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  • Public defence: 2017-08-25 10:00 Aula Svea, Socialhögskolan, Stockholm
    Manhica, Hélio
    Stockholm University, Faculty of Social Sciences, Centre for Health Equity Studies (CHESS).
    Mental health, substance misuse and labour market participation in teenage refugees in Sweden – A longitudinal perspective2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Aim: To fill the knowledge gap about the importance of contextual factors after resettlement on mental health, substance misuse and labour market participation among young refugees who immigrate to Sweden as teenagers. Methods: Register studies in national registers of national cohorts of young refugees, unaccompanied and accompanied, who settled in Sweden as teenagers. Studies 1-4 used Cox regression models to study the risks of psychiatric care consumption and substance misuse, while Study 5 used multinomial regression to study position on the labour. These findings were compared with peers from the same birth cohorts in the general Swedish population and non-European intercountry adoptees (Studies 2 and 5). Results: The overall results suggest that young accompanied and unaccompanied refugees were more likely to be admitted to psychiatric inpatient and compulsory hospital care, but not outpatient care, with refugees born in the Horn of Africa and Iran having the highest risk (Study 1). Young accompanied and unaccompanied refugees also had higher risk of hospitalization and criminal conviction associated with substance misuse (Study 3). Longer duration of residence in Sweden was associated with increased risks of outpatient care (Study 1) and hospitalization related to substance misuse (studies 3 and 4). These increase risks of young refugees were associated with their socioeconomic living conditions (Studies 3 and 4), but risk factors associated with the country of origin of the refugee population and the intercountry adoptees were more important determinants of schizophrenia than socioeconomic conditions in Sweden (Study 2). Young accompanied and unaccompanied refugees and intercountry adoptees had a lower likelihood of being in full employment than native Swedes with comparable levels of education. Secondary education, however, increased employment chances and reduced the risk of being neither employed nor in education or training (Study 5). Conclusion: Evidence suggests that several groups of young refugees are at higher risk of mental health problems and substance misuse. They also face employment disadvantages and barriers to psychiatric care in the early stages of developing a psychiatric disorder.

  • Public defence: 2017-09-01 10:00 Nordenskiöldsalen, Geovetenskapens hus, Stockholm
    Giovanoulis, Georgios
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    What contributes to human body burdens of phthalate esters?: An experimental approach2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Phthalate esters (PEs) and alternative plasticizers used as additives in numerous consumer products are continuously released into the environment leading to subsequent human exposure. The ubiquitous presence and potential adverse health effects (e.g. endocrine disruption and reproductive toxicity) of some PEs are responsible for their bans or restrictions. This has led to increasing use of alternative plasticizers, especially cyclohexane-1,2-dicarboxylic acid diisononyl ester (DINCH). Human exposure data on alternative plasticizers are lacking and clear evidence for human exposure has previously only been found for di(2-ethylhexyl) terephthalate (DEHTP) and DINCH, with increasing trends in body burdens. In this thesis, a study population of 61 adults (age: 20–66; gender: 16 males and 45 females) living in the Oslo area (Norway) was studied for their exposure to plasticizers. Information on sociodemographic and lifestyle characteristics that potentially affect the concentrations of PE and DINCH metabolites in adults was collected by questionnaires. Using the human biomonitoring approach, we evaluated the internal exposure to PEs and DINCH by measuring concentrations of their metabolites in urine (where metabolism and excretion are well understood) and using these data to back-calculate daily intakes. Metabolite levels in finger nails were also determined. Since reference standards of human metabolites for other important alternative plasticizers apart from DINCH (e.g. DEHTP, di(2-propylheptyl) phthalate (DPHP), di(2-ethylhexyl) adipate (DEHA) and acetyl tributyl citrate (ATBC)) are not commercially available, we further investigated the urine and finger nail samples by Q Exactive Orbitrap LC-MS to identify specific metabolites, which can be used as appropriate biomarkers of human exposure. Many metabolites of alternative plasticizers that were present in in vitro extracts were further identified in vivo in urine and finger nail samples. Hence, we concluded that in vitro assays can reliably mimic the in vivo processes. Also, finger nails may be a useful non-invasive matrix for human biomonitoring of specific organic contaminants, but further validation is needed. Concentrations of PEs and DINCH were also measured in duplicate diet, air, dust and hand wipes. External exposure, estimated based on dietary intake, air inhalation, dust ingestion and dermal uptake, was higher or equal to the back-calculated internal intake. By comparing these, we were able to explain the relative importance of different exposure pathways for the Norwegian study population. Dietary intake was the predominant exposure route for all analyzed substances. Inhalation was important only for lower molecular weight PEs, while dust ingestion was important for higher molecular weight PEs and DINCH. Dermal uptake based on hand wipes was much lower than the total dermal uptake calculated via air, dust and personal care products, but still several research gaps remain for this exposure pathway. Based on calculated intakes, the exposure risk for the Norwegian participants to the PEs and DINCH did not exceed the established tolerable daily intake and reference doses, and the cumulative risk assessment for combined exposure to plasticizers with similar toxic endpoints indicated no health concerns for the selected population. Nevertheless, exposure to alternative plasticizers, such as DPHP and DINCH, is expected to increase in the future and continuous monitoring is required. Findings through uni- and multivariate analysis suggested that age, smoking, use of personal care products and many other everyday habits, such as washing hands or eating food from plastic packages are possible contributors to plasticizer exposure.

