8 resultados para Self-etching adhesive system

em Helda - Digital Repository of University of Helsinki


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Whereas it has been widely assumed in the public that the Soviet music policy system had a “top-down” structure of control and command that directly affected musical creativity, in fact my research shows that the relations between the different levels of the music policy system were vague, and the viewpoints of its representatives differed from each other. Because the representatives of the party and government organs controlling operas could not define which kind of music represented Socialist Realism, the system as it developed during the 1930s and 1940s did not function effectively enough in order to create such a centralised control of Soviet music, still less could Soviet operas fulfil the highly ambiguous aesthetics of Socialist Realism. I show that musical discussions developed as bureaucratic ritualistic arenas, where it became more important to reveal the heretical composers, making scapegoats of them, and requiring them to perform self-criticism, than to give directions on how to reach the artistic goals of Socialist Realism. When one opera was found to be unacceptable, this lead to a strengthening of control by the party leadership, which lead to more operas, one after the other, to be revealed as failures. I have studied the control of the composition, staging and reception of the opera case-studies, which remain obscure in the West despite a growing scholarly interest in them, and have created a detailed picture of the foundation and development of the Soviet music control system in 1932-1950. My detailed discussion of such case-studies as Ivan Dzerzhinskii’s The Quiet Don, Dmitrii Shostakovich’s Lady Macbeth of Mtsensk District, Vano Muradeli’s The Great Friendship, Sergei Prokofiev’s Story of a Real Man, Tikhon Khrennikov’s Frol Skobeev and Evgenii Zhukovskii’s From All One’s Heart backs with documentary precision the historically revisionist model of the development of Soviet music. In February 1948, composers belonging to the elite of the Union of Soviet Composers, e.g. Dmitri Shostakovich and Sergei Prokofiev, were accused in a Central Committee Resolution of formalism, as been under the influence of western modernism. Accusations of formalism were connected to the criticism of the conciderable financial, material and social privileges these composers enjoyed in the leadership of the Union. With my new archival findings I give a more detailed picture of the financial background for the 1948 campaign. The independent position of the music funding organization of the Union of Soviet Composers (Muzfond) to decide on its finances was an exceptional phenomenon in the Soviet Union and contradicted the strivings to strengthen the control of Soviet music. The financial audits of the Union of Soviet Composers did not, however, change the elite status of some of its composers, except for maybe a short duration in some cases. At the same time the independence of the significal financial authorities of Soviet theatres was restricted. The cuts in the governmental funding allocated to Soviet theatres contradicted the intensified ideological demands for Soviet operas.

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Bacterial surface-associated proteins are important in communication with the environment and bacteria-host interactions. In this thesis work, surface molecules of Lactobacillus crispatus important in host interaction were studied. The L. crispatus strains of the study were known from previous studies to be efficient in adhesion to intestinal tract and ECM. L. crispatus JCM 5810 possess an adhesive surface layer (S-layer) protein, whose functions and domain structure was characterized. We cloned two S-layer protein genes (cbsA; collagen-binding S-layer protein A and silent cbsB) and identified the protein region in CbsA important for adhesion to host tissues, for polymerization into a periodic layer as well as for attachment to the bacterial cell surface. The analysis was done by extensive mutation analysis and by testing His6-tagged fusion proteins from recombinant Escherichia coli as well as by expressing truncated CbsA peptides on the surface of Lactobacillus casei. The N-terminal region (31-274) of CbsA showed efficient and specific binding to collagens, laminin and extracellular matrix on tissue sections of chicken intestine. The N-terminal region also contained the information for formation of periodic S-layer polymer. This region is bordered at both ends by a conserved short region rich in valines, whose substitution to leucines drastically affected the periodic polymer structure. The mutated CbsA proteins that failed to form a periodic polymer, did not bind collagens, which indicates that the polymerized structure of CbsA is needed for collagen-binding ability. The C-terminal region, which is highly identical in S-layer proteins of L. crispatus, Lactobacillus acidophilus and Lactobacillus helveticus, was shown to anchor the protein to the bacterial cell wall. The C-terminal CbsA peptide specifically bound to bacterial teichoic acid and lipoteichoic acids. In conclusion, the N-terminal domain of the S-layer protein of L. crispatus is important for polymerization and adhesion to host tissues, whereas the C-terminal domain anchors the protein to bacterial cell-wall teichoic acids. Lactobacilli are fermentative organisms that effectively lower the surrounding pH. While this study was in progress, plasminogen-binding proteins enolase and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were identified in the extracellular proteome of L. crispatus ST1. In this work, the cell-wall association of enolase and GAPDH were shown to rely on pH-reversible binding to the cell-wall lipoteichoic acids. Enolase from L. crispatus was functionally compared with enolase from L. johnsonii as well as from pathogenic streptococci (Streptococcus pneumoniae, Streptococcus pyogenes) and Staphylococcus aureus. His6-enolases from commensal lactobacilli bound human plasminogen and enhanced its activation by human plasminogen activators similarly to, or even better than, the enolases from pathogens. Similarly, the His6-enolases from lactobacilli exhibited adhesive characteristics previously assigned to pathogens. The results call for more detailed analyses of the role of the host plasminogen system in bacterial pathogenesis and commensalism as well of the biological role and potential health risk of the extracellular proteome in lactobacilli.

