| 1. |
- Almqvist, Linnea, 1987-
(författare)
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Asthma epidemiology : prognosis of asthma with onset in childhood and in adulthood
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aim: to update the knowledge on the epidemiology of asthma with onset in childhood and adulthood as well as examine the importance of risk factors in early childhood and clinical characteristics on the incidence and prognosis of asthma.Methods: The thesis is based on the epidemiological research program Obstructive Lung Disease in Northern Sweden (OLIN) studies. Pediatric cohort: recruited in 1996 (age 8y, n=3430, 97% of invited) and followed annually by questionnaire about asthma, allergy and risk factors until 19y and a postal questionnaire at 28y. Clinical examinations included skin prick tests (SPT at 8, 12 and 19y) and spirometry (19y). Adult cohort: 309 adults (age 20–60y) with asthma onset in the last 12 months were recruited 1995-99 and re-examined in 2012-14 (n=205). Structured interviews, spirometry and SPT were performed at recruitment and follow-up and bronchial hyperreactivity (BHR) at recruitment.Results: The asthma incidence rate was 10-13/1000/year in childhood and adolescence and 6/1000/year in young adulthood. Several risk factors in early life were associated with asthma onset in childhood, adolescence and young adulthood, e.g. family history of asthma, <3 months breastfeeding, rhinoconjunctivitis and positive SPT at 8y, while low birthweight, maternal smoking during pregnancy, severe respiratory infections and eczema were associated with onset in childhood and adolescence. Among those with asthma at 8y, 62% still had asthma at 28y and this was associated with positive SPT, rhinoconjunctivitis, severe respiratory infection in childhood, and bronchial hyperreactivity (BHR) in adolescence. Coexistence of asthma, rhinitis and eczema increased by age, especially among those with a positive SPT. However, having all three conditions was uncommon. In the 15y follow-up adult onset asthma, 89% had persistent asthma. Better lung function at recruitment and less severe BHR was associated with remission. Remission rate of adult onset asthma was <1% per year.Conclusion: The incidence of asthma was high during childhood and adolescence and then decreased in young adulthood. Factors in early life that were associated with incident asthma during childhood were still associated with the incidence in adult age. Among those with asthma onset by 8 years, 62%, still had asthma as young adults. The coexistence of asthma, rhinitis and eczema varied from 8 to 28y without following a specific pattern, only a small proportion reported having all three conditions. Remission of adult onset asthma was rare.
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| 2. |
- Cai, Yixiao, 1986-
(författare)
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Bio-Nano Interactions : Synthesis, Functionalization and Characterization of Biomaterial Interfaces
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Current strategies for designing biomaterials involve creating materials and interfaces that interact with biomolecules, cells and tissues. This thesis aims to investigate several bioactive surfaces, such as nanocrystalline diamond (NCD), hydroxyapatite (HA) and single crystalline titanium dioxide, in terms of material synthesis, surface functionalization and characterization.Although cochlear implants (CIs) have been proven to be clinically successful, the efficiency of these implants still needs to be improved. A CI typically only has 12-20 electrodes while the ear has approximately 3400 inner hair cells. A type of micro-textured NCD surface that consists of micrometre-sized nail-head-shaped pillars was fabricated. Auditory neurons showed a strong affinity for the surface of the NCD pillars, and the technique could be used for neural guidance and to increase the number of stimulation points, leading to CIs with improved performance.Typical transparent ceramics are fabricated using pressure-assisted sintering techniques. However, the development of a simple energy-efficient production method remains a challenge. A simple approach to fabricating translucent nano-ceramics was developed by controlling the morphology of the starting ceramic particles. Translucent nano-ceramics, including HA and strontium substituted HA, could be produced via a simple filtration process followed by pressure-less sintering. Furthermore, the application of such materials as a window material was investigated. The results show that MC3T3 cells could be observed through the translucent HA ceramic for up to 7 days. The living fluorescent staining confirmed that the MC3T3 cells were visible throughout the culture period.Single crystalline rutile possesses in vitro bioactivity, and the crystalline direction affects HA formation. The HA growth on (001), (100) and (110) faces was investigated in a simulated body fluid in the presence of fibronectin (FN) via two different processes. The HA layers on each face were analysed using different characterization techniques, revealing that the interfacial energies could be altered by the pre-adsorbed FN, which influenced HA formation.In summary, micro textured NCD, and translucent HA and FN functionalized single crystalline rutile, and their interactions with cells and biomimetic HA were studied. The results showed that controlled surface properties are important for enhancing a material’s biological performance.
