Positron emission tomography (PET) is a nuclear medicine imaging techniquethat uses radiotracers to visualize processes like metabolism and perfusion. Theradiotracer emits positrons, which collide with shell electrons of the atomsthat make up the surrounding tissue. Such a collision produces two gammarayphotons, emitted roughly 180 degrees apart [1]. PET captures thesephotons using a cylindrical arrangement of detectors. When two photons aredetected simultaneously by different detectors, it registers as a line of response(LOR). These LORs are then pre-processed into a sinogram. A mathematicalreconstruction method is used to computationally recover the 3D distribution ofthe radiotracer (activity map) from the sinogram. However, genuine LORs can becorrupted by false LORs that come from scattering, random events, and spuriousevents. Mitigating these in reconstruction algorithms is essential for improvingPET imaging accuracy and reliability.This paper explores the theoretical foundation of the Time of Flight (TOF) SingleScatter Simulation (SSS) model by Watson (2007) [2]. It also includes a Pythonimplementation of the MATLAB code associated with [2]. The model modelsCompton scattering to accurately estimate scattered photons in PET.Incorporating TOF data into the SSS model improves estimation accuracy, albeitat the cost of increased computational time. To expedite computations, thealgorithm was simplified by restricting operations to a subset of rings anddetectors and by pre-processing images through cropping and downscaling.Interpolation fills in missing data, ensuring complete estimation.The outcome of this project is a Python implementation that exhibited a strongcorrelation with the estimates obtained using the MATLAB implementation. Anotable issue arose during the comparison between the main components ofthe SSS algorithm in Python and MATLAB. The Euclidean norm between theresults from these two implementations was significant, indicating that they wereon different scales. Nevertheless, both implementations accurately predictedthe scatter in the same locations and relative magnitudes, despite the scalediscrepancy. Investigation into the discrepancy’s cause is ongoing, but theproject demonstrates the feasibility of implementing the TOF SSS algorithm inPython.

Master of Public Health - MPH / This mini-thesis, assessed the use of ORT as a treatment for childhood diarrhoea in primary health care facilities in the Cape Metropole from the caregivers' perspective. Awareness and knowledge of oral rehydration therapy (ORT) and the preparation abilities of sugar salt solution (SSS) by caregivers of children younger than 5 years attending the health facilities were assessed. The availability of resources and utensils for the use of ORS packets and SSS and the accessibility to health facilities by caregivers were also determined. Using a cross sectional descriptive study design, a baseline situation review was carried out. Primary health care facilities in three heath districts namely; Khayelitsha, Nyanga and Oostenberg were purposely selected. Ninety-two caregivers in 12 facilities participated in the study. Basic analyses of quantitative data were done using Epi-Info 2002 software. Qualitative data were analysed manually. The study found that according to caregivers, all facilities used ORS packets as their immediate treatment for uncomplicated diarrhoea, and recommended sugar salt Diarrhoea Management in PHC Facilities solution as home treatment. Ninety-one percent of caregivers used ORT at home before they presented to the health facility.Of the caregivers who were advised by the health worker to use SSS at home, 60.7%, 55.8% and 60.2% in Oostenberg, Khayelitsha and Nyanga districts respectively remembered the correct ingredients and quantities to make the solution at home. Of those given ORS packets, 94.5%, 99.0% and 98.5% respectively, remembered the quantity of water to be mixed with each packet. Packets were found to be convenient and were preferred by many caregivers as compared to SSS. The advice or health education messages given to caregivers were often unclear, and there were language barriers in Brighton and Bloekombos clinics in the Oostenberg district. A litre bottle was available in 47% of caregivers' homes, 82 % had a teaspoon and all of them had access to running water. Twelve percent and 11 % admitted to not having sugar and salt respectively when they wanted to make SSS. Eighty-eight percent walked to the health facility and 12% used taxis or buses. The study concludes that ORT is widely used in primary health care facilities for diarrhoeal disease treatment, however caregiver's knowledge and preparation abilities of SSS is still limited. The resources and utensils to prepare ORT at home were fairly available in many homes, which makes SSS preparation at home feasible and acceptable.