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Stem cells are responsible for tissue turnover throughout lifespan. Only highly controlled specific environment, the stem cell niche , can sustain undifferentiated stem cell-pool. The balance between maintenance and differentiation is crucial for individual s health: uncontrolled stem cell self-renewal or proliferation can lead to hyperplasia and mutations that further provoke malignant transformation of the cells. On the other hand, uninhibited differentiation may result in diminished stem cell population, which is unable to maintain tissue turnover. The mechanisms that control the switch from maintenance to differentiation in stem cells are not well known. The same mechanisms that direct the self-renewal and proliferation in normal stem cells are likely to be also involved in maintenance of cancer stem cell . Cancer stem cells exhibit stem cell like properties such as self-renewal- and differentiation capacity and they can also regenerate the tumor tissue. In this thesis, I have investigated the effect of classical oncogenes E6/E7 and c-Myc, tumor suppressors p53 and retinoblastoma (pRb) family, and vascular endothelial growth factor (VEGF) subfamily and glial cell line-derived neurothropic factor (GDNF) family ligands on behavior of embryonic neural stem cells (NSCs) and progenitors. The study includes also the characterization of cytoskeletal tumor suppressor neurofibromatosis 2 (NF2) protein merlin and ezrin-radixin-moesin (ERM) protein ezrin expression in neural progenitors cells and their progeny. This study reveals some potential mechanisms regarding to NSCs maintenance. In summary, the studied molecules are able to shift the balance either towards stem cell maintenance or differentiation; tumor suppressor p53 represses whereas E6/E7 oncogenes and c-Myc increase the proportion of self-renewing and proliferating NSCs or progenitors. The data suggests that active MEK-ERK signaling is critical for self-renewal of normal and oncogene expressing NSCs. In addition, the results indicate that expression of cytoskeletal tumor suppressor merlin and ERM protein ezrin in central nervous system (CNS) tissue and progenitors indicates their role in cell differentiation. Furthermore, the data suggests that VEGF-C a factor involved in lymphatic system development, angiogenesis, neovascularization and metastasis but also in maintenance of some neural populations in brain is a novel thropic factor for progenitors in early sympathetic nervous system (SNS). It seems that VEGF-C dose dependently through ERK-pathway supports the proliferation and survival of early sympathetic progenitor cells, and the effect is comparable to that of GDNF family ligands.

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Atherosclerosis is an inflammatory disease characterized by accumulation of lipids in the inner layer of the arterial wall. During atherogenesis, various structures that are recognized as non-self by the immune system, such as modified lipoproteins, are deposited in the arterial wall. Accordingly, atherosclerotic lesions and blood of humans and animals with atherosclerotic lesions show signs of activation of both innate and adaptive immune responses. Although immune attack is initially a self-protective reaction, which is meant to destroy or remove harmful agents, a chronic inflammatory state in the arterial wall accelerates atherosclerosis. Indeed, various modulations of the immune system of atherosclerosis-prone animals have provided us with convincing evidence that immunological mechanisms play an important role in the pathogenesis of atherosclerosis. This thesis focuses on the role of complement system, a player of the innate immunity, in atherosclerosis. Complement activation via any of the three different pathways (classical, alternative, lectin) proceeds as a self-amplifying cascade, which leads to the generation of opsonins, anaphylatoxins C3a and C5a, and terminal membrane-attack complex (MAC, C5b-9), all of which regulate the inflammatory response and act in concert to destroy their target structures. To prevent uncontrolled complement activation or its attack against normal host cells, complement needs to be under strict control by regulatory proteins. The complement system has been shown to be activated in atherosclerotic lesions, modified lipoproteins and immune complexes containing oxLDL, for instance, being its activators. First, we investigated the presence and role of complement regulators in human atherosclerotic lesions. We found that inhibitors of the classical and alternative pathways, C4b-binding protein and factor H, respectively, were present in atherosclerotic lesions, where they localized in the superficial proteoglycan-rich layer. In addition, both inhibitors were found to bind to arterial proteoglycans in vitro. Immunohistochemical stainings revealed that, in the superficial layer of the intima, complement activation had been limited to the C3 level, whereas in the deeper intimal layers, complement activation had proceeded to the terminal C5b-9 level. We were also able to show that arterial proteoglycans inhibit complement activation in vitro. These findings suggested to us that the proteoglycan-rich layer of the arterial intima contains matrix-bound complement inhibitors and forms a protective zone, in which complement activation is restricted to the C3 level. Thus, complement activation is regulated in atherosclerotic lesions, and the extracellular matrix is involved in this process. Next, we studied whether the receptors for the two complement derived effectors, anaphylatoxins C3a and C5a, are expressed in human coronary atherosclerotic lesions. Our results of immunohistochemistry and RT-PCR analysis showed that, in contrast to normal intima, C3aR and C5aR were highly expressed in atherosclerotic lesions. In atherosclerotic plaques, the principal cells expressing both C3aR and C5aR were macrophages. Moreover, T cells expressed C5aR, and a small fraction of them also expressed C3aR, mast cells expressed C5aR, whereas endothelial cells and subendothelial smooth muscle cells expressed both C3aR and C5aR. These results suggested that intimal cells can respond to and become activated by complement-derived anaphylatoxins. Finally, we wanted to learn, whether oxLDL-IgG immune complexes, activators of the classical complement pathway, could have direct cellular effects in atherogenesis. Thus, we tested whether oxLDL-IgG immune complexes affect the survival of human monocytes, the precursors of macrophages, which are the most abundant inflammatory cell type in atherosclerotic lesions. We found that OxLDL-IgG immune complexes, in addition to transforming monocytes into foam cells, promoted their survival by decreasing their spontaneous apoptosis. This effect was mediated by cross-linking Fc receptors with ensuing activation of Akt-dependent survival signaling. Our finding revealed a novel mechanism by which oxLDL-IgG immune complexes can directly affect the accumulation of monocyte-macrophages in human atherosclerotic lesions and thus play a role in atherogenesis.

