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- Ekelund, Maria, 1970-
(författare)
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Psoriasis and Temporomandibular Joint Involvement in Juvenile Idiopathic Arthritis (JIA) : A Longitudinal Study of the Nordic JIA Cohort
- 2020
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Juvenile idiopathic arthritis, JIA, is used as an umbrella term covering a heterogeneous group of chronic arthritis forms in children, many of which have important differences compared to adult arthritis, while others possibly represent similar diseases among children and adults. Classification aims to give a better understanding of the pathogenesis, patterns, disease trajectories and treatment responses. For the juvenile psoriatic arthritis, JPsA, the classification criteria are currently being debated. The distribution of affected joints in JIA differs greatly and it is unknown why some joints appear to be more affected than others. The temporomandibular joint (TMJ) can be affected early in the course of the disease and often the symptoms are mild and without obvious swelling.This thesis has its origin in the Nordic Study Group of Paediatric Rheumatology and the population-based prospective study of 510 children with newly diagnosed JIA included between 1997 and 1999. Totally 440 children were included in the eight-year follow-up, and in the TMJ study 265 patients were examined and underwent cone-beam computed tomography, CBCT, 17 years after onset.After eight years a considerable proportion of the children with definite psoriasis were classified as undifferentiated JIA based on the exclusion criteria in the ILAR classification. Our data also presents the heterogenicity of JPsA and the development over time of clinical variables supporting a psoriatic diathesis, as well as the overlap between JPsA and enthesitis-related arthritis in a group of patients. We found that extensive symptoms and dysfunctions of the TMJ are seen in JIA 17 years after disease onset, even in patients registered with inactive disease or remission. Individuals with substantial condylar damage on CBCT were found in all JIA categories. The deeper understanding of a chronic disease over time is crucial for research initiatives to improve care as well as for clinical decisions and planning of the health care.Our findings suggest a need for a more appropriate classification of JPsA and also that aspects of TMJ involvement should be included in the general health assessment in JIA.
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| 2. |
- Forsell, Johan, 1980-
(författare)
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Grupparbetsbedömning på individnivå : Gymnasielärares möjligheter och utmaningar
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Avhandlingens syfte är att öka kunskapen om och förståelsen av gymnasielärares möjligheter och utmaningar med att genomföra grupparbetsbedömning på individnivå av elevers kunskaper och förmågor utvecklade i samarbete. Fokus är på om och i så fall hur lärares perspektiv förändras i samband med genomförandet av en grupparbetsuppgift i klassrummet som inkluderar lärares grupparbetsbedömning på individnivå. Syftet med avhandlingen besvaras genom en kvalitativ forskningsansats. Avhandlingen omfattar fyra empiriska delstudier. Den första delstudien, en systematisk litteraturgenomgång omfattade 83 publikationer. Den andra och tredje delstudien baserades på 12 intervjuer med sex gymnasielärare. Den fjärde delstudien, baserad på 24 videoobservationer av sex gymnasielärare. Avhandlingens resultat visar att tidigare forskning om grupparbetsbedömning har fokuserat på att särskilja vem som bidragit med vad vid grupparbete. Fokus har legat på elevers sociala förmågor och grupprocesser snarare än bedömning av elevers kunskaper och förmågor. Utmaningar lärare beskriver med grupparbetsbedömning är att kunna särskilja enskilda prestationer från gruppens. Att kunna särskilja elevers individuella kunskaper och förmågor hänger också samman med att kunna skaffa ett underlag för grupparbetsbedömning, vilket är avgörande för att få både validitet och reliabilitet i bedömningen. En specifik utmaning med grupparbetsbedömning är att tillgodose dess tudelade syfte att både kunna genomföra bedömningar av god kvalitet och samtidigt stödja gruppers samarbete. Genom att använda en metod för individuell grupparbetsbedömning med muntliga tvärgruppspresentationer kan lärare samla underlag för elevers individuella kunskaper och förmågor och samtidigt stötta gruppers samarbete vid grupparbete. Vid muntliga tvärgruppspresentationer är interaktion mellan lärare och elever och mellan elever viktigt för att kunna möjliggöra ett underlag för bedömning av elevers individuella kunskaper och förmågor. För att interaktion ska uppstå krävs det att läraren tar en aktiv roll vid tvärgruppspresentationer och stimulerar med frågor och reflektioner.
