| 1. |
- Ilskog, Elisabeth, 1965-
(författare)
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And Then They Lived Sustainably Ever After? : Experiences from Rural Electrification in Tanzania, Zambia and Kenya
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Accelerating the introduction of basic, clean energy services is seen as a key strategy for promoting sustainable development in rural areas. Still, many people worldwide lack access to modern energy such as electricity, and Africa lags behind other developing regions of the world. Support to rural electrification is therefore given high priority by the national governments and donor organisations. There is a trend to encourage the involvement of other actors than national utilities for implementation of rural electrification. At the same time, it is required that the activities shall contribute to sustainable development. The objective of the work presented in this thesis has been to reach increased knowledge on the impact from organisational factors on project sustainability, and to examine whether rural electrification implemented by private entrepreneurs or other non-governmental organisations contribute more effectively to sustainable development than the conventional approach where rural electrification is the responsibility of a government utility. A key activity of the research work has been to improve and develop the present methodologies used for evaluations, as to attain a more functional in-field evaluation method. The thesis presents findings from seven rural electrification cases in Eastern and Southern Africa and shows how these can be used to illustrate different dimensions of sustainability by means of indicators. The evaluation indicates that the national utilities perform better from a social/ethical perspective, whereas the private organisations and the community-based organisations manage their client-relation issues in a more sustainable way. In addition, a literature survey shows that among stakeholders there are a number of “concepts-taken-for-granted” as regards to rural electrification. These are not supported by the findings from the seven cases. The observed deviations between expectations and realities can obstruct the development as decision-makers may have unrealistic expectations when planning for new electrification activities. Instead, activities have to be implemented with the empirical reality in mind. By doing so the ambiguities, complexities and all the paradoxes of rural electrification can hopefully be better managed. The study has been funded by The Swedish International Development Agency, Department for Research Cooperation (SAREC), and Ångpanneföreningen’s Foundation for Research and Development (ÅFORSK).
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| 2. |
- Larsson, Jennie K, 1972-
(författare)
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Integrationen och arbetets marknad : Hur jämställdhet, arbete och annat "svenskt" görs av arbetsförmedlare och privata aktörer
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Avhandlingen belyser vad som hänt i svensk integrationspolitik sedan etableringsreformen genomfördes 2010 och ansvaret för flyktingmottagandet överfördes till Arbetsförmedlingen. Utöver förändringen som Arbetsförmedlingens ansvar innebar medförde reformen också ökad marknadsorientering, införande av valfrihetssystem, villkorad aktiveringspolitik samt andra genomgripande organisatoriska förändringar.I fokus står aktörer som på olika sätt har makt att påverka hur integrationspolitiken görs i praktiken. Studien analyserar vad som händer när privata företag bedriver arbetsförmedlande verksamheter där ersättningen kopplas till uppnådda resultat. Vidare analyseras betydelsen av ”svenskhet” i görandet av integrationspolitik.Avhandlingen är etnografisk och det empiriska materialet består av intervjuer och observationer med individer som arbetar på arbetsförmedlingskontor, som etableringslotsar samt samhällskommunikatörer på utbildningsföretag.Genom att syntetisera teorier om gatubyråkratier med en intersektionell ansats visar avhandlingen att görandet av integrationspolitik också är ett görande av ojämlikheter som grundas i stereotypa bilder av ”svenskhet” och ”invandrarskap”. Studien visar vidare hur föreställningen om Sverige som jämställd nation påverkar hur politiken görs. I analysen framkommer att de strategier som arbetsförmedlarna utvecklar för att hantera de krav som ställs på dem, i form av aktivering och resultat, inte leder till att de nyanlända kommer närmare arbetsmarknaden. Studien visar även att privata företag prioriterar resultat, lönsamhet och satsar på de nyanlända som de lättast kan nå resultat med.
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| 3. |
- Larsson, Pär, 1900-
(författare)
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The genetic composition and diversity of Francisella tularensis
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Francisella tularensis is the causative agent of the debilitating, sometimes fatal zoonotic disease tularemia. To date, little information has been available on the genetic makeup of this pathogen, its evolution, and the genetic differences which characterize subspecific lineages. These are the main areas addressed in this thesis.The work indicated a high degree of genetic conservation of F. tularensis, both on the sequence level as determined by sequencing and on the compositional level, determined by array-based comparative genomic hybridizations (aCGH). One striking finding was that subsp. mediasiatica was most similar to subsp. tularensis, despite their natural confinement to Central Asia and North America, respectively. All genetic Regions of Difference RD found by aCGH distinguishing lineages were had resulted from repeat-mediated excision of DNA. This was used to identify additional RDs. Such data along with a multiple locus sequence analysis suggested an evolutionary scenario for F. tularensis. Based on genomic information, a novel typing scheme for F. tularensis was furthermore devised and evaluated. This method provided increased robustness compared to previously used methods for F. tularensis typing, while retaining a capacity for high resolution.Finally, the genomic sequence of the highly virulent F. tularensis strain SCHU S4 was determined and analysed. Evidenced by numerous pseudogenes and disrupted metabolic pathways, the bacterium appears to be undergoing a genome reduction process whereby a large proportion of the genetic capacity gradually is lost. It is likely that F. tularensis has irreversibly has evolved into an obligate host-dependent bacterium, incapable of a free-living existence. Unexpectedly, the bacterium was found to be devoid of common virulence mechanisms such as classic toxins, or type III and IV secretion systems. Instead, the virulence of this bacterium is probably largely the result of specific and unusual mechanisms.
