University of Kaiserslautern
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Zur Bewältigung hybrider Anforderungen am Beispiel schulischer Interpretationstexte: Konzepte und Ergebnisse aus dem Projekt FAMoS
Get PDFDer Beitrag zeigt am Beispiel der schulischen Schreibform Gedichtinterpretation, welche Anforderungen sich Lernenden bei der Textproduktion stellen und wie sie diesen vor allem sprachlich begegnen können. Auf Basis einer differenzierten Beschreibung sprachlich-struktureller Merkmale der Textsorte wurde im Projekt FAMoS ein Förderkonzept entwickelt und erprobt, das sich empirisch als wirksam erwiesen hat. Es nimmt die Sprachlichkeit von Texten stärker in den Blick und plädiert für einen Einsatz von Modellen zur Förderung von Schreibkompetenzen
Das topologische Modell im Sprachunterricht – eine Interviewstudie mit Sekundarstufenlehrkräften
Get PDFDie explorative Studie TopoS (Das topologische Modell im Sprachunterricht) untersucht anhand von leitfadengestützten Interviews den Einsatz des topologischen Modells im Deutschunterricht in Baden-Württemberg. 39 Lehrkräfte der Sekundarstufe geben Auskunft zu ihren Erfahrungen zum grammatischen Lernen mit dem Modell. Die quantitative und qualitative Datenauswertung legt einen Fokus auf die Breite und Kohärenz der mit dem Modell erarbeiteten Gegenstandsbereiche, auf Chancen und Grenzen der Unterrichtsgestaltung sowie auf die Funktion, die das Modell im Unterricht einnimmt. Anhand dieser Kriterien lassen sich vier Gruppen von Lehrkräften voneinander unterscheiden. In zwei „Extremgruppen“ stehen sich die Verwendung des Modells als Werkzeug zum grammatischen Lernen einerseits und die Thematisierung zum Selbstzweck als Prüfungsgegenstand gegenüber. Auf einem dazwischenliegenden Kontinuum finden sich Lehrkräfte, die jeweils eher zu dem einen oder anderen Pol tendieren
WIDERSPRECHEN in der Wikipedia zur Aushandlung des Begriffs der Nachhaltigkeit: Eine sprachreflexive, kommunikative Praktik
Get PDFNachhaltigkeit ist ein Konzept mit einem weiten Bedeutungsspektrum. Dessen Begriffsinhalt wird u. a. von den Autor:innen in den Diskussionen der weltweit vielgenutzten Wikipedia intensiv und mitunter kontrovers ausgehandelt. Für begriffliche Abgrenzungen fechten die Autor:innen die ihres Erachtens inadäquaten Sachverhaltsdarstellungen etc. an, indem sie entsprechende konzeptuelle Aspekte unterschiedlich explizit und sprachbewusst durch die Handlung des Negierens als nicht gültig zurückweisen. Um den Begriff der Nachhaltigkeit zu konturieren, vollziehen die Autor:innen in Wikipedia-Diskussionen folglich die sprachreflexive, kommunikative Praktik des WIDERSPRECHENS. Auf der Basis eines Korpus aus den Diskussionen zu den Artikeln ‚Nachhaltigkeit‘, ‚Nachhaltige Entwicklung‘, ‚Umweltschutz‘ etc. der deutschsprachigen Wikipedia ermittelt dieser Beitrag Tendenzen, welchen Nachhaltigkeitsaspekten zumeist widersprochen wird, die insofern als besonders umkämpft erachtet werden können
Addressing the redundant roles of phytotoxic proteins in the necrotrophic infection of Botrytis cinerea by multi-knockout mutagenesis
Get PDFThe grey mould fungus Botrytis cinerea is a plant pathogen that attacks a wide range of host plants, causing enormous pre- and postharves damage on a large number of economically important fruits, vegetables and ornamental flowers. As a necrotroph, it quickly kills host cells and colonizes dead tissue, supported by the secretion of CWDE, cell death inducing proteins (CDIPs) and metabolites, tissue acidification and detoxification of plant defence compounds. This thesis focused on the role of CDIPs and their contribution to necrotrophic infection and killing of plant cells. The majority of CDIPs is found in the apoplast and are likely to interact with defence-related pattern recognition receptors (PRRs) that