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  • Public defence: 2020-06-01 14:00 Magnélisalen, Kemiska övningslaboratoriet, Stockholm
    Lübcke, Marvin
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Bifunctionalization of Small Organic Molecules Based on Fluorine Incorporation2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The dissertation work that is summarized in this thesis describes novel syntheses of organofluorine compounds with a broad coverage of different fluorine-containing motifs.

    Chapter 2.1 covers works on the exploration of new trifluoromethylthiolating reactions of diazocarbonyl compounds. A rhodium-catalyzed oxy-trifluoromethylthiolation reaction enabled the synthesis of densely functionalized carbonyl compounds. Different oxygen nucleophiles, for instance alcohols, ethers and acetals underwent this transformation.

    A zinc triflimide mediated three-component reaction established an arylation-trifluoromethylthiolation of diazocarbonyl compounds. In situ generation of triarylboranes was rendered most effective for the arylation event. Both procedures made use of the high reactivity of a recently developed electrophilic trifluoromethylthiolating reagent.

    The second chapter (2.2) is dedicated to the late-stage construction of trifluoromethyl motifs. By means of halide exchange, nucleophilic fluoride from a copper(I)-complex could be used to exchange bromide with fluoride in the α-position to carbonyl groups as well as in benzylic positions.

    The third chapter (2.3) covers the development of an enantioselective fluorocyclization reaction. In situ generated aryliodine(III)-fluoride species were used as organocatalysts. Through this oxidative olefin difunctionalization reaction, quaternary C-F stereogenic centers could be constructed with high enantiomeric excesses. DFT calculations enabled deeper understanding of the mechanism and the origin of stereoselectivity.

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  • Public defence: 2020-06-02 13:00 Magnélisalen, Kemiska övningslaboratoriet, Stockholm
    Kapuscinski, Martin
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Following nanoparticle self-assembly in real-time: Small-angle X-ray scattering and quartz crystal microbalance study of self-assembling iron oxide nanocubes2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Self-assembly of nanoparticles is a widely used technique to produce nanostructured materials with crystallographic coherence on the atomic scale, i.e. mesocrystals, which can display useful collective properties. This thesis focusses on the underlying mechanism and dynamics of mesocrystal formation by using real-time techniques. Quartz-crystal microbalance with dissipation monitoring (QCM-D) as well as small-angle X-ray scattering (SAXS) in combination with optical microscopy were used to probe the temporal evolution of growing mesocrystals to elucidate the growth mechanism.

    Time-resolved small-angle X-ray scattering was used to probe the formation and how the structure and defects of the growing mesocrystals in levitating droplets evolve with time. Probing self-assembly of oleate-capped iron oxide nanocubes during evaporation-driven poor-solvent enrichment (EDPSE) showed that a low particle concentration in combination with a short nucleation period can generate large and well-ordered mesocrystals. Information on the formation and transformation of defects in mesocrystals were obtained by analysis of the temporal evolution of crystal strain. A transition from a rapidly increasing isotropic strain to a decreasing anisotropic strain towards the end of the growth stage was observed. The occurrence of anisotropic strain was assigned to the formation of stress-relieving dislocations in the crystal, which were induced by large internal stresses caused by superlattice contraction.

    Directed assembly of superparamagnetic iron oxide nanocubes, subjected to a weak magnetic field, produced one-dimensional mesocrystal fibers. Real-time SAXS as well as optical microscopy revealed a two-stage growth mechanism. The primary stage involved the growth of cuboidal mesocrystals by nanocube self-assembly. In a secondary stage, the cuboidal mesocrystals were assembled and aligned into fibers by the magnetic field. Evaluation of the magnetic dipole-dipole and van der Waals interactions showed that the dipolar forces arising between two nanocubes in a weak magnetic field are negligible compared to the van der Waals forces, but become the dominant force for larger mesocrystals, which drives the formation of fibers.

    QCM-D combined with optical microscopy provided simultaneously information on the rheological properties as well as on the mass of an adsorbed self-assembled layer of iron oxide nanocubes. We show that the iron oxide nanocubes rapidly assembled into an array with primarily viscous characteristics. This fluid-like behaviour can be assigned to a layer of solvent surrounding the nanocubes inside the assembly. Expulsion of the thin solvent layer from the assembled array is responsible for the increase in rigidity observed shortly after the beginning of self-assembly.

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  • Public defence: 2020-06-04 13:00 sal G, Arrheniuslaboratorierna, Stockholm
    Westerman, Johan
    Stockholm University, Faculty of Social Sciences, Department of Sociology.
    Motives matter: Intrinsic motivation in work learning and labor market performance2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This dissertation examines the importance of individual work motivation for two crucial dimensions of inequality: work learning and labor market performance. The first dimension relates to learning activities at work, and the second to wage attainment and knowledge-oriented task assignment. While motivation is a broad concept, the empirical analyses focus on task involvement and the motivation to learn. Job mobility is further used to indicate a motivational strategy aimed at gaining new labor market experiences. 

    These kinds of motivation are related to individual variation in intrinsic motivation, representing: pure curiosity and a strive for competence in novel environments, a focus on personal development rather than on proving ability, satisfaction gained from feelings of competence and autonomy during task performance, and experience of complete absorption in activities of learning and mastery. 

    The connection between intrinsic motivation and extrinsic labor market rewards (such as wage attainment) is theorized to follow from: (a) a higher level of performance in learning activities at work, (b) consequent assignment to more productive work tasks, and (c) a rise in material rewards (wages) linked to this assignment.

    Variation in the extent to which intrinsic motivation can be elicited in individuals, and the extent to which intrinsic motivation is targeted toward performance related activities in the labor market, is thus expected to matter for patterns of inequality. Intrinsic motivation, as a productive factor shaping inequality, is expected to grow in importance in paralell with an increase in the labor market value of skills, and a decline in bureaucratic and closely monitored production organization. As a research agenda, the analysis of intrinsic motivation is thus crucial for understanding evolving patterns of conflict and inequality in contemporary societies.

    Study I analyzes the relationship between task involvement and wage attainment, and shows that task involvement is moderately associated with higher wages in two datasets: the Swedish Level-of-Living Survey (LNU) and the European Social Survey (ESS). Study II analyzes the relationship between repeated job mobility (a ‘new experiences strategy’) and work learning. Two datasets are used: LNU and the Swedish part of the Programme for the International Assessment of Adult Competencies (PIAAC). Results show that repeated job mobility is positively associated with several, but not all, kinds of learning activities. Study III analyzes the associations that motivation to learn shares with knowledge-oriented task assignment and wage attainment using PIAAC data for 17 European countries. Results show that the motivation to learn is strongly correlated with knowledge-oriented task assignment, and moderately correlated with wage attainment. These correlations are similar across distinct levels of numerical proficiency, and across labor market contexts.

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  • Public defence: 2020-06-05 10:00 sal G, Arrheniuslaboratorierna, Stockholm
    Baheru, Haymanot
    Stockholm University, Faculty of Law, Department of Law.
    Hyressättning: Prisets reglering vid bostadshyra2020Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis examines all historical and present day rent control models in the context of the Swedish housing market, both in form and substance. The systematic study of the historical development illustrates how varieties of rent control regimes, i.e. rent setting regulations, have been a permanent feature in the Swedish rental market since 1942 when a rent freezing act was introduced. In a long reregulation process between mid-1950s and mid-1980s, the rent control transformed from a matter of public law to private law. As the latter, legislative initiatives over said decades have effectively established an all-encompassing legislative infrastructure subjecting all residential tenancy contracts in the primary and the secondary housing market, but also hotel like lettings, to regulations which aim to establish a fair rent.

    The aim of the thesis is to determine what constitutes a fair rent in the Swedish residential tenancy law. The thesis finds that the concept of fair rent refers to a rent that does not exceed the applicable price ceiling – the objective price. Fairness of the subjectively applied rent is therefore assessed in relation to compliance with the permissible price. Divergence from the objective price is considered unfair if it contravenes the ceiling. The concept of fair rent derives its meaning from seven regulative models in the legal infrastructure. The main regulative models are found in the use value system – a system that is dominated by the collective bargaining regime where the Tenant's union enjoys a monopolylike position. The alternatives, contract models of different constructions, are found both within the scope of the use value system and outside. Within the co-operative rental sector, both an association model and the models of the use value-system can be found. The regulative models are not necessarily mutually exclusive. Several regulative models can be simultaneously applicable, whereby the same apartment can command several 'fair rents' − none less fair than the other. The arbitrary construction of fairness and its application on the rental market is the result of legislative initiatives, necessitated as reactive measures, and political compromises.  

