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  • Public defence: 2024-03-19 13:00 sal FB42, AlbaNova universitetscentrum, Stockholm
    Florin, Naemi
    Stockholm University, Faculty of Science, Department of Physics.
    Cosmic Molecules and Clusters: Knockout Driven Reactions2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Fullerenes and PAHs (polycyclic aromatic hydrocarbons) are two families of carbon based molecules. These are both present in the interstellar medium, and are there believed to play important roles in various processes, including the formation of stars in the case of PAHs. This thesis presents studies on the structures and dynamics of fullerenes and PAHs and their weakly bound clusters, that all have relevance in an astrophysical context. Here, the focus is on knockout driven reactions in which a single atom is knocked out of a molecule or a molecular cluster as a result of Rutherford-like scattering processes. These are modelled by means of classical molecular dynamics simulations.

    The first study investigates knockout processes where a C60 molecule is collided with helium atoms at 166 eV in the centre-of-mass-frame, similar to the velocities in interstellar shocks. Using a combination of experimental measurements and molecular dynamics simulations we find that highly reactive C59 fragments can be created sufficiently cold to stabilise and survive indefinitely inisolation.

    Following the first study, we model the structures and stabilities of mixed clusters of C60 and C24H12 (coronene) molecules. We find that the two molecular species do not mix very well, but that they like to be in compact formations. For larger pure coronene clusters, we find that the most stable clusters contain two interacting stacks, forming a shape that looks similar to a “handshake”. These results are consistent with earlier modelling studies. Here, we show that such stacks also show up as subclusters in large mixed clusters.

    Finally, we use the most stable clusters from the second study as targets in collisions with 3 keV argon atoms. We find that the simulated mass spectra strongly resemble the corresponding experimental ones. These show that many various forms of new molecular structures, both fragments and large new molecules, are being formed, as a result of the collisions. Here, the simulations give information on the reaction pathways and on the structures of these new species. There are also examples of hydrogenated, but otherwise intact, fullerene and coronene molecules being formed.

    The mechanisms we have studied mimic inter- and circumstellar conditions where shockwaves and stellar winds drive particles (atoms and ions) at velocities similar to those studied here. The reactions covered in this work are thus likely to take place in such environments when carbon-based molecules and grains are energetically processed.

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  • Public defence: 2024-03-20 10:00 lärosal 16, hus 2, Campus Albano, Stockholm
    Akhtar, Reema
    Stockholm University, Faculty of Social Sciences, Stockholm Business School.
    What if your world is outside the oyster?: How highly educated and skilled first-generation immigrant entrepreneurs develop opportunities in knowledge-intensive sectors2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    In the previous decades, immigration has increased significantly from non-EU countries to Western countries including Sweden. Due to different backgrounds, immigrant´s economic integration is even more important for their financial support and the economic growth of the host country. Consequently, the rising unemployment rate poses a threat requiring multiple efforts to integrate immigrants into the labor market. One way immigrants tackle unemployment is by opting for entrepreneurship. However, most prior studies within the field of immigrant entrepreneurship focus mainly on disadvantaged immigrants who face high entry barriers and limit themselves to labor-intensive and low-productive traditional sectors that are not fast-growing nor boost economic growth. This disadvantaged view on immigrants is challenged, and subjected to reassessment, especially in the urban context, due to which I shift the focus to highly educated and skilled first-generation immigrant entrepreneurs from non-EU backgrounds. To understand what facilitates this group of immigrants, I use a consolidated view of opportunity creation and discovery namely opportunity development which is at the core of the entrepreneurship process. Furthermore, opportunities are considered to originate from a business idea making it indisputable that recognition and evaluation of a business idea are vital in their development. Hence I use IPA to analyze data from 30 interviews, cross-checked with secondary data collected through online sources, and contribute with a model, that provides empirical evidence and theoretical perspective within immigrant entrepreneurship literature on how weak and strong social ties, prior work experience, and education of highly educated and skilled first-generation immigrant entrepreneurs influence them to recognize and evaluate business ideas during opportunity development in knowledge-intensive sectors. 

    Results show there was not a specific stage of opportunity development when either of the two social ties was more or less relevant, as knowledge flowed through both that helped bridge social distances. To persevere and overcome their foreign status, immigrants sought out weak social ties to get more acquainted with their host country. While they avoided involving some strong ties directly in business matters, however, they were equally important in providing emotional support and motivation. This resulted in increased self-efficacy in their capabilities and confidence in the feasibility, credibility, and legitimacy of their business ideas that helped overcome fears to make informed assessments, educated investments, and suitable adjustments. Furthermore, some weak ties turned into strong ties with time, such as ex-colleagues and clients who became lifelong friends, business partners, and advisors. Social ties also had a stronger impact when paired with the immigrant´s high human capital from pre-existing sources of specialized knowledge i.e., prior work experience and education as well as new knowledge gained through a systematic search with the help of social ties. Therefore, social ties are a source of new knowledge, while prior work and education are a source of social ties. A marginal number of immigrants felt frustrated with weak ties and as an alternative they relied on social networking websites, to connect with a wider global pool of potential business partners, clients, and skilled people. 

