| 1. |
- Bejnö, Hampus, 1984-
(författare)
-
Early intervention and autism : Improving preschool program quality for children with autism spectrum disorder receiving Early Intensive Behavioral Intervention using the Autism Program Environment Rating Scale (APERS)
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The quality of the learning environment in preschool is of significant importance for children with autism spectrum disorder (ASD). However, very limited research has addressed how this environment can be improved. In regard to early intervention, most previous studies have primarily focused on child characteristics, and intervention content and quantity, rather than the broader learning environment in which interventions are delivered. Thus, the overall aim of this thesis was to study the quality of the learning environment for children with ASD. In particular, the focus was on children who receive Early Intensive Behavioral Intervention (EIBI) in community-based Swedish preschools, using the Autism Program Environment Rating Scale (APERS). Within this framework, three studies were conducted.In study 1, we translated, culturally adapted, and systematically assessed the content validity of APERS, a rating scale designed to assess the program quality for children with ASD in educational settings. In the process, the scale was modified to make the instrument as relevant as possible for the Swedish preschool context, and re-named APERS-P-SE. Nine experts rated the clarity and comprehensiveness of the individual items, as well as the relevance of the scale in its entirety. In study 2, we evaluated APERS-P-SE as the foundation for professional development for preschool staff working with children with ASD receiving EIBI, to promote preschool learning environment quality (primary outcome), and outcomes for autistic children, and preschool staff (secondary outcomes). Using a quasi-experimental design, preschool staff either implemented EIBI enriched by in-service training and on-site coaching based on APERS-P-SE assessments (k = 9), or EIBI only (k = 8) during 8 months. A total of 17 children and 35 preschool staff participated, across 17 preschools. In study 3, individual interviews and focus-group interviews were conducted with preschool staff, preschool principals, habilitation supervisors, and parents to children with ASD who had participated in study 2 and received the APERS-P-SE-based intervention. Through these interviews, the different groups of stakeholders provided their thoughts about what they found to be the most important aspects of preschool programs for autistic children who receive EIBI, and their opinions and experiences of participating in study 2. Study 1 demonstrated a high level of content validity for the Swedish version of the APERS. In study 2, the EIBI/APERS-P-SE preschools significantly improved their learning environment, compared to the preschools that received EIBI only. Outcomes for autistic children and preschool staff did not differ significantly between the groups, despite positive descriptive findings. In study 3, four themes were identified as being key aspects of preschool programs with high quality to promote optimal development of children with ASD: (1) staff’s competence, (2) children’s inclusion and participation, (3) collaboration, and (4) learning environment. Overall, the stakeholders described the APERS-P-SE-based model as helpful in improving children’s participation, preschool staff’s engagement with the child, and optimizing child outcomes.Taken together, the results indicate that APERS-P-SE is an instrument with a high level of content validity, and that it can be used in combination with in-service training and on-site coaching to improve preschool program quality for children with ASD.
|
|
| 2. |
- Bergström, Ulrica, 1970-
(författare)
-
Fragility fractures in fragile people : epidemiology of the age quake
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Osteoporosis-related fracture is already today a major public health problem and the number of hip fractures is expected to double to 2030. Sweden has one of the highest hip fracture incidences worldwide. This may be explained by several factors: e.g. age, genetic, climatologic, geographic and a relative vitamin D deficiency, secondary to the limited sunlight exposure especially during winter months. Intrinsic and extrinsic factors contribute to a fracture, although a prior low energy fracture is one of the strongest predictors for a subsequent one and this should be a target for secondary fracture prevention in an orthopaedic setting. Since 1993 all injured patients admitted to the emergency floor and all in-hospital fractures at Umeå University Hospital, Sweden, were registered according to the Injury Data Base, former EHLASS. There were 31,173 fracture events (one or more fractures at the same time), of which 13,931 were in patients’ ≥ 50 years old. The fracture database was co analyzed with the Northern Sweden Health and Disease Study cohort in a nested case-control study for investigations of associations between osteoporotic fracture and serum markers, lifestyle data, nutrition etc. We found that there were differences in fracture pattern depending on age and sex. Both injury mechanism and fracture site were strongly dependent of age. The most severe fragility fracture, hip fracture, had a decreasing incidence. However, the incidence curve was right-shifting leading to an increase, both in numbers and in incidence of hip fractures among the oldest female. To identify people at high risk for fractures, re-fracture patients are useful. No less than 21% of the fracture patients had suffered more than one fracture event, accounting for 38% of all fracture events. The total risk ratio for a subsequent fracture was 2.2 (2.1-2.3 95% CI). In males the highest risk for re fracture was in the age cohort 70-79 years (RR 2.7, 2.3-3.2 95% CI), in females > 90 years (RR 3.9, 3.2-4.8 95% CI). Another possible risk factor in this subarctic population is the lack of sunlight, leading to a vitamin D deficit. The overall adjusted risk of sustaining a hip fracture in this population was 2.7 (95%CI:1.3-5.4) in subjects with a serum 25 hydroxyvitamin D below 50 nmol/l. The association was, however, different according to age at baseline. Thus in subjects aged 60 years and above at baseline, the adjusted odds ratio of sustaining a hip fracture was 6.2 (1.2-32.5 95%CI) for the group of individuals with a serum 25OHD below 50 nmol/l, whereas no significant association was found in the youngest age group. In the next 30 years the ongoing demographic changes will accelerate. The World War II baby boomers will cause an age quake. We can already see signs heralding a new fracture pattern: an increasing cohort of mobile but fragile elderly, with considerable co-morbidity is now at risk for fragility fractures. In fracture patients, clinical information is sufficient to pinpoint patients with a high risk for re-fractures. It is therefore clinically important to use the information provided by the fracture event. We suggest that trauma units and primary care units should screen for risk factors and inform patients about the treatment options, and to organize fracture liaison services. This seems to be especially cost-efficient for our oldest and frailest patients. Secondary prophylaxis and follow-up treatment after cardiovascular disorders are now a matter of course worldwide, but the screening for risk factors, in order to prevent a second fracture, is often neglected. This is one of the most important issues of fracture care in the future in order to improve general health.
