Schrift / Bild – Lesen. Interdisziplinäre Perspektiven für die Leseforschung

Im Zuge der gegenwärtigen Transformation hin zu einer digitalen, multimodal dominierten Medienkultur vollzieht sich ein Wandel des Lesens. Dieser betrifft nicht nur die Lesemedien und die Rezeptionsbedingungen, sondern auch die Medialität und Materialität von Texten. Im Mittelpunkt des Bandes steht die Frage, wie Texte gelesen werden, die Schrift und Bilder miteinander kombinieren. Vorgestellt werden Zugänge aus den Literatur-, Buch- und Medienwissenschaften, aus der Multimodalitätsforschung und Kognitionspsychologie sowie aus Kunstwissenschaft und Deutschdidaktik. Ziel ist es, das Forschungsfeld des Schrift-Bild-Lesens abzustecken und einen Beitrag zu seiner theoretischen Grundlegung zu leisten

Das metabolische Tumorvolumen beim Hodgkin Lymphom und der Einfluss verschiedener PET Rekonstruktionen auf seine Bestimmung

In der onkologischen Bildgebung hat sich die [18F]FDG-PET/CT insbesondere in der Diagnostik hämatologischer Neoplasien zum Standard entwickelt. Dabei ist der Einsatz quantitativer Methoden wie die Berechnung des metabolischen Tumorvolumens (MTV) ein vielversprechender Ansatz für die genauere Abschätzung der Prognose oder die Entwicklung von risikoadaptierten Therapiestrategien. Ziel dieser Arbeit ist es, den Einfluss verschiedener PET-Rekonstruktionsalgorithmen auf ihren potenziellen Einfluss auf die Messung des MTV hin zu untersuchen. Verwendet wurde dazu die ultra-high definition- (UHD) und ordered subset expectation maximization- (OSEM) Rekonstruktion. Es wurden PET/CT-Datensätze von 40 Patienten mit einem Hodgkin-Lymphom ausgewertet, die nach Erstdiagnose und vor Erstlinien-Therapie mittels [18F]FDG-PET/CT untersucht wurden. In allen PET/CT-Untersuchungen wurde in der UHD- und in der OSEM-Rekonstruktion das MTV zunächst automatisch segmentiert und bei Bedarf manuell angepasst. Dabei wurde zum einen eine relative Schwelle von 41% des lokalen SUVmax (MTV41%), zum anderen eine absolute Schwelle mit einem SUV von 4,0 (MTV4.0) verwendet. Anschließend wurden die absoluten und relativen Differenzen von MTV4.0 und MTV41% in der UHD- und OSEM-Rekonstruktion verglichen. Die zum Erreichen einer Normalverteilung logarithmierten Daten wurden mit dem Shapiro-Wilks-Test auf Normalverteilung geprüft und mit dem Differenzen-t-Test verglichen. Der Vergleich von MTV4.0 und MTV41% zeigte geringere absolute und relative Differenzen zwischen den unterschiedlichen Rekonstruktionsalgorithmen bei Verwendung der MTV4.0-Methode. Demgegenüber zeigten sich größere Unterschiede mit der SUV41%-Methode. Die Ergebnisse waren statistisch signifikant (p < 0,001). Die Ergebnisse der MTV-Berechnung waren bei Verwendung der MTV4.0-Methode deutlich robuster gegenüber der Verwendung unterschiedlicher Rekonstruktionsalgorithmen. Für die klinische Routine und multizentrische Studien erscheint das MTV4.0 damit vielversprechender

