The group of pleurocarpous mosses comprises approximately 5000 species, which corresponds to about half of all mosses. The pleurocarpous mosses (i.e. “the Core Pleurocarps”) form a monophylum, which consists typically of perennial mosses with creeping stems and abundant lateral branches. In pleurocarpous mosses the archegonium and thus also sporophyte development is restricted to the apices of short, specialized lateral branches, in contrast to most other mosses, where archegonia and sporophytes develop terminally on the main axis (acrocarpous) or on major branches (cladocarpous). Traditionally, pleurocarpous mosses have been divided into three orders based mainly on their sporophytic characters. Brotherus described the Neckeraceae in 1925 and placed it into the Leucodontales, later the family has alternatively been divided into two or three separate families: the Thamnobryaceae, the Neckeraceae and the Leptodontaceae. These families have been placed even in different orders (Neckeraceae and Leptodontaceae among the leucodontalean mosses and Thamnobryaceae among hypnalean mosses) according to their peristome structure and the grade of peristome reduction. A growing amount of evidence indicates that a grouping based on sporophytic characters is artificial and based on convergent evolution. According to the latest phylogenetic studies of pleurocarpous mosses, based on molecular data, the Neckeraceae belong to the order Hypnales and share a sister group relationship with the Lembophyllaceae. In the most recent comprehensive classification 28 genera were included in the Neckeraceae family. This classification was based on both morphological and molecular data, but done with limited taxon sampling that did not cover all species of the family. Some previous studies based on molecular data have challenged the family concept of the Neckeraceae, indicating the need for a revision of the family. Here the family concept of the Neckeraceae is revisited, the closest relatives of the family are resolved and its position within pleurocarpous mosses is shown. In addition, new insights into the morphological evolution of the family are provided. Previous phylogenetic studies indicated that branch lengths among pleurocarpous mosses are usually extremely short. Therefore we chose to use mainly non-coding DNA sequences from rapidly evolving DNA regions. The phylogenetic reconstructions are based on extensive sequence data from all genomes: plastid trnS-trnF and rpl16, nuclear ITS1 & 2 and mitochondrial nad5. Both parsimony (PAUP and PRAP2) and Bayesian statistics (MrBayes) were employed for phylogenetic reconstructions. In order to use the information provided by length mutations indels were included in the analyses as binary data using a simple indel coding approach. No severe conflicts appeared between the different methods used, but the indel coding affected the support values of the inferred topologies. Therefore, all support values resulting from different methods are shown along the phylogenetic trees. The morphological features are studied and synapomorphies for each clade formed in the phylogenetic analyses are interpreted. A new delimitation of the family makes it necessary to reconsider the relevance of the morphological description and the morphological features characteristic of the family need to be reconsidered. Due to new groupings, some changes in the morphological circumscriptions of the genera are necessary, resulting in two new genera and several new combinations. Chapter 1 gives a broad overview of the relationships of the pleurocarpous mosses and shows the need for changes in the definition of genera, families and the corresponding nomenclature in this group. Chapter 2 is a population genetic study on the genus Thamnobryum. The main aim of this chapter is to test the species concept in Thamnobryum that are endemic to strictly restricted regions showing only minor differences in the morphological features in comparison to some more common species. In Chapter 3 the monophyly of the Neckeraceae is tested. In addition, in this chapter the ancestral character states of some morphological characters within the Neckeraceae are reconstructed. Chapters 4 and 5 resolve the genus composition and the relationships within the family in more detail. The results of this thesis show that the Neckeraceae need re-circumscription; this includes changes in the genus composition. The Lembophyllaceae is confirmed to be the sister group of the Neckeraceae. In addition to the new phylogeny, the potential evolution of several characters as a result of environmental selection pressures is analyzed. From the ancestral state reconstructions made (using BayesTraits) for both the habitat and a selection of morphological characters, character state distributions and habitat shift appear congruent, peristome reduction being a good example. However, some character states do not correlate with the habitat, suggesting very complex evolutionary patterns underlying these morphological characters. Many widely distributed genera that are composed of several species and seem to be morphologically coherent (Echinodium, Homalia, Thamnobryum, partly Neckera), are shown in this thesis to be polyphyletic. They are replaced by smaller, geographically more restricted genera that at least in some cases (e.g. Thamnomalia, Homalia s.str., Neckera s.str.) seem to form morphologically heterogeneous genera. In other words, morphology can be misleading in the family Neckeraceae even at the genus level and convergent evolution in both morphological and sequence level characters are common within the family. Special habitat conditions have been shown to result in similar morphological structures also in several other moss groups. This kind of convergent evolution occurs in aquatic mosses, and seems to have occurred among the neckeraceous species Thamnobryum alopecurum and its allies. However, similar morphological structure in similar aquatic habitats can also be due to true phylogenetic relationships as is the case within the Neckeraceae for Handeliobryum sikkimense and Hydrocryphae wardii, or the members of Touwia. The geographical grouping seems to be more strongly correlated with the phylogenetic grouping than thought before.

