46 resultados para Exelon Braidwood Nuclear Facility (Will County, Ill.)

em Helda - Digital Repository of University of Helsinki


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Failures in industrial organizations dealing with hazardous technologies can have widespread consequences for the safety of the workers and the general population. Psychology can have a major role in contributing to the safe and reliable operation of these technologies. Most current models of safety management in complex sociotechnical systems such as nuclear power plant maintenance are either non-contextual or based on an overly-rational image of an organization. Thus, they fail to grasp either the actual requirements of the work or the socially-constructed nature of the work in question. The general aim of the present study is to develop and test a methodology for contextual assessment of organizational culture in complex sociotechnical systems. This is done by demonstrating the findings that the application of the emerging methodology produces in the domain of maintenance of a nuclear power plant (NPP). The concepts of organizational culture and organizational core task (OCT) are operationalized and tested in the case studies. We argue that when the complexity of the work, technology and social environment is increased, the significance of the most implicit features of organizational culture as a means of coordinating the work and achieving safety and effectiveness of the activities also increases. For this reason a cultural perspective could provide additional insight into the problem of safety management. The present study aims to determine; (1) the elements of the organizational culture in complex sociotechnical systems; (2) the demands the maintenance task sets for the organizational culture; (3) how the current organizational culture at the case organizations supports the perception and fulfilment of the demands of the maintenance work; (4) the similarities and differences between the maintenance cultures at the case organizations, and (5) the necessary assessment of the organizational culture in complex sociotechnical systems. Three in-depth case studies were carried out at the maintenance units of three Nordic NPPs. The case studies employed an iterative and multimethod research strategy. The following methods were used: interviews, CULTURE-survey, seminars, document analysis and group work. Both cultural analysis and task modelling were carried out. The results indicate that organizational culture in complex sociotechnical systems can be characterised according to three qualitatively different elements: structure, internal integration and conceptions. All three of these elements of culture as well as their interrelations have to be considered in organizational assessments or important aspects of the organizational dynamics will be overlooked. On the basis of OCT modelling, the maintenance core task was defined as balancing between three critical demands: anticipating the condition of the plant and conducting preventive maintenance accordingly, reacting to unexpected technical faults and monitoring and reflecting on the effects of maintenance actions and the condition of the plant. The results indicate that safety was highly valued at all three plants, and in that sense they all had strong safety cultures. In other respects the cultural features were quite different, and thus the culturally-accepted means of maintaining high safety also differed. The handicraft nature of maintenance work was emphasised as a source of identity at the NPPs. Overall, the importance of safety was taken for granted, but the cultural norms concerning the appropriate means to guarantee it were little reflected. A sense of control, personal responsibility and organizational changes emerged as challenging issues at all the plants. The study shows that in complex sociotechnical systems it is both necessary and possible to analyse the safety and effectiveness of the organizational culture. Safety in complex sociotechnical systems cannot be understood or managed without understanding the demands of the organizational core task and managing the dynamics between the three elements of the organizational culture.

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Is the early childhood day care facility possible? The research considering communal development of the early education. In Finland mothers and fathers look after 400 000 pre-school children. Half of these attend day care facilities, in which 50 000 staff are employed. The aim of this research is to develop co-operation practices within the day care centre. This research refines and expands my own interest in and knowledge of day care management and content development. The basis of the research draws upon ethnographic material covering the period 1999–2005. The day care centre chosen as a central informant was the first suburban centre founded in 1963, and it provided a rich local and welfare state research perspective. It became clear that the day care facility’s co-operation practices formed the basis of bringing up children and at the same time produced a new multi-operational and multi-layered community for child participation. Adult day care centre workers bringing up the children as a professional work and solutions defining the conditions for the work are expressed in a child’s upbringing. This obviously has an impact in where as the development of communities. From the human and community scientific point of view, the group of youngest children will take up a future position as key players in communities as essential actors and reformers. The research was carried out as multiphase and multiscientific practical research and iterative data formation. The results verified that the co-operation between parents and day care staff produces important benefits for all the stakeholders. However, the day care staff has difficulties in implementing the benefits. During the research process, it became clear that conceptually day care staff saw the practices as ”very important, but not easily realised in practice”. As a result this demanded further research to address this issue and to extend this to the carefacility’s co-operation practises and their communal and social conditions. The research looks at the carefacility’s co-operation with key stakeholders. At the same time it undertakes an analytical and historical examination of carefacilitys’s with an experimental focus as two day care centres chosen as experimental objects. The results of the research showed that the benefits gained by children were determined by the day care centre’s socio-political structure and the parent’s resources. The research framework categorised early childhood education as generational and gender based structures. As part of the research, the strains endemic to these formations have been examined. The system for bringing up children was created as part of a so called welfare state project by implemented by the Day Care Act in year 1973. The law secured the subjective right for every pre-school child to have access to day care facilities. The law also introduced a labour and sosiopolitical phase and the refinement of the day care facility’s education-care concept. The latest phase that started during the early 1990´s was called the market-based social services strategy. As a result of this phase, state support was limited and the screening function of the law was relaxed. This new strategy resulted in a divisive and bureaucratic social welfare system, that individualised and segregated children and their parents, leaving some families outside the communal and welfare state benefit net. The modern day care centre is a hybrid of different aims. Children spend longer and more irregular time in day care. The families are multicultural and that requires more training for the staff. The work in day care has been enhanced, for example he level of education for the staff has been lowered and productivity has been improved. However, administrative work and different kinds of support and net work functions together with the continuous change have taken over from the work done face to face with children. Staff experiences more pressure as the management and the work load has increased. Consequently the long-term planning and daily implementation of the nuclear task of the day care facility is difficult to control. This will have an effect on both motivation and manageability of the work. Overall quality of the early childhood upbringing has been weakened. The possibilities for the near future were tested in the two day care centres chosen as an experi-ment objects. The analysis of these experiments showed that generative interaction work will benefit everyone: children, parents and employees. The main results of the research are new concepts of an early support day care centre, which can be empirically and theoretically possi-ble for development the near future. Key words: Day care facility’s co-operation practises, early childhood education as generational structure, child’s multi-operational and multi-layered community, multi-subjective operator, generative interaction work, communal composition.

