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| 2. |
- Alm, Jan, 1947-
(författare)
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Dyslexia: Relevance of Concepts, Validity of Measurements, and Cognitive Functions
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis opens with an exposition of different uses of the term dyslexia. In that context its conceptual relevance is discussed. The empirical studies investigate a) different aspects of validity of cognitive and achievement instruments often used in diagnostic assessment of dyslexia, b) different cognitive profiles for adults with dyslexia, and c) the relationship between cognitive and achievement measures.Study I demonstrated the factor structure of the Swedish WAIS-R to be in close agreement with results of comparable analyses on normal and clinical groups in many countries world-wide, giving strong support for the construct validity of the Swedish WAIS-R for a group of adults diagnosed with dyslexia. The results from the three-factor solution were interpreted in terms of theoretical constructs, notably those posited by Carroll (1993) and Horn (1989).The cognitive profiles of a sample of Swedish adults diagnosed with dyslexia—when using the three factors, the ACID profile, and the four-category Bannatyne profile—all resemble closely the profiles observed for a wide array of U.S. samples of children and adults diagnosed with dyslexia or learning disabilities. Gender differences on Digit Symbol, favoring females, were substantial in magnitude for the present sample, consistent with a bulk of research on gender differences for samples of normal individuals and of those identified with learning problems.In Study II, factor analysis of nine Swedish achievement tests often used for dyslexia assessment yielded five meaningful factors in a group of adults diagnosed with dyslexia. Factors appeared to measure decoding, visual speed, reading comprehension, reading fluency, and phonological ability. The relationship between the five achievement factors and WAIS-R variables was subsequently examined. The Visual Speed and Reading Comprehension factors each correlated significantly with four of six global WAIS-R scores (two of three IQs and two of three factor scores). Visual Speed tended to correlate significantly with nonverbal scores and Reading Comprehension with verbal scores. Although the Phonological Ability factor did not correlate significantly with any verbal or nonverbal global score, it did correlate significantly with the Freedom from Distractibility factor and with all its component subtests—Digit Span, Arithmetic, and Digit Symbol. Decoding (technical reading skill) showed no significant relationship to any WAIS-R variable studied. More surprisingly, the Reading Fluency factor failed to show significant relationships to the WAIS-R.Study III examined the validity of The Word Chain Test, a frequently used instrument in Swedish screening and diagnostic assessments of dyslexia. Different sources of validity evidence were evaluated. In summary, the results failed to support validity both for the WRI-index and the Wordchain subtest, suggesting that the instrument seems to be of questionable value in screening or diagnostic assessment of dyslexia.
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| 5. |
- Andersson, Jonas
(författare)
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Essays on financial time series models : Stochastic volatility and long memory
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This work consists of five articles about the statistical aspects of financial time series models. The first three papers investigate and develop the inverse normal Gaussian stochastic volatility (NIGSV) model, initially suggested by Barndorff- Nielsen (1997). In the first paper, Barndorff-Nilsen's model is generalized in order to be able to produce a more flexible lag structure. The moments of the squared process, important properties of volatility models, are derived. The topic of the second paper is the performance of the maximum likelihood estimator of the NIGSV model. In the third paper a comparison of the NIGSV model with two other commonly used volatility models is made.The long memory property is the topic of the last two papers. In the fourth paper two improvements of the commonly used GPH-estimator of Geweke and Porter-Hudak (1983) are proposed and studied by means of a Monte Carlo study. In the fifth paper the problem of distinguishing between short term and long term memory in volatilityis investigated.
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| 6. |
- Andersson, Jenny, 1972-
(författare)
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Older Women and Food : Dietary Intake and Meals in Self-Managing and Disabled Swedish Females Living at Home
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the present thesis was to study elderly self-managing and disabled women’s dietary intake and meals in relation to age, household structure (single-living or cohabitant), disability and cooking ability. The women were aged 64-88 years and living at home, in the mid-eastern part of Sweden. The self-managing women were randomly selected. The disabled women – suffering from Parkinson's disease, rheumatoid arthritis or stroke – were selected from patient records. A total of 139 self-managing and 63 disabled women participated. Two dietary assessment methods were used: a repeated 24-h recall and a three-day estimated food diary, providing dietary intake for five non-consecutive days. The results indicate that elderly women still living in their homes seem to manage a sufficient dietary intake despite disability and high age. The reported energy intakes in all groups of women were low, which might be explained by an actual low intake and/or under-reporting. The portion sizes seemed to be smaller in the highest age group, leading to lower intakes of some nutrients. Thus also the nutrient density of the food should be given greater consideration. The meal pattern was shown to be regular and the distribution of main meals and snacks was found to be satisfactory. Meals and snacks that were defined as such by the women themselves thus seem to be more significant from an energy and nutritional perspective. Perceived cooking ability co-varied with energy and nutrient intake as well as with meal pattern.Further, a qualitative dietary assessment method, FBCE, was analysed. It was concluded that it must be supplemented with a dietary assessment method providing energy intake figures to ensure a sufficient intake, especially when studying groups at risk for low energy intake.Furthermore, the aim was to perform a dropout analysis. When studying older women and food, a low participation rate might be expected since the most active, the very ill as well as the disabled tend to decline participation, but also since food is a gender issue. Food could, especially for women, be a sensitive area of discussion, even though older women seem to choose "healthy foods" and eat "proper meals".
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| 7. |
- Andersson, Kerstin
(författare)
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Reactions to novelties : Developmental aspects
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The present thesis considers different aspects of infants' and children's reactions to novelties, that is, unfamiliar persons, objects, and situations. In Study I, the developmental phenomenon stranger wariness was investigated from a temperamental perspective. Stranger wariness at age 10 months was found to be marginally predicted by 5-month individual variation in reactions to frustration, to sensory stimulation, and to novelties and to be predictive of 2-year social inhibition. These results indicate that 10-month stranger wariness does not only reflect a developmental transition but also an individual disposition to be responsive to social novelties.In line with what has been suggested for the behavioral inhibition construct, Study II showed that 2-year-olds' reactions to social and non-social novelties should be considered as belonging to one construct. Furthermore, the relations within and between latency, negative/inhibited and positive/approaching reactions to social and non-social novelties were found to be very similar, implying that identifying children as uninhibited means that they are disposed not only towards lack of negative/inhibited reactions, but also towards approaching/positive reactions when confronted with novelties. Study III concerned preschool social inhibition in relation to attachment security and social experiences in terms non-parental care. The relative contributions of the three variables to school-age social competence with peers and social self-esteem were also investigated. It was found that attachment security and social inhibition were unrelated to each other and that they made significant independent contributions to the explanation of social competence, whereas social self-esteem was only predicted by preschool social inhibition.
