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  • Public defence: 2019-03-27 14:00 Magnélisalen Kemiska övningslaboratoriet, Stockholm
    Ermilova, Inna
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Modeling of biomembranes: from computational toxicology to simulations of neurodegenerative diseases2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    It was known from the middle of the last century that a cell-membrane is a lipid bilayer. Since that time a large number of experimental studies has been done in order to see how a certain molecule can penetrate through a membrane. Due to the complexity of laboratory experiments computational chemistry became a convenient tool for investigations involving this process. In a real life a compound has to pass through several membranes of different chemical composition before reaching the actual target. Such a diversity in constitution gives a various selectivity to cell-membranes: some molecules will penetrate through them and others will not. That is why the development and a choice of suitable models for lipid bilayers are important steps in such a research. In this thesis new all-atomistic models for polyunsaturated phospholipids in cis conformations have been derived and added to the SLipids force field. After a successful force field validation, the new lipid models were used in molecular dynamics and well-tempered metadynamics simulations of several problems, such as toxicity of hydroxylated polybrominated diphenyl ethers (OH-PBDE), behavior of cholesterol in various membranes, an aggregation of amyloid-β (Aβ) peptides. The significance of the presence of lipid unsaturation has been demonstrated by all computations. 2’-OH-BDE68 (ortho) showed the affinity to saturated lipid bilayer, but had more conformational variations in the center of the unsaturated membrane. Cholesterol did not exhibit the preference to polynsaturated lipid bilayers from free energy calculations, but the diversity in orientations of this molecule, depending on its locations was observed. The behavior of Aβ peptides was dependent on membrane saturation as well. The insertion of Aβ peptides was detected in lipid bilayers containing higher amounts of polyunsaturated phospholipids, while in systems with more saturated membranes amyloids aggregated on membrane surfaces. Moreover, a comparison of simulations for quadro- and mono-component lipid bilayers showed that the membrane built of 18:0-22:6 PC can serve as a good model for the ’healthy’ tissue of a human brain. Also the lipid bilayer built of 14:0-14:0 PC exhibited similar features as the quadro-lipid membrane representing the brain tissue affected by Alzheimer’s disease. Good agreement of some computational results with available experimental findings demonstrated the applicability of computer simulations to real life problems.

  • Public defence: 2019-03-29 10:00 De Geersalen, Geovetenskapens hus, Stockholm
    Snoder, Per
    Stockholm University, Faculty of Humanities, Department of Language Education.
    L2 Instruction and Collocation Learning: Classroom intervention research on input processing with L1 Swedish adolescent learners of English2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    An important dimension of learning a second language (L2) is to build up a store of recurring word combinations that native speakers use. These so-called formulaic sequences (FSs) serve many functions in fluent language use. One category of FSs is collocations, defined in the present thesis as combinations of a verb and a noun in English with a significant attraction to each other, for example ‘carry a risk’. Research has shown that L2 English learners struggle with the appropriate use of collocations but reviews of instructional interventions have concluded that few guidelines for effective pedagogical treatment of collocations are available. 

    The thesis has investigated the impact of L2 instruction on collocation learning by manipulating the conditions for input processing of treatment materials containing target collocations (TCs). Three classroom pre-test/post-test intervention studies (Studies I-III) were conducted, with a total of 165 L1 Swedish adolescent learners of English. Study I compared a form-focused approach to a meaning-focused approach to the same materials to find out why the former may be more effective than the latter as shown in previous studies. Study II focused on the effects of three manipulations of the materials: how deeply the learners process the TCs, whether re-exposures to TCs are spaced or concentrated, and whether the learners process TCs with or without post-test announcement. Study III examined the potential for a collaborative text reconstruction task to facilitate TC learning. Two modified versions of the task were created that contained different types of priming to the TCs in a pre-task activity.