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  • Public defence: 2024-03-21 09:00 L30, NOD-huset, Kista
    Koutsopoulos, Georgios
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    KYKLOS - A modeling method and tool for managing changing capabilities in organizations2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The environments within which modern organizations are operating are characterized by constantly increasing volatility and diversity, which act as a driving force that continuously presents opportunities and threats to the organizations. The result of this situation is that these environments have become so dynamic that the phenomenon of organizational change is slowly becoming the new constant, rather than being an exception as in earlier years. The challenges arising from the need to handle constant change and evolution naturally lead to changing organizational capabilities. Information systems, as one aspect of an organization, can provide efficient support for the design and analysis of capabilities, and enterprise modeling can facilitate the development of specialized methods for this task. Hitherto, a plethora of capability modeling methods exist, providing a wide spectrum of perspectives.

    However, the support provided for managing the phenomenon of changing organizational capabilities remains limited, since existing methods have omitted to capture the elements necessary to depict organizational capabilities in motion and the motivations triggering such transitions. In addition, managing change requires more structured approaches, which should be methodologically supported and conceptualized.

    The goal of this PhD thesis is to develop a capability modeling method, called KYKLOS, that can support organizational change by modeling the changing capabilities of organizations and all the relevant aspects of this phenomenon. This work followed the Design Science Research framework, and started by explicating the problem via a literature review of existing capability meta-models; this was followed by the elicitation of method requirements, drawn from both the existing literature and a case study conducted in the domain of public healthcare in Sweden. Based on these requirements, an initial meta-model was developed, which was then demonstrated using the same case study and evaluated by experts through interviews. This activity resulted in an extension to the initial version of the meta-model, which was then instantiated via a case study conducted in the domain of public arts and culture in Greece. In parallel, the compatibility of other modeling approaches was explored. An extended version of the meta-model was then converted to its final version, which was suitable for the implementation of the modeling language in a tool, using the ADOxx meta-modeling platform. Simultaneously with the development of the tool, the syntax, semantics and procedure of the modeling method were created. The complete method was demonstrated through a case study at a company providing ERP solutions and consulting in Sweden, and the results were used to evaluate the method by two groups representing the stakeholder roles.

    The thesis contributes towards an improved management of change in organizations through the development of a method and complementary supporting tool, with the capability perspective as the focal point for the design and analysis of organizational change.

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  • Public defence: 2024-03-22 10:00 Magnélisalen, Kemiska övningslaboratoriet, Stockholm
    Gohel, Priya
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    The Drosophila POU/Oct factors: multifaceted proteins2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Dysregulation of physiological and cellular processes underlies various pathological conditions, including cancer and inflammatory disorders. Unraveling the molecular mechanisms driving these processes is crucial. The aim of this thesis was to investigate the roles of evolutionarily conserved POU/Oct transcription factors using Drosophila melanogaster as a model organism. The thesis highlights the functions of Nubbin (Nub) protein isoforms (Nub-PB and Nub-PD) in the regulation of cellular proliferation and mitosis, epithelial regeneration, and innate immune responses.

    In paper I, we demonstrate that Nub-PB acts as a potent transcriptional activator of immune and stress response genes, while Nub-PD represses their expression, indicating transcriptional antagonism by these Nub isoforms. Overexpression of Nub-PB in midgut cells effectively cleared local infections. However, prolonged Nub-PB overexpression caused a hyperactive immune response, leading to pro-inflammatory reactions, apoptosis, and reduced adult lifespan. These findings emphasize the importance of Nub protein isoforms in fine-tuning immune responses. 

    In Paper II, we generated and phenotypically characterized a Nub-PB-specific mutant revealing impaired gut morphology, disorganized visceral muscles, and aberrant lineage specification in the midgut. In addition, it displays impaired immune gene activation, shortened lifespan, and enhanced reactive oxygen species (ROS) expression, which correlates with increased numbers of gut microbiota, featuring an important role of Nub-PB in intestinal epithelium homeostasis. 

    In Paper III, we show that Nub-PD is necessary for proper nuclear divisions in transcriptionally silent pre-blastoderm embryos. The Nub-PD protein is enriched around the mitotic spindles in metaphase, requiring intact spindle microtubules. Live imaging of mitotic divisions revealed that Nub-PD is involved in the maintenance of spindle organization and its dynamics. We also infer similar mitotic roles for Nub-PD in S2 cells and for Oct1/POU2F1 in human cell culture. Our findings unveil a direct role of POU/Oct factors in proper mitotic progression, which may be evolutionarily preserved among insects and mammals.

