| 1. |
- Butler, Simon, et al.
(författare)
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An Exploration of Openness in Hardware and Software Through Implementation of a RISC-V Based Desktop Computer
- 2022
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Ingår i: OpenSym '22. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450398459 - 9781450398466
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Konferensbidrag (refereegranskat)abstract
- Open hardware and open source software platforms bring benefits to both implementers and users in the form of system adaptability and maintainability, and through the avoidance of lock-in, for example. Development of the \riscv\ Instruction Set Architecture and processors during the last ten years has made the implementation of a desktop computer using open hardware, including open processors, and open source software an approaching possibility. We use the SiFive Unmatched development board and Ubuntu Linux, and the recorded experiences of system builders using the Unmatched board to explore the extent to which it is possible to create an open desktop computer. The work identifies current limitations to implementing an open computer system, which lie mainly at the interface between the operating system and hardware components. Potential solutions to the challenges uncovered are proposed, including greater consideration of openness during the early stages of product design. A further contribution is made by an account of the synergies arising from open collaboration in a private-collective innovation process.
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| 2. |
- Engdahl, Jenny, et al.
(författare)
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Effects of surgical specialization and surgeon resection volume on postoperative complications and mortality rate after emergent colon cancer resection
- 2023
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Ingår i: BJS Open. - 2474-9842. ; 7:3
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Tidskriftsartikel (refereegranskat)abstract
- Background: The aim of this study was to evaluate the effect of surgical specialization and surgeon resection volume on short-term outcome after emergent colon cancer resections. Methods: A retrospective analysis of all patients who underwent resections for colon cancer between 2011 and 2020 at Helsingborg Hospital, Sweden was performed. The senior surgeon participating in each procedure was classified as a colorectal surgeon or a non-colorectal surgeon. Non-colorectal surgeons were further divided into acute care surgeons or surgeons with other specialties. Surgeons were also divided into three groups based on median yearly resection volumes. Postoperative complications and 30- or 90-day mortality rate after emergent colon cancer resections were compared in patients operated on by surgeons with different specializations and yearly resection volumes. Results: Of 1121 patients resected for colon cancer, 235 (21.0 per cent) had emergent procedures. The complication rate of emergent resections was similar in patients operated on by colorectal surgeons and non-colorectal surgeons (54.1 versus 51.1 per cent respectively), and the subgroup of acute care surgeons (45.8 per cent), whereas resections performed by general surgeons were significantly associated with more frequent complications (odds ratio (OR) 2.5 (95 per cent c.i. 1.1 to 6.1)). The complication rate was numerically highest in patients operated on by surgeons with the highest resection volumes, which differed significantly from that of surgeons with intermediate resection volumes (OR 4.2 (95 per cent c.i. 1.1 to 16.0)). There was no difference in the mortality rate of patients operated on by surgeons with different specializations or yearly resection volumes. Conclusion: This study documented similar morbidity and mortality rates after emergent colon resection performed by colorectal and acute care surgeons, but patients operated on by general surgeons had more frequent complications.
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| 3. |
- Engdahl, Jenny, et al.
(författare)
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Short- and long-term outcome after colon cancer resections performed by male and female surgeons : A single-center retrospective cohort study
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Ingår i: Scandinavian Journal of Surgery. - 1457-4969.
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Tidskriftsartikel (refereegranskat)abstract
- Background and objective: To assess the effect of surgeon sex on short- and long-term outcomes after colon cancer resections. Methods: Clinical data of patients who underwent colon cancer resections between 2010 and 2020 at Helsingborg Hospital, Sweden, were retrospectively obtained from medical records. The sex of the surgeon of each procedure was recorded. Morbidity, mortality, and long-term survival were compared in patients operated by male and female surgeons. Results: Colon cancer resections were performed by 23 male and 9 female surgeons in 1113 patients (79% elective, 21% emergent). After elective surgery, there was no difference in postoperative complications, 30-day mortality, or long-term survival between patients operated by male and female surgeons. Following emergent resections, the complication rate was significantly lower in patients operated by female surgeons (41.3% vs 58.1%, p = 0.019). Similarly, the rates of R1-resections (0% vs 5.2%, p = 0.039), reoperations (3.8% vs 14.2%, p = 0.014), and intensive care unit (ICU) care (6.3% vs 17.4%, p = 0.018) were significantly lower for patients operated by female surgeons, but there was no difference in 30-day mortality (6.3% vs 5.2%, p = 0.767). Cox regression analysis showed that long-term and cancer-free survival in patients emergently operated by male surgeons was significantly shorter than that of patients operated by female surgeons (hazard ratio = 1.9 (95% confidence interval (CI) = 1.3–2.8), p = 0.001 and hazard ratio = 1.7 (95% CI = 1.1–2.7), p = 0.016). Conclusions: The short- and long-term outcome after elective colon cancer resections were similar in patients operated by male and female surgeons. The outcome following emergent resections performed by female surgeons compared favorably with that of male surgeons, with fewer complications and reoperations and better long-term survival.
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| 4. |
- Gamalielsson, Jonas, et al.
(författare)
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On engagement with ICT standards and their implementations in open source software projects : the case of WebRTC
- 2022
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Ingår i: Proceedings 26th EURAS Annual Standardisation Conference. - Aachen : Verlag Mainz. - 9783958864467 ; , s. 143-162
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Konferensbidrag (refereegranskat)abstract
- Real-time communication (RTC) technologies for the web provide opportunities for individuals and organisations to work and collaborate remotely, and the need for such technologies has recently increased. Use of RTC technologies and tools for the web involves a number of challenges concerning data privacy and lock-in effects, such as dependency to specific suppliers and proprietary technologies. Use of open standards for RTC and open source software (OSS) implementing such standards can create conditions for avoiding issues related to data privacy and lock-in, and thereby provides opportunities for long-term sustainable solutions. The paper characterises how engagement with standardisation of WebRTC in the context of IETF and W3C is related to engagement with the WebRTC OSS project.
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| 5. |
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| 6. |
- Lundell, Björn, et al.
(författare)
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Enabling OSS usage through procurement projects : How can lock-in effects be avoided?