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| 3. |
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| 4. |
- Kim, Jaewon, 1978-
(författare)
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Trade, Unemployment and Labour Market Institutions
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis consists of three papers, summarized as follows. "The Determinants of Labour Market Institutions: A Panel Data Study" This paper analyses the argument that labour market institutions can be thought of as devices for social insurance. It investigates the hypotheses that a country's exposure to external risk and ethnic fractionalisation are correlated with labor market institutions. Extreme bounds analysis with panel data of fourty years indicates that countries that are more open to international trade have stricter employment protection, strong unions, and a more coordinated wage bargaining process. Moreover, there is evidence that union density is negatively associated with the degree of ethnic fracationalisation. "Why do Some Studies Show that Generous Unemployment Benefits Increase Unemployment Rates? A Meta-Analysis of Cross-Country Studies" This paper investigates the hypothesis that generous unemployment benefits give rise to high levels of unemployment by systematically reviewing 34 cross-country studies. In contrast to conventional literature surveys, I perform a meta-analysis which applies regression techniques to a set of results taken from the existing literature. The main finding is that the choice of the primary data and estimation method matter for the final outcome. The control variables in the primary studies also affect the results. "The Effects of Trade on Unemployment: Evidence from 20 OECD countries" This study empirically investigates if international trade has an impact on aggregate unemployment in the presence of labour market institutions. Using data for twenty OECD countries for the years 1961-2008, this study finds that an increase in trade leads to higher aggregate unemployment as it interacts with rigid labour market institutions, whereas it may reduce aggregate unemployment if the labour market is characterised by flexibility. In a country with the average degree of the labour market rigidities, an increase in trade has no significant effect on unemployment rates.
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| 5. |
- Manell, Hannes, 1987-
(författare)
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Impaired Glucose Tolerance in Childhood Obesity : Contribution of Glucagon, GLP-1 and Inflammation
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the wake of increased obesity prevalence, impaired glucose tolerance (IGT) and type 2 diabetes (T2D) in childhood and adolescence is increasingly common. Given the negative impacts these conditions have on health over time, understanding the pathophysiology in those affected early in life is important. Both the proglucagon-derived peptides and low-grade inflammation have been implicated in the development of obesity-related complications. The aim of this thesis was to study across the glucose tolerance spectrum in children and adolescents with obesity 1) proglucagon-derived peptides glucagon, GLP-1 and glicentin, 2) dipeptidyl peptidase-4 (DPP-4) and its degradation of GLP-1 and 3) novel inflammatory markers. To this end, children and adolescents of the Uppsala Longitudinal Study of Childhood Obesity were studied. Children and adolescents with obesity had higher fasting plasma glucagon concentrations than lean controls. In particular visceral adiposity, hyperinsulinemia, triglycerides and free fatty acids (FFAs) were associated with high plasma glucagon concentrations. In isolated islets elevated FFAs caused hypersecretion of glucagon. In children and adolescents with IGT or T2D, fasting plasma glucagon was further elevated and the GLP-1 and glicentin response to an oral glucose tolerance test (OGTT) was decreased. In T2D plasma glucagon increased during the first 15 minutes of OGTT. Plasma DPP-4 concentrations were elevated in obesity and associated with lower proportion of intact GLP-1 but not with IGT. Several pro-inflammatory markers were elevated in children and adolescents with obesity but not further elevated in IGT or T2D with the exception of low plasma Tumor necrosis factor-related weak inducer of apoptosis (TWEAK) levels, which were associated with IGT, hyperinsulinemia and hyperglucagonemia. High plasma hepatocyte growth factor (HGF) concentration was associated with increased risk of further weight gain in children and adolescents with obesity.In conclusion, elevated glucagon concentration at fasting, a hyperglucagonemic response to OGTT and reduced GLP-1 and glicentin are characteristics of IGT and T2D development in childhood obesity reflecting altered usage of the proglucagon gene. DPP-4 concentrations are elevated in childhood obesity but not associated with IGT. Reduced circulating TWEAK was identified as a novel marker of IGT early in life. Children with obesity and high HGF are less likely to respond well to lifestyle intervention.