    In Paper IV, we study how the loss of Nub and Pdm2 proteins affects wing growth and development. We found that Nub-PD is specifically required for cell proliferation, while balanced Nub-PB and Nub-PD expression levels at the dorso-ventral boundary are essential for correct wing margin formation. 

    Overall, this thesis elucidates crucial roles of Drosophila POU proteins in maintaining immune and tissue homeostasis and aditionally uncovers mitotic roles of POU/Oct factors, suggesting new functions in regulation of cell proliferation and development.

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  • Public defence: 2024-03-22 10:00 hörsal 4, hus 2, Albano
    Folkesson, Pontus
    Stockholm University, Faculty of Humanities, Department of History.
    Att skola en stormakt: Framväxten av 1600-talets skolsystem genom lokalsamhällets aktörer2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis shows how Swedish urban schools were reformed, expanded and developed into a school system following the 1649 school curriculum. While previous research has emphasized different educational needs within the context of normative school curriculum or in relation to the emerging power of the state, this study argues that the expansion of urban schools must be understood as a response to local community actors and their interests. Gustav II Adolf's school reform comprised a resource-saving reorganisation. In spite of this reform, urban schools expanded, with the crown finally assuming the financial responsibility for the kingdom's schools in 1649. This study examines the reasons for this using the diocesan towns of Västerås and Strängnäs and the market towns of Arboga, Nyköping, Södertälje and Örebro.

    By using a wide range of source material, including school regulations, royal correspondence, cathedral copy books, matriculation registers and especially accounts, this book analyses the development of urban schools. Starting from the schools' funding and how that funding was used, the study identifies different actors and their interests. The involvement of the local community, which responded to the school reforms and their educational interests, explains the expansion of urban schools between 1620 to 1649.

    The results show that local community actors, such as bishops, the bourgeoisie, urban vicars and schoolmasters, played a crucial role in establishing and maintaining urban schools. In contrast to previous research, which has considered the growth of the state to be the result of negotiations between local actors and a central elite, the expansion of the urban schools up to 1649 should be seen as a reaction of local community actors to the state's reduction of resources. The bourgeoisie and bishops then acted to reshape the original school reform that Gustav II Adolf had presented in 1620.

    Rather than an unambiguous top-down or bottom-up process, the expansion of schools up to 1649 can be explained as the result of an interweaving of negotiations, conflicts and restructuring at different levels of society. These interactions led to a gradual hierarchization of existing schools in the kingdom's towns, which were then incorporated into a new school system.

    The political influence of the bourgeoisie was manifested by the preservation of the schools in the market towns; at the same time, their educational goals were incorporated into a common curriculum and school type for the entire kingdom, trivialskolan. The bishops successfully ran their prestige projects, gymnasieskolorna, which significantly strengthened the finances of the dioceses and made the diocesan towns prominent centers of education. At the same time, the crown's influence over urban schools increased. Thus, the expansion of the kingdom's schools up to 1649 can be regarded as a compromise of several actors’ interests.

    The results of this thesis show how the bourgeoisie and the clergy succeeded in manifesting their political influence, which was usually formulated outside the more institutional contexts of the Riksdag. The schools functioned as arenas where local interests and resources were aggregated. The study provides new insights into how the schools' actors influenced and shaped political decisions and processes, which were in turn significant for the overall social development of the early modern towns and the formation of the state in 17th-century Sweden.

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  • Public defence: 2024-03-26 13:00 sal FP41, hus 1, AlbaNova universitetscentrum, Stockholm
    Coates, Michael R.
    Stockholm University, Faculty of Science, Department of Physics.
    Fundamental interactions in transition metal reactions2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Transition metal complexes that participate in homogeneous reactions often perform the role of a catalyst, facilitating novel reaction pathways. When these complexes are pushed away from their equilibrium, the arrangement of the coordinating ligands around the metal center is perturbed and new reaction pathways are opened. By using a light-induced “trigger” to push the metal complex away from its equilibrium, this process can be initiated with precision. This thesis is concerned with the theoretical understanding of light-induced “triggered” reactions that generate transient, short-lived photoproducts in solution, capable of reacting with the surrounding solvent medium. A combination of theoretical and experimental tools are employed to give precise information about the formation and decay of these transient photoproducts.

    In an effort to understand the innate differences between a broad range of transition metal complexes, electron configurations of the metal and its coordinating ligands are a natural starting point. These distinct electronic structures define the physical structure of the transition metal complex and explain the reactivity or lack of reactivity of the transition metal complex. To describe these electronic structures, robust quantum chemistry methods are required. Coinciding with these methods is a theoretical framework that aims to simulate the evolution of molecules by means of a molecular dynamics simulation.

