| 1. |
- Hagström, Peter, 1967-
(författare)
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Biomass Potential for Heat, Electricity and Vehicle Fuel in Sweden
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main objective of this thesis was to determine how far a biomass quantity, equal to the potential produced within the Swedish borders, could cover the present energy needs inSwedenwith respect to economic and ecological circumstances. Three scenarios were studied where the available biomass was converted to heat, electricity and vehicle fuel. Three different amounts of biomass supply were studied for each scenario: 1) potential biomass amounts derived from forestry, non-forest land, forest industry and community; 2) the same amounts as in Case 1, plus the potential biomass amounts derived from agriculture; 3) the same amounts as in Case 1, plus 50% of the potential pulpwood quantity.For evaluating the economic and ecological circumstances of using biomass in the Swedish energy system, the scenarios were complemented with energy, cost and emergy analysis.The scenarios indicated that it may be possible to produce 170.2 PJ (47.3 TWh) per year of electricity from the biomass amounts in Case 2. From the same amount of biomass, the maximum annual production of hydrogen was 241.5 PJ (67.1 TWh) per year or 197.2 PJ (54.8 TWh) per year of methanol.The energy analysis showed that the ratio of energy output to energy input for large-scale applications ranged from 1.9 at electric power generation by gasification of straw to 40 at district heating generation by combustion of recovered wood. The cost of electricity at gasification ranged from 7.95 to 22.58 €/GJ. The cost of vehicle work generated by using hydrogen produced from forestry biomass in novel fuel cells was economically competitive compared to today’s propulsion systems. However, the cost of vehicle work generated by using methanol produced from forestry biomass in combustion engines was rather higher compared to use of petrol in petrol engines.The emergy analysis indicated that the only biomass assortment studied with a larger emergy flow from the local environment, in relation to the emergy flow invested from society after conversion, was fuel wood from non-forest land. However, even use of this biomass assortment for production of heat, electricity or vehicle fuels had smaller yields of emergy output in relation to emergy invested from society compared to alternative conversion processes; thus, the net contribution of emergy generated to the economy was smaller compared to these alternative conversion processes.
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| 2. |
- Moen, Janne, 1980-
(författare)
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Multiple Medicine Use : Patients’ and general practitioners’ perceptions and patterns of use in relation to age and other patient characteristics
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There are widespread concerns about the increasing use of multiple medicines. The aims of this thesis were to identify older patients' and general practitioners' (GPs) attitudes to and experiences of multiple medicine use, as well as to describe patterns of multiple medicine use in different age groups in association with patient-related factors. An additional aim was to contribute to scientific methodological development by providing an empirical example of the application of the Lehoux, Poland, & Daudelin template for the analysis of interaction in focus groups. Data were collected via qualitative focus group discussions and from a cross-sectional community-based population survey conducted during 2001-2005. The patients revealed co-existing accounts of both immediate gratitude that medicines exist and problems with using multiple medicines such as worrying whether multiple medicine use is 'good' for the body. The patient-doctor relationship coloured their attitudes towards their treatment and care. The GPs at times felt insecure, though surrounded by treatment guidelines. Lack of communication with hospital specialists was perceived to reduce treatment quality, while influence of patient pressure was thought to contribute to the development of multiple medicine use. An interaction analysis helped in appreciating and clarifying the contexts in which results from the content analysis were created. Further discussion is needed on how to best report these results. Different cut-offs are useful in defining multiple medicine use in different age groups. Vast majorities of users of multiple medicines were found to have unique medicine combinations. Multiple medicine use was found to be associated with morbidity and poor self-rated health across all age groups.
