| 41. |
- Aden, Hassan
(författare)
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Building futures through Refugee Education: Aspirations, Navigation, and (Non- )citizenship
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This study explores how Somali secondary school and graduate-level youth in Kenya’s Dadaab camps attempt to build their futures through education, despite challenges posed by their non-citizen status. Using ethnographic data, the study specifically analyses the educational journeys, aspirations, and experiences of these refugee youth, shedding light on the everyday practices and dynamic strategies they employ to pursue their goals and manage obstacles. The study demonstrates how secondary school youth actively pursue educational aspirations, which they believe can enable them to exit the camps and potentially overcome their non-citizen status – through routes such as the resettlement-based scholarships for post-secondary education in Canada. Anchoring in their hopes in education, these students leverage various social resources, networks, and strategies to cope with challenges facing their education and aspirations, while simultaneously reflecting on various pathways to navigate post-graduation crossroads. Graduate-level youth, faced with limited opportunities, often adjust their aspirations to align with the available options to move forward, such as scholarships or incentive- (as opposed to wage-) paying jobs in the camps. More and more graduate youth opt to return to Somalia in seek of better employment opportunities, despite the potential security risks. The study also underscores the intergenerational solidarity and support system that emerge as academically successful refugee youth establish and manage nationally accredited schools, significantly contributing to students’ performance in national exams and the quality of education overall. By examining refugee youths’ enterprise of future-building through education within the context of long-term camps –characterised by perpetual precarity and uncertainty due to inhabitants’ exclusion from citizenship rights, freedoms, and advantages – this study provides theoretical insights into the complex and dynamic interplay among aspirations, navigational strategies, and non-citizenship status.
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| 42. |
- Adermark, Louise, 1974
(författare)
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Ethanol-mediated effects on astroglial cells in primary culture. With a focus on acute changes in intracellular Ca2+, cell volume, actin filaments, and gap junction coupling
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The astroglial cells are abundant in the central nervous system (CNS), where they control and regulate the homeostasis of the extracellular milieu. A change in astroglial cell volume, mediated through activation of neuroactive substances or changes in osmolarity, leads to changes in the size and geometry of the extracellular space volume, which could affect the diffusion and concentration of neuroactive substances. The astroglial cells are connected through gap junctions, which are small pores that allow bidirectional communication. The intercellular coupling through gap junctions has been suggested to allow the astroglial network to function as a unit, and to equalize the concentration of intracellular ions.To enable studies of signal transduction systems involved in astroglial cell swelling and volume regulation, we developed a new method for quantifying changes in cell volume at the single-cell level (Paper I). The method, which was based on optical sectioning in combination with image analysis, was used to study changes in astroglial cell volume mediated by ethanol (10 200 mM) in three dimensions (3D) over time (Papers II and IV). The method was proven to be capable of properly reconstructing and segmenting individual cells. Exposure for 5 min to 25 mM or 150 mM ethanol increased astroglial cell volume in 19% and 36% of analyzed cells, while cell shrinkage was detected in 22% and 35%, respectively (Paper IV). The ethanol-mediated volume changes were partially inhibited during incubation in low extracellular sodium ([Na+]o), during blockage of the Na+/K+/2Cl- cotransporter with furosemide, during blockage of the Na+/K+-adenosine triphosphatase (ATPase) with ouabain, or during blockage of the inward-rectifying potassium channels (K+IR) with BaCl2 (Paper IV). Exposure to ethanol-induced morphological changes and ethanol-mediated transformation in filamentous actin led to a more dispersed appearance of the filaments and an increased number of cells with actin in ring formations (Paper II). Ethanol decreased cell-to-cell communication through gap junctions in astroglial cultures from the cerebral cortex, brain stem, or hippocampus, while cultures from the olfactory bulb or hypothalamus remained unaffected (Paper III). The decrease was not seen during incubation in low [Na+]o, or during blockage with furosemide, and ethanol had no additional effect on the decrease in gap junction coupling mediated by ouabain (Paper III). The results presented in Papers II IV suggest that astroglial cells could be important targets during ethanol exposure, and that possible changes in cell volume and gap junction coupling could be of toxicological relevance.
