Dissertations / Theses on the topic 'Date palm in literature'

The main objective of this research was to evaluate the effects of chemical treatment and ultrasound processing (sonication) on the fiber composition and rumen degradability of date palm seeds (DPS). For this purpose, five trials were conducted. In the first trial, the effects of treating DPS with 4% sodium hydroxide (NaOH) at different temperatures (23, 50 and 100 0C) and for different times (30, 60 and 356 min) on seeds fiber content and ruminal degradability were evaluated. Relative to untreated seeds, treated seeds had lower (P<0.05) lignin and hemicellulose, and greater (P<0.05) neutral detergent fiber (NDF), acid detergent fiber (ADF) and cellulose content, particularly at high temperatures. The degradability of seeds organic matter (OM) and NDF were greater (P<0.01) in the treated (41.79 and 35.44%) than untreated seeds (24.71 and 22.77; respectively), particularly when incubated at 23 0C. Treatment time, however, had no effect (P>0.01) on seeds OM and NDF degradability.

Somatic embryogenesis is the mass production system of choice for date palm to increase the rates of vegetative propagation. However, the low rates of conversion to plants are common for somatic embryos. Up to 50% of plant productiqn in the Jimmah Tissue Culture Laboratory, Oman is lost during the stages of somatic embryo germination and conversion. Partial desiccation of date palm somatic embryos of the genotype Khalas Aldahra, either by dehydration for up to 4 hours or supplementation of the maturation Murashige and Skoog-based medium with sorbitol, sucrose and polyethylene glycol, increased significantly the percentage conversion to plants. In contrast, the addition of indol-3-butyric acid (IBA), a-naphthaleneacetic acid (NAA), 6-benzylaminopurine (BAP), abscisic acid (ABA), flurprimidol or activated charcoal to the germination medium did not improve the conversion of embryos to plants compared to the control. A protocol for cryopreservation of somatic embryos and embryogenic cultures of the genotype Buhabisha was developed in the current study using the vitrification method (incorporating PVS2 solution) and pretreatment with glycerol, sorbitol and dimethylsulfoxide as a cryoprotectant prior to freezing. Despite the fact that, there was a low percentage of survival of somatic embryos, the results from this study provided evidence that it is possible to cryopreserve somatic embryos and embryogenic callus of Omani date palms. A cell suspension protocol from the genotype Buhabisha was established in this study in order to utlilise more efficient micropropagation methods and to overcome the problems of the large size of somatic embryos that may lead to an efficient cryopreservation technique. NAA gave the best regeneration frequency of somatic embryos compared to 2,4-dichlorophenoxyacetic acid (2,4-D) or picloram. However, attempts to replace activated charcoal in the date palm cultures with either polyvinylpyrolidone or ascorbic acid were unsuccessful. The use of dialysis membrane to separate cell suspensions from activated charcoal was successful, but the generation of somatic embryos was low. Twenty one genotypes obtained from the Jimmah Research Station, Oman were screened and evaluated with microsatelIite markers to establish a DNA fingerprinting procedure. Simple Sequence Repeats (microsatellites) showed that date palm genotypes analysed had high genetic divergence. Importantly, somaclonal variation was not detected by DNA fingerprinting in tissue culture-derived plants of the genotype Khalas Aldahra.

Effects of various pollen types on the fruit growth and development in two maternal cultivars of Omani Date Palm were studied in the Northern Batinah region of the Sultanate Oman. Discrete stages in the development were identified, quantified and examined with regard to important variables including fruit set, weight, size, maturity, chemical composition, appearance and yield. Procedures were developed to compare across the different maternal cultivars and temperature environments. The pollen types were distinct in their effects, particularly as regards weight, time to maturity, ripening, sugar content, appearance and yield of certain consumable fruit stages. These effects were influenced by the female type and differential fruit set. True metaxenic and xenic effects were evidenced by excluding influences of fruit set. These were on fruit fresh weight, size, maturity and ripening in cv Khasab in 1996 and 1995 and in cv Khalas in 1996. Differences in cv Khalas in 1995 were due to differences in fruit set. Pollen effects could be measured in cv Khalas throughout fruit development, while they appeared in cv Khasab only in the later stages. Khori consistently induced the highest mature fruit fresh weight (14.8 g in cv Khalas, 13.0 g in cv Khasab) compared to Bahlani (12.6 g and 12.3 g, respectively) and AI Arudsabba (12.2 9 and 11.1 g, respectively). However, differences in fruit set between pollen blocks in cv Khalas in 1995 caused the largest ripe fruit fresh weight (16.1 g) in the AI Arudsabba block compared to Bahlani (14.1 g) and Khori (13.4 g). The effect of high fruit set (initial set was 49 % with Khori and 34 % with AI Arudsabba) in masking and modifying pollen effects was evident because AI Arudsabba induced about 40 % less fruit fresh weight than Khori in the initial stages of development. The response to applications of plant growth regulators was specific to the pollen type used. GA increased, by about 100 %, fruit fresh weight in AI Arudsabba pollinated Khalas fruits but reduced it to about 50 % in Khon pollinated ones. NAA caused the abscission of all unfertilized ovaries in Khon pollinated Khalas but not in those pollinated with AI Arudsabba. In the absence of syngamy physiological rather than hereditary causes were implied. Correlations between fruit set and fruit fresh weight did not exist in the early stages suggesting that the observed pollen effects were truly metaxenic or xenic. In the later stages clear and consistent negative correlations existed for the AI Arudsabba block. Probably in the other pollen blocks some mechanism compensated this control of one variable over the other. Late correlations for the Khori block in cv Khalas suggested that high fruit fresh weight induced fruit drop. The absence of pollen effects on late correlations in cv Khasab implied a genetic cause. The strong influence of fruit set on ripening (% ripe fruits) in Khori pOllinated bunches indicated a specifically strong influence exerted by fruit set over ripening. Time to physiological maturity was affected by pollen type only in cv Khalas where AI Arudsabba and Bahlani induced earlier maturity (7 days) than Khori. Khori pollinated fruits appeared to mature later in both female cvs except cv Khalas in 1995. Bahlani induced earlier maturity in both female cvs. Regression analysis between thermal time and fruit fresh weight provided evidence for the effects specific to Khori. As Bahlani induced the same early maturity in both female cvs. Ripening was most uniform in Bahlani pollinated bunches, but faster in Khori pollinated ones. Correlations of thermal time and ripeness indicated that the temperature regime has a strong influence (r=0.99) over ripening in Bahlani pollinated bunches. Early pollen effects were probably due to physiological mechanisms, probably hormonal activity, which could be attributed to pollen type and pollination. Late effects were under the influence of male x female interactions and were thought to be genetic. Bahlani consistently induced the highest fruit fresh weight and size in the early fruit stages, but Khori in the later stages. Only in cv Khasab was Bahlani in the later stages on par with Khori in this regard. The situation was similar for fruit and seed size. Compositional differences between pollen types were not reflected in those between the ovaries one day after pollination with different male types. This largely precluded the possibility that the early growth response was directly due to the mere addition of substances contributed by the pollen grains. Preliminary investigations indicated that pollen types were a priori distinct with regard to their biochemical composition and mineral content in that AI Arudsabba and Bahlani were similar and differed from Khori. Khori's pollen grains were largest (22 mum, less than 20 mum in other types) and its pollen tube growth the most uniform (CV 56% compared to 80-110% with other types), while Bahlani had the most vigorous pollen tube growth (tube length up to 220 JlI1lI24h). Khori contained more growth promoters, possibly GA , than AI Arudsabba. Khori brought about relatively stable bunch yields in cv Khalas (11 kg in 1996, 15 kg in 1995) and large (about 4 cm long), heavy and sweet fruits, but delayed maturity of the fruits (7days in cv Khalas). AI Arudsabba produced a slightly higher cumulative yield (28 kg) of similar yield stability, but produced fruits of poor quality in regard to fruit size (about 3.5 cm in cv Khalas), fresh weight and a low total sugar content (less than 40% in Khalas, less than 50 % in Khasab). Bahlani had clear advantages, in that it induced sweet fruits, but produced the least stable yields of fruits (cv Khalas: 16 kg in 1996, 7 kg in 1995) with relatively low weight and small fruits.

This study aimed to address the current status of the United Arab Emirates date palms. The first chapter focused on the development of the date palm sector in the UAE. A huge increase in the date palm number was achieved in the past few decades. In the same time, there are critical issues facing this development, such as water demand, salinity, and Red Palm Weevil. The second chapter is a greenhouse experiment to test the growth of twelve date palm seeds at four NaCl levels, control, 3000, 6000, and 12000 ppm. Optimal growth found at control and 3000 ppm of NaCl. Relative growth rate (RGR), biomass, and NL decreased significantly by increasing salinity; however, no significant differences were observed in the average SGR for any cultivars. Increased NaCl leads to significant decreases in K+, Mg2+, and Ca2+ contents of plants. Na:K ratios were lower in shoots than in roots. Lulu, Fard, Khnaizi, Nabtat Safi, and Razez cultivars showed higher RGR and biomasses whereas Khnaizi, Mesally, and Safri had higher Na:K ratios than other cultivars in the control indicating higher Na+ discriminations from plant parts. The third chapter studied the vegetation change in the eastern region of the UAE. Due to shortage of fresh water resources, the vegetation of the eastern region of the UAE has experienced a series of declines resulting from salinization of groundwater. To assess these changes, field measurements combined with Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) based Soil Adjusted Vegetation Index (SAVI) were analyzed. Images from two dates, 1987 and 2000 were acquired to enable the computation of the greenness anomalies for three sites in the eastern region, Fujairah, Kalba, and Hatta. The results show an overall increase in the agricultural area, associated with a severe decrease in vegetation greenness and health conditions, particularly in the Kalba study area. The SAVI values decreased with increased soil salinity, permitting the identification of salt-affected areas. Potential areas of further research range from studying the effects of tree spacing and understory crops as immediate and potential solutions to maintain productivity and mitigate the salinity problem.

Date palm (Phoenix dactylifera L.) is a diploid with 18 pairs of chromosomes and an estimated genome size of 658 Mb. It is a dioecious perennial monocot, with a long generation time (a period of 4-5 years until first flowering). Date palm is one of the major fruit crops grown in the Gulf countries and particularly in the Sultanate of Oman. Approximately 250 varieties of date palm are recorded throughout the country with evaluation and characterization based on morphological and reproductive traits (e.g. fruit color, fruit shape and fruit weight). Limited molecular characterization work has been undertaken for date palm germplasm in general and Omani date palm germplasm, in particular. The principal focus of this study was to: investigate the genetic diversity of Omani date palm germplasm and compare it with 'exotic' germplasm, to differentiate between female and male plants at the molecular level and to construct an initial genetic map for date palm. Samples were taken from eight parents of the available Omani date palm controlled crosses (Khalas 4, Khalas 13 male, Um-Alsela, Khori male, Bami, Naghal, Bahlani male, and Khasab) with 90 date palms from the BC1 and F1 populations, from 194 Omani date palm accessions (151 female cultivars and 43 male trees), together with samples from Italy (Sanremo and Bordighera), USDA-ARS, France, Iraq, Libya, Sudan and Iran. The F-statistics analysis showed that the genetic variation between female and male accessions based on random markers was only 2.1 %, while within the broader group of Omani female and male accessions the molecular variation was 97%, suggesting that the Omani female and male accessions have little consistent divergence, compared to the large-scale divergence within Omani germplasm, so male palm have been derived from most genetic origins in Oman. Additionally, the Principal Coordinates Analysis (PCA) and bootstrap consensus phenetic tree showed that the Omani accessions were closely related to each other and there was no clear genetic differentiation between female and male cultivars. A high degree of genetic variation was observed between germplasm from Oman, Italy, USDA-ARS, France, Iraq, Libya, Sudan and Iran as measured by Fst (19.7 %). The PCA showed that the Europe-Africa (Italy, France, Libya and Sudan) accessions are distinguished from West-Asia (Oman, Iraq and Iran) accessions and have their own autochthonous origin, a finding which was strongly validated by bootstrap consensus tree test. A medium density genetic map in date palm was constructed using 53 individuals from BC1 and 30 individuals from F1 populations. The BC1 map consisted of 270 markers (28 SSR and 242 SNP) distributed into 29 linkage groups with total genetic length of 1.486.7 cM, while the F1 map consisted of 591 markers (21 SSR and 570 SNP) distributed into 30 linkage groups with total genetic length of 2,385.6 cM. A total of 25 combined linkage groups were possible by combining both BC1 and F1 maps through common markers. A sex-link marker locus was developed and found to predict a high level of discrimination between male and female date palms among multiple varieties distributed across the wide range of cultivation, with an accuracy of 100% in the Omani crosses, 96% in the broad Omani material and 86% in the broadest date palm germplasm. This marker was also mapped in both BC1 and F1 at 42.8 cM and 4.9 cM in linkage groups 18 and 29, respectively and on combined group 19 at 42.8cM.

