a accentué les effets du NaCl sur l’assimilation de l’ammonium. Le mutant asn2-1 se montre plus sensible au stress salin que le sauvage malgré que l’absence des transcrits du gène ASN2 est associé à une expression importante du gène ASN1. L’inhibition de l’activité glutamine synthétase (GS, EC 6.3.1.2), la faible activité aminatrice de la GDH (NADH-GDH, EC 1.4.1.2) sous stress salin ainsi que l’absence des transcrits ASN2 seraient à l’origine de l’accumulation de l’ammonium chez le mutant asn2-1. Toutefois, l’application exogène de l’ammonium nous a montré que l’action du NaCl sur l’expression de l’asparagine synthétase n’est pas directement liée à l’accumulation endogène d’ammonium. L’accumulation d’autres métabolites tels que l’asparagine, la glutamine et la glutamate pourrait être à l’origine des effets du sel sur l’expression des gènes ASNPlant growth activity is often limited by constraint environment conditions. Soil salinity is one of major abiotic stress which is becoming more problematic every year. In glycophytes species, it induced osmotic, nutritional and metabolic disturbances. The nitrogen nutrition and metabolism constitute an essential step in amino acid and nitrogen compounds synthesis in plants. Therefore, studying the expression of enzymes involved in nitrogen assimilation such as asparagine synthetase (AS, EC 6.3.5.4) in Arabidopsis thaliana will improve our knowledge on the transcriptional regulation of nitrogen metabolism under salt stress. In the present work of this thesis, a special attention was taken on AS gene (ASN2) wild type and mutants. Obtained results showed that ASN2 mutation accentuated the salt-induced effects on ammonium assimilation. The asn2-1 mutant was more sensitive to salt stress than the wild type, while the ASN2 transcript absence was associated with an important ASN1expression. The observed inhibition of glutamine synthetase (GS, EC 6.3.1.2) activity, the low aminatrice GDH (NADH-GDH, EC 1.4.1.2) activity under salt stress as well as the ASN2 transcript loss brought to an ammonium accumulation in asn2-1mutant. However, exogenous ammonium application showed that NaCl effect on asparagine synthetase expression was not directly related to the endogenous ammonium accumulation. Other metabolites accumulation such as asparagine, glutamine and glutamate could be involved in the obtained salt-effects on ASN expression in Arabidopsis
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Multhaupt, Hendrik [Verfasser], Michael [Akademischer Betreuer] Wark, Adrian [Akademischer Betreuer] Schumpe, and Axel [Akademischer Betreuer] Brehm. "Potential of hydrochars obtained by hydrothermal carbonization under saline conditions / Hendrik Multhaupt ; Michael Wark, Adrian Schumpe, Axel Brehm." Oldenburg : BIS der Universität Oldenburg, 2018. http://d-nb.info/1155533070/34.
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El, Mghadmi Z. Y. "Effect of environmental stresses and growing medium amendment with 'Zander' on growth of Acacia saligna under saline conditions." Thesis, Coventry University, 2011. http://curve.coventry.ac.uk/open/items/5727ee90-f827-485e-93d9-94a9b5456f43/1.
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In Libya salinization of land and ground water is a key problem. A. saligna is one species that offers potential for growth under these conditions. Experiments were undertaken to accelerate the germination of Acacia seeds, and various pre-treatment methods were assayed. Boiling water treatment, mechanical scarification and acid improved germination and germination rate. Sowing A. saligna seeds at 30 mm depth gave greatest seedling growth from large and medium seeds whereas 20 mm was more suitable for small seeds. This study aimed to improve the establishment of Acacia saligna irrigated with saline water, plants were grown for seven weeks under greenhouse or field conditions in (Libya) either sand or soil salinized with varying applications of NaCl. Irrigation with NaCl significantly decreased plant survival and growth and concentration of Ca, Na, K, Fe and P ions in plants with 0.5 M or 1.0 M NaCl. The experiments were repeated using a naturally occurring soil amendment called ‘Zander’. Seeds of A. saligna were grown for seven weeks in both greenhouse and field trials as before but with the addition of Zander and NaCl. Zander improved plant survival and growth with salinity and increased the elements in plants (Ca, Na, K, Fe and P). Field experiments were conducted to assess the effects of saline irrigation with 1.0 M NaCl and extra water added to 0% or 10% Zander on survival and growth, consequently, seedling growth significantly decreased with increase in soil salinity. Survival and growth increased with increase in extra water. The additional irrigation water caused an increase in the uptake of Ca++ and increased the Ca++/Na+ and K+/Na+ ratio. Zander did not appear to reduce net uptake of Na+ and its transport to shoot tissues. Mg++, P, K+ and Ca++ content significantly decreased in plants in response to salinity. Possible mechanisms to avoid Na+ toxicity in A. saligna in response to salinity included increasing the supply of Ca++. Extra Ca++ applied into the medium with and without salt increased survival and growth even in the absence of Zander. Calcium increased uptake of Ca++ and increased Ca++/Na+ and K+/Na+ ratio.
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Multhaupt, Hendrik Verfasser], Michael [Akademischer Betreuer] [Wark, Adrian Akademischer Betreuer] Schumpe, and Axel [Akademischer Betreuer] [Brehm. "Potential of hydrochars obtained by hydrothermal carbonization under saline conditions / Hendrik Multhaupt ; Michael Wark, Adrian Schumpe, Axel Brehm." Oldenburg : BIS der Universität Oldenburg, 2018. http://d-nb.info/1155533070/34.
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Bekki, Abdelkader. "Fixation d'azote en conditions de stress salin chez Médicago : sensibilité respective des partenaires symbiotiques." Nice, 1986. http://www.theses.fr/1986NICE4060.
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La germination des graines de Médicago est inhibée en présence de sel et l'espèce Ciliaris est la plus résistante. Rhizobium meliloti, partenaire bactérien de la luzerne, peut se developper sur des milieux de culture fortement enrichis en NACL (600 mm). La souche ABS7 isolée de sols sales algériens manifeste une halo tolérance particulière, avec un temps de latence et de génération faibles. Elle maintient une activité superoxyde dismutase élevée. Il a été proposé que les acides aminés, accumulés et notamment le glutamate participent à l'osmoprotection et constituent aussi des substrats respiratoires
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Bekki, Abdelkader. "Fixation d'azote en conditions de stress salin chez Medicago sensibilité respective des partenaires symbiotiques." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb375958025.
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Krukowski, Elizabeth Gayle. "Carbon dioxide (CO2) sorption to Na-rich montmorillonite at Carbon Capture, Utilization and Storage (CCUS) P-T conditions in saline formations." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/49615.
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Carbon capture, utilization and storage (CCUS) in confined saline aquifers in sedimentary formations has the potential to reduce the impact of fossil fuel combustion on climate change by storing CO2 in geologic formations in perpetuity. At PT conditions relevant to CCUS, CO2 is less dense than the pre-existing brine in the formation, and the more buoyant CO2 will migrate to the top of the formation where it will be in contact with cap rock. A typical cap rock is clay-rich shale, and interactions between shales and CO2 are poorly understood at PT conditions appropriate for CCUS in saline formations. In this study, the interaction of CO2 with clay minerals in the cap rock overlying a saline formation has been examined, using Na-rich montmorillonite as an analog for clay-rich shale. Attenuated Total Reflectance -- Fourier Transform Infrared Spectroscopy (ATR -FTIR) was used to identify potential crystallographic sites (AlAlOH, AlMgOH and interlayer space) where CO2 could interact with montmorillonite at 35"C and 50"C and from 0-1200 psi. Analysis of the data indicates that CO2 that is preferentially incorporated into the interlayer space, with dehydrated montmorillonite capable of incorporating more CO2 than hydrated montmorillonite. No evidence of chemical interactions between CO2 and montmorillonite were identified, and no spectroscopic evidence for carbonate mineral formation was observed. Further work is needed to determine if reservoir seal quality is more likely to be degraded or enhanced by CO2 - montmorillonite interactions.Master of Science
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Sheets, Johnathon P. "Cultivation of Nannochloropsis Salina in Diluted Anaerobic Digester Effluent under Simulated Seasonal Climatic Conditions and in Open Raceway Ponds." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1373452229.
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Mahjoubi, Habib. "Nouvelle stratégie d'amélioration de la productivité végétale en condition de stress environnemental via un meilleur contrôle du cycle cellulaire." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAJ059/document.
