| 1. |
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| 2. |
- Murari, A., et al.
(author)
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A control oriented strategy of disruption prediction to avoid the configuration collapse of tokamak reactors
- 2024
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In: Nature Communications. - 2041-1723 .- 2041-1723. ; 15:1
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Journal article (peer-reviewed)abstract
- The objective of thermonuclear fusion consists of producing electricity from the coalescence of light nuclei in high temperature plasmas. The most promising route to fusion envisages the confinement of such plasmas with magnetic fields, whose most studied configuration is the tokamak. Disruptions are catastrophic collapses affecting all tokamak devices and one of the main potential showstoppers on the route to a commercial reactor. In this work we report how, deploying innovative analysis methods on thousands of JET experiments covering the isotopic compositions from hydrogen to full tritium and including the major D-T campaign, the nature of the various forms of collapse is investigated in all phases of the discharges. An original approach to proximity detection has been developed, which allows determining both the probability of and the time interval remaining before an incoming disruption, with adaptive, from scratch, real time compatible techniques. The results indicate that physics based prediction and control tools can be developed, to deploy realistic strategies of disruption avoidance and prevention, meeting the requirements of the next generation of devices.
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| 3. |
- Eriksson, Olof, et al.
(author)
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The Positron Emission Tomography ligand [11C]5-Hydroxy-Tryptophan can be used as a surrogate marker for the human endocrine pancreas
- 2014
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In: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 63:10, s. 3428-3437
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Journal article (peer-reviewed)abstract
- In humans a well-developed serotonin system is localized to the pancreatic islets while being absent in exocrine pancreas. Assessment of pancreatic serotonin biosynthesis could therefore be used to estimate the human endocrine pancreas. Proof of concept was tested in a prospective clinical trial by comparisons of type 1 diabetic (T1D) patients, with extensive reduction of beta cells, with healthy volunteers (HV).C-peptide negative (i.e. insulin-deficient) T1D subjects (n=10) and HV (n=9) underwent dynamic Positron Emission Tomography with the radiolabeled serotonin precursor [(11)C]5-Hydroxy-Tryptophan ([(11)C]5-HTP).A significant accumulation of [(11)C]5-HTP was obtained in the pancreas of the HV, with large inter-individual variation. A substantial and highly significant reduction (66%) in the pancreatic uptake of [(11)C]5-HTP in T1D subjects was observed, and this was most evident in the corpus and caudal regions of the pancreas where beta-cells normally are the major constituent of the islets.[(11)C]5-HTP retention in the pancreas was reduced in T1D compared to non-diabetic subjects. Accumulation of [(11)C]5-HTP in the pancreas of both HV and subjects with T1D were in agreement with previously reported morphological observations on the beta cell volume implying that [(11)C]5-HTP retention is a useful non-invasive surrogate marker for the human endocrine pancreas.
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| 4. |
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| 5. |
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| 6. |
- Ahlqvist, Emma, et al.
(author)
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A common variant upstream of the PAX6 gene influences islet function in man.
- 2012
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In: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 55, s. 94-104
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Journal article (peer-reviewed)abstract
- AIMS/HYPOTHESIS: Impaired glucose tolerance and impaired insulin secretion have been reported in families with PAX6 mutations and it is suggested that they result from defective proinsulin processing due to lack of prohormone convertase 1/3, encoded by PCSK1. We investigated whether a common PAX6 variant would mimic these findings and explored in detail its effect on islet function in man. METHODS: A PAX6 candidate single nucleotide polymorphism (rs685428) was associated with fasting insulin levels in the Diabetes Genetics Initiative genome-wide association study. We explored its potential association with glucose tolerance and insulin processing and secretion in three Scandinavian cohorts (N = 8,897 individuals). In addition, insulin secretion and the expression of PAX6 and transcriptional target genes were studied in human pancreatic islets. RESULTS: rs685428 G allele carriers had lower islet mRNA expression of PAX6 (p = 0.01) and PCSK1 (p = 0.001) than AA homozygotes. The G allele was associated with increased fasting insulin (p (replication) = 0.02, p (all) = 0.0008) and HOMA-insulin resistance (p (replication) = 0.02, p (all) = 0.001) as well as a lower fasting proinsulin/insulin ratio (p (all) = 0.008) and lower fasting glucagon (p = 0.04) and gastric inhibitory peptide (GIP) (p = 0.05) concentrations. Arginine-stimulated (p = 0.02) insulin secretion was reduced in vivo, which was further reflected by a reduction of glucose- and potassium-stimulated insulin secretion (p = 0.002 and p = 0.04, respectively) in human islets in vitro. CONCLUSIONS/INTERPRETATION: A common variant in PAX6 is associated with reduced PAX6 and PCSK1 expression in human islets and reduced insulin response, as well as decreased glucagon and GIP concentrations and decreased insulin sensitivity. These findings emphasise the central role of PAX6 in the regulation of islet function and glucose metabolism in man.
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| 7. |
- Brukas, Vilis, et al.
(author)
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How Sensitive Are Ecosystem Services in European Forest Landscapes to Silvicultural Treatment?
- 2015
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In: Forests. - : MDPI AG. - 1999-4907. ; 6, s. 1666-1695
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Journal article (peer-reviewed)abstract
- While sustainable forestry in Europe is characterized by the provision of a multitude of forest ecosystem services, there exists no comprehensive study that scrutinizes their sensitivity to forest management on a pan-European scale, so far. We compile scenario runs from regionally tailored forest growth models and Decision Support Systems (DSS) from 20 case studies throughout Europe and analyze whether the ecosystem service provision depends on management intensity and other co-variables, comprising regional affiliation, social environment, and tree species composition. The simulation runs provide information about the case-specifically most important ecosystem services in terms of appropriate indicators. We found a strong positive correlation between management intensity and wood production, but only weak correlation with protective and socioeconomic forest functions. Interestingly, depending on the forest region, we found that biodiversity can react in both ways, positively and negatively, to increased management intensity. Thus, it may be in tradeoff or in synergy with wood production and forest resource maintenance. The covariables species composition and social environment are of punctual interest only, while the affiliation to a certain region often makes an important difference in terms of an ecosystem service's treatment sensitivity.
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| 8. |
- De Marinis, Yang, et al.
(author)
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Serology assessment of antibody response to SARS-CoV-2 in patients with COVID-19 by rapid IgM/IgG antibody test
- 2020
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In: Infection Ecology and Epidemiology. - : Informa UK Limited. - 2000-8686. ; 10:1
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Journal article (peer-reviewed)abstract
- The coronavirus disease 2019 (COVID-19) pandemic has created a global health- and economic crisis. Detection of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which causes COVID-19 by serological methods is important to diagnose a current or resolved infection. In this study, we applied a rapid COVID-19 IgM/IgG antibody test and performed serology assessment of antibody response to SARS-CoV-2. In PCR-confirmed COVID-19 patients (n = 45), the total antibody detection rate is 92% in hospitalized patients and 79% in non-hospitalized patients. The total IgM and IgG detection is 63% in patients with <2 weeks from disease onset; 85% in non-hospitalized patients with >2 weeks disease duration; and 91% in hospitalized patients with >2 weeks disease duration. We also compared different blood sample types and suggest a higher sensitivity by serum/plasma over whole blood. Test specificity was determined to be 97% on 69 sera/plasma samples collected between 2016-2018. Our study provides a comprehensive validation of the rapid COVID-19 IgM/IgG serology test, and mapped antibody detection patterns in association with disease progress and hospitalization. Our results support that the rapid COVID-19 IgM/IgG test may be applied to assess the COVID-19 status both at the individual and at a population level.
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| 9. |
- Ekström, Ola, et al.
