993 resultados para Jo


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DOMESTIC SKILLS AS THE ART OF EVERYDAY LIFE. An inquiry about domestic skills as a way of being-in-the-world in the light of existentialist-hermeneutics phenomenology. This study focuses on analyzing domestic skills in a phenomenological manner. The description phenomenological emerges from the interpretation process, which originates from the ontological question of domestic skills. The ontological question of how domestic skills are directs one s phenomenological gaze to the experiencing of domestic skills, rather than merely viewing their action or technical aspects. Along with the ontological question, the axiological question of what the meaning of domestic skills is drives the analysis. This study is both theoretical and philosophical. Phenomenology is the guiding philosophy, theory and methodology of the inquiry. Existentialist-hermeneutics is the emphasis which most appropriately describes the phenomenological attitude adopted within the analysis. Martin Heidegger s philosophy of being and Maurice Merleau-Ponty s philosophy of the lived body essentially form the theoretical base for the inquiry. The analysis reveals domestic skills within a core of Care and the Other. Care and the Other are anchored both in Heidegger s analysis of Dasein and in Merleau-Ponty s analysis of the reversible being-in-the-world. The social nature of being and the action-oriented intentionality of the lived body are embodied in Care and the Other. This ontological base of domestic skills enables us to see the extensions that inhabit in it. These extensions are redoing, emotional experiencing, adapting and emancipating. The analysis connects ability and action, which is why domestic skills and household activity must be seen as a united whole. This united whole is not the matter of the two components of the phenomenon, but is rather the matter of domestic skills as a way of being-in-the-world. Domestic skills are a channel for the phenomenon Home Economics to manifest in our lives. This is the gaze that presents domestic skills as to be like the poetry of everyday life. The main result of the study is the elucidation of the ontology of domestic skills and the naming of its extensions. This growth of philosophical understanding makes it possible to strengthen the science of home economics.

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From Arithmetic to Algebra. Changes in the skills in comprehensive school over 20 years. In recent decades we have emphasized the understanding of calculation in mathematics teaching. Many studies have found that better understanding helps to apply skills in new conditions and that the ability to think on an abstract level increases the transfer to new contexts. In my research I take into consideration competence as a matrix where content is in a horizontal line and levels of thinking are in a vertical line. The know-how is intellectual and strategic flexibility and understanding. The resources and limitations of memory have their effects on learning in different ways in different phases. Therefore both flexible conceptual thinking and automatization must be considered in learning. The research questions that I examine are what kind of changes have occurred in mathematical skills in comprehensive school over the last 20 years and what kind of conceptual thinking is demonstrated by students in this decade. The study consists of two parts. The first part is a statistical analysis of the mathematical skills and their changes over the last 20 years in comprehensive school. In the test the pupils did not use calculators. The second part is a qualitative analysis of the conceptual thinking of pupils in comprehensive school in this decade. The study shows significant differences in algebra and in some parts of arithmetic. The largest differences were detected in the calculation skills of fractions. In the 1980s two out of three pupils were able to complete tasks with fractions, but in the 2000s only one out of three pupils were able to do the same tasks. Also remarkable is that out of the students who could complete the tasks with fractions, only one out of three pupils was on the conceptual level in his/her thinking. This means that about 10% of pupils are able to understand the algebraic expression, which has the same isomorphic structure as the arithmetical expression. This finding is important because the ability to think innovatively is created when learning the basic concepts. Keywords: arithmetic, algebra, competence

