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No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese_GreisensEpisienitosPotassicos.pdf: 89699509 bytes, checksum: 22e7d0b5f3ac698524af92dcf777f5bc (MD5) Previous issue date: 2002-10-23 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / Na borda oeste do pluton Água Boa, na mina Pitinga (AM), ocorrem três tipos de greisens estaníferos associados espacialmente à fácies granito rapakivi: greisen 1 (Gs1), constituído principalmente por quartzo, topázio, siderofilita marrom e esfalerita; greisen 2 (Gs2), formado essencialmente por quartzo, fengita e clorita; greisen 3 (Gs3), constituído essencialmente por quartzo, fluorita e fengita, com quantidades subordinadas de siderofilita verde. Além disso, associado ao Gs2, ocorre um epi-sienito potássico (EpSK), formado pela dessilicificação do granito rapakivi. Apesar de suas diferenças composicionais e petrográficas, os greisens e epi-sienitos se formaram a partir do mesmo protólito granítico, um hornblenda-biotita-álcali-feldspato-granito a sienogranito. O Gsl apresenta uma zonação interna definida pela predominância de determinados minerais. Assim, ao longo de um halo de alteração contínuo, a zona rica em siderofilita (ZS) está em contato com o granito greisenizado, enquanto que a zona rica em topázio (ZT) situa-se mais afastada do granito. A siderofilita marrom apresenta teores moderados em AI, e sua variação composicional ocorre pela substituição de Fe+2 por A1+3 e Li nos sítios octaédricos, com geração de vacâncias, e concomitante substituição de A1+3por Si+4nos sítios tetraédricos. No Gs2, as zonas mineralógicas estão separadas espacialmente, em níveis onde predomina a fengita (ZF) ou a clorita (ZC). A fengita apresenta um mecanismo evolutivo em que o viAl é substituído por Fe+2 nos sítios octaédricos, com enriquecimento acoplado de Si+4 às expensas de A1+3 nos sítios tetraédricos. Seus teores de Li calculado são ainda menores do que aqueles estimados para a siderofilita do Gs1. No Gs3, a siderofilita verde é composicionalmente mais rica em VIAl e mais pobre em F do que a siderofilita do Gsl, enquanto que a fengita subdivide-se em dois tipos composicionais: uma fengita mais aluminosa, pobre em Fe+2, e uma mais rica em F e Fe+2, que segue os mesmos trends evolutivos apresentados pela fengita do Gs2. A clorita dos três greisens é extremamente rica em Fe, do tipo dafnita. Na sua estrutura, a substituição de 'JIA' por cátions R+2 causa um aumento na ocupação tetraédrica do Si. As cloritas mais aluminosas apresentam as mais altas temperaturas de formação, segundo os geotermômetros clássicos propostos na literatura. Os greisens são resultantes de diferentes processos de interação entre três fluidos principais: (1) fluido aquo-carbônico de baixa salinidade, rico em F, com temperaturas iniciais entre 400° e 350°C, presente durante a formação do Gs1 e Gs3; (2) fluido aquoso de baixa salinidade, e temperatura ao redor de 300°C e que, ao longo de um processo contínuo de salinização, gera um fluido residual de salinidade moderada a alta, com temperaturas entre 200° e 100°C, presente durante a formação do Gs2 e no estágio de silicificação do EpSK; (3) fluido aquoso de baixa salinidade, com temperaturas entre 2000 e 150°C, e que interagiu com os outros dois fluidos, contribuindo, em diferentes graus, para a formação de praticamente todas as rochas hidrotermais. Os dois primeiros fluidos aparentemente têm origem ortomagmática, enquanto que o último tem características de fluido superficial (meteórico?). Além destes, considera-se que o fluido responsável pelo estágio inicial do processo de epi-sienitização não ficou registrado nas amostras estudadas. Estes fluidos foram aprisionados em condições de pressão ao redor de 1 Kb, compatível com níveis crustais rasos, como parece ser o caso dos granitos estaniferos de Pitinga. Tanto a epi-sienitização quanto a greisenização ocorreram sem mudanças no volume original do granito, enquanto as variações de massa decorrentes das transformações causaram as diferenças nas densidades das rochas alteradas. A greisenização causou uma grande remoção em Na2O e K2O, enquanto que SiO2 permaneceu imóvel no Gsl e foi parcialmente removido no Gs2. O Al2O3 sofreu perdas durante a formação do Gs2, mas foi