Wo und wie werden komplexe Regelsätze im Gehirn repräsentiert? Drei empirische Studien dieser Doktorarbeit untersuchen dies experimentell. Eine weitere methodische Studie liefert Beiträge zur Weiterentwicklung der genutzten empirischen Methode. Die empirischen Studien nutzen multivariate Musteranalyse (MVPA) funktioneller Magnetresonanzdaten (fMRT) gesunder Probanden. Die Fragestellungen der methodischen Studie wurden durch die empirischen Arbeiten inspiriert. Wirkung und Anwendungsbreite der entwickelten Methode gehen jedoch über die Anwendung in den empirischen Studien dieser Arbeit hinaus. Die empirischen Studien bearbeiten Fragen wie: Wo werden Hinweisreize und Regeln repräsentiert, und sind deren Repräsentationen voneinander unabhängig? Wo werden Regeln repräsentiert, die aus mehreren Einzelregeln bestehen, und sind Repräsentationen der zusammengesetzten Regeln Kombinationen der Repräsentationen der Einzelregeln? Wo sind Regeln verschiedener Hierarchieebenen repräsentiert, und gibt es einen hierarchieabhängigen Gradienten im ventrolateralen präfrontalen Kortex (VLPFK)? Wo wird die Reihenfolge der Regelausführung repräsentiert? Alle empirischen Studien verwenden informationsbasiertes funktionales Mapping ("Searchlight"-Ansatz), zur hirnweiten und räumlich Lokalisierung von Repräsentationen verschiedener Elemente komplexer Regelsätze. Kernergebnisse der Arbeit beinhalten: Kompositionalität neuronaler Regelrepräsentationen im VLPFK; keine Evidenz für Regelreihenfolgenrepräsentation im VLPFK, welches gegen VLPFK als generelle Task-Set-Kontrollregion spricht; kein Hinweis auf einen hierarchieabhängigen Gradienten im VLPFK. Die komplementierende methodische Studie präsentiert "The Same Analysis Approach (SAA)", ein Ansatz zur Erkennung und Behebung experimentspezifischer Fehler, besonders solcher, die aus Design–Analyse–Interaktionen entstehen. SAA ist für relevant MVPA, aber auch für anderen Bereichen innerhalb und außerhalb der Neurowissenschaften. / Where and how does the brain represent complex rule sets? This thesis presents a series of three empirical studies that decompose representations of complex rule sets to directly address this question. An additional methodological study investigates the employed analysis method and the experimental design. The empirical studies employ multivariate pattern analysis (MVPA) of functional magnetic resonance imaging (fMRI) data from healthy human participants. The methodological study has been inspired by the empirical work. Its impact and application range, however, extend well beyond the empirical studies of this thesis. Questions of the empirical studies (Studies 1-3) include: Where are cues and rules represented, and are these represented independently? Where are compound rules (rules consisting of multiple rules) represented, and are these composed from their single rule representations? Where are rules from different hierarchical levels represented, and is there a hierarchy-dependent functional gradient along ventro-lateral prefrontal cortex (VLPFC)? Where is the order of rule-execution represented, and is it represented as a separate higher-level rule? All empirical studies employ information-based functional mapping ("searchlight" approach) to localise representations of rule set features brain-wide and spatially unbiased. Key findings include: compositional coding of compound rules in VLPFC; no order information in VLPFC, suggesting VLPFC is not a general controller for task set; evidence against the hypothesis of a hierarchy-dependent functional gradient along VLPFC. The methodological study (Study 4) introduces "The Same Analysis Approach (SAA)". SAA allows to detect, avoid, and eliminate confounds and other errors in experimental design and analysis, especially mistakes caused by malicious experiment-specific design-analysis interactions. SAA is relevant for MVPA, but can also be applied in other fields, both within and outside of neuroscience.

