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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
351

Cogito, ergo insomnis : I think, therefore I am sleepless

Norell-Clarke, Annika January 2014 (has links)
Insomnia is a common health complaint that often becomes a persistent problem. The theoretical frameworks for understanding and treating insomnia have mostly been behavioural, yet the importance of cognitive processes has received greater attention over the years. The overall aim of this dissertation was to expand the knowledge on the processes from the Cognitive Model of Insomnia by investigating them in novel contexts. Study I examined the outcomes from cognitive therapy for insomnia on adolescents. Study II explored the relationship between cognitive processes and the association with remission and persistence of insomnia in the general population. Lastly, Study III investigated if cognitive processes mediated between cognitive behavioural therapy for insomnia (CBT-I) and outcomes of insomnia and depressive severity in a sample of people with insomnia comorbid with depressive problems. The findings show that cognitive therapy for insomnia affected sleep for adolescents, thus this is a promising treatment option for this age group. Further, it was found that cognitive processes distinguished between adults with normal sleep and persistent insomnia. For people with insomnia, elevated sleep-related worry at baseline increased the risk of reporting persistent insomnia later on, whereas a lowering of selective attention and monitoring, and safety behaviours over time increased the likelihood of remission from insomnia. This has clinical implications for insomnia assessment and treatment, as well as theoretical implications, and warrants further research. CBT-I was associated with greater reductions in dysfunctional beliefs and sleep-related safety behaviours compared to control treatment. Dysfunctional beliefs mediated between CBT-I and insomnia severity and depressive severity respectively. This supports the importance of negative thought content in both insomnia and depression.
352

Selective incorporation of the C-F bond as a conformational tool in quadruplex DNA ligand design

Smith, Daniel L. January 2012 (has links)
Chapter 1 provides a general introduction to organofluorine chemistry and focuses on recent developments in fluorination techniques. It also details how the C–F bond influences conformational and physiochemical properties of organic molecules. Chapter 2 highlights the biological role of the telomere, telomerase and quadruplex DNA in cells. It discusses the inhibition of telomerase with small molecules that stabilise quadruplex DNA as a treatment for cancer. An overview of the development of structurally related telomerase inhibitors and recent X-ray crystallographic structural data with BSU6039 and BRACO-19 telomeric DNA is presented. Chapter 3 discusses the synthesis of fluorinated BSU6039 analogues for the investigation of the conformational effects of fluorine in 5-membered rings and its influence on binding with quadruplex DNA. These compounds have been successfully co-crystallised with telomeric DNA and their relative stabilisation of telomeric DNA has been assessed. The latter half of this chapter focuses on the co-crystal structures between (S,S)- and (R,R)-144 with Oxytricha nova telomeric DNA, discussing the key differences between the two stereoisomers. Chapter 4 details the synthesis of fluorinated BRACO-19 analogues. The syntheses of such fluorinated analogues were achieved through a base mediated coupling between 3,6-diaminoacridone and an α-fluorinated-β-amino ester. The α-fluorinated-β-amino ester was synthesised through a deoxyfluorination-mediated approach, using the stereochemistry of natural amino acids. Chapter 5 describes the stereo- and regio- selectivity of deoxyfluorination reactions with dipeptides bearing the β-amino alcohol functionality. Understanding this selectivity enabled the development of a method towards α-fluorination of tertiary amides. The application of this fluorination method with an orthogonally protected tertiary amide is described.
353

Unrelenting: a media-focused political economy analysis of antidepressant use in Canada

Smith, Adam 14 October 2016 (has links)
Although extensive evidence suggests antidepressants are a non-effective treatment for the majority of depressive cases where they are prescribed and despite other developed countries taking steps to provide alternative treatments, Canada's prescription rates continue rising and no state action is being taken. The primary purpose of this study is to explore whether the media in English-speaking Canada, represented by its "newspaper of record," The Globe and Mail, has been performing its essential role in informing Canadians about the controversy surrounding antidepressants and the pharmaceutical system that that has made them central to treating depression. Data was collected in the form of newspaper articles from between 2000 and 2015 in order to analyze media coverage to ensure the essential facts were reported and to qualify to what degree a patient advocacy role challenging the norms of contemporary treatment has been adopted. / February 2017
354

