62 resultados para Progressive disinternment

em Helda - Digital Repository of University of Helsinki


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Strategies of scientific, question-driven inquiry are stated to be important cultural practices that should be educated in schools and universities. The present study focuses on investigating multiple efforts to implement a model of Progressive Inquiry and related Web-based tools in primary, secondary and university level education, to develop guidelines for educators in promoting students collaborative inquiry practices with technology. The research consists of four studies. In Study I, the aims were to investigate how a human tutor contributed to the university students collaborative inquiry process through virtual forums, and how the influence of the tutoring activities is demonstrated in the students inquiry discourse. Study II examined an effort to implement technology-enhanced progressive inquiry as a distance working project in a middle school context. Study III examined multiple teachers' methods of organizing progressive inquiry projects in primary and secondary classrooms through a generic analysis framework. In Study IV, a design-based research effort consisting of four consecutive university courses, applying progressive inquiry pedagogy, was retrospectively re-analyzed in order to develop the generic design framework. The results indicate that appropriate teacher support for students collaborative inquiry efforts appears to include interplay between spontaneity and structure. Careful consideration should be given to content mastery, critical working strategies or essential knowledge practices that the inquiry approach is intended to promote. In particular, those elements in students activities should be structured and directed, which are central to the aim of Progressive Inquiry, but which the students do not recognize or demonstrate spontaneously, and which are usually not taken into account in existing pedagogical methods or educational conventions. Such elements are, e.g., productive co-construction activities; sustained engagement in improving produced ideas and explanations; critical reflection of the adopted inquiry practices, and sophisticated use of modern technology for knowledge work. Concerning the scaling-up of inquiry pedagogy, it was concluded that one individual teacher can also apply the principles of Progressive Inquiry in his or her own teaching in many innovative ways, even under various institutional constraints. The developed Pedagogical Infrastructure Framework enabled recognizing and examining some central features and their interplay in the designs of examined inquiry units. The framework may help to recognize and critically evaluate the invisible learning-cultural conventions in various educational settings and can mediate discussions about how to overcome or change them.

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Progressive myoclonus epilepsy of Unverricht-Lundborg type (EPM1) is an autosomal recessively inherited disorder characterized by age of onset at 6-15 years, stimulus-sensitive myoclonus, tonic-clonic epileptic seizures and a progressive course. Mutations in the cystatin B (CSTB) gene underlie EPM1. The most common mutation underlying EPM1 is a dodecamer repeat expansion in the promoter region of CSTB. In addition, nine other mutations have been identified. CSTB, a cysteine protease inhibitor, is a ubiquitously expressed inhibitor of cathepsins, but its physiological function is unknown. The purpose of this study was to investigate CSTB gene expression and CSTB protein function in normal and pathological conditions. The basal CSTB promoter was mapped and characterized using different promoter-luciferase gene constructs. The binding activity of transcription factors to one ARE half, five Sp1 and four AP1 sites in the CSTB promoter was demonstrated. The CSTB promoter activity was clearly decreased using a CSTB promoter with "premutation" repeat expansions and in individuals with alike expansions. The expression of CSTB mRNA and protein was markedly reduced in patient cells. The endogenous CSTB protein localized to the nucleus, cytoplasm and lysosomes, and in differentiated cells merely to the cytoplasm. This suggests that the subcellular distribution of CSTB is dependent on the differentation status of the cells. The proteins representing patient missense mutations failed to associate with lysosomes, implying the importance of the lysosomal association for the proper physiological function of CSTB. Several alternatively spliced CSTB isoforms were identified. Of these CSTB2 was widely expressed with very low levels whereas the other alternatively spliced forms seemed to have limited tissue expression. In patients CSTB2 expression was reduced similarly to that of CSTB. The physiological relevance of CSTB alternative splicing remains unknown. The mouse Cstb transcript was shown to be present in all embryonic stages and adult tissues examined. The expression was highest at embryonic day 7 and in thymus, as well as in postnatal brain in the cortex, caudate putamen, thalamus, hippocampus, and in the Purkinje cell layer of the cerebellum. Our data implies that CSTB expression is tightly temporally and spatially regulated. The data presented in my thesis lay the basis for further understanding of the role of CSTB in health and disease.