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Le stress salin est l'un des principaux facteurs environnementaux limitant la croissance des plantes et entraînant des pertes de rendement des cultures céréalières. Il est ainsi impératif de développer des variétés plus tolérantes à la salinité afin d’augmenter leurs rendements et assurer la sécurité alimentaire. La voie signalétique reliant la perception du stress salin à la réponse cellulaire, encore peu connue, a été abordée ici par l’étude des protéines RSS1-like conservées chez les plantes. La protéine RSS1 (Rice Salt Sensitive 1) du riz joue un rôle primordial dans la tolérance au stress salin en agissant à l’interface entre la perception des stress et le contrôle du développement et de la division dans les méristèmes. Lors de ce travail, l'homologue de RSS1 nommé TdRL1 (Triticum durum RSS-Like 1) a été isolé à partir de la variété tunisienne de blé dur “Oum Rabiaa“. Nous avons démontré que TdRL1 porte les motifs D et DEN-Box conservés impliqués dans la régulation post-traductionnelle de la protéine. En outre nous avons apporté la preuve que TdRL1 est l’homologue fonctionnel de RSS1 puisqu'il est capable de complémenter le mutant de perte de fonction rss1, hypersensible au stress salin. En outre, l’expression hétérologue de TdRL1 améliore la tolérance au stress salin chez la levure ainsi que chez Arabidopsis et ce par l’augmentation du pouvoir germinatif et la réduction de l’accumulation des espèces oxygénées réactives. Nos études cytologiques ont montré que la protéine TdRL1 est cytoplasmique en interphase et se localise au niveau des microtubules kinétochoriens pendant la mitose. Remarquablement, TdRL1 change de localisation cellulaire sous stress salin et montre une accumulation partielle dans le noyau, soulignant le caractère multifonctionnel de cette protéine dans la réponse au stress salin. L’ensemble des données suggère que sous contrainte saline, TdRL1 joue un rôle dans la régulation du cycle cellulaire en relation avec le réseau microtubulaire. L‘étude de la famille RSS1-like multifonctionnelle permettra ainsi d’aborder de nouvelles voies de recherche pour la création variétale de blé plus résilientes aux stress de l'environnementSalt stress is one of the main environmental factors limiting plant growth and yield in cereal crops. It is therefore imperative to develop varieties more tolerant to salt stress in order to increase yield and ensure food security. The signaling pathway linking salt stress perception to cellular response was addressed here by studying RSS1-like proteins in plants. RSS1 (Rice Salt Sensitive 1) protein plays an important role in salt stress tolerance. It acts at the interface of stress perception and developmental control and division in meristems. During this work, the RSS1 counterpart named TdRL1 (Triticum durum RSS-Like 1) was isolated from the durum wheat Tunisian variety "Oum Rabiaa". We have demonstrated that TdRL1 carries the conserved D and DEN-Box motifs involved in the post-translational regulation of the protein. In addition, we show that TdRL1 is the functional homologue of RSS1 since it was able to complement the loss-of-function mutant rss1, hypersensitive to salt stress. In addition, heterologous expression of TdRL1 enhances salt stress tolerance in yeast and in Arabidopsis by increasing germination and reducing the accumulation of reactive oxygen species. Our cytological studies have shown that the TdRL1 protein is cytoplasmic in interphase and is localized at the spindle during mitosis. Remarkably, TdRL1 changes its subcellular localization under salt stress treatment and shows a partial accumulation in the nucleus, highlighting the multifunctional nature of this protein during salt stress response. Our data suggest that under salt stress, TdRL1 plays a role in the regulation of the cell cycle in relation with the microtubule network. Pursuing the study of RSS1-like multifunctional proteins will open up new research areas for the creation of wheat varieties that are more resilient to environmental stresses
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Kumar, Vivek. "Effect of different ionic profiles of inland saline water on growth and agar characteristics of gracilaria cliftonii (Withell, Miller & Kraft, 1994)." Thesis, Curtin University, 2008. http://hdl.handle.net/20.500.11937/941.
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Salinity caused by the mobilisation of geologically stored salt through rising water tables is a major problem in Western Australia. Damage is occurring to aquatic and terrestrial ecosystems, affecting the profitability of agricultural land. However, the resultant inland saline water-bodies with an ionic composition similar to ocean water have the potential to be used for seaweed cultivation. Seaweed cultivation can mitigate the cost of land rehabilitation by making profitable use of saline wastewaters.A series of laboratory trials were conducted to identify the conditions necessary for successful Gracilaria cliftonii cultivation in inland saline water (ISW) and modify the agar extraction process for G. cliftonii to optimise agar yield and properties. This was accomplished by culturing G. cliftonii with different nutrients in ISW, with or without K[superscript]+ fortification and investigating the respective effects on chemical composition, physicochemical properties and agar characteristics. To identify the process required for optimum agar yield and quality from G. cliftonii, the effect of modifying some extraction process variables such as alkali concentration, soaking time and temperature, heating time, seaweed-water ratio, extraction time and temperature was investigated.These trials demonstrated that with the selection of appropriate nutrient media and culture conditions G. cliftonii can be successfully grown in ISW. To achieve higher growth rates of G. cliftonii, it is necessary to fortify ISW with K[superscript]+. The addition of nutrients to ISW and different ionic profiles of ISW had significant positive effects on chemical composition, physicochemical properties and agar characteristics. Agar yield, gel strength, melting point, gelling temperature and sulphate content were found to be a function of G. cliftonii life stages. Modification of alkali treatment with variable alkali concentration (0.3 to 5 %), soaking time and heating time had detrimental effect on agar yield resulting in significant agar loss but improved agar quality from G. cliftonii. However, agar quality can be improved by modifying extraction process variables like soaking time and temperature, seaweed to water ratio, extraction time and temperature without agar loss.
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Bekmirzaev, Gulom. "Relations eau et cultures de légumes : effet des sols salins et conditions de sècheresse sur la croissance, composition minérale et photosynthèse." Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10010/document.
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La salinité est un problème mondial qui retarde la croissance des plantes et ralenti la productivité à cause de la salinisation progressive des sols et de l'eau, une de ces nouvelles techniques est l'utilisation d'espèces végétales pour enlever le sel. Afin d'étudier la capacité potentielle de certaines plantes pour éliminer les sels du sol, deux espèces Portulaca oleracea et Tetragonia tetragonioides et la laitue (Lactuca Sativa L) ont été étudiées pour évaluer leurs efficacités à éliminer les sels d'un sol sableux. Les plantes ont été analysées selon certains critères de croissance et de composition minérale des feuilles et du sol. On constate, d'après les résultats obtenus, que la T. tetragonioides est le meilleur choix des espèces testés qui permet la réduction de la salinité. Il y a d'autres avantages pour l’utilisation de cette espèce comme : 1) une production élevée de biomasse; 2) plusieurs récoltes au cours de l'année (été et hiver); 3) teneurs élevés en minéraux; 4) l'importance de l'horticulture, en tant que culture de feuille végétale; 5) multiplication facile des semences; 6) tolérance à la sécheresse et des conditions arides ; 7) contrôle en raison de son excellente couverture du sol qui réduit les phénomènes d'érosion. L’espèce P. Oleracea a une tolérante élevée pour la sécheresse suivie de l’espèce T. tetragonioides. D'autre part, la laitue est une culture irriguée et par conséquent, ne suffit pas à réduire la salinité du sol. Suite aux observations, il a été montré que cette nouvelle technique de culture permet de contrôler la salinité et c’est un bon outil de remédiation pour maintenir la durabilité du paysage et des zones irriguéesConventional techniques used to control the soil salinization process - soil leaching or fertilization enhancing - contribute highly to soil and aquifers contamination; on the other hand, the use of salt tolerant species will be very useful to the plants, but does not solve the problem of soil or groundwater contamination. Hence, the only way to control the salinization process to maintain the sustainability of landscapes and agricultural fields is to combat the salinization problems with environmentally safe and clean techniques. One of these new techniques is the use of salt removing species. In order to study the potential capacity to remove soil salts, two horticultural species Portulaca oleracea and Tetragonia tetragonioides, and the salt sensitive crop lettuce (Lactuca Sativa L) were evaluated for their efficiency to remove salts from sandy soil. Plants were analysed relatively to total growth and mineral composition of the leaves and soil. According to the results, it was seen that T. tetragonioides is the best salt removing species and complementary, it has other benefits, which are as follows: 1) high biomass production; 2) several harvests; 3) high content of minerals; 4) horticultural importance; 5) easy multiplication; 6) easy crop management; 7) tolerance to drought conditions; 8) soil erosion control. P. oleracea is a high drought tolerant species, followed by T. tetragonioides. As concluding remarks, it was shown that this new technique to control salinity is a powerful and environmental clean tool to maintain the sustainability of the landscape and of the irrigated areas
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Fakiri, Malika. "Obtention chez l'orge (Hordeum vulgare) de régénération par androgenèse et gynogenèse in vitro en conditions de stress salin : application à trois génotypes marocains." Vandoeuvre-les-Nancy, INPL, 1995. http://www.theses.fr/1995INPL020N.