(author)
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Increasing circulating levels of Tenascin C in response to the Wingate Anaerobic test
- 2023
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In: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 43:4, s. 271-277
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Journal article (peer-reviewed)abstract
- AIM: Tenascin C (TNC) is a large extracellular matrix glycoprotein. It is involved in development and upregulated both during tissue repair and in several pathological conditions, including cardiovascular disease. Extracellular matrix proteins play a role in promoting exercise responses, leading to adaptation, regeneration, and repair. The main goal of this study was to investigate whether a short anaerobic effort leads to increased levels of TNC in serum.METHODS: Thirty-nine healthy men performed a Wingate test followed by a muscle biopsy. Myoblasts were isolated from the muscle biopsies and differentiated to myotubes ex vivo. TNC RNA was quantified in the biopsies, myotubes and myoblasts using RNA sequencing. Blood samples were drawn before and 5 min after the Wingate test. Serum TNC levels were measured using ELISA.RESULTS: After the Wingate test, serum TNC increased on average by 23% [15-33], median [IQR]; P Wilcoxon < 0.0001. This increase is correlated with peak power output and power drop, but not with VO 2max . TNC RNA expression is higher in myoblasts and myotubes compared to skeletal muscle tissue. CONCLUSION: TNC is secreted systemically as a response to the Wingate anaerobic test in healthy males. The response was positively correlated with peak power and power drop, but not with VO 2max which implicates a relation to mechanical strain and/or blood flow. With higher expression in undifferentiated myoblast cells than muscle tissue, it is likely that TNC plays a role in muscle tissue remodelling in humans. Our findings open for research on how TNC contributes to exercise adaptation. This article is protected by copyright. All rights reserved.
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| 10. |
- Eriksson, Daniel, et al.
(author)
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Cytokine Autoantibody Screening in the Swedish Addison Registry Identifies Patients With Undiagnosed APS1
- 2018
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In: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 103:1, s. 179-186
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Journal article (peer-reviewed)abstract
- Context: Autoimmune polyendocrine syndrome type 1 (APS1) is a monogenic disorder that features autoimmune Addison disease as a major component. Although APS1 accounts for only a small fraction of all patients with Addison disease, early identification of these individuals is vital to prevent the potentially lethal complications of APS1.Objective: To determine whether available serological and genetic markers are valuable screening tools for the identification of APS1 among patients diagnosed with Addison disease.Design: We systematically screened 677 patients with Addison disease enrolled in the Swedish Addison Registry for autoantibodies against interleukin-22 and interferon-α4. Autoantibody-positive patients were investigated for clinical manifestations of APS1, additional APS1-specific autoantibodies, and DNA sequence and copy number variations of AIRE.Results: In total, 17 patients (2.5%) displayed autoantibodies against interleukin-22 and/or interferon-α4, of which nine were known APS1 cases. Four patients previously undiagnosed with APS1 fulfilled clinical, genetic, and serological criteria. Hence, we identified four patients with undiagnosed APS1 with this screening procedure.Conclusion: We propose that patients with Addison disease should be routinely screened for cytokine autoantibodies. Clinical or serological support for APS1 should warrant DNA sequencing and copy number analysis of AIRE to enable early diagnosis and prevention of lethal complications.
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| 11. |
- Eriksson, Gabriella, et al.
(author)
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Debiasing time saving judgements by manipulation of speed display
- 2014
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In: Proceedings of the Human Factors and Ergonomics Society Europe Chapter 2013 Annual Conference. - Groningen, NL : Human Factors and Ergonomics Society Europe chapter. ; , s. 161-168
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Conference paper (peer-reviewed)abstract
- The time saving bias predicts that when increasing speeding from a high speed (e.g. 100 kph) the time saved is overestimated and underestimated when increasing speed from a slow speed (e.g. 30 kph). An alternative meter indicating the inverted speed (min/km) was used to debias time saving judgements in an active driving task. The simulated driving task was to first drive a distance at a given speed and then drive the same distance again at the speed the driver judged was required in order to gain exactly three minutes in travel time compared to the first drive. A control group performed the same task with a speedometer and saved less than the targeted three minutes when increasing speed from a high speed and more than three minutes when increasing from a low speed, as predicted by the time saving bias. Participants in the alternative meter group were closer to the target. The study shows that biased intuitive judgements can be affected by changing information format.
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| 12. |
- Eriksson, Gabriella, et al.
(author)
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Estimated Time of Arrival and Debiasing the Time Saving Bias
- 2015
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In: Ergonomics. - : Taylor & Francis. - 0014-0139 .- 1366-5847. ; 58:12, s. 1939-1946
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Journal article (peer-reviewed)abstract
- The time saving bias predicts that the time saved when increasing speed from a high speed is overestimated, and underestimated when increasing speed from a slow speed. In a questionnaire, time saving judgements were investigated when information of estimated time to arrival was provided. In an active driving task, an alternative meter indicating the inverted speed was used to debias judgements. The simulated task was to first drive a distance at a given speed, and then drive the same distance again at the speed the driver judged was required to gain exactly three minutes in travel time compared to the first drive. A control group performed the same task with a speedometer and saved less than the targeted three minutes when increasing speed from a high speed, and more than three minutes when increasing from a low speed. Participants in the alternative meter condition were closer to the target. The two studies corroborate a time saving bias and show that biased intuitive judgements can be debiased by displaying the inverted speed.
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| 13. |
- Eriksson, Gabriella, 1983-, et al.
(author)
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The time-saving bias : Judgements, cognition and perception
- 2013
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In: Judgment and Decision Making. - : Cambridge University Press (CUP). - 1930-2975. ; 8:4, s. 492-497
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Journal article (peer-reviewed)abstract
- Biases in people's judgments of time saved by increasing the speed of an activity have been studied mainly with hypothetical scenarios (Svenson, 2008). The present study asked whether the classic time-saving bias persists as a perceptual bias when we control the speed of an activity and assess the perceived time elapsed at different speeds. Specifically, we investigated the time-saving bias in a driving simulator. Each participant was asked to first drive a distance at a given speed and then drive the same distance again at the speed she or he judged necessary to gain exactly three minutes in travel time compared to the first trip. We found that that the time-saving bias applies to active driving and that it affects the choice of driving speed. The drivers' time-saving judgements show that the perception of the time elapsed while driving does not eliminate the time-saving bias.
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| 14. |
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| 15. |
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| 16. |
- Eriksson, Jonas, et al.
(author)
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Strategy to develop a MAO-A-resistant 5-hydroxy-L-[beta-C-11]tryptophan isotopologue based on deuterium kinetic isotope effects
- 2014
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In: EJNMMI Research. - : Springer Science and Business Media LLC. - 2191-219X. ; 4:1
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Journal article (peer-reviewed)abstract
- BackgroundThe serotonin precursor 5-hydroxy-L-[β-11C]tryptophan ([11C]HTP) is in clinical use for localization of neuroendocrine tumors and has been suggested as a proxy marker for pancreatic islet cells. However, degradation by monoamine oxidase-A (MAO-A) reduces retention and the contrast to non-endocrine tissue.MethodsA synthesis method was developed for 5-hydroxy-L-[β-11C2H]tryptophan ([11C]DHTP), an isotopologue of [11C]HTP, labeled with 11C and 2H at the β-position adjacent to the carbon involved in MAO-A decarboxylation. MAO-A-mediated degradation of [11C]DHTP was evaluated and compared to non-deuterated [11C]HTP.Results[11C]DHTP was synthesized with a radiochemical purity of >98%, radioactivity of 620 ± 190 MBq, and deuterium (2H or 2H2) incorporation at the β-position of 22% ±5%. Retention and resistance to MAO-A-mediated degradation of [11C]DHTP were increased in cells but not in non-human primate pancreas.ConclusionsPartial deuteration of the β-position yields improved resistance to MAO-A-mediated degradation in vitro but not in vivo.
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| 17. |
- Eriksson, Mats-Ola, et al.
(author)
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Morphologic Outcome after Endovascular Treatment of Complicated Type B Aortic Dissection
- 2013
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In: Journal of Vascular and Interventional Radiology. - : Elsevier BV. - 1051-0443 .- 1535-7732. ; 24:12, s. 1826-1833
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Journal article (peer-reviewed)abstract
- PURPOSE:To investigate the long-term morphologic changes of the aorta after thoracic endovascular aortic repair (TEVAR) for acute complicated type B aortic dissection and to analyze whether these changes differed between DeBakey class IIIa and IIIb dissections.MATERIALS AND METHODS:During the period 1999-2009, 58 patients with acute complicated type B aortic dissection were treated with TEVAR. Seven patients lacked follow-up data, leaving 51 patients-17 patients with DeBakey IIIa aortic dissection and 34 patients with DeBakey IIIa aortic dissection IIIb-for inclusion in the study. Computed tomography scans performed before and after TEVAR were evaluated. Maximum thoracic and abdominal aortic diameters and diameters of the true lumen and false lumen at the level of the maximum aortic diameter in the thorax and abdomen were analyzed as well as degree of thrombosis of the false lumen.RESULTS:There was an overall significant reduction of the thoracic aortic diameter, increased true lumen diameter, and reduced false lumen diameter (P < .05). Total thrombosis of the false lumen, with or without reintervention, was seen in 53% of all patients, in 41% primarily and in 12% after reintervention. The IIIa group had a higher degree of total false lumen thrombosis. All patients in the IIIb group had total thrombosis of the false lumen along the stent graft.CONCLUSIONS:Long-term follow-up showed favorable aortic remodeling after TEVAR for acute complicated type B aortic dissection. Total thrombosis of the false lumen occurred more often in patients with DeBakey IIIa aortic dissection compared with patients with DeBakey IIIb aortic dissection.