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The progressive myoclonic epilepsies (PMEs) are a clinically and etiologically heterogeneous group of symptomatic epilepsies characterized by myoclonus, tonic-clonic seizures, psychomotor regression and ataxia. Different disorders have been classified as PMEs. Of these, the group of neuronal ceroid lipofuscinoses (NCLs) comprise an entity that has onset in childhood, being the most common cause of neurodegeneration in children. The primary aim of this thesis was to dissect the molecular genetic background of patients with childhood onset PME by studying candidate genes and attempting to identify novel PME-associated genes. Another specific aim was to study the primary protein properties of the most recently identified member of the NCL-causing proteins, MFSD8. To dissect the genetic background of a cohort of Turkish patients with childhood onset PME, a screen of the NCL-associated genes PPT1, TPP1, CLN3, CLN5, CLN6, MFSD8, CLN8 and CTSD was performed. Altogether 49 novel mutations were identified, which together with 56 mutations found by collaborators raised the total number of known NCL mutations to 364. Fourteen of the novel mutations affect the recently identified MFSD8 gene, which had originally been identified in a subset of mainly Turkish patients as the underlying cause of CLN7 disease. To investigate the distribution of MFSD8 defects, a total of 211 patients of different ethnic origins were evaluated for mutations in the gene. Altogether 45 patients from nine different countries were provided with a CLN7 molecular diagnosis, denoting the wide geographical occurrence of MFSD8 defects. The mutations are private with only one having been established by a founder-effect in the Roma population from the former Czechoslovakia. All mutations identified except one are associated with the typical clinical picture of variant late-infantile NCL. To address the trafficking properties of MFSD8, lysosomal targeting of the protein was confirmed in both neuronal and non-neuronal cells. The major determinant for this lysosomal sorting was identified to be an N-terminal dileucine based signal (9-EQEPLL-14), recognized by heterotetrameric AP-1 adaptor proteins, suggesting that MFSD8 takes the direct trafficking pathway en route to the lysosomes. Expression studies revealed the neurons as the primary cell-type and the hippocampus and cerebellar granular cell layer as the predominant regions in which MFSD8 is expressed. To identify novel genes associated with childhood onset PME, a single nucleotide polymorphism (SNP) genomewide scan was performed in three small families and 18 sporadic patients followed by homozygosity mapping to determine the candidate loci. One of the families and a sporadic patient were positive for mutations in PLA2G6, a gene that had previously been shown to cause infantile neuroaxonal dystrophy. Application of next-generation sequencing of candidate regions in the remaining two families led to identification of a homozygous missense mutation in USP19 for the first and TXNDC6 for the second family. Analysis of the 18 sporadic cases mapped the best candidate interval in a 1.5 Mb region on chromosome 7q21. Screening of the positional candidate KCTD7 revealed six mutations in seven unrelated families. All patients with mutations in KCTD7 were reported to have early onset PME, rapid disease progression leading to dementia and no pathologic hallmarks. The identification of KCTD7 mutations in nine patients and the clinical delineation of their phenotype establish KCTD7 as a gene for early onset PME. The findings presented in this thesis denote MFSD8 and KCTD7 as genes commonly associated with childhood onset symptomatic epilepsy. The disease-associated role of TXNDC6 awaits verification through identification of additional mutations in patients with similar phenotypes. Completion of the genetic spectrum underlying childhood onset PMEs and understanding of the gene products functions will comprise important steps towards understanding the underlying pathogenetic mechanisms, and will possibly shed light on the general processes of neurodegeneration and nervous system regulation, facilitating the diagnosis, classification and possibly treatment of the affected cases.