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| 9. |
- Araya, Tadesse
(författare)
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Stereotypes: Suppression, Forgetting, and False Memory
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis presents four studies investigating (1) whether incidentally primed control-related words can attenuate the impact of activated stereotypes on subsequent evaluation of a target person, (2) the impact of motivated forgetting on the recall of stereotypically congruent and incongruent information, and (3) the impact of a directed forgetting instruction on the false recall and recognition of nonpresented stereotypical information.In three experiments, Study I showed that participants initially primed with the social category, immigrant, and subsequently primed with words that were evocative of control or self-control made less negative impression of a target displaying ambiguous behaviors than participants not exposed to such words.Study II, using a directed-forgetting paradigm, demonstrated in two experiments that participants subliminally primed with Swedish facial photographs who later studied stereotypically incongruent words roughly recalled an equal number of items regardless of the forget or remember instructions. Study III showed that participants primed with the social category, immigrant and then studied a list of stereotypically related and unrelated words falsely recognized more nonpresented stereotypical words when they were furnished with a forget than a remember instruction. Similarly, Study IV (Experiment 2) demonstrated that participants primed with the social category, immigrant, but not with a neutral category, falsely recalled more nonpresented stereotypical words when their cognitive capacity was depleted through a concurrent memory load task. The thesis presents a review and a discussion of some of the theoretical underpinnings of the extant literature on stereotyping and intergroup relations and of the social implications of the present findings.
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| 11. |
- Axelson, Martin
(författare)
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On variance estimation for the two-phase regression estimator
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Regression estimation under two-phase sampling is a cost-effective technique for estimating a finite population total. This dissertation consists of four papers, summarized in an introductory chapter, all of which focus on the use of auxiliary information in estimating the variance of the generalted regression estimator under two-phase sampling.The first paper deals with the analysis of results from so-called computersimulation experiments for policy analysis. In particular, we consider applications based on input from the National Resources Inventory, which is a stratified two-stage area sample of nonfederal land in the United States. The estimation problem is formulated in terms of generalised two-phase regression estimation, and a variance estimation strategy is developed.In the second paper, a new approach to variance estimation is suggested. Compared with the reference estimators considered, the new approach, which may be seen as a generalisation of the approach used in paper one, makes more extensive use of the available auxiliary information, and hence it may be expected to be more efficient.Yet another approach to variance estimation is discussed in the third paper. Although conceptually different from the approach discussed in the second paper, it yields very similar results when applied to the generalized regression estimator under two-phase sampling. The approach may readily be extended to allow for variance estimation under multi-phase sampling.The fourth paper, finally, deals with jackknife variance estimation. Twoestimators of potential practical interest are derived, and the estimators are compared empirically by means of a small-scale Monte Carlo study.
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| 12. |
- Barron, Karin
(författare)
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Disability and gender : Autonomy as an indication of adulthood
- 1997
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of this dissertation was initially to examine the relationship between a continuedrequirement of practical assistance in adult life and autonomy. As the work has proceeded, thefocus has come to increasingly be on identifying social obstacles to autonomy, particularly fordisabled young women.The fast part deals with the transition from adolescence to adulthood for physically disabledyoung people. Some of the questions raised in this study are developed further in thesucceeding three articles. The first article (Part II) focuses on physically disabled girls/youngwomen and how they internalize societal norms and values. The interest is on how these normsand values affect the possibility to autonomy in everyday life for the young women. The secondarticle (Part III) emhasizes the importance of a gender perspective in educational research ondisability. The third article (Part IV) deals with ethical problems in qualitative social research onmarginalized groups.The comprehensive summary consists of a discussion on the research process in this work.The methodological approach has been qualitative interviews with 24 physically disabled youngpeople. The summary also includes a discussion on the chosen theoretical perspective, i.e.social constructionism, and a brief overview of some of the results in this work. Then follows adiscussion on the results in a somewhat broader societal framework. Finally them is a briefsummary of the different parts of the dissertation.
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| 13. |
- Bengtsgård, Kerstin
(författare)
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Social inhibition and socioemotional functioning in middle childhood
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Social inhibition, or in lay language "shyness", means a tendency to react with fearful and hesitant behaviors innovel social encounters. Lowinhibition, on the other hand is associated with a capacity to easily approachnovel social situations. However, low-inhibition might co-occur with difficulties in inhabiting undesired socialbehaviors. When disinhibited behavior in the sense of a lack of normal reserve, or indiscriminate socialbahaviors, is seen, this phenomenon is, in this thesis, named overfriendliness.Study I and Study II aimed at investigating socioemotional functioning in socially high and low-inhibitedchildren, with a special focus on overfriendliness. In Study I, high- and low-inhibited groups were compared toa medium-inhibited group with respect to problem behaviors and social competencies. Among low-inhibitedchildren, a group of overfriendly children was compared to a low-overfriendly group. Study II aimed atfurthering the knowledge about socioemotional functioning in high-inhibited children and in low-inhibitedchildren, when considering high and low overfriendliness. Study III considered problem behaviors in high-andlow-inhibited children when taking dysregulation - as indicated by negative emotionality and impersistence invarious activities - into account. Dysregulation was found to be associated with comorbid internalizing,externalizmg and attention problem behaviors. Results from the three studies show that high social inhibitionwas associated with a heightened risk for internalizing problem behaviors, less well developed socialcompetencies and socioemotional distress reactions. Low social inhibition was, if not co-occurring withoverfriendliness or with broad dysregulation, associated with especially well functioning development, and withlow risk for internalizing problems. Overfriendliness was primarily characterized by attention problembehaviors. When compared with the low-overfriendly group the high-overfriendly group also showed morethrill seeking, hyperactivity, externalising problem behaviors, internalizing problem behaviors, and less welldeveloped social competencies.Results indicated presence of different developmental pathways among socially low-inhibited children, andpointed to the importance of taking the heterogeneity among low-inhibited children into account in the study ofsocioemotional development.
