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Adolescent newcomer students bring a wealth of linguistic and cultural resources to their learning environments—resources that become even more dynamic when combined with those of their peers. While a significant body of research has explored students’ deployment of multilingual resources through translanguaging, most of this work does not address other semiotic resources. Multimodality literature, meanwhile, has largely ignored multilingualism. Drawing on Leo van Lier’s ecological notion of affordances, this dissertation contributes to this gap by examining the range of semiotic resources that acted as affordances for additional language development as students supported one another in negotiating classroom tasks. This study was conducted in four classrooms for newcomer students within two school sites in California: Sycamore High School and Cedar International High School. At both schools, data were collected in one classroom focused primarily on English language and literacy development (ELD and reading), and one on content (ethnic studies and biology). Methodologically, the study included participant observation, semi-structured interviews with four teachers and 12 focal students, collection of classroom artifacts, and videorecording of focal students’ interactions. Data analysis revealed a contrast in pedagogical approaches, which contributed to far more opportunities for peer interaction among students in the classrooms Cedar International than Sycamore High. Microanalysis of select peer interactions revealed that affordances for language development included oral and written features of English and Spanish, iconic and deictic gestures, and mutual engagement with material artifacts. Students skillfully pooled semiotic resources by combining their own linguistic, cultural, and content expertise with that of their classmates and material resources in the environment to negotiate the task at hand and ensure that their peers could participate meaningfully. The study suggests the need for expanding translanguaging research to consider semiotic resources other than oral and written language that contribute to language development, challenging notions of fixed expertise in peer interaction, and examining peer interaction across a variety of participant structures. With regard to classroom practice, findings point to the value of affordances for illuminating what students are capable of doing, and to the importance of expanding opportunities for students to engage agentively through meaningful collaboration.

Polyethylen (PE)-Abrieb der Hüft-Totalendoprothesen-Inlays kann abriebbedingte Osteolysen verursachen mit resultierenden Endoprothesenlockerungen, Verankerungsinstabilitäten und Dezentrierung der Hüftgelenke mit Gangunsicherheit. Mit dieser Arbeit soll die Bedeutung des Polyethylen-Abriebs auf die Entstehung einer periprothetischen proximalen Femurfraktur (PPFF) bei Patienten mit einliegender Hüft-Totalendoprothese (HTEP= gezeigt und mit einer asymptomatischen Kontrollgruppe verglichen werden. Diese Studie zeigt, dass Patienten mit einer PPFF und einliegender HTEP vermehrt an Abrieberkrankungen mit Dezentrierung des künstlichen Hüftgelenks sowie daraus resultierenden partikelinduzierten Osteolysen leiden. Im Vergleich mit einer asymptomatischen Kontrollgruppe zeigten sich wesentliche Unterscheidungsmerkmale im Bereich der verwendeten Hüftkopfgröße und beim verwendeten Hüftkopfmaterial. Es wurde festgestellt, das metallische Hüftköpfe in Verwendung als Metall-PE-Gleitpaarung höhere Abrieberscheinungen verursachten. Des Weiteren ergaben unsere Befunde in Bezug auf die Kopfgröße, das kleinere Hüftköpfe ein erhöhtes Risiko auf Verschleiß besitzen. Wir empfehlen den Patienten mit einliegender HTEP regelmäßige klinisch-radiologische Nachkontrollen durchführen zu lassen, um rechtzeitig eine sichtbare Dezentrierung des Hüftgelenks und das Vorhandensein von Osteolysen zu erkennen. Sollte dies der Fall sein und zusätzlich eine Ganginstabilität mit erhöhter Neigung zur Sturzgefahr vorliegen, dann ist die Empfehlung einer frühzeitigen Revisionsoperation mit Austausch der mobilen Teile (Hüftkopf- und Inlay) und das Auffüllen der Osteolysen mit Spongiosa oder Knochenzement durchzuführen. Auf diese Art und Weise kann das Auftreten einer PPFF als schwerwiegende Komplikation mit folgenreichen Konsequenzen reduziert werden.:Inhaltsverzeichnis I Abkürzungsverzeichnis II 1. Einleitung 1 1. 1. Hüft-Endoprothetik 1 1. 1. 1. Definition und Epidemiologie 1 1. 1. 2. Arthrose – Hauptursache und Symptomatik 3 1. 1. 3. Klassifikation und Risikofaktoren der Arthrose 4 1. 2. Periprothetische Frakturen 5 1. 2. 1. Definition und Epidemiologie 5 1. 2. 2. Ursachen und Risikofaktoren für postoperative PPF 6 1. 2. 3. Klassifikationen 7 1. 2. 4. Diagnostik und Symptome 10 1. 2. 5. Therapie 12 1. 2. 5. 1. Therapie postoperativer PPF 12 1. 2. 5. 2. Spezielle operative Behandlung 13 1. 3. Osteolyse und Prothesenlockerung 15 1. 4. Zielsetzung der Arbeit 18 2. Publikation 19 3. Zusammenfassung 26 4. Literaturverzeichnis 30 5. Tabellenverzeichnis 37 6. Abbildungsverzeichnis 37 7. Erklärung über die eigenständige Abfassung der Arbeit 38 8. Danksagung 39 9. Anlagen 40 9.1. Anlage 1 - Bestätigung des Eigenanteils an der Dissertation 40