To meet the challenges of protein price increases from animal sources, the development of new, sustainable and inexpensive proteins sources (nonanimal sources) is of great importance. Date palm (Phoenix dactylifera L.) seeds could be one of these sources. These seeds are considered a waste and a major problem to the food industry. In this thesis we report a physicochemical characterisation of date palm seed protein. Date palm seed was found to be composed of a number of components including protein and amino acids, fat, ash and fibre. The first objective of the project was to extract protein from date palm seed to produce a powder of sufficient protein content to test functional properties. This was achieved using several laboratory scale methods. Protein powders of varying protein content were produced depending on the method used. Most methods were based on solubilisation of the proteins in 0.1M NaOH. Using this method combined with enzymatic hydrolysis of seed polysaccharides (particularly mannans) it was possible to achieve a protein powder of about 40% protein (w/w) compared to a seed protein content of about 6% (w/w). Phenol/TCA extraction gave the protein powder with the highest protein percentage of 68.24% (w/w) and this powder was used for subsequent functional testing. Several factors were found to influence seed protein extraction such as pH, temperature, the extraction time, the solvent to sample ratio and the solvent concentration. Optimum conditions for extraction were found to be pH 10, 45˚C and extraction time of 60 min. The results showed that use of enzymes to hydrolyse and remove seed polysaccharides improved the extraction of date seed protein. Optimal improvement was obtained using Mannaway, which hydrolyses mannans and galactomannans, which gave a powder with 34.82% (w/w) protein compared to the control of 11.15% (w/w) protein. The proteins in the extracted date seed protein were profiled using LC/MSMS. Three-hundred and seventeen proteins were identified. The proteins belonged to all major functional categories. The most abundant proteins were glycinin and β-conglycinin, the two major seed storage proteins of plants. The functional properties of extracted date seed protein were investigated using a range of tests. The thermal properties of date seed proteins were consistent with a powder containing high levels of conglycinin and β-glycinin. The solubility had a similar pH profile to soy protein, but differed in absolute solubility due to differences in non-protein composition. Similarly, water holding and oil holding capacity of date seed protein was lower than for soy protein, probably because of compositional differences. Date seed proteins were able to emulsify oils and had a comparable emulsifying ability and emulsion stability to soy protein isolate. The date seed protein was not a good foaming agent compared to soy protein or whey protein concentrate.

Dates are the fruit of the palm, which the Greeks call “Phoenix”, a word taken from the Phoenician language. Saudi Arabia is currently one of the largest dates producing countries in the world. There are several varieties of dates grown in Saudi Arabia. Date fruits contain compounds that are potentially bioactive, with many health benefits; for example, vitamin E, carotene (precursor for vitamin A) and phenolic compounds. Dates represent an excellent source of antioxidants due to their high concentrations of phenolic compounds as well as the presence of selenoproteins. Moreover, dates are also potentially a very good source of several minerals in fact; there are at least 15 minerals found in dates. The work presented in this thesis will determine the nutritional composition of nineteen varieties of dates sourced from four, environmentally diverse, regions in Saudi Arabia. These varieties were selected because of their popularity, economical price, as well as availability during the year. The results indicated that the range of moisture contents (10% - 30%) found within the four regions were quite similar. For levels of fat, protein and ash all varied significantly between varieties but were all very low. Carbohydrate content was variable between samples (70 - 80%). The results indicated that glucose and fructose concentrations in theses Saudi dates were generally similar and the present of sucrose being normally associated with a corresponding reduction in the level of glucose and fructose. Potassium was the major mineral found in all the varieties with concentrations as high as 1173.29 mg/100g. The mean values for phosphorus in the dates from the different regions were close to each other. The amount of selenium was generally very low in all varieties and some did not contain any selenium at all. It would appear that it is variety and not region of production that has the major impact on nutritional composition. Moreover, this research will also determine the antioxidant capacity and phenolic content of a sub-set of these varieties at four different stages of ripening. Results showed that the levels of phenolics, anthocyanin and antioxidant capacity all decreased throughout development in all the seven selected varieties. There were strong correlations between this antioxidant capacity and the total phenolic and anthocyanin levels suggesting that these are major contributors to this nutritional property of dates. A preliminary screen tentatively identified some phenolic compounds and indicates that there may be some compositional variation between date varieties.

The low cost, abundant, underexploited and underutilised renewable agricultural waste residue, date palm leaves (Phoenix dactylifera), were extracted using supercritical carbon dioxide (scCO2) to obtain valuable waxes. The extraction process was optimised using second order factorial design to obtain high yield of waxes. Date palm leaves exhibited relatively high yield of wax of 3.49%, as compared to other agricultural residues extracted with scCO2. Diverse range of lipophilic compounds were characterised and quantified including n-alkanes, free fatty acids, free fatty alcohols, long chain aldehydes, sterols and wax esters. Waxes extracted at different extraction pressure and temperature exhibited significant difference in melting profile (ranging from 35 °C for extractions at 40°C and 80 Bar to melting points of 78 °C for extractions at 100 °C and 400 Bar). Thus, suggesting the opportunity to tailor extraction to meet a target application. ScCO2 extraction has several advantages over organic solvent extraction which were demonstrated in this work. Date palm leaves wax was tested as structuring agent for sunflower oil along with other commercial natural waxes. Date palm wax based oleogel exhibited low critical gelling concentrations compared to other waxes. Chemical composition and crystal morphology for the waxes and their gels were further explored to gain better understanding of their gelling behaviour. Date palm wax exhibited good gelling ability and high thermal stability compared to other commercial waxes. The rheological profile for date palm wax based oleogel was comparable with other natural waxes making it a promising structuring agent in food industry. The scale up of scCO2 extraction was studied at semi-pilot scale and resulted in comparable yields, chemical composition and melting profile of wax to the lab scale. Attempts to further reduce the complexity of the wax by fractional extraction, yielding three different wax fractions with varying in texture, composition and physical properties. Economic aspects of the extraction process were explored to further assess the viability of the process. Cost of Manufacture of date palm wax was initially €14.01 kg−1 wax, which could be further reduced to €8.80 kg-1 wax by biomass pelletising. If the extracted biomass was utilised to generate electricity the costs are further reduced to 3.88 kg−1 wax.

The present study investigates, for the first time, the production of granular activated carbon (GAC) from date palm pits, a waste material. Reported data indicates.that the t. yearly production of dates in the Kingdom of Saudi Arabia (KSA) is more than 800 ktonnes of which a significant portion is de-stoned prior to sale. Hence the use of date palm pits for the production of GAC would confer two benefits, Le., reduction in waste disposal costs and concerns and production of a very useful material from this waste, Le., GAC, which at the present is imported in the KSA for several industrial applications.

Considering these facts, date palm pits from a local source were used for the production of GAC. Several GAC production variables were investigated in detail, to study their effect on the BET specific surface area (SSA_BET), porosity, and the pore size distribution of the produced material. Variables studied included sample predrying, time of carbonization, time of activation, strength of the activating agent (i.e., phosphoric acid), acid impregnation ratio, pH, and temperature. Nitrogen adsorption isotherm data was used for the determination of respective SSA_BET, and porosity values.

The optimum conditions that produced the best activated carbon were, H₃P0₄ concentration equal to 70%, acid to pits ratio of 1.6:1, and carbonization temperature of 500°C. Additionally, a maximum yield of 24% was noted for the best GAC sample which showed the following characteristics 590 kg m^-3 bulk density, 0.5% ash content, 1100 mg g^-1 iodine number, and 1319 m² g^-1 SSA_BET. Furthermore, this GAC sample showed substantial capability to adsorb phenol and 2-Methylphenol (o-cresol) from the aqueous phase. The respective adsorption data fitted well to the Freundlich adsorption isotherm. Several continuous column studies (using operational variables including flowrate, initial pollutant concentration, pH, temperature and dissolved oxygen) were also conducted to find the suitability of the produced optimum GAC sample for the removal of phenol and 2-Methylphenol from the aqueous phase. For example, the adsorption of both phenol and 2-Methylphenol was influenced both by the flowrate and the initial pollutant concentration. Also, the breakthrough time decreased when the flowrate and the initial concentration values were increased, probably due to insufficient pollutant residence time. The respective optimum activated carbon was also successfully used for the reduction of total organic carbon from an industrial wastewater sample.

Furthermore, to minimize waste disposal cost and concerns related to the exhausted GAC, an attempt was also made to regenerate the used GAC sample from the present work using chemical and electrochemical desorption methodologies. The electrochemical desorption method, which so far has been scantly investigated in the literature, was noted to successfully regenerate the used GAC sample, using a current density value of 50 rnA cm^-2. Factorial experimental design and optimization of parameters for the production of GAC from date pits, using Response Surface Methodology (RSM), was also completed. The respective results were acid to pits ratio of 1.5:1, carbonization temperature of430°C, and H₃P0₄ concentration of 55%.

In summary, a high efficiency GAC sample was successfully produced from an otherwise waste material i.e., the palm date pits. The produced GAC was also noted to be very efficient for the removal of organic pollutants from the aqueous phase. It is suggested that the use of activated carbon produced from date pits would be economical, since date pits are a waste product and available in large quantity in the Kingdom of Saudi Arabia, and phosphoric acid is manufactured from local resources in the Kingdom.

This research examines the variables affecting the production of date palm, the fruit quality of common varieties of dates, and the income of date palm farmers in Sebha, Libya. It provides new insights into factors that affect the technical efficiency of date palm production, and the physical and chemical characterises of dates. The research shows the pros and cons of different types of irrigation systems and outlines important policy implications for irrigation in Libya.

Självframställning handlar om att konstruera identitet i text. Författaren använder olika strategier för att minnas och att konstruera sig själv och sitt själv i en berättande text. I den här uppsatsen har jag analyserat hur den politiska identiteten skapas i socialdemokratiska memoarer. Undersökningen har visat att berättelserna hålls samman av ett antal karakteristiska teman och berättarstrukturella mönster. För det första kan sägas att självframställningarna förefaller vara en förlängning av politikerrollen. Ett tydligt exempel på detta är hur barndomen betraktas med politikerblicken. Det skrivande jaget har inte i första hand ambitionen att gestalta ett skrivet jag, utan använder istället barndomens autentiska livsmaterial som en fond eller kuliss för att skapa en politisk identitet och referera till en stor berättelse om socialdemokratin. Självframställningarna innehåller ofta ett avgörande krismoment – epifani eller omvändelse – då politikeridentiteten tar form. Samtidigt som varje krismoment är unikt, och definierar den enskilda politikeridentiteten, refererar det till en stor berättelse om socialdemokratin. Själva förekomsten av ett sådant här moment pekar också mot att politikeridentiteten är ett färdigt själv, som i grunden behåller sin form under den politiska gärningen. Två återkommande teman i självframställningarna är pragmatismen och plikten. Ofta skildras installationen, företrädesvis i riskdagen eller regeringen, på ett dramatiskt och högtidligt sätt, vilket anknyter till plikttemat. Ett annat utmärkande drag är att politikeridentiteten definieras genom förebilder i det egna partiet. Kritik mot partikamrater är sällsynt. Man är socialdemokrat först och främst, kritik mot det egna partiet innebär också kritik mot sig själv. De socialdemokratiska memoarerna kännetecknas också av en autentisk berättarstruktur. Olika typer av dokument, fotografier och faksimiler används för att underbygga och stödja självframställningen, vilket möjligen kan kopplas samman med att memoarförfattandet är en förlängning av politikerrollen. Uppbrottet skildras inte sällan i form av en slags epilog. Förutom en dramatisk beskrivning av själva uppbrottet innehåller epilogen reflektioner som går både bakåt och framåt i tiden, och som refererar till en stor socialdemokratisk berättelse. Ibland förekommer också en metanivå då författaren betraktar sina egna memoarer. Epilogens funktion är att skapa högtidlighet kring den egna gärningen, och eventuellt även den egna självframställningen, och att referera till en stor berättelse om socialdemokratin. Det är svårt att argumentera för att ovan nämnda mönster och teman enbart skulle förekomma i socialdemokratiska memoarer. Även om undersökningen inte kunnat visa på att det här materialet utgör en egen genre har det varit intressant att betrakta hur politiken och författarens politiska roll genomsyrar självframställningarna.