Individualizing Management Practices

Firm performance relies heavily on employee motivation, yet individuals differ significantly in what motivates them. A substantial body of literature in economics, management, and management accounting explores the impact of management practices on firm performance and employee outcomes, revealing heterogeneity in employee responses based on characteristics such as gender, social preferences, and personality. This dissertation examines two approaches to individualizing management practices: (1) a centralized approach, using AI for tailored assignments, and (2) a decentralized approach, leveraging managerial discretion. Empirical evidence is drawn from proprietary firm data, surveys, field experiments, and online experiments. Chapter 1 explores the centralized approach, applying machine learning to assign incentives based on worker characteristics. Experiments with gig workers reveal that targeted assignments improve performance compared to assigning a single best incentive scheme. The findings underline the importance of reliably measuring worker characteristics for ensuring algorithmic assignment quality. Chapter 2 studies a decentralized approach in a spot bonus system where managers decide bonus timing. Analyses show that managers award a large portion of bonuses at year-end, reflecting a need for better information on performance. However, timely bonuses are associated with higher employee recognition, suggesting that managers face a trade-off. Chapter 3 examines non-monetary practices, testing how highlighting flexibility in job ads affects applications. A field experiment with 176 job ads shows that emphasizing remote work or flexible work hours increases the number of applications, with the improvement partly varying by job characteristics. Overall, the dissertation demonstrates the advantages and challenges of centralized and decentralized approaches, offering insights for academics and practitioners

Bedeutung des Monitorings audiologischer, kind- sowie umweltbezogener Einflussfaktoren für die Entwicklung von Kindern nach Versorgung mit Cochlea-Implantat

Integraler Bestandteil der kindlichen Versorgung mit Cochlea Implantat (CI) ist eine multidisziplinäre familienzentrierte Intervention im Rahmen einer CI-Folgetherapie. Gegenstand der vorliegenden Arbeit ist das Monitoring unterschiedlicher Faktoren, die erwiesenermaßen die Entwicklung von CI-versorgten Kindern beeinflussen. Es konnte gezeigt werden, dass der LittlEARS® Hörfragebogen (LEAQ) zur Beurteilung der präverbalen Entwicklung früh bilateral CI-versorgter Kinder sehr gut geeignet ist. Dabei sollte bei früher CI-Versorgung das Lebensalter als Bezugsmaß in der Diagnostik herangezogen werden. Kinder mit schweren zusätzlichen Behinderungen und CI (CAD) weisen Unterschiede in der technischen Versorgung im Vergleich zu Kindern mit CI ohne zusätzliche schwere Behinderungen (CnonAD) auf. Es ist von hoher Bedeutung, die tägliche CI-Tragedauer der CAD zu optimieren, um auch die T- und MC-Level als Basis für eine erfolgreiche Hör- und Kommunikationsentwicklung individuell bestmöglich einzustellen. Sowohl objektive als auch subjektive Verfahren haben in dem CI-Anpassprozess ihre Berechtigung und sollten standardmäßig zum Einsatz kommen. Eine Einschätzung der elterlichen kindgerichteten Sprache (KGS) mittels der an die Bedürfnisse CI-versorgter Kinder adaptierten EKIE-hör ist möglich ist und kann als Grundlage für eine Elternberatung zur Optimierung der Eltern-Kind-Interaktion dienen. Aufgrund der Zeitökonomie lässt sich das Verfahren gut in den klinischen Alltag integrieren. Insbesondere im Hinblick auf eine individuell bestmögliche Chance auf gelingende Teilhabe ist das frühe Monitoring von diversen Einflussfaktoren sinnvoll und anhand diverser Methoden umsetzbar. Die Ergebnisse dieser Studien sollen therapeutisch/pädagogischen sowie audiologischen Fachkräften mehr Sicherheit in der Versorgung der vulnerablen Gruppe sehr junger Kinder mit CI - mit und ohne zusätzliche schwere Behinderungen - geben und dadurch den CI-Versorgungsprozess optimieren. Des Weiteren können die Ergebnisse herangezogen werden, um die individuellen Interventionsprogramme auf Basis der Internationalen Klassifikation der Funktionsfähigkeit, Behinderung und Gesundheit bei Kindern und Jugendlichen (ICF-CY) zu evaluieren und bei Bedarf möglichst frühzeitig anzupassen

Investigation of current and future anthropogenic chemical regimes in simulation chamber experiments