parcialmente adicionado ao Gsl. Os responsáveis pelo aumento de massa durante a greisenização foram Fe2O3 (Fe total), Sn, S, voláteis (P.F.) e F. No Gsl, a diminuição da atividade do F e o aumento da fO2 durante o resfriamento, causaram mudanças químicas nos fluidos, e a conseqüente diferenciação entre a ZT, nas porções mais internas dos condutos/fraturas, e a ZS, mais próxima do granito encaixante. O Gs3 foi formado sob condições mais oxidantes e por fluidos mais pobres em F do que aqueles aprisionados na ZS. A geração de cavidades de dissolução durante a epi-sienitização aumentou a permeabilidade das rochas alteradas, propiciando o aumento das razões fluido-rocha no sitio de formação do EpSK e Gs2. A interação dos fluidos aquosos com os feldspatos do EpSK, durante a formação do Gs2, causou um aumento contínuo na sua salinidade. A ZF foi formada nos estágios mais precoces desta interação, sob temperaturas relativamente mais altas, enquanto que a ZC é um produto dos fluidos aquosos residuais, mais salinos e mais frios. Estes fluidos residuais também foram aprisionados no quartzo de preenchimento de cavidades no EpSK durante o processo de silicificação tardia. Desta forma, os greisens e epi-sienitos potássicos foram formados pela interação entre, pelo menos, três fluidos de origem aparentemente independente, a partir do mesmo protólito granítico, em condições de crosta rasa. As variações nas condições de fO2, atividade do F e salinidade, durante o resfriamento do sistema hidrotermal, e contrastes nas razões fluido-rocha causadas por diferenças de permeabilidade, foram fatores fundamentais para a diferenciação dos greisens. Estes fatores influenciaram sobremaneira as mudanças composicionais dos fluidos e foram responsáveis pela precipitação de cassiterita e sulfetos nos greisens, e pelo enriquecimento em Sn e S durante a greisenização tardia dos epi-sienitos potássicos. / Three stanniferous greisen types were characterized in the western border of Água Boa pluton, Pitinga mine (AM), associated with the rapakivi granite facies: greisen 1 (Gsl), composed mainly by quartz, topaz, brown siderophyllite and sphalerite; greisen 2 (Gs2), composed essentially by quartz, phengite and chlorite; greisen 3 (Gs3), composed of quartz, fluorite and phengite, with minor green siderophyllite. Besides these rocks, a potassic episyenite (EpSK) was identified associated with the Gs2. In spite of the compositional and petrographic differences, all of these hydrothermal rocks derived from a same protholith, a hornblende biotite aikali feldspar granite to syenogranite. The Gsl shows an inner mineralogical zoning defined by topaz or siderophyllite predominance. Along drill cores, the siderophyllite-rich zone occurs near the contact with the greisenized grafite and the topaz-rich zone is situated far from the grafite contact. The brown siderophyllite displays moderated Al contents, and its compositional changes can be explained by Fe+2 substitution for A1+3 and Li in octahedral sites, with a coupled Al+3 substitution for Si+4 in tetrahedral sites. The mineralogical zones in the Gs2 are physicaliy separated in leveis with phengite or chlorite predominance. The mica of Gs2 is a phengite, whose chemical variation is due to substitution of viAl for Fe+2, coupled with Si+4 enrichment. The calculated Li contents in phengites are lesser than those estimated in siderophyllite. The green siderophyllite from Gs3 is VIAl richer and F poorer than Gs1 brown siderophyllite, and the phengite displays two compositional types: an early Fe+2-poor aluminous phengite and a later Fe+2- F-rich one whose chemical variation is similar to that of Gs2 phengite. The chlorite from the three greisen is a Fe-rich daphnite, and its compositional range is due to VIAl substitution for R+2 cations, coupled with Si+2 enrichment. The aluminous chlorite displays higher temperature formation than ferrous one, according to the geothermeter proposed in the literature. The Pitinga greisens were formed by different processes of interaction among three main fluids: (1) low salinity, F-rich, aquo-carbonic fluid, with initial temperatures between 400° -350°C, present during Gsl and Gs3 formation; (2) low salinity aqueous fluid, with a temperature around 300°C, which during a progressive salinity