| 1. |
- Bergström, Maria, 1983-
(författare)
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Participation and support in everyday life over a decade : perspectives of persons with rheumatoid arthritis and their significant others
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: The treatment of rheumatoid arthritis (RA) has evolved over recent decades. Today, many previous limitations related to, for example, joint damage have become rare, and persons with RA can often continue to work and engage in different aspects of everyday life. Nonetheless, persons with RA still report restrictions in everyday life, as they can be negatively impacted by symptoms like pain, stiffness and fatigue. As these symptoms might be invisible to others, the significant others of persons with RA can find it difficult to comprehend the effect of the disease. As a consequence, both the person with RA and the significant other may be affected, despite today’s effective treatment.As participation is a central concept within healthcare, it is also a prominent factor within rehabilitation and its goals. Despite access to contemporary treatment during the whole disease course, persons with RA still report participation restrictions. Since RA is a chronic disease, these remaining restrictions are of particular interest from a longitudinal perspective. However, support from the social environment, such as significant others, has the possibility to positively influence participation in everyday life. Therefore, it is essential to explore the influence of significant others and their support with the goal of enhanced participation in the everyday life of persons with RA, from a longitudinal perspective.Aim: The general aim of this thesis is to explore participation in the everyday life of persons with RA over a decade, and in relation to this investigate the influence of significant others and their support.Methods: This thesis consists of four studies that used different methodological approaches: qualitative, quantitative and mixed methods.Study I was a qualitative study where 59 persons with RA participated in semi-structured interviews approximately three years after diagnosis. Questions covered experiences in everyday life and participation. The material was analysed through content analysis.In Study II, longitudinal data from 274 persons with RA were analysed regarding disease activity (assessed by DAS28), grip force (assessed by Grippit), pain intensity (VAS mm) and activity limitations (assessed by HAQ). The data were collected at inclusion, year one and year two after diagnosis. Data related to sickness absence were also obtained, as well as self-assessed perceptions of experienced support. Through regression analyses, associations between disease-related variables and sickness absence were investigated, with support as a moderator.The data in Study III comprise semi-structured individual interviews with 16 persons with RA and their significant others, conducted approximately a decade after diagnosis. The interview guide was developed with Study I in mind and included similar topics, with the addition of support. This material was analysed using dyadic analysis, where a person with RA and the significant other comprised a dyad.Finally, in Study IV, a convergent mixed methods approach was used. Longitudinal data regarding disease-related variables (same as Study II) were collected during the first decade after diagnosis and analysed through linear mixed models. The qualitative material consisted of individual interviews conducted three and ten years after diagnosis and analysed by directed content analysis. The quantitative and qualitative results were integrated in accordance with the chosen method.Results: Significant others of persons with RA could encompass both facilitators and hinders to participation in the everyday life of persons with RA. Through the provision of support and helpful attitudes towards needed adaptations, they had a positive influence on participation in the everyday life of persons with RA. This was a continuous process since the persons with RA were still affected by the disease a decade after diagnosis, and adaptations by the significant others might also still be needed.Experiences of RA were found to differ between men and women over the first decade after diagnosis. Moreover, through a mixed methods design, discrepancies were found between the persons’ own descriptions in interviews and the quantitative results. For instance, women expressed issues related to grip force and disease activity in the interviews, but these issues were not detected in the same way in the quantitative results. These discrepancies were additionally not seen in men; however, both men and women still showed signs of disability a decade after RA diagnosis. Nevertheless, over time, the persons with RA and their significant others had learned to live with the disease and there was a sense of togetherness in everyday life with RA. Namely, they approached the disease together as a unit.Support was identified as a positive aspect that facilitated everyday life. It entailed both the support between the person with RA and the significant other, as well as the support from others outside of the dyad. Support could also come in different forms. For example, the person with RA could receive emotional support from a significant other, or healthcare professionals (HCPs) could provide informational support to either or both of the parties. In connection to the latter, a continuous need for knowledge was identified in both the persons with RA and the significant others. Support from significant others also proved to have an impact on work life specifically, as more perceived support was associated with an increased risk of sickness absence.Conclusively, significant others and their support can influence participation in the everyday life of persons with RA, and this influence can be facilitated through positive attitudes and different types of support during the first decade after diagnosis.Conclusions: Significant others are essential providers of support as facilitators for participation in the everyday life of persons with RA, including many years after diagnosis. However, they must also be attentive towards the further need for adaptations and possible emotional burden in the persons with RA. It is also important for significant others to find a balance between overprotecting and contributing to independence.The significant others in their turn might need support in understanding the impact of the disease. In this case, HCPs should be providers of support to both persons with RA and their significant others and consult with both of them as a unit in the rehabilitation process. This also exemplifies the need for support from outside the dyads of persons with RA and their significant others.Support is requested both at an early stage and throughout the disease course. Different types of support from significant others can therefore preferably be part of the rehabilitation process as a way to enhance participation in the everyday life of persons with RA.