In positron emission tomography (PET) the current trend is to use the fully 3D capabilities of the scanner to increase sensitivity, hence improve the quality of data or reduce the scanning time. However, some difficulties have to be resolved. In 3D PET, the largest contributor to image degradation is Compton scatter since the scattered photons may comprise more than 50% out of all coincidences in the whole body studies. Much progress has been achieved the last few years by the use of scatter correction algorithms, such as the single scatter simulation (SSS). In this work, a model-based scatter simulation (MBSS) algorithm has been implemented in a software library called STIR (i.e. Software for Tomographic Image Reconstruction) initially based on SSS. The aim of the current work is to validate the MBSS implementation; investigate the influence of several parameters; and, if possible extend the existing algorithm. The results are compared with both SimSET Monte Carlo simulation package and measured data. The comparison shows that SSS is in excellent agreement with the single scatter distribution produced by SimSET and in several cases can also approximate accurately the total scatter. However, SSS is just an attempt to estimate the total Compton scatter effect, as it is possible that both photons may scatter, and potentially more than once. As shown, the single scatter distribution may have different shape from the total scatter distribution. How accurate this approximation is, it depends on how many detected photons are scattered multiple times. Multiple scatter is more likely to happen if the attenuation medium has large volume, hence it is more severe in 3D studies of the torso than the brain. In this work, the methodology used for the single scatter simulation algorithm is extended to handle twice-scattered events. Detailed description on how to implement the double scatter simulation (DSS) together with a preliminary evaluation is included. The results are promising even if the required computational time for DSS is much higher than for SSS, though not being prohibited. Finally, at the end of the thesis, an efficient recursive formula is proposed to estimate the rest multiple scatter distribution. / Κατά την τομογραφική απεικόνιση εκπομπόμενων ποζιτρονίων είναι αρκετά διαδεδομένη η χρήση της τρισδιάστατης ανίχνευσης, ώστε να βελτιωθεί η ευαισθησία και η ποιότητα των δεδομένων, αλλά και να μειωθεί ο συνολικός χρόνος εξέτασης. Για να είναι αυτά εφικτά πρέπει πρωτίστως να αντιμετωπιστούν αποτελεσματικά κάποιες δυσκολίες. Συγκεκριμένα, ένας από τους σημαντικότερους παράγοντες που υποβαθμίζουν την ποιότητα της εικόνας είναι η σκέδαση Compton, διότι, εξαιτίας αυτής, τα σκεδαζόμενα φωτόνιων που ανιχνεύονται μπορούν να ξεπεράσουν το 50% των συνολικών ανιχνεύσεων σε αρκετές μελέτες του ανθρώπινου κορμού. Σημαντική πρόοδος έχει επιτευχθεί τα τελευταία χρόνια με τη χρήση αλγόριθμων διόρθωσης σκέδασης και, κυρίως, με τη χρήση του αλγόριθμου προσομοίωσης μίας και μόνο σκέδασης (ΠΜΣ). Στην παρούσα μελέτη, ένας αλγόριθμος βασισμένος σε αυτό το μοντέλο δημιουργήθηκε σε μια βιβλιοθήκη λογισμικού για ανακατασκευή τομογραφικής εικόνας. Ο στόχος αυτής της εργασίας είναι να πιστοποιήσει τη σωστή λειτουργία του αλγόριθμου, να μελετήσει την επίδραση διαφόρων παραμέτρων και, εάν είναι εφικτό, να τη βελτιώσει. Η σύγκριση των αποτελεσμάτων έδειξε πως ο ΠΜΣ επιβεβαιώνεται με Μόντε Κάρλο προσομοιώσεις. Ωστόσο, ο αλγόριθμος ΠΜΣ είναι μια προσέγγιση του συνολικού ποσοστού φωτονίων σκέδασης Compton. Υπάρχει πάντα πιθανότητα και τα δύο φωτόνια να σκεδαστούν μία ή και περισσότερες φορές. Όπως αποδεικνύεται στην παρούσα μελέτη, η κατανομή μίας και μόνο σκέδασης έχει διαφορετική μορφή σε σύγκριση με τη συνολική κατανομή της. Πόσο ακριβής είναι αυτή η προσέγγιση εξαρτάται από τον αριθμό των πολλαπλά σκεδαζόμενων φωτονίων που έχουν ανιχνευτεί. Το φαινόμενο πολλαπλής σκέδασης είναι πιθανότερο εάν το μέσον απορρόφησης ακτινοβολίας καταλαμβάνει μεγάλον όγκο και συνεπώς κατά τις τρισδιάστατες μελέτες του κορμού, παρά του εγκεφάλου. Στην παρούσα εργασία η μεθοδολογία που χρησιμοποιήθηκε για τον αλγόριθμο προσομοίωσης μίας και μόνο σκέδασης επεκτάθηκε, ώστε να συμπεριλάβει και γεγονότα διπλής σκέδασης. Μια αναλυτική περιγραφή παρουσιάζεται για το πώς μπορεί να υλοποιηθεί η προσομοίωση διπλής σκέδασης (ΠΔΣ), που ακολουθείται από μία προκαταρκτική αξιολόγηση. Τα αποτελέσματα είναι αρκετά ενθαρρυντικά ακόμη και αν ο απαιτούμενος υπολογιστικός χρόνος για την ΠΔΣ είναι αρκετά μεγαλύτερος από την ΠΜΣ, χωρίς να την καθιστά απαγορευτική. Στο τέλος της διπλωματικής εργασίας προτείνεται ένας ολοκληρωμένος αναδρομικός αλγόριθμος για τον αποδοτικό υπολογισμό του συνολικού ποσοστού σκεδάσεων.