Stigmatized obese individuals tend to internalize the pervasive weight stigma which might lead to self-discrimination and increased psychopathology. While explicit and implicit weight stigma can be measured using self-report questionnaires and Implicit Association Tests (IAT), respectively, the assessment of self-discrimination relied solely on self-report. The present study sought to develop an IAT measuring implicit self-discrimination (SD-IAT) in samples of obese individuals with and without binge-eating disorder (BED). Seventy-eight individuals were recruited from the community and individually matched in three groups. Obese participants with BED, obese participants without BED (OB), and a normal weight control group without eating disorder psychopathology (HC) were assessed with the SD-IAT and other measures relevant for convergent and discriminant validation. Results revealed significantly higher implicit self-discrimination in the BED group when compared to both OB and HC. Furthermore, significant correlations were found between the SD-IAT with body mass index, experiences of weight stigma, depressive symptoms, and implicit self-esteem. Finally, implicit self-discrimination predicted eating disorder psychopathology over and above group membership, and experiences of weight stigma. This study provides first evidence of the validity of the SD-IAT. Assessing implicit self-discrimination might further increase understanding of weight stigma and its significance for psychosocial functioning among vulnerable obese individuals.

The programmable network envisioned in the 1990s within standardization and research for the Intelligent Network is currently coming into reality using IPbased Next Generation Networks (NGN) and applying Service-Oriented Architecture (SOA) principles for service creation, execution, and hosting. SOA is the foundation for both next-generation telecommunications and middleware architectures, which are rapidly converging on top of commodity transport services. Services such as triple/quadruple play, multimedia messaging, and presence are enabled by the emerging service-oriented IPMultimedia Subsystem (IMS), and allow telecommunications service providers to maintain, if not improve, their position in the marketplace. SOA becomes the de facto standard in next-generation middleware systems as the system model of choice to interconnect service consumers and providers within and between enterprises. We leverage previous research activities in overlay networking technologies along with recent advances in network abstraction, service exposure, and service creation to develop a paradigm for a service environment providing converged Internet and Telecommunications services that we call Service Broker. Such a Service Broker provides mechanisms to combine and mediate between different service paradigms from the two domains Internet/WWW and telecommunications. Furthermore, it enables the composition of services across these domains and is capable of defining and applying temporal constraints during creation and execution time. By adding network-awareness into the service fabric, such a Service Broker may also act as a next generation network-to-service element allowing the composition of crossdomain and cross-layer network and service resources. The contribution of this research is threefold: first, we analyze and classify principles and technologies from Information Technologies (IT) and telecommunications to identify and discuss issues allowing cross-domain composition in a converging service layer. Second, we discuss service composition methods allowing the creation of converged services on an abstract level; in particular, we present a formalized method for model-checking of such compositions. Finally, we propose a Service Broker architecture converging Internet and Telecom services. This environment enables cross-domain feature interaction in services through formalized obligation policies acting as constraints