  • Public defence: 2017-09-01 10:00 De Geersalen, Geovetenskapens hus, Stockholm
    Stymne, Anna-Carin
    Stockholm University, Faculty of Humanities, Department of History.
    Hur begriplig är historien?: Elevers möjligheter och svårigheter i historieundervisningen i skolan2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The thesis focuses on how students learn history in the classroom, more precisely on their possibilities and difficulties in developing competence in the school subject of history. There is a particular emphasis on how they explain and understand historical processes and concepts within the subject of history. Participants are students of different grades, 8–19 years old. The purpose of the study is to explore how students learn history in concrete learning situations and my focus is on the types of knowledge students understand, learn, develop and use in comparison with what they are expected to learn.  This is done based on three fundamental and well-established principles of learning. To examine what kinds of knowledge students need I use three main types of knowledge: declarative content knowledge (facts and concepts), procedural knowledge (knowledge about how to do things) and self-regulatory knowledge (knowledge about how to regulate our memory, thought and learning). I also use concepts and insights from systemic functional linguistics (SFL) in order to explain why the students use language and communicate the way they do.

    The thesis shows that history is challenging for young students. Young students have difficulties with complex and abstract concepts in history as they treat concepts as facts. Older, more competent, students use concepts on a more abstract level and use different kinds of linguistic resources when formulating explanations of higher complexity, more similar to the way explanations in the domain of history are commonly written. The youngest students and some of the older students lacked factual knowledge, concept knowledge, domain specific self-regulatory knowledge and linguistic resources.

    Declarative content knowledge and facts are more important and more difficult for young students to understand, develop, organize and learn than previous scholars have shown empirically. Students’ abilities to understand facts and ideas in the context of a conceptual framework and to organize and structure facts with the help of concepts at different level of abstraction (conceptual understanding) are crucial. Students also need linguistic resources, both lexical knowledge and knowledge of text structures. Language is crucial both in the process of acquiring knowledge and in the process of communication. In the learning process, teaching is crucial, since individual students’ potential to develop competence depend on the potential of the teacher to discover and engage their preconceptions and arrange for learning in a way that give students the kind of knowledge they need.

  • Public defence: 2017-09-05 10:00 Högbomsalen, Geovetenskapens hus, Stockholm
    Lane, Nathaniel
    Stockholm University, Faculty of Social Sciences, Department of Economics.
    States of Development: Essays on the Political Economy of Development in Asia2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Manufacturing Revolutions - Industrial Policy and Networks in South Korea. This chapter uses a historic big push intervention and newly digitized data from South Korea to study the effects of industrial policy on industrial development. In 1973 South Korea transitioned to a military dictatorship and drastically changed their development strategy. I find industries targeted by the regime's big push grew significantly more than non-targeted industries along several key dimensions of industrial development. These developmental effects persisted after industrial policies were retrenched, following the 1979 assassination of the president. Furthermore, I estimate the spillovers of the industrial policies using exogenous variation in the exposure to the policy across the input-output network. I find evidence of persistent pecuniary externalities like those posited by big push development theorists, such as Albert Hirschman. In other words, I find that South Korea's controversial industrial policy was successful in producing industrial development, the benefits of which persisted through time and in industries not directly targeted by the policies.