Magister Scientiae (Medical Bioscience) - MSc(MBS)
There is increasing concern worldwide by researchers with regards to the assessing of safety and therapeutic consumption of the plants used in traditional medicine. Date palm pollen (DPP) and flax seed have been used traditionally to improve fertility in Libya. DPP extracts have shown several reproductive beneficial effects. In vivo, studies have revealed the ability of DPP to increase sperm concentrations, ameliorate the testicular toxicity induced by cadmium and lead, raise testosterone, as well as LH and FSH hormone levels. Flax seed phytochemical analysis showed lots of valuable components such as lignans and α linolenic acid to which were attributed its positive health effects like antitumor, antioxidant and protective effects against coronary heart diseases. Moreover, flax lignans have both estrogenic and antiestrogenic potential. This study was aimed at testing the effects of Libyan DPP and flax seed on the Sertoli (TM4) cell line and human breast adenocarcinoma (MCF - 7) cell line. Different concentrations (0.01, 0.1, 1, 10, 100 and 1000 μg/ml) of ethanolic extracts of DPP and flax seed, respectively, were used to assess the morphology of TM4 and MCF - 7 cells after 24 and 72 hours exposure. Mitochondrial dehydrogenase activity as a marker of cell viability was measured by MTT assay after 24 and 72 hours exposure. Apoptotic effects were assessed by flow cytometeric APO percentage assay. TM4 cell production of Inhibin - B hormone and GGT enzyme activity under the effects of DPP or flax seed was determined by use of ELISA kits. Transepithelial electrical resistance (TEER) assay were used to detect the effect of DPP or flax seed on TM4 cell monolayer integrity. Finally the plants potential phytoestrogenic activity was determined by use of E - SCREEN assay in MCF – 7 breast cancer cells. Higher concentrations of DPP significantly increased the activity of mitochondrial dehydrogenase enzyme of TM4 cells after 24 hours associated with increasing cell number as detected in a microphotograph. Flax seed concentrations less than 100 μg/ml reduced TM4 cell viability but there were no morphological changes visible after 24 hours. MCF - 7 cells viability was reduced after 24 and 72 hours treatment with DPP and flax seed. DPP concentrations beyond 1 μg/ml significantly raised the TEER of TM4 monolayer over 72 hours while flax seed treatments caused a significant increase only after 72 hours of exposure. TM4 cells GGT activity increased significantly after exposure to higher concentrations of DPP and all flax seed concentrations. Significant stimulatory effects of all the concentrations of DPP or flax seed on TM4 inhibin - B hormone productions have been detected. Apoptotic studies showed no significant changes. E - SCREEN assay resulted in significant reduction in MCF - 7 proliferation rate under the effect of low concentrations of DPP or flax seed. Higher concentrations of the plant extracts, however, stated to increase MCF – 7 cell proliferation, this exerts weak estrogenic activities. In conclusion, the main finding of this study is that DPP and flax seed showed stimulatory effects on TM4 cells proliferation. The resistivity of TM4 cells monolayer which reflect the integrity of blood – testis barrier (BTB) was also significantly increased as well as inhibin - B production and GGT enzyme activity. In addition DPP and flax seed respectively showed inhibitory effects on MCF - 7 cells viability. This study indicated that DPP or flax seed may enhance spermatogenesis through their stimulatory action on Sertoli cells. Moreover, both plants could reduce breast cancer cells viability. However, further investigations are required to elucidate the exact mechanisms behind these obtained findings.

Date Palm (Phoenix dactylifera L. Family: Arecaceae; sub-family: Poaceae) is thought to be the oldest fruit tree grown in the Sultanate of Oman and is a major crop in terms of the number of trees and their distribution. Dates are widely considered to be a strategic source of food security as well as an important cash crop, and have always been looked upon as a key source of stability for oasis agro-ecosystems. Several insect and mite pests and plant pathogens attack Date Palm trees. The Dubas bug, Ommatissus lybicus DeBergevin (Homoptera: Tropiduchidae), has been considered the key pest of Date Palm plantations in Oman for 40 years due to the total area infested, the severity of infestations and the scale of the crop losses. Current control programmes for Dubas bug are reliant on chemical pesticides, applied by air and from the ground over an area ranging from 12,000-20,000 ha annually. These pesticides are currently the only feasible control measure against this pest, although research is underway on bio-control technologies. The cropping environment resulting from traditional Date Palm cultivation - high planting density, high temperature and humidity, topography of the plantations, intercropping and variability in cultivars and plant height - has an influence on pest and disease incidence and also affects the control options available. The present research attempts to determine the effects of technical, environmental and biological factors on the control of Dubas Bug in order to develop a more integrated control strategy. Data have emerged from this study on: 1) optimal spray droplet spectrum and application rates for improved coverage and placement of spray deposits, including under leaf deposition; 2) information on how Dubas bug daily movement can influence control efficacy; 3) on the selective use of insecticides against Dubas bug at economic threshold levels as a supplement to other IPM methods, including cultural practices such as thinning to maintain optimal distances between trees, irrigation management, the removal of old leaves including pruning cuts and surrounding tissues that may support and harbour Dubas bug.

The main objectives of the work described in this thesis were to determine the technical feasibility of utilising date palm leaves as a potential source of roughage, and to study the effects of providing brackish water as a source of drinking water for dairy cows. Additionally, to investigate the effect of feeding a high concentrate diet on the performance of Friesian cows. Four experiments were performed during the course of three years (November 1988 - June 1991). Three experiments were carried out in Kuwait and one in the North of Scotland. Experiment 1 was designed to compare the effects of feeding locally produced date palm leaves (DPL) with imported barley straw (S) as roughages to milking cows given a high concentrate diet. Fifty-six cows were used from the fifth week of lactation for 12 weeks. Experiment 2 studied the performance of thirty eight non-lactating pregnant cows for about 15 weeks, with the same objective as experiment 1. Each of these experiments included a small trial for more detailed studies. In experiment 3 eight milking cows in the sixth week of lactation were studied for over six months to compare the effects of drinking brackish water (BW) with fresh water (FW) on the performance of the cows fed on a high concentrate diet in addition to DPL and freshly cut alfalfa. Experiment 4 was conducted in the North of Scotland to investigate the effects of feeding a high concentrate diet, similar to that of Kuwait, on the productivity and the ruminal fermentation of high yielding cows. The general conclusions drawn from these four experiments are: 1. Despite the low qulaity of DPL, it might be a suitable alternative to straw as a source of roughage for dairy cows in Kuwait. 2. Brackish water is a palatable and harmless source of drinking water, and its mineral content may be beneficial in contributing to the dairy cows dietary requirements. 3. Feeding a high level of concentrate in diets based on grass silage increases milk yield and favours body gain at the expense of milk fat content. 4. There is a need for better utilization and processing of local agricultural by-products in Kuwait for the feeding of ruminants. 5. Further research is required to investigate the performance of dairy cows under different environments, especially hot-arid conditions.

Le palmier dattier (Phoenix dactylifera L.) a une grande importance écologique et socio-économique dans les zones arides et semi-arides du globe. Cette espèce présente une grande diversité (plus de 2.000 variétés identifiées) qui est menacée par la production à grande échelle de variétés élites. Il est nécessaire de développer des techniques permettant de conserver cette diversité et de gérer la production des variétés élites multipliées in vitro. La cryoconservation (azote liquide, -196°C) est la seule technique disponible à l’heure actuelle permettant la conservation à long terme, à coûts réduits et en sécurité de cette diversité. Dans ce travail, nous avons comparé l’efficacité de deux techniques de cryoconservation, la vitrification en goutte (DV) et la D cryo-plate (DP), pour la cryoconservation de masses proembryogènes (PEM) de deux variétés de palmier dattier, Sokary et Sultany. Avec la DV, la survie des PEM cryoconservées est nulle sans prétraitement au saccharose (3 jours avec 0,5M) et sans traitement avec la solution de vitrification PVS2. Après 15 à 120 min de traitement avec PVS2, la survie est comprise entre 90,9-98,6% et 85,6-88,0%, respectivement pour Sokary et Sultany. Avec un prétraitement au saccharose, 21,1% des PEM de la variété Sokary survivent à la cryoconservation sans traitement avec PVS2. Avec la DP, un effet positif du prétraitement au saccharose est observé sur la survie des PEM cryoconservés. Pour Sokary, la survie la plus importante (de 92,0 à 95,8%) après congélation est obtenue pour des durées de dessiccation comprises entre 60 et 120 min. La survie après cryoconservation est comprise entre 67,0 et 74,6% après des durées de 90 à 120 min de dessiccation pour Sultany. Avec les deux techniques expérimentées, l'intensité de croissance des PEM cryoconservées est supérieure chez Sokary par rapport à Sultany. L’étude histologique réalisée montre qu’en l’absence de prétraitement, c'est le traitement de loading qui induit la plasmolyse des cellules la plus importante, d'environ 26, 40 et 50%, respectivement pour les cellules méristématiques, les cellules embryogènes de la population I (PopI) et de la population II (PopII) par rapport à leur état initial. Le prétraitement au saccharose induit une plasmolyse d'environ 50% uniquement chez les cellules de PopII. Le traitement de loading et de vitrification n'entraîne pas de plasmolyse supplémentaire. Aucune plasmolyse n'est observée chez les cellules méristématiques et les cellules de PopI. En revanche, les mesures de la surface de l'ensemble des cellules montrent chez les cellules méristématiques une diminution significative de surface après le prétraitement au saccharose, mais aucune différence significative après le traitement de loading et de vitrification. Chez les cellules embryogènes de PopI, une diminution supplémentaire de la surface est observée après le traitement de vitrification. L’étude de la circularité des noyaux montre une déformation permanente des noyaux des cellules non prétraitées des trois types cellulaires, alors que seuls les noyaux des cellules de PopII présentent cet aspect chez les PEM prétraitées. Enfin, l'étude du degré de méthylation des PEM par immunolocalisation conclut à l'absence de différences significatives entre les PEM témoins non traitées et les autres conditions expérimentales. Cependant, les tissus différenciés présentent un pourcentage de noyaux méthylés plus important par rapport aux cellules embryogènes et aucun marquage n'est noté chez les cellules méristématiques. Nos résultats ont permis de préciser l’effet de la cryoconservation sur l’intégrité structurale et la physiologie des PEM de palmier dattier. Ils contribuent également à la sauvegarde de la biodiversité du palmier dattier
The date palm (Phoenix dactylifera. L) has a great ecological and socioeconomic importance in arid and semi-arid areas of the globe. This species displays a great diversity, with over 2,000 identified varieties, which is threatened by the large scale production of elite varieties. It is necessary to develop techniques allowing to conserve this biodiversity and to manage the production of in vitro propagated elite varieties. Cryopreservation (liquid nitrogen [LN], -196°C) is currently the only technique available ensuring the safe and cost-effective long-term conservation of this diversity. In this work, we compared the efficiency of two cryopreservation techniques, droplet-vitrification (DV) and D cryo-plate (DP), for the cryopreservation of proembryonic masses (PEMs) of two varieties of date palm, Sokary and Sultany. With DV, recovery of cryopreserved PEMs was nil without sucrose pretreatment (3 days, 0.5 M) and without treatment with PVS2 vitrification solution. After 15 to 120 min of PVS2 treatment, recovery was between 90.9-98.6% and 85.6-88.0% for Sokary and Sultany, respectively. Sucrose pretreatment led to 21.1% recovery of cryopreserved PEMs of variety Sokary without PVS2 treatment. Regrowth intensity of PEMs cryopreserved was generally lower in the Sultany variety compared to the Sokary variety. With DP, a positive effect of sucrose pretreatment on recovery of cryopreserved PEMs was observed. For Sokary, the highest recovery of PEMs (92.0 to 95.8%) after LN exposure was achieved for desiccation periods between 60 and 120 min. Recovery of cryopreserved PEMs of variety Sultany was between 67.0 and 74.6% after desiccation periods between 90-120 min. With DP, the regrowth intensity of cryopreserved PEMs was higher for variety Sokary compared to Sultany. The histological study performed showed that in absence of pretreatment, it was the loading treatment which induced the highest cell plasmolysis, with values of 26, 40 and 50% for meristematic, embryogenic PopI and PopII cells, respectively, compared to their initial state. Sucrose pretreatment induced a 50% plasmolysis only in PopII cells. The loading and vitrification treatments did not cause any additional plasmolysis. No plasmolysis was observed in meristematic or PopI cells. By contrast, the measurement of the surface of all cells revealed a significant decrease in the surface of meristematic cells after pretreatment, but no significant difference after the loading or vitrification treatments. In embryogenic PopI cells, an additional decrease in the cell surface was observed after the PVS2 treatment. The study of nuclei circularity showed a permanent deformation of nuclei of non-pretreated cells of the three cell types. In pretreated PEMs, only the nuclei of PopII cells displayed deformation. Finally, the study of the methylation degree in PEMs by immunolocalization revealed the absence of significant differences between the untreated controls and other experimental conditions. However, the differentiated tissues exhibited a higher percentage of methylated nuclei compared to embryogenic cells, while no stained nuclei were observed in meristematic cells. Our results allowed clarifying the effect of cryopreservation on the structural integrity and on the physiology of date palm PEMs. They also contribute to safeguarding of date palm biodiversity

Uppsatsens syfte är att närmare undersöka några av narratologins termer. Den litteraturteoretiska inriktningen narratologi beskrivs övergripande, några av dess termer beskrivs mer ingående samt att användningen av dem prövas rent praktiskt i en novellanalys. Novellananlysen sker i ett storyavsnitt och ett diskursavsnittt.

För novellananlysen används en novell av Anna-Karin Palm som heter "Öppna ögon". I storyavsnittet undersöks hur begreppen karaktär och händelse beskrivs teoretiskt och hur de kan användas. I avsnittet om diskurs undersöks termerna kronologi, berättare och fokalisation.