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A new rock mass classification scheme, the Host Rock Classification system (HRC-system) has been developed for evaluating the suitability of volumes of rock mass for the disposal of high-level nuclear waste in Precambrian crystalline bedrock. To support the development of the system, the requirements of host rock to be used for disposal have been studied in detail and the significance of the various rock mass properties have been examined. The HRC-system considers both the long-term safety of the repository and the constructability in the rock mass. The system is specific to the KBS-3V disposal concept and can be used only at sites that have been evaluated to be suitable at the site scale. By using the HRC-system, it is possible to identify potentially suitable volumes within the site at several different scales (repository, tunnel and canister scales). The selection of the classification parameters to be included in the HRC-system is based on an extensive study on the rock mass properties and their various influences on the long-term safety, the constructability and the layout and location of the repository. The parameters proposed for the classification at the repository scale include fracture zones, strength/stress ratio, hydraulic conductivity and the Groundwater Chemistry Index. The parameters proposed for the classification at the tunnel scale include hydraulic conductivity, Q´ and fracture zones and the parameters proposed for the classification at the canister scale include hydraulic conductivity, Q´, fracture zones, fracture width (aperture + filling) and fracture trace length. The parameter values will be used to determine the suitability classes for the volumes of rock to be classified. The HRC-system includes four suitability classes at the repository and tunnel scales and three suitability classes at the canister scale and the classification process is linked to several important decisions regarding the location and acceptability of many components of the repository at all three scales. The HRC-system is, thereby, one possible design tool that aids in locating the different repository components into volumes of host rock that are more suitable than others and that are considered to fulfil the fundamental requirements set for the repository host rock. The generic HRC-system, which is the main result of this work, is also adjusted to the site-specific properties of the Olkiluoto site in Finland and the classification procedure is demonstrated by a test classification using data from Olkiluoto. Keywords: host rock, classification, HRC-system, nuclear waste disposal, long-term safety, constructability, KBS-3V, crystalline bedrock, Olkiluoto

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This dissertation reports on research on the contradictions between “right-aged” motherhood accordant with normative life-course and the motherhood of a woman who lives her life according to her own choices and options. The focus of this study is to analyse and interpret the motherhood of women who have become mothers for the first time both at a very young age (under 20) and at an older age (in their 40s), from the viewpoint of life-course, age and social class. The study discusses motherhood both as an experience and as a socially-constructed phenomenon. Research questions are the following: How do mothers at different ages talk about pregnancy and motherhood as a part of their life-course? What meanings do mothers at different ages give to age, growing up and adulthood? How is social class constructed in the speech of different-aged mothers? This dissertation includes five articles and a summary chapter. The theoretical starting points for the study are Finnish critical family studies, Finnish feminist social policy studies and Anglo-American feminist motherhood studies. Additionally, this study draws on sociological age studies and new sociological social class studies. The methodological approach is discursive-materialistic. This approach recognises issues related to language, cultural representation and subjectivity, but it also aims to locate them in their social and historical context. The data is drawn from twenty-four interviews of different-aged mothers and articles collected from popular magazines on babies and parenting. In the interview data, different issues related to motherhood are constructed due not only to the women’s age, but also their social background. Social class becomes visible in the relationship between the interviewed women and nuclear family, expert knowledge or money and livelihood. In this study, social class and age are intertwined. It is almost impossible to analytically distinguish which of the mothers’ experiences are related to class and which are related to age. In this study, young motherhood is shown as quite positive. Even though the interviewed young women did not usually plan to have a child, it was not a great shock either. In the young mothers’ speech, motherhood appears as a natural part of the life-course and growing up. The conditions young mothers suggested as necessary to good motherhood do not depend on standard of living, education or social background. A young age is seen as a resource, not as an obstacle to good motherhood. Postponing one’s motherhood is associated with materialism and a career-oriented lifestyle. The older mothers in this study rarely reported having postponed their motherhood on purpose. Some of them explained the delay with extended studies or financial insecurity caused by part-time unemployment. Others recounted they had been insecure about their abilities to cope with a child or lacked a suitable partner. Some of them may have wanted a child much earlier in life, given the right circumstances. In the older mothers’ speech, motherhood is strongly associated with adult life, permanent employment and a (heterosexual) nuclear family.

