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The public health insurance in Germany will face huge economic challenges in the upcoming years. New diagnostic and therapeutic methods as well as the demographic change contribute to constantly rising expenditure. Although incentives for health-promoting behaviour or financial sanctions for an unhealthy lifestyle have been already discussed in the past, there has been a general reluctance to legally establish corresponding mechanisms for fear of eroding solidarity and increasing state control. In the course of the Coronavirus pandemic however, a stronger awareness rose to the fact that personal health-related life choices can have a huge impact on the stability of the healthcare system including public health insurance. Not only in Germany but throughout much of Europe, the pandemic led to a new and more fundamental debate about the relationship between individual responsibility for personal health and the wider responsibility for public health assumed by the community of solidarity.
Prognose, Planung, Sicherung
(2024)
The automotive industry is a prime example of digital technologies reshaping mobility. Connected, autonomous, shared, and electric (CASE) trends lead to new emerging players that threaten existing industrial-aged companies. To respond, incumbents need to bridge the gap between contrasting product architecture and organizational principles in the physical and digital realms. Over-the-air (OTA) technology, that enables seamless software updates and on-demand feature additions for customers, is an example of CASE-driven digital product innovation. Through an extensive longitudinal case study of an OTA initiative by an industrial- aged automaker, this dissertation explores how incumbents accomplish digital product innovation. Building on modularity, liminality, and the mirroring hypothesis, it presents a process model that explains the triggers, mechanisms, and outcomes of this process. In contrast to the literature, the findings emphasize the primacy of addressing product architecture challenges over organizational ones and highlight the managerial implications for success.
El artículo analiza la corrupción como un fenómeno complejo y con frecuencia ambiguo, relacionado con comportamientos y mentalidades individuales y colectivas, que son percibidos como ilegítimos o inmorales y, por lo tanto, desviados de normas establecidas. Más allá de un acercamiento reduccionista u objetivista a lugares comunes de la corrupción política, o a delitos tipificados por la ley, esta contribución pretende destacar la relevancia del análisis histórico del discurso en el estudio del tema. Este enfoque nos permite reconstruir contextos en los que se identifica la corrupción, así como analizar relatos, no siempre unánimes, sobre estas prácticas. El trabajo se adentra en una época lejana, pero a la vez cercana a nuestro tiempo, el último siglo la República romana. La evidencia nos permite evaluar críticamente aspectos fundamentales de la construcción retórica de la corrupción y de sus zonas grises, como la distinción, a menudo borrosa, entre regalo y soborno.
In Time and the Other Johannes Fabian analysed how modern conceptions of time were “not only secularized and naturalized but also thoroughly spatialized.” According to Fabian, this was particularly visible in modern anthropology which “promoted a scheme in terms of which not only past cultures but all living societies were irrevocably placed on a temporal slope, a stream of Time – some upstream, others downstream.”3 Anthropologists attributed otherness to a distant past which was traditionally associated with cultural retardation, i.e. a lower degree of development, progress, and civilization. Cultural difference was expressed in terms of temporal distance while temporal distance was attributed to spatial remoteness. The result was a phenomenon that Fabian coined “the denial of coevalness” which pointed towards “a persistent and systematic tendency to place the referent(s) of anthropology in a Time other than the present of the producer of anthropological discourse.
In many churches nowadays, there has been a standardized approach to premarital counseling for couples involving social, pastoral, and psychological perspectives. In contrast, many rabbis and other Jewish officials still concentrate on legal aspects alone. The need for resolving important issues on the verge of wedlock is too often left to secular experts in law, psychology, or counseling. However, in recent years, this lack of formal training for marriage preparation has also been acknowledged by the Jewish clergy in order to incorporate it in the preparatory period before the bond is tied. This case study focuses on Jewish and Roman Catholic conceptions of marriage, past and present. We intend to do a comparative analysis of the prerequisites of religious marriage based on the assumption that both Judaism and the Roman Catholic Church have a distinct legal framework to assess marriage preparation.
The experience of premenstrual syndrome (PMS) affects up to 90% of individuals with an active menstrual cycle and involves a spectrum of aversive physiological and psychological symptoms in the days leading up to menstruation (Tschudin et al., 2010). Despite its high prevalence, the precise origins of PMS remain elusive, with influences ranging from hormonal fluctuations to cognitive, social, and cultural factors (Hunter, 2007; Matsumoto et al., 2013).
Biologically, hormonal fluctuations, particularly in gonadal steroids, are commonly believed to be implicated in PMS, with the central factor being varying susceptibilities to the fluctuations between individuals and cycles (Rapkin & Akopians, 2012). Allopregnanolone (ALLO), a neuroactive steroid and progesterone metabolite, has emerged as a potential link to PMS symptoms (Hantsoo & Epperson, 2020). ALLO is a positive allosteric modulator of the GABAA receptor, influencing inhibitory communication (Rupprecht, 2003; Andréen et al., 2006). Different susceptibility to ALLO fluctuations throughout the cycle may lead to reduced GABAergic signal transmission during the luteal phase of the menstrual cycle.
The GABAergic system's broad influence leads to a number of affected physiological systems, including a consistent reduction in vagally mediated heart rate variability (vmHRV) during the luteal phase (Schmalenberger et al., 2019). This reduction in vmHRV is more pronounced in individuals with high PMS symptoms (Baker et al., 2008; Matsumoto et al., 2007). Fear conditioning studies have shown inconsistent associations with cycle phases, suggesting a complex interplay between physiological parameters and PMS-related symptoms (Carpenter et al., 2022; Epperson et al., 2007; Milad et al., 2006).
The neurovisceral integration model posits that vmHRV reflects the capacity of the central autonomous network (CAN), which is responsible for regulatory processes on behavioral, cognitive, and autonomous levels (Thayer & Lane, 2000, 2009). Fear learning, mediated within the CAN, is suggested to be indicative of vmHRV's capacity for successful
VI
regulation (Battaglia & Thayer, 2022). Given the GABAergic mediation of central inhibitory functional connectivity in the CAN, which may be affected by ALLO fluctuations, this thesis proposes that fluctuating CAN activity in the luteal phase contributes to diverse aversive symptoms in PMS.
A research program was designed to empirically test these propositions. Study 1 investigated fear discrimination during different menstrual cycle phases and its interaction with vmHRV, revealing nuanced effects on acoustic startle response and skin conductance response. While there was heightened fear discrimination in acoustic startle responses in participants in the luteal phase, there was an interaction between menstrual cycle phase and vmHRV in skin conductance responses. In this measure, heightened fear discrimination during the luteal phase was only visible in individuals with high resting vmHRV; those with low vmHRV showed reduced fear discrimination and higher overall responses.
Despite affecting the vast majority of menstruating people, there are very limited tools available to reliably assess these symptoms in the German speaking area. Study 2 aimed at closing this gap, by translating and validating a German version of the short version of the Premenstrual Assessment Form (Allen et al., 1991), providing a reliable tool for future investigations, which closes the gap in PMS questionnaires in the German-speaking research area.
Study 3 employed a diary study paradigm to explore daily associations between vmHRV and PMS symptoms. The results showed clear simultaneous fluctuations between the two constructs with a peak in PMS and a low point in vmHRV a few days before menstruation onset. The association between vmHRV and PMS was driven by psychological PMS symptoms.
Based on the theoretical considerations regarding the neurovisceral perspective on PMS, another interesting construct to consider is attentional control, as it is closely related to functions of the CAN. Study 4 delved into attentional control and vmHRV differences between menstrual cycle phases, demonstrating an interaction between cycle phase and PMS symptoms. In a pilot, we found reduced vmHRV and attentional control during the luteal phase only in participants who reported strong PMS.
While Studies 1-4 provided evidence for the mechanisms underlying PMS, Studies 5 and 6 investigated short- and long-term intervention protocols to ameliorate PMS symptomatology. Study 5 explored the potential of heart rate variability biofeedback (HRVB) in alleviating PMS symptoms and a number of other outcome measures. In a waitlist-control design, participants underwent a 4-week smartphone-based HRVB intervention. The results revealed positive effects on PMS, with larger effect sizes on psychological symptoms, as well as on depressive symptoms, anxiety/stress and attentional control.
Finally, Study 6 examined the acute effects of HRVB on attentional control. The study found positive impact but only in highly stressed individuals.
The thesis, based on this comprehensive research program, expands our understanding of PMS as an outcome of CAN fluctuations mediated by GABAA receptor reactivity. The results largely support the model. These findings not only deepen our understanding of PMS but also offer potential avenues for therapeutic interventions. The promising results of smartphone-based HRVB training suggest a non-pharmacological approach to managing PMS symptoms, although further research is needed to confirm its efficacy.
In conclusion, this thesis illuminates the complex web of factors contributing to PMS, providing valuable insights into its etiological underpinnings and potential interventions. By elucidating the relationships between hormonal fluctuations, CAN activity, and psychological responses, this research contributes to more effective treatments for individuals grappling with the challenges of PMS. The findings hold promise for improving the quality of life for those affected by this prevalent and often debilitating condition.
Preisalgorithmenkartelle
(2024)
Mithilfe von Preisalgorithmen sind Unternehmen in der Lage, automatische und wechselseitige Preisanpassungen vorzunehmen. Dadurch können klassische Kartellkonstellationen mangels konspirativer Treffen in den Hintergrund treten. Die Arbeit zeigt auf, unter welchen Voraussetzungen der Einsatz von Preisalgorithmen einen Verstoß gegen das europäische Kartellverbot begründen kann. Dazu werden Fallkonstellationen beleuchtet, die ein algorithmisches Zusammenwirken sowohl unmittelbar zwischen Wettbewerbern als auch mittelbar über einen Dritten begründen. Ferner wird auch auf algorithmenspezifische Compliance-Maßnahmen eingegangen. Schließlich werden die praktischen Herausforderungen bei der Aufdeckung und dem Nachweis solcher Kartelle aufgezeigt.
Leadership plays an important role for the efficient and fair solution of social dilemmas but the effectiveness of a leader can vary substantially. Two main factors of leadership impact are the ability to induce high contributions by all group members and the (expected) fair use of power. Participants in our experiment decide about contributions to a public good. After all contributions are made, the leader can choose how much of the joint earnings to assign to herself; the remainder is distributed equally among the followers. Using machine learning techniques, we study whether the content of initial open statements by the group members predicts their behavior as a leader and whether groups are able to identify such clues and endogenously appoint a “good” leader to solve the dilemma. We find that leaders who promise fairness are more likely to behave fairly, and that followers appoint as leaders those who write more explicitly about fairness and efficiency. However, in their contribution decision, followers focus on the leader’s first-move contribution and place less importance on the content of the leader’s statements.
Have you already swiped or liked this morning? Have you taken part in a video conference at work, used or programmed a database? Have you paid with your smartphone on the way home, listened to a podcast, or extended the lending of books you borrowed from the library? And in the evening, have you filled out your tax return application on ELSTER.de on your tablet, shopped online, or paid invoices before you were tempted to watch a series on a streaming platform?
Our lives are entirely digitalized.
These changes make many things faster, easier, and more efficient. But keeping pace with these changes demands a lot from us, and not everyone succeeds. There are people who prefer to go to the bank to make a transfer, leave the programming to the experts, send their tax return by mail, and only use their smartphone to make phone calls. They don’t want to keep pace, or maybe they can’t. They haven’t learned these things. Others, younger people, grow up as “digital natives” surrounded by digital devices, tools, and processes. But does that mean they really know how to use them? Or do they also need digital education?
But what does successful digital education actually look like? Does it teach us how to use a tablet, how to google properly, and how to write Excel spreadsheets? Perhaps it’s about more than that. It’s about understanding the comprehensive change that has been taking hold of our world since it was broken down into digital ones and zeros and rebuilt virtually. But how do we learn to live in a world of digitality – with all that it entails, and to our benefit?
For the new issue of “Portal Wissen”, we looked around at the university and interviewed researchers about the role that the connection between digitalization and learning plays in the research of various disciplines. We spoke to Katharina Scheiter, Professor of Digital Education, about the future of German schools and had several experts show us examples of how digital tools can improve learning in schools. We also talked to computer science and agricultural researchers about how even experienced farmers can still learn a lot about their land and their work thanks to digital tools. We spoke to educational researchers who are using big data to analyze how boys and girls learn and what the possible causes for differences are. Education and political scientist Nina Kolleck, on the other hand, looks at education against the backdrop of globalization and relies on the analysis of large amounts of social media data.
Of course, we don’t lose sight of the diversity of research at the University of Potsdam. We learn, for example, what alternatives to antibiotics could soon be available. This magazine also looks at stress and how it makes us ill as well as the research into sustainable ore extraction.
A new feature of our magazine is a whole series of shorter articles that invite you to browse and read: from research news and photographic insights into laboratories to simple explanations of complex phenomena and outlooks into the wider world of research to a small scientific utopia and a personal thanks to research. All this in the name of education, of course. Enjoy your read!
Portal Transfer 2024
(2024)
Liebe Leserinnen und Leser, die eigene „Blase“ verlassen, Perspektiven wechseln, Silo-Mentalität überwinden – was der Wissenschaft in ihrem Innern gelingt, ja gelingen muss, um erfolgreich zu sein, stellt sie in ihrer Außenwirkung noch immer vor Herausforderungen. Dabei gehört es doch inzwischen zum Selbstverständnis moderner Universitäten, öffentlich zu erklären, woran in ihren Räumen geforscht wird, sich in gesellschaftliche Diskurse einzubringen und ihre Erkenntnisse zügig in die Praxis zu überführen.
Die Universität Potsdam hat diese Transferaufgaben neben Lehre und Forschung als dritte Säule installiert und ihrem Gebäude damit noch mehr Stabilität verliehen. Seit Jahren gehört sie im nationalen Vergleich zu den erfolgreichsten Hochschulen, wenn es darum geht, Start-ups zu fördern und aus der Forschung heraus Unternehmen zu gründen: In diesem Magazin berichten wir von der Potassco Solutions GmbH des Informatikers Torsten Schaub, der mit seinem KI-System Clingo komplexe Optimierungsprobleme in Betrieben löst. Oder von der SEQSTANT GmbH, die mit innovativer Diagnostik Erreger von Atemwegserkrankungen in Echtzeit bestimmen kann. Wir zeigen aber auch, wie Forschungsteams mit der Industrie kooperieren, zum Beispiel mit der K-UTEC im thüringischen Sondershausen, um mit wissenschaftlichem Knowhow dazu beizutragen, dass dort in Produktionsabfällen kein wertvolles Lithium verloren geht.
Richtet sich der Technologietransfer vor allem an die Wirtschaft, so hilft der Wissenstransfer der gesamten Gesellschaft. Besonders stark ist die Universität Potsdam hier in der Bildung, denn mit ihren Lehramtsabsolventen schickt sie auch gleich den aktuellen Stand der Unterrichtsforschung in die Schulpraxis. Immer häufiger zieht dabei die Digitalisierung in die Klassenzimmer ein. Wie das gut gelingen kann, ist in diesem Magazin zu lesen. Zudem erklären wir, was die Sportwissenschaft zur Therapie von Depressionen beitragen kann oder wie die Umweltforschung das Risikomanagement in von Hochwasser bedrohten Regionen verbessern will. Ob in öffentlichen Verwaltungen oder politischen Institutionen – überall ist wissenschaftliche Expertise gefragt. Wir zeigen das am Beispiel von Frauke Brosius-Gersdorf, die als Juristin die Bundesregierung zur Regulierung des Schwangerschaftsabbruchs berät.
Der kürzeste Weg des Wissens aus der Universität in die Praxis führt zweifelsohne über die Alumni, die als Fach- und Führungskräfte im Land und darüber hinaus wirksam werden. Dass dieser Weg schon während des Studiums beginnen kann, beweisen die vielen studentischen Initiativen, die hier zu Wort kommen. Sie alle scheuen nicht das Rampenlicht: ob bei Science Slams auf den Bühnen im Land Brandenburg, bei den TEDx-Talks im Hans Otto Theater, beim Kunst-Rundgang in der Potsdamer Waschhaus-Arena oder mit englischsprachigem Schauspiel an der Uni. Öffentlich in Erscheinung treten, neue Formen finden, um Wissen in die Breite der Bevölkerung zu tragen – auch das gehört zum Transfer. Genau wie dieses Magazin.
Portal = Welt retten
(2024)
Fragen beantworten, Unbekanntes erklären, Rätsel lösen – und die gewonnenen Erkenntnisse zum Nutzen der Menschheit einsetzen: Das treibt Wissenschaftler*innen auf der ganzen Welt an. Forschung ist keine Geheimwissenschaft, die im stillen Kämmerlein passiert. Sie dient im besten Fall allen. Sie funktioniert voraussetzungsfrei und ergebnisoffen, und gerade deshalb können Forschungsergebnisse notwendige Innovationen, Transformation oder Umdenken fördern und auf diese Weise die Welt verändern. Zum Besseren, so die Hoffnung. Für diese Ausgabe der „Portal“ haben wir Universitätspräsident Prof. Oliver Günther, Ph.D. und die Ökologin Prof. Dr. Damaris Zurell gefragt, ob Wissenschaft die Welt retten kann. Sie sind sich einig: Forschung trägt dazu bei, dass viele Menschen ein lebenswertes und erfülltes Leben führen können. Sie betonen aber auch: Wissenschaft kann das nicht allein erreichen, für echte Veränderungen braucht es Politik, Wirtschaft und Gesellschaft.