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| 18. |
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| 19. |
- Eriksson, Ola, 1967-, et al.
(author)
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In vitro evaluation of brain lesioning electrodes (Leksell) using a computer-assisted video system
- 1999
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In: Neurological Research. - 0161-6412 .- 1743-1328. ; 21:1, s. 89-95
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Journal article (peer-reviewed)abstract
- Radiofrequency (RF) generated thermal brain lesions are widely used in functional neurosurgery. The size, shape and development of the lesions depends on system parameter settings and the electrode configuration. Difficulties in studying the effect of these factors in vivo stimulated us to develop an in vitro system for standardized comparison between different electrodes and physical parameters. A computer-assisted video system was set-up allowing continuous video recording of RF-generated coagulations in either a standard albumin solution or in the fresh white of a hen's egg as transparent test substrates. Ten lesions were made with each test electrode (two bipolar and three monopolar) in each of the two substrates at 70 degrees, 80 degrees and 90 degrees C (t = 60 sec). Due to the better homogeneity the lesions in the albumin solution were much more regular and reproducible. This made it possible to calculate the size (width 2.2 +/- 0.1 to 5.3 +/- 0.1 mm and length 3.0 +/- 0.1 to 8.7 +/- 0.3 mm) as well as the volume (8.5 +/- 1.4 mm3 to 133.5 +/- 26.8 mm3). It is concluded that this in vitro system offers a reproducible way to study and document the effect of different electrode configurations and RF-generator settings on the formation of a heat lesion. Even if the results are not directly applicable to the living human brain they give an estimate of the form and size of a coagulation lesion and can be of value for standardized comparisons between different electrodes.
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| 20. |
- Fagerberg, Nils, 1972-, et al.
(author)
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Evaluation of individual-tree growth models for Picea abies based on a case study of an uneven-sized stand in southern Sweden
- 2022
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In: Scandinavian Journal of Forest Research. - : Taylor & Francis Group. - 0282-7581 .- 1651-1891. ; 37:1, s. 45-58
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Journal article (peer-reviewed)abstract
- To develop recommendations for tree selection in Continuous Cover Forestry (CCF), access to valid tools for simulating growth at individual tree-level is necessary. To assist efforts to develop such tools, in this study, long-term observation data from two uneven-sized Norway spruce plots in southern Sweden are used to evaluate old and new individual-tree growth models (two established Swedish models, two new preliminary models and included as a reference, a Finnish model). The plots' historical management records and site conditions are the same, but their last thinning treatment differs. Observed diameter increment at tree-level is investigated in relation to treatment. Individual tree growth residuals of tested models are evaluated in relation to tree diameter, treatment, projection length and sensitivity to the predictor mean stand age. Furthermore, the relations between displayed residuals and basal area local competition are analysed. The analyses indicate that active thinning made annual diameter increment independent of tree diameter above a threshold level, while the absence of thinning supported a concave relationship. All tested models displayed a significant linear bias leading to overestimation of small trees' growth and increasing underestimations of larger trees' growth with tree diameter. All distance-independent models displayed residual trends related to local competition.
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| 21. |
- Fang, C.M., et al.
(author)
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General trend of the mechanical properties of the ternary carbides M3SiC2 (M=transition metal)
- 2006
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In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 74:5, s. 054106-
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Journal article (peer-reviewed)abstract
- We present results from first-principles calculations of ternary transition metal carbides in the M3SiC2 series (where M=early transition metal). We predict structural and mechanical properties of these new MN+1AXN phases. The bulk modulus of the ternary carbides, M3SiC2, are in the calculations found to be proportional to the bulk modulus of the corresponding binary carbides, MC. We have analyzed this behavior using a simple, nearest-neighbor bond model, as well as from first-principles total energy calculations and have found that it is caused by a considerably weaker M-Si bond compared to the M-C bond.
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| 22. |
- Ljungman, Christer, et al.
(author)
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Propositions for refinement of the hybrid surgical technique for treatment of thoraco-abdominal aortic aneurysm
- 2008
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In: Scandinavian Journal of Surgery. - 1457-4969 .- 1799-7267. ; 97:2, s. 174-177
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Research review (peer-reviewed)abstract
- Traditional open repair of thoraco-abdominal aortic aneurysms Crawford type II-IV carries a high perioperative risk and mortality. The hybrid technique for combined surgical and endovascular treatment offers an interesting alternative with reduced risk of paraparesis and possibly a reduced mortality rate. Propositions for refinement of this approach are outlined based on a single centre experience.
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| 23. |
- Malinovschi, Andrei, 1978-, et al.
(author)
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Consequences of Using Post- or Prebronchodilator Reference Values in Interpreting Spirometry
- 2023
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In: American Journal of Respiratory and Critical Care Medicine. - : American Thoracic Society. - 1073-449X .- 1535-4970. ; 208:4, s. 461-471
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Journal article (peer-reviewed)abstract
- RATIONALE: Post-bronchodilator (BD) spirometry is used for diagnosis of chronic obstructive pulmonary disease (COPD). However, pre-BD reference values are used for spirometry interpretation.OBJECTIVES: To compare the resulting prevalence rates of abnormal spirometry and study the consequences of using pre- or post-BD reference values generated within the Swedish CArdioPulmonary bioImage Study (SCAPIS) when interpreting post-BD spirometry in a general population.METHODS: SCAPIS reference values for post-BD and pre-BD spirometry were based on 10,156 and 1,498 never-smoking, healthy participants, respectively. We studied the associations of abnormal spirometry, defined by using pre- or post-BD reference values, with respiratory burden in the SCAPIS general population (28,851 individuals).MEASUREMENTS AND MAIN RESULTS: Bronchodilation resulted in higher predicted median and lower limit of normal (LLN) for FEV1/FVC ratio. The prevalence of post-BD FEV1/FVC < pre-bronchodilator LLN was 4.8% and that of post-BD FEV1/FVC < post-bronchodilator LLN was 9.9% for the general population. An additional 5.1% was identified as having an abnormal post-BD FEV1/FVC ratio and this group had more respiratory symptoms, emphysema (13.5% vs. 4.1%, p<0.001) and self-reported physician-diagnosed COPD (2.8% vs. 0.5%, p<0.001) than subjects with post-BD FEV1/FVC ratio > LLN for both pre- and post-bronchodilation).CONCLUSIONS: Pre- and post-bronchodilator spirometry reference values differ with regard to FEV1/FVC ratio. Use of post-bronchodilator reference values doubled the population prevalence of airflow obstruction; this was related to a higher respiratory burden. Using post-bronchodilator reference values when interpreting post-bronchodilator spirometry might enable identification of individuals with mild disease and be clinically relevant.
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| 24. |
- Oskolkov, Nikolay, et al.
(author)
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High-throughput muscle fiber typing from RNA sequencing data
- 2022
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In: Skeletal Muscle. - : Springer Science and Business Media LLC. - 2044-5040. ; 12, s. 1-9
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Journal article (peer-reviewed)abstract
- Background: Skeletal muscle fiber type distribution has implications for human health, muscle function, and performance. This knowledge has been gathered using labor-intensive and costly methodology that limited these studies. Here, we present a method based on muscle tissue RNA sequencing data (totRNAseq) to estimate the distribution of skeletal muscle fiber types from frozen human samples, allowing for a larger number of individuals to be tested. Methods: By using single-nuclei RNA sequencing (snRNAseq) data as a reference, cluster expression signatures were produced by averaging gene expression of cluster gene markers and then applying these to totRNAseq data and inferring muscle fiber nuclei type via linear matrix decomposition. This estimate was then compared with fiber type distribution measured by ATPase staining or myosin heavy chain protein isoform distribution of 62 muscle samples in two independent cohorts (n = 39 and 22). Results: The correlation between the sequencing-based method and the other two were rATPas = 0.44 [0.13–0.67], [95% CI], and rmyosin = 0.83 [0.61–0.93], with p = 5.70 × 10–3 and 2.00 × 10–6, respectively. The deconvolution inference of fiber type composition was accurate even for very low totRNAseq sequencing depths, i.e., down to an average of ~ 10,000 paired-end reads. Conclusions: This new method (https://github.com/OlaHanssonLab/PredictFiberType) consequently allows for measurement of fiber type distribution of a larger number of samples using totRNAseq in a cost and labor-efficient way. It is now feasible to study the association between fiber type distribution and e.g. health outcomes in large well-powered studies.