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This thesis studies the experiences of women who have lived in a youth home as girls. There are two main themes: 1) experiences of living in a youth home, and 2) experiences of coping as an adult. Data on the first theme is purely subjective; it derives from personal, recalled experiences. Data on the second theme is partly based on experiences and partly on facts about the current life situation of the research participants. A third theme of the thesis is concerned with the question of how the research participants’ placement in a youth home influenced their later life. The thesis contributes valuable knowledge concerning the experiences of young people who have been raised in substitute care, a topic that is rare in the literature. The empirical data of the study consists of responses to an initial inquiry and subsequent interviews. The inquiry was sent to 116 former inhabitants of a youth home. 62 altogether returned the inquiry, and 34 participated in the interview. The purpose of the inquiry was to produce an overview of the life situations of the research participants and to invite them to participate in the interview. In addition, the inquiry sought to produce an overview of how the participants enjoyed living in a youth home and how they saw its significance in terms of their later lives. The interviews concentrated on the research participants’ experiences concerning the processes of getting into a youth home, living there, and coping independently in life afterwards. The most central result relating to the first main theme was that the experiences were both shared and non-shared. Living in a youth home was characterized by six general sentiments: “wonderful, real home”, “new world!”, “safe haven”, “place to live”, “penal institution”, and “nightmare”. These sentiments seemed to be related first and foremost to whether one’s own, individual needs and expectations had been met in the youth home. The strongest and most common needs, as experienced, were the needs for safety, belongingness and respect. On the basis of the experiences, meeting these needs can be considered as the most important task of a youth home. The results relating to the second main theme of the study were examined in two different ways. Comparisons with the general female population (education, situation in working life and financial circumstances) showed that research participants had coped less well. Differences were also found to exist in family structures: nuclear families and single mother families were more unusual among research participants, and stepfamilies more common, than in the general population. More of the participants’ children than of the general population’s lived with somebody other than their parent. However, the experience of coping well was common among research participants, although the beginning of independent living had been generally experienced as difficult: feelings of loneliness, insecurity and restlessness were dominant. Later, a sense of life control developed and strengthened through joining with others (family, work, friends), through accepting one’s own life history and through creating one’s own model of living. As the most significant explanation of their coping, the research participants identified their own (innate) strength and will to cope. The majority of the research participants felt that the youth home had a positive influence on their later lives. Positive influences can be grouped in three “levels”: I) getting out of the home, II) having good experiences and learning useful things, and III) the essential effect on one’s own way of thinking and living. The second level’s influence includes strengthened self-esteem, increased social understanding and new knowledge and skills. Some research participants did not think the youth home had any significance in terms of their later lives, and some thought it had negative significance.

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"I want there now!" Images of the future in the drawings of Ghanaian, British, Finnish and Tanzanian children The aim of the Thesis is to examine what kind of images children aged between 8 and 12 years in Ghana, Great Britain, Finland and Tanzania hold of their future. The study is a qualitative analysis based on data that consists of 214 drawings, digitally photographed and analysed using AtlasTI computer program. The data was coded and divided into " families " whose frequencies were compared in order to maintain results. The assignment was given to the children in the language used in the school and it was similar in each country. The children were introduced to the idea with a set of stimulating questions and after that they were asked to draw and colour with a pen a picture of 1) him/herself as an adult, 2) his/her future home and 3) the people and the animals they think they will be living with. The children were also asked to write down the country and the place they believe to live in their future. They were also encouraged to write down e.g. their dream profession, what they would like to have as hobbies in their adulthood and other important things in their lives. The analysis focuses on the content of the drawings instead of artistic or psychological interpretations. The differences between the drawings from different countries as well as the differences in a single country were significant. The current trends and the experiences children had lived through were present in the drawings. There were no differences in the colour of the skin and the most popular professions were doctor, police and football player. The football was very strongly present in all of the data; almost fourth of the children had either drawn or mentioned football as their future profession or hobby. Different flora was present in 84% of Tanzanian and 70% of Ghanaian drawings compared to the 23% of British and 17% of Finnish drawings. Of all the family forms a dream of the traditional nuclear family could be found among 29% of the drawings. Compared to that a total of 30% wanted either a child of their own without a spouse (15%) or a spouse without a child (15%). Also grandparents, childhood friends, other adults, animals or even space aliens were present and sharing a home with the children in the drawings. Of all children 15% wanted to live totally alone in the future. This was most typical (38%) among the Finnish boys. The cat and the dog were the most popular animals to appear in the drawings. Moving abroad proved to be purely a western phenomenon, dreamed by 57% of the British and 18% of the Finnish children. As results, a negative self-image, violence, lack of expressions of positive feelings and solitude among the Finnish boys in the data were very concerning. Keywords: Images of the future, future studies, future-education, picture analysis

