| 1. |
- Ahlgren, Joakim, et al.
(author)
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Identification and quantification of organic phosphorus forms in soils from fertility experiments
- 2013
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In: Soil use and management. - : Wiley. - 0266-0032 .- 1475-2743. ; 29, s. 24-35
-
Journal article (peer-reviewed)abstract
- The effects of soil type, crop rotation, fertilizer type and application rate on the composition of organic phosphorus (P) compounds in soils from four sites in a Swedish long-term fertilizer experiment were investigated with 31P-NMR. Soil textures investigated were loamy sand, sandy loam, silty clay loam and clay. Phosphorus has been added to the soils since the 1950s and 1960s at four different rates in the form of either mineral fertilizer or a combination of manure and mineral fertilizer. Results show that in soils receiving no P addition, most of the soil P was present in the form of phosphate monoesters (6070%, depending on soil type). However, a P addition equivalent to the amount of P removed annually by harvest altered this relationship so that the soils were dominated by orthophosphate instead. This trend became more obvious with increasing P addition. At the greatest P application rate, orthophosphate comprised 70% or more of the total extracted P in all the soils. These changes in the soil were due entirely to increase in orthophosphate, because the amounts of monoesters did not change with increasing P additions. This was true both for mineral fertilizer and the combination of manure and mineral fertilizer P. Soil type and crop rotation did not influence the results. The results indicate that there is no apparent build-up of organic P in the soils, but that P addition mainly affects the orthophosphate amounts in the soils regardless of form or amount of fertilizer.
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| 2. |
- Ahmed, Istaq, 1972, et al.
(author)
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Structural study and proton conductivity in Yb-doped BaZrO3
- 2007
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In: Solid State Ionics. - 0167-2738. ; 178:(7-10), s. 515-520
-
Journal article (peer-reviewed)abstract
- Traditional solid state sintering has been used to prepare the perovskite BaZr0.9Yb0.1O3-delta. Analysis of X-ray powder diffraction data shows that an increase of the unit cell parameter, a, was observed compared to undoped BaZrO3. Rietveld analysis of room temperature neutron powder diffraction data confirmed cubic symmetry (space group Pm-3m). Dynamic thermogravimetric analysis (TGA) indicates that the hydration process occurs below 200 degrees C. The strong O-H stretch band, 2500-3500 cm(-1), in the infrared absorbance spectrum clearly manifests the presence of protons in the hydrated material. Proton conductivity was investigated on hydrated and as-prepared samples under dry and wet atmospheres, respectively. Keywords: X-ray diffraction; neutron diffraction; Rietveld refinement; proton conductor; perovskite
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| 3. |
- Ahmed, Istaq, 1972, et al.
(author)
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Synthesis and structural characterization of perovskite type proton conducting BaZr1-xInxO3-delta (0.0 <= x <= 0.75)
- 2006
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In: Solid State Ionics. - : Elsevier BV. - 0167-2738 .- 1872-7689. ; 177:17-18, s. 1395-1403
-
Journal article (peer-reviewed)abstract
- Solid state sintering has been used to prepare the cubic perovskite structured compounds BaZr1-xInxO3-delta (0.0 <= x <= 0.75). Analysis of X-ray powder diffraction (XRPD) data reveals that the unit cell parameter, a, increases linearly with an increased Indium concentration. XRPD data was also used to demonstrate the completion of sample hydration, which was reached when the materials showed a set of single-phase Bragg-peaks. Dynamic thermogravimetric analysis (TGA) data showed that approx. 89% of the total number of available oxygen vacancies can be filled in BaZr1-xInxO3-delta for x=0.50, and that the maximum water uptake occurs below 300 degrees C. Rietveld analysis of the room temperature neutron powder diffraction (NPD) data confirmed the average cubic symmetry (space group Pm-3m), and an expansion of the unit cell parameter after the hydration reaction. The strong O-H stretch band, 2500-3500 cm(-1), in the infrared absorbance spectrum clearly manifests the presence of protons in the hydrated material. Proton conductivity of hydrated BaZr1-xInxO3-delta, x=0.75 was investigated during heating and cooling cycles under dry argon atmosphere. The total conductivity during the heating cycle was nearly two orders of magnitude greater than that of cooling cycle at 300 degrees C, whilst these values were similar at higher temperatures i.e. T > 600 degrees C.
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| 4. |
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| 5. |
- Alvfors, Per, 1954-, et al.