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| 2. |
- Mendoza-Garcia, Patricia, 1988-
(författare)
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Harnessing the power of model systems to investigate regulation of Anaplastic Lymphoma Kinase function
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The anaplastic lymphoma kinase (ALK), initially identified as a translocation partner in anaplastic large cell lymphoma (ALCL), has been described in a number of tumors such as neuroblastoma. Neuroblastoma is a neural crest derived malignancy of the sympathetic nervous system. Therefore, understanding regulation of ALK transcription and activity in the context of normal neural crest development might highlight abnormal events contributing to neuroblastoma initiation. The use of vertebrate model systems has been very important for studying in detail the pathways activated during neural crest development, their contribution to neuroblastoma and the identification of therapeutic targets.Using a yeast one-hybrid approach, we identified Odd-paired (Opa) as a potential transcription factor modulating Alk expression in the Drosophila visceral mesoderm (VM) (Paper I). Opa promotes Alk expression in the VM in combination with Bagpipe (Bap) and Biniou (Bin) through binding to the here identified AlkEB9 enhancer region.In a subsequent paper, we identified ALKAL1 and ALKAL2 as the activating ligands for the human ALK (Paper II). Using a combination of in vitro and cell culture assays we show that the ALKAL proteins can bind and activate human ALK. Moreover, ALKAL proteins can “super-activate” mutant ALK, highlighting a putative role for the ALKALs/ALK axis in neuroblastoma.The third paper shows in vivo evidence of ALKAL activity during zebrafish neural crest development (Paper III). We identified and characterized three zebrafish Alkal proteins and demonstrated their ability to activate human and zebrafish ALK family RTKs. Zebrafish Alkals activate the ALK-related receptor leukocyte tyrosine kinase (LTK) in the neural crest to promote iridophore development.In the last paper, we employed the DamID approach on the Drosophila VM and identified the transcription factor Kahuli (Kah) as an Alk transcriptional target in this tissue (Paper IV). We also addressed the in vivo iv Kah role during embryogenesis and showed that Kah is required for normal midgut invaginations and formation of the body wall musculature.Together, this thesis highlights the importance of ALK receptor signaling during development in vertebrate and invertebrate models. Further, it shows that ALKAL signaling via the activation of the ALK family receptors are involved in neural crest development.