Wie wichtig es ist, dass wissenschaftliche Erkenntnisse uns zum Handeln bewegen, davon erzählen auch die vielen anderen Geschichten in diesem Heft. Denn in Potsdam tragen nicht nur Wissenschaftler*innen, sondern auch Studierende und Beschäftigte in Technik und Verwaltung dazu bei, die Universität, ihr Umfeld oder „die Welt da draußen“ Stück für Stück besser zu machen. Jonathan Schorsch zum Beispiel, Professor für Jüdische Religions- und Geistesgeschichte, hat den „Grünen Sabbat“ ins Leben gerufen: einen Tag in der Woche, an dem wir der Erde – und uns selbst – eine kleine Pause gönnen. Der Jurist Andreas Zimmermann berichtet von einem Verfahren vor dem Internationalen Gerichtshof zum Klimawandel, an dem er als Forscher beteiligt ist, und seine Kollegin Dr. Anna von Rebay kämpft als Anwältin für die Rechte des Meeres vor Ausbeutung und Verschmutzung. Der Voltaire-Preisträger Gera Gizaw erzählt von einem Flüchtlingscamp in Kenia aus die Geschichten der Menschen dort und der Medizinethiker Robert Ranisch zeigt, wie die Pflege künftig für noch mehr Wohl sorgen kann. Hochschulangehörige engagieren sich für den Bildungsaufstieg von Menschen aus nicht-akademischen Familien und der Student Tobias Föhl kämpft bei ONE gegen Armut auf der Welt. Mitarbeiter aus der Musikwissenschaft verlängern das Leben von alten Möbeln und Musikinstrumenten, Studierende arbeiten mit Jugendfeuerwehren aus der Region zusammen. Der Better World Award wirft ein Licht auf innovative Ideen, die schnellstmöglich ihren Weg aus der Uni in die Öffentlichkeit finden sollten. Wie wichtig die Kommunikation wissenschaftlicher Erkenntnisse ist, zeigen Julia Wandt und Kristin Küter, die Menschen aus dem Wissenschaftsbetrieb beraten, die Anfeindungen ausgesetzt sind. Denn damit es vorangeht, damit Lösungen für Probleme dieser Welt gefunden werden, darf eines nicht geschehen: dass die Forschung verstummt.
Verträge über nicht-personenbezogene Daten werden seit dem Data Act immer wichtiger. Gleichwohl ist deren rechtliche Qualifikation immer noch nicht abschließend geklärt. Auch wenn klar ist, dass Daten in aller Regel keinem geistigen Eigentumsrecht unterliegen, nur in seltenen Fällen Know-how sind und an ihnen kein Sacheigentum bestehen kann, benötigen die Verträge eine hinreichende rechtliche Grundlage ihres Gegenstands. Der Beitrag plädiert für eine geringfügige Anpassung, jedenfalls in der Technologiegruppenfreistellungsverordnung.
Digitale Plattformen prägen unsere Rechts- und Wirtschaftsordnung, die Freizeitgestaltung, das Informationsverhalten und im Aggregat die digitale Öffentlichkeit. Die damit verbundenen Rechtsfragen sind im Fluss und berühren alle juristischen Teildisziplinen. Der Tagungsband nähert sich daher den Entwicklungen des Plattformrechts aus disziplinübergreifendem Blickwinkel. Dieser Versuch einer überspannenden Perspektive fokussiert vor allem auf die beiden „Großen“ der jüngsten Rechtsakte (DSA/DMA) unter dem besonderen Gesichtspunkt ihres Vollzugs: Wie kann man ein globales Phänomen wie Plattformen lokal und regional regulieren? Welche Rolle spielt der Schwarm der Vielen in der Effektivierung der neuen Regularien? Passen Regelungsmodelle wie das Urheberrecht zum Plattformphänomen?
Relativistic pair beams produced in the cosmic voids by TeV gamma rays from blazars are expected to produce a detectable GeV-scale cascade emission missing in the observations. The suppression of this secondary cascade implies either the deflection of the pair beam by intergalactic magnetic fields (IGMFs) or an energy loss of the beam due to the electrostatic beam-plasma instability. IGMF of femto-Gauss strength is sufficient to significantly deflect the pair beams reducing the flux of secondary cascade below the observational limits. A similar flux reduction may result in the absence of the IGMF from the beam energy loss by the instability before the inverse Compton cooling. This dissertation consists of two studies about the instability role in the evolution of blazar-induced beams.
Firstly, we investigated the effect of sub-fG level IGMF on the beam energy loss by the instability. Considering IGMF with correlation lengths smaller than a few kpc, we found that such fields increase the transverse momentum of the pair beam particles, dramatically reducing the linear growth rate of the electrostatic instability and hence the energy-loss rate of the pair beam. Our results show that the IGMF eliminates beam plasma instability as an effective energy-loss agent at a field strength three orders of magnitude below that needed to suppress the secondary cascade emission by magnetic deflection. For intermediate-strength IGMF, we do not know a viable process to explain the observed absence of GeV-scale cascade emission and hence can be excluded.
Secondly, we probed how the beam-plasma instability feeds back on the beam, using a realistic two-dimensional beam distribution. We found that the instability broadens the beam opening angles significantly without any significant energy loss, thus confirming a recent feedback study on a simplified one-dimensional beam distribution. However, narrowing diffusion feedback of the beam particles with Lorentz factors less than 1e6 might become relevant even though initially it is negligible. Finally, when considering the continuous creation of TeV pairs, we found that the beam distribution and the wave spectrum reach a new quasi-steady state, in which the scattering of beam particles persists and the beam opening angle may increase by a factor of hundreds. This new intrinsic scattering of the cascade can result in time delays of around ten years, thus potentially mimicking the IGMF deflection. Understanding the implications on the GeV cascade emission requires accounting for inverse Compton cooling and simulating the beam-plasma system at different points in the IGM.
Personalmanagement und KWI
(2024)
With Arctic ground as a huge and temperature-sensitive carbon reservoir, maintaining low ground temperatures and frozen conditions to prevent further carbon emissions that contrib-ute to global climate warming is a key element in humankind’s fight to maintain habitable con-ditions on earth. Former studies showed that during the late Pleistocene, Arctic ground condi-tions were generally colder and more stable as the result of an ecosystem dominated by large herbivorous mammals and vast extents of graminoid vegetation – the mammoth steppe. Characterised by high plant productivity (grassland) and low ground insulation due to animal-caused compression and removal of snow, this ecosystem enabled deep permafrost aggrad-ation. Now, with tundra and shrub vegetation common in the terrestrial Arctic, these effects are not in place anymore. However, it appears to be possible to recreate this ecosystem local-ly by artificially increasing animal numbers, and hence keep Arctic ground cold to reduce or-ganic matter decomposition and carbon release into the atmosphere.
By measuring thaw depth, total organic carbon and total nitrogen content, stable carbon iso-tope ratio, radiocarbon age, n-alkane and alcohol characteristics and assessing dominant vegetation types along grazing intensity transects in two contrasting Arctic areas, it was found that recreating conditions locally, similar to the mammoth steppe, seems to be possible. For permafrost-affected soil, it was shown that intensive grazing in direct comparison to non-grazed areas reduces active layer depth and leads to higher TOC contents in the active layer soil. For soil only frozen on top in winter, an increase of TOC with grazing intensity could not be found, most likely because of confounding factors such as vertical water and carbon movement, which is not possible with an impermeable layer in permafrost. In both areas, high animal activity led to a vegetation transformation towards species-poor graminoid-dominated landscapes with less shrubs. Lipid biomarker analysis revealed that, even though the available organic material is different between the study areas, in both permafrost-affected and sea-sonally frozen soils the organic material in sites affected by high animal activity was less de-composed than under less intensive grazing pressure. In conclusion, high animal activity af-fects decomposition processes in Arctic soils and the ground thermal regime, visible from reduced active layer depth in permafrost areas. Therefore, grazing management might be utilised to locally stabilise permafrost and reduce Arctic carbon emissions in the future, but is likely not scalable to the entire permafrost region.
Does working in a gender-atypical occupation reduce individuals’ likelihood of finding a different-sex romantic partner, and do such occupational partnership penalties contribute to occupational gender segregation? To answer this question, we theorized partnership penalties for working in gender-atypical occupations by drawing on insights from evolutionary psychology, social constructivism, and rational choice theory and exploited the stability of occupational pathways in Germany. In Study 1, we analyzed observational data from a national probability sample (N= 1,634,944) to assess whether individuals in gender-atypical occupations were less likely to be partnered than individuals who worked in gender typical occupations. To assess whether the observed partnership gaps found in Study 1 were causally related to the gender typicality of men’s and women’s occupations, we conducted a field experiment on a dating app (N = 6,778). Because the findings from Study 2 suggested that young women and men indeed experienced penalties for working in a gender-atypical occupation (at least when they were not highly attractive), we employed a choice-experimental design in Study 3 (N = 1,250) to assess whether women and men were aware of occupational partnership penalties and showed that anticipating occupational partnership penalties may keep young and highly educated women from working in gender-atypical occupations. Our main conclusion therefore is that that observed penalties and their anticipation seem to be driven by unconscious rather than conscious processes.
Overcoming natural biomass limitations in gram-negative bacteria through synthetic carbon fixation
(2024)
The carbon demands of an ever-increasing human population and the concomitant rise in net carbon emissions requires CO2 sequestering approaches for production of carbon-containing molecules. Microbial production of carbon-containing products from plant-based sugars could replace current fossil-based production. However, this form of sugar-based microbial production directly competes with human food supply and natural ecosystems. Instead, one-carbon feedstocks derived from CO2 and renewable energy were proposed as an alternative. The one carbon molecule formate is a stable, readily soluble and safe-to-store energetic mediator that can be electrochemically generated from CO2 and (excess off-peak) renewable electricity. Formate-based microbial production could represent a promising approach for a circular carbon economy. However, easy-to-engineer and efficient formate-utilizing microbes are lacking. Multiple synthetic metabolic pathways were designed for better-than-nature carbon fixation. Among them, the reductive glycine pathway was proposed as the most efficient pathway for aerobic formate assimilation. While some of these pathways have been successfully engineered in microbial hosts, these synthetic strains did so far not exceed the performance of natural strains. In this work, I engineered and optimized two different synthetic formate assimilation pathways in gram-negative bacteria to exceed the limits of a natural carbon fixation pathway, the Calvin cycle.
The first chapter solidified Cupriavidus necator as a promising formatotrophic host to produce value-added chemicals. The formate tolerance of C. necator was assessed and a production pathway for crotonate established in a modularized fashion. Last, bioprocess optimization was leveraged to produce crotonate from formate at a titer of 148 mg/L.
In the second chapter, I chromosomally integrated and optimized the synthetic reductive glycine pathway in C. necator using a transposon-mediated selection approach. The insertion methodology allowed selection for condition-specific tailored pathway expression as improved pathway performance led to better growth. I then showed my engineered strains to exceed the biomass yields of the Calvin cycle utilizing wildtype C. necator on formate. This demonstrated for the first time the superiority of a synthetic formate assimilation pathway and by extension of synthetic carbon fixation efforts as a whole.
In chapter 3, I engineered a segment of a synthetic carbon fixation cycle in Escherichia coli. The GED cycle was proposed as a Calvin cycle alternative that does not perform a wasteful oxygenation reaction and is more energy efficient. The pathways simple architecture and reasonable driving force made it a promising candidate for enhanced carbon fixation. I created a deletion strain that coupled growth to carboxylation via the GED pathway segment. The CO2 dependence of the engineered strain and 13C-tracer analysis confirmed operation of the pathway in vivo.
In the final chapter, I present my efforts of implementing the GED cycle also in C. necator, which might be a better-suited host, as it is accustomed to formatotrophic and hydrogenotrophic growth. To provide the carboxylation substrate in vivo, I engineered C. necator to utilize xylose as carbon source and created a selection strain for carboxylase activity. I verify activity of the key enzyme, the carboxylase, in the decarboxylative direction. Although CO2-dependent growth of the strain was not obtained, I showed that all enzymes required for operation of the GED cycle are active in vivo in C. necator.
I then evaluate my success with engineering a linear and cyclical one-carbon fixation pathway in two different microbial hosts. The linear reductive glycine pathway presents itself as a much simpler metabolic solution for formate dependent growth over the sophisticated establishment of hard-to-balance carbon fixation cycles. Last, I highlight advantages and disadvantages of C. necator as an upcoming microbial benchmark organism for synthetic metabolism efforts and give and outlook on its potential for the future of C1-based manufacturing.
Our dignity in your hands
(2024)
Organizational commitments to equality change how people view women’s and men’s professional success
(2024)
To address women’s underrepresentation in high-status positions, many organizations have committed to gender equality. But is women’s professional success viewed less positively when organizations commit to women’s advancement? Do equality commitments have positive effects on evaluations of successful men? We fielded a survey experiment with a national probability sample in Germany (N = 3229) that varied employees’ gender and their organization’s commitment to equality. Respondents read about a recently promoted employee and rated how decisive of a role they thought intelligence and effort played in getting the employee promoted from 1 “Not at all decisive” to 7 “Very decisive” and the fairness of the promotion from 1 “Very unfair” to 7 “Very fair.” When organizations committed to women’s advancement rather than uniform performance standards, people believed intelligence and effort were less decisive in women’s promotions, but that intelligence was more decisive in men’s promotions. People viewed women’s promotions as least fair and men’s as most fair in organizations committed to women’s advancement. However, women’s promotions were still viewed more positively than men’s in all conditions and on all outcomes, suggesting people believed that organizations had double standards for success that required women to be smarter and work harder to be promoted, especially in organizations that did not make equality commitments.
Organic-inorganic hybrids based on P3HT and mesoporous silicon for thermoelectric applications
(2024)
This thesis presents a comprehensive study on synthesis, structure and thermoelectric transport properties of organic-inorganic hybrids based on P3HT and porous silicon. The effect of embedding polymer in silicon pores on the electrical and thermal transport is studied. Morphological studies confirm successful polymer infiltration and diffusion doping with roughly 50% of the pore space occupied by conjugated polymer. Synchrotron diffraction experiments reveal no specific ordering of the polymer inside the pores. P3HT-pSi hybrids show improved electrical transport by five orders of magnitude compared to porous silicon and power factor values comparable or exceeding other P3HT-inorganic hybrids. The analysis suggests different transport mechanisms in both materials. In pSi, the transport mechanism relates to a Meyer-Neldel compansation rule. The analysis of hybrids' data using the power law in Kang-Snyder model suggests that a doped polymer mainly provides charge carriers to the pSi matrix, similar to the behavior of a doped semiconductor. Heavily suppressed thermal transport in porous silicon is treated with a modified Landauer/Lundstrom model and effective medium theories, which reveal that pSi agrees well with the Kirkpatrick model with a 68% percolation threshold. Thermal conductivities of hybrids show an increase compared to the empty pSi but the overall thermoelectric figure of merit ZT of P3HT-pSi hybrid exceeds both pSi and P3HT as well as bulk Si.
Optimizing power analysis for randomized experiments: Design parameters for student achievement
(2024)
Randomized trials (RTs) are promising methodological tools to inform evidence-based reform to enhance schooling. Establishing a robust knowledge base on how to promote student achievement requires sensitive RT designs demonstrating sufficient statistical power and precision to draw conclusive and correct inferences on the effectiveness of educational programs and innovations. Proper power analysis is therefore an integral component of any informative RT on student achievement. This venture critically hinges on the availability of reasonable input variance design parameters (and their inherent uncertainties) that optimally reflect the realities around the prospective RT—precisely, its target population and outcome, possibly applied covariates, the concrete design as well as the planned analysis. However, existing compilations in this vein show far-reaching shortcomings.
The overarching endeavor of the present doctoral thesis was to substantively expand available resources devoted to tweak the planning of RTs evaluating educational interventions. At the core of this thesis is a systematic analysis of design parameters for student achievement, generating reliable and versatile compendia and developing thorough guidance to support apt power analysis to design strong RTs. To this end, the thesis at hand bundles two complementary studies which capitalize on rich data of several national probability samples from major German longitudinal large-scale assessments.
Study I applied two- and three-level latent (covariate) modeling to analyze design parameters for a wide spectrum of mathematical-scientific, verbal, and domain-general achievement outcomes. Three vital covariate sets were covered comprising (a) pretests, (b) sociodemographic characteristics, and (c) their combination. The accumulated estimates were additionally summarized in terms of normative distributions.
Study II specified (manifest) single-, two-, and three-level models and referred to influential psychometric heuristics to analyze design parameters and develop concise selection guidelines for covariate (a) types of varying bandwidth-fidelity (domain-identical, cross-domain, fluid intelligence pretests; sociodemographic characteristics), (b) combinations quantifying incremental validities, and (c) time lags of 1- to 7-year-lagged pretests scrutinizing validity degradation. The estimates for various mathematical-scientific and verbal achievement outcomes were meta-analytically integrated and employed in precision simulations.