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The nuclear receptor (NR) superfamily is comprised of receptors for small lipopfilic ligands such as steroid hormones, thyroid hormone, retinoids, and vitamin D. NRs are ligand-inducible transcription factors capable of both activating and repressing their target gene expression. They control a wide range of biological functions connected to growth, development, and homeostasis. In addition to the ligand-regulated receptors, the family includes a large group of receptors whose physiological ligands are unknown. These receptors are referred to as orphan NRs. Estrogen-related receptor gamma (ERRgamma) belongs to the ERR subfamily of orphan NRs together with the related ERRalpha and ERRbeta. ERRs share amino acid sequence homology with the classical estrogen receptors (ERs) but they are unable to bind natural estrogenic ligands. ERRgamma is expressed in several embryonic and adult tissues but its biological role is still largely unknown. ERRgamma activates reporter gene expression in transfected cells independently of added hormones implying that ERRgamma harbors constitutive activity. However, the intrinsic activity of ERRgamma can be inhibited by synthetic compounds such as the selective estrogen receptor modulator 4-hydroxytamoxifen (4-OHT). Ligands of NRs can act as agonists that activate transcription, as antagonists that prevent activation of transcription, or as inverse agonists that antagonize the constitutive transcriptional activity of receptor. Most of the synthetic ERRgamma ligands act as inverse agonists but recently, a synthetic ERRgamma agonist GSK4716 was identified. This demonstrates that it is possible to design and identify agonists for ERRgamma. Prior to this thesis work, the structural and functional characteristics of ERRgamma were largely unknown. The aim of this study was to define the functional requirements for ERRgamma-mediated transcriptional regulation and to examine the cross-talk between ERRgamma and other NRs. Due to the fact that natural physiological ligands of ERRgamma are unknown, another aim of this study was to seek new natural compounds that may affect transcriptional activity of ERRgamma. Plant-derived phytoestrogens have previously been shown to act as ligands for ERs and ERRalpha, and therefore the effects of these compounds were also studied on ERRgamma-mediated transcriptional regulation. This work demonstrated that ERRgamma-mediated transcriptional regulation was dependent on DNA-binding, dimerization and activation function-2. Heterodimerization with ERRalpha inhibited the transcriptional activity of ERRgamma. In addition to 4-OHT, another anti-estrogen, 4-hydroxytoremifene (4-OHtor), was identified as an inverse agonist of ERRgamma. Interestingly, ERRgamma activated transcription in the presence of 4-OHT and 4-OHtor on activator protein-1 binding sites. ERRgamma was found to interact with another orphan NR Nurr1 by repressing the ability of Nurr1 to activate transcription of the osteopontin gene. Transcriptional activity of ERRgamma was shown to be stimulated by the phytoestrogen equol. Structural model analysis and mutational experiments indicated that equol was able to bind to the ligand binding domain of ERRgamma. The growth inhibitory effect of ERRgamma on prostate cancer cells was found to be enhanced by equol. In summary, this study demonstrates that despite the absence of an endogenous physiological ligand, the activity of ERRgamma can be modulated in other ways such as dimerization with related receptors or by cross-talk with other transcription factors as well as by binding some synthetic or natural compounds.