    Results of Study I show that learners in the form-focused condition, having studied decontextualized TCs and been introduced to the term ‘collocation’, were able to connect words that they previously only knew as single words into collocations. Results also show that a researcher-developed version of stimulated recall interviews was successful in probing learners’ mental processes. As for Study II, surprisingly, neither deep processing nor a spaced re-exposure schedule was effective for TC learning, while post-test announcement was. Results of Study III reveal that a pre-task activity that induced learners to elaborate on TC meaning outperformed a pre-task activity with a form-focused elaboration of TCs, notably for the delayed post-test of productive TC knowledge.

    Taken together, the results of Studies I-III show that L2 English teachers, with relatively small changes in their classroom procedures, can actively contribute to increasing their learners’ collocational competence, an integral part of more advanced proficiency. It is hoped that the successful implementation of the three studies will inspire more instructional interventions on L2 vocabulary learning in Swedish schools and universities, targeting single words and FSs.  

  • Public defence: 2019-03-29 10:00 föreläsningssalen, Filmhuset, Stockholm
    Harkema, Gert Jan
    Stockholm University, Faculty of Humanities, Department of Media Studies.
    Aesthetic Experiences of Presence: Case Studies in Film Exhibition, 1896-18982019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This study investigates viewing experiences that came with the introduction of cinema. Merging (film) history with aesthetic theory, this dissertation entails historically informed theoretical reconstructions of viewing experiences between 1896 and 1898. During this novelty period, projected moving pictures evoked a wide array of reactions: on the one hand, early cinema was an extraordinary and astonishing attraction while, on the other hand, it was deeply rooted in daily life and everyday perception. To contemporary audiences, early moving pictures presented an unevenness hovering between amazement and contemplation. This study argues that the cinematograph, the vitascope, and other animated-picture attractions were popular at this early stage because they immediately appealed to the senses. These sensations are subsequently discussed as effects of presence. Early moving-picture exhibitions, moreover, can be seen as performances involving spectators in a play with presence vis-à-vis absence. While moving-picture attractions had an immediate impact on the viewer’s body as situated in the “here and now” of the auditorium, the pictures presented places and objects that were irrevocably inaccessible and absent. Exploring different viewing situations in two different contexts, the current study therefore proposes the aesthetic experience of presence as a framework to understand these various late 19th-century viewing experiences.

    The three chapters of this dissertation are organized separately around the concepts of intermediality, movement, and space. Chapter 1 proposes that, in the context of fairgrounds in the Netherlands, early cinema’s “intermedial enmeshing” is a probable cause for the aesthetic experience of presence. This chapter employs the concept of intermediality to outline how the kinematograph attraction caused both a semantically rich as well as a sensuously multivalent experience. It then presents a detailed study of the activities and attractions of the showman Henri Grünkorn before he exhibited “Electric Cinematograph.” Chapter 1 also investigates the various layers of discourse involved in Aladin ou la lampe merveilleuse (1897), a series of scenes exhibited by Grünkorn that was popular with local audiences at the time.

    Chapter 2 focuses on the experience of movement. Through a close study of the introduction of moving images in the context of Chicago in 1896 and 1897, it proposes that moving pictures presented a radically familiar form of motion. It was familiar in the sense that it brought together a number of constellations of motion and energy fundamental to modernity. Situating moving images in the rhythms of the city allows us to conceptualize the spectator as physically engaged with the motion of the kinematograph. Chapter 3 studies the paradox of proximity and distance and discusses moving-picture attractions as they were introduced in vaudeville and popular theater in Chicago. It describes the different constellations between screen and live performance from a spatial perspective while focusing on the representation of bodies. In many ways, the paradox of nearness and distance allowed for a spatially oriented play with presences. The study concludes with a discussion on the potential and challenges of including presence effects in film-historical research on viewing experiences in early cinema and beyond.