increasing process, originates a moderate to high salinity residual fluid, with temperatures between 200° - 100°C, present during the Gs2 formation and silicification stage of EpSK; (3) low salinity aqueous fluid, with temperatures between 200° - 150°C, which interplayed with the others two fluids in differents grades, contributing to the formation of ali the hydrothermal rocks. The first two fluids has seemingly an orthomagmatic origin while the latter has a surface characteristic (meteoric water?). Moreover, the data suggests that the fluid responsible by the initial stage of the episyenitization process was not registered in the studied samples. These fluids were trapped in pressure conditions around 1 Kbar, representing high crustal levels conditions, similar to that of the stanniferous granites from Pitinga. Both episyenitization and greisenization processes occurred without volume changes in the granitic protholith, and the density differences of the altered rocks were caused by the mass variations along the alteration processes. The greisenization process caused a extensive loss of Na2O and K2O, while SiO2 showed a immobile behaviour in Gsl but was parcially removed in Gs2. The Al2O3 was depleted during the Gs2 formation but added in Gsl. The Fe2O3 (Fe total), Sn, S, volatiles LOl and F were the responsible by the mass increase at greisenization. In the Gsl, the chemical changes in the fiuids were caused by F activity decrease and fO2 increase during cooling. These changes also originated the differentiation between the ZT, in the inner portions of the fratures/conducts, and the ZS, nearest to surrounding gravite. The Gs3 was formed in more oxidizing conditions by F-poorer fiuids than those trapped in the ZS. The dissolution cavities generated during the episyenitization process increased the permeability of the altered rocks, providing an increase of fluid/rock ratios in the EpSK and Gs2 sites. The interaction between aqueous fluid and EpSK feldspar, during the Gs2 formation, caused a continuous salinity increase. The ZF was formed in the early stages of this interaction, at higher temperatures, while the ZC was originated by the more cold and saline, residual fluid. The latter was also trapped in the quartz filling cavities in the EpSK during the later silicification stage. In this way, the greisens and the potassic episyenites were generated from interactions among, at least, three fluids of seemingly independent origin, from a same protholith, in shallow crust conditions. The fO2, F activity and salinity variations, during the hydrothermal system cooling, and the contrast in fluid/rock ratios caused by permeability differences, were very important factors to greisen differentiation. These factors controlled greatly the fluids compositional changes, and caused the cassiterite and sulphides precipitation in the greisens and the Sn- S-enrichment during later greisenization of EpSK.

Chapter 1. An Overview of Bile Acid Science This chapter deals with an overview of bile acid science (cholanology) compiling elevant literature review, covering bile acid chemistry, biosynthesis, bile salt evolution, physiology and medicinal values. Figure 1. (a) Digestive system; (b) enterohepatic circulation and (c) cholic acid Bile acids are the end products of cholesterol metabolism, secreted in the liver and stored in the gall bladder (Figure 1). They are normally conjugated with glycine (75%) or taurine (25%). Because of their facially amphiphilic nature, bile salts tend to form micellar aggregates in aqueous solution. They have remarkable ability to transform lamellar array of lipids into mixed micelles. All primary bile acids seem to have three features in common: (1) They are major products of cholesterol metabolism; (ii) they are secreted into the bile largely in a conjugated form and (iii) the conjugates are membrane impermeable, water soluble, amphiphilic molecules. Recent advances in molecular biology have greatly accelerated the knowledge relating to the significance of bile salts in a number of physiological functions. The new role of bile salts as pheromones and ligands for nuclear hormone receptors has been discussed. Chapter 2. Pythocholic Acid: A Major Constituent of Python’s Bile and 16α-Hydroxycholic Acid: A Minor Constituent