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| 3. |
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| 4. |
- Hammarsten, Peter, 1977-
(författare)
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Androgen controlled regulatory systems in prostate cancer : potential new therapeutic targets and prognostic markers
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- BACKGROUND: Prostate cancer is by far the most common cancer among Swedish men. Some patients have an aggressive lethal disease, but the majority of affected men have long expected survival. Unfortunately, the diagnostic tools available are insufficient in predicting disease aggressiveness. Novel prognostic markers are therefore urgently needed. Furthermore, metastatic prostate cancer is generally treated with castration, but the long-term effects are insufficient. Additional studies are therefore needed to explore how the effects of this therapy can be enhanced. Prostate growth and regression is beside testosterone controlled by locally produced regulators. Vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) are two of the major regulators in the normal prostate and in prostate tumours. MATERIALS AND METHODS: VEGF and EGFR were explored in the prostate, by treating rats with either anti-VEGF or anti-EGFR treatment during castration and testosterone-stimulated prostate growth. Rats with implanted androgen-independent prostate tumours were treated with an inhibitor of both VEGF receptor-2 (VEGFR-2) and EGFR. Stereological techniques, immunohistochemistry, western blotting and quantitative real-time PCR were used to evaluate these experiments. Furthermore, prostate tissue from untreated prostate cancer patients was used to retrospectively explore the expression of phosphorylated-EGFR (pEGFR) in relation to outcome. RESULTS: Anti-VEGF treatment during testosterone-stimulated prostate growth, inhibited vascular and prostate growth. Anti-EGFR treatment during castration and testosterone-stimulated prostate growth resulted in enhanced castration effects and inhibited prostate growth. Anti-vascular treatment of androgen-independent prostate cancer with an inhibitor of VEGFR-2 and EGFR, that targets the normal and tumour vasculature, enhanced the effects of castration. Low immunoreactivity for pEGFR in prostate epithelial cells, both in the tumour and also in the surrounding non-malignant tissue, was associated with good prognosis. CONCLUSIONS: Anti-vascular treatment, with an inhibitor of VEGFR-2 and EGFR, in combination with castration could be an effective way to treat androgen-insensitive prostate tumours. VEGF and EGFR signalling are necessary components in testosterone-stimulated prostate growth. Phosphorylation of EGFR could be a useful prognostic marker for prostate cancer patients. Tumours may affect the surrounding non-malignant tissue and pEGFR immunoreactivity in the morphologically normal prostate tissue can be used to retrieve prognostic information.
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| 5. |
- Lepp, Håkan, 1977-
(författare)
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Experimental studies of proton translocation reactions in biological systems : Electrogenic events in heme-copper oxidases
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Terminal heme-copper oxidases (HCuOs) are transmembrane proteins that catalyze the final step in the respiratory chain - the reduction of O2 to H2O, coupled to energy conservation by generation of an electrochemical proton gradient. The most extensively investigated of the HCuOs are the aa3-type oxidases, to which cytochrome c oxidase (CytcO) belongs, which uses energy released in the O2-reduction for proton pumping. The bacterial nitric oxide reductases (NORs) have been identified as divergent members of the HCuO-superfamily and are involved in the denitrification pathway where they catalyze the reduction of NO to NO2. Although as exergonic as O2-reduction, this reaction is completely non-electrogenic. Among the traditional HCuOs, the cbb3-type oxidases are the closest relatives to the NORs and as such provide a link between the aa3 oxidases and the NORs. The cbb3 oxidases have been shown to pump protons with nearly the same efficiency as the aa3 oxidases, despite low sequence similarity.This thesis is focused on measurements of membrane potential generating reactions during catalysis in the CytcO and the cbb3 oxidase from Rhodobacter sphaeroides, and the NOR from Paracoccus denitrificans, using a time resolved electrometric technique. The pH dependence of the membrane potential generation in CytcO showed that only one proton is taken up and that no protons are pumped, at high pH. An additional kinetic phase was also detected at high pH that presumably originates to from charge-transfer within the K-pathway. Possible reasons for uncoupling, and the extent of charge-transfer, were studied using structural variants of CytcO. The measurements established that electrons and protons are taken up from the same side of the membrane in NOR. In addition, the directionality for proton uptake in cbb3 oxidase appeared to be dependent on the choice of substrate while proton pumping was indicated to occur only during O2-reduction.