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The aim of this thesis was to study what kind of home-made menstrual pads were used in the early 20th century in Finland, how the home-made pads were made and which techniques and materials were used. The use and taking care of menstrual pads were also explored. The history of menstrual pads has been studied in Sweden, Germany and United States but none of those studies has concentrated on home-made pads. Instead, there are many studies about womanhood and menstruation. In many studies home-made menstrual pads are only briefly mentioned. Menstrual pads were not commonly used in Finland at the beginning of the 20th century, but already in the 1940s the use of menstrual pads had become common in every stratum of society. Home-made menstrual pads were used even until the 1960s. In Finland, factory-made disposable menstrual pads became common only in the 1930s and they were only slowly accepted. The study material consisted of nine interviews, three archival inquiries, health care guidebooks from 1893 to 1943 and authentic menstrual pads, menstrual belts and other objects related to them. The interviewed women were born between 1915 and 1939. The narrative approach was used in the study and it also guided the analysis. The interview and archival data were studied according to the basic rules of oral history studies. Literature consisted of publications from several disciplines. The extensive primary material played the most important role in this study. The reconstructions of the menstrual pads were made according to the interviewed women s advice. In Finland there were innumerable variations of home-made menstrual pads. The pads were most commonly crocheted and knitted either by hand or by knitting machine. Pads were also sewn of cloth, old bed linen or old underwear. The menstrual pads were self-made or made by a female relative. Word of mouth was important in spreading information on how to make pads, because there were hardly any instructions available. The biggest pads were 54 cm long and 13 cm wide. The most widely used pad model was a rectangle, which had triangle-shaped ends with a buttonhole or a loop. The pad was attached to the menstrual belt or to the buttons of the suspender belt. Knitted and crocheted pads had one, two or three layers. In sewn pads, there could be even more layers. Cellulose wadding or pieces of cloth could be placed inside the pad to increase the absorption ability. The experiences of the comfort of self-made pads varied. The crocheted and sewn pads were found chafing, knitted ones were found soft and comfortable. The menstrual pads were laborious to wash and boil in lye water. Therefore disposable pads made everyday life easier. The home-made menstrual pads were part of a unique tradition of handicrafts and folk culture. Hand-made pads were one of the most common handicraft products and were a part of every woman s life. Even so, the menstrual pads were unnoticeable. The large number of variations was probably caused by the silence around menstrual topics and by the lack of instructions for making pads. Variations are also explained by the uniqueness of every handicraft product. In Finland the home-made pads were used until relatively recent times. This was caused by the conditions of wartime and the following years and the rarity of commercial pads. Furthermore, until the late 20th century Finland was an agricultural society where all innovations spread slowly. Home-made menstrual pad was a secret handicraft of women and every woman needed to know how to make it by herself.

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Gender-specific division of crafts is significant in Finnish culture. The aim of craft education in comprehensive schools has been to unify education for both girls and boys during the thirty years of modern comprehensive education, but in reality crafts has diverged into two different subjects for girls and boys. Craft education has taught different things: girls have been taught things that are feminine and included in private life, while the boys’ education has been mostly directed at public and working life. At the same time girls and boys have been educated and socialized towards a certain womanhood and manhood. Craft as a hobby is also very gender divided but there are some clues that tell of the changing positions on the border areas. The starting point of this study has been the assumption that gender structures within crafts can be transformed. But it is important to know the background that creates and maintains these constructions and the expedients for dismantling the structures. The main purpose of this study is to find out how the gender-specific crafts are changing and how they are still maintained. My study analyses why men and woman have chosen untypical hobbies and through that I shall discuss how gendered structures can be dismantled. In the autumn of 2008 I interviewed borderline breakers within crafts: men who had an interest in textile crafts and women who had an interest in technical work. Informants of this study were 20-31 years old and they studied behavioural sciences. The data was collected in 12 theme interviews and document analysis was used to study the results. The dismantling of the gender divide in crafts is slow, but new borders are drawn all the time. The informants have started textile and technical handicrafts soon after comprehensive school or during their studies at university. A main motivation for the new hobby has been the possibility to study for a teacher’s degree with technology or textile studies as a main or a secondary subject. Gender-specific division of crafts is constructed early in childhood as different skills are taught to girls and boys. School teaches gender specific skills and the different skills of girls and boys have not been taken into account. Instead, it has been assumed through comprehensive school that both girls and boys share certain basic skills, and attention has not been paid to the differences between genders. At university the same assumption has still thrived. Skill levels between men and women are substantial and that may have hindered a move by women to technical studies and by men to textile studies. Hence an assumption of naturally gendered crafts has been developed.