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Chronic periodontitis results from a complex aetiology, including the formation of a subgingival biofilm and the elicitation of the host s immune and inflammatory response. The hallmark of chronic periodontitis is alveolar bone loss and soft periodontal tissue destruction. Evidence supports that periodontitis progresses in dynamic states of exacerbation and remission or quiescence. The major clinical approach to identify disease progression is the tolerance method, based on sequential probing. Collagen degradation is one of the key events in periodontal destructive lesions. Matrix metalloproteinase (MMP)-8 and MMP-13 are the primary collagenolytic MMPs that are associated with the severity of periodontal inflammation and disease, either by a direct breakdown of the collagenised matrix or by the processing of non-matrix bioactive substrates. Despite the numerous host mediators that have been proposed as potential biomarkers for chronic periodontitis, they reflect inflammation rather than the loss of periodontal attachment. The aim of the present study was to determine the key molecular MMP-8 and -13 interactions in gingival crevicular fluid (GCF) and gingival tissue from progressive periodontitis lesions and MMP-8 null allele mouse model. In study (I), GCF and gingival biopsies from active and inactive sites of chronic periodontitis patients, which were determined clinically by the tolerance method, and healthy GCF were analysed for MMP-13 and tissue inhibitor of matrix metalloproteinases (TIMP)-1. Chronic periodontitis was characterised by increased MMP-13 levels and the active sites showed a tendency of decreased TIMP-1 levels associated with increments of MMP-13 and total protein concentration compared to inactive sites. In study (II), we investigated whether MMP-13 activity was associated with TIMP-1, bone collagen breakdown through ICTP levels, as well as the activation rate of MMP-9 in destructive lesions. The active sites demonstrated increased GCF ICTP levels as well as lowered TIMP-1 detection along with elevated MMP-13 activity. MMP-9 activation rate was enhanced by MMP-13 in diseased gingival tissue. In study (III), we analysed the potential association between the levels, molecular forms, isoenzyme distribution and degree of activation of MMP-8, MMP-14, MPO and the inhibitor TIMP-1 in GCF from periodontitis progressive patients at baseline and after periodontal therapy. A positive correlation was found for MPO/MMP-8 and their levels associated with progression episodes and treatment response. Because MMP-8 is activated by hypochlorous acid in vitro, our results suggested an interaction between the MPO oxidative pathway and MMP-8 activation in GCF. Finally, in study (IV), on the basis of the previous finding that MMP-8-deficient mice showed impaired neutrophil responses and severe alveolar bone loss, we aimed to characterise the detection patterns of LIX/CXCL5, SDF-1/CXCL12 and RANKL in P. gingivalis-induced experimental periodontitis and in the MMP-8-/- murine model. The detection of neutrophil-chemoattractant LIX/CXCL5 was restricted to the oral-periodontal interface and its levels were reduced in infected MMP-8 null mice vs. wild type mice, whereas the detection of SDF-1/CXCL12 and RANKL in periodontal tissues increased in experimentally-induced periodontitis, irrespectively from the genotype. Accordingly, MMP-8 might regulate LIX/CXCL5 levels by undetermined mechanisms, and SDF-1/CXCL12 and RANKL might promote the development and/or progression of periodontitis.