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Ce travail porte, sur la création par culture in vitro, de nouveaux types adaptés à la sécheresse et à la salinité. Le matériel concerne, Hordeum vulgare, est représenté par des orges de printemps marocaines de la région de Marrakech, cultivars: Asni, Tamelalt et 905, ainsi qu'un témoin des régions tempérées, l'orge de printemps française: Bérénice. La phase expérimentale de départ a consisté en l'adaptation de la technique d'androgenèse, en étudiant la durée de prétraitement au froid, la composition des milieux de culture et le stade de prélèvement des anthères. Les premières plantes ont ainsi été régénérées, essentiellement chez les cultivars marocains, mais avec une forte proportion d'individus albinos. Les difficultés soulevées par ce problème ont amené, de façon fructueuse, à l'établissement d'une autre voie permettant l'obtention de la totalité des plantes régénérées de type chlorophyllien: la gynogenèse, pour laquelle nous obtenons dans le meilleur cas 9 plantes pour 100 ovaires mis en culture. Gynogenèse et androgenèse ont conduit à la formation de cals et embryons qui ont fait l'objet d'une accoutumance progressive à des doses croissantes de chlorure de sodium (NaCl), ajoutées aux milieux de culture à mesure de repiquages successifs. La régénération de plantes à partir des souches tolérantes a été obtenue chez les génotypes: Tamelalt, Asni et Bérénice. La troisième partie a fait l'objet d'analyses des électrophorégrammes des bêta amylases, effectuées sur les produits de croisements diallèles des haplodiploïdes issus de la variété Bérénice. Elles ont montré une dissymétrie d'expression chez les croisements réciproques et ont donc confirmé les conclusions obtenues lors des analyses biométriques
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Pagès-Hélary, Sandy. "Libération en bouche des molécules de la flaveur : influence des composés salivaires au niveau macroscopique et moléculaire." Thesis, Dijon, 2014. http://www.theses.fr/2014DIJOS055/document.
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L’objectif de cette étude est d’étudier le rôle de la salive dans la libération des molécules odorantes, par deux approches, in vitro et in vivo. L’effet des protéines salivaires sur la libération de 10 molécules odorantes (5 esters et 5 cétones, de longueur de chaîne hydrophobe variable) a été étudié in vitro dans des systèmes modèles composés de salives artificielles et humaine. Les salives artificielles contiennent les protéines majoritairement présentes dans la salive (mucine et alpha-amylase), seules et en mélange. Les quantités de chaque molécule odorante présentes dans la phase gazeuse à l’équilibre thermodynamique ont été mesurées par une analyse headspace en mode statique couplée à la chromatographie en phase gazeuse (SH-GC). Les coefficients de partage entre l’air et chacun des systèmes modèles ont été calculés pour chacune des molécules. Cette approche in vitro nous a permis de démontrer une diminution des coefficients de partage air/salive artificielle en présence de mucine et d’alpha-amylase, par un effet hydrophobe. Aucun effet cumulatif n’est observé lorsque les deux protéines sont mises ensemble en solution. En présence de salive humaine, une diminution des coefficients de partage est également observée, les esters étant plus affectés par la présence de salive humaine que les cétones. Cette observation est due à une activité des estérases de la salive, qui augmente avec l’hydrophobicité des esters. La libération in vivo du propanoate d’éthyle et de l’hexanoate d’éthyle a été suivie sur 10 sujets par spectrométrie de masse à ionisation chimique à pression atmosphérique (APCI-MS) dans des conditions physiologiques différentes : au repos, après stimulation et après élimination du film salivaire résiduel. La salive de chaque sujet a été caractérisée dans les différentes conditions physiologiques testées. De grandes variations de flux, viscosité et de composition salivaire ont été mises en évidence entre les sujets, ainsi qu’entre les conditions physiologiques pour un même sujet. Les différences observées sur les paramètres de libération in vivo des molécules odorantes sont discutées en regard de ces paramètres physiologiques. Nous avons ainsi observé qu’une viscosité salivaire élevée diminue la quantité de molécules odorantes libérées sur un temps donné. Dans le même temps, la présence d’une quantité importante d’alpha amylase dans la salive augmente de façon significative le temps de libération de la molécule la plus hydrophobe, l’hexanoate d’éthyle. Nous avons ainsi mis en évidence que la rétention des molécules hydrophobes par les protéines salivaires peut induire une modification de leur cinétique de libération en conditions réelles de consommation et pourrait intervenir dans la persistance aromatiqueThe aim of this work is to give a deeper understanding of the impact of the salivary composition on aroma release, by two approaches, an in vitro and an in vivo approach. The impact of salivary proteins on the release of 10 aroma compounds (5 esters and 5 ketones, varying in their hydrophobic chain length) was first investigated by in vitro model systems composed of artificial and human saliva. Artificial salivas were composed of the main salivary proteins, mucins and alpha amylase, alone and in mixture.The amount of aroma released in the vapor phase at equilibrium was analyzed by Static Headspace Gas Chromatography analysis. Air/system partition coefficients have been calculated. This in vitro approach allowed us to demonstrate the ability of both mucin and alpha-amylase to decrease the release of aroma compounds by hydrophobic effect (increase of retention with aroma hydrophobicity). Interestingly, no cumulative effect was observed when both proteins were mixed together in solution. The release of ketones in presence of human saliva is lower than in water and slightly higher than in the presence of artificial saliva. Esters are more affected by the presence of human saliva than ketones. This observation is due to an esterase activity of saliva, which increases with the hydrophobicity of esters. The in vivo release of ethyl propanoate and ethyl hexanoate was followed on ten subjects by Atmospheric Pressure Chemical Ionization mass spectrometry (APCI-MS) under different physiological conditions: at rest, after stimulation and after removing the superficial salivary coat. The saliva was characterized for each subject and each physiological condition. Great variations were observed between the subjects on the salivary flow, viscosity, composition and for each subject between the physiological conditions. The differences observed on in vivo release parameters are discussed as a function of physiological parameters. We observed that subjects with a more viscous saliva present a lower amount of aroma released. The presence of higher amounts of alpha-amylase increased the time needed to release the more hydrophobic compound, ethyl hexanoate. Our results suggest that the retention of hydrophobic aroma compounds by salivary proteins induces a modification of the kinetics of aroma release in real consumption conditions, and could be responsible for aroma persistence
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Brosius, Jacques. "Les écarts de taux de salaire entre salariés résidents et transfrontaliers : mesure, causes et conséquences : application au luxembourg." Nancy 2, 2004. http://www.theses.fr/2004NAN20013.
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Simard, Mathieu. "L'effet sur le salaire de l'adéquation formation-emploi chez les immigrants qualifiés au Québec." Master's thesis, Université Laval, 2014. http://hdl.handle.net/20.500.11794/25351.
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Ces dernières années, le Québec a favorisé la venue d’immigrants qualifiés afin de combler un manque de main-d’oeuvre. Toutefois plusieurs signaux sur le marché du travail démontrent un important problème d’intégration rencontré par une majorité d’immigrants. Le degré d’intrégration peut être mesuré selon différents aspects notamment au niveau salarial. En ce sens, notre étude porte sur l’effet sur le salaire d’occuper un emploi dont la Classification Nationale des Professions (CNP) correspond au niveau académique d’un immigrant qualifié au Québec. Pour ce faire, en premier lieu nous développerons plusieurs modèles de régressions linéaires multiples, et ce, pour différents sous-groupes de notre échantillon. Par la suite, nous utiliserons la méthode d’appariement basé sur le score de propension développé par Rosenbum et Rubin en 1983. Nos résultats démontrent bel et bien un problème d’intégration des immigrants qualifiés au Québec. Toutefois, ceux qui réussissent à occuper un emploi pour lequel ils sont qualifiés perçoivent un salaire représentatif de leurs compétences.
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Baayoud, Mohammed. "Salaire, consommation et reproduction de la force de travail essai d'analyse de l'évolution des conditions de vie de la population ouvrière urbaine au Maroc." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37595607b.
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Hu, Yuncai. "Growth response of wheat plant to salinity in hydroponics and soil : I Interactive effects of salinity and macronutrients on the growth, yield, and mineral element contents under hydroponic conditions : II Spatial and temporal distribution of growth and the mineral element and carbohydrate contents in the leaves under saline soil conditions /." Zürich, 1996. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=11619.
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Al, Naser Osama. "Effet des conditions environnementales sur les caratéristiques morpho-physiologiques et la teneur en métabolites secondaires chez Inula montana : une plante de la médecine traditionnelle Provençale." Thesis, Avignon, 2018. http://www.theses.fr/2018AVIG0341/document.
