| 1. |
- Andersson, Åsa Scott, et al.
(författare)
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Use of questionnaires and an expert panel to judge the environmental consequences of chemical spills for the development of an environment-accident index
- 2005
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Ingår i: JOURNAL OF ENVIRONMENTAL MANAGEMENT. - : Elsevier BV. - 0301-4797. ; 75:3, s. 247-61
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Tidskriftsartikel (refereegranskat)abstract
- Assessing the environmental consequences of a chemical accident is a complex task. To date, the methods used to evaluate the environmental effects of an acute release of a chemical have often been based on measurements of chemical and physical variables deemed to be important, such as the concentration of the chemical. However, a broader strategy is needed to predict the environmental consequences of potential accidents during the planning process. An Environment-Accident Index (EAI), a simple tool based on such a strategy, has been developed to facilitate the consideration of a multitude of influential variables. The objectives of this study were to evaluate whether questionnaire-based expert panel's judgements could provide useful data on the environmental consequences of chemical spills, and an effective basis for further development of the EAI. As expected, the judgements did not agree perfectly, but they do give rough indications of the environmental effects, and highlight consistent trends that should be useful inputs for planning, prevention and decontamination processes. The different accidents were also judged to have caused everything from minor to very major effects in the environment, implying that a wide range of accident scenarios were represented in the material and covered by the EAL Therefore, questionnaires and expert panel judgements can be used to collect useful data for estimating the likely environmental consequences of chemical accidents and for further development of the EAI.
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| 2. |
- Haghighi, Mona, et al.
(författare)
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A Comparison of Rule-based Analysis with Regression Methods in Understanding the Risk Factors for Study Withdrawal in a Pediatric Study
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Regression models are extensively used in many epidemiological studies to understand the linkage between specific outcomes of interest and their risk factors. However, regression models in general examine the average effects of the risk factors and ignore subgroups with different risk profiles. As a result, interventions are often geared towards the average member of the population, without consideration of the special health needs of different subgroups within the population. This paper demonstrates the value of using rule-based analysis methods that can identify subgroups with heterogeneous risk profiles in a population without imposing assumptions on the subgroups or method. The rules define the risk pattern of subsets of individuals by not only considering the interactions between the risk factors but also their ranges. We compared the rule-based analysis results with the results from a logistic regression model in The Environmental Determinants of Diabetes in the Young (TEDDY) study. Both methods detected a similar suite of risk factors, but the rule-based analysis was superior at detecting multiple interactions between the risk factors that characterize the subgroups. A further investigation of the particular characteristics of each subgroup may detect the special health needs of the subgroup and lead to tailored interventions.
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| 3. |
- Hersh, Evan, et al.
(författare)
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Sexual antagonism in the pistil varies among populations of a hermaphroditic mixed-mating plant.
- 2015
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Ingår i: Journal of evolutionary biology. - : Wiley. - 1420-9101 .- 1010-061X. ; 28:7, s. 1321-1334
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Tidskriftsartikel (refereegranskat)abstract
- Sexual conflicts and their evolutionary outcomes may be influenced by population-specific features such as mating system and ecological context; however, very few studies have investigated the link between sexual conflict and mating system. The self-compatible, mixed-mating hermaphrodite Collinsia heterophylla (Plantaginaceae) is thought to exhibit a sexual conflict over timing of stigma receptivity. This conflict involves 1) delayed stigma receptivity, which intensifies pollen competition, and 2) early fertilization forced by pollen, which reduces seed set. We investigated the potential for the conflict to occur under field conditions and performed greenhouse crosses within eight populations to assess its consistency across populations. Flowers were visited, and produced seeds after pollination, at all developmental stages, suggesting that the conflict can be of significance under natural conditions. In the greenhouse, early pollination imposed costs in all populations. Overall, the timing of first seed set was most strongly affected by the maternal parent, denoting stronger female than male ability to influence onset of stigma receptivity. Crosses also revealed a negative relationship between donor- and recipient-related onset of receptivity within individuals, a novel result hinting at trade-offs in sex-allocation or a history of antagonistic selection. Neither timing of stigma receptivity, timing of first seed set, nor pollen competitive ability covaried with population outcrossing rate. In conclusion, these results indicate that sexually antagonistic selection may be present in varying degrees in different populations of C. heterophylla, but this variation does not appear to be directly related to mating system variation. This article is protected by copyright. All rights reserved.
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| 4. |
- Opedal, Øystein H., et al.