    Waiting for the Great Leap Forward - The Green Revolution and Structural Change in the Philippines. This study explores the short- and long-run impacts of the green revolution on structural transformation. The setting is the revolution’s home country: the Philippines. In 1966, the Philippine’s experienced the widespread introduction of so-called “miracle rice” varieties, invented at the International Rice Research Institute in Los Banos, Laguna. The island republic experienced large gains to agricultural productivity as a result. Using a newly constructed panel of Philippine municipalities, I show that growth in agricultural productivity led to unexpected patterns of structural transformation. In the short-run, the green revolution translated into labor-absorbing technological change, reallocating labor into HYV-intensive rice economies. However, in the long-run, the rising relative cost of labor, meant that rice farms mechanized and displaced the Philippine peasantry into the service sector.

    The Historical State, Local Collective Action, and Economic Development in Vietnam. This study examines how the historical state conditions long-run development, using Vietnam as a laboratory. Northern Vietnam (Dai Viet) was ruled by a strong centralized state in which the village was the fundamental administrative unit. Southern Vietnam was a peripheral tributary of the Khmer (Cambodian) Empire, which followed a patron-client model with weaker, more personalized power relations and no village intermediation. Using a regression discontinuity design across the Dai Viet-Khmer boundary, the study shows that areas historically under a strong state have higher living standards today and better economic outcomes over the past 150 years. Rich historical data document that in villages with a strong historical state, citizens have been better able to organize for public goods and redistribution through civil society and local government. This suggests that the strong historical state crowded in village-level collective action and that these norms persisted long after the original state disappeared.

  • Public defence: 2017-09-05 14:00 De Geersalen, Stockholm
    Österling, Anders
    Stockholm University, Faculty of Social Sciences, Department of Economics.
    Housing Markets and Mortgage Finance2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This Ph.D. thesis deals with questions related to the housing market, and answers the questions: "Does it matter if housing markets are underpriced?" and "How do the legal system and the loan contract affect those who default on their mortgage payments?

    "When selling a home, a popular marketing strategy is to set the list price far below market value. The idea is that a low list price will attract loads of buyers, who will push up the sale price. This thesis finds that a voluntary reform can reduce underpricing in the short run. Further, underpriced housing markets do indeed require more attention from potential buyers during all stages — online, at open houses, and during the bidding. This extra search effort is costly to society. However, underpricing is found not to affect the sale price, the time to sell, who the buyers are, or how hard the real estate agent works.

    The household's choice to default on a mortgage depends on the cost of the default (the legal system) and the mortgage contract. By studying a heterogeneous agent consumption/savings lifecycle model, this thesis finds that households prefer "lender friendly" laws that are costly for the homeowners upon default. This is because costly defaults yield fewer defaulters and thus lower interest rates, and thus are cheaper for non-defaulters. Households always prefer non-amortizing mortgages except when defaults do not have any cost associated with them, and they prefer adjustable rates over fixed rates. The benefits of costly defaults are particularly large for non-amortizing mortgages.

    The thesis concludes with the development of a new mathematical method to solve a particular class of dynamic programming problems, using stochastic simulated grids and nearest-neighbour interpolation.​

  • Public defence: 2017-09-08 10:00 Högbomsalen, Geovetenskapens hus, Stockholm
    Lindqvist, Helena
    Stockholm University, Faculty of Humanities, Department of Romance Studies and Classics.
    Marcadores metadiscursivos, fluidez y participación conversacional en español L2: La evolución de la competencia comunicativa durante la estancia en una comunidad de la lengua meta2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This study investigates the acquisition and use of metadiscourse markers in learners/users of L2 Spanish and the role these markers play in the development of fluency and conversational participation during a five-month stay in Spain as exchange students of business administration.

