1. |
- Averfalk, Helge, 1988-
(författare)
-
Enhanced District Heating Technology : Maintaining Future System Feasibility
- 2017
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- When heat demand and high temperature heat supply gradually decreases in the future, then it will effect district heating systems ability to compete on the heat market. A good way to mitigate less district heating feasibility is to operate systems with lower temperature levels and the most conceivable way to achieve lower temperature levels is to decrease return temperatures.Thus, this thesis emphasise temperature errors embedded in district heating systems. Only a selection of temperature errors are analysed in this thesis. First, the temperature error that occurs due to recirculation in distribution networks at low heat demands. Second, the temperature error that occurs due to hot water circulation in multi-family buildings. Third, the temperature error that occurs due to less than possible heat transfer in heat exchangers, i.e. too short thermal lengths.In order to address these temperature errors three technology changes have been proposed (i) three-pipe distribution network to separate the recirculation return flow from the delivery return flow, (ii) apartment substations to eliminate hot water circulation utilisation, and (iii) improved heat exchangers for lower return temperatures at a constant scenario. Analysis of proposed changes has resulted in annual average return temperatures between 17-21 °C.Furthermore, rapid introduction of intermittent renewable electricity supply in the energy system has prompted an increased necessity of power system balancing capacities. Large-scale conversion of power-to-heat in electric boilers and heat pumps is a feasible alternative to achieve such balancing capacities. Analysis of the unique Swedish experience with utilisation of large heat pumps installations connected to district heating systems show that since the 1980s 1527 MW of heat power has been installed, about 80 % of the capacity was still in use by 2013. Thus, a cumulative value of over three decades of operation and maintenance exists within Swedish district heating systems.The two papers presented in this thesis are related to future district heating systems through the five abilities of fourth generation district heating (4GDH), which are documented in the definition paper of 4GDH.
|
|
2. |
- Amsberg, Susanne
(författare)
-
Health Promotion in Diabetes Care : Studies on Adult Type 1 Diabetes Patients
- 2008
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: A landmark report has shown that improving glycaemic control among type 1 diabetes patients markedly reduces diabetes-related complications. In clinical practice, however, many patients have problems in adhering to the treatment, and thus remain in poor glycaemic control. Research suggests a more behaviour-oriented approach to diabetes, but there is a lack of evidence on the efficacy of interventions, especially for those adult type 1 diabetes patients who are in poor glycaemic control. Diabetes-related distress has been associated with poor adherence to treatment and poor glycaemic control. There is a need for validated measures in this area, to identify patients who experience diabetes-related distress. Additionally, injection technique is crucial for the management of diabetes, and lipohypertrophy is a common side effect which deserves further attention.Objectives: The overall aim of this thesis was to evaluate a behavioural medicine intervention among poorly controlled adult type 1 diabetes patients, and to gain a deeper knowledge in an area of diabetes self-management.Methods: Quantitative design was used for the studies, and the clinical settings comprised two diabetes care units in Stockholm, Sweden. Study I: The Swedish version of the Problem Areas in Diabetes (Swe-PAID-20) scale was evaluated regarding its psychometric properties by type 1 diabetes patients, as well as by an expert panel of diabetes specialist nurses. Study II: A behavioural medicine intervention based on Cognitive Behaviour Therapy (CBT) was evaluated in a randomised controlled trial among poorly controlled adult type 1 diabetes patients. Study III: Using the same sample as in study II, descriptive statistics were produced, and predictive and comparative analyses performed, in order to find predictors of or associations with improvements in glycaemic control as a response to the intervention. Study IV: In a randomised crossover trial insulin absorption in lipohypertrophic injection sites was investigated in type 1 diabetes patients.Results and conclusions: Study I: A three-factor solution of the scale was found, comprising sub-dimensions of diabetes-related emotional problems, treatment-related problems and support-related problems. Cronbach’s alpha for the total score was 0.94 and varied between 0.61 and 0.94 in the three subscales. The findings also supported the convergent and content validity. The Swe-PAID-20 seems to be a reliable and valid outcome for measuring diabetes-related distress in type 1 diabetes patients. Study II: Significant differences were observed with respect to HbA1c, well-being, diabetes-related distress, frequency of blood glucose testing, fear of hypoglycaemia, perceived stress, and depression, all of which improved more in the intervention group compared with the control group. The CBT based behavioural medicine intervention appears to be a promising approach to diabetes self-management. Study III: The participation rate in the study was 41% and attrition was 24%. Of those patients who actually participated in the intervention, 13% withdrew. From the regression models no predictors or associations were found with regard to improvement in HbA1c. The programme proved to be feasible in terms of design and methods. However, no clear pattern was found regarding predictors of or associations with improved metabolic control. Study IV: Impairment of insulin absorption from lipohypertrophic injection sites was also found with analogue insulins. It is suggested that patients should be advised to refrain from injecting insulin aspart into lipohypertrophic subcutaneous tissue.