    The present work involves the study of ironpentacarbonyl or Fe(CO)5 which we use to explain the reactive landscape of a broad class of carbonyl coordinated transition metal complexes. The part of the thesis devoted to Fe(CO)5 is divided into distinct sections (i) the short-time (femtosecond-to-picosecond) gas-phase excited state molecular dynamics that produces the transient species, (ii) the long-time (picosecond-to-nanosecond) liquid-phase ground state molecular dynamics which describes the intermediates formed by the transient species and (iii) the experimental probes of the former sections. A final part of the thesis connects carbonyl containing metal complexes to another broad and detailed class of nitrosyl containing metal complexes.

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  • Public defence: 2024-03-27 10:00 Room 2403, Department of Education, Stockholm
    Munhall, Brendan
    Stockholm University, Faculty of Social Sciences, Department of Education.
    Bounded Horizons: A study of upper secondary school choice for newly arrived students2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Graduating primary school students in Sweden choose their upper secondary school within a unique quasi-market school system. The students may choose specialized programs but must also be accepted based on grade rankings by the schools. Despite equity arguments for the school choice model, opportunities are not equally available for all students. Newly arrived students in particular may face challenges in their school selection process, leading to limited availability, especially within metropolitan areas. However, there is a lack of research exploring newly arrived students’ own experiences and attitudes towards school choice in this setting. The aim of this study is to investigate newly arrived students’ own experiences and their understanding of the upper-secondary school choice process.

    In this study, twenty-two newly arrived year-nine students in the metropolitan Stockholm area were interviewed about their experiences during the school choice process. Semi-structured interviews conducted in the students’ mother tongues explored their educational backgrounds, social interactions, school experiences and academic aspirations during the 2019/2020 school year. In addition, eight of their teachers and guidance counsellors were interviewed. The student responses were analysed through thematic analysis using a combination of concepts including horizon for action, cultural and social capital, the grapevine and structural and symbolic boundaries.

    In the results, the newly arrived students were shown to be a diverse group with varying languages and levels of preparedness for the Swedish education system. They shared similar experiences in the upper secondary school process, marked by subtle differences due to their available resources and the different actors that they interacted with. Marketing strategies used by the upper secondary schools themselves had a substantial influence on the students although many of the students found this information hard to navigate. Guidance from the school, in both a formal sense from guidance counsellors and informally by other educators had a positive effect but was dependent on the engagement of the educators. The students’ parents had a limited influence on their childrens’ choice process, largely due to their own recent arrival in Sweden. Finally, due to the structure of schools, the newly arrived students interacted with other newly arrived students more than with Swedish students, giving them limited peer information about upper secondary schools. 

    These findings shed light on the experiences of an often overlooked group of students, offering a fresh perspective on the Swedish education system. Many of these students faced challenges in choosing upper secondary schools based on the grades they achieved during their relatively brief time in Sweden and the neighborhoods they resided in. Their school preferences were further shaped by the limited support from both their social circles and the educational institutions themselves. Consequently, these students were vulnerable to the influence of targeted marketing and unsubstantiated rumors. However, this phenomenon wasn't universal. Dedicated educators, particularly those who shared a common language or cultural background with the students, provided meaningful guidance. These findings are significant for identifying limited opportunities for an under researched group within the Swedish education system and giving insight into how they may be better supported.

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  • Public defence: 2024-03-27 13:00 Sal FB55, AlbaNova universitetscentrum, Stockholm
    Jansson, Matti
    Stockholm University, Faculty of Science, Department of Physics.
    Improvements for IceCube Event Reconstruction through Geometry Calibration and Photon Timing Distributions2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The origin of high-energy cosmic rays is an unsolved mystery because cosmic rays do not travel in a straight line but are bent by magnetic fields due to their electric charge. High energy neutrinos are predicted to be created close to these origins, and are an unambiguous probe, while gamma rays could be obscured or created by other processes. The IceCube Neutrino Observatory at the South Pole has instrumented one cubic kilometre of ice to a depth of 2.4 km by deploying digital optical modules (DOMs) in 86 drill holes. As neutrinos interact in the ice, they create secondary particles which generate Cherenkov light. The light is detected by DOMs and given the timing and the location of the DOMs the event can be reconstructed and the direction of the neutrino's origin can be determined. 

     

    So far, IceCube has used the original location of the drill towers for the positions of DOMs in the horizontal plane. Previous attempts to determine the x-y coordinates of the DOMs, relying on data from the drill head or in-situ calibration, could not improve on these generic position estimates or reduce their estimated uncertainty below a few metres. This thesis presents a new method for calibrating the positions of the DOMs. A large sample of muon tracks is used as a calibration light source throughout the detector volume, and a maximum likelihood-based approach is used to determine the positions of DOMs. The method has been applied to 18 central strings, and found statistically significant shifts of the order of 1-2 m from nominal positions for four strings. The results led to, and have been corroborated by, a new study using LED flashers,which has also found deviations in other parts of the detector. There are also indications that calibration of individual DOM positions are possible.

