| 1. |
- Nilsson, Maria
(author)
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Capturing semi-automated decision making : the methodology of CASADEMA
- 2010
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Doctoral thesis (other academic/artistic)abstract
- This thesis presents a new methodology named CASADEMA (CApturing Semi-Automated DEcision MAking) which captures the interaction between humans and the technology they use to support their decision-making within the domain of Information Fusion. We are particularly interested in characterising the interaction between human decision makers and artefacts in semi-automated fusion processes. In our investigation we found that the existing approaches are limited in their ability to capture such interactions in sufficient detail. The presented method is built upon a distributed-cognition perspective. The use of this particular theoretical framework from cognitive science enables the method to take into account not only the role of the data captured in the physical and digital artefacts of the fusion system (e.g., radar readings, information from a fax or database, a piece of paper, etc.), but also the cognitive support function of the artefacts themselves (e.g., as an external memory) as part of the fusion process. That is, the interdependencies between the fusion process and decision-making can be captured. This thesis thus contributes to two main fields. Firstly, it enables, through CASADEMA, a distributed-cognition perspective of fusion processes in the, otherwise, rather technology-oriented field of Information Fusion. This has important conceptual implications, since it views fusion processes as extending beyond the boundary of physical/computer systems, to include humans, technology, and tools, as well as the interactions between them. It is argued that a better understanding of these interactions can lead to a better design of fusion processes, making CASADEMA an important contribution to the information fusion field. Secondly, the thesis provides, again in the form of CASADEMA, a practical application of the distributed-cognition theoretical framework. Importantly, the notations and definitions introduced in CASADEMA structure the otherwise currently rather loosely defined concepts and approaches in distributed cognition research. Hence, the work presented here also contributes to the fields of cognitive science and human-computer interaction.
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| 2. |
- Bojsen-Møller, Emil, 1989-
(author)
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Movement Behaviors and Cognitive Health for Office Workers
- 2022
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Doctoral thesis (other academic/artistic)abstract
- The lifetime trajectories of movement behavior and cognitive functioning depend on complex interactions between genetic and environmental factors. There is substantial evidence suggesting that physical activity benefits cognitive functions. However, how sedentary behavior and the composition of movement behaviors (i.e., sleep, physical activity, and sedentary behavior) influences cognitive functions remains to be elucidated. Observational studies suggest that sedentary time is unfavorably related to cognitive functions in older adults, but the majority of evidence comes from self-reported estimates of movement behavior, which are rather weakly related to device-based measures. Furthermore, while evidence suggests that structured exercise can have protective effects on cognition in inactive older adults, much less is known about how midlife movement behavior is related to cognitive functions. Thus, knowledge of how midlife movement behavior relates to and possibly affects cognitive functions and its underlying mechanisms is much needed. This thesis is part of a larger research project investigating how movement behaviors relate to and influence cognitive function, mental health, and neurophysiological mechanisms underpinning these. The project specifically targets healthy office workers and is co-produced with employers of office workers and health-promoting companies. This thesis aimed to investigate how movement behaviors relate to and influence cognitive functions and neuroplasticity among office workers.The first study investigated cross-sectional relationships between device-measured movement behavior and cognitive functions among 334 office workers. The results revealed no association between total time spent in moderate to vigorous physical activity or sedentary behavior and cognitive functions, suggesting that this association may not be as robust as previously suggested in older populations or as inferred from self-report. The second study investigated the extent to which corticospinal excitability is influenced by different movement behaviors. Sixteen sedentary office workers participated in a cross-over randomized controlled trial. We contrasted 3 hours of prolonged sitting with 3 hours of interrupted sitting and 2.5 hours sitting followed by a 25-minute bout of exercise. Acute changes in corticospinal excitability and long-term potentiation-like neuroplasticity were investigated using transcranial magnetic stimulation and paired associative stimulation. Changes in corticospinal excitability over time did not differ between conditions, suggesting that in inactive middle-aged office workers, a physical activity bout or frequently breaking up prolonged sitting does not induce immediate changes in corticospinal excitability or long-term potentiation-like neuroplasticity. The third and fourth studies are based on a 6-month cluster-randomized intervention conducted in 263 healthy office workers. An ecological model for behavior change was used to design two interventions aiming at reducing sedentary behavior or increasing physical activity relative to