  • Public defence: 2020-06-05 10:00 Stockholm
    Stenström, Anders
    Stockholm University, Faculty of Social Sciences, Department of Criminology.
    The Plural Policing of Fraud: Power and the investigation of insurance and welfare fraud in Sweden2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    There is a vast literature on plural policing and the ways in which non-governmental actors now have and are assuming more responsibility for crime control. This literature argues that the connection between policing and the state is being eroded, questioned and sometimes abandoned in favour of networks in which the state acts as one actor among many others. This thesis examines the Swedish policing of insurance and welfare fraud via an analysis of the ways in which power is organized and articulated by actors in the private insurance industry, and at the Swedish Social Insurance Agency and police authority.

    The three articles included in the thesis contribute to a field that has received comparatively little attention, particularly in Sweden but also internationally. The existing literature has primarily been interested in the control of street-level criminality and the operations of uniformed security actors. Investigation practices in general and the plural policing of white-collar crime in particular have received far less attention. In Sweden, studies of policing are primarily state-centred, and the interactions between the police and other policing actors require further consideration. When examining insurance fraud, scholars have not considered the ways in which the insurance institution controls fraud; instead, this literature focuses on the characteristics of fraudsters. Thus the current thesis furthers our knowledge of a field of policing about which we currently know relatively little.

    The thesis takes as its general assumption the view that this form of policing is marked by a basic ambiguity between on the one hand being responsibilized and assuming responsibility for crime control, and on the other being responsible for other goals, such as promoting trust in, and the legitimacy and survival of the insurance institution. Existing research suggests that this ambiguity is resolved by simply denying compensation, adjusting premium levels, and cancelling policies or social benefits. My research shows that there is no Swedish exceptionalism in this sense.

    Based on a Foucauldian understanding of power, the thesis furthers our understanding of how the insurance institution is organized to tolerate fraud. The uncertainty between crime control and additional organizational goals is embedded in attempts to police the policing actors themselves, which is reflected in forces that make the policing of fraud a professional risk for the policing actors. The thesis argues that power relations provide opportunities to ensure that organizational goals are not endangered, while at the same time maintaining the public image that crime is being controlled. In contrast with existing research, the thesis shows that the law and the state – analytical categories that existing research, and particularly post-Foucauldian approaches, tend to reject or avoid – are critical to the plural policing of fraud. It is further suggested that scholars need to pay more attention to the way different technologies of power shape relationships between the actors involved in plural policing and their definitions of their own roles. In particular, scholars need to consider the role of the state and the legal framework in such arrangements. 

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  • Public defence: 2020-06-05 10:00 Magnélisalen, Kemiska övningslaboratoriet, Stockholm
    Oschmann, Michael
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Palladium Catalysis in Directed C-H Bond Activation and Cycloisomerisation Reactions2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The main focus of this thesis concerns the development of Pd(II)-catalysed synthetic methodologies for the preparation of biologically active compounds.

    In the first part (paper I-III), unactivated C–H bonds of a cyclobutane derivative are selectively functionalised using a directing group starting from the feedstock compound verbenone (paper I). In the following part the development of an efficient transamidation protocol for the directing group removal is reported (paper II). Both procedures were then used in conjunction, for the synthesis of diverse C-3 arylated benzofuran-2-carboxylamides, in only 3 steps starting from benzofuran-2-carboxylic acid (paper III).

    The second part (paper IV-V) aimed to evaluate the catalytic efficiency of the heterogeneous catalyst Pd(II)-AmP-MCF in the intramolecular hydroamination of propargylic carbamates. The catalyst was able to promote the formation of various 1,3-oxazolidin-2-ones in high yields, at room temperature with low palladium loadings (paper IV). This investigation is followed by a mechanistic study of the Pd(II)-AmP-MCF catalyst’s deactivation process during a lactone formation, using X-ray absorption spectroscopy (paper V).

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  • Public defence: 2020-06-05 13:00 Lilla hörsalen, Naturhistoriska riksmuseet, Stockholm
    Christidis, Maria
    Stockholm University, Faculty of Social Sciences, Department of Education. The Swedish Red Cross University College.
    Integrated teaching for expanded vocational knowing: Studies in the Swedish upper secondary Health and social care program2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Integrated teaching is emphasized in Swedish upper secondary vocational education and training, for managing sociocultural and historical changes related to: a) increased demands on future competent health care workers, b) educational reforms, c) altered conditions for vocational teachers’ work, and d) vocational contextualization of teaching and learning content. However, national curricula from 1970, 1994, and 2011 recommend integrated teaching as a solution without any specific concretization of what integration could or should contribute with. Thus, the aim of this thesis was to explore the realization of integrated teaching and the vocational knowing made available by integration for students at the Swedish upper secondary Health and social care program, and partly for nursing students in higher education and training. The research questions attended to how integrated teaching is realized, and what vocational knowing is made available by integration.

    Theoretical point of departure was Cultural historical activity theory (CHAT), complemented with New literacy studies (NLS). The methodological framework included ethnographically inspired case studies, interviews, specifically semi-structured interviews and life-history interviews, and a systematic review. Research material was collected in 2012 and 2018. Analysis was performed with selected concepts from CHAT, and in one study also with concepts from NLS. In one study, i.e. the systematic review, GRADE CERQual was used for an assessment of confidence in the review findings.

    Study results showed that integrated teaching, regardless of composition and format, made available a vocational, a general, and an expanded vocational knowing. Also, vocational contextualization of school subjects was shown to be significant as an additional teaching and learning content and as mediational means between school and workplace.

    In conclusion, integrated teaching was shown to respond to the sociocultural and historical developments by making available for students an expanded vocational knowing. Also, vocational contextualization was shown to make possible for students learning knowing relevant for their future profession.

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  • Public defence: 2020-06-05 13:00
    Ramöller, Daniel
    Stockholm University, Faculty of Humanities, Department of Philosophy.
    On the possibility of limited weighing of lives2020Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis discusses the possibility of limited moral trade-offs between different people’s welfare. In chapter 2, I introduce the two central limited trade-off conditions. First, according to minimal infinite superiority, significantly benefiting one person matters more than slightly benefiting each of any number of better-off people. Second, according to minimal finite superiority, significantly benefiting many people matters more than slightly benefiting one person. I consider both axiological and deontic interpretations of these conditions. However, I explain why none of the simple classic moral principles—the simple total and the maximin principles—satisfy both conditions. Furthermore, in chapter 3, I strengthen several proved impossibility results according to which no moral theory satisfies weak interpretations of these central trade-off conditions and several other seemingly plausible minimal conditions. I show that giving up structural axiological and deontic conditions is not a satisfactory solution to these paradoxes. In chapter 4, I discuss the modification of a background assumption of these impossibility results on the measurement of welfare. I show that, given a modification that allows for lexicographically ordered welfare components, a total principle can satisfy all the conditions of the impossibility results. However, I argue that such a modification is not entirely satisfactory because it does not apply in certain instances of the paradoxes. In chapter 5, I discuss a further weakening of minimal infinite superiority. However, I show that a suggested possibility result based on this modification is not valid and that further moral conditions, such as minimal finite superiority, need to be modified. Moreover, I argue that these modified conditions and the principle suggested in the possibility proof—a minimax complaint principle—do not capture the basic idea of the two central limited trade-off conditions sufficiently well. In chapter 6, I argue that other principles suggested for the task—the total claim principles—share the same fate as the simple total principles or the minimax complaint principle. In chapter 7, I propose new principles that take their structural roots from voting theory. I show that, in contrast to the other principles discussed, these principles give plausible verdicts where the other principles failed. Finally, in chapter 8, I consider possible objections levelled against this proposal, and I suggest solutions and avenues for future research.