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| 4. |
- Molnar, Anna
(författare)
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Structure and Function of the Retina in Children Born Extremely Preterm and in Children Born At Term
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Optical coherence tomography (OCT), multifocal electroretinography (mfERG) and full-field electroretinography (ffERG) give important information about retinal structure and function.Purpose: To collect normative data of macular Cirrus Spectral domain (SD)-OCT assessments and of mfERG measurements of healthy children (papers I and II). To assess the macular thickness with Cirrus SD-OCT and the retinal function with ffERG in 6.5-year-old children born extremely preterm and in children born at term (papers III and IV).Methods: Study participants aged 5-15 years and living in Uppsala County were randomly chosen from the Swedish Birth Register (papers I and II). In papers III and IV, the study participants consisted of children born extremely preterm and children born at term – all were aged 6.5 years. In paper III, the children were living in Stockholm and Uppsala health care regions and, in paper IV, in Uppsala health care region only. Macular thickness was assessed with Cirrus SD-OCT and macular function with mfERG, using the Espion Multifocal system and DTL-electrodes. The retinal function was assessed with ffERG and DTL-electrodes, using the Espion Ganzfield system.Results: Altogether, 58 children participated in paper I and 49 children in paper II. In paper I, the repeatability and reproducibility of the OCT assessments were good. In paper II, the results of the mfERG measurements were in accordance with retinal cone density and there were no significant differences between the right and left eyes. In paper III, 134 preterm children and 145 children born at term constituted the study population. The central macular thickness was significantly thicker in the preterm group than in the control group. Within the preterm group, gestational age (GA), former retinopathy of prematurity (ROP) and male gender were all important risk factors for an increased macular thickness. In paper IV, 52 preterm children and 45 control children constituted the study population. Significantly lower amplitudes and prolonged implicit times of the combined rod and cone responses, as well as of the isolated cone responses, were found in the preterm group when compared with the control group. In paper IV, there was no association between GA, ROP or male gender and the ffERG assessments.Conclusion: Normative data of Cirrus SD-OCT and mfERG assessments were reported. The results of the assessments were reliable. Children aged 6.5 years, born extremely preterm, had a significantly thicker central macula and both rod and cone function were significantly reduced in comparison to children born at term. ROP had an influence on retinal structure but not retinal function in the present cohorts. Our results suggest that retinal development is abnormal in children born extremely preterm. Long-term follow-up studies are necessary in order to evaluate the functional ophthalmological outcome in this vulnerable population of children growing up today.
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| 5. |
- Nylander, Ruta
(författare)
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Magnetic resonance imaging markers of cerebral small vessel disease in an elderly population – association with cardiovascular disease and cognitive function
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cerebral small vessel disease (SVD) is identifiable by clinical, neuroimaging, neuropathological and cognitive findings.The aim of this thesis was to assess SVD and cerebral perfusion on magnetic resonance imaging (MRI) in a 75-year-old population and compare the findings with scars of myocardial infarctions, cardiovascular risk markers and cognitive function. In addition, the evolution of SVD over 5 years was studied.The study population included subjects from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study. The subjects had been chosen in a randomized manner from the register of the municipality. MRI of the brain and the heart, cognitive tests and blood tests for cardiovascular risk factors were performed in 406 subjects at age 75 years and 250 of them were re-examined 5 years later at the age of 80.Paper 1 showed that unrecognized myocardial infarctions (UMIs) were found in 120 subjects (30%) and recognized myocardial infarctions (RMIs) in 21 (5%). Men with RMIs displayed an increased prevalence of cortical and lacunar cerebral infarctions, whereas women with UMIs more frequently had cortical cerebral infarctions.Paper 2 showed that one or more brain infarcts were seen in 23% of the subjects (20% had only lacunar infarcts, 1% had only cortical infarcts and 2% had both). Hypertension and obesity were significantly associated with an increased risk of infarction. The newer risk markers investigated were not significantly associated with brain infarcts.Paper 3 showed that MRI manifestations of SVD progressed over 5 years. Relative cerebral blood flow (rCBF) was not associated with WMH volume or progression of WMH volume.Paper 4 showed that moderate to severe WMHs and incident lacunar infarcts on brain MRI were associated with a mild impairment of executive function.In conclusion, this longitudinal population based study compares MRI manifestations of SVD with clinical data, providing knowledge that may be used in further investigations of preventive interventions and for identification of disease in early stages.
