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  • Public defence: 2017-05-29 10:00 Lilla hörsalen, Naturhistoriska riksmuseet, Stockholm
    Haglund, Liza
    Stockholm University, Faculty of Social Sciences, Department of Education.
    Towards Epistemic and Interpretative Holism: A critique of methodological approaches in research on learning2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The central concern of this thesis is to discuss interpretations of learning in educational research. A point of departure is taken in core epistemological and ontological assumptions informing three major approaches to learning: behaviourism, cognitive constructivism and socioculturalism. It is argued that all three perspectives provide important insights into research on learning, but each alone runs the risk of reducing learning and interpretations of learning to single aspects. Specific attention is therefore given to Intentional Analysis, as it has been developed to account for sociocultural aspects that influence learning and individual cognition. It is argued that interpretations of learning processes face challenges, different kinds of holism, underdetermination and the complexity of intentionality, that need to be accounted for in order to make valid interpretations. Interpretation is therefore also discussed in light of philosopher Donald Davidson’s theories of knowledge and interpretation. It is suggested that his theories may provide aspects of an ontological and epistemological stance that can form the basis for interpretations of learning in educational research. A first brief sketch, referred to as ‘epistemic holism’, is thus drawn. The thesis also exemplifies how such a stance can inform empirical research. It provides a first formulation of research strategies – a so-called ‘interpretative holism’. The thesis discusses what such a stance may imply with regard to the nature and location of knowledge and the status of the learning situation. Ascribing meaning to observed behaviour, as it is described in this thesis, implies that an action is always an action under a specific description. Different descriptions may not be contradictory, but if we do not know the learner’s language use, we cannot know whether there is a difference in language or in beliefs. It is argued that the principle of charity and reference to saliency, that is, what appears as the figure for the learner, may help us decide. However, saliency does not only appear as a phenomenon in relation to physical objects and events, but also in the symbolic world, thus requires that the analysis extend beyond the mere transcription of an interview or the description of an observation. Hence, a conclusion to be drawn from this thesis is that the very question of what counts as data in the interpretation of complex learning processes is up for discussion.

  • Public defence: 2017-05-29 10:15 sal FB42, AlbaNova universitetscentrum, Stockholm
    Petrushevska, Tanja
    Stockholm University, Faculty of Science, Department of Physics.
    Supernovae seen through gravitational telescopes2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Galaxies, and clusters of galaxies, can act as gravitational lenses and magnify the light of objects behind them. The effect enables observations of very distant supernovae, that otherwise would be too faint to be detected by existing telescopes, and allows studies of the frequency and properties of these rare phenomena when the universe was young. Under the right circumstances, multiple images of the lensed supernovae can be observed, and due to the variable nature of the objects, the difference between the arrival times of the images can be measured. Since the images have taken different paths through space before reaching us, the time-differences are sensitive to the expansion rate of the universe. One class of supernovae, Type Ia, are of particular interest to detect. Their well known brightness can be used to determine the magnification, which can be used to understand the lensing systems.

    In this thesis, galaxy clusters are used as gravitational telescopes to search for lensed supernovae at high redshift. Ground-based, near-infrared and optical search campaigns are described of the massive clusters Abell 1689 and 370, which are among the most powerful gravitational telescopes known. The search resulted in the discovery of five photometrically classified, core-collapse supernovae at redshifts of 0.671<z<1.703 with significant magnification from the cluster. Owing to the power of the lensing cluster, the volumetric core-collapse supernova rates for 0.4 ≤ z < 2.9 were calculated, and found to be in good agreement with previous estimates and predictions from cosmic star formation history. During the survey, two Type Ia supernovae in A1689 cluster members were also discovered, which allowed the Type Ia explosion rate in galaxy clusters to be estimated. Furthermore, the expectations of finding lensed supernovae at high redshift in simulated search campaigns that can be conducted with upcoming ground- and space-based telescopes, are discussed.

    Magnification from a galaxy lens also allows for detailed studies of the supernova properties at high redshift that otherwise would not be possible. Spectroscopic observations of lensed high-redshift supernovae Type Ia are of special interest since they can be used to test for evolution of the standard candle nature of these objects. If systematic redshift-dependent properties are found, their utility for future surveys could be challenged. In the thesis it is shown that the strongly lensed and very distant supernova Type Ia PS1-10afx at z=1.4, does not deviate from the well-studied nearby and intermediate populations of normal supernovae Type Ia.

    In a different study, the discovery of the first resolved multiply-imaged gravitationally lensed supernova Type Ia is also reported.

  • Public defence: 2017-05-29 13:00 Magnélisalen, Kemiska övningslaboratoriet, Stockholm
    Nedum Kandathil, Reji
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Hydrogen incorporation in Zintl phases and transition metal oxides- new environments for the lightest element in solid state chemistry2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This PhD thesis presents investigations of hydrogen incorporation in Zintl phases and transition metal oxides. Hydrogenous Zintl phases can serve as important model systems for fundamental studies of hydrogen-metal interactions, while at the same time hydrogen-induced chemical structure and physical property changes provide exciting prospects for materials science. Hydrogen incorporation in transition metal oxides leads to oxyhydride systems in which O and H together form an anionic substructure. The H species in transition metal oxides may be highly mobile, making these materials interesting precursors toward other mixed anion systems. 

    Zintl phases consist of an active metal, M (alkali, alkaline earth or rare earth) and a more electronegative p-block metal or semimetal component, E (Al, Ga, Si, Ge, etc.). When Zintl phases react with hydrogen, they can either form polyanionic hydrides or interstitial hydrides, undergo full hydrogenations to complex hydrides, or oxidative decomposition to more E-rich Zintl phases. The Zintl phases investigated here comprised the CaSi2, Eu3Si4, ASi (A= K, Rb) and GdGa systems which were hydrogenated at various temperature, H2 pressure, and dwelling time conditions. For CaSi2, a regular phase transition from the conventional 6R to the rare 3R took place and no hydride formation was observed. In contrast, GdGa and Eu3Si4 were very susceptible to hydrogen uptake. Already at temperatures below 100 ºC the formation of hydrides GdGaH2-x and Eu3Si4H2+x was observed. The magnetic properties of the hydrides (antiferromagnetic) differ radically from that of the Zintl phase precursor (ferromagnetic). Upon hydrogenating ASi at temperatures around 100 oC, silanides ASiH3 formed which contain discrete complex ion units SiH3-. The much complicated β – α order-disorder phase transition in ASiH3 was evaluated with neutron powder diffraction (NPD), 2H NMR and heat capacity measurements. 

    A systematic study of the hydride reduction of BaTiO3 leading to perovskite oxyhydrides BaTiO3-xHx was done. A broad range of reducing agents including NaH, MgH2, CaH2, LiAlH4 and NaBH4 was employed and temperature and dwelling conditions for hydride reduction examined. Samples were characterized by X-ray powder diffraction (XRPD), thermal gravimetric analysis and 1H NMR. The concentration of H that can be incorporated in BaTiO3-xHx was found to be very low, which is in contrast with earlier reports. Instead hydride reduction leads to a high concentration of O vacancies in the reduced BaTiO3. The highly O-deficient, disordered, phases - BaTiO3-xHy(x-y) with x up to 0.6 and y in a range 0.05 – 0.2 and (x-y) > y – are cubic and may represent interesting materials with respect to electron and ion transport as well as catalysis.

  • Public defence: 2017-05-31 10:00 Magnélisalen, Kemiska övningslaboratoriet, Stockholm
    Jaffer Ali, Mohammed Hakim
    Stockholm University, Faculty of Science, Department of Neurochemistry.
    Multifaceted roles of the transmembrane nuclear envelope protein, Samp12017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The eukaryotic nuclear envelope (NE), separates the nucleoplasm from cytoplasm and is made up of two concentric lipid membranes, the outer and the inner nuclear membranes (ONM and INM), the nuclear pore complexes (NPCs) and an underlying filamentous nuclear lamina. The INM contains hundreds of unique transmembrane proteins of which only a handful have been characterized. In this thesis, I aimed to understand the functional organization of proteins in the nuclear envelope and I focused on investigating the functions of a recently identified INM transmembrane protein, Samp1. We have developed a novel and robust approach, MCLIP, to identify specific protein-protein interactions taking place in live cells. Using MCLIP, we have shown that Samp1 interacts with proteins of the LINC complex, the nuclear lamina and components of the mitotic spindle. Samp1's specific interactions with a variety of binding partners, suggest that Samp1 plays important roles both in interphase and in mitosis.  We have also shown that Samp1 can provide a binding site at the INM for the GTPase Ran, a master regulator of protein interactions in interphase and in mitosis. Furthermore, we have also investigated the role of Samp1 in cell differentiation using two independent model systems. In human iPSCs, ectopic expression of Samp1 promoted differentiation despite pluripotent culture conditions. In C2C12 myoblast, depletion of Samp1 completely blocked differentiation into myotubes. The two studies complement each other and suggest that Samp1 has a strong differentiation promoting activity. Taken together, the findings in this thesis, give insights on the unexpected and unforeseen roles played by a transmembrane protein in different fundamental cellular process.

  • Public defence: 2017-05-31 13:00 De Geersalen, Geovetenskapens hus, Stockholm
    Helanow, Christian
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Basal boundary conditions, stability and verification in glaciological numerical models2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    To increase our understanding of how ice sheets and glaciers interact with the climate system, numerical models have become an indispensable tool. However, the complexity of these systems and the natural limitation in computational power is reflected in the simplifications of the represented processes and the spatial and temporal resolution of the models. Whether the effect of these limitations is acceptable or not, can be assessed by theoretical considerations and by validating the output of the models against real world data. Equally important is to verify if the numerical implementation and computational method accurately represent the mathematical description of the processes intended to be simulated. This thesis concerns a set of numerical models used in the field of glaciology, how these are applied and how they relate to other study areas in the same field.

    The dynamical flow of glaciers, which can be described by a set of non-linear partial differential equations called the Full Stokes equations, is simulated using the finite element method. To reduce the computational cost of the method significantly, it is common to lower the order of the used elements. This results in a loss of stability of the method, but can be remedied by the use of stabilization methods. By numerically studying different stabilization methods and evaluating their suitability, this work contributes to constraining the values of stabilization parameters to be used in ice sheet simulations. Erroneous choices of parameters can lead to oscillations of surface velocities, which affects the long term behavior of the free-surface ice and as a result can have a negative impact on the accuracy of the simulated mass balance of ice sheets.

    The amount of basal sliding is an important component that affects the overall dynamics of the ice. A part of this thesis considers different implementations of the basal impenetrability condition that accompanies basal sliding, and shows that methods used in literature can lead to a difference in velocity of 1% to 5% between the considered methods.

    The subglacial hydrological system directly influences the glacier's ability to slide and therefore affects the velocity distribution of the ice. The topology and dominant mode of the hydrological system on the ice sheet scale is, however, ill constrained. A third contribution of this thesis is, using the theory of R-channels to implement a simple numerical model of subglacial water flow, to show the sensitivity of subglacial channels to transient processes and that this limits their possible extent. This insight adds to a cross-disciplinary discussion between the different sub-fields of theoretical, field and paleo-glaciology regarding the characteristics of ice sheet subglacial hydrological systems. In the study, we conclude by emphasizing areas of importance where the sub-fields have yet to unify: the spatial extent of channelized subglacial drainage, to what degree specific processes are connected to geomorphic activity and the differences in spatial and temporal scales.

    As a whole, the thesis emphasizes the importance of verification of numerical models but also acknowledges the natural limitations of these to represent complex systems. Focusing on keeping numerical ice sheet and glacier models as transparent as possible will benefit end users and facilitate accurate interpretations of the numerical output so it confidently can be used for scientific purposes.

  • Public defence: 2017-06-01 10:00 hörsal 9, hus D, Stockholm
    Bortz, Olof
    Stockholm University, Faculty of Humanities, Department of History.
    "I wanted to know how this deed was done": Raul Hilberg, the Holocaust and History2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Raul Hilberg was a pioneer of Holocaust studies and for many decades the Holocaust scholar par excellence. He embarked upon the study of the Nazi genocide after the war, and established the understanding of the Holocaust as a bureaucratically administered “destruction process,” carried out by men who were not different from the German population in general. The present study analyzes and contextualizes his understanding of the Nazi genocide and the Jewish victims’ response to it, as well as the reception of Hilberg’s magnum opus, The Destruction of the European Jews, in relation to scholarly, political and personal contexts. It shows that Hilberg’s major work was far more favorably received than previously believed and that the negative reactions to his thesis on Jewish reactions was a response to the positive reception of his book, as well as an expression of a wider shift in scholarly and popular perceptions of the behavior of Jewish victims during the Holocaust.

    Hilberg’s interest in bureaucracy allowed him to depart from the focus on the Nazi leadership and the interpretation of the Holocaust as a premeditated and centrally organized genocide. The connection to modernity made him interpret it as a form of ominous progress, carrying implications for modern societies in general, as opposed to the interpretation of Nazism and the Holocaust as a form of atavistic aberration. However, Hilberg’s emphasis on the modern character of the genocide also led to a form of veneration of its efficiency.

    Hilberg has been much criticized for his argument that the Jewish victims contributed to their own demise by repeating an outdated and historically conditioned reaction to persecution, which assisted the perpetrators. This study explores his thesis regarding the “Jewish reaction pattern,” as an integral part of his work, which he used as a contrast to what he regarded as the successful and future oriented destruction process. It moreover advances a novel interpretation of this controversial part of Hilberg’s research, seeing it as a call for political action emptied of its positive di­mension, and a form of negative historiographical empowerment of the victims.

  • Public defence: 2017-06-01 10:00 De Geersalen, Geovetenskapens hus, Stockholm
    Greenstein, Stanley
    Stockholm University, Faculty of Law, Department of Law.
    Our Humanity Exposed: Predictive Modelling in a Legal Context2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis examines predictive modelling from the legal perspective. Predictive modelling is a technology based on applied statistics, mathematics, machine learning and artificial intelligence that uses algorithms to analyse big data collections, and identify patterns that are invisible to human beings. The accumulated knowledge is incorporated into computer models, which are then used to identify and predict human activity in new circumstances, allowing for the manipulation of human behaviour.