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  • Public defence: 2020-06-05 14:00 Nordenskiöldsalen, Geovetenskapens hus, Stockholm
    Foltyn, Richard
    Stockholm University, Faculty of Social Sciences, Department of Economics.
    Essays in Macroeconomics and Household Finance2020Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Experience-based Learning, Stock Market Participation and Portfolio Choice

    Recent evidence suggests that lifetime experiences play an important role in determining households' investment choices. I incorporate these findings and the fact that household portfolios are underdiversified into an otherwise standard life-cycle model and examine to what extent they can help resolve long-standing puzzles in the literature regarding stock market participation and the fraction of financial wealth invested in risky assets. I show that experience-based learning about returns creates a positive correlation between a household's position in the wealth distribution and its optimism about future returns. The wealthy consequently increase their investment in risky assets, while participation is limited among poor households. I find that in a reasonably calibrated quantitative model, this mechanism is able to close approximately half of the gap between the participation rates observed in the data and the predictions from standard models.

    Health Dynamics and Heterogeneous Life Expectancies

    In this paper, we provide improved estimates for age-dependent health transitions and survival probabilities for different subsamples of the US population. The estimated yearly transition matrices can be used in any life-cycle model where health and survival dynamics are of interest. The results show substantial heterogeneity in life expectancy in the population. For a 70-year-old man in excellent health, the probability of reaching his 80th birthday is around 75%, while the corresponding probability for a man in poor health is just below 40%.

    Subjective Life Expectancies, Time Preference Heterogeneity and Wealth Inequality

    Time preference heterogeneity is one of the potential sources of wealth inequality, but preferences are difficult to measure and quantify. In this paper, we investigate one source of time preference heterogeneity: heterogeneity in life expectancy. We document a systematic bias in subjective survival beliefs within cohorts that exacerbates the heterogeneity found in the population: individuals with a low survival probability relative to their peers underestimate their life expectancies, while individuals with a high survival probability overestimate theirs. We introduce survival heterogeneity into an otherwise standard overlapping-generations model and let survival probabilities and beliefs evolve stochastically according to a health and death process estimated from micro data. We find strong effects of life expectancy heterogeneity on within-cohort wealth inequality, but small effects on economy-wide wealth inequality.

    On the Redistributive Effects of Government Bailouts in the Mortgage Market

    In this paper we study the aggregate and distributional consequences of government bailout guarantees in the US mortgage market. We construct a model with aggregate risk in which competitive financial intermediaries issue mortgages to households that can default on their debt. Default probabilities are priced into mortgage interest rates unless a government bailout guarantee makes the lenders whole even in economic downturns in which foreclosure rates surge. We use the model to assess the extent to which bailout guarantees lead to excessive mortgage lending, household leverage and foreclosures in episodes of housing crises, as well as excess volatility in house prices in severe recessions.

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  • Public defence: 2020-06-08 13:00 Magnélisalen, Kemiska övningslaboratoriet, Stockholm
    Rathore, Sorbhi
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Structural characterisation of mitochondrial macromolecular complexes using cryo-EM: Mitoribosome biogenesis and respiratory chain supercomplex2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Mitochondria, popularly known as powerhouse of the cell, contain specialised mitoribosomes that synthesise essential membrane proteins. These essential proteins are required to form enzyme complexes, which carry out the process of oxidative phosphorylation (OXPHOS). OXPHOS is carried out by five enzyme complexes (Complex I-V), out of which complex I, III and IV pump protons during electron transfer from NADH to Oand complex V uses the generated proton gradient to synthesise ATP. Cryo-EM, as a revolutionary technique in structural biology made it possible to determine the structures of mitoribosome assembly intermediates and respiratory chain supercomplexes. These structures have allowed us to investigate the mitoribosome biogenesis pathway in human and yeast and to gain deeper insights into the architecture of supercomplexes. In the first area of research, using cryo-EM we were for the first time able to capture mitoribosomes in different late stages of assembly and to determine their high-resolution structures with novel factors bound. Investigation of this process was previously unreachable due to lack of techniques to trap these mitoribosome complexes in different states of assembly. The structures of these assembly intermediates establish the role of assembly factors such as MALSU1, LOR8F8, mt-ACP, MTG1 and mitoribosomal proteins (MRPs) in mitoribosome biogenesis and to ensure proper maturation of each subunit, reflecting their role in regulating translation. Furthermore, genetic deletion studies of MTG1 and uL16m in yeast show the importance of transiently acting factors and MRPs in the mitoribosome assembly process and their effects on translation. The assembly pathway of mitoribosomes is critical for protein synthesis since defects in the translation process causes inherited human pathologies. Therefore, elucidation of mitoribosomal biogenesis pathways may also contribute to the development of potential new therapeutic opportunities. In the second research area, structures of the respiratory chain supercomplex from yeast were determined. These are the first near-atomic resolution structures that show organization of complex III and complex IV into two distinct classes that form higher order assemblies (III2IV1and III2IV2). Moreover, the architecture of the supercomplex structures differs from the previously determined respirasomes (I1III2IV1) structures in mammals. We obtained a near-atomic resolution structure of the yeast complex IV, revealed core protein-protein and protein-lipid interactions that hold the supercomplex together. Moreover we found novel subunits required for supercomplex formation in S. cerevisiae. The last part of my study focuses on cryo-EM sample method development where we could successfully demonstrate the usefulness of a simple pressure-assisted sample preparation method for microcrystals, proteins and mitochondria. Our findings show great resolution improvements of selected area electron diffraction patterns of microcrystals, a significant reduction in needed sample concentration for single particle studies and an enrichment of gold nano-particles for tomographic studies.

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  • Public defence: 2020-06-09 10:00 sal G, Arrheniuslaboratorierna, Stockholm
    Blomqvist, Niklas
    Stockholm University, Faculty of Social Sciences, Department of Economics.
    Essays on Labor Economics: The Role of Government in Labor Supply Choices2020Doctoral thesis, monograph (Other academic)
    Abstract [en]

    "Right to Work Full-time" Policies and Involuntary Part-time Employment

    This paper investigates the effect of right to full-time policies implemented to decrease involuntary part-time work for public care workers employed by Swedish municipalities. Taking advantage of a staggered decision process, these policies are evaluated using a difference-in-differences approach. Results show that involuntary part-time employment is real and significant, with 10% of part-time employed workers choosing full-time when given the opportunity. The effect mainly comes from a decrease in contracts of <75% of full-time and an increase in contracts of 80% of full-time and above. Further results from the full-time policies show that being more flexible in the choice of hours worked is popular among workers, indicated by an increase in tenure and reduced turnover in municipalities that offer more flexibility in the choice of hours worked.

    Hours Constraints and Tax Elasticity Estimates - Evidence from Swedish Public Care Workers

    There is a concern that tax elasticity estimates may be downward biased in the presence of optimization frictions for workers. So far, there is limited evidence on the nature of these optimization frictions. This paper provides new insight into one part of the optimization frictions black box, namely hours constraints. Using unique and newly collected data, I exploit a staggered implementation of a policy that gave some public care workers the opportunity to choose their preferred hours of work. Taking advantage of this policy, I estimate differences in tax elasticities between constrained and unconstrained public care workers by comparing bunching at a large tax kink in the Swedish tax system. The empirical evidence points to the conclusion that hours constraints do not affect tax elasticity estimates.

    Restricting Residence Permits - Short-Run Evidence from a Swedish Reform

    In June 2016, the Swedish parliament decided to restrict the granting of permanent residence permits for asylum seekers in Sweden. The new status quo for a refugee is a temporary rather than a permanent residence permit. In a first evaluation of this reform we use a Regression discontinuity analysis in which we follow refugees, aged 25-65, over their first years after arrival. Our main results show that a temporary residence permit increases the probability of working and enrolling in regular education.

    Mom and Dad Got Jobs: Natural Resources, Economic Activity, and Infant Health

    The impact of local economic shocks, such as the discovery and exploitation of natural resources, on labor markets and health is not well understood. Both positive and negative effects have been documented in the literature. In this paper, we show that the phase before active resource extraction begins directly affects the local economy. This implies that previous estimates – typically based on designs exploiting differences before and after the active phase of extraction begins - may have understated the actual effect of natural resource extraction on outcomes of interest. Using rich data from Sweden combined with differences in the timing and location of mineral exploitation permits, we find a positive impact on female and male employment and earnings and a negative effect on housing prices. Children’s health outcomes are also negatively affected, an effect likely driven by the increase in local economic activity rather than extraction-related externalities.