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Ce travail de thèse s'inscrit dans un projet régional, initié par le Parc du Lubéron et en collaboration avec le Laboratoire de Pharmacognosie et d'Ethnopharmacologie de l’Université de Marseille. Il avait pour objectif d'étudier la possibilité de domestiquer une plante sauvage, Inula montana L. (Asteraceae) connue dans la pharmacopée provençale pour ses effets anti traumatiques semblables à ceux d'Arnica montana L. et de la proposer comme nouvelle production agricole. Inula montana produit notamment des lactones sesquiterpènes, identifiées comme les métabolites secondaires responsables de ses aptitudes biologiques anti inflammatoires. Il s’est agit dans cette étude1) de déterminer les caractéristiques de croissance et de développement de la plante sauvage largement inconnue et d’identifier en conditions naturelles les facteurs les plus favorables à la production de métabolites secondaires, 2)d’étudier sa capacité à se multiplier végétativement in vitro et à former des cultures cellulaires aptes à synthétiser les molécules d’intérêt 3), de proposer un itinéraire technique applicable agronomiquement et 4) de tester les effets de divers facteurs environnementaux (fertilisation, apport de NaCl, modification du rythme circadien de l’éclairement,rayonnement UVB, ablation de feuilles, application de méthyl jasmonate ) sur la production qualitative et quantitative des lactones sesquiterpènes et des composés phénoliques. Les traits phénologiques de la plante sauvage sont impactés par l’altitude qui induit un retard dans la croissance végétative et la phase reproductrice ainsi que des modifications physiologiques et morphologiques. Les teneurs en métabolites secondaires (certaines lactones sesquiterpènes, les polyphénols totaux et flavonoïdes) varient en fonction de la saison et sont plus importantes dans le site qui présente les conditions climatiques les plus contraignantes du point de vue hydrique (sol drainant,température plus élevée et présence d’une période sèche en été). L’observation microscopique a indiqué la présence de deux types de trichomes : glandulaires (bisériés) et non glandulaires (des poils) qui sont potentiellement les structures porteuses des molécules d’intérêt. I. montana est apte à former des cals in vitro à partir d’explants racinaires, foliaires et caulinaires sur lesquels des pousses feuillées se forment. La domestication d’Inula a été réussie à partir de semences issues des plantes sauvages et en conditions agronomiques, les teneurs en lactones sesquiterpènes (costunolide, artémorine, eldarine et hydrocostunolide) et en composés phénoliques sont généralement plus élevées que chez les plantes sauvages. Les différentes contraintes appliquées pour tester les effets des facteurs environnementaux sur la production des métabolites ont montré : 1) qu’il ne peut pas être établi de corrélation entre la présence d’un stress oxydatif et une augmentation des teneurs en métabolites chez Inula 2) que l’accumulation des lactones et composés phénoliques semblent principalement favorisée lorsque la plante dispose d’un surplus de squelettes carbonés, non utilisés pour la croissance 3) enfin, les deux conditions les plus favorables à l’accumulation des métabolites chez Inula, sont : dans les feuilles, une alternance rapide de lumière et d’obscurité durant la photopériode et dans les capitules, l’application de méthyl jasmonate. Ce travail augure de bonnes perspectives en termes de valorisation d’Inula dans le secteur pharmaco-cosmétologique. Il reste à poursuivre la description du profil phytochimique de la plante et à localiser précisément les organes et/ou sous structures anatomiques concentrant les composés considérés. Ayant démontré que cette plante présente une bonne réponse à la domestication, il est également proposé de poursuivre l’étude des leviers environnementaux susceptibles d’influencer positivement et significativement le profil chimique d’InulaThis thesis work is part of a regional project, initiated by the Luberon Park and in collaboration with the Laboratory of Pharmacognosy and Ethnopharmacology of the University of Marseille. It aimed to study the possibility of domesticating a wild plant, Inula montana L. (Asteraceae) known in the Provençal pharmacopoeia for its anti-traumatic effects similar to those of Arnica montana L. and to propose it as a new agricultural production. Inula montana produces lactones sesquiterpenes, identified as the secondary metabolites responsible for its biological anti-inflammatory properties. In this study, 1) to determine the growth and development characteristics of the largely unknown wild plant and to identify under natural conditions the most favorable factors for the production of secondary metabolites, 2) to study its characteristics. ability to multiply vegetatively in vitro and to form cell cultures able to synthesize the molecules of interest 3), to propose an agronomically applicable technical itinerary and 4) to test the effects of various environmental factors (fertilization, NaCl supply, modification circadian rhythm of illumination, UVB radiation, ablation of leaves, application of methyl jasmonate) on the qualitative and quantitative production of sesquiterpene lactones and phenolic compounds. The phenological characteristics of the wild plant are impacted by the altitude which induces a delay in the vegetative growth and the reproductive phase as well as physiological and morphological modifications. Levels of secondary metabolites (certain sesquiterpene lactones, total polyphenols and flavonoids) vary according to the season and are more important in the site which has the most water-constraining climatic conditions (draining soil, higher temperature and presence of a dry period in summer). Microscopic observation indicated the presence of two types of trichomes: glandular (biseriate) and non-glandular (hair) which are potentially the carrying structures of the molecules of interest. I. montana is able to form calli in vitro from root, foliar and shoot explants on which leafy shoots are formed. The domestication of Inula has been successful from seed from wild plants and under agronomic conditions, sesquiterpene lactone (costunolide, artemorine, eldarin and hydrocostunolide) and phenolic compounds are generally higher than in wild plants. The different constraints applied to test the effects of environmental factors on the production of metabolites have shown: 1) that there can be no correlation between the presence of oxidative stress and an increase in metabolite levels in Inula 2) that the accumulation of lactones and phenolic compounds seems mainly favored when the plant has a surplus of carbon skeletons, not used for growth; 3) finally, the two most favorable conditions for the accumulation of metabolites in Inula, are: in the leaves, a rapid alternation of light and darkness during the photoperiod and in the flower heads, the application of methyl jasmonate. This work augurs good prospects in terms of valuation of Inula in the pharmaco-cosmetological sector. It remains to continue the description of the phytochemical profile of the plant and to precisely locate the organs and / or anatomical substructures concentrating the compounds in question. Having demonstrated that this plant has a good response to domestication, it is also proposed to continue the study of environmental levers likely to positively and significantly influence the chemical profile of Inula
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Levionnois, Charlotte. "The employment conditions of native-born people with immigrant parents : a comparison between France and The United States." Thesis, Paris 1, 2017. http://www.theses.fr/2017PA01E042/document.
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Cette thèse propose une analyse empirique et comparative des conditions d’emploi des descendants d’immigrés en France et aux États-Unis. L’objectif est de mieux caractériser l’intégration sur le marché du travail des descendants d’immigrés, en adoptant une approche multidimensionnelle. La comparaison entre la France et les États-Unis permet de mettre en lumière les dimensions sur lesquelles portent les inégalités en termes de conditions d’emploi entre les descendants d’immigrés et de natifs dans chacun des pays, afin de mieux spécifier ces inégalités. Notre analyse explore dans un premier chapitre, le déclassement professionnel, dans un deuxième chapitre, trois aspects de la sécurité socio-économique de la qualité de l’emploi et enfin, dans un dernier chapitre, la distribution des écarts de salaire. Bien que des écarts en termes de conditions d’emploi existent dans les deux pays en défaveur des descendants d’immigrés, ces écarts ne semblent pas être le résultat d’inégalités mais plutôt d’effets de structure, telles que les différences d’âge ou de niveau d’éducation entre les deux groupes. Les professions et secteurs d’activité dans lesquels les descendants d’immigrés travaillent expliquent aussi ces écarts. Les résultats montrent des similarités entre les deux pays : une fois le biais de sélection à l’accès à l’emploi pris en compte, le fait d’avoir des parents immigrés n’a pas d’effet significatif sur le déclassement professionnel (chapitre 1) mais un effet positif et significatif sur le salaire (chapitre 2). En revanche, les deux pays se distinguent sur plusieurs points. En France, être descendant d’immigrés contribue à significativement freiner l’accès à l’emploi et à diminuer la sécurité de l’emploi. En revanche, aux États-Unis cela a un effet négatif uniquement sur le temps de travail (chapitre 2). Cette thèse défend la prise en compte de l’hétérogénéité qui existe au sein de la population des descendants d’immigrés en termes de pays d’origine de leurs parents. En effet, des effets contradictoires selon le pays d’origine des parents peuvent conduire à des effets non significatifs au niveau agrégé, comme c’est le cas pour le déclassement par exemple. Le dernier chapitre montre un écart salarial plus marqué pour les bas salaires dans les deux pays, avec toutefois comme différence majeure que ce qui reste inobservable contribue à diminuer l’écart salarial entre descendants de natifs et d’immigrés aux États-Unis mais à l’augmenter en FranceThe comparison between France and the United States shows how the inequalities in terms of employment conditions between descendants of immigrants and of native-born persons differ.This thesis proposes an empirical and comparative analysis of the employment conditions of immigrants’ offspring in France and in the United States. The goal is to better characterise the labour market integration of immigrants’ offspring, taking a multidimensional approach. The comparison between France and the United States highlight the dimensions of inequalities in terms of employment conditions between the descendants of immigrants and of native-born in each of country, henceforth improving the characterisation of these inequalities. Our analysis explores overeducation in a first chapter, in a second chapter, three aspects of the socio-economic security of job quality and in a final chapter, the distribution of wage differentials. Although differences in terms of employment conditions exist in both countries to the detriment of immigrants’ offspring, these differences do not appear to be the result of inequalities but rather of structural effects such as differences in age or education level between the two groups. The occupations and sectors of activity in which descendants of immigrants work also explain these differences. The results show similarities between the two countries. Once the selection bias to access employment is taken into account, having immigrant parents has no significant effect on overeducation (chapter 1) but a positive and significant effect on wages (chapter 2). On the other hand, the two countries differ on several points. In France, having immigrant parents significantly restricts the access to employment and lowers job security. However, in the United States, there is a negative effect only on working time (chapter 2). This thesis advocates for the consideration of the heterogeneity that exists within the population immigrants’ offspring, according to their parents’country of origin. Indeed, contradictory effects according to the parents’ country of origin may lead to non-significant effects at the aggregate level, as is the case for overeducation, for example. The final chapter shows a wider wage gap for low-wage workers in the two countries. Nevertheless, the major difference between the two countries is that the unobservable component contributes to narrowing the wage gap between natives and of immigrants but to increasing it in France
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El-Azab, Kadria Moustafa. "Mobilité, biodisponibilité et phytotoxicité du plomb et du zinc en conditions salines : cas du ray-grass dans une terre argilo-limoneuse et application aux risques de réutilisation des eaux de drainage pour l'irrigation dans le delta du Nil." Nancy 1, 2005. http://www.theses.fr/2005NAN10011.
