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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.
331

Avaliação oftalmológica e psicofísica do sistema visual de portadores de albinismo / Ophthalmologic and psychophysical evaluation of the visual system of individuals with albinism

Ronaldo Yuiti Sano 21 September 2017 (has links)
O albinismo e uma alteracao genetica rara que compromete a producao de melanina. As alteracoes clinicas consistem na falta de pigmentacao da pele, cabelo e pelos. Apresenta alteracoes oftalmologicas importantes, que comprometem a acuidade visual de forma severa, na grande maioria dos casos. As alteracoes oftalmologicas sao, ametropias, nistagmo, rarefacao do epitelio pigmentado da iris e da retina, hipoplasia foveal e decussacao anomala do nervo optico. Este estudo foi dividido em tres diferentes partes com os seguintes objetivos principais: Parte 1: Analise comparativa entre o grau de transparencia da iris (GTI), o grau de transparencia da retina (GTR) e a espessura da regiao macular com a acuidade visual nos pacientes com albinismo. Parte 2: Teste de sensibilidade ao contraste espacial de luminancia e ofuscamento com lentes de contato filtrantes em ambientes claros e escuros. Parte 3: Avaliacao da visao de cores, utilizando\\se o teste de Pranchas de Ishihara e o Cambridge Color Test (CCT). Material\' e\' Métodos: Participaram do estudo 121 individuos albinos, com idade media de 31,18 (} 15,47) anos, o que totalizou 242 olhos. Os participantes foram divididos em diferentes grupos nas tres partes do estudo, alguns participaram de uma ou mais partes. Na primeira parte os participantes foram submetidos a consulta oftalmologica, classificacao do grau de transparencia da iris e da retina em uma nova classificacao baseada em quatro diferentes graus de transparencia, alem de avaliacao foveal pelo exame de Tomografia de Coerencia Optica (OCT). Na segunda parte, os participantes foram submetidos ao teste de contraste computadorizado, utilizando lentes de contato filtrante e transparentes, em ambientes claros e escuros. Nesta etapa foi avaliada a influencia da lente filtrante na sensibilidade de contraste visual dos individuos com albinismo. Na terceira parte, os participantes foram submetidos aos testes de Pranchas de Ishihara e de Cambridge Colour Test (CCT), para avaliacao da visao de cores nos pacientes albinos. Resultados: Os resultados foram os seguintes: Parte\'1: A correlacao entre AV logMAR e GTI foi positiva (+0,569) e significativa (p<0,001). A correlacao entre AV logMAR e GTR foi positiva (+0,531) e significativa (p<0,001). A correlacao entre AV logMAR e a espessura macular nao foi significativa (p=0,105). A correlacao entre GTI e GTR foi positiva (+ 0,627) e significativa (p<0,001). A correlacao entre espessura macular e GTI nao foi significativa (p=0,397). A correlacao entre espessura macular e GTR nao foi significativa (p=0,458). Parte 2: Houve melhora estatisticamente significante da sensibilidade ao contraste com as lentes filtrantes em relacao as lentes transparentes no ambiente de ofuscamento (claro), na frequencia de 0,3 cpg, 0,6 cpg e 1,0 cpg (ciclos por grau). Nao houve melhora significante nas frequencia 2,0 cpg e 4,0 cpg. Nao houve melhora estatisticamente significante da sensibilidade ao contraste de lentes filtrantes em relacao as lentes transparentes no ambiente escuro (penumbra) em nenhuma das frequencias espaciais estudadas. Parte\' 3: Todos os individuos com albinismo nao apresentaram nenhuma alteracao de visao de cores no teste de Pranchas de Ishihara. O CCT demonstrou piora no limiar de deteccao de cores significativa nos eixos protan (p=0,021) e deutan (p=0,017), mas nao houve diferenca