    Predictive models use big data to represent people. Big data is a term used to describe the large amounts of data produced in the digital environment. It is growing rapidly due mainly to the fact that individuals are spending an increasing portion of their lives within the on-line environment, spurred by the internet and social media. As individuals make use of the on-line environment, they part with information about themselves. This information may concern their actions but may also reveal their personality traits.

    Predictive modelling is a powerful tool, which private companies are increasingly using to identify business risks and opportunities. They are incorporated into on-line commercial decision-making systems, determining, among other things, the music people listen to, the news feeds they receive, the content people see and whether they will be granted credit. This results in a number of potential harms to the individual, especially in relation to personal autonomy.

    This thesis examines the harms resulting from predictive modelling, some of which are recognized by traditional law. Using the European legal context as a point of departure, this study ascertains to what extent legal regimes address the use of predictive models and the threats to personal autonomy. In particular, it analyses Article 8 of the European Convention on Human Rights (ECHR) and the forthcoming General Data Protection Regulation (GDPR) adopted by the European Union (EU). Considering the shortcomings of traditional legal instruments, a strategy entitled ‘empowerment’ is suggested. It comprises components of a legal and technical nature, aimed at levelling the playing field between companies and individuals in the commercial setting. Is there a way to strengthen humanity as predictive modelling continues to develop?

  • Public defence: 2017-06-01 13:00 William-Olssonsalen, Geovetenskapens hus, Stockholm
    Bui, Tuong Thuy
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Assessing human exposure to phthalates, alternative plasticizers and organophosphate esters2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Phthalate esters (PEs) and organophosphate esters (OPEs) are common indoor pollutants frequently detected in environmental (dust, air), personal (hand wipes, diet) and human matrices (urine, serum etc.). In this thesis, mathematical models were used to establish links between intake and body burden for a comprehensive dataset based on a Norwegian study population. Also, the relative importance of different PE uptake pathways was assessed and discussed. Furthermore, the suitability of human nails as an alternative, non-invasive biomonitoring matrix for PEs was investigated. Additionally, information regarding alternative plasticizers to PEs was collected and presented extensively. Results showed that for PEs (paper II), daily intakes based on external exposure media agree with back-calculations using urinary metabolite concentrations, leading to the conclusion that human exposure for the general adult population is well understood and that the most important uptake routes were captured. Overall intake levels are comparable or lower than level presented in recent comprehensive studies and hazard quotients were well below 1 (low risk). As expected, diet was found to be the most important uptake route for all PEs. For lower molecular weight PEs, inhalation becomes a strong contributing pathway whereas for higher molecular weight PEs, dust ingestion was also important. Daily intake based on hand wipes was found to be much lower than the estimated total dermal intake based on air, dust and personal care products, questioning the relevance of hand wipes to represent total dermal exposure. Human nails were found to be unsuitable for replacing urine as a biomonitoring matrix for PEs as internal intake (from blood) cannot explain measured nail concentrations and uptake from air is too slow to reach observed concentrations within a realistic time frame (paper III). Hence, the kinetic links between intake and nail concentrations could not be established. Although exposure to traditional PEs is decreasing, use and body burden of some alternatives are increasing (paper I). Fortunately, most alternative plasticizers have favorable toxicological properties, resulting in low risk for humans. In contrast to PEs, OPEs still remain a group of poorly studied substances in terms of human exposure (paper IV). Due to lack of information regarding human metabolism, reliable links between intake and concentrations in serum and urine could not be established. Modelling results showed that concentrations in serum, and to some extent, urine, were underestimated for 2 compounds. It is likely that a combination of missing intake and suboptimal biomarkers were the cause for this under-prediction. Because of this, further studies regarding human metabolism should be performed for OPEs and potentially more specific biomarkers identified in the future. For PEs, there is a need for more comprehensive datasets to study exposure for high risk groups such as infants and children. Furthermore, dermal uptake remains poorly understood and the uptake of PEs into human nails should be studied in more detail to establish the kinetic links between exposure and body burden.

  • Public defence: 2017-06-02 09:30 Vivi Täckholmsalen (Q-salen), NPQ-huset
    Verschut, Thomas Alexander
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Searching for food in complex environments: Integrating processes at multiple spatial scales2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Resources are often unevenly distributed through the environment, resulting in a challenging task for insects to locate food, mates and oviposition sites. Consequently, there is an ongoing need to unravel how insects rely on behavioural and sensory traits while searching for resources in heterogeneous environments. In the first part of this thesis, I addressed this issue by studying how neighbouring resources can affect the likelihood of insects finding their preferred host resources. These effects of neighbouring resources are commonly referred to as associational effects, and are expected to result from limitations in the sensory physiology of insects. Such limitations constrain the insect’s ability to correctly evaluate resource quality at the different steps involved in insect search behaviour. Furthermore, I determined whether the physiological state of an insect, and sensory experiences made during larval stages, can affect host search behaviour in heterogeneous environments.

    By comparing the behaviour of Drosophila melanogaster in environments with single and multiple resources, I found that the presence of neighbouring recourses increased the selection rates for attractive resources, while it decreased the selection rates for less attractive resources. These effects are referred to as associational susceptibility and associational resistance respectively. Furthermore, by studying oviposition behaviour, I found that during these small-scale behavioural decisions, associational effects are mainly governed by gustatory mediated selection and less by olfactory mediated selection. The oviposition assay eliminated potential misinterpretations of resource quality along the different steps of search behaviour, hence the results suggested that associational effects rely on distinctive selection behaviour between resource types rather than on sensory constraints.

    In the second part of this thesis I determined whether natal experiences can be used by insects as sensory shortcuts to find host resources, and whether this leads to better larval performance on those selected host resources. For this purpose, I studied the interactions between the larval parasitoid Asecodes lucens and the oligophagous leaf beetle Galerucella sagittariae. The results showed that the relationship between oviposition preference and larval performance, of both insect species, depends on an interactive effect between the insects’ natal origin and the quality of the different host resources. Moreover, I found that the natal origin was a better predictor for the adult host preference, rather than for larval performance. This suggests that, aside from the actual quality of the host resources, locating any suitable host might be even more limiting for the female’s fitness. 

  • Public defence: 2017-06-02 10:00 hörsal 11, hus F, Stockholm
    Börstell, Carl
    Stockholm University, Faculty of Humanities, Department of Linguistics.
    Object marking in the signed modality: Verbal and nominal strategies in Swedish Sign Language and other sign languages2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    In this dissertation, I investigate various aspects of object marking and how these manifest themselves in the signed modality. The main focus is on Swedish Sign Language (SSL), the national sign language of Sweden, which is the topic of investigation in all five studies. Two of the studies adopt a comparative perspective, including other sign languages as well. The studies comprise a range of data, including corpus data, elicited production, and acceptability judgments, and combine quantitative and qualitative methods in the analyses.

    The dissertation begins with an overview of the topics of valency, argument structure, and object marking, primarily from a spoken language perspective. Here, the interactions between semantics and morphosyntax are presented from a typological perspective, introducing differential object marking as a key concept. With regard to signed language, object marking is discussed in terms of both verbal and nominal strategies.

    Verbal strategies of object marking among sign languages include directional verbs, object handshape classifiers, and embodied perspective in signing. The first study investigates the use of directionality and object handshapes as object marking strategies in Al-Sayyid Bedouin Sign Language (ABSL), Israeli Sign Language (ISL), and SSL. It is shown that the strategies generally display different alignments in terms of the types of objects targeted, which is uniform across languages, but that directionality is much more marginal in ABSL than in the other two languages. Also, we see that there is a connection between object marking strategies and the animacy of the object, and that the strategies, object animacy, and word order preferences interact. In the second and third studies, SSL is investigated with regard to the transitive–reflexive distinction. Here, we see that there are interactional effects between object handshapes and the perspective taken by the signer. This points to intricate iconic motivations of combining and structuring complex verb sequences, such as giving preference to agent focusing structures (e.g., agent perspective and handling handshapes). Furthermore, the use of space is identified as a crucial strategy for reference tracking, especially when expressing semantically transitive events.

    Nominal strategies include object pronouns and derivations of the sign PERSON. The fourth study provides a detailed account of the object pronoun OBJPRO in SSL, which is the first in-depth description of this sign. It is found that the sign is in widespread use in SSL, often corresponds closely to object pronouns of spoken Swedish, and is argued to be grammaticalized from the lexical sign PERSON. In the final study, the possible existence of object pronouns in other sign languages is investigated by using a sample of 24 languages. This analysis reveals that the feature is found mostly in the Nordic countries, suggesting areal contact phenomena. However, the study also shows that there are a number of derivations of PERSON, such as reflexive pronouns, agreement auxiliaries, and case markers. The use of PERSON as a source of grammaticalization for these functions is attributed to both semantic and phonological properties of the sign.

    This dissertation is unique in that it is dedicated to the topic of object marking in the signed modality. It brings a variety of perspectives and methods together in order to investigate the domain of object marking, cross-linguistically and cross-modally.

  • Public defence: 2017-06-02 10:00 Magnélisalen, Kemiska Övningslaboratoriet, Stockholm
    Stridfeldt, Elin
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Hypervalent Iodine Reagents in Metal-Free Arylations and Vinylations: Investigation of Suitable Coupling Partners and Synthesis of New Reagents2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis concerns the development of metal-free reactions to obtain carbon-heteroatom and carbon-carbon bonds. This is achieved by transferring carbon ligands from hypervalent iodine reagents to suitable nucleophiles.

    The bulk of the work presented herein concerns arylation of oxygen and nitrogen nucleophiles, using the well-known diaryliodonium salts as aryl sources. In the first project, O-arylation of the oxime ethyl acetohydroxamate was studied. It was found that electron-poor as well as electron-rich aryl moieties could be transferred successfully to this nucleophile. Furthermore, the protocol could be extended to a sequential one-pot synthesis of benzo[b]furans. This method allowed for a fast synthesis of the natural product stemofuran A and formal syntheses of other natural products.

    In a successive project, O-arylation of hydroxide and aliphatic alkoxides was investigated. It is known that electron-poor aryl moieties can be transferred to these nucleophiles in moderate to high yields. However, combined with more electron-rich diaryliodonium salts, a large amount of side products were formed. These were suppressed upon addition of aryne traps, suggesting that aryne pathways are competing with the desired ligand coupling. It was also observed that secondary alcohols were oxidized to the corresponding ketones. The mechanism for this oxidation was investigated and aryne pathways could be excluded. Instead we suggest that the carbinol hydrogen gets deprotonated via an internal mechanism, after the alkoxide has coordinated to the iodonium salt. Highly sterically congested alkyl aryl ethers could be obtained in high yields by combining tertiary alcohols with ortho-blocked diaryliodonium salts. 

    Next, N-arylation of secondary acyclic amides was studied using acetanilide as the model substrate. This procedure was suitable for transfer of electron-poor as well as ortho-substituted aryl moieties, but attempts to transfer very electron-rich aryl groups were unsuccessful. On the other hand, the amides displayed a complementary reactivity, allowing phenylation of electron-rich amides. 

    In the final project, a one-pot synthesis of the cyclic iodonium reagent vinylbenziodoxolone is presented. These compounds have not been explored as reagents earlier. Initial screenings showed that the vinyl moiety could be transferred to nitrocyclohexane with opposite regioselectivity compared to the acyclic analogue of the reagent.

  • Public defence: 2017-06-02 13:00 Auditorium 215, Humanistvillan, Stockholm
    Lindström, Matts
    Stockholm University, Faculty of Humanities, Department of Culture and Aesthetics.
    Drömmar om det minsta: Mikrofilm, överflöd och brist, 1900–19702017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis explores the cultural history of microfilm and microphotography during the period 1900–1970, thus contributing to the broader field of research on the history of 20th century information management in the era before digital technology. The aim is to study how microfilm repeatedly, in various contexts and over time, was described and perceived as a new medium. To this end the book examines and analyses the plans, dreams and visionary prognostics put forth by various historical actors with an interest in microfilm – using case studies situated at different junctures and periods (1904–1910, 1937, 1940–1952, 1950–1970), while also ranging geographically from the United States to Europe and Sweden.

    From a theoretical and methodological point of view the thesis seeks to understand the historical formation of microfilm by developing the notions of configuration and reconfiguration, employing a perspective which emphasizes the continuous ontological interplay and interdependence of materiality and discourse in the formation of media. Thus, at the empirical level, the analysis takes into account realized technological materialities as well as unrealized imaginary articulations, dreams and expectations integral to the configuration of microfilm within a broader culture of paperwork. As a result of this approach the study draws on scientific texts and articles in journals, as well as newspaper reports, commercial messages, ads, handbooks and various archival documents.

    The analysis reveals a close relationship between microfilm and experiences of entropy connected to information systems based on paper and paperwork. It is argued that, within the dreams and plans that are studied, the most important function of microfilm was to regulate noise, decay and disorder associated with the materiality of paper – through ordering, operating on and modifying the capacities of paper media. It is also noted that microfilm was perceived and articulated as a new medium over a long period of time, even though very little changed at the technological level. From a historiographical point of view, it is thus argued, microfilm can be characterized as a simultaneously continuous and discontinuous phenomenon, taking part in a history that unfolded through repetitions, returns and non-linear steps rather than along an uninterrupted, linear path.

  • Public defence: 2017-06-02 13:00 David Magnussonsalen (U31), Stockholm
    Larsson Sundqvist, Max
    Stockholm University, Faculty of Social Sciences, Department of Psychology.
    Effects of retrieval and articulation on memory2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Many would agree that learning occurs when new information is stored in memory. Therefore, most learning efforts typically focus on encoding processes, such as additional study or other forms of repetition. However, as I will outline in this thesis, there are other means by which to improve memory, such as retrieval practice in the form of tests. Testing memory has a reinforcing effect on memory, and it improves retention more than an equal amount of repeated study – referred to as the testing effect – and it has been assumed that retrieval processes drive this effect. Recently, however, this assumption has been called into question because of findings that suggest that articulation, that is, the act of providing an explicit response on a memory test, may play a role in determining the magnitude of the testing effect. Therefore, in three studies, I have examined the effects of retrieval and articulation on later retention, in an attempt to ascertain whether the testing effect is entirely driven by retrieval, or if there are additive effects of articulation. I have also explored possible boundary conditions that may determine when, and if, the effects of retrieval and articulation become selective with respect to memory performance. In all three studies, participants studied paired associates and were tested in a cued recall paradigm after a short (~5 min) and a long (1 week) retention interval, and retrieval was either covert (i.e., responses were retrieved but not articulated) or overt (i.e., responses were retrieved and articulated). 