during service discovery, creation, and execution time. / Das programmierbare Netz, das Ende des 20. Jahrhunderts in der Standardisierung und Forschung für das Intelligente Netz entworfen wurde, wird nun Realität in einem auf das Internet Protokoll basierendem Netz der nächsten Generation (Next Generation Network). Hierfür kommen Prinzipien aus der Informationstechnologie, insbesondere aus dem Bereich dienstorientierte Architekturen (Service-Oriented Architecture / SOA) für die Diensterstellung, -ausführung und -betrieb zum Tragen. SOA bietet hierbei die theoretische Grundlage für Telekommunikationsnetze, vor allem jedoch für die dazugehörigen Dienstplattformen. Diese erlauben dem Telekommunikationsbetreiber seine Position in einem offenen Marktplatz der Dienste auszubauen. Dazu bedarf es allerdings möglichst flexibler Dienstumgebungen, die die Kooperation zwischen Dienstanbietern und Nutzern aus unterschiedlichsten Domänen durch Unterstützung geeigneter Werkzeuge und Mechanismen fördert. Im Rahmen dieser Dissertation definieren wir aufbauend auf Forschungsergebnisse im Bereich Overlay-Netze, Netzabstraktion und Zugriff auf exponierte Dienste eine Service Broker genannte Dienstumgebung für konvergente Internet- und Telekommunikationsdienste. Dieser Service Broker stellt Mechanismen für die Komposition von Diensten und Mediation zwischen unterschiedlichen Dienstparadigmen und Domänenspezifika beim Dienstaufruf zur Verfügung. Der Forschungsbeitrag dieser Arbeit findet auf unterschiedlichen Ebenen statt: Aufbauend auf einer Analyse und Klassifikation von Technologien und Paradigmen aus den Bereichen Informationstechnologie (IT) und Telekommunikation diskutieren wir die Problemstellung der Kooperation von Diensten und deren Komposition über Domänengrenzen hinweg. In einem zweiten Schritt diskutieren wir Methoden der Dienstkomposition und präsentieren eine formalisierte Methode der modellbasierten Diensterstellung. Der Schwerpunkt der Arbeit liegt auf der Spezifikation der Service Broker Dienstumgebung und einem zugrundeliegenden Informations- und Datenmodell. Diese Architektur erlaubt die Komposition und Kooperation von Diensten über Domänengrenzen hinweg, um konvergente Internet- und Telekommunikationsdienste zu realisieren. Hierfür wird ein auf Obligationspolitiken basierendes Regelsystemformalisiert, das Interaktionen zwischen Dienstmerkmalen während der Diensterstellung und -ausführung definiert.

Higher frequencies in the MHz and GHz range and the increasing miniaturization lead to a higher load of the SAW (surface acoustic wave) metallizations. This higher SAW load and the intrinsic stresses result in a stress induced material transport, called acoustomigration. These microstructural changes can destroy the characteristic of the SAW device. Different Al based material combinations were investigated by different authors to improve the reliability of the metallizations and to delay the cost-intensive change to Cu based metallizations. The Cu based metallizations with TaSiN diffusion barriers were also investigated in this work. The barrier layers are necessary to impede the oxygen diffusion into the Cu layer and the Cu diffusion into the piezoelectric substrate. Also in this work the analytical TEM were used as a tool to investigate these microstructural changes in the SAW electrodes. Chemical changes in the metallizations were analysed by EDXS and EELS. The locally high resolved stress measurement in metallizations is a challenge for the future. The CBED (convergent beam electron diffraction) technique has shown the best resolution, however, it can only be applied to TEM lamellas. The aim of this work was to measure the stress within the SAW metallizations by using the CBED method. With it, we could correlate the microstructural changes with the causing stresses within the metallizations. To qualify the CBED method the thermal expansion of Al and Cu single crystals was measured by using a new model for thin TEM lamallas.