    The study has been conducted in three steps. The first part focuses on the theory and categorization of metadiscourse markers, followed by an analysis of the use and development of these markers in learners of L2 Spanish. The second part deals with the categorization and operationalization of aspects of fluency and conversational participation that can be associated with the use of metadiscourse markers; followed by an analysis of these aspects in the performance of the learners. The third part of the study is a summary of the results obtained and a discussion of the relationship between the use of metadiscourse markers and the development of fluency and conversational participation.

    The data underlying the current study consists of a selection of 17 recorded conversations between learners of L2 Spanish and native speakers of Spanish taken from the AKSAM database. The conversations belong in two activity types: discussions and simulated negotiations. The selected sample has a duration of approx. 10 hours and comprises 87 683 words. The study focuses on nine learners who have been recorded at the beginning and at the end of their five month study-abroad stay.

    Results show that frequency of use of metadiscourse markers has increased considerably at the end of the stay in the majority of the learners under study. A qualitative development can also be found, through which the metadiscourse markers that characterize the learners’ L1 and/or interlanguage have been substituted by more target-like expressions. Furthermore, both their fluency and level of conversational participation have generally increased. Within this development, however, a notable individual variation can be found. The learners who show the strongest development as regards fluency and conversational participation are also found to exhibit the most salient development of metadiscourse markers. Since disfluency is reduced to a lesser degree in those participants who also exhibit a less developed use of metadiscourse markers, it is argued that the development of metadiscourse markers in the L2 learner runs parallel to the development of discourse skills, but also that acquiring an adequate use of metadiscourse markers helps developing these skills. 

  • Public defence: 2017-09-08 10:00 Nordenskiöldsalen, Geovetenskapens hus, Stockholm
    Hentati, Jannete
    Stockholm University, Faculty of Social Sciences, Department of Social Anthropology.
    En lektion i gemenskap: Ordning och (o)reda bland lärare i Malmö och Marseille2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This ethnographic study is based on comparative fieldwork among teachers at secondary schools in two southern situated cities in Europe: Malmö in Sweden and Marseille in France. The focus of the study is on how teachers make sense of and grapple with their mission to build and foster “good” citizens, which is intended to promote national community and unity. Exploring how the teachers strive and struggle to fulfil this mission provides a better insight into the ideas and practices that permeate their work. At the same time, the everyday tensions that occasionally complicate this task are highlighted. A crucial observation in this study is that teachers in both Sweden and France often find themselves confined to a kind of cross-pressure. Enclosed within it, teachers are torn between, on the one hand, endeavouring to reach certain visions and goals regarding how to instil a sense of national community in their pupils and, on the other, being confronted with an irregular and often far from pliable reality. This study shows how teachers are dealing with this cross-pressure, how – in case of hurdles and friction in their work – they try to maintain order in what they perceive and experience as being a state of great disorder in relation to their educational mission. The thesis contributes to increased knowledge of teachers’ lived professional experiences and situated practices in their day-to-day work. It also brings to light a problematising discussion about the role and importance that teachers expect themselves to play in relation to an overall idea of national community and unity in Sweden and France respectively.

  • Public defence: 2017-09-08 13:00 G-salen, Arrheniuslaboratorierna, Stockholm
    Reath Warren, Anne
    Stockholm University, Faculty of Humanities, Department of Language Education.
    Developing multilingual literacies in Sweden and Australia: Opportunities and challenges in mother tongue instruction and multilingual study guidance in Sweden and community language education in Australia2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis aims to learn about opportunities for and challenges to the development of multilingual literacies in three forms of education in Sweden and Australia that teach or draw on immigrant languages.  In Sweden mother tongue instruction and multilingual study guidance are in focus and in Australia, a community language school. Taking an ecological approach to the research sites, the thesis investigates how language ideologies, organization of the form of education and language practices impact on the development of multilingual literacies. A range of linguistic ethnographic data including 75 lesson observations, 48 interviews, field notes and photographs has been analyzed against the theoretical backdrop of the continua of biliteracy (Hornberger, 1989; Hornberger & Skilton-Sylvester, 2000), heteroglossia (Bakhtin, 1981) and emerging theories of translanguaging (García & Li, 2014) to investigate the questions. The thesis ties together the results of four interlocking case studies investigating the above-mentioned forms of education.