Air pollution is a societal challenge, affecting millions of people world-wide living in urban conglomerates. In cities, emissions are mostly from anthropogenic activities such as traffic, industry, cooking, and use of volatile care products. These emissions are not only hazardous for human health, they also undergo chemical degradation driven by oxidants, forming secondary pollutants such as ozone (O3) and particles. Main tropospheric oxidants are the hydroxyl radical (OH), dominating oxidation processes during the day, the nitrate radical (NO3), predominantly available during the night, and ozone. In the reaction chain of the atmospheric oxidation of volatile organic compounds (VOCs), peroxy (RO2) and hydroperoxy (HO2) radicals are formed, which oxidise nitric oxide (NO) to nitrogen dioxide (NO2), the latter being the main tropospheric source of ozone following its photolysis. Understanding atmospheric oxidation processes is crucial for mitigating air pollution and tackling current and future air quality challenges. In many different field studies, performed in or close to urban areas, measured HO2 and/or RO2 radical concentrations could not be reproduced by chemical model calculations, which represent the current understanding of the atmospheric chemistry. Even though chemical models carry uncertainties, the observed discrepancies in particular for RO2 radicals often exceeded a factor of three, making air quality prediction challenging. Data collected during field campaigns are very valuable in highlighting where our gap of knowledge for atmospheric chemical processes lies. Laboratory studies and experiments in atmospheric simulation chambers can then focus on investigating such processes in a confined and controlled environment. In this thesis, first the performance and comparability of several different atmospheric simulation chambers were studied. Oxidation experiments of alpha-pinene were performed in nine different simulation chambers, which are part of the EUROCHAMP-2020 consortium. Chamber effects, such as the release of small oxygenated compounds from the chamber wall or the loss of trace gases or particles on the chamber wall were characterised. Furthermore, yields of pinonaldehyde, formaldehyde, and acetone, which are products from the oxidation of alpha-pinene by OH, could be derived for experiments in five different chambers. A high variability of the yields of pinonaldehyde and formaldehyde was observed, which is also reflected in the available data from the literature. In contrast, obtained acetone yields agree within the combined uncertainties for the different chambers and within the uncertainties with reported literature values. Overall, well-characterised simulation chambers offer a great opportunity to investigate atmospheric chemistry in a controlled environment. The goal is to simplify the complexity of field studies while still keeping the conditions comparable to the real atmosphere. The main part of the thesis is on the investigation of the daytime and nighttime oxidation of anthropogenic VOCs in the atmospheric simulation chamber SAPHIR at Forschungszentrum Jülich, Germany. Measured trace gas and radical concentrations were compared to zero-dimensional box model calculations, based on the Master Chemical Mechanism (MCM) and complemented by an updated ozonolysis scheme for alkenes, and by state-of-the-art peroxy and alkoxy chemistry from structure-activity relationships (SAR). Photooxidation experiments were performed for a variety of anthropogenic VOCs at different levels of NO, mimicking current (high NO) and future (low NO) chemical regimes. The VOCs investigated were chosen according to their alkoxy chemistry, forming HO2 either in a single-step reaction (propane, propene, trans-2-hexene) or in a multi-step reaction involving the regeneration of RO2 (iso-pentane, n-hexane), which results in a different number of ozone molecules produced per oxidised VOC molecule. A comparison between measured trace gases and radicals with results from the MCM showed overall a good agreement (within 17 %) for most VOCs. An improved agreement of HO2 and RO2 radical concentrations, in experiments with n-hexane, was found for the MCM complemented by SAR, assuming a factor of ~ 1.4 higher organic nitrate yields for first-generation RO2 and RO2 isomerisation reactions. HO2/RO2 ratios were derived from measured and modelled radical concentrations, showing a 20 % smaller ratio for the VOCs forming HO2 in a multi-step reaction compared to VOCs forming HO2 in a single-step reaction. The production of odd oxygen (Ox = O3 + NO2) was calculated from modelled radical concentrations and from measured Ox for 3 < NO < 6 ppbv and for NO < 1 ppbv, where the Ox formation could additionally be determined from measured radical concentrations. Overall, a good agreement was found for the different approaches. In agreement with the observations of the HO2/RO2 ratio, a 20 % higher Ox production was observed for species, regenerating another RO2 radical before eventually forming HO2. Overall, the model-measurement discrepancies of the Ox production rates, as found in urban areas, were not observed in the performed chamber experiments. The nighttime oxidation of cis-2-butene and trans-2-hexene was tested in the presence of NO2 at different temperatures (from 3 °C to 32 °C). At low temperatures, time profiles of measured RO2 radical concentrations were significantly delayed and lower peak concentrations were reached than observed in the modelled RO2 radical time series. The model-measurement agreement could be significantly improved by including the formation of non-acyl peroxynitrates (RO2NO2) from the reaction of RO2 with NO2 in the chemical model for all formed non-acyl peroxy radicals. The formation of non-acyl RO2NO2, with the exception of methyl peroxynitrate, is not implemented in commonly used chemical mechanisms, such as the MCM, as it is thought to be negligible due to the short lifetime of alkyl (non-acyl) RO2NO2 of less than 1 s at 298 K. This study suggests that at 10 °C, 60 % of RO2 radicals are stored as corresponding peroxynitrates in the presence of only few ppbv of NO2, which may impact ambient RO2 and NOx (= NO + NO2) concentrations. In addition, a recent model study found an increase of NOx of up to 25 % on the ground, when including the formation of non-acyl RO2NO2. This suggests that these reactions should be included in chemical mechanisms for a better representation of the underlying chemistry