     

    Modelling how light propagates in the ice is of fundamental importance and over the last decade the knowledge of the ice has progressed and in particular the knowledge on how the birefringent properties of ice impact scattering of light. So in an effort to both improve sensitivity of the geometry calibration above and improve event reconstruction, this thesis also presents work done to better incorporate current knowledge of the glacial ice optical properties when reconstructing muon tracks. There is some evidence that this has resulted in a better description of the light distribution in the detector.

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  • Public defence: 2024-03-28 13:00 Lilla Hörsalen, Kista
    Alam, Mahbub Ul
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Advancing Clinical Decision Support Using Machine Learning & the Internet of Medical Things: Enhancing COVID-19 & Early Sepsis Detection2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis presents a critical examination of the positive impact of Machine Learning (ML) and the Internet of Medical Things (IoMT) for advancing the Clinical Decision Support System (CDSS) in the context of COVID-19 and early sepsis detection.

    It emphasizes the transition towards patient-centric healthcare systems, which necessitate personalized and participatory care—a transition that could be facilitated by these emerging fields. The thesis accentuates how IoMT could serve as a robust platform for data aggregation, analysis, and transmission, which could empower healthcare providers to deliver more effective care. The COVID-19 pandemic has particularly stressed the importance of such patient-centric systems for remote patient monitoring and disease management.

    The integration of ML-driven CDSSs with IoMT is viewed as an extremely important step in healthcare systems that could offer real-time decision-making support and enhance patient health outcomes. The thesis investigates ML's capability to analyze complex medical datasets, identify patterns and correlations, and adapt to changing conditions, thereby enhancing its predictive capabilities. It specifically focuses on the development of IoMT-based CDSSs for COVID-19 and early sepsis detection, using advanced ML methods and medical data.

    Key issues addressed cover data annotation scarcity, data sparsity, and data heterogeneity, along with the aspects of security, privacy, and accessibility. The thesis also intends to enhance the interpretability of ML prediction model-based CDSSs. Ethical considerations are prioritized to ensure adherence to the highest standards.

    The thesis demonstrates the potential and efficacy of combining ML with IoMT to enhance CDSSs by emphasizing the importance of model interpretability, system compatibility, and the integration of multimodal medical data for an effective CDSS.

    Overall, this thesis makes a significant contribution to the fields of ML and IoMT in healthcare, featuring their combined potential to enhance CDSSs, particularly in the areas of COVID-19 and early sepsis detection.

    The thesis hopes to enhance understanding among medical stakeholders and acknowledges the need for continuous development in this sector.

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  • Public defence: 2024-03-28 13:00 hörsal 4, hus 2, Campus Albano, Stockholm
    Tobian, Arne
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Entering the dynamic risk space: Assessing planetary boundary interactions through process-based quantifications2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The planetary boundaries framework is an effort to define a safe operating space for humanity. Its rationale is that sustainable development needs to be achieved in ways that safeguard the stability of the Earth system on which human prosperity relies. However, very few studies explicitly examine the interactions of the Earth system processes that underlie individual boundaries.

    My overarching research question is: how can continued anthropogenic climate change affect the geospatially resolvable land and water planetary boundaries, and what are the implications for human livelihood? For most of my analysis, I use the LPJmL dynamic global vegetation model because it contains suitable process representations that provide a dynamic and adaptive Earth system perspective for my investigation of key planetary boundary interactions of the climate, land, water and ecosystem nexus.

    Paper I emphasizes the importance of green water dynamics (that is terrestrial precipitation, evapotranspiration and plant-available soil moisture) for ecosystem resilience and human well-being. The underlying analysis suggests that the current status of the proposed planetary boundary for green water is already transgressed. Paper II reveals long-term spatiotemporal dynamics of planetary boundary interactions as breaching the climate change boundary critically affects the world’s major forest biomes. Notably, the most extreme climate change scenarios led to the emergence of a southern boreal dieback in the simulations. Tropical forests further show a shift from evergreen to deciduous rainforest, an important process which is not captured by the definition of the land-system change boundary. Maintaining climate change at the planetary boundary co-stabilizes the land-system change boundary. Paper III extends the biophysical understanding of planetary boundary interactions by discussing their impact on human livelihood and the attainment of the Sustainable Development Goals. Future climate change causes increases in dry anomalies of green water in ~30% of the global land area by the end of the century. As of today (here referring to 2015), nearly a quarter of the world population and ~28% of global harvest would be affected. The dynamic risk space terminology is established to fill the conceptual gap in the analysis of planetary boundary interactions. Paper IV highlights how planetary stability constitutes the non-negotiable fundament for human development and argues why the Sustainable Development Goals have to be aligned with the planetary boundaries framework and which perils might arise from their interactions. Paper V presents the land-system change reallocation tool algorithm which allows for a scenario-driven rearrangement of human land-use to meet varying transgression levels of the land-system change boundary. 