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| 6. |
- Nilsson, Malin, 1973-
(författare)
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Att förklara människan : Diskurser i populärvetenskapliga TV-program
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The principle aim of the study is to describe, analyze and problemize the ways in which television science documentaries (within a public service context) discursively represent scientific theories, research results and conclusions about the origins of human nature and the causes of human behavior. The study covers 25 programs broadcasted by SVT and UR during a period of four years,2002-2005 , and 12 additional programs are used as a basis for discussion. Most of the programs included in the study are productions purchased mainly from BBC Science. Thus, managing editors, producers and presenters were interviewed for the purpose of illuminating quality judgements and purchasing criteria. A five stage-model of critical discourse analysis has inspired the method which emphasizes the network of communicative practices in which the media text and representation are embedded. That includes media genre, production and narrative conventions as well as the wider historical, social and political/ideological context and discourse practices of which the issues represented are a part. The critical discourse analysis has been complemented by ideas about different documentary modes of representation or basic ways of organizing documentary texts in relation to certain recurrent features or conventions. In the analysis these modes have been applied to understand the degree of transparency and editorial presence and visibility in the science documentaries. The importance of the discourses presented is related to their more applied meanings. When certain descriptions, explanations and understandings of alleged human “basics” gain priority, it may affect the possibilities to define and handle very concrete social issues in a way that is inconsistent with this fundamental perspective. Thus, the ideological function of the science documentaries (as public service-program and educational media) deserves serious attention.
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| 7. |
- Nilsson, Markus, 1977-
(författare)
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Retrieve and Classify
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Diagnoshjälp för läkareMarkus Nilsson har vid Institutionen för Datavetenskap och Elektronik (IDE) forskat fram ett beslutsstödssytem för kliniker, läkare och psykologer. Systemet använder sig av artificiell intelligens (AI) för att resonera sig fram till nya diagnoser och tolkningar av mätvärden med hjälp av tidigare erfarenheter och kunskap. Systemet fungerar som en nyutexaminerad läkare, det lär och förbättrar sig av sin erfarenhet. Ju mer det används, desto mer lär den sig, desto bättre blir den på att ställa diagnoser. Systemet har vid uppstarten samma kunskapsnivå som en ledande expert inom ämnet psykofysiologisk medicin. Expertens kunskap har lärts in av systemet under översyn. Därefter blir varje individuellt system unikt beroende på sina erfarenheter.Psykofysiologi är interaktionen mellan de psykologiska och fysiologiska aspekterna i kroppen. Hjärnan, hjärtat, lungorna och magen är sammankopplade genom Vagusnerven. Stressrelaterade problem så som utbrändhet kan ofta upptäckas och även förhindras om man analyserar interaktionen mellan dessa delar av kroppen. En viktig faktor är respiratorisk sinus arrhytmi (RSA). RSA är andningens påverkan på hjärtfrekvensen, pulsen. En andning hos en normal och frisk människa påverkar hjärtat på sådant sätt att pulsen ökar vid inandning, och vid en utandning minskar pulsen igen. En lugn och fin våg av hjärtfrekvensen bildas, en sinusvåg. Vissa psykiska eller fysiologiska dysfunktioner kan störa denna interaktion och det är just dessa som är intressanta vid stressprevention och behandling.AI är en del inom datavetenskapen och sägs ofta vara en blandning av psykologi, biologi, filosofi, matematik och lingvistik. Det finns många inriktningar inom AI. Markus har valt att inrikta sig på en paradigm baserad från psykologin som säger att människor resonerar fram nya lösningar från tidigare explicita händelser med hjälp av inlärd kunskap. Man ställer sig frågan, hur gjorde jag när jag senast ställdes inför det här problemet?, och hur löste jag det?Paradigmen som Markus arbetar efter kallas case-based reasoning (CBR). CBR har en dynamisk minnesarktitektur där ny kunskap kan läggas till, tas bort eller ändras lokalt. Hela minnet behöver inte påverkas när kunskapen förändras.