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The number of Finnish pupils attending special education has increased for more than a decade (Tilastokeskus 1999, 2000, 2001, 2003, 2004, 2005a, 2006b, 2007b, 2008b, 2008e, 2009b; Virtanen ja Ratilainen 1996). In the year 2007 nearly third of Finnish comprehensive school pupils took part in special needs education. According to the latest statistics, in the autumn of 2008 approximately 47 000 pupils have been admitted or transferred to special education and approximately 126 000 pupils received part-time special education during the 2007 - 2008 academic year. (Tilastokeskus 2008b, 2009b.) The Finnish special education system is currently under review. The Reform, both in legislation and in practice, began nationwide in the year 2008 (e.g. Special education strategy document, November 2007 and the development project Kelpo). The aim of the study was the statistical description of the Finnish special education system and on the other hand to gain a deeper understanding about the Finnish special education system and its quantitative increase, by analysis based on the nationwide statistical information. Earlier studies have shown that the growth in special education is affected by multiple independent variables and cannot be solely explained by the pupil characteristics. The statistical overview and analysis have been carried out in two parts. In the first part, the description and analysis were based on statistical time series from the academic year 1979 -1980 until 2008. While, in the second, more detailed description and analysis, based on comparable time series from 1995 to 2008 and from 2001-2002 to 2007-2008, is presented. Historical perspective was one part of this study. There was an attempt to find reasons explaining the observed growth in the special needs education from late 1960s to 2008. The majority of the research was based on the nationwide statistics information. In addition to this, materials including educational legislation literature, different kind of records of special education and preceding studies were also used to support the research. The main results of the study, are two statistical descriptions and time series analysis of the quantitative increase of the special needs education. Further, a summary of the plausible factors behind the special education system change and its quantitative increase, is presented. The conclusions coming from the study can be summarised as follows: the comparable statistical time series analysis suggests that the growth in special education after the year 1999 could be a consequence of the changes in the structure of special education and that new group of pupils have been directed to special needs education. Keywords: Special education, comprehensive school, description, statistics, change

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In this research the technical functionality, quality and demands made on endurance runners` running suits in winter conditions were studied. The aim was also to find out how smart clothing and wearable technology are adopted in endurance runners` practise. Referring to previous studies the subject was approached in the theoretical part by studying the profile of endurance running, sports wear and the technology to wear as well as the smart clothing from the point of view of endurance running. The basis of subject was the interest of smart materials and the connection between technical structures and functionality. In the science of handicrafts smart clothing is rarely researched which made it even more interesting for the author. This research was carried out by the principles of the usability research. Usability means the suitability of product to its intended meaning. In the research both quantitative and qualitative methods were used. Researched persons were active competitive long-distance runners and also the long-distance runners doing it as a hobby, 35 male and 12 female runners. User information was gathered by the internet forms which mainly was based on the multiple choices but also included few open questions. Gathered information was considered by using both quantitative and content analysing methods. The functional long-distance running practice suit in winter conditions consisted of layered look which considered the possibilities of functional and smart materials. The Practise suit was humid transformable, easy care and light also comfortable to wear. These suits were hoped to be more functional than the current ones. The future running suit was described to not to feel or notice during running. It will not be too tight or sweltering. The functional abilities of clothing materials were believed to be developed further more. Even if the new technical materials are adopted for the running suits the technology to wear is not even though half of the researched runners used pulse indicators. The runners hoped the technology to wear to change more invisible and easier to use. Some of the runners wished the technology to wear to be integrated straight to the clothes which would reduce the number of devices carried with while running. The rare use of Polar Adidas AdiStar Fusion practise system and some other similar systems for endurance running was surprising. According to the results the smart clothing would not make a big brake through in the near future. In the point of view of the researched persons developing of clothing materials was a good and necessary thing, but integrating too much technology to the hobby smears the main purpose of sports and focuses wrongly on the metres and others minors .