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| 3. |
- Andersson, Anna Karin
(författare)
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Everyday functioning in six year-old children born preterm : From a child perspective towards the child's perspective
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of the thesis was to explore everyday functioning in six year-old children born preterm, from the children’s perspectives and from their parents’ perspectives. The relation between everyday functioning and neonatal risk factors, behavioural characteristics was studied with descriptive and correlational statistics, ANOVA and multiple linear regression (I). Patterns of everyday functioning were explored in a cluster analysis following a person-oriented approach (II). In a mixed method approach, the children’s and their parents’ perceptions on children’s competence in everyday activities were explored with a pictorial instrument and analysed with descriptive statistics and qualitative content analysis (III). The children’s perceptions of meaningful everyday life situations were explored in a photo voice study, analysed with qualitative content analysis. In total, 144 children born preterm and 222 children born at term and their parents were involved.The results indicated that from the parents’ perspective most children born preterm and full-term were perceived with strong everyday functioning featuring strong motor, process and communication skills, a positive interaction pattern and low levels of behaviour problems. As a group, the children born very preterm were perceived weaker in their everyday functioning than the full-term group but the pattern of performance skills, interaction and behaviour varied similar to that of children born full-term. Further, it was found that preterm birth was not the main predictor, instead hyperactivity had most influence on everyday functioning. Moreover, the children born preterm perceived themselves to be overall strong performers of everyday activities. They wanted to be active and do things and for that they wanted to have skills and significant others i.e. siblings, parents, friends and pets to interact with and to feel safe and loved. Further, the children born preterm expressed a will to develop, improve and gain new skills and to have more opportunities to do meaningful things.In conclusion, the results in this thesis indicate that young children born preterm are able to reflect on their everyday functioning, and express needs and desires for their participation in meaningful everyday life situations. Moreover, preterm birth is not the sole predictor of everyday functioning more critical is the interaction of individual, behavioural and contextual factors.
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| 4. |
- Boniface, Raymond, 1977-
(författare)
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Teachers' Retention in Tanzanian Remote Secondary Schools : Exploring Perceived Challenges and Support
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Teacher retention is a global challenge, and many developed and developing countries are struggling to staff and retain teachers in schools, particularly in low-performing, remote, and less desirable areas. In most of these countries, Tanzania in particular, the efficacy of fiscally inclined teachers’ retention strategies continues to be dubious. The aim of this study is to explore teachers’ perceived school level challenges and the support of retaining teachers in remote secondary schools in Tanzania. The study is inspired by a supportive management theoretical framework, particularly Organizational Support, Leader-Member Exchange and Coworkers’ Exchange. It is motivated by a pragmatic knowledge claim. Data were sequentially collected in three phases using interviews and survey questionnaires. A sample included 258 secondary schools teachers from 28 remote schools in the Dodoma region in central Tanzania. Mixed methods data analysis techniques were used.The current study identifies younger males of a well-educated and experienced teaching workforce as being the chief staffing in remote Tanzanian secondary schools. Such a teaching workforce is challenging to retain in remote areas, as it is rarely satisfied with the teaching career and highly susceptible to frequently changing employers and working contexts. Moreover, findings show that teachers perceive problems related to housing, social services, conflicts in schools, the inability to influence changes in schools, the teaching and learning situation and limited opportunities as the chief reasons for not remaining in remote schools. Furthermore, findings show that teachers perceive meaningful retention support as being contextually definitive. The catalyst is high quality exchanges amongst teachers which spearhead the development of intra- and extra-role practices, school citizenship behaviours, intraschool social capital (an investment), all of which could bind teachers together, enhancing performing and supporting each other beyond formal contracts. Such a situation triggers teachers’ beliefs that changes, improvement, adaptability and survival within difficult remote environments is possible, and this consequently influences the intention to voice and/or conversely, to exit. Teachers’ empowerment, justice practices and working voicing arenas are important practices for enhancing retention support, especially in remote areas.