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| 3. |
- Mohammadi, Mohammad
(författare)
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Risk Management in Tunneling Projects : Estimation and Planning
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cost overruns and schedule delays are frequently observed occurrences in the construction of transport infrastructure projects. Such phenomena lead to the mismanagement of significant amounts of both public and private resources.An examination of the literature reveals that uncertainty stands out as one of the potential primary causes of cost overruns and schedule delays. To address the impact of uncertainty on time and cost estimations in transport infrastructure projects, probabilistic approaches can be employed. In this doctoral thesis, first a conceptual risk model has been formulated specifically for the purpose of enhancing time and cost estimations in tunneling projects. This risk model serves as a tool to scrutinize and contrast existing probabilistic time and cost estimation models for tunnel projects, aiming to identify potential areas for improvement. Furthermore, the conceptual model is utilized to delve into the factors influencing the accuracy of subjective assessments regarding the input parameters in time estimation models. It also explores methods for incorporating the role of tunneling phases into the subjective assessment of these input parameters.Then, enhancements and updates are introduced to the existingKTH model for time and cost estimation in tunneling projects. This model primarily targets three main sources of uncertainty: variability in construction performance, geological uncertainties, and the potential incidence of disruptive events. The analysis and improvements related to modelling of construction performance involve three sequential steps. In the first step, the construction process is modeled using the work breakdown structure (WBS), enabling a more realistic assessment of tunneling time. Subsequently, in the second step, PERT distributions are employed to model the uncertainty in the duration of unit activities, compared to the commonly used triangular distributions. The third step involves a detailed examination of a real tunnelling project's data to identify components contributing to construction performance variability for unit activities. This analysis pinpoints three main components: typical performance variability, minor performance delays, and minor machinery delays. These components are integrated into the KTH model, resulting in its further update concerning construction performance variability. A novel approach is introduced into the KTH model by leveraging the Metropolis-Hastings (MH) algorithm within the framework of Markov Chain Monte Carlo (MCMC) simulation to address geological uncertainties along the tunnel route. This method facilitates round-by-round simulation of the tunneling process and allows the model to accommodate uncertainty in the critical path for tunneling projects involving multiple headings. These enhancements aim to improve decision-making processes and mitigate risks associated with schedule delays and cost overruns. Additionally, the magnitude of disruptive events are now modeled as stochastic variables, an improvement on the original version of the KTH model.
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| 4. |
- Szychowska, Malina, 1991-
(författare)
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Effects of visual load on auditory processing
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In daily life, people need to be able to focus on a task while ignoring any task-irrelevant background noise. For example, people who work in an open-space office may have to work on a report while ignoring the background talk among co-workers. Theories of attention argue that processing of task-irrelevant auditory information should become attenuated when attentional capacity is exhausted by task-relevant stimuli, for example a visual task. According to early-filter theory, top-down attenuation of auditory responses is possible at various stages of the auditory pathway through multiple recurrent loops. Furthermore, the adaptive filtering model of selective attention suggests that filtering occurs early when concurrent visual tasks are demanding (e.g., high load) and late when tasks are easy (e.g., low load).The main aim of this thesis was to investigate whether auditory processing is attenuated during concurrent visual load manipulation, and if so, at which stage of the auditory pathway. Recurrent loops that are present throughout the entire auditory pathway should allow top-down modulation of even earliest responses, especially when accompanied by a highly demanding task. Recording these auditory responses during concurrent visual tasks with different levels of load could potentially show at which stages of auditory processing the filtering happens when the task demands are high or low, or there is no task at all.This thesis tested the effects of visual load manipulation on the responses originating from different stages of the auditory pathway: mismatch negativity (MMN) to duration in Study I, MMN to frequency in Study III, auditory steady-state responses (ASSRs) to a 40-Hz modulation frequency in Study IV, and ASSRs to 20-, 40-, and 80-Hz modulation frequencies in Study V. Additionally, Study II compared different control conditions (cascade vs. no-repetition control) for evoking MMN to find a design that reduces confounds in the MMN. Results of Study II showed that cascade and no-repetition control are comparable control conditions for evoking MMN.For the effects of visual load manipulation on auditory MMN (low vs. high load), results showed moderate evidence for the effect of load on duration MMN and moderate evidence for no effect of load on frequency MMN. However, results for the duration MMN might be confounded by physical differences between the low load and high load conditions in the visual task, and by a biased oddball paradigm used to evoke the MMN. Thus, it is most likely that auditory MMN is not affected by visual load (low vs. high).For the effects of visual load on ASSRs (no, low, and high load), results showed moderate to strong evidence for no effects of load manipulation on ASSRs, but some comparisons were inconclusive. The convincing evidence obtained in Studies IV and V points to the robustness of ASSRs against visual load manipulation.Because it is most likely that neither MMN nor ASSRs are affected by visual load manipulation, results presented in this thesis support the idea that attentional resources are modality specific. Because it is possible that filtering occurs at one stage of auditory processing and does not change with the concurrent task demands, the present results do not rule out the early-filter theory. However, results are inconsistent with the adaptive filtering model because filtering of task-irrelevant responses does not vary with the demands of the concurrent task.