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The purpose of the study was to develop a functional web-based learning material for the learning of the nålbinding technique. The study of the research topic was already begun in my pedagogical thesis in 2008 by considering the demands on pedagogic material for the teaching of the technique. This study falls into the field of qualitative design research which was carried out through three stages. In the study three methods of usability testing, i.e. expert analysis, the informants’ thinking aloud and interviews, were used as research methods. At the first stage of the study the first version of the learning material was created. This was done on the basis of theoretical knowledge, the demands set on learning materials as clarified in previous studies, on the basis of previously created learning materials for the learning of the nålbinding technique as well as with the help of two experts on the technique. At the second stage, the learning material was developed on the basis of expert analysis and another version of the material was created. At the third stage, usability testing was carried out on the material. At this stage two informants used the material, practiced stitching with the nålbinding needle and thought aloud while doing so. In the usability testing the Morae –programme was used to record the events on the screen, the actions of the informants and their spoken out thoughts. The Morae –programme was also used when analysing the recordings. After the testing, the informants practised stitching independently and in a few weeks time they were interviewed. The interviews were aimed at finding out the informants’ opinions on the future development of the material. On the basis of the informants’ independent attempts at using the nålbinding technique, the development of their skills after the testing was also discussed at the interviews. The development of the learning material will continue after this study on the basis of the usability testing and the interviews. The web-based learning material was created for the website Käspaikka in the address www.kaspaikka.fi/kinnasneula. By creating a multimodal learning material the dual-coding theory by Paivio was taken into consideration. According to the theory, several methods of presentation help a learner to restore information in his/her memory. The independent construction of the learner’s knowledge, i.e. learning according to the principles of the constructivist learning theory, was also supported by creating a logical navigation system, by linking interrelated topics to one another and by presenting the topics in several different forms. In the test situations the learning material was judged to work well when practising stitching with the nålbinding needle. Both informants learned the basics of the nålbinding technique even though their respective learning strategies were quite different. In the usability testing illogicalities and shortcomings were still noticed in the learning material which will still be further developed in the future.

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Background and aims. Fatness and dieting have been the object of interest between many fields for a long time. Home economics as a discipline enables a comprehensive inspection of fatness and dieting reviewing different disciplines. In addition to the aspect where the pursuit of dieting and health is seen from the perspective of medical and health science it is also been reviewd as a social and cultural phenomena. This study contemplates the influence of history, religion, medicalization and media on dieting and health culture. The objective is to find out if the modern dieting and health culture has gathered influences from centuries ago and absorbed religious features. The stress deriving from appereance has been discussed in the public and there are many solutions conserning weight issues. The purpose of this study is to find out what personal experiences and thoughts female pastors have conserning these questions. The media – which is one of the most influential systems nowadays – has undeniably a great effect on the consumer. The goal is furthermore to estimate the effect of the media on the changing of dieting and health culture. The three main research questions are: 1. What kind of conseptions do female pastors have of dieting and health culture and of its religious features? 2. What kind of personal experiences and conseptions do female pastors have of dieting and strivines of health? 3. How do female pastors regard the image the media has supplied of dieting and health culture? Material and methods. The qualitative data was gathered in year 2009 using the halfstructured theme interview -method. The data consists of interviews conducted with specialists of spiritual matters, i.e. ten female pastors who are between 35 and 60 years old and live in the metropolitan area. The analytical procedure used is called a theory based context analysis. Results and conclusions. Results of this study show that the idealization of slimness and healthiness is a matter discussed in the public on a daily basis. The problem faced was that the media provided contradictory information regarding fatness and dieting and the standard of slimness in commercials focused on females. The pursuit of dieting and healthiness was believed to include also religious elements. In the Middle Ages and the era after that the fatness, overeating and the pleasure one gets from eating was still seen as a condemnable matter in our culture. One could say this was like a sin. The respondents believed that healthiness, healthy living, optimal eating and good looks were a matter more or less equal than a religion. This was a derivative from the fact that treasuring health has become a life stearing value for many people. In the priest’s profession dieting and the pursuit of health was seen in the light of problems arising from weight issues. In ones profession for example the unhealthy eating in festive situations was seen as a matter that leads to unnecessary weight. Another aspect was the job circumstances that limited the degree of movement. The belief was that the female pastors would in a decreasing fashion confront stress deriving from appearence in their job. Keywords: dieting, fatness, healthiness, slimness, female pastors, religion, medicalization, media