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Self-similarity, a concept taken from mathematics, is gradually becoming a keyword in musicology. Although a polysemic term, self-similarity often refers to the multi-scalar feature repetition in a set of relationships, and it is commonly valued as an indication for musical coherence and consistency . This investigation provides a theory of musical meaning formation in the context of intersemiosis, that is, the translation of meaning from one cognitive domain to another cognitive domain (e.g. from mathematics to music, or to speech or graphic forms). From this perspective, the degree of coherence of a musical system relies on a synecdochic intersemiosis: a system of related signs within other comparable and correlated systems. This research analyzes the modalities of such correlations, exploring their general and particular traits, and their operational bounds. Looking forward in this direction, the notion of analogy is used as a rich concept through its two definitions quoted by the Classical literature: proportion and paradigm, enormously valuable in establishing measurement, likeness and affinity criteria. Using quantitative qualitative methods, evidence is presented to justify a parallel study of different modalities of musical self-similarity. For this purpose, original arguments by Benoît B. Mandelbrot are revised, alongside a systematic critique of the literature on the subject. Furthermore, connecting Charles S. Peirce s synechism with Mandelbrot s fractality is one of the main developments of the present study. This study provides elements for explaining Bolognesi s (1983) conjecture, that states that the most primitive, intuitive and basic musical device is self-reference, extending its functions and operations to self-similar surfaces. In this sense, this research suggests that, with various modalities of self-similarity, synecdochic intersemiosis acts as system of systems in coordination with greater or lesser development of structural consistency, and with a greater or lesser contextual dependence.

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The aim of this thesis was to unravel the functional-structural characteristics of root systems of Betula pendula Roth., Picea abies (L.) Karst., and Pinus sylvestris L. in mixed boreal forest stands differing in their developmental stage and site fertility. The root systems of these species had similar structural regularities: horizontally-oriented shallow roots defined the horizontal area of influence, and within this area, each species placed fine roots in the uppermost soil layers, while sinker roots defined the maximum rooting depth. Large radial spread and high ramification of coarse roots, and the high specific root length (SRL) and root length density (RLD) of fine roots indicated the high belowground competitiveness and root plasticity of B. pendula. Smaller radial root spread and sparser branching of coarse roots, and low SRL and RLD of fine roots of the conifers could indicate their more conservative resource use and high association with and dependence on ectomycorrhiza-forming fungi. The vertical fine root distributions of the species were mostly overlapping, implying the possibility for intense belowground competition for nutrients. In each species, conduits tapered and their frequency increased from distal roots to the stem, from the stem to the branches, and to leaf petioles in B. pendula. Conduit tapering was organ-specific in each species violating the assumptions of the general vascular scaling model (WBE). This reflects the hierarchical organization of a tree and differences between organs in the relative importance of transport, safety, and mechanical demands. The applied root model was capable of depicting the mass, length and spread of coarse roots of B. pendula and P. abies, and to the lesser extent in P. sylvestris. The roots did not follow self-similar fractal branching, because the parameter values varied within the root systems. Model parameters indicate differences in rooting behavior, and therefore different ecophysiological adaptations between species.