  • Public defence: 2019-03-29 10:00 Vivi Täckholmsalen (Q-salen) NPQ-huset, Stockholm
    Schramm, Frederic Dominique
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Stress response regulation and protein aggregate inheritance in Caulobacter crescentus2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Many stress conditions a cell encounters threaten the continuation of basic biological processes ultimately endangering its survival. Heat shock and antibiotic exposure can lead to a sudden surge of protein un- and misfolding, while nutrient starvation directly causes a lack of energy and molecular building blocks. Our understanding of how cells integrate environmental stress signals, execute protective functions and handle persistent damage is still far from comprehensive. In this thesis the model bacterium Caulobacter crescentus was used to answer basic questions about the regulation and execution of bacterial stress responses and damage clearance.

    Persistent larger protein aggregates can be maintained as remnants of a past stress exposure and in all of the few bacteria studied to date these particles collect at the poles. In the symmetrically dividing bacterium E. coli this aggregate localization pattern was shown to lead to an old pole lineage-specific retention. In paper I, we studied aggregate formation and inheritance in an asymmetrically dividing bacterium. While aggregates are dissolved by molecular chaperones following moderate heat stress, intense stress induces the emergence of long-lived aggregates. Surprisingly, we find that the majority of persistent aggregates do not collect at the old poles but instead describe a mechanism by which they are constantly displaced towards the new pole. This causes inheritance of aggregates by old and new pole cells at a stable rate without lineage-specific retention, a previously unknown pattern of aggregate inheritance in bacteria.

    While we found that deletion of most chaperones in C. crescentus does not affect viability in the absence of stress, the mechanistic basis for why DnaK, like in other bacteria, is also required in the absence of stress remains unclear. In paper II, we show that DnaK's function as a negative regulator of the heat shock sigma factor σ32 is essential for viability at physiological temperatures and uncover potential new layers of σ32 regulation. We find that the σ32-dependent response comprises a reallocation of resources from proliferative to maintenance functions and in addition to its known function in blocking DNA replication also affects other processes like protein translation, a process vulnerable to proteotoxic stress. Prolonged unrestricted activity of this stress response induced by the absence of DnaK is lethal. We conclude that while DnaK is essential for protein folding at elevated temperatures, its evolutionarily newer function in balancing the cell's proliferative and maintenance programs is a requirement for survival.

    Growth and cell cycle progression is also regulated in response to nutrient limitation. Like under heat shock conditions, we show in paper III that carbon starvation during entry into stationary phase leads to a block of DNA replication for which, in contrast to heat stress, the molecular basis was not yet understood. We find that downregulation of DnaA levels is achieved by an as yet unknown nutrient availability sensing process involving the 5' untranslated region, inhibiting translation of the dnaA mRNA, which combined with constant degradation of DnaA by the protease Lon results in its elimination. This study provided new mechanistic insight into nutrient-dependent control of DNA replication and shows that the same regulatory outcomes can be achieved through different means depending on the stress response.

    In conclusion this thesis describes the discovery of an unanticipated alternative way of protein aggregate inheritance with implications for our view on damage segregation in bacterial populations as well as new mechanistic insight into how cells balance proliferative with protective functions in response to heat shock and nutrient limitation.

  • Public defence: 2019-03-29 13:00 David Magnussonsalen (U31), Stockholm
    Petersén Karlsson, Kristina
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Autobiographical Memory: Depending on sensory retrieval cue and gender2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In my thesis I raised two questions: Does autobiographical memory differ i) depending on the sensory retrieval cue (Study I and II)? and ii) depending on gender (Study III)?

    Concerning retrieval cues, three unimodal cues (i.e., photographs, naturalistic sounds and odors) and one multimodal cue (i.e., the three unimodal cues presented simultaneously) were used to evoke autobiographical memories. The results demonstrated that the memories differed depending on retrieval cue. In particular, the olfactory-cued memories differed in semantic content and were from an earlier age in contrast to the other modalities. The visually and auditory-evoked memories differed less than expected in their semantic content and age distribution in relation to the multimodal condition. The multimodally cued memories could be described as being a combination of the three unimodalities, as illustrated by the semantic content and age distribution, though they were more similar to the visually and auditory-cued memories than to the olfactory-cued memories. One possible explanation for these results could be that we attend more to visual and auditory perceptions than to olfactory.

