Eldorado - Repositorium der TU Dortmund

Ressourcen aus und für Forschung, Lehre und Studium

Bei diesem Service handelt es sich um das Institutionelle Repositorium der Technischen Universität Dortmund. Hier werden Ressourcen aus und für Lehre, Studium und Forschung gespeichert, erschlossen und der Öffentlichkeit zugänglich gemacht.

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Fach- und Universitätsübergreifendes 1318
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Graduate School und Graduiertenkollegs 12
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Sonderforschungsbereiche 1592

Aktuellste Veröffentlichungen

Total syntheses of (-)-Scabrolide B and related marine natural products
(2025) Lin, Davy Sébastien; Fürstner, Alois; Hiersemann, Martin
The furanobutenolide-derived norcembranoid diterpenes are a rare family of natural products isolated mainly in Sinularia-type soft coral. Among these molecules, it was discovered in 2022 that scabrolide B possesses a 6/7/5/5 carbocyclic core, instead of the initially postulated 7/6/5/5 core. The objective of this thesis is to accomplish a total synthesis of that natural product. Two convergent approaches to scabrolide B were investigated, each relying on a ring-closure of the central seven-membered ring: one by ring closing metathesis and one via intramolecular enolate alkenylation. In both approaches, the precursors required for ring-closure were synthesized by a 1,4 addition between a protected bicyclic lactone and a (R)-carvone derivative. If both approaches converge on a common intermediate en route to the total synthesis of scabrolide B, only the alkenylation route afforded a reliable supply of the natural product, providing 110 mg in a single run over 19 steps (longest linear sequence) and 1.2% overall yield. Scabrolide B was subsequently transformed into the sister norcembranoids fragilolide A, sinuscalide C and ineleganolide, the latter could further be converted into horiolide and kavaranolide, supporting the biosynthetic sequence proposed in the literature. Overall, a series of polycyclic norcembranoids and their derivatives were synthesized, providing valuable material and insight for future studies on the biological activity of this rare family of molecules.
Illuminating the top quark
(2025) Wendland, Björn; Kröninger, Kevin; Mitzel, Dominik
The rich datasets collected by the ATLAS and CMS experiments proton–proton collisions of the Large Hadron Collider at a center-of-mass energy of 13 TeV allow high-precision measurements of top-quark properties and enable the experimental exploration of several rare top-quark processes for the first time. The t-channel single-top-quark production in association with a photon is such a process. Measurements of this signal process directly probe the top-quark–photon interaction, which is a cornerstone of electroweak physics. In this work, this process is examined using events selected from the data collected by the ATLAS experiment that contain either an electron or a muon, at least one photon, high missing transverse momentum, and a particle jet initiated by a bottom quark. Studying final states with photons, such as that of the signal process, using proton–proton collision data is challenging, as the majority of reconstructed photon candidates are background photons arising from hadronic activity. This requires excellent rejection of such candidates, which is achieved by applying photon-isolation and photon-identification requirements. Precise measurements of their efficiencies are vital for ensuring consistently high performance and for accurate modeling of the contribution of signal photons in simulation. This work introduces improvements to the method used for measuring the photon-identification efficiency at high photon energies and presents the respective measurement results. The largest background contributions to the selected data arise from the production of top-quark pairs in association with a photon, from events where an electron is misidentified as a photon, and from the production of a W boson in association with a photon and particle jets. Background contributions arising from events with background leptons and background photons are estimated using data-driven techniques. Only a small fraction of the selected events originate from the signal process. Deep neural networks are employed to efficiently discriminate between signal and background contributions. This thesis presents the first observation of the signal process, achieved with a statistical significance of 9.3 standard deviations using these neural networks. This observation represents a milestone in electroweak physics. Two fiducial cross sections of the signal process are measured with a precision of 11%. Their values are found to be compatible with Standard Model predictions at next-to-leading order accuracy in quantum chromodynamics at the level of 2.0 and 2.1 standard deviations.
Digital screening of children with ASD: diagnostic accuracy of emotion recognition and visual preference tasks
(2025-12-25) Pliska, Larissa; Neitzel, Isabel; Buschermöhle, Michael; Kunina-Habenicht, Olga; Ritterfeld, Ute