    My results of Paper I-V advance the understanding of interactions in the planetary boundaries framework. Moreover, my analysis in a process-based and validated modeling environment gives spatiotemporal detail of the processes at play that exceeds the potential of previously used conceptual models. My work fills a crucial gap in the operationalization of the planetary boundary framework by providing insights into how and where different policy options produce positive or negative outcomes across boundaries. The holistic understanding I present is a prerequisite for any application of the planetary boundaries framework that focuses on future conditions.

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  • Public defence: 2024-04-03 09:00 ALB Hörsal 4, hus 2 Albano, Stockholm
    Nyasulu, Maganizo Kruger
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    A Triply Green Revolution: Building water resilience for SDGs on food and poverty for Africa2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Sub-Saharan Africa is confronted with the urgent challenge of ensuring food security in the face of changing demographics, climate change and water vulnerability, which can lead to potential crop failure. Despite the high advocacy for technological solutions, such as irrigation, rainfed agricultural systems, which account for more than 90% of the region's food production, often remain overlooked. This raises the question of which water sources can be sustainably utilized to meet the Sustainable Development Goals. This thesis investigates the significant role of "green water" in addressing these challenges in agricultural production and ecosystem health in the sub-Saharan African region. 

    Application of models reveal the pronounced role of green water in African forest systems, regional ecosystems, and food production systems in studying these societal sustainability questions,. The study projects a decrease in precipitation recycling with increasing severity of climate change. The results suggests that regions with lower water efficiency per yield production can significantly increase agricultural yield by tapping into green water sources as improving rainwater management systems, even as land-sourced precipitation is projected to decline more than oceanic sources. 

    The thesis argues for adoption of a green water-centric approach to be opted in strategic plans at both local and global levels. Moreover, by capitalizing on green water resources, less developed nations such as sub-Saharan Africa can fulfill their Sustainable Development Goals without the need for significant technological investments and the associated environmental risks.

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  • Public defence: 2024-04-05 10:00 Hörsal 6, Stockholm
    Jönsson, Elin
    Stockholm University, Faculty of Social Sciences, Department of Criminology.
    Hardened Responsibility?: Contestations and Contradictions in the Regulation of Corporations2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Throughout the last decades, the social responsibility of corporations has undergone significant changes. From revolving around self-regulation, voluntariness, and soft law, the regulatory landscape has expanded to involve harder demands on corporations, such as mandatory sustainability due diligence. This thesis considers these changes as a hardening of Corporate Social Responsibility (CSR), and explores such hardening as an outcome of contestation and struggle. In doing so, it echoes critical scholars’ call for criminology to direct attention toward the harms committed by powerful entities – in this case, large corporations in the global context – and the interests that frame the regulatory response to such harms. 

    Three papers are included in this thesis, focusing on key actors that participate in the contestation and struggle under study: politicians (Paper I), corporations (Paper II), and non-governmental organizations (Paper III). The first two papers consider struggles for and against regulatory hardening, and shed light on the contradictory dynamics that permeate these struggles, while the third paper explores how organizations struggling for justice in the wake of corporate harm seek to alter the contours of the existing regulatory landscape. Taken together, the papers offer insight into how social actors articulate demands for change, or resist such change, and their underscoring interests or ambitions.

    This thesis situates these findings in previous research on the regulation of corporate social and environmental responsibility, considers the papers’ methodologies, and develops the theoretical lens through which the findings can be understood. The final analytical discussion considers the hardened regulations as solutions, with the problem at hand being the paradigm of self-regulation and voluntariness that has long characterized CSR. This problematization is interpreted as an articulation of internal critique, in which social actors strive for consistency between practices and normative expectations. Thus, new regulatory practices, which conform to these expectations, have been proposed. The analysis then traces this problematization, and the contestation around it, to fundamental contradictions. Drawing attention to the inherent contradictoriness of CSR as a social formation, it argues that this should be understood as the driving force behind contestation and thus the hardening trend itself. In addition, the analysis considers the transformative potential in actors’ struggles, suggesting that some may go beyond an adjustment of regulatory practices to an existing normative framework.

    All in all, the thesis contributes to criminological research on corporate responsibility by highlighting the dynamics of conflict and contradiction involved in contemporary regulation. Moreover, by understanding hardening as a solution to a problem, revolving around the shortcomings of CSR – which was itself introduced as a regulatory solution in the 1990s – the thesis situates the regulation of today in a historical development. By doing so, it draws attention to both continuity and change in this regulatory landscape. 