    In Study I, I demonstrated that uninstructed covert retrieval practice (by means of delayed judgments of learning) produced a testing effect (i.e., improved memory relative to a study-only condition) similar to that of explicit testing, which supports the idea that the testing effect is mainly the result of retrieval processes. In study II, I compared memory performance for covert and overt testing, and found partial support for a relative efficacy in favor of overt retrieval, compared to covert retrieval, although the effect size was small. In Study III, I further explored the distinction between different response formats (i.e., covert retrieval vs. various forms of overt testing), specifically handwriting and keyboard typing. I also examined the relative efficacy of covert versus overt retrieval as a function of list order (i.e., whether covert and overt retrieval is practiced in blocks or random order) and its manipulation within or between subjects. The results of Study III were inconclusive insofar as a relative efficacy of covert versus overt retrieval, with respect to later retention, could not be demonstrated reliably. The list order manipulations did not appear to affect covert and overt retrieval selectively. More importantly, in cases where a relative efficacy was found, the effect size was again small.

    Taken together, the three studies that of thesis indicate that the benefit of testing memory appears to be almost entirely the result of retrieval processes, and that articulation alone adds very little – if anything – to the magnitude of the testing effect, at least in cued-recall paradigms. These findings are discussed in terms of their theoretical implications, as well as their importance for the development of optimal teaching and learning practices in educational settings.

  • Public defence: 2017-06-05 10:00 Magnelisalen, Kemiska övningslaboratoriet, Stockholm
    Nordholm, Johan
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    NA transmembrane domain: Amphiphilic drift to accommodate two functions2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Neuraminidase (NA) is one of two major antigens on the surface of influenza A viruses. It is comprised of a single N-terminal transmembrane domain (TMD), a stalk domain, and a C-terminal enzymatic head domain that cleaves sialic acid, most notably to release new particles from the host cell surface. NA is only enzymatically active as a homo-tetramer. However, it is not known which properties facilitate the oligomerization of NA during assembly. Our results show that, apart from anchoring the protein to the membrane, the NA TMD also contributes to the assembly process by keeping the stalk in a tetrameric conformation. The ability of the TMD to oligomerize is shown to be dependent on its amphiphilic characteristics that was largely conserved across the nine NA subtypes (N1-N9). Over time the NA TMDs in human H1N1 viruses were found to have become more amphiphilic, which correlated with stronger oligomerization. An old H1N1 virus with a more recent N1 TMD had impaired growth, but readily acquired compensatory mutations in the TMD to restore growth, by reverting the TMD oligomerization strength back to that of the old TMD, demonstrating a biological role of the TMD in folding and assembly. NA and the other viral proteins are spatially and temporally coordinated to achieve optimal viral production. By using a co-transfection analysis, the high AU-content in the NA and HA ER-targeting sequence coding regions (for NA TMD as well as the HA signal sequence) were found to inhibit their expression. The inhibition was alleviated by the early expressed influenza RNA-binding protein NS1, which promoted translation and showed enriched foci at the endoplasmic reticulum (ER). NS1, which expresses early during infection, is therefore likely the regulator of NA and HA to prevent premature expression. These results show that the NA TMD is under substantial selection pressure at both the nucleotide and amino acid level to accommodate its roles in ER-targeting, protein folding, and post-transcriptional regulation.

  • Public defence: 2017-06-07 10:00 De Geersalen, Geovetenskapens hus, Stockholm
    Mengiste, Tekalign Ayalew
    Stockholm University, Faculty of Social Sciences, Department of Social Anthropology.
    Struggle for Mobility: Risk, hope and community of knowledge in Eritrean and Ethiopian migration pathways towards Sweden2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    On the basis of the ethnographic fieldwork conducted in Sweden, Italy, Sudan and Ethiopia during 2013–2015, this study examines the motivations, organizations and impact of overland migratory journeys from Ethiopia and Eritrea across the Sahara Desert and Mediterranean Sea to Sweden. The analysis involves the exploring of how migrants strive to prepare, manage and survive the multiple risks and structural barriers they encounter: the exits from Eritrea and Ethiopia, negotiations and contacts with various brokers and facilitators, organized crime and violence, restrictive border controls, passage through the Desert and high Sea and finally, ‘managing the asylum system in Sweden’. Further, it maps how the process of contemporary refugee mobility and multiple transitions is facilitated by the entanglement of transnational social relations and smuggling practices. The study argues for a perspective wherein migration journeys are embedded in and affected by the process of dynamic intergenerational, translocal and transnational social relations, material practices and knowledge productions. It depicts how practices and facilitations of irregular migratory mobility reproduce collective knowledge that refugees mobilize to endure risks during their journey, establishing a community and creating a home after arriving at the destination location.

  • Public defence: 2017-06-07 13:00 Gröjersalen, building 3, Kräftriket, Stockholm
    Björner, Emma
    Stockholm University, Faculty of Social Sciences, Stockholm Business School.
    Imagineering Place: The Branding of Five Chinese Mega-Cities2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Cities, regions, nations and other places have in recent decades become active participants in the global competitive economy, and now operate in a global marketplace, competing with other places all over the world for investors, tourists, residents and workforce. As a result, places use marketing and branding strategies and practices to gain reputation and competitive advantage. Chinese cities have, over the past decades, increasingly engaged in branding activities, and even taken the role of spearheads for China in its positioning in the global economy, seen for example in the organization of mega-events. The branding of Chinese cities nevertheless exhibits some differences compared with city branding in the West. The aim of this dissertation is to contribute to our knowledge of the internal-political aspects of place branding, using field studies of the imagery used in city branding practices in five Chinese mega-cities, namely Beijing, Shanghai, Shenzhen, Chengdu and Chongqing. The focus is on the images and language used in the cities’ branding, and on key political aspects involved in the branding of Chinese mega-cities. The theoretical lens incorporates concepts tied to images, language, imaginaries, ideology and power, and the study relies on an ethnographic, multiple case study approach, including longitudinal fieldwork in China. The findings consist of rich illustrations of the branding of the five Chinese mega-cities, and include an analysis of similar imagery found in all five cities, grouped into economic, international, cultural, social and environmental imaginaries. This shows that city branding in Chinese mega-cities is focused on creating international and competitive cities, while also paying attention to the environment, culture and internal target groups such as residents. A central contribution of this dissertation is the development of the concept ‘imagineering’, used in this study to conceptualize key political aspects of city branding in Chinese mega-cities. Imagineering contains three main elements, namely local adaptations of national directives, policies, plans and concepts; a strong future orientation while also accentuating selected elements from the past; and a focus on local populations with the creation of stability and harmony as a central goal. Imagineering is also conceptualized as a policy instrument exercised by a powerful élite, closely intertwined with urban governance, and used to influence people, values, places and, ultimately, city futures.

  • Public defence: 2017-06-08 10:00 hörsal 10, hus E, Stockholm
    Kaunitz, Niklas
    Stockholm University, Faculty of Social Sciences, Department of Economics. Stockholm University, Faculty of Social Sciences, The Swedish Institute for Social Research (SOFI).
    Workers, Firms and Welfare: Four Essays in Economics2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis comprises four chapters, in two parts. The first part examines the result of a Swedish payroll tax reduction; first from the perspective of the worker, then from that of the employer. The second half of the thesis concerns subjective well-being, both from an individual and from an aggregate viewpoint.

    Payroll Taxes and Youth Labor Demand. In 2007, the Swedish payroll tax was reduced substantially for young workers. This paper examines whether targeted payroll tax reductions are effective in raising youth employment. We estimate a small impact, both on employment and on wages. However, the effect differs markedly across ages, with 4–5 times higher impact on 22–23 year-olds compared to 25-year-olds. Additionally, the employment effects are strongly procyclical, approaching zero in the deep recession. We calculate that the estimated cost per created job is more than four times that of directly hiring workers at the average wage.

    Payroll Taxes and Firm Performance. The Swedish payroll tax reform of 2007 had the effect that firms' average social fees came to depend on the age structure of their employees. This makes it possible to estimate how firms respond to shocks in labor costs. We find a significant, but very small effect on gross investments, and a negative, but not statistically significant, impact on labor productivity. There are no effects on exit rates or profitability.

    Beyond Income: The Importance for Life Satisfaction of Having Access to a Cash Margin. We study how life satisfaction among adult Swedes is influenced by having access to a cash margin, i.e. a moderate amount of money that could be acquired on short notice either through own savings, by loan from family or friends, or by other means. We find that cash margin is a strong and robust predictor of life satisfaction, also when controlling for individual fixed-effects and socio-economic conditions, including income. This suggests that cash margin captures something beyond wealth.

    On Aggregating Subjective Well-Being. This paper discusses the assumptions underlying the aggregation of individually measured well-being. Any aggregation method is associated with measurability assumptions regarding the underlying well-being measure, as well as moral philosophical assumptions with respect to how individual well-being is weighted into a composite metric. I compare welfare across a set of countries, under alternative aggregation methods, and find that countries often can be ranked under comparatively weak measurement assumptions, and, equally important, that aggregation methods can be chosen so as to refrain from strong ethical preconceptions.

  • Public defence: 2017-06-08 13:00 L30, NOD-huset, Stockholm
    Karlsson, Isak
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Order in the random forest2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In many domains, repeated measurements are systematically collected to obtain the characteristics of objects or situations that evolve over time or other logical orderings. Although the classification of such data series shares many similarities with traditional multidimensional classification, inducing accurate machine learning models using traditional algorithms are typically infeasible since the order of the values must be considered.

    In this thesis, the challenges related to inducing predictive models from data series using a class of algorithms known as random forests are studied for the purpose of efficiently and effectively classifying (i) univariate, (ii) multivariate and (iii) heterogeneous data series either directly in their sequential form or indirectly as transformed to sparse and high-dimensional representations. In the thesis, methods are developed to address the challenges of (a) handling sparse and high-dimensional data, (b) data series classification and (c) early time series classification using random forests. The proposed algorithms are empirically evaluated in large-scale experiments and practically evaluated in the context of detecting adverse drug events.

    In the first part of the thesis, it is demonstrated that minor modifications to the random forest algorithm and the use of a random projection technique can improve the effectiveness of random forests when faced with discrete data series projected to sparse and high-dimensional representations. In the second part of the thesis, an algorithm for inducing random forests directly from univariate, multivariate and heterogeneous data series using phase-independent patterns is introduced and shown to be highly effective in terms of both computational and predictive performance. Then, leveraging the notion of phase-independent patterns, the random forest is extended to allow for early classification of time series and is shown to perform favorably when compared to alternatives. The conclusions of the thesis not only reaffirm the empirical effectiveness of random forests for traditional multidimensional data but also indicate that the random forest framework can, with success, be extended to sequential data representations.

  • Public defence: 2017-06-08 13:15 sal FB55, AlbaNova universitetscentrum, Stockholm
    Wesslén, Carl
    Stockholm University, Faculty of Science, Department of Physics.
    Confinement Sensitivity in Quantum Dot Spin Relaxation2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Quantum dots, also known as artificial atoms, are created by tightly confining electrons, and thereby quantizing their energies. They are important components in the emerging fields of nanotechnology where their potential uses vary from dyes to quantum computing qubits. Interesting properties to investigate are e.g. the existence of atom-like shell structures and lifetimes of prepared states.

    Stability and controllability are important properties in finding applications to quantum dots. The ability to prepare a state and change it in a controlled manner without it loosing coherence is very useful, and in some semiconductor quantum dots, lifetimes of up to several milliseconds have been realized. Here we focus on dots in semiconductor materials and investigate how the confined electrons are effected by their experienced potential.

    The shape of the dot will effect its properties, and is important when considering a suitable model. Structures elongated in one dimension, often called nanowires, or shaped as rings have more one-dimensional characteristics than completely round or square dots. The two-dimensional dots investigated here are usually modeled as harmonic oscillators, however we will also consider circular well models.

    The effective potential confining the electrons is investigated both in regard to how elliptical it is, as well as how results differ when using a harmonic oscillator or a circular well potential. By mixing spin states through spin-orbit interaction transitioning between singlet and triplet states becomes possible with spin independent processes such as phonon relaxation. We solve the spin-mixing two-electron problem numerically for some confinement, and calculate the phonon transition rate between the lowest energy singlet and triplet states using Fermi's golden rule.

    The strength of the spin-orbit interaction is varied both by changing the coupling constants, and by applying an external, tilted, magnetic field. The relation between magnetic field parameters and dot parameters are used to maximize state lifetimes, and to model experimental results.

  • Public defence: 2017-06-09 10:00 Nordenskiöldsalen, Geovetenskapens hus, Stockholm
    Goldschmidt, Tina
    Stockholm University, Faculty of Social Sciences, Department of Sociology.
    Immigration, Social Cohesion, and the Welfare State: Studies on Ethnic Diversity in Germany and Sweden2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Can social cohesion and solidarity persist in the face of large-scale migration? One particularly contentious hypothesis states that native majorities will be unwilling to support the provision of government-funded welfare to those whom they do not consider to be part of their own sociocultural ingroup, especially when sociocultural or ethnic otherness and socioeconomic disadvantage overlap. Consequently, majorities’ willingness to accept disadvantaged immigrant groups as legitimate and trusted members of the welfare community is central to the social cohesion of societies diversifying through migration.

    The dissertation consists of a comprehensive summary, followed by four original studies addressing the interplay between migration-induced diversity and social cohesion through the lens of majority attitudes and the micro and macro contexts within which they are embedded. The studies focus on Sweden and Germany, two European societies that host strong welfare states and large immigrant populations. Together, they seek to answer two central questions:

    First, does social distance between native-born citizens and immigrants lead the former to withdraw support from all redistributive policies, or are some types of welfare more affected than others? Second, how does the migration-induced diversification of societies come to matter for majority attitudes toward the welfare state and, as they are closely related, for majority attitudes toward the trustworthiness of others?

    Looking at the case of Germany, Study 1 shows that the conflict between diversity and welfare solidarity is not expressed in a general majority opposition to welfare, but rather in an opposition to government assistance benefiting immigrants – a phenomenon sometimes referred to as welfare chauvinism.