|
|
| 3. |
- Englund, Undis, 1957-
(författare)
-
Physical activity, bone density, and fragility fractures in women
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Scandinavia has among the highest incidence of fragility fractures in the world. The reasons for this are unknown, but might involve differences in genetic and/or environmental factors, such as sunlight exposure and levels of physical activity. Weight-bearing exercise is thought to have a beneficial effect on bone health in the young, but few studies have evaluated whether exercise in older subjects affects bone density and protects against fragility fractures. The initial objective of this thesis was to evaluate whether a combined weight-bearing training programme twice a week would be beneficial as regards bone mineral density (BMD) and neuromuscular function in older women. Forty-eight community living women with a mean age of 73 years were recruited for this 12-month prospective, randomised controlled trial, and were randomly assigned to an intervention group (n=24) or a control group (n=24). The intervention group displayed significant increments in BMD at the Ward’s triangle, maximum walking speed, and isometric grip strength compared to the control group. The second objective was to investigate if training effects were retained in older women five years after the cessation of training. The 40 women who completed the first study included in this thesis were invited to take part in a follow-up assessment five years later, and 34 women (~79 years) agreed to participate. During these five years both groups had sustained significant losses in hip BMD and in all neuromuscular function tests, and the previous exercise-induced intergroup differences were no longer seen. The third and fourth objective of this thesis was to investigate whether exercise and weight-bearing leisure activities in middle-aged women are associated with a decreased risk of sustaining hip or wrist fractures at a later stage. A cohort of women participating in the Umeå Fracture and Osteoporosis (UFO) study, a longitudinal, nested case-control study investigating associations between bone markers, lifestyle, and osteoporotic fractures, was used for the purpose of this investigation. Eighty-one hip fracture cases and 376 wrist fracture cases, which had reported lifestyle data before they sustained their fracture, were identified. These cases were compared with age-matched controls identified from the same cohort. Using conditional logistic regression analysis with adjustments for height, BMI, smoking, and menopausal status, results showed that moderate frequency of leisure physical activities such as gardening and berry/mushroom picking, were associated with reduced hip fracture risk (OR 0.28; 95% CI 0.12 – 0.67), whereas active commuting (especially walking) along with dancing and snow shoveling in leisure time, reduced the wrist fracture risk (OR 0.48; 95% CI 0.27 – 0.88, OR 0.42; 95% CI 0.22 – 0.80 and OR 0.50; 95% CI 0.32 – 0.79 respectively). In summary, this thesis suggests that weight-bearing physical activity is beneficial for BMD and neuromuscular functions such as muscle strength and gait in older women, and that a physically active lifestyle, with outdoor activities, in middle age is associated with reduced risk of both hip and wrist fractures. Possible mechanisms underlying this association include improved muscle strength, coordination, and balance, resulting in a decreased risk of falling and perhaps also direct skeletal benefits.
|
|
| 4. |
- Pettersson, Ulrika, 1981-
(författare)
-
Blood Flow Regulation and Inflammatory Response in Experimental Models of Diabetes
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Type 2 diabetes is caused by defect pancreatic islet β-cells together with peripheral insulin resistance. The disease is often accompanied by obesity with associated low-grade visceral adipose tissue inflammation, which contributes to insulin resistance. As a consequence of, and a possible compensation for the increased insulin demand, blood flow to the pancreatic islets is increased in animal models of diabetes. This increased blood perfusion might with time affect the vascular network as well as β-cells within the islets. This thesis investigates the role of changes of blood perfusion in pancreatic islets and adipose tissues, as well as the recruitment to and composition of leukocyte subpopulations in insulin-sensitive tissues in experimental models of diabetes. Blood flow measurements in islets and adipose tissues of rats and mice were performed using the microsphere technique, while leukocyte recruitment was studied in the mouse cremaster muscle using intravital microscopy. Increased islet blood flow was observed in the GK rat model of type 2 diabetes, which was decreased by acute as well as continuous 2-week inhibition of β3-adrenoceptors without affecting plasma insulin concentrations. Increased inflammatory leukocyte recruitment was observed in both alloxan-induced and high-fat diet-induced diabetes. However, an impaired bacterial clearance was observed in diabetic mice, which was due to impaired phagocytosis. A gender difference was detected in mice fed a high-fat diet, since obese female mice did not show increased levels of pro-inflammatory circulatory markers or inflammatory leukocytes in the adipose tissue. The main effector cell in the adipose tissue inflammation in high-fat-fed male mice seemed to be the pro-inflammatory macrophage. The Treg population in adipose tissue was increased in female mice, but remained unchanged in male mice on high-fat diet. In conclusion, increased islet blood flow in type 2 diabetes could be reversed by β3-adrenoceptor inhibition, which may maintain islet function. The diabetes-associated hyperglycemia activated leukocytes but impaired their phagocytic ability. High-fat-fed female mice showed less peripheral inflammation due to a smaller number of recruited inflammatory macrophages and a high-fat diet-induced Treg population in intra-abdominal adipose tissues.