Les objectifs de ce travail visent à appréhender l'histoire évolutive et biogéographique du palmier dattier (Phoenix dactylifera L.), espèce d'une importance capitale pour les populations humaines des régions chaudes et arides d'Afrique du Nord et du Moyen-Orient, au moyen d'analyses génétiques et morphométriques. En effet, les origines de la domestication du dattier demeurent peu connues malgré les données archéologiques qui semblent attester de sa culture à partir de la fin du 4ème millénaire avant notre ère. L'analyse phylogénétique du genre Phoenix réalisée à partir de séquences chloroplastiques a permis d'identifier les parents proches du dattier. Des populations de dattiers sauvages sont reconnues pour la première fois grâce à des analyses de diversité et de structuration génétiques. De manière congruente, l'analyse morphométrique de contours de la graines s'appuyant sur la méthode des transformées elliptiques de Fourier met en évidence une nette différenciation entre les individus sauvages et cultivés. La caractérisation des changements de traits morphologiques de la graine liés à la domestication est exploitée pour définir le statut sauvage ou domestiqué de matériel mis au jour dans différents sites archéologiques du Pakistan et d'Egypte. En outre, l'étude génétique de dattiers d'origine diverses semble démontrer qu'au moins deux évènements de domestication ont eu lieu : l'un en Afrique et l'autre au Moyen-Orient. Finalement, les études génétiques et morphométriques, menées séparément ou conjointement selon le type et l'ancienneté du matériel analysé, permettent pour la première fois de discuter des origines, de l'histoire biogéographique et de la dynamique de l'agrobiodiversité du palmier dattier, dans le temps et dans l'espace
The objectives of this work are to understand the evolutionary history and biogeography of the date palm (Phoenix dactylifera L.), a species of importance to human populations in hot, arid regions of North Africa and the Middle East using genetic and morphometric analyzes. Indeed, the origins of the domestication of the date palm remain poorly understood despite the archaeological data that seem to attest its culture from the late 4th millennium BCE.Phylogenetic analysis of the genus Phoenix made ​​from chloroplast sequences identified close relatives of the date palm. Populations of wild date palms are recognized for the first time through analyses of genetic diversity and structure. Congruently, morphometric analysis of the seed outline based on the method of elliptic Fourier transform highlights a clear differentiation between wild and cultivated individuals. Characterization of changes in seed morphological traits related to domestication is used to define the status of wild or domesticated material excavated from various archaeological sites in Pakistan and Egypt. In addition, the date palm genetic study of various origins seems to indicate that at least two domestication events took place: one in Africa and one in the Middle East. Finally, genetic and morphometric studies, conducted separately or together depending on the type and age of the material analyzed, allow for the first time to discuss the origins, history and biogeographic dynamics of date palm agrobiodiversity, in time and space

Le Sahel est une zone aride aujourd’hui menacée par les changements climatiques qui entrainent une grande vulnérabilité sociale et environnementale. L’agriculture des pays sahéliens doit faire face à cette évolution pour assurer la sécurité alimentaire de leurs populations croissantes. L’utilisation d’espèces végétales de grande plasticité phénologique comme le palmier dattier (Phoenix dactylifera L.,), fait partie des réponses face à des conditions pédoclimatiques difficiles auxquelles peu de plantes sont adaptées. L’objectif de cette thèse est d’améliorer nos connaissances sur les pratiques culturales, les savoirs locaux autour du palmier dattier et la diversité génétique et morphologique de cette espèce afin de promouvoir le développement durable de l’agriculture oasienne au Sahel. Ainsi, nous avons conduit une enquête socio-économique auprès de 30 producteurs de palmier dattier dans 14 villages du Sud-Est du Niger. Parallèlement à cette enquête nous avons collecté 113 échantillons de jeunes folioles, prélevées sur 31 mâles et 82 femelles de palmier dattier dans 19 cuvettes oasiennes. Notre étude a permis d’identifier 19 variétés-populations de palmier dattier distinguées sur la base de la couleur du fruit. Le palmier dattier présente une particularité de double floraison associée à deux saisons de productions de dattes dans le Sahel. La période février-juillet est la plus productive mais l’arrivée précoce des pluies limite la qualité des fruits. L’évaluation des connaissances locales associées à la phœniciculture a permis d’établir que même si les pratiques culturales sont moins développées que dans le Nord du pays ou dans le Maghreb, les profits dégagés par la culture des dattes contribuent considérablement à la survie des ménages. Par ailleurs, l’analyse génétique des palmiers dattiers du Sud-est du Niger a montré qu’ils constituent un groupe original avec une grande diversité génétique. De plus, cette ressource appartient au pool génétique occidental et est l’une des moins introgressée par des contributions génétiques orientales. L'analyse génétique globale révèle un nouveau groupe au Sud-est Niger différent de celui d'Afrique du Nord et soulève la question de son origine. Enfin, nous avons mis en évidence l’existence de traits architecturaux discriminant les palmiers dattiers du Sahel. Nous avons ainsi élaboré un modèle architectural permettant le calcul de l’interception lumineuse et des espacements nécessaires pour une bonne cohabitation des palmiers et des cultures sous-jacentes afin d’optimiser la production agricole. Notre étude a montré que la culture du palmier dattier constitue un élément clé pour l’amélioration des conditions de vie des populations, la lutte contre la malnutrition et l’équilibre agro-écologique dans le Sahel. Elle constitue un préalable indispensable à la conservation, la valorisation et l’amélioration du patrimoine phoenicicole. Enfin, le modèle architectural fonctionnel permettra de mettre à disposition un outil opérationnel pour la gestion durable des cultures du palmier dattier au Sahel
The Sahel is an arid area threatened by climate change that causes great social and environmental vulnerability. Agriculture in Sahel is facing this change to ensure food security for growing populations. The use of plant species with phenological plasticity such as the date palm (Phoenix dactylifera L.), is one of the responses to hard soil and climate conditions to which few plants are adapted. The objective of this thesis is to improve our knowledge on cultural practices, local knowledge around the date palm and genetic and morphological diversity of this species in order to promote sustainable development of oasis agriculture in the Sahel. Thus, we conducted a socioeconomic survey of 30 date palm farmers in 14 villages in Southeastern Niger. Alongside this survey, we collected 113 samples of young leaflets taken from 31 males and 82 females in 19 date palm oasis basins. Our study identified 19 date palm population varieties distinguished on the basis of the fruit color. Date palm has a special double flowering associated with two fruit production seasons in the Sahel. The February-July period is the most productive but early rains limit fruit quality. The evaluation of local knowledge associated with date palm has shown that even if cultural practices are less developed than in the North of the country or in the Maghreb, the profits from the date cultivation significantly contribute to household survival. Furthermore, genetic analysis of date palms in Southeast of Niger has shown that they are a unique group with high genetic diversity. In addition, this germplasm belongs to the Western gene pool and is one of the least introgressed by oriental genetic contributions. The overall genetic analysis revealed a new group in Southern Niger different from that of North Africa and raises the question of its origin. Finally, we have demonstrated the existence of discriminating architectural features in Sahelian date palms. We have developed an architectural model for the calculation of the light interception and spaces necessary for good cohabitation between date palms and crops to optimize agricultural production. Our study showed that the date palm cultivation plays a key role in improving living conditions of the population, fight against hunger and agro-ecological balance in the Sahel. It is a prerequisite to the preservation, valorization and improvement of date palm genetic resources. Finally, the functional architectural model will enable to provide an operational tool for the sustainable management of date palm cultivation in the Sahel

L'acido polilattico (PLA) è un polimero biodegradabile termoplastico derivato da risorse rinnovabili. È uno dei polimeri biodegradabili più utilizzati al mondo grazie a una vasta gamma di applicazioni di materie prime. Il PLA presenta alcuni punti deboli come bassa stabilità termica, resistenza all'impatto e duttilità; pertanto molti studi di ricerca si concentrano sulla modifica del PLA per estendere la sua gamma di applicazioni. Un approccio consiste nell'aggiungere additivi per migliorarne le proprietà. Il frutto della palma da dattero (DPF) è una ricca fonte di polifenoli, considerati efficaci antiossidanti grazie alla loro elevata capacità di interagire con i radicali liberi, con effetti benefici sulla salute e nella prevenzione delle malattie degenerative. I polifenoli fungono anche da plastificanti e possibili stabilizzanti termici nei polimeri. In questa ricerca, è stata preparata e analizzata una serie di polifenoli estratti da PLA / DPF per applicazioni mediche, nonché per il miglioramento della stabilità termica. Le prime miscele sono state preparate mediante elettrofilatura per essere utilizzate come scaffold di colture cellulari per applicazioni di ingegneria tissutale. I risultati hanno rivelato che gli scaffold sono diventati più idrofili dopo l'aggiunta di polifenoli. È stato anche scoperto che sia la proliferazione cellulare che la vitalità cellulare sono state migliorate con una maggiore concentrazione di polifenoli negli scaffold. Una seconda serie di campioni di PLA contenenti diverse concentrazioni dell'estratto di polifenoli sono state preparate per estrusione. Sono stati determinati la morfologia, le proprietà meccaniche e termiche e si è scoperto che la presenza di polifenoli nel PLA (i) ha migliorato la sua stabilità termica, (ii) ha diminuito il modulo di Young e la resistenza alla trazione e (iii) ha aumentato l'allungamento alla rottura dei campioni di miscela. La temperatura di transizione vetrosa è stata determinata mediante analisi meccanica dinamica (DMA). I risultati hanno mostrato un allargamento del picco di tandelta e una graduale diminuzione della temperatura di picco con aumento del contenuto di polifenoli nel PLA, il che ha confermato che il polifenolo ha aumentato il volume libero nel PLA e ha quindi agito da plastificante.
Polylactic acid (PLA) is a thermoplastic biodegradable polymer derived from renewable resources. It is one of the most consumed biodegradable polymers in the world due to a wide range of commodity applications. PLA has some weaknesses such as low thermal stability, impact strength and ductility; therefore many research studies are focused on PLA modification to extend its range of applications. One approach is to add modifiers in order to enhance its properties. Date palm fruit (DPF) is a rich source of polyphenols, that are considered as effective antioxidants because of their high capacity in scavenging free radicals, that have health promoting effects in the prevention of degenerative diseases. Polyphenols also act as plasticizers and possible thermal stabilizers in polymers. In this research, a set of PLA/DPF extracted polyphenols were prepared and analyzed for medical applications, as well as for thermal stability improvement. The first blends were prepared by electrospinning to be used as cell culture scaffolds for tissue engineering applications. The results revealed that the scaffolds became more hydrophilic after the addition of polyphenols. It was also found that both cell proliferation and cell viability were enhanced with increased polyphenol concentration in the scaffolds. A second set of PLA samples containing different concentrations of the polyphenol extract were prepared by extrusion. The morphology, mechanical and thermal properties were determined, and it was found that the presence of polyphenol in PLA (i) improved its thermal stability, (ii) decreased Young’s modulus and tensile strength, and (iii) increased the elongation at break of the blend samples. The glass transition temperature were determined through dynamic mechanical analysis (DMA). The results showed a broadening in the tan  peak, and a gradual decrease in the peak temperature with increasing polyphenol content in PLA, which confirmed that the polyphenol increased the free volume in PLA and thus acted as a plasticizer.