    Study I analyses the syllabus for mother tongue instruction in Sweden and finds that while aligning with the overall values of the curriculum for the compulsory school, a hidden curriculum constrains implementation. In Study II, multilingual practices during multilingual study guidance in Sweden are analysed, and demonstrate how translanguaging helps recently arrived students reach the learning goals of subjects in the Swedish curriculum. In study III, systematic analysis of indexicals reveals contrasting language narratives about language and language development in and around a Vietnamese community language school in Australia. Study IV focuses on mother tongue instruction in Sweden and through analysis of audio-recordings of lessons, interviews and field notes, finds three dimensions of linguistic diversity infuse the subject. 

    Opportunities for the development of multilingual literacies are created when there is equal access to spaces for developing literacies in different immigrant languages, within which language ideologies that recognize and build on the heteroglossic diversity of students’ linguistic repertoires dynamically inform the organization of education and classroom practices. Challenges are created when monoglossic ideologies restrict access to or ignore linguistic diversity and when there is a lack of dynamic engagement with implementation and organization. Basing organization, and classroom strategies around the linguistic reality of the students and the genres they need, benefits the development of multilingual literacies in both settings and can help students become resourceful language users (Pennycook, 2012b, 2014).

  • Public defence: 2017-09-08 13:00 sal FB42, AlbaNova universitetscentrum, Stockholm
    Fremling, Christoffer
    Stockholm University, Faculty of Science, Department of Astronomy.
    Stripped-envelope supernovae discovered by the Palomar Transient Factory2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is based on research made by the intermediate Palomar Transient Factory [(i)PTF]. The focus is on stripped-envelope (SE) supernovae (SNe) discovered by (i)PTF, and it is closely tied to the research on the SE SN iPTF13bvn, that occurred in the nearby galaxy NGC 5806. This SN was initially thought to have been the explosion of a very massive Wolf-Rayet star, but we have shown that this is very likely not the case. We suggest instead that iPTF13bvn originated from a binary system where the envelope was stripped off from the SN progenitor by tidal forces from a companion (Paper I). PTF12os exploded in the same galaxy as iPTF13bvn, and our analysis shows that PTF12os and  iPTF13bvn were very similar, and that both were also remarkably similar to the Type IIb SN 2011dh, in terms of their light-curves and spectra. In Paper II, hydrodynamical models were used to constrain the explosion parameters of iPTF13bvn, PTF12os and SN 2011dh; finding 56Ni masses in the range 0.063-0.075 solar masses (Ms), ejecta masses in the range 1.85-1.91 Ms, and kinetic energies in the range 0.54-0.94 x 1051 erg. Furthermore, using nebular models and late-time spectroscopy we were able to constrain the Zero-Age Main Sequence (ZAMS) mass to ~ 12 Ms, for iPTF13bvn and ≤ 15 Ms for PTF12os. In current stellar evolution models, stars with these masses on the ZAMS cannot lose their envelopes and become SE SNe without binary interactions. In Paper III we investigate a peculiar SE SN, iPTF15dtg; this SN lacks both hydrogen and helium and shows a double-peaked LC with a broad main LC peak. Using hydrodynamical modeling we show that iPTF15dtg had a very large ejecta mass (~ 10 Ms), resulting from an explosion of a very massive star (~ 35 Ms). The initial peak in the LC can be explained by the presence of extended material around the star, likely due to an episode of strong mass-loss experienced by the progenitor prior to the explosion. In Paper IV we perform a statistical study of the spectra of all 176 SE SNe (Type IIb, Ib and Ic) discovered by (i)PTF. The spectra of Type Ic SNe show O absorption features that are both stronger and broader (indicating faster expansion velocities) compared to Type IIb and Type Ib SNe. These findings along with very weak He absorption support the traditional picture with Type Ic SNe being heavily stripped of their He envelopes prior to the explosions, and argue against alternative explanations, such as differences in explosive mixing of 56Ni among the SE SN subtypes.