upon activation induce programmed cell death, which supports infection by B. cinerea. Based on a highly efficient CRISPR/Cas9 editing protocol, a consecutive mutagenesis was performed to eliminate all known CDIPs in a single B. cinerea strain. This resulted in series of multiple mutants lacking up to 27 CDIPs and two phytotoxic metabolites. These mutants still showed almost normal growth and differentiation in vitro but decreased virulence with increasing numbers of deleted CDIPs. Similarly, the secretomes of these mutants showed a strongly reduced phytotoxic activity compared to the wild type secretome. Genome and secretome analysis confirmed the targeted elimination of the CDIPs from the secretome and the absence of CRISPR/Cas-induced off-target mutations. The Bc29x mutant caused strongly reduced lesion formation on leaves and almost no infection of fruits of different species. Besides of the two major polygalacturonases PG1 and PG2, none of the other CDIPs made a major contribution to necrotic lesion formation on most tissues. Overexpression of the highly phytotoxic CDIP Nep1 in a multi-knockout mutant did not increase its virulence, raising doubt on a central role of CDIPs in B. cinerea infection. The remaining virulence and phytotoxicity of the secretome of the Bc29x mutant further confirmed an extraordinary degree of redundancy of secreted phytotoxic proteins in B. cinerea, and the existence of even more as yet unknown CDIPs. The search for remaining CDIPs is ongoing, with the final goal to generate a non-necrotrophic B. cinerea mutant. Based on their homology to known CDIPs, new CDIPs with low to moderate phytotoxic activity were discovered that are currently under investigation. To get insights into the plant defence pathways that are triggered by CDIPs and fungal infection, the sensitivity of plant mutants defective in the PRR coreceptors BAK1 and SOBR1, and the signaling protein EDS1 was investigated. Whereas the loss of BAK1 and SOBIR1 had no effect on infection, Arabidopsis eds1 mutants showed reduced sensitivity to B. cinerea, confirming a positive role of EDS1 in triggering the programmed cell death of the plant cells and supporting fungal infection. This is the first systematic, large-scale mutagenesis approach to address the functional redundancy of virulence factors in a filamentous fungus.Der Grauschimmelpilz Botrytis cinerea ist ein pflanzenpathogener Erreger, der ein breites Spektrum von Wirtspflanzen befällt und große Ernteausfälle bei einer Vielzahl wirtschaftlich bedeutender Obst-, Gemüse- und Zierpflanzenarten verursacht. Als nekrotropher Organismus tötet er die Wirtszellen schnell ab und besiedelt das abgestorbene Gewebe, unterstützt durch die Sekretion von zellwandabbauenden Enzymen (CWDE), zelltodinduzierenden Proteinen (CDIPs) und Metaboliten, Gewebeansäuerung und die Entgiftung pflanzlicher Abwehrmoleküle. Diese Dissertation konzentrierte sich auf die Rolle der CDIPs und ihren Beitrag zur Infektion und Abtötung pflanzlicher Wirtszellen. Die meisten CDIPs werden in den Apoplasten sekretiert und interagieren wahrscheinlich mit Mustererkennungsrezeptoren (PRRs), die nach ihrer Aktivierung den programmierten Zelltod auslösen, wodurch die Infektion durch B. cinerea gefördert wird. Mithilfe eines hocheffizienten CRISPR/Cas9-basierten Transformationsprotokolls wurde eine sequenzielle Mutagenese durchgeführt, um sämtliche bekannten CDIPs in einem einzigen Stamm von B. cinerea auzuschalten. Dies führte zu einer Serie multipler Mutanten, denen bis zu 27 CDIPs sowie zwei phytotoxische Metaboliten fehlten. Diese Mutanten zeigten ein nahezu normales Verhalten bei Wachstum und Differenzierung in vitro, jedoch eine abnehmende Virulenz mit steigender Anzahl fehlender CDIPs. Die Sekretome dieser Mutanten zeigten entsprechend eine stark