(author)
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Research and development challenges for Swedish biofuel actors – three illustrative examples : Improvement potential discussed in the context of Well-to-Tank analyses
- 2010
-
Reports (other academic/artistic)abstract
- Currently biofuels have strong political support, both in the EU and Sweden. The EU has, for example, set a target for the use of renewable fuels in the transportation sector stating that all EU member states should use 10% renewable fuels for transport by 2020. Fulfilling this ambition will lead to an enormous market for biofuels during the coming decade. To avoid increasing production of biofuels based on agriculture crops that require considerable use of arable area, focus is now to move towards more advanced second generation (2G) biofuels that can be produced from biomass feedstocks associated with a more efficient land use. Climate benefits and greenhouse gas (GHG) balances are aspects often discussed in conjunction with sustainability and biofuels. The total GHG emissions associated with production and usage of biofuels depend on the entire fuel production chain, mainly the agriculture or forestry feedstock systems and the manufacturing process. To compare different biofuel production pathways it is essential to conduct an environmental assessment using the well-to-tank (WTT) analysis methodology. In Sweden the conditions for biomass production are favourable and we have promising second generation biofuels technologies that are currently in the demonstration phase. In this study we have chosen to focus on cellulose based ethanol, methane from gasification of solid wood as well as DME from gasification of black liquor, with the purpose of identifying research and development potentials that may result in improvements in the WTT emission values. The main objective of this study is thus to identify research and development challenges for Swedish biofuel actors based on literature studies as well as discussions with the the researchers themselves. We have also discussed improvement potentials for the agriculture and forestry part of the WTT chain. The aim of this study is to, in the context of WTT analyses, (i) increase knowledge about the complexity of biofuel production, (ii) identify and discuss improvement potentials, regarding energy efficiency and GHG emissions, for three biofuel production cases, as well as (iii) identify and discuss improvement potentials regarding biomass supply, including agriculture/forestry. The scope of the study is limited to discussing the technologies, system aspects and climate impacts associated with the production stage. Aspects such as the influence on biodiversity and other environmental and social parameters fall beyond the scope of this study. We find that improvement potentials for emissions reductions within the agriculture/forestry part of the WTT chain include changing the use of diesel to low-CO2-emitting fuels, changing to more fuel-efficient tractors, more efficient cultivation and manufacture of fertilizers (commercial nitrogen fertilizer can be produced in plants which have nitrous oxide gas cleaning) as well as improved fertilization strategies (more precise nitrogen application during the cropping season). Furthermore, the cultivation of annual feedstock crops could be avoided on land rich in carbon, such as peat soils and new agriculture systems could be introduced that lower the demand for ploughing and harrowing. Other options for improving the WTT emission values includes introducing new types of crops, such as wheat with higher content of starch or willow with a higher content of cellulose. From the case study on lignocellulosic ethanol we find that 2G ethanol, with co-production of biogas, electricity, heat and/or wood pellet, has a promising role to play in the development of sustainable biofuel production systems. Depending on available raw materials, heat sinks, demand for biogas as vehicle fuel and existing 1G ethanol plants suitable for integration, 2G ethanol production systems may be designed differently to optimize the economic conditions and maximize profitability. However, the complexity connected to the development of the most optimal production systems require improved knowledge and involvement of several actors from different competence areas, such as chemical and biochemical engineering, process design and integration and energy and environmental systems analysis, which may be a potential barrier.
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| 6. |
- Alvors, Per, et al.
(author)
-
Research and development challenges for Swedish biofuel actors – three illustrative examples : Improvement potential discussed in the context of Well-to-Tank analyses
- 2010
-
Reports (other academic/artistic)abstract
- Currently biofuels have strong political support, both in the EU and Sweden. The EU has, for example, set a target for the use of renewable fuels in the transportation sector stating that all EU member states should use 10% renewable fuels for transport by 2020. Fulfilling this ambition will lead to an enormous market for biofuels during the coming decade. To avoid increasing production of biofuels based on agriculture crops that require considerable use of arable area, focus is now to move towards more advanced second generation (2G) biofuels that can be produced from biomass feedstocks associated with a more efficient land use.Climate benefits and greenhouse gas (GHG) balances are aspects often discussed in conjunction with sustainability and biofuels. The total GHG emissions associated with production and usage of biofuels depend on the entire fuel production chain, mainly the agriculture or forestry feedstock systems and the manufacturing process. To compare different biofuel production pathways it is essential to conduct an environmental assessment using the well-to-tank (WTT) analysis methodology.In Sweden the conditions for biomass production are favourable and we have promising second generation biofuels technologies that are currently in the demonstration phase. In this study we have chosen to focus on cellulose based ethanol, methane from gasification of solid wood as well as DME from gasification of black liquor, with the purpose of identifying research and development potentials that may result in improvements in the WTT emission values. The main objective of this study is thus to identify research and development challenges for Swedish biofuel actors based on literature studies as well as discussions with the the researchers themselves. We have also discussed improvement potentials for the agriculture and forestry part of the WTT chain. The aim of this study is to, in the