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  • Public defence: 2020-06-09 13:15 sal FB42, AlbaNova universitetscentrum, Stockholm
    Mahyaeh, Iman
    Stockholm University, Faculty of Science, Department of Physics.
    Study of the phase diagram of Zn symmetric chains2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis we study the phase diagrams of Zn symmetric chains. We start with investigating the topological phases of the Kitaev chain, a Z2 symmetric model, with long range couplings and a phase gradient. Then we go beyond the free fermion classification of topological phases and consider the effect of interactions by studying the Kitaev-Hubbard chain, incorporating a density-density interaction. Next we move on to the Z3 symmetric models and present a frustration free model with an exact three-fold degenerate ground state. In the end we present the phase diagram of a hopping model of Z3 Fock parafermions, the generalization of polarized Dirac fermions which could host at most two particles per site. The model has a pairwise hopping which is forbidden for fermions. In our studies we use analytical methods like the Lieb-Schultz-Mattis method, bosonization and conformal field theory, as well as numerical ones like exact diagonalization and the density matrix renormalization group.

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  • Public defence: 2020-06-10 10:00 Magnélisalen, Kemiska övningslaboratoriet, Stockholm
    Gestin, Maxime
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    PepFect14, a Versatile Cell-Penetrating Peptide2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Cell-penetrating peptides have been discovered almost three decades ago and there are, nowadays, thousands of available sequences. They offer multiple applications in the field of drug delivery as they are able to carry therapeutic macromolecules across the plasma membrane. Throughout the years, new sequences have been developed and designed to achieve new applications such as specificity for certain kinds of cargoes, intrinsic therapeutic effects and targeted delivery.

    In this thesis, we focused on a single most promising cell-penetrating peptide named PepFect14 and aimed at reaching a better understanding of the factors involved in the cellular uptake through paper I and paper II. Notably, in paper I we screened a library of small molecule drugs that influences signaling pathways and discovered that three drugs had an unreported influence on endocytosis. In paper II, After performing an RNA sequencing on cells treated with PepFect14, we demonstrated the involvement of autophagy in the intracellular trafficking of the cell-penetrating peptide. A second aim of this thesis, covered in paper III and paper IV, was to discover new applications for PepFect14 in order to broaden its potential. In paper III, we successfully used PepFect14 to mediate the intracellular delivery of heat shock protein 70kDa. This was the first protein delivery assisted by PepFect14. In paper IV, PepFect14 was covalently fused to mtCPP1, a cell-penetrating peptide that targets mitochondria and reduce the level of reactive oxygen species. The constructs showed the ability to keep the properties of both peptides and achieved a mitochondria-targeted antisense therapy.

    Overall, this thesis summarizes our effort to develop and bring to their full potential already existing cell-penetrating peptides instead of developing new sequences for each new application.

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  • Public defence: 2020-06-10 13:00 sal 14, hus 5, Kräftriket, Stockholm
    Muhinyuza, Stanislas
    Stockholm University, Faculty of Science, Department of Mathematics.
    Statistical Inference of Tangency Portfolio in Small and Large Dimension2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis considers statistical test theory in portfolio theory. It analyses the asymptotic behavior of the considered tests in the high-dimensional setting, meaning k/n c ∈ (0, ∞) as n → ∞, where k and n are portfolio size and sample size, respectively. It also considers the high-dimensional asymptotic of the product of components involved in the computation of the optimal portfolio. The thesis comprises four manuscripts:

    Paper I is concerned with the test on the location of the tangency portfolio on the set of feasible portfolios. Considering the independent and normally multivariate asset returns, we propose a finite-sample test on the mean-variance efficiency of the tangency portfolio (TP). We derive the distribution of the proposed test statistic under both the null and alternative hypotheses, using which we assess the power of the test and construct a confidence interval. The out-of-sample performance of the portfolio determined by the proposed test is conducted and through an extensive simulation study, we show the robustness of the developed test towards the violation of the normality assumptions. We also apply the developed test to real data in the empirical study.

    Paper II extends the results of paper I. It is concerned with the study of the asymptotic distributions of the test on the existence of efficient frontier (EF) and the efficiency of the tangency portfolio in the mean-variance space in the high-dimension setting under both the null and alternative hypotheses. Finite-sample performance and robustness of the proposed tests are studied through an extensive simulation study.

    In paper III, we study the distributional properties of the TP weights under the assumption of normally distributed logarithmic returns. The distribution of the weights of the TP is given under the form of a stochastic representation (SR). Using the derived SR we deliver the asymptotic distribution of the TP weights under a high-dimensional asymptotic regime. Besides, we consider tests about the elements of the TP weights and derive the asymptotic distribution of the test statistic under the null and alternative hypotheses. In a simulation study, we compare the power function of the high-dimensional asymptotic and the exact tests. Moreover, in an empirical study, we apply the developed theory in analysing the TP weights in a portfolio made of stocks from the S&P 500 index.

    In paper IV, we derive a stochastic representation of the product of a singular Wishart matrix and a singular Gaussian vector. We then use the derived SR in the obtention of the characteristic function of that product and in proving the asymptotic normality under the double asymptotic regime. The performance of the obtained asymptotic is shown in the simulation study.

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    Statistical Inference of Tangency Portfolio in Small and Large Dimension
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  • Public defence: 2020-06-11 10:00 Magnélisalen, Kemiska övningslaboratoriet, Stockholm
    Stephan, Katharina
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Biogenesis of the bc1 complex in mitochondria2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Mitochondria perform a variety of tasks, but the function they are most prominent for is the energy conversion to form ATP, the universal energy equivalent of the cell. The majority of this ATP is created by the oxidative phosphorylation system, consisting of the respiratory chain and the ATP synthase. These elaborate machineries channel electrons through the respiratory complexes and thereby generate an electrochemical gradient across the inner mitochondrial membrane. This, so called proton motive force, is in turn utilized by the ATP Synthase to produce ATP.

    A particularity of the oxidative phosphorylation complexes is that their subunits are derived from two genetic sources. As a result, and the fact that the respiratory chain complexes contain redox cofactors, the biogenesis of these enzymes is challenging and involves multiple, highly coordinated and regulated assembly steps. For the obligate homodimeric bc1 complex, a handful of assembly factors are known and its assembly can be divided into distinct assembly intermediates. In this work we provided insights into the maturation of the catalytic subunit cytochrome b. We revealed that the insertion of the redox active heme b groups is sequential and that it depends on the interaction with the early assembly factor Cbp4. With successful insertion of both heme bs, the binding of the structural subunit Qcr7 is necessary for stabilization and further assembly.

    Furthermore, we were able to delineate the dimerization event in detail. We could establish that the interaction of the two matrix subunits, Cor1 and Cor2, with the bc1 complex assembly intermediate II, as well as the dissociation of Cbp4, are the triggering point for dimerization.

    In our subsequent work we investigated the roles of the fairly uncharacterized assembly factor Bca1 and its interplay with the structural subunit Qcr7. We could demonstrate that Bca1 interacts early and transiently during assembly and is an important factor for efficient assembly. Additionally, we could show that Qcr7 is not only a structural subunit but also serves as an assembly checkpoint for the maturation of the bc1 complex.

    With our work we could illustrate the necessity for basic biochemical research within the model organism yeast, as the fundamental molecular mechanisms are well conserved. This is exemplified by our work on UQCC3, the human orthologue of the bc1 complex assembly factor Cbp4.

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  • Public defence: 2020-06-11 13:00 Auditorium (215), Manne Siegbahnhusen, Stockholm
    Wahlin, Claes
    Stockholm University, Faculty of Humanities, Department of Culture and Aesthetics.
    Att anlita översättning: Chaucer, Dryden, Arnold, Pound2020Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis – Translation employed – Chaucer, Dryden, Arnold, Pound – investigates the motives and circumstances of translations of four authors/translators: Geoffrey Chaucer, John Dryden, Matthew Arnold and Ezra Pound. All four employ translation for purposes that exceed linguistically faithful transmission of a source text.

    My point of departure is the theoretical framework known as translation studies, which places critical focus less on the semantic transfer of texts than on a translator’s motivation for choosing a specific text to translate and the projected function of that text in a target literary system.

    In the first section I contrast the Chaucer’s translation of Boethius’ De consolatione philosophiae, with Chaucer’s Troilus and Criseyde. Chaucer’s Boece is a rather literal translation of its predecessor, linguistically faithful, though with the target text expanded and commented. In Troilus and Criseyde, by contrast, Chaucer semi-hides his sources, among them Petrarch. Chaucer’s Boece follows a primary mode of translation. By silently adapting Petrarch’s text, Troilus and Criseyde is translation in the secondary mode.