    With regard to gender, previous research has found gender differences in the manifest content (i.e., the actual words used) of autobiographical memories. However, to my knowledge none has investigated gender differences in the latent content (i.e., the underlying meaning in the expressed words). The results indicated that there was no difference between the genders in the manifest content. However, the females latently described their memories in more communal terms than males did, which supports the assumption that females are more communally oriented than are males.

  • Public defence: 2019-03-29 13:00 Nordenskiöldsalen, Geovetenskapens hus, Stockholm
    Eyice, Mari
    Stockholm University, Faculty of Humanities, Department of History.
    An emotional landscape of devotion: Religious experience in Reformation-period Sweden2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis explores how the Reformation in Sweden was experienced by 16th century people through an examination of emotional practices. It argues that religious texts such as prayer books, sermon collections and instruction manuals were formative for the religious setting of the 16th century and that the use of these texts would therefore involve emotional practices for the 16thcentury Christian, thus creating an emotional experience of the Reformation for the Christian who used these texts.

    The thesis has shown that religious texts from the early Reformation, ca 1526–1571, were abundantly emotional but that the emotions they would create in the Christian who used them would vary both depending on the type of emotional practice that the texts would entail and depending on when during the period examined the texts were from. There was a greater span of different emotions in the earlier texts examined, while the emotions in the later texts examined were more uniform, thus possibly creating a more forceful emotional experience of the Reformation.

    The results of this thesis question the view in previous research that the Reformation in Sweden lead to an intellectualisation of religion. It shows that emotions were central in 16thcentury religious experience, which concurs with recent research on the Reformations around Europe, in which the spatial, social, corporal, material and emotional aspects of religious experience in the 16th century have been highlighted.

  • Public defence: 2019-04-03 13:00 sal FB42, AlbaNova universitetscentrum, Stockholm
    Giri, Sambit K.
    Stockholm University, Faculty of Science, Department of Astronomy.
    Tomographic studies of the 21-cm signal during reionization: Going beyond the power spectrum2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The formation of the first luminous sources in the Universe, such as the first generation of stars and accreting black holes, led to the ionization of hydrogen gas present in the intergalactic medium (IGM). This period in which the Universe transitioned from a cold and neutral state to a predominantly hot and ionized state is known as the Epoch of Reionization (EoR). The EoR is one of the least understood epochs in the Universe's evolution mostly due to the lack of direct observations. We can probe the reionization process with the  21-cm signal, produced by the spin-flip transition in neutral hydrogen. However, current radio telescopes have not been able to detect this faint signal. The low-frequency component of the Square Kilometre Array (SKA-Low), will be sensitive enough not only to detect the 21-cm signal produced during EoR but also to produce images of its distribution on the sky. A sequence of such 21-cm images from different redshifts will constitute a three-dimensional, tomographic, data set. Before the SKA comes online, it is prudent to develop methods to analyse these tomographic images in a statistical sense. In this thesis, we study the prospect of understanding the EoR using such tomographic analysis methods. In Paper I, II and V, we use simulated 21-cm data sets to investigate methods to extract and interpret information from those images.  We implement a new image segmentation technique, known as superpixels, to identify ionized regions in the images and find that it performs better than previously proposed methods. Once we have identified the ionized regions (also known as bubbles), we can determine the bubble size distribution (BSD) using various size finding algorithms and use the BSDs as a summary statistics of the 21-cm signal during reionization. We also investigate the impact of different line of sight effects, such as light-cone effect and redshift space distortions on the measured BSDs. During the late stages of reionization, the BSDs become less informative since most of the IGM has become ionized. We therefore propose to study the neutral regions (also known as islands) during these late times. In Paper V, we find that most neutral islands will be relatively easy to detect with SKA-Low as they remain quite large until the end of reionization and their size distribution depends on the properties of the sources of reionization. Previous studies have shown that the 21-cm signal is highly non-Gaussian. Therefore the power spectrum cannot characterize the signal completely. In Paper III and IV, we use the bispectrum, a higher-order statistics related to the three-point correlation function, to characterize the signal. In Paper III, we probe the non-Gaussianity in the 21-cm signal caused by temperature fluctuations due to the presence of X-Ray sources. We find that the evolution of the normalized bispectrum is different from that of the power spectrum, which is useful for breaking the degeneracy between models which use different types of X-Ray sources. We also show that the 21-cm bispectrum can be constructed from observations with SKA-Low. Paper IV presents a fast and simple method to study the so-called squeezed limit version of the bispectrum, which describes how the small-scale fluctuations respond to the large-scale environment. We show that this quantity evolves during reionization and differs between different reionization scenarios.