a passive control group, with the ultimate aim of improving cognitive functions and mental health. The third study investigated how effective each intervention was at changing the 24-hour movement behavior, and the fourth study examined intervention effects on cognitive functions. The results showed that the interventions were ineffective in reducing sedentary behavior and increasing physical activity, respectively, with no detected beneficial effects on cardiorespiratory fitness or cognitive functions relative to the control group. Changes in cognition from baseline to follow-up were not associated with changes in the composition of movement behaviors or cardiorespiratory fitness, but some associations between changes in movement behaviors and cognition were moderated by sex, age, and cardiorespiratory fitness. Thus, the third and fourth studies of the thesis have highlighted the challenges involved in successfully achieving movement behavior change to address the possible effects on cognitive improvements in an ecological setting.In summary, the results presented in this thesis did not provide support for an association between movement behaviors and cognitive functions in healthy physically active office workers, demonstrated no acute effect of a single session of physical activity or breaking up prolonged sitting on corticospinal excitability in sedentary office workers, and revealed no evidence for successful movement behavior change or benefits for cognition in an ecological cluster-randomized intervention in healthy physically active office workers. The findings suggest that among physically active office workers, sedentary behavior may not be as detrimental for cognition and neuroplasticity as previously suggested and shows that changing movement behavior in office workers at the workplace represents a challenging endeavor. Still, these findings do not exclude the possibility that changes in movement behaviors might benefit cognitive functions in physically inactive office workers at higher cardiovascular risk, with lower cardiorespiratory fitness and/or lower daily cognitive stimulation.
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| 3. |
- Furberg, Maria, 1970-
(author)
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Towards the Limits – Climate Change Aspects of Life and Health in Northern Sweden : studies of tularemia and regional experiences of changes in the environment
- 2016
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Doctoral thesis (other academic/artistic)abstract
- BackgroundIndigenous peoples with traditional lifestyles worldwide are considered particularly vulnerable to climate change effects. Large climate change impacts on the spread of infectious vector-borne diseases are expected as a health outcome. The most rapid climate changes are occurring in the Arctic regions, and as a part of this region northernmost Sweden might experience early effects. In this thesis, climate change effects on the lives of Sami reindeer herders are described and 30 years of weather changes are quantified. Epidemiology of the climate sensitive human infection tularemia is assessed, baseline serologic prevalence of tularemia is investigated and the disease burden is quantified across inhabitants in the region.MethodsPerceptions and experiences of climate change effects among the indigenous Sami reindeer herders of northern Sweden were investigated through qualitative analyses of fourteen interviews. The results were then combined with instrumental weather data from ten meteorological stations in a mixed-methods design to further illustrate climate change effects in this region. In two following studies, tularemia ecology and epidemiology were investigated. A total of 4,792 reported cases of tularemia between 1984 and 2012 were analysed and correlated to ecological regions and presence of inland water using geographical mapping. The status of tularemia in the Swedish Arctic region was further investigated through risk factor analyses of a 2012 regional outbreak and a cross-sectional serological survey to estimate the burden of disease including unreported cases.ResultsThe reindeer herders described how the winters of northern Sweden have changed since the 1970s – warmer winters with shorter snow season and cold periods, and earlier spring. The adverse effects on the reindeer herders through the obstruction of their work, the stress induced and the threat to their lifestyle was demonstrated, forcing the reindeer herders towards the limit of resilience. Weather data supported the observations of winter changes; some stations displayed a more than two full months shorter snow cover season and winter temperatures increased significantly, most pronounced in the lowest temperatures. During the same time period a near tenfold increase in national incidence of tularemia was observed in Sweden (from 0.26 to 2.47/100,000 p<0.001) with a clear overrepresentation of cases in the north versus the south (4.52 vs. 0.56/100,000 p<0.001). The incidence was positively correlated with the presence of inland water (p<0.001) and higher than expected in the alpine and boreal ecologic regions (p<0.001). In the outbreak investigation a dose-response relationship to water was identified; distance from residence to water – less than 100 m, mOR 2.86 (95% CI 1.79–4.57) and 100 to 500 m, mOR 1.63 (95% CI 1.08–2.46). The prevalence of tularemia antibodies in the two northernmost counties was 2.9% corresponding to a 16 times higher number of cases than reported indicating that the reported numbers represent only a minute fraction of the true tularemia.ConclusionsThe extensive winter changes pose a threat to reindeer herding in this region. Tularemia is increasing in Sweden, it has a strong correlation to water and northern ecoregions, and unreported tularemia cases are quite common.