In doing so, Studies I and II addressed essential gaps identified in previous repertoires in six major dimensions: Taken together, this thesis accumulated novel design parameters and deliberate guidance for RT power analysis (1) tailored to four German student (sub)populations across the entire school career from Grade 1 to 12, (2) matched to 21 achievement (sub)domains, (3) adjusted for 11 covariate sets enriched by empirically supported guidelines, (4) adapted to six RT designs, (5) suitable for latent and manifest analysis models, (6) which were cataloged along with quantifications of their associated uncertainties. These resources are complemented by a plethora of illustrative application examples to gently direct psychological and educational researchers through pivotal steps in the process of RT design.
The striking heterogeneity of the design parameter estimates across all these dimensions constitutes the overall, joint key result of Studies I and II. Hence, this work convincingly reinforces calls for a close match between design parameters and the specific peculiarities of the target RT’s research context.
All in all, the present doctoral thesis offers a—so far unique—nuanced and extensive toolkit to optimize power analysis for sound RTs on student achievement in the German (and similar) school context. It is of utmost importance that research does not tire to spawn robust evidence on what actually works to improve schooling. With this in mind, I hope that the emerging compendia and guidance contribute to the quality and rigor of our randomized experiments in psychology and education.
Large parts of the Earth’s interior are inaccessible to direct observation, yet global geodynamic processes are governed by the physical material properties under extreme pressure and temperature conditions. It is therefore essential to investigate the deep Earth’s physical properties through in-situ laboratory experiments. With this goal in mind, the optical properties of mantle minerals at high pressure offer a unique way to determine a variety of physical properties, in a straight-forward, reproducible, and time-effective manner, thus providing valuable insights into the physical processes of the deep Earth. This thesis focusses on the system Mg-Fe-O, specifically on the optical properties of periclase (MgO) and its iron-bearing variant ferropericlase ((Mg,Fe)O), forming a major planetary building block. The primary objective is to establish links between physical material properties and optical properties. In particular the spin transition in ferropericlase, the second-most abundant phase of the lower mantle, is known to change the physical material properties. Although the spin transition region likely extends down to the core-mantle boundary, the ef-fects of the mixed-spin state, where both high- and low-spin state are present, remains poorly constrained.
In the studies presented herein, we show how optical properties are linked to physical properties such as electrical conductivity, radiative thermal conductivity and viscosity. We also show how the optical properties reveal changes in the chemical bonding. Furthermore, we unveil how the chemical bonding, the optical and other physical properties are affected by the iron spin transition. We find opposing trends in the pres-sure dependence of the refractive index of MgO and (Mg,Fe)O. From 1 atm to ~140 GPa, the refractive index of MgO decreases by ~2.4% from 1.737 to 1.696 (±0.017). In contrast, the refractive index of (Mg0.87Fe0.13)O (Fp13) and (Mg0.76Fe0.24)O (Fp24) ferropericlase increases with pressure, likely because Fe Fe interactions between adjacent iron sites hinder a strong decrease of polarizability, as it is observed with increasing density in the case of pure MgO. An analysis of the index dispersion in MgO (decreasing by ~23% from 1 atm to ~103 GPa) reflects a widening of the band gap from ~7.4 eV at 1 atm to ~8.5 (±0.6) eV at ~103 GPa. The index dispersion (between 550 and 870 nm) of Fp13 reveals a decrease by a factor of ~3 over the spin transition range (~44–100 GPa). We show that the electrical band gap of ferropericlase significantly widens up to ~4.7 eV in the mixed spin region, equivalent to an increase by a factor of ~1.7. We propose that this is due to a lower electron mobility between adjacent Fe2+ sites of opposite spin, explaining the previously observed low electrical conductivity in the mixed spin region. From the study of absorbance spectra in Fp13, we show an increasing covalency of the Fe-O bond with pressure for high-spin ferropericlase, whereas in the low-spin state a trend to a more ionic nature of the Fe-O bond is observed, indicating a bond weakening effect of the spin transition. We found that the spin transition is ultimately caused by both an increase of the ligand field-splitting energy and a decreasing spin-pairing energy of high-spin Fe2+.
Openness indicators for the evaluation of digital platforms between the launch and maturity phase
(2024)
In recent years, the evaluation of digital platforms has become an important focus in the field of information systems science. The identification of influential indicators that drive changes in digital platforms, specifically those related to openness, is still an unresolved issue. This paper addresses the challenge of identifying measurable indicators and characterizing the transition from launch to maturity in digital platforms. It proposes a systematic analytical approach to identify relevant openness indicators for evaluation purposes. The main contributions of this study are the following (1) the development of a comprehensive procedure for analyzing indicators, (2) the categorization of indicators as evaluation metrics within a multidimensional grid-box model, (3) the selection and evaluation of relevant indicators, (4) the identification and assessment of digital platform architectures during the launch-to-maturity transition, and (5) the evaluation of the applicability of the conceptualization and design process for digital platform evaluation.
This thesis focuses on the molecular evolution of Macroscelidea, commonly referred to as sengis. Sengis are a mammalian order belonging to the Afrotherians, one of the four major clades of placental mammals. Sengis currently consist of twenty extant species, all of which are endemic to the African continent. They can be separated in two families, the soft-furred sengis (Macroscelididae) and the giant sengis (Rhynchocyonidae). While giant sengis can be exclusively found in forest habitats, the different soft-furred sengi species dwell in a broad range of habitats, from tropical rain-forests to rocky deserts.
Our knowledge on the evolutionary history of sengis is largely incomplete. The high level of superficial morphological resemblance among different sengi species (especially the soft-furred sengis) has for example led to misinterpretations of phylogenetic relationships, based on morphological characters. With the rise of DNA based taxonomic inferences, multiple new genera were defined and new species described. Yet, no full taxon molecular phylogeny exists, hampering the answering of basic taxonomic questions. This lack of knowledge can be to some extent attributed to the limited availability of fresh-tissue samples for DNA extraction. The broad African distribution, partly in political unstable regions and low population densities complicate contemporary sampling approaches. Furthermore, the DNA information available usually covers only short stretches of the mitochondrial genome and thus a single genetic locus with limited informational content.
Developments in DNA extraction and library protocols nowadays offer the opportunity to access DNA from museum specimens, collected over the past centuries and stored in natural history museums throughout the world. Thus, the difficulties in fresh-sample acquisition for molecular biological studies can be overcome by the application of museomics, the research field which emerged from those laboratory developments.
This thesis uses fresh-tissue samples as well as a vast collection museum specimens to investigate multiple aspects about the macroscelidean evolutionary history. Chapter 4 of this thesis focuses on the phylogenetic relationships of all currently known sengi species. By accessing DNA information from museum specimens in combination of fresh tissue samples and publicly available genetic resources it produces the first full taxon molecular phylogeny of sengis. It confirms the monophyly of the genus Elephantulus and discovers multiple deeply divergent lineages within different species, highlighting the need for species specific approaches. The study furthermore focuses on the evolutionary time frame of sengis by evaluating the impact of commonly varied parameters on tree dating. The results of the study show, that the mitochondrial information used in previous studies to temporal calibrate the Macroscelidean phylogeny led to an overestimation of node ages within sengis. Especially soft-furred sengis are thus much younger than previously assumed. The refined knowledge of nodes ages within sengis offer the opportunity to link e.g. speciation events to environmental changes.
Chapter 5 focuses on the genus Petrodromus with its single representative Petrodromus tetradactylus. It again exploits the opportunities of museomics and gathers a comprehensive, multi-locus genetic dataset of P. tetradactylus individuals, distributed across most the known range of this species. It reveals multiple deeply divergent lineages within Petrodromus, whereby some could possibly be associated to previously described sub-species, at least one was formerly unknown. It underscores the necessity for a revision of the genus Petrodromus through the integration of both molecular and morphological evidence. The study, furthermore identifies changing forest distributions through climatic oscillations as main factor shaping the genetic structure of Petrodromus.
Chapter 6 uses fresh tissue samples to extent the genomic resources of sengis by thirteen new nuclear genomes, of which two were de-novo assembled. An extensive dataset of more than 8000 protein coding one-to-one orthologs allows to further refine and confirm the temporal time frame of sengi evolution found in Chapter 4. This study moreover investigates the role of gene-flow and incomplete lineage sorting (ILS) in sengi evolution. In addition it identifies clade specific genes of possible outstanding evolutionary importance and links them to potential phenotypic traits affected. A closer investigation of olfactory receptor proteins reveals clade specific differences. A comparison of the demographic past of sengis to other small African mammals does not reveal a sengi specific pattern.
The urban heat island (UHI) effect, describing an elevated temperature of urban areas compared with their natural surroundings, can expose urban dwellers to additional heat stress, especially during hot summer days. A comprehensive understanding of the UHI dynamics along with urbanization is of great importance to efficient heat stress mitigation strategies towards sustainable urban development. This is, however, still challenging due to the difficulties of isolating the influences of various contributing factors that interact with each other. In this work, I present a systematical and quantitative analysis of how urban intrinsic properties (e.g., urban size, density, and morphology) influence UHI intensity.
To this end, we innovatively combine urban growth modelling and urban climate simulation to separate the influence of urban intrinsic factors from that of background climate, so as to focus on the impact of urbanization on the UHI effect. The urban climate model can create a laboratory environment which makes it possible to conduct controlled experiments to separate the influences from different driving factors, while the urban growth model provides detailed 3D structures that can be then parameterized into different urban development scenarios tailored for these experiments. The novelty in the methodology and experiment design leads to the following achievements of our work.
First, we develop a stochastic gravitational urban growth model that can generate 3D structures varying in size, morphology, compactness, and density gradient. We compare various characteristics, like fractal dimensions (box-counting, area-perimeter scaling, area-population scaling, etc.), and radial gradient profiles of land use share and population density, against those of real-world cities from empirical studies. The model shows the capability of creating 3D structures resembling real-world cities. This model can generate 3D structure samples for controlled experiments to assess the influence of some urban intrinsic properties in question. [Chapter 2]
With the generated 3D structures, we run several series of simulations with urban structures varying in properties like size, density and morphology, under the same weather conditions. Analyzing how the 2m air temperature based canopy layer urban heat island (CUHI) intensity varies in response to the changes of the considered urban factors, we find the CUHI intensity of a city is directly related to the built-up density and an amplifying effect that urban sites have on each other. We propose a Gravitational Urban Morphology (GUM) indicator to capture the neighbourhood warming effect. We build a regression model to estimate the CUHI intensity based on urban size, urban gross building volume, and the GUM indicator. Taking the Berlin area as an example, we show the regression model capable of predicting the CUHI intensity under various urban development scenarios. [Chapter 3]
Based on the multi-annual average summer surface urban heat island (SUHI) intensity derived from Land surface temperature, we further study how urban intrinsic factors influence the SUHI effect of the 5,000 largest urban clusters in Europe. We find a similar 3D GUM indicator to be an effective predictor of the SUHI intensity of these European cities. Together with other urban factors (vegetation condition, elevation, water coverage), we build different multivariate linear regression models and a climate space based Geographically Weighted Regression (GWR) model that can better predict SUHI intensity. By investigating the roles background climate factors play in modulating the coefficients of the GWR model, we extend the multivariate linear model to a nonlinear one by integrating some climate parameters, such as the average of daily maximal temperature and latitude. This makes it applicable across a range of background climates. The nonlinear model outperforms linear models in SUHI assessment as it captures the interaction of urban factors and the background climate. [Chapter 4]
Our work reiterates the essential roles of urban density and morphology in shaping the urban thermal environment. In contrast to many previous studies that link bigger cities with higher UHI intensity, we show that cities larger in the area do not necessarily experience a stronger UHI effect. In addition, the results extend our knowledge by demonstrating the influence of urban 3D morphology on the UHI effect. This underlines the importance of inspecting cities as a whole from the 3D perspective. While urban 3D morphology is an aggregated feature of small-scale urban elements, the influence it has on the city-scale UHI intensity cannot simply be scaled up from that of its neighbourhood-scale components. The spatial composition and configuration of urban elements both need to be captured when quantifying urban 3D morphology as nearby neighbourhoods also cast influences on each other. Our model serves as a useful UHI assessment tool for the quantitative comparison of urban intervention/development scenarios. It can support harnessing the capacity of UHI mitigation through optimizing urban morphology, with the potential of integrating climate change into heat mitigation strategies.
In this paper, we present data from an elicitation study and a corpus study that support the observation that the Yucatec Maya progressive aspect auxiliary táan is replaced by the habitual auxiliary k in sentences with contrastively focused fronted objects. Focus has been extensively studied in Yucatec, yet the incompatibility of object fronting and progressive aspect in Yucatec Maya remains understudied. Both our experimental results and our corpus study point in the direction that this incompatibility may very well be categorical. Theoretically, we take a progressive reading to be derived from an imperfectivity operator in combination with a singular operator, and we propose that this singular operator implicates the negation of event plurality, leading to an exhaustive interpretation which ranks below corrective focus on a contrastive focus scale. This means that, in a sentence with object focus fronting, the use of the marked auxiliary táan (as opposed to the more general k) would trigger two contrastive foci, which would be an unlikely and probably dispreferred speech act.
This thesis presents an attempt to use source code synthesised from Coq formalisations of device drivers for existing (micro)kernel operating systems, with a particular focus on the Linux Kernel.
In the first part, the technical background and related work are described. The focus is here on the possible approaches to synthesising certified software with Coq, namely the extraction to functional languages using the Coq extraction plugin and the extraction to Clight code using the CertiCoq plugin. It is noted that the implementation of CertiCoq is verified, whereas this is not the case for the Coq extraction plugin. Consequently, there is a correctness guarantee for the generated Clight code which does not hold for the code being generated by the Coq extraction plugin. Furthermore, the differences between user space and kernel space software are discussed in relation to Linux device drivers. It is elaborated that it is not possible to generate working Linux kernel module components using the Coq extraction plugin without significant modifications. In contrast, it is possible to produce working user space drivers both with the Coq extraction plugin and CertiCoq. The subsequent parts describe the main contributions of the thesis.
In the second part, it is demonstrated how to extend the Coq extraction plugin to synthesise foreign function calls between the functional language OCaml and the imperative language C. This approach has the potential to improve the type-safety of user space drivers. Furthermore, it is shown that the code being synthesised by CertiCoq cannot be used in kernel space without modifications to the necessary runtime. Consequently, the necessary modifications to the runtimes of CertiCoq and VeriFFI are introduced, resulting in the runtimes becoming compatible components of a Linux kernel module. Furthermore, justifications for the transformations are provided and possible further extensions to both plugins and solutions to failing garbage collection calls in kernel space are discussed.
The third part presents a proof of concept device driver for the Linux Kernel. To achieve this, the event handler of the original PC Speaker driver is partially formalised in Coq. Furthermore, some relevant formal properties of the formalised functionality are discussed. Subsequently, a kernel module is defined, utilising the modified variants of CertiCoq and VeriFFI to compile a working device driver. It is furthermore shown that it is possible to compile the synthesised code with CompCert, thereby extending the guarantee of correctness to the assembly layer. This is followed by a performance evaluation that compares a naive formalisation of the PC speaker functionality with the original PC Speaker driver pointing out the weaknesses in the formalisation and possible improvements. The part closes with a summary of the results, their implications and open questions being raised.
The last part lists all used sources, separated into scientific literature, documentations or reference manuals and artifacts, i.e. source code.
Off-road adventures
(2024)
This article focuses on the visual qualities of Alexander von Humboldt’s statistical tables in his Political Essay on the Kingdom of New Spain (1808–1811, 2nd ed. 1825–1827) with special attention to how such composites of numbers, alphabetical script, and semiotic elements relate to narrative writing. I argue that Humboldt’s tables/tableaus open up spaces inside his narrative that fragment the reading process, inviting new conversations, connections, and ideas.
The remarkable antifouling properties of zwitterionic polymers in controlled environments are often counteracted by their delicate mechanical stability. In order to improve the mechanical stabilities of zwitterionic hydrogels, the effect of increased crosslinker densities was thus explored. In a first approach, terpolymers of zwitterionic monomer 3-[N -2(methacryloyloxy)ethyl-N,N-dimethyl]ammonio propane-1-sulfonate (SPE), hydrophobic monomer butyl methacrylate (BMA), and photo-crosslinker 2-(4-benzoylphenoxy)ethyl methacrylate (BPEMA) were synthesized. Thin hydrogel coatings of the copolymers were then produced and photo-crosslinked. Studies of the swollen hydrogel films showed that not only the mechanical stability but also, unexpectedly, the antifouling properties were improved by the presence of hydrophobic BMA units in the terpolymers.
Based on the positive results shown by the amphiphilic terpolymers and in order to further test the impact that hydrophobicity has on both the antifouling properties of zwitterionic hydrogels and on their mechanical stability, a new amphiphilic zwitterionic methacrylic monomer, 3-((2-(methacryloyloxy)hexyl)dimethylammonio)propane-1-sulfonate (M1), was synthesized in good yields in a multistep synthesis. Homopolymers of M1 were obtained by free-radical polymerization. Similarly, terpolymers of M1, zwitterionic monomer SPE, and photo-crosslinker BPEMA were synthesized by free-radical copolymerization and thoroughly characterized, including its solubilities in selected solvents.
