Ten-millijoule, thirty-five femtosecond, 800 nm (~40 nm bandwidth) laser pulses are used to study high-order harmonic generation in helium- and neon-filled gas cells of various lengths. Harmonic orders in the range of 50 to 100 are investigated. A semi-infinite cell geometry produces brighter harmonics than cells of sub-centimeter length. In the semi-infinite geometry, the gas occupies the region from the focusing lens to a thin exit foil near the laser focus. Counter-propagating light is used to directly probe where the high harmonics are generated within the laser focus and to investigate phase matching. The phase matching under optimized harmonic generation conditions was found to be unexpectedly good with phase zones many millimeters long. Restricting the laser beam with an 8 mm aperture in front of the focusing lens increases the emission of most harmonic orders observed by as much as an order of magnitude. Optimal harmonic generation pressures were found to be about 55 torr in neon and 110 torr in helium. The optimal position of the laser focus was found to be a few millimeters inside the exit foil of the gas cell. Probing with counter-propagating light reveals that in the case of neon the harmonics are generated in the last few millimeters before the exit foil. In helium, the harmonics are produced over a longer distance. Direct measurement shows that the re-absorption limit for mid-range harmonics in neon has been reached.

Cardiovascular diseases (CVDs) are a leading cause of death worldwide, emphasizing the need for advanced and effective intervention and treatment measures. Hypertension, a significant risk factor for CVDs, is characterized by reduced vascular compliance in arterial vessels. There is a significant rise in interest in exploring the viscoelastic properties of arteries in the last few years, for the treatment of these diseases. This study aims to develop an experimental setup using 3D Printing Technology to test viscoelastic arterial models for the validation of a diagnostic device for cardiovascular diseases. The research investigates the selection of polymer-based materials that closely mimic the viscoelastic properties of arterial vessels. An experimental setup is designed and fabricated to perform mechanical tests on 3D-printed specimens. The study utilizes a mathematical model to describe the viscoelastic behavior of the materials. The model's predictions are validated using experimental data obtained from the mechanical tests. This study demonstrates the potential of 3D printing technology in fabricating specimens using elastic and flexible resin materials. These specimens closely replicate the mechanical properties of native arteries, offering a tangible platform for controlled mechanical testing. Stress relaxation tests on the3D printed specimens highlight the viscoelastic properties of fabricated materials, shedding light on their behavior under strain. The study goes further to model the mechanics of these materials, utilizing the Fractional Voigt model to capture the intricate balance between elastic and resistive behaviors under varying deformation levels. The results highlight the successful fitting of the Fractional Voigt model to the experimental data, confirming the viscoelastic behavior of the specimens. The obtained values of α and RMSE indicate a good representation of arterial mechanical properties within the viscoelastic arterial model, under different loading conditions. This research contributes to improving cardiovascular device validation and offers a practical and reliable alternative to invasive experiments. Future works include exploring different materials and conditions for arterial modeling and enhancing the precision and scope of the viscoelastic model. Overall, this study advances the understanding of cardiovascular biomechanics, contributing to the development of more effective diagnostic devices for cardiovascular diseases.

Selected fungal strain for production of raw-starch-digesting enzyme by solid state fermentation was improved by sequential exposures to γ-irradiation of Co60, ultraviolet and treatments with Nmethyl-N'-nitrosoguanidine. Mutant Aspergillus sp. CXN2-3A was chosen and its production of raw-starch-digesting enzyme (RSDE) was improved 2 folds higher than that of wild type. Optimal condition for the production of the enzyme using wheat bran as the substrate was accomplished for the CXN2-3A. With the optimal fermentation condition and the solid medium supplemented with urea and NH4NO3, CoSO4, Tween 80, 1% glucose, CXN2-3A produced RSDE 19.23 folds higher than wild type cultured in pre-optimized condition and un-supplemented medium. / Chủng nấm chọn lọc sản xuất enzyme thủy phân tinh bột bằng cách lên men trạng thái rắn, chủng nấm được cải thiện bằng chiếu xạ tia cực tím, tia Co60 và các phương pháp xử lí với N-methyl-N'-nitrosoguanidine. Mutant Aspergillus sp. CXN2-3A, đã được lựa chọn để sản xuất enzyme (RSDE) thủy phân tinh bột sống cải thiện cao hơn 2 lần so với chủng dại. Điều kiện tối ưu cho việc sản xuất các enzyme bằng cách sử dụng cám, lúa mì đã được thực hiện cho CXN2-3A. Với điều kiện lên men xốp tối ưu và bổ sung urê và NH4NO3, CoSO4, Tween 80, 1% glucose, CXN2-3A đã sản xuất RSDE cao gấp 19,23 lần so với kiểu dại ở cùng điều kiện.