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ABSTRACT Bakhshandeh, Soheila. Periodontal and dental health and oral self-care among adults with diabetes mellitus. Department of Oral Public Health, Institute of Dentistry, Faculty of Medicine, University of Helsinki, Helsinki, Finland. 2011. 49 pp. ISBN 978-952-10-7193-5(paperback). The aim of the present study was to assess oral health and treatment needs among Iranian adults with diabetes according to socio-demographic status, oral hygiene, diabetes related factors, and to investigate the relation between these determinants and oral health. Moreover, the effect of an educational oral health promotion intervention on their oral health and periodontal treatment needs was studied. The target population comprised adults with diabetes in Tehran, Iran. 299 dentate patients with diabetes, who were regular attendants to a diabetic clinic, were selected as the study subjects. Data collection was performed through a clinical dental examination and self-administered structured questionnaire. The questionnaire covered information of the subject s social background, medical history, oral health behaviour and smoking. The clinical dental examinations covered the registration of caries experience (DMFT), community periodontal index (CPI) and plaque index (PI). The intervention provided the adults with diabetes dental health education through a booklet. Reduction in periodontal treatment needs one year after the baseline examination was used as the main outcome. A high prevalence of periodontal pockets among the study population was found; 52% of the participants had periodontal pockets with a pocket depth of 4 to 5 mm and 35% had periodontal pockets with pocket depth of 6 mm or more. The mean of the DMFT index was 12.9 (SD=6.1), being dominated by filled teeth (mean 6.5) and missing teeth (mean 5.0). Oral self-care among adults with diabetes was inadequate and poor oral hygiene was observed in more than 80% of the subjects. The educational oral health promotion decreased periodontal treatment needs more in the study groups than in the control group. The poor periodontal health, poor oral hygiene and insufficient oral self-care observed in this study call for oral health promotion among adult with diabetes. An educational intervention showed that it is possible to promote oral health behaviour and to reduce periodontal treatment needs among adults with diabetes. The simplicity of the model used in this study allows it to be integrated to diabetes programmes in particular in countries with a developing health care system.

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Menneinä vuosikymmeninä maatalouden työt ovat ensin koneellistuneet voimakkaasti ja sittemmin mukaan on tullut automaatio. Nykyään koneiden kokoa suurentamalla ei enää saada tuottavuutta nostettua merkittävästi, vaan työn tehostaminen täytyy tehdä olemassa olevien resurssien käyttöä tehostamalla. Tässä työssä tarkastelun kohteena on ajosilppuriketju nurmisäilörehun korjuussa. Säilörehun korjuun intensiivisyys ja koneyksiköiden runsas määrä ovat työnjohdon kannalta vaativa yhdistelmä. Työn tavoitteena oli selvittää vaatimuksia maatalouden urakoinnin tueksi kehitettävälle tiedonhallintajärjestelmälle. Tutkimusta varten haastateltiin yhteensä 12 urakoitsijaa tai yhteistyötä tekevää viljelijää. Tutkimuksen perusteella urakoitsijoilla on tarvetta tietojärjestelmille.Luonnollisesti urakoinnin laajuus ja järjestelyt vaikuttavat asiaan. Tutkimuksen perusteella keskeisimpiä vaatimuksia tiedonhallinnalle ovat: • mahdollisimman laaja, yksityiskohtainen ja automaattinen tiedon keruu tehtävästä työstä • karttapohjaisuus, kuljettajien opastus kohteisiin • asiakasrekisteri, työn tilaus sähköisesti • tarjouspyyntöpohjat, hintalaskurit • luotettavuus, tiedon säilyvyys • sovellettavuus monenlaisiin töihin • yhteensopivuus muiden järjestelmien kanssa Kehitettävän järjestelmän tulisi siis tutkimuksen perusteella sisältää seuraavia osia: helppokäyttöinen suunnittelu/asiakasrekisterityökalu, toimintoja koneiden seurantaan, opastukseen ja johtamiseen, työnaikainen tiedonkeruu sekä kerätyn tiedon käsittelytoimintoja. Kaikki käyttäjät eivät kuitenkaan tarvitse kaikkia toimintoja, joten urakoitsijan on voitava valita tarvitsemansa osat ja mahdollisesti lisätä toimintoja myöhemmin. Tiukoissa taloudellisissa ja ajallisissa raameissa toimivat urakoitsijat ovat vaativia asiakkaita, joiden käyttämän tekniikan tulee olla toimivaa ja luotettavaa. Toisaalta inhimillisiä virheitä sattuu kokeneillekin, joten hyvällä tietojärjestelmällä työstä tulee helpompaa ja tehokkaampaa.