    Study 2 turns to the case of Sweden and investigates three pathways into welfare chauvinism: via the first-hand experience of immigrant unemployment and putative welfare receipt in the neighborhood context; via exposure to immigrant competition at the workplace; and via negative prejudice against immigrants. We find that the direct observation of immigrant unemployment in the neighborhood increases natives’ preference for spending on other Swedes over spending on immigrants, while competition with immigrants at the workplace does not.

    Using the same Swedish data, Study 3 hypothesizes that ethnically diverse workplaces imply trust-fostering inter-group contact. Yet, like in Study 2, we find a negative relationship between majority Swedes’ exposure to certain immigrant groups in the neighborhood and their trust in neighbors, while diverse workplaces neither seem to increase trust nor to affect the negative neighborhood-level association.

    Both Studies 2 and 3 show that negative attitudes toward immigrants increase welfare chauvinism and lower trust, even disregarding majority Swedes’ actual experience of immigrant presence or unemployment. Study 4 thus turns to a social force outside the realm of first-hand experience and explores German online news media debates on the welfare deservingness of various sociodemographic groups – among them, immigrants (as refugees in particular). However, rather than observing the persistent and particular stigmatization of immigrants as undeserving recipients or untrustworthy abusers of welfare, we find much more nuanced descriptions in our vast corpus of news stories.

  • Public defence: 2017-06-09 10:00 Högbomsalen, Geovetenskapens hus, Stockholm
    Croon, Adam
    Stockholm University, Faculty of Law, Department of Law.
    Jura Novit Curia: En rättsgenetisk undersökning av den juridiska metodlärans utveckling under 1800-talet2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Under Swedish law, the courts must clearly, independently of the parties’ legal arguments, both define and resolve any legal questions raised in the case in accordance with the applicable law. This is the general meaning of the principle, jura novit curia, a principle common to most European jurisdictions. Under Swedish law, a legal decision must be in accordance with the applicable law defined as the law-in-force, geltendes Recht or gällande rätt, the latter a concept found within Swedish legal methodology. The concept of law-in-force therefore is not simply at the core of any litigation. As a definition of the law, it constitutes an objective for both legal practitioners generally as well as mainstream legal science.

    Despite being perceived of as a well-known and self-evident principle to Swedish lawyers and academicians, the concept of law-in-force is complex, with many theoretical and practical implications. A better understanding of this concept is arguably achieved through an investigation of the historical developments leading up to its introduction in Swedish legal methodology, the concept’s underlying goals and considerations, as well as its immediate effects. This dissertation provides such an investigation, with a main focus on the influence of the German Historical School of Jurisprudence on Swedish legal methodology during the 19th century. Finally, it is argued that the principle of jura novit curia provides a suitable framework for such an investigation.

  • Public defence: 2017-06-09 10:00 Sal P216, NPQ-huset, Stockholm
    Strandmark, Alma
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Baltic shore-lands facing climate change2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis provides new insight concerning drivers behind differences in arthropod diversity and abundance in Baltic shore ecosystems and how the arthropod communities might be affected when the conditions in the Baltic Sea are altered due to climate change.  The focus has been on climate related changes that are unique for coastal ecosystems, especially sea level rise and changes in the inflow of marine nutrients.

    As sea levels rise, features in coastal landscapes will be altered, islands and habitats will be flooded and diminished, and structural connectivity within the island landscape will therefore change. This thesis shows that arthropod diversity within the two arthropod groups, spiders and beetles, increases with island size but also that diversity is positively influenced by a high number of islands in the surroundings.

    A changed distribution and occurrence of marine species, due to climate change or eutrophication, can also affect terrestrial organisms on the shore.  In the Baltic Sea the new conditions following climate change will decrease the prevalence of bladder-wrack and benefit filamentous algae. Algal deposits on shores reflect the marine species composition and a decreased prevalence of bladder-wrack in the Baltic Sea will also be visible on the shores.  This thesis shows that a lower proportion of bladder-wrack in the algal deposits will decrease the diversity and abundance of arthropods in these deposits.

    Changes in the marine environment may also affect the inflow of insects with aquatic life stages and terrestrial adult stages.  On Baltic shores, prey species with aquatic life stages, especially chironomids, constitute a large proportion of the diet of the terrestrial predatory group, wolf spiders. In freshwater system, the inflow of chironomids is known to decrease with elevated water temperatures if this is true in the Baltic Sea prey availability of wolf spiders would decrease.  This thesis supports the importance of chironomids as a prey for coastal wolf spiders, but also shows that the diet varies over season with dominance of terrestrial prey in early summer shifting to a dominance of marine prey in late summer and autumn. This seasonal variation is primarily due to a gradual increase in the consumption of chironomids over season.

    Climate change has the potential to alter the biogeographical conditions in coastal landscapes as well as the density and quality of marine nutrient inflow. Sea level rise will diminish and flood islands and this thesis shows that a moderate sea level rise of 0.5 meters would make the total number of islands in the outer part of Stockholm archipelago decrease with about 25 %. Sea level rise could thus have consequences for arthropod diversity in Baltic shore meadows in the near future. The combined effects of sea level rise and changed prevalence of marine species in the Baltic Sea will affect the abundance and diversity of arthropods substantially. The abundance and diversity of spiders and beetles will decrease on shores that today have a high occurrence of bladder-wrack and prey availability for coastal predators might decrease due to a decreased inflow of chironomids. Changes in the arthropod communities could have consequences also further up in the food chain, such as for shore birds feeding on these arthropods.

  • Public defence: 2017-06-09 10:00 Vivi Täckholmsalen (Q-salen), NPQ-huset, Stockholm
    Behm, Mikaela
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute. Stockholms universitet.
    Regulation of RNA Editing: The impact of inosine on the neuronal transcriptome2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The transcriptome of the mammalian brain is extensively modified by adenosine to inosine (A-to-I) nucleotide conversion by two adenosine deaminases (ADAR1 and ADAR2). As adenosine and inosine have different base pairing properties, A-to-I RNA editing shapes the functional output of both coding and non-coding RNAs (ncRNAs) in the brain. The aim of this thesis was to identify editing events in small regulatory ncRNAs (miRNAs) and to determine their temporal and spatial editing status in the developing and adult mouse brain. To do this, we initially analyzed the editing status of miRNAs from different developmental time points of the mouse brain. We detected novel miRNA substrates subjected to A-to-I editing and found a general increase in miRNA editing during brain development, implicating a more stringent control of miRNAs as the brain matures. Most of the edited miRNAs were found to be transcribed as a single long consecutive transcript from a large gene cluster. However, maturation from this primary miRNA (pri-miRNA) transcript into functional forms of miRNAs is regulated individually, and might be influenced by the ADAR proteins in an editing independent matter. We also found that edited miRNAs were highly expressed at the synapse, implicating a role as local regulators of synaptic translation. We further show that the increase in editing during development is explained by a gradual accumulation of the ADAR enzymes in the nucleus. Specifically for ADAR2, we found a developmentally increasing interaction with two factors, importin-α4 and Pin1, that facilitate nuclear localization of the editing enzyme. We have also found that selectively edited stem loops often are flanked by other long stem loop structures that induce editing in cis. This may explain why multiple pri-miRNAs are edited within the same cluster. In conclusion, this thesis has significantly increased the understanding of the dynamics of both editing substrates and enzymes in the developing and mature brain.

  • Public defence: 2017-06-09 10:00 Magnélisalen, Kemiska övningslaboratoriet, Stockholm
    Srimanee, Artita
    Stockholm University, Faculty of Science, Department of Neurochemistry.
    Cell-penetrating peptides targeting glioblastomas for nucleic acid delivery in the blood-brain barrier model2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Glioblastoma multiforme is the most aggressive form of malignant brain tumor with poor prognosis. The efficacy of brain cancer treatment by chemotherapeutics is limited by the blood-brain barrier (BBB) which allows less than 2% of the small molecules and blocks almost all the macromolecules to transport into the brain. Delivery of the large molecules such as proteins and nucleic acids across the BBB is a great challenge for brain-targeted drug delivery. To overcome this obstacle, cell-penetrating peptides (CPPs) were used as vectors for delivery of nucleic acids across the BBB targeting glioblastomas. The CPPs have shown such promising carriers to deliver various cargoes ranging from small molecules to large molecules into the cells. This thesis is focused on the development of glioblastoma-targeting vectors based on modifications of the CPPs and the targeting peptides. The peptide-based vectors were developed to improve the transport of the nucleic acids across the BBB and specifically target glioblastomas.

    In this thesis, a series of peptide-based vectors targeting glioblastomas were synthesized and modified with targeting peptides by either covalent conjugation or non-covalent complex formation. The delivery of plasmid DNA (pDNA) in the complex with the peptide-based vectors was studied in the in vitro model of the BBB. The role of receptors expressed on the BBB was investigated. Scavenger receptors class A and B were found to be expressed on the BBB, and they were involved in the delivery of the pDNA across the BBB model. Moreover, various targeting peptides were modified with hexaglutamate to form non-covalent complexes with the CPPs for small interfering RNA (siRNA) delivery to glioblastoma cells. The non-covalent complex of the CPP and the targeting peptide showed greater gene-silencing efficiency than the consecutively covalent conjugation of the CPP and the targeting peptide for siRNA delivery to glioblastoma cells. Lastly, a number of novel, amphipathic peptides were developed based on the model amphipathic peptide. The prediction of the biological effect of the designed peptides using quantitative structure-activity relationship model showed a correlation with the experimental data.

    Finally, the CPP-based nucleic acid delivery vectors with homing peptide strategy have a potential for the BBB shuttle and the future use as a glioblastoma-targeted drug carrier in the in vivo studies and the clinical applications.

  • Public defence: 2017-06-09 10:00 hörsal 3, hus B, Stockholm
    Pettersson, Theresia
    Stockholm University, Faculty of Humanities, Department of Swedish Language and Multilingualism.
    Stockholms stads tänkeböcker: Funktionell texthistoria 1476-16262017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The aim of this thesis is to shed light on language variation and language change in judicial protocols from the municipal court in Stockholm during the period 1476−1626. These documents provide a unique insight into late medieval and early modern use of written vernacular. The main material consists of 700 courtroom notes from seven different periods of time, a hundred documents from each year: 1476, 1499, 1525, 1550, 1575, 1600, and 1626. The study draws theoretically on functional linguistics; more specifically, it utilizes Halliday’s systemic-functional grammar, Ulf Teleman’s (1985) theoretical model of language change, as well as dialogism.

    The results are presented in four analytical chapters. In the first of these, the aim is to systemize the somewhat heterogeneous material, and the corpus is divided in two different ways: one due to judicial content (‘categories of matter’), and one due to textual structure (‘discourse levels’). These systemizations also serve as a methodological foundation for the lexicogrammatical analysis in the following chapters. A main result is that multi-party cases over time develop a functional need for new communication strategies, while unilateral cases already from the beginning seem to bear a more deep-rooted textual stability. In addition, there is a significant increase of discourse level 3, representing communicative events outside the courtroom, in multi-party cases found in texts from 1600 and 1626. In the two following chapters, lexicogrammatical resources of ‘personal reference’ and ‘time and tense’ are analysed. The texts realize different patterns of anaphora, where individuation explains much of the variation: texts with high degree of individuation (criminal cases) materialize a high degree of pronouns, whereas texts regarding property issues materialize low individuation with few pronouns and many full NPs. Regarding the use of tense, the past tense is the most common tense. Still, the study shows an diachronic increase in the use of present tense. The last analytical chapter examines the use of three lexical features: judicial pronouns; word pairs; and nominalizations. The results show that judicial pronouns and word pairs typically occur in registrations matters; nominalizations occur throughout the genre. In the last chapter, the results and implications of the thesis are summated and discussed.

    The results point towards a pragmatic use of the written language. Although the lexicogrammatical resources are the same during the period, the usages vary. Hence, linguistic variation and change are highly motivated by an intercommunion of contextual factors such as a more solid administrative literacy, a changing litigation, and an increase of legal demands for linguistic precision and documentation. It is argued that the language variety in the genre can be understood as instantiations of different registers.  

  • Public defence: 2017-06-09 10:00 William-Olssonsalen, Geovetenskapens hus, Stockholm
    Johansson, Jana
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Stockholm University.
    Sources, transport and fate of perfluoroalkyl acids in the atmosphere2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Perfluoroalkyl acids (PFAAs) are man-made chemicals which have been observed in the global environment, even in locations far away from where they are emitted. These persistent substances are taken up in humans and biota and may have toxic effects. Knowledge about how PFAAs are dispersed in the environment is needed to discern strategies to manage their sources and to evaluate the efficacy of adopted legislation. This thesis aimed to increase our understanding of the sources of PFAAs to the atmosphere and how PFAAs are transported in air. The results of Paper I demonstrated that gaseous perfluorooctanoic acid (PFOA) sorbs to typical glass fibre filters (GFFs) used in high-volume air sampling of PFAAs. As a consequence, the fraction of gaseous PFOA present in sampled air is underestimated, while the fraction of PFOA associated with aerosols is overestimated. Replacing GFFs with filters deactivated through silanisation and siliconisation did not eliminate this sampling artefact and is therefore not recommended as a means to determine the gas-particle partitioning of PFAAs. In Paper II, monitoring of the mass of PFOA transferred from water solutions of pH 0.2-5.5 demonstrated that the acid dissociation constant of linear PFOA and the four most ubiquitous branched PFOA isomers is around or below 1. Furthermore, the results demonstrated that the presence of counter ions and organic matter in water retarded, rather than enhanced, the volatilisation of PFOA. Therefore, volatilisation of all isomers of PFOA from environmental waters is expected to be negligible. To further study the transfer of PFAAs from environmental waters to air, Paper III simulated the process of sea spray generation in the laboratory. Strong enrichment of PFAAs was observed from bulk water to the surface microlayer and to aerosols. The enrichment increased with PFAA chain length, indicating that this process is of greater importance for more surface active substances. The highest enrichment was observed in aerosols < 1.6 µm, which can travel over long distances if not rained out. Based on the measured aerosol enrichment factors we estimated that approximately 70 metric tonnes of PFAAs are aerosolised from the global oceans yearly and that 3% of this mass is deposited in terrestrial environments. Paper IV reported the occurrence of branched PFOA isomers in deposition sampled in five geographical locations. The presence of these isomers demonstrated that atmospheric transformation of fluorotelomer alcohols is not the only ongoing source of PFAAs to air. We hypothesised that, additionally, both sea spray aerosols and direct emissions from manufacturing sources contributed to the contamination of the precipitation on different spatial scales. Although further research is required to determine the relative importance of different sources to the atmosphere locally and globally, this thesis has substantially advanced the state-of-the-science by i) demonstrating the significance of an air sampling artefact discussed as an uncertainty in the scientific literature over the past decade, ii) definitively ruling out volatilisation from environmental waters as a source of PFOA to air, iii) demonstrating transfer of PFAAs from seawater to air via sea spray aerosols and thus quantifying the environmental importance of this process, and iv) ultimately demonstrating that several types of sources of PFAAs impact the global atmosphere and thus PFAA contamination patterns in precipitation.

