| 1. |
- Adolfsson, Emelie, 1985-
(författare)
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Lithium formate EPR dosimetry for accurate measurements of absorbed dose in radiotherapy
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lithium formate has shown to be a material with properties suitable for electron paramagnetic resonance (EPR) dosimetry, among them up to 7 times higher sensitivity compared to alanine, which is a well-established EPR detector material for dose determinations in radiotherapy.The aim of this thesis was to further investigate the properties of lithium formate and develop the dosimetry system towards applications in radiotherapy. The intrinsic efficiency for energies of relevance to brachytherapy and the signal stability were investigated. The dosimetry system was expanded to include a smaller dosimeter model, suitable for measurements in dose gradient regions. An individual sensitivity correction method was applied to the smaller dosimeters to be able to perform dose determinations with the same precision as for the larger ones. EPR dosimetry in general is time consuming and effort was spent to optimize the signal readout procedure regarding measurement time and measurement precision.The system was applied in two clinical applications chosen for their high demands on the dosimetry system: 1) a dosimetry audit for external photon beam therapy and 2) dose verification measurements around a low energy HDR brachytherapy source.The conclusions drawn from this thesis were: dose determinations can be performed with a standard uncertainty of 1.8-2.5% using both the original size dosimeters and the new developed smaller ones. The dosimetry system is robust and useful for applications when high measurement precision and accuracy is prioritized. It is a good candidate for dosimetry audits, both in external beam therapy and brachytherapy.
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| 2. |
- Berg, Håkan, 1972-
(författare)
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Teleost reproduction: Aspects of Arctic char (Salvelinus alpinus) oocyte growth and maturation
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In all vertebrate species, reproduction is a hormonally controlled process, important for growth and maturation of gonads and germ cells. Production of functional germ cells is of outmost importance to secure the survival of a species. Fish comprises 50% of the known vertebrates and are found in aquatic habitats all over the world. Even though fish have evolved a wide variety of morphological and physiological characteristics, due to large differences in the living environment, the growth an maturation of germ cells follows the same pattern in all species. In this thesis the focus has been directed on oocyte growth and development in Arctic char (Salvelinus alpinus), and if stress might inflict disturbances on the reproductive systems.All sexually mature female egg laying vertebrates produces yolky eggs surrounded by an eggshell. Production of yolk and egg shell is under estrogenic control and it is known that production of egg components can be induced in male and juvenile fish by estrogenic substances. Many manmade chemicals have been found to interfere with hormonally controlled processes. Therefore production of the egg yolk precursor, vitellogenin (VTG), and the egg shell components, vitelline envelope proteins (VEP), have been used as biomarkers for estrogenic effect. Exposure to endocrine disrupting substances (EDS) does not only give rise to hormonal effects on the organism, but in addition it also gives rise to an increase in stress hormone, cortisol (F), levels.It is evident that a wide variety of substances may affect Arctic char oocyte growth and maturation. VTG and VEP production is found to be under dose dependent estrogenic control, but the production was directly affected by F. Under natural condition it has been found that F increases towards ovulation. Even though both VTG and VTG is under estrogenic control, these studies showed that stress lead to a decrease of VTG while the VEP production increased. These effects was only observed on protein levels indicating that a post transcriptional down regulation of VTG production is mediated by F in Arctic char.In order for an egg to become fertilizatible, it must undergo a maturation phase. This maturation phase is primarily induced by gonadotropins, which in turn induce the production of species specific maturation inducing substances (MIS). To investigate oocyte development in Arctic char a characterization of its MIS receptor was made. The MIS receptor is localized on the oocyte surface and displays a single class of high affinity and low capacity binding sites. The binding moieties displays association and dissociation kinetics typical of steroid membrane receptors.Even though high specificity for Arctic char MIS was observed, it was found that some EDS bind to the Arctic char oocyte membrane receptor. This suggest that certain EDS might affect oocyte maturation and thereby might alter the reproductive success. Furthermore, it was found that F did not bind to the MIS receptor in Arctic char. It is therefore suggested that oocytes are more sensitive to stress during the growth phase than during maturation
