| 1. |
- Larsson, Gunilla, 1960-
(författare)
-
Ship and Society : Maritime Ideology in Late Iron Age Sweden
- 2007
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis analyses the relation between ship and society against a background of ideological and technological changes in Late Iron Age Sweden. It discusses the factors behind the development of ‘a maritime society’, why ships and seafaring came to play an important role that was also reflected in the use of the ship as a symbol and a metaphor in a military context, as well as in religion, administration, jurisdiction and social life. The author argues that this society is disappearing when it is first encountered in the Early Middle Ages, because of a fundamental ideological change.There is a myth about the appearance of the ‘Viking ship’ and the Iron Age seafarer. The ships are supposed to be big and wide. An analysis of the archaeological material presented here shows that this picture is not correct. Instead the ships of the Svear were quite small and built in a way that made them very light. This was a result of shipbuilding methods introduced in the Late Iron Age, and it had consequences for the trade communication network as well as for naval operations. Because of the light ships, it was possible to land on any shallow shore and navigate the shallow rivers in the East.The ship became a key symbol used by the authorities to structure the society for administrative and military purposes, using a terminology based on the Late Iron Age warship.In the Middle Ages, ideology, shipbuilding and seafaring changed. New key symbols were introduced, and they were used by an increasing royal power to consolidate what would become a united Sweden, inspired by feudal Europe.
|
|
| 2. |
- Bergmann, Astrid, 1972-
(författare)
-
Remote Ischemic Preconditioning and its Effects on the Respiratory System
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Mechanical ventilation in itself can lead to pulmonary damage, and one-lung ventilation (OLV), necessary for thoracic surgery, accentuates this injury. Remote ischemic preconditioning (RIP) is a potential tool to reduce lung injury after mechanical ventilation, including OLV. However, current data on pulmonary RIP-effects are contradictory. Therefore, the overall purpose of this Ph.D. project was to assess the effects of RIP on the respiratory system. In Study I, in healthy spontaneously breathing volunteers, oxygenation was impaired early after RIP, which was possibly induced by transient ventilation-perfusion inequality. Studies II, III, and IV were performed in a porcine OLV model. In Study II, we found that RIP possibly enhances alveolar injury, but attenuates the immune response. In Study III, we confirmed that an immune response to RIP takes place, which shows a different time pattern in each cytokine, depending on the site of measurement as well. In Study IV, we studied the porcine model for eight hours and found that RIP improved oxygenation after two hours of OLV and impeded the decline of exhaled nitric oxide (NO) during and after OLV. These findings indicate that RIP mitigates hypoxic pulmonary vasoconstriction (HPV).In summary, RIP has a complex effect on the respiratory system, which partly explains the previous contradictory findings.
|
|
| 3. |
- Bodin, Ingrid, 1944-
(författare)
-
Impairment of intra-oral sensation, discrimination ability, and swallowing function following radiotherapy and surgery for oral and pharyngeal cancer
- 2004
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Oral and pharyngeal cancer is commonly treated with a combination of radiotherapy and surgery. It is a clinical knowledge that patients often experience severe swallowing disorders following treatment. Since surgical sequelae are instantaneous and obvious, little attention has been paid to other concurrent effects of the treatment. To shed light on this subject, the aim of this thesis was twofold (i) to make a retrospective inventory of the sequelae following treatment and (ii) to perform a prospective, inceptive examination at diagnosis, and to follow-up after radiotherapy, six months and 12 months after surgery. The files of ninety-nine patients revealed that following treatment one-third had to use gastric fistulas and more than nine of ten patients had restricted swallowing capacity. Every second patient could only swallow puréed or liquid food. Adequate intra-oral sensation and discrimination ability is essential for bolus preparation and bolus control, for appropriate elicitation of the swallowing reflex and, hence, for the oral phase of swallowing. At the inceptive examination, the prospective part of the study demonstrated intra-oral discrimination ability in patients was equal to that in healthy controls but was impaired six months after treatment and there was no significant improvement after 12 months. It had been expected that the patient’s healthy, non-tumor side would compensate but it did not. An explanation was found when it was revealed that radiotherapy induced a delayed decline in intra-oral sensation. Sensory decline was not demonstrated within a month after radiotherapy but was manifest six months later. Since the radiotherapy field includes the neck, because of the risk for metastasis, it is highly plausible that pharyngeal sensation declines in a manner corresponding to that found intra-orally when the healthy side is irradiated. In accord with this presumption, pharyngeal swallowing function deteriorated in patents with oral tumors. Cineradiographic evaluation of oral and pharyngeal swallowing function disclosed a significant association between the degree of swallowing dysfunction and the degree of sensory decline and with the degree of impairment of shape recognition. Conclusions: Delayed intra-oral sensory decline, found to be induced by radiotherapy, can be expected to appear in the entire radiation field, including the oral cavity and the pharynx, with adverse effect on swallowing. Testing intra-oral sensation close to the last radiotherapy session is not advisable, because sensory decline does not develop immediately after radiotherapy but manifests after six months. Spontaneous sensory rehabilitation cannot be expected after six months. The significant association between degree of swallowing dysfunction and degree of intra-oral sensory decline and impaired discrimination ability must be considered in the quest for functional rehabilitation of patients treated for oral or pharyngeal cancer.