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Effective processing of powdered particles can facilitate powder handling and result in better drug product performance, which is of great importance in the pharmaceutical industry where the majority of active pharmaceutical ingredients (APIs) are delivered as solid dosage forms. The purpose of this work was to develop a new ultrasound-assisted method for particle surface modification and thin-coating of pharmaceutical powders. The ultrasound was used to produce an aqueous mist with or without a coating agent. By using the proposed technique, it was possible to decrease the interparticular interactions and improve rheological properties of poorly-flowing water-soluble powders by aqueous smoothing of the rough surfaces of irregular particles. In turn, hydrophilic polymer thin-coating of a hydrophobic substance diminished the triboelectrostatic charge transfer and improved the flowability of highly cohesive powder. To determine the coating efficiency of the technique, the bioactive molecule β-galactosidase was layered onto the surface of powdered lactose particles. Enzyme-treated materials were analysed by assaying the quantity of the reaction product generated during enzymatic cleavage of the milk sugar. A near-linear increase in the thickness of the drug layer was obtained during progressive treatment. Using the enzyme coating procedure, it was confirmed that the ultrasound-assisted technique is suitable for processing labile protein materials. In addition, this pre-treatment of milk sugar could be used to improve utilization of lactose-containing formulations for populations suffering from severe lactose intolerance. Furthermore, the applicability of the thin-coating technique for improving homogeneity of low-dose solid dosage forms was shown. The carrier particles coated with API gave rise to uniform distribution of the drug within the powder. The mixture remained homogeneous during further tabletting, whereas the reference physical powder mixture was subject to segregation. In conclusion, ultrasound-assisted surface engineering of pharmaceutical powders can be effective technology for improving formulation and performance of solid dosage forms such as dry powder inhalers (DPI) and direct compression products.

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This study deals with language change and variation in the correspondence of the eighteenth-century Bluestocking circle, a social network which provided learned men and women with an informal environment for the pursuit of scholarly entertainment. Elizabeth Montagu (1718 1800), a notable social hostess and a Shakespearean scholar, was one of their key figures. The study presents the reconstruction of Elizabeth Montagu s social networks from her youth to her later years with a special focus on the Bluestocking circle, and linguistic research on private correspondence between Montagu and her Bluestocking friends and family members between the years 1738 1778. The epistolary language use is investigated using the methods and frameworks of corpus linguistics, historical sociolinguistics, and social network analysis. The approach is diachronic and concerns real-time language change. The research is based on a selection of manuscript letters which I have edited and compiled into an electronic corpus (Bluestocking Corpus). I have also devised a network strength scale in order to quantify the strength of network ties and to compare the results of the linguistic research with the network analysis. The studies range from the reconstruction and analysis of Elizabeth Montagu s most prominent social networks to the analysis of changing morphosyntactic features and spelling variation in Montagu s and her network members correspondence. The linguistic studies look at the use of the progressive construction, preposition stranding and pied piping, and spelling variation in terms of preterite and past participle endings in the regular paradigm (-ed, - d, -d, - t, -t) and full / contracted spellings of auxiliary verbs. The results are analysed in terms of social network membership, sociolinguistic variables of the correspondents, and, when relevant, aspects of eighteenth-century linguistic prescriptivism. The studies showed a slight diachronic increase in the use of the progressive, a significant decrease of the stigmatised preposition stranding and increase of pied piping, and relatively informal but socially controlled epistolary spelling. Certain significant changes in Elizabeth Montagu s language use over the years could be attributed to her increasingly prominent social standing and the changes in her social networks, and the strength of ties correlated strongly with the use of the progressive in the Bluestocking Corpus. Gender, social rank, and register in terms of kinship/friendship had a significant influence in language use, and an effect of prescriptivism could also be detected. Elizabeth Montagu s network ties resulted in language variation in terms of network membership, her own position in a given network, and the social factors that controlled eighteenth-century interaction. When all the network ties are strong, linguistic variation seems to be essentially linked to the social variables of the informants.