Hierdie studie handel oor die invloed van twee onderrigbenaderings naamlik tradisioneel en sosiaal-konstruktivisties, op Graad 6-leerders se studieoriëntasie in Wiskunde. Om die omvang hiervan beter in perspektief te plaas is daar gekyk na wat die moontlike verskille is tussen die tradisionele sowel as die sosiaal-konstruktivistiese onderrigbenaderings ten opsigte van Graad 6-leerders se studieoriëntasie in Wiskundeprestasie. Literatuur dui aan dat leerders swak presteer en noem faktore wat moontlik bydra. Verder dui die literatuur aan dat daar nie genoeg navorsing is ten opsigte van ontoereikende wiskundeprestasie nie. Dit is kommerwekkend dat daar tot dusver redelik min navorsing gedoen is wat Graad 6-leerders se ontoereikende prestasie in Wiskunde aanbetref (Rademeyer, 2009) aangesien dit so ’n belangrike rol speel tot die beroepswêreld (Salman et al, 2010). Maree, Pretorius en Eiselen (2003) meen dat verbetering in Wiskundeprestasie moontlik gefasiliteer kan word deur op die leerders se ontoereikende studieoriëntasie te fokus en dít dan so te probeer verbeter. Die konseptuele raamwerk van hierdie studie rus op Vygotsky se sone van proksimale ontwikkeling (Maimane, 2006) sowel as Bronfenbrenner se ekologiese teorie en die konseptuele raamwerk (Santrock, 2001; Bronfenbrenner,2012) Die navorsingsvrae lui dan as volg: Primêre navorsingsvraag: Wat is die verskil tussen die tradisionele sowel as die sosiaal-konstruktivistiese onderrigbenadering ten opsigte van Graad 6-leerders se studieoriëntasie in Wiskundeprestasie? Eerste sekondêre vraag: Hoe verskil die tradisionele onderrigbenadering ten opsigte van die sosiaal-konstruktivistiese onderrigbenadering? Tweede sekondêre vraag en hipotese: Wat is die verskil in Wiskundeprestasie voor en na die intervensie ten opsigte van die twee onderrigbenaderings? Derde sekondêre vraag en hipotese: Wat is die verskil in studieoriëntasie voor en na die intervensie ten opsigte van die twee onderrigbenaderings? Hierdie studie word beskou deur pragmatisme as ’n wêreldbeskouing en filosofiese fondasie aangesien pragmatisme die heel beste pas by die gemengde navorsingsmetode. Die konvergente navorsingsontwerp is die ideale navorsings-ontwerp vir hierdie studie aangesien dit die bekendste benadering tot die gemengde navorsingsmetode is. Vir die kwalitatiewe data-insameling is ek gebruik gemaak van fokusgroeponderhoude wat drie maal gehou is met beide die groepe, altesaam ses sessies. Daar was sewe leerders wat elk van die groepe verteenwoordig het, veertien leerders altesaam. Daar is gebruik gemaak van ’n individuele onderhoud met die Wiskundeonderwyseres aan die einde van die intervensie tydperk. Die data was geanaliseer deur inhoudsanalise. Die kwantitatiewe data is ingesamel deur die Studieoriëntasievraelys in Wiskunde (Primêr) (SOW(P)) en ook ’n formele wiskunde toets aan die begin en aan die einde van die intervensie tydperk. Daar was twintig leerders wat deelgeneem het aan die tradisionele groep en twintig leerders wat deelgeneem het aan die sosiaal-konstruktivistiese groep. Daar was altesaam veertig leerders betrokke by die studie. Die kwalitatiewe data-analise het uitgedraai op vier verskillende temas: faktore wat Wiskunde makliker maak vir leerders, faktore van Wiskunde wat vir leerders onaangenaam is, faktore van introspeksie en ook ander interessante faktore. Ek het ook observasies en addisionele data vanaf die Wiskundeonderwyseres verkry deur die individuele onderhoud. Vir die doeleindes van die kwantitatiewe data is gebruik gemaak van beskrywende sowel as inferensiële statistieke om die data te analiseer. Daar is gebruik gemaak van die paar-steekproef studente t-toets. Alles is dan na aanleiding van die data-analise bespreek en na aanleiding van my bevindinge en resultate is daar gevind dat daar wel ’n verskil is tussen die tradisionele onderrigmetode en die sosiaal-konstruktivistiese onderrigbenadering. Dit was ook duidelik dat daar ’n waarskynlike verskil tussen die voor-toets en die na-toets van die tradisionele sowel as die sosiaal-konstruktivistiese groep se Wiskundeprestasie is en dus is beide as statisties beduidend aanvaar. Wat die studieoriëntasie aanbetref het die uitkoms getoon dat daar geen verskil was tussen die voor-toets en die na-toets van die tradisionele groep nie, dus toon dit om nie statisties beduidend te wees nie . Daar was wel ’n waarskynlike verandering tussen die voor-toets en die na-toets van die sosiaal-konstruktivistiese groep se studie-oriëntasie en aanvaar ek dit dus as statisties beduidend. / Dissertation (MEd)--University of Pretoria, 2013. / gm2014 / Educational Psychology / unrestricted

Stigmatized obese individuals tend to internalize the pervasive weight stigma which might lead to self-discrimination and increased psychopathology. While explicit and implicit weight stigma can be measured using self-report questionnaires and Implicit Association Tests (IAT), respectively, the assessment of self-discrimination relied solely on self-report. The present study sought to develop an IAT measuring implicit self-discrimination (SD-IAT) in samples of obese individuals with and without binge-eating disorder (BED). Seventy-eight individuals were recruited from the community and individually matched in three groups. Obese participants with BED, obese participants without BED (OB), and a normal weight control group without eating disorder psychopathology (HC) were assessed with the SD-IAT and other measures relevant for convergent and discriminant validation. Results revealed significantly higher implicit self-discrimination in the BED group when compared to both OB and HC. Furthermore, significant correlations were found between the SD-IAT with body mass index, experiences of weight stigma, depressive symptoms, and implicit self-esteem. Finally, implicit self-discrimination predicted eating disorder psychopathology over and above group membership, and experiences of weight stigma. This study provides first evidence of the validity of the SD-IAT. Assessing implicit self-discrimination might further increase understanding of weight stigma and its significance for psychosocial functioning among vulnerable obese individuals.