Also, a new family of vinyl amide zwitterionic monomomers, namely 3-(dimethyl(2-(N -vinylacetamido)ethyl)ammonio)propane-1-sulfonate (M2), 4-(dimethyl(2-(N-vinylacetamido)ethyl)ammonio)butane-1-sulfonate (M3), and 3-(dimethyl(2-(N-vinylacetamido)ethyl)ammonio)propyl sulfate (M4), together with the new photo-crosslinker 4-benzoyl-N-vinylbenzamide (M5) that is well-suited for copolymerization with vinylamides, are introduced within the scope of the present work. The monomers are synthesized with good yields developing a multistep synthesis. Homopolymers of the new vinyl amide zwitterionic monomers are obtained by free-radical polymerization and thoroughly characterized. From the solubility tests, it is remarkable that the homopolymers produced are fully soluble in water, evidence of their high hydrophilicity. Copolymerization of the vinyl amide zwitterionic monomers, M2, M3, and M4 with the vinyl amide photo-crosslinker M5 proved to require very specific polymerization conditions. Nevertheless, copolymers were successfully obtained by free-radical copolymerization under appropriate conditions.
Moreover, in an attempt to mitigate the intrinsic hydrophobicity introduced in the copolymers by the photo-crosslinkers, and based on the proven affinity of quaternized diallylamines to copolymerize with vinyl amides, a new quaternized diallylamine sulfobetaine photo-crosslinker 3-(diallyl(2-(4-benzoylphenoxy)ethyl)ammonio)propane-1-sulfonate (M6) is synthesized. However, despite a priori promising copolymerization suitability, copolymerization with the vinyl amide zwitterionic monomers could not be achieved.
Die deutsch-kubanische Forschungs- und Digitalisierungsinitiative „Proyecto Humboldt Digital“ (ProHD) hat während ihrer Projektlaufzeit (2019–2023) wichtige Quellen zum Thema „Humboldt und Kuba“ erstmals digital erschlossen. Als Kooperation zwischen der Berlin-Brandenburgischen Akademie der Wissenschaften und der Oficina del Historiador de la Ciudad de La Habana hat ProHD damit wichtige Akzente für die Archivdigitalisierung, die digitale Editionsphilologie und die digitale Wissenschaftskommunikation in Kuba gesetzt. Das Korpus der erschlossenen Bestände wird hier in fünf Schlaglichtern vorgestellt: 1) Quellen zur Humboldt’schen Forschungsreise, 2) Juan Luis de la Cuesta, 3) Materialien zu Kuba aus dem Humboldt-Nachlass, 4) Zensur und Beschlagnahme des Essai politique sur l’île de Cuba, 5) Francisco de Arango y Parreño.
Navigating the unknown
(2024)
Visionary leadership is considered to be one of the most important elements of effective leadership. Among other things, it is related to followers' perceived meaningfulness of their work. However, little is known about whether uncertainty in the workplace affects visionary leadership's effects. Given that uncertainty is rising in many, if not most, workplaces, it is vital to understand whether this development influences the extent to which visionary leadership is associated with followers' perceived meaningfulness. In a two-source, lagged design field study of 258 leader-follower dyads from different settings, we show that uncertainty moderates the relation between visionary leadership and followers' perceived meaningfulness such that this relation is more strongly positive when uncertainty is high, rather than low. Moreover, we show that with increasing uncertainty, visionary leadership is more negatively related to followers' turnover intentions via perceived meaningfulness. This research broadens our understanding of how visionary leadership may be a particularly potent tool in times of increasing uncertainty.
La traduction en langue chinoise du premier volume du monumental ouvrage scientifique d'Alexander von Humboldt, intitulé «Cosmos», a vu le jour en 2023 sous l՚égide de la prestigieuse maison d՚édition de l՚Université de Pékin. Dans sa postface éclairée, la traductrice émérite, Gao Hong, éclaire la lanterne des lecteurs chinois sur la fresque cosmique esquissée par Humboldt, révélant ainsi les intrications entre les phénomènes naturels et leur pertinence à l՚échelle de l'univers tout entier. Gao Hong narre son propre périple aux côtés de Humboldt, tout en distillant ses réflexions personnelles sur cette fresque cosmique. «Cosmos» d՚Humboldt, œuvre scientifique par excellence, transcende également les sphères esthétiques et artistiques, exprimant invariablement une profonde vénération pour l՚univers. Restituer en chinois la «beauté géométrique» de la langue allemande, empreinte d՚une rigueur structurelle, constitue un défi singulier, le chinois se caractérisant par sa fluidité, sa souplesse et sa poésie imagée, en totale antithèse avec l՚allemand. En qualité de traducteur, il importe de naviguer librement entre ces deux mondes linguistiques distincts.
Die Zusammenarbeit zwischen Lehr- und anderen Fachkräften stellt in Modellen inklusiver Schul- und Unterrichtsentwicklung sowie Schuleffektivität ein wichtiges Element dar. Wenngleich Kooperation als bedeutsam postuliert wird, so belegen Studien, dass diese bisher überwiegend in autonomieerhaltenden Formen praktiziert wird. Als entwicklungsförderlich gelten jedoch v.a. komplexere Formen der Zusammenarbeit. Vor dem Hintergrund inklusiver Bildung und dem Anspruch einer bestmöglichen individuellen Entwicklung der Schüler*innen stellt die Zusammenarbeit von Lehr- und Fachkräften folglich ein sehr bedeutsames Thema dar. Es ist zu hinterfragen, wie sich die Zusammenarbeit zwischen Lehr- und Fachkräften im Primar- wie Sekundarstufenbereich an inklusiven Schulen gestaltet, welche Faktoren diese beeinflussen und welche Relevanz die unterschiedlichen Formen der Zusammenarbeit im Prozess inklusiver Schulentwicklung einnehmen. Bestehende Forschungsdesiderata aufgrei-fend, fokussiert die vorliegende Dissertation auf die realisierte Zusammenarbeit von Lehr- und Fachkräften im Primar- und Sekundarstufenbereich inklusiver Schulen, am Beispiel des Landes Brandenburg. Neben den realisierten Formen der Zusammenarbeit, stehen insbesondere die Identifikation von Kooperationsmustern von Lehr- und Fachkräften sowie von Schulen, und deren Zusammenhänge mit der Leistungsentwicklung von Schüler*innen im Kern des Forschungsinteresses.
Die vorliegende Dissertation bearbeitet insgesamt sechs Forschungsfragen, welche in drei Teilstudien adressiert werden: Zunächst werden mittels deskriptiver Analysen sowie Mehrebenenmodellierungen die Ausgangslage multiprofessioneller Kooperation (erste Forschungsfrage) sowie deren Rahmenbedingungen (zweite Forschungsfrage) im Primar- wie Sekundarstufenbereich erfasst (Teilstudie 1). Lehr- und Fachkräfte kooperierten überwiegend in autonomieerhaltenden, austauschbasierten Formen. Weiterhin zeigte sich, dass insbesondere die individuelle Offenheit zur Zusammenarbeit sowie die subjektiv wahrgenommene Unterstützung durch die Schulleitung bedeutsame Faktoren für die Realisierung multiprofessioneller Kooperation darstellten. Die Fragestellungen drei und vier befassen sich mit der Identifikation von Mustern im Kooperationsverhalten (Teilstudie 2). Zum einen geht es hierbei um personenbezogene Profile von Lehr- und Fachkräften (dritte Forschungsfrage), zum anderen um schulbezogene Profile (vierte Forschungsfrage), welche mittels des personenzentrierten Ansatzes der latenten Profilanalysen unter Berücksichtigung der Mehrebenenstruktur identifiziert werden. Hinsichtlich des individuellen Kooperationsverhaltens konnten vier Profile eruiert werden, bzgl. des schulspezifischen Kooperationsverhaltens drei. Die Mehrheit der Lehr- und Fachkräfte konnte im „regularly“-Profil verortet werden, d.h. nach eigener Einschätzung kooperierten diese überdurchschnittlich häufig im Austausch miteinander und arbeitsteilig, aber auch regelmäßig kokonstruktiv. Auf Schulebene zeigte sich, dass etwa jede zweite inklusive Schule im Land Brandenburg über eine hoch ausgeprägte Kooperationskultur verfügte. Im Fokus der Teilstudie 3 wird den Fragen nachgegangen, in welchem Zusammenhang die schulspezifischen Kooperationskulturen mit der Leistungsentwicklung von Schüler*innen in der Primar- wie Sekundarstufe steht. Mittels autoregressiver Mehrebenenanalysen wird einerseits der Zusammenhang mit der Leistungsentwicklung aller Schüler*innen (fünfte Forschungsfrage) untersucht, sowie spezifisch auf die Entwicklung von Schüler*innen mit und ohne sonderpädagogischem Förderbedarf (sechste Forschungsfrage) fokussiert. Ein zentrales Ergebnis war hierbei, dass Schüler*innen mit sonderpädagogischem Förderbedarf in der Primar- wie Sekundarstufe in ihrer Leistungsentwicklung am stärksten profitierten, wenn sie an Schulen lernten, an denen sich die Lehr- und Fachkräfte sehr regelmäßig über Lernstände der Schüler*innen austauschten (Austausch), Arbeitspakete für differenzierte Lernangebote erarbeiteten und verteilten (Arbeitsteilung) und darüber hinaus gelegentlich gemeinsam Problemlösungen entwickelten (Kokonstruktion).
Die Ergebnisse werden vor dem Hintergrund der postulierten Relevanz multiprofessioneller Kooperation für inklusive Schul- und Unterrichtsentwicklungsprozesse eingeordnet und diskutiert. Weiterhin werden verschiedene praktische Implikationen für die Unterstützung multiprofessioneller Zusammenarbeit im Primar- und Sekundarstufenbereich abgeleitet.
Motivation and Emotion in Learning and Teaching across Educational Contexts brings together current theoretical and methodological perspectives as well as examples of empirical implementations from leading international researchers focusing on the context specificity and situatedness of their core theories in motivation and emotion.
The book is compiled of two main sections. Section I covers theoretical reflections and perspectives on the main theories on emotion and motivation in learning and teaching and their transferability across different educational contexts illustrated with empirical examples. Section II addresses the methodological reflections and perspectives on the methodology that is needed to address the complexity and context specificity of motivation and emotion. In addition to general reflections and perspectives regarding methodology, concrete empirical examples are provided. All cutting-edge chapters include current empirical studies on emotions and motivation in learning and teaching across different contexts (age groups, domains, countries, etc.) making them applicable and relevant to a wide range of contexts and settings.
This high-quality volume with contributions from leading international experts will be an essential resource for researchers, students and teacher trainers interested in the vital role that motivation and emotions can play in education.
Moss-microbe associations are often characterised by syntrophic interactions between the microorganisms and their hosts, but the structure of the microbial consortia and their role in peatland development remain unknown.
In order to study microbial communities of dominant peatland mosses, Sphagnum and brown mosses, and the respective environmental drivers, four study sites representing different successional stages of natural northern peatlands were chosen on a large geographical scale: two brown moss-dominated, circumneutral peatlands from the Arctic and two Sphagnum-dominated, acidic peat bogs from subarctic and temperate zones.
The family Acetobacteraceae represented the dominant bacterial taxon of Sphagnum mosses from various geographical origins and displayed an integral part of the moss core community. This core community was shared among all investigated bryophytes and consisted of few but highly abundant prokaryotes, of which many appear as endophytes of Sphagnum mosses. Moreover, brown mosses and Sphagnum mosses represent habitats for archaea which were not studied in association with peatland mosses so far. Euryarchaeota that are capable of methane production (methanogens) displayed the majority of the moss-associated archaeal communities. Moss-associated methanogenesis was detected for the first time, but it was mostly negligible under laboratory conditions. Contrarily, substantial moss-associated methane oxidation was measured on both, brown mosses and Sphagnum mosses, supporting that methanotrophic bacteria as part of the moss microbiome may contribute to the reduction of methane emissions from pristine and rewetted peatlands of the northern hemisphere.
Among the investigated abiotic and biotic environmental parameters, the peatland type and the host moss taxon were identified to have a major impact on the structure of moss-associated bacterial communities, contrarily to archaeal communities whose structures were similar among the investigated bryophytes. For the first time it was shown that different bog development stages harbour distinct bacterial communities, while at the same time a small core community is shared among all investigated bryophytes independent of geography and peatland type.
The present thesis displays the first large-scale, systematic assessment of bacterial and archaeal communities associated both with brown mosses and Sphagnum mosses. It suggests that some host-specific moss taxa have the potential to play a key role in host moss establishment and peatland development.
Money matters!
(2024)
This paper examines the context dependency of attitudes toward maternal employment. We test three sets of factors that may affect these attitudes—economic benefits, normative obligations, and child-related consequences—by analyzing data from a unique survey experimental design implemented in a large-scale household panel survey in Germany (17,388 observations from 3,494 respondents). Our results show that the economic benefits associated with maternal employment are the most important predictor of attitudes supporting maternal employment. Moreover, we find that attitudes toward maternal employment vary by individual, household, and contextual characteristics (in particular, childcare quality). We interpret this variation as an indication that negative attitudes toward maternal employment do not necessarily reflect gender essentialism; rather, gender role attitudes are contingent upon the frames individuals have in mind.
This chapter provides an overview of methods to capture developments and changes in motivational beliefs. Motivational research has recently begun to venture beyond just examining average developmental trends in motivational variables by starting to investigate how developmental changes in motivational variables differ between and within individuals in different learning situations and across contexts. Although studies have started to uncover differences in motivational changes, a systematic overview of suitable methods for capturing motivational differences in developmental processes is still missing. In this chapter, we review key methods of change modelling, bringing together variable-centred approaches, such as growth modelling and true intraindividual change (TIC) models, and person-centred approaches, such as latent transition and growth mixture models. We illustrate the value of the reviewed statistical methods for the analysis of context-specific motivational changes by reviewing recent empirical studies that identify different patterns and trajectories of such motivational beliefs across time. Our focus is thereby on research grounded in situated expectancy-value theory as a core theory in motivational research.
To manage tabular data files and leverage their content in a given downstream task, practitioners often design and execute complex transformation pipelines to prepare them. The complexity of such pipelines stems from different factors, including the nature of the preparation tasks, often exploratory or ad-hoc to specific datasets; the large repertory of tools, algorithms, and frameworks that practitioners need to master; and the volume, variety, and velocity of the files to be prepared. Metadata plays a fundamental role in reducing this complexity: characterizing a file assists end users in the design of data preprocessing pipelines, and furthermore paves the way for suggestion, automation, and optimization of data preparation tasks.
Previous research in the areas of data profiling, data integration, and data cleaning, has focused on extracting and characterizing metadata regarding the content of tabular data files, i.e., about the records and attributes of tables. Content metadata are useful for the latter stages of a preprocessing pipeline, e.g., error correction, duplicate detection, or value normalization, but they require a properly formed tabular input. Therefore, these metadata are not relevant for the early stages of a preparation pipeline, i.e., to correctly parse tables out of files. In this dissertation, we turn our focus to what we call the structure of a tabular data file, i.e., the set of characters within a file that do not represent data values but are required to parse and understand the content of the file. We provide three different approaches to represent file structure, an explicit representation based on context-free grammars; an implicit representation based on file-wise similarity; and a learned representation based on machine learning.
In our first contribution, we use the grammar-based representation to characterize a set of over 3000 real-world csv files and identify multiple structural issues that let files deviate from the csv standard, e.g., by having inconsistent delimiters or containing multiple tables. We leverage our learnings about real-world files and propose Pollock, a benchmark to test how well systems parse csv files that have a non-standard structure, without any previous preparation. We report on our experiments on using Pollock to evaluate the performance of 16 real-world data management systems.
Following, we characterize the structure of files implicitly, by defining a measure of structural similarity for file pairs. We design a novel algorithm to compute this measure, which is based on a graph representation of the files' content. We leverage this algorithm and propose Mondrian, a graphical system to assist users in identifying layout templates in a dataset, classes of files that have the same structure, and therefore can be prepared by applying the same preparation pipeline.
Finally, we introduce MaGRiTTE, a novel architecture that uses self-supervised learning to automatically learn structural representations of files in the form of vectorial embeddings at three different levels: cell level, row level, and file level. We experiment with the application of structural embeddings for several tasks, namely dialect detection, row classification, and data preparation efforts estimation.
Our experimental results show that structural metadata, either identified explicitly on parsing grammars, derived implicitly as file-wise similarity, or learned with the help of machine learning architectures, is fundamental to automate several tasks, to scale up preparation to large quantities of files, and to provide repeatable preparation pipelines.