no eixo tritan (p=0,212). Os testes estatisticos sugerem que uma amostra maior seja estudada para validacao dos resultados / Albinism is a rare genetic alteration that compromises the production of melanine in all body tissues. The clinical alterations are the lack of pigment in the skin and hair. It presents important ophthalmological changes that compromise the visual acuity, in most cases. The ophthalmological changes are: ametropia, nystagmus, iris pigmented epithelium rarefaction, retina pigmented epithelium rarefaction, foveal hipoplasia and abnormal optic nerve decussation. This study has been divided in three different parts and had the following main objectives: Part 1, comparative analysis of the iris transparency degree (ITD), the retina transparency degree (RTD) and macular thickness with the visual acuity in albino patients. Part 2: Spatial contrast sensitivity test of luminance and outshine wearing contact lenses with filters in light and dark environments. Part 3: color vision evaluation using the Ishihara Test and the Cambridge Color Test (CCT). For the study 121 individuals with albinism were included with an average of 31,18 years old } 15,47, a total of 242 eyes. The participants were divided in different groups in the three parts of the study, some participated in one or more parts. In the first part the participants have been through an ophthalmological exam, classification of the iris transparency degree (ITD) and the retinal transparency degree (RTD) by a new classification based in 4 different degrees of transparency. Foveal evaluation by the Optic Coherence Tomography exam (OCT) was made in the first part of this study. In the second part, the participants have been submitted to the computerized contrast test, using filtered and transparent contact lenses in light and dark environments. In this part the influence of the filtering lenses in the visual contrast sensitivity in the albinism patients has been evaluated. In the third part, the participants have been submitted to Ishihara Test and Cambridge Color Test in order to evaluate the color vision in albino patients. The results are as follows: Part\' 1: the correlation between visual acuity in Logarithm of the Minimum Angle of Resolution (logMAR) and ITD was positive (+0,569) and significant (p<0,001). The correlation between visual acuity in logMAR and RTD was positive (+0,531) and significant (p<0,001). The correlation between visual acuity in logMAR and the macular thickness was not significant (p=0,105). The correlation between ITD and RTD was positive (+ 0,627) and significant (p<0,001). The correlation between the macular thickness and the ITD was not significant (p=0,397). The correlation between the macular thickness and the RTD was not significant (p=0,458). Part\'2: There has been a statistically significant improvement of the contrast sensitivity wearing the filtering lenses in relation to the transparent ones in bright environment, in the frequencies of 0,3 cycles per degree (cpd), 0,6 cpd and 1,0 cpd. There has been no significant improvement in the frequencies 2,0 cpd and 4,0 cpd. There has been no statistically significant improvement in contrast sensitivity wearing the filtering lenses in relation to the transparent one in the dark environment (shadow) in any of the spatial frequencies studied. Part\' 3: all albinism patients did not present any color vision change in the Ishihara Test. The CCT has shown a worsening in the color detection threshold in the protan axis (p=0,021) and deutan axis (p=0,017), but there has been no difference in the tritan axis (p=0,212). The statistic tests show that a bigger sample is recommended to confirm part 3 results
332