Background In Germany, there is a need to improve care for suspected autism spectrum disorder (ASD) cases, as the time between parents’ initial suspicion and an official clinical diagnosis can reach three years. New technologies for digital screening promise relief in addressing children’s difficulties in recognizing emotions and social attention. This study investigated the diagnostic validity of tablet-based screening to differentiate between children with and without ASD via emotion recognition and visual preference tasks involving prior calibration. Method This study involved 24 boys with ASD and a matched control group of 24 typically developing (TD) boys aged 6–11 years. Mixed logistic models were applied for the emotion recognition task, while mixed linear models were used for the visual preference task, along with decision trees for both tasks. Results The results indicate significant group differences in recognizing the emotion “fear” and naming an example for “sadness”. The emotion recognition of fear and sadness was relevant to the decision tree to differentiate between the groups, with an accuracy of 81.25%, a sensitivity of 91.67%, and a specificity of 70.83%. For the visual preference task, no significant group differences were found between groups; however, significant differences emerged between social and non-social image stimuli. Gaze fixation and gaze changes in video stimuli were relevant to the decision tree to differentiate between the groups. The accuracy was 81.25%, with a sensitivity of 70.83% and specificity of 91.67%. Conclusion Overall, this study suggests that automated digital screening might provide support and relief to families and clinicians, as it can distinguish between children with and without ASD using a combination of selected emotion recognition and visual preference tasks.
Zur Kenntnis der Indolo[2,3-d]tropone und Indolo[2,3-d]tropolone
(2025) Benedix, Lars; Hiersemann, Martin; Steffen, Andreas
Die nachfolgende Arbeit beschäftigt sich mit der Synthese und gezielten Strukturmanipulation von Indolo[2,3-d]troponen 143 und Indolo[2,3-d]tropolonen 144. Diese neuartigen Aromatensysteme setzen sich formal aus einem Tropon 1 bzw. Tropolon 2 anelliert an ein Indol 145 zusammen. Während zu 143 bereits wenige Arbeiten in der Literatur existieren, fehlen Arbeiten zu 144 bis dato völlig. Im Ergebnis der Arbeit wurde ein robuster, modularer, synthetischer Zugang zum Strukturmotiv 143 etabliert; auf derselben Route konnten auch die ersten Beispiele für das Strukturmotiv 144 aufgebaut werden. Im Rahmen von Versuchen der gezielten Strukturmanipulation wurde ausgehend von 143h eine Bibliothek von 20 lumineszenten Tolanoiden 153 aufgebaut und die photophysikalischen Eigenschaften anhand zweier Beispiele untersucht. Des Weiteren wurde das Tautomerieverhalten von 144 mithilfe von DFT-Rechnungen untersucht.
Addressing affordable housing in the Kurdistan Region of Iraq
(2025) M. Ameen, Ali Ibrahim; Hellmanzik, Christiane; Gruehn, Dietwald
This dissertation examines the distribution of affordable housing in the Kurdistan Region of Iraq (KRI) from 2006 to 2022, with a primary analytical focus on 2008 to 2014, a period marked by conflict, displacement, and oil-linked revenue volatility. It asks how market conditions, government programmes, and political dynamics shape access to housing and with what distributional consequences. Affordable housing is defined, following Hilber et al. (2022), as dwellings whose monthly housing costs are below 30% of household income. Affordable supply in the KRI is channelled through two legal tracks: a public low-income programme delivered by the Ministry of Construction and Housing (MoCH) under Law No. 7 of 2008 and its First Amendment (Law No. 16 of 2011), and a Housing Fund that co-finances private developer projects licensed under Investment Law No. 4 of 2006. In broad terms, the MoCH track offers core units and concessional mortgages, while the Investment-Law track supports purchases through partial loans to eligible buyers and requires developers to provide on-site infrastructure. A convergent mixed-methods design combines two main data sources: (1) secondary data on construction, prices, and budgets obtained from the Kurdistan Regional Statistical Office (KRSO), United Nations Human Settlements Programme (UN-Habitat), and the World Bank; (2) surveys of 87 real-estate brokers, and 386 Duhok residents (63 programme beneficiaries and 323 non-beneficiaries), alongside 30 stakeholder interviews. These dynamics included a documented programme-launch deficit of approximately 71,000 dwellings and steep cost escalation, with average unit costs rising from USD 31,154 in 2011 to USD 56,078 in 2013; Erbil remained among the highest-price markets. As oil rents supplied 90–95% of the Kurdistan Regional Government’s (KRG) revenue, housing budgets were exposed to price shocks. Distributionally, inter-governorate allocations depart from population and indicator-based benchmarks in ways consistent with territorial coalition dominance and network-mediated access; legal instruments do not establish governorate quotas. Interview evidence indicates that departures from benchmark allocations are often driven by liaison routines, political endorsements, and the frequent presence of applicants or intermediaries in the capital. Similarly, Housing Fund loans skewed toward moderate-income buyers who could meet collateral and guarantor conditions, limiting reach to the poorest. The dissertation concludes that improving affordability and distributional fairness requires both programme and governance measures: transparent, published need-scoring for MoCH allocations; retargeting Housing Fund support toward instruments that reach very-low-income households; stronger rules for land release, developer selection, and regulatory oversight; public geocoded reporting on projects and beneficiaries; and counter-cyclical funding arrangements to reduce shock-induced delivery collapses.