Higher frequencies in the MHz and GHz range and the increasing miniaturization lead to a higher load of the SAW (surface acoustic wave) metallizations. This higher SAW load and the intrinsic stresses result in a stress induced material transport, called acoustomigration. These microstructural changes can destroy the characteristic of the SAW device. Different Al based material combinations were investigated by different authors to improve the reliability of the metallizations and to delay the cost-intensive change to Cu based metallizations. The Cu based metallizations with TaSiN diffusion barriers were also investigated in this work. The barrier layers are necessary to impede the oxygen diffusion into the Cu layer and the Cu diffusion into the piezoelectric substrate. Also in this work the analytical TEM were used as a tool to investigate these microstructural changes in the SAW electrodes. Chemical changes in the metallizations were analysed by EDXS and EELS. The locally high resolved stress measurement in metallizations is a challenge for the future. The CBED (convergent beam electron diffraction) technique has shown the best resolution, however, it can only be applied to TEM lamellas. The aim of this work was to measure the stress within the SAW metallizations by using the CBED method. With it, we could correlate the microstructural changes with the causing stresses within the metallizations. To qualify the CBED method the thermal expansion of Al and Cu single crystals was measured by using a new model for thin TEM lamallas.

The group of pleurocarpous mosses comprises approximately 5000 species, which corresponds to about half of all mosses. The pleurocarpous mosses (i.e. “the Core Pleurocarps”) form a monophylum, which consists typically of perennial mosses with creeping stems and abundant lateral branches. In pleurocarpous mosses the archegonium and thus also sporophyte development is restricted to the apices of short, specialized lateral branches, in contrast to most other mosses, where archegonia and sporophytes develop terminally on the main axis (acrocarpous) or on major branches (cladocarpous). Traditionally, pleurocarpous mosses have been divided into three orders based mainly on their sporophytic characters. Brotherus described the Neckeraceae in 1925 and placed it into the Leucodontales, later the family has alternatively been divided into two or three separate families: the Thamnobryaceae, the Neckeraceae and the Leptodontaceae. These families have been placed even in different orders (Neckeraceae and Leptodontaceae among the leucodontalean mosses and Thamnobryaceae among hypnalean mosses) according to their peristome structure and the grade of peristome reduction. A growing amount of evidence indicates that a grouping based on sporophytic characters is artificial and based on convergent evolution. According to the latest phylogenetic studies of pleurocarpous mosses, based on molecular data, the Neckeraceae belong to the order Hypnales and share a sister group relationship with the Lembophyllaceae. In the most recent comprehensive classification 28 genera were included in the Neckeraceae family. This classification was based on both morphological and molecular data, but done with limited taxon sampling that did not cover all species of the family. Some previous studies based on molecular data have challenged the family concept of the Neckeraceae, indicating the need for a revision of the family. Here the family concept of the Neckeraceae is revisited, the closest relatives of the family are resolved and its position within pleurocarpous mosses is shown. In addition, new insights into the morphological evolution of the family are provided. Previous phylogenetic studies indicated that branch lengths among pleurocarpous mosses are usually extremely short. Therefore we chose to use mainly non-coding DNA sequences from rapidly evolving DNA regions. The phylogenetic reconstructions are based on extensive sequence data from all genomes: plastid trnS-trnF and rpl16, nuclear ITS1 & 2 and mitochondrial nad5. Both parsimony (PAUP and PRAP2) and Bayesian statistics (MrBayes) were employed for phylogenetic reconstructions. In order to use the information provided by length mutations indels were included in the analyses as binary data using a simple indel coding approach. No severe conflicts appeared between the different methods used, but the indel coding affected