  • Public defence: 2017-06-09 13:00 Magnélisalen, Kemiska övningslaboratoriet, Stockholm
    Michel, Mirco
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    From Sequence to Structure: Using predicted residue contacts to facilitate template-free protein structure prediction2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Despite the fundamental role of experimental protein structure determination, computational methods are of essential importance to bridge the ever growing gap between available protein sequence and structure data. Common structure prediction methods rely on experimental data, which is not available for about half of the known protein families.

    Recent advancements in amino acid contact prediction have revolutionized the field of protein structure prediction. Contacts can be used to guide template-free structure predictions that do not rely on experimentally solved structures of homologous proteins. Such methods are now able to produce accurate models for a wide range of protein families.

    We developed PconsC2, an approach that improved existing contact prediction methods by recognizing intra-molecular contact patterns and noise reduction. An inherent problem of contact prediction based on maximum entropy models is that large alignments with over 1000 effective sequences are needed to infer contacts accurately. These are however not available for more than 80% of all protein families that do not have a representative structure in PDB. With PconsC3, we could extend the applicability of contact prediction to families as small as 100 effective sequences by combining global inference methods with machine learning based on local pairwise measures.

    By introducing PconsFold, a pipeline for contact-based structure prediction, we could show that improvements in contact prediction accuracy translate to more accurate models. Finally, we applied a similar technique to Pfam, a comprehensive database of known protein families. In addition to using a faster folding protocol we employed model quality assessment methods, crucial for estimating the confidence in the accuracy of predicted models. We propose models tobe accurate for 558 families that do not have a representative known structure. Out of those, over 75% have not been reported before.

  • Public defence: 2017-06-09 13:00 sal 108, Gösta Ekmans laboratorium, Stockholm
    Matson, Inga-Lill
    Stockholm University, Faculty of Social Sciences, Department of Special Education.
    Grus i maskineriet?: Några kommunala tjänstemäns, politikers, föräldrars och lärares syn på en skola för alla2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The overall aim of this thesis is to investigate experiences, perceptions and experiences of "a school for all" in one municipality by means of a case study. The municipality is medium-sized and, for many years, has had a clearly expressed intention of providing "a school for all". This means that all pupils are included in regular comprehensive school classes, where no separate schools or groups are available for pupils with intellectual disabilities.

    The empirical material consists of three studies. The pilot study is a licentiate thesis published in 2007, with a societal bias and is based on web-based documentation and interviews with politicians and civil servants (n=5). This study describes regional administrators’ initiatives to promote the implementation of ”a school for all” within the entire municipality. A major finding was the importance of committed and engaged leadership.  Bronfenbrenner’s (1979) model for ecological systems constitutes the theoretical starting point. The respondents in sub-studies I and II, which are the focus in this section of the thesis, are parents (n=14) and teachers (n=8). The common denominator is children/pupils who have an intellectual disability, and study according to the curriculum for special schooling but are taught in regular comprehensive school classes. Previous research into inclusion and national policy documents are of central concern to this thesis. Interpretative Phenomenological Analysis is employed as an interpretative tool for the interviews.

    Parents discuss the benefits of "a school for all"; good role models, social relationships and opportunities for the child to develop both socially and intellectually. They also describe how they must always be prepared to fight for their child, "keeping a watchful eye" on the school, and they imply that it is never possible to "become complacent". Teachers' attitudes and knowledge are described as crucial. A few parents wanted to have the opportunity to choose a special school for children with intellectual disabilities (ID). Their arguments are presented. In the teacher interviews, a conviction emerges about the importance of "a school for all" for the pupils' self-image, social and academic development. Organizational support, in-service training and skills’ development are seen as the prerequisites for successful inclusion, as well as educational strategies such as family groups and model learning. Respondents indicate that inclusion works most satisfactorily between years 1 and 6 in the comprehensive school and is viewed more detrimentally between years 7 and 9, in order to be better viewed again in the upper secondary school (senior high school) and the reasons for this are discussed. The case study contributes to a broader understanding of  the processes of implementation and change regarding inclusion of pupils with special school status and the importance of understanding the connections and relationships between the levels within Bronfenbrenner’s ecological systems theory which directly or indirectly affect the child’s/pupil’s development and well-being.

  • Public defence: 2017-06-09 13:00 Nordenskiöldsalen, Geovetenskapens hus, Stockholm
    Malmberg, Hannes
    Stockholm University, Faculty of Social Sciences, Department of Economics.
    Human Capital in Development Accounting and Other Essays in Economics2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Human Capital and Development Accounting Revisited. I quantify the effects on development accounting of allowing for imperfectly substitutable labor services.  To estimate the degree of substitutability between skilled and unskilled labor services in a cross-country setting, it is sufficient to estimate the relative price of skilled labor services, and I develop a novel method for estimating this relative price using international trade data. My method exploits the negative relationship between relative prices of skilled labor services and relative export values in skill-intensive industries. I find an approximately constant elasticity of substitution with a value of about 1.3. When integrating my results into a development accounting exercise, I find that efficiency differences in skilled labor are more important than uniform efficiency differences in explaining world income differences. Under the traditional development accounting assumption of neutral technology differences, the skilled labor efficiency differences reflect human capital quality differences, and human capital differences can explain a majority of world income differences. Relaxing the assumption of neutral technology differences, an alternative explanation is that there are large skill-biased technology differences between rich and poor countries.

    Price Level Determination When Tax Payments Are Required in Money. We formalize the idea that the price level can be determined by a requirement that taxes be paid in money. We show that if households have to pay a money tax of a fixed real value and the money supply is constant, there is a unique stationary price level, and a continuum of non-stationary deflationary equilibria. The non-stationary equilibria can be excluded if we introduce an arbitrarily lax borrowing constraint. Thus, in the basic model, tax requirements can uniquely determine the price level. When money has liquidity value, tax requirements can exclude self-fulfilling hyperinflations.

    Swedish Unemployment Dynamics. We decompose the sources of unemployment variations into contributions from variations in different labor market flows. We develop a decomposition method that allows for a distinction between permanent and temporary employment and slow convergence to the steady state, and we apply the method to the Swedish labor market for the period 1987-2012. Variations in unemployment are driven to an approximately equal degree by variations in (i) flows from unemployment to employment, (ii) flows from employment to unemployment, and (iii) flows in and out of the labor force. Flows involving temporary contracts account for 44% of unemployment variation, even though temporary workers only constitute 13% of the working-age population. Neglecting out-of-steady-state dynamics leads to an overestimation of the importance of flows involving permanent contracts.

    Supply Chain Risk and the Pattern of Trade. This paper analyzes the interaction of supply chain risk and trade patterns. We construct a model where an industry's risk sensitivity is determined by the number of customized components that it uses, and countries with a low supply chain risk specialize in risk-sensitive goods. Based on our theory, we construct an empirical measure of risk sensitivity from input-output tables and customization measures. Using industry-level trade data and a variety of risk proxies, we show that countries with a low supply chain risk disproportionately export risk-sensitive goods.

  • Public defence: 2017-06-09 13:00 hörsal 7, hus D, Stockholm
    Neuser, Hannah
    Stockholm University, Faculty of Humanities, Department of English.
    Source Language of Lexical Transfer in Multilingual Learners: A Mixed Methods Approach2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The study reported in this thesis investigates the source language of lexical transfer in multilingual learners using a mixed methods approach. Previous research has shown that the source language of crosslinguistic influence can be related to factors such as proficiency, recency/exposure, psychotypology, the L2 status, and item-specific transferability. The present study employed a mixed methods approach in order to best serve the particularities of each of the five factors under investigation. Multinomial logistic regression was emloyed to test the predictive power of the first four factors, thereby addressing the issue of confounding variables found in previous studies. A more exploratory qualitative analysis was used to investigate item-specific transferability due to the lack of prior empirical studies focusing on this aspect. Both oral and written data were collected, offering an analysis of modal differences in direct comparison. The results show a significant effect of proficiency and exposure, but inconsistent patterns for psychotypology. Most importantly, in this study of lexical transfer, a significant L1 status effect was found, rather than an L2 status effect. In addition, the statistical model predicted the source language of transfer better in the spoken than in the written mode. Finally, learners were found to assess, as well as actively improve, an item’s transferability in relation to target language norms and constraints. All of these findings contribute to our understanding of lexical organization, activation, and access in the multilingual mind. 

  • Public defence: 2017-06-09 13:00 De Geersalen, Geovetenskapens hus, Stockholm
    Koutsouris, Alexander
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Building a coherent hydro-climatic modelling framework for the data limited Kilombero Valley of Tanzania2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis explores key aspects for synthesizing data across spatiotemporal scales relevant for water resources management in an Eastern Africa context. Specifically, the potential of large scale global precipitation datasets (GPDs) in data limited regions to overcome spatial and temporal data gaps is considered. The thesis also explores the potential to utilize limited and non-continuous streamflow and stream water chemistry observations to increase hydrological process understanding. The information gained is then used to build a coherent hydro-climatic framework for streamflow modelling. In this thesis, Kilombero Valley Drainage Basin (KVDB) in Tanzania is used as an example of a data limited region targeted for rapid development, intensification and expansion of agriculture. As such, it is representative for many regions across the Eastern Africa. With regards to the data synthesis, two satellite products, three reanalysis products and three interpolated products were evaluated based on their spatial and temporal precipitation patterns. Streamflow data from KVDB and eight subcatchments were then assessed for quality with regards to missing data. Furthermore, recession analysis was used to estimate catchment-scale characteristic drainage timescale. Results from these streamflow analyses, in conjunction with a hydrological tracer-based analysis, were then used for improved understanding of streamflow generation in the region. Finally, a coherent modelling framework using the HBV rainfall-runoff model was implemented and evaluated based on daily streamflow simulation. Despite the challenges of data limited regions and the often large uncertainty in results, this thesis demonstrates that improved process understanding could be obtained from limited streamflow records and a focused hydrochemical sampling when experimental design natural variability were leveraged to gain a large  signal to noise ratio. Combining results across all investigations rendered information useful for the conceptualization and implementation of the hydro-climatic modelling framework relevant in Kilombero Valley. For example, when synthesized into a coherent framework the GPDs could be downscaled and used for daily streamflow simulations at the catchment scale with moderate success. This is promising when considering the need for estimating impacts of potential future land use and climate change as well as agricultural intensification.

  • Public defence: 2017-06-10 13:00 Nordenskiöldsalen, Geovetenskapens hus, Stockholm
    Montero-Melis, Guillermo
    Stockholm University, Faculty of Humanities, Department of Swedish Language and Multilingualism.
    Thoughts in Motion: The Role of Long-Term L1 and Short-Term L2 Experience when Talking and Thinking of Caused Motion2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is about whether language affects thinking. It deals with the linguistic relativity hypothesis, which proposes that the language we speak influences the way we think. This hypothesis is investigated in the domain of caused motion (e.g., ‘The man rolled the tyre into the garage’), by looking at Spanish and Swedish, two languages that show striking differences in how motion events are encoded. The thesis consists of four studies. The first two focus on native speakers of Spanish and Swedish. Study I compares how Spanish and Swedish speakers describe the same set of caused motion events, directing the spotlight at how variable the descriptions are in each language. The results confirm earlier findings from semantic typology regarding the dominant ways of expressing the events in each language: Spanish behaves like a verb-framed language and Swedish like a satellite-framed language (Talmy, 2000). Going beyond previous findings, the study demonstrates—using the tools of entropy and Monte Carlo simulations—that there is markedly more variability in Spanish than in Swedish descriptions. Study II tests whether differences in how Spanish and Swedish speakers describe caused motion events are reflected in how they think about such events. Using a novel similarity arrangement task, it is found that Spanish and Swedish speakers partly differ in how they represent caused motion events if they can access language during the task. However, the differences disappear when the possibility to use language is momentarily blocked by an interference task. The last two studies focus on Swedish learners of Spanish as a second language (L2). Study III explores how Swedish learners (compared to native Spanish speakers) adapt their Spanish motion descriptions to recently encountered input. Using insights from the literature on structural priming, we find that Swedish learners initially expect to encounter in their L2, Spanish, those verb types that are typical in Swedish (manner verbs like ‘roll’) but that, with increasing proficiency, their expectations become increasingly attuned to the typical Spanish pattern of using path verbs (like ‘enter’).  These expectations are reflected in the way L2 learners adapt their own production to the Spanish input. Study IV asks whether recent linguistic experience in an L2 can affect how L2 learners think about motion events. It is found that encountering motion descriptions in the L2 that emphasize different types of information (path or manner) leads L2 speakers to perceive similarity along different dimensions in a subsequent similarity arrangement task. Taken together, the thesis argues that the study of the relation between language and thought affords more valuable insights when not posed as an either-or question (i.e., does language affect thought or not?). In this spirit, the thesis contributes to the wider aim of investigating the conditions under which language does or does not affect thought and explores what the different outcomes tell us about language, thought, and the intricate mechanisms that relate them.

  • Public defence: 2017-06-12 10:00 rum 2403, Institutionen för pedagogik och didaktik, Stockholm
    Odero, Jared O.
    Stockholm University, Faculty of Social Sciences, Department of Education.
    ICT-based Distance Education: A Study of University Students’ Views and Experiences in Early Post-Apartheid South Africa2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The overall aim of this study was to investigate how the introduction of ICT into distance education at public institutions of higher learning in South Africa during the early post-apartheid period from 1994 to 2002, provided learning opportunities for students and facilitated the delivery of learning content. More explicitly, it examined and analyzed the views and experiences of students and course facilitators at selected higher education institutions, which provided ICT-based distance education. The study also examined and analyzed the views and experiences of students regarding the services of a private on-campus Internet café located in a South African technikon (a technological institution). The empirical part of the current study was conducted in 2002, when some public higher education institutions in the country were involved in the provision of distance education as a means of increasing student participation and generating income. However, the proliferation of private actors who collaborated with some of these institutions to provide ICT-based distance education caused concern to the government that questioned their quality of content delivery.