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| 25. |
- Parikh, Hemang M, et al.
(author)
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Relationship between insulin sensitivity and gene expression in human skeletal muscle
- 2021
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In: BMC Endocrine Disorders. - : Springer Science and Business Media LLC. - 1472-6823. ; 21:1
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Journal article (peer-reviewed)abstract
- BACKGROUND: Insulin resistance (IR) in skeletal muscle is a key feature of the pre-diabetic state, hypertension, dyslipidemia, cardiovascular diseases and also predicts type 2 diabetes. However, the underlying molecular mechanisms are still poorly understood.METHODS: To explore these mechanisms, we related global skeletal muscle gene expression profiling of 38 non-diabetic men to a surrogate measure of insulin sensitivity, i.e. homeostatic model assessment of insulin resistance (HOMA-IR).RESULTS: We identified 70 genes positively and 110 genes inversely correlated with insulin sensitivity in human skeletal muscle, identifying autophagy-related genes as positively correlated with insulin sensitivity. Replication in an independent study of 9 non-diabetic men resulted in 10 overlapping genes that strongly correlated with insulin sensitivity, including SIRT2, involved in lipid metabolism, and FBXW5 that regulates mammalian target-of-rapamycin (mTOR) and autophagy. The expressions of SIRT2 and FBXW5 were also positively correlated with the expression of key genes promoting the phenotype of an insulin sensitive myocyte e.g. PPARGC1A.CONCLUSIONS: The muscle expression of 180 genes were correlated with insulin sensitivity. These data suggest that activation of genes involved in lipid metabolism, e.g. SIRT2, and genes regulating autophagy and mTOR signaling, e.g. FBXW5, are associated with increased insulin sensitivity in human skeletal muscle, reflecting a highly flexible nutrient sensing.
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| 26. |
- Puuvuori, Emmi, et al.
(author)
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Potential of [C-11]UCB-J as a PET tracer for islets of Langerhans
- 2021
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In: Scientific Reports. - : Springer Nature. - 2045-2322. ; 11
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Journal article (peer-reviewed)abstract
- Biomarkers for the measurement of islets of Langerhans could help elucidate the etiology of diabetes. Synaptic vesicle glycoprotein 2 A (SV2A) is a potential marker reported to be localized in the endocrine pancreas. [C-11]UCB-J is a novel positron emission tomography (PET) radiotracer that binds to SV2A and was previously evaluated as a synaptic marker in the central nervous system. Here, we evaluated whether [C-11]UCB-J could be utilized as a PET tracer for the islets of Langerhans in the pancreas by targeting SV2A. The mRNA transcription of SV2A was evaluated in human isolated islets of Langerhans and exocrine tissue. In vitro autoradiography was performed on pancreas and brain sections from rats and pigs, and consecutive sections were immunostained for insulin. Sprague-Dawley rats were examined with PET-MRI and ex vivo autoradiography at baseline and with administration of levetiracetam (LEV). Similarly, pigs were examined with dynamic PET-CT over the pancreas and brain after administration of [C-11]UCB-J at baseline and after pretreatment with LEV. In vivo radioligand binding was assessed using a one-compartment tissue model. The mRNA expression of SV2A was nearly 7 times higher in endocrine tissue than in exocrine tissue (p < 0.01). In vitro autoradiography displayed focal binding of [C-11]UCB-J in the pancreas of rats and pigs, but the binding pattern did not overlap with the insulin-positive areas or with ex vivo autoradiography. In rats, pancreas binding was higher than that in negative control tissues but could not be blocked by LEV. In pigs, the pancreas and brain exhibited accumulation of [C-11]UCB-J above the negative control tissue spleen. While brain binding could be blocked by pretreatment with LEV, a similar effect was not observed in the pancreas. Transcription data indicate SV2A to be a valid target for imaging islets of Langerhans, but [C-11]UCB-J does not appear to have sufficient sensitivity for this application.
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| 27. |
- Sallnäs, Ola, et al.
(author)
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Forest owner behavioral models, policy changes, and forest management. An agent-based framework for studying the provision of forest ecosystem goods and services at the landscape level
- 2019
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In: Forest Policy and Economics. - : Elsevier BV. - 1389-9341 .- 1872-7050. ; 103, s. 79-89
-
Journal article (peer-reviewed)abstract
- In this paper, we develop an interdisciplinary agent-based framework for studying the provision of forest ecosystem goods and services (ES) at the landscape level. It combines forest owner types and their behavioral models with forest decision support systems (DSS). For this, we draw on mainstream decision-making theories in social sciences and relevant empirical evidence from Europe and beyond to suggest how economic, sociological and psychological rationalities can be combined to build a typology and behavioral models of forest owner decision-making including responsiveness to policy and socioeconomic changes. We then discuss how the theory-driven and evidence-based behavioral models in combination with forest owner and forest management insights can be used to analyze forest management behavior and responsiveness to policy and socioeconomic developments. By comparing standard forest DSS modeling results to exemplary results using the agent-based framework in terms of long-term simulations of timber production and biodiversity conservation in a case study in Sweden, we illustrate how the framework accounts for more differentiated and more realistic forest management practices at the forest landscape level. We discuss how the agent-based framework also helps explore and explain the impacts of future policy and socioeconomic changes on the provision of forest ES. We then suggest directions for future research that can further develop the framework and its use in forest modeling and DSS to better analyze the impact of future developments on forest management and the provision of forest ES at the landscape level.
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| 28. |
- Ström, Kristoffer, et al.
(author)
-
Genetic variation at RAB3GAP2 and its role in exercise-related adaptation and recovery
- 2021
-
Other publication (other academic/artistic)abstract
- Skeletal muscle fiber composition and capillary density influence physical performance and whole-body metabolic properties. ~45% of the variance in fiber type is heritable, which motivated us to perform a genome-wide association study of skeletal muscle histology from 656 Swedish men. Four independent variants were associated (p
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| 29. |
- Tornberg, Åsa, et al.
(author)
-
Relation between cycling exercise capacity, fiber-type composition, and lower extremity muscle strength and muscle endurance.
- 2011
-
In: Journal of Strength and Conditioning Research. - 1533-4287. ; 25:1, s. 16-22
-
Journal article (peer-reviewed)abstract
- Segerström, ÅB, Holmbäck, AM, Hansson, O, Elgzyri, T, Eriksson, K-F, Ringsberg, K, Groop, L, Wollmer, P, and Thorsson, O. Relation between cycling exercise capacity, fiber-type composition, and lower extremity muscle strength and muscle endurance. J Strength Cond Res 25(1): 16-22, 2011-The aim of the study was to determine the relation between peak oxygen uptake (&OV0312;o2peak), peak work rate (WRpeak), fiber-type composition, and lower extremity strength and endurance during a maximal incremental cycle test. Thirty-nine healthy sedentary men, aged 30-46, participated in the study. Subjects performed a maximal incremental cycle test and isokinetic knee extension (KE) and flexion (KF) strength and endurance tests at velocities of 60 and 180°·s. Muscle biopsies were taken from m. vastus lateralis and analyzed for fiber-type composition. A significant correlation existed between KE strength and &OV0312;o2peak and WRpeak. Also, KF endurance correlated significantly to &OV0312;o2peak and WRpeak. The KE endurance correlated significantly to WRpeak (rp = 0.32, p < 0.05) and almost significantly to &OV0312;o2peak (rp = 0.28, p = 0.06). Stepwise multiple regression analyses showed that KE strength, KF endurance, and the percentage of type I fibers could explain up to 40% of the variation in &OV0312;o2peak and WRpeak. The performance of sedentary subjects in a maximal incremental cycle test is highly affected by knee muscle strength and endurance. Fiber-type composition also contributes but to a smaller extent.
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| 30. |
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| 31. |
- Abrahamsson, Maria, et al.
(author)
-
Steric influence on the excited-state lifetimes of ruthenium complexes with bipyridyl-alkanylene-pyridyl ligands.