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| 6. |
- Sundelin, Heléne E.K. 1965-
(författare)
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Comorbidity and complications in neurological diseases
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Neurological diseases are complex and many share etiology as well as comorbidities. Epilepsy, a brain disorder characterized by an enduring predisposition to generate epileptic seizures and autism spectrum disorder (ASD), are considered to be associated, but the connection is still not fully uncovered. Cerebral palsy (CP), a lifelong, nonspecific, non-progressive disorder of posture and movement control, and Ehlers-Danlos Syndrome (EDS), a connective tissue disorder, both have many consequences for health and wellbeing throughout life.Aims: The aim of this thesis was to explore the impact of comorbidity and complications in neurological diseases and EDS. The objective was to gain information on the nature of the connection between epilepsy and ASD, if EDS, ASD and CP have consequences for pregnancy outcome, and the risk of traffic accidents in individuals with epilepsy.Materials and methods: The studies are all historical observational population- based cohort studies with prospectively collected data from national registers. The risk of ASD was analysed in 85,201 individuals with epilepsy and compared with 425,760 controls as well as for their firstdegree relatives. In a cohort of 1,248,178 singleton births, 314 births to women with EDS, 2,072 births to women with ASD, and 770 births to women with CP, pregnancy outcome was explored. The risk of traffic accidents was estimated in 29,220 individuals with epilepsy and 267,637 matched controls.Results: There is an increased risk of; ASD in individuals with epilepsy and their relatives, moderately preterm birth and pre-eclampsia in maternal ASD, of preterm birth in maternal CP and transport accidents in individuals with epilepsy. There is no increased risk of adverse pregnancy outcome in women with EDS.Conclusions: This thesis found proofs of a bidirectional association between epilepsy and ASD, that ASD and CP have consequences for pregnancy outcome and epilepsy is a risk factor for traffic accidents.
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| 7. |
- Söderström, Elisabet, 1975-
(författare)
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Homocysteine and its determinants in relation to cardiovascular risk factors and myocardial infarction
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Globally, cardiovascular diseases (CVD), including myocardial infarction (MI) and stroke, are the leading cause of illness and death and constitute a significant part of the disease burden in Sweden and Western Europe. Age, hypertension, smoking, obesity, dyslipoproteinemia, diabetes, and impaired renal function are considered established risk factors for CVD. However, these factors do not explain all MI cases, and much is still unknown. Homocysteine is a sulfur-containing amino acid used in clinical practice as a biomarker of functional vitamin B12 and folate status. Earlier observational studies have shown associations with higher plasma homocysteine concentrations (tHcy) and CVD. The causal relationship between tHcy and MI has been debated as homocysteine-lowering prevention studies have not shown a protective effect on MI, although there may be a protective effect on ischemic stroke. Still, tHcy is a prognostic biomarker or risk determinant of MI. There is a need for more knowledge on the pathophysiologic mechanisms of how homocysteine interacts with its determinants, and other risk factors, on the risk of MI.Aims: The overall aim of the thesis was to expand knowledge about how homocysteine, as a risk determinant, can have an impact on cardiovascular disease. Specifically, the purposes were to explore the associations between tHcy, determinants of homocysteine and risk factors of CVD, and the associated risk of prospectively developing a first-ever MI.Material and methods: In papers I, III, and IV, a prospective incident nested case-referent study design was used with 545 cases of MI and 1054 matched referents. In paper II the design was cross-sectional, comparing strictly defined smokers and snus users. All study subjects emanated from the Northern Sweden Health and Disease Study (NSHDS). Blood samples stored frozen at -80ºC were later thawed, and analyses of biomarkers for renal function, lipids, B-vitamins, tHcy, cotinine, and genetic polymorphisms related to homocysteine metabolism were performed. Results: In a prospective setting, folate, but not tHcy, was positively associated with apolipoprotein A1 (Apo A1). The association was seen among referents and not among those later developing an MI. Among strictly defined smokers and snus users, cotinine was positively associated with tHcy among smokers but not among snus users, despite higher cotinine concentrations in snus users. No association was observed between tHcy and the number of cigarettes/day.The CTH G1208T and MTHFR A1298C polymorphisms were, among women, associated with a higher risk of developing a first-ever MI with a fatal outcome. No such associations were seen among men or all MI patients. Further, no associations were seen between the MTHFR C677T polymorphism and the risk of having an MI, fatal or non-fatal. Mild impairment of renal glomerular function defined by eGFRcystatin C /eGFRcreatinine ratio and the associated risk of MI is previously not studied prospectively. In the present study, a lower eGFRcystatin C/eGFRcreatinine ratio was associated with a higher risk of later developing a first-ever MI among women, both when analyzed as a continuous variable and across the quartiles of the ratio. These associations did not appear among men.Conclusions: The independent association of folate but not tHcy with Apo A1 emphasizes the need to adjust for possible confounding effects in studies on homocysteine and endpoints or biomarkers. The results suggest a possible link between one-carbon metabolism and lipid metabolism. The independent association between cotinine and tHcy in smokers and not among snus users indicate that nicotine per se may not mediate higher tHcy concentrations. Cotinine concentrations in plasma appeared as a better predictor of tHcy than self-reported smoking data. Thus, whenever possible, self-reported smoking should be supplemented by biomarkers, such as cotinine, in epidemiological studies. After outcome stratification, fatal or non-fatal MI, the associated higher risk among women of a fatal MI and CTH G1208T and MTHFR A1298C polymorphisms, respectively, may indicate that women with the minor alleles risk having a more serious MI leading to death than women with the wild-type alleles. In a prospective setting, the eGFRcystatin C/eGFR creatinine ratio was associated with an increased risk of later developing a first-ever MI among women. The eGFRcystatin C/eGFRcreatinine ratio may be a tool, easily implemented at clinical laboratories, for evaluating the risk of having a future first-ever MI.