How do young people in Paraguay develop social identities as they engage in multilingual language practices? What are the impacts of language policies that at times encourage the use of Guaraní, and at others discourage it? The primary goal of this study is to explore the relationships between children's language ideologies and the sociohistorical roots of societal level discourses regarding the power and prestige associated with Spanish and Guaraní in Paraguay. Of equal importance is the role of educators in either challenging or reinforcing those discourses. Field-work was conducted in an urban school in Paraguay's capital, Asunción. Participants' language use, language ideologies, and processes of social identification were analyzed through classroom observations, unstructured interviews, and surveys. Findings revealed that students' and teachers' use of Guaraní is closely related to perceptions of the language's ability to provide opportunities for upward social mobility. Data also suggests a generational decrease in the use of Guaraní amongst students, and a tendency to reserve Guaraní for the private sphere. Despite efforts to elevate the status of Guaraní, prestige is overwhelmingly associated with European languages (Spanish, English, and Portuguese). Guaraní, in contrast, is strongly associated with Paraguayan national identity, and communicating closeness. While English and Portuguese are perceived to potentially provide financial and social capital, students lack similar motivation to learn Guaraní within the context of the classroom. Although teachers cannot change societal discourses that devalue Guaraní, they can facilitate a critical inquiry into such attitudes, and encourage students to challenge the status quo

Beating-heart image-guided intracardiac interventions have been evolving rapidly. To extend the domain of catheter-based and transcardiac interventions into reconstructive surgery, a new robotic tool delivery platform and a tissue approximation device have been developed. Initial results using these tools to perform patent foramen ovale closure are described.A robotic tool delivery platform comprising superelastic metal tubes provides the capability of delivering and manipulating tools and devices inside the beating heart. A new device technology is also presented that uses a metal-based microelectromechanical systems-manufacturing process to produce fully assembled and fully functional millimeter-scale tools. As a demonstration of both technologies, patent foramen ovale creation and closure was performed in a swine model. In the first group of animals (n=10), a preliminary study was performed. The procedural technique was validated with a transcardiac hand-held delivery platform and epicardial echocardiography, video-assisted cardioscopy, and fluoroscopy. In the second group (n=9), the procedure was performed percutaneously using the robotic tool delivery platform under epicardial echocardiography and fluoroscopy imaging. All patent foramen ovales were completely closed in the first group. In the second group, the patent foramen ovale was not successfully created in 1 animal, and the defects were completely closed in 6 of the 8 remaining animals.In contrast to existing robotic catheter technologies, the robotic tool delivery platform uses a combination of stiffness and active steerability along its length to provide the positioning accuracy and force-application capability necessary for tissue manipulation. In combination with a microelectromechanical systems tool technology, it can enable reconstructive procedures inside the beating heart.