  • Public defence: 2019-04-05 09:30 Vivi Täckholmssalen (Q-salen), NPQ-huset, Stockholm
    Golz, Anna-Lea
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Role of ecological processes in determining effects of contaminants in aquatic ecosystems2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Aquatic ecosystems cover approximately 70% of the Earth’s surface and support a wide range of ecosystem services. Despite their importance, aquatic ecosystems are increasingly exposed to anthropogenic stressors, such as contaminants and climate change impacts. Ecosystems comprise a complex web of interactions both between organisms and between organisms and the abiotic environment. While there is extensive evidence for the importance of ecological processes in determining net ecosystem effects of contaminants, most often their effects are studied in isolation and in a single species setting.

    The aim of this thesis is to investigate the ecological effects of contaminants in aquatic ecosystems, ranging from cellular to ecosystem endpoints, by using model ecosystems of increasing complexity. This thesis studies the effects of ionising radiation on the biochemical composition of microalgae and how these may affect consumers (Paper I), as well its effects on an artificial freshwater ecosystem (microcosms) in terms of ecological processes (Paper II) and carbon flows (Paper III). Finally, the thesis investigates the combined effects of a flame retardant and increased temperature on a model ecosystem comprised of a semi-natural Baltic Sea community (Paper IV).

    Ionising radiation caused biochemical changes in primary producers that affected the next trophic level, where the consumer responded with an increased feeding rate, suggesting a change in the food quality of the primary producer (Paper I). The microcosms exposed to ionising radiation showed significant dose related effects on photosynthetic parameters for all macrophyte species. Dose dependent trends were seen in snail grazing rates and reproduction indicating a potential for long-term effects (Paper II). Similarly, the carbon flow networks (Paper III) also indicated that the main effect of radiation was a decline in primary production of the macrophytes, while pelagic bacterial production increased. However, the relative distribution of flows from dissolved carbon changed only slightly with increasing dose rates, which mainly triggered an increase in the amount of carbon dissipated through respiration. Finally, in Paper IV, higher temperatures induced the release of PO4 from the sediment, which stimulated the growth of the cyanobacteria, in turn leading to an increase in copepod abundance.

    These results demonstrate that the effects of contaminants on ecosystems depend on ecological processes, which may influence species-specific responses and lead to indirect effects. This thesis builds on a body of literature calling for a more holistic approach of ecotoxicology and radioecology, where ecosystem level responses to contaminants are taken into consideration.

  • Public defence: 2019-04-05 14:00 Air & Fire, SciLifeLab, Solna
    Morgan, Daniel
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics. SciLifeLab.
    Towards Reliable Gene Regulatory Network Inference2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Phenotypic traits are now known to stem from the interplay between genetic variables across many if not every level of biology. The field of gene regulatory network (GRN) inference is concerned with understanding the regulatory interactions between genes in a cell, in order to build a model that captures the behaviour of the system. Perturbation biology, whereby genes or RNAs are targeted and their activity altered, is of great value for the GRN field. By first systematically perturbing the system and then reading the system's reaction as a whole, we can feed this data into various methods to reverse engineer the key agents of change.