The evaluation of process-oriented cognitive theories through time-ordered observations is crucial for the advancement of cognitive science. The findings presented herein integrate insights from research on eye-movement control and sentence comprehension during reading, addressing challenges in modeling time-ordered data, statistical inference, and interindividual variability. Using kernel density estimation and a pseudo-marginal likelihood for fixation durations and locations, a likelihood implementation of the SWIFT model of eye-movement control during reading (Engbert et al., Psychological Review, 112, 2005, pp. 777–813) is proposed. Within the broader framework of data assimilation, Bayesian parameter inference with adaptive Markov Chain Monte Carlo techniques is facilitated for reliable model fitting. Across the different studies, this framework has shown to enable reliable parameter recovery from simulated data and prediction of experimental summary statistics. Despite its complexity, SWIFT can be fitted within a principled Bayesian workflow, capturing interindividual differences and modeling experimental effects on reading across different geometrical alterations of text. Based on these advancements, the integrated dynamical model SEAM is proposed, which combines eye-movement control, a traditionally psychological research area, and post-lexical language processing in the form of cue-based memory retrieval (Lewis & Vasishth, Cognitive Science, 29, 2005, pp. 375–419), typically the purview of psycholinguistics. This proof-of-concept integration marks a significant step forward in natural language comprehension during reading and suggests that the presented methodology can be useful to develop complex cognitive dynamical models that integrate processes at levels of perception, higher cognition, and (oculo-)motor control. These findings collectively advance process-oriented cognitive modeling and highlight the importance of Bayesian inference, individual differences, and interdisciplinary integration for a holistic understanding of reading processes. Implications for theory and methodology, including proposals for model comparison and hierarchical parameter inference, are briefly discussed.
The European Water Framework Directive (WFD) has identified river morphological alteration and diffuse pollution as the two main pressures affecting water bodies in Europe at the catchment scale. Consequently, river restoration has become a priority to achieve the WFD's objective of good ecological status. However, little is known about the effects of stream morphological changes, such as re-meandering, on in-stream nitrate retention at the river network scale. Therefore, catchment nitrate modeling is necessary to guide the implementation of spatially targeted and cost-effective mitigation measures. Meanwhile, Germany, like many other regions in central Europe, has experienced consecutive summer droughts from 2015-2018, resulting in significant changes in river nitrate concentrations in various catchments. However, the mechanistic exploration of catchment nitrate responses to changing weather conditions is still lacking.
Firstly, a fully distributed, process-based catchment Nitrate model (mHM-Nitrate) was used, which was properly calibrated and comprehensively evaluated at numerous spatially distributed nitrate sampling locations. Three calibration schemes were designed, taking into account land use, stream order, and mean nitrate concentrations, and they varied in spatial coverage but used data from the same period (2011–2019). The model performance for discharge was similar among the three schemes, with Nash-Sutcliffe Efficiency (NSE) scores ranging from 0.88 to 0.92. However, for nitrate concentrations, scheme 2 outperformed schemes 1 and 3 when compared to observed data from eight gauging stations. This was likely because scheme 2 incorporated a diverse range of data, including low discharge values and nitrate concentrations, and thus provided a better representation of within-catchment heterogenous. Therefore, the study suggests that strategically selecting gauging stations that reflect the full range of within-catchment heterogeneity is more important for calibration than simply increasing the number of stations.
Secondly, the mHM-Nitrate model was used to reveal the causal relations between sequential droughts and nitrate concentration in the Bode catchment (3200 km2) in central Germany, where stream nitrate concentrations exhibited contrasting trends from upstream to downstream reaches. The model was evaluated using data from six gauging stations, reflecting different levels of runoff components and their associated nitrate-mixing from upstream to downstream. Results indicated that the mHM-Nitrate model reproduced dynamics of daily discharge and nitrate concentration well, with Nash-Sutcliffe Efficiency ≥ 0.73 for discharge and Kling-Gupta Efficiency ≥ 0.50 for nitrate concentration at most stations. Particularly, the spatially contrasting trends of nitrate concentration were successfully captured by the model. The decrease of nitrate concentration in the lowland area in drought years (2015-2018) was presumably due to (1) limited terrestrial export loading (ca. 40% lower than that of normal years 2004-2014), and (2) increased in-stream retention efficiency (20% higher in summer within the whole river network). From a mechanistic modelling perspective, this study provided insights into spatially heterogeneous flow and nitrate dynamics and effects of sequential droughts, which shed light on water-quality responses to future climate change, as droughts are projected to be more frequent.
Thirdly, this study investigated the effects of stream restoration via re-meandering on in-stream nitrate retention at network-scale in the well-monitored Bode catchment. The mHM-Nitrate model showed good performance in reproducing daily discharge and nitrate concentrations, with median Kling-Gupta values of 0.78 and 0.74, respectively. The mean and standard deviation of gross nitrate retention efficiency, which accounted for both denitrification and assimilatory uptake, were 5.1 ± 0.61% and 74.7 ± 23.2% in winter and summer, respectively, within the stream network. The study found that in the summer, denitrification rates were about two times higher in lowland sub-catchments dominated by agricultural lands than in mountainous sub-catchments dominated by forested areas, with median ± SD of 204 ± 22.6 and 102 ± 22.1 mg N m-2 d-1, respectively. Similarly, assimilatory uptake rates were approximately five times higher in streams surrounded by lowland agricultural areas than in those in higher-elevation, forested areas, with median ± SD of 200 ± 27.1 and 39.1 ± 8.7 mg N m-2 d-1, respectively. Therefore, restoration strategies targeting lowland agricultural areas may have greater potential for increasing nitrate retention. The study also found that restoring stream sinuosity could increase net nitrate retention efficiency by up to 25.4 ± 5.3%, with greater effects seen in small streams. These results suggest that restoration efforts should consider augmenting stream sinuosity to increase nitrate retention and decrease nitrate concentrations at the catchment scale.
While Information Systems Research exists at the individual and workgroup levels, research on IS at the enterprise level is less common. The potential synergies between the study of enterprise systems (ES) and related fields have been underexplored and often treated as separate entities. The ongoing challenge is to seamlessly integrate technological advances and align business processes across organizations. While systems integration within an organization is common, changes occur when industry and ecosystem perspectives come into play. The four selected papers address different facets of the future role of enterprise ecosystems, including implementation challenges, ecosystem boundaries, and B2B platform specifics.
Mindful Eating
(2024)
Maladaptive eating behaviors such as emotional eating, external eating, and loss-of-control eating are widespread in the general population. Moreover, they are associated to adverse health outcomes and well-known for their role in the development and maintenance of eating disorders and obesity (i.e., eating and weight disorders). Eating and weight disorders are associated with crucial burden for individuals as well as high costs for society in general. At the same time, corresponding treatments yield poor outcomes. Thus, innovative concepts are needed to improve prevention and treatment of these conditions.
The Buddhist concept of mindfulness (i.e., paying attention to the present moment without judgement) and its delivery via mindfulness-based intervention programs (MBPs) has gained wide popularity in the area of maladaptive eating behaviors and associated eating and weight disorders over the last two decades. Though previous findings on their effects seem promising, the current assessment of mindfulness and its mere application via multi-component MBPs hampers to draw conclusions on the extent to which mindfulness-immanent qualities actually account for the effects (e.g., the modification of maladaptive eating behaviors). However, this knowledge is pivotal for interpreting previous effects correctly and for avoiding to cause harm in particularly vulnerable groups such as those with eating and weight disorders.
To address these shortcomings, recent research has focused on the context-specific approach of mindful eating (ME) to investigate underlying mechanisms of action. ME can be considered a subdomain of generic mindfulness describing it specifically in relation to the process of eating and associated feelings, thoughts, and motives, thus including a variety of different attitudes and behaviors. However, there is no universal operationalization and the current assessment of ME suffers from different limitations. Specifically, current measurement instruments are not suited for a comprehensive assessment of the multiple facets of the construct that are currently discussed as important in the literature. This in turn hampers comparisons of different ME facets which would allow to evaluate their particular effect on maladaptive eating behaviors. This knowledge is needed to tailor prevention and treatment of associated eating and weight disorders properly and to explore potential underlying mechanisms of action which have so far been proposed mainly on theoretical grounds.
The dissertation at hand aims to provide evidence-based fundamental research that contributes to our understanding of how mindfulness, more specifically its context-specific form of ME, impacts maladaptive eating behaviors and, consequently, how it could be used appropriately to enrich the current prevention and treatment approaches for eating and weight disorders in the future.
Specifically, in this thesis, three scientific manuscripts applying several qualitative and quantitative techniques in four sequential studies are presented. These manuscripts were published in or submitted to three scientific peer-reviewed journals to shed light on the following questions:
I. How can ME be measured comprehensively and in a reliable and valid way to advance the understanding of how mindfulness works in the context of eating?
II. Does the context-specific construct of ME have an advantage over the generic concept in advancing the understanding of how mindfulness is related to maladaptive eating behaviors?
III. Which ME facets are particularly useful in explaining maladaptive eating behaviors?
IV. Does training a particular ME facet result in changes in maladaptive eating behaviors?
To answer the first research question (Paper 1), a multi-method approach using three subsequent studies was applied to develop and validate a comprehensive self-report instrument to assess the multidimensional construct of ME - the Mindful Eating Inventory (MEI). Study 1 aimed to create an initial version of the MEI by following a three-step approach: First, a comprehensive item pool was compiled by including selected and adapted items of the existing ME questionnaires and supplementing them with items derived from an extensive literature review. Second, the preliminary item pool was complemented and checked for content validity by experts in the field of eating behavior and/or mindfulness (N = 15). Third, the item pool was further refined through qualitative methods: Three focus groups comprising laypersons (N = 16) were used as a check for applicability. Subsequently, think-aloud protocols (N = 10) served as a last check of comprehensibility and elimination of ambiguities.
The resulting initial MEI version was tested in Study 2 in an online convenience sample (N = 828) to explore its factor structure using exploratory factor analysis (EFA). Results were used to shorten the questionnaire in accordance with qualitative and quantitative criteria yielding the final MEI version which encompasses 30 items. These items were assigned to seven ME facets: (1) ‘Accepting and Non-attached Attitude towards one’s own eating experience’ (ANA), (2) ‘Awareness of Senses while Eating’ (ASE), (3) ‘Eating in Response to awareness of Fullness‘ (ERF), (4) ‘Awareness of eating Triggers and Motives’ (ATM), (5) ‘Interconnectedness’ (CON), (6) ‘Non-Reactive Stance’ (NRS) and (7) Focused Attention on Eating’ (FAE).
Study 3 sought to confirm the found facets and the corresponding factor structure in an independent online convenience sample (N = 612) using confirmatory factor analysis (CFA). The study served as further indication of the assumed multidimensionality of ME (the correlational seven-factor model was shown to be superior to a single-factor model). Psychometric properties of the MEI, regarding factorial validity, internal consistency, retest-reliability, and observed criterion validity using a wide range of eating-specific and general health-related outcomes, showed the inventory to be suitable for a comprehensive, reliable and valid assessment of ME. These findings were complemented by demonstrating measurement invariance of the MEI regarding gender. In accordance with the factor structure of the MEI, Paper 1 offers an empirically-derived definition of ME, succeeding in overcoming ambiguities and problems of previous attempts at defining the construct.
To answer the second and third research questions (Paper 2) a subsample of Study 2 from the MEI validation studies (N = 292) was analyzed. Incremental validity of ME beyond generic mindfulness was shown using hierarchical regression models concerning the outcome variables of maladaptive eating behaviors (emotional eating and uncontrolled eating) and nutrition behaviors (consumption of energy-dense food). Multiple regression analyses were applied to investigate the impact of the seven different ME facets (identified in Paper 1) on the same outcome variables. The following ME facets significantly contributed to explaining variance in maladaptive eating and nutrition behaviors: Accepting and Non-attached Attitude towards one`s own eating experience (ANA), Eating in Response to awareness of Fullness (ERF), the Awareness of eating Triggers and Motives (ATM), and a Non-Reactive Stance (NRS, i.e., an observing, non-impulsive attitude towards eating triggers). Results suggest that these ME facets are promising variables to consider when a) investigating potential underlying mechanisms of mindfulness and MBPs in the context of eating and b) addressing maladaptive eating behaviors in general as well as in the prevention and treatment of eating and weight disorders.
To answer the fourth research question (Paper 3), a training on an isolated exercise (‘9 Hunger’) based on the previously identified ME facet ATM was designed to explore its particular association with changes in maladaptive eating behaviors and thus to preliminary explore one possible mechanism of action. The online study was realized using a randomized controlled trial (RCT) design. Latent Change Scores (LCS) across three measurement points (before the training, directly after the training and three months later) were compared between the intervention group (n = 211) and a waitlist control group (n = 188). Short- and longer-term effects of the training could be shown on maladaptive eating behaviors (emotional eating, external eating, loss-of-control eating) and associated outcomes (intuitive eating, ME, self-compassion, well-being). Findings serve as preliminary empirical evidence that MBPs might influence maladaptive eating behaviors through an enhanced non-judgmental awareness of and distinguishment between eating motives and triggers (i.e., ATM). This mechanism of action had previously only been hypothesized from a theoretical perspective. Since maladaptive eating behaviors are associated with eating and weight disorders, the findings can enhance our understanding of the general effects of MBPs on these conditions.
The integration of the different findings leads to several suggestions of how ME might enrich different kinds of future interventions on maladaptive eating behaviors to improve health in general or the prevention and treatment of eating and weight disorders in particular. Strengths of the thesis (e.g., deliberate specific methodology, variety of designs and methods, high number of participants) are emphasized. The main limitations particularly regarding sample characteristics (e.g., higher level of formal education, fewer males, self-selected) are discussed to arrive at an outline for future studies (e.g., including multi-modal-multi-method approaches, clinical eating disorder samples and youth samples) to improve upcoming research on ME and underlying mechanisms of action of MBPs for maladaptive eating behaviors and associated eating and weight disorders.
This thesis enriches current research on mindfulness in the context of eating by providing fundamental research on the core of the ME construct. Thereby it delivers a reliable and valid instrument to comprehensively assess ME in future studies as well as an operational definition of the construct. Findings on ME facet level might inform upcoming research and practice on how to address maladaptive eating behaviors appropriately in interventions. The ME skill ‘Awareness of eating Triggers and Motives (ATM)’ as one particular mechanism of action should be further investigated in representative community and specific clinical samples to examine the validity of the results in these groups and to justify an application of the concept to the general population as well as to subgroups with eating and weight disorders in particular.
In conclusion, findings of the current thesis can be used to set future research on mindfulness, more specifically ME, and its underlying mechanism in the context of eating on a more evidence-based footing. This knowledge can inform upcoming prevention and treatment to tailor MBPs on maladaptive eating behaviors and associated eating and weight disorders appropriately.
This dissertation examines the lack of clarity in the scientific literature regarding gender and negotiation performance. It is often claimed that men negotiate better than women, yet it is simultaneously emphasized that results strongly depend on context. Through the use of qualitative methods such as content analysis and critical mixed-methods review, the research question: "Are women truly inferior negotiators compared to men?" is addressed. The study comprises a descriptive and an interpretive part. The descriptive section illuminates various interpretations of gender-specific negotiation theory among citing authors, with 67% arguing for a general superiority of men. However, given the high variance in gender-specific differences, the focus should instead be on the context-dependency of negotiation performance. Generalized statements can be made within contexts, but not across them. In the interpretive section, several factors contributing to this misinterpretation are highlighted, including discrepancies in the definition of negotiation performance and distortions in research communication.. From a scientific perspective, this study underscores the need for a nuanced sociological analysis and warns against the one-sided acceptance of inaccurate scientific interpretations. From a practical standpoint, it amplifies the voices of women affected by biased research paradigms. Overall, the dissertation clarifies the theory of gender-specific negotiation performance and advocates for the elimination of biases in scientific discourse.
The wide distribution of location-acquisition technologies means that large volumes of spatio-temporal data are continuously being accumulated. Positioning systems such as GPS enable the tracking of various moving objects' trajectories, which are usually represented by a chronologically ordered sequence of observed locations. The analysis of movement patterns based on detailed positional information creates opportunities for applications that can improve business decisions and processes in a broad spectrum of industries (e.g., transportation, traffic control, or medicine). Due to the large data volumes generated in these applications, the cost-efficient storage of spatio-temporal data is desirable, especially when in-memory database systems are used to achieve interactive performance requirements.
To efficiently utilize the available DRAM capacities, modern database systems support various tuning possibilities to reduce the memory footprint (e.g., data compression) or increase performance (e.g., additional indexes structures). By considering horizontal data partitioning, we can independently apply different tuning options on a fine-grained level. However, the selection of cost and performance-balancing configurations is challenging, due to the vast number of possible setups consisting of mutually dependent individual decisions.
In this thesis, we introduce multiple approaches to improve spatio-temporal data management by automatically optimizing diverse tuning options for the application-specific access patterns and data characteristics. Our contributions are as follows:
(1) We introduce a novel approach to determine fine-grained table configurations for spatio-temporal workloads. Our linear programming (LP) approach jointly optimizes the (i) data compression, (ii) ordering, (iii) indexing, and (iv) tiering. We propose different models which address cost dependencies at different levels of accuracy to compute optimized tuning configurations for a given workload, memory budgets, and data characteristics. To yield maintainable and robust configurations, we further extend our LP-based approach to incorporate reconfiguration costs as well as optimizations for multiple potential workload scenarios.