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Maila Pylkkönen (1931 1986) was one of the most important modernist poets in Finland and a central figure in developing the dramatic monologue in Finnish literature. The study examines Pylkkönen s poetic work Arvo. Vanhaäiti puhuu runonsa (Value. An old woman speaks her poem, 1959) as an example of the dramatic monologue, approaching it from three perspectives: its generic features and background, and the poetic framework to which it connects in the context of Pylkkönen s poetry. In addition to methods of literary scholarship, the poetic analysis benefits from a linguistic approach. The study shows that the dramatic monologue genre drives Pylkkönen s first work, Klassilliset tunteet (Classical feelings, 1957), in a context of finding poetic identity, characterised by the expression to be the words of a living creature . The study demonstrates that important generic features of the dramatic monologue, namely, a poem representing a speech-event and a hierarchical structure, are also Arvo s most significant generic features. Arvo s poems as speech-events are examined for their internal progressive, pragmatic unity constructed through single line units; for their function as narratives dealing with the life story of an old woman, Arvo s speaker; and from the perspective of the communication between the old woman and the poems other characters. Arvo s speech-events can also be seen as semantic shifts from one poem to another: the poems construct semantic stages representing different phases of the old woman s life. The study demonstrates that analysis of Arvo s hierarchical structure, that is, the relationship between the speaker and the rhetorical levels, reveals the work s structural and ideological wholeness by focusing on the old woman s emotions: longing, loneliness and alienation from the world. In other words, the contradictions between the explicit level of the speaker and an implied rhetorical level open up the tragedy of an old woman s daily life. Study of Arvo s hierarchical structure also highlights the special position of the reader in the framework of a dramatic monologue. The elements of a dramatic present in which the old woman s emotions are conveyed, an italicized opening poem, and the work s title Value invite the reader to consider Arvo as a structural and ideological whole. The function of Arvo s hierarchical structure is to ask the reader to recognise the hopelessness of the old woman s situation, understand it, and even identify with it.

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Acute encephalitis is an inflammation of the brain, mostly caused by viral infection. A variety of cognitive symptoms may persist after the acute stage, and neuropsychological assessment is crucial in evaluation of the outcome. The most commonly reported sequelae are memory deficits. The main aims of this study were to investigate the types of memory impairment in various encephalitides, the frequency of global amnesia following encephalitis, and the changes in the deficits during follow-up. Between 1 January 1985 and 31 December 1994, 77 adult patients under the age of 75 with acute encephalitis but without alcohol abuse, or coexisting or previous neurological diseases were consecutively referred for neuropsychological examination at the Department of Neurology, Helsinki University Central Hospital. The aetiology was established in 44/77 (57%) patients; 17 had Herpes simplex virus encephalitis (HSVE). Transient amnesia (TENA) at the acute stage of the disease was found in 70% of patients. Furthermore, similarly to brain trauma, TENA was found to indicate cognitive outcome. The frequency of persisting global amnesia syndrome with both anterograde and retrograde amnesia in all encephalitic patients was 6%. One patient had isolated retrograde amnesia, which is very rare. In HSVE the frequency of global amnesia was 12.5%, which is lower than expected. As a group, HSVE patients were not found to have a homogeneous pattern of amnesia, instead subgroups among all encephalitic patients were observed: some patients had impaired semantic memory, some had difficulty predominantly with executive functions and some suffered from an increased forgetting rate. Herpes zoster encephalitis was found to result in mild memory impairment only, and the qualitative features indicated a subcortical dysfunction. On the whole, the cognitive deficits were predominantly found to diminish during follow-up. Progressive deterioration was often associated with intractable epilepsy. The frequency of dementia was 12.5%. In conclusion, the neuropsychological outcome, especially in HSVE, was more favourable than has previously been reported, possibly due to early acyclovir medication. Memory disorders after encephalitis should not be considered uniform, and the need for neuropsychological rehabilitation should be considered case-by-case

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Neuronal oscillations are thought to underlie interactions between distinct brain regions required for normal memory functioning. This study aimed at elucidating the neuronal basis of memory abnormalities in neurodegenerative disorders. Magnetoencephalography (MEG) was used to measure oscillatory brain signals in patients with Alzheimer s disease (AD), a neurodegenerative disease causing progressive cognitive decline, and mild cognitive impairment (MCI), a disorder characterized by mild but clinically significant complaints of memory loss without apparent impairment in other cognitive domains. Furthermore, to help interpret our AD/MCI results and to develop more powerful oscillatory MEG paradigms for clinical memory studies, oscillatory neuronal activity underlying declarative memory, the function which is afflicted first in both AD and MCI, was investigated in a group of healthy subjects. An increased temporal-lobe contribution coinciding with parieto-occipital deficits in oscillatory activity was observed in AD patients: sources in the 6 12.5 Hz range were significantly stronger in the parieto-occipital and significantly weaker in the right temporal region in AD patients, as compared to MCI patients and healthy elderly subjects. Further, the auditory steady-state response, thought to represent both evoked and induced activity, was enhanced in AD patients, as compared to controls, possibly reflecting decreased inhibition in auditory processing and deficits in adaptation to repetitive stimulation with low relevance. Finally, the methodological study revealed that successful declarative encoding and retrieval is associated with increases in occipital gamma and right hemisphere theta power in healthy unmedicated subjects. This result suggests that investigation of neuronal oscillations during cognitive performance could potentially be used to investigate declarative memory deficits in AD patients. Taken together, the present results provide an insight on the role of brain oscillatory activity in memory function and memory disorders.