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| 16. |
- Berlin, Lisa, 1973-
(författare)
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The Role of Inhibitory Control and Executive Functioning in Hyperactivity/ADHD
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis examined inhibition, executive functioning and their possible relation to childhood problems of hyperactivity and inattention, in its clinical form referred to as Attention Deficit Hyper-activity Disorder (ADHD). Concurrent as well as longitudinal relations were of interest, and both clinical and non-clinical samples were studied. Study I demonstrated concurrent relations between executive inhibition and both hyperactivity and conduct problems in preschool. However, the relation between inhibition and conduct problems could be attributed to the large overlap between hyperactivity and conduct problems.In Study II, linear relations were found between executive inhibition and hyperactivity, whereas inhibition to the unfamiliar was related to hyperactivity, social initiative, as well as social anxiety. Non-linear analyses showed that children with high levels of both types of inhibition were at risk for developing low social initiative and social anxiety, whereas children with low levels of inhibition were at risk for developing hyperactivity, but at the same time protected from social anxiety. In Study III, executive inhibition was longitudinally related to ADHD symptoms in both school and at home for boys, but only in the school context for girls. Executive inhibition was also related to more general executive functioning deficits, and concurrent relations were found between executive functioning and ADHD symptoms, although in both cases only for boys. Inhibition and executive functioning made independent contributions to the understanding of ADHD symptoms for boys, and together explained about half the variance in inattention problems. In Study IV, group differences were found between ADHD children and controls for both inhibition and various other executive function measures. These measures also discriminated well between groups. The best model, which included measures tapping inhibition, working memory and emotion regulation, classified 86% of the children correctly. In summary, the results of the present thesis were mostly supportive of Barkley’s hybrid model of ADHD, although it should be noted that the question of whether inhibition should be regarded as primary to other executive functions requires further investigation.
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| 17. |
- Birgegård, Andreas, 1972-
(författare)
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Producing, Preventing, and Explaining Persistent Complex Subliminal Stimulation Effects
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Strong recent focus on unconscious processes has increased interest in subliminal stimulation and similar experimental technologies. Assumptions about the persistence of effects of unconscious stimulation are generally conservative, referring to seconds or minutes (Silverman, 1977; Velmans, 1991). In Study I, five experiments (N = 365) showed complex effects of unconscious stimulation ten days after subliminal exposure, implying that persistence estimates need reevaluation. Experimental stimuli were "mommy and I are one" (MIO) and "mommy and I are dissimilar" (MIDIS), and neutral control stimuli. Effects consisted of higher correlations between measures pertaining to the self-mother relationship and measures of psychological adjustment. These ethically problematic findings prompted investigation in Study II of whether debriefing information to participants could prevent persistent effects of subliminal stimuli, an issue not previously investigated. Two experiments (N=188) tested two kinds of information to participants following subliminal MIDIS or control stimulation. Results showed different persistent effects depending on participant sex. Simple information about the stimulus was effective in preventing these, but elaborate information describing the effects and mechanisms for them was not. The findings have implications for ethical recommendations for subliminal research, and suggest that this unexplored area requires more attention. In Study III, a theoretical account for the persistent effects is presented, based on unconscious activation of a relational schema containing goal motivation. Unless the goal is fulfilled or activation dissipates due to attributability or irrelevance of the goal, the activation will be maintained (motivated maintenance). Being unconscious, the influence results in automatic schematic processing of environmental cues, including perceptual, judgment, and behavioral biases. These in turn interactively maintain the activation of the schema (interactive maintenance). The discussion includes the conclusion that previous estimates of the persistence of unconscious stimulation effects need revision. Theoretical and empirical questions concerning the studies are discussed and ethical research implications are considered.
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| 20. |
- Carlbring, Per, 1972-
(författare)
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Panic! Its Prevalence, Diagnosis and Treatment via the Internet
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- As evidenced by several trials, cognitive behavior therapy (CBT) is a highly effective treatment for Panic disorder with or without agoraphobia (PD). However, therapists are short in supply, and patients with agoraphobia may not seek therapy due to fear of leaving their homes or traveling certain distances. A major challenge therefore is to increase the accessibility and affordability of evidence-based psychological treatments.This thesis is based on five studies; three treatment studies set up as randomized controlled trails (RCT), one prevalence study, and one study testing the equivalence of an Internet-administered diagnostic assessment tool with a clinician-administered interview.Study I showed that the Swedish 12-month PD prevalence is consistent with findings in most other parts of the Western world (2.2%; CI 95% 1.0%-3.4%). There was a significant sex difference, with a greater prevalence for women (3.6%) compared to men (0.7%).Study II showed that the validity of the computerized diagnostic interview (CIDI-SF) was generally low. However, the agoraphobia and obsessive-compulsive disorder modules had good specificity and sensitivity, respectively.The three RCTs showed, directly or indirectly, that Internet-based self-help is superior to a waiting-list. When 10 individual weekly sessions of CBT for PD was compared with a 10-module self-help program on the Internet, the results suggest that Internet-administered self-help, plus minimal therapist contact via e-mail, is as effective as traditional individual CBT (80% vs. 67% no longer met criteria for panic disorder; composite within-group effect size was Cohen’s d= 0.78 vs. 0.99). One-year follow-up confirmed the results (92% vs. 88% no longer met criteria for panic disorder; d= 0.80 vs. 0.93). The results generally provide evidence to support the continued use and development of Internet-distributed self-help programs.