context of WTT analyses, (i) increase knowledge about the complexity of biofuel production, (ii) identify and discuss improvement potentials, regarding energy efficiency and GHG emissions, for three biofuel production cases, as well as (iii) identify and discuss improvement potentials regarding biomass supply, including agriculture/forestry. The scope of the study is limited to discussing the technologies, system aspects and climate impacts associated with the production stage. Aspects such as the influence on biodiversity and other environmental and social parameters fall beyond the scope of this study.We find that improvement potentials for emissions reductions within the agriculture/forestry part of the WTT chain include changing the use of diesel to low-CO2-emitting fuels, changing to more fuel-efficient tractors, more efficient cultivation and manufacture of fertilizers (commercial nitrogen fertilizer can be produced in plants which have nitrous oxide gas cleaning) as well as improved fertilization strategies (more precise nitrogen application during the cropping season). Furthermore, the cultivation of annual feedstock crops could be avoided on land rich in carbon, such as peat soils and new agriculture systems could be introduced that lower the demand for ploughing and harrowing. Other options for improving the WTT emission values includes introducing new types of crops, such as wheat with higher content of starch or willow with a higher content of cellulose.From the case study on lignocellulosic ethanol we find that 2G ethanol, with co-production of biogas, electricity, heat and/or wood pellet, has a promising role to play in the development of sustainable biofuel production systems. Depending on available raw materials, heat sinks, demand for biogas as vehicle fuel and existing 1G ethanol plants suitable for integration, 2G ethanol production systems may be designed differently to optimize the economic conditions and maximize profitability. However, the complexity connected to the development of the most optimal production systems require improved knowledge and involvement of several actors from different competence areas, such as chemical and biochemical engineering, process design and integration and energy and environmental systems analysis, which may be a potential barrier.Three important results from the lignocellulosic ethanol study are: (i) the production systems could be far more complex and intelligently designed than previous studies show, (ii) the potential improvements consist of a large number of combinations of process integration options wich partly depends on specific local conditions, (iii) the environmental performance of individual systems may vary significantly due to systems design and local conditons.From the case study on gasification of solid biomass for the production of biomethane we find that one of the main advantages of this technology is its high efficiency in respect to converting biomass into fuels for transport. For future research we see a need for improvements within the gas up-grading section, including gas cleaning and gas conditioning, to obtain a more efficient process. A major challenge is to remove the tar before the methanation reaction.Three important results from the biomethane study are: (i) it is important not to crack the methane already produced in the syngas, which indicates a need for improved catalysts for selective tar cracking, (ii) there is a need for new gas separation techniques to facilitate the use of air oxidation agent instead of oxygen in the gasifier, and (iii) there is a need for testing the integrated process under realistic conditions, both at atmospheric and pressurized conditions.From the case study on black liquor gasification for the production of DME we find that the process has many advantages compared to other biofuel production options, such as the fact that black liquor is already partially processed and exists in a pumpable, liquid form, and that the process is pressurised and tightly integrated with the pulp mill, which enhances fuel production efficiency. However, to achieve commercial status, some challenges still remain, such as demonstrating that materials and plant equipment meet the high availability required when scaling up to industrial size in the pulp mill, and also proving that the plant can operate according to calculated heat and material balances. Three important results from the DME study are: (i) that modern chemical pulp mills, having a potential surplus of energy, could become important suppliers of renewable fuels for transport, (ii) there is a need to demonstrate that renewable DME/methanol will be proven to function in large scale, and (iii) there is still potential for technology improvements and enhanced energy integration.Although quantitative improvement potentials are given in the three biofuel production cases, it is not obvious how these potentials would affect WTT values, since the biofuel production processes are complex and changing one parameter impacts other parameters. The improvement potentials are therefore discussed qualitatively. From the entire study we have come to agree on the following common conclusions: (i) research and development in Sweden within the three studied 2G biofuel production technologies is extensive, (ii) in general, the processes, within the three cases, work well at pilot and demonstration scale and are now in a phase to be proven in large scale, (iii) there is still room for improvement although some processes have been known for decades, (iv) the biofuel production processes are complex and site specific and process improvements need to be seen and judged from a broad systems perspective (both within the production plant as well as in the entire well-to-tank perspective), and (v) the three studied biofuel production systems are complementary technologies. Futher, the process of conducting this study is worth mentioning as a result itself, i.e. that many different actors within the field have proven their ability and willingness to contribute to a common report, and that the cooperation climate was very positive and bodes well for possible future collaboration within the framework of the f3 center.Finally, judging from the political ambitions it is clear that the demand for renewable fuels will significantly increase during the coming decade. This will most likely result in opportunities for a range of biofuel options. The studied biofuel options all represent 2G biofuels and they can all be part of the solution to meet the increased renewable fuel demand.
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| 7. |
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| 8. |
- Andert, Janet, et al.