La distribution électronique : franchise et Internet

Cheaib, Wassim 04 1900 (has links)
"Mémoire présenté à la Faculté des études supérieures En vue de l'obtention du grade de LL.M. Dans le programme de maîtrise en droit" / Depuis que le commerce électronique est devenu un environnement commercial assez répandu, les réseaux de distribution (nouveaux et préexistants) composés de fournisseurs et de distributeurs essayent de développer une réelle activité commerciale sur la toile. Cet enjeu a bouleversé l'organisation de la revente des produits en se posant en concurrent et en complément des réseaux traditionnels de distribution. Notre travail porte sur l'analyse juridique de l'incidence d'Internet sur les relations entre distributeurs et fournisseurs, plus particulièrement sur le contrat cadre qui lie ces deux parties. Nous avons articulé notre travail autour de la comparaison des systèmes juridiques européen et nord-américain. Nous examinons la coexistence et la compatibilité entre ces réseaux de distribution et la vente virtuelle, pour ensuite, proposer certaines pistes pour le développement des réseaux existant via Internet. / Ever since ecommerce has become a widespread commerciai environment, the distribution networks (new and preexistent), composed of suppliers and distributors, have tried to develop a real commercial activity on the web. This objective upsets the organization of the resale of the products by becoming competitor and complement of the traditional networks of distribution. Our work deals with the legal analysis of the incidence of Internet on the relations between distributors and suppliers, more particularly on the contract which bind these two parties. We articulated our work around the comparison of the European and North-American legal systems. We examine the coexistence and compatibility between of these distribution networks and the virtual merchandising, with the goal of proposing certain avenues for the future development of the existing networks through the Internet.
355

Improved Recovery And Rapid Identification Of Strains, Mixed Strains, Mixed Species, And Various Physiological States Of Foodborne Pathogens Using Infrared Spectroscopy

Nyarko, Esmond Boafo 01 January 2014 (has links)
Challenges encountered in pathogen identification and detection include the genetic heterogeneity of strains within species of some foodborne pathogens, isolation of injured cells, mixed strains or mixed species contamination of foods, and differentiation between viable and dead cells. The first objective of this research was to evaluate an isolation medium that was based on time-delayed release (5 to 6 h) of selective agents in tablet format to a modified Listeria recovery enrichment broth (mLRB) medium for enhanced and rapid recovery of injured Listeria. The second objective involved the use of Fourier transform infrared (FT-IR) spectroscopy and chemometric analysis for the differentiation of: Listeria monocytogenes epidemic clones (ECs); viable versus heat-killed populations; different mixed strains and mixed species of Listeria; and different injury treatments and repair in Listeria populations. Nitrite- or acid-injured Listeria at approximately 10 CFU/ml were recovered in mLRB medium, and cell populations enumerated at various times (12 to 48 h) of incubation at 37oC. Analysis of variance revealed that acid-injured Listeria populations in mLRBS6 (mLRB plus the selective agents at 6 h) were significantly higher (P < 0.05) than those in mLRBS0 (mLRB plus the selective agents at 0 h) at 24 h; however, the differences in populations on these two media were not significant for nitrite-injured Listeria. Cell populations of four strains of Listeria recovered in mLRBTD (mLRB plus the time-delayed release tablets of the selective agents) were significantly higher than when those strains were enriched in the U.S. Food and Drug Administration (FDA), International Organization for Standardization (ISO), and U.S. Department of Agriculture (USDA) broths at 24 h. Comparison between artificially contaminated milk and meat samples with a four-strain cocktail of Listeria resulted in cell populations that were significantly higher (P < 0.05) on mLRBTD for contaminated meat than on mLRBTD for contaminated milk at 24 h. FT-IR spectroscopy in the mid-infrared region (4000 to 600 cm-1) and chemometrics was successfully applied to discriminate L. monocytogenes strains belonging to the same EC (ECII or ECIV) (100% accurate spectral classification), intact and heat-killed populations of each EC strain (100% accurate spectral classification), and spectral wavenumbers 1650 to 1390 cm-1 were used to differentiate heat-killed from intact populations. FT-IR spectroscopy and chemometrics in the wavelength region 1800 to 900 cm-1 could successfully discriminate different mixed strains of L. monocytogenes (98.15% accurate spectral classification) and different mixed species of L. monocytogenes and L. innocua (92.06% accurate spectral classification) from individual strains; Wavelength range 1800 to 900 cm-1 was successfully used to discriminate between intact, acid-injured, and heat-injured Listeria, with repaired cells from acid and heat treatments clustering closer to intact cells (93.33% of spectra accurately classified). Delayed-addition of selective agents to broth medium improves recovery of injured Listeria by allowing repair time, could minimize contamination through manual addition of selective agents, and saves analyst time; FT-IR spectroscopy is a highly discriminatory and reproducible technique that can be used for the differentiation of strains and various physiological states of Listeria.
356