of Avian’s Bile The first chemical synthesis of pythocholic acid (major constituent of python’s bile) and 16α-Hydroxycholic acid (a minor constituent of avian’s bile) were accomplished starting from cholic acid with overall yields of 5.0% and 5.5%, respectively. A biomimetic remote functionalization strategy was utilized as a key step to achieve the selective chlorination at C-17. Dehydrochlorination of 17-chlorosteroid resulted in the Δ16 olefin. Hydroboration-oxidation of the Δ16 olefin followed by the selective oxidation of the pentol under TEMPO mediated oxidation resulted in an ε-lactone. Hydrolysis of the lactone using 5% KOH in MeOH furnished the 16α-Hydroxycholic acid. On the other hand, selective oxidation of 7-OH of the lactone was achieved using N-bromosuccinimide in acetone/H2O to yield the 7-keto lactone. The ketolactone when subjected to the Huang-Minlon modification of the Wolf-Kishner reduction furnished pythocholic acid. Pythocholic acid showed unusual aggregation behavior and high cholesterol solubilization ability, compared to other trihydroxy bile acids. Chapter 3. 16-Epi-pythocholic acid: An Unnatural Analogue of Pythocholic Acid The synthesis of 16-epi-pythocholic acid, an unnatural analogue of pythocholic acid, was accomplished starting from cholic acid. Cholic acid was converted to Δ8-14) olefin using ZnCl2 in refluxing acetone. Methylation followed by isomerization in CHCl3 by passing dry. HCl at -78 oC resulted in the Δ14 olefin. Allylic oxidation using Na2Cr2O7.2H2O in the presence of N-hydroxysuccinimide in acetone furnished the enone. Selective reduction of the olefin using Pd/C-H2 resulted in 16-Epi-pythocholic acid the 16-keto steroid. NaBH4 reduction of this ketone in MeOH/THF (2:1 v/v) followed by hydrolysis produced the 16-OH bile acid. Analysis of spectral data confirmed that it is a 16β-epimer of pythocholic acid (3α,12α,16β-trihydroxy-5β-cholan-24-oic acid). Critical micellar concentration and cholesterol solubilization properties were studied. Chapter 4. Low Molecular Mass Organogelators Derived from Simple Esters of Cholic Acid This chapter begins with an introduction to low molecular mass organogelators and highlights their applications. Serendipitous gelation of a number of organic solvents by allyl cholate and the design of related simple esters of cholic acid are discussed. A series of simple and easily accessible esters of bile acids were prepared. Ethyl cholate and propyl cholate were found to immobilize a variety of organic solvents like benzene, toluene, xylene, mesitylene, 1,2-dichlorbenzene (DCB) and chlorobenzene (Figure 2). The morphology of the xerogels was well characterized using SEM, AFM and polarizing optical microscopy (POM) techniques, Which revealed the presence of highly entangled self-assembled 3D-fibrillar network (SAFINs). The fiber diameter was found to vary between 300-500 nm. Direct imaging of the collapse of this fibrillar network and direct observation of the evolution of nanofibers was achieved for the first time using variable temperature POM techniques. FT-IR studies, X-ray powder diffraction and variable temperature POM studies revealed the resemblance of SAFINs to the bulk solid. Formation of helical fibrillar network was observed in SEM images and the existence of chiral aggregates was confirmed by induced circular dichroism experiment using achiral Reichardt’s dye as the chromophore. Chapter 5. Ambidextrous Gelators Derived from Spacer Linked Bile Acid Derivatives Based on our observation of simple esters of cholic acid as organogelators a rational design of a series of spacer linked dimers and tripodal derivatives were carried out. Some of these molecules formed highly transparent gels in solvents like haloarenes, anisole, xylene and dibromoalkanes. These molecules also showed rapid gelation in DMF/H2O and DMSO/H2O mixtures in varying proportions of water and the co-solvent. These types of gelators are known as ambidextrous gelators. The xerogels were characterized using SEM, TEM and POM techniques and the presence of highly entangled 3D-fibrillar network (Figure 3) was observed. XRPD showed crystalline nature of bulk solid, whereas the xerogels were shown to lose their crystalline nature. (For figures and structural formula pl see the pdf file.)