- 2021
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Ingår i: Open Source Systems. - Cham : Springer. - 9783030752507 - 9783030752538 - 9783030752514 ; , s. 16-27
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Konferensbidrag (refereegranskat)abstract
- Formulation of mandatory requirements in procurement projects has significant influence on opportunities for development and deployment of Open Source Software (OSS). The paper contributes insights on a widespread practice amongst public procurement projects which causes problematic lock-in effects and thereby inhibits opportunities for use of OSS solutions. Through a systematic investigation of 30 randomly selected procurement projects in the software domain the paper highlights illustrative examples of mandatory requirements which cause lock-in and presents five recommendations for how requirements instead should be formulated in order to avoid causing lock-in. Findings show significant lock-in caused by current procurement practices with a stark preference for proprietary software and SaaS solutions amongst procuring organisations.
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| 7. |
- Lundell, Björn, et al.
(författare)
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Half a step behind – bulk disclosure of confidential data in third-party GenAI solutions under the Swedish Public Access to Information and Secrecy Act
- 2024
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Ingår i: Digital Government: Research and Practice. - : ACM Digital Library. - 2691-199X .- 2639-0175.
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Tidskriftsartikel (refereegranskat)abstract
- Technological progress poses unique challenges for the public sector. New technology should be adopted, but it must always be done within the framework of good administration. It follows laws governing public administration must be continuously adapted. Sweden recently amended its secrecy legislation to facilitate the use of third-party cloud solutions by public authorities. When the amendment was enacted, most public sector organisations had already been using external cloud solutions for a long time. Today, there is as much pressure on authorities to implement AI technology as there ever was to move administration into the cloud. This paper uses traditional legal methodology to investigate if the Swedish secrecy legislation adequately enables the use of cloud-based GenAI solutions. Findings indicate that the recent amendment is likely insufficient and that there are significant practical hurdles for the application of the law, particularly with services from global cloud providers. The paper contributes to the understanding of Swedish law, and of the difficulties that can occur anywhere when policy makers and legislators do not move in tandem.
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| 8. |
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| 9. |
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| 10. |
- Öberg, Tomas, 1956-, et al.
(författare)
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Different catalytic effects by copper and chromium on the formation and degradation of chlorinated aromatic compounds in fly ash.
- 2007
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Ingår i: Environmental Science and Technology. - Washington : American Chemical Society. - 0013-936X .- 1520-5851. ; 41:10, s. 3741-3746
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Tidskriftsartikel (refereegranskat)abstract
- Fly ash from municipal solid waste incineration may catalytically enhance the formation and degradation of chlorinated aromatic compounds. The activities of three Deacon catalysts in this process were investigated in a statistically designed experiment. Chlorides of copper, chromium, and nickel were added to fly ash samples and the resulting samples heated at 300 degrees C for 2 h in an air atmosphere. The addition of copper increases the formation of all chlorinated aromatic compounds except the low chlorinated congeners of polychlorinated dibenzo-p-dioxins and dibenzofurans. The addition of chromium decreased the formation of most chlorinated aromatic compounds except the highest chlorinated species, where it was without effect. The addition of nickel did not show any significant effect. The outcome of the experiment can be interpreted as two competing processes: the chlorination of aromatic rings and the oxidation of carbon-carbon and carbon-oxygen bonds. The delicate balance between chlorination and oxidation could probably be further exploited to minimize both the emissions and the net production of chlorinated aromatic compounds from combustion.
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| 11. |
- Öberg, Tomas, 1956-, et al.
(författare)
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Metal catalyzed formation of chlorinated aromatic compounds : a study of the correlation pattern in incinerator fly ash.
- 2007
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Ingår i: Chemosphere. - Oxford : Pergamon Press. - 0045-6535 .- 1879-1298. ; 67:9, s. S185-S190
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Tidskriftsartikel (refereegranskat)abstract
- Chlorinated aromatics are unintentionally formed and released from combustion and other thermal processes involving organic matter and chlorine. The catalytic activity of incinerator fly ash in the low-temperature formation of chlorinated aromatics has been demonstrated in both laboratory experiments and full-scale trials. Copper has been shown to be an effective catalyst, but several other transition metals possess a similar activity. Here results are reported from a series of full-scale combustion trials with different fractions of household and industrial wastes, with waste from forestry as a reference fuel. The composition of elements and chlorinated aromatics in the fly ash was evaluated with principal component analysis and partial least squares regression. The observed correlation pattern indicates that metals other than copper are of equal importance for the catalytic activity. Chromium and nickel are two of these metals, which may contribute to the de novo formation of chlorinated benzenes, phenols, PCDD and PCDF.
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| 12. |
- Öberg, Tomas, 1956-, et al.
(författare)
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The correlation pattern of fly ash components : Chromium as a potential catalyst in the thermal formation of chlorinated aromatic compounds
- 2004
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Ingår i: Environmental Chemistry. - 1448-2517 .- 1449-8979. ; 1:1, s. 18-21
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Tidskriftsartikel (refereegranskat)abstract
- Chlorinated aromatic compounds are unintentionally released from combustion sources into the environment. This thermal formation is catalyzed by fly ash components and much interest has been focussed on the role of copper. This study report results from a series of 16 full-scale trials with different fuel compositions. The correlation pattern of fly ash components seem to suggest that the catalytic effect may be due also to other metal oxychlorination catalysts. Chromium shows particularly strong and statistically significant correlations with many of the chlorinated phenols, benzenes, dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs).
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| 13. |
- Al Mukhtar, Ali, et al.
(författare)
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The epidemiology of and management of pediatric patients with head trauma : a hospital-based study from Southern Sweden
- 2022
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Ingår i: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. - : Springer Science and Business Media LLC. - 1757-7241. ; 30:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Traumatic brain injury (TBI) is a common cause of morbidity and mortality in children worldwide. In Scandinavia, the epidemiology of pediatric head trauma is poorly documented. This study aimed to investigate and compare the epidemiology and management of pediatric patients with isolated head trauma (IHT) and head trauma in connection with multitrauma (MHT). Methods: We conducted a retrospective review of medical records of patients < 18 years of age who attended any of the five emergency departments (ED) in Scania County in Sweden in 2016 due to head trauma. Clinical data of patients with IHT were analyzed and compared with those of patients with MHT. Results: We identified 5046 pediatric patients with head trauma, 4874 with IHT and 186 with MHT, yielding an incidence of ED visits due to head trauma of 1815/100,000 children/year. There was male predominance, and the median age was four years. Falls were the dominating trauma mechanism in IHT patients, while motor vehicle accidents dominated in MHT patients. The frequencies of CT head-scans, ward admissions and intracranial injuries (ICI) were 5.4%, 11.1% and 0.7%, respectively. Four patients (0.08%) required neurosurgical intervention. The relative risks for CT-scans and admissions to a hospital ward and ICI were 10, 4.5 and 19 times higher for MHT compared with IHT patients. Conclusion: Head trauma is a common cause of ED visits in our study. Head-CTs and ICIs were less frequent than in previous studies. MHT patients had higher rates of CT-scans, admissions, and ICIs than IHT patients, suggesting that they are separate entities that should ideally be managed using different guidelines to optimize the use of CT-scans of the head.