Philosophiae Doctor - PhD
In different parts of the world, medicinal plants have demonstrated a lot of health benefits to mankind and remains an important source for the discovery of new bio-active compounds. Libya is a typical example of a country where medicinal plants are widely used. Plant extracts of five Libyan medicinal plants were used in this study to investigate their in vivo effects on spermatogenesis and steroidogenesis in male rats and on ovulation and fertility in female rats. The In vitro effects of these plant extracts were also investigated on TM3 Leydig cells and MCF 7 breast cancer cells. A phyto-chemical analysis of the five Libyan medicinal plants (flaxseed, black seeds, radish seed, date palm pollen and nutmeg) was done. The results showed that date palm pollen had a higher antioxidant activity than all of the above mentioned plants. In addition to this, Nigella sativa was observed to possess high flavonol content as well as high antioxidant activity. Male rats exposed to flaxseed, radish seeds and date palm pollen showed no significant alterations in body weight gain, whereas date palm pollen (240 mg/kg, p < 0.05) promoted an increase in body gain. This study also revealed a significant increase in the relative testicular weight of animals exposed to either flaxseed (300mg/kg) or date palm pollen (120mg/kg). In addition, the relative weights of the seminal vesicles of all treated groups showed significant increased values. The level of serum testosterone showed a significant increase after exposure to radish seed (80mg/kg) and a significant dose- dependent increase for date palm pollen when compared to control (P< 0.05). In contrast, flaxseed caused a dose-dependent significant (p <0.01) decrease in testosterone level at radish seed (300mg/Kg). All plant extracts caused a significant increase in sperm concentration. Sperm vitality significantly (p < 0.05) increased by radish seed (80mg/kg), flaxseed (300mg/kg) and date palm pollen (120, 240mg/kg) respectively. Total progressive motility improved significantly at flaxseed (300 mg/kg) (p < 0.001) as well as date palm pollen (p < 0.01). Histological examination of the cross sections of the testis showed clear presence of all stages of spermatogenesis in all the treated groups. Rat epididymides showed normal morphological appearance and their lumen were filled with spermatozoa. The diameter of seminiferous tubules in male rats exposed to date palm pollen (120 and 240 mg/kg) was significantly higher (p < 0.001). The heights of the germ cell epithelia within the eminiferous tubules were also significantly increased in all treated groups. Liver and renal functions tests showed a significant decrease in Alanine transaminase (ALT) and creatinine in all treated groups (p < 0.05), and this demonstrates the lack of cytotoxic effects of date palm pollen, radish seed and flaxseed on the rats. However, these plant extracts produced a non-significant (p > 0.05) increase in Aspartate transaminase (AST) levels. Besides this, superoxide dismutase activity (SOD) in testis was increased significantly by radish seed (160 mg/kg), flaxseed (200 mg/kg) and date palm pollen (120 mg/kg). There was also improved catalase activity in testis of male rats exposed to radish seed and date palm pollen. Regarding male sexual behavior, the time to reach the female and the mount frequency decreased significantly in male rats exposed to flaxseed (300 mg/kg) and date palm pollen (120 and 240 mg/kg; p > 0.05) thus, these plant extracts exhibit aphrodisiac properties. In addition, exposure of male rats to date palm pollen (120 mg/kg) produced a significant (p < 0.01) increase in the number of embryos in untreated female rats. In the female rats, the body weight gain was not affected (p > 0.05). However, the relative uterus weights exposed to nutmeg (200 mg/kg) and date palm pollen (120 and 240 mg/kg) were significantly decreased (p < 0.05). In addition, the relative weights of ovaries after treatment with nutmeg (400 mg/kg) and black seed (400 mg/kg) showed significantly increased values (p < 0.01). Serum FSH was significantly increased (p > 0.05 or 0.01) when the female rats have been exposed to black seed (200 mg/kg), nutmeg (200 mg/kg) or date palm pollen (120 mg/kg). The LH level significantly (p < 0.01) decreased following exposure to black seed (200 mg/kg), date palm pollen (120 mg/kg). On the other hand, serum LH concentration was significantly increased in female rats exposed nutmeg (400 mg/kg; p > 0.05). The creatinine activity in female rat serum in all treated groups was significantly decreased (p < 0.05). Whereas the higher dose of date palm pollen (240 mg/kg) caused only a non-significant decrease. ALT activity in serum of female rat exposed to either black seed (400 mg/kg) or date palm pollen (120 and 240 mg/kg) was shown to decrease significantly (p < 0.05). Histology of the reproductive organs, kidney and liver in the female rats showed no obvious alterations in any of the treated groups. In addition, the number of embryos in female rats significantly increased (p < 0.01; p < 0.001) following exposure of female rats to black seeds 400 and date palm pollen 240 mg/kg, respectively. Incubation of TM3 Leydig cells with radish seeds for 24, 48 or 72 hours caused a significant (p < 0.01) decrease in mitochondrial dehydrogenase activity. Besides that, date palm pollen and flaxseed increased the mitochondrial dehydrogenases activity of TM3 Leydig cells. In addition, higher concentration of date palm pollen, nutmeg and black seed were cytotoxic to MCF7 breast cells. In testis slices testosterone secretion in vitro was significantly increased by flaxseed (500 μg/ml; p > 0·05) and date palm pollen (500 μg/ml; p > 0·01). MCf-7 cells treated with BS 10-50 μg/ml black seed and nutmeg 10-50μg/ml significantly increased cell proliferation. However, the treatment with date palm pollen produced only a weak estrogenic effect, which resulted in a concentration dependent significant increase as observed between 50-1000 μg/ml date palm pollen. In conclusion, in this study, we observed that date palm pollen, radish seed and flaxseed increased libido as well as steroidogenesis and spermatogenesis, improved hepato and nephron-protective effects. In female rats, the plant extracts NM, BS and date palm pollen potentiated the production of gonadotropic hormones. In addition to this, at lower concentrations these medicinal plants promoted cell growth, whereas at higher concentrations they inhibited cell proliferation of MCF- 7 breast cancer cells. The anti-oxidant effects of these plant extracts have been implicated for the above mention effects.

Issues of sexual assault have become pervasive across all social strata in American society. Citizens need to start having conversations regarding these issues. To combat the issue of sexual assault, children need to be educated regarding the multifaceted aspects of sex through sex education in order to understand consent and resources they have available to them. Utilizing grounded theory methodology, this thesis analyzes sex education literature provided to Palm Beach County Middle School students. Using Burke’s theory of terministic screens and Foucauldian theories of power and control; an understanding of the ideological underpinnings of this literature and discourse were acquired. After analysis, suggestions for disclosure and sex education programs are provided.

Children living in risk environments can experience traumatic events that could affect their future life. Providing these children with the necessary strategies to cope with adversity and to develop in an optimal way is needed in order to avoid trauma or being damaged for the rest of their lives. Because of this reason, a systematic literature review was performed with the aim to examine how resilience is defined and implemented in studies focusing on young children at risk. The search was done through five electronic databases and conducted during the spring semester of 2016. During the research process, inclusion and exclusion criteria were taken into account and different search words were used for each database. According to the inclusion/exclusion criteria a title/abstract screening was performed. Thereafter, for the articles which were not excluded a full text review screening was conducted, which led to the inclusion of 14 articles in total. Articles were analysed using a data extraction tool (protocol). All the articles were about resilience, aimed at children between 0 and 12 years old. Eight out of the fourteen were studies that evaluated the resilience degree in young children, while seven were aimed at developing resilience with specially designed intervention programmes. A range of definitions of the term resilience were found, showing that resilience can be understood as a process or as ability. On this basis, studies focused on resilience were found to be mainly of two kinds: related to observation or intervention, using different methodologies and tools to measure or develop resilience in children. The outcomes found were in line with previous research, showing the great importance of supportive relationships, developing within a certain environment and having a positive self-perception as facts that can influence the development of resilience.

Seasonal fluctuations, development and phylogeny of Dubas bug Ommatissus lybicus de Bergevin (Hemiptera: Tropiduchidae) and its native natural enemy Pseudoligosita babylonica Viggiani (Hymenoptera: Trichogrammatidae) were studied on date palm Phoenix dactylifera Linnaeus (Arecales: Arecaceae) in the Sultanate of Oman. P. babylonica emergence and 0. lybicus egg hatching were significantly influenced by temperature whereas relative humidity had no significant effect. P. babylonica developed successfully at temperatures between 22.3°C and 32.4°C with an optimum at 30.0°C whilst no development occurred at temperatures of 17.6,34.4 and 37.2°C. 0. lybicus eggs developed at temperatures between 17.6°C and 32.4°C with an optimum at 27.5°C, whereas no development occurred at 34.4 and 37.2°C. Linear regression estimated the lower thermal threshold (Tzower) and thermal constant (DD) whereas non-linear models (Briere l " and Briere 2nd equations) estimated TZowen upper (Tmax) and optimum thermal threshold (Topt). P. babylonica successfully parasitised 0. lybicus eggs of 1 to 42 days old with embryogenesis of 1.3% to 57.2%. There was a negative response of P. babylonica female density on parasitism %. P. babylonica showed arrhenotokous parthenogenesis where male progeny developed from unfertilised eggs and females from fertilised eggs. Three sex forms were recorded (female, normal kale and deformed male). Deformed males successfully mated with females and this resulted in the production of all three forms. The results of phylogenic analysis on samples of 0. lybicus and P. babylonica collected from four different geographical locations in Oman revealed 98.1-100% nucleotide similarity among 0. lybicus samples with 8 different genotypes of which two were dominant based on sequences of the Cytochrome Oxidase Subunit I (COl) and showed 85% nucleotide similarity with Hemiptera species. P. babylonica samples shared 96.8-100% nucleotide similarity among each other with 10 different genotypes based on sequences of Cytochrome B (CytB) and shared 86% nucleotide similarity with Achrysocharoides sp. Predictive models were developed and tested for P. babylonica emergence and 0. lybicus egg hatching and showed promise for increasing the efficiency of P. babylonica in suppressing 0. lybicus populations and suggested improved timings for the applications of non-persistent insecticides used in an rPM programme. VI.

La Maladie de la Feuille Cassante du Palmier dattier (Phoenix dactylifera L.) constitue un cas d'émergence d'une maladie à fort impact économique causée par un agent étiologique inconnu. Notre stratégie a visé à élaborer une approche sans à priori de l'émergence pouvant être transposée à n'importe quelle situation de ce type. En nous appuyant sur des caractérisations successives des compartiments viraux, bactériens et fongiques de tissus sains et malades, nous avons cherché à mettre en évidence des différences de composition spécifiques et de distribution de ces flores sur 2 campagnes de prélèvements réalisées en 2010 et 2012. Alors que la microscopie électronique à transmission nous a permis de visualiser des structures d'origine virale probable au niveau des chloroplastes du parenchyme chlorophyllien, une étude moléculaire de séquençage de gènes ribosomaux nous a permis de corréler l'apparition de ces structures a de profondes modifications qualitative et quantitative de la microflore endophyte. Ainsi il nous est apparu que la symptomologie de la maladie était corrélée à une modification profonde de la distribution spécifique de la microflore endophyte, visible à la fois au niveau du compartiment fongique et bactérien, suggérant la complète disparition de la pression de sélection exercée par le palmier sain sur sa flore et mise en évidence dans les 2 cas, par un shift d'une répartition de type Poisson vers une répartition normale. Dans le compartiment fongique, une claire déplétion des Pleosporaceae, associées à la plante saine pouvait ainsi être liée à une apparition de nouvelles familles (Trichocomaceae et Mycosphaerellaceae). De même, parmi les bactéries, une disparition des Rhizobium et Ensifer sp associés au compartiment racinaire de la plante saine a ainsi pu être mise en évidence, ces espèces pouvant servir ultérieurement d'indicatrices de bonne santé des palmiers. Dans une deuxième partie de notre travail nous avons cherché à utiliser des éléments de la flore endophyte mais également de substances naturelles dans la lutte biologique contre d'autres pathogènes du palmier. Ainsi, un antagonisme a été mis en évidence entre une souche endophyte d'Arthrobacter agilis et un pathogène majeur, Fusarium oxysporum sp Albedinis
The Brittle Leaf Disease of the Date Palm Tree (Phoenix dactylifera L.) constitutes a case study of an emerging disease of economic impact caused by a yet uncharacterized etiologic agent. Our strategy was to develop an approach that could be indistinctly transposed to any situation of this type. While basing our investigations on the successive characterization of the diversity of viral, bacterial and fungal endophytic compartments of healthy and diseased Palm trees, we aimed at enlightening differences in species composition but also distribution over two sampling campaigns performed in 2010 and 2012. While transmission electronic microscopy allowed us to visualize structures of probable viral origin affecting chloroplasts of the chlorophyllic cell layer, a molecular approach based on ribosomal gene sequencing allowed us to evidence correlations between the occurrence of such structures and deep modifications of the structure of the palm date tree associated endophytic flora suggesting a strong depletion of the ability of the palm to control its associated endophytes. This was evidenced in both fungal and bacterial compartments by a shift from a Poisson like diversity distribution towards a Gaussian distribution in the flora associated to MFC affected palms. In the fungal compartment, Pleosporaceae, that dominated in healthy palms were replaced by an opportunistic flora of Trichocomaceae and Mycosphaerellaceae. Among bacteria, the disappearance of Rhizobium and Ensifer species, typically associated to the root compartment of healthy palms was enlighten, suggesting that these species could indeed be used as biomarkers of healthy plant status. In a second part of this study, we investigated the potential use of cultivable palm endophytes, but also natural compounds for biocontrol applications. In particular, we evidence the antagonistic potential of Arthrobacter agilis, a palm endophyte, against a major palm date disease agent, Fusarium oxysporum sp. Albedinis

Le palmier dattier (Phoenix dactylifera L.) est une espèce fruitière dioïque tropicale qui revêt une importance capitale sur le plan alimentaire, socio-économique et écologique pour les régions arides du globe. Malgré l'intérêt de disposer d'un outil moléculaire pour discriminer les plante s mâles et femelles pour les programmes d'amélioration génétique, aucun marqueur spécifique du sexe n'a été identifié et validé à ce jour. Afin de pouvoir étudier et comprendre le déterminisme sexuel du palmier dattier, nous avons entrepris la description et la caractérisation des processus cellulaires et moléculaires associés à la différenciation des organes sexuels. L'étude histologique du développement reproducteur a montré que le bourgeon floral est d'apparence bisexuelle jusqu'à l'initiation des primordia de l'androcée et du gynécée. Le premier dimorphisme sexuel observé à ce stade correspondant à un gynécée plus large dans les fleurs femelles résulterait d'une activité mitotique plus importante dans les cellules du gynécée fertile par rapport à son équivalent non fonctionnel. Les organes sexuels stériles, staminodes et pistillodes, cessent ensuite leur développement et présentent une différentiation incomplète. Des études d'hybridation in situ de l'expression du gène codant l'histone H4, marqueur de l'activité mitotique, ont montré que le blocage du développement des staminodes et des pistillodes serait dû à un arrêt des divisions cellulaires. Nos investigations de l'intégrité cellulaire par des observations en microscopie électronique à transmission et par coloration de l'ADN confirmeraient que l'avortement des organes stériles ne résulte pas d'un processus de dégradation cellulaire et nucléaire. De plus, l'étude de la méthylation de l'ADN par immunodétection des cytosines méthylées révèle que, par rapport aux organes fertiles, les pistillodes et les staminodes se distinguent par leur niveau plus élevé de méthylation. Ces résultats sont en cohérence avec la réversibilité du blocage de ces organes observés in planta ou in vitro en réponse à une induction hormonale. L'ensemble de ces données montrent que l'unisexualisation des fleurs de palmier dattier est associée à une hyperméthylation globale de l'ADN suivi d'un arrêt des divisions cellulaires dans les organes sexuels stériles. Cette étude a permis d'améliorer nos connaissances sur les mécanismes qui gouvernent la différenciation des organes sexuels et permettra d'ouvrir des perspectives pour l'identification de marqueurs moléculaires du sexe chez le palmier dattier
The date palm (Phoenix dactylifera L.) is a dioecious tropical fruit crop plant which has vital dietary, socio-economic and ecological importance in arid regions of the world. Despite the interest of developing molecular tools to discriminate male and female plants for the benefit of biodiversity preservation and genetic improvement programs, no sex-specific markers have been identified and validated to date. To study and understand the sex determination of date palm, we undertook to characterise the cellular and molecular processes underlying sex organ differentiation in this plant.A histological study of date palm reproductive development showed that the immature flower is bisexual in appearance until the initiation of the androecium and gynoecium. The first sign of sexual dimorphism is observed at this stage, namely a wider gynoecium in female flowers resulting from greater mitotic activity in the functional gynoecium of female flowers compared to the pistillode of male ones. The sterile sex organs (pistillode and staminodes) were observed to cease their development by progressive loss of cell proliferation and ultimately displayed incomplete differentiation.Cell division patterns and the nuclear integrity of reproductive organs were investigated respectively by RNA in situ hybridization to a histone H4 gene probe and by DNA coloration combined with scanning electron microscopy. The results obtained revealed an absence of cell cycle activity and nuclear degradation in the residual sex organs. In addition, a study of DNA methylation, by immunodetection of methylated cytosines revealed that compared to the fertile reproductive organs, staminodes and pistillodes displayed relatively high levels of global DNA methylation. These results are consistent with the observed reversibility of sterile organ developmental arrest observed in planta or in vitro in response to hormonal induction. Overall, these data demonstrate that the floral unisexuality of date palm is characterized by cell cycle arrest, higher DNA methylation in sterile sexual organs and an absence of cell degeneration rather than a cell death process. This study has improved our understanding of the mechanisms that govern the differentiation of sex organs and forms a useful starting point for research on the identification of molecular markers of sex determination in date palm.Kewords: Date palm - flower - sex determination - cell cycle - DNA methylation