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γ-aminobutyric acid (GABA) is the main inhibitory transmitter in the nervous system and acts via three distinct receptor classes: A, B, and C. GABAC receptors are ionotropic receptors comprising ρ subunits. In this work, we aimed to elucidate the expression of ρ subunits in the postnatal brain, the characteristics of ρ2 homo-oligomeric receptors, and the function of GABAC receptors in the hippocampus. In situ hybridization on rat brain slices showed ρ2 mRNA expression from the newborn in the superficial grey layer of the superior colliculus, from the first postnatal week in the hippocampal CA1 region and the pretectal nucleus of the optic tract, and in the adult dorsal lateral geniculate nucleus. Quantitative RT-PCR revealed expression of all three ρ subunits in the hippocampus and superior colliculus from the first postnatal day. In the hippocampus, ρ2 mRNA expression clearly dominated over ρ1 and ρ3. GABAC receptor protein expression was confirmed in the adult hippocampus, superior colliculus, and dorsal lateral geniculate nucleus by immunohistochemistry. From the selective distribution of ρ subunits, GABAC receptors may be hypothesized to be specifically involved in aspects of visual image motion processing in the rat brain. Although previous data had indicated a much higher expression level for ρ2 subunit transcripts than for ρ1 or ρ3 in the brain, previous work done on Xenopus oocytes had suggested that rat ρ2 subunits do not form functional homo-oligomeric GABAC receptors but need ρ1 or ρ3 subunits to form hetero-oligomers. Our results demonstrated, for the first time, that HEK 293 cells transfected with ρ2 cDNA displayed currents in whole-cell patch-clamp recordings. Homomeric rat ρ2 receptors had a decreased sensitivity to, but a high affinity for picrotoxin and a marked sensitivity to the GABAC receptor agonist CACA. Our results suggest that ρ2 subunits may contribute to brain function, also in areas not expressing other ρ subunits. Using extracellular electrophysiological recordings, we aimed to study the effects of the GABAC receptor agonists and antagonists on responses of the hippocampal neurons to electrical stimulation. Activation of GABAC receptors with CACA suppressed postsynaptic excitability and the GABAC receptor antagonist TPMPA inhibited the effects of CACA. Next, we aimed to display the activation of the GABAC receptors by synaptically released GABA using intracellular recordings. GABA-mediated long-lasting depolarizing responses evoked by high-frequency stimulation were prolonged by TPMPA. For weaker stimulation, the effect of TPMPA was enhanced after GABA uptake was inhibited. Our data demonstrate that GABAC receptors can be activated by endogenous synaptic transmitter release following strong stimulation or under conditions of reduced GABA uptake. The lack of GABAC receptor activation by less intensive stimulation under control conditions suggests that these receptors are extrasynaptic and activated via spillover of synaptically released GABA. Taken together with the restricted expression pattern of GABAC receptors in the brain and their distinctive pharmacological and biophysical properties, our findings supporting extrasynaptic localization of these receptors raise interesting possibilities for novel pharmacological therapies in the treatment of, for example, epilepsy and sleep disorders.

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Intact function of working memory (WM) is essential for children and adults to cope with every day life. Children with deficits in WM mechanisms have learning difficulties that are often accompanied by behavioral problems. The neural processes subserving WM, and brain structures underlying this system, continue to develop during childhood till adolescence and young adulthood. With functional magnetic resonance imaging (fMRI) it is possible to investigate the organization and development of WM. The present thesis aimed to investigate, using behavioral and neuroimaging methods, whether mnemonic processing of spatial and nonspatial visual information is segregated in the developing and mature human brain. A further aim in this research was to investigate the organization and development of audiospatial and visuospatial information processing in WM. The behavioral results showed that spatial and nonspatial visual WM processing is segregated in the adult brain. The fMRI result in children suggested that memory load related processing of spatial and nonspatial visual information engages common cortical networks, whereas selective attention to either type of stimuli recruits partially segregated areas in the frontal, parietal and occipital cortices. Deactivation mechanisms that are important in the performance of WM tasks in adults are already operational in healthy school-aged children. Electrophysiological evidence suggested segregated mnemonic processing of visual and auditory location information. The results of the development of audiospatial and visuospatial WM demonstrate that WM performance improves with age, suggesting functional maturation of underlying cognitive processes and brain areas. The development of the performance of spatial WM tasks follows a different time course in boys and girls indicating a larger degree of immaturity in the male than female WM systems. Furthermore, the differences in mastering auditory and visual WM tasks may indicate that visual WM reaches functional maturity earlier than the corresponding auditory system. Spatial WM deficits may underlie some learning difficulties and behavioral problems related to impulsivity, difficulties in concentration, and hyperactivity. Alternatively, anxiety or depressive symptoms may affect WM function and the ability to concentrate, being thus the primary cause of poor academic achievement in children.