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| 22. |
- Carter, Ned
(författare)
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Functional analyses of stimuli influencing retail theft
- 1996
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Ingår i: Comprehensive Summaries of Uppsala Dissertations from the Faculty of Social Sciences 58.. - Uppsala : Acta Universitatis Upsaliensis.
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)
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| 27. |
- Eldén, Åsa, 1969-
(författare)
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Heder på liv och död : Våldsamma berättelser om rykten, oskuld och heder
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation discusses how reputation, virginity and honour are made topical in the stories of the lives of Arab and Kurdish women and connected with understandings of culture and religion. The dissertation is composed of five articles, which contain the principal analysis, and five chapters that discuss the project as a whole; the development of the main topics, and choices concerning methodological, ethical and theoretical approaches. The empirical material of the dissertation consists of interviews with ten Arab and Kurdish women in Sweden, and seven legal cases of honor related violence. The interview material is analysed as a whole – focusing on the importance of reputation in women’s creation of identity, and how this may be related to cultural conceptions of divided femininity (virgin-whore) and honour (article 4). I also conduct an in-depth analysis of one interview, where meaning is created through a story, in which liberty is contrasted with constraint (article 3). In the analysis of the legal cases, I discuss the arguments of verdicts concerning honour related violence, and criticise the courts’ understanding of crimes as demarcated acts (articles 1 & 5). I also analyse the (violent) stories of the actual lives of women found in the legal cases in their contexts (articles 2 & 5).Throughout the dissertation, I aim at a constructivist attempt that sees culture and gender as creative frames of interpretation. This attempt is connected with a hermeneutic perspective, which sees a statement or an act as comprehensible only when interpreted in its context (e.g. in a cultural context of honour). It is also connected with a feminist understanding of men’s violence against women, which relates the meaning of an act of violence to culturally accepted forms of control and cultural conceptions of gender.In the analysis of the empirical material, I show how culture is created as contrast in the lives of women. ’Arab/Kurdish’ and ’Swedish’ appear as exclusive categories, and are connected with cultural conceptions of divided femininity and honour. Within these categories, a woman is either a virgin or a whore, and a woman that has been branded as a whore will be stained forever. Men’s honour will not be restored until she is extinguished. When these cultural conceptions are used in the life of a woman who lives with these highly normative demands, they may be crucial and signify experiences of violence. A woman with bad reputation may be defined as a ”Swedish whore” be her male relatives, contrasted with being an ”Arab/Kurdish virgin”. The honour of these men will not be restored until she is excluded from the family or dies: to be a virgin or a whore may be a life-and-death matter.
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| 31. |
- Fichtel, Åsa, 1967-
(författare)
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Recurrent Headache among Swedish Adolescents : Psychosocial Factors, Coping and Effects of Relaxation Treatment
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Overall aims of the present thesis were to study the prevalence and psychosocial impact of recurrent headache within a school population in comparison with other types of pain and to examine the use and efficacy of various coping strategies. Further aims were to compare the effects of relaxation treatment among adolescents with recurrent headache to a waiting-list control group, and finally to examine the efficacy of relaxation training administered in a school setting.From 8 schools, 793 adolescents were recruited to a questionnaire study. The results showed that headache is a very common health complaint particularly among girls. Subjects with frequent headache also reported higher levels of depressive symptoms, anxiety, functional disability and other types of recurrent pain, than those with infrequent headache.A Swedish version of the pain coping questionnaire (PCQ) was translated and administered to the same sample of 793 adolescents. Its psychometric properties were replicated and problem solving was regarded to be the most effective coping strategy.In a treatment study 36 subjects suffering from migraine and tension-type headache were randomized to either relaxation treatment or a waiting list control group. Results showed that half of the adolescents were clinically improved after treatment. In a final effectiveness study 63 subjects were randomized to one of two types of relaxation training, administered by school nurses. The results showed similar positive outcomes but small differences compared to a non-treated post hoc comparison group. Positive outcomes of relaxation treatment were predicted by one pain coping strategy, positive self-statements but also by higher functional disability before treatment.In conclusion, more active strategies such as positive self-statements and problem solving were found to co-vary with a better efficacy or outcome after relaxation training. A further exploration of how to optimize treatment for adolescent headache is warranted in future studies. Generally a broader perspective including social, psychological as well as biological factors could give more information on the complex mechanisms behind headache.
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| 32. |
- Fischer, Håkan
(författare)
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Imaging fear and anxiety in the human brain : Positron emission tomographic studies
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Fear and anxiety are central human experiences. However, the relation between aspects of these aversive emotional states and brain function have previously been studied mostly in animals. To investigate human brain function during normal fear and anxiety, the present thesis employed positron emission tomography methodology in conjunction with activation and symptom provocation paradigms. Classical fear conditioning (i.e., the acquired ability of a neutral stimulus to induce stress after pairings with an aversive stimulus), trauma re-experience and panic anxiety were investigated.During the memory formation phase of fear conditioning, regional cerebral blood flow (rCBF), which is an index of neural activity, increased in the right prefrontal gyrus and decreased bilaterally in the superior temporal gyrus and the left hippocampus. After fear conditioning during the memory expression phase, increases in rCBF were evident bilaterally in the hypothalamus, the thalamus, the central grey of the midbrain, the cerebellum, the anterior cingulate cortex and in the left striatum and right prefrontal cortex, whereas rCBF decreased bilaterally in the amygdala, the prefrontal, temporal, parietal and occipital cortices. Hence, fear-related memory formation and expression involve both overlapping and unique cortical networks.In contrast to a neutral state, rCBF increased during an anxiety episode resulting from trauma re-experience in the left orbitofrontal cortex and bilaterally in the posterior cingulate and occipital cortices. Decreased rCBF was found in Brocas' area and in the left operculum, angular gyrus and secondary somatosensory cortex. During unexpected panic resulting from electric shock stimulation, as opposed to electric shocks without panic, rCBF decreased in the right orbitofrontal, prelimbic, anterior cingulate and temporal cortices.In accordance with numerous brain imaging studies, the present papers implicate anterior paralimbic and prefrontal structures in the functional neuroanatomy of symptomatic fear and anxiety.