    The initial study sets the groundwork for the rest, and deals with finding common ground among the sundry methods in order to compare and rank performance in an unbiased setting. The GeneSPIDER (GS) MATLAB package is an inference benchmarking platform whereby methods can be added via a wrapper for testing in competition with one another. Synthetic datasets and networks spanning a wide range of conditions can be created for this purpose. The evaluation of methods across various conditions in the benchmark therein demonstrates which properties influence the accuracy of which methods, and thus which are more suitable for use under given characterized condition.

    The second study introduces a novel framework NestBoot for increasing inference accuracy within the GS environment by independent, nested bootstraps, \ie repeated inference trials. Under low to medium noise levels, this allows support to be gathered for links occurring most often while spurious links are discarded through comparison to an estimated null distribution of shuffled-links. While noise continues to plague every method, nested bootstrapping in this way is shown to increase the accuracy of several different methods.

    The third study applies NestBoot on real data to infer a reliable GRN from an small interfering RNA (siRNA) perturbation dataset covering 40 genes known or suspected to have a role in human cancers. Methods were developed to benchmark the accuracy of an inferred GRN in the absence of a true known GRN, by assessing how well it fits the data compared to a null model of shuffled topologies. A network of high confidence was recovered containing many regulatory links known in the literature, as well as a slew of novel links.

    The fourth study seeks to infer reliable networks on large scale, utilizing the high dimensional biological datasets of the LINCS L1000 project.  This dataset has too much noise for accurate GRN inference as a whole, hence we developed a method to select a  subset that is sufficiently informative to accurately infer GRNs. This is a first step in the direction of identifying probable submodules within a greater genome-scale GRN yet to be uncovered.

  • Public defence: 2019-04-12 10:00 Magnélisalen, Kemiska övningslaboratoriet, Stockholm
    Yang, Taimin
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    3D Electron Microscopy Methods and Applications: Structures from Atomic Scale to Mesoscale2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The crystal structure determines the physical properties of a material. The structure can be analysed at different levels, from atomic level, mesoscale level, all the way up to the macroscale level. Transmission Electron Microscope (TEM) is a powerful tool for studying the structure of materials at atomic scale level and mesoscale level because of the short wavelength of the electrons. At atomic scale level, structure determination using TEM can be performed in diffraction mode. The recent developments in 3D electron diffraction methods make structure determination from nano- and micron-sized crystals much easier than before. However, due to the strong interactions, electrons can be scattered multiple times through the crystal, causing the measured intensities to be less accurate than that in the X-ray case.

    In this thesis, we use the continuous rotation electron diffraction (cRED) developed in our group to investigate the structure of materials and the accuracy of this method. In the third chapter, we use cRED method to determine the structure of two aluminophosphate zeolites, PST-13 and PST-14. We presented that these structures can be built from two pairs of enantiomeric structural building units. In the fourth chapter, we show that despite the inaccuracy in measured intensities originated from dynamical effect, it is still possible to determine the structure accurately. We show that the atomic coordinates of ZSM-5 and sucrose crystal structure determined by multiple electron diffraction datasets is identical to that determined from X-ray data or neutron data. We also assessed the linearity between calculated structure factor and observed structure factor and use this as a coarse assessment indicator for diffraction data quality for protein crystals.

    Apart from atomic structure, mesoscale structures, such as mesopores, can also determine the property of materials. For the 3D structures of these nanoscale structures, we can also use TEM electron tomography techniques to investigate. In chapter five, we performed electron tomography for two different materials with mesoporous structure and illustrated the formation mechanism of mesoporous magnesium carbonate and the internal tunnel structure of hierarchical TS-1 zeolite.