- 2008
-
In: Inorganic Chemistry. - : ACS. - 0020-1669 .- 1520-510X. ; 47:9, s. 3540-3548
-
Journal article (peer-reviewed)abstract
- The structural effect on the metal-to-ligand charge transfer (MLCT) excited-state lifetime has been investigated in bis-tridentate Ru(II)-polypyridyl complexes based on the terpyridine-like ligands [6-(2,2'-bipyridyl)](2-pyridyl)methane (1) and 2-[6-(2,2'-bipyridyl)]-2-(2-pyridyl)propane (2). A homoleptic ([Ru(2)(2)](2+)) and a heteroleptic complex ([Ru(ttpy)(2)](2+)) based on the new ligand 2 have been prepared and their photophysical and structural properties studied experimentally and theoretically and compared to the results for the previously reported [Ru(1)(2)](2+). The excited-state lifetime of the homoleptic Ru-II complex with the isopropylene-bridged ligand 2 was found to be 50 times shorter than that of the corresponding homoleptic Ru-II complex of ligand 1, containing a methylene bridge. A comparison of the ground-state geometries of the two homoleptic complexes shows that steric interactions involving the isopropylene bridges make the coordination to the central Ru-II ion less octahedral in [Ru(2)(2)](2+) than in [Ru(1)(2))(2+). Calculations indicate that the structural differences in these complexes influence their ligand field splittings as well as the relative stabilities of the triplet metal-to-ligand charge transfer ((MLCT)-M-3) and metal-centered ((MC)-M-3) excited states. The large difference in measured excited-state lifetimes for the two homoleptic Ru-II complexes is attributed to a strong influence of steric interactions on the ligand field strength, which in turn affects the activation barriers for thermal conversion from (MLCT)-M-3 states to short-lived (MC)-M-3 states.
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| 32. |
- Ahmad, Shafqat, et al.
(author)
-
Telomere length in blood and skeletal muscle in relation to measures of glycaemia and insulinaemia.
- 2012
-
In: Diabetic Medicine: A journal of the British Diabetic Association. - : Wiley. - 1464-5491 .- 0742-3071. ; 29:10, s. 377-381
-
Journal article (peer-reviewed)abstract
- Aims: Skeletal muscle is a major metabolic organ and plays important roles in glucose metabolism, insulin sensitivity and insulin action. Muscle telomere length reflects the myocyte's exposure to harmful environmental factors. Leukocyte telomere length is considered a marker of muscle telomere length and is used in epidemiologic studies to assess associations with ageing-related diseases where muscle physiology is important. However, the extent to which leucocyte and muscle telomere length are correlated is unknown, as are their relative correlations with glucose and insulin concentrations. The purpose of this study was to determine the extent of these relationships. Methods: Leucocyte and muscle telomere length were measured by quantitative real-time polymerase chain reaction in participants from the Malmö Exercise Intervention (n = 27) and the Prevalence, Prediction and Prevention of Diabetes-Botnia studies (n = 31). Participants in both studies were free from Type 2 diabetes. We assessed the association between leucocyte telomere length, muscle telomere length and metabolic traits using Spearmen correlations and multivariate linear regression. Bland-Altman analysis was used to assess agreement between leucocyte and muscle telomere length. Results: In age-, study-, diabetes family history- and sex-adjusted models, leucocyte and muscle telomere length were positively correlated (r = 0.39, 95% CI 0.15-0.59). Leucocyte telomere length was inversely associated with 2-h glucose concentrations (r = -0.58, 95% CI -1.0 to -0.16), but there was no correlation between muscle telomere length and 2-h glucose concentrations (r = 0.05, 95% CI -0.35 to 0.46) or between leucocyte or muscle telomere length with other metabolic traits. Conclusions: In summary, the current study supports the use of leucocyte telomere length as a proxy for muscle telomere length in epidemiological studies of Type 2 diabetes aetiology.
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| 33. |
- Alterbeck, Max, et al.
(author)
-
Designing and Implementing a Population-based Organised Prostate Cancer Testing Programme.
- 2022
-
In: European urology focus. - : Elsevier BV. - 2405-4569. ; 8:6, s. 1568-1574
-
Journal article (peer-reviewed)abstract
- European guidelines recommend that well-informed men at elevated risk of having prostate cancer (PCa) should be offered prostate-specific antigen (PSA) testing with risk-stratified follow-up. The Swedish National Board of Health and Welfare recommends against screening for PCa but supports regional implementation of organised prostate cancer testing (OPT).To report the process for designing and implementing OPT programmes.Population-based OPT programmes in two Swedish regions, designed to include men aged between 50 and 74 yr, launched in September 2020 for 50-yr-old men.The number of men invited, the participation rate, and the numbers of magnetic resonance imaging (MRI) scans, urological visits, and biopsies from September 2020 to June 2021 were recorded.Two Swedish regions co-designed an OPT programme with a risk-stratified diagnostic algorithm based on prostate-specific antigen (PSA), PSA density, MRI findings, and age. An automated administrative system was developed on a nationwide web-based platform. Invitation letters and test results are automatically generated and sent out by post. Men with PSA ≥3ng/ml, a suspicious MRI lesion, and/or PSA density ≥0.15ng/ml/cm3 are referred for a prostate biopsy. Test results are registered for quality control and research. By June 2021, a total of 16515 men were invited, of whom 6309 (38%) participated; 147 had an MRI scan and 39 underwent prostate biopsy. The OPT framework, algorithm, and diagnostic pathways have been working well.We designed and implemented a framework for OPT with a high grade of automation. The framework and organisational experiences may be of value for others who plan a programme for early detection of PCa.We describe the implementation of an organised testing programme for early detection of prostate cancer in two Swedish regions. This model is the first of its kind and may serve as a template for similar programmes.
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| 34. |
- Andersen, Niklas, et al.
(author)
-
Wind turbines’ end-of-life : Quantification and characterisation of future waste materials on a national level
- 2016
-
In: Energies. - : MDPI AG. - 1996-1073. ; 9:12
-
Journal article (peer-reviewed)abstract
- Globally, wind power is growing fast and in Sweden alone more than 3000 turbines have been installed since the mid-1990s. Although the number of decommissioned turbines so far is few, the high installation rate suggests that a similarly high decommissioning rate can be expected at some point in the future. If the waste material from these turbines is not handled sustainably the whole concept of wind power as a clean energy alternative is challenged. This study presents a generally applicable method and quantification based on statistics of the waste amounts from wind turbines in Sweden. The expected annual mean growth is 12% until 2026, followed by a mean increase of 41% until 2034. By then, annual waste amounts are estimated to 240,000 tonnes steel and iron (16% of currently recycled materials), 2300 tonnes aluminium (4%), 3300 tonnes copper (5%), 340 tonnes electronics (<1%) and 28,000 tonnes blade materials (barely recycled today). Three studied scenarios suggest that a well-functioning market for re-use may postpone the effects of these waste amounts until improved recycling systems are in place.
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| 35. |
- Andersson, Anders, et al.
(author)
-
A Driving Simulation Platform using Distributed Vehicle Simulators and HLA
- 2015
-
In: Proceedings of the DSC 2015 Europe. - 9783981309935 ; , s. 123-130
-
Conference paper (peer-reviewed)abstract
- Modern vehicles are complex systems consisting of an increasing large multitude of components that operate together. While functional verification on individual components is important, it is also important to test components within a driving environment, both from a functional perspective and from a driver perspective. One proven way for testing is vehicle simulators and in this work the main goals have been to increase flexibility and scalability by introducing a distributed driving simulator platform.As an example, consider a workflow where a developer can go from a desktop simulation to an intermediate driving simulator to a high fidelity driving simulator with Hardware-In-the-Loop systems close to a finished vehicle in an easy way. To accomplish this, a distributed simulation architecture was designed and implemented that divides a driving simulator environment into four major entities with well-defined interfaces, using HLA as the method of communication. This platform was evaluated on two aspects, flexibility/scalability and timing performance. Results show that increased flexibility and scalability was achieved when using a distributed simulation platform. It is also shown that latency was only slightly increased when using HLA.
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| 36. |
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| 37. |
- Andersson, Maria, 1977, et al.