Interdisziplinäre Zusammenarbeit zur Verbesserung der Versorgung junger Menschen in psychischen Krisen. Eine Evaluation der Inanspruchnahme des niedrigschwelligen Kontakt- und Beratungsangebots soulspace in Berlin-Kreuzberg

Eine Vielzahl psychischer Erkrankungen manifestiert sich im Jugend- oder jungen Erwachsenenalter. Doch gerade diese Altersgruppe weist besonders geringe Inanspruchnahme- und Behandlungszahlen auf. Zudem sind therapeutische Interventionen in diesem Alter von starker Diskontinuität geprägt. Dazu tragen u.a. die eher unstete, teils durch Instabilität gekennzeichnete Lebensphase der Adoleszenz sowie die defizitäre Versorgungslage alters- und zielgruppenspezifischer Angebote bei. Angesichts langfristiger und gravierender persönlicher sowie gesamtgesellschaftlicher Folgen einer verzögerten Behandlung psychischer Krisen und Erkrankungen besteht demnach Handlungsbedarf. Vor diesem Hintergrund wurde 2018 das multidisziplinär geführte Früherkennungs- und Interventionszentrum soulspace in Berlin-Kreuzberg gegründet. In einer Kooperation bestehend aus der lokalen Kontakt- und Beratungsstelle transit und dem Vivantes Klinikum Am Urban (KAU) arbeiten im soulspace Psycholog*innen, Sozialarbeiter*innen und Fachärzt*innen unter einem Dach. Im Sinne der Niedrigschwelligkeit und zugunsten der Entstigmatisierung erfolgte die Verortung bewusst abseits des Klinikgeländes in einem neutralen Gebäude ohne „Krankenhaus-Charakter“. Für eine erste Evaluation der Inanspruchnahme wurden in zwei Angeboten des soulspace (transit, FIT) die dortigen Erstkontakte analysiert. Ziel der Untersuchung war die Auswertung soziodemografischer und erkrankungsbezogener Daten der Klient*innen beider Angebote sowie von Daten zu dem Erstkontakt folgenden Prozedere. Die Ergebnisse dieser Evaluation wurden in der vorliegenden Arbeit deskriptiv analysiert und angebotsspezifisch miteinander verglichen. Im Untersuchungszeitraum (transit: Juni 2018 – Dezember 2021; FIT: Januar 2016 – Dezember 2021) nutzten 899 Personen den transit-Erstkontakt (MAlter = 24,74 ± 5,06) und 592 Personen die FIT-Sprechstunde (MAlter = 23,51 ± 4,79). Nach dem Erstkontakt wurden vor allem weiterführende interne Angebote häufig genutzt, was auf eine erfolgreiche Annahme des Angebots hindeutet. Im transit-Erstkontakt vorstellige Klient*innen waren mehrheitlich nicht vorbehandelt (53,5 %; n = 347). Dem gegenüber steht, dass die deutliche Mehrheit der Klient*innen der FIT-Sprechstunde zu einem früheren Zeitpunkt bereits Versorgungsangebote genutzt hatten (85,4 %; n = 437) und überwiegend zur Diagnostik in die FIT-Sprechstunde vermittelt wurde (92 %; n = 183). Durch seine gute Zugänglichkeit konnte der transit-Erstkontakt den niedrigschwelligen Charakter des soulspace somit stärken und fungierte dabei wie intendiert als Bindeglied in der Versorgungsstruktur. Neben einem hohen Anteil bereits manifester Diagnosen konnte in der FIT-Sprechstunde bei 110 Personen (71,4 %) eine Hochrisikokonstellation festgestellt werden. Somit wurde die angestrebte Zielgruppe mehrheitlich erreicht. Um bereits erreichte Erfolge in der Versorgung synergistisch zu nutzen, sind weitere Kooperationen mit bereits bestehenden Angeboten anzustreben. Grundsätzlich sollte der Aufbau weiterer Früherkennungszentren und niedrigschwelliger Präventionsangebote mit Nachdruck vorangetrieben werden

