57 research outputs found
Untersuchung der elektronischen Struktur der Ăbergangsmetalloxide NiO(100) und CoO(100) mittels Schwellenenergie-, Energieverlust- und Bremsstrahlungsabsorptionskantenspektroskopie
Im Mittelpunkt der experimentellen Arbeit stand die systematische Untersuchung der elektronischen Struktur der einkristallinen Ăbergangsmetallmonoxide NiO(100) und CoO(100) mit Hilfe der Schwellenenergie - , der Energieverlust - und der Bremsstrahlungsabsorptionskantenspektroskopie an der Kohlenstoff K - Absorptionskante bei einer Photonenenergie von 283,8 eV. Durch den direkten Vergleich zwischen den differenzierten und integrierten CEELS Ergebnissen, den SXAPS - Messungen an der Sauerstoff 1s  Anregungsschwelle und den Bremsstrahlungsisochromatenmessungen an den NiO(100) - und CoO(100) SpaltflĂ€chen konnten die ausgeprĂ€gten Hauptstrukturen elektronischen ĂbergĂ€ngen innerhalb des Konfigurations - Interaktions - Modells zugeordnet werden. Durch die Kombination und den Vergleich mit den unterschiedlichen Spektroskopieverfahren konnten Zwei Teilchen AnregungskanĂ€le bestimmt werden und die Korrelationsenergie Udd fĂŒr NiO(100) und CoO(100) auf indirekten Weg ermittelt werden
Contextualising Apartheid at the End of Empire: Repression, âDevelopmentâ and the Bantustans
This article examines the global dynamics of late colonialism and how these informed
South African apartheid. More specifically, it locates the programmes of mass
relocation and bantustan âself-governmentâ that characterised apartheid after 1959 in
relation to three key dimensions. Firstly, the article explores the global circulation of
idioms of âdevelopmentâ and trusteeship in the first half of the twentieth century and its
significance in shaping segregationist policy; secondly, it situates bantustan âselfgovernmentâ
in relation to the history of decolonisation and the partitions and
federations that emerged as late colonial solutions; and, thirdly, it locates the
tightening of rural village planning in the bantustans after 1960 in relation to the
elaboration of anti-colonial liberation struggles, repressive southern African settler
politics and the Cold War. It argues that, far from developing policies that were at odds
with the global âwind of changeâ, South African apartheid during the 1960s and 1970s
reflected much that was characteristic about late colonial strategy
Bcl-3 and NF kappa B p50-p50 homodimers act as transcriptional repressors in tolerant CD4(+) T cells
The transcriptional events that control T cell tolerance are still poorly understood. To investigate why tolerant T cells fail to produce interleukin (IL)-2, we analyzed the regulation of NFkappaB-mediated transcription in CD4(+) T cells after tolerance induction in vivo. We demonstrate that a predominance of p50-p50 homodimers binding to the IL-2 promoter kappaB site in tolerant T cells correlated with repression of NFkappaB-driven transcription. Impaired translocation of the p65 subunit in tolerant T cells was a result from reduced activation of IkappaB kinase and poor phosphorylation and degradation of cytosolic IkappaBs. Moreover, tolerant T cells expressed high amounts of the p50 protein. However, the increased expression of p50 could not be explained by activation-induced de novo synthesis of the precursor p105, which was constitutively expressed in tolerant T cells. We also demonstrate the exclusive induction of the IkappaB protein B cell lymphoma 3 (Bcl-3) in tolerant T cells as well as its specific binding to the NFkappaB site. These results suggest that the cellular ratio of NFkappaB dimers, and thus the repression of NFkappaB activity and IL-2 production, are regulated at several levels in tolerant CD4(+) T cells in vivo
Sonohistologie - Ultraschall und kĂŒnstliche Intelligenz zur DignitĂ€tsbestimmung von SpeicheldrĂŒsentumoren?
Trotz Weiterentwicklungen der B-Bild-Sonographie, des Farbdopplers und der Kontrastmittelanwendung im Ultraschall können bis heute keine sicheren DignitĂ€tsbestimmungen von SpeicheldrĂŒsentumoren durch den Ultraschall erfolgen. In der Regel erfolgt eine histologische Sicherung.Bei der "Sonohistologie" werden die PrimĂ€rdaten des Ultraschalls am GerĂ€t abgeleitet und diese auf charakteristische Muster untersucht. Eine eigens entwickelte lernende Software ("kĂŒnstliche Intelligenz") kann die histologischen Gewebecharakteristika diesen Daten zuordnen und bei weiteren Untersuchungen wiedererkennen.In einer Vorstudie wurde an 17 FĂ€llen die Verdachtsdiagnose der Parotistumoren anhand des B-Bildes zugeordnet und die PrimĂ€rdatensĂ€tze gesichert. Alle Patienten wurden einer Parotidektomie unterzogen, die Tumoren histologisch aufgearbeitet. AnschlieĂend lernte das System mit den Daten und den Histologien von 12 FĂ€llen die Diagnosefindung. An 5 weiteren DatensĂ€tzen wurde geprĂŒft, wie die Diagnose der Software und die Histologie ĂŒbereinstimmen.Trotz der geringen Anzahl der LehrfĂ€lle stimmte die histologische Diagnose mit der sonohistologisch bestimmten bei 80% (4/5) der FĂ€lle ĂŒberein.Diese Unersuchung zeigt, dass die "Sonohistologie" eine vielversprechende Methode zur DignitĂ€tsbestimmung mittels Ultraschall sein könnte. Es folgt eine Untersuchung an einem groĂen Kollektiv
Ultrasonic Tissue Characterization â Assessment of Prostate Tissue Malignancy in vivo using a conventional Classifier based Tissue Classification Approach and Elastographic Imaging
Abstract- In this paper we present the development of a combined system which is able to exploit the benefits of two methods used for tissue characterization, strain imaging and tissue classification using a trainable classification system. Our system is able to acquire in vivo multi-compression rf-data for the calculation of the tissue strain, i.e. the elastic properties of tissue, induced by tissue compression. At the same time a Neuro-Fuzzy classification system is used to map the tissue malignancy. In vivo Classification results and in vivo strain images are presented. The images of the two new modalities are compared to demonstrate the advantages and restrictions of both methods
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Proxy wars and the contemporary security environment
The chapter is structured as follows: first, attention is be paid to the issue of theorising proxy wars. The chapter defines proxy wars by observing how they differ from cases of third-party military intervention. Here, the focus is on differentiating the Proxy Agent from third parties such as mediators or auxiliaries. Second, the chapter addresses the question of âWhy do states engage in proxy wars?â, and attempts an examination of contenting and competing explanations. These two aims are then put to the empirical test. By using two recent and ongoing cases of proxy wars, the theoretical discussion is brought into the empirical realm. The chosen cases are, first, the situation in Ukraine emerging from the 2013 protests and culminating with the annexation of Crimea in 2014, and, second, the collapse of the Syrian state and the rise of the Islamic State of Iraq and Syria (ISIS). Because proxy wars have generally been linked to the Cold War period and, thus, came to be associated with a superpower practice of avoiding direct interaction, the chapter moves away from discussing classic proxy wars such as the 1954 Guatemalan coup dâĂ©tat, the civil war in Angola (1975â2002), or the Ogaden War between Ethiopia and Somalia (1977â1978). A view from a post-Cold War security standpoint significantly expands our understanding of this ever-present security problem
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