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| 3. |
- Brundin, Pia, 1974-
(författare)
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Politics on the net : NGO practices and experiences
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This study investigates how different kinds of non-governmental organisations (NGOs), operating in different national political contexts, perceive and use the Internet as a political space. The political space concept, as defined here, encompasses two dimensions of Internet use: one external, where organisations use the Internet for online activism and campaigning, and one internal, signifying organisational use of the Internet to promote engagement and interactivity with members and/or supporters. Another question raised is whether Internet use for political purposes by NGOs varies between different national political contexts. Moreover, do the organisations believe that the Internet has affected their political influence to any extent? The empirical data consist of the results of two surveys, one directed primarily to American NGOs, the other explicitly comparative, analysing NGOs in Sweden and the USA. Furthermore, content analyses of NGO websites have been conducted and additive indexes constructed. The findings of the study suggest that, overall, the Internet is most important to the studied organisations as a space for external political initiatives. There were, however, important differences in this regard, which could be related to the organisations’ national political contexts. For example, the American NGOs have oriented their websites primarily towards relatively superficial forms of member involvement, while the Swedish NGOs provided more interactive grassroots features on their websites. Regarding political influence, the Internet arguably has the potential to make the most dramatic difference by reinforcing the organisations’ offline political activities. The present results indicate that, despite the possible converging effect of the Internet on NGO political activism, national political culture exerts an inescapable influence on how the Internet is used as a political space by the studied organisations.
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| 4. |
- Caspillo, Nasim Reyhanian, 1982-
(författare)
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Hitting the mark : studies of alterations in behaviour and fertility in ethinyl estradiol-exposed zebrafish and search related biomarkers
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis, we have analysed the effects of EE2 on non-reproductive behaviours and fertility. We have showed that two doses of EE2 in male adult short-term exposures evokes opposite behaviours in the novel tank test. A lower dose induced increased bottom-dwelling, a sign of increased anxiety and a higher dose increased surface-dwelling, which would likely expose themselves to predation in a natural environment. Increased shoaling was observed in both exposures, possibly affecting feeding and reproduction opportunities. Fertility analysis of these fish demonstrated a complete inhibition of spawning in the highest dose group. To investigate mechanisms behind the spawning failure, we examined expression levels of genes involved in zebrafish sex differentiation and maintenance of gonadal function. We found downregulated transcription levels of male-predominant genes, suggesting a demasculinization of the testes contributing to functional sterility in these fish. We have demonstrated that non-reproductive behaviour in zebrafish is highly sensitive to EE2 exposure during development. After exposing male and female zebrafish to low doses of EE2 followed by remediation in clean water until adulthood, the fish displayed increased anxiety and shoaling behaviour, demonstrating persistent effects of EE2. Furthermore, behavioural effects were transferred to their progeny. Decreased fertilisation success of the developmentally exposed fish was observed in both sexes when mated to untreated animals of the opposite sex. These fertility effects persisted although the fish had a long remediation period, implying likely reduced fitness of fish populations in aquatic environments. Based on our findings on non-reproductive behaviours and fertility, we performed RNAsequencing analysis of the brain and testes in order to investigate possible biological mechanisms behind the persistent effects. There is a need for biomarkers allowing detection of both reversible and irreversible effects in animals exposed to estrogenic substances, hopefully contributing to better risk assessments for EDCs. Results from RNA-sequencing would serve as a basis for continued studies in pursuit of potential biomarkers.