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| 6. |
- Staaf, Johan, 1983-
(författare)
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Childhood Obesity and Islet Function
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The prevalence of childhood obesity and Type 2 Diabetes Mellitus (T2DM) has increased during recent decades. T2DM is accompanied with functional changes in the islets of Langerhans, which can be identified early in the pathogenesis. The aim of this thesis was to explore how metabolic changes caused by obesity early in life relate to islet function prior to overt T2DM.To address this, Uppsala Longitudinal Study of Childhood Obesity (ULSCO) was established (paper I). Initially, the association between palmitate and insulin secretion was investigated using a translational approach with obese and lean normoglycemic juveniles and isolated human islets (paper II). Secondly, dynamics of islet-hormones insulin and glucagon, and gut-hormones glucagon like-peptide 1 (GLP-1) and glicentin (paper III) and magnetic resonance imaging of pancreatic fat fraction (PFF) (paper IV) were studied in association to glucose tolerance and beta-cell function. Finally, a novel method of analysing shape features of oral glucose tolerance test (OGTT) curves was introduced and evaluated (paper V).Obese subjects had high prevalence of prediabetes and metabolic syndrome (MetS) (paper I). In obese pre-pubertal children with elevated palmitate levels, hyperinsulinemia was observed (paper II). In contrast, obese pubertal adolescents with similar palmitate levels showed moderate insulin levels during OGTT with delayed first phase insulin response. To explore mechanisms for these variations, isolated human islets were exposed to palmitate for different time periods in vitro. After 2 days accentuated insulin response was observed. Impaired beta-cell function and apoptosis were evident after 7 days, however. Hyperglucagonemia and disturbed GLP-1 and glicentin levels were associated with obesity and glycaemic status, with fasting glicentin being predictive of prediabetes (paper III). Furthermore, PFF was increased in obese subjects and associated to MetS and visceral adipose tissue, but not to beta-cell function (paper IV). OGTT curves were converted into geometric centres, centroids, which correlated with differences in glucose tolerance (paper V).In conclusion, the islet function in obese children was associated with elevated levels of palmitate, but not pancreatic fat. Fasting palmitate and glicentin levels, as well as centroid analyses of OGTT curves, could potentially identify obese children at risk of prediabetes and subsequent T2DM.
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| 7. |
- Andersson, Fredrik, 1972-
(författare)
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Causes and Labor Market Consequences of Producer Heterogeneity
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Essay I studies establishment-level employment changes in the Swedish Manufacturing sector over the 1972-96 period. The results show that modest changes in the aggregated employment record have been the resulting sum of rather large gross flows of jobs and that this constant reshuffling of jobs has important implications for the workforce and is closely related to process of economic growth. Shifts in employment across industries or other observable characteristic of establishments cannot explain the different employment outcomes across establishments. Essay II (with Altin Vejsiu) studies the determinants of plant closures in Swedish Manufacturing. From our theoretical framework we derive and empirically test hypotheses regarding the linkages between the probability of plant failure and industry-specific characteristics; local labor market conditions; and plant-specific sources of heterogeneity, including insider mechanisms in wage determination, plant specific human capital, selection mechanisms and technology vintage effects. Our results suggest that all these factors matter in ways that by and large conform to the a priori hypotheses. Essay III investigates the importance of access to product markets in explaining the spatial wage distribution by estimating the parameters of a spatial labor demand model. The model takes into account the effects of sorting of heterogeneous labor and heterogeneity in transportation costs. The results are consistent with the idea that increasing returns to scale together with transportation costs is an important driving force behind urban agglomeration and sizeable spatial wage differentials.Essay IV (with Harry Holzer and Julia Lane) presents a dynamic analysis of workers who persistently have low earnings over a period of three or more years. Some of these workers manage to escape from this low-earning status over subsequent years, while many do not. We analyze the characteristics of persons and especially of their firms and jobs that enable some to improve their earnings status over time.
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| 8. |
- Andersson, Josefine, 1988-
(författare)
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Insurances against job loss and disability : Private and public interventions and their effects on job search and labor supply
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Essay I: Employment Security Agreements, which are elements of Swedish collective agreements, offer a unique opportunity to study very early job search counselling of displaced workers. These agreements provide individual job search assistance to workers who are dismissed due to redundancy, often as early as during the period of notice. Compared to traditional labor market policies, the assistance provided is earlier and more responsive to the needs of the individual worker. In this study, I investigate the effects of the individual counseling and job search assistance provided through the Employment Security Agreement for Swedish blue-collar workers on job finding and subsequent job quality. The empirical strategy is based on the rules of eligibility in a regression discontinuity framework. I estimate the effect for workers with short tenure, who are dismissed through mass-layoffs. My results do not suggest that the program has an effect on the probability of becoming unemployed, the duration of unemployment, or income. However, the results indicate that the program has a positive effect on the duration of the next job.Essay II: The well-known positive relationship between the unemployment benefit level and unemployment duration can be separated into two potential sources; a moral hazard effect, and a liquidity effect pertaining to the increased ability to smooth consumption. The latter is a socially optimal response due to credit and insurance market failures. These two effects are difficult to separate empirically, but the social optimality of an unemployment insurance policy can be evaluated by studying the effect of a non-distortionary lump-sum severance grant on unemployment durations. In this study, I evaluate the effects on unemployment duration and subsequent job quality of a lump-sum severance grant provided to displaced workers, by means of a Swedish collective agreement. I use a regression discontinuity design, based on the strict age requirement to be eligible for the grant. I find that the lump-sum grant has a positive effect on the probability of becoming unemployed and the length of the completed unemployment duration, but no effect on subsequent job quality. My analysis also indicates that spousal income is important for the consumption smoothing abilities of displaced workers, and that the grant may have a greater effect in times of more favorable labor market conditions.Essay III: Evidence from around the world suggest that individuals who are awarded disability benefits in some cases still have residual working capacity, while disability insurance systems typically involve strong disincentives for benefit recipients to work. Some countries have introduced policies to incentivize disability insurance recipients to use their residual working capacities on the labor market. One such policy is the continuous deduction program in Sweden, introduced in 2009. In this study, I investigate whether the financial incentives provided by this program induce disability insurance recipients to increase their labor supply or education level. Retroactively determined eligibility to the program with respect to time of benefit award provides a setting resembling a natural experiment, which could be used to estimate the effects of the program using a regression discontinuity design. However, a simultaneous regime change of disability insurance eligibility causes covariate differences between treated and controls, which I adjust for using a matching strategy. My results suggest that the financial incentives provided by the program have not had any effect on labor supply or educational attainment.