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| 5. |
- Flyborg, Johan, et al.
(författare)
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Results of objective brushing data recorded from a powered toothbrush used by elderly individuals with mild cognitive impairment related to values for oral health
- 2024
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Ingår i: Clinical Oral Investigations. - : Springer Nature. - 1432-6981 .- 1436-3771. ; 28:1
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The study aimed to investigate how the objective use of a powered toothbrush in frequency and duration affects plaque index, bleeding on probing, and periodontal pocket depth ≥ 4 mm in elderly individuals with MCI. A second aim was to compare the objective results with the participants’ self-estimated brush use.Materials and methods: Objective brush usage data was extracted from the participants’ powered toothbrushes and related to the oral health variables plaque index, bleeding on probing, and periodontal pocket depth ≥ 4 mm. Furthermore, the objective usage data was compared with the participants’ self-reported brush usage reported in a questionnaire at baseline and 6- and 12-month examination.Results: Out of a screened sample of 213 individuals, 170 fulfilled the 12-month visit. The principal findings are that despite the objective values registered for frequency and duration being lower than the recommended and less than the instructed, using powered toothbrushes after instruction and information led to improved values for PI, BOP, and PPD ≥ 4 mm in the group of elderly with MIC.Conclusions: Despite lower brush frequency and duration than the generally recommended, using a powered toothbrush improved oral health. The objective brush data recorded from the powered toothbrush correlates poorly with the self-estimated brush use.Clinical relevance: Using objective brush data can become one of the factors in the collaboration to preserve and improve oral health in older people with mild cognitive impairment. Trial registration: ClinicalTrials.gov Identifier: NCT05941611, retrospectively registered 11/07/2023.
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| 6. |
- Jacobson, Sofie, 1961-
(författare)
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Severe sepsis : epidemiology and sex-related differences in inflammatory markers
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background. Sepsis is a syndrome associated with high mortality rates, substantial morbidity and high costs of care. The incidents of sepsis is reported to be high and controversy exists whether gender affect severity or outcome. Little is known about factors determining susceptibility for developing the syndrome and severity of the syndrome once developed. Early detection and adequate antibiotic administration are the mainstay of treatment and means to identify patients with particular high risk of adverse outcome are desirable. There are data to suggest that the course of sepsis and outcome from the syndrome may be influenced by inherited differences in the immunological response among humansAims: Paper I: Assess incidence and outcome for ICU-treated sepsis patients in this region; Paper II: Assess if there are gender differences related to characteristics, aspects of treatment or outcome in sepsis in this region. Paper III: Assess the association of baseline levels of leptin and adiponectin and future sepsis event, and association of these adipokines in the cute phase and sepsis severity and outcome. Paper IV: Assess association of baseline levels of mannose-binding lectin (MBL) and future sepsis event, and MBL levels in the acute phase in relation to sepsis severity and outcome.Results. Paper I: Overall ICU mortality rate was 25%, while the ICU mortality for patients with septic shock was 58% in this retrospective single university hospital cohort analysis. Cardiovascular disease and diabetes were the most prevalent comorbidities among patients who died during hospital stay. Paper II: No gender-related differences in mortality or length of stay was found in this prospective single center observational study. Differences in aspects of treatment were related to differences in site of infection. Men had more often infections in skin and skin-structures, whereas women more often had abdominal infections. Early organ dysfunction assessed as SOFA score at admission was a stronger predictor for hospital mortality for women than for men. The discrepancy was related to the SOFA coagulation-sub score. Paper III: In this nested case-referent study hyperleptinemia at baseline predicted a first-ever sepsis event, even after adjustment for BMI and other cardiovascular risk factors. Hyperleptinemia in the acute sepsis phase was associated with reduced risk of in-hospital death in men, but associated with increased risk of in-hospital death in women. Paper IV: In the same matched cohort as in Paper III high baseline levels of MBL predicted a first ever sepsis event. High MBL levels in the acute phase or an increase from baseline to the acute phase associate with increased in-hospital death in women but not in men. Low MBL levels was not identified as a risk for acute sepsis or in-hospital death.Conclusions. Mortality from severe sepsis is high, equally affecting men and women. There are differences in patient characteristics and inflammatory markers, which associate with in-hospital mortality differentially in men and women. Aspects of gender should be mandatory, and genetic analysis are desired in future sepsis research.
