El presente trabajo consiste en un estudio sistemático de la importancia del mar en la pintura del norte de España de los últimos 70 años. No se trata de un estudio genérico, sino que busca la concreción, no contemplando las obras y autores en los que el mar es un mero acompañamiento, como podría serlo cualquier otro elemento, o en los que el tratamiento de este género ha sido ocasional o puntual. El mar debe ser el protagonista, aunque en ocasiones sea paralelo -o incluso secundario- a otro posible protagonista, de la misma manera que en un cuadro de paisaje consiste en una representación de la naturaleza con otros elementos posibles, incluso con preeminencia. Así pues, es - haciendo una recopilación de pintores que hayan abordado el tema de la marina, de forma directa y en la pintura figurativa- un análisis de la obra general, y ubicarla en su contexto histórico para poder establecer la dinámica de la creación pictórica en este tema y en esta área.

La tesis tiene como objeto de investigación el paisaje de Río de Janeiro, consolidada por una estructura topográfica - la naturaleza - y otra humana - la arquitectura -. El deseo por la conciliación que la arquitectura impregna ante el paisaje, es la hipótesis de un embate inalcanzable. Y una vez que se entiende el paisaje como un hecho cultural, su estudio está acotado por la mirada artística de pintores y arquitectos entre un límite histórico que en Brasil va desde la llegada del Neoclasicismo hasta la consolidación del Arte Moderno. Si el punto inicial es en los comienzos del siglo XIX, cuando varios artistas europeos desembarcaron en Brasil a menudo como integrantes de misiones expedicionarias con el objetivo de catalogar, registrar, observar, más tarde con el Arte Moderno, que se opone al Neoclasicismo, llega una nueva etapa del arte producido en Brasil, pues es cuando la cultura brasileña finalmente reconoce una expresión propia en si misma. Dividido en dos partes, en la cual la primera trata de las representaciones de Río de Janeiro a través de los pintores, mientras la segunda está dedicada a las representaciones de los arquitectos, la tesis tiene su organización según relaciones dialécticas. Así, si una parte trata de la mirada de los pintores y la otra la de los arquitectos, por su vez cada parte está subdividida en dos capítulos, los dos primeros referentes al ojo extranjero, mientras que el segundo de cada parte trata del ojo local, es decir, de los artistas brasileños o extranjeros radicados en Brasil que retrataron el paisaje inmerso en el ambiente cultural de la ciudad de Río de Janeiro. / This thesis has the landscape of Rio de Janeiro, as a case study. Such a landscape is both consolidated by a "topographic structure" - the nature - and a "human structure" - the architecture -. The wish for conciliation which the architecture assumes as regards to landscape is the possibility of a confrontation that will be proved to be unreachable. As landscape is understood as a cultural fact, this research takes the artistic look of painters and architects to delimitate the universe of analysis which, in terms of Brazil, starts with the advent of the Neoclassicism and extends until the consolidation of the Modernism. The starting point for investigation is then, the beginning of the XIX century, when several European artists had disembarked in Brazil, most frequently as members of missionary expeditions whose objectives were essentially to catalogue, to register, to observe. Contrasting to this, this study points out that the Modernism, opposing to the Neoclassicism, come to establish a new path for the art produced in Brazil, as Brazilian culture eventually recognizes in itself its own expression. To reach such findings, this thesis is divided in two parts organized according to dialectic relations. The first part deals with the representations of Rio de Janeiro through the painters, and the second is dedicated to the representations of the architects. Each one of these two parts is further divided into two chapters. Both first chapters refer to the foreign look, whereas both second deal with the domestic look. Such a look encompasses Brazilian, as well as foreign artists, who had portrayed the landscape, at the time they were living and participating to the cultural environment of the city of Rio de Janeiro.