Synthesis and properties of novel cage-functionalized crown ethers and cryptands.

Hazlewood, Anna 08 1900 (has links)
A novel cryptand was synthesized which contained a 3,5-disubstituted-4- oxahexacyclo[5.4.1.02,6.03,10.05,9.08,11] dodecane "cage" moiety. In alkali metal picrate extraction experiments the cryptand exhibited high avidity towards Rb+ and Cs+, when compared with the corresponding model compound. A computational study of a series of cage-functionalized cryptands and their alkali metal-complexes was performed. The X-ray crystal structure of a K+-complexed bis-cage-annulated 20-crown-6 was obtained. The associated picrate anion was found to be intimately involved in stabilization of the host-guest complex. The interaction energy between the host-guest complex and picrate anion has been calculated, and the energy thereby obtained has been corrected for basis set superposition error.
357

Stainless steels fabricated by laser melting : Scaled-down structural hierarchies and microstructural heterogeneities

Saeidi, Kamran January 2016 (has links)
Additive manufacturing is revolutionizing the way of production and use of materials. The clear tendency for shifting from mass production to individual production of net-shape components has encouraged using selective laser melting (SLM) or electron beam melting (EBM). In this thesis, austenitic, duplex and martensitic stainless steel parts were fabricated by laser melting technique using fixed laser scanning parameters. The fabricated steel parts were characterised using XRD, SEM, TEM/STEM, SADP and EBSD techniques. Mechanical properties of the fabricated steel parts were also measured. The mechanism of the evolution of microstructure during laser melting as well as the mechanism of the effect of developed microstructure on the mechanical properties was investigated. It was found that the intense localized heating, non-uniform and asymmetric temperature gradients and subsequently fast cooling introduces unique high level structural hierarchies and microstructure heterogeneities in laser melted steel parts. A unique structural hierarchy from the millimetre scale melt pools down to the sub-micron/nano scale cellular sub-grains was observed. The cellular sub-grains were 0.5-1μm with Molybdenum enriched at the sub-grain boundaries in SLM 316L. The Mo enriched cell boundaries affected the chemical and microstructure stability of the post heat treated samples. Well dispersed and large concentration of dislocations around the cell boundaries and well distributed oxide nano inclusions, imposed large strengthening and hardening effect that led to relatively superior tensile strength (700 MPa), yield strength (456 MPa), and microhardness (325Hv) compared to those of HIP 316L steel. The in-situ formation of oxide nano inclusions provided a unique way for preparation of oxide dispersion-strengthened (ODS) steel in a single process. The formation of oxide nano inclusions in the very low oxygen partial pressure of laser chamber was thermodynamically explained. High concentration of nano size dislocation loops, formation of nitride phases along with nitrogen enriched islands and oxide nano inclusions lead to strong dislocation pinning effect which strengthened the laser melted duplex stainless steel with a total tensile strength of 1321 MPa, yield strength of 1214 MPa and microhardness of 450HV. The grade 420 stainless steel was laser melted in Ar and N2 atmosphere which also showed a two level hierarchy with nanometric martensite lathes embedded in parental austenite cellular grains. The Ar treated sample had relatively higher retained austenite, lower YS (680-790 MPa) and UTS (1120-1200 MPa) compared to those treated in N2 (YS= 770-1100 MPa, UTS=1520-1560 MPa). The mechanism of the effect of atmosphere on phase transformation was explained. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Submitted.</p>
358