(author)
-
The effects of environmental management systems on source separation in the work and home settings
- 2012
-
In: Sustainability. - Basel : MDPI AG. - 2071-1050. ; 4, s. 1292-1308
-
Journal article (peer-reviewed)abstract
- Measures that challenge the generation of waste are needed to address the global problem of the increasing volumes of waste that are generated in both private homes and workplaces. Source separation at the workplace is commonly implemented by environmental management systems (EMS). In the present study, the relationship between source separation at work and at home was investigated. A questionnaire that maps psychological and behavioural predictors of source separation was distributed to employees at different workplaces. The results show that respondents with awareness of EMS report higher levels of source separation at work, stronger environmental concern, personal and social norms, and perceive source separation to be less difficult. Furthermore, the results support the notion that after the adoption of EMS at the workplace, source separation at work spills over into source separation in the household. The potential implications for environmental management systems are discussed. © 2012 by the authors.
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| 38. |
- Antoniadou-Plytaria, Kyriaki, 1989, et al.
(author)
-
Effect of Short-term and High-resolution Load Forecasting Errors on Microgrid Operation Costs
- 2022
-
In: IEEE PES Innovative Smart Grid Technologies Conference Europe. - 9781665480321 ; 2022-October
-
Conference paper (peer-reviewed)abstract
- The aim of this paper is to evaluate the effect of the load forecasting errors to the operation costs of a grid-connected microgrid. To this end, a microgrid energy scheduling optimization model was tested with deterministic and stochastic formulations under two solution approaches i.e., day-ahead and rolling horizon optimization. In total, twelve simulation test cases were designed receiving as input the forecasts provided by one of the three implemented machine learning models: linear regression, artificial neural network with backpropagation, and long short-term memory. Simulation results of the weekly operation of a real residential building (HSB Living Lab) showed no significant differences among the costs of the test cases for a daily mean absolute percentage forecast error of about 12%. These results suggest that operators of similar microgrid systems could use simplifying approaches, such as day-ahead deterministic optimization, and forecasts of similar, non-negligible accuracy without substantially affecting the microgrid's total cost as compared to the ideal case of perfect forecast. Improving the accuracy would mainly reduce the microgrid's peak power cost as shown by its 20.2% increase in comparison to the ideal case.
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| 39. |
- Antonsson, Johan, et al.
(author)
-
Diffuse reflectance spectroscopy measurements for tissue type discrimination during deep brain stimulation
- 2008
-
In: Journal of neural engineering. - : IOP Publishing. - 1741-2560 .- 1741-2552. ; 5:2, s. 185-190
-
Journal article (peer-reviewed)abstract
- Diffuse reflectance spectroscopy as a method for improving intracerebral guidance during functional neurosurgery has been investigated. An optical probe was developed for measurements during stereotactic and functional neurosurgery in man. The aim of the study was to investigate the spectral differences between white and grey matter and between white matter and functional targets. Diffuse reflectance spectroscopy measurements in ten patients were recorded at incremental steps towards and in three different functional targets (STN, GPi and Zi). The recorded spectra along the trajectory were sorted into white or grey matter, based on preoperative MRI images or the recorded spectral shape and intensity. The difference between tissue types was calculated as a quotient. Significant intensity differences between white and grey matter were found to be at least 14% (p < 0.05) and 20% (p < 0.0001) for MRI and spectral-sorted data respectively. The reflectance difference between white matter and the functional targets of GPi was higher than for STN and Zi. The results indicate that diffuse reflectance spectroscopy has a potential to be developed to a suitable complement to other intracerebral guidance methods.
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| 40. |
- Antonsson, Johan, et al.
(author)
-
In-vivo reflection spectroscopy measurements in pig brain during stereotactic surgery
- 2003
-
In: Biophotonics West. - : SPIE. ; , s. 242-250
-
Conference paper (peer-reviewed)abstract
- Radiofrequency (RF) lesioning in the human brain is a commonsurgical therapy for relieving severe pain as well as formovement disorders such as Parkinsonia. During the procedure a smallelectrode is introduced by stereotactic means towards a target arealocalized by CT or MRI. An RF-current is applied throughthe electrode tip when positioned in the target area. Thetissue in the proximity of the tip is heated bythe current and finally coagulated.The overall aim of this studywas to improve the RF-technique and its ability to estimatelesion size by means of optical methods. Therefore, the opticaldifferences between white and gray matter, as well as lesionedand unlesioned tissue were investigated. Reflection spectroscopy measurements in therange of 450-800 nm were conducted on fully anesthetized pigsduring stereotactic RF-lesioning (n=6). Light from a tungsten lamp wasguided to the electrode tip through optical fibers, inserted alonga 2 mm in diameter monopolar RF-electrode. Measurements were performedin steps of 0-10 mm from the target in eachhemisphere towards the entry point of the skull. In thecentral gray of the porcine brain measurements were performed bothbefore and after the creation of a lesion. A totalof 55 spectra were collected during this study. Correlation totissue type was done using post-operative MR-images. The spectral signaturefor white and gray matter differs significantly for the entirespectral range of 450-800 nm. Pre- and post-lesioning reflection spectroscopyshowed the largest differences below 600 and above 620 nm,which implies that lasers within this wavelength range may beuseful for in-vivo measurements of tissue optical changes during RF-lesioning.
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| 41. |
- Antonsson, Johan, et al.
(author)
-
Optical measurements during experimental stereotactic radiofrequency lesioning
- 2006
-
In: Stereotactic and Functional Neurosurgery. - : S. Karger. - 1011-6125 .- 1423-0372. ; 84:2-3, s. 118-124
-
Journal article (peer-reviewed)abstract
- The aim of this study was to evaluate in vivo a laser Doppler measurement system in porcine brain tissue during thermal lesioning. A 2-mm monopolar radiofrequency lesioning electrode was equipped with optical fibers in order to monitor the lesioning procedure. Laser Doppler and backscattered light intensity signals were measured along the electrode trajectory and during bilateral lesioning in the central gray (70, 80 and 90°C, n = 14). The time course of the coagulation process could be followed by optical recordings. Two separate groups of tissue were identified from the intensity signals. The changes in the perfusion levels in both groups displayed significant changes (p < 0.05, n = 48) at all temperature settings, while backscattered light intensity was significant for only one group at the different temperatures (p < 0.05, n = 39). These results indicate that optical measurements correlate with lesion development in vivo. The study also indicates that it is possible to follow the lesioning process intra-operatively.
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| 42. |
- Antonsson, Johan, et al.
(author)
-
Radio frequency electrode system for optical lesion size estimation in functional neurosurgery
- 2005
-
In: Journal of Biomedical Optics. - : SPIE - International Society for Optical Engineering. - 1083-3668 .- 1560-2281. ; 10:3, s. 1-6
-
Journal article (peer-reviewed)abstract
- Radiofrequency(RF) lesioning in the human brain is one possible surgicaltherapy for severe pain as well as movement disorders. Oneobstacle for a safer lesioning procedure is the lack ofsize monitoring. The aim of this study was to investigateif changes in laser Doppler or intensity signals could beused as markers for size estimation during experimental RF lesioning.A 2 mm in diameter monopolar RF electrode was equippedwith optical fibers and connected to a digital laser Dopplersystem. The optical RF electrode's performance was equal to astandard RF electrode with the same dimensions. An albumin solutionwith scatterers was used to evaluate the intensity and laserDoppler signal changes during lesioning at 70, 80, and 90 °C.Significant signal changes were found for these three different clotsizes, represented by the temperatures (p<0.05, n=10). The volume, width, andlength of the created coagulations were correlated to the intensitysignal changes (r=0.88, n=30, p<0.0001) and to the perfusion signalchanges (r=0.81, n=30, p<0.0001). Both static and Doppler-shifted light canbe used to follow the lesioning procedure as well asbeing used for lesion size estimation during experimental RF lesioning.
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| 43. |
- Arfan, Muhammad, et al.
(author)
-
Biogas as a transport fuel—a system analysis of value chain development in a Swedish context
- 2021
-
In: Sustainability. - : MDPI. - 2071-1050. ; 13:8
-
Journal article (peer-reviewed)abstract
- Biofuels policy instruments are important in the development and diffusion of biogas as a transport fuel in Sweden. Their effectiveness with links to geodemographic conditions has not been analysed systematically in studying biogas development in a less urbanised regions, with high potential and primitive gas infrastructure. One such region identified is Gävleborg in Sweden. By using value chain statistics, interviews with related actors, and studying biofuels policy instruments and implications for biogas development, it is found that the policy measures have not been as effective in the region as in the rest of Sweden due to different geodemographic characteristics of the region, which has resulted in impeded biogas development. In addition to factors found in previous studies, the less-developed biogas value chain in this region can be attributed particularly to undefined rules of the game, which is lack of consensus on trade-off of resources and services, unnecessary competition among several fuel alternatives, as well as the ambiguity of municipalities’ prioritization, and regional cultural differences. To strengthen the regional biogas sector, system actors need a strategy to eliminate blocking effects of identified local factors, and national policy instruments should provide mechanisms to process geographical conditions in regulatory, economic support, and market formation.