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| 43. |
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| 44. |
- Adielsson, Anna, 1973
(författare)
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The epidemiology of cardiac arrest - In-hospital risk assessment, treatment and outcome
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- AIM: To describe and analyse sudden cardiac arrest, both in hospital and out of hospital, from an epidemiological perspective, by early prediction, by comparing changes over time in relation to aetiology, characteristics, treatment, survival or mortality and by identifying factors associated with outcome. METHODS: This thesis is based on four observational studies, including patient information from the Swedish Registry for Cardiopulmonary Resuscitation, in and out of hospital, and from a local registry on medical emergency team assessment at Sahlgrenska University Hospital. RESULTS: In Paper I, the 30-day survival after out-of-hospital cardiac arrest in Sweden among patients found in a shockable rhythm increased from 12% in 1992 to 23% in 2009. Strong predictors of survival were a short interval from collapse to defibrillation, bystander cardiopulmonary resuscitation (CPR), female gender and out-of-hospital cardiac arrest outside home. In Paper II, in Sahlgrenska University Hospital, the 30-day survival after an in-hospital cardiac arrest, on monitoring wards, increased significantly from 43.5% in 1994 to 55.6% in 2013. There was a significant reduction in the delay from collapse to the start of CPR and an increase in the proportion of patients defibrillated before the cardiac arrest team arrived. On the non-monitoring wards, there were no significant changes in survival; there was nonetheless a significant decrease in the proportion of patients found in shockable rhythms, from 46% in 1994 to 26% in 2013. In Paper III, adjusted trends indicated an overall increase in 30-day survival after in-hospital cardiac arrest in Sweden, from 24.7% in 2008 to 32.5% in 2018 (monitoring wards, 32.5% to 43.1%, and non-monitoring wards, 17.6% to 23.1%). The proportion of patients found in shockable rhythms decreased in overall terms from 31.6% in 2008 to 23.6% in 2018 (monitoring ward 42.5% to 35.8%, and non-monitoring wards, 20.1% to 12.9%). In Paper IV, the overall 30-day mortality among patients assessed by a medical emergency team in Sahlgrenska University Hospital was high (29.0%) and almost twice as high on medical wards as on surgical wards (37.1% vs 19.8%). Factors associated with increased 30-day mortality were reflected in age, type of ward, vital parameters, laboratory biomarkers, previous medical history and acute medical condition. CONCLUSIONS: Over the past few decades, the overall survival after a sudden cardiac arrest has increased, both in and out of hospital, despite a declining trend in the proportion of shockable cardiac arrests. Part of the reason appears to be a shorter delay from collapse to treatment. Several factors associated with an increased risk of dying of a sudden cardiac arrest have been identified and, if appropriately risk stratified and immediately treated, the fatal outcome may be averted.
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| 45. |
- Adler, Johan, 1970
(författare)
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Aspects of Macroeconomic Saving
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis deals with various aspects of macroeconomic saving. It consists of an introduction and four self-contained papers. Paper I, "From closed to open door policy: An empirical study of China's international capital mobility, 1958-98," is an empirical application of the open economy permanent income hypothesis (PIH). The purpose of this paper is to use the PIH to test and measure the degree of China's international capital mobility during the period 1958-98. In contrast to all previous known country studies using this framework, the hypothesis that capital has been at least mobile enough to allow for optimal consumption smoothing behavior is rejected. In this model, it appears that a country experiences suboptimally low capital mobility only when severe restrictions are placed on the capital account, as in the case of China. Partial barriers to international capital movements do not necessarily imply inability to smooth consumption optimally. Paper II, "The open economy excess sensitivity hypothesis: Theory and Swedish evidence," extends the theory of open economy consumption behavior by applying Flavin's (1993) excess sensitivity hypothesis (ESH) to the current account. The ESH can be interpreted as a generalization of the PIH that allows for any degree of international capital mobility. As such, the ESH can account for why the PIH fails and for the related puzzle of an "excessively volatile" current account. Furthermore, the ESH suggests an alternative approach for assessing a country's degree of international capital mobility. Using annual Swedish data for the period 1951-99, the empirical results imply that, in contrast to the PIH, the ESH cannot be rejected. The results suggest that Sweden's degree of international capital mobility is higher than the degree that is perfect according to the PIH. Paper III, "The PIH and the standard deviation ratio: A Monte Carlo Study," evaluates the coverage accuracy of small-sample confidence intervals for the standard deviation ratio summary statistic. This is the statistic that is used to test and measure the degree of international capital mobility in the PIH framework. Three methods are considered to construct the confidence intervals: the asymptotic delta method, Runkle's (1987) standard bootstrap method, and Kilian's (1998) bias-corrected bootstrap-after-bootstrap method. Monte Carlo simulations suggest that the asymptotic delta method is unreliable and that researchers should rather use bias-corrected bootstrap confidence intervals when making inference from the standard deviation ratio. Paper IV, "Has Sweden's government budget policy been too discretionary? Evidence from a generalization of the tax smoothing hypothesis," deals with the saving behavior of the government. Barro's (1979) tax smoothing hypothesis (TSH) assumes that the government is always subject to an "optimal" degree of discretion in budget policy, i.e., optimal in the sense that it minimizes the welfare costs from taxation. Paper IV proposes a generalization of the TSH that relaxes this crucial assumption. Postwar evidence for Sweden indicates that in contrast to the TSH, the generalized model provides close to a perfect fit: Tax smoothing behavior in combination with more discretion in budget policy relative to what is optimal, can explain all shifts in the central government's budget balance, including the dramatic shifts during the period 1970-96.