(author)
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Temporal Changes in Methane Oxidizing and Denitrifying Communities and Their Activities in a Drained Peat Soil
- 2012
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In: Wetlands. - : Springer Science and Business Media LLC. - 0277-5212 .- 1943-6246. ; 32, s. 1047-1055
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Journal article (peer-reviewed)abstract
- Northern peat soils are both sources and sinks of the greenhouse gases nitrous oxide (N2O) and methane (CH4). These fluxes are regulated by the activity of microbial communities. Temporal, spatial and depth related differences in potential activity and composition of the denitrifier and methanotrophic bacterial communities were compared between winter and summer in relation to in situ fluxes of N2O and CH4 from a drained and forested peat land in Sweden. The composition of the genetic pool of these guilds was assessed using terminal fragment length polymorphism analysis of signature genes in the denitrification and methane oxidation pathways, respectively. The composition of the communities was similar throughout the soil profile, although both denitrification and methane oxidation rates decreased with soil depth. The potential methane oxidation rates were significantly correlated to soil N content, and , indicating a nitrogen induced stimulation of methane oxidation capacity. The site was a source of N2O and a small sink for CH4, and although the fluxes did not vary significantly over time, both the methane oxidizing and denitrifier community composition exhibited temporal patterns. Differences in the composition of the methanotrophic community reflected that the peat site shifted from a summer to a winter community. The denitrifiers exhibited a similar trend, but also differed significantly between the sampling occasions during summer, as well as between locations at the site. The latter was explained by differences in soil pH. It was only the differences in the methane oxidizer community composition that correlated with its corresponding potential activity, which implies a higher degree of functional redundancy within the denitrifier community.
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| 9. |
- Angenete, Eva, 1972, et al.
(author)
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Physical activity before radical prostatectomy reduces sick leave after surgery : results from a prospective, non-randomized controlled clinical trial (LAPPRO)
- 2016
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In: BMC Urology. - : Springer Science and Business Media LLC. - 1471-2490. ; 16:1, s. 50-
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Studies have reported that early physical rehabilitation after surgical procedures is associated with improved outcome measured as shorter hospital stay and enhanced recovery. The aim of this study was to explore the relationship between the preoperative physical activity level and subsequent postoperative complications, sick-leave and hospital stay after radical prostatectomy for prostate cancer in the setting of the LAPPRO trial (LAParoscopic Prostatectomy Robot Open). METHODS: LAPPRO is a prospective controlled trial, comparing robot-assisted laparoscopic and open surgery for localized prostate cancer between 2008 and 2011. 1569 patients aged 64 or less with an occupation were included in this sub-study. The Gleason score was <7 in 52 % of the patients. Demographics and the level of self-assessed preoperative physical activity, length of hospital stay, complications, quality of life, recovery and sick-leave were extracted from clinical record forms and questionnaires. Multivariable logistic regression, with log-link and logit-link functions, was used to adjust for potential confounding variables. RESULTS: The patients were divided into four groups based on their level of activity. As the group with lowest engagement of physical activity was found to be significantly different in base line characteristics from the other groups they were excluded from further analysis. Among patients that were physically active preoperativelly (n = 1467) there was no significant difference between the physical activity-groups regarding hospital stay, recovery or complications. However, in the group with the highest self-assessed level of physical activity, 5-7 times per week, 13 % required no sick leave, compared to 6.3 % in the group with a physical activity level of 1-2 times per week only (p < 0.0001). CONCLUSIONS: In our study of med operated with radical prostatectomy, a high level of physical activity preoperatively was associated with reduced need for sick leave after radical prostatectomy compared to men with lower physical activity. TRIAL REGISTRATION: The trial is registered at the ISCRTN register. ISRCTN06393679 .
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| 10. |
- Arvidson, E., et al.
(author)
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The level of leisure time physical activity is associated with work ability-a cross sectional and prospective study of health care workers
- 2013
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In: Bmc Public Health. - : Springer Science and Business Media LLC. - 1471-2458. ; 13:855
-
Journal article (peer-reviewed)abstract
- Background: With increasing age, physical capacity decreases, while the need and time for recovery increases. At the same time, the demands of work usually do not change with age. In the near future, an aging and physically changing workforce risks reduced work ability. Therefore, the impact of different factors, such as physical activity, on work ability is of interest. Thus, the aim of this study was to evaluate the association between physical activity and work ability using both cross sectional and prospective analyses. Methods: This study was based on an extensive questionnaire survey. The number of participants included in the analysis at baseline in 2004 was 2.783, of whom 2.597 were also included in the follow-up in 2006. The primary outcome measure was the Work Ability Index (WAI), and the level of physical activity was measured using a single-item question. In the cross-sectional analysis we calculated the level of physical activity and the prevalence of poor or moderate work ability as reported by the participants. In the prospective analysis we calculated different levels of physical activity and the prevalence of positive changes in WAI-category from baseline to follow-up. In both the cross sectional and the prospective analyses the prevalence ratio was calculated using Generalized Linear Models. Results: The cross-sectional analysis showed that with an increased level of physical activity, the reporting of poor or moderate work ability decreased. In the prospective analysis, participants reporting a higher level of physical activity were more likely to have made an improvement in WAI from 2004 to 2006. Conclusions: The level of physical activity seems to be related to work ability. Assessment of physical activity may also be useful as a predictive tool, potentially making it possible to prevent poor work ability and improve future work ability. For employers, the main implications of this study are the importance of promoting and facilitating the employees' engagement in physical activity, and the importance of the employees' maintaining a physically active lifestyle.