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| 14. |
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| 15. |
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| 16. |
- Alriksson, Stina, 1971-
(författare)
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Conjoint analysis as a tool for communication and corporate environmental decision-making
- 2008
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Conjoint analysis has been used extensively in marketing, transportation and healthcare for the past 50 years. Since the mid-1990s, it has also been applied to an increasing number of environmental issues. In this thesis, conjoint analysis is applied to environmental objectives of the Swedish steel industry. The aim of the research project has been to develop a method for eliciting stakeholder preferences for environmental issues and to present the results to the stakeholders through the multivariate data analysis method of partial least squares regression. This licentiate thesis is based on three studies: a literature review of all conjoint studies conducted on environmental issues, a pilot study in which a new method was developed, and a main study where this method was tested on four environmental objectives of the Swedish steel industry. Up to the present, 109 environmental conjoint studies have been carried out. Recently, studies in environ¬mental economy have dominated, with investigators trying to estimate a mone¬tary value on environmental values or products. The problem selection has varied widely, from ecosystem management and green products to waste and risk management. One trend among environmental conjoint studies has been to use conjoint methods that report results at a group level. In the pilot study here, conjoint analysis was combined with partial least squares regression to enable presentation of results at individual level. The benefit of individual-level results is that they can be used to initiate a dialogue between an industry and its stakeholders, as well as between different stakeholder groups. The presentation mode also allows the researcher to find segments of respondents that think alike, although perhaps from different groups. In the pilot study, cluster analysis was used successfully to find hidden segments among the respondents. In the main study, the method from the pilot study was used to elicit preferences for four environmental objectives of the Swedish steel industry: reduced use of non-renewable energy, reduced use of non-renewable resources, decreased emission of carbon dioxide and weight reduction of products. Six stakeholder groups participated in the study, and the results showed that decreased emission of carbon dioxide was the environmental objective that most participants prioritised highest. Lowest priority was given to weight reduction of products. Conjoint analysis combined with multivariate data analysis methods such as partial least squares regression, principal component analysis and cluster analysis has been verified as an effective method for eliciting stake¬holder preferences on industry-wide environmental issues.
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| 17. |
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| 18. |
- Alriksson, Stina, et al.
(författare)
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Conjoint analysis for environmental evaluation : a review of methods and applications.
- 2008
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Ingår i: Environmental Science and Pollution Research. - : Springer Berlin. - 0944-1344 .- 1614-7499. ; 15:3, s. 244-257
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND, AIM AND SCOPE: Conjoint analysis and the related choice-modelling methods have been used for many years in marketing research to evaluate consumer behaviour and preferences for different kinds of product attributes. Recently, the number of applications in environmental science and management has started to grow. Conjoint analysis is found in many different forms, and the environmental studies evaluated in this review display the same range of methods as in other fields. The key characteristic of all these methods is that trade-offs are evaluated by jointly considering a number of important attributes. MAIN FEATURES: This paper is a review of the literature on environmental applications of conjoint analysis and assesses in which environmental area conjoint analysis has been most successful. The method and the design of the studies are reviewed as well. RESULTS: A total of 84 studies were found, dealing with environmental issues that were evaluated by conjoint analysis. The studies concern agriculture, ecosystem management, energy, environmental evaluation, forestry, land management, pollution, products, recreation, environmental risk analysis and waste management. DISCUSSION: Choice experiments seem to have a comparatively stronger position in environmental studies than elsewhere. Most of the environmental applications are related to natural resource management. This is somewhat surprising, but a number of reports have appeared also on product evaluation, which could be a key application area in the future. CONCLUSIONS: Compared to marketing and transportation, the number of environmental conjoint studies is rather small but increasing, and the method has proven to work effectively in eliciting preferences on environmental issues. In environmental issues, experimenters often use choice experiments, especially concerning ecosystem management and environmental evaluations. When it comes to evaluating preferences concerning agriculture, forestry, energy and products, a more traditional approach of conjoint analysis is favoured. RECOMMENDATIONS AND PERSPECTIVES: Two new areas of application are identified in this review--environmental communication and expert elicitation. Conjoint analysis can thus be developed into a useful instrument for environmental risk analysis and communication, both of which are necessary for an efficient approach to risk governance.
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| 19. |
- Alriksson, Stina, 1971-, et al.
(författare)
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Towards a closed steel eco-cycle - cojoint analysis as a decision tool
- 2005
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Ingår i: Proceedings Kalmar ECO-TECH´ 05. - Kalmar : Högskolan i Kalmar. ; , s. 27-36
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Konferensbidrag (refereegranskat)abstract
- The Swedish steel industry has over the past 20 years made substantial efforts to promote energy efficiency and environment protection. However, the dominant part of these investments has been directed to the individual production sites, most of which today have 'solved' their own acute environmental problems. The focus has therefore switched to the properties and performance of the steel products where the evaluation of environmental performance is a complex task that often requires simultaneous consideration of many different attributes. Conjoint analysis is commonly used in marketing research, to evaluate how consumers appreciate specific attributes in products. It has also been widely used in health care, traffic planning and quality management. Conjoint analysis has also been applied to environmental issues such as energy, recreation, environmental valuation, ecosystem management, consumer preferences to products, public preferences to industrial projects, waste management, and environmental policy development. This previous research has shown that the method is well suited for evaluating environmental issues. Here we briefly present the methodology and review some papers on environmental applications. It is our intention to use this approach as a tool to integrate environmental considerations into both process and product development within the steel industry.
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| 20. |
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| 21. |
- Augustsson, Anna, et al.