reduzierte phytotoxische Aktivität im Vergleich zum Wildtyp-Sekretom. Genom- und Sekretomanalysen bestätigten die gezielte Eliminierung der CDIPs aus dem Sekretom und das weitgehende Fehlen von unerwünschten CRISPR/Cas-induzierten ‚off-target‘ Mutationen. Die 29-fach-Mutante verursachte stark reduzierte Läsionsbildung auf Blättern und nahezu keine Infektion mehr auf Früchten verschiedener Pflanzenarten. Neben den zwei dominierenden Polygalacturonasen PG1 und PG2 trugen keine der weiteren CDIPs wesentlich zur Läsionsbildung auf den meisten Geweben bei. Die verbliebene Virulenz und Phytotoxizität des Sekretoms der 29-fach-Mutante offenbarte einen außergewöhnlichen Grad an Redundanz sekretierter phytotoxischer Proteine bei B. cinerea und das Vorhandensein einer bislang unbekannten Anzahl noch nicht identifizierter CDIPs. Die Suche nach den verbleibenden CDIPs wird fortgesetzt, mit dem endgültigen Ziel, eine nicht-nekrotrophe B. cinerea-Mutante zu erzeugen. Basierend auf ihrer Homologie zu bereits bekannten CDIPs wurden neue CDIPs mit geringer bis mäßiger phytotoxischer Aktivität entdeckt, die derzeit weiter untersucht werden. Um Einblicke in die pflanzlichen Abwehrmechanismen zu erhalten, die durch CDIPs und die Pilzinfektion ausgelöst werden, wurde die Empfindlichkeit von Pflanzenmutanten mit Defekten in den PRR-Corezeptoren BAK1 und SOBR1 sowie das Signalprotein EDS1 untersucht. Während der Verlust von BAK1 und SOBIR1 keine Auswirkungen auf die Infektion hatte, zeigten Arabidopsis eds1-Mutanten eine geringere Empfindlichkeit gegenüber B. cinerea, was eine positive Rolle von EDS1 bei der Auslösung des programmierten Zelltods der Pflanzenzellen und der Unterstützung der Pilzinfektion bestätigt. Diese Studie stellt den ersten systematischen und umfassenden Mutagenese-Ansatz zur Untersuchung der funktionellen Redundanz von Virulenzfaktoren in einem filamentösen Pilz dar
Linear Functions – a Matter of Context? Toward Understanding Students' Learning Processes in Mathematics and Physics
Get PDFLearning processes of linear functions in mathematics and physics are widely unclear. In this work, we replicate and extend existing results on learning processes of linear functions in mathematics and physics and use triangulation of gaze data and interview data for a deeper understanding of cognitive processes. Furthermore, we utilize mathematical structures such as networks to algorithmically detect solution strategies from gaze data and to distinguish between correct and incorrect solvers.
Although there are validated tests of linear functions in mathematics and physics, they are not sufficiently validated and remain unused across countries and age groups. Furthermore, these tests are paper-based, making it impossible to investigate visual attention processes. There is also a lack of research on analyzing students’ visual data when solving math and physics problems using algorithmic, network-based approaches. In this thesis, we improve tools in learning systems that can guide learning without the help of teachers.
A three-step approach was taken to fill these research gaps:
1. We conducted a large-scale study using the paper-based test instrument on linear functions in mathematics and physics by Ceuppens et al. (2019), which was validated for 9th grade students in Belgium. We evaluated this test instrument for German students in the same grade with a sample size of N = 249. In addition, we used the test instrument in the upper school (grade 11) to check whether the challenges identified by Ceuppens et al. (2019) persist across school years (N = 298). Results show that German 9th graders perform significantly worse than Belgian 9th graders. However, the challenges surprisingly identified by Ceuppens et al. (2019) remain, and are even more serious for German students.