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| 11. |
- Baldanzi, Gabriel, et al.
(author)
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Accelerometer-based physical activity is associated with the gut microbiota in 8416 individuals in SCAPIS.
- 2024
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In: EBioMedicine. - : Elsevier. - 2352-3964. ; 100
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Journal article (peer-reviewed)abstract
- BACKGROUND: Previous population-based studies investigating the relationship between physical activity and the gut microbiota have relied on self-reported activity, prone to reporting bias. Here, we investigated the associations of accelerometer-based sedentary (SED), moderate-intensity (MPA), and vigorous-intensity (VPA) physical activity with the gut microbiota using cross-sectional data from the Swedish CArdioPulmonary bioImage Study.METHODS: In 8416 participants aged 50-65, time in SED, MPA, and VPA were estimated with hip-worn accelerometer. Gut microbiota was profiled using shotgun metagenomics of faecal samples. We applied multivariable regression models, adjusting for sociodemographic, lifestyle, and technical covariates, and accounted for multiple testing.FINDINGS: Overall, associations between time in SED and microbiota species abundance were in opposite direction to those for MPA or VPA. For example, MPA was associated with lower, while SED with higher abundance of Escherichia coli. MPA and VPA were associated with higher abundance of the butyrate-producers Faecalibacterium prausnitzii and Roseburia spp. We observed discrepancies between specific VPA and MPA associations, such as a positive association between MPA and Prevotella copri, while no association was detected for VPA. Additionally, SED, MPA and VPA were associated with the functional potential of the microbiome. For instance, MPA was associated with higher capacity for acetate synthesis and SED with lower carbohydrate degradation capacity.INTERPRETATION: Our findings suggest that sedentary and physical activity are associated with a similar set of gut microbiota species but in opposite directions. Furthermore, the intensity of physical activity may have specific effects on certain gut microbiota species.FUNDING: European Research Council, Swedish Heart-Lung Foundation, Swedish Research Council, Knut and Alice Wallenberg Foundation.
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| 12. |
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| 13. |
- Bergström, Göran, 1964, et al.
(author)
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Prevalence of Subclinical Coronary Artery Atherosclerosis in the General Population
- 2021
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In: Circulation. - Philadelphia : American Heart Association. - 0009-7322 .- 1524-4539. ; 144:12, s. 916-929
-
Journal article (peer-reviewed)abstract
- Background: Early detection of coronary atherosclerosis using coronary computed tomography angiography (CCTA), in addition to coronary artery calcification (CAC) scoring, may help inform prevention strategies. We used CCTA to determine the prevalence, severity, and characteristics of coronary atherosclerosis and its association with CAC scores in a general population.Methods: We recruited 30 154 randomly invited individuals age 50 to 64 years to SCAPIS (the Swedish Cardiopulmonary Bioimage Study). The study includes individuals without known coronary heart disease (ie, no previous myocardial infarctions or cardiac procedures) and with high-quality results from CCTA and CAC imaging performed using dedicated dual-source CT scanners. Noncontrast images were scored for CAC. CCTA images were visually read and scored for coronary atherosclerosis per segment (defined as no atherosclerosis, 1% to 49% stenosis, or ≥50% stenosis). External validity of prevalence estimates was evaluated using inverse probability for participation weighting and Swedish register data.Results: In total, 25 182 individuals without known coronary heart disease were included (50.6% women). Any CCTA-detected atherosclerosis was found in 42.1%; any significant stenosis (≥50%) in 5.2%; left main, proximal left anterior descending artery, or 3-vessel disease in 1.9%; and any noncalcified plaques in 8.3% of this population. Onset of atherosclerosis was delayed on average by 10 years in women. Atherosclerosis was more prevalent in older individuals and predominantly found in the proximal left anterior descending artery. Prevalence of CCTA-detected atherosclerosis increased with increasing CAC scores. Among those with a CAC score >400, all had atherosclerosis and 45.7% had significant stenosis. In those with 0 CAC, 5.5% had atherosclerosis and 0.4% had significant stenosis. In participants with 0 CAC and intermediate 10-year risk of atherosclerotic cardiovascular disease according to the pooled cohort equation, 9.2% had CCTA-verified atherosclerosis. Prevalence estimates had excellent external validity and changed marginally when adjusted to the age-matched Swedish background population.Conclusions: Using CCTA in a large, random sample of the general population without established disease, we showed that silent coronary atherosclerosis is common in this population. High CAC scores convey a significant probability of substantial stenosis, and 0 CAC does not exclude atherosclerosis, particularly in those at higher baseline risk.