|
|
3. |
- Blom Johansson, Monica, 1965-
(författare)
-
Aphasia and Communication in Everyday Life : Experiences of persons with aphasia, significant others, and speech-language pathologists
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aims of this thesis were to describe the experiences of persons with aphasia and their significant others of their conversations and use of communication strategies, examine current practice of family-oriented speech-language pathology (SLP) services, and test a family-oriented intervention in the early phase of rehabilitation.The persons with aphasia valued having conversations despite perceiving their aphasia as a serious social disability. They acknowledged the importance of the communication partners’ knowledge and understanding of aphasia and their use of supporting conversation strategies. Their own use of communication strategies varied considerably. The persons with aphasia longed to regain language ability and to be active participants in society.A majority of the significant others perceived their conversations with the person with aphasia as being less stimulating and enjoyable than conversations before stroke onset. Aphasia was considered a serious problem. The significant others took on increased communicative responsibility, where two thirds had changed their communicative behaviour to facilitate conversations. Type and severity of aphasia were especially related to the communicative experiences of the significant others and their motivation to be involved in SLP services.Thirty percent of the speech-language pathologists worked with people with aphasia and typically met with their families. They considered the involvement of significant others in SLP services as very important, especially in providing information about aphasia and communication partner training (CPT). However, involvement of significant others was restricted because of a time shortage and perceived limited skills and knowledge. In addition, there were national differences regarding aphasia rehabilitation services.The intervention consisted of three sessions directed to significant others (primarily emotional support and information) and three directed to the dyads (a person with aphasia and a significant other) (primarily CPT). All six participants (three dyads) felt that their knowledge and understanding of aphasia had increased and that their conversations had improved. These improvements were also evident to some extent with formal assessments.These results suggest the following: CPT should be an integral part of SLP services, national clinical guidelines are needed, and further education of speech-language pathologists and implementation of new knowledge into clinical practice requires consideration.
|
|
4. |
- Dzansi, James
(författare)
-
Essays on Financing and Returns on Investment
- 2011
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation consists of an introductory chapter and three independent essays on financing investment and their returns. The first essay studies the impact of remittances on domestic investment. The analysis is carried out with a focus on the moderating roles of domestic financial development and institutional quality. The empirical results suggest that remittance inflows are associated with increased domestic investment spending, particularly under conditions of inadequate financial intermediation and poor institutional quality. The second essay evaluates whether remittance inflows into the developing world impedes or spurs manufacturing growth. This study uses manufacturing data on a sample of 40 remittance dependent economies over the period from 1991 to 2004. The results suggest that remittance inflows accelerate manufacturing growth. This evidence is robust to industry- and year-specific effects, a range of country level control variables, and a number of estimators. The final essay examines the monitoring role of large shareholders and returns on investment. Specifically, the paper investigates the relevance of intrinsic motives of the large shareholder to monitor management in order to induce optimal return on investment. The findings suggest that large shareholders are actuated by both intrinsic and extrinsic motives to minimize managerial opportunism and inefficiency.