    A case study research design was applied to collect, analyze and interpret quantitative and qualitative data at four universities and one technikon. Two electronic surveys were administered by email and on the Web, to self-selected students at the five case institutions. The first survey examined the views and experiences of respondents (n = 605) who participated in ICT-based distance education, while the second one investigated the views and experiences of respondents (n = 274) who used a private campus-based Internet café. Non-participant observations were made at some learning centers to understand how classes were carried out, and at the Internet café, to understand the type of services offered. Unstructured interviews were held with selected students and course facilitators at one institution, whereas informal interviews were conducted with some students and the Internet café manager. Further, a literature review was undertaken to understand certain issues and trends in ICT-based distance education, within and beyond South Africa.

    The findings indicate that the majority of respondents chose ICT-based distance education because it was flexible. They were also comfortable with using the English language for instruction. However, some complained that the learning materials were irrelevant and were not delivered on time. The course facilitators were generally satisfied with their work, although they were disappointed for not having the opportunity to influence changes in the study guides. Many respondents used the Internet café because they did not have any other means of accessing the Internet. Moreover, it was affordable and they used it for socializing.

    The study concludes that the system of instructional design and content delivery to distance education students in South Africa should be improved to become efficient. Further studies are recommended to examine the ongoing development of ICT-based distance higher education in South Africa.

  • Public defence: 2017-06-12 13:00 L50, NOD-huset, DSV, Kista
    Hodosi, Georg
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Information Technology Outsourcing in Large Companies in Sweden: A Perspective on Risks, Relationships and Success Factors2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis investigates large private companies in Sweden that have outsourced their information technology (IT). A considerable proportion of IT outsourcing (ITO) is unsuccessful. For IT service buyers, this could cause IT that does not fully work, entailing problems with the network, application, infrastructure and security, with serious consequences such as a loss of customers’ confidence and significantly increased costs. Therefore, the main research goal was to analyse and define ways to improve ITO for buyer organizations. This main research goal was accomplished through three research goals that are the followings: 1) To develop a method for risk assessment in IT outsourcing; 2) To identify the important factors in IT outsourcing relationship; and 3) To identify the success factors in IT outsourcing.                      

    The research strategies applied in conducting this research were design science research and survey research. To achieve the first research goal, a method was developed for assessing the ITO risks, including support for mitigating these risks. This method could help both researchers and practitioners in estimating the ITO risks and in this way improve ITO. An application based on the developed method was used to facilitate the testing of this method by several ITO decision makers in large companies concerning its usability, correctness and functionality. Moreover, a study was performed to explore ITO decision makers’ acceptance of the developed method and their use of it for assessing the ITO risks.            

    The second research goal investigated how to improve service buyers’ ITO relationship with their providers. A well-working ITO relationship is a critical determinant of successful ITO and is relevant to the whole ITO life cycle. This research goal was achieved by identifying and analysing the most important factors in ITO relationships, including a prioritized list of those factors that are highly recommended for use in creating and maintaining a good ITO relationship.                      

    The third research goal examined how to improve ITO by identifying and prioritizing the success factors (SFs) in ITO. This research identified the ITO SFs in large companies and provided a prioritized list of them to be applied in these companies with a description of the value that they could create from implementation during the ITO life cycle. Moreover, the SFs identified in large companies were compared with those identified in medium-sized companies, which could give an indication to the researchers in this field that company size matters in regard to the implementation order of the identified SFs.              

    In summary, the research presented in this thesis contributes with: 1) a method for assessing the risks of outsourcing IT and, in the case that IT has been outsourced, suggested ways to mitigate them; 2) the important factors that could improve ITO relationships and 3) a prioritized list of success factors that could improve IT outsourcing.

  • Public defence: 2017-06-12 13:00 sal FB42, AlbaNova universitetscentrum, Stockholm
    Flis, Samuel
    Stockholm University, Faculty of Science, Department of Physics.
    Searching for dark matter in the Galactic Halo with IceCube using high energy cascades2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The presence of dark matter is inferred at scales ranging from rotations of galaxies to imprints in the CMB – the Big Bang after-glow. The nature of dark matter is, however, still unknown as no detection other than the gravitational one has been made. This thesis presents two analyses searching for a neutrino signal from dark matter annihilations in the Milky Way.

    The first analysis searched for an excess of νμ charged current events with directions from the central region of the dark matter halo and, was focused on low energy events, thus probing low dark matter particle masses. Approximately 319 days of data collected with the 79-string configuration of the IceCube detector was used in the analysis. Despite a large deficit in the number of observed events the data were found to be consistent with background and upper limits were set on <σⱴ>. At the time of the analysis these limits were the strongest set by a neutrino experiment below 100 GeV.

    The second analysis was performed on a data sample originally used in an unfolding analysis of the atmospheric and astrophysical neutrino spectra. The data consisted of contained cascade events above 1 TeV collected with the 79-string configuration and the completed detector in the 86-string configuration during two years of data-taking. The limits set by this analysis were more constraining by up to a factor of 10 compared to previous IceCube analyses, and the most competitive limits are set assuming a Burkert halo profile. These two analyses prompted the development of a signal subtraction likelihood method to address the problem of signal contamination in background estimates based on scrambled data.

    Additionally a study concerning future extensions of IceCube in the Gen2 project is presented. The cascade reconstruction performance was examined and compared for different proposed detector extensions.

  • Public defence: 2017-06-13 10:00 hörsal 12, hus F, Stockholm
    Belmar Shagulian, Jasmin
    Stockholm University, Faculty of Humanities, Department of Romance Studies and Classics.
    El mito de la Quintrala: Estructuras simbólicas en dos novelas de Gustavo Frías2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The purpose of this comparative study is to analyse La Quintrala’s myth as a symbolic discourse, thereby filling a gap in the previous studies about La Quintrala.

    The theoretical and methodological framework of this analysis consists of a hermeneutical approach based on the method of figurative structuralism: mythocriticism. This is a dual classification method of symbols: Diurnal and Nocturnal Orders that expose the symbolic structures formed by symbols and archetypes found in mythemes in a compilation of corpora. The first one is Gustavo Frías’ novels Tres Nombres para Catalina: Catrala (2008) and Tres nombres para Catalina: la doña de Campofrío (2008); the second is a historic essay (hypotext), Benjamín Vicuña Mackenna’s Los Lisperguer y la Quintrala (1944), and four novels: Magdalena Petit’s (2009) La Quintrala, Mercedes Valdivieso’s (1991) Maldita yo entre las Mujeres, Virginia Vidal’s (2002) Oro, veneno y puñal, and Gustavo Frías’ El Inquisidor (2008).

    Mythocriticism is employed in the analysis to show what the mythical structure of the hero’s journey (Separation, Initiation, Return) reveal. Such journey is combined structurally with the Mother archetype (White, Red and Black Goddess), the intrinsic archetype of La Quintrala’s myth. The heroic structure unveils its own mythemes, La Quintrala’s and the first corpus’s mytheme through the diachronic and synchronic flow of the hero’s journey. This method permits to identify and compare the progression of the symbolic structures.

    The analysis demonstrates a transformation of the symbolic structures between both corpora. This survey reveals that Vicuña Mackenna and Petit, and partially Vidal and El Inquisidor, exhibit an inclination to the diurnal symbols that strengthen, through a heterodiegetic narrator, the representations of the witch-femme fatale, counteractive attributes of the Red and Black Goddesses in the myth. Valdivieso, on the other hand, shows a propensity to the nocturnal symbols of inversion and intimacy that emphasize the Red Goddess’ features, though the novel also exposes La Quintrala as a witch-femme fatale. This exposure occurs through the use of both an autodiegetic narrator –La Quintrala– and a heterodiegetic one –the hypotext embodied in the popular voice– that appear to contrast each other. Finally, in Tres Nombres para Catalina, La Quintrala as the autodiegetic narrator dominates the whole story. She personifies the Great Goddess archetype who bestows her new positive attributes during the adventure. This novel assumes primordially the nocturnal symbolism incarnated by both the mystical and the synthetical structures and relegates the diurnal discourse of the hypotext to a secondary position in the narrative. Nonetheless, Tres Nombres para Catalina’s narrative still relies on the hypotext to reproduce and reconstruct all the mythemes in the myth of La Quintrala.

    Conclusively, the results of this analysis indicate that the identification of all the mythemes supports the hypothesis of a transformation in the symbolic structures which characterize La Quintrala in both corpora. This reveals the embodiment of Tres Nombres para Catalina’s own mytheme, consisting of a vindication and a recognition to her indigenous heritage, and the acceptance of her mestizaje. As a consequence, Tres nombres para Catalina, in comparison to the second corpus, diverges and expands the symbolic structures, but still shows a continuity of the myth.

  • Public defence: 2017-06-13 13:00 sal FB42, AlbaNova universitetscentrum, Stockholm
    Majidzadeh Garjani, Babak
    Stockholm University, Faculty of Science, Department of Physics. Nordita.
    On Aspects of Anyons and Quantum Graphs2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis consists of two distinct parts. The first part, based on the first two accompanied papers, is in the field of topological phases of matter and the second part, based on the third accompanied paper, looks at a problem in the field of quantum graphs, a rapidly growing field of mathematical physics.

    First, we investigate the entanglement property of the Laughlin state by looking at the rank of the reduced density operator when particles are divided into two groups. We show that the problem of determining this rank translates itself into a  question about symmetric polynomials, namely, one has to determine the lower bound for the degree in each variable of the symmetric polynomials that vanish under a transformation that clusters the particles into groups of equal size and then brings the particles in each group together. Although we were not able to prove this, but we were able to determine the lower bound for the total degree of symmetric polynomials that vanish under the  transformation described. Moreover, we were able to characterize all symmetric polynomials that vanish under this transformation.

    In the second paper, we introduce a one-dimensional model of interacting su(2)k anyons. The specific feature of this model is that, through pairing terms present in the Hamiltonian,  the number of anyons of the chain can fluctuate. We also take into account the possibility that anyons hop to empty neighboring sites. We investigate the model in five different points of the parameter space. At one of these points, the Hamiltonian of the model becomes a sum of projectors and we determine the explicit form of all the zero-energy ground states for odd values of k. At the other four points, the system is integrable and we determine the behavior of the model at these integrable points. In particular, we show that the system is critical and determine the CFT describing the system at these points.

    It is known that there are non-Hermitian Hamiltonians whose spectra are entirely real. This property can be understood in terms of a certain symmetry of these Hamiltonians, known as PT-symmetry. It is also known that the spectrum of a non-Hermitian PT-symmetric Hamiltonian has reflection symmetry with respect to the real axis. We then ask the reverse question whether or not the reflection symmetry of a non-Hermitian Hamiltonian necessarily implies that the Hamiltonian is PT-symmetric. In the context of quantum graphs, we introduce a model for which the answer to this question is positive.

  • Public defence: 2017-06-13 13:00 Magnélisalen, Kemiska övningslaboratoriet, Stockholm
    Li, Yunxiang
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Modification of zeolites and synthesis of SAPO-templated carbon2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Zeolites are crystalline aluminosilicates with diverse structures and uniform porosities. They are widely used as catalysts, adsorbents and ion-exchangers in industry. Direct or post modifications optimize the performance of zeolites for different applications. In this thesis, IZM-2 and TON-type zeolites were synthesized, modified and studied. In addition, FAU-type zeolite and silicoaluminophosphate (SAPO) molecular sieves were applied as templates for the preparation of microporous carbons.

    In the first part of this thesis, the IZM-2 zeolite with an unknown structure was synthesized. We focused on the increasing the secondary porosity and the varied framework compositions upon post modifications.

    The structure determination of this IZM-2 zeolite was hindered by the small size of crystals. In the second part of this thesis, the synthesis composition was directly modified in order to increase the crystal sizes. IZM-2 crystals were enlarged by excluding the aluminium atoms from the framework. The micropores of the obtained pure-silica polymorphs were activated by ion-exchanging alkali-metal ions with protons.

    Typically, TON-type zeolites that are synthesized at hydrothermal conditions under stirring have needle-shaped crystals. In the third part of this thesis, snowflake-shaped aggregates were produced by using static hydrothermal conditions for the synthesis of TON-type zeolites. The effects of synthesis parameters on the growth and morphology of crystals were discussed in detail.

    In the last part of this thesis, microporous carbons with a structural regularity were prepared by chemical vapour deposition (CVD) of propylene using a silicoaluminophosphate (SAPO-37) template. Compared to the conventional zeolite templates, the SAPO template could be removed under mild conditions, without using hydrofluoric acid, and the generated carbons had a large specific surface area and a high fraction of ultrasmall micropores.

  • Public defence: 2017-06-13 13:00 Lilla hörsalen, NOD-huset, Kista
    Xiao, Bin
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Data-Centric Network of Things: A Method for Exploiting the Massive Amount of Heterogeneous Data of Internet of Things in Support of Services2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Internet of things (IoT) generates massive amount of heterogeneous data, which should be efficiently utilized to support services in different domains. Specifically, data need to be supplied to services by understanding the needs of services and by understanding the environment changes, so that necessary data can be provided efficiently but without overfeeding. However, it is still very difficult for IoT to fulfill such data supply with only the existing supports of communication, network, and infrastructure; while the most essential issues are still unaddressed, namely the heterogeneity issue, the recourse coordination issue, and the environments’ dynamicity issue. Thus, this necessitates to specifically study on those issues and to propose a method to utilize the massive amount of heterogeneous data to support services in different domains.

    This dissertation presents a novel method, called the data-centric network of things (DNT), which handles heterogeneity, coordinates resources, and understands the changing IoT entity relations in dynamic environments to supply data in support of services. As results, various services based on IoT (e.g., smart cities, smart transport, smart healthcare, smart homes, etc.) are supported by receiving enough necessary data without overfeeding.