2. To explicitly understand the cognitive processes behind the students’ problems, we conducted an eye-tracking study in schools (N = 131), in which we were able to cognitively resolve transfer difficulties in adequately applying mathematical content in a physical context using gaze- and interview data for two forms of representation: formulas and graphs. Here, we showed that cognitive processes are context sensitive.
3. In a final step, we use network analysis methods to detect solution strategies based on geometric patterns (for example slope triangles) from gaze data. It was investigated which network metrics are suitable for distinguishing correct from incorrect solvers. There exist suitable network metrics—a first step toward the development of a predictor to distinguish between correct and incorrect solvers.
In summary, based on three extensive studies with samples ranging from 131 (eye-tracking studies) to about 250 people (paper-pencil tests), this thesis uses various different methods (paper and pencil, eye-tracking, interviews, network analysis) to empirically analyze learning processes for linear functions regarding mathematics and physics. The results show that students face challenges in interpreting mathematical content adequately in a physical context. The analysis of the cognitive processes form a basis for the sustainable improvement of learning in the future. A teacher training course on this topic has already put this into practice
Supporting Knowledge Workers through Personal Information Assistance with Context-aware Recommender Systems
Get PDFThis PhD thesis explores how Recommender Systems (RSs) can be leveraged to develop Personal Knowledge Assistance (PKA), aimed at improving the productivity of Knowledge Workers (KWers) such as programmers and scientists who primarily handle information rather than manual labor and spend significant time searching for information at the expense of productivity.
The thesis introduces this novel application of RSs to create a more intelligent and supportive working environment for KWers and identifies key challenges such as dealing with heterogeneous information items and capturing dynamic needs. Based on a conducted systematic literature review, the thesis distinguishes the unique characteristics that set this domain of RSs apart from others and highlights the potential of the most relevant RS categories to address these challenges. It explores technological foundations developed over two decades of PKA research that can support the development of the targeted RSs, and also introduces the concept of Contextual States (CSs) as multi-dimensional sessions representing relevant contextual information.
This study divides the information space of KWers into three layers (personal, corporate, and global spaces) and proposes a framework to integrate these layers along with the concept of CSs into PKA technologies. It then conducts a case study based on the proposed framework with real-world data from the DFKI's Smart Data and Knowledge Services (SDS) department. Using a TF-IDF-based method, 1,987 recommendations were generated across 128 contexts, with 54% of these recommendations evaluated as relevant and half of them considered helpful.
Recognizing the lack of comprehensive, public datasets for PKA research, the thesis introduces the Real-Life Knowledge Work in Context (RLKWiC) dataset. RLKWiC provides extensive contextual information and annotations, including over 61,000 desktop events, 211 personal concepts, 393 DBpedia resources, and personal KGs with over 6,400 nodes and 3,100 inter-relations. It aims to support benchmarking and evaluating PKA services.
The study establishes a benchmark on RLKWiC for context-based Entity Recommendation (ER), offering full transparency and reproducibility with over a thousand entities labeled with explicit relevance scores. The baseline recommendation scenario achieved 56% precision for relevant entities and 25% for representative entities. This performance was subsequently improved by integrating a semantic-based approach with an Adaptive Relevance Prediction (ARP) module, which increased the precision for representative entities by 20%. Semantic methods, particularly those using Laplacian kernel and Euclidean distance metrics, were shown to effectively maintain context-based relevance. Finally, the thesis explored integrating Large Language Models (LLMs) into RSs for KWers. By using Mistral 7B and an ARP mechanism, the LLM-based approach significantly outperformed both the baseline and semantic-based methods in ER, demonstrating LLMs' potential for enhancing PKA recommendations.