This study which is the product of library research and fieldwork seeks, on account of the persistent marginalisation of African Traditional Religion (ATR) in Sierra Leone by Islam and Christianity, to investigate the place of ATR in inter-religious encounters in the country since the advent of Islam and Christianity. As in most of sub-Saharan Africa, ATR is the indigenous religion of Sierra Leone. When the early forebears and later progenitors of Islam and Christianity arrived, they met Sierra Leone indigenes with a remarkable knowledge of God and a structured religious system. Successive Muslim clerics, traders, and missionaries were respectful of and sensitive to the culture and religion of the indigenes who accommodated them and offered them hospitality. This approach resulted in a syncretistic brand of Islam. In contrast, most Christian missionaries adopted an exclusive and insensitive approach to African culture and religiosity. Christianity, especially Protestantism, demanded a complete abandonment of African culture and religion, and a total dedication to Christianity. This attitude has continued by some indigenous clerics and religious leaders to the extent that Sierra Leone Indigenous Religion (SLIR) and it practitioners continue to be marginalised in Sierra Leone's inter-religious dialogue and cooperation. Although the indigenes of Sierra Leone were and continue to be hospitable to Islam and Christianity, and in spite of the fact that SLIR shares affinity with Islam and Christianity in many theological and practical issues, and even though there are many Muslims and Christians who still hold on to traditional spirituality and culture, Muslim and Christian leaders of these immigrant religions are reluctant to include Traditionalists in interfaith issues in the country. The formation and constitution of the Inter-Religious Council of Sierra Leone (IRCSL) which has local and international recognition did not include ATR. These considerations, then beg the questions: * Why have Muslim and Christian leaders long marginalised ATR, its practices and practitioners from interfaith dialogue and cooperation in Sierra Leone? * What is lacking in ATR that continues to prevent practitioners of Christianity and Islam from officially involving Traditionalists in the socio-religious development of the country? Muslim and Christians have given several factors that are responsible for this exclusion: * The prejudices that they inherited from their forebears * ATR lacks the hallmarks of a true religion * ATR is primitive and economically weak * The fear that the accommodation of ATR will result in syncretism and nominalism * Muslims see no need to dialogue with ATR practitioners, most of whom they considered to be already Muslims Considering the commonalities ATR shares with Islam and Christianity, and the number of Muslims and Christians who still hold on to traditional spirituality, these factors are not justifiable. Although Islam and Christianity are finding it hard to recognise and include ATR in interfaith dialogue and cooperation in Sierra Leone, ATR continues to play a vital role in Sierra Leone's national politics, in the search and maintenance of employment, and in the judicial sector. ATR played a crucial part during and after the civil war. The national government in its Truth and Reconciliation Commission (TRC) report acknowledged the importance and contribution of traditional culture and spirituality during and after the war. Outside of Sierra Leone, the progress in the place and level of the recognition of ATR continues. At varying degrees, the Sociétié Africaine de Culture (SAC) in France, the All Africa Conference of Churches (AACC), the Vatican, and the World Council of Churches, have taken positive steps to recognise and find a place for ATR in their structures. Much about the necessity for dialogue and cooperation with ATR can be learnt in the works and efforts of these secular and religious bodies. If nothing else, there are two main reasons why Islam and Christianity in Sierra Leone must be in dialogue with ATR: * Dialogue of life or in community. People living side-by-side meet and interact personally and communally on a regular basis. They share common resources and communal benefits. These factors compel people to be in dialogue * Dual religiosity. As many Muslims and Christians in Sierra Leone are still holding on to ATR practices, it is crucial for Muslims and Christians to dialogue with ATR practitioners. If Muslims and Christians are serious about meeting and starting a process of dialogue with Traditionalists, certain practical issues have to be considered: * Islam and Christianity have to validate and accept ATR as a true religion