    Dryden updated Chaucer (as founder of English poetry and language), and I recount here the political, social and cultural climate in a time when social upheaval rendered reading suspicious and the printed words itself a danger to public order. In this climate, the Royal Society, as well as some individual authors, set out to develop a pure and perfect language. I examine in particular Dryden’s translation of the prologue to one of Chaucer’s Canterbury tales and discuss how Dryden’s notion of metempsychosis, and his idea that poets through history can be thought of as a long chain of father-son relations, legitimised his domestication of the source text.

    In the mid-19th Century, Arnold’s critique of Francis Newman’s translation of Homer’s The Iliad reflects a Victorian view of the Greek classics, as well as substantial ambitions for Homer. I sketch this background and compare Newman’s and Arnold’s distinct prescriptions for an English Homer. I argue that Newman’s main purpose was to make Homer known to the uneducated, but interested public, whereas Arnold’s vision was for a domesticated Homer, who functioned as an ethical and cultural beacon and nationalistic ideal.

    In the 20th century Pound’s translation of a sirventes by the occitan troubadour Bertran de Born, shows how Pound developed his own language partly by making his predecessors seem contemporaneous. The aim of this chapter is not only to rehearse this, but also to downplay the supposedly radically new in Pound’s translation practice. Here I compare Bertran de Born’s poems, as translated by Victorian John F. Rowbotham with the two translations made by Pound. The difference between Rowbotham’s domesticated version and Pound’s, shows how Pound in his first, so-called pedagogical translation, keeps close to the source text, and in his second, poetical translation, employs the Born’s work for his poetical ambitions. Pound had at least two literary objectives for the translations of Bertran de Born: one concerning his own poetic idiom, and the other his ambition to reinvigorate the contemporary literary culture. Pound sought to blend the past with the present in his own poetry, a purpose that he realises in the poem “Sestina: Altaforte”.

    Certain translation strategies recur, such as the idea of metempsychosis in Dryden and Pound, and the need to appropriate the target text in full, particularly for Chaucer and Pound. Political considerations have bearing in the case of Chaucer (the church), and are also prominent for Dryden and Arnold. Pound by contrast is almost exclusively interested in aesthetics. All four authors/translators employ translation for purposes that have less to do with an historical understanding of an original, source text than their own contemporary use of a target text.

     

     

  • Public defence: 2020-06-11 13:00 Endast online: https://stockholmuniversity.zoom.us/j/5073530222 (inte i Lilla hörsalen, NOD-huset, Kista)
    Aspling, Fredrik
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Unleashing Animal-Computer Interaction: A Theoretical Investigation of the “I” in ACI2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Non-human animals have had a long co-existence and relationship with human culture and society, and we interact with them in a number of ways, and for various reasons. Their involvement in technology can be traced back more than half a century, initially restricted to scientific contexts, for example, for the study of animal behavior, cognition, or language learning abilities. The advancement and growing ubiquity of technology has extended their interactions with technology beyond scientific settings to other domains and everyday contexts, and for a broader set of reasons. This development is also driven by the emerging research area of animal-computer interaction (ACI), in which scholars of human-computer interaction (HCI) are starting to explore the possibilities of designing interactive technology for and with animals. This requires engagement with the difficult task of understanding this new set of actors and the types of interactions and functionality they possibly would like to have with computing. This is a challenge even when it comes to humans, but the challenge escalates when considering other animals, and presents even more challenges. Animals live different lives to us, and include a broad and diverse category of species, with different ways of experiencing and being in the world, and we have difficulty understanding each other due to these interspecies differences. The shift from human to animal interaction is far from straightforward.

    This new and embryonic situation contests traditional notions of what a “user” is and can be, and how both digital technologies and other species, are being used. Consequently, it also challenges previous theoretical foundations and methods for understanding and designing user-computer interactions. The latter has received special attention, where user-centered design approaches and methods from the field of HCI and interaction design (IxD) has become a natural point of departure. As a complement, ACI needs a bolder and more creative way of progressing when it comes to building a theoretical framework to account for these new forms of interaction. There is a need to extend our thinking and the conventional ways of doing research and design, and to preserve curiosity and theoretical and methodological openness. As an alternative to many other design approaches, this thesis advocates the theoretical investigation of the “I” in ACI, aiming to extend the conventional notion of how interaction is conceptualized, a topic that has suffered from negligence. Drawing on ethnomethodological and ethnographic fieldwork – covering a maximum variation of extreme and deviant of cases – this thesis investigates the boundaries of the field and different theoretical perspectives and empirical insights, in order to increase our understanding of the emerging dynamics of multispecies-computer interactions, and also how these insights can excite the imagination and generate topics for zoocentric design and computing.

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  • Public defence: 2020-06-12 10:00 Magnélisalen, Kemiska övningslaboratoriet, Stockholm
    Menon, Preeti
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    The amyloid-β precursor protein (APP) and its adaptor protein Fe65: Two key players in Alzheimer’s disease2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Alzheimer’s disease (AD) is a neurodegenerative disease characterized by the abnormal accumulation and aggregation of amyloid beta (Aβ) peptides within the brain. Generation of Aβ occur when the amyloid-beta precursor protein (APP) is proteolytically processed by β- and then γ-secretase in the amyloidogenic pathway. However, if APP instead is cleaved by α- and γ-secretase in the non-amyloidogenic pathway, Aβ formation is prevented and neuroprotective sAPPα is generated. In addition to these canonical processing pathways, APP can also be cleaved along non-canonical pathways by Δ, η, caspase or Meprinβ, resulting in numerous fragments that have different functional properties. The trafficking and processing of APP is a complex process and can be regulated by the adaptor protein Fe65. Following γ-secretase mediated cleavage of APP, the intracellular domain of APP and Fe65 can together translocate into the nucleus and regulate nuclear signaling. However, the exact mechanisms of how APP processing and APP/Fe65 nuclear signaling are regulated is still unclear.  

    The aim of this thesis was to study different factors that may influence the regulation of APP processing and Fe65 nuclear localization. We found that phosphorylation of APP at Ser675 alters APP processing resulting in reduced levels of sAPPα and total sAPP, without affecting the plasma membrane level of APP. We could further observe an increased level of a slower migrating C99 like CTF, which was not generated by β-secretase cleavage of APP as there was no expression of BACE1 in the cell model used. Instead, generation of this CTF was blocked upon Meprinβ siRNA knockdown. Taken together these findings suggest that APP-Ser675 phosphorylation promotes Meprinβ processing of APP. In another study, we found that mutation of Ser228 at the Fe65 N-terminal dramatically increased the interaction between Fe65 and full-length APP. Moreover, this enhanced interaction resulted in decreased levels of non-amyloidogenic processing of APP and thus neuroprotective sAPPα. This suggest that the level of Fe65-APP interaction is important in regulating APP processing. Therefore, we also wanted to elucidate more about how the adaptor protein Fe65 is regulated. We found that Fe65 is likely phosphorylated on several residues in the N-terminus and that these phosphorylated forms preferentially localized in the cytoplasm. In addition, we could show that the nuclear level and nuclear/cytoplasmic ratio of Fe65 was decreased upon mutation of Fe65-Ser228 to glutamic acid, mimicking phosphorylation. Taken together this suggest that phosphorylation of Ser228 together with other residues in the N-terminus of Fe65 negatively regulate the Fe65 nuclear localization. In a third study, we could also show that the Fe65 PTB2 domain, rather than the WW domain, plays an important role in localizing Fe65 to the nucleus. Lastly, using different inhibitors, we found that blocking α-secretase processing decrease the Fe65 nuclear localization to the same extent as γ-secretase inhibition in both undifferentiated and RA or PMA differentiated cells. This suggest that α-secretase processing of APP or other Fe65 interacting transmembrane proteins play a more important role in regulation of Fe65 nuclear localization than previously thought. Interestingly, while ADAM10 was the most important α-secretase mediating this effect in undifferentiated cells, other α-secretases, likely ADAM17, played a more important role in RA or PMA differentiated neuroblastoma cells.

    In summary, the results obtained in this thesis have increased the understanding of APP processing and how the adaptor protein Fe65 may act as a molecular switch altering APP cleavage.