In conclusion, this research highlights RSs as a promising way to mitigate information overload in KW scenarios by delivering relevant information to enhance productivity. It includes a comprehensive literature review, a proposed framework, the creation of RLKWiC, a benchmark for ER evaluation, and incremental improvements using semantic and LLM-based methods
Kulturelle Bildung trifft partizipative Forschung – Ziele und Herausforderungen in der Startphase multidisziplinärer Kollaboration
Get PDFAuf Basis von qualitativen Daten aus einem EU-finanzierten Projekt zu machtkritischer Kultureller Bildung
in Schulen diskutieren wir die Annahme, dass es für eine gelingende multidisziplinäre Kollaboration und
die Ermöglichung von Perspektivenwechseln in einem partizipativen Projekt kontinuierliche
Beziehungsarbeit zwischen den Kollaborationspartner*innen in Form einer machtkritischen Reflexion
braucht. Dazu analysieren wir anhand von zwei exemplarischen Materialauszügen soziale Räume, in
denen wir als Team aus Filmvermittlerinnen und universitär Forschenden Perspektivenwechsel und
Verantwortungsübernahmen aushandeln, und arbeiten im Anschluss relevante Aspekte für die Schaffung
solcher kontinuierlichen Räume der Reflexion heraus
Characterization of Mitochondrial Protein Import Machineries in Plasmodium falciparum
Get PDFMalaria remains a significant global health threat, with an estimated 263 million cases and 597,000 related deaths annually, especially among children under five years old. It is caused by Plasmodium parasites, which are transmitted to vertebrates through the bite of infected female Anopheles mosquitoes. Of the five parasites known to cause malaria in humans, P. falciparum is the deadliest and accounts for most malaria-related illness and death. Although significant progress has been made in reducing malaria, challenges such as drug and insecticide resistance remain.
Malaria parasites contain a small mitochondrion during the merozoite stage, which develops into an elongated tubular network in the schizont stage after invading red blood cells. This development requires the de novo synthesis of mitochondrial components, including the import and sorting of mitochondrial proteins. Although all living organisms have their own mitochondrial genome, nearly 99% of mitochondrial proteins are encoded in the nucleus, synthesized on cytosolic ribosomes, and then imported into the mitochondria. The process of importing proteins into mitochondria is believed to be highly conserved among eukaryotes. However, recent studies have revealed that the import machinery itself has undergone significant changes in various major eukaryotic lineages. The differences between the mitochondrial import machinery of malaria parasites and their hosts make mitochondria a promising target for drug development. Nevertheless, our understanding of mitochondrial protein import in malaria parasites and related apicomplexan parasites relies on poorly characterized components of the import machinery. To date, studies on the mitochondrial protein import machinery of malaria parasites have primarily relied on bioinformatics, with little experimental evidence validating their composition, sub-organellar localization, or interaction networks.
This thesis examined the composition and localizations of the components of the mitochondrial protein import machineries in malaria parasites. It also analyzed the interactomes of validated core components of these machineries. The findings demonstrated, for the first time in malaria parasites, the production and mitochondrial localization of the core components of mitochondrial import machineries. Specifically, the core subunits of the TOM and SAM complexes, PfTom40 and PfSam50, respectively, were successfully confirmed through confocal microscopy and western blot analyses. Similarly, two subunits of the PAM complex (PfHsp70 and PfMge1) and the central subunit of the OXA pathway, PfOxa1, were shown to be produced and localized in the mitochondria of malaria parasites. Western blot analyses also suggested the possible formation of Tim8/Tim13 hexamers in P. falciparum. Confocal microscopy revealed that Tim8, Tim13, and Pam16 are localized to the mitochondria of malaria parasites. Interactome analysis of PfMge1 showed significant enrichment in the pulldown assay; however, PfMge1's interacting partners were not significantly enriched overall in this study. Additionally, the pulldown experiments for PfTom40 and PfSam50 did not show significant enrichment in the MS analyses. Future studies could explore chemical crosslinking and denaturing affinity purification methods to capture transient interacting partners and improve solubilization of integral membrane proteins. Gene knockout attempts for PFHSP70 and PFTOM40 indicated that transfection with circular plasmids could result in unwanted insertions or single crossovers in the parasite's genome; linearized plasmids are recommended
Quantum Computing in Option Pricing
Get PDFOptions are financial instruments whose payoffs are determined by the value of an
underlying asset. These underlying assets are typically stocks, interest rates, or exchange rates, but can also include commodities such as energy or agricultural products. Options serve diverse purposes, including hedging against price volatility and speculating on market movements. Additionally, they play a critical role in assessing certain positions on the balance sheets of insurance companies, particularly in the context of solvency capital requirement calculations. As an option’s payoff lies in the future and is stochastic in nature, finding a fair price today is a non-trivial task. The focus of this work is finding quantum algorithms for calculating these prices and compare them to algorithms designed
for classical computers. This work follows two different directions on how to improve on classical methods for option pricing. The first direction is improving on Monte-Carlo (MC) methods and the second one is adapting Fourier based pricing algorithms.