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Glaucoma is a group of progressive optic neuropathies causing irreversible blindness if not diagnosed and treated in the early state of progression. Disease is often, but not always, associated with increased intraocular pressure (IOP), which is also the most important risk factor for glaucoma. Ophthlamic timolol preparations have been used for decades to lower increased intraocular pressure (IOP). Timolol is locally well tolerated but may cause e.g. cardiovascular and pulmonary adverse effects due to systemic absorption. It has been reported that approximately 80% of a topically administered eye drop is systemically absorbed. However, only limited information is available on timolol metabolism in the liver or especially in the human eye. The aim of this work was to investigate metabolism of timolol in human liver and human ocular tissues. The expression of drug metabolizing cytochrome P450 (CYP) enzymes in the human ciliary epithelial cells was studied. The metabolism of timolol and the interaction potential of timolol with other commercially available medicines were investigated in vitro using different liver preparations. The absorption of timolol to the aqueous humor from two commercially available products: 0.1% eye gel and 0.5% eye drops and the presence of timolol metabolites in the aqueous humor were investigated in a clinical trial. Timolol was confirmed to be metabolized mainly by CYP2D6 as previously suggested. Potent CYP2D6 inhibitors especially fluoxetine, paroxetine and quinidine inhibited the metabolism of timolol. The inhibition may be of clinical significance in patients using ophthalmic timolol products. CYP1A1 and CYP1B1 mRNAs were expressed in the human ciliary epithelial cells. CYP1B1 was also expressed at protein level and the expression was strongly induced by a known potent CYP1B1 inducer 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The CYP1B1 induction is suggested to be mediated by aryl hydrocarbon receptor (AHR). Low levels of CYP2D6 mRNA splice variants were expressed in the human ciliary epithelial cells and very low levels of timolol metabolites were detected in the human aqueous humor. It seems that negligible amount of CYP2D6 protein is expressed in the human ocular tissues. Timolol 0.1% eye gel leads to aqueous humor concentration high enough to achieve therapeutic effect. Inter-individual variation in concentrations is low and intraocular as well as systemic safety can be increased when using this product with lower timolol concentration instead of timolol 0.5% eye drops.

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Cathepsin D (CTSD) is a lysosomal protease, the deficiency of which is fatal and associated with neurodegeneration. CTSD knock-out mice, which die at the age of four weeks, show intestinal necrosis, loss of lymphoid cells and moderate pathological changes in the brain. An active-site mutation in the CTSD gene underlies a neurodegenerative disease in newborn sheep, characterized by brain atrophy without any changes to visceral tissues. The CTSD deficiences belong to the group of neuronal ceroid-lipofuscinoses (NCLs), severe neurodegenerative lysosomal storage disorders. The aim of this thesis was to examine the molecular and cellular mechanisms behind neurodegeneration in CTSD deficiency. We found the developmental expression pattern of CTSD to resemble that of synaptophysin and the increasing expression of CTSD to coincide with the active period of myelination in the rat brain, suggesting a role for CTSD in early rat brain development. An active-site mutation underlying the congenital ovine NCL not only affected enzymatic activity, but also changed the stability, processing and transport of the mutant protein, possibly contributing to the disease pathogenesis. We also provide CTSD deficiency as a first molecular explanation for human congenital NCL, a lysosomal storage disorder, characterized by neuronal loss and demyelination in the central nervous system. Finally, we show the first evidence for synaptic abnormalities and thalamocortical changes in CTSD-deficient mice at the molecular and ultrastructural levels. Keywords: cathepsin D, congenital, cortex, lysosomal storage disorder, lysosome, mutation, neurodegeneration, neuronal ceroid-lipofuscinosis, overexpression, synapse, thalamus