Die Agrar- und Forstpolitiken der EU und Deutschlands stehen in einem politökonomischen Spannungsverhältnis zwischen Wertschöpfung und Rohstoffproduktion als ökonomieorientierte Ziele einerseits, der Ökologisierung der Landnutzung andererseits und schließlich dem Ziel der Förderung der ländlichen Entwicklung. In wissenschaftlichen und staatlich-politischen Diskursen und Analysen hinsichtlich der Politiksektoren Land- und Forstwirtschaft wurden Nachhaltigkeitsaspekte in den letzten 25 Jahren stark betont. Insbesondere dem politisch-praktischen Konzept der Politikintegration kommt in den Diskursen und Analysen eine zentrale Bedeutung zu. Die Studie untersucht die agrar- und forstpolitischen Prozesse der Umsetzung von EU-Umweltschutz in der deutschen Land- und Forstwirtschaft und leistet einen Beitrag zur qualitativen Erforschung sektoraler Machtverhältnisse. Im Hinblick auf die Entwicklung der Policy-Analyse entspricht die Studie dem Anspruch der Theorieintegration, da eine kritisch-materialistische Perspektive auf politische Prozesse, eine materialistische Staatstheorie, das Konzept der Politiksektoren zusammengeführt werden und dazu beitragen Politikintegrationsprozesse zu analysieren. Im Ergebnis stellt die Studie anhand von vier Fallstudien in den Bundesländern Brandenburg (BB), Niedersachsen (NI), Nordrhein-Westfalen (NW) und Sachsen-Anhalt (ST) und anhand der drei policy issues Reduzierung von Treibhausgasemissionen, Reduzierung von Stoffeinträgen in die Umweltmedien Boden und Wasser und Förderung der biologischen Vielfalt den Ist-Zustand der Umsetzung von Nachhaltigkeitszielen und EU-Umweltschutzpolitiken in der Land- und Forstwirtschaft dar. Anhand der Agrar- und Forstpolitiken in BB, NI, NW und ST in den Förderperioden 2000-2006 und 2007-2013 wird aufgezeigt, dass die Umsetzung von EU-Umweltschutzzielen von der politökonomischen Entwicklung der Sektoren abhängt. Sowohl die Agrar- und Forstbürokratien als auch privatwirtschaftliche AkteurInnen dominieren die Umsetzung von EU-Umweltschutz. Profitorientierung und ökonomische Regionalentwicklung als Ideologiefragmente der dominanten Status quo- und ökonomieorientierten AkteurInnen setzen Ökologisierungsansätze permanent dem Sachzwang der Profitabilität aus. In den Machtverhältnissen und Kämpfen um die Verallgemeinerung von AkteurInneninteressen dominieren die Status quo- und ökonomieorientierten AkteurInnen die politischen Prozesse durch einen privilegierten Zugang zu den Entscheidungszentren, die ideologische Kongruenz zwischen der Ministerialbürokratie und den dominanten Unternehmensverbänden, die Abhängigkeit der öffentlichen Bürokratien von einer gelingenden Wertschöpfung und der Befassungskontinuität zentraler policy entrepreneure innerhalb der Ministerialbürokratien und der damit verbundenen Policy-Stabilität. Politikintegrationsprojekte wie der produktionsintegrierter Natur- und Umweltschutz (Integrativer Naturschutz) in der deutschen Forst- und Landwirtschaft als Modus der Umsetzung von EU-Umweltschutz führen zur Legitimation und Reproduktion der bestehenden Produktionsweise.

In recent years, a compound N-nitrosodimethylamine (NDMA), a probable human carcinogen, has been identified as an emerging disinfection by-product (DBP) since its formation and detection were linked to chlorine-based disinfection processes in several water utilities in the U.S. and Canada. Numerous organic nitrogen compounds present in water may impact the formation of NDMA during disinfection. Amine-based water treatment polymers used as coagulants and flocculants have been suggested as potential NDMA precursors due to the presence of amine functional groups in their structures, as well as the possible presence of dimethylamine (DMA) residues in polymer products. To minimize the potential risk of NDMA associated with water treatment polymers, the mechanisms of how the polymers behave as NDMA precursors and their contribution to the overall NDMA formation under actual water treatment conditions need to be elucidated. This research involved a systematic investigation to determine whether amine-based water treatment polymers contribute to NDMA formation under drinking water and wastewater treatment conditions, to probe the involved reaction mechanisms, and to develop strategies to minimize the polymers NDMA formation potential. The investigation included five research tasks: (1) General screening of NDMA formation potential of commonly used amine-based water treatment polymers, (2) NDMA formation from amine-based water treatment polymers under relevant water treatment conditions, (3) Probing the mechanisms of NDMA formation from polyamine and PolyDADMAC, (4) Effect of water treatment processes on NDMA formation from amine-based water treatment polymers, and (5) Developing strategies to reduce polymers NDMA formation potential. Direct chloramination or chlorination of high doses of polymers in deionized water at longer than typical contact time was used in the general screening of the NDMA formation potential of water treatment polymers and in the studies to identify reaction mechanisms. On the other hand, realistic dosages of chloramines and polymers and contact time were used in simulating representative water treatment conditions to evaluate the contribution of polymers to the overall NDMA formation in real systems. On the basis of the study results, strategies were developed to reduce the NDMA formation potential of amine-based water treatment polymers, which include modification of polymer structures and treatment parameters.