(2) To optimize the storage layout of timestamps in columnar databases, we present a heuristic approach for the workload-driven combined selection of a data layout and compression scheme. By considering attribute decomposition strategies, we are able to apply application-specific optimizations that reduce the memory footprint and improve performance.
(3) We introduce an approach that leverages past trajectory data to improve the dispatch processes of transportation network companies. Based on location probabilities, we developed risk-averse dispatch strategies that reduce critical delays.
(4) Finally, we used the use case of a transportation network company to evaluate our database optimizations on a real-world dataset. We demonstrate that workload-driven fine-grained optimizations allow us to reduce the memory footprint (up to 71% by equal performance) or increase the performance (up to 90% by equal memory size) compared to established rule-based heuristics.
Individually, our contributions provide novel approaches to the current challenges in spatio-temporal data mining and database research. Combining them allows in-memory databases to store and process spatio-temporal data more cost-efficiently.
This study pushes our understanding of research reliability by reproducing and replicating claims from 110 papers in leading economic and political science journals. The analysis involves computational reproducibility checks and robustness assessments. It reveals several patterns. First, we uncover a high rate of fully computationally reproducible results (over 85%). Second, excluding minor issues like missing packages or broken pathways, we uncover coding errors for about 25% of studies, with some studies containing multiple errors. Third, we test the robustness of the results to 5,511 re-analyses. We find a robustness reproducibility of about 70%. Robustness reproducibility rates are relatively higher for re-analyses that introduce new data and lower for re-analyses that change the sample or the definition of the dependent variable. Fourth, 52% of re-analysis effect size estimates are smaller than the original published estimates and the average statistical significance of a re-analysis is 77% of the original. Lastly, we rely on six teams of researchers working independently to answer eight additional research questions on the determinants of robustness reproducibility. Most teams find a negative relationship between replicators' experience and reproducibility, while finding no relationship between reproducibility and the provision of intermediate or even raw data combined with the necessary cleaning codes.
MARLA
(2024)
To achieve the Paris climate target, deep emissions reductions have to be complemented with carbon dioxide removal (CDR). However, a portfolio of CDR options is necessary to reduce risks and potential negative side effects. Despite a large theoretical potential, ocean-based CDR such as ocean alkalinity enhancement (OAE) has been omitted in climate change mitigation scenarios so far. In this study, we provide a techno-economic assessment of large-scale OAE using hydrated lime ('ocean liming'). We address key uncertainties that determine the overall cost of ocean liming (OL) such as the CO2 uptake efficiency per unit of material, distribution strategies avoiding carbonate precipitation which would compromise efficiency, and technology availability (e.g., solar calciners). We find that at economic costs of 130–295 $/tCO2 net-removed, ocean liming could be a competitive CDR option which could make a significant contribution towards the Paris climate target. As the techno-economic assessment identified no showstoppers, we argue for more research on ecosystem impacts, governance, monitoring, reporting, and verification, and technology development and assessment to determine whether ocean liming and other OAE should be considered as part of a broader CDR portfolio.
Margrethe, the 80, and who?
(2024)
Lust auf Verzicht
(2024)
Der globale Klimawandel nimmt weiter bedrohlich zu. Hitzewellen, Flutkatastrophen und Waldbrände gehören fast schon zum Alltag. Trotzdem ist die Bereitschaft in der deutschen Bevölkerung gering, selbst einen Beitrag zum Klimaschutz zu leisten. Das überrascht, denn in Umfragen bekennt sich immer eine große Mehrheit zum Klimaschutz. Allerdings haben wohl viele einen Klimaschutz im Kopf, der persönlich nichts kosten und nichts verändern darf.
Ingo Balderjahn setzt sich mit diesem Widerspruch aus verhaltenswissenschaftlicher Sicht auseinander und legt offen, warum viele weiterhin ungebremst verschwenderisch und klimaschädlich konsumieren. Andererseits gibt es durchaus Menschen, die deutlich weniger konsumieren, als sie sich finanziell leisten könnten. Diese Minderheit in Deutschland verzichtet freiwillig auf eher unnötige und kurzlebige Güter - ohne irgendetwas dabei zu entbehren. Im Gegenteil: Genügsame Konsumgewohnheiten stärken die persönliche Selbstbestimmung, Unabhängigkeit und Zufriedenheit.
Long-term bacteria-fungi-plant associations in permafrost soils inferred from palaeometagenomics
(2024)
The arctic is warming 2 – 4 times faster than the global average, resulting in a strong feedback on northern ecosystems such as boreal forests, which cover a vast area of the high northern latitudes. With ongoing global warming, the treeline subsequently migrates northwards into tundra areas. The consequences of turning ecosystems are complex: on the one hand, boreal forests are storing large amounts of global terrestrial carbon and act as a carbon sink, dragging carbon dioxide out of the global carbon cycle, suggesting an enhanced carbon uptake with increased tree cover. On the other hand, with the establishment of trees, the albedo effect of tundra decreases, leading to enhanced soil warming. Meanwhile, permafrost thaws, releasing large amounts of previously stored carbon into the atmosphere. So far, mainly vegetation dynamics have been assessed when studying the impact of warming onto ecosystems. Most land plants are living in close symbiosis with bacterial and fungal communities, sustaining their growth in nutrient poor habitats. However, the impact of climate change on these subsoil communities alongside changing vegetation cover remains poorly understood. Therefore, a better understanding of soil community dynamics on multi millennial timescales is inevitable when addressing the development of entire ecosystems. Unravelling long-term cross-kingdom dependencies between plant, fungi, and bacteria is not only a milestone for the assessment of warming on boreal ecosystems. On top, it also is the basis for agriculture strategies to sustain society with sufficient food in a future warming world.
The first objective of this thesis was to assess ancient DNA as a proxy for reconstructing the soil microbiome (Manuscripts I, II, III, IV). Research findings across these projects enable a comprehensive new insight into the relationships of soil microorganisms to the surrounding vegetation. First, this was achieved by establishing (Manuscript I) and applying (Manuscript II) a primer pair for the selective amplification of ancient fungal DNA from lake sediment samples with the metabarcoding approach. To assess fungal and plant co-variation, the selected primer combination (ITS67, 5.8S) amplifying the ITS1 region was applied on samples from five boreal and arctic lakes. The obtained data showed that the establishment of fungal communities is impacted by warming as the functional ecological groups are shifting. Yeast and saprotroph dominance during the Late Glacial declined with warming, while the abundance of mycorrhizae and parasites increased with warming. The overall species richness was also alternating. The results were compared to shotgun sequencing data reconstructing fungi and bacteria (Manuscripts III, IV), yielding overall comparable results to the metabarcoding approach. Nonetheless, the comparison also pointed out a bias in the metabarcoding, potentially due to varying ITS lengths or copy numbers per genome.
The second objective was to trace fungus-plant interaction changes over time (Manuscripts II, III). To address this, metabarcoding targeting the ITS1 region for fungi and the chloroplast P6 loop for plants for the selective DNA amplification was applied (Manuscript II). Further, shotgun sequencing data was compared to the metabarcoding results (Manuscript III). Overall, the results between the metabarcoding and the shotgun approaches were comparable, though a bias in the metabarcoding was assumed. We demonstrated that fungal shifts were coinciding with changes in the vegetation. Yeast and lichen were mainly dominant during the Late Glacial with tundra vegetation, while warming in the Holocene lead to the expansion of boreal forests with increasing mycorrhizae and parasite abundance. Aside, we highlighted that Pinaceae establishment is dependent on mycorrhizal fungi such as Suillineae, Inocybaceae, or Hyaloscypha species also on long-term scales.
The third objective of the thesis was to assess soil community development on a temporal gradient (Manuscripts III, IV). Shotgun sequencing was applied on sediment samples from the northern Siberian lake Lama and the soil microbial community dynamics compared to ecosystem turnover. Alongside, podzolization processes from basaltic bedrock were recovered (Manuscript III). Additionally, the recovered soil microbiome was compared to shotgun data from granite and sandstone catchments (Manuscript IV, Appendix). We assessed if the establishment of the soil microbiome is dependent on the plant taxon and as such comparable between multiple geographic locations or if the community establishment is driven by abiotic soil properties and as such the bedrock area. We showed that the development of soil communities is to a great extent driven by the vegetation changes and temperature variation, while time only plays a minor role. The analyses showed general ecological similarities especially between the granite and basalt locations, while the microbiome on species-level was rather site-specific. A greater number of correlated soil taxa was detected for deep-rooting boreal taxa in comparison to grasses with shallower roots. Additionally, differences between herbaceous taxa of the late Glacial compared to taxa of the Holocene were revealed.
With this thesis, I demonstrate the necessity to investigate subsoil community dynamics on millennial time scales as it enables further understanding of long-term ecosystem as well as soil development processes and such plant establishment. Further, I trace long-term processes leading to podzolization which supports the development of applied carbon capture strategies under future global warming.
We conduct a laboratory experiment to study how locus of control operates through people’s preferences and beliefs to influence their decisions. Using the principal–agent setting of the delegation game, we test four key channels that conceptually link locus of control to decision-making: (i) preference for agency, (ii) optimism and (iii) confidence regarding the return to effort, and (iv) illusion of control. Knowing the return and cost of stated effort, principals either retain or delegate the right to make an investment decision that generates payoffs for themselves and their agents. Extending the game to the context in which the return to stated effort is unknown allows us to explicitly study the relationship between locus of control and beliefs about the return to effort. We find that internal locus of control is linked to the preference for agency, an effect that is driven by women. We find no evidence that locus of control influences optimism and confidence about the return to stated effort, or that it operates through an illusion of control.
Der Band präsentiert eine systematische Aufbereitung empirischer Befunde zum Lobbyismus in Deutschland und vermittelt, wie Lobbyist*innen, Entscheidungsträger*innen und institutionelle Rahmen miteinander interagieren. Untersucht werden politische Aktivitäten von sozialen Bewegungen, Verbänden, Unternehmen und Beratungsfirmen im Bundestag, der Bundesregierung und der Öffentlichkeit.
Leitfaden für die Erstellung von kommunalen Aktionsplänen zur Steigerung der urbanen Klimaresilienz
(2024)
Die durch Klimaveränderungen hervorgerufenen Auswirkungen auf Menschen und Umwelt werden immer offensichtlicher: Neben der gesundheitlichen Gefährdung durch Hitzewellen, die deutschlandweit seit einigen Jahren eine steigende Rate an Todes- und Krankheitsfällen zur Folge hat sind in den letzten Jahren zunehmend Starkniederschläge und daraus resultierenden Überschwemmungen bzw. Sturzfluten aufgetreten. Diese ziehen zum Teil immensen wirtschaftlichen Schäden, aber auch Beeinträchtigungen für die menschliche Gesundheit – sowohl physisch als auch psychisch – sowie gar Todesopfer nach sich. Es ist davon auszugehen, dass diese Extremwetterereignisse zukünftiger noch häufiger auftreten werden.
Um die Bevölkerung besser vor den Folgen dieser Wetterextreme zu schützen, sind neben Klimaschutzmaßnahmen auch Vorsorge- und Anpassungsmaßnahmen zur Steigerung der kommunalen Klimaresilienz dringend notwendig. Dazu bedarf es einerseits einer Auseinandersetzung mit den eigenen kommunalen Risiken und daraus resultierenden Handlungsbedarfen, und andererseits eines interdisziplinären, querschnittsorientierten und prozessorientierten Planens und Handelns. Aktionspläne sollen diese beiden Aspekte bündeln.
In den letzten Jahren sind einige kommunale und kommunenübergreifende (Hitze-) aufgestellt worden. Diese unterscheiden sich jedoch in ihrem Inhalt und Umfang zum Teil erheblich. Mit dem vorliegenden Leitfaden soll eine effektive Hilfestellung geschaffen werden, um Kommunen bzw. die kommunale Verwaltung auf dem Weg zum eigenen Aktionsplan zu unterstützt. Dabei fokussiert der Leitfaden auf die Herausforderungen, die sich durch vermehrte Hitze- und Starkregenereignisse ergeben. Er stützt sich auf schon vorhandene Arbeitshilfen, Handlungsempfehlungen, Leitfäden und weitere Hinweise und verweist an vielen Stellen auch darauf. So soll ein praxistauglicher Leitfaden entstehen, der flexibel anwendbar ist. Mit Hilfe des vorliegenden Leitfadens können Kommunen ihre Aktivitäten auf Hitze oder Starkregen fokussieren oder einen umfassenden Aktionsplan für beide Themenbereiche erstellen.
Legitimiertes Unrecht
(2024)
Das Oberste Gericht der DDR war integraler Bestandteil der sozialistischen Staatsführung und unterlag strengen Denk- und Organisationsstrukturen. Es war eng in die politische Agenda der SED eingebunden und genoss keinerlei Unabhängigkeit. Die Auslegung des DDR-Rechts durch das Gericht orientierte sich ausschließlich an den innen- und außenpolitischen Interessen der SED. Dies galt auch für die Rechtsprechung in Fällen der Republikflucht und ihrer gesetzlichen Vorläufer. Die höchste Gerichtsinstanz im Staat war aktiv an der Gestaltung und Umsetzung der Strafjustiz gegen Republikflüchtige beteiligt, was wesentlich zur Festigung der Herrschaftsgewalt der SED beitrug. Die vorliegende Untersuchung analysiert Urteile des Obersten Gerichts im historisch-politischen Kontext und zeigt auf, dass die Urteilspraxis ausschließlich im Interesse parteipolitischer Ziele handelte und weder dem Volk noch der eigentlichen Rechtsfindung verpflichtet war. Des Weiteren wird der maßgebliche Beitrag des Obersten Gerichts an der schrittweisen Kriminalisierung der Bürger der DDR beleuchtet. Dies wirft ein kritisches Licht auf die Rolle des Rechtssystems bei der Sicherung von Rechtsstaatlichkeit und Menschenrechten in autoritären Regimen.
The icosahedral non-hydrostatic large eddy model (ICON-LEM) was applied around the drift track of the Multidisciplinary Observatory Study of the Arctic (MOSAiC) in 2019 and 2020. The model was set up with horizontal grid-scales between 100m and 800m on areas with radii of 17.5km and 140 km. At its lateral boundaries, the model was driven by analysis data from the German Weather Service (DWD), downscaled by ICON in limited area mode (ICON-LAM) with horizontal grid-scale of 3 km.
The aim of this thesis was the investigation of the atmospheric boundary layer near the surface in the central Arctic during polar winter with a high-resolution mesoscale model. The default settings in ICON-LEM prevent the model from representing the exchange processes in the Arctic boundary layer in accordance to the MOSAiC observations. The implemented sea-ice scheme in ICON does not include a snow layer on sea-ice, which causes a too slow response of the sea-ice surface temperature to atmospheric changes. To allow the sea-ice surface to respond faster to changes in the atmosphere, the implemented sea-ice parameterization in ICON was extended with an adapted heat capacity term.
The adapted sea-ice parameterization resulted in better agreement with the MOSAiC observations. However, the sea-ice surface temperature in the model is generally lower than observed due to biases in the downwelling long-wave radiation and the lack of complex surface structures, like leads. The large eddy resolving turbulence closure yielded a better representation of the lower boundary layer under strongly stable stratification than the non-eddy-resolving turbulence closure. Furthermore, the integration of leads into the sea-ice surface reduced the overestimation of the sensible heat flux for different weather conditions.
The results of this work help to better understand boundary layer processes in the central Arctic during the polar night. High-resolving mesoscale simulations are able to represent temporally and spatially small interactions and help to further develop parameterizations also for the application in regional and global models.
Landesrecht Brandenburg
(2024)
Die topaktuelle 27. Auflage mit den wichtigsten Vorschriften des Landes Brandenburg für Studium, Referendariat und juristische Praxis berücksichtigt u.a. Änderungen des Landeswahlgesetzes, des Polizei- und des Pressegesetzes, des Juristenausbildungsgesetzes und der Juristenausbildungsordnung sowie des Schiedsstellen-, Schlichtungs- und Gütestellengesetzes. Schaubilder verdeutlichen den Aufbau der Gerichtsbarkeit und der Verwaltung. Gliederungen und ein ausführliches Register führen schnell zur gesuchten Norm, die durchgängige Satznummerierung gewährleistet präzise Zitierfähigkeit. Die Sammlung ist in Brandenburg zu den Staatsexamina zugelassen.
Comparamos la labialización no asimiladora de nasales finales en español en tres corpus de español americano (mexicano, colombiano y paraguayo). Si bien es conocida la labialización no asimiladora en español yucateco, es en gran parte desconocida en otras regiones de habla hispana, por lo que a menudo se atribuye a la influencia maya. Ahora bien, se han señalado casualmente hábitos de pronunciación similares tanto en Paraguay como en Colombia. Comparando empíricamente la labialización en tres corpus constituidos sobre la misma base metodológica, concluimos que la evidencia a favor del contacto lingüístico es como mucho sumamente indirecta. Independientemente de esto, encontramos que la diferencia más marcada es que la tasa de labialización parece ser determinada por la duración de la pausa subsiguiente en los datos de la península yucateca, mas no en aquellos de Colombia y Paraguay. Argumentamos que es cierto que el contacto puede eventualmente haber desencadenado el desarrollo de este rasgo en el español yucateco, puesto que el español actual casi no conoce nasales labiales finales, pero el maya sí. Sin embargo, el perfil lingüístico (hablantes monolingües vs. bilingües) no tiene ningún efecto en nuestros datos yucatecos y paraguayos, y en el total de nuestros datos tampoco encontramos evidencia en favor de la hipótesis que el contacto lingüístico hubiera jugado un rol (importante) en el desarrollo de las labiales nasales en las tres variedades.