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Pour la plupart des pays des régions arides et semi-arides, l'eau est devenue le facteur limitant principal de leur développement. L'Egypte est l'un des pays du bassin méditerranéen affecté par des pénuries de ressources en eau. C'est pourquoi la réutilisation agricole des eaux usées est largement répandue en Egypte. La réutilisation de ces eaux pour la production agricole s'accompagne, dans un certain nombre de cas, de phénomènes de dégradation des sols par la salinisation sensu stricto. Le problème de la salinisation des sols s'amplifie toujours en raison des mauvaises pratiques d'irrigation et de drainage, surtout avec l'agriculture irriguée dans des zones arides avec des taux élevés d'évapotranspiration. L'irrigation avec de l'eau de drainage ou des effluents d'eaux usées est non seulement une source de sels dissous mais également d'éléments traces métalliques (ETM). Le but principal de ce travail était d'étudier certains effets possibles de la réutilisation des eaux de qualité médiocre avec différents niveaux de salinité sur le comportement des ETM tels que le Zn et le Pb en présence ou en absence de plantes. Les effets combinés de la salinité et de la présence d'ETM sur la croissance du ray-grass, et sa production de biomasse ont pu être étudiés. Deux techniques expérimentales ont été utilisée : des cultures en pots avec deux systèmes différents d'irrigation, avec et sans excès d'eau, et des cultures hydroponiques pour évaluer les effets sur la biodisponibilité, la bioaccumulation et la phytotoxicité du Zn et Pb pour le ray-grass. La salinité a eu un effet toxique semblable sur la croissance des plantes avec une sensibilité plus élevée en conditions hydroponiques. La biodisponibilité du Pb est limitée comparée à celle du Zn qui montre un transfert plus élevé dans les plantes, à la fois par sa translocation aux parties aériennes et par ses effets phytotoxiques sur la croissance des plantes. Cependant, celle du Pb est accrue dans les conditions où la plante lutte activement contre le stress salin. Ainsi, la biodisponibilité des ETM peut varier avec la salinité. La bioaccumulation et la translocation des ETM dans les parties aériennes du ray-grass augmente quand la plante réagit activement au stress salin. L'effet toxique de la salinité du sol et de l'eau d'irrigation sur la croissance de plantes et la production de biomasse peut être modifié par les ETM selon l'interaction entre ces deux facteurs de risquesThe wastewater re-use is a very world wide practice in the areas affected by shortages of water resources. For the majority of the countries of the arid and semi arid regions, water became the principal factor limiting their development. Egypt is one of the Mediterranean countries which is affected by shortages of water good quality resources. The re-use of this water for agricultural production is accompanied with salinization problems, which always develops because of the bad irrigation and drainage practices, especially with the irrigated agriculture in arid regions with high rates of evapotranspiration. The irrigation with wastewater is not only one source of dissolved salts but also of metallic trace elements (MTEs). The principal goal of this work was to study the effect of wastewater re-use with different salinity levels on the behaviour of metallic trace elements (MTEs) such as Zn and Pb in the presence or absence of plants. The combined effects of salinity and MTEs on the growth of rye-grass, and its production of biomass as been studied. Two experimental techniques were used : pot cultures with two different irrigation systems, with and without water excess, and hydroponic cultures to evaluate the effects of various salinity levels on the bioavailability, bioaccumulation, and phytotoxicity of Zn and Pb for the rye-grass. Salinity had a similar toxic effect on the growth of plants even if the sensitivity of plants is higher in hydroponic conditions. The bioavailability of Pb is limited compared with Zn which shows a higher transfer to the plants, with its higher translocation in the shoots and its phytotoxic effects on the growth of plants. However, the bioavailability of Pb is increased when the plant react actively to salinity stress. Thus, the bioavailability of MTEs can vary with the salinity. The bioaccumulation and the translocation of the MTEs in the shoots of the rye-grass increase when the plant reacts actively to a saline stress. The toxic effect of soil and irrigation water salinity on the growth of rye-grass and production of biomass can be affected by the MTEs according to the interaction between these two risk factors
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Nziengui, Ikapi Moukagni Hugues John Sylvain. "Variabilité après culture in vitro de gamétophytes chez deux céréales : analyse de descendance d'haplodiploi͏̈des d'orge (Hordeum vulgare) en conditions de tests salins in situ : obtention de régénérants en présence de sel après gynogenèse chez le blé dur (Triticum durum)." Vandoeuvre-les-Nancy, INPL, 2004. http://www.theses.fr/2004INPL053N.
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Chez l'orge (Hordeum vu/gare, var. Tamelalt), un test salin a été effectué ih situ sur neuf descendances andro- et gynogénétiques, dont les régénérants ont été obtenus avec ou sans NaCI dans le milieu de culture in vitro. Il révèle une variabilité d'expression pour le nombre de talles, la hauteur de plante, la masse en grains et la masse de 100 grains. Les gynogénétiques, dont GOa, produisent plus de talles que les androgénétiques et que Tamelalt. Au traitement sans sel, GOa, dont le régénérant a été obtenu in vitro sans NaCI, produit 9,20% de masse en grains de plus que Tamelalt. Au traitement 5 g/L de NaCI, la masse en grains des gynogénétiques est de 16,10 à 27,12% supérieure à celle de Tamelalt. Au traitement limitant de 10 g/L de NaCI, il y a peu de différences. L'adjonction de NaCI en culture in vitro n'a pas eu d'impact sur la tolérance au sel in situ. Par ailleurs, une corrélation négative apparaît entre le nombre de grains et la masse de 100 grains. L'analyse diallèle 3x3, comprenant GOa, met en évidence en génération F1 des effets d'A. G. C. Significatifs pour la hauteur de plante, le nombre de talles et la masse de 100 grains, montrant que l'expression moyenne des variations est très marquée. En génération F2, la ségrégation des caractères nombre de talles et hauteur de plante chez GOa suggère que les éléments héréditaires impliqués seraient nucléaires. Chez le blé dur (Triticum durum), le pseudo-tallage des régénérants après gynogenèse a été effectué jusqu'au 14ème repiquage. La production en pseudo-talles suit un profil linéaire ou de type exponentiel. Ceci montre que l'activité de multiplication des régénérants est spécifique de chaque unité de départFrom barley (Hordeum vu/gare, var. Tamelalt), in situ comparative saline test ofnine androgenetic and gynogenetic descents, the regenerants of which were obtained with or without NaCI in the in vitro culture medium, showed a large variability for the number of tillers, plant height, total seed weight and 100-seeds weight. The gynogenetic families produced more tillers than the androgenetics and Tamelalt. With the treatment without salt, gynogenetic GOa, the regenerant of which was obtained without NaCI in vitro, gave the best output in seeds and produced an increased seed weight of 9,20% over Tamelalt. Under 5 g/L NaCI, the seed weights of gynogenetic families showed an increase of 16,10 to 27,12% over Tamelalt. When irrigated with 10 g/L NaCI, the differences between the families are low. Ln vitro salt had no effect on families behaviour under in situ salt stress. Furthermore, a negative correlation showed to be established between the number of seeds and 100-seeds weight. Diallel analysis 3x3, inc1uding GOa, expressed in F1 generation significant GCA effects for plant height, number of tillers and 100-seeds weight, showing that average transmission of the variations re1ated to these characters was very strong. Ln F2 generation, the segregation of tillers number and the plant height variations from GOa suggest that implied hereditary elements wou1d be nuclear. From durum wheat (Triticum durum), pseudo-tillering of regenerants was carried out in vitro up to the 14th transfer. The production of pseudo-tillers followed linear or exponential profile, showing a specific multiplication activity for each regenerant
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Sarrazin, Jean-Luc. "La campagne et la mer : les pays du littoral poitevin au Moyen Age (fin XIIe siècle - milieu XVe siècle)." Paris 4, 1998. http://www.theses.fr/1997PA040292.