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The aim of the study was to analyze and facilitate collaborative design in a virtual learning environment (VLE). Discussions of virtual design in design education have typically focused on technological or communication issues, not on pedagogical issues. Yet in order to facilitate collaborative design, it is also necessary to address the pedagogical issues related to the virtual design process. In this study, the progressive inquiry model of collaborative designing was used to give a structural level of facilitation to students working in the VLE. According to this model, all aspects of inquiry, such as creating the design context, constructing a design idea, evaluating the idea, and searching for new information, can be shared in a design community. The study consists of three design projects: 1) designing clothes for premature babies, 2) designing conference bags for an international conference, and 3) designing tactile books for visually impaired children. These design projects constituted a continuum of design experiments, each of which highlighted certain perspectives on collaborative designing. The design experiments were organized so that the participants worked in design teams, both face-to-face and virtually. The first design experiment focused on peer collaboration among textile teacher students in the VLE. The second design experiment took into consideration end-users needs by using a participatory design approach. The third design experiment intensified computer-supported collaboration between students and domain experts. The virtual learning environments, in these design experiments, were designed to support knowledge-building pedagogy and progressive inquiry learning. These environments enabled a detailed recording of all computer-mediated interactions and data related to virtual designing. The data analysis was based on qualitative content analysis of design statements in the VLE. This study indicated four crucial issues concerning collaborative design in the VLE in craft and design education. Firstly, using the collaborative design process in craft and design education gives rise to special challenges of building learning communities, creating appropriate design tasks for them, and providing tools for collaborative activities. Secondly, the progressive inquiry model of collaborative designing can be used as a scaffold support for design thinking and for reflection on the design process. Thirdly, participation and distributed expertise can be facilitated by considering the key stakeholders who are related to the design task or design context, and getting them to participate in virtual designing. Fourthly, in the collaborative design process, it is important that team members create and improve visual and technical ideas together, not just agree or disagree about proposed ideas. Therefore, viewing the VLE as a medium for collaborative construction of the design objects appears crucial in order to understand and facilitate the complex processes in collaborative designing.