(författare)
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Climate change - an uncertainty factor in risk analysis of contaminated land
- 2011
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 409:22, s. 4693-4700
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Tidskriftsartikel (refereegranskat)abstract
- Metals frequently occur at contaminated sites, where their potential toxicity and persistence require risk assessments that consider possible long-term changes. Changes in climate are likely to affect the speciation, mobility, and risks associated with metals. This paper provides an example of how the climate effect can be inserted in a commonly used exposure model, and how the exposure then changes compared to present conditions. The comparison was made for cadmium (Cd) exposure to 4-year-old children at a highly contaminated iron and steel works site in southeastern Sweden. Both deterministic and probabilistic approaches (through probability bounds analysis, PBA) were used in the exposure assessment. Potential climate-sensitive variables were determined by a literature review. Although only six of the total 39 model variables were assumed to be sensitive to a change in climate (groundwater infiltration, hydraulic conductivity, soil moisture, soil:water distribution, and two bioconcentration factors), the total exposure was clearly affected. For example, by altering the climate-sensitive variables in the order of 15% to 20%, the deterministic estimate of exposure increased by 27%. Similarly, the PBA estimate of the reasonable maximum exposure (RME, defined as the upper bound of the 95th percentile) increased by almost 20%. This means that sites where the exposure in present conditions is determined to be slightly below guideline values may in the future exceed these guidelines, and risk management decisions could thus be affected. The PBA, however, showed that there is also a possibility of lower exposure levels, which means that the changes assumed for the climate-sensitive variables increase the total uncertainty in the probabilistic calculations. This highlights the importance of considering climate as a factor in the characterization of input data to exposure assessments at contaminated sites. The variable with the strongest influence on the result was the soil:water distribution coefficient (Kd).
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| 22. |
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| 23. |
- Barlow, Sue, et al.
(författare)
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Scientific report of the Endocrine Active Substances Task Force
- 2010
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Ingår i: EFSA Journal. - Parma, Italy : European Food Safety Authority. - 1831-4732. ; 8:11
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Discussions within the Scientific Committee and the Advisory Forum have called for the development of a common approach within EFSA towards endocrine active substances. The aim of this report by an internal EFSA task force is to clarify the state-of-play, and provide recommendations for scientific and communication issues. Both specific issues and new regulations make it necessary to follow up on recent developments with the EU bodies, Member States, and internationally, in order to avoid diverging assessment approaches and the duplication of work. The proposed actions for EFSA are to contribute to the work in progress under the auspices of DG Environment and to continue its participation in the ongoing OECD activities in the area of testing of chemicals. The development of a generally accepted risk assessment methodology is an additional challenge due to the complexity of the issues involved. Here, the task force recommends that EFSA continues its activities aimed at developing harmonised methodologies for risk assessment of combined exposures to endocrine active substances in food. EFSA should continue to build a dialogue to develop a common strategy with the EC, other EU bodies, Member States’ Competent Authorities, international organisations and partners, as well as external experts and stakeholders on the before mentioned issues. In line with these recommendations, it is proposed that EFSA creates a working group of Panel experts and national experts to advise on prioritising the work on endocrine active substances. EFSA should also work with the experts in its Advisory Group on Risk Communications in conjunction with the communication experts from Member States, and continues to monitor and analyse media and stakeholder developments, in order to define a strategy for communications addressing both the collective group and specific endocrine active substances.
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| 24. |
- Bergius, Kristine, et al.
(författare)
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Initial screening of contaminated land : a comparison of US and Swedish methods.
- 2007
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Ingår i: Environmental Management. - : Springer Science and Business Media LLC. - 0364-152X .- 1432-1009. ; 39:2, s. 226-34
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Tidskriftsartikel (refereegranskat)abstract
- Preliminary surveys are used to prioritize between contaminated sites to select those to be investigated more thoroughly. The data-gathering steps are almost identical between countries; however, the assessment procedures differ significantly. In this study, we have investigated 21 contaminated sites assessed as belonging to the high-risk or the very high-risk class using the Swedish Methods for Inventories of Contaminated Sites (MICS). We then applied the US Preliminary Assessment (PA) method to the same sites and compared the results and conclusions from the two screening procedures. In both cases, all sites were recommended for further investigation and the two approaches seem to corroborate one another; however, the PA assessment scores and the preliminary MICS classifications did not correlate. The results obtained with the PA method were easier to explain than the final MICS classification. The PA method also seems more transparent and easier to standardize, although objections could be made regarding the weighting scheme, because the outcome in this study was entirely dependent on the surface exposure pathway. However, to examine this in greater detail, it is necessary to include sites with less contamination: The importance of preliminary surveys in the overall risk management process gives a strong motivation for such an evaluation. Generally, the lack of research and scientific support for the various assessment procedures in use suggests that there is a need for method development, standardization, and validation.
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| 25. |
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| 26. |
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| 27. |
- Bhhatarai, Barun, et al.
(författare)
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CADASTER QSPR Models for Predictions of Melting and Boiling Points of Perfluorinated Chemicals
- 2011
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Ingår i: Molecular Informatics. - : John Wiley & Sons. - 1868-1751 .- 1868-1743. ; 30:2-3, s. 189-204
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Tidskriftsartikel (refereegranskat)abstract
- Quantitative structure property relationship (QSPR) studies on per- and polyfluorinated chemicals (PFCs) on melting point (MP) and boiling point (BP) are presented. The training and prediction chemicals used for developing and validating the models were selected from Syracuse PhysProp database and literatures. The available experimental data sets were split in two different ways: a) random selection on response value, and b) structural similarity verified by self-organizing-map (SOM), in order to propose reliable predictive models, developed only on the training sets and externally verified on the prediction sets. Individual linear and non-linear approaches based models developed by different CADASTER partners on 0D-2D Dragon descriptors, E-state descriptors and fragment based descriptors as well as consensus model and their predictions are presented. In addition, the predictive performance of the developed models was verified on a blind external validation set (EV-set) prepared using PERFORCE database on 15 MP and 25 BP data respectively. This database contains only long chain perfluoro-alkylated chemicals, particularly monitored by regulatory agencies like US-EPA and EU-REACH. QSPR models with internal and external validation on two different external prediction/validation sets and study of applicability-domain highlighting the robustness and high accuracy of the models are discussed. Finally, MPs for additional 303 PFCs and BPs for 271 PFCs were predicted for which experimental measurements are unknown.
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| 28. |
- Brandmaier, Stefan, et al.