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| 14. |
- Bergström, Göran, et al.
(author)
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Prevalence of Subclinical Coronary Artery Atherosclerosis in the General Population
- 2021
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In: Circulation. - : Wolters Kluwer. - 0009-7322 .- 1524-4539. ; 144:12, s. 916-929
-
Journal article (peer-reviewed)abstract
- Background: Early detection of coronary atherosclerosis using coronary computed tomography angiography (CCTA), in addition to coronary artery calcification (CAC) scoring, may help inform prevention strategies. We used CCTA to determine the prevalence, severity, and characteristics of coronary atherosclerosis and its association with CAC scores in a general population.Methods: We recruited 30 154 randomly invited individuals age 50 to 64 years to SCAPIS (the Swedish Cardiopulmonary Bioimage Study). The study includes individuals without known coronary heart disease (ie, no previous myocardial infarctions or cardiac procedures) and with high-quality results from CCTA and CAC imaging performed using dedicated dual-source CT scanners. Noncontrast images were scored for CAC. CCTA images were visually read and scored for coronary atherosclerosis per segment (defined as no atherosclerosis, 1% to 49% stenosis, or ≥50% stenosis). External validity of prevalence estimates was evaluated using inverse probability for participation weighting and Swedish register data.Results: In total, 25 182 individuals without known coronary heart disease were included (50.6% women). Any CCTA-detected atherosclerosis was found in 42.1%; any significant stenosis (≥50%) in 5.2%; left main, proximal left anterior descending artery, or 3-vessel disease in 1.9%; and any noncalcified plaques in 8.3% of this population. Onset of atherosclerosis was delayed on average by 10 years in women. Atherosclerosis was more prevalent in older individuals and predominantly found in the proximal left anterior descending artery. Prevalence of CCTA-detected atherosclerosis increased with increasing CAC scores. Among those with a CAC score >400, all had atherosclerosis and 45.7% had significant stenosis. In those with 0 CAC, 5.5% had atherosclerosis and 0.4% had significant stenosis. In participants with 0 CAC and intermediate 10-year risk of atherosclerotic cardiovascular disease according to the pooled cohort equation, 9.2% had CCTA-verified atherosclerosis. Prevalence estimates had excellent external validity and changed marginally when adjusted to the age-matched Swedish background population.Conclusions: Using CCTA in a large, random sample of the general population without established disease, we showed that silent coronary atherosclerosis is common in this population. High CAC scores convey a significant probability of substantial stenosis, and 0 CAC does not exclude atherosclerosis, particularly in those at higher baseline risk.
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| 15. |
- Bergström, Lars, et al.
(author)
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Turnover and Losses of Phosphorus in Swedish Agricultural Soils: Long-Term Changes, Leaching Trends, and Mitigation Measures
- 2015
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In: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 44, s. 512-523
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Journal article (peer-reviewed)abstract
- Transport of phosphorus (P) from agricultural fields to water bodies deteriorates water quality and causes eutrophication. To reduce P losses and optimize P use efficiency by crops, better knowledge is needed of P turnover in soil and the efficiency of best management practices (BMPs). In this review, we examined these issues using results from 10 Swedish long-term soil fertility trials and various studies on subsurface losses of P. The fertility trials are more than 50 years old and consist of two cropping systems with farmyard manure and mineral fertilizer. One major finding was that replacement of P removed by crops with fertilizer P was not sufficient to maintain soil P concentrations, determined with acid ammonium lactate extraction. The BMPs for reducing P leaching losses reviewed here included catch crops, constructed wetlands, structure liming of clay soils, and various manure application strategies. None of the eight catch crops tested reduced P leaching significantly, whereas total P loads were reduced by 36% by wetland installation, by 39 to 55% by structure liming (tested at two sites), and by 50% by incorporation of pig slurry into a clay soil instead of surface application. Trend analysis of P monitoring data since the 1980s for a number of small Swedish catchments in which various BMPs have been implemented showed no clear pattern, and both upward and downward trends were observed. However, other factors, such as weather conditions and soil type, have profound effects on P losses, which can mask the effects of BMPs.