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Tutkimus käsittelee verkko-opetusinnovaation leviämistä perusasteen ja lukion maantieteeseen vuosina 1998–2004. Työssä sovellettiin opetusinnovaation leviämismallia ja innovaatioiden diffuusioteoriaa. Aineisto hankittiin seitsemänä vuotena kyselylomakkeilla maantieteen verkko-opetuksen edelläkävijäopettajilta, jotka palauttivat 326 lomaketta. Tutkimuksen pääongelmat olivat 1) Millaisia edellytyksiä edelläkävijäopettajilla on käyttää verkko-opetusta koulun maantieteessä? 2) Mitä sovelluksia ja millä tavoin edelläkävijäopettajat käyttävät maantieteen verkko-opetuksessa? 3) Millaisia käyttökokemuksia edelläkävijäopettajat ovat saaneet maantieteen verkko-opetuksesta? Tutkimuksessa havaittiin, että tietokoneiden riittämätön määrä ja puuttuminen aineluokasta vaikeuttivat maantieteen verkko-opetusta. Työssä kehitettiin opettajien digitaalisten mediataitojen kuutiomalli, johon kuuluvat tekniset taidot, informaation prosessointitaidot ja viestintätaidot. Opettajissa erotettiin kolme verkko-opetuksen käyttäjätyyppiä: informaatiohakuiset kevytkäyttäjät, viestintähakuiset peruskäyttäjät ja yhteistyöhakuiset tehokäyttäjät. Verkko-opetukseen liittyi intensiivisiä myönteisiä ja kielteisiä kokemuksia. Se toi iloa ja motivaatiota opiskeluun. Sitä pidettiin rikastuttavana lisänä, joka haluttiin integroida opetukseen hallitusti. Edelläkävijäopettajat ottivat käyttöön tietoverkoissa olevaa informaatiota ja sovelsivat työvälineohjelmia. He pääsivät alkuun todellisuutta jäljittelevien virtuaalimaailmojen: satelliittikuvien toistaman maapallon, digitaalikarttojen ja simulaatioiden käytössä. Opettajat kokeilivat verkon sosiaalisia tiloja reaaliaikaisen viestinnän, keskusteluryhmien ja ryhmätyöohjelmien avulla. Mielikuvitukseen perustuvat virtuaalimaailmat jäivät vähälle sillä opettajat eivät juuri pelanneet viihdepelejä. He omaksuivat virtuaalimaailmoista satunnaisia palasia käytettävissä olevan laite- ja ohjelmavarustuksen mukaan. Virtuaalimaailmojen valtaus eteni tutkimuksen aikana digitaalisen informaation hyödyntämisestä viestintäsovelluksiin ja aloittelevaan yhteistyöhön. Näin opettajat laajensivat virtuaalireviiriään tietoverkkojen dynaamisiksi toimijoiksi ja pääsivät uusin keinoin tyydyttämään ihmisen universaalia tarvetta yhteyteen muiden kanssa. Samalla opettajat valtautuivat informaation kuluttajista sen tuottajiksi, objekteista subjekteiksi. Verkko-opetus avaa koulun maantieteelle huomattavia mahdollisuuksia. Mobiililaitteiden avulla informaatiota voidaan kerätä ja tallentaa maasto-olosuhteissa, ohjelmilla sitä voidaan muuntaa muodosta toiseen. Internetin autenttiset ja ajantasaiset materiaalit tuovat opiskeluun konkretiaa ja kiinnostavuutta, mallit, simulaatiot ja paikkatieto havainnollistavat ilmiöitä. Viestintä- ja yhteistyövälineet sekä sosiaaliset informaatiotilat vahvistavat yhteistyötä. Avainsanat: verkko-opetus, internet, virtuaalimaailmat, maantiede, innovaatiot

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The study examines one case of students' experiences from the activity in a collaborative learning process in a networked learning environment, and explores whether or not the experiences explain the participation or lack of participation in the activities. As a research task the students' experiences in the database of the networked learning environment, participating in its construction, and the ways of working needed to build the database, were examined. To contrast the students' experiences, their actual participation in the building of the database was clarified. Based on actual participation, groups more active and more passive than average were separated, and their experiences were compared to each other. The research material was collected from the course Cognitive and Creative Processes, which was offered to studentsof the Department of Textile Teacher Education in University of Helsinki, and students of the Departments of Teacher Education Units giving textile education in Turku, Rauma and Savonlinna in the beginning of 2001. In this course, creativity was examined from a psychological and sosiocultural context with the aim of realizing a collaborative progressive inquiry process. The course was held in a network-based Future Learning Environment (Fle 2) except for the starting lecture and training the use of the learning environment. This study analyzed the learning diaries that the students had sent to the tutor once a week for four weeks, and the final thoughts written into the database of the learning environment. Content analysis was applied as the research method. The case was enriched from another point of view by examining the messages the students had written into the learning environment with the social network analysis. The theoretical base of the study looks at the research of computer-supported collaborative learning, the conceptions of learning as a process of participation