  • Public defence: 2017-09-08 13:00 Magnélisalen, Kemiska övningslaboratoriet, Stockholm
    Zhong, Yuan
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Sub-grain structure in additive manufactured stainless steel 316L2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The thesis focuses on exploring the sub-grain structure in stainless steel 316L prepared by additive manufacturing (AM). Two powder-bed based AM methods are involved: selective laser melting (SLM) and electron beam melting (EBM). It is already known that AM 316L has heterogeneous property and hierarchy structure: micro-sized melt pools, micro-sized grains, nano-sized sub-grain structure and nano-sized inclusions. Yet, the relation among these structures and their influence on mechanical properties have not been clearly revealed so far. Melt pool boundaries having lower amount of sub-grain segregated network structures (Cellular structure) are weaker compared to the base material. Compared with cell boundaries, grain boundaries have less influence on strength but are still important for ductility. Cell boundaries strengthen the material without losing ductility as revealed by mechanical tests. Cellular structure can be continuous across the melt pool boundaries, low angle sub-grain boundaries, but not grain boundaries. Based on the above understanding, AM process parameters were adjusted to achieve customized mechanical properties. Comprehensive characterization were carried out to investigate the density, composition, microstructure, phase, magnetic permeability, tensile property, Charpy impact property, and fatigue property of both SLM and EBM SS316L at room temperature and at elevated temperatures (250°C and 400°C). In general, SLM SS316L has better strength while EBM SS316L has better ductility due to the different process conditions. Improved cell connection between melt pools were achieved by rotating 45° scanning direction between each layer compared to rotating 90°. Superior mechanical properties (yield strength 552 MPa and elongation 83%) were achieved in SLM SS316L fabricated with 20 µm layer thickness and tested in the building direction. Y2O3 added oxide dispersed strengthening steel (ODSS) were also prepared by SLM to further improve its performance at elevated temperatures. Slightly improved strength and ductility (yield strength 574 MPa and elongation 90%) were obtained on 0.3%Y2O3-ODSS with evenly dispersed nanoparticles (20 nm). The strength drops slightly  but ductility drops dramatically at elevated temperatures. Fractographic analysis results revealed that the coalescence of nano-voids is hindered at room temperature but not at elevated temperatures. The achieved promising properties in large AM specimens assure its potential application in nuclear fusion. For the first time, ITER first wall panel parts with complex inner pipe structure were successfully fabricated by both SLM and EBM which gives great confidence to application of AM in nuclear industry. 

  • Public defence: 2017-09-08 13:00 Vivi Täckholmsalen (Q-salen), NPQ-huset, Stockholm
    Roufidou, Chrysoula
    Stockholm University, Faculty of Science, Department of Zoology.
    Reproductive physiology of the female three-spined stickleback, Gasterosteus aculeatus2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Reproduction in vertebrates, including fishes, is under control of the brain-pituitary-gonad (BPG) axis. The female three-spined stickleback, Gasterosteus aculeatus, produces egg clutches at intervals of a few days and spawns them in a nest built by male. Following ovulation, eggs are stored in the ovarian cavity surrounded by the ovarian fluid (OF). If spawning or spontaneous release do not occur, the eggs can undergo overripening, a phenomenon occurring both in nature and captivity.

    In this PhD thesis, the changes of reproductive hormones and vitellogenesis were studied at overripening of eggs and over the natural spawning cycle. OF properties were also examined at overripening of eggs and after treatment with sex steroids.

    Plasma levels of steroids: testosterone (T), estradiol (E2), 17,20β-dihydroxypregn-4-en-3-one (17,20β-P) and 17,20β,21-trihydroxypregn-4-en-3-one (17,20β,21-P) were measured by radioimmunoassay, and relative mRNA levels of the pituitary gonadotropins (fsh-β/lh-β), brain gonadotropin-releasing hormones (gnrh2/gnrh3) and kisspeptin and its receptor (kiss2/gpr54) by qPCR. Overripening of eggs was accompanied with a significant reduction in most of endocrine parameters of BPG axis (T, E2, 17,20β-P; lh-β; kiss2, gpr54). Low level of hormones could be advantageous for the overripe egg-bound females, since this would reduce further ovulations giving higher chances to survive and reproduce again. Over the 3-day spawning cycle, T and E2 were highly correlated, showed cyclicity with low levels at ovulation and increasing from 24 and 6 hours post-spawning (hps), respectively. Spawning may give rise to this increase as these rises did not occur if release of the eggs does not happen (overripe females). A peak at pituitary lh-β mRNA levels appeared 48 hps, a day before the next ovulation. No significant changes were found for the other studied hormones.