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| 44. |
- Arfan, Muhammad, et al.
(author)
-
Life cycle assessment and life cycle costing of hydrogen production from biowaste and biomass in Sweden
- 2023
-
In: Energy Conversion and Management. - : Elsevier. - 0196-8904 .- 1879-2227. ; 291
-
Journal article (peer-reviewed)abstract
- In this study, an environmental and economic assessment of hydrogen production from biowaste and biomass is performed from a life cycle perspective, with a high degree of primary life cycle inventory data on materials, energy, and investment flows. Using SimaPro LCA software and CML-IA, 2001 impact assessment method, ten environmental impact categories are analyzed for environmental analysis. Economic analysis includes capital and operational expenditures and monetization cost of life cycle environmental impacts. The hydrogen production from biowaste has a high climate impact, photochemical oxidant, and freshwater eutrophication than biomass while it performs far better in ozone depletion, terrestrial ecotoxicity, abiotic depletion-fossil, abiotic depletion, human toxicity, and freshwater ecotoxicity. The sensitivity analysis of LCA results indicates that feedstock to biogas/pyrolysis-oil yields ratio and the type of energy source for the reforming process can significantly influence the results, particularly climate change, abiotic depletion, and human toxicity. The life cycle cost (LCC) of 1 kg hydrogen production has been accounted as 0.45–2.76 € with biowaste and 0.54–3.31 € with biomass over the plant's lifetime of 20 years. From the environmental impacts of climate change, photochemical oxidant, and freshwater eutrophication hydrogen production from biomass is a better option than biowaste while from other included impact categories and LCC perspectives it’s biowaste. This research contributes to bioresources to hydrogen literature with some new findings that can be generalized in Europe and even globally as it is in line with and endorse existing theoretical and simulation software-based studies.
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| 45. |
- Arfan, Muhammad
(author)
-
Utilization of local bioresources for transport fuels - System analysis for decision support
- 2023
-
Licentiate thesis (other academic/artistic)abstract
- This thesis presents a comprehensive system analysis of the utilization of biowaste and forest industry residues to produce transportation fuels. It explores various aspects such as the constraints to the production system’s value chain development, the utilization of the geographical proximity of biofuel technology innovation system components, environmental impacts, and economic costs. The primary goal is to establish a knowledge base that can aid regional policymakers and decision-makers in formulating informed policies for the efficient management of local bioresources for transport fuel production. By addressing these aspects, the study seeks to contribute to the wider discourse on efficient local bioresource management and transition to a low-carbon economy. The focused bioresources in this thesis are municipal biowaste and forest industry residues (i.e., sawdust, black liquor, crude tall oil, and fiber waste of the pulp and paper industry). The study focuses on three systems: i) biowaste to biogas for transport, ii) biowaste and sawdust to hydrogen, and iii) forest industry residues to liquid biofuels for transport.The biofuel policy instruments in Sweden have proven to be effective in introducing alternative transport fuels, particularly in big cities or urban areas. The results of the biowaste to biogas value chain analysis show that development in the Gävleborg region is stagnated throughout the value chain compared to the national average. This stagnation is mainly attributed to local geodemographic factors. The identified obstacles to development include a lack of regional political agreement regarding the use of biogas as a viable transport fuel, insufficient connectivity and communication among the various regional actors and stakeholders, and a limited understanding among stakeholders of the potential and socio-economic impacts of biogas. The environmental and economic assessment of hydrogen production from biowaste and sawdust is performed from a life cycle perspective, using SimaPro LCA software and CML-IA, 2001 impact assessment method. Economic analysis includes capital and operational expenditures and monetization cost of life cycle environmental impacts. The results show that hydrogen production from biowaste has a higher global warming, photochemical oxidant, and freshwater eutrophication potential than sawdust. Biowaste conversion to hydrogen performs far better in ozone depletion, terrestrial ecotoxicity, abiotic depletion-fossil, abiotic depletion, human toxicity, and freshwater ecotoxicity potential. The fossil energy inputs in biogas and pyrolysis oil reforming, emissions from the digestate treatment, storage, and utilization as bio-fertilizer are the main contributing processes to the overall environmental impacts of biowaste and sawdust conversion to hydrogen. The sensitivity analysis of the LCA results indicates that feedstock to biogas/pyrolysis oil yield ratio and the type of energy source for the reforming process can significantly influence the results, particularly climate change, abiotic depletion, and human toxicity. The life cycle cost (LCC) analysis reveals that the production of hydrogen from biowaste exhibits a lower cost compared to sawdust. This significant cost reduction in the biowaste case can be attributed to lower variable operating expenses (OPEX), primarily due to the price of the biowaste itself. Whereas, in the sawdust case, the feedstock contributes the highest percentage (54%) to the system's OPEX, indicating that variable OPEX is highly sensitive to sawdust prices. Additionally, the capital investment required for the biowaste case was 50% lower, which further contributes to the lower overall LCC compared to the sawdust case.The results of forest industry residues to liquid biofuel technology development and the utilization of system components in geographical proximity indicate that geographical proximity can significantly influence the system’s structural growth, trajectory, and development pace. An adapted version of the technological innovation system (TIS) framework was operationalized with the lens of geographical proximity utilization of the system components to the technology development and diffusion. The method of data acquisition involved document analysis and interviews with subsystem actors. The study found that the development of the system is hampered by competition between technologies and low utilization of geographical proximity of the system components, which was partly attributed to a lack of network among subsystem actors and with the national TIS structure. Bioresources in Gävleborg are present in substantial amounts, particularly biowaste from agriculture, the food industry, and households, as well as biomass from the forest industry, which have the potential to be utilized for transport fuel production. However, the evolution of their utilization to power transportation in Gävleborg has been delayed in comparison to several other regions in Sweden. In the case of the technology development of forest industry residue-based transport fuels, the utilization of geographical proximity of artefacts and institutions has played a crucial role. Significant strides have been accomplished in diverse technology domains. However, these advancements have faced obstacles, partially due to the rivalry among system actors aiming to secure a competitive edge in acquiring both knowledge and capital resources and the underutilization of the geographical proximity of actors and industry networks. Based on these research findings, recommendations are provided to support policy and strategy aiming to enhance the utilization of local bioresources for transportation fuels sustainably and cost-effectively with increased local benefits. For example, the study recommends addressing the identified local political, communication, and networking issues, along with integrating regional geodemographic conditions into national biofuel policies and measures. By addressing identified challenges, the Gävleborg region can overcome the stagnation in bioresource to transportation fuel technological systems development and leverage its significant potential.This thesis adds valuable insights to the sustainability transition literature about the environment, economy, and the geography of innovation processes. The findings highlight the need for policy interventions to foster collaboration, coordination, and knowledge sharing among stakeholders, as well as support for the development and commercialization of emerging technologies, including forest-based transport fuel technologies. The analysis of cost and environmental impacts of bioresource utilization for hydrogen production provides insights into the potential trade-offs and benefits of different feedstocks and impact categories. The study provides important input for policy and strategy development towards a more sustainable and cost-effective use of local bioresources for transport fuel production in Gävleborg. This study can also serve as a valuable reference for researchers, policymakers, and stakeholders interested in the sustainable utilization of renewable resources for biofuel production, contributing to the advancement of knowledge in this critical area.
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| 46. |
- Arushanyan, Yevgeniya, et al.
(author)
-
Environmental Assessment of Possible Future Waste Management Scenarios
- 2017
-
In: Energies. - : MDPI AG. - 1996-1073. ; 10:2
-
Journal article (peer-reviewed)abstract
- Waste management has developed in many countries and will continue to do so. Changes towards increased recovery of resources in order to meet climate targets and for society to transition to a circular economy are important driving forces. Scenarios are important tools for planning and assessing possible future developments and policies. This paper presents a comprehensive life cycle assessment (LCA) model for environmental assessments of scenarios and waste management policy instruments. It is unique by including almost all waste flows in a country and also allow for including waste prevention. The results show that the environmental impacts from future waste management scenarios in Sweden can differ a lot. Waste management will continue to contribute with environmental benefits, but less so in the more sustainable future scenarios, since the surrounding energy and transportation systems will be less polluting and also because less waste will be produced. Valuation results indicate that climate change, human toxicity and resource depletion are the most important environmental impact categories for the Swedish waste management system. Emissions of fossil CO2 from waste incineration will continue to be a major source of environmental impacts in these scenarios. The model is used for analyzing environmental impacts of several policy instruments including weight based collection fee, incineration tax, a resource tax and inclusion of waste in a green electricity certification system. The effect of the studied policy instruments in isolation are in most cases limited, suggesting that stronger policy instruments as well as combinations are necessary to reach policy goals as set out in for example the EU action plan on circular economy.