and a viable partner in the socio-religious landscape of Sierra Leone * Muslims and Christians must educate themselves about ATR, and the scriptures and teachings of their respective religious traditions in order to relate well with Traditionalists These are starting points that can produce successful results. Although at present Muslims and Christians in Sierra Leone are finding it difficult to initiate dialogue and cooperation with Traditionalists, all hope is not lost. It is now the task of the established IRCSL to ensure the inclusion of ATR. Islam and Christianity must remember that when they came as strangers, ATR, played host to them and has played and continues to play a vital role in providing hospitality, and allowing them to blossom on African soil. / Religious Studies and Arabic / D.Litt. et Phil. (Religious Studies)

This study which is the product of library research and fieldwork seeks, on account of the persistent marginalisation of African Traditional Religion (ATR) in Sierra Leone by Islam and Christianity, to investigate the place of ATR in inter-religious encounters in the country since the advent of Islam and Christianity. As in most of sub-Saharan Africa, ATR is the indigenous religion of Sierra Leone. When the early forebears and later progenitors of Islam and Christianity arrived, they met Sierra Leone indigenes with a remarkable knowledge of God and a structured religious system. Successive Muslim clerics, traders, and missionaries were respectful of and sensitive to the culture and religion of the indigenes who accommodated them and offered them hospitality. This approach resulted in a syncretistic brand of Islam. In contrast, most Christian missionaries adopted an exclusive and insensitive approach to African culture and religiosity. Christianity, especially Protestantism, demanded a complete abandonment of African culture and religion, and a total dedication to Christianity. This attitude has continued by some indigenous clerics and religious leaders to the extent that Sierra Leone Indigenous Religion (SLIR) and it practitioners continue to be marginalised in Sierra Leone's inter-religious dialogue and cooperation. Although the indigenes of Sierra Leone were and continue to be hospitable to Islam and Christianity, and in spite of the fact that SLIR shares affinity with Islam and Christianity in many theological and practical issues, and even though there are many Muslims and Christians who still hold on to traditional spirituality and culture, Muslim and Christian leaders of these immigrant religions are reluctant to include Traditionalists in interfaith issues in the country. The formation and constitution of the Inter-Religious Council of Sierra Leone (IRCSL) which has local and international recognition did not include ATR. These considerations, then beg the questions: * Why have Muslim and Christian leaders long marginalised ATR, its practices and practitioners from interfaith dialogue and cooperation in Sierra Leone? * What is lacking in ATR that continues to prevent practitioners of Christianity and Islam from officially involving Traditionalists in the socio-religious development of the country? Muslim and Christians have given several factors that are responsible for this exclusion: * The prejudices that they inherited from their forebears * ATR lacks the hallmarks of a true religion * ATR is primitive and economically weak * The fear that the accommodation of ATR will result in syncretism and nominalism * Muslims see no need to dialogue with ATR practitioners, most of whom they considered to be already Muslims Considering the commonalities ATR shares with Islam and Christianity, and the number of Muslims and Christians who still hold on to traditional spirituality, these factors are not justifiable. Although Islam and Christianity are finding it hard to recognise and include ATR in interfaith dialogue and cooperation in Sierra Leone, ATR continues to play a vital role in Sierra Leone's national politics, in the search and maintenance of employment, and in the judicial sector. ATR played a crucial part during and after the civil war. The national government in its Truth and Reconciliation Commission (TRC) report acknowledged the importance and contribution of traditional culture and spirituality during and after the war. Outside of Sierra Leone, the progress in the place and level of the recognition of ATR continues. At varying degrees, the Sociétié Africaine de Culture (SAC) in France, the All Africa Conference of Churches (AACC), the Vatican, and the World Council of Churches, have taken positive steps to recognise and find a place for ATR in their structures. Much about the necessity for dialogue and cooperation