    The contributions of the DNT to IoT and big data research are: firstly the DNT enables IoT to perceive data, resources, and the relations among IoT entities in dynamic environments. This perceptibility enhances IoT to handle the heterogeneity in different levels. Secondly, the DNT coordinates IoT edge resources to process and disseminate data based on the perceived results. This releases the big data pressure caused by centralized analytics to certain degrees. Thirdly, the DNT manages entity relations for data supply by handling the environment dynamicity. Finally, the DNT supply necessary data to satisfy different service needs, by avoiding either data-hungry or data-overfed status.

  • Public defence: 2017-06-14 10:00 Auditoriet, Humanistvillan, Stockholm
    Israelson, Per
    Stockholm University, Faculty of Humanities, Department of Culture and Aesthetics.
    Ecologies of the Imagination: Theorizing the participatory aesthetics of the fantastic2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This book is about the participatory aesthetics of the fantastic. In it, the author argues that the definition of the fantastic presented by Tzvetan Todorov in 1970 can be used, provided it is first adapted to a media-ecological framework, to theorize the role of aesthetic participation in the creation of secondary worlds. Working within a hermeneutical tradition, Todorov understands reader participation as interpretation, in which the creative ambiguities of the literary object are primarily epistemological. However, it is here argued that the aesthetic object of the fantastic is also characterized by material ambiguity.

    The purpose of this dissertation is then to present a conceptual framework with which to theorize the relation between the material and the epistemological ambiguity of the fantastic. It is argued that such a framework can be found in an ecological understanding of aesthetic participation. This, in turn, entails understanding human subjectivity as a process always already embodied in a material environment. To this extent, the proposed theoretical framework questions the clear and oppositional distinction between form and matter, as well as that between mind and body, nature and culture, and human and non-human, on which a modern and humanist notion of subjectivity is based. And in this sense, the basic ecological assumptions of this dissertation are posthumanist, or non-humanist. From this position, it is argued that an ecological understanding of participation offers a means to reformulate the function of a number of concepts central to studying the aesthetics of the fantastic, most notably the concepts of media, genre and text. As the fantastic focuses on the creation of other worlds, it is an aesthetics of coming into being, of ontogenesis. Accordingly, it will be argued that the participatory aesthetics of the fantastic operationalizes the ontogenesis of media, genres and texts.

    By mapping the ontogenesis of three distinct media ecologies – the media ecology of fantasy and J. R. R. Tolkien’s secondary world Middle-earth; the media ecology of the American comic book superhero Miracleman; and the media ecology of William Blake – this book argues that the ecological imagination generates world.

    Per Israelson has been a doctoral candidate in the Research School of Studies in Cultural History at the department of Culture and Aesthetics, Stockholm University. Ecologies of the Imagination is his dissertation.

  • Public defence: 2017-06-14 13:00 William-Olssonsalen, Geovetenskapens hus, Stockholm
    Ridderstedt, Margareta
    Stockholm University, Faculty of Humanities, Department of Culture and Aesthetics.
    Vackert och värdigt: Liturgiska textilier från svenska ateljéer 1880 - 19302017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis deals with the production of liturgical textiles in five Swedish studios between 1880 and 1930. It is based on a survey of what was delivered to and preserved in the buildings of the Church of Sweden, more than 4,000 recorded objects. Ecclesiastical liturgical textile art in Sweden forms part of an uninterrupted tradition from the Middle Ages.

    A new era in ecclesiastical textiles began in Sweden in five major studios in Stockholm and Göteborg. Earlier production during the 19th century had become increasingly stereotypical and there was little interest in ecclesiastical art and liturgy in the parishes of the Swedish church.

    My survey of this extensive material has enabled me to make conclusions about when new textiles were produced and where, as well as when important changes took place. The iconography, symbols, figurative motifs and texts used in the textiles reveal trends in the historical development of the church’s liturgy. It is also possible to see when the different liturgical colours began to come back into use. Differences in the designs of the textiles show which artistic figures had a dominant influence on ecclesiastical liturgical textiles at a certain time. Five sections in chapter IV deal with a few larger special commissions. The first were for two newly-built churches in the early 1910s by two eminent architects who also designed the textiles. The third church was provided with new textiles in 1917 in connection with an extensive restoration. The fourth case concerns a private initiative to acquire new textiles for an old church. Finally, the ecumenical archbishop’s robes were produced for the Archbishop Nathan Söderblom and worn at the ecumenical meeting in 1925. The archbishop had a firm opinion about its iconographic programme.

    The five colours were launched in practice on the west coast of Sweden during the 1880s and 1890s. The textile artist Agnes Bran­ting introduced them at the Stockholm Exhibition in 1897. Supplementary commissions for white and green textiles were made from the parishes, for both frontals and chasubles at the end of the 1920s.

    A wealth of different motifs and differences began to appear between the iconography of the various studios in the 20th century. By no means all liturgical textiles were provided with texts, but enough to make it possible to describe a new trend.

    Many women and a few male artists developed their aesthetic expression working with ecclesiastical textiles during the fifty years covered by this thesis. The work of the professional studios was fundamental for the development of many young women into resolute, modern professional practitioners.

    What was linked to the ecclesiastical, the sacred, found expression and was described in words such as beautiful, true and dignified. The textiles embodied an intention to enhance the aesthetic values of worship and ecclesiastical space, to add variation and solemnity. This involved a deeper and more widespread use of motifs and symbols, of high-quality material and of craftsmanship. This study has contributed new knowledge about the period, its aesthetics and its theology.

  • Public defence: 2017-06-14 13:00 Lilla hörsalen, NOD-huset, Kista
    Uppström, Elin
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Designing, Theorizing, and Reflecting on Information Systems Artifacts and Value Co-Creation in e-Government2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    E-government services in the form of information systems (IS) artifacts create a new arena for co-creation that governments aim to leverage. Design of and knowledge about IS artifacts in value co-creation in e-government can thereby be considered valuable for the future development of e-government. How IS artifacts are used in value co-creation and co-destruction and how the artifacts are developed is however not well understood.

    This thesis addresses the problem of how to design for and understand value co-creation in e-government. To address the problem stated, three research questions are posed. (i) How can IS artifacts be designed to enable value co-creation in e-government and what aspects can inhibit value being co-created through the designed artifacts? (ii) How can boundary object theory facilitate the understanding of IS artifacts used in value co-creation and co-destruction in e-government? (iii) How can retrospectives in design science contribute to research on value co-creation in e-government?

    Two artifacts in the form of instantiations are designed and evaluated. Design science research methodology is used in two different projects at Swedish municipalities. Secondary analysis is used to identify aspects that inhibit value being co-created through the designed IS artifacts. From these inhibitors, core aspects for public value co-creation are derived. Thereafter, this thesis delves further into how IS artifacts are used in collaborations between citizens, private businesses, and government agencies in order to co-create value. Two case studies are carried out at Swedish government agencies and sociomaterial boundary object theory is used to enhance understanding. The thesis research process ends with a retrospective evaluation of the performed research, using critical realism as its philosophical foundation and guidance.

    The result includes one configurable process model that enables value co-creation by facilitating shared understanding between collaborating parties; one mobile service that enables value co-creation through citizen sourcing; aspects that inhibit the realization of co-created value; and four core aspects that need to be considered when designing artifacts for value co-creation. That IS artifacts can be regarded as boundary objects when you aim to study and understand value co-creation and co-destruction between communities in e-government. Descriptions of how IS artifacts, viewed as sociomaterial boundary objects, are used in value co-creation processes between governments, citizens, and businesses and outcomes in terms of value co-creation and co-destruction. The benefit of performing critical realism-guided retrospectives in design science in order to complement prescriptive knowledge with explanatory and critical knowledge is motivated. It is showed that the design of artifacts generates knowledge through the design efforts, regardless of whether they also yield utility.

    This thesis contributes to e-government research and practice with knowledge on how to design artifacts that enable value co-creation. Establishes sociomaterial boundary object theory as a theoretical lens that offers a tool to evaluate and design IS artifacts that enable value co-creation and with knowledge on how IS artifacts are used in value co-creation. The thesis also motivates the usefulness of retrospective evaluation in design science. Suggestions for future research include further developing design science retrospectives. 

  • Public defence: 2017-06-14 14:00 sal E306, Arrheniuslaboratorierna, Stockholm
    Olsen, Jessica M.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    β-Adrenergic Signalling Through mTOR2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Adrenergic signalling is part of the sympathetic nervous system and is activated upon stimulation by the catecholamines epinephrine and norepinephrine. This regulates heart rate, energy mobilization, digestion and helps to divert blood flow to important organs. Insulin is released to regulate metabolism of carbohydrates, fats and proteins, mainly by taking up glucose from the blood. The insulin and the catecholamine hormone systems are normally working as opposing metabolic regulators and are therefore thought to antagonize each other.

    One of the major regulators involved in insulin signalling is the mechanistic target of rapamycin (mTOR). There are two different complexes of mTOR; mTORC1 and mTORC2, and they are essential in the control of cell growth, metabolism and energy homeostasis. Since mTOR is one of the major signalling nodes for anabolic actions of insulin it was thought that catecholamines might oppose this action by inhibiting the complexes. However, lately there are studies demonstrating that this may not be the case. mTOR is for instance part of the adrenergic signalling pathway resulting in hypertrophy of cardiac and skeletal muscle cells and inhibition of smooth muscle relaxation and helps to regulate browning in white adipose tissue and thermogenesis in brown adipose tissue (BAT).

    In this thesis I show that β-adrenergic signalling leading to glucose uptake occurs independently of insulin in skeletal muscle and BAT, and does not activate either Akt or mTORC1, but that the master regulator of this pathway is mTORC2. Further, my co-workers and I demonstrates that β-adrenergic stimulation in skeletal muscle and BAT utilizes different glucose transporters. In skeletal muscle, GLUT4 is translocated to the plasma membrane upon stimulation. However, in BAT, β-adrenergic stimulation results in glucose uptake through translocation of GLUT1. Importantly, in both skeletal muscle and BAT, the role of mTORC2 in β-adrenergic stimulated glucose uptake is to regulate GLUT-translocation.

  • Public defence: 2017-06-15 13:00 Nordenskiöldsalen, Geovetenskapens hus, Stockholm
    Lam, Norris
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Modeling rating curves from close-range remote sensing data: Application of laser and acoustic ranging instruments for capturing stream channel topography2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A rating curve provides a functional relationship between water height (i.e. stage) and discharge at a specified cross-section in a river. Used in combination with a time series of stage, rating curves become one of the central components for generating continuous records of streamflow. Since developing and maintaining rating curves can be time consuming, hydraulic models have shown potential to reduce the effort required for developing rating curves. A central challenge with modeling procedures, however, is the acquisition of accurate stream channel and floodplain topography. From this perspective, this thesis focuses on the real-world application of close-range remote sensing techniques such as laser-based ranging technologies (i.e. Light detection and ranging or LiDAR) or acoustic based ranging technologies (i.e. acoustic Doppler current profiler or ADCP) to capture topographic information for hydraulic modeling applications across various spatial scales. First, a review of the current LiDAR literature was carried out to identify potential ways to take full advantage of these novel data and technologies in the future. This was followed by four interconnected studies whereby: (i) a low-cost custom laser scanning system was designed to capture grain size distributions for a small stream; (ii) synthetically thinned airborne laser scanning (ALS) data was applied in a physically-based hydraulic modelling framework to develop rating curves; (iii) low-resolution national-scale ALS was coupled with ADCP bathymetry to be used in conjunction with a hydraulic model to develop rating curves; and (iv) the impact of measurement uncertainties on generating rating curves with a hydraulic model were investigated. This thesis highlights the potential of close-range remote sensing techniques for capturing accurate stream channel topography and derive from these data, the necessary parameters required for hydraulic modeling applications.

  • Public defence: 2017-06-16 10:00 Magnélisalen, Kemiska övningslaboratoriet, Stockholm
    Ferreira Vasconcelos, Luis Daniel
    Stockholm University, Faculty of Science, Department of Neurochemistry.
    Complexes of cell-penetrating peptides with oligonucleotides: Structure, binding and translocation in lipid membranes2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The fundamental element of life known to man is the gene. The information contained in genes regulates all cellular functions, in health and disease. The ability to selectively alter genes or their transcript intermediates with designed molecular tools, as synthetic oligonucleotides, represents a paradigm shift in human medicine.

    The full potential of oligonucleotide therapeutics is however dependent on the development of efficient delivery vectors, due to their intrinsic characteristics, as size, charge and low bioavailability. Cell-penetrating peptides are short sequences of amino acids that are capable of mediating the transport of most types of oligonucleotide therapeutics to the cell interior. It is the interaction of cell-penetrating peptides with oligonucleotides and the transport of their non-covalently formed complexes across the cellular membrane, that constitutes the main subject of this thesis.

    In Paper I we studied the effects of different types of oligonucleotide cargo in the capacity of cationic and amphipathic peptides to interact with lipid membranes. We found that indeed the cargo sequesters some of the peptide’s capacity to interact with membranes. In Paper II we revealed the simultaneous interaction of different molecular and supramolecular peptide and peptide/oligonucleotide species in equilibrium, with the cellular membrane. In Paper III we developed a series of peptides with improved affinity for oligonucleotide cargo as well as enhanced endosomal release and consequently better delivery capacity. In Paper IV we investigated the effect of saturated fatty acid modifications to a cationic cell-penetrating peptide. The varying amphipathicity of the peptide correlated with the complex physicochemical properties and with its delivery efficiency.

    This thesis contributes to the field with a set of characterized mechanisms and physicochemical properties for the components of the ternary system – cell-penetrating peptide, oligonucleotide and cell membrane – that should be considered for the future development of gene therapy.