Modèles statistiques avancés pour la segmentation non supervisée des images dégradées de l'iris / Advanced statistical models for unsupervised segmentation of degraded iris images

Yahiaoui, Meriem 11 July 2017 (has links)
L'iris est considérée comme une des modalités les plus robustes et les plus performantes en biométrie à cause de ses faibles taux d'erreurs. Ces performances ont été observées dans des situations contrôlées, qui imposent des contraintes lors de l'acquisition pour l'obtention d'images de bonne qualité. Relâcher ces contraintes, au moins partiellement, implique des dégradations de la qualité des images acquises et par conséquent une réduction des performances de ces systèmes. Une des principales solutions proposées dans la littérature pour remédier à ces limites est d'améliorer l'étape de segmentation de l'iris. L'objectif principal de ce travail de thèse a été de proposer des méthodes originales pour la segmentation des images dégradées de l'iris. Les chaînes de Markov ont été déjà proposées dans la littérature pour résoudre des problèmes de segmentation d'images. Dans ce cadre, une étude de faisabilité d'une segmentation non supervisée des images dégradées d'iris en régions par les chaînes de Markov a été réalisée, en vue d'une future application en temps réel. Différentes transformations de l'image et différentes méthodes de segmentation grossière pour l'initialisation des paramètres ont été étudiées et comparées. Les modélisations optimales ont été introduites dans un système de reconnaissance de l'iris (avec des images en niveaux de gris) afin de produire une comparaison avec les méthodes existantes. Finalement une extension de la modélisation basée sur les chaînes de Markov cachées, pour une segmentation non supervisée des images d'iris acquises en visible, a été mise en place / Iris is considered as one of the most robust and efficient modalities in biometrics because of its low error rates. These performances were observed in controlled situations, which impose constraints during the acquisition in order to have good quality images. The renouncement of these constraints, at least partially, implies degradations in the quality of the acquired images and it is therefore a degradation of these systems’ performances. One of the main proposed solutions in the literature to take into account these limits is to propose a robust approach for iris segmentation. The main objective of this thesis is to propose original methods for the segmentation of degraded images of the iris. Markov chains have been well solicited to solve image segmentation problems. In this context, a feasibility study of unsupervised segmentation into regions of degraded iris images by Markov chains was performed. Different image transformations and different segmentation methods for parameters initialization have been studied and compared. Optimal modeling has been inserted in iris recognition system (with grayscale images) to produce a comparison with the existing methods. Finally, an extension of the modeling based on the hidden Markov chains has been developed in order to realize an unsupervised segmentation of the iris images acquired in visible light
333

Florists and feasts: a critical digital edition of Ralph Knevet's Rhodon and Iris

Howard, Ashley 08 September 2020 (has links)
One spring afternoon in 1631, the Norwich Society of Florists held a feast to celebrate and display its exquisite flowers. The celebration included an entertainment written just for the occasion—Ralph Knevet's quirky play about a war among flowers. Early modern florists were not the sort of people who sold cut flowers in shops; rather, they were experts in floriculture who applied this knowledge to cultivate new flowers. Norwich was already renowned for its gardens, but flowers soon became even more significant. Rhodon and Iris was performed just before tulipomania, a frenzy of tulip cultivation lasting from c.1634 – 1637. During this period, florists grew elaborate multi-coloured flower bulbs that sold for extremely high prices. In other words, the florists' feast and Knevet's play emerged when flowers were important to the economy and identity of Norwich. My thesis presents an open-access, digital critical edition of Rhodon and Iris encoded in TEI-P5. This edition offers an old-spelling transcription of the 1631 playbook, a modernized text with annotations, and a critical introduction. Responding to the need for more editions of non-canonical early modern plays, my research widens the otherwise Shakespeare-centric canon and helps make more early modern drama accessible to student readers. Rhodon and Iris also merits critical attention on its own grounds: an example of Caroline occasional drama, the play experiments with convention and offers a rare glimpse into the Society of Florists. My thesis approaches the play with special interest in editorial praxis, ecotheory, and the history of floriculture. The florists' feast delighted audiences and participated in a tradition of floral celebrations—one reaching, at least, from the ancient Roman ludi Florales to the modern Netflix series The Big Flower Fight. / Graduate / 2021-06-26
334

Výpočetní analýza chování aktivní zóny tlakovodního jaderného reaktoru pomocí kódu PARCS / Computational analysis of pressurized water reactor core behaviour using PARCS code

Novotný, Filip January 2014 (has links)
The Master Thesis performs search concerning advanced small and medium power light-water reactors’ designs, including different possibilities to gain a license for their development and operation. The work covers the principal theory about the area of neutronics calculations, principal equations and simplifications. There are several different methods for solution of neutronics calculations. The thesis gives an overview of two principal groups of codes – deterministic methods and Monte Carlo method. The survey shows computational codes examples based on mentioned methods. The computational code PARCS is chosen for further study, which contained description of the input and output file, process of the model creation and conditions for neutronics calculation the of selected reactor design. Based on these facts, the transient calculation has been prepared within the thesis. Thee analyses are described – reactor emergency shutdown, reactor shutdown with stuck group of control and emergency shutdown rods and reactor shutdown with faulty reaction of emergency shutdown rods.
335