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| 4. |
- Skeppstedt, Maria, 1977-
(author)
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Extracting Clinical Findings from Swedish Health Record Text
- 2014
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Doctoral thesis (other academic/artistic)abstract
- Information contained in the free text of health records is useful for the immediate care of patients as well as for medical knowledge creation. Advances in clinical language processing have made it possible to automatically extract this information, but most research has, until recently, been conducted on clinical text written in English. In this thesis, however, information extraction from Swedish clinical corpora is explored, particularly focusing on the extraction of clinical findings. Unlike most previous studies, Clinical Finding was divided into the two more granular sub-categories Finding (symptom/result of a medical examination) and Disorder (condition with an underlying pathological process). For detecting clinical findings mentioned in Swedish health record text, a machine learning model, trained on a corpus of manually annotated text, achieved results in line with the obtained inter-annotator agreement figures. The machine learning approach clearly outperformed an approach based on vocabulary mapping, showing that Swedish medical vocabularies are not extensive enough for the purpose of high-quality information extraction from clinical text. A rule and cue vocabulary-based approach was, however, successful for negation and uncertainty classification of detected clinical findings. Methods for facilitating expansion of medical vocabulary resources are particularly important for Swedish and other languages with less extensive vocabulary resources. The possibility of using distributional semantics, in the form of Random indexing, for semi-automatic vocabulary expansion of medical vocabularies was, therefore, evaluated. Distributional semantics does not require that terms or abbreviations are explicitly defined in the text, and it is, thereby, a method suitable for clinical corpora. Random indexing was shown useful for extending vocabularies with medical terms, as well as for extracting medical synonyms and abbreviation dictionaries.
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| 5. |
- Sundqvist, Nicolas, 1993-
(author)
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Mathematical Modelling of Cerebral Metabolism : From Ion Channels to Metabolic Fluxes
- 2024
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Doctoral thesis (other academic/artistic)abstract
- The brain is the most metabolically active organ in the human body and therefore rely on a continuous supply of oxygen and glucose. Neuronal stimulation in specific regions of the leads to the firing of action potentials, a process facilitated by voltage-gated ion channels in the neurons’ cell membranes. This activation of the ion channels significantly elevates the brain’s metabolic energy demand, compelling neurons to ramp up their metabolic activity in response. Concurrently, this neuronal activation also initiates a signalling cascade that induces vasodilation and increases blood flow, thereby ensuring that regions with elevated neural activity are adequately supplied with oxygen and nutrients. This dynamic interplay between neuronal activity and cerebral blood flow (CBF) regulation constitutes the neurovascular coupling (NVC). The NVC is a cornerstone in interpreting functional Magnetic Resonance Imaging (fMRI) Blood Oxygen Level-Dependent (BOLD) responses. The BOLD response is an indirect, non-invasive, and highly sensitive indicator of neuronal activity, reflecting changes in blood oxygenation and flow associated with the neuronal and metabolic activity in the brain. By examining these responses, we can gain insights into the complex interactions between neuronal activity, energy metabolism, and CBF.Additionally, techniques such as 13C Metabolic Flux Analysis (13C MFA) makes it possible to gain further insight into the cerebral metabolism. This method enables a detailed examination of metabolic