(författare)
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An evaluation of experimental design in QSAR modelling utilizing the k-medoid clustering
- 2012
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Ingår i: Journal of Chemometrics. - : Wiley. - 0886-9383 .- 1099-128X. ; 26:10, s. 509-517
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Tidskriftsartikel (refereegranskat)abstract
- A reliable selection of a representative subset of chemical compounds has been reported to be crucial for numeroustasks in computational chemistry and chemoinformatics. We investigated the usability of an approach on the basisof the k-medoid algorithm for this task and in particular for experimental design and the split between training andvalidation set. We therefore compared the performance of models derived from such a selection to that of modelsderived using several other approaches, such as space-filling design and D-optimal design. We validated the performance on four datasets with different endpoints, representing toxicity, physicochemical properties and others.Compared with the models derived from the compounds selected by the other examined approaches, those derivedwith the k-medoid selection show a high reliability for experimental design, as their performance was constantlyamong the best for all examined datasets. Of all the models derived with all examined approaches, those derivedwith the k-medoid approach were the only ones that showed a significantly improved performance compared witha random selection, for all datasets, the whole examined range of selected compounds and for each dimensionalityof the search space.
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| 29. |
- Brandmaier, Stefan, et al.
(författare)
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PLS-Optimal: A stepwise D-Optimal design based on latent variables
- 2012
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Ingår i: Journal of Chemical Information and Modeling. - : American Chemical Society (ACS). - 1549-9596 .- 1549-960X. ; 52:4, s. 975-983
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Tidskriftsartikel (refereegranskat)abstract
- Several applications, such as risk assessment within REACH or drug discovery, require reliable methods for the design of experiments and efficient testing strategies. Keeping the number of experiments as low as possible is important from both a financial and an ethical point of view, as exhaustive testing of compounds requires significant financial resources and animal lives. With a large initial set of compounds, experimental design techniques can be used to select a representative subset for testing. Once measured, these compounds can be used to develop quantitative structure–activity relationship models to predict properties of the remaining compounds. This reduces the required resources and time. D-Optimal design is frequently used to select an optimal set of compounds by analyzing data variance. We developed a new sequential approach to apply a D-Optimal design to latent variables derived from a partial least squares (PLS) model instead of principal components. The stepwise procedure selects a new set of molecules to be measured after each previous measurement cycle. We show that application of the D-Optimal selection generates models with a significantly improved performance on four different data sets with end points relevant for REACH. Compared to those derived from principal components, PLS models derived from the selection on latent variables had a lower root-mean-square error and a higher Q2 and R2. This improvement is statistically significant, especially for the small number of compounds selected.
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| 30. |
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| 31. |
- Brandmaier, Stefan, et al.
(författare)
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The QSPR-THESAURUS : The Online Platform of the CADASTER Project
- 2014
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Ingår i: ATLA (Alternatives to Laboratory Animals). - : SAGE Publications. - 0261-1929. ; 42:1, s. 13-24
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the CADASTER project (CAse Studies on the Development and Application of in Silico Techniques for Environmental Hazard and Risk Assessment) was to exemplify REACH-related hazard assessments for four classes of chemical compound, namely, polybrominated diphenylethers, per and polyfluorinated compounds, (benzo)triazoles, and musks and fragrances. The QSPR-THESAURUS website (http: / /qspr-thesaurus.eu) was established as the project's online platform to upload, store, apply, and also create, models within the project. We overview the main features of the website, such as model upload, experimental design and hazard assessment to support risk assessment, and integration with other web tools, all of which are essential parts of the QSPR-THESAURUS.
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| 32. |
- Cederqvist, Lars, et al.
(författare)
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Improved process stability during friction stir welding of 5 cm thick copper canisters through shoulder geometry and parameter studies
- 2009
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Ingår i: Science and technology of welding and joining. - London : Institute of Materials. - 1362-1718 .- 1743-2936. ; 14:2, s. 178-184
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Tidskriftsartikel (refereegranskat)abstract
- The spent nuclear fuel from Swedish power plants will be placed in copper canisters that are sealed with friction stir welding and the stability and robustness of this process is now being optimised in three steps: first, the shoulder geometry was identified that produced the most stable weld cycle, then the welding parameters were optimised for that geometry with regards to stability, and finally, the chosen geometry and welding parameters were verified and evaluated during multiple weld cycles. The shoulder study showed that stable welds could be produced repeatedly with a convex scroll geometry which proved more stable than various concave and flat scroll geometries. In the subsequent parameter study, not only were the most stable values for the welding parameters derived, but a clear relationship was shown between power input and tool temperature. This relationship can be used to more accurately control the process within the parameter windows, not only for this application but for other applications where the welding temperature needs to be kept within a specified range. Similarly, the potential of the convex scroll shoulder geometry for use in applications with other metals and thicknesses is evident.
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| 33. |
- Cederqvist, Lars, et al.
(författare)
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Reliability study of friction stir welded copper canisters containing Sweden's nuclear waste
- 2008
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Ingår i: Reliability Engineering & System Safety. - : Elsevier. - 0951-8320 .- 1879-0836. ; 93:10, s. 1491-1499
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Tidskriftsartikel (refereegranskat)abstract
- The plan for the final disposal of spent fuel from Swedish nuclear power plants is to place it in copper canisters that are sealed and stored in a deep repository. The canisters will be sealed by friction stir welding (FSW) and the reliability of this process has now been evaluated. The reliability study was performed in three steps: first an optimization experiment to identify optimal process settings and establish the process window; then a demonstration experiment with welding under production-like conditions; and finally a post-demonstration series to evaluate an adjustment in the welding equipment. A process window was defined around the optimal process setting, i.e., the limits within which the welding variables must lie in order for the process to produce the desired result. In the demonstration experiment, a series of 20 sealing welds was carried out under production-like conditions. The maximum discontinuity in each weld — detected by non-destructive testing — was fitted to a generalized extreme value distribution. The 95% confidence interval for the maximum discontinuity in a production series of 4500 canisters was estimated at 4.5–7.7 mm. The best estimate from the post-demonstration series suggests that the maximum size of a discontinuity will not exceed 2.3 mm. A main conclusion is that the FSW process produces reliable results, fulfilling the predetermined requirements for minimum copper thickness by a very good margin.
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| 34. |
- Dagöö, Jesper, et al.