|
|
5. |
- Jans, Jenny, 1984-
(författare)
-
Causes and Consequences of Early-life Conditions : Alcohol, Pollution and Parental Leave Policies
- 2017
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Essay I: This paper studies the effect of air pollution on infant health in Sweden. Combining register panel data on birth outcomes and family characteristics with pollution data, I estimate the effect of particulate matter (PM10) on several birth outcomes that previously have been shown to be predictive of future outcomes. The results suggest that pollution adversely affects infant health (birth weight and gestational length). Moreover, quantile estimates suggests that the effects are larger in the lower tail of the health distribution. The effect is stronger both among children from low income households and among children born to mothers who smoke. I also find suggestive evidence of non-linearities in the relationship between PM10 and health at birth.
|
|
6. |
- Johansson, Adam Johannes, 1976-
(författare)
-
Biomimetic Transition Metal Catalysts : Insights from Theoretical Modeling
- 2008
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The scientific interest in the chemistry of synthetic transition metal complexes is motivated by at least two arguments:1.These can be regarded as models of biological transition metal complexes, e.g. metalloenzymes, whose functions can be difficult to reveal in detail due to their complexity.2.Transition metal complexes are used for catalytic purposes in the industrial synthesis of chemicals. There is a large potential for further development of this technology, which can be motivated both by economic and environmental arguments.In the present thesis, density functional theory (a quantum mechanical method) has been applied to model reactions involving synthetic iron and copper complexes in solution. The complexity of the solvent environment is a challenging problem for theoretical investigations and a significant part of the theses has been to investigate the mechanistic effects of metal-coordinating solvent molecules, Lewis bases and counter ions. For example, it is explained why the cleavage of the O-O bond in heme-diiron-peroxides is faster in the presence of a coordinating Lewis base. Furthermore, the experimentally observed structure-activity relationship between the Fe(III)(µ-O)2Fe(IV) and (H2O)Fe(III)(µ-O)Fe(IV)O motifs is given an explanation. In addition, the present thesis presents a systematic investigation of how the self-interaction error in density functional theory (DFT) affects the modeling of transition metal catalysis.
|
|
7. |
- Johansson, Elly-Ann, 1978-
(författare)
-
Essays on schooling, gender, and parental leave
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis consists of four self-contained essays. Essay 1: Mixed-aged classes (MA-classes) are a common phenomenon around the world. In Sweden, these types of classes increased rapidly during the 1980:s and 1990:s, despite the fact that existing empirical support for MA-classes is weak. In this paper, we estimate the effect of attending an MA-class during grades 4-6 on students’ cognitive skills. Using a unique survey with information on students, parents and teachers, we are able to control for many factors that could otherwise bias the results. We find a negative effect on short-run cognitive skills, as measured by grade 6 cognitive tests, and this effect is robust to a rigorous sensitivity analysis. Essay 2: We examine whether the impact of pre-school interventions on cognitive skills differs by immigrant background. The analysis is based on Swedish data containing information on childcare attendance, rich family background information, the performance on cognitive tests at age 13, and long-run educational attainment for cohorts born between 1967 and 1982. We find that childcare attendance reduces the gap in language skills between children from immigrant backgrounds relative to native-born children. We find no differential effects on inductive skills, however. Nor does childcare appear to affect the distribution of long-run educational attainment. Essay 3: This paper estimates the effect of child gender on mothers’ and fathers’ parental leave. The focus on Sweden, a highly gender equal society, yields additional knowledge on the prevalence of gender biases in industrialized countries. The results show that a first born son increases fathers’ parental leave with 0.6 days (1.5 percent) and decreases mothers’ leave by a similar amount, leaving the total leave unchanged. Both the sign and size of this effect is in line with previous research. However, there are interesting differences between groups that departs from previous studies. Non-traditional families, with high maternal relative earnings and/or educational levels, show even larger gender biases, indicating that it may be mothers, rather than fathers, that are the driving force behind this child gender bias. Essay 4: This paper investigates the effect of parental leave – both own and spousal – on subsequent earnings using different sources of variation. Using fixed-effects models, and in line with previous results, parental leave is found to decrease each parent’s future earnings. Also spousal leave is important, but only for mothers. In fact, each month the father stays on parental leave has a larger positive effect on maternal earnings than a similar reduction in the mother’s own leave. Using two reforms of the parental leave system as exogenous sources of variation yields only imprecisely estimated effects, even though the reforms had a strong effect on parental leave usage. However, the point estimates tentatively suggest effects in the same range or larger than the fixed-effects model found.