|
|
| 5. |
- Pettersson, Ulrika, 1970-
(författare)
-
Bone mass in the young athlete
- 1999
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Bone mass and bone size accumulate during childhood and adolescence and peak in the twenties. The obtained peak bone mass has been suggested to be a major determinant of bone mass even in the very elderly. Although, genetic factors are the main determinants, environmental and lifestyle factors also play a crucial role in modulating maximal bone mass. Assessing these lifestyle factors would be of great importance for the intervention strategies against osteoporosis. The first aim of this thesis was to compare the bone mass and bone size in male and female young adults on a high level of physical activity with males or females on a low level of physical activity. Furthermore, it also aimed to investigate the influence of pubertal maturity, menstrual disturbances, and different body constitutional factors on bone mass and size during adolescence and young adulthood. The female activity groups consisted of cross-county skiers, soccer players, and rope skippers. Compared to their age-matched inactive controls, all these athletic groups demonstrated a significantly higher bone mineral density (BMD) at those sites subjected to the sport-specific loading. Rope-skipping, a very high impact activity was associated with a higher bone size, preferentially in the lower extremity, suggesting an effect of weight-bearing activity also on bone geometry. The effect of menstrual disturbances was evaluated in a group of long-distance runners, where amenorrheic runners had significantly lower BMD in both trabecular and also cortical bone in the lower extremity compared to eumenorrheic runners, suggesting that weight-bearing activity cannot compensate for the shortfall of reduced estrogen levels. The male activity groups consisted of ice hockey players and badminton players. Compared to their age-matched controls, both athletic groups demonstrated a significantly higher BMD at those sites subjected to the sport-specific loading. Especially badminton was associated with a high BMD, suggesting that physical activity, including jumps in unusual directions has a great osteogenic potential. The main determinants of BMD in both male and females were, except for type of physical activity, activity, muscle strength, height, and different body constitutional factors. However, the relationships with muscle strength and body constitution were somewhat weaker in the athletic groups, especially in the males, indicating that impact forces may be of greater importance in regulating bone mass in highly trained athletes. Yet bone size was largely determined by parameters related to body size and less strongly to physical activity. In a prospective study on adolescent boys, the changes in bone mass during late puberty were mainly accounted for by growth and development, including height and pubertal maturation, and less to physical activity level. Thus, the osteogenic effect from physical activity seems to be of importance for bone mass achievement predominantly before late puberty.
|
|
| 6. |
- Pettersson, Ulrika, 1975-
(författare)
-
Surfaces Designed for High and Low Friction
- 2005
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis comprises tribological studies of extremely well-defined surfaces of different designs. Both low-friction and high-friction surfaces were manufactured and experimentally evaluated.In the low-friction studies, lithography and anisotropic etching of silicon was first used as a texturing technique. The textured surfaces were subsequently PVD coated with TiN or DLC to achieve tribologically relevant interfaces. The results showed that under starved lubricated conditions, fine surface textures lowered the coefficient of friction and the wear rate. It was shown that also the orientation of the texture is of major importance for the lubricating function.Further, a novel embossing technique was developed, permitting texturing of steel and other materials. A micro mechanically designed diamond tool was used to emboss steel surfaces. The roller/piston contact from a hydraulic motor was simulated and introduction of an embossed texture on the piston decreased the level and the fluctuation of the friction. The effect of the texture was here similar to the effect of an additional polish step. However, in general it is not an easy task to substantially improve a boundary lubricated contact by introducing a texture. Studies of high friction surfaces were performed on micro mechanically designed diamond surfaces equipped with sharp pyramids or ridges. Just as theory predicts, the coefficient of friction was dependent on the shape of the ploughing bodies, but not on the counter material or the load. The tested surfaces resulted in static coefficients of friction between 1.1 and 1.6, depending on surface design and orientation. These are extremely high values, and therefore very interesting for practical applications requiring a high static friction.Conclusively, the present thesis shows that it is possible to design and produce surfaces both for improved lubrication in sliding contact and for substantially improved high friction performance in static contacts.
|
|