Körper – Karte – Text
(2024)
Rabelais' Pentalogie um die Riesen Gargantua und Pantagruel spiegelt Aspekte des sich verändernden Weltbildes ihrer Entstehungszeit. Diese Studie untersucht auf der Folie der Theorie des Simulakrum Schrift, wie Körpermodellierungen und kartographisches imaginaire durch den Autor als Strategien der Verhüllung verborgener Botschaften eingesetzt werden. Sie zeigt an ausgewählten Beispielen des Quart Livre die Aufweichung der Grenzen von Körper, Karte und Text und deren Durchdringung. Die Metaphorizität des Textes gibt Aufschluss über seine Autoreflexivität und bewirkt eine gleichsam ganzheitliche Lektüreerfahrung. Schließlich avanciert die Fiktion in ihrer Trugbildhaftigkeit als grotesk-sinnlicher Körper und polysemantische Karte zum Welterklärungsmodell, das jedoch erst dechiffriert werden muss.
Vergangenheit ist vergangen, Geschichte wird gemacht. An diesem Konstruktionsprozess sind nicht nur die historischen Akteur:innen und deren Quellen, sondern in besonderem Maße auch die Historiker:innen, die sich mit diesen auseinandersetzen, beteiligt. Sie sind es, die die Quellen erst zum Sprudeln bringen. Was dabei zutage tritt, ist somit in hohem Maße von den Forschenden selbst, von ihren Vorannahmen und Methoden aber auch von ihren sozialen, kulturellen und biografischen Prägungen abhängig. Das hier vorgestellte Prozessmodell versucht, diese als Einflussfaktoren zu fassen und sichtbar zu machen, um auf dieser Basis eine erweiterte wissenschaftliche (Selbst-)Reflexion zu ermöglichen.
Zum dreißigjährigen Bestehen des Kommunalwissenschaftlichen Instituts an der Universität Potsdam vereint dieser Jubiläumsband kurze Aufsätze von ehemaligen und aktuellen Vorstandsmitgliedern, von Ehrenmitgliedern des Vorstands, langjährigen wissenschaftlichen Mitarbeitern des Instituts und aktuellen wissenschaftlichen Kooperationspartnern. Die insgesamt zwölf Beiträge befassen sich mit den Kommunalwissenschaften und der Geschichte des Kommunalwissenschaftlichen Instituts, mit aktuellen kommunalwissenschaftlichen Fragestellungen und wissenschaftlichen Kooperationen des KWI. Der vom KWI-Vorstand herausgegebene Band soll einen breiten Blick auf 30 Jahre Kommunalwissenschaften in Brandenburg und an der Universität Potsdam werfen und einen Ausblick auf zukünftige kommunalwissenschaftliche Forschung geben.
Dieser Beitrag vergleicht die kommunale Verwaltungsdigitalisierung in Deutschland, Österreich und der Schweiz (DACH-Länder) als Vertreter der kontinentaleuropäisch-föderalen Verwaltungstradition bei zugleich unterschiedlichen Digitalisierungsansätzen und -fortschritten. Basierend auf Interviews mit 22 Expert*innen und Beobachtungen in je einer Kommune pro Land sowie Dokumenten-, Literatur- und Sekundärdatenanalysen untersucht die Studie, wie Verwaltungsdigitalisierung im Mehrebenensystem organisiert ist und welche Rolle dabei das Verwaltungsprofil spielt sowie welche Innovationsschwerpunkte die Kommunen im Hinblick auf die Leistungserbringung und die internen Prozesse setzen. Die Ergebnisse zeigen, dass der hohe Grad lokaler Autonomie den Kommunen ermöglicht, eigene Akzente in der Verwaltungsdigitalisierung zu setzen. Zugleich wirken die stark verflochtenen komplexen Entscheidungsstrukturen und hohen Koordinationsbedarfe in verwaltungsföderalen Systemen, die in Deutschland am stärksten, in Österreich etwas schwächer und in der Schweiz am geringsten ausgeprägt sind, als Digitalisierungshemmnisse. Ferner weisen die Befunde auf eine unitarisierende Wirkung der Verwaltungsdigitalisierung als Reformbereich hin. Insgesamt trägt die Studie zu einem besseren Verständnis dafür bei, welche Problematik die Verwaltungsdigitalisierung für föderal-dezentrale Verwaltungsmodelle mit sich bringt.
Kochbücher à la religion
(2024)
Der Semi-Parlamentarismus beschreibt das Regierungssystem, in dem die Regierung von einem Teil des Parlaments gewählt wird und abberufen werden kann, von einem anderen Teil des Parlaments aber unabhängig ist. Beide Kammern müssen dabei der Gesetzgebung zustimmen. Dieses von Steffen Ganghof klassifizierte System ergänzt gängige Regierungssystemtypologien, wie sie beispielsweise von David Samuels und Matthew Shugart genutzt werden. Der Semi-Parlamentarismus ist der logische Gegenpart zum Semi-Präsidentialismus, bei dem nur ein Teil der Exekutive von der Legislative abhängt, während im Semi-Parlamentarismus die Exekutive von nur einem Teil der Legislative abhängt. Der Semi-Parlamentarismus verkörpert so ein System der Gewaltenteilung ohne einen exekutiven Personalismus, wie er durch die Direktwahl und Unabhängigkeit der Regierungchef:in im Präsidentialismus hervorgerufen wird. Dadurch ist der Semi-Parlamentarismus geeignet, Unterschiede zwischen Parlamentarismus und Präsidentialismus auf den separaten Einfluss der Gewaltenteilung und des exekutiven Personalismus zurückzuführen. Die Untersuchung des Semi-Parlamentarismus ist daher für die Regierungssystemliteratur insgesamt von Bedeutung. Der Semi-Parlamentarismus ist dabei kein rein theoretisches Konstrukt, sondern existiert im australischen Bundesstaat, den australischen Substaaten und Japan.
Die vorliegende Dissertation untersucht erstmals umfassend die Gesetzgebung der semi-parlamentarischen Staaten als solchen. Der Fokus liegt dabei auf den zweiten Kammern, da diese durch die Unabhängigkeit von der Regierung der eigentliche Ort der Gesetzgebung sind. Die Gesetzgebung in Parlamentarismus und Präsidentialismus unterscheidet sich insbesondere in der Geschlossenheit der Parteien, der Koalitionsbildung und dem legislativen Erfolg der Regierungen. Diese Punkte sind daher auch von besonderem Interesse bei der Analyse des Semi-Parlamentarismus. Die semi-parlamentarischen Staaten unterscheiden sich auch untereinander teilweise erheblich in der institutionellen Ausgestaltung wie den Wahlsystemen oder den verfügbaren Mitteln zur Überwindung von Blockadesituationen. Die Darstellung und die Analyse der Auswirkungen dieser Unterschiede auf die Gesetzgebung ist neben dem Vergleich des Semi-Parlamentarismus mit anderen Systemen das zweite wesentliche Ziel dieser Arbeit.
Als Fundament der Analyse habe ich einen umfangreichen Datensatz erhoben, der alle Legislaturperioden der australischen Staaten zwischen 1997 und 2019 umfasst. Wesentliche Bestandteile des Datensatzes sind alle namentlichen Abstimmungen beider Kammern, alle
eingebrachten und verabschiedeten Gesetzen der Regierung sowie die mit Hilfe eines Expert-Surveys erhobenen Parteipositionen in den relevanten Politikfeldern auf substaatlicher Ebene.
Hauptsächlich mit der Hilfe von Mixed-Effects- und Fractional-Response-Analysen kann ich so zeigen, dass der Semi-Parlamentarismus in vielen Aspekten eher parlamentarischen als präsidentiellen Systemen gleicht. Nur die Koalitionsbildung erfolgt deutlich flexibler und unterscheidet sich daher von der typischen parlamentarischen Koalitionsbildung. Die Analysen legen nahe, dass wesentliche Unterschiede zwischen Parlamentarismus und Präsidentialismus eher auf den exekutiven Personalismus als auf die Gewaltenteilung zurückzuführen sind.
Zwischen den semi-parlamentarischen Staaten scheinen vor allem die Kontrolle des Medians beider Parlamentskammern durch die Regierung und die Möglichkeit der Regierung, die zweite Kammer mitaufzulösen, zu entscheidenden Unterschieden in der Gesetzgebung zu führen. Die Kontrolle des Medians ermöglicht eine flexible Koalitionsbildung und führt zu höheren legislativen Erfolgsraten. Ebenso führt eine möglichst leichte Auflösungsmöglichkeit der zweiten Kammern zu höheren legislativen Erfolgsraten. Die Parteigeschlossenheit ist unabhängig von diesen Aspekten in beiden Kammern der semi-parlamentarischen Parlamente sehr hoch.
Kaschrut
(2024)
Kants Recht der Freiheit
(2024)
Das vorliegende Buch berücksichtigt neben den drei Kritiken und der späten Rechtslehre Kants Grundlegung zur Metaphysik der Sitten, seine Anthropologie in pragmatischer Hinsicht, den Weltbürgeressay, den Streit der Fakultäten, die Friedensschrift und die Abhandlung über den Gemeinspruch, aus der die Formulierung ‚Recht der Freiheit‘ stammt.
Erstes Kant-Buch zu seiner eigenen Wortschöpfung "Recht der Freiheit".
Erörtert Kants "Rechtslehre und Gerichtsbarkeit" in der Kritik der reinen Vernunft
This paper provides novel evidence on the impact of public transport subsidies on air pollution. We obtain causal estimates by leveraging a unique policy intervention in Germany that temporarily reduced nationwide prices for regional public transport to a monthly flat rate price of 9 Euros. Using DiD estimation strategies on air pollutant data, we show that this intervention causally reduced a benchmark air pollution index by more than eight percent and, after its termination, increased again. Our results illustrate that public transport subsidies – especially in the context of spatially constrained cities – offer a viable alternative for policymakers and city planers to improve air quality, which has been shown to crucially affect health outcomes.
Jahresbericht 2023
(2024)
Dieser Jahresbericht umfasst den Berichtszeitraum 2023, in dem Forschung und Lehre wieder in Präsenz stattfinden konnten. Begegnung und Austausch in Hörsaal und Seminarraum, auf Konferenzpaneln und während Kaffeepausen sind wieder möglich, aber die Möglichkeiten von Homeoffice und Onlinekommunikation bleiben weiter bestehen, wie die Erfahrung zeigt.
Das MenschenRechtsZentrum als interdisziplinär arbeitende, zentrale wissenschaftliche Einrichtung der Universität Potsdam hat es im Berichtszeitraum erneut unternommen, juristische, philosophische, geschichts- und kultur- sowie politikwissenschaftliche Perspektiven auf das Thema Menschenrechte in Forschung und Lehre miteinander zu verbinden.
Die Wissenschaftler*innen des MenschenRechtsZentrums lehren an den Fakultäten, denen sie angehören. Hier werden daher nur diejenigen Aktivitäten angeführt, die einen Bezug zur Arbeit des MenschenRechtsZentrums sowie zu menschenrechtlichen Fragestellungen haben; weitergehende Informationen finden sich auf den Homepages der jeweiligen Personen.
Invisible iterations: how formal and informal organization shape knowledge networks for coordination
(2024)
This study takes a network approach to investigate coordination among knowledge workers as grounded in both formal and informal organization. We first derive hypotheses regarding patterns of knowledge-sharing relationships by which workers pass on and exchange tacit and codified knowledge within and across organizational hierarchies to address the challenges that underpin contemporary knowledge work. We use survey data and apply exponential random graph models to test our hypotheses. We then extend the quantitative network analysis with insights from qualitative interviews and demonstrate that the identified knowledge-sharing patterns are the micro-foundational traces of collective coordination resulting from two underlying coordination mechanisms which we label ‘invisible iterations’ and ‘bringing in the big guns’. These mechanisms and, by extension, the associated knowledge-sharing patterns enable knowledge workers to perform in a setting that is characterized by complexity, uncertainty and ambiguity. Our research contributes to theory on the interplay between formal and informal organization for coordination by showing how self-directed, informal action is supported by the formal organizational hierarchy. In doing so, it also extends understanding of the role that hierarchy plays for knowledge-intensive work. Finally, it establishes the collective need to coordinate work as a previously overlooked driver of knowledge network relationships and network patterns. © 2024 The Authors. Journal of Management Studies published by Society for the Advancement of Management Studies and John Wiley & Sons Ltd.
In the aftermath of the Shoah and the ostensible triumph of nationalism, it became common in historiography to relegate Jews to the position of the “eternal other” in a series of binaries: Christian/Jewish, Gentile/Jewish, European/Jewish, non-Jewish/Jewish, and so forth. For the longest time, these binaries remained characteristic of Jewish historiography, including in the Central European context. Assuming instead, as the more recent approaches in Habsburg studies do, that pluriculturalism was the basis of common experience in formerly Habsburg Central Europe, and accepting that no single “majority culture” existed, but rather hegemonies were imposed in certain contexts, then the often used binaries are misleading and conceal the complex and sometimes even paradoxical conditions that shaped Jewish life in the region before the Shoah.
The very complexity of Habsburg Central Europe both in synchronic and diachronic perspective precludes any singular historical narrative of “Habsburg Jewry,” and it is not the intention of this volume to offer an overview of “Habsburg Jewish history.” The selected articles in this volume illustrate instead how important it is to reevaluate categories, deconstruct historical narratives, and reconceptualize implemented approaches in specific geographic, temporal, and cultural contexts in order to gain a better understanding of the complex and pluricultural history of the Habsburg Empire and the region as a whole.
A comprehensive study on seismic hazard and earthquake triggering is crucial for effective mitigation of earthquake risks. The destructive nature of earthquakes motivates researchers to work on forecasting despite the apparent randomness of the earthquake occurrences. Understanding their underlying mechanisms and patterns is vital, given their potential for widespread devastation and loss of life. This thesis combines methodologies, including Coulomb stress calculations and aftershock analysis, to shed light on earthquake complexities, ultimately enhancing seismic hazard assessment.
The Coulomb failure stress (CFS) criterion is widely used to predict the spatial distributions of aftershocks following large earthquakes. However, uncertainties associated with CFS calculations arise from non-unique slip inversions and unknown fault networks, particularly due to the choice of the assumed aftershocks (receiver) mechanisms. Recent studies have proposed alternative stress quantities and deep neural network approaches as superior to CFS with predefined receiver mechanisms. To challenge these propositions, I utilized 289 slip inversions from the SRCMOD database to calculate more realistic CFS values for a layered-half space and variable receiver mechanisms. The analysis also investigates the impact of magnitude cutoff, grid size variation, and aftershock duration on the ranking of stress metrics using receiver operating characteristic (ROC) analysis. Results reveal the performance of stress metrics significantly improves after accounting for receiver variability and for larger aftershocks and shorter time periods, without altering the relative ranking of the different stress metrics.
To corroborate Coulomb stress calculations with the findings of earthquake source studies in more detail, I studied the source properties of the 2005 Kashmir earthquake and its aftershocks, aiming to unravel the seismotectonics of the NW Himalayan syntaxis. I simultaneously relocated the mainshock and its largest aftershocks using phase data, followed by a comprehensive analysis of Coulomb stress changes on the aftershock planes. By computing the Coulomb failure stress changes on the aftershock faults, I found that all large aftershocks lie in regions of positive stress change, indicating triggering by either co-seismic or post-seismic slip on the mainshock fault.
Finally, I investigated the relationship between mainshock-induced stress changes and associated seismicity parameters, in particular those of the frequency-magnitude (Gutenberg-Richter) distribution and the temporal aftershock decay (Omori-Utsu law). For that purpose, I used my global data set of 127 mainshock-aftershock sequences with the calculated Coulomb Stress (ΔCFS) and the alternative receiver-independent stress metrics in the vicinity of the mainshocks and analyzed the aftershocks properties depend on the stress values. Surprisingly, the results show a clear positive correlation between the Gutenberg-Richter b-value and induced stress, contrary to expectations from laboratory experiments. This observation highlights the significance of structural heterogeneity and strength variations in seismicity patterns. Furthermore, the study demonstrates that aftershock productivity increases nonlinearly with stress, while the Omori-Utsu parameters c and p systematically decrease with increasing stress changes. These partly unexpected findings have significant implications for future estimations of aftershock hazard.
The findings in this thesis provides valuable insights into earthquake triggering mechanisms by examining the relationship between stress changes and aftershock occurrence. The results contribute to improved understanding of earthquake behavior and can aid in the development of more accurate probabilistic-seismic hazard forecasts and risk reduction strategies.