|
|
8. |
- Johansson, Robert
(författare)
-
Treating depression and its comorbidity : From individualized Internet-delivered cognitive behavior therapy to affect-focused psychodynamic psychotherapy
- 2013
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overarching goal of this thesis has been to enhance Internet-delivered psychological treatments for depression and its comorbidity. To this end, three randomized controlled trials (Study II, III and IV) with a total of 313 participants were conducted. A prevalence study (Study I) was also conducted to provide an up-to-date estimate of the prevalence of depression, anxiety disorders, and their comorbidity in the Swedish general population.Study I showed that more than every sixth individual in Sweden suffers from symptoms of depression and/or anxiety. Comorbidity between depression and anxiety was substantial and associated with higher symptom burden and lower health-related quality of life. Study II showed that a tailored Internet-based CBT protocol (ICBT) was effective in reducing symptoms of depression when compared to a control group. Among individuals with more severe depression and comorbidities, the tailored ICBT treatment worked better than standardized ICBT. Study III showed that a psychodynamic Internet-based psychotherapy was highly effective in the treatment of depression, when compared to a group who received psychoeducation and online support. In Study IV, an Internet-delivered affect-focused psychodynamic psychotherapy proved to have a large effect on depression and a moderately large effect on anxiety disorders.In conclusion, this thesis shows that in the context of treating depression and its comorbidity, Internet-delivered psychological treatments can be potentially enhanced by psychodynamic psychotherapy and by individualization.
|
|
9. |
- Reitsma, Ewout
(författare)
-
Sourcing strategising in the new product development process : Insights from the strategy-as-practice lens and engineer-to-order context
- 2022
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In many cases, manufacturers have changed from sourcing only a few, simple, and separate components from local suppliers to sourcing a high variety of modules from globally dispersed suppliers. This has resulted in the implementation of a wide variety of sourcing strategies, including, for example, multiple sourcing and supplier integration. All these and other sourcing strategies are aimed at achieving a certain level of supply chain (SC) responsiveness. The level of SC responsiveness ideally matches the characteristics of a product. For example, highly innovative products typically require highly responsive SCs.In order to match products with their SCs, manufacturers are advised to engage in sourcing strategy in their new product development (NPD) process. However, there are at least two knowledge gaps in the literature on this topic: (1) the lack of a widely accepted, comprehensive conceptualisation of how manufacturers can engage in sourcing strategy in NPD, and (2) the lack of empirical insights into manufacturers operating in the engineer-to-order (ETO) context. This dissertation focuses on filling these knowledge gaps.Addressing the first gap, the dissertation uses the theoretical lens of ‘strategy-as-practice’ (SAP) and the literature to conceptualise the ‘doing of sourcing strategy’ in NPD as three interrelated dimensions: (1) practitioners, (2) activities, and (3) practices. Through discussing these dimensions and their potential interplay throughout NPD, the dissertation demonstrates the potential of the SAP lens in providing a common framework and reducing the fragmented nature of the literature. By using the SAP lens, the dissertation also contributes to practice. Despite not being ‘actionable’ in the sense of constituting detailed guidelines for acting, the SAP lens produces insights that can help practitioners to become more reflective. For example, they can learn to see sourcing strategising as a multidimensional, dynamic concept and the place it can occupy in the NPD process.The second knowledge gap in the literature regards the lack of empirical research focusing on the ETO context. Therefore, the dissertation includes a case study focusing on practitioners’ sourcing strategising activities and practices in this context. First, five approaches to performing sourcing strategising activities in NPD are explored in terms of their conditions and intended outcomes. Secondly, four practices that can support sourcing strategising in NPD are identified. These practices – referred to as ‘Design for Supply Chain’ (DFSC) practices – are also examined in terms of their interrelations. Practitioners can use the case study findings to compare the advantages of the five sourcing strategising approaches when sourcing items or services. Furthermore, the findings allow practitioners to assess how the four interrelated DFSC practices can support their sourcing strategising efforts in NPD.