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| 9. |
- Gartell, Marie, 1977-
(författare)
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Educational Choice and Labor Market Outcomes : Essays in Empirical Labor Economics
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The Importance of Education for the Reallocation of Labor: Evidence from Swedish Linked Employer-Employee Data 1986-2002 Using employer-employee data covering the whole Swedish economy over a uniquely long time period from 1986 to 2002, we examine how job flows and worker flows have been distributed both on an aggregate level and across educational levels. We find that job and worker flows vary by educational level, not only with respect to magnitude and variation, but with respect to direction as well. We find job reallocation to be countercyclical. However, when examining the correlations between different educational groups, the countercyclical behavior was only found among those with low educational level. Unemployment and Subsequent Earnings for Swedish College Graduates This paper shows that unemployment immediately upon college graduation is associated with substantial and permanent future earnings losses. The sample studied consists of all graduates from Stockholm and Uppsala University during 1991–1999; data used combine data from various administrative registers. The results are stable for the inclusion of a rich set of observable control variables, including the grade point average from high school and parental educational level, and for choice of method, i.e. OLS and propensity score matching. A Comparison of College Ranking Methods – A Study of Relative Earnings Estimates There are several studies on differences in returns to higher education focusing on old colleges versus new colleges founded after the great expansion of higher education in Sweden. The results vary substantially. This paper shows that the different results are not due to the different ways to control for student ability, as is often claimed. I find that the rankings of individual colleges are robust to choice of ability controls. However, when colleges are grouped into new and old colleges, the results vary, mainly as a result of just a few influential observations.
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| 10. |
- Grönberg, Annika, 1970-
(författare)
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Predictors of long-term glycemic control, pancreatic function and BMI trajectory in children with type 1 diabetes
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: The maintenance of normal metabolic control underpins all management of insulin dependent diabetes whether in terms of preserved beta-cell function, body composition, or family support. The hypothesis of this work was that preserved C-peptide predicts better glycemic control and lowers risk of severe hypoglycemia. It was additionally investigated whether Body Mass Index (BMI) and family structure contributes to the prediction of long-term glycemic control. Objectives: This thesis aimed to 1) identify the factors associated with residual C peptide production at least 10 years after diagnosis, 2) evaluate the association of BMI trajectory and long-term glycemic control, 3) identify early characteristics associated with rapid or slow decline of beta-cell function and how it affects the clinical course, and 4) investigate the relations of family structure at diagnosis and long-term glycemic control. Methods: Data from four cohorts were used: In the Uppsala cohort, measurement of long-term residual C-peptide was undertaken using ultrasensitive C-peptide ELISA in 73 children and adolescents <25 years, BMI trajectory prior diagnosis was evaluated in 295 children, while family structure at diagnosis was evaluated in 215 children in relation to glycemic control. In the Linköping cohort, stimulated C-peptide was assessed by mixed meal tolerance test in 50 children. Results: The cohort studies showed that better early glycemic control predicted long term residual C-peptide and that long term residual C-peptide, in turn, was protective against severe hypoglycemia. Additionally, BMI trajectory was predicted by BMI prior to the presentation of type 1 diabetes. There was no association with glycemic outcome. Children living in a whole family had a lower probability of long-term dysglycemia. Conclusions: Residual C-peptide is important for better glycemic control and to reduce complications in children with type 1 diabetes. Family structure, but not BMI trajectory, contributes to the prediction of long-term glycemic control. However, more research is needed to understand how to preserve the beta-cell function in children and to target and support families in those children with early deteriorating glycemic control to reduce future complications.
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