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- Lindberg, Gunnar
(author)
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Valuation and pricing of traffic safety
- 2006
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Doctoral thesis (other academic/artistic)abstract
- This thesis consists of six essays covering the topic of valuation and pricing of accidents. In the first essay a theory of the external marginal cost of accidents is presented. The external cost is dependent on the value of statistical life, the proportion internal cost and the so called risk elasticity, i.e. the relationship between traffic flow and accident risk. The two following essays present CV-studies on value of statistical life. Both CV-studies are based on the community approach built on the Swedish Vision Zero and ask respondents about their willingness-to-pay for absolute safety from fatal and severe accidents in one city.The first study focuses on the problem of scope and hypothetical bias and shows that ex post calibration based on respondents’ certainty in answering the WTP question reduces the willingness-to-pay with up to 30% for a public good. Based on these certain responses a lower bound VSL value is presented of SEK 53 million for a private good and 20 million for a public good. The second essay discusses the topic of nonselfish preferences and willingness-to-pay for children’s safety as well as for relatives and friends. The essay suggests that WTP for children safety is higher than private safety and that a WTP for the safety of relatives and friends is prevailing. Also this essay shows a big difference between the WTP for a private good and for a public good. The two following essays estimate the risk elasticity for railway level crossing accidents as well as for heavy goods vehicles in Sweden. Both essays find that the risk decreases with increased traffic i.e. negative risk elasticity. The last essay presents the result from a field experiment with speed related charges and bonuses. The experiment shows that internalisation of the external accident cost through speed related economic incentives strongly will affect drivers choice of speed. It is proposed that this can be achieved on a voluntary basis.
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| 2. |
- Lindberg, Olof
(author)
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The aging frontal lobe in health and disease : a structural magnetic resonance imaging study
- 2012
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Doctoral thesis (other academic/artistic)abstract
- Cortical and subcortical regions of the brain decrease in volume in normal as well as pathological aging. Previous studies indicate that certain parts of the brain, like the prefrontal cortex, may be particularly vulnerable to age-related processes which are manifested by significant volume loss in this region. Cortical volume loss may be further enhanced by different kinds of pathology in the brain. The purpose of this study was to further investigate regional volumetric changes of the frontal lobe in normal aging and in aging patients with dementia. In study I-III patients with frontotemporal lobar degeneration (FTLD), Alzheimer’s disease (AD) and healthy controls are investigated. Cortical atrophy is related to clinical symptoms (study I), discussed in relation to gross morphology and cytoarchitecture (study II), and compared with the atrophy in the hippocampus (study III). In study IV a large number of normal elderly participants are investigated. Age-related volume loss in the limbic system (the dorsal anterior cingulate cortex and the hippocampus) is compared with atrophy of a region of the prefrontal cortex (the orbitofrontal cortex). Volumetric data of frontal and temporal cortical regions and the hippocampus was acquired by manual delineation on structural magnetic resonance images. Results of study I and III reveal that the clinical symptoms displayed by the subtypes of FTLD are commonly reflected in a specific pattern of atrophy in frontotemporal cortices as well as in the hippocampus. Study II suggests that the surface morphology of sulci and gyri may be unreliable landmarks for cyto-architectonic regions of the frontal cortex. Study IV finally indicates that a common characteristic of limbic regions may be that age-related volume loss is delayed in comparison to regions of the prefrontal cortex. Results also suggest that the dorsal anterior cingulate is more resistant to age-related volume loss than hippocampus, which implies that age-related volume loss occurs at different rates for different regions also within the limbic system.
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| 3. |
- Rastad, Cecilia, 1953-
(author)
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Winter Fatigue and Winter Depression : Prevalence and Treatment with Bright Light
- 2009
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Doctoral thesis (other academic/artistic)abstract
- The aim of this thesis is to study prevalence of winter depressive mood and treatment effects of bright light for persons with winter fatigue and winter depression. Study I is a cross-sectional survey of a random sample (N=1657) from the general population between 18-65 years of age in Dalarna, Sweden (latitude 60°N). Study II is a similar survey of 17-18 year old students (N=756) in the municipality of Falun. Approximately 20% of both samples report seasonal symptoms, mainly fatigue, lowered mood and increased sleep duration, appetite and weight. Study III examines the effects of treatment in light rooms for persons from the sample in Study I (40 women, 10 men) with clinically assessed Seasonal Affective Disorder (SAD) or subclinical SAD (S-SAD). Subjects were randomised either to an experimental group receiving ten days of bright light treatment or to a three-week waiting-list control condition followed by bright light treatment. There was a >50% reduction of depressed mood in 13 of the 24 subjects in the experimental group, while none of the 24 controls reported a similar reduction. At the one-month follow-up, results were maintained and 39 of 47 subjects were improved >50%. Fatigue and excessive daytime sleepiness, which were high at baseline, were normal/below population norms for 39 of 47 subjects at the one-month follow-up. Mean values for the mental health aspect of health-related quality of life, which were low at baseline, improved and were close to norms at the one-month follow-up. Study IV is a person-oriented subgroup/cluster analysis of the subjects in Study III. A common trait in all three clusters was a high level of fatigue hence the denomination ´Winter Fatigue´ is used for the merged group. Even though the degree of depressive mood and daytime sleepiness differed between the subgroups, all three groups improved following bright light treatment. The results suggest that an increase in fatigue and depressed mood during the winter season is common in the general population. Bright light treatment reduces depressive mood, fatigue and excessive daytime sleepiness and improves health-related quality of life in persons with winter fatigue and winter depression.
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