Vývoj MAC protokolu pro bezdrátové senzorové sítě / MAC Protocol for Wireless Sensor Networks

Michálek, Tomáš January 2016 (has links)
The work focuses on introduction to the topic of wireless sensor networks and brings readers the various aspects of problem solving in these networks. Work is closely focused on the energy performance when communicating between devices on a network and discusses the causes of excessive energy consumption. It also addresses the mechanisms for saving energy and is also engaged today protocols that its contribution to proposing solutions to problems. The author had also proposes an adapted protocol, based on lessons learned from previous theoretical sources.
336

Le concept de responsabilité politique selon I.M. Young appliqué dans le contexte des déchets électriques et électroniques

Labrecque, Steven Éric 08 1900 (has links)
Ce mémoire court a comme objectif d’appliquer le concept de responsabilité politique développé par Iris Marion Young dans Responsibility for Justice, ainsi que son modèle de connexion sociale, au contexte du recyclage des déchets électriques et électroniques. Au premier chapitre, il sera question en un premier temps d’explorer comment Young définit ses concepts et comment ils diffèrent des conceptions plus traditionnelles de la responsabilité. Au chapitre suivant, il s’agira de comprendre à quels problèmes philosophiques Young tente de répondre. Il sera intéressant ici de voir comment Young se distingue de J. Rawls, de comment elle s’inspire d’H. Arendt et comment elle se distance de l’approche nationaliste de D. Miller. Enfin, au dernier chapitre, ce travail termine par une application du modèle de Young au contexte du recyclage des déchets électriques et électroniques. Bien qu’il y ait des similitudes avec l’étude de cas présenté par Young dans Responsibility for Justice, des différences marquées dans les types d’interactions sociales à la source des injustices structurelles illustrent la pertinence d’utiliser le modèle de Young afin d’entamer une réflexion sur les solutions possibles. Ce mémoire court se veut donc être une sorte d’hommage à la pensée de Young qui est toujours d’actualité. / The objective of this short-form master thesis is to put in application the concept of political responsibility and its social connexion model developed by Iris Marion Young in Responsibility for Justice to the context of e-waste. In the first chapter, we will start by exploring how Young define her concepts and how they differ from traditional conceptions of responsibility. In the second chapter, we will see which philosophical questions Young wanted to address with her model. It will be interesting to see how she distinguishes her theory to the one of J. Rawls, how she seeks inspiration in the thoughts of H. Arendt, and how she distances herself from the national conception of responsibility developed by D. Miller. Finally, in the last chapter, this work ends with an application of Young’s social connection model to the context of e-waste. While there are some similarities with the case study presented by Young in Responsibility for Justice, the context of e-waste provides a different insight on the many types of social interactions at the source of structural injustices, and how Young’s theory is useful for a reflection about the possible solutions. This work is a kind of tribute to the thoughts of Young which are still relevant today.
337

Classification, réduction de dimensionnalité et réseaux de neurones : données massives et science des données

Sow, Aboubakry Moussa January 2020 (has links) (PDF)
No description available.
338

Разнообразие морфологических и структурных признаков поглощающих корней четырех семейств бореальных однодольных : магистерская диссертация / Variety of morphological and structural signs of absorbing roots of four families of breal monocots