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    The amyloid-β precursor protein (APP) and its adaptor protein Fe65
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  • Public defence: 2020-06-12 10:00 Vivi Täckholmsalen (Q-salen), Stockholm
    Scher, Sebastian
    Stockholm University, Faculty of Science, Department of Meteorology .
    Artificial intelligence in weather and climate prediction: Learning atmospheric dynamics2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Weather and climate prediction is dominated by high dimensionality, interactions on many different spatial and temporal scales and chaotic dynamics. This makes many problems in the field quite complex ones, and also state-of-the-art numerical models are - despite their immense computational costs - not sufficient for many applications. Therefore, it is appealing to use emerging new technologies such as artificial intelligence to tackle these problems.

    We show that it is possible to use deep neural networks to emulate the full dynamics of a strongly simplified general circulation model, providing both good forecasts of the model state several days ahead as well as stable long-term climate timeseries. This method partly also works on more complex and realistic models, but only for forecasting the model's weather several days ahead, not for creating climate runs. It is sufficient to use 50-100 years of data for training the networks. The same neural network method can be combined with singular value decomposition from numerical ensemble weather forecasting in order to generate probabilistic ensemble forecasts with the neural networks.

    On a more fundamental level, we show that in a simple dynamical systems setting there seem to be limitations in the ability of feed-forward neural networks to generalize to new regions of the system. This is caused by different parts of the network learning to model different parts of the system. Contradictory, for another simple dynamical system this is shown not to be an issue, raising doubts on the usefulness of results from simple models in the context of more complex ones. Additionally, we show that neural networks are to some extent able to “learn” the influence of slowly changing external forcings on the dynamics of the system, but only given broad enough forcing regimes.

    Finally, we present a method to complement operational weather forecasts. Given the initial fields and the error of past weather forecasts, a neural network is used to predict the uncertainty in new forecasts, given only the initial field of the new forecast.

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    Artificial intelligence in weather and climate prediction: Learning atmospheric dynamics
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  • Public defence: 2020-06-12 10:00 Sal P216, NPQ-huset, Stockholm
    Hurtig, Fredrik
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Divisive structures: Two billions years of biofilament evolution2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Our understanding of the functional and regulatory complexity that existed in the eukaryotic progenitor is poor, and investigations have been hindered by our nebulous understanding of where eukaryotes stem from. Recently discovered archaeal lineages with hitherto unseen homology to eukaryotic systems suggest archaea can further our understanding of the eukaryotic cell’s ancestry. However, much of archaeal biology remains largely unexplored. Two eukaryotic systems with archaeal homologues, namely the actin and ESCRT-III protein filament systems, are essential for diverse processes in eukaryotic biology. In this thesis, we show that an archaeal homologue of ESCRT-III divides the cell under proteasomal regulation, a regulatory mechanism central to eukaryotic cell cycle regulation. Additionally, we show how predicted putative profilin and gelsolin homologues regulate the postulated proto-cytoskeleton of Asgard archaea. In investigating the function and regulation of these archaeal systems we demonstrate compelling parallels between archaeal and eukaryotic regulatory strategies which stresses the close evolutionary relationship that exists between these two domains.

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    Divisive structures
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  • Public defence: 2020-06-12 13:00 rum 2427 på Institutionen för pedagogik och didaktik, Stockholm
    Malm, Tobias
    Stockholm University, Faculty of Social Sciences, Department of Education.
    Konsten att hålla ihop: Om lärande och organisering i rockband2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Rock bands are foundational for modern day music life. These small groups provide well-being and self-fulfillment to its members, as well as fuel for the cultural life and the increasingly highlighted creative industries. Rock bands, however, are particularly difficult to organize. Bands face a range of challenges in keeping together and developing as a group.

    The aim of this doctoral thesis is to develop knowledge on rock band formation and development over time. Based in the discipline of education, the thesis mainly contributes to the fields of organization studies, social theories of learning, and music and cultural life research.

    The thesis uses the theory of situated learning to explore rock band formation and development. The methodology is qualitative and ethnographic, and the research design builds on three studies: an interview study with three rock bands and two case studies. All five bands are Swedish and have found different degrees of success and popularity.

    The thesis investigates band activities and courses of events, band members’ identities, and challenges faced. The findings indicate that a rock band’s activities shift between a production mode – i.e. highly productive times associated with public performances, record releases and marketing, and behind the scenes processes of creating, recording and planning – and a contrasting less active hibernation mode without bigger public projects or goals. The amount of time spent in production mode depends on the band’s degree of “membership” in the music industry. Moreover, a band member forms and actualizes identities of colleague, creator, entrepreneur, friend, hobbyist and professional, in differing combinations, situations and modes. Furthermore, the members’ most significant challenges relate to identity dilemmas.

    Based on these findings, the thesis formulates a model for a rock band’s learning trajectory and argues that a band may develop as it approaches, or becomes a more central member in, the music industry. This development demands increased public success and organizational ability: the band members’ ability to form business-oriented practices, to participate uniformly in an overarching community of practice, and to be flexible as they must identify with, and ascribe meaning to, a variety of activities in different and sometimes contradictory ways.

    The thesis concludes that the challenges of persistence as a rock band or similar group relates chiefly to group member difficulties in identifying with different activities and situations that are necessary to sustain and develop as a collective. Eventually, individual members tend to handle the experience of uncertainty and ambivalence by holding on to one singular identity, which may prevent group development, foster intra- and interpersonal tensions, and ultimately can lead to significant conflicts and/or a band’s breakup.

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    Konsten att hålla ihop
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  • Public defence: 2020-06-12 13:00 sal FB52, AlbaNova universitetscentrum, Stockholm
    Späh, Alexander
    Stockholm University, Faculty of Science, Department of Physics.
    X-Ray Investigations of the Liquid-Liquid Critical Point Hypothesis in Supercooled Water2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis presents experimental x-ray scattering studies on supercooled liquid water. A liquid-liquid transition between two structurally distinct configurations has been found in deeply supercooled water, indicating the existence of a liquid- liquid critical point. The experiments were performed at large-scale x-ray facilities, mostly using free electron x-ray lasers including PAL-XFEL in Korea, SACLA in Japan, LCLS in the USA, SwissFEL in Switzerland and European XFEL in Germany, as well as using synchrotrons including APS in the USA, PETRA III in Germany and ESRF in France.

    Two conceptually different experimental approaches have been used to investigate the metastable phase of supercooled water. The first approach is based on rapid evaporative cooling of μm-sized water droplets that are injected into a vacuum chamber. Using this method, supercooled liquid water samples with temperatures down to approximately 227 K have been obtained, with the lowest temperature limited by homogeneous ice crystallization occurring after just a few milliseconds. In a second approach, structurally arrested high-pressure and therefore high-density amorphous ice samples are heated by an ultrafast infrared laser pulse. The fast heating melts the ice into a corresponding high-density liquid. At short time delays between the heating laser pulse and a subsequent x-ray probe pulse, the supercooled liquefied sample still experiences the high internal pressure of the initial state. At longer pump-probe delay times the supercooled water sample releases its internal pressure through structural relaxation. Hence, varying the pump-probe delay allows to probe the sample at different pressures.

    Together, these two approaches have been used to access a region within the metastable phase diagram of supercooled water that has previously been inaccessible. Using elastic x-ray scattering measurements as a structural probe of the liquid, we identified the existence of a liquid-liquid phase transition in deeply supercooled water. The observed phase transition is interpreted as the transition between a high-density and a low-density liquid phase. At high pressure this phase transition is discontinuous or first-order like, featuring a characteristic double-peak feature in the observed x-ray scattering intensity of the first diffraction maxima. At ambient pressure, however, we observe a continuous shift of the first diffraction maxima that is consistent with a continuous or second-order phase transition between the two liquids. Further evidence of a continuous phase transition at ambient pressure is seen in the temperature dependent maxima of the measured correlation length, isothermal compressibility and heat capacity, which indicate the existence of a Widom line.

    In summary, the experiments support the existence of a liquid-liquid critical point where the experimentally observed Widom line and phase coexistence line would both meet. The main result, however, is the first experimental observation of a liquid-liquid transition within a pure liquid.

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  • Public defence: 2020-06-12 13:00 sal G, Arrheniuslaboratorierna, Stockholm
    Almén, Daniel
    Stockholm University, Faculty of Social Sciences, Department of Economics.
    Societal Impacts of Modern Conscription: Human Capital, Social Capital and Criminal Behaviour2020Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Opportunity Costs and Conscription: An Unintended Progressive Tax?