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La thèse présente une étude des campagnes littorales du Poitou entre le début de la grande expansion du moyen âge central et la sortie relative des épreuves des XIVe et XVe siècles. Elle se divise en trois parties : la première (prolégomènes) s'attache à décrire les composantes géographiques, en particulier la configuration du littoral et le rapport à la mer des pays riverains ; la seconde (livre 1 croissance et organisation d'un espace -vers 1170-vers 1340-) forme le cœur de 1'ouvrage:y sont analysées la genèse du marais poitevin l'extension des marais salants, la conquête des retraits de mer ainsi que les structures de production et les structures seigneuriales. L'immense effort d'aménagement aboutit vers le début du XIVe siècle à un niveau exceptionnel de maitrise du milieu et d'occupation de toute la frange littorale. La troisième partie (livre II crises et consolidation -vers 1340;vers 1460) est consacrée à une étude des épreuves (insécurité/chocs épidémiques) qui affectent la région à partir de 1346-1350. Elle met en évidence la solidité de la seigneurie qui traverse sans dommage majeur la tourmente. Les principaux thèmes abordés sont les suivants: organisation de l'espace littoral, maitrise des eaux, mode de production salicole, structures seigneuriales et sociales, turbulences paysannes au XVe siècleThe thesis presents a study of littoral countries of Poitou between the great expansion that hat taken place during the central years of the middle ages and the relative ending of the ordeals of the XIVth and XVth centuries. It consists in three parts. The first one (prolegomena) describes the geographical components especially the lay-out of the coast and the link between the ocean and the sea-side countries. The second one (book i: expanding and organization of the space - around 1170; around 1340) is the core of the work where are studied the genesis of the marais poitevin, the salt marshes spreading, the conquest of the intended coastline as well as production and seigniorial structures. Towards the beginning of the XIVth century the huge development effort leads to a high con, trol of the environment and to an exceptional occupation of the whole coastline. The third part (book II: crisis and strengthening -around 1340; around 1460-) deals with a study of the ordeals which affect the region starting from 1346-1350 (insecurity, plagues). This part puts into light the firmness of the seigniory which goes through the turmoil without major damage. The main themes studied are: organization of the coastline, control of the waters, salt production means, social and seigniorial structures, peasants agitations
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Alburquerque, Kira d'. "Giovanni Battista Foggini et la sculpture à Florence à l'époque des derniers Médicis (1670-1737) : la condition sociale de l'artiste et la pratique du dessin." Thesis, Paris, EPHE, 2015. http://www.theses.fr/2015EPHE4054.
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Cette thèse, qui présente les sculpteurs actifs à Florence à l’époque des deux derniers grands-ducs de la dynastie des Médicis, Cosme III (1670-1723) et Jean-Gaston (1723-1737), est une étude de synthèse permettant de situer les sculpteurs dans un contexte social et historique. Elle considère le métier de sculpteur sous tous ses aspects : la formation, les conditions de vie et de travail, le statut social, l’organisation des ateliers, la répartition du travail entre les différents collaborateurs, le processus de création des sculptures et des décors sculptés, ainsi que le rôle essentiel du dessin dans l’élaboration et l’exécution de ces sculptures. En arrivant au pouvoir, Cosme III voulut donner un nouvel essor à la sculpture florentine et prit de nombreuses initiatives dans cette direction : il transforma l’enseignement, développa la production d’objets de luxe au sein de la Galleria dei Lavori et facilita le travail des sculpteurs de nombreuses manières, offrant à la plupart d’entre eux des pensions, des charges officielles et des ateliers. Les sculpteurs étaient certes nombreux, mais la vie artistique s’articulait en réalité autour de quelques figures majeures. Le plus important était Giovanni Battista Foggini, installé dans le célèbre atelier des sculpteurs de cour situé Borgo Pinti. Il cumula les fonctions de Premier sculpteur et d’architecte de la Galleria dei Lavori, dirigeant ainsi une très vaste équipe d’assistants et de collaborateurs. Notre recherche est fondée sur un ample dépouillement d’archives et sur l’étude de dessins préparatoires. Un volume d’annexe comprend un répertoire des sculpteurs ainsi que la transcription de nombreux documents inéditsThis thesis, presenting sculptors active in Florence at the time of the last two grand dukes of the Medici dynasty, Cosimo III (1670-1723) and Gian Gastone (1723-1737), is a synthetic study which situates these sculptors in their historical and societal contexts. The work takes into account all the aspects of the profession: the training, in Rome and in Florence, the living and working conditions, the social status, the organisation of the workshops, the creative process, the division of work among the specialists, as well as the important role of drawing in designing and executing the works. When Cosimo III came into power, he decided to bring about a revival in Florentine sculpture and rapidly took many initiatives in this direction: he reformed artistic education, developed the production of luxury artefacts within the Galleria dei Lavori and facilitated the work of sculptors in many ways, offering many of them monthly pensions, official functions and locations for workshops. Even though the period saw a significant number of sculptors working in Florence, artistic life actually centred around a limited number of major figures. Giovanni Battista Foggini, the most important, was settled in the famous sculpture workshop located in Borgo Pinti. At the height of his long career, Foggini was First sculptor as well as Architect of the Galleria dei Lavori, hence managing a vast team of collaborators, assistants and craftsmen. The research is based on a thorough analysis of the archives related to the period as well as an extensive study of the preparatory drawings. A volume of appendices contains a repertory of the sculptors and also the transcription of many unpublished documents
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Yalimendet, Pierre. "L'économie forestière dans le sud-ouest de la R. C. A." Bordeaux 3, 1986. http://www.theses.fr/1986BOR30049.
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La foret dense centrafricaine, situee dans le sud-ouest est tres riche et tres variee en essences de valeur. Son exploitation recente par les societes etrangeres est entravee par les problemes d'evacuation. Neanmoins, elle occupe une place importante dans l'economie nationaleThe thick central african forest, situated in the south-west is very rich and has a variety of valuable trees. Its recent exploitation by foreign companies is hampered by transportation problems. Nervertheless it occupies an important place in the national economy
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Avrane, Colette. "Les ouvrières à domicile en France de la fin du XIXe siècle à la Seconde Guerre mondiale : Genèse et application de la loi de 1915 sur le salaire minimum dans l'industrie du vêtement." Phd thesis, Université d'Angers, 2010. http://tel.archives-ouvertes.fr/tel-00560477.
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À la fin du XIXe siècle, lorsque la condition ouvrière commence à s'améliorer en Occident, la situation des travailleuses à domicile exploitées jusqu'à épuisement pour un salaire de famine, scandalise les personnes de bonne volonté (chrétiens sociaux, féministes, francs-maçons...). Après l'échec de tentatives coopératives à contre-courant de la fabrication de masse, le recours au législateur paraît la seule solution. Votée en 1915, révisée en 1928, 1941 et 1957, la loi n'apporte pourtant pas les résultats escomptés. Cette étude s'efforce de démontrer, chiffres en mains, l'impuissance de cette loi à réduire l'inégalité genrée des salaires qui repose sur une conception idéologique de l'un et l'autre sexe. Néanmoins, elle a contribué à améliorer légèrement le revenu des travailleuses en chambre et suscité tout un mouvement d'idées fécondes comme celle d'un salaire vital minimum ou d'une négociation paritaire des rémunérations par branche. Ses effets se font encore sentir dans la législation actuelle du travail à domicile.
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Tandjigora, Abdou Karim. "L’évolution économique et sociale comparée de deux régions sénégalaises dans le processus de colonisation, décolonisation et développement : le boundou et le gadiaga, 1885-1980." Thesis, Bordeaux 4, 2012. http://www.theses.fr/2012BOR40040/document.