Exploring the Multifunctional Potential of the Cell-Penetrating Peptide sC18: Drug Delivery, Organelle Targeting, and Antimicrobial Activity

The study and application of peptides have transformed clinical research, offering innovative approaches to combat cancer, organelle-specific diseases, and bacterial antibiotic resistance. This work focuses on developing, characterizing, and designing the cell-penetrating peptide sC18 and its variants to improve drug delivery to cancer cells, achieve organelle-specific targeting, and improve antimicrobial properties. In the first study, three variants of sC18 were developed to improve its efficacy as a carrier for the anti-cancer drug Doxorubicin. By optimizing the amphipathic structure or net charge, some of them showed enhanced cytotoxicity towards cancer cells while sparing healthy cells. Peptide-drug conjugates (PDCs) containing Doxorubicin were developed, with the peptide sC18ΔE in particular proving to be the most promising candidate for future studies. Then, sC18 variants bearing peroxisomal targeting sequences were investigated regarding their ability to be transported into the peroxisome via the cellular peroxisomal import machinery. The uptake efficiency varied depending on the utilized PTS and CPP. Moreover, peptides PX1 and PX9 showed high internalization efficiency and good biocompatibility in MCF-7 cells and might enhance the level of Pex5, a major peroxisomal receptor protein. However, colocalization with peroxisomes remained limited. Thus, further optimization is needed to investigate the developed peptides' targeting efficiency and therapeutic relevance. Finally, the peptide sC18*R,L, was further developed regarding its antimicrobial potential, and several new derivatives were created and biologically tested. The chemical modification using a triazolyl bridge in the peptide RL-8 increased the activity against both Gram-positive and Gram-negative bacteria and improved the peptide stability against proteolytic degradation. In particular, the triazolyl-bridged peptide 8B showed significantly increased bacterial membrane disruption with low cytotoxicity in human cells, making it a potential candidate for combating resistant pathogens. This peptide was further modified in a retro-inverso manner, which increased its antimicrobial activity further. This work highlights the versatility of sC18 peptides in addressing pressing challenges in drug delivery, organelle-specific targeting, and antimicrobial resistance. Future studies could provide novel insights to improve these peptides for clinical applications