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Distinct endogenous network events, generated independently of sensory input, are a general feature of various structures of the immature central nervous system. In the immature hippocampus, these type of events are seen as "giant depolarizing potentials" (GDPs) in intracellular recordings in vitro. GABA, the major inhibitory neurotransmitter of the adult brain, has a depolarizing action in immature neurons, and GDPs have been proposed to be driven by GABAergic transmission. Moreover, GDPs have been thought to reflect an early pattern that disappears during development in parallel with the maturation of hyperpolarizing GABAergic inhibition. However, the adult hippocampus in vivo also generates endogenous network events known as sharp (positive) waves (SPWs), which reflect synchronous discharges of CA3 pyramidal neurons and are thought to be involved in cognitive functions. In this thesis, mechanisms of GDP generation were studied with intra- and extracellular recordings in the neonatal rat hippocampus in vitro and in vivo. Immature CA3 pyramidal neurons were found to generate intrinsic bursts of spikes and to act as cellular pacemakers for GDP activity whereas depolarizing GABAergic signalling was found to have a temporally non-patterned facilitatory role in the generation of the network events. Furthermore, the data indicate that the intrinsic bursts of neonatal CA3 pyramidal neurons and, consequently, GDPs are driven by a persistent Na+ current and terminated by a slow Ca2+-dependent K+ current. Gramicidin-perforated patch recordings showed that the depolarizing driving force for GABAA receptor-mediated actions is provided by Cl- uptake via the Na-K-C1 cotransporter, NKCC1, in the immature CA3 pyramids. A specific blocker of NKCC1, bumetanide, inhibited SPWs and GDPs in the neonatal rat hippocampus in vivo and in vitro, respectively. Finally, pharmacological blockade of the GABA transporter-1 prolonged the decay of the large GDP-associated GABA transients but not of single postsynaptic GABAA receptor-mediated currents. As a whole the data in this thesis indicate that the mechanism of GDP generation, based on the interconnected network of bursting CA3 pyramidal neurons, is similar to that involved in adult SPW activity. Hence, GDPs do not reflect a network pattern that disappears during development but they are the in vitro counterpart of neonatal SPWs.

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Androgens control a variety of developmental processes that create the male phenotype and are important for maintaining male fertility and normal functions of tissues and organs that are not directly involved in procreation. Androgen receptor (AR) that mediates the biological actions of androgens is a member of the nuclear receptor superfamily of ligand-inducible transcription factors. Although AR was cloned over 15 years ago, the mechanisms by which it regulates gene expression are not well understood. A growing body of in vitro experimental evidence suggests that a complex network of proteins is involved in the androgen-dependent transcriptional regulation. However, the process of AR-dependent transcriptional regulation under physiological conditions is largely elusive. In the present study, a series of experiments were performed, including quantitative chromatin immunoprecipitation (ChIP) assays, to investigate AR-mediated transcription process using living prostate cancer cells. Our results show that the loading of AR and recruitment of coactivators and RNA polymerase II (Pol II) to both the promoter and enhancer of AR target genes are a transient and cyclic event that in addition to hyperacetylation, also involves dynamic changes in methylation, phosphorylation of core histone H3 in androgen-treated LNCaP cells. The dynamics of testosterone (T)-induced loading of AR onto the proximal promoters of the genes clearly differed from that loaded onto the distal enhancers. Significantly, more holo-AR was loaded onto the enhancers than the promoters, but the principal Pol II transcription complex was assembled on the promoters. By contrast, the pure antiandrogen bicalutamide (CDX) complexed to AR elicited occupancy of the PSA promoter, but was unable to load onto the PSA enhancer and was incapable of recruiting Pol II, coactivators and following changes of covalent histone modifications. The partial antagonist cyproterone acetate (CPA) and mifepristone (RU486) were capable of promoting AR loading onto both the PSA promoter and enhancer at a comparable efficiency with androgen in LNCaP cells expressing mutant AR. However, CPA- and RU486-bound AR not only recruited Pol II and coactivator p300 and GRIP1 onto the promoter and enhancer, but also recruited the corepressor NCoR onto the promoter as efficiently as CDX. In addition, we demonstrate that both proteasome and protein kinases are implicated in AR-mediated transcription. Even though proteasome inhibitor MG132 and protein kinase inhibitor DRB (5, 6-Dichlorobenzimidazole riboside) can block ligand-dependent accumulation of PSA mRNA with same efficiency, their use results in different molecular profiles in terms of the formation of AR-mediated transcriptional complex. Collectively, these results indicate that transcriptional activation by AR is a complicated process, which includes transient loading of holo-AR and recruitment of Pol II and coregulators accompanied by a cascade of distinct covalent histone modifications; This process involves both the promoter and enhancer elements, as well as other general components of the cell machineries e.g. proteasome and protein kinase; The pure antiandrogen CDX and the partial antagonist CPA and RU486 exhibit clearly different profiles in terms of their ability to induce the formation of AR-dependent transcriptional complexes and the histone modifications associated with the target genes in human prostate cancer cells. Finally, by using quantitative RT-PCR to compare the expression of sixteen AR co-regulators in prostate cancer cell lines, xenografts, and clinical prostate cancer specimens we suggest that AR co-regulators protein inhibitor of activated STAT1 (PIAS1) and steroid receptor coactivator 1(SRC1) could be involved in the progression of prostate cancer.