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| 16. |
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| 17. |
- Bertilsson, Emil, 1979-
(author)
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Skollärare : Rekrytering till utbildning och yrke 1977-2009
- 2014
-
Doctoral thesis (other academic/artistic)abstract
- This study is about the school teachers’ positions in contemporary Swedish society. In order to grasp the social characteristics of their profession and its transformations it has been important to conduct thorough analyses of the recruitment of teacher students and the recruitment to the teaching professions. The explanations to the findings are mainly based on analyses of how different kinds of assets – such as for example cultural capital and educational capital – are distributed among the students and within the school teacher corps.The data material consists of individual based statistic of all teachers 1978–2008 and all students enrolled in higher education 1977–2009, and of interviews with teachers and students. Regarding theory and methods, the study belongs to the sociological tradition founded by Pierre Bourdieu, which means that capital, strategies and social space are key concepts. The statistical techniques employed comprise mainly of different variants of correspondence analysis as well as logistic regression.As shown in the first part of the thesis an increasing share of the teacher students possess small amounts of acquired school capital, as well as weak resources inherited from their parental home. This change has been especially noticeable within the programmes educating upper secondary school teachers. In the second part, the focus is on the social positions of those upper secondary teachers. The correspondence analyses indicate a cleavage within the profession based on the teachers’ qualification and merits. Teachers richer in educational capital tend to occupy more stable professional positions and are also overrepresented at schools where the pupils feature significant educational and social assets, which in turn further contributes to the density of educational capital.One of the main results is that school teachers have been exposed to two partly opposing processes during the past decades. On the one hand, there has been increasing homogeneity, namely convergences between the employment conditions of different categories of school teachers and between different teacher education programmes. On the other hand, the social divergences within the profession tend to widen. Those gaps have increased over time because of the more differentiated school system and changes in recruitment patterns.
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| 18. |
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| 19. |
- Bolinder, Martin, et al.
(author)
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Net primary productivity and below-ground crop residue inputs for root crops: Potato (Solanum tuberosum L.) and sugar beet (Beta vulgaris L.)
- 2015
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In: Canadian Journal of Soil Science. - 0008-4271. ; 95, s. 87-93
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Journal article (peer-reviewed)abstract
- Root crops are significant in agro-ecosystems of temperate climates. However, the amounts of crop residues for these crop types are not well documented and they need to be accounted for in the modeling of soil organic carbon dynamics. Our objective was to review field measurements of root biomass left in the soil as crop residues at harvest for potato and sugar beet. We considered estimates for crop residue inputs as root biomass presented in the literature and some unpublished results. Our analysis showed that compared to, for example, cereals, the contribution of below-ground net primary productivity (NPP) to crop residues is at least two to three times lower for root crops. Indeed, the field measurements indicated that root biomass for topsoils only represents on average 25 to 30 g dry matter (DM) m(-2) yr(-1). Other estimates, albeit variable and region-specific, tended to be higher. We suggest relative plant DM allocation coefficients for agronomic yield (R-P), above-ground biomass (R-S) and root biomass (R-R) components, expressed as a proportion of total NPP. These coefficients, representative for temperate climates (0.739:0.236:0.025 for potato and 0.626:0.357:0.017 for sugar beet), should be useful in the modeling of agro-ecosystems that include root crops.
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| 20. |
- Braun, Sabina, et al.
(author)
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Assessing the ability of soil tests to estimate labile phosphorus in agricultural soils : Evidence from isotopic exchange
- 2019
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In: Geoderma. - : Elsevier. - 0016-7061 .- 1872-6259. ; 337, s. 350-358
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Journal article (peer-reviewed)abstract
- Efficient phosphorus (P) fertilization strategies are essential for intensive crop production with minimal negative environmental impacts. A key factor in sustainable P use is assessment of the plant available soil P pool using soil P tests. This study determined isotopically exchangeable P after six days of reaction with 33PO4 (P-E (6 d)) to determine how accurately two commonly used P tests, Olsen and AL (acid ammonium acetate lactate) can quantify the amount of labile P. Soil samples were taken from both highly P-amended and unamended plots at six sites within the Swedish long-term soil fertility experiments. According to P K-edge XANES spectroscopy, the P speciation was dominated by Al-bound P and organic P, with additional contributions from Fe-bound P and Ca phosphates in most soils. The results showed that the AL test overestimated P-E (6 d) by a factor of 1.70 on average. In contrast, the Olsen test underestimated P-E (6 d), with the mean ratios of P-Olsen to P-E (6 d) being 0.52 for high-P and 0.19 for low-P soils. The 33P/31P ratio in the Olsen extract of a 33PO4 spiked soil was closer to that of a 0.005 mol L−1 CaCl2 soil extract than the corresponding ratio in the AL extract, suggesting that AL extraction solubilized more non-labile P. In conclusion, the AL and Olsen methods are not suitable for direct quantification of the isotopically exchangeable soil P pool after 6 days of equilibration. However, based on the results, Olsen may be superior to AL for classification of soil P status, due to its even performance for calcareous and non-calcareous soils and lower extraction of non-labile P.