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| 5. |
- Estvall, Martin, 1968-
(författare)
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Sjöfart på stormigt hav : Sjömannen och Svensk Sjöfarts tidning inför den nazistiska utmaningen 1932-1945
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of this study is to discuss German Nazism and Nazi Germany from the point of view of two specific representatives, namely, labour and capital. This has been facilitated by analysing the content of the Swedish Seamen’s Union’s newspaper, The Seafarer [Sjömannen] and its union counterpart, the Swedish Shipowners Association’s periodical, Scandinavian Shipping Gazette [Svensk Sjöfarts Tidning], from November 1932 up to and including 1945. The shipping industry was chosen because trade was of central importance to the Swedish economy and to relations with Nazi Germany. Direct contact with Nazi Germany meant that the organisations were kept up-to-date about what was happening there.A qualitative analysis of texts and images constitutes the major part of the study. This is complemented by a quantitative examination of the intensity of reporting on Nazi Germany.There were enormous differences between the two papers, both in terms of intensity and bias, with regard to the Nazi challenge. While The Seafarer described both Nazism and Nazis in strongly negative terms, the Scandinavian Shipping Gazette chose to remain silent. The Seafarer encouraged counteractions like demonstrations, strikes, boycotts and sanctions, whereas the Scandinavian Shipping Gazette considered such measures to be “undemocratic” and argued against them. The material in The Seafarer is strongly propagandist and always keenly opposed to Nazism and anti-Semitism. The paper served as an anti-Nazi mouth-piece. The means of expression range from poems, drawings and illustrations via highly factual and biased reports to weightier multi-page ideological analyses. All in all, the Nazi regime is described as one of violence and terror that is bent on stifling both the working class and people of other “races”. In sharp contrast, the study shows that the Scandinavian Shipping Gazette dedicates itself to describing events and developments taking place in Nazi Germany.There was no class-transgressing national ideology or policy within the shipping industry with which to facilitate an understanding of the Nazi challenge. In the study, class affinity has proved to be an important, and clearly distinct, factor in the approach to Nazism.
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| 6. |
- Fohlin, Helena, 1979-
(författare)
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Long-term prognostic and predictive factors in hormone receptor positive breast cancer
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The breast cancer survival in Sweden is good (almost 90 % 5-year relative survival) and has increased over time. For women with hormone receptor negative tumors, most relapses occur within the first 5 years after diagnosis. Thereafter the recurrence risk decreases rapidly. For women with estrogen receptor positive (ER+) tumors the annual risk for late recurrences is 1 – 2 %, even after 5 years of endocrine therapy. This risk accumulates so that approximately 25 % of the patients that are recurrence-free after five years from diagnosis may experience a relapse within further 15 years of follow-up. The relatively high long-term risk calls for identification of prognostic and predictive markers with long-term effect. Though, the number of such markers with proven significance is limited. Of the clinical characteristics, only nodal status and to some extent tumor size and tumor grade have been shown to have long-term prognostic value. In this thesis, we propose long-term prognostic and predictive markers for breast cancer.In paper I, we suggest the protein v-akt murine thymoma viral oncogene homologue 2 (AKT2) as a long-term prognostic marker among patients with ER+ tumors. In our study, besides nodal status, AKT2 was the only factor with long-term prognostic value. This is in accordance with some other studies, though we also showed that the significance of AKT2 was limited to ER+ tumors and that the impact increased with higher ER expression.Approximately 75 – 85 % of the ER+ tumors are also progesterone receptor positive (PR+). ER+/progesterone receptor negative (PR-) tumors are considered to be more aggressive and patients with such tumors are often treated with chemotherapy. In this group, more specific subgroups for targeted therapy are needed.Whereas ER has long been established as a predictive factor regarding tamoxifen benefit, the role of PR has not been clarified to date. In paper II, we showed that PR status adds predictive value to ER considering the long-term benefit from tamoxifen.In paper III, we aimed to identify new prognostic markers among patients with ER+ tumors. Systemically untreated patients with ER+/PR- tumors and high expression of the Ras-related protein RAB6C (RAB6C) had reduced distant recurrence rate. Therefore, we suggest RAB6C as a candidate marker for subgroup division among patients with ER+/PR- tumors.According to the results from paper II, there might be subgroups of patients with ER+/PRtumors that do benefit from tamoxifen. The aim of paper IV was to identify such subgroups. Here, we suggest that patients with ER+/PR- tumors and low RAB6C expression do benefit from tamoxifen.The results from this thesis may encourage further studies for more specific subgroup divisions. Such studies may lead to changes in the management program, where some patients with ER+ tumors should receive prolonged or more intense treatment and others reduced treatment based on the pathological markers AKT2, PR and RAB6C.