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| 33. |
- Frans, Örjan, 1951-
(författare)
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Posttraumatic Stress Disorder (PTSD) in the General Population
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis explored the epidemiology of Posttraumatic Stress Disorder (PTSD) and different aspects of the disorder. Firstly, we investigated the lifetime prevalence of traumatic experiences and PTSD in the general adult population in Sweden and evaluated the impact of different trauma types, trauma frequency, and perceived distress. The results show that traumatic experiences are common and PTSD is not rare; roughly one out of ten traumatic events results in PTSD, with a 5.6% lifetime prevalence. The female/male ratio is 2:1. The risk for PTSD increases considerably with a high trauma-associated emotional impact. The distressing impact of a given trauma appears to be higher in women than in men, indicating an increased vulnerability in women. Secondly, we hypothesized that traffic road accidents (TRA’s) are one of the most prevalent types of traumatic events in Swedish society; therefore, we examined the impact of event and response characteristics associated with TRA’s on PTSD development. The data demonstrate that of those who had experienced a TRA (n=1074, 58.9%), 6.1% reported lifetime PTSD. TRA’s associated with fatal accidents and injury to oneself and related to high distress more than double the risk for PTSD. Thirdly, we compared the relative merits of the DSM-IV’s three-factor solution for PTSD symptoms to alternative models. We found that the symptomatology is equally well accounted for using all factor analytic models as yet presented in the literature; the DSM-IV, we found, provides as good a fit to data as other models. Fourthly, we examined the neurofunctional correlates of PTSD symptoms and whether a treatment-induced (serotonin reuptake inhibitor - SSRI) reduction of PTSD symptoms is associated with altered rCBF during symptom provocation. Our results indicate that PTSD symptoms correlates with areas involved in memory, emotion, attention, and motor control and that SSRI treatment normalizes provocation-induced rCBF in these areas.
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| 34. |
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| 35. |
- Furmark, Tomas
(författare)
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Social Phobia. From Epidemiology to Brain Function
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Social phobia is a disabling anxiety disorder characterized by an excessive fear of negative evaluation in social situations. The present thesis explored the epidemiology and neurobiology of the disorder. By means of a mailed questionnaire, the point prevalence of social phobia in the Swedish general population was estimated at 15.6%. However, prevalence rates varied between 1.9 and 20.4% across the different levels of distress and impairment used to define cases. Thus, although social anxiety is widespread within the community, the precise diagnostic boundaries for social phobia are difficult to determine. Social phobia was associated with female gender, low educational attainment, psychoactive medication use, and lack of social support. A cluster analysis revealed that subtypes of social phobia mainly differed dimensionally on a mild-moderate-severe continuum, with number of cases declining with increasing severity. Public speaking was the most common social fear in all groups of social phobics and in the population at large.In the neurobiological studies, positron emission tomography was used to examine brain serotonin metabolism and changes in the regional cerebral blood flow (rCBF) response to public speaking stress following treatment with a selective serotonin reuptake inhibitor (SSRI) or cognitive-behavioral group therapy. Social phobics exhibited lowered serotonin turnover, relative to non-phobics, mainly in the medial temporal cortex including the bilateral rhinal and periamygdaloid regions. Symptom improvement with cognitive-behavioral- as well as SSRI-treatment was accompanied by a reduced rCBF-response to public speaking in the amygdala, hippocampus and adjacent temporal cortex, i.e. regions that serve important functions in anxiety. Thorough suppression of rCBF in limbic brain regions was associated with favorable long-term treatment outcome. These results provide neuroimaging evidence for a presynaptic serotonergic dysfunction in social phobia and for a common neural mechanism whereby psychological and pharmacological anti-anxiety treatments act.
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| 36. |
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| 37. |
- Ghaderi, Ata
(författare)
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Eating disorders : Prevalence, incidence, and prospective risk factors for eating disorders among young adult women in the general population
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Eating disorders (ED) constitute a significant source of psychiatric morbidity and are an important public health concern in Western societies. Knowledge about risk factors for ED is crucial for early detection and implementation of preventive interventions. The aim of the present thesis was to examine the prevalence, incidence, correlates, and the risk factors for ED among 1,157 young adult women in the general population. The studies in the thesis used a prospective design with the potential of addressing methodological limitations in earlier research.In Study I, conducted in 1997, the lifetime and point prevalence of DSM-IV-based diagnoses of ED was, respectively, 7.85% and 2.59%. Participants with ED reported higher body dissatisfaction, lower perceived social support from the family, and lower self-esteem compared to participants with no ED. In Study II, it was shown that highest relative use of escape-avoidance coping was reported among participants with ED, followed by dieting participants with no ED, and least among those neither dieting nor with ED. In Study III, (i.e., the follow-up in 1999), the point prevalence of ED was 3.15% and the cumulative 2-year first time incidence was .0105 (n=8). The total incidence group (n=34), as compared to the participants with no ED (controls, n=643), reported significantly lower premorbid self-esteem, and perceived social support from the family and higher body dissatisfaction, higher relative use of escape-avoidance coping, and dieting. Furthermore, the incidence group reported a significant increase in body dissatisfaction and relative use of escape-avoidance coping, and a significant decrease in self-esteem as compared to controls from 1997 to 1999. In Study IV, it was shown that the Survey for Eating Disorders is a reliable and valid self-report questionnaire for the screening of ED and case ascertainment. In conclusion, it is suggested that premorbid low self-esteem, perceived low social support, high body dissatisfaction, high relative use of escape-avoidance coping, and dieting be regarded as risk factors for a later development of ED among young adult women. It is also proposed that more attention be devoted to these factors both in designing prevention interventions and in refining current treatments.