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Androgen receptor (AR) is necessary for normal male phenotype development and essential for spermatogenesis. AR is a classical steroid receptor mediating actions of male sex steroids testosterone and 5-alpha-dihydrotestosterone. Numerous coregulators interact with the receptor and regulate AR activity on target genes. This study deals with the characterization of androgen receptor-interacting protein 4 (ARIP4). ARIP4 binds DNA, interacts with AR in vitro and in cultured yeast and mammalian cells, and modulates AR-dependent transactivation. ARIP4 is an active DNA-dependent ATPase, and this enzymatic activity is essential for the ability of ARIP4 to modulate AR function. On the basis of sequence homology in its ATPase domain, ARIP4 belongs to the SNF2 family of proteins involved in chromatin remodeling, DNA repair, and homologous recombination. Similar to its closest homologs ATRX and Rad54, ARIP4 does not seem to be a classical chromatin remodeling protein in that it does not appear to form large protein complexes in vivo or remodel mononucleosomes in vitro. However, ARIP4 is able to generate superhelical torsion on linear DNA fragments. ARIP4 is covalently modified by SUMO-1, and mutation of six potential SUMO attachment sites abolishes the ability of ARIP4 to bind DNA, hydrolyze ATP, and activate AR function. ARIP4 expression starts in early embryonic development. In mouse embryo ARIP4 is present mainly in the neural tube and limb buds. In adult mouse tissues ARIP4 expression is virtually ubiquitous. In mouse testis ARIP4 is expressed in the nuclei of Sertoli cells in a stage-dependent manner. ARIP4 is also present in the nuclei of Leydig cells, spermatogonia, pachytene and diplotene spermatocytes. Testicular expression pattern of ARIP4 does not differ significantly in wild-type, FSHRKO, and LuRKO mice. In the testis of hpg mice, ARIP4 is found mainly in interstitial cells and has very low, if any, expression in Sertoli and germ cells. Heterozygous Arip4+/ mice are fertile and appear normal; however, they are haploinsufficient with regard to androgen action in Sertoli cells. In contrast, Arip4 / embryos are not viable. They have significantly reduced body size at E9.5 and die by E11.5. Compared to wild-type littermates, Arip4 / embryos possess a higher percentage of apoptotic cells at E9.5 and E10.5. Fibroblasts derived from Arip4 / embryos cease growing after 2-3 passages and exhibit a significantly increased apoptosis and decreased proliferation rate than cells from wild-type embryos. Our findings demonstrate that ARIP4 plays an essential role in mouse embryonic development. In addition, testicular expression and AR coregulatory activity of ARIP4 suggest a role of ARIP4-AR interaction in the somatic cells of the testis.