|
|
| 4. |
- Jacobson, Sofie, 1961-
(författare)
-
Severe sepsis : epidemiology and sex-related differences in inflammatory markers
- 2014
-
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.
|
|
| 5. |
- Larsson, Jimmy, 1977-
(författare)
-
Neural Stem and Progenitor Cells : Cellular Responses to Known and Novel Factors
- 2010
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Neural stem cell self-renewal and differentiation are tightly regulated events during CNS development, leading to cell division into new neural stem cells or the formation of neurons and glial cells. This thesis focuses on the cellular responses induced by known and novel factors in neural stem and progenitor cells (NSPCs).Platelet-derived growth factor (PDGF) signaling has previously been implicated in NSPC regulation as well as in tumor formation. In order to evaluate the differentiation process and find new regulators of NSPCs a micro-array screen was performed, evaluating transcription during normal differentiation and the effect of PDGF-AA in this process. The transcriptional profile of PDGF-AA treated NSPCs was shown to be an intermediate between the profiles of neural stem cells and their progeny. The NSPC transcriptome was also found to have similarities with that of experimental glioma. A previously non-characterized transcript, the nuclear receptor binding protein 2 (NRBP2), was identified and found to be expressed in the developing and adult mouse brain and in medulloblastoma. NRBP2 down-regulation rendered neural progenitors sensitive to induced cell death.Different PDGF ligands interact with different combinations of PDGF receptors. Therefore NSPCs were stimulated with either PDGF-AA or -BB to further evaluate cellular responses with regard to the two specific isoforms. A divergent effect between the two isoforms in long-term proliferation and cell survival was found, with PDGF-BB being the most efficient stimulator.Stem cell factor (SCF) has previously been identified as a regulator in the hematopoietic system and we showed that SCF induces a migratory response in NSPCs. In addition, SCF positively affected cell survival but had no effect on NSPC differentiation. Insights into the regulatory mechanisms involved in neural stem cell signaling are needed to develop diagnostic tools and novel treatments.