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| 38. |
- Ghilagaber, Gebrenegus
(författare)
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Five essays on models and methods for the analysis of survival data with single and multiple causes of failure : With applications in family demography
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The dissertation consists of five self-contained essays dealing with analytical investigations, simulation studies, and demographic applications of statistical models and associated methods for the analysis of the so-called survival data.Our analytical results in the first paper indicate that models for grouped survival data which, depending on the application, are labeled different names, practically, make use of the same method in the process of parameter estimation and inference. Further, we find, empirically, that estimates of covariate-effects are not always robust to distributional assumptions for the duration variable.The second paper demonstrates, both analytically and empirically, that results of inference concerning covariate-effects as obtained from a dynamic model for the cause-specific hazard rate, and a static logistic regression model for a conditional probability, are generally the same.In the third paper we provide analytical and empirical justification to demonstrate that separate and simultaneous modeling of multiple causes of failure lead to the same estimates of hazard rates, Wedemonstrate further, that simultaneous modeling is based on the assumption of independence among thecauses of failure in which case it is impossible to distinguish between crude and net hazard rates.The fourth paper demonstrates, analytically, that in situations where a covariate interacts with two other covariates in the same multiplicative model, the traditional approach of using two first-order interaction terms leads to estimates of relative hazards that are not identified. A model involving a single second-order interaction term is proposed as a solution.In the fifth paper we examine the effects of differences in sample sizes and heteroscedasticity levels on the power and size of the conventional Chow test for the equality of two log-normal duration models.The main result, on the basis of simulated data, is that the test performs well from both aspects of size and power when the sample sizes from the two models are equal, and the error terms in the two models have the same form of heteroscedasticity.
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| 39. |
- Gitahy, Leda
(författare)
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A new paradigm of industrial organization : The diffusion of technological and managerial innovations in the Brazilian industry
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Based on the concepts of techno-economic paradigm, network and production chain, the main purpose of this dissertation is to analyse the diffusion of technological and managerial innovations in the Brazilian industry during the 1980s and the 1990s. It consists of a summary and six selected papers. Empirical studies were conducted at different moments of the re-structuring process and at different points of the production chain. The samples cover large leading firms as well as small second and third-tier suppliers in the automotive and footwear industries. They throw light on the process of diffusion and establishment of a new paradigm of industrial organization, mostly in conflict with the Taylorist/Fordist.Ideas, methods and management techniques were largely adopted and imitated from the so-called "Japanese model", but the diffusion of the new paradigm in Brazil is also the result of adapting and modifying this model by trial and error. At the firm level, the adoption of these innovations entails a highly complex process of social change, reversing norms and models of behaviour hitherto dominant. They modify the daily practices at work, and the division of labour within and between companies, as well as between companies and other institutions, such as those within the educational system. These transformations are studied by distinguishing competition, management, and technological patterns.The results show that, under the conditions of a an extremely large domestic market, the re-structuring of the Brazilian industry occurs in a context characterized by crisis, economic instability, recession and unemployment as well as by political re-democratization and growing influence of the labour movement. The diffusion of the new paradigm of efficiency together with the increasing globalization of the economy and the ongoing abandonment of import substitution, transformed the organization of work and inter-firms relations, changing the volume, structure, and location of employment as well as the content and hierarchy of skills.
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| 40. |
- Granqvist, Pehr, 1973-
(författare)
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Attachment and Religion : An Integrative Developmental Framework
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the thesis was to examine the applicability of attachment theory to adult and adolescent religiosity. Attachment theory is an empirically oriented research paradigm that takes evolutionary theory as the starting point in the study of child-parent relations and their socioemotional correlates in development. The work consisted of two interrelated tasks. First, limitations in theory and research in the psychology of religion, particularly the traditional psychodynamic perspectives, were highlighted, and attachment theory was proposed as an integrative framework to remedy some of those limitations. Second, four empirical studies (I-IV), based on attachment theoretical predictions, were conducted to investigate relations between individual differences in attachment and religiosity. The combined results from the studies suggest the existence of two religiosity profiles in relation to attachment. Both profiles resemble influential descriptions of individual religiosity differences in the psychology of religion literature. The religiosity of individuals in the first profile is similar to their parents' religiosity and is likely to be stable over time. If religious changes have been experienced, these are likely to be gradual, to occur early in life, and in a context pointing to the importance of relationships with religious significant others. Such individuals' God image is likely to be loving, and not distant. It was hypothesized that these religiosity characteristics stern from experiences with sensitive attachment figures in childhood, and that such experiences have promoted partial adoption of the attachment figures' religious standards. The mental representations of attachment resulting from the favorable experiences were suggested to be responsible for a corresponding image of a loving God. The religiosity of individuals in the second profile is independent of parental religiosity, and is likely to fluctuate (increase and decrease) over time. Their religious changes are more sudden and intense, occur relatively later in life, and in a context pointing to an emotionally supportive function for religion. Such individuals' God image is more distant, and less loving. These religiosity characteristics were hypothesized to stem from experiences with insensitive attachment figures in childhood. It was suggested that they reflect an affect regulation strategy to obtain/maintain a sense of felt security, and that God is utilized as a compensatory attachment-like figure in this regard. Findings pertaining to the profiles generally emerged regardless of whether the design was cross-sectional (I-IV) or longitudinal (III); whether participants were adults (I, II, and IV) or adolescents (Study III); and whether attachment was assessed with self-report questionnaires (I-IV) or independent ratings based on a semi-structured interview (IV).
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| 41. |
- Gredebäck, Gustaf, 1974-
(författare)
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Infants’ Knowledge of Occluded Objects: Evidence of Early Spatiotemporal Representations
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis demonstrates that infants represent temporarily non-visible, or occluded, objects. From 4 months of age, infants could accurately predict the reappearance of a moving object after 660 ms of non visibility; indicating accurate spatiotemporal representations. At this age predictions were dominated by associations between specific events and outcomes (associative rules). Between 6 and 8 months of age predictions became dominated by extrapolations (Study III). From 6 months infants could represent occluded objects for up to 4 seconds. The number of successful predictions decreased, however, if the information contained in the occlusion event diminished (time of accretion and deletion). As infants grew older (up to 12 months) they produced more accurate predictions. (Study II). The similarities between adult and infant performances were numerous (Study I). These conclusion are based on one cross sectional (Study I) and two longitudinal studies (Study II & III) in which an object, a ‘happy face’, moved on circular (Study I, II, & III) and other complex trajectories (Study III). One portion of each trajectory was covered by a screen that blocked the object from sight. In each study participants gaze were recorded with an infrared eye tracking system (ASL 504) and a magnetic head tracker (Flock of Birds). This data was combined with data from the stimulus and stored for of line analysis.