with ATR can be learnt in the works and efforts of these secular and religious bodies. If nothing else, there are two main reasons why Islam and Christianity in Sierra Leone must be in dialogue with ATR: * Dialogue of life or in community. People living side-by-side meet and interact personally and communally on a regular basis. They share common resources and communal benefits. These factors compel people to be in dialogue * Dual religiosity. As many Muslims and Christians in Sierra Leone are still holding on to ATR practices, it is crucial for Muslims and Christians to dialogue with ATR practitioners. If Muslims and Christians are serious about meeting and starting a process of dialogue with Traditionalists, certain practical issues have to be considered: * Islam and Christianity have to validate and accept ATR as a true religion and a viable partner in the socio-religious landscape of Sierra Leone * Muslims and Christians must educate themselves about ATR, and the scriptures and teachings of their respective religious traditions in order to relate well with Traditionalists These are starting points that can produce successful results. Although at present Muslims and Christians in Sierra Leone are finding it difficult to initiate dialogue and cooperation with Traditionalists, all hope is not lost. It is now the task of the established IRCSL to ensure the inclusion of ATR. Islam and Christianity must remember that when they came as strangers, ATR, played host to them and has played and continues to play a vital role in providing hospitality, and allowing them to blossom on African soil. / Religious Studies and Arabic / D.Litt. et Phil. (Religious Studies)

Η οπτική συνεκτική τομογραφία με τη χρήση συχνοτήτων ( FD-OCT) είναι μια ενδαγγειακή απεικονιστική μέθοδος που χρησιμοποιεί εγγύς στο υπέρυθρο φως, για να παράγει υψηλής ανάλυσης εικόνες του τοιχώματος του αυλού του αγγείου. Όπως και στην τεχνολογία υπερήχων, εκπέμπεται φωτεινή ενέργεια η οποία ανακλάται και εξασθενεί, σύμφωνα με την υφή του προσπιπτομένου ιστού. Το OCT μπορεί να απεικονίσει, με ανάλυση από 10 έως 20 μm, μικροδομές του αγγειακού τοιχώματος με εξαίσια λεπτομέρεια. Μέχρι σήμερα, η δυνατότητα εφαρμογής της μεθόδου είχε περιοριστεί σε μικρές αρτηρίες διαμέτρου έως 4mm και δεν είχε εφαρμοστεί in vivo στα αγγεία των κάτω άκρων, κάτωθεν του επιπέδου των βουβώνων. Σκοπός της παρούσας μελέτης είναι να αναφερθεί για παγκοσμίως πρώτη φορά η ασφάλεια και η σκοπιμότητα της απεικόνισης με Οπτική Συνεκτική Τομογραφία του αρτηριακού άξονα των κάτω άκρων , κάτωθεν του επιπέδου της βουβώνας ( μηροϊγνυακός άξονας και κνημιαία αγγεία), καθώς και οι σχετιζόμενες με το FD-OCT επιπλοκές. Επιπρόσθετα, να διερευνηθούν για πρώτη φορά, με τη χρήση FD-OCT, τα χαρακτηριστικά του αγγειακού τοιχώματος του ανωτέρω άξονα (τόσο πριν όσο και μετά από αγγειοπλαστική ή/και τοποθέτηση stent), η μορφολογία της αθηρωματικής πλάκας, η μορφολογία και η ποσοτικοποίηση της υπερπλασίας του νέου εσωτερικού χιτώνα (neointima) εντός του stent, η επαναστένωση εντός του stent (ISR) και η κακή εναπόθεση (malapposition) των stent struts σε μια σειρά από ασθενείς που πάσχουν από περιφερική αρτηριοπάθεια (PAD). Μελετήθηκαν, με ποσοτική ανάλυση του αυλού τους (Quantitative vascular analysis), αρτηρίες με διάμετρο έως 7 χιλιοστά. Μικτά χαρακτηριστικά από περιοχές πλούσιες σε λιπίδια, εναποθέσεις ασβεστίου και ασβεστοποιημένες πλάκες, νεκρωτικές περιοχές και ίνωση εντοπίστηκαν σε όλες τις απεικονιζόμενες αθηροσκληρωτικές βλάβες. Ωστόσο, με βάση το επικρατέστερο από τα παραπάνω απεικονιστικά χαρακτηριστικά, οι βλάβες στο πλαίσιο της έρευνας ταξινομήθηκαν ως αμιγώς ινωτικές, ως ινοασβεστοποιημένες, ως πλούσιες σε λιπίδια και τέλος ως νεκρωτικές/ασβεστοποιημένες. Συσσώρευση των μακροφάγων εντός της αθηρωματικής πλάκας σημειώθηκε σε μικρό ποσοστό των de novo αθηρωματικών αλλοιώσεων. Ποικίλοι βαθμοί υπερπλασίας του νέου έσω χιτώνα απεικονίσθηκαν σε όλες τις περιπτώσεις ISR αλλοιώσεων, με καθαρά ινωτικά χαρακτηριστικά και σημαντική νεοαγγείωση σε κάποιες από αυτές. Η νεοαγγείωση συνέπεσε με το επίπεδο της μέγιστης στένωσης του αγγειακού αυλού. Σημαντικού βαθμού διαχωρισμός με μεγάλο περιορισμό του αγγειακού αυλού, τέτοιος ώστε να απαιτηθεί να τοποθετηθεί ενδοαυλικό stent, ανιχνεύθηκε σε αρκετές περιπτώσεις της de novo αθηρωμάτωσης. Η ψηφιακή αφαιρετική αγγειογραφία παρέλειψε να προσδιορίσει μεγάλο ποσοστό των σοβαρών διαχωρισμών μετά από αγγειοπλαστική. Η νεοαθηροσκλήρυνση εντός του νέου έσω χιτώνα των κνημιαίων φαρμακευτικών stents (DES), είναι ένα συχνό εύρημα τόσο στους συμπτωματικούς όσο και στους ασυμπτωματικούς ασθενείς. Μπορούμε να υποθέσουμε ότι, κατά αναλογία με τα εμφυτευμένα DES στα στεφανιαία αγγεία, η ελαττωματική ενδοθηλιοποίηση