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| 7. |
- Krounis, Alexandra
(författare)
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Sliding stability re-assessment of concrete dams with bonded concrete-rock interfaces
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The shear strength of the concrete-rock interface is an important parameter in sliding stability analyses of concrete dams founded on rock and depends, in addition to the normal stress state, on the bonding conditions of the interface; concrete-rock interfaces can be either unbonded, partially bonded or fully bonded.In the Swedish guidelines for dam safety all dam-foundation contacts are treated as unbonded. This has the benefit of eliminating all uncertainties related to the cohesive strength of bonded contacts but it might also lead to unnecessary strengthening of dams. Other national guidelines deal with the uncertainties related to cohesion by applying higher safety factors, mainly determined based on previous experience, when both cohesion and friction are taken into account.The main objective of this project is to study if and how cohesion can be included when evaluating the shear strength of bonded or partially bonded interfaces. To accomplish this, uncertainties associated with cohesion are identified and their influence on the assessed stability is investigated.The results show that the influence on the assessed sliding stability is strongly dependent on the magnitude of the involved uncertainties that might vary significantly for different dams. It is thus questionable if one safety factor applicable for all dams can be established for use in deterministic analyses.Taking into account cohesion when reliability methods are used is somewhat less complicated because of the possibility of directly incorporating the uncertainties in the analysis. The main challenge in such cases is the quantification of the involved uncertainties due to lack of proper data and, in some cases, knowledge. In this thesis, a framework for quantification of parameter uncertainty is suggested and the model error due to brittle failure in combination with spatial variation in cohesion is analysed. Areas that require more research to further refine the analysis are also identified.
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| 8. |
- Lefébure, Robert, 1980-
(författare)
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Effects of temperature and terrestrial carbon on fish growth and pelagic food web efficiency
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Both temperature and terrestrial dissolved organic carbon (TDOC) have strong impacts on aquatic food web dynamics and production. Temperature affects vital rates of all organisms and terrestrial carbon has been shown to alter the dynamics of phytoplankton and bacterial production and affect the trophic structure of planktonic food webs. As climate change predictions for the Baltic Sea suggests future increases in both terrestrial carbon run-off and increases in temperature, the aim of thesis was to adopt a system-ecological approach and study effects of these abiotic variables, not only on interactions within planktonic food webs, but also on the growth and consumption rates of one of the most common zooplanktivorous fish in the Baltic Sea, the three-spined stickleback Gasterosteus aculeatus. Results showed that three-spined sticklebacks display a high degree of resilience against increasing temperatures, as both growth rates as well as consumption rates on zooplankton were high at temperatures well over 20 °C. Furthermore, it was shown that the minimal resource densities required to sustain individual and population growth, actually decreased with increasing temperatures, implying that sticklebacks around their optimum temperature for growth at 21 °C will actually have an increased scope for growth. As stickleback population densities have increased over the last decade in the Baltic Sea and are now suggested to out-compete other coastal fish species for shared zooplankton resources, the results presented in this thesis suggest that increased water temperatures would only serve to increase sticklebacks competitive advantage. As the structuring role of this small zooplanktivore on pelagic communities might be considerable, further studies investigating competitive interactions as well as patterns of population abundances are definitely warranted. TDOC was overall shown to stimulate bacterial production and the microbial food web. Because of the longer trophic pathways required to transport carbon from bacterial production to higher trophic levels, the addition of TDOC always reduced food web transfer efficiency. However, it became apparent that the full effect of TDOC additions on pelagic food webs was complex and depended heavily not only on the existing trophic structure to which the carbon was introduced, but also on ambient temperature levels. When three-spined sticklebacks were part of food webs with significant TDOC inputs, the presence of fish, indirectly, through predator release of lower trophic levels, amplified the magnitude of the effects of carbon addition on bacterial production, turning the base of the system significantly more heterotrophic, which ultimately, impacted negatively on their own production. However, when a pelagic food web containing sticklebacks was simultaneously subjected to realistic increases in temperature and TDOC concentrations, food web efficiency and fish production increased compared to present day conditions. These results were explained by a temperature dependent increased production potential of zooplankton, sustained by an increased production of heterotropic microzooplankton via TDOC additions, which lead to higher fish production. Although the increased number of trophic linkages in heterotrophic food webs should have reduced energy transfer efficiency, these negative effects seem here to have been overridden by the positive increases in zooplankton production as a result of increased temperature. These results show that heterotrophic carbon transfer can be a viable pathway to top-consumers, but also indicates that in order to understand the full effects of climate change on trophic dynamics and fish production, abiotic variables cannot be studied in isolation.