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  • Public defence: 2024-04-05 13:00 Vivi Täckholmsalen (Q-salen), NPQ-huset, Stockholm
    Dort, Hanna Nicole
    Stockholm University, Faculty of Science, Department of Zoology.
    Exploring the role of gene duplications in plant-insect interactions2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    As evolutionary biologists, we are often curious about the genomic origins of our favorite adaptations. Although some innovations certainly arose de novo, many more originated through the process of whole-gene or within-gene duplication. Following whole-gene duplication events, at least one gene copy is thought to be under relaxed selective constraints, meaning that mutations can accumulate within the gene and potentially give rise to novel adaptive traits. In this thesis, I aim to identify how gene duplication events have helped caterpillars cope with toxic host plants. Building upon the already-extensive literature on plant-insect coevolution, I highlight the complexity underlying detoxification phenotypes.

    The research presented in Chapters II and III focuses on a family of genes coding for insect nitrile-specifier proteins (NSPs). These NSP-like genes are the canonical detoxification genes in Pierinae butterflies, allowing for the detoxification of the glucosinolates defenses present in their host plants. Importantly, the NSP-like gene family was formed through gene duplication events, with two key genes (NSP and MA) originating from the same ancestral gene. In Chapter II, Crispr-Cas9 methods were used to create lines of Pieris brassicae that lacked functional copies of NSP and/or MA. Through feeding assays on natural host plants, we showed that either NSP or MA are necessary for larval survival on plants containing aliphatic or benzyl glucosinolates – but not indole glucosinolates. Further, NSP seemed to be specialized for aliphatic glucosinolate detoxification, suggesting that some degree of subfunctionalisation occurred following gene duplication.  Expanding on these findings, we focused on the regulatory consequences of NSP-like family gene knockouts in Chapter III, looking specifically at the transcriptomic response to three host plants with vastly different glucosinolate profiles. We ultimately discovered that the response to host plant change was strongest when all NSP-like genes were functional, suggesting that the NSP-like gene family is part of a larger regulatory response to host plant defenses. 

    While the above chapters center around gene duplicates that have already been associated with adaptations to host chemistry, there are likely more gene families out there that have been important for caterpillars overcoming ever-escalating plant defenses. In Chapters I and IV, I sought to identify some of these families using comparative genomic analyses. In Chapter I, I used genomes from across the Lepidoptera to see if diet breadth could be correlated with gene family sizes. I found that two serine protease families were larger in specialists and that a family of glutathione-S-transferases was larger in generalists. Due to the scope of the study, I was unable to associate gene duplication events with any particular host plant toxins. This knowledge gap ultimately led to the development of the work in Chapter IV, which centered specifically on instances of gene duplication and death in the Pieridae that occurred following major chemical changes in hosts. In addition to confirming that NSP-like genes are lost upon shifts away from Brassicales-feeding, we found that a subset of sulfotransferases existed in higher copy number in species that feed on glucosinolates.

    Overall, this thesis shows that gene duplication may be important for insect dietary transitions, and that gene duplicates can become specialized to dynamically respond to host plant chemical profiles. It also provides a starting point for future studies, as open questions remain about the role of general detoxification mechanisms during initial transitions on to plants with novel chemical defenses. 

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  • Public defence: 2024-04-08 13:00 Hörsal 3, hus B, Södra huset, Stockholm
    John, Ben Malinga
    Stockholm University, Faculty of Social Sciences, Department of Sociology. Max Planck Institute for Demographic Research.
    Union-Fertility Nexus and Fertility Variation in Sub-Saharan Africa: The Role of Marital Dissolution and Repartnering2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The role of marital dissolution and repartnering in shaping fertility patterns in sub-Saharan Africa (SSA) has been largely overlooked, even though marital dissolution and repartnering are fundamental features of marriage dynamics in this region. This dissertation addresses this gap by using existing statistical and demographic techniques and developing new demographic methods to (i) examine the relationship between union dissolution and fertility at the micro level (Study I); (ii) assess the dynamics of union dissolution, including the levels of all-cause first union dissolution, the timing of first union dissolution, and the reproductive years spent outside of marriage due to union dissolution (Studies II & III); and (iii) analyze the influence of marital dissolution and repartnering on macro fertility patterns in SSA (Study IV). The analyses are mainly based on Demographic Health Survey data collected in 34 SSA countries since 1986. The findings show that marital dissolution is associated with reduced fertility at both the individual and the population level, and remarriage does not fully compensate for lost fertility at the individual level. The assessment of the dynamics of union dissolution indicates that union dissolution is common, it typically occurs at relatively early reproductive ages, and the number of reproductive years lost due to union dissolution is minimal. Furthermore, this dissertation documents that cross-country differences in union dissolution and repartnering rates account for 9.4% of cross-country fertility differences in SSA. In addition, the results show that changes in marital dissolution and repartnering rates and the fertility behaviour of women who experience these events mostly contributed to the slow pace of fertility decline in this region. For the SSA region (as a whole), fertility would have declined 1.24 times faster in the absence of such changes. These findings demonstrate that marital dissolution and repartnering are important drivers of fertility variation in SSA, and thus highlight the value of integrating these dynamics into the discourse on the union-fertility nexus and fertility variation in SSA and beyond.