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| 46. |
- Adolfsson, Kerstin, 1988
(författare)
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Blaming victims of rape : Studies on rape myths and beliefs about rape
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Rape is a crime characterized by low reporting and conviction rates. Many victims who do report, drop out during the justice process. This is a problem both for the victims themselves and for the legal certainty of societies. One explanation for low reporting rates is victims’ justified fear of being badly treated, mistrusted, and blamed. Victim-blaming attitudes have been extensively studied and reported both among the general public and among professionals in the justice and healthcare systems. Several variables have been investigated to understand victim blaming, both aspects of the rape situation and variables connected to personal beliefs. However, previous studies have predominantly investigated only a few variables at a time. The aim of this thesis was partly to experimentally investigate whether situation-specific variables or participants’ personal beliefs are more important in seeking to understand blame attribution. Possible effects of age, gender, force, and number of perpetrators were also investigated. In addition, the aim was to include the perspective of professionals who meet, treat, and interact with rape victims. All three studies were conducted using a multi-analytical approach incorporating both analyses of variance (ANOVAs) as well as more elaborated and exploratory analyses. In Study I, the effects of victim and participant age, participant gender, sympathy for the victim, trust in the justice system, belief in a just world, and rape myth acceptance (RMA) were investigated in three experiments, employing a vignette methodology. In total, 877 Swedish adolescents and adults read scenarios describing common acquaintance rape situations. Victim age (18 or 31 years) was manipulated, but did not affect attributed blame. Effects of participant age and gender varied markedly across scenarios. Sympathy for the victim and RMA were the best individual predictors of attributed blame, indicating that blame attributions are more affected by personal beliefs than by situation-specific variables. Study II investigated effects of multiple perpetrators and their use of force on blame attributions, in two experiments. A total of 2928 participants read a vignette where number of perpetrators or perpetrators’ use of force was manipulated. Subsequently, they completed items rating blame, RMA, just-world beliefs, sympathy for the victim, perception of consent, and trust in the legal system. No effect of force was found, but the depicted victim of a multiple-perpetrator rape was attributed more blame than the victim of lone-perpetrator rape. The best individual predictors of attributed blame were participants’ perception of consent, sympathy for the victim, and RMA. In line with Study I, the results indicated that participants’ beliefs about rape were more predictive than situational factors. In Study III, the thesis was broadened by including the perspective of professionals encountering victims of rape. A total of 237 police employees, prosecutors, and healthcare personnel responded to a survey concerning barriers and problematic practices as well as questions regarding rape myths, belief in a just world, and trust in the justice system. Profession, age, and RMA affected their estimates of false rape reports, while age and profession affected trust in the justice system. Lack of resources was the most prominent barrier, and detailed and repeated questioning of the victims was the most highlighted problematic practice. The results further identified professionals’ need for more education in order to improve treatment of rape victims. In conclusion, this thesis indicates that personal beliefs are more predictive of blame attributions than are situational factors related to the rape itself. RMA, sympathy for the victim, and perception of consent were the most predictive variables of both victim and perpetrator blame. It also highlights the requirement for more resources and knowledge among professionals in both the justice and healthcare systems. This thesis has implications for future projects to prevent victim blame with the long-term goal of reducing attrition rates. It identifies what to focus on: reducing RMA, increasing sympathy for rape victims, and increasing awareness of the concept of sexual consent.
