| 1. |
- Thormar, Jonas, et al.
(författare)
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Eelgrass (Zostera marina) food web structure in different environmental settings.
- 2016
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- This study compares the structure of eelgrass (Zostera marina L.) meadows and associated food webs in two eelgrass habitats in Denmark, differing in exposure, connection to the open sea, nutrient enrichment and water transparency. Meadow structure strongly reflected the environmental conditions in each habitat. The eutrophicated, protected site had higher biomass of filamentous algae, lower eelgrass biomass and shoot density, longer and narrower leaves, and higher above to below ground biomass ratio compared to the less nutrient-enriched and more exposed site. The faunal community composition and food web structure also differed markedly between sites with the eutrophicated, enclosed site having higher biomass of consumers and less complex food web. These relationships resulted in a column shaped biomass distribution of the consumers at the eutrophicated site whereas the less nutrient-rich site showed a pyramidal biomass distribution of consumers coupled with a more diverse consumer community. The differences in meadow and food web structure of the two seagrass habitats, suggest how physical setting may shape ecosystem response and resilience to anthropogenic pressure. We encourage larger, replicated studies to further disentangle the effects of different environmental variables on seagrass food web structure.
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| 2. |
- Abrahamsson, Jonas, 1954, et al.
(författare)
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Improved outcome after relapse in children with acute myeloid leukaemia.
- 2007
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Ingår i: British journal of haematology. - : Wiley. - 0007-1048 .- 1365-2141. ; 136:2, s. 229-236
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Tidskriftsartikel (refereegranskat)abstract
- In the Nordic Society for Paediatric Haematology and Oncology paediatric study acute myeloid leukaemia (AML) 93, event-free survival was 50% and overall survival was 66%, indicating that many patients were cured following relapse. Factors influencing outcome in children with relapsed AML were investigated. The study included all 146 children in the Nordic countries diagnosed with AML between 1988 and 2003, who relapsed. Data on disease characteristics and relapse treatment were related to outcome. Sixty-six percentage achieved remission with survival after relapse (5 years) 34 +/- 4%. Of 122 patients who received re-induction therapy, 77% entered remission with 40 +/- 5% survival. Remission rates were similar for different re-induction regimens but fludarabine, cytarabine, granulocyte colony-stimulating factor-based therapy had low treatment-related mortality. Prognostic factors for survival were duration of first complete remission (CR1) and stem cell transplantation (SCT) in CR1. In early relapse (<1 year in CR1), survival was 21 +/- 5% compared with 48 +/- 6% in late relapse. For children receiving re-induction therapy, survival in early relapse was 29 +/- 6% and 51 +/- 6% in late. Patients treated in CR1 with SCT, autologous SCT or chemotherapy had a survival of 18 +/- 9, 5 +/- 5 and 41 +/- 5%, respectively. Survival was 62 +/- 6% in 64 children given SCT as part of their relapse therapy. A significant proportion of children with relapsed AML can be cured, even those with early relapse. Children who receive re-induction therapy, enter remission and proceed to SCT can achieve a cure rate of 60%.
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| 3. |
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| 4. |
- Clausen, Jonas, et al.
(författare)
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Generalizing the Safety Factor Approach
- 2006
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Ingår i: Reliability Engineering & System Safety. - : Elsevier BV. - 0951-8320 .- 1879-0836. ; 91:8, s. 964-973
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Tidskriftsartikel (refereegranskat)abstract
- Safety factors (uncertainty factors) are used to avoid failure in a wide variety of practices and disciplines, in particular engineering design and toxicology. Although these two areas have similar problems in their use of safety factors, there are no signs of previous communication between the two disciplines. The present contribution aims at initiating such communications by pointing out parallel practices and joint issues between the two disciplines. These include the distinction between probabilistic variability and epistemic uncertainty, the importance of distribution tails, and the problem of countervailing risks. In conclusion, it is proposed that future research in this area should be interdisciplinary and make use of experiences from the various areas in which safety factors are used.
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| 5. |
- Clausen Mork, Jonas
(författare)
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Dealing with uncertainty
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Uncertainty is, it seems, more or less constantly present in our lives. Even so, grasping the concept philosophically is far from trivial. In this doctoral thesis, uncertainty and its conceptual companion information are studied. Axiomatic analyses are provided and numerical measures suggested. In addition to these basic conceptual analyses, the widespread practice of so-called safety factor use in societal regulation is analyzed along with the interplay between science and policy in European regulation of chemicals and construction.
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| 6. |
- Clausen Mork, Jonas, et al.