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Nurr1, NGFI-B and Nor1 (NR4A2, NR4A1 and NR4A3, respectively) belong to the NR4A subfamily of nuclear receptors. The NR4A receptors are orphan nuclear receptors which means that activating or repressing ligands for these receptors have not been found. NR4A expression is rapidly induced in response to various stimuli including growth factors and the parathyroid hormone (PTH). The studies concerning the NR4A receptors in the central nervous system have demonstrated that they have a major role in the development and function of the dopaminergic neurons of the midbrain and in regulating hypothalamus-pituitary-adrenal-axis. However, the peripheral functions of the NR4A family are largely unknown. Cultured mouse primary osteoblasts, a preosteoblastic cell line and several osteoblastic cell lines were used to investigate the role of NR4A receptors in osteoblasts. NR4A receptors were shown to directly bind to and activate the promoter of the osteopontin gene (OPN) in osteoblastic cells, thus regulating its expression. OPN is a major bone matrix protein expressed throughout the differentiation of preosteoblastic cells into osteoblasts. The activation of the OPN promoter was shown to be dependent on the activation function-1 located in the N-terminal part of Nurr1 and to occur in both monomeric and RXR heterodimeric forms of NR4A receptors. Furthermore, PTH was shown to upregulate OPN expression through the NR4A family. It was also demonstrated that the fibroblast growth factor-8b (FGF-8b) induces the expression of NR4A receptors in osteoblasts as immediate early genes. This induction involved phosphatidylinositol-3 kinase, protein kinase C, and mitogen activated protein kinase, which are all major pathways of FGF signalling. Nurr1 and NGFI-B were shown to induce the proliferation of preosteoblastic cells and to reduce their apoptosis. FGF-8b was shown to stimulate the proliferation of osteoblastic cells through the NR4A receptors. These results suggest that NR4A receptors have a role both in the differentiation of osteoblasts and in the proliferation and apoptosis of preosteoblast. The NR4A receptors were found to bind to the same response element on OPN as the members of the NR3B family of orphan receptors do. Mutual repression was observed between the NR4A receptors and the NR3B receptors. This repression was shown to be dependent on the DNA-binding domains of both receptor families, but to result neither from the competition of DNA binding nor from the competition for coactivators. As the repression was dependent on the relative expression levels of the NR4As and NR3Bs, it seems likely that the ratio of the receptors mediates their activity on their response elements. Rapid induction of the NR4As in response to various stimuli and differential expression of the NR3Bs can effectively control the gene activation by the NR4A receptors. NR4A receptors can bind DNA as monomers, and Nurr1 and NGFI-B can form permissive heterodimers with the retinoid X receptor (RXR). Permissive heterodimers can be activated with RXR agonists, unlike non-permissive heterodimers, which are formed by RXR and retinoic acid receptor or thyroid hormone receptor (RAR and TR, respectively). Non-permissive heterodimers can only be activated by the agonists of the heterodimerizing partner. The mechanisms behind differential response to RXR agonists have remained unresolved. As there are no activating or repressing ligands for the NR4A receptors, it would be important to find out, how they are regulated. Permissiviness of Nurr1/RXR heterodimers was linked to the N-terminal part of Nurr1 ligand-binding domain. This region has previously been shown to mediate the interaction between NRs and corepressors. Non-permissive RAR and TR, permissive Nurr1 and NGFI-B, and RXR were overexpressed with corepressors silencing mediator for retinoic acid and thyroid hormone receptors (SMRT), and with nuclear receptor corepressor in several cell lines. Nurr1 and NGFI-B were found to be repressed by SMRT. The interaction of RXR heterodimers with corepressors was weak in permissive heterodimers and much stronger in non-permissive heterodimers. Non-permissive heterodimers also released corepressors only in response to the agonist of the heterodimeric partner of RXR. In the permissive Nurr1/RXR heterodimer, however, SMRT was released following the treatment with RXR agonists. Corepressor release in response to ligands was found to differentiate permissive heterodimers from non-permissive ones. Corepressors were thus connected to the regulation of NR4A functions. In summary, the studies presented here linked the NR4A family of orphan nuclear receptors to the regulation of osteoblasts. Nurr1 and NGFI-B were found to control the proliferation and apoptosis of preosteoblasts. The studies also demonstrated that cross-talk with the NR3B receptors controls the activity of these orphan receptors. The results clarified the mechanism of permissiviness of RXR-heterodimers. New information was obtained on the regulation and functions of NR4A receptors, for which the ligands are unknown.

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Candida yeast species are widespread opportunistic microbes, which are usually innocent opportunists unless the systemic or local defense system of the host becomes compromised. When they adhere on a fertile substrate such as moist and warm, protein-rich human mucosal membrane or biomaterial surface, they become activated and start to grow pseudo and real hyphae. Their growth is intricately guided by their ability to detect surface defects (providing secure hiding , thigmotropism) and nutrients (source of energy, chemotropism). The hypothesis of this work was that body mobilizes both non-specific and specific host defense against invading candidal cells and that these interactions involve resident epithelial cells, rapidly responding non-specific protector neutrophils and mast cells as well as the antigen presenting and responding den-dritic cell lymphocyte plasma cell system. It is supposed that Candida albicans, as a result of dar-winistic pressure, has developed or is utilizing strategies to evade these host defense reactions by e.g. adhering to biomaterial surfaces and biofilms. The aim of the study was to assess the host defense by taking such key molecules of the anti-candidal defense into focus, which are also more or less characteristic for the main cellular players in candida-host cell interactions. As a model for candidal-host interaction, sections of chronic hyperplastic candidosis were used and compared with sections of non-infected leukoplakia and healthy tissue. In this thesis work, neutrophil-derived anti-candidal α-defensin was found in the epithelium, not only diffusely all over in the epithelium, but as a strong α-defensin-rich superficial front probably able to slow down or prevent penetration of candida into the epithelium. Neutrophil represents the main host defence cell in the epithelium, to which it can rapidly transmigrate from the circulation and where it forms organized multicellular units known as microabscesses (study I). Neutrophil chemotactic inter-leukin-8 (IL-8) and its receptor (IL-8R) were studied and were surprisingly also found in the candidal cells, probably helping the candida to keep away from IL-8- and neutrophil-rich danger zones (study IV). Both leukocytes and resident epithelial cells contained TLR2, TLR4 and TLR6 receptors able to recognize candidal structures via utilization of receptors similar to the Toll of the banana fly. It seems that candida can avoid host defence via stimulation of the candida permissive TLR2 instead of the can-dida injurious TLR4 (study V). TLR also provides the danger signal to the immune system without which it will not be activated to specifically respond against candidal antigens. Indeed, diseased sites contained receptor activator of nuclear factor kappa B ligand (RANKL; II study), which is important for the antigen capturing, processing and presenting dendritic cells and for the T lymphocyte activation (study III). Chronic hyperplastic candidosis provides a disease model that is very useful to study local and sys-temic host factors, which under normal circumstances restrain C. albicans to a harmless commensal state, but failure of which in e.g. HIV infection, cancer and aging may lead to chronic infection.