(författare)
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Cognitive behavior therapy versus interpersonal psychotherapy for social anxiety disorder delivered via smartphone and computer: A randomized controlled trial
- 2014
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Ingår i: Journal of Anxiety Disorders. - : Elsevier BV. - 1873-7897 .- 0887-6185. ; 28:4, s. 410-417
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a previously evaluated guided Internet-based cognitive behavior therapy for social anxiety disorder (SAD) was adapted for mobile phone administration (mCBT). The treatment was compared with a guided self-help treatment based on interpersonal psychotherapy (mIPT). The treatment platform could be accessed through smartphones, tablet computers, and standard computers. A total of 52 participants were diagnosed with SAD and randomized to either mCBT (n = 27) or mIPT (n = 25). Measures were collected at pre-treatment, during the treatment, post-treatment and 3-month follow-up. On the primary outcome measure, the Liebowitz Social Anxiety Scale - self-rated, both groups showed statistically significant improvements. However, mCBT performed significantly better than mIPT (between group Cohen's d = 0.64 in favor of mCBT). A larger proportion of the mCBT group was classified as responders at post-treatment (55.6% versus 8.0% in the mIPT group). We conclude that CBT for SAD can be delivered using modern information technology. IPT delivered as a guided self-help treatment may be less effective in this format. (c) 2014 Elsevier Ltd. All rights reserved.
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| 35. |
- Farnelid, Hanna, et al.
(författare)
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Identity and dynamics of putative N-2-fixing picoplankton in the Baltic Sea proper suggest complex patterns of regulation
- 2009
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Ingår i: Environmental Microbiology Reports. - : Wiley. - 1758-2229. ; 1, s. 145-154
-
Tidskriftsartikel (refereegranskat)abstract
- Heterocystous filamentous cyanobacteria are regarded as the main N-2-fixing organisms (diazotrophs) in the Baltic Sea. However, some studies indicate that picoplankton may also be important. The aim of this study was to examine the composition of putative diazotrophs in the picoplankton (< 3 mu m) and to identify links to environmental factors. Nitrogenase (nifH) genes were amplified from community DNA by nested PCR, followed by cloning and sequencing. Clone libraries from nine environmental samples collected from the central Baltic Sea (April-October 2003, 3 m depth) and a negative control yielded a total of 433 sequences with an average clone library coverage of 92%. The sequences fell within nifH Clusters I, II and III and formed 15 distinct groups (> 96% amino acid similarity). Most of the sequences (77%) fell into nifH Cluster I (cyanobacteria and alpha-, beta- and gamma-Proteobacteria). However, only 26 sequences were related to cyanobacteria (e. g. Pseudanabaena) and among these no unicellular phylotypes were found. Sequences clustering with alternative nitrogenases (anfH) and Archaea were found in one sample while sequences related to anaerobic phylotypes were found in six samples distributed throughout the season. The identified phylogenetic groups showed covariance with several environmental factors but no strong links could be established. This suggests a variable and complex regulation of diazotrophic groups within Baltic Sea picoplankton.
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| 36. |
- Filipsson, Monika, et al.
(författare)
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Exponeringsfaktorer vid riskbedömning : Inventering av dataunderlag
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Exponering definieras som kontakten mellan ett kemiskt, fysikaliskt eller biologiskt agens och den yttre avgränsningen för en organism. Människors exponering för kemiska ämnen i miljön styrs inte bara av förekomsten av en förorening, utan även av beteende, fysiologiska egenskaper och olika yttre faktorer. De mätbara variabler som används i exponeringsmodeller för att beskriva detta benämns exponeringsfaktorer. Den mest omfattande sammanställningen av data för olika exponeringsfaktorer härrör från USA, men det finns även ett par europeiska sammanställningar. Beteenden, fysiologiska egenskaper och yttre miljöfaktorer skiljer dock mellan olika länder. Det finns därför skäl att sammanställa sådana data även för svenskt vidkommande. En sammanställning kan även bidra till en viss standardisering av riskbedömningar. I föreliggande rapport redovisas exponeringsfaktorer för olika områden och i stora stycken överensstämmer urvalet med de tidigare nämnda internationella sammanställningarna. Redovisningen och dess omfattning påverkas även i hög grad av tillgången på data. Det innebär exempelvis att variabilitet (naturlig variation) och osäkerhet inte kan anges för alla faktorer. Dessa databrister är särskilt påtagliga vad gäller konsumtion av dricksvatten och hemodlade vegetabilier samt tidsanvändning. Dataunderlaget är däremot gott för fysiologiska parametrar som kroppsvikt och hudyta liksom den allmänna konsumtionen av livsmedel. För dessa exponeringsfaktorer redovisas statistiska parametrar som medelvärde, standardavvikelse, skevhet och kurtosis. Dessutom anges osäkerhetsintervall för dessa parametrar. Percentiler utgör ett användbart alternativ för presentera variabilitet (naturlig variation) och även sådana redovisas tillsammans med tillhörande osäkerhetsintervall. Ytterligare exponeringsfaktorer som behandlas i rapporten är åldersfördelning och flyttningsfrekvens, boende och byggnader, kontakt med mark och damm och markegenskaper. Förutom tabellerade värden återfinns även referenser till de primära datakällorna så att det är möjligt att själv gå vidare och fördjupa sig i underlaget. I rapporten jämförs även insamlade data med remissversionen av den svenska beräkningsmodellen för riktvärden för mark. Jämförelsen med denna modell visar att valda värden för exponeringsfaktorerna ibland motsvarar en bästa skattning (medelvärde/median), ofta en konservativ skattning och ibland en mycket konservativ skattning. Det går inte att utifrån dessa jämförelser dra några säkra slutsatser om dess inverkan på den slutliga riskbedömningen och beslut avseende åtgärder. Det är rapportförfattarnas förhoppning att föreliggande sammanställning ska underlätta och påskynda en övergång till riskbedömningsmetoder där variabilitet och osäkerhet kan uppskattas och redovisas kvantitativt.
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| 37. |
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| 38. |
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| 39. |
- Filipsson, Monika, et al.