Carbapenem resistance in Acinetobacter baumannii is a growing public health concern and represents a serious problem for treatment of the infection. Several carbapenem-hydrolysing &beta / -lactamases have been identified from A. baumannii so far. In this study carbapenem resistance in A.baumannii strains recovered from intensive care units of Gulhane Military Medical Academy, Turkey, were investigated via multiplex PCR and with parallel phenotypic tests. From June 2006 to January 2010, 138 clinical A. baumannii isolates were collected. Identification and antimicrobial susceptibility tests of the isolates were performed. The MICs of imipenem and meropenem were determined by using E-test method. Carbapenem resistant A. baumannii strains were included for further study. Firstly, the presence of carbapenemases were determined. The presence of Metallo-beta-lactamase (MBL) were also investigated. Detection of the four groups of OXA carbapenemases (OXA- 23, OXA-24, OXA-51 and OXA-58) was carried out using a multiplex PCR assay. Sequence analyses were performed. Non-duplicate, multidrug resistant 61 clinical A. baumannii isolates were found to be resistant to imipenem and meropenem. In the 61 isolates, the MIC50 of imipenem and meropenem were 16 and &gt / 32 / MIC90 were 192 and &gt / 32 respectively. Modified Hodge Tests (MHT) were positive for all 61 A. baumannii strains. None of these isolates showed MBL activity. As determined through multiplex PCR, all of the 61 isolates had blaOXA-51 genes, 50 isolates had blaOXA-23, and 11 isolated had blaOXA-58 genes. Alleles encoding OXA-24-like enzymes were not detected in any isolates. This study indicated that the clinical isolates in our region contained blaOXA-51, blaOXA-23, and blaOXA-58 resistance genes. However, blaOXA-24 gene was either absent or occur in very low frequency.

In this thesis, a novel hybrid approach for tracking variable numbers of network structured deformable objects is presented. The hybrid technique developed is a combination of the Network Snakes parametric active contours technique, and the Reversible Jump Markov Chain Monte Carlo (RJMCMC)-based particle filter approach. Additionally, a novel method for (semi-)automatic initialization of the network snakes is implemented. The proposed technique is applied to the real biological problem of tissue-level segmentation, and automatic tracking, of a network of cells in confocal images showing the roots of the model plant Arabidopsis thaliana. The Network Snake component is used to model the structure of cells in Arabidopsis roots, which are clustered together and delineated by shared object boundaries forming a network topology.The RJMCMC tracker is allowed to track the network node points over image sequences, and these tracked nodes are then used to control and reparameterise the topology of the network snakes at each time step. This is followed by energy minimization of the network snakes which refines the tracked nodes and cell boundaries to settle at the energy minimum. Thus the component techniques complement each other in the hybrid approach. A novel method of evaluating such network-structured multi-target tracking is also presented in this thesis, and is used to evaluate the developed tracking framework for accuracy and robustness using several real and synthetic time-varying and depth varying(z-stack) image sequences of growing Arabidopsis roots.

Teaching a subject which involves a long process and inter-related problems can sometimes be difficult through conventional classroom activities. This is particularly difficult at the UK Key Stage 3 (13-14 years) where students are only beginning to understand the processes of reason. Often what the teacher would like to encourage is group discussion but for many reasons, young students may be reluctant to put forward ideas in a conventional classroom setting. An area where this becomes less of a problem is once they get involved in playing a game together. In addition to this certain subjects are difficult to teach because they involve complex interactions that are largely outside the general knowledge of young students. An example of this is the issue of human contributions to climate change. The subject is one of recent heated debate, much of which involves complex arguments on the relationship between the natural contribution to climate variation and those produced by human beings. In the work reported here a computer game has been developed which tries to incorporate the various processes involved in a realistic way. In principle this game can be used individually. However, it also provides the opportunity for generating group discussion and reasoning processes. The game which has been developed uses a non-player character which is controlled by the teacher. The game is played in a networked environment with a number of teams of two players each trying to provide solutions to a complex climate issue. The non player character is able to monitor the performance of the different teams and provide feedback that will be of a more realistic/less predictable nature. This thesis addresses the design and the implementation of the game as a tool for teaching and learning purposes for learning about the human contribution to climate change. Three experiments have been done using this computer game to investigate the effectiveness of game-based learning towards tackling these issues. The first two studies were carried out in the UK while the third study was carried out in Malaysia to investigate educational cultural background. The initial study involved two groups of Key Stage 3 children in a Geography class. The study was undertaken in the normal teaching sequence. The children were divided into pairs during game-play and each session lasted about one hour. The behaviour of the whole group and individual teams was monitored throughout the game-play. Analysis of this shows that the game not only allowed the students to investigate the science but also to communicate with each other during the process. Overall, it is felt that by introducing an environment with which they were sufficiently familiar (playing a game together) the normal inhibitions to communication were removed. The control based experiment reinforced these findings.