Unit testing is defined as a test activity usually performed by a developer for the purpose of demonstrating program functionality and meeting the requirements specification of module. Nowadays, unit testing is considered as an integral part in the software development cycle. However, performing unit testing by developers is still considered as a major concern because of the time and cost involved in it. Automation support for unit testing, in the form of various automation tools, could significantly lower the cost of performing unit testing phase as well as decrease the time developer involved in the actual testing. The problem is how to choose the most appropriate tool that will suit developer requirements consisting of cost involved, effort needed, level of automation provided, language support, etc. This research work presents results from a systematic literature review with the aim of finding all unit testing tools with an automation support. In the systematic literature review, we initially identified 1957 studies. After performing several removal stages, 112 primary studies were listed and 24 tools identified in total. Along with the list of tools, we also provide the categorization of all the tools found based on the programming language support, availability (License, Open source, Free), testing technique, level of effort required by developer to use tool, target domain, that we consider as good properties for a developer to make a decision on which tool to use. Additionally, we categorized type of error(s) found by some tools, which could be beneficial for a developer when looking at the tool’s effectiveness. The main intent of this report is to aid developers in the process of choosing an appropriate unit testing tool from categorization table of available tools with automation unit testing support that ease this process significantly. This work could be beneficial for researchers considering to evaluate efficiency and effectiveness of each tool and use this information to eventually build a new tool with the same properties as several others.

Le palmier-dattier constitue une des rares cultures à vocation alimentaire adaptées aux conditions climatiques extrêmes (sécheresse, salinité), telles que rencontrées à Djibouti. Dans un contexte de ressources en eau fortement limitées, la connaissance des modalités de l’alimentation hydrique du palmier dattier est essentielle. L’objectif de ce travail de recherche est d’acquérir cette connaissance, dans le contexte pédoclimatique de Djibouti, par la réalisation d’un suivi in situ du fonctionnement hydrique du système sol-palmier, à l’échelle d’un individu, et la quantification du puits racinaire du palmier-dattier. Un palmier-dattier, pleinement développé, a été instrumenté à l’échelle de la cuvette d’irrigation, à l’aide de plusieurs tubes d’accès de sonde à neutrons, pour le suivi de la teneur en eau volumique du sol, et de plusieurs tensiomètres, répartis de 10 à 160 cm de profondeur. Trois expériences d’infiltration/redistribution a été réalisées successivement, la première sans altérer le fonctionnement du système sol-palmier, la seconde après avoir coupé le palmier, tout en permettant l’évaporation de la surface du sol, la dernière après avoir couvert la surface du sol afin d’empêcher l’évaporation. Les résultats mettent en évidence une forte hétérogénéité des propriétés hydriques du sol, avec une stratification liée au contexte sédimentaire littoral. L’impact du puits racinaire sur la dynamique hydrique du sol est observé jusqu’à 80 cm de profondeur. Pour la période fraîche, les besoins en eau du palmier dattier sont estimés à 130 L par jour, avec une fréquence d’irrigation d’une fois toutes les 2 semaines. Pour la première fois, le coefficient cultural du palmier dattier (kc = 1,39) a été établi dans les conditions climatiques de Djibouti. Les résultats obtenus contribueront à une meilleure gestion de l’irrigation et à une meilleure maîtrise du risque de salinisation du sol dans le contexte pédoclimatique de la République de Djibouti
Date palm is one of the few food crops adapted to the extreme weather conditions (drought, salinity), such as encountered in Djibouti. In the context of highly limited water resources, knowledge of the date palm water requirements is essential. The objective of this research was to determine the date palm water requirements, in the Djibouti pedoclimatic context, using in situ monitoring of water transport in the soil-plantatmosphere system, at the scale of a single date palm tree, and to quantify the date palm root water uptake. A fully developed date palm tree was instrumented at the irrigation basin scale, using several access tubes for neutron probe for monitoring the soil volumetric water content, and several tensiometers, installed from 10 to 160 cm depth. Three infiltration/redistribution experiments have been performed successively, the first without alteration of the soil-plant system, the second after cutting off a date palm tree while allowing the surface evaporation, the last with covering the soil surface to avoid evaporation. The results show large heterogeneity in soil hydraulic properties, with stratification linked to the coastline sedimentary context. The root water uptake is observed up to 80 cm depth. The date palm water requirements in the fresh period are estimated at 130 liters per day with a frequency of irrigation of one time every two weeks. For the first time, the date palm cultural coefficient has been established in the Djibouti climatic conditions (kc = 1.39). The obtained results will contribute to better management of irrigation and to improve the control of soil salinization in the pedoclimatic context of the Republic of Djibouti

La production de dattes ne cesse d’augmenter d’une saison à une autre ce qui engendre des pertes essentiellement lors des étapes de manutention et de commercialisation. De plus, l’étape de manutention post-récolte joue un rôle important dans le maintien de la qualité des dattes. Dans ce cadre et afin de préserver les qualités organoleptique et nutritionnelle des dattes après récolte tout en améliorant leur valeur commerciale, des essais de conservation et de traitement post-récolte ont été mis en place. L’effet de la conservation des dattes en fonction de la température, du temps, de l’utilisation d’atmosphère modifiée lors du stockage et d’un traitement thermique sur la fermeté, la couleur, et les teneurs en sucres, acides organiques, polyphénols et parois cellulaires a été étudié. Les dattes du cultivar ‘Deglet Nour’ récoltées en 2017 et 2018 au stade Tamr ainsi que les dattes communes ‘Arichti’, ‘Bouhattam’, ‘Bser Hlou’ consommées à un stade de maturité précoce (stade Khalal) ont été conservées à -18, 0, 2 et 4 °C pendant 3, 6 et 9 mois et à 2 °C pendant 30 et 60 jours, respectivement. La spectroscopie Moyen Infrarouge (MIR) en tant que méthode non destructive et non ciblée a permis de mettre en évidence l’effet de l’année de récolte par rapport à la composition chimique et de discriminer les échantillons de dattes ‘Deglet Nour’ conservés à 4 et 2 °C. Le rendement en parois cellulaires assimilées aux fibres, ainsi que les procyanidines représentant 98% des polyphénols totaux sont stables durant la conservation du cultivar ‘Deglet Nour’ et du cultivar ‘Arichti’ quel que soit la température et la durée de conservation. En revanche, ces composants sont ceux qui sont les plus affectés par les conditions de conservations dans le cas des cultivars ‘Bouhattam’ et ‘Bser Hlou’. Ce dernier est le cultivar le plus ferme et le plus apprécié par les consommateurs, en raison notamment de l’augmentation des teneurs en sucres réducteurs affectant son goût sucré lors de la conservation. De ce fait, une conservation des dattes ‘Deglet Nour’ à -18 °C pourrait être une solution pour un stockage à long terme, par contre en raison des coûts énergétiques élevés, 2 °C est la température optimale de conservation. En outre, afin de bien valoriser les dattes communes et prolonger leur durée de vie, la durée de conservation peut être prolongée pour le cultivar ‘Arichti’, une optimisation de la température de conservation pour le cultivar ‘Bser Hlou’ et ‘Bouhattam’ sera cependant nécessaire. Les dattes précédemment citées ont été également conservées dans différents types d’emballages à atmosphère modifiée (EAM) à 2 °C pendant 3, 6 et 9 mois pour le cultivar ‘Deglet Nour’ et pendant 30 et 60 jours pour les cultivars ‘Arichti’, ‘Bouhattam’ and ‘Bser Hlou’. D’une façon générale, ces résultats ont montré que les EAM ont le même impact que la température et la durée de conservation sur la qualité des dattes. Par conséquent, leur utilisation dans les industries de conditionnement de dattes va entrainer des coûts supplémentaires sans effets bénéfiques. L’impact d’un traitement d’hydratation sur les qualités organoleptique et nutritionnelle des dattes a également été évalué. Le traitement des dattes ‘Deglet Nour’ de trois usines de conditionnement différentes, à une vapeur d’eau saturée à 60-62 °C pendant 4 heures a montré qu’elles deviennent plus souples comme attendu, tandis que les paramètres nutritionnels sont resté stables. La spectroscopie Moyen Infrarouge (MIR) a permis de discriminer les dattes des trois usines et il est suggéré qu’elle soit adoptée par les stations de conditionnement comme une nouvelle technique prédictive et non destructive. Ce résultat confirme que le traitement d’hydratation pourrait être fortement recommandé pour valoriser les dattes sèches de faible valeur commerciale, cependant il doit être optimisé pour les dattes très sèches
The production of dates is increasing every season, causing losses especially during post-harvest handling andmarketing. Post-harvest handling plays an important role in maintaining date palm. In order to preserve organolepticand nutritional quality of date palm fruits after harvest with improving their commercial value, storage experiments andpost-harvest treatments have been assayed.The effect of different storage conditions of temperature, time and modified atmosphere, as well as the effectof heat treatment of dates, on firmness, colour, sugars, organic acids, polyphenols and cell walls and compositions havebeen studied.‘Deglet Nour’ date palm fruits of two harvest seasons (2017 and 2018) as well as common date cultivars‘Arichti’, ‘Bouhattam’ and ‘Bser Hlou’ consumed at early maturity stage (Khalal stage), were stored at -18, 0, 2 and 4°C for 3, 6 and 9 months and at 2 °C for 30 and 60 days, respectively. Mid Infrared Spectroscopy (MIR) as a nontargetedmethod allowed to highlight a year effect on 'Deglet Nour’ chemical composition and to discriminate samplesstored at 4 and 2 °C regarding to major components (moisture, sugar, organic acids...). Cell wall yields (assimilated tofiber) as well as procyanidins, accounting for 98% of total polyphenols, were stable during ‘Deglet Nour’ and ‘Arichti’cultivars storage regardless of temperature and time conditions. However, these same components were the mostaffected by storage conditions for ‘Bouhattam’ and ‘Bser Hlou’ cultivar. This latter, was the softest cultivar and themost appreciated by consumers, may be because of reducing sugars increase affecting its sweet taste. Thus, stored fruitsat -18 °C could be the solution for a long-term storage but due to its high energetic costs, 2 °C must be the optimaltemperature. Moreover, in order to valorize common dates palm and prolong their shelf life, storage time could beprolonged for ‘Arichti’ cultivar with temperature storage ptimization for ‘Bser Hlou’ and ‘Bouhattam’ cultivars.Date palm fruits mentioned above, were also stored under Modified Atmosphere packaging (MAP) at 2°Cduring 3, 6 and 9 months for ‘Deglet Nour’ and during 30 and 60 days for commons cultivars (‘Arichti’, ‘Bouhattam’and ‘Bser Hlou’). In general, differences were observed on physical and chemical parameters using different MAPstreatments for ‘Deglet Nour’date palm fruits. Dates became darke with MAPT and MAPA storage. Dates palm storedunder this latter MAP bag showed an increase on procyanidins, some cell walls compositions, fructose and citric acid.Firmness loss of this cultivar was delayed with MAPZ storage with polyphenols stability. This latter bag type conservedfirmness and colour of the three studied cultivars (‘Arichti’, ‘Bouhattam’ and ‘Bser Hlou’) were stabe with no differencecomparing to control (without MAP). Organic acids, cell walls yield and composition, polyphenols were also stableduring storage. Only sugars contents of every cultivars had different behaviour.These results showed that MAP bags had very lower benefical effects than storage time and temperature on ‘date palmquality. So, their use in date processing industries could have more costs with no apparent effects.The organoleptic and nutritional quality of ‘Deglet Nour’ date palm was also evaluated before and afterhydration treatment commonly used in date prcessing units (DPU), in order to become more commercially valued andto minimize waste generated along the date palm fruit supply chain. Hydration treatment under saturated steam at 60-62°C for 4 hours impoved date fruits texture as expected while nutritional parameters were quite stable. Mid InfraredSpectroscopy (MIR) allowed to discriminate samples from the three DPUs suggesting to be adopted in DPU as a newpredictive and no destructive technique. So, hydration treatment could be highly recommended to valorize fruit byproducts.However, it needs to be optimized for the very hard-type dates
انتاج التمور في ارتفاع مستمر من موسم الى اخر مما يجعل مراكزالفرز و التخزين تتخلص من كميات هائلة من التمور المتضررة أثناءعمليات الفرز والتسويق. هذه العمليات تلعب دورا هاما في الحفاظ على جودة التمور. ومن أجل الحفاظ على الجودة الغذائية للتمور بعد الجنيمع تحسين قيمتها التسويقية، تم القيلم بتجارب التخزين وبعض معالجات ما بعد الجني.وقد تم دراسة تأثير ظروف التخزين المختلفة من درجة الحرارة، مدة الخزن وتقنية الجو الهوائي المعدل، وكذلك تأثير معالجة التمور الجافةعلى الصلابة، اللون، السكريات، الأحماض العضوية، البوليفينول وجدران الخلايا النباتية (الالياف) ومكوناتها.تم تخزين تمور ’ دقلة النور’ لصابة 2017 و 2018 والأصناف الأخرى من التمور الأقل انتشارا مثل ’ الارشتي’، ’ بو حتم’، ’ بسر حلو’18 درجة مائوية وفي 2 درجة مائوية لمدة - ,0 ,2 , التي تستهلك في مرحلة متقدمة من النضج (خلال)، لمدة ثلاثة، ستة وتسعة أشهر في 430 و 60 على التوالي. اثبت التحليل الطيفي بالأشعة تحت الحمراء الوسطى ان سنة الجني لها تاثير على العناصر الكيميلئية للتمور’ دقلةالنور’ وقامت بتمييز التمور المخزنة في 2 و 4 درجة مائوية بالنسبة لاهم مكوناتها (الماء، السكريات، الأحماض العضوية...). اثبت النتائجان جدران الخلايا النباتية (الالياف) وان أكبر مكونات البوليفينول (بروسيانيدين) كانت مستقرة اثناء تخزين تمور’ دقلة النور’ و ’ الارشتي’،بغض النظر عن درجة حرارة ومدة التخزين. نفس هذه العناصر كانت الأكثر تاثرا بعوامل التخزين بالنسبة لاصناف’ بو حتم’ و ’ بسرحلو’. هذا الصنف الأخير كان الأكثر ليونة مع تغير بنية جدران الخلايا على الرغم من انه أكثر صنف قابلية لدى المستهلك، من الممكنبسبب ارتفاع كمية السكريلت السريعة التي اثرت على مذاقه الحلو.فبحيث ان تخزين التمور ’ دقلة النور’ في - 18 درجة مائوية من الممكن ان يكون أحسن حل على مدى طويل، لكن نظرا لتكاليفة الطاقيةالباهضة، تخزين التمور في 2 درجة مائوية يجب ان يكون أفضل حل. بصفة عامة لم يكن هناك خسائر هامة للقيمة الغذائية بالنسبة لاصنافالتمور الاخرى اثناء التخزين، مما يجعل التمديد في مدة التخزين ممكنا بالنسبة اصنف’ الارشتي’ مع البحث عن درجة حرارة تخزين ناجعةالصنف ’ بسر حلو’ و’ بو حتم’.تم ايضا تخزين انواع التمور المذكورة اعلاه بتقنية الجو الهوائي المعدل في 2 درجة مائوية لمدة ثلاثة، ستة وتسعة أشهربالنسبة ’ لدقلةالنور’ ولمدة 30 و 60 يوم بالنسبة للاصناف الأخرى. بصفة عامة هناك اختلافات في العناصر الفيزيلئية والكيميلئية ’ لدقلة النور' المخزنةفي كل أنواع تقنيات الجو الهوائي. ' دقلة النور' المخزنة في أكياس ترندلايف و ايباك. أصبحت داكنة الون.دقلة النور المخزنة في أكياس ' سجلت ارتفاعا في مكونات جدران الخلايل, بروسيانيدين, الفروكتوز و حامض السيتريك. تخزين' دقلة النور'في أكياس زويباك اخرت في ليونتها مع استقرار في البوليفينول. هذه النتائج اثبتت ان تخزين التمور في اكياس الجو الهوائي المعدل لم تكنذو نجاعة عالية مقارنة بعوامل الحرارة والمدة الزمنية.لون وصلابة التمور من اصناف ’ الارشتي’، ’ بو حتم’، ’ بسر حلو’ اثبتت استقرارها بعد تخزينها في أكياس زويباك, لكن بعدم ايجاد فرقمقارنة بالتمور المخزنة بدون اكياس الجو الهوائي المعدل, مثلها مثل بقية العناصر الفيزيلئية والكيميلئي بصفة عامة. هذا يثبت ان استعمالهافي مصانع تخزين التمور ليس له جدوى اقتصادية واضحة.تم دراسة مدى تاثر القيمة الغذائية لتمور ’ دقلة النور’ الجافة على إثر معالجتها وترطيبها بالطريقة الهعتدة في اغلب مصانع تخزين التمور62 درجة مائوية لمدة 4 ساعات - لتكون ذات قيمة تسويقية عالية ولتقليص كمية الخسائر. تقنية ترطيب التمور على طريقة البخار في 60اثبتت نتائج ناجعة كما كان متوقع مع المحافضة على استقرار المكونات الغذائية. طريقة معالجة التمور بترطيبها هي طريقة متصوح بهالكنها غير ناجة للتمور الأكثر جفافا التي تحتاج تطوير في هذه التقنية