Exploring Matter-Antimatter Asymmetry in a Rotating Universe

This thesis investigates the potential role of spatial anisotropies and global rotation in addressing the observed matter-antimatter asymmetry in the universe. The standard cosmological model, ΛCDM, faces several unresolved puzzles, in- cluding CMB anomalies, dark matter, and the matter-antimatter asymmetry. The CMB anomalies suggest deviations from isotropy, prompting the exploration of more general anisotropic models. Additionally, current solutions to dark matter and matter- antimatter asymmetry imply the need for extensions beyond the Standard Model. Given these issues, it is crucial to question the accuracy of the FLRW geometry in ΛCDM. This thesis explores the rotating Bianchi IX universe, motivated by the BKL conjecture and the potential role of global rotation in cosmological angular momentum generation, in an effort to investigate the anisotropic effects of geometry on the particle spectrum. The Weyl and Dirac spinor fields are studied within the Bianchi IX universe, con- sidering a range of models, from the axisymmetric Bianchi IX universe to the more general rotating Bianchi IX model. The Hamiltonian for spinor fields in this back- ground is formulated, and the corresponding equations of motion for Weyl and Dirac spinors are derived. The field equations are solved in a fixed background as an initial step toward understanding the particle spectrum in such spacetimes. This approach sets the stage for future refinements using the adiabatic approximation and the WKB approximation. Generalized spinor spherical harmonics are obtained using analogies with the asymmetric “ideal” top. Building on previous work on the diagonal Bianchi IX model, we generalize this approach for spinor fields in a broader Bianchi IX framework. Our work builds on earlier studies of Weyl spinors and the phenomenon of level crossing, which results in the creation of neutrinos instead of antineutrinos in an ax- isymmetric Bianchi IX universe as the universe evolves toward isotropy. We extend this analysis to a broader class of models, examining how these effects manifest in more general rotating and anisotropic cosmological backgrounds. While Weyl fermions do not describe neutrinos in nature, the mathematical framework developed here is useful for analyzing the Dirac equations in this context. For Dirac fermions in the axisymmetric Bianchi IX model, we find that the energy spectrum is significantly influenced by the spin orientation, resulting in spin-dependent enhancements or suppressions for both particles and antiparticles. The inclusion of global rotation introduces further contributions due to the coupling between particle spin and the universe’s rotational motion. Specifically, rotational contributions to the energyspectrumcauseenergyshiftswithoppositeeffectsforparticlesandantiparticles. Depending on the alignment of the spin with the universe’s rotation, energy levels are either increased or decreased, leading to complex modifications in the energy structure. This spin-angular velocity coupling uncovers previously unexplored mechanisms that could contribute to the observed asymmetry between matter and antimatter—effects absent in homogeneous and isotropic models. Therefore, these results underscore the importance of background anisotropies in the search for an explanation of the matter-antimatter asymmetry and encourage fur- ther investigation in this direction. The next logical step in this research is to solve the equations in a time-dependent background, beginning with the adiabatic approx- imation and later employing the WKB approximation to account for more realistic conditions. Furthermore, the analysis could be extended to include interactions within quantum electrodynamics (QED), enabling the exploration of whether these geomet- ric effects influence particle creation and annihilation processes. These efforts could provide valuable insights into the role of geometric effects in fundamental interactions, contributing to our understanding of the mechanisms driving the matter-antimatter asymmetry in the Universe

Building blocks for cluster Mott insulators: from elementary models to potential realizations

The Hubbard model is a paradigmatic model in condensed matter physics, which provides a rich playground for investigating the physics of a wide range of strongly correlated electronic systems. The core principle of the Hubbard model is the competition between Coulomb repulsions and hoppings. An important limit in the model is the Mott insulating regime, which is realized in the strong interaction limit. As a result, electrons get localized on single atomic sites at half-filling. In this thesis, we investigate extensions of this idea to cluster Mott insulators. These are special materials where electrons are now localized on clusters of sites. We use the theoretical framework that we develop to explore the physics of real cluster Mott materials. To that end, in a first study, we construct and study the cluster Hubbard model on a plethora of different clusters. We propose a new selection rule, called the cluster Hund's rule, which provides guidelines as to which states qualify as ground states in the pure interaction limit of the cluster Hubbard Hamiltonian. Using a combination of analytical insights and exact diagonalization, we conducted a comprehensive investigation of the emergent degrees of freedom in clusters of different geometries and fillings. This study helped us understand how these cluster Mott degrees of freedom respond to the interplay of strong correlations and hopping. In a second study, we investigated the cause of the observed magnetic signatures in $\mathrm{Ba_4LiIr_3O_{12}}$. This material hosts iridium dimers, and was expected to be non-magnetic since it possesses completely filled shells. Using insights from our previous study, we were able to detect non-trivial ground state degeneracies called non-Kramers doublets as the reason behind the observed magnetism of the material. Hence, we established $\mathrm{Ba_4LiIr_3O_{12}}$as the first cluster Mott material whose physics is driven by non-Kramers doublets. Having constructed this theoretical framework so far, we used it in our third study to investigate real materials which host trimer clusters – hexagonal perovskites of the form $\mathrm{A_4BM_3O_{12}}$, and considered different fillings of $3d$ to $5d$transition-metal “M” ions. Through a systematic treatment, we verified the observed magnetic moments for a wide variety of trimer materials. In addition, we also obtained the composition of magnetic moments in different directions. We use this study to propose ground state properties and phase diagrams for materials that are likely to be synthesized in the future