La presente tesis doctoral es resultado de una investigación sobre la posibilidad de estimular la imaginación a través de la creación de imágenes en la mente, utilizando la Zona de Desarrollo Próximo como espacio de trabajo y la intertextualidad e interdisciplinariedad como recursos didácticos. La intervención didáctica se ha realizado con el álbum ilustrado Concertina y el dragón, creado para esta investigación, y en el cual los diversos textos dialogan con la finalidad de conseguir silencios necesarios para la creatividad (siguiendo la ruta de Barjou). Se han llevado a cabo experiencias grupales con alumnado de Educación Primaria de dos países (España y Marruecos) y diferentes entornos sociales con el objetivo de recabar los dibujos que nos faciliten las distintas informaciones. En este sentido, hemos evaluado los resultados, demostrando así que la creatividad en el modelo interdisciplinar e intertextual determinan la validez de nuestra tesis. / he current doctoral thesis is the outcome of the research about the possibility to encourage the imagination by creating images in somebody’s mind. We would use the Zone of Proximal Development as the work area and the intertextuality and interdisciplinary nature as didactic resources. The didactic intervention has been done using the ilustrated book Concertina y el dragón, purposely created for the investigation. This book’s texts work together to find needed silences to allow creativity (following Barjou’s way). Group experiences have been carried out with pupils from Primary School in two countries (Spain and Marocco) as well as in diverse social enviroments, in order to gather drawings which would give us all different information. In this sense, we have evaluated the results, and can prove that creativity in a interdisciplinar and intertextual model, determine the validity of our thesis.

Στην Πυρηνική Ιατρική, κατά τη διαδικασία ιατρικής απεικόνισης, η κίνηση των οργάνων λόγω της αναπνευστικής λειτουργίας και της σύσπασης του μυοκαρδίου αλλά και των υπόλοιπων κινούμενων οργάνων, δημιουργεί αλλοιώσεις στη διαγνωστική πληροφορία. Η σημαντικότερη αλλοίωση παρατηρείται στον καθορισμό των ορίων συγκεκριμένων οργάνων. Η μελέτη και η ποσοτικοποίηση του φαινομένου καθίσταται αναγκαία στα ευρέως χρησιμοποιούμενα κλινικά πρωτόκολλα πυρηνικής απεικόνισης (SPECT, PET). Το πακέτο προσομοιώσεων Gate είναι ένα πολύ δυνατό εργαλείο που παρέχει τη δυνατότητα ρεαλιστικής μοντελοποίησης συστημάτων πυρηνικής ιατρικής και χρήσης διακριτοποιημένων ομοιωμάτων. Με τη βοήθεια αυτού του εργαλείου και κάνοντας χρήση διακριτοποιημένων ομοιωμάτων XCAT και ITIS μπορούν να προσομοιωθούν ρεαλιστικά κλινικές εξετάσεις που επηρεάζονται από την κίνηση οργάνων. Τα XCAT και ITIS είναι ρεαλιστικά και ευέλικτα μοντέλα ανθρώπινης ανατομίας και φυσιολογίας. Τα XCAT παρέχουν την επιπλέον δυνατότητα της εισαγωγής κίνησης. Αυτή η μελέτη είναι σημαντική, καθώς πολλές ομάδες της επιστημονικής κοινότητας ασχολούνται με την παραγωγή αλγορίθμων διόρθωσης της κίνησης των πνευμόνων και της καρδιάς, κάνοντας χρήση προσομοιώσεων Monte Carlo, με σκοπό τη βελτίωση της απεικόνισης σημαντικών ιατρικών πληροφοριών που αλλοιώνονται λόγω της κίνησης. Οι προσομοιώσεις κλινικών εξετάσεων με το GATE, εισάγοντας ρεαλιστικά ανθρώπινα ομοιώματα, είναι μια μεθοδολογία αιχμής η οποία ανοίγει το δρόμο στη βελτιστοποίηση των διαγνωστικών και θεραπευτικών προσεγγίσεων, παρέχοντας ένα ισχυρό εργαλείο για το σχεδιασμό κλινικών πρωτοκόλλων, την ανάπτυξη διορθωτικών αλγορίθμων και τη μοντελοποίηση παραμέτρων όπως η κίνηση του σώματος εξαιτίας της λειτουργίας της καρδιάς καθώς και του αναπνευστικού συστήματος. / In nuclear medicine, during medical imaging procedures, organs' motion creates artifacts and loss in the diagnostic information, due to respiratory motion and myocardial contraction. The most significant challenge is to define the limits of specific organs and quantify the blurring caused by this motion. The study and quantification of this phenomenon is necessary for clinical protocols used in nuclear imaging (SPECT, PET), so as to achieve accurate diagnosis. GATE is a powerful Monte Carlo simulation toolkit, which enables the realistic modeling of a nuclear imaging system, using voxelized phantoms as input. Using this tool and computational anthropomorphic phantoms such as XCAT and ITIS phantom series can simulate realistically clinical tests. XCAT and ITIS are realistic and flexible models of human anatomy and physiology. XCAT provide the additional capability of importing motion. In the present thesis the XCAT and the ITIS anthropomorphic computational phantoms are used in a series of simulations modeling several clinical cases. Several groups in the scientific community are dealing with the development of motion correction algorithms in order to decrease the blurring in specific organs of interest and to increase the diagnostic value of nuclear imaging. Monte Carlo techniques combined with realistic human models can provide the ground truth for such applications. This is a cutting edge methodology that paves the way for optimization of diagnostic and therapeutic approaches, providing a powerful tool for the design of clinical protocols, developing algorithms and modeling parameters such as body movement due to pulmonary and heart motion.