Σκοπός της παρούσας διδακτορικής διατριβής είναι η ανάπτυξη αλγορίθμων επεξεργασίας ιατρικής εικόνας για την ενσωμάτωση τους σε ιατρικές εφαρμογές ακτινοθεραπευτικού ενδιαφέροντος. Οι αλγόριθμοι αυτοί στηρίζονται στην αρχή λειτουργίας των χαρτών αυτο-οργάνωσης Kohonen και αξιοποιούν την πληροφορία που περιέχεται σε περιοχές των εικόνων γύρω από σημεία ενδιαφέροντος, ώστε να εντοπίσουν αυτόματα, με ακρίβεια και αξιοπιστία, αντιστοιχίες μεταξύ των εικόνων. Πιο συγκεκριμένα, ένας επαναληπτικός αλγόριθμος προτείνεται για την αυτόματη εύρεση αντίστοιχων σημείων σε ιατρικές εικόνες δύο διαστάσεων. Ο προτεινόμενος αλγόριθμος προϋποθέτει την εύρεση σημείων ενδιαφέροντος μόνο στη μια από τις δύο εικόνες και εντοπίζει τα αντίστοιχα σημεία στη δεύτερη εικόνα μέσα από μια επαναληπτική διαδικασία, η οποία προσομοιάζει τη φάση εκπαίδευσης του νευρωνικού δικτύου. Με βάση τα ζεύγη των αντίστοιχων σημείων, υπολογίζονται στη συνέχεια οι παράμετροι ενός μετασχηματισμού, κατάλληλου για να περιγράψει τη σχέση μεταξύ των δεδομένων εικόνων. Ο αλγόριθμος ευθυγράμμισης εφαρμόζεται σε δεδομένες εικόνες ηλεκτρονικής πυλαίας απεικόνισης (Electronic Portal Images), που λαμβάνονται πριν από κάθε συνεδρία της ακτινοθεραπείας, για τον υπολογισμό του σφάλματος τοποθέτησης του ασθενούς. Το ζήτημα της επαλήθευσης της θέσης του ασθενούς στην ακτινοθεραπεία αντιμετωπίζεται επίσης με τη βοήθεια μιας αυτόματης μεθόδου εύρεσης αντίστοιχων σημείων σε τρισδιάστατα δεδομένα, η οποία εφαρμόζεται για την ευθυγράμμιση της αξονικής τομογραφίας του σχεδιασμού της ακτινοθεραπείας και μιας αξονικής τομογραφίας επαλήθευσης, που λαμβάνεται πριν την πρώτη συνεδρία της ακτινοθεραπείας. Ο προτεινόμενος αλγόριθμος εντοπίζει αντίστοιχα σημεία ενδιαφέροντος στις δεδομένες τομογραφικές εικόνες και υπολογίζει τις παραμέτρους ενός μη γραμμικού μετασχηματισμού ευθυγράμμισης. Μετά την ευθυγράμμιση των δύο τομογραφιών, υπολογίζεται η μετατόπιση του ισοκέντρου στην τομογραφία επαλήθευσης σε σχέση με τη θέση του ισοκέντρου που προβλέπεται στην αρχική τομογραφία του σχεδιασμού. Με την ενσωμάτωση αυτής της μεθόδου ευθυγράμμισης στη διαδικασία της ακτινοθεραπείας, ικανοποιούνται δύο ανάγκες της κλινικής πρακτικής. Αφενός, η μετατόπιση του ισοκέντρου, όπως υπολογίζεται από την προτεινόμενη μέθοδο, παρέχει μια αξιόπιστη ένδειξη για τη μετατόπιση του ασθενούς που απαιτείται πριν τη χορήγηση της ακτινοβολίας. Αφετέρου, επιχειρείται η καλύτερη αξιοποίηση των πόρων του τμήματος της ακτινοθεραπείας με τη διαδικασία της εύρεσης του ισοκέντρου της ακτινοθεραπείας να λαμβάνει χώρα στην αίθουσα του αξονικού τομογράφου και να μειώνεται συνεπώς ο χρόνος που απαιτείται για την προετοιμασία του ασθενούς στον γραμμικό επιταχυντή κατά την πρώτη συνεδρία της ακτινοθεραπείας. / Aim of the present thesis is the development of image processing algorithms for radiotherapy applications. These algorithms are based on the principles of Kohonen Self Organizing Maps and exploit the information contained in image regions around distinctive points of interest, in order to determine image correspondences in an automatic, accurate and robust way. In particular, an iterative algorithm is proposed for automatic detection of point correspondences in two-dimensional medical images. The proposed algorithm requires the extraction of interest points only in one image and detects the homologous points in the second image through an iterative procedure, respective to the training phase of a neural network. Subsequently, the parameters of an appropriate registration transformation are computed to describe the mapping between the two images. The computation is based on the detected point correspondence. The proposed registration algorithm is applied to Electronic Portal Images, acquired prior to the radiotherapy treatment delivery, in order to estimate the setup error of the patient. The issue of patient position verification in radiotherapy is also addressed in the present thesis by developing an algorithm for automatic detection of point correspondences in three-dimensional medical data. The algorithm is used to register the CT data of radiotherapy planning to an additional verification CT, acquired prior to the first treatment fraction. The proposed algorithm detects corresponding points in the two CT images and computes the parameters of a non-rigid registration transformation. After the registration of the two CT images, the isocenter displacement of the verification CT is calculated with respect to the ideal isocenter position, defined in the planning CT. By integrating the proposed registration procedure in the clinical practice, two needs are met. Firstly, the isocenter displacement, calculated by the proposed method, provides a reliable indication of the patient shift, needed before the treatment delivery, for optimization of the dose delivery. Secondly, an improvement of the radiotherapy department efficiency is attempted by performing the procedure of isocenter marking in the CT scanner room and, consequently, reducing the time expenditure of the patient in the LINAC during the first radiotherapy fraction.