    Throughout history to present days, policymakers, social commentators and others have oftentimes viewed conscription as a natural extension of secondary education, and an important institution for vocational training. This paper uses Swedish administrative data and exploits a reform in 2004, implying a sudden downsizing of the military, to identify the causal effects of peacetime conscription on later labour market outcomes and education. I find that unemployment increased in the short run, and lasted up to four years after service. There are no significant overall effects on income or educational attainment. However, these average effects hide a large heterogeneity. High ability conscripts fall behind their counterparts who did not start military service, both in terms of income and employment. Furthermore, the results suggest that the effect is attributed to high ability conscripts assigned as privates. In contrast, no such evidence is found for conscripts assigned to officer training, despite the fact that all of them have a high ability, and a longer time in service. Plausibly, high ability conscripts have high opportunity costs of doing military service, and the civilian benefits from training as privates are too small to counteract these costs. The results highlight the importance of precise matching of aptitude to type of training or education, an insight that might be generalized to other contexts beyond conscription.

    Citizenship, Social Capital and the Role of Conscription: Evidence from Sweden

    Many scholars have argued that conscription has played an important role as a nation-builder throughout history. Today, advocates of conscription often put forward its potential to induce citizenship and civic engagement. This paper addresses this claim by studying the causal effects of military service on civic engagement by using Swedish administrative data on election participation, blood donation, and the payment of a mandatory, but highly evaded, fee to the public broadcasting service. I study two qualitatively very different conscription systems from two different eras in Sweden, yielding a high external validity. To study the effects of universal conscription (almost all healthy and fit men serve) during the early 1990s, I use an empirical strategy similar in spirit to work using randomly assigned judges as an instrument. To identify the effects of selective conscription (a small fraction of motivated and positively selected men serve), I exploit a reform in 2004, implying a sudden downsizing of the military. In contrast to the previous correlational literature, the results show small and insignificant point estimates for all outcomes in both populations studied. Hence, I find no evidence of any causal effects of military service on civic engagement in either a selective-, or in a universal conscription system

    The Effect of Military Conscription on the Formation of Criminal Behaviour: Evidence from a Natural Experiment

    Conscription has been suggested to be a policy-tool to break young men's anti-social life-trajectories. This paper uses Swedish administrative data and exploits a reform in 2004, implying a sudden downsizing of the military, to identify the causal effects of peacetime conscription on contemporaneous, short- and medium-term crime. I find no evidence of any effects on criminal activity while in service. However, the post-service results show crime increasing effects of military service at the intensive margin (number of convictions), but not at the extensive margin (probability of conviction). The overall crime increasing effect seems to be primarily driven by thefts. This study finds no support for increased overall violent behaviour or that the military context per se induces anti-social behaviour. Rather, some suggestive evidence for worsened labour market opportunities for some groups is documented as a plausible mechanism behind the crime increasing results.

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  • Public defence: 2020-06-12 15:00 Hörsal 7, hus D, Stockholm
    Kalniņš, Aigars
    Stockholm University, Faculty of Humanities, Department of Slavic and Baltic Studies, Finnish, Dutch, and German.
    Studies in Latvian Comparative Dialectology: —with special focus on word-final *–āj(s)/*–ēj(s) and *–āji(s)/*–ēji(s)2020Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The thesis consists of four interconnected studies of various topics in the fields of Latvian dialectology and historical linguistics: (1) apocope and shortening; (2) loss of the present 2nd singular endings *i and *ɨ; (3) the development of the participle desinences *–ājis *ējis; (4) the ā and ēstem locative singular endings. A recurrent theme is a potential loss of *j in the phonological sequences *āji(s) *ēji(s), which were subsequently contracted to *āj(s) *ēj(s). In this regard, the first study provides the necessary East Baltic context, while studies 2, 3 and 4 investigate the relevant evidence in the Latvian dialects. At the same time, however, each of the topics is also studied on its own terms.

    In the first study, an improved account of apocope and shortening is formulated. It is argued that the primary apocope affected all unaccented short vowels, including *u, but that it took place before the accent retraction. Endings that were only affected in immobile paradigms were restored on the model of their counterparts in mobile paradigms. The secondary apocope in second posttonic syllables, which traditionally accounts for the occasional loss of inherited long vowels and diphthongs, is dated after accent retraction but restricted to *i. This implies that a series of endings such as d.sg. am, d.pl. Vms, ill.sg. Vn, 1.pl. Vm a.o. contained short vowels when the primary apocope set in. Unless Leskien’s Law operated in Latvian, the evidence suggests that the final vowels in these endings were short. If Lithuanian excludes Leskien’s Law in a given case, then the Latvian evidence is compelling, e.g., PEB d.sg.m. *amu or *ami rather than *amọ̄(i̯).

    The second study investigates present 2nd singular forms with and without a distinct ending in the Latvian dialects. The most archaic distribution seems to be the one found in Blīdene106, where only the derived presents are endingless in the indicative. Studies 2, 3 and 4 also give a comprehensive overview of the development of word-final *āj(s) *ēj(s) and *āji(s) *ēji(s). Both *āj *ēj and *āji *ēji yielded ā ē in Low Latvian, while High Latvian might have a contrast between accented āi̯ ēi̯ and unaccented ā ē. High Latvian reflects *ājs *ējs and *ājis *ējis as ājs ējs, but the Low Latvian developments are unclear. Accented *ājs *ējs yield āš ēš but in unaccented position there may be up to three phonologically regular reflexes: āš ēš, aiš eiš and ais eis. In Vidzeme and Zemgale, *ājis *ējis must have merged with *ājs *ējs, but in Courland *ājis *ējis were possibly apocopated only after *ājs *ējs had become āš ēš.

    Accordingly, only Low Latvian â ê can be reflexes of the old inessive. Low Latvian ai ei cannot be cognate with â ê but might continue the old adessive. If Low Latvian ã2 2 reflect the illative, then the three pairs, along with dialectal adverbs in uop, represent all four East Baltic local cases, which therefore must have existed at least as syntactic constructions in ProtoEast Baltic. The enigmatic High Latvian āstem locative singular ending â is identified with Low Latvian ai rather than â, which explains its remarkable lack of labialisation but implies a development *ˌaî > ˌâ.

    The utility of the proposed phonetic loss of *j is limited to disyllabic forms like l.sg. *tâji ‘that’ prs.2.sg. *smeji ‘laugh’ ptc. *gãjis ‘go,’ all of which might also be analogical, and it seems best to reject it.

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    Studies in Latvian Comparative Dialectology: —with special focus on word-final *–āj(s)/*–ēj(s) and *–āji(s)/*–ēji(s)
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  • Public defence: 2020-06-15 10:00 sal FB42, AlbaNova universitetscentrum, Stockholm
    K Manikandan, Sreekanth
    Stockholm University, Faculty of Science, Department of Physics.
    Non-equilibrium thermodynamics at the microscopic scales2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    An inherent feature of small systems in contact with thermal reservoirs, be it a pollen grain in water, or an active microbe flagellum, is fluctuations. Even with advanced microscopic techniques, distinguishing active, non-equilibrium processes defined by a constant dissipation of energy to the environment from passive, equilibrium processes is a very challenging task and a vastly developing field of research. For small (microscopic) systems in contact with thermal reservoirs, the experimental / theoretic framework that addresses these fundamental questions, is called stochastic thermodynamics.

    In this thesis, we study the stochastic thermodynamics of microscopic machines with colloidal particles as working substances. In particular, we use a path integral based framework to characterize the fluctuations of thermodynamic observables, such as Work, Heat and Entropy production in colloidal heat engines. We obtain exact analytic solutions at finite operational times and the results reveal model independent features of Work and Efficiency fluctuations.

    We also discuss the thermodynamic uncertainty relations, which relate current fluctuations in non-equilibrium steady states to the average rate of entropy production. Based on this relation, as well as exact analytical solutions for explicit models, we propose a simple and effective way to infer dissipation from current fluctuations in non-equilibrium systems, from short empirical trajectories.

    Finally, we conclude with a discussion on possible extensions of our results.