Absolute quantification of the 3D distribution of a radionuclide within a patient has been one of the greatest challenges of nuclear medicine. This is due to the fact that nuclear medicine images are degraded by several factors, which limit the quantitative ability of this modality. Quantitative SPECT has wide applications in many areas in nuclear medicine from radiation dosimetry calculations to clinical applications. It has use in image analysis studies to extract information about areas, volumes, and/or amounts of radioactivity in specific regions of interest. The information that derived from these studies is then applied to estimate radiation dosimetry, volumes or to aid in clinical diagnoses. Absolute quantitation means precise and accurate measurements of volume and the amount of radioactivity in a specific region of interest. For absolute quantitation of volume the measurements can be expressed in cubic centimetres, for radioactivity in μCi or Bq. Quantitation of organ volumes using planar imaging technique is a procedure often performed in nuclear medicine but face difficulties due to structure containing radioactivity, which overlie or underlie the organ of interest. SPECT overcomes these difficulties since it is able to separate these structures in the reconstructed images, which have higher contrast than planar images. In the theoretical part of this work, there is a description of the operation and the characteristics of a gamma camera system. Following that, there is a mention to the quality control procedures of the system both for planar and SPECT techniques. Also, there is an extended discussion of the factors that affect to the image quantitation and the corrections that must be applied in order to achieve better volume and activity estimation. At the end of the theoretical part, there is a presentation of procedure for volume and activity quantitation on I-131 sources using threshold technique. In the practical part, there is a study on volume and activity quantitation for I-131 sources with volumes 0.5,1,5,8,10,20 and activities from 300 to 529 μCi using threshold technique. The practical part of this work was performed in the department of Nuclear Medicine of the “THEAGENION” Cancer Institute of Thessaloniki (Greece), with association with the department of Medical Physics. / Η απόλυτη ποσοτικοποίηση της κατανομής ενός ραδιοφαρμάκου στον ασθενή, είναι μια από τις μεγαλύτερες προκλήσεις στην πυρηνική ιατρική, καθώς οι εικόνες από τη γ-κάμερα υποβαθμίζονται από διάφορους παράγοντες, που περιορίζουν την ικανότητα ποσοτικοποίησης. Η ποσοτικοποίηση μέσω SPECT έχει πολλές εφαρμογές στην πυρηνική ιατρική, στο διαγνωστικό τομέα και στο θεραπευτικό στη δοσιμετρία. Χρησιμοποιείται κατά την ανάλυση των εικόνων με σκοπό τον προσδιορισμό όγκων και την μέτρηση ραδιενέργειας σε συγκεκριμένες περιοχές ενδιαφέροντος. Η απόλυτη ποσοτικοποίηση σημαίνει σαφή και όσο το δυνατόν, ακριβή μέτρηση όγκου και ραδιενέργειας σε κάποια περιοχή ενδιαφέροντος. Ο όγκος μπορεί να εκφραστεί σε κυβικά εκατοστά και η ραδιενέργεια σε μCi ή Bq. Η ποσοτικοποίηση του όγκου των οργάνων, χρησιμοποιώντας planar τεχνικη, είναι μια διαδικασία που χρησιμοποιείται συχνά στην πυρηνική ιατρική. Παρ’όλα αυτά αντιμετωπίζει δυσκολίες λόγω των δομών, που βρίσκονται πάνω και κάτω από την περιοχή ενδιαφέροντος, και περιέχουν ραδιενέργεια. Το SPECT αντιμετωπίζει αυτές τις δυσκολίες, αφού έχει τη δυνατότητα να ξεχωρίσει αυτές τις δομές, στις εικόνες που έχουν ανακατασκευαστεί, και να τις παρουσιάσει με μεγαλύτερη αντίθεση από την planar τεχνική. Στο θεωρητικό μέρος της εργασίας γίνεται περιγραφή των χαρακτηριστικών και της λειτουργίας του απεικονιστικού συστήματος της γ-camera. Ακολουθεί η περιγραφή των διαδικασιών ποιοτικού έλεγχου του συστήματος τόσο για την Planar όσο και για την SPECT τεχνική. Στη συνέχεια, γίνεται παρουσίαση της μεθόδου ποσοτικοποίησης όγκου και ραδιενέργειας, στην περίπτωση πηγών Ι-131, εφαρμόζοντας την τεχνική κατωφλίου, ανάλυση των παραγόντων που την επηρεάζουν, καθώς και των διορθώσεων, που πρέπει να γίνονται, ώστε να επιτυγχάνεται η όσο το δυνατόν μεγαλύτερη ακρίβεια. Στο πειραματικό μέρος της εργασίας γίνεται εφαρμογή της παραπάνω μεθόδου σε πηγές Ι-131, όγκου 0.5-20 ml ραδιενέργειας 300-529μCi και σύγκριση των αποτελεσμάτων. Η συγκεκριμένη εργασία εκπονήθηκε στο Τμήμα Πυρηνικής Ιατρικής του ΑΝΘ ‘’ΘΕΑΓΕΝΕΙΟ’’ σε συνεργασία με το Τμήμα Ιατρικής Φυσικής του Νοσοκομείου.