The foot and mouth disease is an acute, very contagious virus disease of even-toed ungulates (cattle, Wheel, pigs). The primary source of the infection is an ill animal, a secondary source are all the subject contaminated by the originator of the illness. Also people often pass the illness (on their shoes and also clothes). At present, the foot and mouth disease in Great Britain is mentioned at most; however, the epi-centers of the contagion of this illness may be found in many other places all around the world. Although the last occurrence of the foot and mouth disease was recorded in 1975 in the Czech Republic, the real risk of spreading this infection in our territory exists also at present. The people get infected with foot and mouth disease may very seldom. Also the most animals are able to survive this disease; in spite of this fact, spreading the infection in the breeding causes immense economic loss. For this reason, many countries consider necessary to fight against the infection by all the possible means. First of all the prevention and preparation of various plans and preparation of experts is accentuated. In case of any suspicion concerning the foot and mouth disease it is necessary to take the necessary measures. Only thanks to a thorough preparation and correct observation of all the measures it is possible to fight effectively with this dangerous infection, although at the expense of lives of many animals.

Cette thèse interroge la performativité de l’instrumentation au cœur du processus de prise de décision de l’union européenne en étudiant la procédure d’analyse d’impact de la Commission européenne (AI-CE), et son application en particulier aux politiques environnementales. Mise en place en 2002 afin d’évaluer les impacts économiques, sociaux et environnementaux des propositions émises par la CE, la procédure d’AI est formellement l’instrument de la stratégie de développement durable (SDD), mais elle est aussi un pilier de la politique de ‘Better Regulation’ (BR) (« Mieux légiférer ») et penche progressivement dans le sens de ce second agenda avec une préférence pour l’analyse coûts-bénéfices et le choix d’instruments non légaux. En réponse à la question de la rationalité et de la performativité de l’AI-CE, la thèse défendue dans cette recherche conçoit l’analyse d’impact de la CE comme une technique de la gouvernementalité néolibérale placée au cœur de la fabrique des politiques environnementales de l’UE, en appui notamment sur l’opération de monétarisation des impacts. L’hypothèse est celle du renforcement du discours de la modernisation écologique, avec pour effet de contribuer au phénomène d’économicisation des problématiques environnementales dans le sens d’un nécessaire alignement sur l’étalon d’une utilité économique. Pour mener à bien ce projet, la thèse déploie une analyse du discours de la CE et combine analyse de documents, entretiens et analyse lexicométrique. A la suite de nos investigations, il s’avère que les résultats sont partiellement congruents par rapport à l’hypothèse introduite supra. En effet, la mise en œuvre du dispositif n’entraine, pour les cas spécifiques étudiés, ni la monétarisation systématique, ni même la quantification systématique des impacts environnementaux d’une part, ou le choix systématique d’instruments volontaires ou de marché d’autre part. De plus, l’analyse lexicométrique nous permet de mettre en évidence la cohabitation de deux types de gouvernementalités distinctes, bien que se chevauchant partiellement, au travers des discours de la modernisation écologique et de la gouvernementalité verte. Cependant, nous constatons également le poids et la force structurante du terme et de la notion de « coût » et le recours systématique à un registre de justification économique de l’action environnementale au travers de ressorts typiques du discours de la modernisation écologique, avatar de la gouvernementalité néolibérale. En dépit de l’incomplétude de la réalisation des engagements pris par la CE, ou de ce fait même, nous constatons que la mise en œuvre de l’AI-CE contribue à l’économicisation de la fabrique des politiques environnementales comme insertion des problématiques environnementales dans une