the support values of the inferred topologies. Therefore, all support values resulting from different methods are shown along the phylogenetic trees. The morphological features are studied and synapomorphies for each clade formed in the phylogenetic analyses are interpreted. A new delimitation of the family makes it necessary to reconsider the relevance of the morphological description and the morphological features characteristic of the family need to be reconsidered. Due to new groupings, some changes in the morphological circumscriptions of the genera are necessary, resulting in two new genera and several new combinations. Chapter 1 gives a broad overview of the relationships of the pleurocarpous mosses and shows the need for changes in the definition of genera, families and the corresponding nomenclature in this group. Chapter 2 is a population genetic study on the genus Thamnobryum. The main aim of this chapter is to test the species concept in Thamnobryum that are endemic to strictly restricted regions showing only minor differences in the morphological features in comparison to some more common species. In Chapter 3 the monophyly of the Neckeraceae is tested. In addition, in this chapter the ancestral character states of some morphological characters within the Neckeraceae are reconstructed. Chapters 4 and 5 resolve the genus composition and the relationships within the family in more detail. The results of this thesis show that the Neckeraceae need re-circumscription; this includes changes in the genus composition. The Lembophyllaceae is confirmed to be the sister group of the Neckeraceae. In addition to the new phylogeny, the potential evolution of several characters as a result of environmental selection pressures is analyzed. From the ancestral state reconstructions made (using BayesTraits) for both the habitat and a selection of morphological characters, character state distributions and habitat shift appear congruent, peristome reduction being a good example. However, some character states do not correlate with the habitat, suggesting very complex evolutionary patterns underlying these morphological characters. Many widely distributed genera that are composed of several species and seem to be morphologically coherent (Echinodium, Homalia, Thamnobryum, partly Neckera), are shown in this thesis to be polyphyletic. They are replaced by smaller, geographically more restricted genera that at least in some cases (e.g. Thamnomalia, Homalia s.str., Neckera s.str.) seem to form morphologically heterogeneous genera. In other words, morphology can be misleading in the family Neckeraceae even at the genus level and convergent evolution in both morphological and sequence level characters are common within the family. Special habitat conditions have been shown to result in similar morphological structures also in several other moss groups. This kind of convergent evolution occurs in aquatic mosses, and seems to have occurred among the neckeraceous species Thamnobryum alopecurum and its allies. However, similar morphological structure in similar aquatic habitats can also be due to true phylogenetic relationships as is the case within the Neckeraceae for Handeliobryum sikkimense and Hydrocryphae wardii, or the members of Touwia. The geographical grouping seems to be more strongly correlated with the phylogenetic grouping than thought before.

Ökomorphologische Konvergenz tritt auf, wenn Arten mit demselben Lebensstil unabhängig voneinander ähnliche morphologische Merkmale evolvieren. Neue Fallstudien können dabei helfen, die diesem Prozess zugrunde liegenden Mechanismen aufzuklären. Diese Arbeit befasst sich mit einigen konvergent evolvierten, langsamen, baumbewohnenden Säugetieren, d. h. zwei Linien baumlebender Faultieren, dem Zwergameisenbär, den Lorisiden, zwei Kladen ausgestorbener Lemuren, d. h. Paläopropithekiden und Megaladapis, und dem Koala. Es werden funktionsmorphologische Konvergenzen in diesen Taxa erforscht, indem ihr Humerus und ihr Femur sowie jene ihrer nah verwandten, aber ökologisch unterschiedlichen Taxa untersucht werden. Erstmals werden Knochen mittels phylogenetisch vergleichender Methoden auf vier anatomischen Ebenen, d.h. äußere Form, diaphysäre Mikrostruktur und Anatomie sowie epiphysäre Trabekelarchitektur, analysiert. Viele langsame, baumbewohnende Säugetiere teilen eine geringe kortikale Kompaktheit, was wahrscheinlich mit ihrer extrem