pathways and fluxes by tracking the incorporation of 13C-labelled substrates into various metabolites. By using 13C MFA, researchers can quantify the flow of substrates through metabolic networks, offering a deeper understanding of how cell such as neurons adapt their metabolism during different functional states and conditions.Central to exploring these multifaceted aspects of cerebral metabolism is the use of mathematical modelling and systems biology. These disciplines provide a framework for integrating diverse biological data, allowing for the simulation and prediction of complex neurovascular interactions under various physiological and pathological conditions. Mathematical models can encapsulate the dynamics of ion channel kinetics, metabolic pathways, and neurovascular coupling, offering a comprehensive view of the interplay between neuronal activity, metabolism, and cerebral blood flow. This approach is instrumental in bridging the gap between molecular-scale events and observable physiological phenomena, enhancing our understanding of cerebral metabolism and its critical role in the brain’s function.Paper I sets the foundation by developing a mechanistic model that integrates the mechanisms of the NVC with the metabolism. This model connects cerebral regulation of blood flow and metabolism, using small mechanistic model to represent the central metabolism. By integrating experimental data based on nuclear magnetic resonance spectroscopy (NMRS), the model successfully captures the dynamics of metabolites in response to neuronal stimuli, providing a crucial link between metabolic changes and NVC.Paper II extends the investigation to the realm of ion channel kinetics. By developing a generic model structure for voltage-gated ion channels, this paper explores how ion channel activity, a fundamental aspect of neuronal function, influences cerebral metabolism. The model, validated against experimental data and existing kinetic models, accurately predicts various channel behaviours and action potential characteristics. It includes mechanisms like voltage sensor movements and rate constants dependent on membrane voltage, offering a universal approach for studying all types of voltage-gated ion channels in neural networks and other applications.Paper III further explores the neurovascular relationship by examining the influence of inhibitory neurons on CBF and metabolism. This study introduces an expanded mathematical model that integrates the effects of γ-aminobutyric acid(GABA)ergic inhibitory neurons on vascular responses, aligning with new experimental evidence and enhancing understanding of neurovascular coupling (NVC). The model, validated with data from various studies, not only captures vascular changes triggered by inhibitory neuron activation but also reveals how these neurovascular responses vary with stimulation frequency, underscoring the important role of inhibitory neuron in the NVC.Paper IV tackles the critical aspect of accurately measuring metabolic fluxes in cells, focusing on 13C MFA. This study introduces a novel approach for model selection in MFA, ensuring that the chosen models accurately represent the underlying metabolic processes. This method enhances our ability to identify and understand key metabolic pathways and reactions, providing deeper insights into various metabolic conditions. Connecting back to the cerebral metabolism, application of 13C MFA to neuronal systems offers a powerful tool for studying metabolically linked neuropathology such as the development of Alzheimer’s disease.In Conclusion, this thesis establishes key components for understanding the mechanisms of the cerebral metabolism. The integration of mathematical modelling across different scales, from ion channels to cerebral blood flow, is used to provide a comprehensive perspective on how cerebral metabolism is regulated and how it interacts with other physiological processes. This work not only advances our basic scientific knowledge but also holds significant potential for improving our understanding of neurological disorders where metabolism and neurovascular function are impaired.