Promouvoir le béton à base de bois de palmier dattier (DPC) dans la construction neuve et dans la rénovation des bâtiments existants nécessite en premier lieu une caractérisation complète de son comportement hygrothermique à multi échelle (matériau, paroi et bâtiment). Dans ce travail de thèse, le comportement hygrothermique du béton de bois palmier dattier a été étudié expérimentalement à l'échelle matériau, puis à l'échelle mur. Dans une première partie, les isothermes d’adsorption-désorption ainsi que l’effet d’hystérésis du DPC ont été caractérisés dans des conditions statiques. Les résultats recueillis ont révélé une capacité hydrique élevée de ce matériau par rapport à d’autres matériaux de construction. Par ailleurs, la valeur du tampon hydrique et l'effet de la température sur les cycles successifs d'adsorption / désorption ont également été évalués dans des conditions dynamiques. Il a été constaté que le processus de sorption est fortement affecté par la variation de la température. Les résultats obtenus ont permis de classer le DPC comme un matériau hygroscopique possédant une excellente capacité de régulation d’humidité. Dans la deuxième partie de la thèse, le comportement hygrothermique d’un mur en DPC a été étudié expérimentalement à l’aide d’une chambre climatique. Plusieurs scénarios de variations de température et d'humidité relative ont été appliqués sur une seule face du mur. Les variations de la température et d'humidité à différentes profondeurs de la paroi ont été mesurées à l'aide de capteurs. Plusieurs phénomènes thermo-hydriques ont été mis en évidence tels que l'effet du couplage de transfert de chaleur et d'humidité relatif aux phénomènes d'évaporation-condensation et d’adsorption-désorption. En outre, une inertie thermique et hydrique importante a été observée à travers le mur de DPC, ce qui permet de limiter la surchauffe et de réduire la condensation interstitielle pour des constructions durables
Promoting the date palm concrete in new constructions and renovating buildings requires a full hygrothermal characterization at several scales (material, wall and building). In this thesis, the hygrothermal behavior of date palm concrete was experimentally investigated, firstly at material scale then at wall scale. In the first part, the adsorption-desorption isotherms and the hysteresis effect of DPC were characterized under static conditions.The results revealed a high hygric capacity for this material compared with other classical building materials. The moisture buffer value and the effect of temperature on successive adsorption/desorption cycles were also assessed under dynamic conditions. It was found that the sorption process is highly affected by the temperature. Furthermore, this bio-based mortar was classified as hygroscopic and breathable material with excellent moisture buffer capacity. In the second part of the thesis, we have experimentally investigated the hygrothermal behavior at wall scale. The investigation was performed using a climatic chamber where the variation of temperature and relative humidity were applied on one side of the wall. These both parameters were measured at different depths of the biobased wall using sensors. Several thermo-hygric phenomena were highlighted such as the high coupling effect between the heat and moisture transfer due to the evaporation-condensation and adsorption-desorption phenomena. Besides, significant thermal and hygric inertia was observed through the DPC wall which allows mitigating overheating and reducing interstitial condensation for sustainable constructions

La compréhension des mécanismes moléculaires impliqués dans la détermination du sexe chez les plantes à fleurs est primordiale d’un point de vue fondamental et appliqué. Des processus liés à la biosynthèse des hormones, tel que l’éthylène, ou la régulation de l’expression génique via des petits ARN et des facteurs de transcription ont été associés à l’unisexualisation des fleurs chez des espèces dioïques. Cependant, les déterminants contrôlant le sexe chez les plantes sont encore largement méconnus. Le palmier dattier, Phoenix dactylifera L, est une espèce dioïque dont le dimorphisme sexuel est observé très tôt au cours du développement des fleurs. Des gènes différentiellement exprimés (DEGs) ont été identifiés pendant les stades précoces du développement floral mâle et femelle. Pour cela, un transcriptome de référence rassemblant des données d’expression relatives aux deux sexes a été généré. L’analyse d'enrichissement GO des DEGs, a révélé des processus biologiques communs aux mâles et aux femelles, associés au développement reproducteur et à la réponse aux stimuli. Ce résultat indique que des mêmes processus peuvent solliciter des gènes différents au cours du développement floral précoce en fonction du sexe. Cette analyse a également mis en évidence que le développement des fleurs mâles requiert des processus biologiques spécifiques impliqués dans la régulation cellulaire et l'expression des gènes. En outre, deux DEGs femelles, une S-adenosylmethionine synthase et une Flap endonuclease et un DEG mâle, un élément transposable, ont été identifiés dans les régions non-recombinantes du génome du palmier dattier.Cette étude est la première analyse globale des processus biologiques associés à l’acquisition du dimorphisme sexuel. Elle contribue également à la compréhension de la détermination du sexe chez le palmier dattier, et plus largement à la connaissance de ces processus chez les espèces dioïques
Unraveling molecular mechanisms involved in sex determination in flowering plants is of outstanding basic and applied interest. Several studies on dioecious species have highlighted the molecular basis of sex determination, such as cell death and ethylene biosynthesis pathway. Sex determination mechanisms in plants are, however, still largely unknown. The date palm, Phoenix dactylifera L, is a dioecious species where sexual dimorphism is observed very early in development of flowers. Differentially expressed genes (DEGs) were identified during the early stages of the male and female flower development. A reference transcriptome including male and female data was constructed to gain insight into this process in the dioecious palm Phoenix dactylifera L. Differentially expressed genes (DEG) were subsequently identified between males and females in the early flower development stages in which the first morphological gender difference occurs in date palms.Gene ontology enrichment analysis of DEG revealed biological processes shared between males and females involved in reproductive development and response to stimulus, indicating that same processes could require different genes during early flower development in date palm. This analysis also suggested that date palm triggers biological processes specifically involved in cellular regulation and gene expression to develop male flowers. Furthermore, two female DEGs related to DNA methylation S-adenosylmethionine synthase and DNA metabolism Flap endonuclease, and one male DEGs, a transposable element were found in non-recombinant date palm regions. This study provided the first insight into biological processes involved in sex determination in date palms and more widely to knowledge of this process in dioecious species