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| 8. |
- Nilsson, Peter, 1979-
(författare)
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Essays on Social Interactions and the Long-term Effects of Early-Life Conditions
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis consists of four self-contained essays. Essay 1: From the late 1970s through mid 1990s blood-lead levels decreased drastically in Swedish children due to the sharp phase-out of leaded gasoline. Exploiting the distinct geographical variation in early childhood lead exposure induced by the regulations together with micro data on all children in nine birth cohorts I show that reduced lead exposure early in life improves scholastic performance, cognitive ability, and labor market outcomes among young adults. At the relatively low levels of exposure considered, the analysis reveals a nonlinear relationship between local air lead levels in early childhood and adult outcomes, indicating the existence of a threshold below which further reductions no longer improve adult outcomes. Importantly, the effect is greater for children of lower socioeconomic status (SES), suggesting that pollution is one mechanism through which SES affects long-term economic outcomes and that environmental policies could potentially reduce the intergenerational correlation in economic outcomes. Essay 2: During a policy experiment in two Swedish regions in 1967 alcohol availability increased sharply, particularly for people under age 21. The policy experiment was abruptly ended after only 8.5 months due to a sharp increase in alcohol consumption. I exploit the distinct temporal, spatial and age-specific changes in alcohol availability induced by the policy shift to estimate the long-term effects on those in utero during it. I find that children in utero during the short period of increased alcohol availability have significantly lower educational attainments, earnings and increased welfare dependency rates at age 30 in comparison with the surrounding cohorts. Any direct effects of the increased availability on birth-cohort composition (e.g. through an increase in unplanned pregnancies) are not driving the results as the richness of the data allows for a focus on exposed children conceived before the policy experiment started. The results provide compelling evidence that investments in early-life health can yield large effects on outcomes later on in life. Essay 3: We utilize a large-scale randomized social experiment to identify how co-workers affect each other’s effort as measured by work absence. The experiment altered the work absence incentives for half of all employees living in Göteborg, Sweden. Using administrative data we are able to recover the treatment status of all workers in more than 3,000 workplaces. We first document that employees in workplaces with a high proportion treated co-workers increase their own absence level significantly. We then examine the heterogeneity of the treatment effect in order to explore what mechanisms are underlying the peer effect. While a strong effect of having a high proportion of treated co-workers is found for the non-treated workers, no significant effects are found for the treated workers. These results suggest that pure altruistic social preferences can be ruled out as the main motivator for the behaviour of a non-negligible proportion of the employees in our sample. Essay 4: We examine the influence that co-workers’ childbearing has on each other’s fertility decisions. Using linked-employer employee panel data for Sweden we show that female individual fertility increases with on average 10% if a co-worker had a child within the previous 13-24 months. The timing of births among co-workers of the same sex, educational level and co-workers who are close in age is even more influential. Consistent with models of social learning we find that the peer effect for first time mothers is similar irrespective of the birth order of the co-worker’s child, while for higher order births within-parity peer effects are strong but cross-parity peer effects are entirely absent. A causal interpretation of our estimates is strengthened by several falsification test showing that neither unobserved common shocks at the workplace level, nor sorting of workers between workplaces are likely to explain the observed peer effect. We also provide evidence suggesting that peers not only affect timing of births but potentially also completed fertility, and that fertility peer influences spills-over across multiple networks. Our results suggest that social interactions could be an important factor behind the strong inter-temporal fluctuations in total fertility rates observed in many countries.
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| 9. |
- Nilsson, Stefan, 1978-
(författare)
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Functional studies of the PreP peptidasome in Arabidopsis thaliana
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Two independent endosymbiotic events gave rise to mitochondria and chloroplasts. Despite the fact that both organelles have their own small genome the majority of organellar proteins are encoded in the nucleus, synthesized in the cytosol and imported into the organelles. The targeting information for most organellar proteins is located in an N-terminal extension called a targeting peptide. Targeting peptides are cleaved off after import by organellar processing peptidases. The cleaved targeting peptides are toxic to organellar functions and are degraded by the PreP peptidasome, the metalloendopeptidase which is the main topic of this thesis.We have overexpressed, purified and determined the first structure of a plant mitochondrial targeting peptide, the F1β presequence from Nicotiana plumbaginifolia, by NMR in a membrane mimetic environment. The structure showed that the targeting peptide formed two helices separated by an unstructured domain. The N-terminal helix being amphipatic. The F1β targeting peptide has been used as a model substrate for the mitochondrial and chloroplast PreP peptidasome. In Arabidopsis thaliana the PreP peptidasome is present as two isoforms, AtPreP1 and AtPreP2. We have shown that both forms are expressed and dually targeted to mitochondria and chloroplasts. Both AtPreP1 and AtPreP2 degrade targeting peptides and other non-related unstructured peptides up to 65 amino acid residues. Substrate specificity studies showed that both PreP isoforms have a preference for positively charged amino acid residues in the P1′ position and small uncharged residues in the P1 position. Mapping of cleavage sites revealed unique cleavage sites for both isoforms. We have generated and characterized both single and double AtPreP1 and AtPreP2 knockouts in A. thaliana. AtPreP1 was shown to be the major isoform. The double knockout exhibited a chlorotic phenotype with altered mitochondrial and chloroplast morphology. Furthermore,mitochondria were partially uncoupled. Throughout the development there was a slower growth rate and 40% lower biomass production. These results show that the PreP peptidasome is important for efficient organellar functions and normal plant development.