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| 6. |
- Göras, Camilla, 1969-
(author)
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Open the door to complexity : Safety climate and work processes in the operating room
- 2019
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Doctoral thesis (other academic/artistic)abstract
- A complex adaptive system such as the operating room (OR), consists of different safety cultures, sub-cultures and ways of working. When measuring, a strong safety climate has been associated with lower rates of surgical complications. Teamwork is an important factor of safety climate. Discrepancies among professionals’ perceptions of teamwork climate exists. Hence it seems crucial to explore if diversity exists in the perception of factors related to safety climate and between managers and front-line staff in the OR. Complex work processes including multitasking and interruptions are other challenges with potential effect on patient safety. However, multitasking and interruptions may have positive impact on patient safety, but are not well understood in clinical work. Despite challenges a lot of things go well in the OR. Thus, the overall aim of this thesis was to evaluate an instrument for assessing safety climate, to describe and compare perceptions of safety climate, and to explore the complexity of work processes in the OR.To evaluate the Safety Attitudes Questionnaire-operating room (SAQ-OR) version and elicit estimations of the surgical team a cross-sectional study design was used. How work was done was studied by observations using the Work Observation Method by Activity Timing and by group interviews with OR professionals.The results show that the SAQ-OR is a relatively acceptable instrument to assess perceptions of safety climate within Swedish ORs. OR professionals´ perceptions of safety climate showed variations and some weak areas which cohered fairly well with managers' estimations. Work in the OR was found to be complex and consisting of multiple tasks where communication was most frequent. Multitasking and interruptions, mostly followed by communication, were common. This reflects interactions and adaptations common for a complex adaptive system. Managing complexity and creating safe care in the OR was described as a process of planning and preparing for the expected and preparedness to be able to adapt to the unexpected.
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| 7. |
- Nilsson, Maria, 1984-
(author)
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Tumor instructed normal tissue : studies of potential extratumoral biomarkers and therapeutic targets in prostate cancer
- 2021
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Doctoral thesis (other academic/artistic)abstract
- Prostate cancer is the most common cancer in men in Sweden and but luckily the majority of the patients will carry on their life without any consequences from the disease. Unfortunately, some will develop aggressive tumors and eventually die. However, current prognostic and diagnostic techniques used to distinguish lethal prostate cancer from harmless prostate cancer are insufficient. It is therefore necessary to find novel diagnostic and prognostic markers, so aggressive prostate cancer can be detected and treated as early as possible whilst allowing non-aggressive variants to be safely left without extensive treatment. Interestingly, aggressive tumors have been shown to induce certain adaptive changes in the non-malignant parts of the tumor-bearing prostate – changes probably necessary for subsequent tumor growth and spread. Our research group have termed this response “Tumor Instructed (and thus Indicating) Normal Tissue (TINT)” and proposed this tissue as an alternative source of diagnostic/ prognostic markers. The aim of this thesis is to analyze factors related to tumor aggressiveness in prostate TINT. Experimental studies and studies on patient material were executed to investigate potential TINT markers at the mRNA and protein level.In patients we saw that high expression of lysyl oxidase (LOX) in TINT epithelial cells was associated with poor prognosis and served as a prognostic factor. In an animal model, created by injecting tumor cells into rat prostates, expression of LOX was increased in the surrounding non-malignant tissue. If LOX was inhibited while tumors were establishing in the prostate, tumor growth was decreased. In contrast, if LOX was inhibited after tumors were established, tumor growth was increased. Taken together, this suggests that tumors can induce LOX expression in TINT and that the function of LOX is context dependent.Another gene that was significantly increased in TINT was heme oxygenase-1 (HO-1). TINT in rat prostates injected with aggressive tumor cells was infiltrated by HO-1 expressing macrophages. In patients, HO-1 expressing macrophages was mainly seen in the invasive front of high-grade primary tumors, which also correlated with the presence of bone metastases. HO-1 expressing macrophages was more common in bone metastases than in primary tumors, and had an inverse correlation to AR expression in castration resistant prostate cancer.Microseminoprotein-β (MSMB) is normally expressed by prostate epithelial cells but is reduced in prostate tumors. Decreased levels of MSMB in serum are currently used as a biomarker for prostate cancer. Both in experimental studies and in patients, we saw that levels of MSMB were also decreased in TINT and related to tumor aggressiveness. This suggests that decreased levels of MSMB in serum could be caused by decreased levels of MSMB in the non-malignant prostate tissue and that TINT-markers possibly could be measured in blood.In conclusion, findings presented in this thesis show several alterations in TINT associated with tumor aggressiveness which have good potential of being useful as clinical prognostic markers for prostate cancer after further research.