HETEROATOM-DOPED NANOPOROUS CARBONS: SYNTHESIS, CHARACTERIZATION AND APPLICATION TO GAS STORAGE AND SEPARATION

Ashourirad, Babak 01 January 2015 (has links)
Activated carbons as emerging classes of porous materials have gained tremendous attention because of their versatile applications such as gas storage/separations sorbents, oxygen reduction reaction (ORR) catalysts and supercapacitor electrodes. This diversity originates from fascinating features such as low-cost, lightweight, thermal, chemical and physical stability as well as adjustable textural properties. More interestingly, sole heteroatom or combinations of various elements can be doped into their framework to modify the surface chemistry. Among all dopants, nitrogen as the most frequently used element, induces basicity and charge delocalization into the carbon network and enhances selective adsorption of CO2. Transformation of a task-specific and single source precursor to heteroatom-doped carbon through a one-step activation process is considered a novel and efficient strategy. With these considerations in mind, we developed multiple series of heteroatom doped porous carbons by using nitrogen containing carbon precursors. Benzimidazole-linked polymers (BILP-5), benzimidazole monomer (BI) and azo-linked polymers (ALP-6) were successfully transformed into heteroatom-doped carbons through chemical activation by potassium hydroxide. Alternative activation by zinc chloride and direct heating was also applied to ALP-6. The controlled activation/carbonization process afforded diverse textural properties, adjustable heteroatom doping levels and remarkable gas sorption properties. Nitrogen isotherms at 77 K revealed that micropores dominate the porous structure of carbons. The highest Brunauer-Emett-Teller (BET) surface area (4171 m2 g-1) and pore volume (2.3 cm3 g-1) were obtained for carbon synthesized by KOH activation of BI at 700 °C. In light of the synergistic effect of basic heteroatoms and fine micropores, all carbons exhibit remarkable gas capture and selectivity. Particularly, BI and BIPL-5 derived carbons feature unprecedented CO2 uptakes of 6.2 mmol g-1 (1 bar) and 2.1 mmol g-1 (0.15 bar) at 298 K, respectively. The ALP-6 derived carbons retained considerable amount of nitrogen dopants (up to 14.4 wt%) after heat treatment owing to the presence of more stable nitrogen-nitrogen bonds compared to nitrogen-carbon bonds in BILP-5 and BI precursors. Subsequently, the highest selectivity of 62 for CO2/N2 and 11 for CO2/CH4 were obtained at 298 K for a carbon prepared by KOH activation of ALP-6 at 500 °C.
359