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L’évolution économique et sociale comparée de deux régions sénégalaise dans le processus de décolonisation : Le Boundou et le Gadiaga 1885-1980Ce travail est le diagnostic de l’évolution interne du Boundou et du Gadiaga (Sénégal oriental) dont les économies respectives n’ont suscité que peu d’intérêt pour le pouvoir colonial et les élites postcoloniales. Le processus et les mécanismes de leur marginalisation sont jusqu’ici mollement signalés pour ce qui concerne le Gadiaga et ne sont pas envisagés dans le cas du Boundou ; d’ailleurs, les travaux antérieurs sont exclusivement circonscrits dans la période de la domination coloniale, et n’établissent aucune "passerelle" entre les manifestations coloniales et postcoloniales de la marginalisation.Cette exclusion de l’économie globale du Sénégal en toute époque est la résultante de l’orientation des politiques économiques et de la faible opportunité offertes par les politiques publiques à certaines régions. Les facteurs de la marginalisation du Boundou et du Gadiaga sont pour ainsi dire d’ordre structurels (absence d’investissement digne de ce nom et de solutions économiques durables) et non conjoncturels. Sur le plan social, les conséquences économiques sont lourdement ressenties, avec la genèse de phénomènes tels l’exode rural, l’émigration massive et organisée de travail et le bouleversement des structures sociales, ce qui accentue à rebours le retard économique. Il se produit à terme une sorte de cercle vicieux de la marginalisation puisque l’accentuation du retard économique par les phénomènes sociaux, encourage les autorités publiques à différer les investissements, voire à y renoncer, en prenant parfois pour seul prétexte la régression démographique dont sont victimes toutes les "périphéries".La similarité de la situation économique entre le « temps partagé » colonial et le « temps propre » postcolonial et les comportements sociaux considérés comme leurs effets induits ne permettent-elle pas de dire que le schéma de gestion de l’État moderne du Sénégal est simplement le rejeton de la politique colonialeThe economic and social evolution compared by two regions of Senegal in the process of decolonisation: Boundou and Gadiaga on 1885-1980This thesis is the analysis of the internal evolution of Boundou and Gadiaga (Eastern Senegal) whose economies have been little entitled to the colonial and postcolonial elites. The processes and mechanisms of marginalisation are so far softly reported regarding the Gadiaga’s area but this has not been considered in the case of Boundou, and indeed previous work exclusively restricted to the period of colonial domination and makes no “link” between the colonial and postcolonial manifestations of marginalisation.This exclusion of the overall economy of Senegal in many ways and any time is the result of the orientation of economic policies and low opportunities offered by public policies in certain areas. The factors of marginalisation of Boundou Gadiaga are basically structural order (lack of substantial investment and lack of vision and strategy on long run but weakness of sustainable economic approaches) and non-cyclical economic mechanism. Along the social aspects, the population undergoes heavily the economic consequences of the lackluster of the region, and the conditions entail the mass movement of population from rural to urban area (rural exodus) and the disruption of social structures, which increase the pressure of the economic on backwardness. It occurs on short run vicious circle of marginalisation since the accentuation of economic backwardness by social phenomena, encourages public authorities to push back investment’s programs or cancel it, by spotlighting the pretext of the declining population.The similarity of the economic condition between the “shared time” colonial and “owned time” postcolonial and the social behaviours considered induced effects does not allow the scheme management of the modern state of Senegal is simply the offshoot of colonial policy
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Phan, Thi Thanh Hoai. "Investigating the Role of Arabidopsis Plasma Membrane Intrinsic Protein AtPIP2;1 in Seed Germination." Thesis, 2021. https://hdl.handle.net/2440/135687.
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Soil salinity can cause osmotic stress during seed germination by limiting water uptake and causing NaCl accumulation. Exposure to salinity stress during seed imbibition can alter germination percentage, slow the germination rate and seedling growth. Subsets of membrane intrinsic proteins called aquaporins contribute to salinity stress tolerance in plants, and some isoforms of these proteins could have roles in helping seeds to germinate in saline conditions. Aquaporins have multiple roles in many physiological processes, such as solute transport, hydraulic conductance, signalling, development and adjusting to changes in the environment. Recent studies have revealed that some plant aquaporins are candidates for being involved in both water and Na+ transport. For example, Arabidopsis thaliana Plasma Membrane Intrinsic (PIP) proteins AtPIP2;1 and AtPIP2;2 transported both water and univalent cations (Na+ and K+) when tested in heterologous systems. To explore whether AtPIP2;1 influenced Na+ transport in plants, Atpip2;1 loss of function mutants and wild type Columbia-0 seed were germinated on media containing 50 mM NaCl. The wild type Arabidopsis seed appeared to germinate earlier than the seed from the Atpip2;1 mutant lines. This preliminary observation led to the hypothesis that there may be a link between the function of AtPIP2;1 and factors that influence seed germination percentage in Arabidopsis. To test this hypothesis, wild type Arabidopsis, two Atpip2;1 mutant lines, a Atpip2;1*Atpip2;2 mutant line, and two transgenic lines overexpressing AtPIP2;1 (35S::AtPIP2;1) and a null control line were propagated in controlled conditions and seed was harvested from each of these seven genotypes. The seed was used to test whether the seven genotypes differed in germination percentage and seed area, weight and Na+ and K+ content when imbibed in control or saline treatment. This research aims to investigate the role of an aquaporin protein, AtPIP2;1, in seeds in the model plant Arabidopsis thaliana. A series of exploratory experiments were carried to explore possible roles for this protein in seed germination, with a particular focus in germination under salt stress. In saline conditions, seed from Atpip2;1 mutant lines and lines overexpressing AtPIP2;1 germinated slower than wild type and null control lines, respectively. Fifty hours after sowing, the seedlings of one mutant Atpip2;1 line weighed more than wild type, and seedlings of both 35S::AtPIP2;1 overexpression lines weighed less than null controls. When imbibed in saline conditions, Atpip2;1 mutant line seed contained more K+ than wild type seed. Whereas seed from lines overexpressing AtPIP2;1 contained more K+ than null line seed when imbibed for 30 h in water then transferred to a solution containing 75 mM NaCl from 30 to 50 h after sowing, but not when imbibed in the saline treatment from 0 to 50 h. In conclusion, the potential for these observations to be a consequence of AtPIP2;1 transport of water, ions or hormones, or linked to protein-protein interactions and signaling roles are discussed. Options for future experiments targeted at distinguishing which aspects of AtPIP2;1 functions are important in contributing to optimal seed germination in saline treatment are considered.Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2022
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Pennington, Karrie Sellers. "Alfalfa water-production functions under conditions of deficit irrigation with saline water." 1986. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_1986_461_sip1_w.pdf&type=application/pdf.
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Mogany, Trisha. "Optimization of culture conditions and extraction method for phycocyanin production from a hypersaline cyanobacterium." Thesis, 2014. http://hdl.handle.net/10321/1117.
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Submitted in fulfilment of the requirements of the degree of Master of Technology: Biotechnology, Durban University of Technology, 2014.Cyanobacteria contain phycocyanin a light harvesting pigment found to have numerous biotechnological applications, such as: a natural colorant in food and cosmetics, fluorescent tags employed in clinical and immunological research and also in therapeutic processes. Successful phycocyanin production depends on growth characteristics, ability to accumulate high quantities of the pigment, and an effective downstream process. Therefore, the aim of this research was to optimize the extraction method and production by determining the optimal cultivation conditions for phycocyanin producing cyanobacterium. This cyanobacterium was isolated from a hypersaline water body in Kwa-Zulu Natal, and subsequently purified using traditional streak and spread plate techniques. Different cell disruption techniques and a range of buffers were evaluated for the extraction of phycocyanin. The buffer concentrations and pH was subsequently optimized. Results showed that maximum phycocyanin was extracted when cells were suspended in 50mM sodium phosphate buffer (pH-7.5) supplemented with 10 % lysozyme and then disrupted using the freeze–thaw method at -20 & 4°C. The UV-Vis absorption spectral scan of the crude extracted pigments showed a peak at 620 nm. This corresponds to phycocyanin production. Unwanted proteins were removed using a 25and 50% saturated ammonium sulphate precipitation, followed by dialysis. SDS-PAGE showed two subunits with molecular masses of 19 and 20 kDa. These masses corresponded to phycocyanin α and β subunits. Furthermore, a food grade purity ratio (A615/A280) of 1.20 was achieved. The effects of various abiotic factors (temperature, light and pH) on growth and phycocyanin production of the Cyanothece sp. was investigated. Temperature ranging from 20-45°C and pH (5-10) was evaluated for 2 weeks. Cultures were then subjected to four photoperiods (24:0, 18:06 12:12 and 8:16 h light: dark) three light intensities (25, 75 and 125 µmol photons per m2 per –s) at varying wavelengths i.e. blue, red and green and Grolux light. Ideal conditions were observed at 35°C, 125 µmol photons.m2.s-1 of Grolux light for a 16:8 light and dark photoperiod. It was observed that the highest biomass and phycocyanin production was found to be at 35°C, temperatures below or above resulted in a decrease in both growth and pigment synthesis. Phycocyanin concentration changed in response to light quality and intensity. A significantly higher (p<0.05) phycocyanin yield was found when the culture was exposed to 125 µmol photons.m2.s-1 of Grolux light compared with the other three light conditions. Using Design of experiments, a series of fractional factorial experiments were carried out to optimize media components for pigment production. The final optimized growth medium was determined from a central composite design using response surface plots together with a mathematical point-prediction tool and consisted of 2g/L NaNO3, 0.06g/L K2HPO4, 0.12 g/L MgSO4.7H2O, 0.033 g/L CaCl2.2H2O, 100g/L NaCl, 12mL minor nutrients and 0.5 trace metal. A 72 % increase in phycocyanin was observed. This research revealed that this particular Cyanothece sp. shows great potential as a reliable source of phycocyanin.
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Guerrero-Rodriguez, Juan de Dios. "Growth and nutritive value of lucerne ( Medicago sativa L. ) and Melilotus ( Melilotus albus Medik. ) under saline conditions." 2006. http://hdl.handle.net/2440/37866.