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| 8. |
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| 9. |
- Sulistyawati, Sulistyawati, 1983-
(author)
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Dengue Prevention and Control in Indonesia : a case study in Yogyakarta City
- 2020
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Doctoral thesis (other academic/artistic)abstract
- Background: Integrated efforts that involve many public health sectors are required to combatdengue in any setting. Hospitals are responsible for providing accurate diagnosis and reportingconfirmed dengue cases to the health authorities, which serves as an alarm for increasingpreventive measures. Community participation in dengue vector control is essential becauseit affects sustainability and cost-effectiveness of preventive and control. This thesis aimed toprovide an in-depth understanding of dengue prevention and control in Yogyakarta, Indonesia,in order to contribute to strengthening the country’s health system and the implementation ofstandardized and well-accepted dengue control strategies. Several aspects have been studiedin term of dengue prevention and control (case management and reporting, surveillance andvector control) in a dengue-endemic region of Indonesia – namely, Yogyakarta.Methods: This thesis comprises four individual research studies: Knowledge, Attitude andPractice (KAP) survey, control card intervention, implementation of the Jumantik programmeand dengue case management and reporting in hospital. A descriptive analysis, followed by apre-post assessment, was performed in the community. A mixed-method approach was usedfor assessing the Jumantik programme and qualitative approach was conducted for the hospitalstudy.Results: The findings indicated that: (i) KAP regarding dengue vector control were sufficient butcertain aspects still had weaknesses; (ii) level of community participation in vector control wasnot satisfactory for several reasons, including lacking time, being busy with work and memberof the community feel that vector control was not their responsibility; (iii) the Jumantikprogramme dealt with various obstacles, especially those related to public acceptance; (iv)coordination between the district health office and hospitals for early dengue detection didnot run optimally. We also found that standard operating procedures for dengue managementdiffered between hospitals.Conclusions: The results clearly show that dengue prevention and control efforts in Yogyakartaface certain challenges that must be addressed. While many World Health Organizationrecommendations are being followed, the weaknesses found in some aspects of theimplementation, as well as the lack of integration for various dengue prevention and controlelements, need to be promptly addressed.
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| 10. |
- Trang, Phan Minh, 1974-
(author)
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Weather and extreme heat in association to mental disorders : The case of Hanoi, Vietnam
- 2017
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Doctoral thesis (other academic/artistic)abstract
- Background: Vietnam suffers consequences of global warming. There is limited data of the relationship between weather, extreme heat and potential mental health problems. It is therefore crucial to study heat-related mental illnesses and to establish good solutions with relevant adaptations to global warming. The adaptation measures should give attention to people that live in areas facing annual extreme weather, and protecting health in general and more specifically mental health of citizens. The study aimed to examine relationships between weather patterns, extreme heat or heatwaves, and mental disorders, and to investigate factors contributing to increased vulnerability and susceptibility.Methods: The thesis includes a systematic review and a hospital-based study using data from the Hanoi Mental Hospital for five years (2008 – 2012), with mental disorders diagnosed by ICD10 (F00-99) to estimate the effects of weather variation, seasonality, increased temperatures, and heatwaves on hospital admissions for depression and other mental disorders. A negative binomial regression model accounting for yearly study period, time trends, and day of the week was used to analyze the relationship between seasonality, heatwaves, and monthly and daily mental disorder hospitalizations.Results: Our findings showed (i) a general tendency for more admissions between May and December, with a seasonal bi-annual high between May-June and November-December, and elevated ambient temperature was significantly related to increasing admissions for depressive disorders; (ii) the number of hospital cases for mental disorders increased in the summer seasone specially in June, and two percent of cases emerged during elevated temperature of one degree Celsius; and (iii) when compared with non-heatwave periods, heatwaves amounted to increasing risks for admission for the whole group of mental disorders (F00-79), and admissions for mental disorders among residents in rural communities and in the elderly population increased significantly during heatwaves.Conclusion: There were associations between hospital admissions for depression and other mental disorders and seasonality, weather patterns, elevated temperatures, and heatwaves. The associations grew stronger with the length of the heatwaves and particularly the elderly appeared more sensitive to seasonality, hot weather and heatwaves.
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