and knowledge building, and the possibilities and limitations of network-based learning environments. The research results show, that both using the network-based learning environment and collaborative ways of studying were new to the students. The students were positively surprised by the feedback and support provided by the community. On the other hand, they also experienced problems with facelessness and managing the information in the learning environment. The active students seemed to be more ready for a progressive inquiry process. It can be seen from their attitudes and actions that they have strived to participate actively and invested into the process both from their own and the community's point of view. The more passive students reported their actions to get credits and they had a harder time of perceiving the thoughts presented in the net as common progression. When arranging similar courses in the future, attention should be paid to how to get the students to act in ways necessary for knowledge building, and different from more traditional ways of studying. The difficulties of students used to traditional studying methods to adapt to collaborative knowledge building were evident on the course Cognitive and Creative Processes. Keywords: computer supported collaborative learning, knowledge building, progressive Inquiry, participation

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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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The present study aims to elucidate the modifications in the structure and functionality of the phospholipid matrix of biological membranes brought about by free radical-mediated oxidative damage of its molecular constituents. To this end, the surface properties of two oxidatively modified phospholipids bearing an aldehyde or carboxyl function at the end of truncated sn-2 acyl chain were studied using a Langmuir balance. The results obtained reveal both oxidized species to have a significant impact on the structural dynamics of phospholipid monolayers, as illustrated by the progressive changes in force-area isotherms with increasing mole fraction of the oxidized lipid component. Moreover, surface potential measurements revealed considerable modifications in the electric properties of oxidized phospholipid containing monolayers during film compression, suggesting a packing state-controlled reorientation of the intramolecular electric dipoles of the lipid headgroups and acyl chains. Based on the above findings, a model describing the conformational state of oxidized phospholipid molecules in biological membranes is proposed, involving the protrusion of the acyl chains bearing the polar functional groups out from the hydrocarbon phase to the surrounding aqueous medium. Oxidative modifications alter profoundly the physicochemical properties of unsaturated phospholipids and are therefore readily anticipated to have important implications for their interactions with membrane-associating molecules. Along these lines, the carboxyl group bearing lipid was observed to bind avidly the peripheral membrane protein cytochrome c. The binding was reversed following increase in ionic strength or addition of polyanionic ATP, thus suggesting it to be driven by electrostatic interactions between cationic residues of the protein and the deprotonated lipid carboxyl exposed to the aqueous phase. The presence of aldehyde function bearing oxidized phospholipid was observed to enhance the intercalation of four antimicrobial peptides into phospholipid monolayers and liposomal bilayers. Partitioning of the peptides to monolayers was markedly attenuated by the aldehyde scavenger methoxyamine, revealing it to be mediated by the carbonyl moiety possibly through efficient hydrogen bonding or, alternatively, formation of covalent adduct in form of a Schiff base between the lipid aldehydes and primary amine groups of the peptide molecules. Lastly, both oxidized phospholipid species were observed to bind with high affinity three small membrane-partitioning therapeutic agents, viz. chlorpromazine, haloperidol, and doxorubicin. In conclusion, the results of studies conducted using biomimetic model systems support the notion that oxidative damage influences the molecular architecture as well as the bulk physicochemical properties of phospholipid membranes. Further, common polar functional groups carried by phospholipids subjected to oxidation were observed to act as molecular binding sites at the lipid-water interface. It is thus plausible that oxidized phospholipid species may elicit cellular level effects by modulating integration of various membrane-embedded and surface-associated proteins and peptides, whose conformational state, oligomerization, and functionality is known to be controlled by highly specific lipid-protein interactions and proper physical state of the membrane environment.