  • Public defence: 2019-04-12 10:00 Nordenskiöldsalen, Geovetenskapens hus, Stockholm
    Voss, Katharina
    Stockholm University, Faculty of Law, Department of Law.
    Between Enforcement and Regulation: A Study of the System of Case Resolution Mechanisms Used by the European Commission in the Enforcement of Articles 101 and 102 TFEU2019Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis examines the current design of the system of case resolution mechanisms used by the European Commission (the Commission) where an infringement of Articles 101 and 102 TFEU is suspected and advances some proposals regarding this design. Infringements of Articles 101 and 102 TFEU cause considerable damage to the EU economy and ultimately, to consumers. Despite intensified enforcement of Articles 101 and 102 TFEU and ever-growing fines imposed for such infringements, the Commission continues to discover new infringements, which indicates a widespread non-compliance with EU competition rules. This raises the question of whether the enforcement currently carried out by the Commission is suitable for achieving compliance with Articles 101 and 102 TFEU.

    The thesis is divided into four main parts: First, the objectives pursued by the system of case resolution mechanisms used by the Commission are identified. Second, taking stock, the case resolution mechanisms currently employed are assessed in the light of these objectives. Third, the question of whether and how the different case resolution mechanisms could be viewed through the lens of regulatory enforcement is considered. Fourth, an assessment is made as to whether a different approach to case resolution could be employed based on a prescriptive theory of regulatory enforcement, responsive regulation.

    The research conducted shows that the main objectives pursued by the system of case resolution mechanisms used by the Commission are: to bring infringements to an end, to punish and deter infringers, to prevent infringements and to clarify competition rules. These objectives shall be achieved in an effective and efficient manner.

    The case resolution mechanisms that are assessed are Article 7 decisions, Article 9 decisions and cartel settlements. These mechanisms pursue varying sets of objectives. Their fulfilment depends, on the one hand, on the legal and procedural modalities of each case resolution mechanism and, on the other, on the types of cases allocated to that case resolution mechanism. The assessment returns varied results showing that some objectives are difficult for the Commission to achieve. Moreover, the choices made by the Commission when allocating case resolution mechanisms to cases are sometimes counterproductive with regard to the fulfilment of the relevant objectives.

    Taking into account the different characteristics exhibited by the case resolution mechanisms, an attempt is made to categorise these mechanisms as pursuing different regulatory enforcement styles. The conclusion is that this is not fully possible, exposing the multi-faceted nature of the case resolution mechanisms currently at the Commission’s disposal.

    Finally, a potential design of a case resolution system based on the theory of responsive regulation is advanced. This design is specifically aimed at remedying some of the deficiencies identified in the current approach to resolving potential infringements of Articles 101 and 102 TFEU. Instead of choosing a case resolution mechanism on a case-by-case basis, a prescriptive system based on infringement history and the cooperation offered by the undertaking would determine what case resolution mechanism to employ. The aim of such case resolution mechanisms would be to reduce the focus on fines. Instead, focus would be placed on cooperation as a means of bringing infringements to an end and preventing infringements by way of corporate compliance programmes.

  • Public defence: 2019-04-12 13:00 sal FB52, AlbaNova universitetscentrum, Stockholm
    Kunst, Flore Kiki
    Stockholm University, Faculty of Science, Department of Physics.
    Solvable Topological Boundaries2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The hallmark of topological phases of matter is the presence of robust boundary states. In this dissertation, a formalism is developed with which analytical solutions for these states can be straightforwardly obtained by making use of destructive interference, which is naturally present in a large family of lattice models. The validity of the solutions is independent of tight-binding parameters, and as such these lattices can be seen as a subset of solvable systems in the landscape of tight-binding models. The approach allows for a full control of the topological phase of the system as well as the dispersion and localization of the boundary states, which makes it possible to design lattice models possessing the desired topological phase from the bottom up. Further applications of this formalism can be found in the fields of higher-order topological phases—where boundary states localize to boundaries with a codimension larger than one—and of non-Hermitian Hamiltonians—which is a fruitful approach to describe dissipation, and feature many exotic features, such as the possible breakdown of bulk-boundary correspondence—where the access to exact solutions has led to new insights.