Анянова, Ю. А., Anyanova, Y. A. January 2021 (has links)
Данная работа содержит 52 страницы машинописного текста, включая 19 рисунков, 1 таблицу и 106 литературных источников. Работа посвящена изучению разнообразия совокупности признаков корней четырех семейств однодольных растений – Orchidaceae Juss., Iridaceae L., Poaceae Barnhart и Cyperaceae Juss., в условиях бореальной климатической зоны. В анализ вошли материалы, предоставленные научным руководителем (данные по строению корней представителей семейств Orchidaceae, Poaceae, Cyperaceae) и оригинальные сборы. Цель – выявить разнообразие синдромов корневых признаков у четырех семейств однодольных растений бореальной зоны. Для достижения цели были поставлены следующие задачи: изучить строение поглощающих корней представителей семейств Orchidaceae, Iridaceae, Poaceae, Cyperaceae; изучить внешние признаки корневых систем представителей семейств Orchidaceae, Iridaceae, Poaceae, Cyperaceae; сравнить комплекс количественных и качественных признаков в масштабе всей корневой системы у таксонов с разными типами микориз, а также с преобладанием немикоризных видов. С помощью классических методов структурной ботаники были изучены внешние признаки корневых систем и строение поглощающих корней. Получали микротомные срезы поглощающих корней, которые анализировали под микроскопом Leica DM 5000 в светлом поле и в синих лучах длиной волны 365 нм (флуоресцентная микроскопия). С помощью окулярмикрометра измеряли диаметр корня и стелы, толщину коры, длину корневых волосков, подсчитывали число сосудов ксилемы. На продольных препаратах определяли встречаемость корневых волосков. Число порядков ветвления корневой системы фиксировали по функциональной классификации [McCormack et al., 2015]. Установление микоризации выполняли методом световой микроскопии (Leica DM 5000; ×100) после предварительной мацерации корней в КОН и окрашивания анилиновым синим [Селиванов, 1981]. Обработка данных производилась в программе EXCEL, а с помощью программы STATISTICA был проведен однофакторный дисперсионный анализ ANOVA. Результаты исследований показали, что корни разных таксонов однодольных сильно различаются по внешнему и внутреннему строению. Были выявлены синдромы корневых признаков: Orchidaceae – толстые не ветвящиеся корни с сильно развитой специализированной микоризой, с относительно толстой корой и стелой, длинными корневыми волосками и без выраженной экзодермы; Iridaceae – толстые сильно разветвленные корни с мощной экзодермой, короткими редко встречающимися корневыми волосками и интенсивной АМ; Poaceae – тонкие разветвленные корни с невыраженной экзодермой, с короткими, часто встречающимися корневыми волосками и интенсивной АМ; Cyperaceae – тонкие, сильно разветвленные корни с хорошо развитыми корневыми волосками и другими приспособлениями к автономному почвенному питанию, АМ встречается редко. / This work contains 52 pages of typewritten text, including 19 figures, 1 table and 106 literature sources. The work is devoted to the study of the diversity of the totality of the traits of the roots of four families of monocotyledonous plants – Orchidaceae Juss., Iridaceae L., Poaceae Barnhart and Cyperaceae Juss., in the conditions of the boreal climatic zone. The analysis included materials provided by the scientific advisor (data on the structure of roots of representatives of the families Orchidaceae, Poaceae, Cyperaceae) and original collections. The goal is to identify the diversity of root trait syndromes in four families of monocotyledonous plants in the boreal zone. To achieve the goal, the following tasks were set: to study the structure of absorbing roots of representatives of the families Orchidaceae, Iridaceae, Poaceae, Cyperaceae; to study the external signs of root systems of representatives of the families Orchidaceae, Iridaceae, Poaceae, Cyperaceae; to compare the complex of quantitative and qualitative characters on the scale of the entire root system in taxa with different types of mycorrhizal, as well as with a predominance of nonmycorrhizal species. Using classical methods of structural botany, the external signs of root systems and the structure of absorbing roots were studied. Received microtome sections of absorbing roots, which were analyzed under a Leica DM 5000 microscope in a bright field and in blue beams with a wavelength of 365 nm (fluorescence microscopy). Using an eyepiece micrometer, the following was measured: the diameter of the root and stele, the thickness of the cortex, the length of root hairs, and the number of xylem vessels was counted. On longitudinal preparations, the occurrence of root hairs was determined. The number of orders of branching of the root system was fixed according to the functional classification [McCormack et al., 2015]. Mycorrhiza was determined by light microscopy (Leica DM 5000; × 100) after preliminary maceration of the roots in KOH and staining with aniline blue [Selivanov, 1981]. The data were processed using the EXCEL program, and the one-way ANOVA was carried out using the STATISTICA program. The research results showed that the roots of different monocotyledonous taxa differ greatly in their external and internal structure. Syndromes of root signs were identified: Orchidaceae – thick non-branching roots of with highly developed specialized mycorrhiza, with relatively thick bark and stele, long root hairs and without pronounced exoderm; Iridaceae – thick, highly branched roots of with powerful exoderm, short rare root hairs and intense AM; Poaceae – thin branched roots of with an indistinct exoderm, with short, frequently occurring root hairs and intense AM; Cyperaceae – thin, highly branched roots of with well-developed root hairs and other adaptations to autonomous soil nutrition, AM is rare.
339