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| 5. |
- Schyllert, Christian, 1983-
(författare)
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Social determinants in asthma : population-based studies on asthma and respiratory symptoms in relation to occupation, occupational exposure and socioeconomic status
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Asthma is one of the most common chronic obstructive airway diseases among children and adults, with a prevalence between 6-11% in European countries. It is also the most common work-related occupational respiratory disease. There are different methods to classify occupational exposure and, even though there is no clear consensus on which method is the most accurate, the single-item question on exposure to the composite measure vapour, gas, dust or fumes (VGDF) is commonly used in epidemiological research. Low socioeconomic status is associated with asthma and also behavioural factors such as smoking and over-weight, which by themselves are risk factors for asthma. Socioeconomic status is, however, truly a multifaceted concept and using only one measure does not encompass its entire effect on health-related outcomes. Asthma does also have a negative impact on the quality of life among adolescents: they report less physical fitness compared to their peers and more school absenteeism due to respiratory symptoms. Still, research on whether childhood asthma has any impact on socioeconomic status in young adulthood is scarce.Aim: The overall aim is to study social determinants of health such as socioeconomic status, occupation and occupational exposure and their relationship with asthma and respiratory symptoms among adults and further, to evaluate if asthma during childhood or adolescence is associated with social determinants in young adulthood.Method: This thesis includes four papers based on data from the Obstructive Lung Disease in Northern Sweden (OLIN) studies. Papers I-III are cross-sectional studies among adults; a structured interview from clinical examinations between 2002-04 (paper I, n=4036) and postal questionnaire surveys from 2006 (paper II, n=9992) and 2016 (paper III, n=6854) with the addition of register-based data in paper III. Paper IV is a longitudinal prospective cohort study; the first OLIN paediatric cohort followed from 7 to 19 years of age and a postal questionnaire follow-up at ages 27-28 in 2015 (n=2017). Asthma was defined as physician diagnosis (paper I) together with respiratory symptoms (paper II-IV) or use of asthma medication (paper IV). In paper IV asthma was further categorized based on age of onset and p v and adolescence. Main or longest held occupation was used to categorize occupational and socioeconomic groups. In papers III and IV additional measures of socioeconomic status were included; educational level (papers III and IV) and income (paper III). In all papers, occupational exposure to vapour and/or gas, dust and fumes (VGDF or GDF) were taken into consideration and in paper I further divided into subgroups based on a detailed questionnaire on occupational exposure.Results: In paper I we found that the association between occupational exposure to VGDF and asthma and rhinitis was driven by the component of chemicals rather than dusts. In paper II, the ISCO-based manual Swedish Standard Classification of Occupations (SSYK) and the manual Socioeconomic classification (SEI), could both identify occupational and socioeconomic groups at risk for respiratory symptoms and asthma, while the older ISCO-based manual Nordic Classification of Occupations (NYK) was not as sensitive.In paper III, behavioural risk factors for respiratory symptoms and asthma such as smoking and obesity and, occupational exposure to GDF were associated with low educational level. Interaction analyses between income level and sex revealed different patterns among women and men. Among women, low income was associated with all respiratory symptoms as well as asthma, while among men only with productive cough.In paper IV, early onset asthma was associated with lower educational level in young adulthood, especially not continuing after compulsory school. Further, those with asthma during childhood or adolescence did not seem to refrain from smoking at age 19, nor did they as young adults seem to avoid occupations with known or expected exposure to GDF.Conclusions: Increased automation in industries have decreased the number of manual workers in industries with typically dirty tasks, meaning that the interrelationships between the subgroups included in VGDF may have changed. This may also affect the meaning of occupational exposure to VGDF, at least with regard to asthma and rhinitis, and according to our findings exposure to the component of chemicals may be the most important. We also found that the use of an ISCO-based manual (SSYK) as well as socioeconomic classification based on job-title (SEI) can be useful and easily applicable tools to identify occupational and socioeconomic groups at risk for respiratory symptoms and asthma. Further, low socioeconomic status is associated with respiratory vi symptoms and asthma. It seems as these associations relies more on low income than low educational level. Low educational level as well as low income are furthermore related to known behavioural risk factors for respiratory symptoms and asthma such as obesity, smoking and, also potentially modifiable risk factors as occupational exposure to gas dust or fumes. Having a persisting asthma since childhood is associated with lower educational level as a young adult. This may, in turn, be related with behavioural risk factors as discussed above and, there were no indications that those with child or adolescent asthma refrained from smoking at age 19. Neither did they in young adulthood avoid occupations with known or expected exposure to gas, dust or fumes, such as manufacturing, construction and transportation work. To conclude, our results indicate a vicious circle with regard to the relationship between the studied social determinants of health and asthma and respiratory symptoms.
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| 6. |
- Andersson, Anton B., 1986-
(författare)
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Networks and Success : Access and Use of Social Capital among Young Adults in Sweden
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis explores the role of social capital in shaping inequality among young adults. Social capital is defined as resources embedded in a social network and the thesis investigates differences in access to social capital, and the effects in the labor market and the housing market. The thesis consists of four empirical studies and an introductory chapter that develops the theoretical and empirical background. The four empirical studies use a Swedish survey titled “Social Capital and Labor Market Integration” that includes individuals born in 1990 living in Sweden. A gross sample based on three subsamples was selected based on the country of birth of the respondents’ parents (Sweden, former Yugoslavia, or Iran). The survey consists of two waves of panel data and most respondents were 19 years old at the time of the first survey and 22 at the time of the second. The four studies investigate: (1) the effect of social class and migration background on access to social capital through national and transnational ties, (2) the effect of socioeconomic segregation in schools and neighborhoods on access to social capital through occupational networks and close friendship ties, (3) the effect of social capital in the process of labor market entry, and (4) the effect of social capital on the likelihood to move away from parents. All four studies measure social capital with ego network measures and the main measurement is the position generator that asks the respondent about contacts in occupational positions spanning the socioeconomic structure. Results show that family background factors and socioeconomic segregation affects access to social capital, and that social capital affects labor market and housing market outcomes. The thesis concludes that social capital is an important factor to understand unequal outcomes among young adults.