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  • Public defence: 2024-04-09 13:00 Aula NOD, NOD-huset, Kista
    Öberg, Johanna
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Digitala resursers påverkan på delaktighet i lärmiljöer: En studie av högstadieelevers delaktighet2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This dissertation explores the potential of digital resources to support students' participation in learning environments. The research questions focus on the student perspective on participation in formal and informal learning environments, as well as the role digital resources can play in promoting student participation in school instruction.

    Four participant-based studies investigate students' and teachers' views on how technology-enhanced learning can benefit the significant interactions that promote participation in learning environments. Students express a lack of digital resources actively supporting their participation in school compared to experiences from their personal lives. They emphasize the need for increased use of digital resources for information management and interactions in the learning process. Teachers stress the importance of being able to provide timely and specific feedback to students through digital platforms. They also express the need to visualize students' reasoning and to compile and have updated results at both individual and group levels. Both teachers and students identify the potential of digital resources to increase student participation, for example, by developing digital resources that can handle information flows and provide a common platform for interaction and collaboration. Learning is facilitated and strengthened by meaningful social participation, which needs to be related to the ongoing development of learning environments in the rapidly changing digital landscape.

    To promote student participation with the support of a technology-enhanced learning environment, a balance is required between meeting students' needs, content requirements, and teachers' challenges in conducting quality teaching with digital resources as support. The dissertation presents principles regarding the use of digital resources to promote student participation. The principles focus on accessibility, individual adaptation to different learning styles, and strengthening students' community. These principles, derived from teachers' experiences, are believed to support teachers' pedagogical practices in the aim of increasing student participation in the learning process. Teachers see many applications within technology-enhanced learning to support both student participation and engagement. However, the low availability and reliability of digital resources in schools constitute a significant barrier.

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  • Public defence: 2024-05-02 13:00 Vivi Täckholmssalen (Q-salen), NPQ-huset, Stockholm
    Larm, Malin
    Stockholm University, Faculty of Science, Department of Zoology.
    Relationship between wildlife and tourism: interdisciplinary insights from Arctic fox tourism in Sweden2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Interactions between wildlife and tourism can be studied from several different perspectives and the effects of such interactions can influence animals both positively and negatively with effects on both individual and population levels. This thesis takes an interdisciplinary approach, combining both natural and social perspectives, when studying the effects of tourism activity on a small population of the endangered arctic fox (Vulpes lagopus). We have studied arctic foxes inhabiting disturbed and undisturbed den sites in Helagsfjällen, which is the southernmost population of arctic foxes in Sweden and a popular area for recreational activities such as hiking, skiing and camping. The overall objective of the thesis has been to contribute to good management of both arctic foxes and tourism within the study area, as well as to contribute with a comprehensive study of simultaneous disturbance effects and fitness consequences of wildlife tourism activities to the scientific field of wildlife-tourism interactions. The first two papers focus on different aspects of behavioral responses of arctic foxes towards human activity, the third paper evaluates potential fitness consequences and the fourth paper focus on the tourist aspect of the interaction. Behavioral changes in response to tourism disturbance that have been identified in the foxes include changes in vigilance and probability of hiding (Paper I), temporal activity shift at the den site (Paper II) and increased tolerance to human activity (Paper I, Paper II). Juvenile summer survival was higher at disturbed dens compared with undisturbed dens during years of declining small rodent densities (Paper III). Small rodent decline years is when the predation on arctic foxes is presumed to be highest and we suggest that the positive fitness effect could be mediated by a human-induced predator refuge for the foxes in close proximity of human activity. On the tourist aspect, we have identified effects on behavior, knowledge and awareness of the situation for arctic foxes and related conservation work (Paper IV). Overall, results in this thesis showed a high level of context-dependency, which highlights the importance of considering factors such as food availability, intra-species interactions and individual traits such as previous experience with humans. Consequently, the work in this thesis together with ongoing studies of hormonal stress responses constitutes one of the more comprehensive scientific studies of tourism effects on terrestrial mammals. The output from this thesis brings important deliverables for species-specific management and conservation, but also for other species given the rapidly growing interest for wildlife tourism.