Le traitement de boues de station d'épuration (Boues activées de Marrakech) en mélange avec déchets verts (Palmier dattier) selon deux mélanges dont les proportions : A (1/3 Boues + 2/3 Déchets de palmier) et B (1/2 Boues + 1/2 Déchets de palmier), a été effectué par la filière du compostage, pendant six mois. Au cours du co-compostage, l’intense activité microbienne s’est traduite par une augmentation de température (autour 65 C°) au cours des premières semaines (phase thermophile) et un taux de décomposition final de l’ordre de 40%. Après six mois de co-compostage, le compost final est caractérisé par un rapport C/N voisin de 10, un rapport de NH4+/NO3- < 1, un pH autour de la neutralité signe de maturité des composts. L’analyse FTIR a montré une diminution de l'absorbance des bandes aliphatiques et l'augmentation de la structure de bandes d'absorbance aromatiques reflètent l'état d'avancement du processus d'humification. Le taux d’abattement des lipides totaux est de l’ordre de 43%. Les esters méthyliques d’acide gras (FAMEs) des Gram-positif (i,C15 :0) ont augmenté durant la phase thermophile. Les FAMEs d’origine non spécifique (C6 :0, C14 :0) ont connu une intense diminution, les FAMEs de bactéries non spécifiques représentent une grande teneur durant la phase thermophile. L’indice CPI a augmenté à la fin du co-compostage indiquant l’enrichissement du compost en FAMEs d’origine végétale. Les principaux composés ligneux identifiés, au cours du co-compostage, par Py-GC-MS, sont classés en deux groupes. Le premier est constitué de 7 composés dont la teneur diminue au cours du co-compostage, parmi lesquels : Toluène, 2,4-diméthylbenzène, éthylbenzène, Styrène, 1-éthyl-2-méthylbenzène, 4-méthylphénol et 2-méthylnaphthalène. Le deuxième groupe est constitué de 4 composés qui augmentent au cours du co-compostage : phénol, benzofuran, éthylméthoxyphénol et diméthoxyphénol. Les principaux stéroïdes identifiés sont les C27-C29 sterènes, stanols, 5β-cholesta-3-one, cholesta-3,5-diène et 2 thiostéranes. A l’exception des thiosteranes et quelques composés de C27-C29 cholestenes la concentration relative des stéroides diminue au cours du processus suit à leur attaque microbien. L’abattement total de la teneur des stéroïdes est corrélé positivement avec les indicateurs de maturité du compost (C/N et NH4+/NO3-) ce qui ouvre la voie à une éventuelle utilisation des stéroïdes comme indicateur de dépollution et de maturité de compost. 12 isolats d’actinomycètes ayant une activité antimicrobienne vis-à-vis d’un large spectre des germes pathogènes ont été isolés sur le milieu sélectif CTEA. Le degré d’hygiénisation est confirmé par la diminution de la concentration des coliformes fécaux et totaux, et l’abattement des œufs d’helminthes identifiés (Ascaris sp., Capillaria sp., et Trichuris sp.) vers la fin du co-compostage. La phytotoxicité, déterminée par l’effet des extraits hydrosolubles à différents stades de co-compostage sur la germination et la croissance des radicules (Navet, Cresson, Laitue, Luzerne), a diminué et l’indice de germination dépasse 100%, après six mois de co-compostage. La génotoxicité du chrome hexavalent (Cr(VI)) du substrat de co-compostage est corrélée positivement avec la fréquence des micronoyaux (MN). Après six mois de co-compostage le taux des MN diminue avec un taux d’abattement de 70,4% et 77,2% avec l’abattement de la concentration du Cr(VI) avec 58 et 58,6% respectivement pour le mélange A et B. Ceci ouvrira la voie d’utilisation de cet indice comme un indice de maturité des composts. La diminution de la phytotoxicité et la génotoxicté au cours du co-compostage confirme l’état de stabilisation et de la maturité des co-composts, ce qui pemettra l’épandage de ces composts en tant qu’amendement organique des sols sans risque de contamination du système sol-plante
The co-composting of activated sludge and lignocellulose waste (palm tree waste) was monitored to study the behaviour of two mixtures, referred to as A (1/3 sludge + 2/3 palm waste) and B (1/2 sludge + 1/2 waste palm) for 6 months. The biotransformation was evaluated by physicochemical and spectroscopic analyses. The thermophilic phase is characterized by a rise in temperature, which peaked at 65°C. This is the result of intense microbial activities. The final composts exhibited a higher degree of decomposition than the controls as shown by a decomposition rate of about 40%, decrease of C/N ratio to around 10 and NH4 +/NO3 - ratio below 1. The decrease of aliphatic absorbance bands and the increase of aromatic absorbance bands follow the progress of the humification process. Total extractable lipid was decreased by 43%. The fatty acid methyl esters (FAMEs) from Gram-positive bacteria (i, C15: 0) increased during the thermophilic phase. FAMEs from non-spécific origin (C6 :0, C14 :0) exhibited a decrease toward the end of co-compostin, linear FAMEs from non-specific bacteria underwent a decrease during co-composting. The CPI index thus increased at the end of the composting process, indicating that the final product was proportionally richer in fatty acids of plant origin. Two lignin groups were distinguished by Py-GC-MS. Group 1 contained toluene, 2,4-dimethylbenzene, ethylbenzene, styrene, 1-ethyl-2-methylbenzene, 4-methylphenol and 2-methylnaphthalene; their relative proportions decreased during co-composting. A second group of 4 components showed concentrations that increased with co-composting time: phenol, benzofuran, ethylmethoxyphenol and dimethoxyphenol. The main steroids identified were C27-C29 sterenes and stanols, 5β-cholesta-3-one, cholesta-3,5-diene and 2 thiosteranes. Except for thiosteranes and some of the C27-C29 cholestenes, the relative concentrations decreased during co-composting due to microbial degradation. The changes in steroids during co-composting, was positively correlated with the physico-chemical parameters of mature compost, especially C/N and NH4 +/NO3 - ratios, opening the way for the use of steroids as indicators of pollution and compost maturity. On the selective CTEA medium, 12 active strains of isolated actinobacteria presented a suppressive action against various pathogens. This may justify that a biotic factor is also an important factor contributing to making co-composting substrates hygienic. The degree hygiene reached is confirmed by the reduction in the faecal and total coliforms, and by the abatement of identified helminth eggs (Ascaris sp., Capillaria sp., and Trichuris sp.) towards the end of the process. The phytotoxicity determined by the effect of aqueous extract, at various stages of the co-composting, performed by monitoring the number of germinated seeds and the rootlets growth of turnip, watercress, alfalfa, and lettuce was decreased, and the growth of radicals that have a germination index that exceeds 100% after six months of co-composting. Hexavalent chromium (Cr(VI)) genotoxicity showed a positive correlation with micronucleus (MN) frequency. After six months of co-composting, the MN rate decreased significantly by 70.4 and 77.2% with decreasing Cr(VI) concentration with 58 and 58.6%, for mixtures A and B respectively. That indicates their suitability for use as a maturity index. During co-composting the abatement rate of phytotoxicity and genotoxicity confirme the maturation and stabilization degree of co-composting end products which encourages their recycling in agriculture as a fertilizer for the soil without any contamination of the soil-plant system

Date palms (Phoenix dactylifera L.) and papayas (carica papaya L.) are two commercially important plantation crops. Their economic potential in South Africa and worldwide is increasing. However, due to disease, pests and socio-economic reasons, planting material is in short supply. Micropropagation provides a method for rapidly propagating selected superior cultivars for commercial and environmental interests. A satisfactory process for the regeneration of elite cultivars should result in individuals phenotypically and genetically identical to the explant from which they were derived. However, due to somaclonal variation generated during in vitro culture, the true-to-typeness is questionable. For this reason a southern African survey for off-types on date palms produced using somatic embryogenesis was conducted. Plant growth variations such as leaf variegation, seedless fruit, broad leaves, compact growth habit and parthenocarpic fruit were recorded and possible explanations for each phenomenon given. Factors influencing the date palm initiation process such as decontaminating agents, plant growth regulators, explant type and nurse cultures were investigated. A double decontamination process with 2.6% and 1.3% sodium hypochlorite was most effective at reducing contamination. Alternative plant growth regulators, TIBA and NAA were ineffective as a substitute to 2,4-D for somatic embryogenesis. The size of the explant and "nurse cultures" played an important role in explant growth and initiating callogenesis. A "nurse culture" reduced the time in culture significantly. The problem areas in the three commercial tissue culture techniques used for date palms were outlined. In the second part of the study, factors influencing initiation, multiplication and rooting of papaya were determined. Presoaking with antibiotic, Rifampicin, and various fungicides had a positive effect on decontaminating papaya explants, while Bronocide™ had little effect. Various methods and materials were used to optimize papaya multiplication and rooting in vitro. The growth and multiplication of papaya was optimal at 50 g l ¯¹ sucrose. Gelling agent, Gelrite, increased multiplication rates significantly but had a negative effect on overall growth causing plants to become vitrified. The addition of activated charcoal reduced vitrification but also reduced multiplication rate. Activated charcoal greatly improved overall growth of papaya and reduced leaf senescence. No vitrification was observed in multiplying papaya cultures where agar and Gelrite combinations were used, but multiplication rate was reduced compared to cultures grown on Gelrite alone. callus removal from the bases of papaya at subculturing reduced multiplication rate and influenced elongation, growth and leaf senescence. Lower concentrations magar and Gelrite improved rooting percentages, but did not provide good support. Damaged roots and lower rooting percentages were observed on plantlets treated with IBA for four weeks compared to those exposed for only two days. A one hour pulse with a higher concentration (5 mg l ¯¹) of IBA greatly improved rooting percentage and further eliminated a second subculture onto an IBA-free medium after two days. Good, strong roots with root hairs were produced on vermiculite medium containing equal volumes of DS salts and vitamins. Modified lids with cotton-wool plugs also reduced leaf abscission. In vitro grafting using stericrepe proved impractical, while grafting in vitro unrooted papaya plants onto ex vitro seedlings was more successful, using wedge and slant grafts. Grafts sealed with pegs and Parafilm™ were less effective.
Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2000.

Date palm (Phoenix dactylifera L.) is a fruit-bearing tree with numerous potential sustainable applications. Since ancient times, it has been considered a stable, secure, and sustainable food. This work provides comprehensive metabolic profiling of both parts, flesh and seed, of four P. dactylifera cultivars; Ajwa, Anbara, Sukkari, and Degelt Nour, which originated from two countries, Saudi Arabia, Tunisia. The analysis performed using mass spectrometry-untargeted metabolomics approaches, included a combination of LC-MS and GC-MS coupled to multivariate statistical analysis to reveal the differences in metabolite compositions among date varieties. The LC-MS seed results showed several classes of metabolites that belong to the flavonoids, phenolic acids, and amino acids derivatives, including citric acid, malic acid, lactic acid, hydroxyadipic acid, caffeic acid, which were at high concentrations in AJS followed by DNS and ARS. The LC-MS flesh analysis displayed that DNF had a high level of Isoquercitrin (flavonoid compound) and sinapic acid, and AJF was high concentrations level in hydroxyadipic acid and ascorbic acid. GC-MS concluded that seed samples of four date varieties are richer in metabolites classes than the flesh samples. The metabolites contributed to the seed metabolite compositions included several classes of amino acids, hydrocinnamic acids (caffeic, ferulic and sinapic acids), antioxidant phenolics, and long-chain fatty acids. The PCA and its loading analysis demonstrated the discriminating metabolites that were responsible for date varieties segregation, as HCA displayed the metabolic patterns and groups of metabolites that drive the clustering of the date samples, two groups of dates clustered together (AR and AJ) and (SR and DN). These clusterings are based on the similarities and differences observed in the metabolite compositions of the studied date samples that could be explained by differences in various metabolic responses and the environmental conditions, genotypes and geographical regions. This extensive date palm information would increase the potential of date fruits and seeds as low-cost sources of natural diet that may provide nutritious and bioactive components in the food and pharmaceutical fields to produce value-added products.

A thesis report submitted in partial fulfilment of the requirement for the degree of Master of Arts in Media Studies to the Faculty of Humanities, University of the Witwatersrand, 2019
This study examines contemporary representation and imaginings of the black South African family structure in a popular reality television programme, Date My Family. Further categorised in the sub-genre of reality dating television, the programme is also a significant study of the ways in which reality television values intersect with discourses about family, romantic partnering and romantic love. These are the three main themes that have been identified in Date My Family, and are all fundamental and significant social practices that will be explored in a critical discussion of dynamics in black South African families. This study aims to outline the ways in which Date My Family displays contemporary understandings of black identity in relation to the family structure, as well as how the programme either imagines or renegotiates traditional conceptions of family, romantic partnering and romantic love. The study’s examination of its three main themes is informed by literature that serves an introductory and contextual function. Subsequently, I apply theories of identity, race and representation. Using discourse analysis to focus on the visual and verbal discourses, I show that the programme displays significant cultural relevance and a representation of the social circumstances in which it is produced. Date My Family portrays instances in which Western/ European traditions and conceptions of family, romantic partnering and romantic love have been continued in the African context, how some of these traditions and conceptions co-exist with those of Africa, and how these traditions and conceptions have been renegotiated. The structure of the black South African family seems to remain in its traditional form – the extended unit - and notions of female-headed households and an absence of fathers in the family remain topics of representation in the current, local context.
NG (2020)

This diploma thesis deals with the issue of the usage of comic processing in the lessons of literary education at the second grade of the elementary school. The theoretical part defines the basic expressions concerning the area of literary education, the theory of comic, the theory of adaptation, and effective teaching. The set of four educational scripts employing comic processing of classical works of Czech and world literature, highlighting the up-to-date conception of the literary education in accord with demands on the education which is set down by Framework Education Programme for Elementary Education, was created within the practical part. The main aim of scripts was to support the progress in reader´s literacy and the communicative skills. These educational scripts are not only intended for university students, primarily within the didactics of the Czech language and literature, and beginning teachers, but also for experienced pedagogues. The quality of the scripts was proved in practise.

This thesis is a study of the shifting philosophical trends in the works of Samuel Beckett, Donald Barthelme, and Kurt Vonnegut as representations of a greater shift from modernism to postmodernism. I have chosen to explore Beckett's plays Waiting for Godot and Krapp's Last Tape, Barthelme's short stories "Nothing: A Preliminary Account," "The New Music," and "Kierkegaard Unfair to Schlegal," and Vonnegut's book Timequake to see how each author seeks to find a new hope in the face of a collapsed causal system. This work is an examination of the form and content of each author's work as it pertains to their own philosophical standing and in relation to the other two authors' works. I argue that each author finds a different hope for humanity depending on their place among the philosophical trends during their time.
Graduation date: 2012