I denna uppsats beskrivs metoder för att skapa en arm i 3D samt att lägga in den i ett foto där den ersätter en riktigt arm. Anledningen till detta är att kunna skapa effekter i filmer och bilder som inte är möjliga med analog teknik. I denna uppsats kan man läsa om tekniker som används i varje del av utvecklingsprocessen och problem som uppstår samt lösningar och tips. I uppgiften finns det med delar som Modellering, Texturering, Rendering, Kamera Matchmoving och Compositing.

The focus of this thesis is on the process of myth-making (mythopoeia) in the Dutch National Socialist Movement (NSB) and the Swedish National Socialist Workers' Party (NSAP), using a cultural pragmatic approach to analyse the practicalities and implementation of mythopoeia comparatively. A variety of fascist performances, scripted and unscripted, are considered as having mythopoeic potential, and understood as performative in character, i.e. constituting the thing they claimed to represent. Multiple parts of this mythopoeic process are analysed: the resources, organisation, and technologies required to implement it, and the nature of the process, the events, performances, in other words the actual implementation, and reception by audiences. Secondly, it uses respectability as a means of seeing how in a national context this process was limited, inhibited, or otherwise defined by the standards of the public and media, to which fascists ultimately tried to appeal, thus providing an external perspective on fascist activities to contextualise them. The thesis is divided into four chapters, which deal with the party apparatus, leader myth, political uniforms, and the role of aesthetics and spectacle respectively. Together these chapters explore the relationship between mythopoeia and respectability as refracted through party organisation and administration, as embodied by the 'charismatic' fascist Leader, in the day-to-day behaviour and appearance of the rank-and-file, and ultimately the holistic experience of fascist aesthetics, i.e. the fully scripted and organised spectacles of party congresses. Ultimately it is shown that the fascist movements of Sweden and the Netherlands were highly innovative organisations. Mythopoeia had a powerful mobilising capacity, which could make up for the diminutive financial power and low membership figures of fascist parties. Finally it appears that the relationship between myth and respectability was not a straightforward dialectical one, but multivalent, and highly dynamic.