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| 9. |
- Lundberg, Kristian
(författare)
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Effect Oriented Planning in Military Mission Support Systems : Models and Heuristic Approaches
- 2013
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Today there are many aspects of model based planning, probably much more than for just 20 years ago. Today data is not the problem, data is everywhere, but the big issue is to understand how to gain advantage of data in decision making - a growing focus is now on modeling!This work is devoted to this task and can be seen as a three part study. First a general problem of multi-resource routing with sequence dependent costs is studied both in terms of models, as well as the development of methods to solve this class of problems efficiently. Sequence dependent costs among resources arise in situations where for instance, one resource is allocated to a task which influence another task and makes that easier in the sense that it can be conducted to a lower cost or shorter time or some other measured effort. This is a useful building block in military decision making when making plans for troops, attacks or missions in general.The next part is founded by Vinnova via the research project “Effect Oriented Planning in Dynamic Scenarios”, and deals with a military ground attack problem with simultaneous attacks against a plurality of targets. This part deals with the difficulties of the attacker-defender problem which is modeled in a Nonlinear Mixed Integer Programming formulation. Suggestions are given how to refine and transform this into robust solution methods.The last part, also included in the Vinnova research project, deals with mission support modeling of Air to Ground missions including multiple aircrafts and a plurality of targets. In this case, sequencing is most important and a strong effort has been put in the understanding and transformation of the problem into models and methods.In these last two parts implementations of models and heuristics as well as computer runs and simulations, originates from the work in [19] and [20] which has been an invaluable contribution to this work.The results are very promising where fast execution and sufficient planning accuracy have drawn the attention as a foundation for future work and research in model based decision making applicable to industry needs and ambitions.
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| 10. |
- Mohammadi, Mohammad
(författare)
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Probabilistic time estimation in tunnel projects
- 2021
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Transport infrastructure projects, including tunneling, suffer from timedelays and cost overrun. A literature review shows that the effect ofuncertainty has been neglected in explaining time and cost overrunmeaning that technical explanations matter. Probabilistic estimations oftime and cost can be employed for dealing with uncertainty in transportinfrastructure projects.In this licentiate thesis, KTH’s probabilistic time and cost estimationmodel for tunneling projects (Isaksson and Stille, 2005, Rock Mech. RockEng., 38, 373-398) was improved. The improvements include breakingdown the production activities into their sub-activities, which form thebasis for assessing times (or costs) for tunnel construction. In addition, theexceptional time and the length of model’s geotechnical zones aredescribed as stochastic variables instead of deterministic values used in theoriginal model. Given its hierarchical structure, the model can be used fortime and cost estimation of all types of tunnels and all constructionmethods in various geological condition.The improved version of the model uses three types of input parametersthat are probabilities of occurrences of different geological condition andidentified undesirable events, production effort of sub-activities (i.e. timespent for performing the sub-activity per unit length of tunnel) andadditive delay time that is imposed as a result of occurrence of undesirableevents. The important issues in modeling the uncertainty in the productionefforts of sub-activities are also explained.
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