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In 3D positron emission tomography the scatter effect is a significant physical factor degrading image quality. The advancements in computing that occurred the last decades al lowed us to simulate the scatter coincidences fast and ef ficiently. The main concern now is how accurately do we simulate the scatter events. The scope of this project is the implementation and the evaluation of a scatter simulation algorithm that would be able to simulate the scat ter ef fect more precisely than the existing ones. One way to simulate the scatter distribut ion is with an algorithm, first published by Watson and Ollinger, that is based on the Klein-Nishina formula. These methods have been implemented taking into account only the single scatter events (where a photon scatters once in the at tenuation medium). Multiple scatter is generally taken into account by some scaling or filtering procedure. Their main advantages are short computational time and relatively good precision compared to previous more heuristical methods. Although these single scatter algorithms have been effective there are cases where their results are not that accurate. For low energy thresholds and large at tenuation mediums multiple scatter is increased. Given that a significant percentage of people are over -weight (thus the at tenuation medium has large volume) we should consider introducing multiple scatter events in our simulations. Moreover, the distribut ion of all scatter events is broader than the one of single scatter events therefore even if the single scatter distribution is scaled it will not match the total scatter one. In previous work by C. Tsoumpas et al, a new scatter simulation algorithm was developed that attempts to approximate the total scatter distribution by taking into account the case where the one annihilated photon is scattered twice and the case where both annihilated photons are scattered once. These two cases describe the double scatter events and by introducing them into our scatter simulation algorithm we aim to obtain a better approximation of the total scatter distribution. In this thesis we have improved this double scatter simulation algorithm in two important ways. When both annihilated photons scatter they acquire a favourable polarization direction with respect to each other and this influences thei r detect ion probabilities, especially when low energy photons are detected. In the algorithm that we implemented we considered this effect by using the polarized Klein-Nishina formula for this case. In addition, we investigated and validated the need to introduce extra solid angle factors in the implementation. The whole implementation is based on the STIR library (Software for Tomographic Image Reconstruction) written in the C++ programming language. Scatter events can also be simulated by Monte Carlo simulation packages such as SimSET. SimSET is a public domain package designed to simulate positron emission tomography (PET) (and Single Photon Emission Tomography) and was used extensively in this project. Monte Carlo packages because of their ability to exclude any unknown physical parameter they can simulate physical processes like the ones that take place in PET very accurately. Thus they were essential for the evaluation of our scatter correction algorithm. The reason why Monte Carlo packages are not used inclinical practice instead of the model-based methods is that they demand a large computational time. Besides Monte Carlo packages we also per formed a series of experimental scans in order to evaluate our scatter simulation algorithm. The tomograph used for the experiments was the ECAT 962 used in a 3D mode. / -