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| 47. |
- Adolfsson, Lisa, 1984
(författare)
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Role of mycorrhiza symbiosis and phosphorus nutrition in plant growth, photosynthesis and secondary metabolism
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Inorganic phosphorus (Pi) is an important and often limiting nutrient for plants. Large amounts of Pi fertilizers derived from non-renewable rock phosphorus, are used in agriculture. These are applied in excess but crops take up only a small amount of Pi; the residual Pi ends up in water systems where it causes problems with eutrophication. Plants can increase their Pi uptake efficiency by forming a symbiotic association between their roots and arbuscular mycorrhizal (AM) fungi. During symbiosis, AM fungi provide the host with Pi in return for carbohydrates synthesized in the leaf chloroplast through photosynthetic assimilation of CO2. For AM symbiosis to be a plausible tool in modern agriculture, the symbiotic interaction needs to be optimized for generating a positive growth response of the crop. To achieve this, knowledge about the signaling between the plant and the fungus is crucial. It is known that both Pi signalling and AM symbiosis are tightly connected to metabolic processes in the chloroplast. In response to Pi limitation, more sugars and starch accumulate in leaves, and transport of sucrose towards roots increases. AM symbiosis increases the flow of sucrose towards the root system and induces production of secondary metabolites, which is initiated in the chloroplast. An Arabidopsis thaliana mutant lacking the chloroplast-localized Pi transporter PHT4;1, was studied in Paper I to get a deeper understanding about the role of Pi supply in the chloroplast. The mutant displayed a reduced activity of the chloroplast ATP synthase due to Pi limitation, which resulted in less CO2 assimilation, decreased levels of sugars in the shoot, reduced leaf size and biomass. The influence of AM symbiosis and Pi fertilization on growth and chloroplast processes such as photosynthesis and secondary metabolism was studied in Medicago truncatula. In Paper II, it is shown that AM symbiosis and Pi fertilization stimulate the expansion of shoot branches and leaves, whereas AM symbiosis specifically increases the number of chloroplasts. The increased surface area of the shoot enables the plant to harvest more sunlight. These morphological alterations are attributed to an enhanced level of cytokinins in leaves of AM- and Pi-treated plants (Paper III). In Paper III, it is also shown that AM symbiosis and Pi fertilization induce largely different transcriptional and metabolic responses. AM-specific responses were increased expression of secondary metabolite genes, and enhanced production of flavonoids and the hormone abscisic acid (ABA). In conclusion, a model is proposed where a long distance signal in mycorrhized roots, derived from the enhanced carbon demand of the fungus, affects production of secondary metabolites in leaf chloroplasts. Validating this model will help to better understand the signaling between the plant and the fungus during AM symbiosis. This will allow the development of systems where AM symbiosis is used in agriculture for more efficient Pi uptake by crop plants.
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| 48. |
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| 49. |
- Adolfsson, Tobias, 1970
(författare)
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Statistical Methods for Designed Experiments and Spectroscopic Data
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis consists of six papers related to saturated orthogonal designs, spectroscopic and high dimension data analysis. The first two papers deals with testing procedures for saturated orthogonal designs. Both the presented methods controls the multiple level of significance. In paper C a regression method is constructed for both multivariate and univariate situations. The correctness of the subspace of regression can be tested using the multiple testing technique constructed in paper A. Paper D gives a method for testing the chemical rank of spectroscopic data. In paper E the effectiveness of high-dimension data gathered in a random way is examined and compared to an optimality criteria. Paper F deals with partial least squares and cross validation. The paper explores, and partly explains, some of the strange behaviour of partial least squares. 2000 Mathematical subject classification: 62F03, 62F25, 62H25, 62J05, 62K15
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| 50. |
- Adouane, Wafia, 1985
(författare)
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Natural Language Processing for Low-resourced Code-switched Colloquial Languages – The Case of Algerian Language
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis we explore to what extent deep neural networks (DNNs), trained end-to-end, can be used to perform natural language processing tasks for code-switched colloquial languages lacking both large automated data and processing tools, for instance tokenisers, morpho-syntactic and semantic parsers, etc. We opt for an end-to-end learning approach because this kind of data is hard to control due to its high orthographic and linguistic variability. This variability makes it unrealistic to either find a dataset that exhaustively covers all the possible cases that could be used to devise processing tools or to build equivalent rule-based tools from the bottom up. Moreover, all our models are language-independent and do not require access to additional resources, hence we hope that they will be used with other languages or language varieties with similar settings. We deal with the case of user-generated textual data written in Algerian language as naturally produced in social media. We experiment with five natural language processing tasks, namely Code-switch Detection, Semantic Textual Similarity, Spelling Normalisation and Correction, Sentiment Analysis, and Named Entity Recognition. For each task, we created a dataset from user-generated data reflecting the real use of the language. Our experimental results in various setups indicate that end-to-end DNNs combined with character-level representation of the data are promising. Further experiments with advanced models, such as Transformer-based models, could lead to even better results. Completely solving the challenge of code-switched colloquial languages is beyond the scope of this experimental work. Even so, we believe that this work will extend the utility of DNNs trained end-to-end to low-resource settings. Furthermore, the results of our experiments can be used as a baseline for future research.
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