|
|
| 6. |
- Larsson, Ola
(författare)
-
Essays on Risk in International Financial Markets
- 2007
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis deals with techniques to model risk in financial markets and consists of four separate essays. The thesis begins with an introduction in chapter one, while chapter two to chapter five contains the four essays. The first essay examines the implication of using various risk measures for portfolio selection. Specifically, three risk measures are examined: variance, Value at Risk (VaR) and Conditional Value at Risk (CVaR). The theoretical properties of these measures are first examined using the theory of stochastic dominance, and it is established that variance and VaR is only consistent with stochastic dominance of first order, while CVaR is consistent with stochastic dominance of second order. In the empirical part of the essay, the optimal portfolios under the various risk measures are examined using stock market data from the US. It is found that although VaR and variance have less attractive theoretical properties, in practice, the difference between the measures is small. Furthermore, a test for stochastic dominance of first and second order is employed. The test suggests that none of the risk measures dominates the others. In the second essay the forecasting performance of GARCH and stochastic volatility models is examined and compared. The results for volatility forecasting is generally quite disappointing, with no model passing the tests for complete unbiased forecasts. The stochastic volatility model delivers in general slightly better forecasts compared to the GARCH model, but the difference is not significant. Moreover, the choice of distribution seems to be unimportant. The VaR forecasts are in general quite satisfying, both for the GARCH model and for the stochastic volatility model. The models are about equally good. Best results are obtained with the student t distribution and skewed student t distribution. The third essay examines various multivariate models for forecasting purposes. A special interest is taken in copulas. Copulas are functions that tie marginal distributions together into a multivariate model. In this essay a new way to incorporate time varying dependence in copulas is suggested and evaluated. Furthermore, alternative time varying as well as constant copulas are also examined, as well as traditional multivariate models. The results suggest that copulas are a valuable tool for VaR forecasting. In the fourth essay, the non-linear dependence between stocks and bonds is examined using a multivariate regime switching model. With the model, each market can, at each point in time, being characterized as being in a high volatility state and in a low volatility state. In a bivariate setting, this corresponds to four separate states. The dependence between the stock market and the bond market is examined across the different states using data from the US, the UK and Japan. It is found for all markets that the dependence is not constant across the regimes. Furthermore, for the US and the UK bond market, it is found that when both the stock market and the bond market are in the high volatility state, the dependence is negative.
|
|
| 7. |
- Larsson, Ola
(författare)
-
Transcriptome studies of cell-fate and aging
- 2005
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Microarrays enable the researcher to capture the expression levels from most genes in a single experiment. The methodology has opened up a new field with possibilities and challenges. This thesis focuses on both methodological and bioinformatics improvements in the application of microarrays; and in particular on the use of such approaches in cell-fate and aging research. We have introduced a method to fabricate microarrays on unmodified glass that enables a cost effective approach to produce microarrays; and refined the SAM (significance analysis of microarrays) approach, highlighting important technical aspects of this, the most widely used method to identify differentially expressed genes. Cell-fate is a term to describe how a cell ends its normal life span. We have used microarrays to identify genes that are associated with cell-fate outcomes. Initially, we studied early changes of gene expression during induction of cellular senescence and separated them from changes that are associated with growth arrest. We thereby identified a set of genes that are induced during induction of cellular senescence but not during growth arrest. We also studied a model-system that recapitulates a characteristic of cancer cells, apoptosis resistance, mediated by overexpression of the translation initiation factor eIF4E. We identified a set of transcripts that are overtranslated when eIF4E is overexpressed and demonstrated that two of them act as mediators of apoptosis resistance. These studies have contributed to the understanding of how the transcriptome is regulated during induction cell-fates and how regulation of translation can influence cell-fate decisions. Senescence has been hypothesized to cause aging. When analyzing microarray studies of cellular senescence and aging we found a common mammalian aging transcriptome that had at least two components and established that cellular senescence resembles aging in mice but not humans. These findings are important as it indicates that aging in mice and humans could be substantially different and that cellular senescence in tissues, probably does not contribute to aging in humans.
|
|
| 8. |
- Larsson, Per-Ola
(författare)
-
Optimization of Low-Level Controllers and High-Level Polymer Grade Changes
- 2011
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Two design problems at different levels in the control hierarchy are considered; optimization of robust low-level controllers with constrained control signal activity and optimization of economical high-level polyethylene grade changes. As for the first design problem, a constraint on control signal activity due to measurement noise is presented and used when optimizing and comparing PI/PID controllers with measurement filters of different orders. The results show increased performance when roll-off is present in the feedback loop and that similarities exist between PID and high-order Youla-parametrized controllers. Robustness margins separating the dead-time uncertainty from other process uncertainties are presented. Methods to compute the margins, posed as optimization problems based on Nyquist diagram interpretations, are given. PID and predictive PI (PPI) controllers with measurement filters are optimized and compared using the presented control signal activity constraint and robustness margins. The two controllers show similar performance on industrially representative processes, with a few exceptions where the PID controller outperforms the PPI controller. Concerning the second design problem mentioned above, a cost function for optimization of economical polyethylene grade changes is proposed. It considers inflow costs, on- and off-grade polymer production revenues and polymer quality variable intervals to define on-grade production as well as economical incentives for on-target production. Using the JModelica.org platform, several stationary operating points and dynamic grade changes are optimized with regards to economy. The optimizations are based on Modelica models of both a gas-phase polyethylene reactor and the polyethylene plant PE3 at Borealis AB. The results show that economically optimal grade changes can be divided into three phases with distinguishing features, and that the synchronization of control flows and the usage of recycle area off-gas flows are important. A Modelica library for the plant PE3 at Borealis AB, including three reactors and three distillation columns, is presented.