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Tutkimuksen aiheita olivat yhteiskuntaluokkien väliset erot sairastavuudessa ja alentuneessa toimintakyvyssä, sekä fyysisen työkuormituksen ja joidenkin muiden työolojen vaikutus sairastavuuteen. Empiirisestä työstä on raportoitu myös neljässä kansainvälisissä tieteellisissä aikakauskirjoissa julkaistussa artikkelissa. Tässä julkaistu yhteenveto sisältää tulosten yhteenvedon lisäksi myös tutkimusta koskevien käsitteellisten ja teoreettisten kysymysten sekä tutkimustradition kriittisen katsauksen. Työn päätavoitteita olivat 1) tutkia fyysisesti kuormittavan työn, ja jossain määrin muiden työolojen osuutta yhteiskuntaluokkien välisiin eroihin sairaudessa ja toimintakyvyn alentuneisuudessa; 2) tutkia työn fyysisen kuormittavuuden, työhön liittyvien vaikutusmahdollisuuksien ja hallinnan (decision latitude), luokka-aseman, iän ja sukupuolen yhteisvaikutuksia heikentyneeseen terveydentilaan; sekä 3) tutkia missä määrin mekaanisten työaltisteiden ja tuki- ja liikuntaelinsairastavuuden välinen yhteys voi selittää yhteiskuntaluokkien välisiä eroja heikentyneessä yleisessä terveydentilassa. Tutkittavat olivat keski-ikäisiä Helsingin kaupungin työntekijöitä. Analyysit perustuivat poikittaisasetelmaan, ja käytetty aineisto oli Helsinki Health Studyn vuosien 2000 ja 2002 välill kerättyä aineistoa. Analyyseihin käytetyssä aineistossa oli 3740:stä 8002:een tutkittavaa. Tulosten perusteella fyysisill (sekä fysikaalisilla) työoloilla on merkittävä vaikutus yhteiskuntaluokkien välisiin eroihin yleisessä sairastavuudessa, toimintakyvyn heikentymisessä, tuki- ja liikuntaelinsairastavuudessa sekä itsearvioidussa terveydentilassa. Naisilla lähes puolet heikentyneen toimintakyvyn ja koetun terveydentilan luokkaeroista vaikutti olevan selitettävissä fyysisellä työkuormituksella. Hallintamahdollisuuksien ei havaittu merkittävästi muuttavan fyysisen kuormituksen vaikutusta toimintakykyyn. Fyysisen kuormittavuuden terveysvaikutus voimistui kasvavan iän mukaan enemmän naisilla kuin miehill. Osa, mutta ei koko fyysisen kuormituksen vaikutus yhteiskuntaluokkien eroihin heikentyneessä terveydessä vaikutti välittyvän tuki- ja liikuntaelinsairastavuuden kautta. Terveys ja sairaus eivät ole yhtenäisiä tiloja, ja siksi monet eri sosiaalisesti ja rakenteellisesti määräytyvät olosuhteet todennäköisesti vaikuttavat yhteiskunnallisten terveyserojen syntymiseen. Fyysis-materiaalisten olojen vaikutusta terveyserojen syntyyn nyky-yhteiskunnassa on mahdollisesti aliarvioitu. Yhteiskuntaluokkien väliset erot fyysis-materiaalisissa olosuhteissa eivät ole kadonneet, ja nämä erot todennäköisesti vaikuttavat terveyserojen syntyyn.

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In line with major demographic changes in other Northern European and North American countries and Australia, being nonmarried is becoming increasingly common in Finland, and the proportion of cohabiters and of persons living alone has grown in recent decades. Official marital status no longer reflects an individual s living arrangement, as single, divorced and widowed persons may live alone, with a partner, with children, with parents, with siblings, or with unrelated persons. Thus, more than official marital status, living arrangements may be a stronger discriminator of one s social bonds and health. The general purpose of this study was to deepen our current understanding of the magnitude, trends, and determinants of ill health by living arrangements in the Finnish working-age population. Distinct measures of different dimensions of poor health, as well as an array of associated factors, provided a comprehensive picture of health differences by living arrangements and helped to assess the role of other factors in the interpretation of these differences . Mortality analyses were based on Finnish census records at the end of 1995 linked with cause-of-death registers for 1996 2000. The data included all persons aged 30 and over. Morbidity analyses were based on two comparable cross-sectional studies conducted twenty years apart (the Mini-Finland Survey in 1978 80 and the Health 2000 Survey in 2000 01). Both surveys were based on nationally representative samples of Finns aged 30 and over, and benefited from high participation rates. With the exception of mortality analyses, this study focused on health differences among the working-age population (mortality in age groups 30-64 and 65 and over, self-rated health and mental health in the age group 30-64, and unhealthy alcohol use in the age group 30-54). Compared with all nonmarried groups, married men and women exhibited the best health in terms of mortality, self-rated health, mental health and unhealthy alcohol use. Cohabiters did not differ from married persons in terms of self-rated health or mental health, but did exhibit excess unhealthy alcohol use and high mortality, particularly from alcohol-related causes. Compared with the married, persons living alone or with someone other than a partner exhibited elevated mortality as well as excess poor mental health and unhealthy alcohol use. By all measures of health, men and women living alone tended to be in the worst position. Over the past twenty years, SRH had improved least among single men and women and widowed women, and most among cohabiting women. The association between living arrangements and health has many possible explanations. The health-related selection theory suggests that healthy people are more likely to enter and maintain a marriage or a consensual union than those who are unhealthy (direct selection) or that a variety of health-damaging behavioural and social factors increase the likelihood of ill health and the probability of remaining without a partner or becoming separated from one s partner (indirect selection). According to the social causation theory, marriage or cohabitation has a health-promoting effect, whereas living alone or with others than a partner has a detrimental effect on health. In this study, the role of other factors that are mainly assumed to reflect selection, appeared to be rather modest. Social support, which reflects social causation, contributed only modestly to differences in unhealthy alcohol use by living arrangements, but had a larger effect on differences in poor mental health. Socioeconomic factors and health-related behaviour, which reflect both selection and causation, appeared to play a more important role in the excess poor health of cohabiters and of persons living alone or with someone other than a partner, than of married persons. Living arrangements were strongly connected to various dimensions of ill health. In particular, alcohol consumption appeared to be of great importance in the association between living arrangements and health. To the extent that the proportion of nonmarried persons continues to grow and their health does not improve at the same rate as that of married persons, the challenges that currently nonmarried persons pose to public health will likely increase.