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| 7. |
- Granberg, Albina, Doktorand i kostvetenskap, 1986-
(författare)
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Koka sjuda steka : Ett sociokulturellt perspektiv på matlagning i hem- och konsumentkunskap på grundsärskolan
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In Swedish schools, the subject Home Economics (HE) is the formal setting for teaching and learning about food and how to cook. All students are obliged to learn HE, but in schools for students with mild intellectual disabilities (ID) students are offered four times as much teaching in the subject than students in regular schools. However, this learning context is underexplored. This thesis aims to create an understanding of what cooking in HE is by studying the teaching content in regard to HE cooking practices for students with mild ID through a sociocultural standpoint. Accompanying observations and qualitative semi-structured interviews were used for data collection. The observations included 16 lessons in HE in schools for students with mild ID. The interviews were conducted with 22 qualified and experienced HE teachers. Field notes from the observations and transcripts from the interviews were analyzed using a thematic analysis. A sociocultural perspective, along with the concept of cuisine, constituted the theoretical framework. The findings reveal that the teaching of cooking in HE is focused on one particular artifact, the recipe. This causes difficulties for the students concerning skills related to the design, purport and arithmetic of the recipe. The prominent role of the recipe in cooking in HE was hence captured in a novel concept, recipe literacy. The teachers also reported using a task-centered approach to teaching certain techniques and methods, such as frying, kneading and simmering. The cuisine that is represented in the data from the observations and interviews is framed within baking, primarily sweet baking. The focus on sweet baking and the students’ various difficulties when using recipes limited the possibilities for students to learn how to cook proper meals for everyday life. Thereby, a conscious choice of dishes and attention to didactics is necessary to improve the validity of the subject. By overcoming such obstacles, opportunities can therefore be created for students with mild ID to learn how to cook.
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| 8. |
- Jonsson, Fredrik, 1972-
(författare)
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Design and Calibration of integrated PLL Frequency Synthesizers
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Thanks to its ability to generate a stable yet programmable output frequency, Phase Locked Loop (PLL) frequency synthesizers are found in most modern radio transceivers. All practical PLL implementations suffer from unwanted frequency components such as phasenoise and spurious tones, and since these components affect system performance they must be predicted and minimized. This thesis discuss the design and implementation of fully integrated PLL circuits. Techniques to predict system performance are investigated. The strongly non-linear operation of PLL building blocks are analyzed, using both analytical and numerical methods. Techniques to reduce impact of interferer down-conversion and noise folding are suggested. Methods to perform automatic calibration in order to make circuits less sensitive to process variations are proposed. The techniques are verified through a number of PLL implementations. The design and implementation of a transceiver targeting a dual band IEEE 802.11 a/b/g wireless LAN operation is discussed. The circuit use two PLL:s operating at 1310 to 1510 MHz and 3.84 GHz respectively. Noise contributions of various PLL building blocks and their impact on over all system performance are analyzed. The combined integrated phase noise is below -34 dBc, and measured transceiver Error Vector Magnitude (EVM) is better than 2.5 dB in both the 2.4 and 5 GHz bands. A low power frequency synthesizer targeting Frequency Shift Keying applications such as ZigBee and BlueTooth is presented. The synthesizer use open-loop direct modulation of the carrier, but unlike conventional implementations, the proposed synthesizer is open both when transmitting and receiving data. This allows the use of a small area on-chip loop filter without violating noise or spurious requirements. To handle the frequency drift normally associated with open-loop implementations, a low-leakage charge-pump is proposed. The synthesizer is implemented using a 0.18μm CMOS process. Total power consumption is 9 mW and the circuit area including the VCO inductors and on-chip loopfilter is 0.32mm2. Measured leakage current is less than 2 fA. A small area amplitude detector circuit is proposed. The wide-band operation and small input capacitance make the circuit suitable for embedding in an RF system on-chip, allowing measurement of on-chip signal levels and automatic calibration. Finally an oscillator topology reducing the phase noise in voltage controlled oscillators is suggested. By using on-chip decoupling and an amplitude control circuit to adjust oscillator bias, the impact of current source noise is eliminated. The theoretical phase noise is reduced 3.9 dB compared to a conventional LC oscillator using the same bias current.