Den mångfasetterade Guden : Att inte begränsa Gud / The multifaceted God : Not to limit God

Söderberg Almén, Björn January 2020 (has links)
Detta är en uppsats som tar sig an, på ett semantiskt sätt, ordet Gud och människors syn på vad ordet Gud har för betydelse. Genom att göra en idéanalys av Jonna Bornemarks analys av Nicolas Cusanus för att se om detta kan vara en väg för att ge en mera mångfasetterad bild och värde av ordet Gud och gudsbilden till den scientistiska människan i Sverige. Uppsatsen tar avstamp i att försöka visa på de nycklar Cusanus filosofi ger genom Jonna Bornemarks tolkning av Cusanus i Det omätbaras renässans. / Nicholas Cusanus levde mellan åren 1401 och 1464. Cusanus var astronom, matematiker, teolog och filosof. En verklig renässansmänniska. Cusanus var en man som var på gränsen mellan skolastiken på medeltiden och renässansens mera kosmopolitiska livshållning som tiden gav. Cusanus var starkt influerad av den mystiken som bland annat Mäster Eckhart stod bakom. Den mystika negativa teologin som talade om att det är enklare att beskriva vad den kristna Gud inte är, än att berätta vad som Gud är. Cusanus studerade både Aristoteles och den Plotinos nyplatonska filosofin. Denna filosof kom jag kontakt med genom Cusanus lilla bok Gudsseendet med stort innehåll, vilket han skrev som en guide till munkarna i Tegernsee. Den behandlar den sinnliga bilden och de begrepp som gör att man kan se det som kan finnas bakom den ikoniska bilden. Den ikoniska bilden uppfattar Cusanus vara det djup som en bild kan vara bärare av. Det symboliska värdet på den bild som väcker åskådarens reflektion och reaktion. Den ikoniska bilden är bärare av detta djup som kan vara en utlösande av det personliga symboliska värdet för den specifika bilden. I Gudseendet är det en ikon som Cusanus kallar för ”Guds ikon”. Cusanus öppnade dörrar för mig i hur man kan tänka om att inte ser med de fysiska sinnena, utan måste använda sitt inre öga för att kunna se det som är större än det jag bara kan med de fysiska sinnena erfara. Startpunkten till denna uppsats är att kanske kunna förstå hur människan kan komma närmare det som inte sinnligt kan erfaras, den kunskapen menar Cusanus behöver människan för att vara en hel människa. Bornemark tar Cusanus filosofi till dagens samhällsproblem med att samhället alltid vill mäta allting. Studiens inriktning är att försöka svara på de frågor som uppsatsen ställer inför Bornemarks tolkning av Cusanus filosofi. / <p>På grund av corona utfördes framläggningen online.</p>
340

An Approach to Lens Regeneration in Mice Following Lentectomy and the Implantation of a Biodegradable Hydrogel Encapsulating Iris Pigmented Tissue in Combination with Basic Fibroblast Growth Factor

Baddour, Joelle 11 May 2012 (has links)
No description available.

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