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| 42. |
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| 43. |
- Haglund, Mats
(författare)
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Speed Choice : The Driver, the Road and Speed Limits
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Speed choice is one of the more characteristic features of driver behaviour. The speed a driver chooses to travel at determines the degree of difficulty he or she operates under. Higher speeds lead to more accidents, higher accident risk and more severe consequences of an accident. The present thesis examines factors that are associated with drivers’ speed choice. Repeated measures of drivers’ speed showed a reasonably high correlation, but also that stability in speed varied with road layout between measurement sites. Effects of police enforcement were studied on roads with temporary reduced speed limits (from 50 km/h to 30 km/h) during school hours. Lower speeds were found on roads with enforcement and drivers observed on one such road showed a higher perceived probability of detection than did drivers observed on a non-enforced road. However, in a laboratory study higher driving speeds and lower accident risk was associated with enforced roads. Drivers not informed about existing speed limits overestimated the limits to a large extent and chose driving speeds above the limit as did drivers informed about the limits. In an on-the-road survey, fast drivers reported higher driving speed, thought a higher percentage of other drivers were speeding and had a more positive attitude towards speeding than did slower drivers. The results suggest that drivers’ travel speed is influenced by road factors, other road users and enforcement. Furthermore, drivers’ own judgements of what is an appropriate speed are also important for speed choice.
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| 44. |
- Haglund, Åsa
(författare)
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Sensory quality of tomato, carrot and wheat : Influences of growing systems
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The sensory variation in products, conventionally and ecologically grown has been described and the effect of sensory training on the reliability of the assessors has been evaluated.Ecologically grown tomatoes scored higher for sweetness while conventionally grown tomatoes scored higher for firmness. For total taste intensity, acidity and bitterness, there was an interaction between growing system and variety. In a controlled experiment, nutritiously poor growing substrate produced a low yield of sweet, firm and less juicy tomatoes. Nutritiously rich growing substrate produced a high yield of less sweet, less firm but juicier tomatoes. Late harvest resulted in an increase of total taste intensity and a decrease of the bitter taste of the tomatoes.Conventionally grown carrots scored high for carrot-taste, while ecologically grown scored high for bitter taste. In one out of two years conventionally grown carrots were sweeter and crunchier while ecologically grown carrots were harder. Conventionally produced wheat samples had significantly higher protein levels compared with ecologically produced wheat samples. The volume of the wholemeal bread was related to the protein content and there was a close relationship between volume and elasticity of the bread.It was observed that information on labelling as being ecologically grown caused an increase in product rating. For sweet tomatoes with high tomato taste intensity, the information on them being grown ecologically was less important for consumer preference. During training the variation in reproducibility within assessors decreased and the assessors' ability to detect differences between samples increased.
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| 45. |
- Halvarsson, Klara
(författare)
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Dieting and eating attitudes in girls : Development and prediction
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aims of the present thesis were to study: 1. reported eating attitudes, dieting behavior and body image over a 1-year period among preadolescent girls (age 7-8); 2. differences in eating attitudes and coping between groups of teenage girls differing in dieting frequency, and to assess changes with increasing age (age 13-17); and 3. to what extent eating attitudes, self-esteem and coping predict disturbed eating attitudes. A final aim was to explore differences in the reported wish to be thinner, dieting, and eating attitudes between two age-matched cohorts of girls in 1995 and 1999 (7-15 years).The project is designed as a longitudinal prospective study, spanning seven years. 1300 girls in the ages (1995) 7, 9, 11, 13 and 15 years have been assessed annually for three consecutive years (1995-1997) (Main Cohort). An additional group matched for age with the original group was recruited in 1999 (Societal Cohort). The results suggest that dieting and the wish to be thinner starts as early as at 7 years of age, and that repeated dieting attempts correlate with disturbed eating attitudes. A marked increase of the wish to be thinner was evident in the 10- to 14-year age range, and significant increases in dieting attempts occurred mainly between ages 9 and 13. There were no differences between 1995 (Main Cohort) and 1999 (Societal Cohort) (except among 7 and 11-year-olds) with regard to dieting, the wish to be thinner and disturbed eating attitudes. Eating patterns and attitudes were shown to be the strongest predictors of disturbed eating attitudes three years later. Assessment of dieting, the wish to be thinner and eating attitudes is suggested BS a component in school health care.
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| 46. |
- Hammarberg, Annie
(författare)
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Pre-school Teachers’ Perceived Control and Behaviour Problems in Children
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis, pre-school teachers’ perceived control, is examined in relation to problem behaviours of children and the actions of teachers in the classroom. In addition, other factors that are thought to relate to teachers’ perceived control were studied.The results of Study I indicate that pre-school teachers’ high perceived control was related to high intentions to act in the event of child behaviour problems. Teachers’ high satisfaction with their work was also related to high perceived control. Study II showed that low perceived control was associated with having a high proportion of children with a high level of externalising behaviours and of boys in the classroom. Study III shows that children who had a high level of externalising behaviours at the beginning and throughout the school year had teachers with low perceived control. Teachers’ perceived control was not related to their perception of internalising behaviours in the same way as to externalising behaviours and it was unrelated to a change in any direction of problem behaviours. Concerning changes in problem behaviours, no other factor was found, except a low child to adult ratio for a positive change of internalising behaviours. In Study IV, the aim was to examine naturally occurring child–teacher interactions. Teachers’ responding with commands to children was associated with teachers’ low perceived control, whereas restrictive teacher responses were not related to teachers’ perceived control.The present study indicates that teachers’ perceptions of children are important for their perceived control. It provides evidence that teachers’ low perceived control is associated with their difficulties in handling externalising behaviours and the behaviour of the boys in the classroom. Responding to problem behaviours can be explained by teachers’ perceived control, and their perception of a child’s sex and externalising behaviours.