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| 10. |
- Petersson, Ulla, 1947-
(författare)
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Screening for Cardiovascular Risk and Diabetes in Primary Health Care : The Söderåkra Risk Factor Screening Study
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Cardiovascular disease (CVD) has been the predominant cause of morbidity and mortality for many decades in Sweden. Preventive work in primary health care through individual approach and community-based programmes has shown some success. Still, we need better risk assessment tools and health strategies to lessen the burden of CVD in our population.Methods: This thesis is based on four studies that explore the cardiovascular risk factor pattern and its development to CVD morbidity and mortality in the middle-aged (40-59 years) population in Söderåkra, southern Sweden, 1989-2006. At a single physician consultation in 1989-1990 the participants provided information about lifestyle in a self-administered questionnaire, underwent a physical examination and received medical advice after a laboratory investigation. The laboratory tests consisted mainly of blood glucose, serum lipids and thyroid function tests. Blood samples were also frozen for later analyses. A telephone interview on self-reported lifestyle changes was conducted ten years later. In 2006, primary health care medical records were studied for incident diabetes and also for impaired glucose tolerance (IGT). Finally, national registers were studied for incident fatal or nonfatal cardiovascular disease until 2006. Cardiovascular risk assessments using three separate risk algorithms were applied on the population.Results: The participation rate was high with 90% attendance. The conclusion of this cross-sectional baseline analysis was that it is meaningful to check for a secondary cause of hyperlipidemia, hypothyroidism, in women with a cholesterol value above 7.0 mmol/L. After 10 years follow-up women reported significantly more lifestyle changes than men, odds ratio (OR) 1.56 (95% CI: 1.11- 2.18; p= 0.010). Men with a history of smoking or CVD at baseline and women with treated hypertension at baseline made successful lifestyle changes, OR 4.77 (95% CI: 2.18-10.5; p<0.001 and OR 1.84 (95% CI: 1.12-3.02; p= 0.016), respectively, than those without these characteristics. Until 2006, 38 participants had developed diabetes and four subjects IGT out of 664 participants, excluding 10 with diabetes at baseline. A low level of IGFBP-1 at baseline was associated with the development of type 2 diabetes/IGT, hazard ratio (HR) 3.54 (95% CI: 1.18-10.6, p=0.024). This was independent of abdominal obesity or inflammation (CRP). After excluding 16 participants with prevalent CVD at baseline, 71 first fatal or nonfatal CVD events in 689 men and women were registered. Several known risk factors and risk markers were applied on this population.Those that turned out to be significantly associated with development of incident CVD in univariate Cox´s regression proportional hazard analyses where used in three different risk assessment models: the consultation model, SCORE and the extensive model. A non-laboratory-based risk assessment model, including variables easily obtained during one consultation visit to a general practitioner (GP), predicted cardiovascular events as accurately, HR 2.72; (CI 95% 2.18-3.39, p<0.001), as the established SCORE algorithm, HR 2.73; (CI 95% 2.10-3.55, p<0.001), which requires laboratory testing. Furthermore, adding laboratory measurements covering lipids, inflammation and endothelial dysfunction, did not confer any additional value to the prediction of CVD risk, HR 2.72; (CI 95% 2.19-3.37, p<0.001). The c-statistics for the consultation model (0.794; CI 95% 0.762-0.823) was not significantly different from SCORE (0.767; CI 95% 0.733-0.798, p=0.12) or the extended model (0.806; CI 95% 0.774-0.835, p=0.55).Conclusions: Our study showed that it is worth searching for hypothyroidism, in women with a cholesterol value above 7 mmol/L. The study identified female gender, previous CVD, hypertension and smoking as predictors of positive lifestyle change during follow-up. A low level of IGFBP-1 predicted future diabetes/IGT in this population as did increased waist and CRP. Finally, data on nonlaboratory risk factors obtained during one GP visit predicted future cardiovascular risk as accurately as SCORE or a laboratory-based risk algorithm.
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