    Vitellogenesis was studied by measurement of the vitellogenin mRNA levels in the liver by qPCR. The levels were highest at 24 and 48 hps and were positively correlated to both E2 and T over the cycle. However, changes were small suggesting a rather continuous vitellogenesis over the stickleback spawning cycle which could be an advantage for a multiple spawner with a limited spawning season. Overripening reduced vitellogenin mRNA levels but did not abolish it.

    OF amount was diminished in overripe females and had a lower viscocity but higher dry weight and protein levels than in non-overripe ovulated females, suggesting that changes in OF properties are related to the egg overripening. The effects of steroids were studied using Silastic capsules. T and 17,20β-P induced an increase of OF amount, but protein levels were only increased in 17,20β-P-treated females, proposing a role of this steroid in the control of OF secretion. 1-D SDS-PAGE showed that OF contained several proteins, some of them came from eggs, but no consistent differences between groups.

    Concluding, the knowledge of the reproductive physiological changes is important for understanding their essential roles in the production of viable eggs in this species but also in the reproductive physiology of female fishes in general.

  • Public defence: 2017-09-08 15:00 hörsal 8, hus D, Stockholm
    Bukelskytė-Čepelė, Kristina
    Stockholm University, Faculty of Humanities, Department of Slavic and Baltic Studies, Finnish, Dutch, and German.
    Nominal Compounds in Old Latvian Texts in the 16th and 17th Centuries2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis investigates the system of compounding attested in the earliest written Latvian texts of the 16th and 17th centuries. The philological analysis presented in this work is the first systematic attempt to extensively treat compounds in Old Latvian. The purpose of this thesis is to thoroughly describe the system of compounding of the earliest period of written Latvian. One of the main aims of the analysis provided in this work is to determine whether the Old Latvian compounds were distinguished in terms of their meaning and form. This is why another important aim of this study is to discern the most characteristic formal properties of each category of compounds in Old Latvian. This study also addresses the morphological variation of the components of compounds and seeks to explain why one finds different tendencies of compounding in the texts of this period.   

    Firstly, it is shown in this thesis that compounds in Old Latvian were clearly distinguished in terms of their meaning. The main semantic types of Old Latvian compounds, which were analyzed in this study, are the determinative compounds, the possessive compounds, the verbal governing compounds, and the copulative compounds. Secondly, it is argued that the aforementioned types of compounds were clearly differentiated in terms of the formal properties of their components. A large number of possessive compounds and verbal governing compounds had the compositional suffix -is (m.)/-e (f.). By contrast, only a handful of determinative compounds had this suffix. In view of the distribution of the suffix found in the Old Latvian compounds, it is suggested that the suffix was originally restricted to adjectival compounds. Furthermore, the different types of compounds in Old Latvian were also distinguished in terms of the first component. In the majority of cases, both the possessive compounds and the verbal governing compounds were coined without linking elements, while the determinative compounds had linking elements to a larger extent. Thirdly, it is proposed in this thesis that a part of linking elements used in the determinative compounds in Old Latvian originated from the original stem vowels of the first components. Thus, it is argued that stem compounds were still attested in the Old Latvian texts, although this Baltic model of coining compounds is no longer visible in Modern Latvian. Lastly, it is suggested that the tendencies of compounding found in the texts under discussion represent dialectal differences.

    Another contribution of this study is that the Old Latvian compounds are not treated in isolation, but analyzed in drawing parallels with compounds in the other Baltic languages, Lithuanian in particular. Hence, by analyzing common features and similarities between the compounding systems, the Old Latvian compounds are positioned within the context of the Baltic system of compounding.