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| 21. |
- Braun, Sabina, et al.
(author)
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Phosphorus desorption and isotope exchange kinetics in agricultural soils
- 2020
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In: Soil use and management. - : Wiley. - 0266-0032 .- 1475-2743.
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Journal article (peer-reviewed)abstract
- To improve phosphorus (P) fertilization and environmental assessments, a better understanding of release kinetics of solid-phase P to soil solution is needed. In this study, Fe (hydr)oxide-coated filter papers (Fh papers), isotopic exchange kinetics (IEK) and chemical extractions were used to assess the sizes of fast and slowly desorbing P pools in the soils of six long-term Swedish field experiments. The P desorption data from the Fh-paper extraction of soil (20 days of continual P removal) were fitted with the Lookman two-compartment desorption model, which estimates the pools of fast (Q1) and slowly (Q2) desorbing P, and their desorption rates k1 and k2. The amounts of isotope-exchangeable P (E) were calculated (E1min to E>3 months) and compared with Q1 and Q2. The strongest relationship was found between E1 min and Q1 (r2 =.87, p <.01). There was also an inverse relationship between the IEK parameter n (the rate of exchange) and k1 (r2 =.52, p <.01) and k2 (r2 =.52, p <.01), suggesting that a soil with a high value of n desorbs less P per time unit. The relationships between these results show that they deliver similar information, but both methods are hard to implement in routine analysis. However, Olsen-extractable P was similar in magnitude to Q1 (P-Olsen = 1.1 × Q1 + 2.3, r2 =.96), n and k1 were related to P-Olsen/P-CaCl2, while k2 was related to P-oxalate/P-Olsen. Therefore, these extractions can be used to estimate the sizes and desorption rates of the different P pools, which could be important for assessments of plant availability and leaching.
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| 22. |
- Båth, Magnus, 1974, et al.
(author)
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Investigation of image components affecting the detection of lung nodules in digital chest radiography
- 2005
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In: Progress in Biomedical Optics and Imaging - Proceedings of SPIE. - : SPIE. - 1605-7422. ; 5749, s. 231-242
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Journal article (other academic/artistic)abstract
- The aim of this work was to investigate and quantify the effects of system noise, nodule location, anatomical noise and anatomical background on the detection of lung nodules in different regions of the chest x-ray. Simulated lung nodules of diameter 10 mm but with varying detail contrast were randomly positioned in four different kinds of images: 1) clinical images collected with a 200 speed CR system, 2) images containing only system noise (including quantum noise) at the same level as the clinical images, 3) clinical images with removed anatomical noise, 4) artificial images with similar power spectrum as the clinical images but random phase spectrum. An ROC study was conducted with 5 observers. The detail contrast needed to obtain an Az of 0.80, C0.8, was used as measure of detectability. Five different regions of the chest x-ray were investigated separately. The C0.8 of the system noise images ranged from only 2% (the hilar regions) to 20% (the lateral pulmonary regions) of those of the clinical images. Compared with the original clinical images, the C0.8 was 16% lower for the de-noised clinical images and 71% higher for the random phase images, respectively, averaged over all five regions. In conclusion, regarding the detection of lung nodules with a diameter of 10 mm, the system noise is of minor importance at clinically relevant dose levels. The removal of anatomical noise and other noise sources uncorrelated from image to image leads to somewhat better detection, but the major component disturbing the detection is the overlapping of recognizable structures, which are, however, the main aspect of an x-ray image.
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| 23. |
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| 24. |
- Båth, Magnus, 1974, et al.
(author)
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Nodule detection in digital chest radiography: effect of anatomical noise.
- 2005
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In: Radiation protection dosimetry. - : Oxford University Press (OUP). - 0144-8420 .- 1742-3406. ; 114:1-3, s. 109-13
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Journal article (peer-reviewed)abstract
- The image background resulting from imaged anatomy can be divided into those components that are meaningful to the observers, in the sense that they are recognised as separate structures, and those that are not. These latter components (reffered to as anatomical noise) can be removed using a method developed within the RADIUS group. The aim of the present study was to investigate whether the removal of the anatomical noise results in images where lung nodules with lower contrast can be detected. A receiver operating characteristic (ROC) study was therefore conducted using two types of images: clinical chest images and chest images in which the anatomical noise had been removed. Simulated designer nodules with a full-width-at-fifth-maximum of 10 mm but with varying contrast were added to the images. The contrast needed to obtain an area under the ROC curve of 0.80, C0.8, was used as a measure of detectability (a low value of C0.8 represents a high detectability). Five regions of the chest X ray were investigated and it was found that in all regions the removal of anatomical noise led to images with lower C0.8 than the original images. On average, C0.8 was 20% higher in the original images, ranging from 7% (the lateral pulmonary regions) to 41% (the upper mediastinal regions).
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| 25. |
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