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| 7. |
- Andersson Granberg, Tobias, 1973-, et al.
(författare)
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Sensor Requirements for Logistics Analysis of Emergency Incident Sites
- 2020
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Ingår i: Proceedings of the 17th ISCRAM Conference. - : Information Systems for Crisis Response and Management. - 9781949373271 ; , s. 952-960
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Konferensbidrag (refereegranskat)abstract
- Using sensors to collect data at emergency incident sites can facilitate analysis of the logistic operations. This can be used to improve planning and preparedness for new operations. Furthermore, real-time information from the sensors can serve as operational decision support. In this work in progress, we investigate the requirements on the sensors, and on the sensor data, to facilitate such an analysis. Through observations of exercises, the potential of using sensors for data collection is explored, and the requirements are considered. The results show that the potential benefits are significant, especially for tracking patients, and understanding the interaction between the response actors. However, the sensors need to be quite advanced in order to capture the necessary data.
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| 8. |
- Andersson, Henrik, 1968-, et al.
(författare)
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The early chain of care in bacteraemia patients: Early suspicion, treatment and survival in prehospital emergency care
- 2018
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Ingår i: American Journal of Emergency Medicine. - : Elsevier BV. - 0735-6757 .- 1532-8171. ; 36:12, s. 2211-2218
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Bacteraemia is a first stage for patients risking conditions such as septic shock. The primary aim of this study is to describe factors in the early chain of care in bacteraemia, factors associated with increased chance of survival during the subsequent 28 days after admission to hospital. Furthermore, the long-term outcome was assessed. Methods: This study has a quantitative design based on data from Emergency Medical Services (EMS) and hospital records. Results: In all, 961 patients were included in the study. Of these patients, 13.5% died during the first 28 days. The EMS was more frequently used by non-survivors. Among patients who used the EMS, the suspicion of sepsis already on scene was more frequent in survivors. Similarly, EMS personnel noted the ESS code "fever, infection" more frequently for survivors upon arriving on scene. The delay time from call to the EMS and admission to hospital until start of antibiotics was similar in survivors and non-survivors. The five-year mortality rate was 50.8%. Five-year mortality was 62.6% among those who used the EMS and 29.5% among those who did not (p < 0.0001). Conclusion: This study shows that among patients with bacteraemia who used the EMS, an early suspicion of sepsis or fever/infection was associated with improved early survival whereas the delay time from call to the EMS and admission to hospital until start of treatment with antibiotics was not. 50.8% of all patients were dead after five years. (C) 2018 Elsevier Inc. All rights reserved.
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| 9. |
- Andersson, Martin, 1987-
(författare)
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Microfluidics at High Pressures : Understanding, Sensing, and Control
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis explores understanding, sensing, and control in high-pressure microfluidics. The high-pressure regime allows fluids to be forced through narrow channels at substantial speed and creates conditions for fluids of high density and low viscosity—features desired in flow-based chemical analyses. With changes to pressure and temperature, fluid properties vary, and for miniaturized flow systems, sensing and control are needed.For miniaturized chemical analytics to utilize high-pressure fluids, like supercritical CO2, sensors are required for flow characterization. In this thesis, high-pressure tolerant sensors in glass chips have been developed and investigated. By the use of chip-integrated temperature, flow, and relative permittivity sensors, the variable behavior of supercritical CO2 or binary component CO2-alcohol mixtures have been investigated. To be able to change flow rates, a heat-based actuator chip has been developed. By a flow control system, which combines a relative permittivity sensor and heat actuated flow regulators on a modular system, the composition of binary component CO2-alcohol mixtures can be tuned and controlled with feedback.Flows of multiphase CO2-H2O hold promise for miniaturized extraction systems. In this thesis, parallel multiphase CO2-H2O flow has been studied. To achieve control, methods have been investigated where channels have been modified by the introduction of a guiding ridge and altered by a chemical coating. Flow is a dynamic process, where pressure and temperature can vary with time and place. As the properties of fluids containing CO2 may change with pressure and temperature, properties will also change with time and place. Because of this, instruments with spatial and temporal resolution are needed to better understand dynamic chemical effects at flow. In this thesis, a tool is presented to study the dynamic acidification of aqueous solutions that come in contact with flowing CO2.By a study performed to understand the strength and pressure tolerance of glass chips, it has been found that the fracture is not only determined by the applied pressure, but also on time and environment.
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| 10. |
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