(författare)
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Exposure to contaminated sediments during recreational activities at a public bathing place
- 2009
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Ingår i: Journal of Hazardous Materials. - : Elsevier. - 0304-3894 .- 1873-3336. ; 171:1-3, s. 200-207
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Tidskriftsartikel (refereegranskat)abstract
- More and more time is spent on recreational activities, but few risk assessments focus specifically on these situations and exposure factor data are often scarce. To assess exposure to contaminants at a public bathing place in an urban environment, we have compiled literature data, conducted observation studies, and analyzed water and sediment samples. The levels of anthropogenic contaminants are high in urban environments and traffic frequently plays an important role. In this study, to characterize variability and uncertainty, the deterministic exposure calculations for metal pollutants were supplemented by a probability bounds analysis for the polycyclic aromatic hydrocarbons (PAH). The results from these calculations show that oral intake is the major exposure route for metals, while skin absorption, with present assumptions, is more important for the PAH. The presently measured levels of contaminants, at this public bathing place, cannot be anticipated to cause any significant adverse influence on public health.
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| 40. |
- Filipsson, Monika, et al.
(författare)
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Gender differences in risk management of contaminated land at a Swedish authority
- 2014
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Ingår i: Journal of Risk Research. - : Informa UK Limited. - 1366-9877 .- 1466-4461. ; 17:3, s. 353-365
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Tidskriftsartikel (refereegranskat)abstract
- Any risk analysis process leading to the remediation of contaminated land will be affected by individual judgements. Many contaminated land risk assessments in Sweden are reviewed by the County Administrative Board (CAB), a regional government authority. The cost for risk assessments and eventually remediation is funded by whichever operator is legally responsible; however, when the responsible party is unknown, the cost can be met by government grants. A questionnaire was sent to all employees working with contaminated land at each of Sweden’s CABs to investigate whether gender, age and work experience, as well as funding source, affect the reviewing of risk assessments, and the employees’ perception of knowledge gained from the Sustainable Remediation (Hållbar Sanering) research programme. It was found that gender was the most significant factor, but also age and experience of the employees influenced the respondent’s answers. The reviews of risk assessments also varied depending on funding source.
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| 41. |
- Filipsson, Monika
(författare)
-
Uncertainty, variability and environmental risk analysis
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The negative effects of hazardous substances and possible measures that can be taken are evaluated in the environmental risk analysis process, consisting of risk assessment, risk communication and risk management. Uncertainty due to lack of knowledge and natural variability are always present in this process. The aim of this thesis is to evaluate some tools as well as discuss the management of uncertainty and variability, as it is necessary to treat them both in a reliable and transparent way to gain regulatory acceptance in decision making.The catalytic effects of various metals on the formation of chlorinated aromatic compounds during the heating of fly ash were investigated (paper I). Copper showed a positive catalytic effect, while cobalt, chromium and vanadium showed a catalytic effect for degradation. Knowledge of the catalytic effects may facilitate the choice and design of combustion processes to decrease emissions, but it also provides valuable information to identify and characterize the hazard.Exposure factors of importance in risk assessment (physiological parameters, time use factors and food consumption) were collected and evaluated (paper II). Interindividual variability was characterized by mean, standard deviation, skewness, kurtosis and multiple percentiles, while uncertainty in these parameters was estimated with confidence intervals.How these statistical parameters can be applied was shown in two exposure assessments (papers III and IV). Probability bounds analysis was used as a probabilistic approach, which enables separate propagation of uncertainty and variability even in cases where the availability of data is limited. In paper III it was determined that the exposure cannot be expected to cause any negative health effects for recreational users of a public bathing place. Paper IV concluded that the uncertainty interval in the estimated exposure increased when accounting for possible changes in climate-sensitive model variables. Risk managers often need to rely on precaution and an increased uncertainty may therefore have implications for risk management decisions.Paper V focuses on risk management and a questionnaire was sent to employees at all Swedish County Administrative Boards working with contaminated land. It was concluded that the gender, age and work experience of the employees, as well as the funding source of the risk assessment, all have an impact on the reviewing of risk assessments. Gender was the most significant factor, and it also affected the perception of knowledge.
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| 42. |
- Filipsson, Monika, et al.
(författare)
-
Undersökning och riskbedömning av Trekantens badplats : Riskkarakterisering
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Trekanten är en av Stockholms mer förorenade sjöar. Sedimenten i sjöns djupare delar innehåller höga halter tungmetaller och polycykliska aromatiska kolväten (PAH). Frågan om det kan vara hälsofarligt att komma i kontakt med sedimenten har uppkommit och oron har främst gällt bad vid badplatsen. Det har därför funnits skäl för att närmare utreda föroreningshalterna i anslutning till badplatsen och fastställa om någon hälsofara kan förekomma vid bad. I föreliggande rapport redovisas de exponeringsberäkningar och den riskbedömning som har gjorts utifrån de undersökningar som genomfördes under sommaren 2006 och 2007. Undersökningarna har omfattat dels en studie av badvanor, dels provtagning och analys av föroreningar i sediment och ytvatten. Exponeringsberäkningarna baseras även på sammanställningar av modeller och exponeringsfaktorer från den vetenskapliga litteraturen liksom svenska undersökningar. Ett informationsutbyte har även skett med tjänstemän vid det amerikanska naturvårdsverket (U.S. EPA). Undersökningarna har visat att föroreningshalterna i sand vid badplatsen och i ytvatten är låga. Halterna av PAH och metaller i sanden var lägre än de generella riktvärdena för förorenad mark som avser känslig markanvändning. Halterna av PAH och metaller (med undantag för krom) i ytvatten var lägre än normerna för dricksvatten. Exponeringsberäkningarna har genomförts separat för barn och vuxna. Huvudsakligen avser beräkningarna punktskattningar, dels en bästa skattning, dels en skattning av rimlig maximal exponering. För PAH-föreningar har utvärderingen även kompletterats med en sannolikhetsberäkning för att beskriva variabilitet och osäkerheter i dataunderlaget. Den beräknade exponeringen är i de flesta fall under de toxikologiska referensvärden som har använts. Slutsatsen från de genomförda undersökningarna är att exponeringen för PAH och metaller vid bad i sjön Trekanten, vid nu uppmätta halter, inte kan förutses medföra någon ogynnsam påverkan av betydelse för befolkningens hälsa.
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| 43. |
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| 44. |
- Filipsson, Monika, et al.