Le droit de la distribution en Tunisie / Distribution law in Tunisia

Mellouli, Chams 11 January 2013 (has links)
Les relations de distribution sont soumises à différentes contraintes juridiques. Ces contraintes relèvent plus spécialement du droit des contrats et du droit de la concurrence. D'autres matières juridiques, tel le droit du travail ou encore le droit des sociétés, peuvent être concernées. La technique contractuelle permet de répondre et satisfaire à ces contraintes. L'expérience européenne, et en particulier française, a permis de révéler des formules contractuelles identifiables ; il s'agit du contrat de franchise, de concession, de distribution agréée ou sélective et également des contrats de regroupement entre distributeurs. Ces formes particulières d'accords de distribution s'agrègent à des formules plus générales, tel la vente, le mandat, la commission ainsi qu'à des techniques contractuelles tel le contrat-cadre. L'objet de la thèse est d'apprécier la transposition de ces formules de contrats et techniques contractuelles en droit tunisien. L'étude des règles régissant les contrats de la distribution et les rapports entre les différents intervenants, permettra de systématiser un droit de la distribution en Tunisie. / The distribution relationships are subject to various legal obligations and regulations. These obligations rise mainly from contract law and competition law. However, other legal subject matters, such as labor law or corporate law could be involved. The contractual technique allows to meet these obligations. The European experience and more particularly the French one, have allowed to reveal identifiable contractual methods, mostly related to franchising agreements, concession agreements, approved or selective distribution agreements, and consolidation agreements between distributors. These specific distribution agreements aggregates with more general methods such as the sale deeds, the mandates, the commissions in addition to contractual techniques as the master agreement. The subject matter of this thesis is to estimate the transposition of these contractual methods and techniques in Tunisian law. The study and analysis of the rules governing distribution agreements and relationship between the different intervening parties, shall allow to systematize and set standards for distribution law in Tunisia.
360

Les communautés endosymbiotiques des insectes vecteurs de virus : diversité bactérienne, effets phénotypiques, conséquences écologiques et épidémiologiques / Endosymbiotic communities in insects vectoring viruses : bacterial diversity, phenotypic effects, ecological and epidemiological consequences

Gueguen, Gwénaelle 29 September 2009 (has links)
Les bactéries symbiotiques facultatives, transmises verticalement de mère à descendants, sont connues pour avoir des effets importants sur la reproduction de leurs hôtes (incompatibilité cytoplasmique et biais de sex-ratio), sur l’adaptation à des situations de stress (spécialisation, résistance aux pathogènes et aux fortes températures) ainsi que sur l’évolution de l’ADN mitochondrial par l’induction de balayages sélectifs. Bemisia tabaci est un complexe d’espèces divisé en nombreux biotypes, principalement différenciés sur la base de marqueurs moléculaires (essentiellement mitochondrial). Cet insecte héberge 7 symbiotes, 1 symbiote nutritionnel obligatoire et 6 symbiotes facultatifs. Nos résultats ont montré une extrême diversité ainsi qu’une prévalence exceptionnelle des bactéries symbiotiques chez B. tabaci. Leur dynamique rapide a entraîné de nombreux balayages sélectifs sur l’ADN mitochondrial influençant nettement son évolution. La très forte fréquence des infections multiples chez cet insecte peut certainement être expliquée par la co-localisation de l’ensemble des bactéries au sein des mêmes cellules, avec le symbiote nutritionnelle. Enfin, la coexistence de différents cytotypes en sympatrie offre l’opportunité d’étudier les interactions qui se mettent en place entre différentes communautés symbiotiques et comment ces systèmes vont évoluer / Facultative endosymbiotic bacteria that are vertically transmitted from mother to offsprings, have important effects on their host reproduction (cytoplasmic incompatibilities and sex-ratio biais), on host adaptation to situation of stress (specialization, resistance against pathogens or high temperature) and also on the evolution of mtDNA, by inducing selective sweeps. Bemisia tabaci is a species complex divided into numerous, mainly differentiated based on molecular markers (essentially mtDNA markers). This insect is infected by 7 bacterial symbionts, one nutritionnal symbiont that is obligatory and 6 facultative symbionts. Our results show an extreme diversity of symbionts in this insect and a very high prevalence in B. tabaci populations. Moreover their rapid dynamic has strongly influenced mtDNA evolution by inducing recurrent selective sweeps. The colocalization of the whole symbiotic community in the same cells, with the nutritional symbiont, might certainly explain the very high frequency of multiple infections in B. tabaci. Finally, coexistence of very different cytotypes in sympatry allows to study the interactions that take place between different symbiotic communities and how these systems will evolve

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