Column-oriented database systems can efficiently process transactional and analytical queries on a single node. However, increasing or peak analytical loads can quickly saturate single-node database systems. Then, a common scale-out option is using a database cluster with a single primary node for transaction processing and read-only replicas. Using (the naive) full replication, queries are distributed among nodes independently of the accessed data. This approach is relatively expensive because all nodes must store all data and apply all data modifications caused by inserts, deletes, or updates.
In contrast to full replication, partial replication is a more cost-efficient implementation: Instead of duplicating all data to all replica nodes, partial replicas store only a subset of the data while being able to process a large workload share. Besides lower storage costs, partial replicas enable (i) better scaling because replicas must potentially synchronize only subsets of the data modifications and thus have more capacity for read-only queries and (ii) better elasticity because replicas have to load less data and can be set up faster. However, splitting the overall workload evenly among the replica nodes while optimizing the data allocation is a challenging assignment problem.
The calculation of optimized data allocations in a partially replicated database cluster can be modeled using integer linear programming (ILP). ILP is a common approach for solving assignment problems, also in the context of database systems. Because ILP is not scalable, existing approaches (also for calculating partial allocations) often fall back to simple (e.g., greedy) heuristics for larger problem instances. Simple heuristics may work well but can lose optimization potential.
In this thesis, we present optimal and ILP-based heuristic programming models for calculating data fragment allocations for partially replicated database clusters. Using ILP, we are flexible to extend our models to (i) consider data modifications and reallocations and (ii) increase the robustness of allocations to compensate for node failures and workload uncertainty. We evaluate our approaches for TPC-H, TPC-DS, and a real-world accounting workload and compare the results to state-of-the-art allocation approaches. Our evaluations show significant improvements for varied allocation’s properties: Compared to existing approaches, we can, for example, (i) almost halve the amount of allocated data, (ii) improve the throughput in case of node failures and workload uncertainty while using even less memory, (iii) halve the costs of data modifications, and (iv) reallocate less than 90% of data when adding a node to the cluster. Importantly, we can calculate the corresponding ILP-based heuristic solutions within a few seconds. Finally, we demonstrate that the ideas of our ILP-based heuristics are also applicable to the index selection problem.
This article analyses the institutional design variants of local crisis governance responses to the COVID-19 pandemic and their entanglement with other locally impactful crises from a cross-country comparative perspective (France, Germany, Poland, Sweden, and the UK/England). The pandemic offers an excellent empirical lens for scrutinizing the phenomenon of polycrises governance because it occurred while European countries were struggling with the impacts of several prior, ongoing, or newly arrived crises. Our major focus is on institutional design variants of crisis governance (dependent variable) and the influence of different administrative cultures on it (independent variable). Furthermore, we analyze the entanglement and interaction of institutional responses to other (previous or parallel) crises (polycrisis dynamics). Our findings reveal a huge variance of institutional designs, largely evoked by country-specific administrative cultures and profiles. The degree of de-/centralization and the intensity of coordination or decoupling across levels of government differs significantly by country. Simultaneously, all countries were affected by interrelated and entangled crises, resulting in various patterns of polycrisis dynamics. While policy failures and “fatal remedies” from previous crises have partially impaired the resilience and crisis preparedness of local governments, we have also found some learning effects from previous crises.
The landscape of software self-adaptation is shaped in accordance with the need to cost-effectively achieve and maintain (software) quality at runtime and in the face of dynamic operation conditions. Optimization-based solutions perform an exhaustive search in the adaptation space, thus they may provide quality guarantees. However, these solutions render the attainment of optimal adaptation plans time-intensive, thereby hindering scalability. Conversely, deterministic rule-based solutions yield only sub-optimal adaptation decisions, as they are typically bound by design-time assumptions, yet they offer efficient processing and implementation, readability, expressivity of individual rules supporting early verification. Addressing the quality-cost trade-of requires solutions that simultaneously exhibit the scalability and cost-efficiency of rulebased policy formalism and the optimality of optimization-based policy formalism as explicit artifacts for adaptation. Utility functions, i.e., high-level specifications that capture system objectives, support the explicit treatment of quality-cost trade-off. Nevertheless, non-linearities, complex dynamic architectures, black-box models, and runtime uncertainty that makes the prior knowledge obsolete are a few of the sources of uncertainty and subjectivity that render the elicitation of utility non-trivial.
This thesis proposes a twofold solution for incremental self-adaptation of dynamic architectures. First, we introduce Venus, a solution that combines in its design a ruleand an optimization-based formalism enabling optimal and scalable adaptation of dynamic architectures. Venus incorporates rule-like constructs and relies on utility theory for decision-making. Using a graph-based representation of the architecture, Venus captures rules as graph patterns that represent architectural fragments, thus enabling runtime extensibility and, in turn, support for dynamic architectures; the architecture is evaluated by assigning utility values to fragments; pattern-based definition of rules and utility enables incremental computation of changes on the utility that result from rule executions, rather than evaluating the complete architecture, which supports scalability. Second, we introduce HypeZon, a hybrid solution for runtime coordination of multiple off-the-shelf adaptation policies, which typically offer only partial satisfaction of the quality and cost requirements. Realized based on meta-self-aware architectures, HypeZon complements Venus by re-using existing policies at runtime for balancing the quality-cost trade-off.
The twofold solution of this thesis is integrated in an adaptation engine that leverages state- and event-based principles for incremental execution, therefore, is scalable for large and dynamic software architectures with growing size and complexity. The utility elicitation challenge is resolved by defining a methodology to train utility-change prediction models. The thesis addresses the quality-cost trade-off in adaptation of dynamic software architectures via design-time combination (Venus) and runtime coordination (HypeZon) of rule- and optimization-based policy formalisms, while offering supporting mechanisms for optimal, cost-effective, scalable, and robust adaptation. The solutions are evaluated according to a methodology that is obtained based on our systematic literature review of evaluation in self-healing systems; the applicability and effectiveness of the contributions are demonstrated to go beyond the state-of-the-art in coverage of a wide spectrum of the problem space for software self-adaptation.
Sigmund Freud, the founder of psychoanalysis, began his intellectual life with the Jewish Bible and also ended it with it. He began by reading the Philippson Bible together, especially with his father Jacob Freud, and ended by studying the figure of Moses. This study systematically traces this preoccupation and shows that the Jewish Bible was a constant reference for Freud and determined his Jewish identity. This is shown by analysing family documents, religious instruction and references to the Bible in Freud's writings and correspondence.
Improving permafrost dynamics in land surface models: insights from dual sensitivity experiments
(2024)
The thawing of permafrost and the subsequent release of greenhouse gases constitute one of the most significant and uncertain positive feedback loops in the context of climate change, making predictions regarding changes in permafrost coverage of paramount importance. To address these critical questions, climate scientists have developed Land Surface Models (LSMs) that encompass a multitude of physical soil processes. This thesis is committed to advancing our understanding and refining precise representations of permafrost dynamics within LSMs, with a specific focus on the accurate modeling of heat fluxes, an essential component for simulating permafrost physics.
The first research question overviews fundamental model prerequisites for the representation of permafrost soils within land surface modeling. It includes a first-of-its-kind comparison between LSMs in CMIP6 to reveal their differences and shortcomings in key permafrost physics parameters. Overall, each of these LSMs represents a unique approach to simulating soil processes and their interactions with the climate system. Choosing the most appropriate model for a particular application depends on factors such as the spatial and temporal scale of the simulation, the specific research question, and available computational resources.
The second research question evaluates the performance of the state-of-the-art Community Land Model (CLM5) in simulating Arctic permafrost regions. Our approach overcomes traditional evaluation limitations by individually addressing depth, seasonality, and regional variations, providing a comprehensive assessment of permafrost and soil temperature dynamics. I compare CLM5's results with three extensive datasets: (1) soil temperatures from 295 borehole stations, (2) active layer thickness (ALT) data from the Circumpolar Active Layer Monitoring Network (CALM), and (3) soil temperatures, ALT, and permafrost extent from the ESA Climate Change Initiative (ESA-CCI). The results show that CLM5 aligns well with ESA-CCI and CALM for permafrost extent and ALT but reveals a significant global cold temperature bias, notably over Siberia. These results echo a persistent challenge identified in numerous studies: the existence of a systematic 'cold bias' in soil temperature over permafrost regions. To address this challenge, the following research questions propose dual sensitivity experiments.
The third research question represents the first study to apply a Plant Functional Type (PFT)-based approach to derive soil texture and soil organic matter (SOM), departing from the conventional use of coarse-resolution global data in LSMs. This novel method results in a more uniform distribution of soil organic matter density (OMD) across the domain, characterized by reduced OMD values in most regions. However, changes in soil texture exhibit a more intricate spatial pattern. Comparing the results to observations reveals a significant reduction in the cold bias observed in the control run. This method shows noticeable improvements in permafrost extent, but at the cost of an overestimation in ALT. These findings emphasize the model's high sensitivity to variations in soil texture and SOM content, highlighting the crucial role of soil composition in governing heat transfer processes and shaping the seasonal variation of soil temperatures in permafrost regions.
Expanding upon a site experiment conducted in Trail Valley Creek by \citet{dutch_impact_2022}, the fourth research question extends the application of the snow scheme proposed by \citet{sturm_thermal_1997} to cover the entire Arctic domain. By employing a snow scheme better suited to the snow density profile observed over permafrost regions, this thesis seeks to assess its influence on simulated soil temperatures. Comparing this method to observational datasets reveals a significant reduction in the cold bias that was present in the control run. In most regions, the Sturm run exhibits a substantial decrease in the cold bias. However, there is a distinctive overshoot with a warm bias observed in mountainous areas. The Sturm experiment effectively addressed the overestimation of permafrost extent in the control run, albeit resulting in a substantial reduction in permafrost extent over mountainous areas. ALT results remain relatively consistent compared to the control run. These outcomes align with our initial hypothesis, which anticipated that the reduced snow insulation in the Sturm run would lead to higher winter soil temperatures and a more accurate representation of permafrost physics.
In summary, this thesis demonstrates significant advancements in understanding permafrost dynamics and its integration into LSMs. It has meticulously unraveled the intricacies involved in the interplay between heat transfer, soil properties, and snow dynamics in permafrost regions. These insights offer novel perspectives on model representation and performance.
Existing curricula for entrepreneurship education do not necessarily represent the best way of teaching. How could entrepreneurship curricula be improved? To answer this question, we aim to identify and rank desirable teaching objectives, teaching contents, teaching methods, and assessment methods for higher entrepreneurship education. To this end, we employ an international real-time Delphi study with an expert panel consisting of entrepreneurship education instructors and researchers. The study reveals 17 favorable objectives, 17 items of content, 25 teaching methods, and 15 assessment methods, which are ranked according to their desirability and the group consensus. We contribute to entrepreneurship curriculum research by adding a normative perspective.
Heat stress (HS) is a major abiotic stress that negatively affects plant growth and productivity. However, plants have developed various adaptive mechanisms to cope with HS, including the acquisition and maintenance of thermotolerance, which allows them to respond more effectively to subsequent stress episodes. HS memory includes type II transcriptional memory which is characterized by enhanced re-induction of a subset of HS memory genes upon recurrent HS. In this study, new regulators of HS memory in A. thaliana were identified through the characterization of rein mutants.
The rein1 mutant carries a premature stop in CYCLIN-DEPENDENT-KINASE 8 (CDK8) which is part of the cyclin kinase module of the Mediator complex. Rein1 seedlings show impaired type II transcriptional memory in multiple heat-responsive genes upon re-exposure to HS. Additionally, the mutants exhibit a significant deficiency in HS memory at the physiological level. Interaction studies conducted in this work indicate that CDK8 associates with the memory HEAT SHOCK FACTORs HSAF2 and HSFA3. The results suggest that CDK8 plays a crucial role in HS memory in plants together with other memory HSFs, which may be potential targets of the CDK8 kinase function. Understanding the role and interaction network of the Mediator complex during HS-induced transcriptional memory will be an exciting aspect of future HS memory research.
The second characterized mutant, rein2, was selected based on its strongly impaired pAPX2::LUC re-induction phenotype. In gene expression analysis, the mutant revealed additional defects in the initial induction of HS memory genes. Along with this observation, basal thermotolerance was impaired similarly as HS memory at the physiological level in rein2. Sequencing of backcrossed bulk segregants with subsequent fine mapping narrowed the location of REIN2 to a 1 Mb region on chromosome 1. This interval contains the At1g65440 gene, which encodes the histone chaperone SPT6L. SPT6L interacts with chromatin remodelers and bridges them to the transcription machinery to regulate nucleosome and Pol II occupancy around the transcriptional start site. The EMS-induced missense mutation in SPT6L may cause altered HS-induced gene expression in rein2, possibly triggered by changes in the chromatin environment resulting from altered histone chaperone function.
Expanding research on screen-derived factors that modify type II transcriptional memory has the potential to enhance our understanding of HS memory in plants. Discovering connections between previously identified memory factors will help to elucidate the underlying network of HS memory. This knowledge can initiate new approaches to improve heat resilience in crops.
Volcanic hydrothermal systems are an integral part of most volcanoes and typically involve a heat source, adequate fluid supply, and fracture or pore systems through which the fluids can circulate within the volcanic edifice. Associated with this are subtle but powerful processes that can significantly influence the evolution of volcanic activity or the stability of the near-surface volcanic system through mechanical weakening, permeability reduction, and sealing of the affected volcanic rock. These processes are well constrained for rock samples by laboratory analyses but are still difficult to extrapolate and evaluate at the scale of an entire volcano. Advances in unmanned aircraft systems (UAS), sensor technology, and photogrammetric processing routines now allow us to image volcanic surfaces at the centimeter scale and thus study volcanic hydrothermal systems in great detail. This thesis aims to explore the potential of UAS approaches for studying the structures, processes, and dynamics of volcanic hydrothermal systems but also to develop methodological approaches to uncover secondary information hidden in the data, capable of indicating spatiotemporal dynamics or potentially critical developments associated with hydrothermal alteration. To accomplish this, the thesis describes the investigation of two near-surface volcanic hydrothermal systems, the El Tatio geyser field in Chile and the fumarole field of La Fossa di Vulcano (Italy), both of which are among the best-studied sites of their kind. Through image analysis, statistical, and spatial analyses we have been able to provide the most detailed structural images of both study sites to date, with new insights into the driving forces of such systems but also revealing new potential controls, which are summarized in conceptual site-specific models. Furthermore, the thesis explores methodological remote sensing approaches to detect, classify and constrain hydrothermal alteration and surface degassing from UAS-derived data, evaluated them by mineralogical and chemical ground-truthing, and compares the alteration pattern with the present-day degassing activity. A significant contribution of the often neglected diffuse degassing activity to the total amount of degassing is revealed and constrains secondary processes and dynamics associated with hydrothermal alteration that lead to potentially critical developments like surface sealing. The results and methods used provide new approaches for alteration research, for the monitoring of degassing and alteration effects, and for thermal monitoring of fumarole fields, with the potential to be incorporated into volcano monitoring routines.
I need to move it, move It!
(2024)
Purpose
Student interest and learning success is an important component of teaching learning research. However, while the impact of emotions and psychological needs on students' achievements has been a focus of research, the impact of their physiological needs has been under studied. In this explorative study, I examine what impact the physiological and psychological needs of student teachers have on their feelings, motivation, and interest in different learning settings.
Approach
The research method used was the daily reconstruction method and included the Felix-App, a new digital research and feedback tool that allows the measurement of feelings, needs, motivation, and interest in real time.
Findings
The results suggest the importance of physiological needs for perceived emotions, motivation, and interest in the learning subject. The psychological needs, on the other hand, are of less importance.
Originality
The Felix-App is an innovative tool to learn more about learners' emotions and needs in real learning settings. The importance of physiological needs has been known since Maslow, but should be considered much more in the context of teaching and learning research in the future. There is a need for further research on the importance of physical aspects in learning.
Hässlich aber gut
(2024)
Werner Krause and Christina Gahn argue that we need to pay more attention to how the media communicates the results of opinion polls to the public. Reporting methodological details, such as margins of error, can alter citizens’ vote choices on election day. This has important implications for elections around the world
-Ottmar Ette, Ingo Schwarz: „Ein junges, neues Geschlecht wird besseres liefern als das alte“. Ein Empfehlungsbrief Alexander von Humboldts für Carl Ludwig
-GAO Hong: Nachgedanken zur Übersetzung des ersten Bandes von Humboldts Kosmos
-Tobias Kraft: Neue Quellen zu Humboldts Kuba-Forschung. Das „Digitale Dossier“ des Proyecto Humboldt Digital (2019 – 2023)
-Vera Kutzinski: Off-Road Adventures: Reading Statistics in Alexander von Humboldt’s Political Essay on the Kingdom of New Spain
-Krzysztof Zielnica: Alexander von Humboldt und Polen – zum 150. Jahrestag seiner Reise nach Warschau. Mit einleitenden Worten von Ingo Schwarz
Habsburg Central Europe
(2024)
Central Europe is characterized by linguistic and cultural density as well as by endogenous and exogenous cultural influences. These constellations were especially visible in the former Habsburg Empire, where they influenced the formation of individual and collective identities. This led not only to continual crises and conflicts, but also to an equally enormous creative potential as became apparent in the culture of the fin-de-siècle.