(författare)
-
Variability and uncertainty in Swedish exposure factors for use in quantitative exposure assessments
- 2011
-
Ingår i: Risk Analysis. - : Wiley. - 0272-4332 .- 1539-6924. ; 31:1, s. 108-119
-
Tidskriftsartikel (refereegranskat)abstract
- Information of exposure factors used in quantitative risk assessments has previously been compiled and reported for U.S. and European populations. However, due to the advancement of science and knowledge, these reports are in continuous need of updating with new data. Equally important is the change over time of many exposure factors related to both physiological characteristics and human behavior. Body weight, skin surface, time use, and dietary habits are some of the most obvious examples covered here. A wealth of data is available from literature not primarily gathered for the purpose of risk assessment. Here we review a number of key exposure factors and compare these factors between northern Europe—here represented by Sweden—and the United States. Many previous compilations of exposure factor data focus on interindividual variability and variability between sexes and age groups, while uncertainty is mainly dealt with in a qualitative way. In this article variability is assessed along with uncertainty. As estimates of central tendency and interindividual variability, mean, standard deviation, skewness, kurtosis, and multiple percentiles were calculated, while uncertainty was characterized using 95% confidence intervals for these parameters. The presented statistics are appropriate for use in deterministic analyses using point estimates for each input parameter as well as in probabilistic assessments.
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| 45. |
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| 46. |
- Grenegård, Magnus, et al.
(författare)
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The ATP-gated P2X1 receptor plays a pivotal role in activation of aspirin-treated platelets by thrombin and epinephrine
- 2008
-
Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 283:27, s. 18493-18504
-
Tidskriftsartikel (refereegranskat)abstract
- Human platelets express protease-activated receptor 1 (PAR1) and PAR4 but limited data indicate for differences in signal transduction. We studied the involvement of PAR1 and PAR4 in the cross-talk between thrombin and epinephrine. The results show that epinephrine acted via alpha(2A)-adrenergic receptors to provoke aggregation, secretion, and Ca(2+) mobilization in aspirin-treated platelets pre-stimulated with subthreshold concentrations of thrombin. Incubating platelets with antibodies against PAR4 or the PAR4-specific inhibitor pepducin P4pal-i1 abolished the aggregation. Furthermore, platelets pre-exposed to the PAR4-activating peptide AYPGKF, but not to the PAR1-activating peptide SFLLRN, were aggregated by epinephrine, whereas both AYPGKF and SFLLRN synergized with epinephrine in the absence of aspirin. The roles of released ATP and ADP were elucidated by using antagonists of the purinergic receptors P2X(1), P2Y(1), and P2Y(12) (i.e. NF449, MRS2159, MRS2179, and cangrelor). Intriguingly, ATP, but not ADP, was required for the epinephrine/thrombin-induced aggregation. In Western blot analysis, a low concentration of AYPGKF, but not SFLLRN, stimulated phosphorylation of Akt on serine 473. Moreover, the phosphatidyl inositide 3-kinase inhibitor LY294002 antagonized the effect of epinephrine combined with thrombin or AYPGKF. Thus, in aspirin-treated platelets, PAR4, but not PAR1, interacts synergistically with alpha(2A)-adrenergic receptors, and the PI3-kinase/Akt pathway is involved in this cross-talk. Furthermore, in PAR4-pretreated platelets, epinephrine caused dense granule secretion, and subsequent signaling from the ATP-gated P2X(1)-receptor and the alpha(2A)-adrenergic receptor induced aggregation. These results suggest a new mechanism that has ATP as a key element and circumvents the action of aspirin on epinephrine-facilitated PAR4-mediated platelet activation.
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| 47. |
- Hansen, Karin, et al.
(författare)
-
Torvutvinningens miljöpåverkan
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Syftet med detta arbete har varit att klargöra aktuellt kunskapsläge gällande torvutvinning och dess miljöpåverkan i Sverige, att identifiera brister i underlag som behövs för att ge en bild av de svenska torvtäkternas miljöpåverkan och att föreslå, om möjligt, åtgärder för hur torvtäkters och efterbehandlingsmetoders miljöpåverkan kan minimeras. Torv är en organisk jordart som bildas genom ofullständig nedbrytning av främst växtmaterial i våt, syrefattig miljö. Torven bildas i myrar som antingen uppstått genom igenväxning av sjöar eller genom försumpning av fastmark. Sverige är ett av jordens torvmarkstätaste länder. De vanligaste användningsområdena för torv i Sverige är för energiändamål (energitorv) och som odlingssubstrat (odlingstorv). Dessutom används även torv som stallströ vid djurhållning (strötorv). Miljöpåverkan vid torvtäktverksamhet uppstår vid dikning och utvinning som medför förändrade vattenflöden (mark- och grundvatten) och vattenkemi (suspendering, surhet, näringsämnen och metaller), vilket kan förändra de biologiska förutsättningarna nedströms och bidra till övergödning och förlust av akvatisk biodiversitet. Annan viktig miljöpåverkan vid täktverksamhet är risk för brand, damning samt buller och emissioner till luft från arbetsmaskiner och vid förbränning. This report is only available in Swedish. English summary is available in the report.
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| 48. |
- Iqbal, Muhammad Sarfraz, et al.
(författare)
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Description and Propagation of Uncertainty in Input Parameters in Environmental Fate Models
- 2013
-
Ingår i: Risk Analysis. - : Wiley. - 0272-4332 .- 1539-6924. ; 33:7, s. 1353-66
-
Tidskriftsartikel (refereegranskat)abstract
- Today, chemical risk and safety assessments rely heavily on the estimation of environmental fate by models. The key compound-related properties in such models describe partitioning and reactivity. Uncertainty in determining these properties can be separated into random and systematic (incompleteness) components, requiring different types of representation. Here, we evaluate two approaches that are suitable to treat also systematic errors, fuzzy arithmetic, and probability bounds analysis. When a best estimate (mode) and a range can be computed for an input parameter, then it is possible to characterize the uncertainty with a triangular fuzzy number (possibility distribution) or a corresponding probability box bound by two uniform distributions. We use a five-compartment Level I fugacity model and reported empirical data from the literature for three well-known environmental pollutants (benzene, pyrene, and DDT) as illustrative cases for this evaluation. Propagation of uncertainty by discrete probability calculus or interval arithmetic can be done at a low computational cost and gives maximum flexibility in applying different approaches. Our evaluation suggests that the difference between fuzzy arithmetic and probability bounds analysis is small, at least for this specific case. The fuzzy arithmetic approach can, however, be regarded as less conservative than probability bounds analysis if the assumption of independence is removed. Both approaches are sensitive to repeated parameters that may inflate the uncertainty estimate. Uncertainty described by probability boxes was therefore also propagated through the model by Monte Carlo simulation to show how this problem can be avoided.
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| 49. |
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| 50. |
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