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| 8. |
- Tumula V. K., Chaitanya, 1982-
(författare)
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HARQ Systems: Resource Allocation, Feedback Error Protection, and Bits-to-Symbol Mappings
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Reliability of data transmission is a fundamental problem in wireless communications. Fading in wireless channels causes the signal strength to vary at the receiver and this results in loss of data packets. To improve the reliability, automatic repeat request (ARQ) schemes were introduced. However these ARQ schemes suffer from a reduction in the throughput. To address the throughput reduction, conventional ARQ schemes were combined with forward error correction (FEC) schemes to develop hybrid-ARQ (HARQ) schemes. For improving the reliability of data transmission, HARQ schemes are included in the present wireless standards like LTE, LTE-Advanced and WiMAX.Conventional HARQ systems use the same transmission power and the same number of channel uses in different ARQ rounds. However this is not optimal in terms of minimizing the average transmit power or the average energy spent for successful transmission of a data packet. We address this issue in the first part of the dissertation, where we consider optimal resource allocation in HARQ systems with a limit on the maximum number of allowed transmissions for a data packet. Specifically, we consider the problem of minimizing the packet drop probability (PDP) under an average transmit power constraint or equivalently minimizing the average transmit power under a fixed PDP constraint. We consider both incremental redundancy (IR)-based and Chase combining (CC)-based HARQ systems in our work. For an IR-HARQ system, for the special case of two allowed transmissions for each packet, we provide a solution for the optimal number of channel uses and the optimal power to be used in each ARQ round. For a CC-HARQ system, we solve the problem of optimal power allocation in i.i.d. Rayleigh fading channels as well as correlated Rayleigh fading channels. For the CC-HARQ case, we also provide a low complexity geometric programming (GP) solution using an approximation of the outage probability expression.HARQ systems conventionally use one bit acknowledgement (ACK)/negative ACK (NACK) feedback from the receiver to the transmitter. In the 3GPP-LTE systems, one method for sending these HARQ acknowledgement bits is to jointly code them with the other control signaling information using a specified Reed-Muller code consisting of 20 coded bits. Even though the resources used for sending this control signaling information can inherently provide a diversity gain, the Reed-Muller code with such a short block size is not good at extracting all of the available diversity. To address this issue, in the second part of this dissertation, we propose two new methods: i) based on complex-field coding (CFC), and ii) using repetition across frequency bands, to extract the inherent diversity available in the channel resources and improve the error protection for the HARQ acknowledgement bits along with the other control signaling information. In the second part of the dissertation, we also propose a new signal space diversity (SSD) scheme, which results in transmit signals having constant envelope (CE). The proposed CE-SSD scheme results in a better overall power efficiency due to the reduced back-off requirements on the radio frequency power amplifier. Moreover, the proposed CE-SSD technique can be useful for application scenarios involving transmission of small number of information bits, such as in the case of control signaling information transmission.In conventional HARQ systems, during the retransmission phase, the channel resources are exclusively used for the retransmitted data packet. This is not optimal in terms of efficient resource utilization. For efficient utilization of channel resources during the retransmissions, a superposition coding (SPC) based HARQ scheme was proposed in the literature. In an SPC based HARQ system, an erroneous packet is transmitted together with a new data packet by superposition in the Euclidean space. In the final part of this dissertation, we study performance of different bits-to-symbol mappings for such an SPC based HARQ system.
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