|
|
10. |
- Bernhardsson, Susanne, 1958-
(författare)
-
Advancing evidence-based practice in primary care physiotherapy : Guideline implementation, clinical practice, and patient preferences
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Research on physiotherapy treatment interventions has increased dramatically in the past 25 years and it is a challenge to transfer research findings into clinical practice, so that patients benefit from effective treatment. Development of clinical practice guidelines is a potentially useful strategy to implement research evidence into practice. However, the impact of guideline implementation in Swedish primary care physiotherapy is unknown. To achieve evidence-based practice (EBP), research evidence should be integrated with clinical expertise and patient preferences, but knowledge is limited about these factors in Swedish primary care physiotherapy.The overall aim of this thesis was to increase understanding of factors of importance for the implementation of EBP in Swedish primary care physiotherapy. Specific aims were: to translate and adapt a questionnaire for the measurement of EBP and guidelines; to investigate physiotherapists’ attitudes, knowledge and behaviour related to EBP and guidelines; to examine clinical practice patterns; to evaluate the effects of a tailored guideline implementation strategy; and to explore patients’ preferences for physiotherapy.The thesis comprises four studies (A-D), reported in five papers. In Study A, a questionnaire for the measurement of EBP and guidelines was translated, cross-culturally adapted, and tested for validity (n=10) and reliability (n=42). Study B was a cross-sectional study in which this questionnaire was used to survey primary care physiotherapists in the county council Region Västra Götaland (n=271). In Study C, a strategy for the implementation of guidelines was developed and evaluated, using the same questionnaire (n=271 at baseline, n=256 at follow-up), in a prospective controlled trial. The strategy was based on an implementation model, was tailored to address the determinants of guideline use identified in Study B, and comprised several components including an educational seminar. Study D was an exploratory qualitative study of patients with musculoskeletal disorders (n=20), using qualitative content analysis.The validity and reliability of the questionnaire was found to be satisfactory. Most physiotherapists have a positive regard for EBP and guidelines, although these attitudes are not fully reflected in the reported use of guidelines. The most important determinants of guideline use were considering guidelines important to facilitate practice and knowing how to integrate patient preferences with guidelines. The tailored, multi-component guideline implementation significantly affected awareness of, knowledge of, and access to guidelines. Use of guidelines was significantly affected among those who attended an implementation seminar. Clinical practice for common musculoskeletal conditions included interventions supported by evidence of various strengths as well as interventions with insufficient research evidence. The most frequently reported interventions were advice and exercise therapy. The interviewed patients expressed trust and confidence in the professionalism of physiotherapists and in the therapists’ ability to choose appropriate treatment, rendering treatment preferences subordinate. This trust seemed to foster active engagement in their physiotherapy.In conclusion: The adapted questionnaire can be used to reliably measure EBP in physiotherapy. The positive attitudes found do not necessarily translate to guideline use, due to several perceived barriers. The tailored guideline implementation strategy used can be effective to reduce barriers and contribute to increased use of guidelines. The clinical practice patterns identified suggest that physiotherapists rely both on research evidence and their clinical expertise when choosing treatment methods. Patients’ trust in their physiotherapist’s competence and preference for active engagement in their therapy need to be embraced by the clinician and, together with the therapist’s clinical expertise, integrated with guideline use in the clinical decision making. Further research is needed on how the EBP components and different knowledge sources can be integrated in physiotherapy practice, as well as on implementation effects on patient outcomes.
|
|