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Neurofibromatosis 2 (NF2) is a dominantly inherited disorder, which predisposes to multiple tumours of the nervous system, typically schwannomas and meningiomas. Biallelic inactivation of the NF2 gene occurs both in sporadic and NF2-related schwannomas and in most meningiomas. The NF2 gene product merlin (or schwannomin) is structurally related to the ERM proteins, ezrin, radixin and moesin, which act as molecular linkers between the actin cytoskeleton and the plasma membrane. Merlin is a tumor suppressor that participates in cell cycle regulation. Merlin s phosphorylation status appears to be associated with its tumour suppressor activity, i.e. non-phosphorylated merlin functions as a tumour suppressor, whereas protein phosphorylation results in loss of functional activity. This thesis study was initiated to investigate merlin s role as a tumor suppressor and growth inhibitor. These studies show, that like many other tumor suppressors, also merlin is targeted to the nucleus at some stages of the cell cycle. Merlin s nuclear localization is regulated by cell cycle phase, contact inhibition and adhesion. In addition, a potential nuclear binding partner for merlin was identified, Human Enhancer of Invasion 10 (HEI10), a cyclin B interacting protein. Many tumor suppressors interact with microtubules and this thesis work shows that also merlin colocalizes with microtubules in mitotic structures. Merlin binds microtubules directly, and increases their polymerization in vitro and in vivo. In addition, primary mouse Schwann cells lacking merlin displays disturbed microtubule cytoskeleton. Fourth part of this thesis work began from the notion that PKA phosphorylates an unidentified site from the merlin N-terminus. Our studies show that serine 10 is a target for PKA and modulation of this residue regulates cytoskeletal organization, lamellipodia formation and cell migration. In summary, this thesis work shows that merlin s role is much more versatile than previously thought. It has a yet unidentified role in the nucleus and it participates in the regulation of both microtubules and the actin cytoskeleton. These studies have led to a better understanding of this enigmatic tumor suppressor, which eventually will aid in the design of specific drugs for the NF2 disease.

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Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a recently characterized cancer syndrome which predisposes to cutaneous and uterine leiomyomas as well as renal cell carcinoma (RCC). Uterine leiomyosarcoma (ULMS) has also been observed in certain Finnish HLRCC families. The predisposing gene for this syndrome, fumarate hydratase (FH), was identified in 2002. The well-known function of FH is in the tricarboxylic acid cycle (TCAC) in the energy metabolism of cells. As FH is a novel cancer gene, the role of FH mutations in tumours is in general unknown. Similarly, the mechanisms through which defective FH is associated with tumourigenesis are unclear. The loss of a wild type allele has been observed in virtually all HLRCC patients tumours and the FH enzyme activities are either totally lost or remarkably reduced in the tissues of mutation carrier patients. Therefore, FH is assumed to function as a tumour suppressor. Mutations in genes encoding subunits of other TCAC enzyme SDH have also been reported recently in tumours: mutations in SDHB, SDHC, and SDHD genes predispose to paraganglioma and pheochromocytoma. In the present study, mutations in the SDHB gene were observed to predispose to RCC. This was the first time that mutations in SDHB have been detected in extra-paraganglial tumours. Two different SDHB mutations were observed in two unrelated families. In the first family, the index patient was diagnosed with RCC at the age of 24 years. Additionally, his mother with a paraganglioma (PGL) of the heart and his maternal uncle with lung cancer were both carriers of the mutation. The RCC of the index patient and the PGL of his mother showed LOH. In the other family, an SDHB mutation was detected in two siblings who were both diagnosed with RCC at the ages of 24 and 26 years. Both of the siblings also suffered PGL. All these tumours showed LOH. Therefore, we concluded that mutations in SDHB predispose also for RCC in certain families. Several tumour types were analysed for FH mutations to define the role of FH mutations in these tumour types. In addition, patients with a putative cancer phenotype were analysed to identify new HLRCC families. Three FH variants were detected, of which two were novel. One of the variants was observed in a patient diagnosed with ULMS at the age of 41 years. However, LOH was not detected in the tumour tissue. The FH enzyme activity of the mutated protein was clearly reduced, being 43% of the activity of the normal protein. Together with the results from an earlier study we calculated that the prevalence of FH mutations in Finnish non-syndromic ULMS is around 2.4%. Therefore, FH mutations seem to have a minor role in the pathogenesis on non-syndromic ULMS. Two other germline variants were detected in a novel tumour type, ovarian mucinous cystadenoma. However, tumour tissues of the patients were not available for LOH studies and therefore LOH status remained unclear. Therefore, it is possible that FH mutations predispose also for ovarian tumours but further studies are needed to verify this result. A novel variant form of the FH gene (FHv) was identified and characterized in more detail. FHv contains an alternative first exon (1b), which appeared to function as 5 UTR sequence. The translation of FHv is initiated in vitro from exons two and three. The localization of FHv is both cytosolic and nuclear, in contrast to the localization of FH in mitochondria. FHv is expressed at low levels in all human tissues. Interestingly, the expression was induced after heat shock treatment and in chronic hypoxia. Therefore, FHv might have a role e.g. in the adaptation to unfavourable growth conditions. However, this remains to be elucidated.