niedrigen Stoffwechselrate und ihren biomechanischen Anforderungen zusammenhängt. Langsame, arboreale Xenarthra, d. h. baumbewohnende Faultiere und der Zwergameisenbär, weisen ein Muster unvollständiger Konvergenz für eine Reihe äußerer und innerer anatomischer Merkmale auf, was möglicherweise durch die relativ unterschiedliche Ökologie des Zwergameisenbären erklärt wird. Auf einer breiteren Säugetierskala konvergieren andere Merkmale, die möglicherweise mit der Ökologie der langsamen baumbewohnenden Lebensweise in einigen der untersuchten Taxa zusammenhängen, obwohl komplexe Muster auch durch andere evolutionäre Prozesse erklärt werden können. Nur suspensorisch lebende Taxa tragen signifikant zur Konvergenz bei. Diese Arbeit hebt die stärkere Konvergenz hervor, die sich in der inneren Struktur des Knochens widerspiegelt. / Ecomorphological convergence occurs when similar morphological traits are independently evolved by species with the same lifestyle. Novel case studies can help to elucidate the underlying mechanisms of this process. This work addresses some convergent slow arboreal mammals, i.e. two lineages of ‘tree sloths’, the silky anteater, ‘Lorisidae’, two clades of extinct lemurs, i.e. palaeopropithecids and Megaladapis, and the koala. Functional morphological convergences are searched in these taxa, studying their humerus and femur as well as those of their closely related ecologically distinct taxa. For the first time, bones are analyzed at four anatomical levels, i.e. external shape, diaphyseal microstructure and anatomy and epiphyseal trabecular architecture, through phylogenetic comparative methods. Many slow arboreal mammals share a low cortical compactness, probably related to their extremely low metabolic rate and biomechanical demands. Slow arboreal xenarthrans, i.e. ‘tree sloths’ and the silky anteater, exhibit a pattern of incomplete convergence for a set of external and internal anatomical features, possibly explained by the relatively distinct ecology of the silky anteater. On a wider mammalian scale, other traits possibly related to slow arboreal ecology converge in some of the studied taxa, although with complex patterns also explained by other evolutionary processes. Only suspensory taxa significantly contribute to convergence. This thesis highlights the stronger convergence reflected by bone internal structure. By providing potential explanations for convergence in slow arboreal mammals, the inherent complexity of this process is here emphasized.

In der vorliegenden Arbeit werden epitaktische BaFe2As2 (Ba122)- Dünnschichten, die auf Spinell-Substraten mit einer Pufferschicht aus Eisen mit gepulster Laserabscheidung hergestellt wurden, durch Transmissions- (TEM) und Rasterelektronenmikroskopie (REM) untersucht. Idealerweise weisen die Ba122-Dünnschichten eine biaxiale Zugdehnung von etwa 2% auf, die zur Supraleitung in ihnen führt. Der Schwerpunkt dieser Arbeit richtet sich auf die Defektanalyse und die Untersuchung des Dehnungszustandes auf Inhomogenitäten. Auf allen Dünnschichten werden Droplets des Targetmaterials beobachtet. Wenn die Höhe der Ba122-Schicht mehr als 60 nm beträgt, erfolgt eine Relaxation der Dehnung durch die Bildung von Rissen. Experimente mit konvergenter Elektronenbeugung in einem TEM sind problematisch, weil der Dehnungszustand durch die Probenpräparation (Krümmung der TEM-Lamelle) beeinflusst wird. Durch die Verwendung hochauflösender Beugung rückgestreuter Elektronen (HREBSD) in einem REM wird gezeigt, dass in allen Ba122-Dünnschichten kleine Orientierungsänderungen des Kristallgitters (≤ 0,2°) und Inhomogenitäten des Dehnungszustandes (≤ 2 × 10-4) auf Längenskalen von wenigen 100 nm oder darunter vorliegen. Auf einer Probe werden teilweise dehnungsrelaxierte Stellen nachgewiesen. Es wird außerdem belegt, dass die Eisenpufferschicht eine sehr wichtige Rolle bei der Realstruktur der Ba122-Schicht spielt. Abschließend wird HREBSD mit konventioneller Auswertung der Beugung rückgestreuter Elektronen (EBSD) verglichen. Dabei wird ermittelt, dass mit großem Aufwand und mit optimalen experimentellen Bedingungen auch durch konventionelle Auswertung der EBSD-Pattern Orientierungsunterschiede mit einer Genauigkeit, die besser ist als 0,1°, gemessen werden können. In der Gegenwart von Probenstellen mit unterschiedlichen Dehnungszuständen ergeben sich jedoch deutliche Abweichungen im Gegensatz zu der exakten Auswertung durch HREBSD.