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Dryland salinity is a major and expanding threat to agricultural land in Australia. Animal production from forages grown on saline land is perhaps its most promising economic use. Glycophytic forage legumes have been evaluated under saline conditions mainly for agronomic characteristics and, to a lesser extent, for nutritive quality to animals. Plant growth and its nutritive quality are interrelated, but a decline in yield in response to salinity may be associated with effects on the chemical constituents of the plant since soil salinity affects plant metabolism. This research aimed to investigate changes in the components of yield and nutritive value of two legumes species. Lucerne ( Medicago sativa ) and Melilotus ( Melilotus albus ) were exposed to different levels of NaCl in the range of 0 to 110 mM NaCl. The research tested the hypothesis that the components of plant nutritive value are not as sensitive to salinity as shoot biomass production since the adaptive mechanisms of the plant lessen harmful effects of the salts. For both plant species, salinity decreased leaf and stem dry matter production, but increased leaf - to - stem ratio. In addition, salinity resulted in earlier flowering in Melilotus. Mineral composition was the most sensitive component of forage quality. Calculated sodium chloride concentrations were up to 125 g / kg DM in lucerne and 39 g / kg DM in Melilotus when irrigated with 110 mM NaCl. The concentrations of calcium and magnesium decreased in both species and approached the marginal range for animal production. Zinc concentration also decreased while potassium decreased in stems of lucerne only. The digestible organic matter ( DOMD ) in response to salinity varied between species. At the highest salt concentration, the whole shoot ( i.e., leaf and stem ) of lucerne decreased up to 4 percentage units while Melilotus increased by 6 percentage units. In lucerne, DOMD was influenced by a high concentration of soluble ash in leaf and stem and, in Melilotus, by an increase in the organic matter content of leaf and a reduction in lignin concentration in stem, which favoured higher digestibility. These results were supported by a histological study in which an increase in starch in Melilotus leaf, and a lower proportion of xylem in relation to parenchyma in stems, was measured. Crude protein concentration was not compromised and, in relation to Melilotus, coumarin concentration did not increase with salinity. In conclusion, the reduction in DM production of species with similar salt tolerance does not necessarily correspond to an equivalent reduction in nutritive value. This research represents the most detailed study into effects of salinity on glycophytic forage legumes. Results show that while some aspects of forage quality ( e.g., minerals composition and energy ) are strongly influenced by salinity, other aspects ( e.g., protein ) remain relatively unaffected. These findings have implications for development of productive grazing systems on saline agricultural land.Thesis (Ph.D.)--School of Agriculture, Food and Wine, 2006.
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Liu, Chung-Wei, and 劉仲維. "Effects of Nitric Oxide or Calcium Chloride Treatment on Sweet Pepper and Melon Seedling under Saline or Waterlogging Conditions." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/87256176341535955071.
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碩士國立宜蘭大學
園藝學系碩士班
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Taiwan often suffered from plum rain or cloudburst hit in spring and summer season causes waterlogging. In addition large-scale use of chemical fertilizers resulted in accelerated soil salinization. These stresses cause vegetable quality and yield damage. In the study, we investigated plant growth, oxidative stress levels and the functioning of the free-radical scavenging system under salt and waterlogging. The nitric oxide or calcium chloride applied as a soil drench modifies the adverse effects of these stresses at the same time. Hopeful that provided salt and flooding stress resistance as to improve summer vegetable production in Taiwan. Experimental materials were sweet pepper (Trim Star) and melon (KY Silver Light and KY Jill). When plant seedlings expand the third true leaves entirely, they were pretreated 300 mM NaCl twice. Exogenous nitric oxide or calcium chloride was performed. The group of exogenously-applied nitric oxide include Hyponex No. 2 of 300 mg L-1, NaCl of 300 mM and three different concentration sodium nitroprusside (SNP; a NO donor ; 0, 100, 150 μM) mixture solution. The group of calcium chloride treatment include Hyponex No. 2 of 300 mg L-1, NaCl of 300 mM and three different concentration sodium calcium chloride (25, 50, 75 mM) mixture solution. As a result shows exogenous nitric oxide or calcium chloride increased shoot length, number of leaves, stem width, root length, leaves length and leaves width, shoot fresh weight, root fresh weight, shoot dry weight and root dry weight, and promoted activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR), and decreased electrolyte leakage (EL%), malonaldehyde (MDA), superoxide anion and hydrogen peroxide content in sweet pepper and melon seedling under salt stress. Among the treatments of three different concentration medicaments, Exogenous 150 μM SNP treatment had a best protective effect to alleviate adverse effect of salt stress in sweet pepper, however, and the best effect for melon was50 μM SNP. Calcium chloride of 25 mM pre-treatment can markedly reduce the injury of salt stress. One cultivar of sweet pepper and two cultivar of melon were carried out waterlogging experiment in the simple green house. The experiment of exogenous nitric oxide was plants were treated with 0, 50 or 150 μM SNP 2 and 4 day prior to waterlogging, applied as a soil drench. Calcium chloride treatment use Hyponex No. 2 of 300 mg L-1 add to CaCl2 of 25, 50 or 75 mM mixture solution 1, 7 and 14 day prior to waterlogging, applied as a soil drench. The period of flooding was 14 d followed by a 7 d drainage period. As a result shows nitric oxide or calcium chloride treatment alleviated growth inhibition and lipid peroxidation, induced antioxidant enzymatic activities. The SNP of 150 μM and 50 μM pretreatment demonstrated the greatest effect in sweet pepper and melon, respectively. Exogenous 75 mM CaCl2 can significantly alleviate the waterlogging damage.
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Jayakumar, J. S. "Analysis Of Two Phase Natural Circulation System Under Oscillatory Conditions." Thesis, 1999. http://etd.iisc.ernet.in/handle/2005/1519.
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Katulanda, Panchali. "SYMBIOTIC NITROGEN FIXATION AND SEED DEVELOPMENT OF GENETICALLY MODIFIED SOYBEAN IN RELATION TO BRADYRHIZOBIUM INOCULATION AND NITROGEN USE UNDER ACIDIC AND SALINE DYKELAND SOIL CONDITIONS." 2011. http://hdl.handle.net/10222/14325.
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The objectives of this study were to examine the effects of starter N inputs and Bradyrhizobium inoculation on soybean symbiotic N fixation and grain yield under field and greenhouse conditions. The study was conducted in the Wellington and the Habitant dykelands in NS. The treatments consisted of 0, 1.5, 3 and 4.5 g/kg seed rates of inoculant and 0, 10, 20, and 30 kg/ha rates of N fertilizer. Under acidic soil conditions, the inoculated plants showed significant N fixation responses in the Wellington field while saline soil conditions suppressed N fixation in the Habitant field. The soybean grain yield showed an increasing trend with the inoculant rate 4.5 g/kg seed. The starter N fertilizer did not facilitate the soybean grain yield in the dykelands. Under controlled environment conditions, inoculant rate 3 g/kg seed alone produced the same amount of yield as 1.5 and 4.5 g/kg seed rates with N fertilizer.
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Teiva, Salmon. "Étude des déterminants de la relation positive entre la taille des organisations et les salaires au Canada." Mémoire, 2010. http://www.archipel.uqam.ca/2737/1/M11263.pdf.
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Cette étude empirique évalue l'importance des écarts salariaux entre les grandes et les petites organisations à partir des données transversales issues de l'Enquête sur la dynamique du travail et du revenu des années 1996, 2000, 2002 et 2004. Les résultats que nous obtenons démontrent que l'ampleur de cette relation varie fortement, selon que l'on tienne compte de la taille des établissements ou des entreprises en tant que variables principales dans notre modèle. Dans les établissements, ces écarts s'estiment en moyenne entre 45 et 50% entre 1996 et 2004, dépendamment des sexes, alors que dans les entreprises, ils s'évaluent entre 28 et 33%. Nos principaux résultats indiquent que 45% de ces divergences proviennent d'une différence dans le niveau de qualification et du nombre d'années d'expériences professionnelles des individus. Ces disparités se réduisent davantage lorsque nous tenons compte des différences intersectorielles, interprofessionnelles et des conditions de travail. Cependant, nous ne pouvons pas confirmer l'importance de la théorie hédonique des salaires dans notre modèle. Concernant l'analyse des syndicats, l'hypothèse selon laquelle les employeurs des grandes organisations chercheraient à éviter la création de groupements collectifs ne semble pas se vérifier dans notre analyse. Les coefficients que nous obtenons ne sont pas tous du bon signe et parfois même, sont non significatifs. Suivant la théorie des salaires d'efficience, nous avons supposé que la persistance des écarts observés pouvait provenir du fait que les employeurs des grandes organisations cherchaient à substituer leurs coûts de surveillance du personnel par des rehaussements de salaires, afin que cela puisse accroître l'effort des employés et ainsi leur productivité. Nos résultats sont mitigés, mais dans l'ensemble, ils n'apportent pas de réelles évidences en faveur de cette hypothèse. Toutefois, à l'issue de cette étude, nous pouvons affirmer qu'il existe bien une relation positive entre la taille des organisations et le niveau des salaires au Canada et que cette relation persiste aux hypothèses des théories traditionnelles. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Taille des établissements et des entreprises, Qualification, Conditions de travail, Syndicat, Salaires d'efficience, Étude empirique.