(författare)
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Evolvability and trait function predict phenotypic divergence of plant populations
- 2023
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 120:1
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the causes and limits of population divergence in phenotypic traits is a fundamental aim of evolutionary biology, with the potential to yield predictions of adaptation to environmental change. Reciprocal transplant experiments and the evaluation of optimality models suggest that local adaptation is common but not universal, and some studies suggest that trait divergence is highly constrained by genetic variances and covariances of complex phenotypes. We analyze a large database of population divergence in plants and evaluate whether evolutionary divergence scales positively with standing genetic variation within populations (evolvability), as expected if genetic constraints are evolutionarily important. We further evaluate differences in divergence and evolvability- divergence relationships between reproductive and vegetative traits and between selfing, mixed-mating, and outcrossing species, as these factors are expected to influence both patterns of selection and evolutionary potentials. Evolutionary divergence scaled positively with evolvability. Furthermore, trait divergence was greater for vegetative traits than for floral (reproductive) traits, but largely independent of the mating system. Jointly, these factors explained -40% of the variance in evolutionary divergence. The consistency of the evolvability-divergence relationships across diverse species suggests substantial predictability of trait divergence. The results are also consistent with genetic constraints playing a role in evolutionary divergence.
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| 5. |
- Scott Andersson, Åsa, et al.
(författare)
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A method to relate chemical accident properties and expert judgements in order to derive useful information for the development of Environment-Accident Index.
- 2007
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Ingår i: Journal of Hazardous Materials. - : Elsevier BV. - 0304-3894. ; 147, s. 524-33
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Tidskriftsartikel (refereegranskat)abstract
- The environment consists of a variety of different compartments and processes that act together in a complex system that complicate the environmental risk assessment after a chemical accident. The Environment-Accident Index (EAI) is an example of a tool based on a strategy to join the properties of a chemical with site-specific properties to facilitate this assessment and to be used in the planning process. In the development of the EAI it is necessary to make an unbiased judgement of relevant variables to include in the formula and to estimate their relative importance. The development of EAI has so far included the assimilation of chemical accidents, selection of a representative set of chemical accidents, and response values (representing effects in the environment after a chemical accident) have been developed by means of an expert panel. The developed responses were then related to the chemical and site-specific properties, through a mathematical model based on multivariate modelling (PLS), to create an improved EAI model. This resulted in EAInew, a PLS based EAI model connected to a new classification scale. The advantages of EAInew compared to the old EAI (EAIold) is that it can be calculated without the use of tables, it can estimate the effects for all included responses and make a rough classification of chemical accidents according to the new classification scale. Finally EAInew is a more stable model than EAIold, built on a valid base of accident scenarios which makes it more reliable to use for a variety of chemicals and situations as it covers a broader spectra of accident scenarios. EAInew can be expressed as a regression model to facilitate the calculation of the index for persons that do not have access to PLS. Future work can be; an external validation of EAInew; to complete the formula structure; to adjust the classification scale; and to make a real life evaluation of EAInew.
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| 6. |
- Scott Andersson, Åsa, 1970-
(författare)
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Development of an Environment-Accident Index : A planning tool to protect the environment in case of a chemical spill
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The increasing mass and complexity of chemicals being produced and transported has resulted in more rigorous demands on both authorities as well as chemical-handling industries to assess the risks involved. The Environment-Accident Index (EAI), has been proposed as a planning tool created as an equation in which chemical properties (variables describing the chemical involved) are combined with site-specific properties (variables describing the accident site). The EAI is intended to facilitate assessment of the environmental effects related to chemical accident scenarios and hence assist the organisation of preventative programs. The main objective of the work described in this thesis was to evaluate, develop and improve the proposed EAI. The steps involved in the development process included I) evaluation of the feasibility of the EAI approach, II) selection of a representative and diverse set of chemical accidents to be used in the development III) the use of questionnaires and expert judgements to develop response values for environmental effects of a chemical accident, and IV) to create a new EAI model using multivariate modelling (PLS). The EAI approach proved to be useful in the work to protect the environment in case of a chemical accident. A representative set of accidents was selected by means of statistical multivariate design (PCA) based on assembled data related to a set of 55 chemical accidents. The selection generated a set of accidents representing a diverse spectrum of chemical accident scenarios. To develop a measure of environmental effects of the chemical accidents i.e. responses, an expert panel was asked to judge their environmental effects (such as effects on animal life in the aquatic or terrestrial environment). The results showed that the judgements give a rough estimate of environmental effects that could be used as responses in the development of the EAI. The developed responses were then related to the chemical and site-specific properties to create a new EAI model. This resulted in a PLS-based EAI connected to a new classification scale. The advantages of the new EAI are that it can be calculated without the use of tables; it can estimate the effects for all included responses, and make a rough classification of chemical accidents according to the new classification scale. Finally, the new EAI is a more stable model than the previously proposed EAI, and it is founded on a valid base of accident scenarios, making its use for a variety of chemicals and situations more reliable since it covers a broader spectrum of accident scenarios. The new EAI can be expressed as a regression model to facilitate calculation of the index for people that do not have access to PLS. The highest priorities for further refining the new EAI in the future are: external validation of the EAI; further refinement of the formula’s structure; adjustment of the new classification scale; and real-life evaluation of the EAI.
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