La recherche de nouvelles molécules pour la médecine nucléaire est un domaine en expansion croissante. Ces dernières années, le développement de nouveaux radiopharmaceutiques à visée thérapeutique a relancé l'intérêt pour la chimie du rhénium. En effet, les deux isotopes 186Re et 188Re, du fait de leurs propriétés adéquates et de leur analogie avec le 99mTc, largement utilisé pour les examens cliniques, semblent très prometteurs pour la préparation de radiopharmaceutiques.<br />Dans la première partie de ce manuscrit, la synthèse de complexes du rhénium et du technétium-99, [M(RPhCS3)2(RPhCS2)] (M = Re, Tc), est décrite. La préparation de radiopharmaceutiques à base de technétium-99m, analogues des composés obtenus à l'échelle pondérale, est également décrite. La stabilité/réactivité de ces complexes a été étudiée, au moyen de réactions d'échange avec d'autres ligands potentiels, et notamment par des dithiocarbamates, ainsi que par spectrophotométrie d'absorption UV-visible et analyse thermogravimétrique.<br />La réactivité des complexes vis-à-vis des dithiocarbamates conduit à la possibilité du greffage de biomolécules sur le cœur métallique, via le fragment dithiocarbamate. Cette méthode constitue une alternative potentielle aux procédures actuelles utilisant l'approche bifonctionnelle.<br /><br />Dans la seconde partie de ce manuscrit, la mise au point d'un kit pour le marquage du lipiodol par le rhénium-188 est décrite, à partir du complexe analogue des complexes décrits dans la première partie. L'huile radiomarquée ainsi obtenue est potentiellement utilisable pour le traitement de l'hépatocarcinome. La stabilité in vitro et in vivo du complexe rhénié 188Re-SSS lipiodol et de son analogue technétié 99mTc-SSS lipiodol a été étudiée, ainsi que leur comportement in vivo sur un modèle de porc sain.<br />Cette étude a permis de montrer la fixation quasi-exclusive du radiopharmaceutique au niveau du foie, ainsi que la stabilité de ce composé. Sa sélectivité pour les tumeurs reste à démontrer avant de passer aux premiers essais chez l'homme.

The purpose of this study was to determine and examine the impact of student support services (SSS) on academic success at a historically black college. The study was grounded in the theoretical framework of Astin’s Input-Environment-Outcome Model (IEO), Scholssberg’s theory of marginality, holistic theory , facilitation theory, and the theory of sensory simulation (Dunn, 2002; Anderson et. al., 2011; Dennick, 2014 and Pritchard, 2013) A mixed method approach was used to quantify and explicate triangulated data, which included the N-LSSI survey, archival data, and focus group interviews. The N-LSSI survey used a 7-point Likert Scale, and students from The College completed the instrument. The longitudinal nature of the study meant that the assumption of independent observations required by ANOVA was violated. Therefore, I used MANOVA to analyze SSS and Non-SSS student academic achievement data (i.e., GPA, Accuplacer test scores). This analysis also determined whether significant differences existed between the SSS and Non-SSS student participant groups based on means of the predictors. Qualitative data were organized, evaluated, and interpreted using open, axial and selective coding with MAXQDA, a qualitative data analysis software program. The results of the analyses showed there were no significant differences between the two student groups relative to GPAs. In contrast, Accuplacer math scores, reading scores, and writing scores were significantly different. The retention differences between SSS and Non-SSS students were significant in 2011 and 2012, while graduation data revealed significant differences in 2012. Results from the N-LSSI survey produced no significant difference between SSS and Non-SSS satisfaction with The College, while focus group interviews revealed student satisfaction levels were virtually the same.

Un regain d'intérêt pour la télédétection de la salinité de surface de l'océan (SSS) par radiométrie en bande-L (21cm) est apparu dans les années 1990 et a conduit au lancement des missions spatiales SMOS (nov. 2009) et Aquarius (juin 2011). Cependant, en raison du faible rapport signal sur bruit, l'inversion de la SSS à partir des mesures radiométriques en bande-L est très difficile. Ce travail porte sur l'étude de la signature radiométrique en bande-L des propriétés de la surface de l'océan (en particulier SSS et rugosité) à partir des mesures du radiomètre aéroporté en bande-L CAROLS, acquises dans le golfe de Gascogne en 2009 et 2010. Une première étude a montré que la SSS déduite des mesures du radiomètre CAROLS était précise à mieux que 0.3 pss dans une zone de forte variabilité spatio-temporelle avec une meilleure précision que les modèles océanographiques côtiers. La seconde étude qui combine les mesures passives (CAROLS) et active (diffusiomètre en bande-C STORM) a mis en évidence l'amélioration des nouveaux modèles de rugosité par rapport aux modèles pré-lancement satellitaires. Par ailleurs, l'étude a montré l'importance de la prise en compte des moyennes et grandes échelles de rugosité (> 20 cm) pour l'interprétation des mesures radiomé- triques loin du nadir.