|
|
| 9. |
- Malm, Tobias, 1980-
(författare)
-
Konsten att hålla ihop : Om lärande och organisering i rockband
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Rock bands are foundational for modern day music life. These small groups provide well-being and self-fulfillment to its members, as well as fuel for the cultural life and the increasingly highlighted creative industries. Rock bands, however, are particularly difficult to organize. Bands face a range of challenges in keeping together and developing as a group.The aim of this doctoral thesis is to develop knowledge on rock band formation and development over time. Based in the discipline of education, the thesis mainly contributes to the fields of organization studies, social theories of learning, and music and cultural life research.The thesis uses the theory of situated learning to explore rock band formation and development. The methodology is qualitative and ethnographic, and the research design builds on three studies: an interview study with three rock bands and two case studies. All five bands are Swedish and have found different degrees of success and popularity.The thesis investigates band activities and courses of events, band members’ identities, and challenges faced. The findings indicate that a rock band’s activities shift between a production mode – i.e. highly productive times associated with public performances, record releases and marketing, and behind the scenes processes of creating, recording and planning – and a contrasting less active hibernation mode without bigger public projects or goals. The amount of time spent in production mode depends on the band’s degree of “membership” in the music industry. Moreover, a band member forms and actualizes identities of colleague, creator, entrepreneur, friend, hobbyist and professional, in differing combinations, situations and modes. Furthermore, the members’ most significant challenges relate to identity dilemmas.Based on these findings, the thesis formulates a model for a rock band’s learning trajectory and argues that a band may develop as it approaches, or becomes a more central member in, the music industry. This development demands increased public success and organizational ability: the band members’ ability to form business-oriented practices, to participate uniformly in an overarching community of practice, and to be flexible as they must identify with, and ascribe meaning to, a variety of activities in different and sometimes contradictory ways.The thesis concludes that the challenges of persistence as a rock band or similar group relates chiefly to group member difficulties in identifying with different activities and situations that are necessary to sustain and develop as a collective. Eventually, individual members tend to handle the experience of uncertainty and ambivalence by holding on to one singular identity, which may prevent group development, foster intra- and interpersonal tensions, and ultimately can lead to significant conflicts and/or a band’s breakup.
|
|
| 10. |
- Segnestam Larsson, Ola, 1971-
(författare)
-
Standardizing Civil Society : Interpreting Organizational Development in the Tension Between Instrumentalism and Expressivism
- 2011
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This book focuses on empirical phenomenon of organizational development, which seems to be trusted as the solution to many problems in civil society and the key to ‘the good society’. But can organizational development fulfil such expectations?As civil society becomes increasingly prominent in local struggles, national debates, and international politics, scholars are paying attention to how it should be promoted and developed. One approach deployed to foster a vibrant civil society is organizational development. In addition to improved project and organizational performance, it is believed that more and better organizing will promote desirable qualities inherent in civil society and therefore the development of a good society.In this book the author questions if organizational development within civil society can fulfil such expectations. Drawing on institutional theory and studies of cooperation among trade unions, faith-based organizations, and organizations of people with disabilities, he argues that organizational development of civil society organizations was never meant for implementa- tion. Instead it serves more as a legitimacy device for the involved actors in addition to protecting organizational praxis from conflicting internal and external demands.
|
|