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| 9. |
- Lennqvist-Lindén, Ann-Sofie
(författare)
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Att lägga politiken tillrätta : kommunala chefers professionalisering
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The desire for many people today is to be professional, and many occupations seek professional status. The idea of a profession has a higher status than a mere occupation; professionals have lot of knowledge and power to decide about their own work and they can also voice opinions about others. Occupations are driven towards attaining professional status. This process is not driven by single individuals aiming to exercise power in relation to other individuals. It is a collective, national process by an occupation. The overall aim of this dissertation is to examine, describe and analyze the process of professionalization of local public managers. There are four researchtopics: a) What are the characteristics of a professional group, and do these apply to local public managers? b) How is municipal organization portrayed with regard to the roles of politicians and administrators? c) How do politicians,managers, and public servants view themselves and each other in a normative and descriptive way? d) In what ways are managers trying to increase their influence to reach a position from which it is possible to choose to follow, or notfollow, a political decision? The methods used in this research are several; a deep case study in which surveys, observations, document studies and interviews are conducted. As theoretical framework theories of power, professionalization and discourse are used to analyze the empirical material from the case study.The results show top managers’ ongoing quest for professional status. They exclude other groups in order to handle their work without interference from others – discretion, the driving force behind professionalization. Usurpation is a strategy to get into the area of the politicians. Politicians are talked of as children in need for raise and a municipality is perceived as a private business enterprise. In this discourse values such as effectiveness, customer satisfaction, competition and value-for-money are important. The municipality is heavily inspired by thei deas of New Public Management. This development is quite problematic withregard to democracy. The democratic values such as public ethics, political democracyand the rule of law – the public ethos - are not spoken of. My hope is that this dissertation can prompt managers to reflect, since I have tried to see their work from a different perspective than what they most probably use.
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| 10. |
- Lyth, Johan, 1980-
(författare)
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Clinical-epidemiological studies on cutaneous malignant melanoma : A register approach
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The incidence of cutaneous malignant melanoma (CMM) is steadily increasing. Most of the patients have thin CMM with a good prognosis and a 5-year survival of about 90%. The prognosis is highly related to tumour thickness and clinical stage at diagnosis. Effective systemic treatment for patients with metastatic disease has only recently been available. This thesis aims to increase knowledge of trends in tumour thickness, prognostic factors, socioeconomic differences and medical costs in patients with CMM.The population-based Swedish melanoma register is the main source of data in all papers in the thesis. Papers I-III include patients from all of Sweden while paper IV is delimited to the County of Östergötland. Cox regression and logistic regression are the main multivariable methods used. Paper IV is focused on stage-specific costs of CMM by comparing direct healthcare costs to a general population.For men, there has been a shift over time towards thinner tumours at diagnosis accompanied by an improved survival. Women are still diagnosed with considerably thinner tumours and they experience a better survival than men. Tumour ulceration, tumour thickness and Clark’s level of invasion all showed significant independent long-term prognostic information in T1 CMMs. By combining these factors, three distinct prognostic subgroups were identified. Lower level of education was associated with reduced CMM-specific survival, which may at least partially be attributed to a more advanced stage at diagnosis. The direct healthcare costs for CMM patients were significantly higher than for the general population, independent of clinical stage. CMM patients diagnosed in clinical stage III-IV were associated with particularly high costs.Even though the survival among Swedish patients with CMM is among the highest in the world and still seems to improve, the results of this thesis emphasise the need of improved early detection strategies. This may be of particular concern in men, older women, and groups with a low level of education. The results also imply that the costs for the management of CMM patients may be reduced if early detection efforts are successful and lead to a more favourable stage distribution. The finding of a better risk stratification of thin CMMs may help to improve the management of this large patient group.
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