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Germline mutations in fumarate hydratase (FH) cause hereditary leiomyomatosis and renal cell cancer (HLRCC). FH is a nuclear encoded enzyme which functions in the Krebs tricarboxylic acid cycle, and homozygous mutation in FH lead to severe developmental defects. Both uterine and cutaneous leiomyomas are components of the HLRCC phenotype. Most of these tumours show loss of the wild-type allele and, also, the mutations reduce FH enzyme activity, which indicate that FH is a tumour suppressor gene. The renal cell cancers associated with HLRCC are of rare papillary type 2 histology. Other genes involved in the Krebs cycle, which are also implicated in neoplasia are 3 of the 4 subunits encoding succinate dehydrogenase (SDH); mutations in SHDB, SDHC, and SDHD predispose to paraganglioma and phaeochromocytoma. Although uterine leiomyomas (or fibroids) are very common, the estimations of affected women ranging from 25% to 77%, not much is known about their genetic background. Cytogenetic studies have revealed that rearrangements involving chromosomes 6, 7, 12 and 14 are most commonly seen in fibroids. Deletions on the long arm of chromosome 7 have been reported to be involved in about 17 to 34 % of leiomyomas and the small commonly deleted region on 7q22 suggests that there might be an underlying tumour suppressor gene in that region. The purpose of this study was to investigate the genetic mechanisms behind the development of tumours associated with HLRCC, both renal cell cancer and uterine fibroids. Firstly, a database search at the Finnish cancer registry was conducted in order to identify new families with early-onset RCC and to test if the family history was compatible with HLRCC. Secondly, sporadic uterine fibroids were tested for deletions on 7q in order to define the minimal deleted 7q-region, followed by mutation analysis of the candidate genes. Thirdly, oligonucleotide chips were utilised to study the global gene expression profiles of uterine fibroids in order to test whether 7q-deletions and FH mutations significantly affected fibroid biology. In the screen for early-onset RCC, 214 families were identified. Subsequently, the pedigrees were constructed and clinical data obtained. One of the index cases (RCC at the age of 28) had a mother who had been diagnosed with a heart tumour, which in further investigation turned out to be a paraganglioma. This lead to an alternative hypothesis that SDH, instead of FH, could be involved. SDHA, SDHB, SDHC and SDHD were sequenced from these individuals; a germline SDHB R27X mutation was detected with loss of the wild-type allele in both tumours. These results suggest that germline mutations in the SDHB gene predispose to early-onset RCC establishing a novel form of hereditary RCC. This has immediate clinical implications in the surveillance of patients suffering from early-onset RCC and phaeochromocytoma/paraganglioma. For the studies on sporadic uterine fibroids, a set of 166 fibroids from 51 individuals were collected. The 7q LOH mapping defined a commonly deleted region of about 3.2 mega bases in 11 of the 166 tumours. The deletion was consistent with previously reported allelotyping studies of leiomyomas and it therefore suggested the presence of a tumour suppressor gene in the deleted region. Furthermore, the high-resolution aCGH-chip analysis refined the deleted region to only 2.79Mb. When combined with previous data, the commonly deleted region was only 2.3Mb. The mutation screening of the known genes within the commonly deleted region did not reveal pathogenic mutations, however. The expression microarray analysis revealed that FH-deficient fibroids, both sporadic and familial, had their distinct gene expression profile as they formed their own group in the unsupervised clustering. On the other hand, the presence or absence of 7q-deletions did not significantly alter the global gene expression pattern of fibroids, suggesting that these two groups do not have different biological backgrounds. Multiple differentially expressed genes were identified between FH wild-type and FH-mutant fibroids, and the most significant increase was seen in the expression of carbohydrate metabolism-related and hypoxia inducible factor (HIF) target genes.