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| 47. |
- Hansson, Lisbeth
(författare)
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Statistical Considerations in the Analysis of Matched Case-Control Studies. With Applications in Nutritional Epidemiology
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The case-control study is one of the most frequently used study designs in analytical epidemiology. This thesis focuses on some methodological aspects in the analysis of the results from this kind of study.A population based case-control study was conducted in northern Norway and central Sweden in order to study the associations of several potential risk factors with thyroid cancer. Cases and controls were individually matched and the information on the factors under study was provided by means of a self-completed questionnaire. The analysis was conducted with logistic regression. No association was found with pregnancies, oral contraceptives and hormone replacement after menopause. Early pregnancy and artificial menopause were associated with an increased risk, and cigarette smoking with a decreased risk, of thyroid cancer (paper I). The relation with diet was also examined. High consumption with fat- and starch-rich diet was associated with an increased risk (paper II).Conditional and unconditional maximum likelihood estimations of the parameters in a logistic regression were compared through a simulation study. Conditional estimation had higher root mean square error but better model fit than unconditional, especially for 1:1 matching, with relatively little effect of the proportion of missing values (paper III). Two common approaches to handle partial non-response in a questionnaire when calculating nutrient intake from diet variables were compared. In many situations it is reasonable to interpret the omitted self-reports of food consumption as indication of "zero-consumption" (paper IV).The reproducibility of dietary reports was presented and problems for its measurements and analysis discussed. The most advisable approach to measure repeatability is to look at different correlation methods. Among factors affecting reproducibility frequency and homogeneity of consumption are presumably the most important ones (paper V). Nutrient variables can often have a mixed distribution form and therefore transformation to normality will be troublesome. When analysing nutrients we therefore recommend comparing the result from a parametric test with an analogous distribution-free test. Different methods to transform nutrient variables to achieve normality were discussed (paper VI).
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| 48. |
- Hellbom, Maria, 1966-
(författare)
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Individual Support for Cancer Patients : Effects, Patient Satisfaction and Utilisation
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aims of this thesis are threefold: (1) To investigate cancer patients’ satisfaction with and utilisation of an Individual Psychological Support (IPS) intervention. (2) To evaluate the effects of Individual Support (IS), comprising IPS combined with Intensified Primary Health Care and Nutritional Support, on psychological distress and quality of life during the first year after diagnosis. (3) To explore to what extent aspects of quality of life and emotional functioning one year after diagnosis can be predicted by medical, psychological and socio-demographic factors at diagnosis. The analyses are based on data from the Support-Care-Rehabilitation project, using a prospective randomised design to compare four conditions: (1) Individual Support (IS) starting at diagnosis, (2) Group Rehabilitation (GR) starting three months later, (3) a combination of IS and GR, and (4) Standard Care (SC). The study sample consisted of patients newly diagnosed with breast cancer, colorectal cancer, gastric cancer or prostate cancer. A total of 481 patients were randomised and followed for 24 months.The IPS was an individually tailored, problem-focused intervention based on psychosocial oncology and cognitive behaviour therapy. Half of the patients receiving IPS had more than 2 sessions. Patients reporting that they had problems to address received more IPS sessions and reported more benefits of the intervention. Receiving an extensive medical treatment, young age, and not having someone besides the family to rely on in times of difficulties increased the odds of receiving tree or more sessions of IPS. The IS had limited impact on psychological distress and quality of life in intention-to-treat analyses. Additional analyses with stratification for baseline anxiety and/or depression levels suggested that for IS patients with higher levels of anxiety and/or depression, these problems continued to diminish below those of Control patients during the first year after diagnosis.Linear regression models were used to explore, one year after diagnosis, quality of life aspects indicative of rehabilitation needs. High levels of baseline anxiety and / or depressive symptoms were associated with lower levels of Emotional Functioning, and high self-rated well-being was associated with higher levels of Emotional Functioning. Extensive medical treatment and presence of comorbid conditions during the year before diagnosis predicted a low Global Quality of Life, whereas self-rated wellbeing predicted a high Global Quality of Life. Advanced disease, one or more comorbid conditions and high age were found to be associated with lower levels of Physical Functioning. A high level of activities outside the home during the year before diagnosis and high self-rated wellbeing were predictive of a better Physical Functioning. In conclusion, a large proportion of cancer patients offered IPS in conjunction with diagnosis and primary treatments seized this opportunity to discuss their situation, and perceived the experience as beneficial. Thus, offering newly diagnosed cancer patients these psychosocial support services may facilitate their situation.
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| 49. |
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| 50. |
- Holmberg, Anders, 1967-
(författare)
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Essays on Model Assisted Survey Planning
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The quality of sample survey results is to a large degree dependent on decisions made by survey statisticians at the planning stage. The first paper studies two issues related to the planning stage: (i) the sensitivity of model assumptions concerning the relation between the size measure and a study variable in without replacement probability proportional-to-size sampling (πps sampling), and (ii) properties of practicable sample selection schemes for fixed size πps sampling. These two issues are also addressed in the second paper, which furthermore discusses the consequences of the presence of more than one study variable and to what extent the auxiliary information used in the design and that used in the estimators interact.The evident problem in both the first and the second paper is how to choose an overall efficient sampling design when there are several important study variables with various relationships to the available auxiliary variables. The third paper suggests a diagnostic tool to support the choice of design, and on the basis of three criteria of overall efficiency optimal designs are derived.The optimal designs presented in the third paper may not be fully satisfactory in meeting specified precision requirements for separate estimators. To achieve a design that is tailor-made to meet such requirements, optimisation must be done under restrictions. Though the underlying optimisation problem is only outlined in paper III, a solution involving non-linear programming methods is given in the fourth paper. By way of an example based on an application to a Swedish business population, the fourth paper compares a design obtained through non-linear programming algorithms with designs discussed in paper III as well as designs based on the same principal ideas as those discussed in the first two papers. The paper suggests a flexible solution regarding how to use auxiliary information exhaustively and to provide diagnostic support for the final design choice.
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