που προκαλείται από την εκλυόμενη φαρμακευτική ουσία, μαζί με την νεοαγγείωση που αναπτύσσεται μεταξύ των stent struts, μπορούν να υποδαυλίσουν την νεοαθηροσκλήρυνση εντός του νέου έσω χιτώνα των κνημιαίων DES, η οποία μπορεί να οδηγήσει σε επαναστένωση εντός του stent (ISR) και απώλεια του εμβαδού του αυλού των περιφερικών αρτηριών. Οι παρατηρήσεις της μελέτης αυτής θέτουν σε αμφισβήτηση το παραδοσιακό τρόπο κατανόησης της περιφερειακής επαναστένωσης εντός του stent ως μιας απλής υπερπολλαπλασιαστικής απάντησης στο βαρότραυμα. Η απεικόνιση με FD-OCT είναι ένα βέλτιστο πειραματικό εργαλείο για την αξιολόγηση της εξέλιξης της αθηροσκληρωματικής νόσου και την επαναστένωση του αγγείου. Μπορεί να παρέχει υψηλής ευκρίνειας ενδοαγγειακή απεικόνιση κατά τη διάρκεια αγγειοπλαστικών επεμβάσεων στα κάτω άκρα και θα μπορούσε να αποδειχθεί κλινικά χρήσιμο για τον προσδιορισμό της εντός του stent πρόπτωσης ιστού και του strut malapposition. Παρ 'όλα αυτά, δεν πρέπει να χρησιμοποιηθεί ως εργαλείο για τη συνήθη κλινική πρακτική μέχρι να προκύψουν στοιχεία από περαιτέρω κλινικές δοκιμές για τον καθορισμό των ειδικών ενδείξεων της απεικόνισης με FD-OCT στις περιφερικές αρτηρίες. / Optical coherence tomography (OCT) is a catheter-based imaging method that employs near-infrared light to produce high-resolution intravascular images. OCT can readily visualize vessel microstructure at a 10- to 20-μm resolution with exquisite detail. To date, however, applicability of the method has been limited to small diameter arteries (≤4 mm). To the best of the author’s knowledge, this study is the first worldwide that demonstrates the safety and clinical feasibility of frequency domain Optical Coherence Tomography (FD-OCT) imaging of infrainguinal vessels in vivo during infrainguinal angioplasty procedures. It is also the first study that reports the use of intravascular FD-OCT to detect and characterize in-stent neointimal tissue following infrapopliteal drug eluting stent (DES) placement in patients suffering from critical limb ischemia. Quantitative lumen analysis of arteries with diameter up to 7 mm was performed. High-resolution OCT images provided exquisite two-dimensional axial and longitudinal views of the infrainguinal arteries and allowed thorough investigation of a variety of angioplasty sequela, including and not limited to intimal tears and dissection flaps, white and red thrombus, stent mesh malapposition, and intrastent plaque prolapse. Of interest, OCT identified cases of suboptimal postangioplasty outcome that single-plane subtraction angiography did not recognize and accounted. Mixed features of lipid pool areas, calcium deposits and calcified plaques, necrotic areas, and fibrosis were identified in all of the imaged atherosclerotic lesions. However, based on the predominant baseline imaging findings, lesions under investigation were classified as purely fibrotic, fibrocalcific, mostly lipid-laden and necrotic/calcified. Intraplaque accumulation of macrophages was noted in some of de novo atheromatic lesions. Varying degrees of neointimal hyperplasia were demonstrated in all cases of in stent restenosis (ISR) lesions with purely fibrotic features and considerable neovascularization in some of them. The latter finding coincided with the level of maximum vessel stenosis in all cases. Neoatherosclerosis following infrapopliteal DES placement is a frequent finding in both symptomatic and asymptomatic patients. Our preliminary observations allow us to speculate that analogous to coronary implanted DES, defective endothelialization induced by the eluted drug, along with neovascularization developing between the stent struts, may incite neointimal neoatherosclerosis, which may result in ISR and lumen loss of the peripheral arteries. It also seems that infrapopliteal neoatherosclerosis may be a significant contributing factor for ISR rather than a minor and sporadic process, highlighting the clinical significance of the phenomenon. Our observations put in dispute the traditional way of understanding peripheral in-stent restenosis as a simple hyperproliferative response to barotraumas and may explain the paramount importance of aggressive risk factor modification strategies. Neointimal neoatherosclerosis as identified by FD-OCT may have a role in the development of below-the-knee restenosis and thus warrants further investigation by larger controlled studies. Moreover, it may prove clinically useful for the determination of intrastent tissue prolapse and strut malapposition. FD-OCT should not be utilized as a tool for routine clinical practice until evidence from further clinical trials emerge to determine the specific indications for OCT imaging of the peripheral arteries.