logique d’utilité économique et à la subordination de l’évaluation des impacts « économiques, sociaux et environnementaux » à la question du coût de l’intervention et aux critères de comparaison favorables à la dimension économique. / This PhD thesis questions the performativity of the European Commission Impact Assessment (EC-IA) as decision-support instrument at the heart of the European policy process in the case of European environmental policy-making.Adopted in 2002, the EC-IA is meant to address “all” significant economic, social and environmental impacts of the EC proposals. It is an instrument of the Sustainable Development strategy, as well as of the Better Regulation agenda. It will progressively mainly contribute to this second agenda, with a focus of the guidelines on cost-benefit analysis and non-legal instruments.Questioning the EC-IA rational and performativity, the thesis conceives the EC-IA as a neoliberal governmentality technique within the European environmental policy-making process, among other leaning on the monetisation of impacts. The hypothesis is the reinforcement of the ecological modernisation discourse, contributing to the economicisation of environmental issues, with economic utility as yardstick.Following our investigations (made of discourse analysis, combining document analysis, interviews and lexicometry), it turns out that results are only partially congruent with our research hypothesis. As a matter of fact, the implementation of the EC-IA does not involve, for the case studied, systematic monetisation, nor quantification of environmental impacts or the systematic proposal of voluntary or market instruments. Moreover, the lexicometric analysis highlights two parallel types of governmentalities, partially overlapping, with the ecological modernization and green governmentality discourses.However, we also highlights the important weight and structuring strength of the word and concept of “cost”, and the systematic economic justification of environmental action, a.o. through storyline elements typical of the modernization discourse, avatar of neoliberal governmentality. In spite of the partial implementation of the EC-IA guidelines, or du to this incompleteness, we observe that EC-IA implementation contributes to the economicisation of the making of European environmental policies through the embedding of environmental issues in an economic utility logic, and through the subordination of the assessment of “economic, social and environmental” impacts to the question of the cost of action and to comparison criteria in line with the economic dimension. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

This research study examines the manner in which a cardiological sample presents in terms of their psychological make-up by making specific reference to the constructs self-concept and emotions. A literature overview of different aspects of self-concept, emotion and cardiology places the results and discussions of the study within a theoretical background. The study supplies descriptive information relating to the demographic profile of the sample, followed by a description of various aspects of self-concept and emotions, as well as a correlational exploration of the manner in which the sample group presents. The sample consisted of 29 individuals, all who had been diagnosed with coronary heart disease (CHD) and been subjected to surgery as a result thereof. The participants completed a questionnaire, containing two measurement instruments, namely the Adolescent Self-Concept Scale (ASCS) and the Emotions Profile Index (EPI). The scores, obtained by the sample, were subjected to statistical analysis to provide a self-conceptual and emotional profile of the sample. The Spearman Rank-Order Correlation Coefficient was then used to indicate the extent to which the sample tended towards portraying themselves in a positive light, more than they might be experiencing. The study further refers to the views of the sample group, relating to these findings, as obtained from an information and discussion session held with them. The study indicate a significant statistical trend amongst the sample group to portray themselves in a positive light in relation to emotions, even though they were not in reality experiencing such positive emotions. Although the same positive trend was indicated with self-concept, the study cannot conclusively indicate that this is not a realistic presentation of the sample group as a whole. / Dissertation (Counselling Psychology)--University of Pretoria, 2006. / Psychology / unrestricted

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