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| 47. |
- Arvedson, Mats, et al.
(author)
-
Packet or Circuit Switched Voice Radio Bearers-A Capacity Evaluation for GERAN
- 2002
-
Conference paper (peer-reviewed)abstract
- GERAN, including the EDGE radio interface, con-stitutes the 3G evolution of GSM. The use of packet switched voice radio bearers has been discussed in the GERAN standardization, but has as yet not been adopted. This paper presents a thorough capacity comparison of circuit and packet switched voice bearers, applied to GERAN. Thus the standardization decision is verified, but also a framework for future similar investigations is provided. Several parameters affect the relative performance of circuit and packet switching. This report evaluates the effect of four of these parameters, expected to have major impact on the relative performance: reuse factor, resource pool size, voice activity, and additional overhead in the packet switched case. Varying the above parameters, it is seen that in certain blocking-limited scenarios packet switching may increase capacity significantly. The highest overall capacity is however achieved in inter-ference-limited scenarios, for which packet switching provides no capacity gain.
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| 48. |
- Assefa, Getachew, et al.
(author)
-
Environmental assessment of building properties — Where natural and social sciences meet : the case of EcoEffect
- 2007
-
In: Building and Environment. - : Elsevier BV. - 0360-1323 .- 1873-684X. ; 42:3, s. 1458-1464
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Journal article (peer-reviewed)abstract
- The EcoEffect method of assessing external and internal impacts of building properties is briefly described. The external impacts of manufacturing and transport of the building materials, the generation of power and heat consumed during the operation phase are assessed using life-cycle methodology. Emissions and waste; natural resource depletion and toxic substances in building materials are accounted for. Here methodologies from natural sciences are employed. The internal impacts involve the assessment of the risk for discomfort and ill-being due to features and properties of both the indoor environment and outdoor environment within the boundary of the building properties. This risk is calculated based on data and information from questionnaires; measurements and inspection where methodologies mainly from social sciences are used. Life-cycle costs covering investment and utilities costs as well as maintenance costs summed up over the lifetime of the building are also calculated.The result presentation offers extensive layers of diagrams and data tables ranging from an aggregated diagram of environmental efficiency to quantitative indicators of different aspects and factors. Environmental efficiency provides a relative measure of the internal quality of a building property in relation to its external impact vis-à-vis its performance relative to other building properties.
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| 49. |
- Assefa, Getachew, et al.
(author)
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Kompostering eller förbränning av hushållsavfall i Stockholm : En systemstudie av effekter på miljö, energi och ekonomi
- 2001
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Reports (other academic/artistic)abstract
- En systemanalys som utvärderar potentiella effekter på miljön, energiomsättning och ekonomi har genomförts där storskalig kompostering jämförts med förbränning. Studien har utförts på uppdrag av Birka Värme och är tänkt som en jämförelse av olika former av kapacitetsökning för behandling av avfall i Stockholmsområdet. Förebilder för behandlingsprocesserna är avfallsförbränningsanläggningen Högdalenverket som drivs av Birka Energi och en planerad storskalig komposteringsanläggning i Stora Vika i Rondecos regi. Avfallet samlas in från Stockholm med närområden. Avfallet består till större delen av lättnedbrytbart organiskt avfall och slam från reningsverk. Även rötning har jämförts där en mindre del av totala avfallet, motsvarande ledig kapacitet i rötningsanläggningen, behandlas.Studien visar att det ur de flesta av de betraktade aspekterna är fördelaktigare att förbränna avfallet än att kompostera det. Detta beror på miljöpåverkan (övergödning och höga tungmetallhalter) i hanteringen av kompostpelletsen och inverkan av att förlorad fjärrvärmeproduktion vid kompostering måste ersättas.Kompostering är att föredra ur klimatsynpunkt då dess bidrag till global uppvärmning (växthuseffekten) är totalt sett något lägre än för förbränning. Det beror till största del på att koldioxid från förbränning av plast som finns i avfallet frigörs vid avfallsförbränningen. Skillnaden är dock inom felmarginalen och resultatet bör ej tas för självklart.För den potentiella miljöeffekten försurning är det dött lopp mellan kompostering och förbränning. Förbränningen av avfall ger visserligen högre försurande utsläpp än komposteringen men när hänsyn tas till att förlorad fjärrvärme måste ersättas vid kompostering och att det går åt mer elektricitet vid kompostering, elektricitet som antas framställas från förbränning av kol, jämnar resultatet ut sig.Det finns en hel del svagheter i analysen, bland annat är det inte fullständigt klarlagt vilka materialbalanser som råder i komposteringsprocessen. Även för spridningen av kompostpelletsen råder stora osäkerheter. I dessa fall har antaganden gjorts men det är viktigt att i den fortsatta granskningen använda tillförlitligare data.
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| 50. |
- Assefa, Getachew, et al.
(author)
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Life Cycle Assessment of Thermal Treatment Technologies : An environmental and financial systems analysis of gasification, incineration and landfilling of waste
- 2002
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Reports (other academic/artistic)abstract
- A technology which is currently developed by researchers at KTH is catalytic combustion which is one component of a gasification system. Instead of performing the combustion in the gas turbine by a flame, a catalyst is used. When the development of a new technology (as catalytic combustion) reaches a certain step where it is possible to quantify material-, energy- and capital flows, the prerequisites for performing a systems analysis is at hand. The systems analysis can be used to expand the know-how about the potential advantages of the catalytic combustion technology by highlighting its function as a component of a larger system. In this way it may be possible to point out weak points which have to be investigated more, but also strong points to emphasise the importance of further development.The aim of this project was to assess the energy turnover as well as the potential environmental impacts and economic costs of thermal treatment technologies in general and catalytic combustion in particular. By using a holistic assessment of the advantages and disadvantages of catalytic combustion of waste it was possible to identify the strengths and weaknesses of the technology under different conditions. Following different treatment scenarios have been studied: (1) Gasification with catalytic combustion, (2) Gasification with flame combustion, (3) Incineration with energy recovery and (4) Landfilling with gas collection. In the study compensatory district heating is produced by combustion of biofuel. The power used for running the processes in the scenarios is supplied by the waste-to-energy technologies themselves while compensatory power is assumed to be produced from natural gas. The emissions from the system studied were classified and characterised using methodology from Life Cycle Assessment into the following environmental impact categories: Global Warming Potential (also called the green house effect), Acidification Potential, Eutrophication Potential and finally Formation of Photochemical Oxidants.It is obvious that a decreased use of landfilling in favour of an increased energy recovery from waste is positive from all considered impact categories. Gasification with energy recovery in a combi cycle using catalytic combustion in the gas turbine is the most competitive technology from primarily an environmental point of view. The financial costs are however a bit higher than for incineration with energy recovery. This conclusion depends, however, on the assumption that the gasification and catalyst technologies work as the researchers presume and that the fuel is of high quality. For this, the pelletising unit is vital in the technology chain.A comparison of the catalytic combustion and the flame combustion shows that all impact categories except acidification, eutrophication and photochemical oxidants remain the same. The gasification process is identical between the two alternatives; it is just the combustion technology in the gas turbine that is different. This explains why the fuel consumption and the financial costs are not changed (a minor extra investment is made for the catalyst but is not noticeable in comparison to the total impact). Emissions of greenhouse gases are also identical. For the other impact categories there are differences for several of the emissions involved in the impact assessment but NOX is clearly the dominating one.Gasification with catalytic combustion is competitive to incineration. The small difference for eutrophication is within the error margin and is strongly dependent on the reduction of NOX in the incineration plant. The explanation to this result is that a combi cycle in combination with natural gas as the alternative power generation is a better system solution than incineration with biofuel as compensatory fuel. Financial costs are somewhat higher than for incineration but could also claimed to be within the error margin since the inventory of costs are more uncertain due to the fact that there is no plant with gasification and catalytic combustion in operation.
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