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Dissertation
Algorithmic Reduction of Biochemical Reaction Networks
(2022-02-25)
The dynamics of species concentrations of chemical reaction networks are given by autonomous first-order ordinary differential equations. Singular perturbation methods allow the computation of approximate reduced systems that make explicit several time scales with corresponding invariant manifolds. This thesis presents:
1. An algorithmic approach for the computation of such reductions on solid analytical grounds. Required scalings are derived using tropical geometry. The existence of invariant manifolds is subject ...
Dissertation
The tRNA binding protein Kti12 and its role in the regulation of Elongator complex
(2020-06-08)
[Summary] Kti12 is a conserved eukaryotic protein showing sequence homology to O-phosphoseryltRNA kinase (Pstk), which is required for the synthesis of selenocysteine tRNA. Saccharomyces cerevisiae Kti12 was originally discovered in a genetic screening for resistance against zymocin, a protein toxin produced by Kluyveromyces lactis. The cytotoxicity of zymocin lies in its anticodon nuclease activity, causing tRNA depletion and cell death in sensitive yeast cells. It recognizes and cleaves a particular wobble uridine ...
Dissertation
Investigation of the functional synergy and involvement of different tRNA modifications in translational control
(2020-07-02)
Transfer RNAs are essential adapter molecules employed in the translational process and are highly modified all over their structure. Specific modification of the four canonical ribonucleotides (A, U, C, G) is accomplished by various proteins and/or protein complexes, ranging from simple isomerisations (e.g. Ψ) and methylations (e.g. m5C) up to complex chemical structures (e.g. mcm5s2U, ct6A). The functions of tRNA modifications are linked to the specific position and may influence translation by supporting the native ...
Dissertation
A new perspective to strongly-interacting lattice fermions in the framework of density functional theory
(2020)
Die in dieser Arbeit formulierte Theorie betrachtet das Vielteilchenproblem wechselwirkender Fermionen auf einem Gitter aus einem neuen Blickwinkel.
Dissertation
High temperature-stable InGaAs QDs for the monolithic integration in external-cavity surface-emitting lasers
(2021)
Optically pumped vertical external-cavity surface-emitting lasers (VECSELs), also called semiconductor disk lasers (SDLs), benefit from the flexibility and versatility of the semiconductor material. With a simple cavity layout, fundamental transverse mode operation with a circular output beam and high beam quality is possible. They have excellent heat-sink properties and only require inexpensive multimode diode lasers for pumping. The complete VECSEL structure is only a few micrometers thick which leads to a strong ...
Dissertation
Ausprägung und Entwicklung wissenschaftlichen Denkens in der Professionalisierung von Lehr-amtsstudierenden
(2021-09)
Wissenschaftliches Denken ermöglicht Lehramtsstudierenden auf der einen Seite den Prozess na-turwissenschaftlicher Erkenntnisgewinnung zu durchdringen, zu evaluieren und problemlösend anzuwenden. Auf der anderen Seite ist es eine wesentliche Voraussetzung, um standardbezoge-nen Unterricht im Kompetenzbereich der Erkenntnisgewinnung zu konzipieren. Dabei handelt es sich jedoch nicht um intuitive und angeborene Kenntnisse und Fertigkeiten, sondern es bedarf einer qualitativen Schulung. Im Lehramtsstudium sollte darauf ...
Dissertation
Die koordinationschemische Ambivalenz zweier mesoionischer Triazoliumaminide
(2020-05)
Die vorliegende Arbeit beleuchtet die Koordinationschemie zweier Mesoionen, die in Abhängigkeit vom angebotenen Zentralatom als N-heterocyclische Carben- (NHC-) oder Amido-Liganden fungieren. Durch Tautomerisierung der Triazoliumaminid-Form zum korrespondierenden Amino-NHC ermöglichen das seit über einem Jahrhundert bekannte analytische Reagenz »Nitron« (1) sowie dessen in dieser Arbeit entwickeltes Alkyl-Homolog 1-tert-Butyl-4-methyl-1,2,4-triazol-4-ium-3-tert-butylaminid (2) einen bequemen Zugang zur Chemie der ...
Dissertation
Explicit Description Of Isogeny And Isomorphism Classes Of Drinfeld Modules Of Higher Rank Over Finite Fields
(2020)
When jumping from the number fields theory to the function fields theory, one cannot miss the deep analogy between rank 1 Drinfeld modules and the group of root of unity and the analogy between rank 2 Drinfeld modules and elliptic curves. But so far, there is no known structure in number fields theory that is analogous to the Drinfeld modules of higher rank r ≥ 3. In this thesis we investigate the classes of those Drinfeld modules of higher rank r ≥ 3 defined over a finite field L. We describe explicitly the Weil ...
Dissertation
Fabrication and characterization of diamond nanopillars, waveguides and AFM tips with incorporated color centers
(2020-06)
Diamond is a unique material with outstanding properties and the perfect host for different crystal defects in its lattice, so-called color centers, which provide exceptional spin properties, rendering them a promising platform for the development of novel devices and components in quantum information technologies (QIT) and quantum sensing applications. To overcome diamond's high internal reflection due to its high refractive index, color centers need to be incorporated in photonic diamond structures, leading to ...
Dissertation
Beliefs von Lehramtsstudierenden zur doppelten Diskontinuität
(2021-09)
Das Ziel der Forschungsarbeit ist die Untersuchung von Überzeugungen von Lehramtsstudierenden zur sogenannten doppelten Diskontinuität. Genauer geht es um die Beforschung von Überzeugungen zur Kohärenz zwischen Schulmathematik und Hochschulmathematik und die Überzeugungen zur Relevanz der universitären Mathematik für die spätere Tätigkeit als Lehrkraft in der Schule. Dabei soll erstens der Frage nachgegangen werden, welche Überzeugungen Lehramtsstudierende zur doppelten Diskontinuität haben und zweitens eine Antwort ...