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    Non-equilibrium thermodynamics at the microscopic scales
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  • Public defence: 2020-06-15 10:00 sal G, Arrheniuslaboratorierna, Stockholm
    Lorentzon, Louise
    Stockholm University, Faculty of Social Sciences, Department of Economics.
    Empirical Essays on Public Policies: Social Insurances, Safety Nets, and Health Care2020Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Screening Efficiency in Sickness Insurance: Evidence from a Spell Limit Reform

    I estimate the effects of the removal of a limit on sick leave spells in the Swedish Sickness Insurance program, on labor market outcomes and sick leave. The removal of the spell limit led to longer sick leave spells. I also find that the removal led to a reduction in the share of people who are neither working, nor receiving sickness benefits. A conceptual framework is used to interpret the results in terms of benefits screening efficiency, which is found to increase through the removal of the spell limit. The identification is based on a regression discontinuity design, using the timing of sick leave start dates and the abolition of the spell limit.

    Long-Term Effects of Cash Transfers: Evidence from a Swedish Reform

    Do short-term cash transfers to the poor deliver long-term benefits? This paper studies a unique program introduced in Sweden in the 1930s. The program made large transfers – on average approximately 30 percent of total income in the collected sample – to widows with children. Income and family-size thresholds, combined with child age cutoffs, generate plausibly exogenous variation in program exposure. By digitizing and linking historical records to later administrative datasets, I study the long-term effects of this program. Focusing on life expectancy, I find no significant long-term effects; however, the estimates are imprecisely measured due to the limited sample size.

    Inertia of Dominated Pension Investments: Evidence from an Information Intervention

    In this paper we empirically investigate potential causes of imperfect competition in the fund market, as characterized by high price dispersion among comparable funds. We discriminate between three main hypotheses on the demand side: a lack of awareness of price dispersion, search costs, and financial illiteracy. A large-scale field experiment is conducted in the Swedish Premium Pension system. Information letters are sent to pension savers in two index funds, where there exists a cheaper fund with the same index strategy. We show that an information intervention that increases awareness of a cheaper, dominating fund, and reduces search costs to find such an alternative, can significantly improve households’ real investment allocations. Nonetheless, a vast majority of savers who are sent information about the name of the dominating fund do not switch funds. Thus, the high degree of inertia in pension investments remains even when search friction for identifying dominating alternatives are eliminated.

    Midwives and Maternal Mortality: Evidence from a Midwifery Policy Experiment in 19th Century Sweden

    This paper estimates the effect of a historical midwifery policy experiment on maternal mortality, infant mortality, and stillbirth during the period from 1830 to 1894 in Sweden. Exploiting sharp changes or “discontinuities” across time and place in the availability of trained and licensed midwives as an exogenous source of variation, we find that a doubling of trained midwives leads to a 20-40 percent reduction in maternal mortality and to a 20 percent increase in the uptake of midwife-assisted homebirths. The results thus suggest that a 1 percent increase in the share of midwife-assisted homebirths decreases maternal mortality by as much as 2 percent, which is a remarkable finding given that midwife training was only 6-12 months at that time. The results of this study contribute to the current debate about the most effective strategy to reduce the unacceptably high rate of maternal mortality in many developing countries, especially in low-resource settings.

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  • Public defence: 2020-06-15 10:00 The link will be made available at su.se/romklass/evenemang, Stockholm
    Berton, Marco
    Stockholm University, Faculty of Humanities, Department of Romance Studies and Classics.
    Riqueza léxica y expresión escrita en aprendices suecos de ELE: Proficiencia general, competencia léxica pasiva, tipo y complejidad de la tarea2020Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The present study explored lexical richness in the written production of Swedish university students of Spanish as a foreign language. Two aspects of lexical richness were investigated in the study, i.e., diversity (the ability to use a varied lexical repertoire), and sophistication (the proportion of relatively infrequent words). The written data were elicited by means of two task types, namely a narrative task and a decision-making task. The main aim of the study was investigating the effect of the factors overall proficiency, passive vocabulary knowledge, manipulation of task complexity and task type on lexical richness. Moreover, the study inquired into the predicting power of the first three factors in relation to lexical richness within each task type. Overall proficiency was measured by means of a cloze test, while an estimation of passive vocabulary knowledge was obtained through a word recognition test. The effect of the manipulation of task complexity was examined by using two different versions of each task. The less complex version of the narrative task was based on a cartoon strip with a tight structure and no background events. On the contrary, in the more complex version the cartoon strip depicted a story without a clear sequence and with background events which are relevant to the story plot. Regarding the decision-making task, task complexity was manipulated by changing the number of elements involved. The task itself consisted in writing a message to a friend suggesting a holiday destination. To do so, the participants had to consider the friend´s needs and check them against the possibilities offered by a travel agency. The less complex version included two destinations, while the more complex one contained six. When analysing the effect of manipulating task complexity, structural complexity measures were included with the purpose of investigating if changes in lexical richness go hand in hand with or at the expense of changes in structural complexity. The results of the analysis of these three factors showed different patterns depending on the task type examined. These results suggest that overall proficiency seems to have an effect on lexical richness only in the narrative task, whereas passive vocabulary knowledge would influence lexical richness only in the decision-making task. The manipulation of task complexity apparently affected lexical diversity and structural complexity in the narrative task, on the one hand, and lexical sophistication in the decision-making task, on the other hand. When manipulating task complexity, the relationship between lexical richness and structural complexity turned out to be unclear, as it varied in unpredictable ways depending on the learners´ overall proficiency and passive vocabulary knowledge. The intrinsic complexity inherent to task type, i.e. the different cognitive load that different task types place on the learner, showed the most consistent effect in the study, as it was supported by all the measures of lexical richness and some measures of structural complexity. Finally, the regression model conformed by overall proficiency, passive vocabulary knowledge, and the manipulation of task complexity did not prove to be suitable to predict lexical richness in either of the task types under investigation in the study.

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  • Public defence: 2020-08-21 13:00 Oskar Kleins auditorium (FR4), AlbaNova universitetscentrum, Stockholm
    Calissendorff, Per
    Stockholm University, Faculty of Science, Department of Astronomy.
    Characterising Emblematic Binaries at the Lowest Stellar and Substellar Masses2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Stars are involved in most research fields of astronomy, ranging from studies of faraway galaxies, exploding supernovae, to more nearby exoplanets and even our own Sun. As such, it is paramount that our physical interpretation of stars is accurate. By observing stars at different epochs, we can fashion evolutionary models to predict important events that occur at different phases during their life-cycle. Thus, exemplary stars where properties including mass, age and luminosity can be observed become increasingly valuable as benchmarks for calibrating said models with. Sometimes, all of these essential properties can be measured for a single system. For instance, for a binary star which circles a common centre of mass we can from its orbital motion calculate the dynamical mass of the system. If the stellar system also has a well-determined age we may use it as a benchmark for our models, and hence refer to it as an emblematic binary system.

    In this thesis we are searching for exactly these emblematic binaries, both among lowmass stars and substellar brown dwarfs. We also show how to measure the different characteristics that make the systems into exemplary touchstones. We provide an overview over the different types of stellar binaries, how mass and age estimates are performed, as well as discuss the implications multiplicity has for the formation and evolution of stars and brown dwarfs. In Paper I we present the results from an orbital fit we constrained for a low-mass binary with a known age, making into a valuable and relatively rare benchmark. We also show in Paper II how long baseline astrometry can be exploited in order to place better constraints for orbital fits and dynamical masses for low-mass companions to stars by measuring the perturbation in proper motion over time. The dynamical masses are sequentially tested against evolutionary models, which at these low masses display several discrepancies compared to the observables, and are thus questioned. We explore more uncharted mass-regimes in Paper III, where we employ laser guide star assisted adaptive optics to search for multiplicity among faint substellar objects in young moving groups, detecting 3 new young brown dwarf binary systems. These new binaries will prove to be highly valuable systems for future research of brown dwarfs, and will be able to be studied further with for instance the Extremely Large Telescope or James Webb Space Telescope, which also makes them into prominent benchmarks for substellar evolutionary models. Furthermore, age estimation typically dominates the error budget for low-mass stars and brown dwarfs, requiring several different approaches for a robust assessment. In Paper IV we test and compare different techniques for age determination of 7 low-mass binary stars. These binaries have had their orbital motion monitored for a longer time, and will soon be constrained well enough that dynamical masses may be procured. As such, these low-mass binaries will extend the so far scarce number of exemplary systems where both mass, luminosity and age can be determined, to later be used to calibrate theoretical evolutionary models.

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