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This dissertation critically evaluates the issue of the `silencing' of the subaltern woman in the 1988 version of Gayatri Spivak's essay `Can the Subaltern Speak?' The conclusions reached are then related to the novel The Purple Violet of Oshaantu by the Namibian woman writer Neshani Andreas. Chapter 1 deals with the essay `Can the Subaltern Speak?' and the `silenced' subaltern woman, examining both Spivak's theory on this issue as well as criticism of this theory by different postcolonial theorists. Chapter 2 presents aspects of both the creative and political practice of women, specifically the woman writer, in certain countries in Africa. Chapter 3 deals with the novel The Purple Violet of Oshaantu by Neshani Andreas and explores issues like the `silencing' of the subaltern women in the novel, opposition to patriarchal oppression and the engendering of agency by both the writer and the characters in the novel. / English Studies / M. A. (English)

This study explores text and music relations in Canadian composer Violet Archer’s “The Twenty-Third Psalm” by analysing the text of Psalm 23, Fibonacci numbers, melodic contours, motives, and the role of the accompaniment. The text focuses on David’s faith in God and his acceptance of God as his shepherd on earth. The four other approaches allow us to examine the work on three different structural levels: background through Fibonacci numbers, middleground through melodic contour analysis, and foreground through motivic analysis and the role of the accompaniment. The measure numbers that align with Fibonacci numbers overlap with some of the melodic contour phrases, which are demarcated by rests, as well as with the most important moments at the surface level, such as the emphasis on the word “death” through recurring and symbolic motives. The piano accompaniment further supports these moments in the text.

La réparation par excision de nucléotides (NER) permet l'élimination des lésions provoquant une distorsion de la double hélice de l’ADN. Ces lésions sont induites par plusieurs agents environnementaux comme les rayons UV, ainsi que par certaines drogues chimio- thérapeutiques tel que le cisplatine. Des défauts dans la NER conduisent à de rares maladies autosomiques héréditaires : La xérodermie pigmentaire (XP), le syndrome de Cockayne (CS), le syndrome de sensibilité aux UVSS et la trichothiodystrophie (TTD). Ces maladies sont associées soit à une prédisposition élevée au cancer de la peau et / ou à de graves anomalies du développement neurologique. Le groupe de patients XP-A représente le deuxième groupe (XP) le plus fréquent, et possède la forme la plus sévère combinant cancer de la peau avec un haut risque de dégénérescence neurologique. À date, aucune explication n`a été proposée pour les symptômes neurologiques observés chez ces patients. Nous avions suggéré ainsi que la protéine XPA possède d`autres fonctions dans d`autres processus cellulaires, ceci en interagissant avec des partenaires protéiques différents de ceux déjà connus. Afin de confirmer cette hypothèse nous avions réalisé une étude protéomique à grande échelle en combinant la spectrométrie de masse à une immunoprécipitation en Tandem d`affinité (TAP), afin d`identifier de nouvelles protéines interagissant directement avec XPA. Nous avions montré que XPA peut interagir avec MRE11, la protéine clé de la réparation par recombinaison homologue. Des études additionnelles sont requises pour confirmer cette interaction et comprendre sa fonction / To maintain genome integrity and ensure the continuation of transcription, helix distorting DNA lesions induced by UV and other environmental mutagens are eliminated through a highly-versatile DNA repair pathway: nucleotide excision repair (NER). Mutations in 11 genes (XPC, XPE, XPB, XPD, XPG, XPA, XPG, TTD-A, CSA, CSB and UVSSA), among the 30 genes directly involved in NER, have been associated with the human genetic disorders: xeroderma pigmentosum (XP), cockayne syndrome (CS), trichothiodystrophy (TTD), and UV-sensitive syndrome (UVSS). Patients of these syndromes display a wide variety of clinical features that range from normal development with extreme predisposition to cancer, to neurodevelopmental defects associated with premature aging abnormalities. The connection between DNA damage and neurodegeneration remains unclear, i.e. cannot be explained by a DNA-repair deficiency alone, implying that various repair factors perform other functions beyond the repair process. XP-A is the second most common form of XP. XP-A cells have very low levels of NER activity and are sensitive to killing by UV light. It is one of the most severely affected XP groups, with the onset of cutaneous features, skin cancer, ocular features, and severe early onset neurological disease. Therefore we hypothesize that XPA interacts with cellular proteins that regulate its functions either in UV damage repair or in neurological development. To test this, our major aim was to carry out a large-scale proteomics investigation to identify novel interacting partners for XPA in the absence or presence of genotoxic stress, thus providing clues on the origins of neurodegeneration observed in many XP-A patients. We provide evidence that XPA can interact with MRE11, the key factor in repair of double strand breraks by homologous Recombination. Future experiments will be aimed at determining the impact of the XPA/MRE11 interaction functions in cells.