(författare)
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Eurocodes and REACH - differences and similarities
- 2007
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Ingår i: Risk Management. - : Springer Science and Business Media LLC. - 1460-3799 .- 1743-4637. ; :19, s. 19-35
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Tidskriftsartikel (refereegranskat)abstract
- The developments of the new European construction standard (Eurocodes) and the new European chemical legislation (REACH) have taken place in parallel, and they are now both in their final stages. Both consist in European harmonization of safety regulations that concern major industries. In this paper, we compare Eurocodes and REACH in terms of purpose, intended level of harmonization, the science-policy interface and controversies about the costs of the regulations. We have found that the science-policy interface of REACH is characterized by public controversy and by attempts to keep risk assessment and risk management apart while the science-policy interface of Eurocodes is characterized by trust in experts, limited public involvement and organizational confluence of risk assessment and risk management. Furthermore, the costs of REACH have been a major issue in discussions between the Commission and the chemical industry while, in contrast, the costs of Eurocodes have not even been calculated either by the Commission or by the construction industry. A major reason for this is that construction industry does not seem to regard possible cost increases due to Eurocodes as a threat to their business interests. Regulators seem to have treated the cost issue as a business interest, not as an aspect of the decision that they should be concerned with even in the absence of external pressure.
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| 7. |
- Clausen Mork, Jonas
(författare)
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Information gain and approaching true belief
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Recent years has seen a renewed interest in the philosophical study of information. In this paper a two-part analysis of information gain – objective and subjective – in the context of doxastic change is presented and discussed. Objective information gain is analyzed in terms of doxastic movement towards true belief, while subjective information gain is analyzed as an agent’s expectation value of her objective information gain for a given doxastic change. The resulting expression for subjective information gain turns out to be a familiar one with well-known formal properties: the Kullback-Leibler divergence. The suggested measure of subjective information gain is then compared with the view that information gain equals uncertainty reduction. Three counterexamples to the latter view are suggested and it is also argued that the numerical results given by the suggested measure of subjective information gain in those three cases are considerably more intuitive.
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| 8. |
- Clausen Mork, Jonas, 1975-
(författare)
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Is it safe? safety factor reasoning in policy-making under uncertainty
- 2006
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis examines the practice of using safety factors in decision-making under uncertainty, in particular in the areas of toxicology and civil engineering. The aim is to expose and clarify some of the philosophical issues surrounding the practice. Paper I (co-written with Sven Ove Hansson and Fred Nilsson) gives an historical background to the practice of formal safety factor and safety margin use. The notion of an uncertainty function is presented as a more general concept covering safety margins, safety factors and the related uncertainty factors. Three categories of uncertainty functions are identified: explicit, implicit and natural safety reserves. Finally, the problems of countervailing risks and distribution arbitrariness are discussed. Paper II (co-written with John Cantwell) discusses the relation between decision-making with safety factor rules and the ideal of formal normative decision theory. The role of safety factor rules in practical and theoretical reasoning is also examined and certain difficulties regarding normative evaluation of safety factor rules are pointed out. Paper III (co-written with Sven Ove Hansson) looks at two current regulatory systems under development: Eurocodes for construction and REACH for chemicals. The two regulations have many similarities but reactions to them have been highly divergent. The differences are discussed and some hypotheses as to their explanation are suggested.
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| 9. |
- Clausen Mork, Jonas, et al.
(författare)
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Reasoning with Safety Factor Rules
- 2007
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Ingår i: Techné. - 1091-8264 .- 2691-5928. ; 11:1, s. 55-70
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Tidskriftsartikel (refereegranskat)abstract
- Safety factor rules are used for drawing putatively reasonable conclusions from incomplete datasets. The paper attempts to provide answers to four questions: “How are safety factors used?”, “When are safety factors used?”, “Why are safety used?” and “How do safety factor rules relate to decision theory?”. The authors conclude that safety factor rules should be regarded as decision methods rather than as criteria of rightness and that they can be used in both practical and theoretical reasoning. Simplicity of application and inability or unwillingness to defer judgment appear to be important factors in explaining why the rules are used.
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| 10. |
- Clausen Mork, Jonas
(författare)
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Uncertainty, credal sets and second order probability
- 2013
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Ingår i: Synthese. - : Springer Science and Business Media LLC. - 0039-7857 .- 1573-0964. ; 190:3, s. 353-378
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Tidskriftsartikel (refereegranskat)abstract
- The last 20 years or so has seen an intense search carried out within Dempster–Shafer theory, with the aim of finding a generalization of the Shannon entropy for belief functions. In that time, there has also been much progress made in credal set theory—another generalization of the traditional Bayesian epistemic representation—albeit not in this particular area. In credal set theory, sets of probability functions are utilized to represent the epistemic state of rational agents instead of the single probability function of traditional Bayesian theory. The Shannon entropy has been shown to uniquely capture certain highly intuitive properties of uncertainty, and can thus be considered a measure of that quantity. This article presents two measures developed with the purpose of generalizing the Shannon entropy for (1) unordered convex credal sets and (2) possibly non-convex credal sets ordered by second order probability, thereby providing uncertainty measures for such epistemic representations. There is also a comparison with the results of the measure AU developed within Dempster–Shafer theory in a few instances where unordered convex credal set theory and Dempster–Shafer theory overlap.
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