  • Public defence: 2017-06-16 10:00 Nordenskiöldsalen, Geovetenskapens hus, Stockholm
    Andersson, Anton B.
    Stockholm University, Faculty of Social Sciences, Department of Sociology.
    Networks and Success: Access and Use of Social Capital among Young Adults in Sweden2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The thesis explores the role of social capital in shaping inequality among young adults. Social capital is defined as resources embedded in a social network and the thesis investigates differences in access to social capital, and the effects in the labor market and the housing market. The thesis consists of four empirical studies and an introductory chapter that develops the theoretical and empirical background. The four empirical studies use a Swedish survey titled “Social Capital and Labor Market Integration” that includes individuals born in 1990 living in Sweden. A gross sample based on three subsamples was selected based on the country of birth of the respondents’ parents (Sweden, former Yugoslavia, or Iran). The survey consists of two waves of panel data and most respondents were 19 years old at the time of the first survey and 22 at the time of the second. The four studies investigate: (1) the effect of social class and migration background on access to social capital through national and transnational ties, (2) the effect of socioeconomic segregation in schools and neighborhoods on access to social capital through occupational networks and close friendship ties, (3) the effect of social capital in the process of labor market entry, and (4) the effect of social capital on the likelihood to move away from parents. All four studies measure social capital with ego network measures and the main measurement is the position generator that asks the respondent about contacts in occupational positions spanning the socioeconomic structure. Results show that family background factors and socioeconomic segregation affects access to social capital, and that social capital affects labor market and housing market outcomes. The thesis concludes that social capital is an important factor to understand unequal outcomes among young adults.

  • Public defence: 2017-06-16 13:00 sal E306, Arrheniuslaboratorierna, Stockholm
    Favati, Anna
    Stockholm University, Faculty of Science, Department of Zoology.
    The relationship between personality and social dominance in the domestic fowl – a critical perspective2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Social dominance relationships are formed within numerous animal species and reduce costly fights over resources. Dominant individuals often enjoy greater access to important resources such as food and mating partners, and are generally more aggressive, bold, active and explorative compared to subdominant individuals. These behavioural traits can differ among individuals, but they can also be consistent within the individual, thereby describing the individual’s personality type. However, the causal direction of the observed correlation between dominance and personality is not well studied. One possibility is that some personality types have higher chances of obtaining a dominant social position. This would suggest that personality has consequences for fitness. Another possible explanation is that possessing different social positions gives rise to consistent behavioural differences among individuals on various timescales. If social status has a lasting effect on behaviour, social status would constitute a ‘stable state’ that explains some of the diversity of personality types that has been observed in a multitude of animal species. Dominance and personality may also share underlying proximate factors. In this thesis, I investigate the relationship between social dominance and personality using male domestic fowl, Gallus gallus domesticus. The species is group-living with pronounced dominance hierarchies, and dominance increases male access to mating partners. I show that some aspects of personality, exploration, vigilance and in particular aggressiveness, increased a male’s chances of obtaining dominance (paper III, IV, V), and that aggressiveness can be even more important than body weight and ornament size (comb size, paper V) or recent experience of winning or losing (paper IV). Winning a social interaction resulted in an increase in aggressiveness, while a decrease was seen in males that experienced a loss (paper IV). By observing behaviour before and after changes in male dominance relationships, I further show that a recent (2 days earlier) change in social status induced behavioural adjustments to the new social status in activity, exploration and vigilance (paper I). By extending the time of the new social relationship to 3 weeks, I show that such behavioural changes did not continue (paper II). Finally, I show that the social environment during juvenile development had little impact on adult male competitiveness (paper V). Social interactions appear to have several short-term effects on behaviour, but did not contribute significantly to variation and long-term consistency of personality in male fowl. Instead, a male's personality, and in particular his aggressiveness, affected the outcome of dominance interactions. Overall, my studies reveal important consequences of individual differences in behaviour, and contribute to the highly sought-after empirical testing of hypotheses explaining variation in animal personality.

  • Public defence: 2017-06-16 13:00 hörsal 3, hus B, Stockholm
    Quartararo, Geraldine
    Stockholm University, Faculty of Humanities, Department of Romance Studies and Classics.
    Evidencialidad indirecta en aimara y en el español de La Paz: Un estudio semántico-pragmático de textos orales2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This dissertation investigates the expression of the indirect evidential subdomain in two languages in contact, i.e. the northern variety of Central Aymara and the variety of Spanish spoken in La Paz (Bolivia).

    For this aim, the study uses first-hand data collected in La Paz and El Alto (Bolivia) during 2014 and 2015. Data was elicited through: the “Family Problems Picture” task (San Roque et al. 2012), formulated by the members of the Max Planck Institute for Psycholinguistics and created specifically for the activation of cognitive categories such as evidentiality and mirativity; the “Pear Story” designed for Wallace Chafe, professor at the University of California, to collect narrative texts that show how humans perceive, elaborate and verbalize experience; and, finally, personal narratives, traditional narratives and interviews. Thirty-three recordings (12h 48’) of 48 Spanish-Aymara bilingual speakers (17 males, age range: 18-64) were fully transcribed and annotated. The resulting corpus consists of 33 transcriptions of which 14 are in Aymara (c. 19 154 words), whereas 19 are in Spanish (c. 46 245 words).

    The dissertation is built around four research questions.

    First, the dissertation shows the functions of the forms identified in the data in both languages. The study identifies for each form both evidential and non-evidential functions. Indirect evidential functions are systematically analyzed and classified by combining Willett’s (1988) and Aikhnvald’s (2004) classifications. The analysis shows evidential functions of forms that have not been previously studied as such, i.e. digamos and diciendo in Spanish and sañani and sapxi in Aymara, but it also reveals unnoticed evidential functions for previously described forms.

    Second, the dissertation provides a clear view of the relationship between the evidential and the epistemic modal domain involved in the use of the forms identified. Two types of correlation are found. Both languages, indeed, show forms that only point out the way in which speakers acquired information and forms where the two domains overlap.

    Third, the dissertation investigates speakers’ epistemic stance, in terms of commitment, towards information involved in the use of the evidential forms identified. The study shows that the forms which convey merely evidential information express mainly a medium-high commitment degree, whereas the forms in which the distinction between the evidential and the epistemic modal domain is blurred indicate a low degree of commitment.

    Forth, the dissertation sheds light on the relationship between the expressions of the indirect evidential subdomain in the two languages. The study proposes a quantitative and qualitative analysis of the evidential types and subtypes in both languages. The results show a high degree of convergence between the two languages, suggesting also situations of influence of one language on the other.

  • Public defence: 2017-06-16 13:00 Nordenskiöldsalen, Geovetenskapens hus, Stockholm
    Weiss, Niels
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Permafrost carbon in a changing Arctic: On periglacial landscape dynamics, organic matter characteristics, and the stability of a globally significant carbon pool2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Organic matter (OM) in arctic permafrost ground contains about twice as much carbon (C) as is currently present in the atmosphere. Climate change is particularly strong in the Arctic, and could cause a considerable part of the OM in permafrost to thaw out, decompose, and be released as greenhouse gases; further enhancing global warming. The exact size of the northern circumpolar C pool remains unclear, and processes that control decomposition and mineralization rates are even more uncertain. Superimposed on the long-term release of C through microbial decomposition of OM in the gradually deepening active layer, is the rapid release of currently sequestered OM through geomorphological processes. This thesis considers the quantity, quality, and availability of permafrost C, and explores interactions and common controls.

    To better understand the potential effects of thawing permafrost, it is vital to: i) obtain more accurate size and distribution estimates of permafrost C stocks, and develop methods to accurately and efficiently implement these in models, ii) identify OM characteristics that control decomposition, specifically for permafrost material, and iii) determine and quantify key geomorphological processes that cause large amounts of OM to become available for rapid decomposition.

    Detailed C quantifications are valuable to increase our fundamental understanding of permafrost soil processes and C sequestration, but including high levels of heterogeneity in models is challenging. Simple upscaling tools based on e.g. elevation parameters (Paper I) can help to bridge the gap between detailed field studies and global C models.

    Permafrost OM quality is controlled by different factors than those commonly observed in temperate soils (without permafrost). We observed an unexpected (significant) correlation in upper permafrost samples, where material that is generally considered more recalcitrant showed the highest CO2 production rates per g C, indicating high lability (Paper II). In ancient Pleistocene permafrost, labile samples related significantly to OM that was enriched in decomposed microbial remains, whereas less-decomposed plant material was more stable (Paper III). Investigation of multiple incubation datasets revealed that the unusual relationship between %C and CO2 production occurred in contrasting field sites throughout the Arctic, indicating important permafrost-specific controls over OM quality (Paper IV). We discuss several possible explanations for the observed high lability of permafrost OM, such as a pool of labile dissolved organic C in the upper permafrost, or increased lability caused by past decomposition. In order to conclusively identify causal relationships, and to answer the question whether or not the same mechanisms control OM quality in different environments, further investigation of permafrost-specific OM quality is required.

    Geomorphology plays a key role in C reworking and OM decomposition. Vast amounts of OM can be released abruptly (e.g. in thaw slumps and thermokarst lakes, Paper II), resulting in C turnover that will likely outweigh decomposition through gradual active layer deepening. Climate change could enhance this rapid release of C, and changes in surface hydrology and increased fire activity are expected to become the largest contributors to C loss from permafrost regions. Together with C quantity and quality, availability through gradual and abrupt processes must be parameterized and included in models in order to accurately assess the potential permafrost C climate feedback.

  • Public defence: 2017-06-16 14:00 William-Olssonsalen, Geovetenskapens hus, Stockholm
    Öberg, Erik
    Stockholm University, Faculty of Social Sciences, Department of Economics.
    On Money and Consumption2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Price Level Determination When Tax Payments Are Required in Money. We formalize the idea that the price level can be determined by a requirement that taxes be paid in money. We show that if households have to pay a money tax of a fixed real value and the money supply is constant, there is a unique stationary price level, and a continuum of non-stationary deflationary equilibria. The non-stationary equilibria can be excluded if we introduce an arbitrarily lax borrowing constraint. Thus, in the basic model, tax requirements can uniquely determine the price level. When money has liquidity value, tax requirements can exclude self-fulfilling hyperinflations.

    The New Keynesian Transmission Mechanism: A Heterogeneous-Agent Perspective. We argue that a two-agent version of the standard New Keynesian model - where a "worker'' receives only labor income and a "capitalist'' only profit income - offers insights about how income inequality affects the monetary transmission mechanism. Under rigid prices, monetary policy has no effect on output as workers choose not to change their hours worked in response to wage movements. In the corresponding representative-agent model, in contrast, hours do rise after a monetary policy loosening due to a wealth effect on labor supply: profits fall, thus reducing the representative worker's income. If wages are rigid too, however, the monetary transmission mechanism is active and resembles that in the corresponding representative-agent model.

    Consumption Dynamics under Time-varying Unemployment Risk. We argue that adjustment frictions for durable goods generate a powerful amplification channel from fluctuations in unemployment risk to aggregate consumption demand. First, we use survey data to document that durable expenditures react strongly to increased unemployment risk, while the effect on nondurable expenditures is indistinguishable from zero. Second, we propose and calibrate a buffer-stock savings model that includes adjustment frictions for durable goods. Although not targeted in the calibration, we find that the model reproduces the semi-elasticities of expenditures to unemployment risk estimated in the data. Using the model, we find that the inclusion of adjustment frictions raises the aggregate demand response of durable goods to fluctuations in perceived unemployment risk by approximately 200 percent. Moreover, upon experiencing an adverse risk shock, the responsiveness of aggregate demand for durable goods to the interest rate and transitory income shocks is dampened.

    Consumption Dynamics under Time-varying Unemployment Risk: Evidence from Time Series Data. We investigate the relationship between consumption expenditures and unemployment risk using aggregate time series data for the US and ten EU countries. As a proxy for perceived unemployment risk, we use data on households' subjective expectations over the future unemployment rate. First, we employ a single-equation framework to test whether subjective unemployment expectations predict aggregate consumption growth when controlling for predicted aggregate income growth. Second, we exploit the timing of the survey interviews in relation to the publication of official statistics to isolate exogenous innovations to unemployment expectations in a small-scale vector autoregression. For the US, both methods suggest that there is a large effect of unemployment risk on aggregate consumption. For the ten EU countries, the evidence is mixed.

  • Public defence: 2017-08-18 10:00 hörsal 11, hus F, Stockholm
    Berlin, Martin
    Stockholm University, Faculty of Social Sciences, Department of Economics.
    Essays on the Determinants and Measurement of Subjective Well-Being2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis consists of four self-contained essays in economics, all concerned with different aspects of subjective well-being. The abstracts of the four studies are as follows.

    Beyond Income: The Importance for Life Satisfaction of Having Access to a Cash Margin. We study how life satisfaction among adult Swedes is influenced by having access to a cash margin, i.e. a moderate amount of money that could be acquired on short notice either through own savings, by loan from family or friends, or by other means. We find that cash margin is a strong and robust predictor of life satisfaction, also when controlling for individual fixed effects and socio-economic conditions, including income.

    Decomposing Variation in Daily Feelings: The Role of Time Use and Individual Characteristics. I explore the potential of using time-use data for understanding variation in affective well-being. Using the Princeton Affect and Time Survey, I decompose variation in daily affect into explained and unexplained within- and between person variation. Time use is found to mostly account for within-variation. Hence, its explanatory power is largely additive to that of individual characteristics. The explanatory power of time use is small, however. Activities only account for 1–7% of the total variation and this is not increased much by adding contextual variables.

    The Association Between Life Satisfaction and Affective Well-Being. We estimate the correlation between life satisfaction and affect — two conceptually distinct dimensions of subjective well-being. We propose a simple model that distinguishes between a stable and a transitory component of affect, and which also accounts for measurement error in self-reports of both variables, including current-mood bias effects on life satisfaction judgments. The model is estimated using momentarily measured well-being data, from an experience sampling survey that we conducted on a population sample of Swedes aged 18–50 (n=252). Our main estimates of the correlation between life satisfaction and long-run affective well-being range between 0.78 and 0.91, indicating a stronger convergence between these variables than many previous studies that do not account for measurement issues.

    Do OLS and Ordinal Happiness Regressions Yield Different Results? A Quantitative Assessment. Self-reported subjective well-being scores are often viewed as ordinal variables, but the conventional wisdom has it that OLS and ordered regression models (e.g. ordered probit) produce similar results when applied to such data. This claim has rarely been assessed formally, however, in particular with respect to quantifying the differences. I shed light on this issue by comparing the results from OLS and different ordered regression models, in terms of both statistical and economic significance, and across data sets with different response scales for measuring life satisfaction. The results are mixed. The differences between OLS, probit and logit estimates are typically small when the response scale has few categories, but larger, though not huge, when an 11-point scale is used. Moreover, when the error term is assumed to follow a skewed distribution, larger discrepancies are found throughout. I find a similar pattern in simulations, in which I assess how different methods perform with respect to the true parameters of interest, rather than to each other.