The Amplitude Estimation (AE) algorithm promises a quadratic speedup compared to
classical MC. This fact makes this algorithm an interesting candidate for improvements by quantum algorithms. It was shown in the literature, that simple options with very crude discretization of the underlying stochastic models, can be implemented on a quantum device and evaluated with AE. One big challenge is the efficient implementation of the option’s payoff profile. To solve this problem colleagues and I have introduced a multi-objective genetic algorithm to automatically find well performing and efficient circuits to implement the payoff of non-path-dependent European options on one or more underlyings.
Another strategy for pricing options is based on the fact, that in many models the
characteristic function of the underlying is numerically more tractable than its distribution function. There are methods that make use of this fact and the performance of the Fast Fourier Transform (FFT) to efficiently calculate prices for European call options for many strikes in one go. The quantum version of the FFT, the Quantum Fourier Transform (QFT), is in some sense, even faster than its classical counterpart. We have adapted the existing classical method to make use of QFT, to benefit from its performance.
Finally, the different strategies are benchmarked and compared regarding their accuracy, their potential for scaling and their adaptability to different styles of derivatives and models. The result of this comparison are requirements on the quantum hardware for the methods to be viable as well as use cases where each method has its benefits over the others
Scalable User Interfaces for Collaborative Extended Reality Environments
Get PDFExtended Reality (XR) unlocks new opportunities for interacting with spatial content, supporting both individual users and diverse collaborative settings. Different degrees of virtuality like Augmented/Mixed Reality (AR/MR) and Virtual Reality (VR) as well as different devices like head-mounted displays (HMDs) and handheld displays (HHDs) offer distinct benefits for different use cases. Despite the immense interest XR has sparked in numerous domains, it is rarely used in practice where scalability limitations outweigh XR's intrinsic potential. Since users are typically involved in multiple use cases, leveraging technology-specific benefits requires switching between use cases and XR technologies. However, existing user interfaces (UIs) impede these transitions because they are tailored to specific use cases. Thus, this dissertation is concerned with the development of highly scalable UIs which facilitate switching between XR applications that differ in technology and number of users.
First, Scalable Extended Reality (XRS) is introduced as a novel concept for XR spaces which scale across different devices, degrees of virtuality, and varying numbers of potentially distributed users. A research agenda addressing the barriers to the realization of XRS is established based on an extensive compilation of related research. As an initial step towards XRS and as the basis for this dissertation the XRS framework is developed.
By sharing spatial content among collaborators, XR could overcome a key limitation of conventional videoconferencing tools. However, collaboration support features face scalability issues when different XR technologies are used in large groups. A particular challenge concerns the accurate representation of HHD users. In response, the dissertation presents new insights from a detailed study on how humans interact with HHDs across different display sizes, display orientations, and body poses. Extending these results, mechanisms for individually activating the visibility of awareness cues are designed to reduce visual overload in large groups.
Next, interaction techniques scaling with devices and degrees of virtuality are presented. Starting with MR-HHDs, a unified paradigm for object translation and rotation is developed and evaluated. By combining tablet movement and peripheral touch input its minimalist design overcomes key issues of prior methods. Extending HMDs with a tablet controller using this paradigm yields consistent interaction with MR-HHDs, MR-HMDs, and VR-HMDs. In a comparative study, this solution outperformed state-of-the-art methods and revealed high scalability. Eventually, the novel UIs are implemented and evaluated for robot control and factory layout planning, showcasing their practical applicability